[Tolk] AST-based semantic analysis, get rid of Expr

This is a huge refactoring focusing on untangling compiler internals
(previously forked from FunC).
The goal is to convert AST directly to Op (a kind of IR representation),
doing all code analysis at AST level.

Noteable changes:
- AST-based semantic kernel includes: registering global symbols,
  scope handling and resolving local/global identifiers,
  lvalue/rvalue calc and check, implicit return detection,
  mutability analysis, pure/impure validity checks,
  simple constant folding
- values of `const` variables are calculated NOT based on CodeBlob,
  but via a newly-introduced AST-based constant evaluator
- AST vertices are now inherited from expression/statement/other;
  expression vertices have common properties (TypeExpr, lvalue/rvalue)
- symbol table is rewritten completely, SymDef/SymVal no longer exist,
  lexer now doesn't need to register identifiers
- AST vertices have references to symbols, filled at different
  stages of pipeline
- the remaining "FunC legacy part" is almost unchanged besides Expr
  which was fully dropped; AST is converted to Ops (IR) directly

tolk-tester/tests/allow_post_modification.tolk

@@ -10,6 +10,11 @@ fun `~inc`(mutate self: int, y: int): int {
     return newY;
 }
 
+fun eq<X>(v: X): X { return v; }
+fun eq2(v: (int, int)) { return v; }
+fun mul2(mutate dest: int, v: int): int { dest = v*2; return dest; }
+fun multens(mutate self: (int, int), v: (int, int)): (int, int) { var (f, s) = self; var (m1, m2) = v; self = (f*m1, s*m2); return self; }
+
 @method_id(11)
 fun test_return(x: int): (int, int, int, int, int, int, int) {
     return (x, x.`~inc`(x / 20), x, x = x * 2, x, x += 1, x);
@@ -53,8 +58,7 @@ fun test_call_2(x: int): (int, int, int, int, int, int, int) {
 }
 
 fun asm_func(x1: int, x2: int, x3: int, x4: int, x5: int, x6: int, x7: int): (int, int, int, int, int, int, int)
-asm
-        (x4 x5 x6 x7 x1 x2 x3->0 1 2 3 4 5 6) "NOP";
+    asm (x4 x5 x6 x7 x1 x2 x3->0 1 2 3 4 5 6) "NOP";
 
 @method_id(17)
 fun test_call_asm_old(x: int): (int, int, int, int, int, int, int) {
@@ -68,9 +72,9 @@ fun test_call_asm_new(x: int): (int, int, int, int, int, int, int) {
 
 global xx: int;
 @method_id(19)
-fun test_global(x: int): (int, int, int, int, int, int, int) {
+fun test_global(x: int) {
     xx = x;
-  return (xx, xx.`~inc`(xx / 20), xx, xx = xx * 2, xx, xx += 1, xx);
+    return (x, xx, xx.`~inc`(xx / 20), eq(xx += (x *= 0)), xx = xx * 2, xx, xx += 1, xx, x);
 }
 
 @method_id(20)
@@ -83,6 +87,29 @@ fun test_if_else(x: int): (int, int, int, int, int) {
     }
 }
 
+@method_id(21)
+fun test_assign_with_inner(x: int) {
+    return (x, x += 10, [(x, x += 20, eq(x -= 50), x)], eq2((x, x *= eq(x /= 2))));
+}
+
+@method_id(22)
+fun test_assign_with_mutate(x: int) {
+    return (x, mul2(mutate x, x += 5), x.`~inc`(mul2(mutate x, x)), x);
+}
+
+@method_id(23)
+fun test_assign_tensor(x: (int, int)) {
+    var fs = (0, 0);
+    return (x, x = (20, 30), fs = x.multens((1, 2)), fs.multens(multens(mutate x, (-1, -1))), x, fs);
+}
+
+global fs: (int, int);
+@method_id(24)
+fun test_assign_tensor_global(x: (int, int)) {
+    fs = (0, 0);
+    return (x, x = (20, 30), fs = x.multens((1, 2)), fs.multens(multens(mutate x, (-1, -1))), x, fs);
+}
+
 fun main() {
 }
 
@@ -96,9 +123,13 @@ fun main() {
 @testcase | 16 | 100 | 100 50 105 210 210 211 211
 @testcase | 17 | 100 | 101 50 106 212 100 101 101
 @testcase | 18 | 100 | 210 210 211 211 100 50 105
-@testcase | 19 | 100 | 100 50 105 210 210 211 211
+@testcase | 19 | 100 | 100 100 50 105 210 210 211 211 0
 @testcase | 20 | 80  | 80 89 1 8 8
 @testcase | 20 | 9   | 9 -40 -10 -1 13
+@testcase | 21 | 100 | 100 110 [ 110 130 80 80 ] 80 3200
+@testcase | 22 | 100 | 100 210 4200 630
+@testcase | 23 | 1 1 | 1 1 20 30 20 60 -400 -3600 -20 -60 -400 -3600
+@testcase | 24 | 1 1 | 1 1 20 30 20 60 -400 -3600 -20 -60 -400 -3600
 
 @fif_codegen
 """
@@ -107,5 +138,5 @@ fun main() {
     inc CALLDICT // self newY
   }>
 """
-@code_hash 97139400653362069936987769894397430077752335662822462908581556703209313861576
+@code_hash 33262590582878205026101577472505372101182291690814957175155528952950621243206
 */

tolk-tester/tests/cells-slices.tolk

@@ -216,15 +216,15 @@ Note, that since 'compute-asm-ltr' became on be default, chaining methods codege
 """
   test6 PROC:<{
     //
-    NEWC	//  _1
-    1 PUSHINT	//  _1 _2=1
-    SWAP	//  _2=1 _1
+    NEWC	//  _0
+    1 PUSHINT	//  _0 _1=1
+    SWAP	//  _1=1 _0
     32 STU	//  _0
-    2 PUSHINT	//  _0 _6=2
-    SWAP	//  _6=2 _0
+    2 PUSHINT	//  _0 _5=2
+    SWAP	//  _5=2 _0
     32 STU	//  _0
-    3 PUSHINT	//  _0 _10=3
-    SWAP	//  _10=3 _0
+    3 PUSHINT	//  _0 _9=3
+    SWAP	//  _9=3 _0
     32 STU	//  _0
   }>
 """

tolk-tester/tests/codegen_check_demo.tolk

@@ -35,7 +35,7 @@ Below, I just give examples of @fif_codegen tag:
 """
 main PROC:<{
   // s
-  17 PUSHINT     //  s _3=17
+  17 PUSHINT     //  s _1=17
   OVER           //  s z=17 t
   WHILE:<{
     ...

tolk-tester/tests/invalid-call-1.tolk

@@ -5,5 +5,5 @@ fun main() {
 /**
 @compilation_should_fail
 The message is weird now, but later I'll rework error messages anyway.
-@stderr cannot apply expression of type int to an expression of type (): cannot unify type () -> ??3 with int
+@stderr cannot apply expression of type int to an expression of type (): cannot unify type () -> ??2 with int
  */

tolk-tester/tests/invalid-call-5.tolk

@@ -8,6 +8,6 @@ fun main() {
 
 /**
 @compilation_should_fail
-@stderr rvalue expected
+@stderr `_` can't be used as a value; it's a placeholder for a left side of assignment
 @stderr inc(_)
  */

tolk-tester/tests/invalid-const-1.tolk

@@ -0,0 +1,8 @@
+fun main() {
+    return 9999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999;
+}
+
+/**
+@compilation_should_fail
+@stderr invalid integer constant
+ */

tolk-tester/tests/invalid-mutate-1.tolk

@@ -7,5 +7,5 @@ fun cantAssignToVal() {
 
 /**
 @compilation_should_fail
-@stderr modifying an immutable variable `x`
+@stderr modifying immutable variable `x`
  */

tolk-tester/tests/invalid-mutate-11.tolk

@@ -4,5 +4,5 @@ fun load32(self: slice): int {
 
 /**
 @compilation_should_fail
-@stderr modifying `self` (call a mutating method), which is immutable by default
+@stderr modifying `self`, which is immutable by default
  */

tolk-tester/tests/invalid-mutate-2.tolk

@@ -6,5 +6,5 @@ fun cantAssignToVal() {
 
 /**
 @compilation_should_fail
-@stderr modifying an immutable variable `x`
+@stderr modifying immutable variable `x`
  */

tolk-tester/tests/invalid-mutate-3.tolk

@@ -7,5 +7,5 @@ fun cantAssignToConst() {
 
 /**
 @compilation_should_fail
-@stderr modifying an immutable variable `op_increase`
+@stderr modifying immutable constant
  */

tolk-tester/tests/invalid-mutate-4.tolk

@@ -10,5 +10,5 @@ fun cantPassToMutatingFunction() {
 
 /**
 @compilation_should_fail
-@stderr modifying an immutable variable `myVal`
+@stderr modifying immutable variable `myVal`
  */

tolk-tester/tests/invalid-mutate-5.tolk

@@ -9,6 +9,6 @@ fun cantCallMutatingMethod(c: cell) {
 
 /**
 @compilation_should_fail
-@stderr modifying an immutable variable `s` (call a mutating method)
+@stderr modifying immutable variable `s`
 @stderr s.loadUint
  */

tolk-tester/tests/invalid-mutate-6.tolk

@@ -11,6 +11,6 @@ fun cantCallMutatingFunctionWithImmutable() {
 
 /**
 @compilation_should_fail
-@stderr modifying an immutable variable `op_increase` (call a mutating function)
+@stderr modifying immutable constant
 @stderr inc(mutate op_increase)
  */

tolk-tester/tests/invalid-mutate-7.tolk

@@ -10,6 +10,6 @@ fun cantCallMutatingFunctionWithRvalue() {
 
 /**
 @compilation_should_fail
-@stderr lvalue expected (call a mutating function)
+@stderr literal can not be used as lvalue
 @stderr incBoth(mutate x, mutate 30)
  */

tolk-tester/tests/invalid-mutate-8.tolk

@@ -6,5 +6,5 @@ fun cantRedefImmutable() {
 
 /**
 @compilation_should_fail
-@stderr modifying an immutable variable `x` (left side of assignment)
+@stderr `redef` for immutable variable
  */

tolk-tester/tests/invalid-mutate-9.tolk

@@ -4,6 +4,6 @@ fun increment(self: int) {
 
 /**
 @compilation_should_fail
-@stderr modifying `self` (left side of assignment), which is immutable by default
+@stderr modifying `self`, which is immutable by default
 @stderr probably, you want to declare `mutate self`
  */

tolk-tester/tests/invalid-pure-1.tolk

@@ -4,7 +4,7 @@ fun f_pure(): int {
     return f_impure();
 }
 
-fun f_impure(): int {}
+fun f_impure(): int { return 0; }
 
 fun main(): int {
     return f_pure();

tolk-tester/tests/invalid-pure-3.tolk

@@ -2,6 +2,7 @@
 fun validate_input(input: cell): (int, int) {
     var (x, y, z, correct) = calculateCellSize(input, 10);
     assert(correct) throw 102;
+    return (x, y);
 }
 
 @pure

tolk-tester/tests/invalid-pure-4.tolk

@@ -0,0 +1,16 @@
+global set: int;
+
+@pure
+fun someF(): int {
+    var set redef = 0;
+    return set;
+}
+
+/**
+@compilation_should_fail
+@stderr
+"""
+an impure operation in a pure function
+var set
+"""
+*/

tolk-tester/tests/invalid-redefinition-6.tolk

@@ -0,0 +1,10 @@
+const s1 = "asdf";
+
+fun main() {
+    var s1 redef = "d";
+}
+
+/**
+@compilation_should_fail
+@stderr `redef` for unknown variable
+ */

tolk-tester/tests/invalid-typing-6.tolk

@@ -0,0 +1,8 @@
+fun failWhenTernaryConditionNotInt(cs: slice) {
+    return cs ? 1 : 0;
+}
+
+/**
+@compilation_should_fail
+@stderr condition of ternary ?: operator must be an integer
+ */

tolk-tester/tests/mutate-methods.tolk

@@ -118,12 +118,19 @@ fun updateTwoItems(mutate self: (int, int), byValue: int) {
     self = (first + byValue, second + byValue);
 }
 
+global t107_1: int;
+global t107_2: int;
+
 @method_id(107)
 fun testMutableTensor() {
     var t = (40, 50);
     t.updateTwoItems(10);
     updateTwoItems(mutate t, 10);
-    return t;
+    t107_1 = 1;
+    t107_2 = 2;
+    (t107_1, t107_2).updateTwoItems(10);
+    updateTwoItems(mutate (t107_1, t107_2), 10);
+    return (t, t107_1, t107_2);
 }
 
 @pure
@@ -278,7 +285,7 @@ fun main(){}
 @testcase | 104 |    | 1 2 3
 @testcase | 105 |    | 5 5 110
 @testcase | 106 |    | 160 110
-@testcase | 107 |    | 60 70
+@testcase | 107 |    | 60 70 21 22
 @testcase | 110 |    | 320
 @testcase | 111 |    | 55 55
 @testcase | 112 |    | [ 1 13 3 23 33 ]
@@ -300,7 +307,7 @@ fun main(){}
     ...
     incrementTwoInPlace CALLDICT        //  x y sum1
     -ROT
-    10 PUSHINT  //  sum1 x y _9=10
+    10 PUSHINT  //  sum1 x y _8=10
     incrementTwoInPlace CALLDICT        //  sum1 x y sum2
     s1 s3 s0 XCHG3       //  x y sum1 sum2
   }>
@@ -310,8 +317,8 @@ fun main(){}
 """
  load_next PROC:<{
     //  cs
-    32 LDI      //  _1 cs
-    SWAP        //  cs _1
+    32 LDI      //  _3 cs
+    SWAP        //  cs _3
   }>
 """
 
@@ -319,7 +326,7 @@ fun main(){}
 """
   testStoreUintPureUnusedResult PROC:<{
     //
-    0 PUSHINT	//  _12=0
+    0 PUSHINT	//  _11=0
   }>
 """
 
@@ -330,7 +337,7 @@ fun main(){}
     NEWC	//  b
     STIX	//  _2
     DROP	//
-    0 PUSHINT	//  _12=0
+    0 PUSHINT	//  _11=0
   }>
 """
 

tolk-tester/tests/null-keyword.tolk

@@ -145,14 +145,14 @@ fun main() {
 """
   test7 PROC:<{
     ...
-    LDOPTREF	//  b _20 _19
+    LDOPTREF	//  b _18 _17
     DROP	    //  b c
-    ISNULL	    //  b _13
-    10 MULCONST	//  b _15
-    SWAP	    //  _15 b
-    ISNULL	    //  _15 _16
-    0 EQINT     // _15 _17
-    ADD	        //  _18
+    ISNULL	    //  b _11
+    10 MULCONST	//  b _13
+    SWAP	    //  _13 b
+    ISNULL	    //  _13 _14
+    0 EQINT     // _13 _15
+    ADD	        //  _16
   }>
 """
 */

tolk-tester/tests/self-keyword.tolk

@@ -158,6 +158,44 @@ fun testNotMutatingChainableSelfMutateAnother(initial: int) {
     return (arg, c108, c109, x);
 }
 
+fun pickG110(mutate self: int, mutate pushTo: tuple): self {
+    self += 10;
+    pushTo.tuplePush(c110);
+    return self;
+}
+
+global tup110: tuple;
+global c110: int;
+
+@method_id(110)
+fun testMutateGlobalsLValue(init: int) {
+    c110 = init;
+    tup110 = createEmptyTuple();
+    c110.incChained().incChained().pickG110(mutate tup110).incChained().pickG110(mutate tup110).incChained();
+    return (c110, tup110);
+}
+
+fun myTuplePush<T>(mutate self: tuple, value: T): self {
+    self.tuplePush(value);
+    return self;
+}
+
+fun myTupleAt<T>(self: tuple, idx: int): T {
+    return self.tupleAt(idx);
+}
+
+global tup111: tuple;
+
+@method_id(111)
+fun testForallFunctionsWithSelf() {
+    var t = createEmptyTuple();
+    tup111 = createEmptyTuple();
+    t.myTuplePush(10);
+    tup111.myTuplePush(1).myTuplePush(2).myTuplePush(3);
+    return (t.myTupleAt(0), tup111.myTupleAt(tup111.tupleSize() - 1), tup111);
+}
+
+
 
 fun main() { }
 
@@ -179,6 +217,8 @@ fun main() { }
 @testcase | 109 | 200 | 200 3 1 2
 @testcase | 109 | 100 | 100 0 0 1
 @testcase | 109 | 102 | 102 2 1 2
+@testcase | 110 | 0   | 24 [ 2 13 ]
+@testcase | 111 |     | 10 3 [ 1 2 3 ]
 
 @fif_codegen
 """

tolk-tester/tests/try-func.tolk

@@ -1,7 +1,6 @@
 fun unsafeGetInt<X>(any: X): int
     asm "NOP";
 
-@method_id(11)
 fun foo(x: int): int {
   try {
     if (x == 7) {
@@ -14,7 +13,6 @@ fun foo(x: int): int {
 }
 
 @inline
-@method_id(12)
 fun foo_inline(x: int): int {
   try {
     assert(!(x == 7)) throw 44;
@@ -25,7 +23,6 @@ fun foo_inline(x: int): int {
 }
 
 @inline_ref
-@method_id(13)
 fun foo_inlineref(x: int): int {
   try {
     if (x == 7) { throw (44, 2); }
@@ -35,26 +32,25 @@ fun foo_inlineref(x: int): int {
   }
 }
 
-@method_id(1)
+@method_id(101)
 fun test(x: int, y: int, z: int): int {
   y = foo(y);
   return x * 100 + y * 10 + z;
 }
 
-@method_id(2)
+@method_id(102)
 fun test_inline(x: int, y: int, z: int): int {
   y = foo_inline(y);
   return x * 100 + y * 10 + z;
 }
 
-@method_id(3)
+@method_id(103)
 fun test_inlineref(x: int, y: int, z: int): int {
   y = foo_inlineref(y);
   return x * 100 + y * 10 + z;
 }
 
 @inline
-@method_id(14)
 fun foo_inline_big(
         x1: int, x2: int, x3: int, x4: int, x5: int, x6: int, x7: int, x8: int, x9: int, x10: int,
         x11: int, x12: int, x13: int, x14: int, x15: int, x16: int, x17: int, x18: int, x19: int, x20: int
@@ -69,7 +65,7 @@ fun foo_inline_big(
   }
 }
 
-@method_id(4)
+@method_id(104)
 fun test_inline_big(x: int, y: int, z: int): int {
   y = foo_inline_big(
           y, y + 1, y + 2, y + 3, y + 4, y + 5, y + 6, y + 7, y + 8, y + 9,
@@ -77,7 +73,6 @@ fun test_inline_big(x: int, y: int, z: int): int {
   return x * 1000000 + y * 1000 + z;
 }
 
-@method_id(15)
 fun foo_big(
         x1: int, x2: int, x3: int, x4: int, x5: int, x6: int, x7: int, x8: int, x9: int, x10: int,
         x11: int, x12: int, x13: int, x14: int, x15: int, x16: int, x17: int, x18: int, x19: int, x20: int
@@ -92,7 +87,7 @@ fun foo_big(
   }
 }
 
-@method_id(5)
+@method_id(105)
 fun test_big(x: int, y: int, z: int): int {
   y = foo_big(
           y, y + 1, y + 2, y + 3, y + 4, y + 5, y + 6, y + 7, y + 8, y + 9,
@@ -100,7 +95,7 @@ fun test_big(x: int, y: int, z: int): int {
   return x * 1000000 + y * 1000 + z;
 }
 
-@method_id(16)
+@method_id(106)
 fun test_catch_into_same(x: int): int {
   var code = x;
   try {
@@ -112,7 +107,7 @@ fun test_catch_into_same(x: int): int {
 }
 
 
-@method_id(17)
+@method_id(107)
 fun test_catch_into_same_2(x: int): int {
   var code = x;
   try {
@@ -124,28 +119,77 @@ fun test_catch_into_same_2(x: int): int {
   return code;
 }
 
+global after046: int;
+
+// this bug existed in FunC and is fixed in v0.4.6
+fun bug_046_internal(op: int) {
+  if (op == 1) {
+    return;
+  } else if (op == 2) {
+    return;
+  } else {
+    throw 1;
+  }
+}
+
+fun bug_046_called() {
+  after046 = 0;
+  try {
+    bug_046_internal(1337);
+    after046 = 1;  // shouldn't be called
+  } catch(n) {
+    return;
+  }
+  return;
+}
+
+@method_id(108)
+fun bug_046_entrypoint() {
+  bug_046_called();
+  return after046;
+}
+
+global g_reg: int;
+
+@method_id(109)
+fun test109(): (int, int) {
+  var l_reg = 10;
+  g_reg = 10;
+  try {
+    // note, that regardless of assignment, an exception RESTORES them to previous (to 10)
+    // it's very unexpected, but is considered to be a TVM feature, not a bug
+    g_reg = 999;
+    l_reg = 999;
+    bug_046_internal(999);  // throws
+  } catch {
+  }
+  // returns (10,10) because of an exception, see a comment above
+  return (g_reg, l_reg);
+}
+
 fun main() {
 }
 
 /**
     method_id   | in    | out
-@testcase | 1  | 1 2 3 | 123
-@testcase | 1  | 3 8 9 | 389
-@testcase | 1  | 3 7 9 | 329
-@testcase | 2  | 1 2 3 | 123
-@testcase | 2  | 3 8 9 | 389
-@testcase | 2  | 3 7 9 | 329
-@testcase | 3  | 1 2 3 | 123
-@testcase | 3  | 3 8 9 | 389
-@testcase | 3  | 3 7 9 | 329
-@testcase | 4  | 4 8 9 | 4350009
-@testcase | 4  | 4 7 9 | 4001009
-@testcase | 5  | 4 8 9 | 4350009
-@testcase | 5  | 4 7 9 | 4001009
-@testcase | 16 | 5     | 5
-@testcase | 16 | 20    | 44
-@testcase | 17 | 5     | 5
-@testcase | 17 | 20    | 20
+@testcase | 101 | 1 2 3 | 123
+@testcase | 101 | 3 8 9 | 389
+@testcase | 101 | 3 7 9 | 329
+@testcase | 102 | 1 2 3 | 123
+@testcase | 102 | 3 8 9 | 389
+@testcase | 102 | 3 7 9 | 329
+@testcase | 103 | 1 2 3 | 123
+@testcase | 103 | 3 8 9 | 389
+@testcase | 103 | 3 7 9 | 329
+@testcase | 104 | 4 8 9 | 4350009
+@testcase | 104 | 4 7 9 | 4001009
+@testcase | 105 | 4 8 9 | 4350009
+@testcase | 105 | 4 7 9 | 4001009
+@testcase | 106 | 5     | 5
+@testcase | 106 | 20    | 44
+@testcase | 107 | 5     | 5
+@testcase | 107 | 20    | 20
+@testcase | 108 |       | 0
 
-@code_hash 73240939343624734070640372352271282883450660826541545137654364443860257436623
+@code_hash 39307974281105539319288356721945232226028429128341177951717392648324358675585
 */

tolk-tester/tests/unreachable-1.tolk

@@ -0,0 +1,14 @@
+fun main(x: int) {
+    if (x) {
+        x = 10;;;;;
+        return x;;;
+        x = 20;
+    }
+    return -1;
+}
+
+/**
+@testcase | 0 | 1 | 10
+@stderr warning: unreachable code
+@stderr x = 20;
+ */

tolk-tester/tests/unreachable-2.tolk

@@ -0,0 +1,22 @@
+fun main(x: int) {
+    if (x) {
+        if (x > 10) {
+            return 1; // throw 1;
+        } else if (true) {
+            return -1;
+        } else {
+            return 2; // throw 2;
+        }
+    } else {
+        {{return 1;}
+            x = 30;}
+    }
+    assert(false, 10);
+}
+
+/**
+@testcase | 0 | 1 | -1
+@stderr warning: unreachable code
+@stderr assert(false, 10)
+@stderr x = 30
+ */

tolk-tester/tests/var-apply.tolk

@@ -15,8 +15,101 @@ fun testVarApply1() {
     return (s.loadInt(32), s.loadInt(32));
 }
 
+@inline
+fun my_throw_always() {
+    throw 1000;
+}
+
+@inline
+fun get_raiser() {
+    return my_throw_always;
+}
+
+@method_id(102)
+fun testVarApplyWithoutSavingResult() {
+    try {
+        var raiser = get_raiser();
+        raiser();   // `some_var()` is always impure, the compiler has no considerations about its runtime value
+        return 0;
+    } catch (code) {
+        return code;
+    }
+}
+
+@inline
+fun sum(a: int, b: int) {
+    assert(a + b < 24, 1000);
+    return a + b;
+}
+
+@inline
+fun mul(a: int, b: int) {
+    assert(a * b < 24, 1001);
+    return a * b;
+}
+
+fun demo_handler(op: int, query_id: int, a: int, b: int): int {
+    if (op == 0xF2) {
+        val func = query_id % 2 == 0 ? sum : mul;
+        val result = func(a, b);
+        return 0;  // result not used, we test that func is nevertheless called
+    }
+    if (op == 0xF4) {
+        val func = query_id % 2 == 0 ? sum : mul;
+        val result = func(a, b);
+        return result;
+    }
+    return -1;
+}
+
+@method_id(103)
+fun testVarApplyInTernary() {
+    var t: tuple = createEmptyTuple();
+    try {
+        t.tuplePush(demo_handler(0xF2, 122, 100, 200));
+    } catch(code) {
+        t.tuplePush(code);
+    }
+    try {
+        t.tuplePush(demo_handler(0xF4, 122, 100, 200));
+    } catch(code) {
+        t.tuplePush(code);
+    }
+    try {
+        t.tuplePush(demo_handler(0xF2, 122, 10, 10));
+    } catch(code) {
+        t.tuplePush(code);
+    }
+    try {
+        t.tuplePush(demo_handler(0xF2, 123, 10, 10));
+    } catch(code) {
+        t.tuplePush(code);
+    }
+    return t;
+}
+
+fun always_throw2(x: int) {
+    throw 239 + x;
+}
+
+global global_f: int -> ();
+
+@method_id(104)
+fun testGlobalVarApply() {
+    try {
+        global_f = always_throw2;
+        global_f(1);
+        return 0;
+    } catch (code) {
+        return code;
+    }
+}
+
 fun main() {}
 
 /**
 @testcase | 101 |    | 1 2
+@testcase | 102 |    | 1000
+@testcase | 103 |    | [ 1000 1000 0 1001 ]
+@testcase | 104 |    | 240
  */

tolk-tester/tolk-tester.js

@@ -347,11 +347,11 @@ class TolkTestFile {
         if (exit_code === 0 && this.compilation_should_fail)
             throw new TolkCompilationSucceededError("compilation succeeded, but it should have failed")
 
-        if (exit_code !== 0 && this.compilation_should_fail) {
-            for (let should_include of this.stderr_includes)
+        for (let should_include of this.stderr_includes)  // @stderr is used to check errors and warnings
             should_include.check(stderr)
+
+        if (exit_code !== 0 && this.compilation_should_fail)
             return
-        }
 
         if (exit_code !== 0 && !this.compilation_should_fail)
             throw new TolkCompilationFailedError(`tolk exit_code = ${exit_code}`, stderr)

tolk-tester/tolk-tester.py

@@ -327,9 +327,10 @@ class TolkTestFile:
         if exit_code == 0 and self.compilation_should_fail:
             raise TolkCompilationSucceededError("compilation succeeded, but it should have failed")
 
-        if exit_code != 0 and self.compilation_should_fail:
-            for should_include in self.stderr_includes:
+        for should_include in self.stderr_includes: # @stderr is used to check errors and warnings
             should_include.check(stderr)
+
+        if exit_code != 0 and self.compilation_should_fail:
             return
 
         if exit_code != 0 and not self.compilation_should_fail:

tolk/CMakeLists.txt

@@ -7,14 +7,22 @@ set(TOLK_SOURCE
         compiler-state.cpp
         ast.cpp
         ast-from-tokens.cpp
+        constant-evaluator.cpp
         pipe-discover-parse-sources.cpp
         pipe-register-symbols.cpp
+        pipe-resolve-symbols.cpp
+        pipe-calc-rvalue-lvalue.cpp
+        pipe-detect-unreachable.cpp
+        pipe-infer-check-types.cpp
+        pipe-refine-lvalue-for-mutate.cpp
+        pipe-check-rvalue-lvalue.cpp
+        pipe-check-pure-impure.cpp
+        pipe-constant-folding.cpp
         pipe-ast-to-legacy.cpp
         pipe-find-unused-symbols.cpp
         pipe-generate-fif-output.cpp
         unify-types.cpp
         abscode.cpp
-        gen-abscode.cpp
         analyzer.cpp
         asmops.cpp
         builtins.cpp

tolk/abscode.cpp

@@ -25,17 +25,6 @@ namespace tolk {
  * 
  */
 
-TmpVar::TmpVar(var_idx_t _idx, TypeExpr* _type, sym_idx_t sym_idx, SrcLocation loc)
-    : v_type(_type), idx(_idx), sym_idx(sym_idx), coord(0), where(loc) {
-  if (!_type) {
-    v_type = TypeExpr::new_hole();
-  }
-}
-
-void TmpVar::set_location(SrcLocation loc) {
-  where = loc;
-}
-
 void TmpVar::dump(std::ostream& os) const {
   show(os);
   os << " : " << v_type << " (width ";
@@ -55,8 +44,8 @@ void TmpVar::dump(std::ostream& os) const {
 }
 
 void TmpVar::show(std::ostream& os, int omit_idx) const {
-  if (!is_unnamed()) {
-    os << G.symbols.get_name(sym_idx);
+  if (v_sym) {
+    os << v_sym->name;
     if (omit_idx >= 2) {
       return;
     }
@@ -149,10 +138,6 @@ void VarDescr::set_const(std::string value) {
   val = _Const;
 }
 
-void VarDescr::set_const_nan() {
-  set_const(td::make_refint());
-}
-
 void VarDescr::operator|=(const VarDescr& y) {
   val &= y.val;
   if (is_int_const() && y.is_int_const() && cmp(int_const, y.int_const) != 0) {
@@ -273,7 +258,7 @@ void Op::show(std::ostream& os, const std::vector<TmpVar>& vars, std::string pfx
     case _Call:
       os << pfx << dis << "CALL: ";
       show_var_list(os, left, vars);
-      os << " := " << (fun_ref ? fun_ref->name() : "(null)") << " ";
+      os << " := " << (f_sym ? f_sym->name : "(null)") << " ";
       if ((mode & 4) && args.size() == right.size()) {
         show_var_list(os, args, vars);
       } else {
@@ -332,11 +317,11 @@ void Op::show(std::ostream& os, const std::vector<TmpVar>& vars, std::string pfx
     case _GlobVar:
       os << pfx << dis << "GLOBVAR ";
       show_var_list(os, left, vars);
-      os << " := " << (fun_ref ? fun_ref->name() : "(null)") << std::endl;
+      os << " := " << (g_sym ? g_sym->name : "(null)") << std::endl;
       break;
     case _SetGlob:
       os << pfx << dis << "SETGLOB ";
-      os << (fun_ref ? fun_ref->name() : "(null)") << " := ";
+      os << (g_sym ? g_sym->name : "(null)") << " := ";
       show_var_list(os, right, vars);
       os << std::endl;
       break;
@@ -458,22 +443,22 @@ void CodeBlob::print(std::ostream& os, int flags) const {
   os << "-------- END ---------\n\n";
 }
 
-var_idx_t CodeBlob::create_var(TypeExpr* var_type, var_idx_t sym_idx, SrcLocation location) {
-  vars.emplace_back(var_cnt, var_type, sym_idx, location);
+var_idx_t CodeBlob::create_var(TypeExpr* var_type, const LocalVarData* v_sym, SrcLocation location) {
+  vars.emplace_back(var_cnt, var_type, v_sym, location);
   return var_cnt++;
 }
 
-bool CodeBlob::import_params(FormalArgList arg_list) {
+bool CodeBlob::import_params(FormalArgList&& arg_list) {
   if (var_cnt || in_var_cnt) {
     return false;
   }
   std::vector<var_idx_t> list;
   for (const auto& par : arg_list) {
     TypeExpr* arg_type;
-    SymDef* arg_sym;
+    const LocalVarData* arg_sym;
     SrcLocation arg_loc;
     std::tie(arg_type, arg_sym, arg_loc) = par;
-    list.push_back(create_var(arg_type, arg_sym ? arg_sym->sym_idx : 0, arg_loc));
+    list.push_back(create_var(arg_type, arg_sym, arg_loc));
   }
   emplace_back(loc, Op::_Import, list);
   in_var_cnt = var_cnt;

tolk/analyzer.cpp

@@ -46,7 +46,7 @@ int CodeBlob::split_vars(bool strict) {
     if (k != 1) {
       var.coord = ~((n << 8) + k);
       for (int i = 0; i < k; i++) {
-        auto v = create_var(comp_types[i], vars[j].sym_idx, vars[j].where);
+        auto v = create_var(comp_types[i], vars[j].v_sym, vars[j].where);
         tolk_assert(v == n + i);
         tolk_assert(vars[v].idx == v);
         vars[v].coord = ((int)j << 8) + i + 1;
@@ -732,15 +732,18 @@ VarDescrList Op::fwd_analyze(VarDescrList values) {
     }
     case _Call: {
       prepare_args(values);
-      auto func = dynamic_cast<const SymValAsmFunc*>(fun_ref->value);
-      if (func) {
+      if (!f_sym->is_regular_function()) {
         std::vector<VarDescr> res;
         res.reserve(left.size());
         for (var_idx_t i : left) {
           res.emplace_back(i);
         }
         AsmOpList tmp;
-        func->compile(tmp, res, args, where);  // abstract interpretation of res := f (args)
+        if (f_sym->is_asm_function()) {
+          std::get<FunctionBodyAsm*>(f_sym->body)->compile(tmp);  // abstract interpretation of res := f (args)
+        } else {
+          std::get<FunctionBodyBuiltin*>(f_sym->body)->compile(tmp, res, args, where);
+        }
         int j = 0;
         for (var_idx_t i : left) {
           values.add_newval(i).set_value(res[j++]);
@@ -878,27 +881,10 @@ bool Op::set_noreturn(bool flag) {
   return flag;
 }
 
-void Op::set_impure(const CodeBlob &code) {
-  // todo calling this function with `code` is a bad design (flags are assigned after Op is constructed)
-  // later it's better to check this somewhere in code.emplace_back()
-  if (code.flags & CodeBlob::_ForbidImpure) {
-    throw ParseError(where, "an impure operation in a pure function");
-  }
+void Op::set_impure_flag() {
   flags |= _Impure;
 }
 
-void Op::set_impure(const CodeBlob &code, bool flag) {
-  if (flag) {
-    if (code.flags & CodeBlob::_ForbidImpure) {
-      throw ParseError(where, "an impure operation in a pure function");
-    }
-    flags |= _Impure;
-  } else {
-    flags &= ~_Impure;
-  }
-}
-
-
 bool Op::mark_noreturn() {
   switch (cl) {
     case _Nop:

tolk/asmops.cpp

@@ -52,10 +52,10 @@ std::ostream& operator<<(std::ostream& os, AsmOp::SReg stack_reg) {
   }
 }
 
-AsmOp AsmOp::Const(int arg, std::string push_op, td::RefInt256 origin) {
+AsmOp AsmOp::Const(int arg, const std::string& push_op) {
   std::ostringstream os;
   os << arg << ' ' << push_op;
-  return AsmOp::Const(os.str(), origin);
+  return AsmOp::Const(os.str());
 }
 
 AsmOp AsmOp::make_stk2(int a, int b, const char* str, int delta) {
@@ -161,36 +161,36 @@ AsmOp AsmOp::UnTuple(int a) {
   return AsmOp::Custom(os.str(), 1, a);
 }
 
-AsmOp AsmOp::IntConst(td::RefInt256 x) {
+AsmOp AsmOp::IntConst(const td::RefInt256& x) {
   if (x->signed_fits_bits(8)) {
-    return AsmOp::Const(dec_string(x) + " PUSHINT", x);
+    return AsmOp::Const(dec_string(x) + " PUSHINT");
   }
   if (!x->is_valid()) {
-    return AsmOp::Const("PUSHNAN", x);
+    return AsmOp::Const("PUSHNAN");
   }
   int k = is_pos_pow2(x);
   if (k >= 0) {
-    return AsmOp::Const(k, "PUSHPOW2", x);
+    return AsmOp::Const(k, "PUSHPOW2");
   }
   k = is_pos_pow2(x + 1);
   if (k >= 0) {
-    return AsmOp::Const(k, "PUSHPOW2DEC", x);
+    return AsmOp::Const(k, "PUSHPOW2DEC");
   }
   k = is_pos_pow2(-x);
   if (k >= 0) {
-    return AsmOp::Const(k, "PUSHNEGPOW2", x);
+    return AsmOp::Const(k, "PUSHNEGPOW2");
   }
   if (!x->mod_pow2_short(23)) {
-    return AsmOp::Const(dec_string(x) + " PUSHINTX", x);
+    return AsmOp::Const(dec_string(x) + " PUSHINTX");
   }
-  return AsmOp::Const(dec_string(x) + " PUSHINT", x);
+  return AsmOp::Const(dec_string(x) + " PUSHINT");
 }
 
 AsmOp AsmOp::BoolConst(bool f) {
   return AsmOp::Const(f ? "TRUE" : "FALSE");
 }
 
-AsmOp AsmOp::Parse(std::string custom_op) {
+AsmOp AsmOp::Parse(const std::string& custom_op) {
   if (custom_op == "NOP") {
     return AsmOp::Nop();
   } else if (custom_op == "SWAP") {

tolk/ast-from-tokens.cpp

@@ -75,7 +75,7 @@ static void fire_error_mix_and_or_no_parenthesis(SrcLocation loc, std::string_vi
 // the only way to suppress this error for the programmer is to use parenthesis
 // (how do we detect presence of parenthesis? simple: (0!=1) is ast_parenthesized_expr{ast_binary_operator},
 //  that's why if rhs->type == ast_binary_operator, it's not surrounded by parenthesis)
-static void diagnose_bitwise_precedence(SrcLocation loc, std::string_view operator_name, AnyV lhs, AnyV rhs) {
+static void diagnose_bitwise_precedence(SrcLocation loc, std::string_view operator_name, AnyExprV lhs, AnyExprV rhs) {
   // handle "flags & 0xFF != 0" (rhs = "0xFF != 0")
   if (rhs->type == ast_binary_operator && is_comparison_binary_op(rhs->as<ast_binary_operator>()->tok)) {
     fire_error_lower_precedence(loc, operator_name, rhs->as<ast_binary_operator>()->operator_name);
@@ -90,7 +90,7 @@ static void diagnose_bitwise_precedence(SrcLocation loc, std::string_view operat
 // similar to above, but detect potentially invalid usage of && and ||
 // since anyway, using parenthesis when both && and || occur in the same expression,
 // && and || have equal operator precedence in Tolk
-static void diagnose_and_or_precedence(SrcLocation loc, AnyV lhs, TokenType rhs_tok, std::string_view rhs_operator_name) {
+static void diagnose_and_or_precedence(SrcLocation loc, AnyExprV lhs, TokenType rhs_tok, std::string_view rhs_operator_name) {
   if (auto lhs_op = lhs->try_as<ast_binary_operator>()) {
     // handle "arg1 & arg2 | arg3" (lhs = "arg1 & arg2")
     if (is_bitwise_binary_op(lhs_op->tok) && is_bitwise_binary_op(rhs_tok) && lhs_op->tok != rhs_tok) {
@@ -105,7 +105,7 @@ static void diagnose_and_or_precedence(SrcLocation loc, AnyV lhs, TokenType rhs_
 }
 
 // diagnose "a << 8 + 1" (equivalent to "a << 9", probably unexpected)
-static void diagnose_addition_in_bitshift(SrcLocation loc, std::string_view bitshift_operator_name, AnyV rhs) {
+static void diagnose_addition_in_bitshift(SrcLocation loc, std::string_view bitshift_operator_name, AnyExprV rhs) {
   if (rhs->type == ast_binary_operator && is_add_or_sub_binary_op(rhs->as<ast_binary_operator>()->tok)) {
     fire_error_lower_precedence(loc, bitshift_operator_name, rhs->as<ast_binary_operator>()->operator_name);
   }
@@ -122,7 +122,7 @@ static void fire_error_FunC_style_var_declaration(Lexer& lex) {
 }
 
 // replace (a == null) and similar to isNull(a) (call of a built-in function)
-static AnyV maybe_replace_eq_null_with_isNull_call(V<ast_binary_operator> v) {
+static AnyExprV maybe_replace_eq_null_with_isNull_call(V<ast_binary_operator> v) {
   bool has_null = v->get_lhs()->type == ast_null_keyword || v->get_rhs()->type == ast_null_keyword;
   bool replace = has_null && (v->tok == tok_eq || v->tok == tok_neq);
   if (!replace) {
@@ -130,9 +130,9 @@ static AnyV maybe_replace_eq_null_with_isNull_call(V<ast_binary_operator> v) {
   }
 
   auto v_ident = createV<ast_identifier>(v->loc, "__isNull"); // built-in function
-  AnyV v_null = v->get_lhs()->type == ast_null_keyword ? v->get_rhs() : v->get_lhs();
-  AnyV v_arg = createV<ast_argument>(v->loc, v_null, false);
-  AnyV v_isNull = createV<ast_function_call>(v->loc, v_ident, createV<ast_argument_list>(v->loc, {v_arg}));
+  AnyExprV v_null = v->get_lhs()->type == ast_null_keyword ? v->get_rhs() : v->get_lhs();
+  AnyExprV v_arg = createV<ast_argument>(v->loc, v_null, false);
+  AnyExprV v_isNull = createV<ast_function_call>(v->loc, v_ident, createV<ast_argument_list>(v->loc, {v_arg}));
   if (v->tok == tok_neq) {
     v_isNull = createV<ast_unary_operator>(v->loc, "!", tok_logical_not, v_isNull);
   }
@@ -230,7 +230,7 @@ static TypeExpr* parse_type(Lexer& lex, V<ast_genericsT_list> genericsT_list) {
   return res;
 }
 
-AnyV parse_expr(Lexer& lex);
+AnyExprV parse_expr(Lexer& lex);
 
 static AnyV parse_parameter(Lexer& lex, V<ast_genericsT_list> genericsT_list, bool is_first) {
   SrcLocation loc = lex.cur_location();
@@ -256,7 +256,6 @@ static AnyV parse_parameter(Lexer& lex, V<ast_genericsT_list> genericsT_list, bo
   } else if (lex.tok() != tok_underscore) {
     lex.unexpected("parameter name");
   }
-  auto v_ident = createV<ast_identifier>(lex.cur_location(), param_name);
   lex.next();
 
   // parameter type after colon, also mandatory (even explicit ":auto")
@@ -269,7 +268,7 @@ static AnyV parse_parameter(Lexer& lex, V<ast_genericsT_list> genericsT_list, bo
     throw ParseError(loc, "`self` parameter must be strictly typed");
   }
 
-  return createV<ast_parameter>(loc, v_ident, param_type, declared_as_mutate);
+  return createV<ast_parameter>(loc, param_name, param_type, declared_as_mutate);
 }
 
 static AnyV parse_global_var_declaration(Lexer& lex, const std::vector<V<ast_annotation>>& annotations) {
@@ -316,7 +315,7 @@ static AnyV parse_constant_declaration(Lexer& lex, const std::vector<V<ast_annot
     }
   }
   lex.expect(tok_assign, "`=`");
-  AnyV init_value = parse_expr(lex);
+  AnyExprV init_value = parse_expr(lex);
   if (lex.tok() == tok_comma) {
     lex.error("multiple declarations are not allowed, split constants on separate lines");
   }
@@ -341,7 +340,7 @@ static V<ast_parameter_list> parse_parameter_list(Lexer& lex, V<ast_genericsT_li
 }
 
 // "arguments" are at function call: `f(arg1, mutate arg2)`
-static AnyV parse_argument(Lexer& lex) {
+static AnyExprV parse_argument(Lexer& lex) {
   SrcLocation loc = lex.cur_location();
 
   // keyword `mutate` is necessary when a parameter is declared `mutate` (to make mutation obvious for the reader)
@@ -351,13 +350,13 @@ static AnyV parse_argument(Lexer& lex) {
     passed_as_mutate = true;
   }
 
-  AnyV expr = parse_expr(lex);
+  AnyExprV expr = parse_expr(lex);
   return createV<ast_argument>(loc, expr, passed_as_mutate);
 }
 
 static V<ast_argument_list> parse_argument_list(Lexer& lex) {
   SrcLocation loc = lex.cur_location();
-  std::vector<AnyV> args;
+  std::vector<AnyExprV> args;
   lex.expect(tok_oppar, "`(`");
   if (lex.tok() != tok_clpar) {
     args.push_back(parse_argument(lex));
@@ -371,7 +370,7 @@ static V<ast_argument_list> parse_argument_list(Lexer& lex) {
 }
 
 // parse (expr) / [expr] / identifier / number
-static AnyV parse_expr100(Lexer& lex) {
+static AnyExprV parse_expr100(Lexer& lex) {
   SrcLocation loc = lex.cur_location();
   switch (lex.tok()) {
     case tok_oppar: {
@@ -380,12 +379,12 @@ static AnyV parse_expr100(Lexer& lex) {
         lex.next();
         return createV<ast_tensor>(loc, {});
       }
-      AnyV first = parse_expr(lex);
+      AnyExprV first = parse_expr(lex);
       if (lex.tok() == tok_clpar) {
         lex.next();
-        return createV<ast_parenthesized_expr>(loc, first);
+        return createV<ast_parenthesized_expression>(loc, first);
       }
-      std::vector<AnyV> items(1, first);
+      std::vector<AnyExprV> items(1, first);
       while (lex.tok() == tok_comma) {
         lex.next();
         items.emplace_back(parse_expr(lex));
@@ -399,7 +398,7 @@ static AnyV parse_expr100(Lexer& lex) {
         lex.next();
         return createV<ast_tensor_square>(loc, {});
       }
-      std::vector<AnyV> items(1, parse_expr(lex));
+      std::vector<AnyExprV> items(1, parse_expr(lex));
       while (lex.tok() == tok_comma) {
         lex.next();
         items.emplace_back(parse_expr(lex));
@@ -408,9 +407,13 @@ static AnyV parse_expr100(Lexer& lex) {
       return createV<ast_tensor_square>(loc, std::move(items));
     }
     case tok_int_const: {
-      std::string_view int_val = lex.cur_str();
+      std::string_view orig_str = lex.cur_str();
+      td::RefInt256 intval = td::string_to_int256(static_cast<std::string>(orig_str));
+      if (intval.is_null() || !intval->signed_fits_bits(257)) {
+        lex.error("invalid integer constant");
+      }
       lex.next();
-      return createV<ast_int_const>(loc, int_val);
+      return createV<ast_int_const>(loc, std::move(intval), orig_str);
     }
     case tok_string_const: {
       std::string_view str_val = lex.cur_str();
@@ -459,8 +462,8 @@ static AnyV parse_expr100(Lexer& lex) {
 }
 
 // parse E(args)
-static AnyV parse_expr90(Lexer& lex) {
-  AnyV res = parse_expr100(lex);
+static AnyExprV parse_expr90(Lexer& lex) {
+  AnyExprV res = parse_expr100(lex);
   if (lex.tok() == tok_oppar) {
     return createV<ast_function_call>(res->loc, res, parse_argument_list(lex));
   }
@@ -468,8 +471,8 @@ static AnyV parse_expr90(Lexer& lex) {
 }
 
 // parse E.method(...) (left-to-right)
-static AnyV parse_expr80(Lexer& lex) {
-  AnyV lhs = parse_expr90(lex);
+static AnyExprV parse_expr80(Lexer& lex) {
+  AnyExprV lhs = parse_expr90(lex);
   while (lex.tok() == tok_dot) {
     SrcLocation loc = lex.cur_location();
     lex.next();
@@ -482,27 +485,27 @@ static AnyV parse_expr80(Lexer& lex) {
 }
 
 // parse ! ~ - + E (unary)
-static AnyV parse_expr75(Lexer& lex) {
+static AnyExprV parse_expr75(Lexer& lex) {
   TokenType t = lex.tok();
   if (t == tok_logical_not || t == tok_bitwise_not || t == tok_minus || t == tok_plus) {
     SrcLocation loc = lex.cur_location();
     std::string_view operator_name = lex.cur_str();
     lex.next();
-    AnyV rhs = parse_expr75(lex);
+    AnyExprV rhs = parse_expr75(lex);
     return createV<ast_unary_operator>(loc, operator_name, t, rhs);
   }
   return parse_expr80(lex);
 }
 
 // parse E * / % ^/ ~/ E (left-to-right)
-static AnyV parse_expr30(Lexer& lex) {
-  AnyV lhs = parse_expr75(lex);
+static AnyExprV parse_expr30(Lexer& lex) {
+  AnyExprV lhs = parse_expr75(lex);
   TokenType t = lex.tok();
   while (t == tok_mul || t == tok_div || t == tok_mod || t == tok_divC || t == tok_divR) {
     SrcLocation loc = lex.cur_location();
     std::string_view operator_name = lex.cur_str();
     lex.next();
-    AnyV rhs = parse_expr75(lex);
+    AnyExprV rhs = parse_expr75(lex);
     lhs = createV<ast_binary_operator>(loc, operator_name, t, lhs, rhs);
     t = lex.tok();
   }
@@ -510,14 +513,14 @@ static AnyV parse_expr30(Lexer& lex) {
 }
 
 // parse E + - E (left-to-right)
-static AnyV parse_expr20(Lexer& lex) {
-  AnyV lhs = parse_expr30(lex);
+static AnyExprV parse_expr20(Lexer& lex) {
+  AnyExprV lhs = parse_expr30(lex);
   TokenType t = lex.tok();
   while (t == tok_minus || t == tok_plus) {
     SrcLocation loc = lex.cur_location();
     std::string_view operator_name = lex.cur_str();
     lex.next();
-    AnyV rhs = parse_expr30(lex);
+    AnyExprV rhs = parse_expr30(lex);
     lhs = createV<ast_binary_operator>(loc, operator_name, t, lhs, rhs);
     t = lex.tok();
   }
@@ -525,14 +528,14 @@ static AnyV parse_expr20(Lexer& lex) {
 }
 
 // parse E << >> ~>> ^>> E (left-to-right)
-static AnyV parse_expr17(Lexer& lex) {
-  AnyV lhs = parse_expr20(lex);
+static AnyExprV parse_expr17(Lexer& lex) {
+  AnyExprV lhs = parse_expr20(lex);
   TokenType t = lex.tok();
   while (t == tok_lshift || t == tok_rshift || t == tok_rshiftC || t == tok_rshiftR) {
     SrcLocation loc = lex.cur_location();
     std::string_view operator_name = lex.cur_str();
     lex.next();
-    AnyV rhs = parse_expr20(lex);
+    AnyExprV rhs = parse_expr20(lex);
     diagnose_addition_in_bitshift(loc, operator_name, rhs);
     lhs = createV<ast_binary_operator>(loc, operator_name, t, lhs, rhs);
     t = lex.tok();
@@ -541,14 +544,14 @@ static AnyV parse_expr17(Lexer& lex) {
 }
 
 // parse E == < > <= >= != <=> E (left-to-right)
-static AnyV parse_expr15(Lexer& lex) {
-  AnyV lhs = parse_expr17(lex);
+static AnyExprV parse_expr15(Lexer& lex) {
+  AnyExprV lhs = parse_expr17(lex);
   TokenType t = lex.tok();
   if (t == tok_eq || t == tok_lt || t == tok_gt || t == tok_leq || t == tok_geq || t == tok_neq || t == tok_spaceship) {
     SrcLocation loc = lex.cur_location();
     std::string_view operator_name = lex.cur_str();
     lex.next();
-    AnyV rhs = parse_expr17(lex);
+    AnyExprV rhs = parse_expr17(lex);
     lhs = createV<ast_binary_operator>(loc, operator_name, t, lhs, rhs);
     if (t == tok_eq || t == tok_neq) {
       lhs = maybe_replace_eq_null_with_isNull_call(lhs->as<ast_binary_operator>());
@@ -558,14 +561,14 @@ static AnyV parse_expr15(Lexer& lex) {
 }
 
 // parse E & | ^ E (left-to-right)
-static AnyV parse_expr14(Lexer& lex) {
-  AnyV lhs = parse_expr15(lex);
+static AnyExprV parse_expr14(Lexer& lex) {
+  AnyExprV lhs = parse_expr15(lex);
   TokenType t = lex.tok();
   while (t == tok_bitwise_and || t == tok_bitwise_or || t == tok_bitwise_xor) {
     SrcLocation loc = lex.cur_location();
     std::string_view operator_name = lex.cur_str();
     lex.next();
-    AnyV rhs = parse_expr15(lex);
+    AnyExprV rhs = parse_expr15(lex);
     diagnose_bitwise_precedence(loc, operator_name, lhs, rhs);
     diagnose_and_or_precedence(loc, lhs, t, operator_name);
     lhs = createV<ast_binary_operator>(loc, operator_name, t, lhs, rhs);
@@ -575,14 +578,14 @@ static AnyV parse_expr14(Lexer& lex) {
 }
 
 // parse E && || E (left-to-right)
-static AnyV parse_expr13(Lexer& lex) {
-  AnyV lhs = parse_expr14(lex);
+static AnyExprV parse_expr13(Lexer& lex) {
+  AnyExprV lhs = parse_expr14(lex);
   TokenType t = lex.tok();
   while (t == tok_logical_and || t == tok_logical_or) {
     SrcLocation loc = lex.cur_location();
     std::string_view operator_name = lex.cur_str();
     lex.next();
-    AnyV rhs = parse_expr14(lex);
+    AnyExprV rhs = parse_expr14(lex);
     diagnose_and_or_precedence(loc, lhs, t, operator_name);
     lhs = createV<ast_binary_operator>(loc, operator_name, t, lhs, rhs);
     t = lex.tok();
@@ -591,8 +594,8 @@ static AnyV parse_expr13(Lexer& lex) {
 }
 
 // parse E = += -= E and E ? E : E (right-to-left)
-static AnyV parse_expr10(Lexer& lex) {
-  AnyV lhs = parse_expr13(lex);
+static AnyExprV parse_expr10(Lexer& lex) {
+  AnyExprV lhs = parse_expr13(lex);
   TokenType t = lex.tok();
   if (t == tok_set_plus || t == tok_set_minus || t == tok_set_mul || t == tok_set_div ||
       t == tok_set_mod || t == tok_set_lshift || t == tok_set_rshift ||
@@ -601,36 +604,36 @@ static AnyV parse_expr10(Lexer& lex) {
     SrcLocation loc = lex.cur_location();
     std::string_view operator_name = lex.cur_str();
     lex.next();
-    AnyV rhs = parse_expr10(lex);
+    AnyExprV rhs = parse_expr10(lex);
     return createV<ast_binary_operator>(loc, operator_name, t, lhs, rhs);
   }
   if (t == tok_question) {
     SrcLocation loc = lex.cur_location();
     lex.next();
-    AnyV when_true = parse_expr10(lex);
+    AnyExprV when_true = parse_expr10(lex);
     lex.expect(tok_colon, "`:`");
-    AnyV when_false = parse_expr10(lex);
+    AnyExprV when_false = parse_expr10(lex);
     return createV<ast_ternary_operator>(loc, lhs, when_true, when_false);
   }
   return lhs;
 }
 
-AnyV parse_expr(Lexer& lex) {
+AnyExprV parse_expr(Lexer& lex) {
   return parse_expr10(lex);
 }
 
 AnyV parse_statement(Lexer& lex);
 
-static AnyV parse_var_declaration_lhs(Lexer& lex, bool is_immutable) {
+static AnyExprV parse_var_declaration_lhs(Lexer& lex, bool is_immutable) {
   SrcLocation loc = lex.cur_location();
   if (lex.tok() == tok_oppar) {
     lex.next();
-    AnyV first = parse_var_declaration_lhs(lex, is_immutable);
+    AnyExprV first = parse_var_declaration_lhs(lex, is_immutable);
     if (lex.tok() == tok_clpar) {
       lex.next();
-      return createV<ast_parenthesized_expr>(loc, first);
+      return createV<ast_parenthesized_expression>(loc, first);
     }
-    std::vector<AnyV> args(1, first);
+    std::vector<AnyExprV> args(1, first);
     while (lex.tok() == tok_comma) {
       lex.next();
       args.push_back(parse_var_declaration_lhs(lex, is_immutable));
@@ -640,7 +643,7 @@ static AnyV parse_var_declaration_lhs(Lexer& lex, bool is_immutable) {
   }
   if (lex.tok() == tok_opbracket) {
     lex.next();
-    std::vector<AnyV> args(1, parse_var_declaration_lhs(lex, is_immutable));
+    std::vector<AnyExprV> args(1, parse_var_declaration_lhs(lex, is_immutable));
     while (lex.tok() == tok_comma) {
       lex.next();
       args.push_back(parse_var_declaration_lhs(lex, is_immutable));
@@ -679,12 +682,12 @@ static AnyV parse_local_vars_declaration(Lexer& lex) {
   bool is_immutable = lex.tok() == tok_val;
   lex.next();
 
-  AnyV lhs = parse_var_declaration_lhs(lex, is_immutable);
+  AnyExprV lhs = parse_var_declaration_lhs(lex, is_immutable);
   if (lex.tok() != tok_assign) {
     lex.error("variables declaration must be followed by assignment: `var xxx = ...`");
   }
   lex.next();
-  AnyV assigned_val = parse_expr(lex);
+  AnyExprV assigned_val = parse_expr(lex);
 
   if (lex.tok() == tok_comma) {
     lex.error("multiple declarations are not allowed, split variables on separate lines");
@@ -708,7 +711,7 @@ static V<ast_sequence> parse_sequence(Lexer& lex) {
 static AnyV parse_return_statement(Lexer& lex) {
   SrcLocation loc = lex.cur_location();
   lex.expect(tok_return, "`return`");
-  AnyV child = lex.tok() == tok_semicolon   // `return;` actually means `return ();` (which is void)
+  AnyExprV child = lex.tok() == tok_semicolon   // `return;` actually means `return ();` (which is void)
     ? createV<ast_tensor>(lex.cur_location(), {})
     : parse_expr(lex);
   lex.expect(tok_semicolon, "`;`");
@@ -720,7 +723,7 @@ static AnyV parse_if_statement(Lexer& lex, bool is_ifnot) {
   lex.expect(tok_if, "`if`");
 
   lex.expect(tok_oppar, "`(`");
-  AnyV cond = parse_expr(lex);
+  AnyExprV cond = parse_expr(lex);
   lex.expect(tok_clpar, "`)`");
   // replace if(!expr) with ifnot(expr) (this should be done later, but for now, let this be right at parsing time)
   if (auto v_not = cond->try_as<ast_unary_operator>(); v_not && v_not->tok == tok_logical_not) {
@@ -748,7 +751,7 @@ static AnyV parse_repeat_statement(Lexer& lex) {
   SrcLocation loc = lex.cur_location();
   lex.expect(tok_repeat, "`repeat`");
   lex.expect(tok_oppar, "`(`");
-  AnyV cond = parse_expr(lex);
+  AnyExprV cond = parse_expr(lex);
   lex.expect(tok_clpar, "`)`");
   V<ast_sequence> body = parse_sequence(lex);
   return createV<ast_repeat_statement>(loc, cond, body);
@@ -758,7 +761,7 @@ static AnyV parse_while_statement(Lexer& lex) {
   SrcLocation loc = lex.cur_location();
   lex.expect(tok_while, "`while`");
   lex.expect(tok_oppar, "`(`");
-  AnyV cond = parse_expr(lex);
+  AnyExprV cond = parse_expr(lex);
   lex.expect(tok_clpar, "`)`");
   V<ast_sequence> body = parse_sequence(lex);
   return createV<ast_while_statement>(loc, cond, body);
@@ -770,13 +773,13 @@ static AnyV parse_do_while_statement(Lexer& lex) {
   V<ast_sequence> body = parse_sequence(lex);
   lex.expect(tok_while, "`while`");
   lex.expect(tok_oppar, "`(`");
-  AnyV cond = parse_expr(lex);
+  AnyExprV cond = parse_expr(lex);
   lex.expect(tok_clpar, "`)`");
   lex.expect(tok_semicolon, "`;`");
   return createV<ast_do_while_statement>(loc, body, cond);
 }
 
-static AnyV parse_catch_variable(Lexer& lex) {
+static AnyExprV parse_catch_variable(Lexer& lex) {
   SrcLocation loc = lex.cur_location();
   if (lex.tok() == tok_identifier) {
     std::string_view var_name = lex.cur_str();
@@ -794,7 +797,7 @@ static AnyV parse_throw_statement(Lexer& lex) {
   SrcLocation loc = lex.cur_location();
   lex.expect(tok_throw, "`throw`");
 
-  AnyV thrown_code, thrown_arg;
+  AnyExprV thrown_code, thrown_arg;
   if (lex.tok() == tok_oppar) {   // throw (code) or throw (code, arg)
     lex.next();
     thrown_code = parse_expr(lex);
@@ -802,12 +805,12 @@ static AnyV parse_throw_statement(Lexer& lex) {
       lex.next();
       thrown_arg = parse_expr(lex);
     } else {
-      thrown_arg = createV<ast_empty>(loc);
+      thrown_arg = createV<ast_empty_expression>(loc);
     }
     lex.expect(tok_clpar, "`)`");
   } else {   // throw code
     thrown_code = parse_expr(lex);
-    thrown_arg = createV<ast_empty>(loc);
+    thrown_arg = createV<ast_empty_expression>(loc);
   }
 
   lex.expect(tok_semicolon, "`;`");
@@ -819,8 +822,8 @@ static AnyV parse_assert_statement(Lexer& lex) {
   lex.expect(tok_assert, "`assert`");
 
   lex.expect(tok_oppar, "`(`");
-  AnyV cond = parse_expr(lex);
-  AnyV thrown_code;
+  AnyExprV cond = parse_expr(lex);
+  AnyExprV thrown_code;
   if (lex.tok() == tok_comma) {   // assert(cond, code)
     lex.next();
     thrown_code = parse_expr(lex);
@@ -840,7 +843,7 @@ static AnyV parse_try_catch_statement(Lexer& lex) {
   lex.expect(tok_try, "`try`");
   V<ast_sequence> try_body = parse_sequence(lex);
 
-  std::vector<AnyV> catch_args;
+  std::vector<AnyExprV> catch_args;
   lex.expect(tok_catch, "`catch`");
   SrcLocation catch_loc = lex.cur_location();
   if (lex.tok() == tok_oppar) {
@@ -889,13 +892,13 @@ AnyV parse_statement(Lexer& lex) {
     case tok_semicolon: {
       SrcLocation loc = lex.cur_location();
       lex.next();
-      return createV<ast_empty>(loc);
+      return createV<ast_empty_statement>(loc);
     }
     case tok_break:
     case tok_continue:
       lex.error("break/continue from loops are not supported yet");
     default: {
-      AnyV expr = parse_expr(lex);
+      AnyExprV expr = parse_expr(lex);
       lex.expect(tok_semicolon, "`;`");
       return expr;
     }
@@ -976,7 +979,7 @@ static V<ast_annotation> parse_annotation(Lexer& lex) {
   if (lex.tok() == tok_oppar) {
     SrcLocation loc_args = lex.cur_location();
     lex.next();
-    std::vector<AnyV> args;
+    std::vector<AnyExprV> args;
     args.push_back(parse_expr(lex));
     while (lex.tok() == tok_comma) {
       lex.next();
@@ -1038,7 +1041,7 @@ static AnyV parse_function_declaration(Lexer& lex, const std::vector<V<ast_annot
   }
 
   V<ast_parameter_list> v_param_list = parse_parameter_list(lex, genericsT_list)->as<ast_parameter_list>();
-  bool accepts_self = !v_param_list->empty() && v_param_list->get_param(0)->get_identifier()->name == "self";
+  bool accepts_self = !v_param_list->empty() && v_param_list->get_param(0)->param_name == "self";
   int n_mutate_params = v_param_list->get_mutate_params_count();
 
   TypeExpr* ret_type = nullptr;
@@ -1069,7 +1072,7 @@ static AnyV parse_function_declaration(Lexer& lex, const std::vector<V<ast_annot
     ret_tensor_items.reserve(1 + n_mutate_params);
     for (AnyV v_param : v_param_list->get_params()) {
       if (v_param->as<ast_parameter>()->declared_as_mutate) {
-        ret_tensor_items.emplace_back(v_param->as<ast_parameter>()->param_type);
+        ret_tensor_items.emplace_back(v_param->as<ast_parameter>()->declared_type);
       }
     }
     ret_tensor_items.emplace_back(ret_type ? ret_type : TypeExpr::new_hole());
@@ -1079,7 +1082,7 @@ static AnyV parse_function_declaration(Lexer& lex, const std::vector<V<ast_annot
   AnyV v_body = nullptr;
 
   if (lex.tok() == tok_builtin) {
-    v_body = createV<ast_empty>(lex.cur_location());
+    v_body = createV<ast_empty_statement>(lex.cur_location());
     lex.next();
     lex.expect(tok_semicolon, "`;`");
   } else if (lex.tok() == tok_opbrace) {
@@ -1098,7 +1101,7 @@ static AnyV parse_function_declaration(Lexer& lex, const std::vector<V<ast_annot
   f_declaration->is_entrypoint = is_entrypoint;
   f_declaration->genericsT_list = genericsT_list;
   f_declaration->marked_as_get_method = is_get_method;
-  f_declaration->marked_as_builtin = v_body->type == ast_empty;
+  f_declaration->marked_as_builtin = v_body->type == ast_empty_statement;
   f_declaration->accepts_self = accepts_self;
   f_declaration->returns_self = returns_self;
 
@@ -1142,7 +1145,7 @@ static AnyV parse_tolk_required_version(Lexer& lex) {
     loc.show_warning("the contract is written in Tolk v" + semver + ", but you use Tolk compiler v" + TOLK_VERSION + "; probably, it will lead to compilation errors or hash changes");
   }
 
-  return createV<ast_tolk_required_version>(loc, tok_eq, semver);  // semicolon is not necessary
+  return createV<ast_tolk_required_version>(loc, semver);  // semicolon is not necessary
 }
 
 static AnyV parse_import_statement(Lexer& lex) {

tolk/ast-from-tokens.h

@@ -16,12 +16,10 @@
 */
 #pragma once
 
-#include "src-file.h"
+#include "fwd-declarations.h"
 
 namespace tolk {
 
-struct ASTNodeBase;
-
-const ASTNodeBase* parse_src_file_to_ast(const SrcFile* file);
+AnyV parse_src_file_to_ast(const SrcFile* file);
 
 } // namespace tolk

tolk/ast-replacer.h

@@ -35,25 +35,39 @@ namespace tolk {
 
 class ASTReplacer {
 protected:
-  GNU_ATTRIBUTE_ALWAYS_INLINE static AnyV replace_children(const ASTNodeLeaf* v) {
+  GNU_ATTRIBUTE_ALWAYS_INLINE static AnyExprV replace_children(const ASTExprLeaf* v) {
     return v;
   }
 
-  GNU_ATTRIBUTE_ALWAYS_INLINE AnyV replace_children(const ASTNodeUnary* v) {
-    auto* v_mutable = const_cast<ASTNodeUnary*>(v);
+  GNU_ATTRIBUTE_ALWAYS_INLINE AnyExprV replace_children(const ASTExprUnary* v) {
+    auto* v_mutable = const_cast<ASTExprUnary*>(v);
     v_mutable->child = replace(v_mutable->child);
     return v_mutable;
   }
 
-  GNU_ATTRIBUTE_ALWAYS_INLINE AnyV replace_children(const ASTNodeBinary* v) {
-    auto* v_mutable = const_cast<ASTNodeBinary*>(v);
+  GNU_ATTRIBUTE_ALWAYS_INLINE AnyExprV replace_children(const ASTExprBinary* v) {
+    auto* v_mutable = const_cast<ASTExprBinary*>(v);
     v_mutable->lhs = replace(v->lhs);
     v_mutable->rhs = replace(v->rhs);
     return v_mutable;
   }
 
-  GNU_ATTRIBUTE_ALWAYS_INLINE AnyV replace_children(const ASTNodeVararg* v) {
-    auto* v_mutable = const_cast<ASTNodeVararg*>(v);
+  GNU_ATTRIBUTE_ALWAYS_INLINE AnyExprV replace_children(const ASTExprVararg* v) {
+    auto* v_mutable = const_cast<ASTExprVararg*>(v);
+    for (AnyExprV& child : v_mutable->children) {
+      child = replace(child);
+    }
+    return v_mutable;
+  }
+
+  GNU_ATTRIBUTE_ALWAYS_INLINE AnyV replace_children(const ASTStatementUnary* v) {
+    auto* v_mutable = const_cast<ASTStatementUnary*>(v);
+    v_mutable->child = replace(v_mutable->child);
+    return v_mutable;
+  }
+
+  GNU_ATTRIBUTE_ALWAYS_INLINE AnyV replace_children(const ASTStatementVararg* v) {
+    auto* v_mutable = const_cast<ASTStatementVararg*>(v);
     for (AnyV& child : v_mutable->children) {
       child = replace(child);
     }
@@ -64,27 +78,14 @@ public:
   virtual ~ASTReplacer() = default;
 
   virtual AnyV replace(AnyV v) = 0;
+  virtual AnyExprV replace(AnyExprV v) = 0;
 };
 
 class ASTReplacerInFunctionBody : public ASTReplacer {
 protected:
   using parent = ASTReplacerInFunctionBody;
 
-  virtual AnyV replace(V<ast_empty> v)                   { return replace_children(v); }
-  virtual AnyV replace(V<ast_parenthesized_expr> v)      { return replace_children(v); }
-  virtual AnyV replace(V<ast_tensor> v)                  { return replace_children(v); }
-  virtual AnyV replace(V<ast_tensor_square> v)           { return replace_children(v); }
-  virtual AnyV replace(V<ast_identifier> v)              { return replace_children(v); }
-  virtual AnyV replace(V<ast_int_const> v)               { return replace_children(v); }
-  virtual AnyV replace(V<ast_string_const> v)            { return replace_children(v); }
-  virtual AnyV replace(V<ast_bool_const> v)              { return replace_children(v); }
-  virtual AnyV replace(V<ast_null_keyword> v)            { return replace_children(v); }
-  virtual AnyV replace(V<ast_function_call> v)           { return replace_children(v); }
-  virtual AnyV replace(V<ast_dot_method_call> v)         { return replace_children(v); }
-  virtual AnyV replace(V<ast_underscore> v)              { return replace_children(v); }
-  virtual AnyV replace(V<ast_unary_operator> v)          { return replace_children(v); }
-  virtual AnyV replace(V<ast_binary_operator> v)         { return replace_children(v); }
-  virtual AnyV replace(V<ast_ternary_operator> v)        { return replace_children(v); }
+  virtual AnyV replace(V<ast_empty_statement> v)               { return replace_children(v); }
   virtual AnyV replace(V<ast_return_statement> v)              { return replace_children(v); }
   virtual AnyV replace(V<ast_sequence> v)                      { return replace_children(v); }
   virtual AnyV replace(V<ast_repeat_statement> v)              { return replace_children(v); }
@@ -94,14 +95,33 @@ protected:
   virtual AnyV replace(V<ast_assert_statement> v)              { return replace_children(v); }
   virtual AnyV replace(V<ast_try_catch_statement> v)           { return replace_children(v); }
   virtual AnyV replace(V<ast_if_statement> v)                  { return replace_children(v); }
-  virtual AnyV replace(V<ast_local_var> v)               { return replace_children(v); }
   virtual AnyV replace(V<ast_local_vars_declaration> v)        { return replace_children(v); }
   virtual AnyV replace(V<ast_asm_body> v)                      { return replace_children(v); }
 
-  AnyV replace(AnyV v) final {
+  virtual AnyExprV replace(V<ast_empty_expression> v)          { return replace_children(v); }
+  virtual AnyExprV replace(V<ast_parenthesized_expression> v)  { return replace_children(v); }
+  virtual AnyExprV replace(V<ast_tensor> v)                    { return replace_children(v); }
+  virtual AnyExprV replace(V<ast_tensor_square> v)             { return replace_children(v); }
+  virtual AnyExprV replace(V<ast_identifier> v)                { return replace_children(v); }
+  virtual AnyExprV replace(V<ast_int_const> v)                 { return replace_children(v); }
+  virtual AnyExprV replace(V<ast_string_const> v)              { return replace_children(v); }
+  virtual AnyExprV replace(V<ast_bool_const> v)                { return replace_children(v); }
+  virtual AnyExprV replace(V<ast_null_keyword> v)              { return replace_children(v); }
+  virtual AnyExprV replace(V<ast_self_keyword> v)              { return replace_children(v); }
+  virtual AnyExprV replace(V<ast_argument> v)                  { return replace_children(v); }
+  virtual AnyExprV replace(V<ast_argument_list> v)             { return replace_children(v); }
+  virtual AnyExprV replace(V<ast_function_call> v)             { return replace_children(v); }
+  virtual AnyExprV replace(V<ast_dot_method_call> v)           { return replace_children(v); }
+  virtual AnyExprV replace(V<ast_underscore> v)                { return replace_children(v); }
+  virtual AnyExprV replace(V<ast_unary_operator> v)            { return replace_children(v); }
+  virtual AnyExprV replace(V<ast_binary_operator> v)           { return replace_children(v); }
+  virtual AnyExprV replace(V<ast_ternary_operator> v)          { return replace_children(v); }
+  virtual AnyExprV replace(V<ast_local_var> v)                 { return replace_children(v); }
+
+  AnyExprV replace(AnyExprV v) final {
     switch (v->type) {
-      case ast_empty:                           return replace(v->as<ast_empty>());
-      case ast_parenthesized_expr:              return replace(v->as<ast_parenthesized_expr>());
+      case ast_empty_expression:                return replace(v->as<ast_empty_expression>());
+      case ast_parenthesized_expression:        return replace(v->as<ast_parenthesized_expression>());
       case ast_tensor:                          return replace(v->as<ast_tensor>());
       case ast_tensor_square:                   return replace(v->as<ast_tensor_square>());
       case ast_identifier:                      return replace(v->as<ast_identifier>());
@@ -110,12 +130,23 @@ protected:
       case ast_bool_const:                      return replace(v->as<ast_bool_const>());
       case ast_null_keyword:                    return replace(v->as<ast_null_keyword>());
       case ast_self_keyword:                    return replace(v->as<ast_self_keyword>());
+      case ast_argument:                        return replace(v->as<ast_argument>());
+      case ast_argument_list:                   return replace(v->as<ast_argument_list>());
       case ast_function_call:                   return replace(v->as<ast_function_call>());
       case ast_dot_method_call:                 return replace(v->as<ast_dot_method_call>());
       case ast_underscore:                      return replace(v->as<ast_underscore>());
       case ast_unary_operator:                  return replace(v->as<ast_unary_operator>());
       case ast_binary_operator:                 return replace(v->as<ast_binary_operator>());
       case ast_ternary_operator:                return replace(v->as<ast_ternary_operator>());
+      case ast_local_var:                       return replace(v->as<ast_local_var>());
+      default:
+        throw UnexpectedASTNodeType(v, "ASTReplacerInFunctionBody::replace");
+    }
+  }
+
+  AnyV replace(AnyV v) final {
+    switch (v->type) {
+      case ast_empty_statement:                 return replace(v->as<ast_empty_statement>());
       case ast_return_statement:                return replace(v->as<ast_return_statement>());
       case ast_sequence:                        return replace(v->as<ast_sequence>());
       case ast_repeat_statement:                return replace(v->as<ast_repeat_statement>());
@@ -125,11 +156,13 @@ protected:
       case ast_assert_statement:                return replace(v->as<ast_assert_statement>());
       case ast_try_catch_statement:             return replace(v->as<ast_try_catch_statement>());
       case ast_if_statement:                    return replace(v->as<ast_if_statement>());
-      case ast_local_var:                       return replace(v->as<ast_local_var>());
       case ast_local_vars_declaration:          return replace(v->as<ast_local_vars_declaration>());
       case ast_asm_body:                        return replace(v->as<ast_asm_body>());
-      default:
-        throw UnexpectedASTNodeType(v, "ASTReplacerInFunctionBody::visit");
+      default: {
+        // be very careful, don't forget to handle all statements (not expressions) above!
+        AnyExprV as_expr = reinterpret_cast<const ASTNodeExpressionBase*>(v);
+        return replace(as_expr);
+      }
     }
   }
 
@@ -139,22 +172,18 @@ public:
   }
 };
 
-class ASTReplacerAllFunctionsInFile : public ASTReplacerInFunctionBody {
-protected:
-  using parent = ASTReplacerAllFunctionsInFile;
-
-  virtual bool should_enter_function(V<ast_function_declaration> v) = 0;
-
-public:
-  void start_replacing_in_file(V<ast_tolk_file> v_file) {
-    for (AnyV v : v_file->get_toplevel_declarations()) {
-      if (auto v_function = v->try_as<ast_function_declaration>()) {
-        if (should_enter_function(v_function)) {
-          replace(v_function->get_body());
+template<class BodyReplacerT>
+void replace_ast_of_all_functions(const AllSrcFiles& all_files) {
+  for (const SrcFile* file : all_files) {
+    for (AnyV v : file->ast->as<ast_tolk_file>()->get_toplevel_declarations()) {
+      if (auto v_func = v->try_as<ast_function_declaration>()) {
+        if (v_func->is_regular_function()) {
+          BodyReplacerT visitor;
+          visitor.start_replacing_in_function(v_func);
+        }
       }
     }
   }
 }
-};
 
 } // namespace tolk

tolk/ast-stringifier.h

@@ -31,8 +31,9 @@ namespace tolk {
 
 class ASTStringifier final : public ASTVisitor {
   constexpr static std::pair<ASTNodeType, const char*> name_pairs[] = {
-    {ast_empty, "ast_empty"},
-    {ast_parenthesized_expr, "ast_parenthesized_expr"},
+    {ast_empty_statement, "ast_empty_statement"},
+    {ast_empty_expression, "ast_empty_expression"},
+    {ast_parenthesized_expression, "ast_parenthesized_expression"},
     {ast_tensor, "ast_tensor"},
     {ast_tensor_square, "ast_tensor_square"},
     {ast_identifier, "ast_identifier"},
@@ -115,7 +116,7 @@ class ASTStringifier final : public ASTVisitor {
       case ast_identifier:
         return static_cast<std::string>(v->as<ast_identifier>()->name);
       case ast_int_const:
-        return static_cast<std::string>(v->as<ast_int_const>()->int_val);
+        return static_cast<std::string>(v->as<ast_int_const>()->orig_str);
       case ast_string_const:
         if (char modifier = v->as<ast_string_const>()->modifier) {
           return "\"" + static_cast<std::string>(v->as<ast_string_const>()->str_val) + "\"" + std::string(1, modifier);
@@ -146,21 +147,21 @@ class ASTStringifier final : public ASTVisitor {
         return annotation_kinds[static_cast<int>(v->as<ast_annotation>()->kind)].second;
       case ast_parameter: {
         std::ostringstream os;
-        os << v->as<ast_parameter>()->param_type;
-        return static_cast<std::string>(v->as<ast_parameter>()->get_identifier()->name) + ": " + os.str();
+        os << v->as<ast_parameter>()->declared_type;
+        return static_cast<std::string>(v->as<ast_parameter>()->param_name) + ": " + os.str();
       }
       case ast_function_declaration: {
         std::string param_names;
         for (int i = 0; i < v->as<ast_function_declaration>()->get_num_params(); i++) {
           if (!param_names.empty())
             param_names += ",";
-          param_names += v->as<ast_function_declaration>()->get_param(i)->get_identifier()->name;
+          param_names += v->as<ast_function_declaration>()->get_param(i)->param_name;
         }
         return "fun " + static_cast<std::string>(v->as<ast_function_declaration>()->get_identifier()->name) + "(" + param_names + ")";
       }
       case ast_local_var: {
         std::ostringstream os;
-        os << v->as<ast_local_var>()->declared_type;
+        os << (v->as<ast_local_var>()->inferred_type ? v->as<ast_local_var>()->inferred_type : v->as<ast_local_var>()->declared_type);
         if (auto v_ident = v->as<ast_local_var>()->get_identifier()->try_as<ast_identifier>()) {
           return static_cast<std::string>(v_ident->name) + ":" + os.str();
         }
@@ -202,8 +203,9 @@ public:
 
   void visit(AnyV v) override {
     switch (v->type) {
-      case ast_empty:                         return handle_vertex(v->as<ast_empty>());
-      case ast_parenthesized_expr:            return handle_vertex(v->as<ast_parenthesized_expr>());
+      case ast_empty_statement:               return handle_vertex(v->as<ast_empty_statement>());
+      case ast_empty_expression:              return handle_vertex(v->as<ast_empty_expression>());
+      case ast_parenthesized_expression:      return handle_vertex(v->as<ast_parenthesized_expression>());
       case ast_tensor:                        return handle_vertex(v->as<ast_tensor>());
       case ast_tensor_square:                 return handle_vertex(v->as<ast_tensor_square>());
       case ast_identifier:                    return handle_vertex(v->as<ast_identifier>());

tolk/ast-visitor.h

@@ -37,20 +37,40 @@ namespace tolk {
 
 class ASTVisitor {
 protected:
-  GNU_ATTRIBUTE_ALWAYS_INLINE static void visit_children(const ASTNodeLeaf* v) {
+  GNU_ATTRIBUTE_ALWAYS_INLINE static void visit_children(const ASTExprLeaf* v) {
     static_cast<void>(v);
   }
 
-  GNU_ATTRIBUTE_ALWAYS_INLINE void visit_children(const ASTNodeUnary* v) {
+  GNU_ATTRIBUTE_ALWAYS_INLINE void visit_children(const ASTExprUnary* v) {
     visit(v->child);
   }
 
-  GNU_ATTRIBUTE_ALWAYS_INLINE void visit_children(const ASTNodeBinary* v) {
+  GNU_ATTRIBUTE_ALWAYS_INLINE void visit_children(const ASTExprBinary* v) {
     visit(v->lhs);
     visit(v->rhs);
   }
 
-  GNU_ATTRIBUTE_ALWAYS_INLINE void visit_children(const ASTNodeVararg* v) {
+  GNU_ATTRIBUTE_ALWAYS_INLINE void visit_children(const ASTExprVararg* v) {
+    for (AnyExprV child : v->children) {
+      visit(child);
+    }
+  }
+
+  GNU_ATTRIBUTE_ALWAYS_INLINE void visit_children(const ASTStatementUnary* v) {
+    visit(v->child);
+  }
+
+  GNU_ATTRIBUTE_ALWAYS_INLINE void visit_children(const ASTStatementVararg* v) {
+    for (AnyV child : v->children) {
+      visit(child);
+    }
+  }
+
+  GNU_ATTRIBUTE_ALWAYS_INLINE static void visit_children(const ASTOtherLeaf* v) {
+    static_cast<void>(v);
+  }
+
+  GNU_ATTRIBUTE_ALWAYS_INLINE void visit_children(const ASTOtherVararg* v) {
     for (AnyV child : v->children) {
       visit(child);
     }
@@ -66,8 +86,9 @@ class ASTVisitorFunctionBody : public ASTVisitor {
 protected:
   using parent = ASTVisitorFunctionBody;
 
-  virtual void visit(V<ast_empty> v)                     { return visit_children(v); }
-  virtual void visit(V<ast_parenthesized_expr> v)        { return visit_children(v); }
+  virtual void visit(V<ast_empty_statement> v)           { return visit_children(v); }
+  virtual void visit(V<ast_empty_expression> v)          { return visit_children(v); }
+  virtual void visit(V<ast_parenthesized_expression> v)  { return visit_children(v); }
   virtual void visit(V<ast_tensor> v)                    { return visit_children(v); }
   virtual void visit(V<ast_tensor_square> v)             { return visit_children(v); }
   virtual void visit(V<ast_identifier> v)                { return visit_children(v); }
@@ -76,6 +97,8 @@ protected:
   virtual void visit(V<ast_bool_const> v)                { return visit_children(v); }
   virtual void visit(V<ast_null_keyword> v)              { return visit_children(v); }
   virtual void visit(V<ast_self_keyword> v)              { return visit_children(v); }
+  virtual void visit(V<ast_argument> v)                  { return visit_children(v); }
+  virtual void visit(V<ast_argument_list> v)             { return visit_children(v); }
   virtual void visit(V<ast_function_call> v)             { return visit_children(v); }
   virtual void visit(V<ast_dot_method_call> v)           { return visit_children(v); }
   virtual void visit(V<ast_underscore> v)                { return visit_children(v); }
@@ -87,6 +110,8 @@ protected:
   virtual void visit(V<ast_repeat_statement> v)          { return visit_children(v); }
   virtual void visit(V<ast_while_statement> v)           { return visit_children(v); }
   virtual void visit(V<ast_do_while_statement> v)        { return visit_children(v); }
+  virtual void visit(V<ast_throw_statement> v)           { return visit_children(v); }
+  virtual void visit(V<ast_assert_statement> v)          { return visit_children(v); }
   virtual void visit(V<ast_try_catch_statement> v)       { return visit_children(v); }
   virtual void visit(V<ast_if_statement> v)              { return visit_children(v); }
   virtual void visit(V<ast_local_var> v)                 { return visit_children(v); }
@@ -95,8 +120,9 @@ protected:
 
   void visit(AnyV v) final {
     switch (v->type) {
-      case ast_empty:                           return visit(v->as<ast_empty>());
-      case ast_parenthesized_expr:              return visit(v->as<ast_parenthesized_expr>());
+      case ast_empty_statement:                 return visit(v->as<ast_empty_statement>());
+      case ast_empty_expression:                return visit(v->as<ast_empty_expression>());
+      case ast_parenthesized_expression:        return visit(v->as<ast_parenthesized_expression>());
       case ast_tensor:                          return visit(v->as<ast_tensor>());
       case ast_tensor_square:                   return visit(v->as<ast_tensor_square>());
       case ast_identifier:                      return visit(v->as<ast_identifier>());
@@ -105,6 +131,8 @@ protected:
       case ast_bool_const:                      return visit(v->as<ast_bool_const>());
       case ast_null_keyword:                    return visit(v->as<ast_null_keyword>());
       case ast_self_keyword:                    return visit(v->as<ast_self_keyword>());
+      case ast_argument:                        return visit(v->as<ast_argument>());
+      case ast_argument_list:                   return visit(v->as<ast_argument_list>());
       case ast_function_call:                   return visit(v->as<ast_function_call>());
       case ast_dot_method_call:                 return visit(v->as<ast_dot_method_call>());
       case ast_underscore:                      return visit(v->as<ast_underscore>());
@@ -129,27 +157,23 @@ protected:
   }
 
 public:
-  void start_visiting_function(V<ast_function_declaration> v_function) {
+  virtual void start_visiting_function(V<ast_function_declaration> v_function) {
     visit(v_function->get_body());
   }
 };
 
-class ASTVisitorAllFunctionsInFile : public ASTVisitorFunctionBody {
-protected:
-  using parent = ASTVisitorAllFunctionsInFile;
-
-  virtual bool should_enter_function(V<ast_function_declaration> v) = 0;
-
-public:
-  void start_visiting_file(V<ast_tolk_file> v_file) {
-    for (AnyV v : v_file->get_toplevel_declarations()) {
+template<class BodyVisitorT>
+void visit_ast_of_all_functions(const AllSrcFiles& all_files) {
+  for (const SrcFile* file : all_files) {
+    for (AnyV v : file->ast->as<ast_tolk_file>()->get_toplevel_declarations()) {
       if (auto v_func = v->try_as<ast_function_declaration>()) {
-        if (should_enter_function(v_func)) {
-          visit(v_func->get_body());
+        if (v_func->is_regular_function()) {
+          BodyVisitorT visitor;
+          visitor.start_visiting_function(v_func);
+        }
       }
     }
   }
 }
-};
 
 } // namespace tolk

tolk/ast.cpp

@@ -79,7 +79,7 @@ int Vertex<ast_genericsT_list>::lookup_idx(std::string_view nameT) const {
 
 int Vertex<ast_parameter_list>::lookup_idx(std::string_view param_name) const {
   for (size_t idx = 0; idx < children.size(); ++idx) {
-    if (children[idx] && children[idx]->as<ast_parameter>()->get_identifier()->name == param_name) {
+    if (children[idx] && children[idx]->as<ast_parameter>()->param_name == param_name) {
       return static_cast<int>(idx);
     }
   }
@@ -96,8 +96,64 @@ int Vertex<ast_parameter_list>::get_mutate_params_count() const {
   return n;
 }
 
-void Vertex<ast_import_statement>::mutate_set_src_file(const SrcFile* file) const {
-  const_cast<Vertex*>(this)->file = file;
+// ---------------------------------------------------------
+// "assign" methods
+//
+// From the user's point of view, all AST vertices are constant, fields are public, but can't be modified.
+// The only way to modify a field is to call "mutate()" and then use these "assign_*" methods.
+// Therefore, there is a guarantee, that all AST mutations are done via these methods,
+// easily searched by usages, and there is no another way to modify any other field.
+
+void ASTNodeExpressionBase::assign_inferred_type(TypeExpr* type) {
+  this->inferred_type = type;
+}
+
+void ASTNodeExpressionBase::assign_rvalue_true() {
+  this->is_rvalue = true;
+}
+
+void ASTNodeExpressionBase::assign_lvalue_true() {
+  this->is_lvalue = true;
+}
+
+void Vertex<ast_identifier>::assign_sym(const Symbol* sym) {
+  this->sym = sym;
+}
+
+void Vertex<ast_self_keyword>::assign_param_ref(const LocalVarData* self_param) {
+  this->param_ref = self_param;
+}
+
+void Vertex<ast_function_call>::assign_fun_ref(const FunctionData* fun_ref) {
+  this->fun_maybe = fun_ref;
+}
+
+void Vertex<ast_dot_method_call>::assign_fun_ref(const FunctionData* fun_ref) {
+  this->fun_ref = fun_ref;
+}
+
+void Vertex<ast_global_var_declaration>::assign_var_ref(const GlobalVarData* var_ref) {
+  this->var_ref = var_ref;
+}
+
+void Vertex<ast_constant_declaration>::assign_const_ref(const GlobalConstData* const_ref) {
+  this->const_ref = const_ref;
+}
+
+void Vertex<ast_parameter>::assign_param_ref(const LocalVarData* param_ref) {
+  this->param_ref = param_ref;
+}
+
+void Vertex<ast_function_declaration>::assign_fun_ref(const FunctionData* fun_ref) {
+  this->fun_ref = fun_ref;
+}
+
+void Vertex<ast_local_var>::assign_var_ref(const Symbol* var_ref) {
+  this->var_maybe = var_ref;
+}
+
+void Vertex<ast_import_statement>::assign_src_file(const SrcFile* file) {
+  this->file = file;
 }
 
 } // namespace tolk

tolk/ast.h

@@ -17,10 +17,12 @@
 #pragma once
 
 #include <string>
+#include "fwd-declarations.h"
 #include "platform-utils.h"
 #include "src-file.h"
 #include "type-expr.h"
 #include "lexer.h"
+#include "symtable.h"
 
 /*
  *   Here we introduce AST representation of Tolk source code.
@@ -32,14 +34,18 @@
  *
  *   From the user's point of view, all AST vertices are constant. All API is based on constancy.
  * Even though fields of vertex structs are public, they can't be modified, since vertices are accepted by const ref.
- *   Generally, there are two ways of accepting a vertex:
+ *   Generally, there are three ways of accepting a vertex:
  *   * AnyV (= const ASTNodeBase*)
  *     the only you can do with this vertex is to see v->type (ASTNodeType) and to cast via v->as<node_type>()
+ *   * AnyExprV (= const ASTNodeExpressionBase*)
+ *     in contains expression-specific properties (lvalue/rvalue, inferred type)
  *   * V<node_type> (= const Vertex<node_type>*)
  *     a specific type of vertex, you can use its fields and methods
  *   There is one way of creating a vertex:
  *   * createV<node_type>(...constructor_args)   (= new Vertex<node_type>(...))
  *     vertices are currently created on a heap, without any custom memory arena, just allocated and never deleted
+ *   The only way to modify a field is to use "mutate()" method (drops constancy, the only point of mutation)
+ *   and then to call "assign_*" method, like "assign_sym", "assign_src_file", etc.
  *
  *   Having AnyV and knowing its node_type, a call
  *     v->as<node_type>()
@@ -59,8 +65,9 @@
 namespace tolk {
 
 enum ASTNodeType {
-  ast_empty,
-  ast_parenthesized_expr,
+  ast_empty_statement,
+  ast_empty_expression,
+  ast_parenthesized_expression,
   ast_tensor,
   ast_tensor_square,
   ast_identifier,
@@ -111,10 +118,6 @@ enum class AnnotationKind {
   unknown,
 };
 
-struct ASTNodeBase;
-
-using AnyV = const ASTNodeBase*;
-
 template<ASTNodeType node_type>
 struct Vertex;
 
@@ -167,46 +170,120 @@ struct ASTNodeBase {
   void error(const std::string& err_msg) const;
 };
 
-struct ASTNodeLeaf : ASTNodeBase {
+struct ASTNodeExpressionBase : ASTNodeBase {
+  TypeExpr* inferred_type = nullptr;  // todo make it const
+  bool is_rvalue: 1 = false;
+  bool is_lvalue: 1 = false;
+
+  ASTNodeExpressionBase* mutate() const { return const_cast<ASTNodeExpressionBase*>(this); }
+  void assign_inferred_type(TypeExpr* type);
+  void assign_rvalue_true();
+  void assign_lvalue_true();
+
+  ASTNodeExpressionBase(ASTNodeType type, SrcLocation loc) : ASTNodeBase(type, loc) {}
+};
+
+struct ASTNodeStatementBase : ASTNodeBase {
+  ASTNodeStatementBase(ASTNodeType type, SrcLocation loc) : ASTNodeBase(type, loc) {}
+};
+
+struct ASTExprLeaf : ASTNodeExpressionBase {
   friend class ASTVisitor;
   friend class ASTReplacer;
 
 protected:
-  ASTNodeLeaf(ASTNodeType type, SrcLocation loc)
-    : ASTNodeBase(type, loc) {}
+  ASTExprLeaf(ASTNodeType type, SrcLocation loc)
+    : ASTNodeExpressionBase(type, loc) {}
 };
 
-struct ASTNodeUnary : ASTNodeBase {
+struct ASTExprUnary : ASTNodeExpressionBase {
+  friend class ASTVisitor;
+  friend class ASTReplacer;
+
+protected:
+  AnyExprV child;
+
+  ASTExprUnary(ASTNodeType type, SrcLocation loc, AnyExprV child)
+    : ASTNodeExpressionBase(type, loc), child(child) {}
+};
+
+struct ASTExprBinary : ASTNodeExpressionBase {
+  friend class ASTVisitor;
+  friend class ASTReplacer;
+
+protected:
+  AnyExprV lhs;
+  AnyExprV rhs;
+
+  ASTExprBinary(ASTNodeType type, SrcLocation loc, AnyExprV lhs, AnyExprV rhs)
+    : ASTNodeExpressionBase(type, loc), lhs(lhs), rhs(rhs) {}
+};
+
+struct ASTExprVararg : ASTNodeExpressionBase {
+  friend class ASTVisitor;
+  friend class ASTReplacer;
+
+protected:
+  std::vector<AnyExprV> children;
+
+  ASTExprVararg(ASTNodeType type, SrcLocation loc, std::vector<AnyExprV> children)
+    : ASTNodeExpressionBase(type, loc), children(std::move(children)) {}
+
+public:
+  int size() const { return static_cast<int>(children.size()); }
+  bool empty() const { return children.empty(); }
+};
+
+struct ASTStatementUnary : ASTNodeStatementBase {
   friend class ASTVisitor;
   friend class ASTReplacer;
 
 protected:
   AnyV child;
 
-  ASTNodeUnary(ASTNodeType type, SrcLocation loc, AnyV child)
-    : ASTNodeBase(type, loc), child(child) {}
+  AnyExprV child_as_expr() const { return reinterpret_cast<AnyExprV>(child); }
+
+  ASTStatementUnary(ASTNodeType type, SrcLocation loc, AnyV child)
+    : ASTNodeStatementBase(type, loc), child(child) {}
 };
 
-struct ASTNodeBinary : ASTNodeBase {
-  friend class ASTVisitor;
-  friend class ASTReplacer;
-
-protected:
-  AnyV lhs;
-  AnyV rhs;
-
-  ASTNodeBinary(ASTNodeType type, SrcLocation loc, AnyV lhs, AnyV rhs)
-    : ASTNodeBase(type, loc), lhs(lhs), rhs(rhs) {}
-};
-
-struct ASTNodeVararg : ASTNodeBase {
+struct ASTStatementVararg : ASTNodeStatementBase {
   friend class ASTVisitor;
   friend class ASTReplacer;
 
 protected:
   std::vector<AnyV> children;
 
-  ASTNodeVararg(ASTNodeType type, SrcLocation loc, std::vector<AnyV> children)
+  AnyV child(int i) const { return children.at(i); }
+  AnyExprV child_as_expr(int i) const { return reinterpret_cast<AnyExprV>(children.at(i)); }
+
+  ASTStatementVararg(ASTNodeType type, SrcLocation loc, std::vector<AnyV> children)
+    : ASTNodeStatementBase(type, loc), children(std::move(children)) {}
+
+public:
+  int size() const { return static_cast<int>(children.size()); }
+  bool empty() const { return children.empty(); }
+};
+
+struct ASTOtherLeaf : ASTNodeBase {
+  friend class ASTVisitor;
+  friend class ASTReplacer;
+
+protected:
+  ASTOtherLeaf(ASTNodeType type, SrcLocation loc)
+    : ASTNodeBase(type, loc) {}
+};
+
+struct ASTOtherVararg : ASTNodeBase {
+  friend class ASTVisitor;
+  friend class ASTReplacer;
+
+protected:
+  std::vector<AnyV> children;
+
+  AnyV child(int i) const { return children.at(i); }
+
+  ASTOtherVararg(ASTNodeType type, SrcLocation loc, std::vector<AnyV> children)
     : ASTNodeBase(type, loc), children(std::move(children)) {}
 
 public:
@@ -217,309 +294,383 @@ public:
 // ---------------------------------------------------------
 
 template<>
-struct Vertex<ast_empty> final : ASTNodeLeaf {
+struct Vertex<ast_empty_statement> final : ASTStatementVararg {
   explicit Vertex(SrcLocation loc)
-    : ASTNodeLeaf(ast_empty, loc) {}
+    : ASTStatementVararg(ast_empty_statement, loc, {}) {}
 };
 
 template<>
-struct Vertex<ast_parenthesized_expr> final : ASTNodeUnary {
-  AnyV get_expr() const { return child; }
-
-  Vertex(SrcLocation loc, AnyV expr)
-    : ASTNodeUnary(ast_parenthesized_expr, loc, expr) {}
+struct Vertex<ast_empty_expression> final : ASTExprLeaf {
+  explicit Vertex(SrcLocation loc)
+    : ASTExprLeaf(ast_empty_expression, loc) {}
 };
 
 template<>
-struct Vertex<ast_tensor> final : ASTNodeVararg {
-  const std::vector<AnyV>& get_items() const { return children; }
-  AnyV get_item(int i) const { return children.at(i); }
+struct Vertex<ast_parenthesized_expression> final : ASTExprUnary {
+  AnyExprV get_expr() const { return child; }
 
-  Vertex(SrcLocation loc, std::vector<AnyV> items)
-    : ASTNodeVararg(ast_tensor, loc, std::move(items)) {}
+  Vertex(SrcLocation loc, AnyExprV expr)
+    : ASTExprUnary(ast_parenthesized_expression, loc, expr) {}
 };
 
 template<>
-struct Vertex<ast_tensor_square> final : ASTNodeVararg {
-  const std::vector<AnyV>& get_items() const { return children; }
-  AnyV get_item(int i) const { return children.at(i); }
+struct Vertex<ast_tensor> final : ASTExprVararg {
+  const std::vector<AnyExprV>& get_items() const { return children; }
+  AnyExprV get_item(int i) const { return children.at(i); }
 
-  Vertex(SrcLocation loc, std::vector<AnyV> items)
-    : ASTNodeVararg(ast_tensor_square, loc, std::move(items)) {}
+  Vertex(SrcLocation loc, std::vector<AnyExprV> items)
+    : ASTExprVararg(ast_tensor, loc, std::move(items)) {}
 };
 
 template<>
-struct Vertex<ast_identifier> final : ASTNodeLeaf {
+struct Vertex<ast_tensor_square> final : ASTExprVararg {
+  const std::vector<AnyExprV>& get_items() const { return children; }
+  AnyExprV get_item(int i) const { return children.at(i); }
+
+  Vertex(SrcLocation loc, std::vector<AnyExprV> items)
+    : ASTExprVararg(ast_tensor_square, loc, std::move(items)) {}
+};
+
+template<>
+struct Vertex<ast_identifier> final : ASTExprLeaf {
+  const Symbol* sym = nullptr;    // always filled (after resolved); points to local / global / function / constant
   std::string_view name;
 
+  Vertex* mutate() const { return const_cast<Vertex*>(this); }
+  void assign_sym(const Symbol* sym);
+
   Vertex(SrcLocation loc, std::string_view name)
-    : ASTNodeLeaf(ast_identifier, loc), name(name) {}
+    : ASTExprLeaf(ast_identifier, loc)
+    , name(name) {}
 };
 
 template<>
-struct Vertex<ast_int_const> final : ASTNodeLeaf {
-  std::string_view int_val;
+struct Vertex<ast_int_const> final : ASTExprLeaf {
+  td::RefInt256 intval;         // parsed value, 255 for "0xFF"
+  std::string_view orig_str;    // original "0xFF"; empty for nodes generated by compiler (e.g. in constant folding)
 
-  Vertex(SrcLocation loc, std::string_view int_val)
-    : ASTNodeLeaf(ast_int_const, loc), int_val(int_val) {}
+  Vertex(SrcLocation loc, td::RefInt256 intval, std::string_view orig_str)
+    : ASTExprLeaf(ast_int_const, loc)
+    , intval(std::move(intval))
+    , orig_str(orig_str) {}
 };
 
 template<>
-struct Vertex<ast_string_const> final : ASTNodeLeaf {
+struct Vertex<ast_string_const> final : ASTExprLeaf {
   std::string_view str_val;
   char modifier;
 
+  bool is_bitslice() const {
+    char m = modifier;
+    return m == 0 || m == 's' || m == 'a';
+  }
+  bool is_intval() const {
+    char m = modifier;
+    return m == 'u' || m == 'h' || m == 'H' || m == 'c';
+  }
+
   Vertex(SrcLocation loc, std::string_view str_val, char modifier)
-    : ASTNodeLeaf(ast_string_const, loc), str_val(str_val), modifier(modifier) {}
+    : ASTExprLeaf(ast_string_const, loc)
+    , str_val(str_val), modifier(modifier) {}
 };
 
 template<>
-struct Vertex<ast_bool_const> final : ASTNodeLeaf {
+struct Vertex<ast_bool_const> final : ASTExprLeaf {
   bool bool_val;
 
   Vertex(SrcLocation loc, bool bool_val)
-    : ASTNodeLeaf(ast_bool_const, loc), bool_val(bool_val) {}
+    : ASTExprLeaf(ast_bool_const, loc)
+    , bool_val(bool_val) {}
 };
 
 template<>
-struct Vertex<ast_null_keyword> final : ASTNodeLeaf {
+struct Vertex<ast_null_keyword> final : ASTExprLeaf {
   explicit Vertex(SrcLocation loc)
-    : ASTNodeLeaf(ast_null_keyword, loc) {}
+    : ASTExprLeaf(ast_null_keyword, loc) {}
 };
 
 template<>
-struct Vertex<ast_self_keyword> final : ASTNodeLeaf {
+struct Vertex<ast_self_keyword> final : ASTExprLeaf {
+  const LocalVarData* param_ref = nullptr;  // filled after resolve identifiers, points to `self` parameter
+
+  Vertex* mutate() const { return const_cast<Vertex*>(this); }
+  void assign_param_ref(const LocalVarData* self_param);
+
   explicit Vertex(SrcLocation loc)
-    : ASTNodeLeaf(ast_self_keyword, loc) {}
+    : ASTExprLeaf(ast_self_keyword, loc) {}
 };
 
 template<>
-struct Vertex<ast_argument> final : ASTNodeUnary {
+struct Vertex<ast_argument> final : ASTExprUnary {
   bool passed_as_mutate;      // when called `f(mutate arg)`, not `f(arg)`
 
-  AnyV get_expr() const { return child; }
+  AnyExprV get_expr() const { return child; }
 
-  explicit Vertex(SrcLocation loc, AnyV expr, bool passed_as_mutate)
-    : ASTNodeUnary(ast_argument, loc, expr), passed_as_mutate(passed_as_mutate) {}
+  Vertex(SrcLocation loc, AnyExprV expr, bool passed_as_mutate)
+    : ASTExprUnary(ast_argument, loc, expr)
+    , passed_as_mutate(passed_as_mutate) {}
 };
 
 template<>
-struct Vertex<ast_argument_list> final : ASTNodeVararg {
-  const std::vector<AnyV>& get_arguments() const { return children; }
+struct Vertex<ast_argument_list> final : ASTExprVararg {
+  const std::vector<AnyExprV>& get_arguments() const { return children; }
   auto get_arg(int i) const { return children.at(i)->as<ast_argument>(); }
 
-  explicit Vertex(SrcLocation loc, std::vector<AnyV> arguments)
-    : ASTNodeVararg(ast_argument_list, loc, std::move(arguments)) {}
+  Vertex(SrcLocation loc, std::vector<AnyExprV> arguments)
+    : ASTExprVararg(ast_argument_list, loc, std::move(arguments)) {}
 };
 
 template<>
-struct Vertex<ast_function_call> final : ASTNodeBinary {
-  AnyV get_called_f() const { return lhs; }
+struct Vertex<ast_function_call> final : ASTExprBinary {
+  const FunctionData* fun_maybe = nullptr;  // filled after resolve; remains nullptr for `localVar()` / `getF()()`
+
+  AnyExprV get_called_f() const { return lhs; }
   auto get_arg_list() const { return rhs->as<ast_argument_list>(); }
   int get_num_args() const { return rhs->as<ast_argument_list>()->size(); }
   auto get_arg(int i) const { return rhs->as<ast_argument_list>()->get_arg(i); }
 
-  Vertex(SrcLocation loc, AnyV lhs_f, V<ast_argument_list> arguments)
-    : ASTNodeBinary(ast_function_call, loc, lhs_f, arguments) {}
+  Vertex* mutate() const { return const_cast<Vertex*>(this); }
+  void assign_fun_ref(const FunctionData* fun_ref);
+
+  Vertex(SrcLocation loc, AnyExprV lhs_f, V<ast_argument_list> arguments)
+    : ASTExprBinary(ast_function_call, loc, lhs_f, arguments) {}
 };
 
 template<>
-struct Vertex<ast_dot_method_call> final : ASTNodeBinary {
+struct Vertex<ast_dot_method_call> final : ASTExprBinary {
+  const FunctionData* fun_ref = nullptr;  // points to global function (after resolve)
   std::string_view method_name;
 
-  AnyV get_obj() const { return lhs; }
+  AnyExprV get_obj() const { return lhs; }
   auto get_arg_list() const { return rhs->as<ast_argument_list>(); }
+  int get_num_args() const { return rhs->as<ast_argument_list>()->size(); }
+  auto get_arg(int i) const { return rhs->as<ast_argument_list>()->get_arg(i); }
 
-  Vertex(SrcLocation loc, std::string_view method_name, AnyV lhs, V<ast_argument_list> arguments)
-    : ASTNodeBinary(ast_dot_method_call, loc, lhs, arguments), method_name(method_name) {}
+  Vertex* mutate() const { return const_cast<Vertex*>(this); }
+  void assign_fun_ref(const FunctionData* fun_ref);
+
+  Vertex(SrcLocation loc, std::string_view method_name, AnyExprV lhs, V<ast_argument_list> arguments)
+    : ASTExprBinary(ast_dot_method_call, loc, lhs, arguments)
+    , method_name(method_name) {}
 };
 
 template<>
-struct Vertex<ast_global_var_declaration> final : ASTNodeUnary {
-  TypeExpr* declared_type;      // may be nullptr
+struct Vertex<ast_global_var_declaration> final : ASTStatementUnary {
+  const GlobalVarData* var_ref = nullptr;  // filled after register
+  TypeExpr* declared_type;
 
   auto get_identifier() const { return child->as<ast_identifier>(); }
 
+  Vertex* mutate() const { return const_cast<Vertex*>(this); }
+  void assign_var_ref(const GlobalVarData* var_ref);
+
   Vertex(SrcLocation loc, V<ast_identifier> name_identifier, TypeExpr* declared_type)
-    : ASTNodeUnary(ast_global_var_declaration, loc, name_identifier), declared_type(declared_type) {}
+    : ASTStatementUnary(ast_global_var_declaration, loc, name_identifier)
+    , declared_type(declared_type) {}
 };
 
 template<>
-struct Vertex<ast_constant_declaration> final : ASTNodeBinary {
+struct Vertex<ast_constant_declaration> final : ASTStatementVararg {
+  const GlobalConstData* const_ref = nullptr;  // filled after register
   TypeExpr* declared_type;      // may be nullptr
 
-  auto get_identifier() const { return lhs->as<ast_identifier>(); }
-  AnyV get_init_value() const { return rhs; }
+  auto get_identifier() const { return child(0)->as<ast_identifier>(); }
+  AnyExprV get_init_value() const { return child_as_expr(1); }
 
-  Vertex(SrcLocation loc, V<ast_identifier> name_identifier, TypeExpr* declared_type, AnyV init_value)
-    : ASTNodeBinary(ast_constant_declaration, loc, name_identifier, init_value), declared_type(declared_type) {}
+  Vertex* mutate() const { return const_cast<Vertex*>(this); }
+  void assign_const_ref(const GlobalConstData* const_ref);
+
+  Vertex(SrcLocation loc, V<ast_identifier> name_identifier, TypeExpr* declared_type, AnyExprV init_value)
+    : ASTStatementVararg(ast_constant_declaration, loc, {name_identifier, init_value})
+    , declared_type(declared_type) {}
 };
 
 template<>
-struct Vertex<ast_underscore> final : ASTNodeLeaf {
+struct Vertex<ast_underscore> final : ASTExprLeaf {
   explicit Vertex(SrcLocation loc)
-    : ASTNodeLeaf(ast_underscore, loc) {}
+    : ASTExprLeaf(ast_underscore, loc) {}
 };
 
 template<>
-struct Vertex<ast_unary_operator> final : ASTNodeUnary {
+struct Vertex<ast_unary_operator> final : ASTExprUnary {
   std::string_view operator_name;
   TokenType tok;
 
-  AnyV get_rhs() const { return child; }
+  AnyExprV get_rhs() const { return child; }
 
-  Vertex(SrcLocation loc, std::string_view operator_name, TokenType tok, AnyV rhs)
-    : ASTNodeUnary(ast_unary_operator, loc, rhs), operator_name(operator_name), tok(tok) {}
+  Vertex(SrcLocation loc, std::string_view operator_name, TokenType tok, AnyExprV rhs)
+    : ASTExprUnary(ast_unary_operator, loc, rhs)
+    , operator_name(operator_name), tok(tok) {}
 };
 
 template<>
-struct Vertex<ast_binary_operator> final : ASTNodeBinary {
+struct Vertex<ast_binary_operator> final : ASTExprBinary {
   std::string_view operator_name;
   TokenType tok;
 
-  AnyV get_lhs() const { return lhs; }
-  AnyV get_rhs() const { return rhs; }
+  AnyExprV get_lhs() const { return lhs; }
+  AnyExprV get_rhs() const { return rhs; }
 
-  Vertex(SrcLocation loc, std::string_view operator_name, TokenType tok, AnyV lhs, AnyV rhs)
-    : ASTNodeBinary(ast_binary_operator, loc, lhs, rhs), operator_name(operator_name), tok(tok) {}
+  bool is_set_assign() const {
+    TokenType t = tok;
+    return t == tok_set_plus || t == tok_set_minus || t == tok_set_mul || t == tok_set_div ||
+           t == tok_set_mod || t == tok_set_lshift || t == tok_set_rshift ||
+           t == tok_set_bitwise_and || t == tok_set_bitwise_or || t == tok_set_bitwise_xor;
+  }
+
+  bool is_assign() const {
+    return tok == tok_assign;
+  }
+
+  Vertex(SrcLocation loc, std::string_view operator_name, TokenType tok, AnyExprV lhs, AnyExprV rhs)
+    : ASTExprBinary(ast_binary_operator, loc, lhs, rhs)
+    , operator_name(operator_name), tok(tok) {}
 };
 
 template<>
-struct Vertex<ast_ternary_operator> final : ASTNodeVararg {
-  AnyV get_cond() const { return children.at(0); }
-  AnyV get_when_true() const { return children.at(1); }
-  AnyV get_when_false() const { return children.at(2); }
+struct Vertex<ast_ternary_operator> final : ASTExprVararg {
+  AnyExprV get_cond() const { return children.at(0); }
+  AnyExprV get_when_true() const { return children.at(1); }
+  AnyExprV get_when_false() const { return children.at(2); }
 
-  Vertex(SrcLocation loc, AnyV cond, AnyV when_true, AnyV when_false)
-    : ASTNodeVararg(ast_ternary_operator, loc, {cond, when_true, when_false}) {}
+  Vertex(SrcLocation loc, AnyExprV cond, AnyExprV when_true, AnyExprV when_false)
+    : ASTExprVararg(ast_ternary_operator, loc, {cond, when_true, when_false}) {}
 };
 
 template<>
-struct Vertex<ast_return_statement> : ASTNodeUnary {
-  AnyV get_return_value() const { return child; }
+struct Vertex<ast_return_statement> : ASTStatementUnary {
+  AnyExprV get_return_value() const { return child_as_expr(); }
 
-  Vertex(SrcLocation loc, AnyV child)
-    : ASTNodeUnary(ast_return_statement, loc, child) {}
+  Vertex(SrcLocation loc, AnyExprV child)
+    : ASTStatementUnary(ast_return_statement, loc, child) {}
 };
 
 template<>
-struct Vertex<ast_sequence> final : ASTNodeVararg {
+struct Vertex<ast_sequence> final : ASTStatementVararg {
   SrcLocation loc_end;
 
   const std::vector<AnyV>& get_items() const { return children; }
   AnyV get_item(int i) const { return children.at(i); }
 
   Vertex(SrcLocation loc, SrcLocation loc_end, std::vector<AnyV> items)
-    : ASTNodeVararg(ast_sequence, loc, std::move(items)), loc_end(loc_end) {}
+    : ASTStatementVararg(ast_sequence, loc, std::move(items))
+    , loc_end(loc_end) {}
 };
 
 template<>
-struct Vertex<ast_repeat_statement> final : ASTNodeBinary {
-  AnyV get_cond() const { return lhs; }
-  auto get_body() const { return rhs->as<ast_sequence>(); }
+struct Vertex<ast_repeat_statement> final : ASTStatementVararg {
+  AnyExprV get_cond() const { return child_as_expr(0); }
+  auto get_body() const { return child(1)->as<ast_sequence>(); }
 
-  Vertex(SrcLocation loc, AnyV cond, V<ast_sequence> body)
-    : ASTNodeBinary(ast_repeat_statement, loc, cond, body) {}
+  Vertex(SrcLocation loc, AnyExprV cond, V<ast_sequence> body)
+    : ASTStatementVararg(ast_repeat_statement, loc, {cond, body}) {}
 };
 
 template<>
-struct Vertex<ast_while_statement> final : ASTNodeBinary {
-  AnyV get_cond() const { return lhs; }
-  auto get_body() const { return rhs->as<ast_sequence>(); }
+struct Vertex<ast_while_statement> final : ASTStatementVararg {
+  AnyExprV get_cond() const { return child_as_expr(0); }
+  auto get_body() const { return child(1)->as<ast_sequence>(); }
 
-  Vertex(SrcLocation loc, AnyV cond, V<ast_sequence> body)
-    : ASTNodeBinary(ast_while_statement, loc, cond, body) {}
+  Vertex(SrcLocation loc, AnyExprV cond, V<ast_sequence> body)
+    : ASTStatementVararg(ast_while_statement, loc, {cond, body}) {}
 };
 
 template<>
-struct Vertex<ast_do_while_statement> final : ASTNodeBinary {
-  auto get_body() const { return lhs->as<ast_sequence>(); }
-  AnyV get_cond() const { return rhs; }
+struct Vertex<ast_do_while_statement> final : ASTStatementVararg {
+  auto get_body() const { return child(0)->as<ast_sequence>(); }
+  AnyExprV get_cond() const { return child_as_expr(1); }
 
-  Vertex(SrcLocation loc, V<ast_sequence> body, AnyV cond)
-    : ASTNodeBinary(ast_do_while_statement, loc, body, cond) {}
+  Vertex(SrcLocation loc, V<ast_sequence> body, AnyExprV cond)
+    : ASTStatementVararg(ast_do_while_statement, loc, {body, cond}) {}
 };
 
 template<>
-struct Vertex<ast_throw_statement> final : ASTNodeBinary {
-  AnyV get_thrown_code() const { return lhs; }
-  AnyV get_thrown_arg() const { return rhs; }    // may be ast_empty
-  bool has_thrown_arg() const { return rhs->type != ast_empty; }
+struct Vertex<ast_throw_statement> final : ASTStatementVararg {
+  AnyExprV get_thrown_code() const { return child_as_expr(0); }
+  AnyExprV get_thrown_arg() const { return child_as_expr(1); }    // may be ast_empty
+  bool has_thrown_arg() const { return child_as_expr(1)->type != ast_empty_expression; }
 
-  Vertex(SrcLocation loc, AnyV thrown_code, AnyV thrown_arg)
-    : ASTNodeBinary(ast_throw_statement, loc, thrown_code, thrown_arg) {}
+  Vertex(SrcLocation loc, AnyExprV thrown_code, AnyExprV thrown_arg)
+    : ASTStatementVararg(ast_throw_statement, loc, {thrown_code, thrown_arg}) {}
 };
 
 template<>
-struct Vertex<ast_assert_statement> final : ASTNodeBinary {
-  AnyV get_cond() const { return lhs; }
-  AnyV get_thrown_code() const { return rhs; }
+struct Vertex<ast_assert_statement> final : ASTStatementVararg {
+  AnyExprV get_cond() const { return child_as_expr(0); }
+  AnyExprV get_thrown_code() const { return child_as_expr(1); }
 
-  Vertex(SrcLocation loc, AnyV cond, AnyV thrown_code)
-    : ASTNodeBinary(ast_assert_statement, loc, cond, thrown_code) {}
+  Vertex(SrcLocation loc, AnyExprV cond, AnyExprV thrown_code)
+    : ASTStatementVararg(ast_assert_statement, loc, {cond, thrown_code}) {}
 };
 
 template<>
-struct Vertex<ast_try_catch_statement> final : ASTNodeVararg {
+struct Vertex<ast_try_catch_statement> final : ASTStatementVararg {
   auto get_try_body() const { return children.at(0)->as<ast_sequence>(); }
   auto get_catch_expr() const { return children.at(1)->as<ast_tensor>(); }    // (excNo, arg), always len 2
   auto get_catch_body() const { return children.at(2)->as<ast_sequence>(); }
 
   Vertex(SrcLocation loc, V<ast_sequence> try_body, V<ast_tensor> catch_expr, V<ast_sequence> catch_body)
-    : ASTNodeVararg(ast_try_catch_statement, loc, {try_body, catch_expr, catch_body}) {}
+    : ASTStatementVararg(ast_try_catch_statement, loc, {try_body, catch_expr, catch_body}) {}
 };
 
 template<>
-struct Vertex<ast_if_statement> final : ASTNodeVararg {
+struct Vertex<ast_if_statement> final : ASTStatementVararg {
   bool is_ifnot;  // if(!cond), to generate more optimal fift code
 
-  AnyV get_cond() const { return children.at(0); }
-  auto get_if_body() const { return children.at(1)->as<ast_sequence>(); }
-  auto get_else_body() const { return children.at(2)->as<ast_sequence>(); }    // always exists (when else omitted, it's empty)
+  AnyExprV get_cond() const { return child_as_expr(0); }
+  auto get_if_body() const { return child(1)->as<ast_sequence>(); }
+  auto get_else_body() const { return child(2)->as<ast_sequence>(); }    // always exists (when else omitted, it's empty)
 
-  Vertex(SrcLocation loc, bool is_ifnot, AnyV cond, V<ast_sequence> if_body, V<ast_sequence> else_body)
-    : ASTNodeVararg(ast_if_statement, loc, {cond, if_body, else_body}), is_ifnot(is_ifnot) {}
+  Vertex(SrcLocation loc, bool is_ifnot, AnyExprV cond, V<ast_sequence> if_body, V<ast_sequence> else_body)
+    : ASTStatementVararg(ast_if_statement, loc, {cond, if_body, else_body})
+    , is_ifnot(is_ifnot) {}
 };
 
 template<>
-struct Vertex<ast_genericsT_item> final : ASTNodeLeaf {
+struct Vertex<ast_genericsT_item> final : ASTOtherLeaf {
   TypeExpr* created_type;   // used to keep same pointer, since TypeExpr::new_var(i) always allocates
   std::string_view nameT;
 
   Vertex(SrcLocation loc, TypeExpr* created_type, std::string_view nameT)
-    : ASTNodeLeaf(ast_genericsT_item, loc), created_type(created_type), nameT(nameT) {}
+    : ASTOtherLeaf(ast_genericsT_item, loc)
+    , created_type(created_type), nameT(nameT) {}
 };
 
 template<>
-struct Vertex<ast_genericsT_list> final : ASTNodeVararg {
+struct Vertex<ast_genericsT_list> final : ASTOtherVararg {
   std::vector<AnyV> get_items() const { return children; }
   auto get_item(int i) const { return children.at(i)->as<ast_genericsT_item>(); }
 
   Vertex(SrcLocation loc, std::vector<AnyV> genericsT_items)
-    : ASTNodeVararg(ast_genericsT_list, loc, std::move(genericsT_items)) {}
+    : ASTOtherVararg(ast_genericsT_list, loc, std::move(genericsT_items)) {}
 
   int lookup_idx(std::string_view nameT) const;
 };
 
 template<>
-struct Vertex<ast_parameter> final : ASTNodeUnary {
-  TypeExpr* param_type;
+struct Vertex<ast_parameter> final : ASTOtherLeaf {
+  const LocalVarData* param_ref = nullptr;    // filled after resolved
+  std::string_view param_name;
+  TypeExpr* declared_type;
   bool declared_as_mutate;      // declared as `mutate param_name`
 
-  auto get_identifier() const { return child->as<ast_identifier>(); } // for underscore, name is empty
-  bool is_underscore() const { return child->as<ast_identifier>()->name.empty(); }
+  bool is_underscore() const { return param_name.empty(); }
 
-  Vertex(SrcLocation loc, V<ast_identifier> name_identifier, TypeExpr* param_type, bool declared_as_mutate)
-    : ASTNodeUnary(ast_parameter, loc, name_identifier), param_type(param_type), declared_as_mutate(declared_as_mutate) {}
+  Vertex* mutate() const { return const_cast<Vertex*>(this); }
+  void assign_param_ref(const LocalVarData* param_ref);
+
+  Vertex(SrcLocation loc, std::string_view param_name, TypeExpr* declared_type, bool declared_as_mutate)
+    : ASTOtherLeaf(ast_parameter, loc)
+    , param_name(param_name), declared_type(declared_type), declared_as_mutate(declared_as_mutate) {}
 };
 
 template<>
-struct Vertex<ast_parameter_list> final : ASTNodeVararg {
+struct Vertex<ast_parameter_list> final : ASTOtherVararg {
   const std::vector<AnyV>& get_params() const { return children; }
   auto get_param(int i) const { return children.at(i)->as<ast_parameter>(); }
 
   Vertex(SrcLocation loc, std::vector<AnyV> params)
-    : ASTNodeVararg(ast_parameter_list, loc, std::move(params)) {}
+    : ASTOtherVararg(ast_parameter_list, loc, std::move(params)) {}
 
   int lookup_idx(std::string_view param_name) const;
   int get_mutate_params_count() const;
@@ -527,57 +678,64 @@ struct Vertex<ast_parameter_list> final : ASTNodeVararg {
 };
 
 template<>
-struct Vertex<ast_asm_body> final : ASTNodeVararg {
+struct Vertex<ast_asm_body> final : ASTStatementVararg {
   std::vector<int> arg_order;
   std::vector<int> ret_order;
 
   const std::vector<AnyV>& get_asm_commands() const { return children; }    // ast_string_const[]
 
   Vertex(SrcLocation loc, std::vector<int> arg_order, std::vector<int> ret_order, std::vector<AnyV> asm_commands)
-    : ASTNodeVararg(ast_asm_body, loc, std::move(asm_commands)), arg_order(std::move(arg_order)), ret_order(std::move(ret_order)) {}
+    : ASTStatementVararg(ast_asm_body, loc, std::move(asm_commands))
+    , arg_order(std::move(arg_order)), ret_order(std::move(ret_order)) {}
 };
 
 template<>
-struct Vertex<ast_annotation> final : ASTNodeUnary {
+struct Vertex<ast_annotation> final : ASTOtherVararg {
   AnnotationKind kind;
 
-  auto get_arg() const { return child->as<ast_tensor>(); }
+  auto get_arg() const { return child(0)->as<ast_tensor>(); }
 
   static AnnotationKind parse_kind(std::string_view name);
 
   Vertex(SrcLocation loc, AnnotationKind kind, V<ast_tensor> arg_probably_empty)
-    : ASTNodeUnary(ast_annotation, loc, arg_probably_empty), kind(kind) {}
+    : ASTOtherVararg(ast_annotation, loc, {arg_probably_empty})
+    , kind(kind) {}
 };
 
 template<>
-struct Vertex<ast_local_var> final : ASTNodeUnary {
+struct Vertex<ast_local_var> final : ASTExprUnary {
+  const Symbol* var_maybe = nullptr;    // typically local var; can be global var if `var g_v redef`; remains nullptr for underscore
   TypeExpr* declared_type;
   bool is_immutable;       // declared via 'val', not 'var'
   bool marked_as_redef;    // var (existing_var redef, new_var: int) = ...
 
-  AnyV get_identifier() const { return child; } // ast_identifier / ast_underscore
+  AnyExprV get_identifier() const { return child; } // ast_identifier / ast_underscore
 
-  Vertex(SrcLocation loc, AnyV name_identifier, TypeExpr* declared_type, bool is_immutable, bool marked_as_redef)
-    : ASTNodeUnary(ast_local_var, loc, name_identifier), declared_type(declared_type), is_immutable(is_immutable), marked_as_redef(marked_as_redef) {}
+  Vertex* mutate() const { return const_cast<Vertex*>(this); }
+  void assign_var_ref(const Symbol* var_ref);
+
+  Vertex(SrcLocation loc, AnyExprV name_identifier, TypeExpr* declared_type, bool is_immutable, bool marked_as_redef)
+    : ASTExprUnary(ast_local_var, loc, name_identifier), declared_type(declared_type), is_immutable(is_immutable), marked_as_redef(marked_as_redef) {}
 };
 
 template<>
-struct Vertex<ast_local_vars_declaration> final : ASTNodeBinary {
-  AnyV get_lhs() const { return lhs; } // ast_local_var / ast_tensor / ast_tensor_square
-  AnyV get_assigned_val() const { return rhs; }
+struct Vertex<ast_local_vars_declaration> final : ASTStatementVararg {
+  AnyExprV get_lhs() const { return child_as_expr(0); } // ast_local_var / ast_tensor / ast_tensor_square
+  AnyExprV get_assigned_val() const { return child_as_expr(1); }
 
-  Vertex(SrcLocation loc, AnyV lhs, AnyV assigned_val)
-    : ASTNodeBinary(ast_local_vars_declaration, loc, lhs, assigned_val) {}
+  Vertex(SrcLocation loc, AnyExprV lhs, AnyExprV assigned_val)
+    : ASTStatementVararg(ast_local_vars_declaration, loc, {lhs, assigned_val}) {}
 };
 
 template<>
-struct Vertex<ast_function_declaration> final : ASTNodeVararg {
-  auto get_identifier() const { return children.at(0)->as<ast_identifier>(); }
-  int get_num_params() const { return children.at(1)->as<ast_parameter_list>()->size(); }
-  auto get_param_list() const { return children.at(1)->as<ast_parameter_list>(); }
-  auto get_param(int i) const { return children.at(1)->as<ast_parameter_list>()->get_param(i); }
-  AnyV get_body() const { return children.at(2); }   // ast_sequence / ast_asm_body
+struct Vertex<ast_function_declaration> final : ASTOtherVararg {
+  auto get_identifier() const { return child(0)->as<ast_identifier>(); }
+  int get_num_params() const { return child(1)->as<ast_parameter_list>()->size(); }
+  auto get_param_list() const { return child(1)->as<ast_parameter_list>(); }
+  auto get_param(int i) const { return child(1)->as<ast_parameter_list>()->get_param(i); }
+  AnyV get_body() const { return child(2); }   // ast_sequence / ast_asm_body
 
+  const FunctionData* fun_ref = nullptr;  // filled after register
   TypeExpr* ret_type = nullptr;
   V<ast_genericsT_list> genericsT_list = nullptr;
   bool is_entrypoint = false;
@@ -591,42 +749,49 @@ struct Vertex<ast_function_declaration> final : ASTNodeVararg {
   V<ast_int_const> method_id = nullptr;
 
   bool is_asm_function() const { return children.at(2)->type == ast_asm_body; }
+  bool is_regular_function() const { return children.at(2)->type == ast_sequence; }
+  bool is_builtin_function() const { return marked_as_builtin; }
+
+  Vertex* mutate() const { return const_cast<Vertex*>(this); }
+  void assign_fun_ref(const FunctionData* fun_ref);
 
   Vertex(SrcLocation loc, V<ast_identifier> name_identifier, V<ast_parameter_list> parameters, AnyV body)
-    : ASTNodeVararg(ast_function_declaration, loc, {name_identifier, parameters, body}) {}
+    : ASTOtherVararg(ast_function_declaration, loc, {name_identifier, parameters, body}) {}
 };
 
 template<>
-struct Vertex<ast_tolk_required_version> final : ASTNodeLeaf {
-  TokenType cmp_tok;
+struct Vertex<ast_tolk_required_version> final : ASTOtherLeaf {
   std::string_view semver;
 
-  Vertex(SrcLocation loc, TokenType cmp_tok, std::string_view semver)
-    : ASTNodeLeaf(ast_tolk_required_version, loc), cmp_tok(cmp_tok), semver(semver) {}
+  Vertex(SrcLocation loc, std::string_view semver)
+    : ASTOtherLeaf(ast_tolk_required_version, loc)
+    , semver(semver) {}
 };
 
 template<>
-struct Vertex<ast_import_statement> final : ASTNodeUnary {
-  const SrcFile* file = nullptr;    // assigned after includes have been resolved
+struct Vertex<ast_import_statement> final : ASTOtherVararg {
+  const SrcFile* file = nullptr;    // assigned after imports have been resolved
 
-  auto get_file_leaf() const { return child->as<ast_string_const>(); }
+  auto get_file_leaf() const { return child(0)->as<ast_string_const>(); }
 
-  std::string get_file_name() const { return static_cast<std::string>(child->as<ast_string_const>()->str_val); }
+  std::string get_file_name() const { return static_cast<std::string>(child(0)->as<ast_string_const>()->str_val); }
 
-  void mutate_set_src_file(const SrcFile* file) const;
+  Vertex* mutate() const { return const_cast<Vertex*>(this); }
+  void assign_src_file(const SrcFile* file);
 
   Vertex(SrcLocation loc, V<ast_string_const> file_name)
-    : ASTNodeUnary(ast_import_statement, loc, file_name) {}
+    : ASTOtherVararg(ast_import_statement, loc, {file_name}) {}
 };
 
 template<>
-struct Vertex<ast_tolk_file> final : ASTNodeVararg {
+struct Vertex<ast_tolk_file> final : ASTOtherVararg {
   const SrcFile* const file;
 
   const std::vector<AnyV>& get_toplevel_declarations() const { return children; }
 
   Vertex(const SrcFile* file, std::vector<AnyV> toplevel_declarations)
-    : ASTNodeVararg(ast_tolk_file, SrcLocation(file), std::move(toplevel_declarations)), file(file) {}
+    : ASTOtherVararg(ast_tolk_file, SrcLocation(file), std::move(toplevel_declarations))
+    , file(file) {}
 };
 
 } // namespace tolk

tolk/builtins.cpp

@@ -20,82 +20,64 @@
 namespace tolk {
 using namespace std::literals::string_literals;
 
-/*
- *
- *   SYMBOL VALUES
- * 
- */
-
-SymDef* define_builtin_func_impl(const std::string& name, SymValAsmFunc* func_val) {
-  sym_idx_t name_idx = G.symbols.lookup_add(name);
-  SymDef* def = define_global_symbol(name_idx);
-  tolk_assert(!def->value);
-
-  def->value = func_val;
-#ifdef TOLK_DEBUG
-  def->value->sym_name = name;
-#endif
-  return def;
-}
-
-// given func_type = `(slice, int) -> slice` and func flags, create SymDef for parameters
+// given func_type = `(slice, int) -> slice` and func flags, create SymLocalVarOrParameter
 // currently (see at the bottom) parameters of built-in functions are unnamed:
 // built-in functions are created using a resulting type
-static std::vector<SymDef*> define_builtin_parameters(const TypeExpr* func_type, int func_flags) {
+static std::vector<LocalVarData> define_builtin_parameters(const TypeExpr* func_type, int func_flags) {
   // `loadInt()`, `storeInt()`: they accept `self` and mutate it; no other options available in built-ins for now
-  bool is_mutate_self = func_flags & SymValFunc::flagHasMutateParams;
+  bool is_mutate_self = func_flags & FunctionData::flagHasMutateParams;
   // func_type a map (params_type -> ret_type), probably surrounded by forall (internal representation of <T>)
   TypeExpr* params_type = func_type->constr == TypeExpr::te_ForAll ? func_type->args[0]->args[0] : func_type->args[0];
-  std::vector<SymDef*> parameters;
+  std::vector<LocalVarData> parameters;
 
   if (params_type->constr == TypeExpr::te_Tensor) {   // multiple parameters: it's a tensor
     parameters.reserve(params_type->args.size());
     for (int i = 0; i < static_cast<int>(params_type->args.size()); ++i) {
-      SymDef* sym_def = define_parameter(i, {});
-      SymValVariable* sym_val = new SymValVariable(i, params_type->args[i]);
+      LocalVarData p_sym("", {}, i, params_type->args[i]);
       if (i == 0 && is_mutate_self) {
-        sym_val->flags |= SymValVariable::flagMutateParameter;
+        p_sym.flags |= LocalVarData::flagMutateParameter;
       }
-      sym_def->value = sym_val;
-      parameters.emplace_back(sym_def);
+      parameters.push_back(std::move(p_sym));
     }
   } else {  // single parameter
-    SymDef* sym_def = define_parameter(0, {});
-    SymValVariable* sym_val = new SymValVariable(0, params_type);
+    LocalVarData p_sym("", {}, 0, params_type);
     if (is_mutate_self) {
-      sym_val->flags |= SymValVariable::flagMutateParameter;
+      p_sym.flags |= LocalVarData::flagMutateParameter;
     }
-    sym_def->value = sym_val;
-    parameters.emplace_back(sym_def);
+    parameters.push_back(std::move(p_sym));
   }
 
   return parameters;
 }
 
-static SymDef* define_builtin_func(const std::string& name, TypeExpr* func_type, const simple_compile_func_t& func, int flags) {
-  return define_builtin_func_impl(name, new SymValAsmFunc(define_builtin_parameters(func_type, flags), func_type, func, flags | SymValFunc::flagBuiltinFunction));
+static void define_builtin_func(const std::string& name, TypeExpr* func_type, const simple_compile_func_t& func, int flags) {
+  auto* f_sym = new FunctionData(name, {}, func_type, define_builtin_parameters(func_type, flags), flags, new FunctionBodyBuiltin(func));
+  G.symtable.add_function(f_sym);
 }
 
-static SymDef* define_builtin_func(const std::string& name, TypeExpr* func_type, const AsmOp& macro, int flags) {
-  return define_builtin_func_impl(name, new SymValAsmFunc(define_builtin_parameters(func_type, flags), func_type, make_simple_compile(macro), flags | SymValFunc::flagBuiltinFunction));
+static void define_builtin_func(const std::string& name, TypeExpr* func_type, const AsmOp& macro, int flags) {
+  auto* f_sym = new FunctionData(name, {}, func_type, define_builtin_parameters(func_type, flags), flags, new FunctionBodyBuiltin(make_simple_compile(macro)));
+  G.symtable.add_function(f_sym);
 }
 
-static SymDef* define_builtin_func(const std::string& name, TypeExpr* func_type, const simple_compile_func_t& func, int flags,
+static void define_builtin_func(const std::string& name, TypeExpr* func_type, const simple_compile_func_t& func, int flags,
                                 std::initializer_list<int> arg_order, std::initializer_list<int> ret_order) {
-  return define_builtin_func_impl(name, new SymValAsmFunc(define_builtin_parameters(func_type, flags), func_type, func, flags | SymValFunc::flagBuiltinFunction, arg_order, ret_order));
+  auto* f_sym = new FunctionData(name, {}, func_type, define_builtin_parameters(func_type, flags), flags, new FunctionBodyBuiltin(func));
+  f_sym->arg_order = arg_order;
+  f_sym->ret_order = ret_order;
+  G.symtable.add_function(f_sym);
 }
 
-bool SymValAsmFunc::compile(AsmOpList& dest, std::vector<VarDescr>& out, std::vector<VarDescr>& in,
+void FunctionBodyBuiltin::compile(AsmOpList& dest, std::vector<VarDescr>& out, std::vector<VarDescr>& in,
                                      SrcLocation where) const {
-  if (simple_compile) {
-    return dest.append(simple_compile(out, in, where));
-  } else if (ext_compile) {
-    return ext_compile(dest, out, in);
-  } else {
-    return false;
+  dest.append(simple_compile(out, in, where));
 }
+
+void FunctionBodyAsm::compile(AsmOpList& dest) const {
+  dest.append(ops);
 }
 
+
 /*
  * 
  *   DEFINE BUILT-IN FUNCTIONS
@@ -1119,91 +1101,71 @@ void define_builtins() {
   TypeExpr* throw_arg_op = TypeExpr::new_forall({X}, TypeExpr::new_map(TypeExpr::new_tensor({X, Int}), Unit));
 
   define_builtin_func("_+_", arith_bin_op, compile_add,
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("_-_", arith_bin_op, compile_sub,
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("-_", arith_un_op, compile_unary_minus,
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("+_", arith_un_op, compile_unary_plus,
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("_*_", arith_bin_op, compile_mul,
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("_/_", arith_bin_op, std::bind(compile_div, _1, _2, _3, -1),
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("_~/_", arith_bin_op, std::bind(compile_div, _1, _2, _3, 0),
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("_^/_", arith_bin_op, std::bind(compile_div, _1, _2, _3, 1),
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("_%_", arith_bin_op, std::bind(compile_mod, _1, _2, _3, -1),
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("_<<_", arith_bin_op, compile_lshift,
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("_>>_", arith_bin_op, std::bind(compile_rshift, _1, _2, _3, -1),
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("_~>>_", arith_bin_op, std::bind(compile_rshift, _1, _2, _3, 0),
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("_^>>_", arith_bin_op, std::bind(compile_rshift, _1, _2, _3, 1),
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("!_", arith_un_op, compile_logical_not,
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("~_", arith_un_op, compile_bitwise_not,
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("_&_", arith_bin_op, compile_bitwise_and,
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("_|_", arith_bin_op, compile_bitwise_or,
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("_^_", arith_bin_op, compile_bitwise_xor,
-                                SymValFunc::flagMarkedAsPure);
-  define_builtin_func("^_+=_", arith_bin_op, compile_add,
-                                SymValFunc::flagMarkedAsPure);
-  define_builtin_func("^_-=_", arith_bin_op, compile_sub,
-                                SymValFunc::flagMarkedAsPure);
-  define_builtin_func("^_*=_", arith_bin_op, compile_mul,
-                                SymValFunc::flagMarkedAsPure);
-  define_builtin_func("^_/=_", arith_bin_op, std::bind(compile_div, _1, _2, _3, -1),
-                                SymValFunc::flagMarkedAsPure);
-  define_builtin_func("^_%=_", arith_bin_op, std::bind(compile_mod, _1, _2, _3, -1),
-                                SymValFunc::flagMarkedAsPure);
-  define_builtin_func("^_<<=_", arith_bin_op, compile_lshift,
-                                SymValFunc::flagMarkedAsPure);
-  define_builtin_func("^_>>=_", arith_bin_op, std::bind(compile_rshift, _1, _2, _3, -1),
-                                SymValFunc::flagMarkedAsPure);
-  define_builtin_func("^_&=_", arith_bin_op, compile_bitwise_and,
-                                SymValFunc::flagMarkedAsPure);
-  define_builtin_func("^_|=_", arith_bin_op, compile_bitwise_or,
-                                SymValFunc::flagMarkedAsPure);
-  define_builtin_func("^_^=_", arith_bin_op, compile_bitwise_xor,
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("_==_", arith_bin_op, std::bind(compile_cmp_int, _1, _2, 2),
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("_!=_", arith_bin_op, std::bind(compile_cmp_int, _1, _2, 5),
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("_<_", arith_bin_op, std::bind(compile_cmp_int, _1, _2, 4),
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("_>_", arith_bin_op, std::bind(compile_cmp_int, _1, _2, 1),
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("_<=_", arith_bin_op, std::bind(compile_cmp_int, _1, _2, 6),
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("_>=_", arith_bin_op, std::bind(compile_cmp_int, _1, _2, 3),
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("_<=>_", arith_bin_op, std::bind(compile_cmp_int, _1, _2, 7),
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("mulDivFloor", TypeExpr::new_map(Int3, Int), std::bind(compile_muldiv, _1, _2, _3, -1),
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("mulDivRound", TypeExpr::new_map(Int3, Int), std::bind(compile_muldiv, _1, _2, _3, 0),
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("mulDivCeil", TypeExpr::new_map(Int3, Int), std::bind(compile_muldiv, _1, _2, _3, 1),
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("mulDivMod", TypeExpr::new_map(Int3, Int2), AsmOp::Custom("MULDIVMOD", 3, 2),
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("__true", TypeExpr::new_map(TypeExpr::new_unit(), Int), /* AsmOp::Const("TRUE") */ std::bind(compile_bool_const, _1, _2, true),
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("__false", TypeExpr::new_map(TypeExpr::new_unit(), Int), /* AsmOp::Const("FALSE") */ std::bind(compile_bool_const, _1, _2, false),
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("__null", TypeExpr::new_forall({X}, TypeExpr::new_map(TypeExpr::new_unit(), X)), AsmOp::Const("PUSHNULL"),
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("__isNull", TypeExpr::new_forall({X}, TypeExpr::new_map(X, Int)), compile_is_null,
-                                SymValFunc::flagMarkedAsPure);
+                                FunctionData::flagMarkedAsPure);
   define_builtin_func("__throw", impure_un_op, compile_throw,
                                 0);
   define_builtin_func("__throw_arg", throw_arg_op, compile_throw_arg,
@@ -1211,23 +1173,28 @@ void define_builtins() {
   define_builtin_func("__throw_if_unless", TypeExpr::new_map(Int3, Unit), compile_throw_if_unless,
                                 0);
   define_builtin_func("loadInt", fetch_int_op_mutate, std::bind(compile_fetch_int, _1, _2, true, true),
-                                SymValFunc::flagMarkedAsPure | SymValFunc::flagHasMutateParams | SymValFunc::flagAcceptsSelf, {}, {1, 0});
+                                FunctionData::flagMarkedAsPure | FunctionData::flagHasMutateParams | FunctionData::flagAcceptsSelf,
+                                {}, {1, 0});
   define_builtin_func("loadUint", fetch_int_op_mutate, std::bind(compile_fetch_int, _1, _2, true, false),
-                                SymValFunc::flagMarkedAsPure | SymValFunc::flagHasMutateParams | SymValFunc::flagAcceptsSelf, {}, {1, 0});
+                                FunctionData::flagMarkedAsPure | FunctionData::flagHasMutateParams | FunctionData::flagAcceptsSelf,
+                                {}, {1, 0});
   define_builtin_func("loadBits", fetch_slice_op_mutate, std::bind(compile_fetch_slice, _1, _2, true),
-                                SymValFunc::flagMarkedAsPure | SymValFunc::flagHasMutateParams | SymValFunc::flagAcceptsSelf, {}, {1, 0});
+                                FunctionData::flagMarkedAsPure | FunctionData::flagHasMutateParams | FunctionData::flagAcceptsSelf,
+                                {}, {1, 0});
   define_builtin_func("preloadInt", prefetch_int_op, std::bind(compile_fetch_int, _1, _2, false, true),
-                                SymValFunc::flagMarkedAsPure | SymValFunc::flagAcceptsSelf);
+                                FunctionData::flagMarkedAsPure | FunctionData::flagAcceptsSelf);
   define_builtin_func("preloadUint", prefetch_int_op, std::bind(compile_fetch_int, _1, _2, false, false),
-                                SymValFunc::flagMarkedAsPure | SymValFunc::flagAcceptsSelf);
+                                FunctionData::flagMarkedAsPure | FunctionData::flagAcceptsSelf);
   define_builtin_func("preloadBits", prefetch_slice_op, std::bind(compile_fetch_slice, _1, _2, false),
-                                SymValFunc::flagMarkedAsPure | SymValFunc::flagAcceptsSelf);
+                                FunctionData::flagMarkedAsPure | FunctionData::flagAcceptsSelf);
   define_builtin_func("storeInt", store_int_mutate, std::bind(compile_store_int, _1, _2, true),
-                                SymValFunc::flagMarkedAsPure | SymValFunc::flagHasMutateParams | SymValFunc::flagAcceptsSelf | SymValFunc::flagReturnsSelf, {1, 0, 2}, {});
+                                FunctionData::flagMarkedAsPure | FunctionData::flagHasMutateParams | FunctionData::flagAcceptsSelf | FunctionData::flagReturnsSelf,
+                                {1, 0, 2}, {});
   define_builtin_func("storeUint", store_int_mutate, std::bind(compile_store_int, _1, _2, false),
-                                SymValFunc::flagMarkedAsPure | SymValFunc::flagHasMutateParams | SymValFunc::flagAcceptsSelf | SymValFunc::flagReturnsSelf, {1, 0, 2}, {});
+                                FunctionData::flagMarkedAsPure | FunctionData::flagHasMutateParams | FunctionData::flagAcceptsSelf | FunctionData::flagReturnsSelf,
+                                {1, 0, 2}, {});
   define_builtin_func("tupleAt", TypeExpr::new_forall({X}, TypeExpr::new_map(TupleInt, X)), compile_tuple_at,
-                                SymValFunc::flagMarkedAsPure | SymValFunc::flagAcceptsSelf);
+                                FunctionData::flagMarkedAsPure | FunctionData::flagAcceptsSelf);
   define_builtin_func("debugPrint", TypeExpr::new_forall({X}, TypeExpr::new_map(X, Unit)),
                                 AsmOp::Custom("s0 DUMP DROP", 1, 1),
                                 0);

tolk/codegen.cpp

@@ -314,7 +314,7 @@ bool Op::generate_code_step(Stack& stack) {
       return true;
     }
     case _GlobVar:
-      if (dynamic_cast<const SymValGlobVar*>(fun_ref->value)) {
+      if (g_sym) {
         bool used = false;
         for (auto i : left) {
           auto p = next->var_info[i];
@@ -325,8 +325,7 @@ bool Op::generate_code_step(Stack& stack) {
         if (!used || disabled()) {
           return true;
         }
-        std::string name = G.symbols.get_name(fun_ref->sym_idx);
-        stack.o << AsmOp::Custom(name + " GETGLOB", 0, 1);
+        stack.o << AsmOp::Custom(g_sym->name + " GETGLOB", 0, 1);
         if (left.size() != 1) {
           tolk_assert(left.size() <= 15);
           stack.o << AsmOp::UnTuple((int)left.size());
@@ -343,14 +342,14 @@ bool Op::generate_code_step(Stack& stack) {
         }
         stack.o << "CONT:<{";
         stack.o.indent();
-        auto func = dynamic_cast<SymValAsmFunc*>(fun_ref->value);
-        if (func) {
+        if (f_sym->is_asm_function() || f_sym->is_builtin_function()) {
           // TODO: create and compile a true lambda instead of this (so that arg_order and ret_order would work correctly)
           std::vector<VarDescr> args0, res;
-          TypeExpr::remove_indirect(func->sym_type);
-          tolk_assert(func->get_type()->is_map());
-          auto wr = func->get_type()->args.at(0)->get_width();
-          auto wl = func->get_type()->args.at(1)->get_width();
+          TypeExpr* func_type = f_sym->full_type;
+          TypeExpr::remove_indirect(func_type);
+          tolk_assert(func_type->is_map());
+          auto wr = func_type->args.at(0)->get_width();
+          auto wl = func_type->args.at(1)->get_width();
           tolk_assert(wl >= 0 && wr >= 0);
           for (int i = 0; i < wl; i++) {
             res.emplace_back(0);
@@ -358,10 +357,13 @@ bool Op::generate_code_step(Stack& stack) {
           for (int i = 0; i < wr; i++) {
             args0.emplace_back(0);
           }
-          func->compile(stack.o, res, args0, where);  // compile res := f (args0)
+          if (f_sym->is_asm_function()) {
+            std::get<FunctionBodyAsm*>(f_sym->body)->compile(stack.o);  // compile res := f (args0)
           } else {
-          std::string name = G.symbols.get_name(fun_ref->sym_idx);
-          stack.o << AsmOp::Custom(name + " CALLDICT", (int)right.size(), (int)left.size());
+            std::get<FunctionBodyBuiltin*>(f_sym->body)->compile(stack.o, res, args0, where);  // compile res := f (args0)
+          }
+        } else {
+          stack.o << AsmOp::Custom(f_sym->name + " CALLDICT", (int)right.size(), (int)left.size());
         }
         stack.o.undent();
         stack.o << "}>";
@@ -438,10 +440,9 @@ bool Op::generate_code_step(Stack& stack) {
       if (disabled()) {
         return true;
       }
-      // fun_ref can be nullptr for Op::_CallInd (invoke a variable, not a function)
-      SymValFunc* func = (fun_ref ? dynamic_cast<SymValFunc*>(fun_ref->value) : nullptr);
-      auto arg_order = (func ? func->get_arg_order() : nullptr);
-      auto ret_order = (func ? func->get_ret_order() : nullptr);
+      // f_sym can be nullptr for Op::_CallInd (invoke a variable, not a function)
+      const std::vector<int>* arg_order = f_sym ? f_sym->get_arg_order() : nullptr;
+      const std::vector<int>* ret_order = f_sym ? f_sym->get_ret_order() : nullptr;
       tolk_assert(!arg_order || arg_order->size() == right.size());
       tolk_assert(!ret_order || ret_order->size() == left.size());
       std::vector<var_idx_t> right1;
@@ -488,23 +489,25 @@ bool Op::generate_code_step(Stack& stack) {
       };
       if (cl == _CallInd) {
         exec_callxargs((int)right.size() - 1, (int)left.size());
-      } else if (auto asm_fv = dynamic_cast<const SymValAsmFunc*>(fun_ref->value)) {
+      } else if (!f_sym->is_regular_function()) {
         std::vector<VarDescr> res;
         res.reserve(left.size());
         for (var_idx_t i : left) {
           res.emplace_back(i);
         }
-        asm_fv->compile(stack.o, res, args, where);  // compile res := f (args)
+        if (f_sym->is_asm_function()) {
+          std::get<FunctionBodyAsm*>(f_sym->body)->compile(stack.o);  // compile res := f (args)
         } else {
-        auto fv = dynamic_cast<const SymValCodeFunc*>(fun_ref->value);
-        std::string name = G.symbols.get_name(fun_ref->sym_idx);
-        if (fv->is_inline() || fv->is_inline_ref()) {
-          stack.o << AsmOp::Custom(name + " INLINECALLDICT", (int)right.size(), (int)left.size());
-        } else if (fv->code && fv->code->require_callxargs) {
-          stack.o << AsmOp::Custom(name + (" PREPAREDICT"), 0, 2);
+          std::get<FunctionBodyBuiltin*>(f_sym->body)->compile(stack.o, res, args, where);  // compile res := f (args)
+        }
+      } else {
+        if (f_sym->is_inline() || f_sym->is_inline_ref()) {
+          stack.o << AsmOp::Custom(f_sym->name + " INLINECALLDICT", (int)right.size(), (int)left.size());
+        } else if (f_sym->is_regular_function() && std::get<FunctionBodyCode*>(f_sym->body)->code->require_callxargs) {
+          stack.o << AsmOp::Custom(f_sym->name + (" PREPAREDICT"), 0, 2);
           exec_callxargs((int)right.size() + 1, (int)left.size());
         } else {
-          stack.o << AsmOp::Custom(name + " CALLDICT", (int)right.size(), (int)left.size());
+          stack.o << AsmOp::Custom(f_sym->name + " CALLDICT", (int)right.size(), (int)left.size());
         }
       }
       stack.s.resize(k);
@@ -515,7 +518,7 @@ bool Op::generate_code_step(Stack& stack) {
       return true;
     }
     case _SetGlob: {
-      tolk_assert(fun_ref && dynamic_cast<const SymValGlobVar*>(fun_ref->value));
+      tolk_assert(g_sym);
       std::vector<bool> last;
       for (var_idx_t x : right) {
         last.push_back(var_info[x] && var_info[x]->is_last());
@@ -534,8 +537,7 @@ bool Op::generate_code_step(Stack& stack) {
         stack.o << AsmOp::Tuple((int)right.size());
       }
       if (!right.empty()) {
-        std::string name = G.symbols.get_name(fun_ref->sym_idx);
-        stack.o << AsmOp::Custom(name + " SETGLOB", 1, 0);
+        stack.o << AsmOp::Custom(g_sym->name + " SETGLOB", 1, 0);
       }
       stack.s.resize(k);
       return true;
@@ -826,6 +828,8 @@ bool Op::generate_code_step(Stack& stack) {
       catch_stack.push_new_var(left[1]);
       stack.rearrange_top(catch_vars, catch_last);
       stack.opt_show();
+      stack.o << "c1 PUSH";
+      stack.o << "c3 PUSH";
       stack.o << "c4 PUSH";
       stack.o << "c5 PUSH";
       stack.o << "c7 PUSH";
@@ -842,6 +846,8 @@ bool Op::generate_code_step(Stack& stack) {
       stack.o << "c7 SETCONT";
       stack.o << "c5 SETCONT";
       stack.o << "c4 SETCONT";
+      stack.o << "c3 SETCONT";
+      stack.o << "c1 SETCONT";
       for (size_t begin = catch_vars.size(), end = begin; end > 0; end = begin) {
         begin = end >= block_size ? end - block_size : 0;
         stack.o << std::to_string(end - begin) + " PUSHINT";

tolk/compiler-state.cpp

@@ -27,6 +27,19 @@ void ExperimentalOption::mark_deprecated(const char* deprecated_from_v, const ch
   this->deprecated_reason = deprecated_reason;
 }
 
+std::string_view PersistentHeapAllocator::copy_string_to_persistent_memory(std::string_view str_in_tmp_memory) {
+  size_t len = str_in_tmp_memory.size();
+  char* allocated = new char[len];
+  memcpy(allocated, str_in_tmp_memory.data(), str_in_tmp_memory.size());
+  auto new_chunk = std::make_unique<ChunkInHeap>(allocated, std::move(head));
+  head = std::move(new_chunk);
+  return {head->allocated, len};
+}
+
+void PersistentHeapAllocator::clear() {
+  head = nullptr;
+}
+
 void CompilerSettings::enable_experimental_option(std::string_view name) {
   ExperimentalOption* to_enable = nullptr;
 

tolk/compiler-state.h

@@ -19,6 +19,7 @@
 #include "src-file.h"
 #include "symtable.h"
 #include "td/utils/Status.h"
+#include <functional>
 #include <set>
 #include <string>
 
@@ -64,6 +65,26 @@ struct CompilerSettings {
   void parse_experimental_options_cmd_arg(const std::string& cmd_arg);
 };
 
+// AST nodes contain std::string_view referencing to contents of .tolk files (kept in memory after reading).
+// It's more than enough, except a situation when we create new AST nodes inside the compiler
+// and want some "persistent place" for std::string_view to point to.
+// This class copies strings to heap, so that they remain valid after closing scope.
+class PersistentHeapAllocator {
+  struct ChunkInHeap {
+    const char* allocated;
+    std::unique_ptr<ChunkInHeap> next;
+
+    ChunkInHeap(const char* allocated, std::unique_ptr<ChunkInHeap>&& next)
+      : allocated(allocated), next(std::move(next)) {}
+  };
+
+  std::unique_ptr<ChunkInHeap> head = nullptr;
+
+public:
+  std::string_view copy_string_to_persistent_memory(std::string_view str_in_tmp_memory);
+  void clear();
+};
+
 // CompilerState contains a mutable state that is changed while the compilation is going on.
 // It's a "global state" of all compilation.
 // Historically, in FunC, this global state was spread along many global C++ variables.
@@ -71,14 +92,13 @@ struct CompilerSettings {
 struct CompilerState {
   CompilerSettings settings;
 
-  SymTable symbols;
-  int scope_level = 0;
-  SymDef* sym_def[SymTable::SIZE_PRIME + 1]{};
-  SymDef* global_sym_def[SymTable::SIZE_PRIME + 1]{};
-  std::vector<std::pair<int, SymDef>> symbol_stack;
-  std::vector<SrcLocation> scope_opened_at;
+  GlobalSymbolTable symtable;
+  PersistentHeapAllocator persistent_mem;
 
-  std::vector<SymDef*> all_code_functions, all_global_vars, all_get_methods, all_constants;
+  std::vector<const FunctionData*> all_code_functions;
+  std::vector<const FunctionData*> all_get_methods;
+  std::vector<const GlobalVarData*> all_global_vars;
+  std::vector<const GlobalConstData*> all_constants;
   AllRegisteredSrcFiles all_src_files;
 
   bool is_verbosity(int gt_eq) const { return settings.verbosity >= gt_eq; }

tolk/constant-evaluator.cpp

@@ -0,0 +1,313 @@
+/*
+    This file is part of TON Blockchain Library.
+
+    TON Blockchain Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 2 of the License, or
+    (at your option) any later version.
+
+    TON Blockchain Library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with TON Blockchain Library.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#include "constant-evaluator.h"
+#include "ast.h"
+#include "tolk.h"
+#include "openssl/digest.hpp"
+#include "crypto/common/util.h"
+#include "td/utils/crypto.h"
+#include "ton/ton-types.h"
+
+namespace tolk {
+
+// parse address like "EQCRDM9h4k3UJdOePPuyX40mCgA4vxge5Dc5vjBR8djbEKC5"
+// based on unpack_std_smc_addr() from block.cpp
+// (which is not included to avoid linking with ton_crypto)
+static bool parse_friendly_address(const char packed[48], ton::WorkchainId& workchain, ton::StdSmcAddress& addr) {
+  unsigned char buffer[36];
+  if (!td::buff_base64_decode(td::MutableSlice{buffer, 36}, td::Slice{packed, 48}, true)) {
+    return false;
+  }
+  td::uint16 crc = td::crc16(td::Slice{buffer, 34});
+  if (buffer[34] != (crc >> 8) || buffer[35] != (crc & 0xff) || (buffer[0] & 0x3f) != 0x11) {
+    return false;
+  }
+  workchain = static_cast<td::int8>(buffer[1]);
+  std::memcpy(addr.data(), buffer + 2, 32);
+  return true;
+}
+
+// parse address like "0:527964d55cfa6eb731f4bfc07e9d025098097ef8505519e853986279bd8400d8"
+// based on StdAddress::parse_addr() from block.cpp
+// (which is not included to avoid linking with ton_crypto)
+static bool parse_raw_address(const std::string& acc_string, int& workchain, ton::StdSmcAddress& addr) {
+  size_t pos = acc_string.find(':');
+  if (pos != std::string::npos) {
+    td::Result<int> r_wc = td::to_integer_safe<ton::WorkchainId>(acc_string.substr(0, pos));
+    if (r_wc.is_error()) {
+      return false;
+    }
+    workchain = r_wc.move_as_ok();
+    pos++;
+  } else {
+    pos = 0;
+  }
+  if (acc_string.size() != pos + 64) {
+    return false;
+  }
+
+  for (int i = 0; i < 64; ++i) {    // loop through each hex digit
+    char c = acc_string[pos + i];
+    int x;
+    if (c >= '0' && c <= '9') {
+      x = c - '0';
+    } else if (c >= 'a' && c <= 'z') {
+      x = c - 'a' + 10;
+    } else if (c >= 'A' && c <= 'Z') {
+      x = c - 'A' + 10;
+    } else {
+      return false;
+    }
+
+    if ((i & 1) == 0) {
+      addr.data()[i >> 1] = static_cast<unsigned char>((addr.data()[i >> 1] & 0x0F) | (x << 4));
+    } else {
+      addr.data()[i >> 1] = static_cast<unsigned char>((addr.data()[i >> 1] & 0xF0) | x);
+    }
+  }
+  return true;
+}
+
+
+static std::string parse_vertex_string_const_as_slice(V<ast_string_const> v) {
+  std::string str = static_cast<std::string>(v->str_val);
+  switch (v->modifier) {
+    case 0: {
+      return td::hex_encode(str);
+    }
+    case 's': {
+      unsigned char buff[128];
+      long bits = td::bitstring::parse_bitstring_hex_literal(buff, sizeof(buff), str.data(), str.data() + str.size());
+      if (bits < 0) {
+        v->error("invalid hex bitstring constant '" + str + "'");
+      }
+      return str;
+    }
+    case 'a': {  // MsgAddress
+      ton::WorkchainId workchain;
+      ton::StdSmcAddress addr;
+      bool correct = (str.size() == 48 && parse_friendly_address(str.data(), workchain, addr)) ||
+                     (str.size() != 48 && parse_raw_address(str, workchain, addr));
+      if (!correct) {
+        v->error("invalid standard address '" + str + "'");
+      }
+      if (workchain < -128 || workchain >= 128) {
+        v->error("anycast addresses not supported");
+      }
+
+      unsigned char data[3 + 8 + 256];  // addr_std$10 anycast:(Maybe Anycast) workchain_id:int8 address:bits256 = MsgAddressInt;
+      td::bitstring::bits_store_long_top(data, 0, static_cast<uint64_t>(4) << (64 - 3), 3);
+      td::bitstring::bits_store_long_top(data, 3, static_cast<uint64_t>(workchain) << (64 - 8), 8);
+      td::bitstring::bits_memcpy(data, 3 + 8, addr.bits().ptr, 0, ton::StdSmcAddress::size());
+      return td::BitSlice{data, sizeof(data)}.to_hex();
+    }
+    default:
+      tolk_assert(false);
+  }
+}
+
+static td::RefInt256 parse_vertex_string_const_as_int(V<ast_string_const> v) {
+  std::string str = static_cast<std::string>(v->str_val);
+  switch (v->modifier) {
+    case 'u': {
+      td::RefInt256 intval = td::hex_string_to_int256(td::hex_encode(str));
+      if (str.empty()) {
+        v->error("empty integer ascii-constant");
+      }
+      if (intval.is_null()) {
+        v->error("too long integer ascii-constant");
+      }
+      return intval;
+    }
+    case 'h':
+    case 'H': {
+      unsigned char hash[32];
+      digest::hash_str<digest::SHA256>(hash, str.data(), str.size());
+      return td::bits_to_refint(hash, (v->modifier == 'h') ? 32 : 256, false);
+    }
+    case 'c': {
+      return td::make_refint(td::crc32(td::Slice{str}));
+    }
+    default:
+      tolk_assert(false);
+  }
+}
+
+
+struct ConstantEvaluator {
+  static bool is_overflow(const td::RefInt256& intval) {
+    return intval.is_null() || !intval->signed_fits_bits(257);
+  }
+
+  static ConstantValue handle_unary_operator(V<ast_unary_operator> v, const ConstantValue& rhs) {
+    if (!rhs.is_int()) {
+      v->error("invalid operator, expecting integer");
+    }
+    td::RefInt256 intval = std::get<td::RefInt256>(rhs.value);
+
+    switch (v->tok) {
+      case tok_minus:
+        intval = -intval;
+        break;
+      case tok_plus:
+        break;
+      case tok_bitwise_not:
+        intval = ~intval;
+      break;
+      case tok_logical_not:
+        intval = td::make_refint(intval == 0 ? -1 : 0);
+        break;
+      default:
+        v->error("not a constant expression");
+    }
+
+    if (is_overflow(intval)) {
+      v->error("integer overflow");
+    }
+    return ConstantValue::from_int(std::move(intval));
+  }
+
+  static ConstantValue handle_binary_operator(V<ast_binary_operator> v, const ConstantValue& lhs, const ConstantValue& rhs) {
+    if (!lhs.is_int() || !rhs.is_int()) {
+      v->error("invalid operator, expecting integer");
+    }
+    td::RefInt256 lhs_intval = std::get<td::RefInt256>(lhs.value);
+    td::RefInt256 rhs_intval = std::get<td::RefInt256>(rhs.value);
+    td::RefInt256 intval;
+
+    switch (v->tok) {
+      case tok_minus:
+        intval = lhs_intval - rhs_intval;
+        break;
+      case tok_plus:
+        intval = lhs_intval + rhs_intval;
+        break;
+      case tok_mul:
+        intval = lhs_intval * rhs_intval;
+        break;
+      case tok_div:
+        intval = lhs_intval / rhs_intval;
+        break;
+      case tok_mod:
+        intval = lhs_intval % rhs_intval;
+        break;
+      case tok_lshift:
+        intval = lhs_intval << static_cast<int>(rhs_intval->to_long());
+        break;
+      case tok_rshift:
+        intval = lhs_intval >> static_cast<int>(rhs_intval->to_long());
+        break;
+      case tok_bitwise_and:
+        intval = lhs_intval & rhs_intval;
+        break;
+      case tok_bitwise_or:
+        intval = lhs_intval | rhs_intval;
+        break;
+      case tok_bitwise_xor:
+        intval = lhs_intval ^ rhs_intval;
+        break;
+      case tok_eq:
+        intval = td::make_refint(lhs_intval == rhs_intval ? -1 : 0);
+        break;
+      case tok_lt:
+        intval = td::make_refint(lhs_intval < rhs_intval ? -1 : 0);
+        break;
+      case tok_gt:
+        intval = td::make_refint(lhs_intval > rhs_intval ? -1 : 0);
+        break;
+      case tok_leq:
+        intval = td::make_refint(lhs_intval <= rhs_intval ? -1 : 0);
+        break;
+      case tok_geq:
+        intval = td::make_refint(lhs_intval >= rhs_intval ? -1 : 0);
+        break;
+      case tok_neq:
+        intval = td::make_refint(lhs_intval != rhs_intval ? -1 : 0);
+        break;
+      default:
+        v->error("unsupported binary operator in constant expression");
+    }
+
+    if (is_overflow(intval)) {
+      v->error("integer overflow");
+    }
+    return ConstantValue::from_int(std::move(intval));
+  }
+
+  static ConstantValue handle_identifier(V<ast_identifier> v) {
+    // todo better handle "appears, directly or indirectly, in its own initializer"
+    const Symbol* sym = lookup_global_symbol(v->name);
+    if (!sym) {
+      v->error("undefined symbol `" + static_cast<std::string>(v->name) + "`");
+    }
+    const GlobalConstData* const_ref = sym->try_as<GlobalConstData>();
+    if (!const_ref) {
+      v->error("symbol `" + static_cast<std::string>(v->name) + "` is not a constant");
+    }
+    return {const_ref->value};
+  }
+
+  static ConstantValue visit(AnyExprV v) {
+    if (auto v_int = v->try_as<ast_int_const>()) {
+      return ConstantValue::from_int(v_int->intval);
+    }
+    if (auto v_bool = v->try_as<ast_bool_const>()) {
+      return ConstantValue::from_int(v_bool->bool_val ? -1 : 0);
+    }
+    if (auto v_unop = v->try_as<ast_unary_operator>()) {
+      return handle_unary_operator(v_unop, visit(v_unop->get_rhs()));
+    }
+    if (auto v_binop = v->try_as<ast_binary_operator>()) {
+      return handle_binary_operator(v_binop, visit(v_binop->get_lhs()), visit(v_binop->get_rhs()));
+    }
+    if (auto v_ident = v->try_as<ast_identifier>()) {
+      return handle_identifier(v_ident);
+    }
+    if (auto v_par = v->try_as<ast_parenthesized_expression>()) {
+      return visit(v_par->get_expr());
+    }
+    if (v->try_as<ast_string_const>()) {
+      return eval_const_init_value(v);
+    }
+    v->error("not a constant expression");
+  }
+
+  static ConstantValue eval_const_init_value(AnyExprV init_value) {
+    // it init_value is incorrect, an exception is thrown
+    return visit(init_value);
+  }
+};
+
+ConstantValue eval_const_init_value(AnyExprV init_value) {
+  // at first, handle most simple cases, not to launch heavy computation algorithm: just a number, just a string
+  // just `c = 1` or `c = 0xFF`
+  if (auto v_int = init_value->try_as<ast_int_const>()) {
+    return {v_int->intval};
+  }
+  // just `c = "strval"`, probably with modifier (address, etc.)
+  if (auto v_string = init_value->try_as<ast_string_const>()) {
+    if (v_string->is_bitslice()) {
+      return {parse_vertex_string_const_as_slice(v_string)};
+    } else {
+      return {parse_vertex_string_const_as_int(v_string)};
+    }
+  }
+  // something more complex, like `c = anotherC` or `c = 1 << 8`
+  return ConstantEvaluator::eval_const_init_value(init_value);
+}
+
+} // namespace tolk

tolk/constant-evaluator.h

@@ -0,0 +1,45 @@
+/*
+    This file is part of TON Blockchain Library.
+
+    TON Blockchain Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 2 of the License, or
+    (at your option) any later version.
+
+    TON Blockchain Library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with TON Blockchain Library.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#pragma once
+
+#include "fwd-declarations.h"
+#include "crypto/common/refint.h"
+#include <variant>
+
+namespace tolk {
+
+struct ConstantValue {
+  std::variant<td::RefInt256, std::string> value;
+
+  bool is_int() const { return std::holds_alternative<td::RefInt256>(value); }
+  bool is_slice() const { return std::holds_alternative<std::string>(value); }
+
+  td::RefInt256 as_int() const { return std::get<td::RefInt256>(value); }
+  const std::string& as_slice() const { return std::get<std::string>(value); }
+
+  static ConstantValue from_int(int value) {
+    return {td::make_refint(value)};
+  }
+
+  static ConstantValue from_int(td::RefInt256 value) {
+    return {std::move(value)};
+  }
+};
+
+ConstantValue eval_const_init_value(AnyExprV init_value);
+
+} // namespace tolk

tolk/fwd-declarations.h

@@ -0,0 +1,39 @@
+/*
+    This file is part of TON Blockchain Library.
+
+    TON Blockchain Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 2 of the License, or
+    (at your option) any later version.
+
+    TON Blockchain Library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with TON Blockchain Library.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#pragma once
+
+namespace tolk {
+
+struct ASTNodeBase;
+struct ASTNodeExpressionBase;
+struct ASTNodeStatementBase;
+
+using AnyV = const ASTNodeBase*;
+using AnyExprV = const ASTNodeExpressionBase*;
+using AnyStatementV = const ASTNodeStatementBase*;
+
+struct Symbol;
+struct LocalVarData;
+struct FunctionData;
+struct GlobalVarData;
+struct GlobalConstData;
+
+struct TypeExpr;
+
+struct SrcFile;
+
+} // namespace tolk

tolk/gen-abscode.cpp

@@ -1,429 +0,0 @@
-/*
-    This file is part of TON Blockchain Library.
-
-    TON Blockchain Library is free software: you can redistribute it and/or modify
-    it under the terms of the GNU Lesser General Public License as published by
-    the Free Software Foundation, either version 2 of the License, or
-    (at your option) any later version.
-
-    TON Blockchain Library is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU Lesser General Public License for more details.
-
-    You should have received a copy of the GNU Lesser General Public License
-    along with TON Blockchain Library.  If not, see <http://www.gnu.org/licenses/>.
-*/
-#include "tolk.h"
-#include "compiler-state.h"
-
-using namespace std::literals::string_literals;
-
-namespace tolk {
-
-/*
- * 
- *   EXPRESSIONS
- * 
- */
-
-Expr* Expr::copy() const {
-  auto res = new Expr{*this};
-  for (auto& arg : res->args) {
-    arg = arg->copy();
-  }
-  return res;
-}
-
-Expr::Expr(ExprCls c, sym_idx_t name_idx, std::initializer_list<Expr*> _arglist) : cls(c), args(std::move(_arglist)) {
-  sym = lookup_symbol(name_idx);
-  if (!sym) {
-  }
-}
-
-void Expr::deduce_type() {
-  if (e_type) {
-    return;
-  }
-  switch (cls) {
-    case _Apply: {
-      if (!sym) {
-        return;
-      }
-      SymValFunc* sym_val = dynamic_cast<SymValFunc*>(sym->value);
-      if (!sym_val || !sym_val->get_type()) {
-        return;
-      }
-      std::vector<TypeExpr*> arg_types;
-      arg_types.reserve(args.size());
-      for (const Expr* arg : args) {
-        arg_types.push_back(arg->e_type);
-      }
-      TypeExpr* fun_type = TypeExpr::new_map(TypeExpr::new_tensor(arg_types), TypeExpr::new_hole());
-      try {
-        unify(fun_type, sym_val->sym_type);
-      } catch (UnifyError& ue) {
-        std::ostringstream os;
-        os << "cannot apply function " << sym->name() << " : " << sym_val->get_type() << " to arguments of type "
-           << fun_type->args[0] << ": " << ue;
-        throw ParseError(here, os.str());
-      }
-      e_type = fun_type->args[1];
-      TypeExpr::remove_indirect(e_type);
-      return;
-    }
-    case _VarApply: {
-      tolk_assert(args.size() == 2);
-      TypeExpr* fun_type = TypeExpr::new_map(args[1]->e_type, TypeExpr::new_hole());
-      try {
-        unify(fun_type, args[0]->e_type);
-      } catch (UnifyError& ue) {
-        std::ostringstream os;
-        os << "cannot apply expression of type " << args[0]->e_type << " to an expression of type " << args[1]->e_type
-           << ": " << ue;
-        throw ParseError(here, os.str());
-      }
-      e_type = fun_type->args[1];
-      TypeExpr::remove_indirect(e_type);
-      return;
-    }
-    case _GrabMutatedVars: {
-      tolk_assert(args.size() == 2 && args[0]->cls == _Apply && sym);
-      SymValFunc* called_f = dynamic_cast<SymValFunc*>(sym->value);
-      tolk_assert(called_f->has_mutate_params());
-      TypeExpr* sym_type = called_f->get_type();
-      if (sym_type->constr == TypeExpr::te_ForAll) {
-        TypeExpr::remove_forall(sym_type);
-      }
-      tolk_assert(sym_type->args[1]->constr == TypeExpr::te_Tensor);
-      e_type = sym_type->args[1]->args[sym_type->args[1]->args.size() - 1];
-      TypeExpr::remove_indirect(e_type);
-      return;
-    }
-    case _ReturnSelf: {
-      tolk_assert(args.size() == 2 && sym);
-      Expr* this_arg = args[1];
-      e_type = this_arg->e_type;
-      TypeExpr::remove_indirect(e_type);
-      return;
-    }
-    case _Letop: {
-      tolk_assert(args.size() == 2);
-      try {
-        // std::cerr << "in assignment: " << args[0]->e_type << " from " << args[1]->e_type << std::endl;
-        unify(args[0]->e_type, args[1]->e_type);
-      } catch (UnifyError& ue) {
-        std::ostringstream os;
-        os << "cannot assign an expression of type " << args[1]->e_type << " to a variable or pattern of type "
-           << args[0]->e_type << ": " << ue;
-        throw ParseError(here, os.str());
-      }
-      e_type = args[0]->e_type;
-      TypeExpr::remove_indirect(e_type);
-      return;
-    }
-    case _CondExpr: {
-      tolk_assert(args.size() == 3);
-      auto flag_type = TypeExpr::new_atomic(TypeExpr::_Int);
-      try {
-        unify(args[0]->e_type, flag_type);
-      } catch (UnifyError& ue) {
-        std::ostringstream os;
-        os << "condition in a conditional expression has non-integer type " << args[0]->e_type << ": " << ue;
-        throw ParseError(here, os.str());
-      }
-      try {
-        unify(args[1]->e_type, args[2]->e_type);
-      } catch (UnifyError& ue) {
-        std::ostringstream os;
-        os << "the two variants in a conditional expression have different types " << args[1]->e_type << " and "
-           << args[2]->e_type << " : " << ue;
-        throw ParseError(here, os.str());
-      }
-      e_type = args[1]->e_type;
-      TypeExpr::remove_indirect(e_type);
-      return;
-    }
-    default:
-      throw Fatal("unexpected cls=" + std::to_string(cls) + " in Expr::deduce_type()");
-  }
-}
-
-void Expr::define_new_vars(CodeBlob& code) {
-  switch (cls) {
-    case _Tensor:
-    case _MkTuple: {
-      for (Expr* item : args) {
-        item->define_new_vars(code);
-      }
-      break;
-    }
-    case _Var:
-      if (val < 0) {
-        val = code.create_var(e_type, sym->sym_idx, here);
-        sym->value->idx = val;
-      }
-      break;
-    case _Hole:
-      if (val < 0) {
-        val = code.create_tmp_var(e_type, here);
-      }
-      break;
-    default:
-      break;
-  }
-}
-
-void Expr::predefine_vars() {
-  switch (cls) {
-    case _Tensor:
-    case _MkTuple: {
-      for (Expr* item : args) {
-        item->predefine_vars();
-      }
-      break;
-    }
-    case _Var:
-      if (!sym) {
-        tolk_assert(val < 0 && here.is_defined());
-        sym = define_symbol(~val, false, here);
-        // std::cerr << "predefining variable " << symbols.get_name(~val) << std::endl;
-        if (!sym) {
-          throw ParseError{here, std::string{"redefined variable `"} + G.symbols.get_name(~val) + "`"};
-        }
-        sym->value = new SymValVariable(-1, e_type);
-        if (is_immutable()) {
-          dynamic_cast<SymValVariable*>(sym->value)->flags |= SymValVariable::flagImmutable;
-        }
-      }
-      break;
-    default:
-      break;
-  }
-}
-
-var_idx_t Expr::new_tmp(CodeBlob& code) const {
-  return code.create_tmp_var(e_type, here);
-}
-
-void add_set_globs(CodeBlob& code, std::vector<std::pair<SymDef*, var_idx_t>>& globs, SrcLocation here) {
-  for (const auto& p : globs) {
-    auto& op = code.emplace_back(here, Op::_SetGlob, std::vector<var_idx_t>{}, std::vector<var_idx_t>{ p.second }, p.first);
-    op.set_impure(code);
-  }
-}
-
-std::vector<var_idx_t> pre_compile_let(CodeBlob& code, Expr* lhs, Expr* rhs, SrcLocation here) {
-  if (lhs->is_mktuple()) {
-    if (rhs->is_mktuple()) {
-      return pre_compile_let(code, lhs->args.at(0), rhs->args.at(0), here);
-    }
-    auto right = rhs->pre_compile(code);
-    TypeExpr::remove_indirect(rhs->e_type);
-    auto unpacked_type = rhs->e_type->args.at(0);
-    std::vector<var_idx_t> tmp{code.create_tmp_var(unpacked_type, rhs->here)};
-    code.emplace_back(lhs->here, Op::_UnTuple, tmp, std::move(right));
-    auto tvar = new Expr{Expr::_Var, lhs->here};
-    tvar->set_val(tmp[0]);
-    tvar->set_location(rhs->here);
-    tvar->e_type = unpacked_type;
-    pre_compile_let(code, lhs->args.at(0), tvar, here);
-    return tmp;
-  }
-  auto right = rhs->pre_compile(code);
-  std::vector<std::pair<SymDef*, var_idx_t>> globs;
-  auto left = lhs->pre_compile(code, &globs);
-  for (var_idx_t v : left) {
-    code.on_var_modification(v, here);
-  }
-  code.emplace_back(here, Op::_Let, std::move(left), right);
-  add_set_globs(code, globs, here);
-  return right;
-}
-
-std::vector<var_idx_t> pre_compile_tensor(const std::vector<Expr *>& args, CodeBlob &code,
-                                          std::vector<std::pair<SymDef*, var_idx_t>> *lval_globs) {
-  const size_t n = args.size();
-  if (n == 0) {  // just `()`
-    return {};
-  }
-  if (n == 1) {  // just `(x)`: even if x is modified (e.g. `f(x=x+2)`), there are no next arguments
-    return args[0]->pre_compile(code, lval_globs);
-  }
-  std::vector<std::vector<var_idx_t>> res_lists(n);
-
-  struct ModifiedVar {
-    size_t i, j;
-    std::unique_ptr<Op>* cur_ops; // `LET tmp = v_ij` will be inserted before this
-  };
-  std::vector<ModifiedVar> modified_vars;
-  for (size_t i = 0; i < n; ++i) {
-    res_lists[i] = args[i]->pre_compile(code, lval_globs);
-    for (size_t j = 0; j < res_lists[i].size(); ++j) {
-      TmpVar& var = code.vars.at(res_lists[i][j]);
-      if (!lval_globs && !var.is_unnamed()) {
-        var.on_modification.push_back([&modified_vars, i, j, cur_ops = code.cur_ops, done = false](SrcLocation here) mutable {
-          if (!done) {
-            done = true;
-            modified_vars.push_back({i, j, cur_ops});
-          }
-        });
-      } else {
-        var.on_modification.push_back([](SrcLocation) {
-        });
-      }
-    }
-  }
-  for (const auto& list : res_lists) {
-    for (var_idx_t v : list) {
-      tolk_assert(!code.vars.at(v).on_modification.empty());
-      code.vars.at(v).on_modification.pop_back();
-    }
-  }
-  for (size_t idx = modified_vars.size(); idx--; ) {
-    const ModifiedVar &m = modified_vars[idx];
-    var_idx_t orig_v = res_lists[m.i][m.j];
-    var_idx_t tmp_v = code.create_tmp_var(code.vars[orig_v].v_type, code.vars[orig_v].where);
-    std::unique_ptr<Op> op = std::make_unique<Op>(code.vars[orig_v].where, Op::_Let);
-    op->left = {tmp_v};
-    op->right = {orig_v};
-    op->next = std::move((*m.cur_ops));
-    *m.cur_ops = std::move(op);
-    res_lists[m.i][m.j] = tmp_v;
-  }
-  std::vector<var_idx_t> res;
-  for (const auto& list : res_lists) {
-    res.insert(res.end(), list.cbegin(), list.cend());
-  }
-  return res;
-}
-
-std::vector<var_idx_t> Expr::pre_compile(CodeBlob& code, std::vector<std::pair<SymDef*, var_idx_t>>* lval_globs) const {
-  if (lval_globs && !(cls == _Tensor || cls == _Var || cls == _Hole || cls == _GlobVar)) {
-    std::cerr << "lvalue expression constructor is " << cls << std::endl;
-    throw Fatal{"cannot compile lvalue expression with unknown constructor"};
-  }
-  switch (cls) {
-    case _Tensor: {
-      return pre_compile_tensor(args, code, lval_globs);
-    }
-    case _Apply: {
-      tolk_assert(sym);
-      std::vector<var_idx_t> res = pre_compile_tensor(args, code, lval_globs);;
-      auto rvect = new_tmp_vect(code);
-      auto& op = code.emplace_back(here, Op::_Call, rvect, res, sym);
-      if (flags & _IsImpure) {
-        op.set_impure(code);
-      }
-      return rvect;
-    }
-    case _GrabMutatedVars: {
-      SymValFunc* func_val = dynamic_cast<SymValFunc*>(sym->value);
-      tolk_assert(func_val && func_val->has_mutate_params());
-      tolk_assert(args.size() == 2 && args[0]->cls == _Apply && args[1]->cls == _Tensor);
-      auto right = args[0]->pre_compile(code);    // apply (returning function result and mutated)
-      std::vector<std::pair<SymDef*, var_idx_t>> local_globs;
-      if (!lval_globs) {
-        lval_globs = &local_globs;
-      }
-      auto left = args[1]->pre_compile(code, lval_globs);   // mutated (lvalue)
-      auto rvect = new_tmp_vect(code);
-      left.push_back(rvect[0]);
-      for (var_idx_t v : left) {
-        code.on_var_modification(v, here);
-      }
-      code.emplace_back(here, Op::_Let, std::move(left), std::move(right));
-      add_set_globs(code, local_globs, here);
-      return rvect;
-    }
-    case _ReturnSelf: {
-      tolk_assert(args.size() == 2 && sym);
-      Expr* this_arg = args[1];
-      auto right = args[0]->pre_compile(code);
-      return this_arg->pre_compile(code);
-    }
-    case _Var:
-    case _Hole:
-      if (val < 0) {
-        throw ParseError{here, "unexpected variable definition"};
-      }
-      return {val};
-    case _VarApply:
-      if (args[0]->cls == _GlobFunc) {
-        auto res = args[1]->pre_compile(code);
-        auto rvect = new_tmp_vect(code);
-        auto& op = code.emplace_back(here, Op::_Call, rvect, std::move(res), args[0]->sym);
-        if (args[0]->flags & _IsImpure) {
-          op.set_impure(code);
-        }
-        return rvect;
-      } else {
-        auto res = args[1]->pre_compile(code);
-        auto tfunc = args[0]->pre_compile(code);
-        if (tfunc.size() != 1) {
-          throw Fatal{"stack tuple used as a function"};
-        }
-        res.push_back(tfunc[0]);
-        auto rvect = new_tmp_vect(code);
-        code.emplace_back(here, Op::_CallInd, rvect, std::move(res));
-        return rvect;
-      }
-    case _Const: {
-      auto rvect = new_tmp_vect(code);
-      code.emplace_back(here, Op::_IntConst, rvect, intval);
-      return rvect;
-    }
-    case _GlobFunc:
-    case _GlobVar: {
-      if (auto fun_ref = dynamic_cast<SymValFunc*>(sym->value)) {
-        fun_ref->flags |= SymValFunc::flagUsedAsNonCall;
-        if (!fun_ref->arg_order.empty() || !fun_ref->ret_order.empty()) {
-          throw ParseError(here, "saving `" + sym->name() + "` into a variable will most likely lead to invalid usage, since it changes the order of variables on the stack");
-        }
-        if (fun_ref->has_mutate_params()) {
-          throw ParseError(here, "saving `" + sym->name() + "` into a variable is impossible, since it has `mutate` parameters and thus can only be called directly");
-        }
-      }
-      auto rvect = new_tmp_vect(code);
-      if (lval_globs) {
-        lval_globs->push_back({ sym, rvect[0] });
-        return rvect;
-      } else {
-        code.emplace_back(here, Op::_GlobVar, rvect, std::vector<var_idx_t>{}, sym);
-        return rvect;
-      }
-    }
-    case _Letop: {
-      return pre_compile_let(code, args.at(0), args.at(1), here);
-    }
-    case _MkTuple: {
-      auto left = new_tmp_vect(code);
-      auto right = args[0]->pre_compile(code);
-      code.emplace_back(here, Op::_Tuple, left, std::move(right));
-      return left;
-    }
-    case _CondExpr: {
-      auto cond = args[0]->pre_compile(code);
-      tolk_assert(cond.size() == 1);
-      auto rvect = new_tmp_vect(code);
-      Op& if_op = code.emplace_back(here, Op::_If, cond);
-      code.push_set_cur(if_op.block0);
-      code.emplace_back(here, Op::_Let, rvect, args[1]->pre_compile(code));
-      code.close_pop_cur(args[1]->here);
-      code.push_set_cur(if_op.block1);
-      code.emplace_back(here, Op::_Let, rvect, args[2]->pre_compile(code));
-      code.close_pop_cur(args[2]->here);
-      return rvect;
-    }
-    case _SliceConst: {
-      auto rvect = new_tmp_vect(code);
-      code.emplace_back(here, Op::_SliceConst, rvect, strval);
-      return rvect;
-    }
-    default:
-      std::cerr << "expression constructor is " << cls << std::endl;
-      throw Fatal{"cannot compile expression with unknown constructor"};
-  }
-}
-
-}  // namespace tolk

tolk/lexer.cpp

@@ -15,9 +15,9 @@
     along with TON Blockchain Library.  If not, see <http://www.gnu.org/licenses/>.
 */
 #include "lexer.h"
-#include "compiler-state.h"
-#include "symtable.h"
 #include <cassert>
+#include <cstdint>
+#include <cstring>
 
 namespace tolk {
 
@@ -406,7 +406,6 @@ struct ChunkIdentifierOrKeyword final : ChunkLexerBase {
     if (TokenType kw_tok = maybe_keyword(str_val)) {
       lex->add_token(kw_tok, str_val);
     } else {
-      G.symbols.lookup_add(str_val);
       lex->add_token(tok_identifier, str_val);
     }
     return true;
@@ -421,7 +420,7 @@ struct ChunkIdentifierInBackticks final : ChunkLexerBase {
     const char* str_begin = lex->c_str();
     lex->skip_chars(1);
     while (!lex->is_eof() && lex->char_at() != '`' && lex->char_at() != '\n') {
-      if (std::isspace(lex->char_at())) { // probably, I'll remove this restriction after rewriting symtable and cur_sym_idx
+      if (std::isspace(lex->char_at())) {
         lex->error("an identifier can't have a space in its name (even inside backticks)");
       }
       lex->skip_chars(1);
@@ -432,7 +431,6 @@ struct ChunkIdentifierInBackticks final : ChunkLexerBase {
 
     std::string_view str_val(str_begin + 1, lex->c_str() - str_begin - 1);
     lex->skip_chars(1);
-    G.symbols.lookup_add(str_val);
     lex->add_token(tok_identifier, str_val);
     return true;
   }

tolk/lexer.h

@@ -57,10 +57,29 @@ enum TokenType {
   tok_dot,
 
   tok_plus,
+  tok_set_plus,
   tok_minus,
+  tok_set_minus,
   tok_mul,
+  tok_set_mul,
   tok_div,
+  tok_set_div,
   tok_mod,
+  tok_set_mod,
+  tok_lshift,
+  tok_set_lshift,
+  tok_rshift,
+  tok_set_rshift,
+  tok_rshiftR,
+  tok_rshiftC,
+  tok_bitwise_and,
+  tok_set_bitwise_and,
+  tok_bitwise_or,
+  tok_set_bitwise_or,
+  tok_bitwise_xor,
+  tok_set_bitwise_xor,
+  tok_bitwise_not,
+
   tok_question,
   tok_comma,
   tok_semicolon,
@@ -77,32 +96,14 @@ enum TokenType {
   tok_logical_not,
   tok_logical_and,
   tok_logical_or,
-  tok_bitwise_and,
-  tok_bitwise_or,
-  tok_bitwise_xor,
-  tok_bitwise_not,
 
   tok_eq,
   tok_neq,
   tok_leq,
   tok_geq,
   tok_spaceship,
-  tok_lshift,
-  tok_rshift,
-  tok_rshiftR,
-  tok_rshiftC,
   tok_divR,
   tok_divC,
-  tok_set_plus,
-  tok_set_minus,
-  tok_set_mul,
-  tok_set_div,
-  tok_set_mod,
-  tok_set_lshift,
-  tok_set_rshift,
-  tok_set_bitwise_and,
-  tok_set_bitwise_or,
-  tok_set_bitwise_xor,
 
   tok_return,
   tok_repeat,

tolk/pipe-calc-rvalue-lvalue.cpp

@@ -0,0 +1,192 @@
+/*
+    This file is part of TON Blockchain source code.
+
+    TON Blockchain is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License
+    as published by the Free Software Foundation; either version 2
+    of the License, or (at your option) any later version.
+
+    TON Blockchain is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with TON Blockchain.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#include "tolk.h"
+#include "ast.h"
+#include "ast-visitor.h"
+
+/*
+ *   This pipe assigns lvalue/rvalue flags for AST expressions.
+ *   It happens after identifiers have been resolved, but before type inferring (before methods binding).
+ *
+ *   Example: `a = b`, `a` is lvalue, `b` is rvalue.
+ *   Example: `a + b`, both are rvalue.
+ *
+ *   Note, that this pass only assigns, not checks. So, for `f() = 4`, expr `f()` is lvalue.
+ * Checking (firing this as incorrect later) is performed after type inferring, see pipe-check-rvalue-lvalue.
+ */
+
+namespace tolk {
+
+enum class MarkingState {
+  None,
+  LValue,
+  RValue,
+  LValueAndRValue
+};
+
+class CalculateRvalueLvalueVisitor final : public ASTVisitorFunctionBody {
+  MarkingState cur_state = MarkingState::None;
+
+  MarkingState enter_state(MarkingState activated) {
+    MarkingState saved = cur_state;
+    cur_state = activated;
+    return saved;
+  }
+
+  void restore_state(MarkingState saved) {
+    cur_state = saved;
+  }
+
+  void mark_vertex_cur_or_rvalue(AnyExprV v) const {
+    if (cur_state == MarkingState::LValue || cur_state == MarkingState::LValueAndRValue) {
+      v->mutate()->assign_lvalue_true();
+    }
+    if (cur_state == MarkingState::RValue || cur_state == MarkingState::LValueAndRValue || cur_state == MarkingState::None) {
+      v->mutate()->assign_rvalue_true();
+    }
+  }
+
+  void visit(V<ast_empty_expression> v) override {
+    mark_vertex_cur_or_rvalue(v);
+  }
+  
+  void visit(V<ast_parenthesized_expression> v) override {
+    mark_vertex_cur_or_rvalue(v);
+    parent::visit(v);
+  }
+
+  void visit(V<ast_tensor> v) override {
+    mark_vertex_cur_or_rvalue(v);
+    parent::visit(v);
+  }
+  
+  void visit(V<ast_tensor_square> v) override {
+    mark_vertex_cur_or_rvalue(v);
+    parent::visit(v);
+  }
+
+  void visit(V<ast_identifier> v) override {
+    mark_vertex_cur_or_rvalue(v);
+  }
+
+  void visit(V<ast_int_const> v) override {
+    mark_vertex_cur_or_rvalue(v);
+  }
+
+  void visit(V<ast_string_const> v) override {
+    mark_vertex_cur_or_rvalue(v);
+  }
+
+  void visit(V<ast_bool_const> v) override {
+    mark_vertex_cur_or_rvalue(v);
+  }
+
+  void visit(V<ast_null_keyword> v) override {
+    mark_vertex_cur_or_rvalue(v);
+  }
+
+  void visit(V<ast_self_keyword> v) override {
+    mark_vertex_cur_or_rvalue(v);
+  }
+
+  void visit(V<ast_argument> v) override {
+    mark_vertex_cur_or_rvalue(v);
+    MarkingState saved = enter_state(v->passed_as_mutate ? MarkingState::LValueAndRValue : MarkingState::RValue);
+    parent::visit(v);
+    restore_state(saved);
+  }
+
+  void visit(V<ast_argument_list> v) override {
+    mark_vertex_cur_or_rvalue(v);
+    parent::visit(v);
+  }
+
+  void visit(V<ast_function_call> v) override {
+    mark_vertex_cur_or_rvalue(v);
+    MarkingState saved = enter_state(MarkingState::RValue);
+    parent::visit(v);
+    restore_state(saved);
+  }
+
+  void visit(V<ast_dot_method_call> v) override {
+    mark_vertex_cur_or_rvalue(v);
+    MarkingState saved = enter_state(MarkingState::RValue);
+    parent::visit(v->get_obj());
+    enter_state(MarkingState::RValue);
+    parent::visit(v->get_arg_list());
+    restore_state(saved);
+  }
+
+  void visit(V<ast_underscore> v) override {
+    // underscore is a placeholder to ignore left side of assignment: `(a, _) = get2params()`
+    // so, if current state is "lvalue", `_` will be marked as lvalue, and ok
+    // but if used incorrectly, like `f(_)` or just `_;`, it will be marked rvalue
+    // and will fire an error later, in pipe lvalue/rvalue check
+    mark_vertex_cur_or_rvalue(v);
+  }
+
+  void visit(V<ast_unary_operator> v) override {
+    mark_vertex_cur_or_rvalue(v);
+    MarkingState saved = enter_state(MarkingState::RValue);
+    parent::visit(v);
+    restore_state(saved);
+  }
+
+  void visit(V<ast_binary_operator> v) override {
+    mark_vertex_cur_or_rvalue(v);
+    MarkingState saved = enter_state(v->is_set_assign() ? MarkingState::LValueAndRValue : v->is_assign() ? MarkingState::LValue : MarkingState::RValue);
+    parent::visit(v->get_lhs());
+    enter_state(MarkingState::RValue);
+    parent::visit(v->get_rhs());
+    restore_state(saved);
+  }
+
+  void visit(V<ast_ternary_operator> v) override {
+    mark_vertex_cur_or_rvalue(v);
+    MarkingState saved = enter_state(MarkingState::RValue);
+    parent::visit(v);  // both cond, when_true and when_false are rvalue, `(cond ? a : b) = 5` prohibited
+    restore_state(saved);
+  }
+
+  void visit(V<ast_local_vars_declaration> v) override {
+    MarkingState saved = enter_state(MarkingState::LValue);
+    parent::visit(v->get_lhs());
+    enter_state(MarkingState::RValue);
+    parent::visit(v->get_assigned_val());
+    restore_state(saved);
+  }
+
+  void visit(V<ast_local_var> v) override {
+    tolk_assert(cur_state == MarkingState::LValue);
+    mark_vertex_cur_or_rvalue(v);
+    parent::visit(v);
+  }
+
+  void visit(V<ast_try_catch_statement> v) override {
+    parent::visit(v->get_try_body());
+    MarkingState saved = enter_state(MarkingState::LValue);
+    parent::visit(v->get_catch_expr());
+    restore_state(saved);
+    parent::visit(v->get_catch_body());
+  }
+};
+
+void pipeline_calculate_rvalue_lvalue(const AllSrcFiles& all_src_files) {
+  visit_ast_of_all_functions<CalculateRvalueLvalueVisitor>(all_src_files);
+}
+
+} // namespace tolk

tolk/pipe-check-pure-impure.cpp

@@ -0,0 +1,107 @@
+/*
+    This file is part of TON Blockchain source code.
+
+    TON Blockchain is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License
+    as published by the Free Software Foundation; either version 2
+    of the License, or (at your option) any later version.
+
+    TON Blockchain is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with TON Blockchain.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#include "tolk.h"
+#include "ast.h"
+#include "ast-visitor.h"
+#include "platform-utils.h"
+
+/*
+ *   This pipe checks for impure operations inside pure functions.
+ *   It happens after type inferring (after methods binding) since it operates fun_ref of calls.
+ */
+
+namespace tolk {
+
+GNU_ATTRIBUTE_NORETURN GNU_ATTRIBUTE_COLD
+static void fire_error_impure_operation_inside_pure_function(AnyV v) {
+  v->error("an impure operation in a pure function");
+}
+
+class CheckImpureOperationsInPureFunctionVisitor final : public ASTVisitorFunctionBody {
+  static void fire_if_global_var(AnyExprV v) {
+    if (auto v_ident = v->try_as<ast_identifier>()) {
+      if (v_ident->sym->try_as<GlobalVarData>()) {
+        fire_error_impure_operation_inside_pure_function(v);
+      }
+    }
+  }
+
+  void visit(V<ast_local_var> v) override {
+    if (v->marked_as_redef) {
+      fire_if_global_var(v->get_identifier());
+    }
+  }
+
+  void visit(V<ast_binary_operator> v) override {
+    if (v->is_set_assign() || v->is_assign()) {
+      fire_if_global_var(v->get_lhs());
+    }
+
+    parent::visit(v);
+  }
+
+  void visit(V<ast_function_call> v) override {
+    // most likely it's a global function, but also may be `some_var(args)` or even `getF()(args)`
+    if (!v->fun_maybe) {
+      // calling variables is always impure, no considerations about what's there at runtime
+      fire_error_impure_operation_inside_pure_function(v);
+    }
+
+    if (!v->fun_maybe->is_marked_as_pure()) {
+      fire_error_impure_operation_inside_pure_function(v);
+    }
+
+    parent::visit(v);
+  }
+
+  void visit(V<ast_dot_method_call> v) override {
+    if (!v->fun_ref->is_marked_as_pure()) {
+      fire_error_impure_operation_inside_pure_function(v);
+    }
+
+    parent::visit(v);
+  }
+
+  void visit(V<ast_argument> v) override {
+    if (v->passed_as_mutate) {
+      fire_if_global_var(v->get_expr());
+    }
+
+    parent::visit(v);
+  }
+
+  void visit(V<ast_throw_statement> v) override {
+    fire_error_impure_operation_inside_pure_function(v);
+  }
+
+  void visit(V<ast_assert_statement> v) override {
+    fire_error_impure_operation_inside_pure_function(v);
+  }
+
+public:
+  void start_visiting_function(V<ast_function_declaration> v_function) override {
+    if (v_function->marked_as_pure) {
+      parent::visit(v_function->get_body());
+    }
+  }
+};
+
+void pipeline_check_pure_impure_operations(const AllSrcFiles& all_src_files) {
+  visit_ast_of_all_functions<CheckImpureOperationsInPureFunctionVisitor>(all_src_files);
+}
+
+} // namespace tolk

tolk/pipe-check-rvalue-lvalue.cpp

@@ -0,0 +1,172 @@
+/*
+    This file is part of TON Blockchain source code.
+
+    TON Blockchain is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License
+    as published by the Free Software Foundation; either version 2
+    of the License, or (at your option) any later version.
+
+    TON Blockchain is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with TON Blockchain.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#include "tolk.h"
+#include "ast.h"
+#include "ast-visitor.h"
+#include "platform-utils.h"
+
+/*
+ *   This pipe checks lvalue/rvalue for validity.
+ *   It happens after type inferring (after methods binding) and after lvalue/rvalue are refined based on fun_ref.
+ *
+ *   Example: `f() = 4`, `f()` was earlier marked as lvalue, it's incorrect.
+ *   Example: `f(mutate 5)`, `5` was marked also, it's incorrect.
+ */
+
+namespace tolk {
+
+GNU_ATTRIBUTE_NORETURN GNU_ATTRIBUTE_COLD
+static void fire_error_cannot_be_used_as_lvalue(AnyV v, const std::string& details) {
+  // example: `f() = 32`
+  // example: `loadUint(c.beginParse(), 32)` (since `loadUint()` mutates the first argument)
+  v->error(details + " can not be used as lvalue");
+}
+
+// handle when a function used as rvalue, like `var cb = f`
+static void handle_function_used_as_noncall(AnyExprV v, const FunctionData* fun_ref) {
+  fun_ref->mutate()->assign_is_used_as_noncall();
+  if (!fun_ref->arg_order.empty() || !fun_ref->ret_order.empty()) {
+    v->error("saving `" + fun_ref->name + "` into a variable will most likely lead to invalid usage, since it changes the order of variables on the stack");
+  }
+  if (fun_ref->has_mutate_params()) {
+    v->error("saving `" + fun_ref->name + "` into a variable is impossible, since it has `mutate` parameters and thus can only be called directly");
+  }
+}
+
+class CheckRValueLvalueVisitor final : public ASTVisitorFunctionBody {
+  void visit(V<ast_binary_operator> v) override {
+    if (v->is_lvalue) {
+      fire_error_cannot_be_used_as_lvalue(v, "operator `" + static_cast<std::string>(v->operator_name));
+    }
+    parent::visit(v);
+  }
+
+  void visit(V<ast_unary_operator> v) override {
+    if (v->is_lvalue) {
+      fire_error_cannot_be_used_as_lvalue(v, "operator `" + static_cast<std::string>(v->operator_name));
+    }
+    parent::visit(v);
+  }
+
+  void visit(V<ast_ternary_operator> v) override {
+    if (v->is_lvalue) {
+      fire_error_cannot_be_used_as_lvalue(v, "operator ?:");
+    }
+    parent::visit(v);
+  }
+
+  void visit(V<ast_int_const> v) override {
+    if (v->is_lvalue) {
+      fire_error_cannot_be_used_as_lvalue(v, "literal");
+    }
+  }
+
+  void visit(V<ast_string_const> v) override {
+    if (v->is_lvalue) {
+      fire_error_cannot_be_used_as_lvalue(v, "literal");
+    }
+  }
+
+  void visit(V<ast_bool_const> v) override {
+    if (v->is_lvalue) {
+      fire_error_cannot_be_used_as_lvalue(v, "literal");
+    }
+  }
+
+  void visit(V<ast_null_keyword> v) override {
+    if (v->is_lvalue) {
+      fire_error_cannot_be_used_as_lvalue(v, "literal");
+    }
+  }
+
+  void visit(V<ast_function_call> v) override {
+    if (v->is_lvalue) {
+      fire_error_cannot_be_used_as_lvalue(v, "function call");
+    }
+    if (!v->fun_maybe) {
+      parent::visit(v->get_called_f());
+    }
+    // for `f(...)` don't visit identifier `f`, to detect `f` usage as non-call, like `var cb = f`
+
+    for (int i = 0; i < v->get_num_args(); ++i) {
+      parent::visit(v->get_arg(i));
+    }
+  }
+
+  void visit(V<ast_dot_method_call> v) override {
+    if (v->is_lvalue) {
+      fire_error_cannot_be_used_as_lvalue(v, "method call");
+    }
+
+    parent::visit(v->get_obj());
+
+    for (int i = 0; i < v->get_num_args(); ++i) {
+      parent::visit(v->get_arg(i));
+    }
+  }
+
+  void visit(V<ast_local_var> v) override {
+    if (v->marked_as_redef) {
+      tolk_assert(v->var_maybe);    // always filled, but for `var g_var redef` might point not to a local
+      if (const LocalVarData* var_ref = v->var_maybe->try_as<LocalVarData>(); var_ref && var_ref->is_immutable()) {
+        v->error("`redef` for immutable variable");
+      }
+    }
+  }
+
+  void visit(V<ast_identifier> v) override {
+    if (v->is_lvalue) {
+      tolk_assert(v->sym);
+      if (const auto* var_ref = v->sym->try_as<LocalVarData>(); var_ref && var_ref->is_immutable()) {
+        v->error("modifying immutable variable `" + var_ref->name + "`");
+      } else if (v->sym->try_as<GlobalConstData>()) {
+        v->error("modifying immutable constant");
+      } else if (v->sym->try_as<FunctionData>()) {
+        v->error("function can't be used as lvalue");
+      }
+    }
+
+    // a reference to a function used as rvalue, like `var v = someFunction`
+    if (const FunctionData* fun_ref = v->sym->try_as<FunctionData>(); fun_ref && v->is_rvalue) {
+      handle_function_used_as_noncall(v, fun_ref);
+    }
+  }
+
+  void visit(V<ast_self_keyword> v) override {
+    if (v->is_lvalue && v->param_ref->is_immutable()) {
+      v->error("modifying `self`, which is immutable by default; probably, you want to declare `mutate self`");
+    }
+  }
+
+  void visit(V<ast_underscore> v) override {
+    if (v->is_rvalue) {
+      v->error("`_` can't be used as a value; it's a placeholder for a left side of assignment");
+    }
+  }
+
+  void visit(V<ast_try_catch_statement> v) override {
+    parent::visit(v->get_try_body());
+    // skip catch(_,excNo), there are always vars due to grammar, lvalue/rvalue aren't set to them
+    parent::visit(v->get_catch_body());
+  }
+};
+
+void pipeline_check_rvalue_lvalue(const AllSrcFiles& all_src_files) {
+  visit_ast_of_all_functions<CheckRValueLvalueVisitor>(all_src_files);
+}
+
+} // namespace tolk

tolk/pipe-constant-folding.cpp

@@ -0,0 +1,68 @@
+/*
+    This file is part of TON Blockchain source code.
+
+    TON Blockchain is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License
+    as published by the Free Software Foundation; either version 2
+    of the License, or (at your option) any later version.
+
+    TON Blockchain is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with TON Blockchain.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#include "tolk.h"
+#include "ast.h"
+#include "ast-replacer.h"
+
+/*
+ *   This pipe is supposed to do constant folding, like replacing `2 + 3` with `5`.
+ *   It happens after type inferring and validity checks, one of the last ones.
+ *
+ *   Currently, it just replaces `-1` (ast_unary_operator ast_int_const) with a number -1.
+ *   More rich constant folding should be done some day, but even without this, IR optimizations
+ * (operating low-level stack variables) pretty manage to do all related optimizations.
+ * Constant folding in the future, done at AST level, just would slightly reduce amount of work for optimizer.
+ */
+
+namespace tolk {
+
+class ConstantFoldingReplacer final : public ASTReplacerInFunctionBody {
+  static V<ast_int_const> create_int_const(SrcLocation loc, td::RefInt256&& intval) {
+    auto v_int = createV<ast_int_const>(loc, std::move(intval), {});
+    v_int->assign_inferred_type(TypeExpr::new_atomic(TypeExpr::_Int));
+    v_int->assign_rvalue_true();
+    return v_int;
+  }
+
+  AnyExprV replace(V<ast_unary_operator> v) override {
+    parent::replace(v);
+
+    TokenType t = v->tok;
+    // convert "-1" (tok_minus tok_int_const) to a const -1
+    if (t == tok_minus && v->get_rhs()->type == ast_int_const) {
+      td::RefInt256 intval = v->get_rhs()->as<ast_int_const>()->intval;
+      tolk_assert(!intval.is_null());
+      intval = -intval;
+      if (intval.is_null() || !intval->signed_fits_bits(257)) {
+        v->error("integer overflow");
+      }
+      return create_int_const(v->loc, std::move(intval));
+    }
+    // same for "+1"
+    if (t == tok_plus && v->get_rhs()->type == ast_int_const) {
+      return v->get_rhs();
+    }
+
+    return v;
+  }
+};
+
+void pipeline_constant_folding(const AllSrcFiles& all_src_files) {
+  replace_ast_of_all_functions<ConstantFoldingReplacer>(all_src_files);
+}
+
+} // namespace tolk

tolk/pipe-detect-unreachable.cpp

@@ -0,0 +1,127 @@
+/*
+    This file is part of TON Blockchain source code.
+
+    TON Blockchain is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License
+    as published by the Free Software Foundation; either version 2
+    of the License, or (at your option) any later version.
+
+    TON Blockchain is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with TON Blockchain.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#include "tolk.h"
+#include "ast.h"
+#include "ast-visitor.h"
+
+/*
+ *    This pipe does two things:
+ * 1) detects unreachable code and prints warnings about it
+ *    example: `fun main() { if(1){return;}else{return;} var x = 0; }` — var is unreachable
+ * 2) if control flow reaches end of function, store a flag to insert an implicit return
+ *    example: `fun main() { assert(...); }` — has an implicit `return ()` statement before a brace
+ *
+ *   Note, that it does not delete unreachable code, only prints warnings.
+ *   Actual deleting is done much later (in "legacy" part), after AST is converted to Op.
+ *
+ *   Note, that it's not CFG, it's just a shallow reachability detection.
+ *   In the future, a true CFG should be introduced. For instance, in order to have nullable types,
+ * I'll need to implement smart casts. Then I'll think of a complicated granular control flow graph,
+ * considering data flow and exceptions (built before type inferring, of course),
+ * and detecting unreachable code will be a part of it.
+ */
+
+namespace tolk {
+
+class UnreachableStatementsDetectVisitor final {
+  bool always_returns(AnyV v) {
+    switch (v->type) {
+      case ast_sequence:              return always_returns(v->as<ast_sequence>());
+      case ast_return_statement:      return always_returns(v->as<ast_return_statement>());
+      case ast_throw_statement:       return always_returns(v->as<ast_throw_statement>());
+      case ast_function_call:         return always_returns(v->as<ast_function_call>());
+      case ast_repeat_statement:      return always_returns(v->as<ast_repeat_statement>());
+      case ast_while_statement:       return always_returns(v->as<ast_while_statement>());
+      case ast_do_while_statement:    return always_returns(v->as<ast_do_while_statement>());
+      case ast_try_catch_statement:   return always_returns(v->as<ast_try_catch_statement>());
+      case ast_if_statement:          return always_returns(v->as<ast_if_statement>());
+      default:
+        // unhandled statements (like assert) and statement expressions
+        return false;
+    }
+  }
+
+  bool always_returns(V<ast_sequence> v) {
+    bool always = false;
+    for (AnyV item : v->get_items()) {
+      if (always && item->type != ast_empty_statement) {
+        item->loc.show_warning("unreachable code");
+        break;
+      }
+      always |= always_returns(item);
+    }
+    return always;
+  }
+
+  static bool always_returns([[maybe_unused]] V<ast_return_statement> v) {
+    // quite obvious: `return expr` interrupts control flow
+    return true;
+  }
+
+  static bool always_returns([[maybe_unused]] V<ast_throw_statement> v) {
+    // todo `throw excNo` currently does not interrupt control flow
+    // (in other words, `throw 1; something` - something is reachable)
+    // the reason is that internally it's transformed to a call of built-in function __throw(),
+    // which is a regular function, like __throw_if() or loadInt()
+    // to fix this later on, it should be deeper, introducing Op::_Throw for example,
+    // to make intermediate representations and stack optimizer also be aware that after it there is unreachable
+    return false;
+  }
+
+  static bool always_returns([[maybe_unused]] V<ast_function_call> v) {
+    // neither annotations like @noreturn nor auto-detection of always-throwing functions also doesn't exist
+    // in order to do this in the future, it should be handled not only at AST/CFG level,
+    // but inside Op and low-level optimizer (at least if reachability detection is not moved out of there)
+    // see comments for `throw` above, similar to this case
+    return false;
+  }
+
+  bool always_returns(V<ast_repeat_statement> v) {
+    return always_returns(v->get_body());
+  }
+
+  bool always_returns(V<ast_while_statement> v) {
+    return always_returns(v->get_body());
+  }
+
+  bool always_returns(V<ast_do_while_statement> v) {
+    return always_returns(v->get_body());
+  }
+
+  bool always_returns(V<ast_try_catch_statement> v) {
+    return always_returns(v->get_try_body()) && always_returns(v->get_catch_body());
+  }
+
+  bool always_returns(V<ast_if_statement> v) {
+    return always_returns(v->get_if_body()) && always_returns(v->get_else_body());
+  }
+
+public:
+  void start_visiting_function(V<ast_function_declaration> v_function) {
+    bool control_flow_reaches_end = !always_returns(v_function->get_body()->as<ast_sequence>());
+    if (control_flow_reaches_end) {
+      v_function->fun_ref->mutate()->assign_is_implicit_return();
+    }
+  }
+};
+
+
+void pipeline_detect_unreachable_statements(const AllSrcFiles& all_src_files) {
+  visit_ast_of_all_functions<UnreachableStatementsDetectVisitor>(all_src_files);
+}
+
+} // namespace tolk

tolk/pipe-discover-parse-sources.cpp

@@ -28,6 +28,14 @@
 #include "ast-from-tokens.h"
 #include "compiler-state.h"
 
+/*
+ *   This is the starting point of compilation pipeline.
+ *   It parses Tolk files to AST, analyzes `import` statements and loads/parses imported files.
+ *
+ *   When it finishes, all files have been parsed to AST, and no more files will later be added.
+ *   If a parsing error happens (invalid syntax), an exception is thrown immediately from ast-from-tokens.cpp.
+ */
+
 namespace tolk {
 
 AllSrcFiles pipeline_discover_and_parse_sources(const std::string& stdlib_filename, const std::string& entrypoint_filename) {
@@ -50,7 +58,7 @@ AllSrcFiles pipeline_discover_and_parse_sources(const std::string& stdlib_filena
 
         SrcFile* imported = G.all_src_files.locate_and_register_source_file(rel_filename, v_import->loc);
         file->imports.push_back(SrcFile::ImportStatement{imported});
-        v_import->mutate_set_src_file(imported);
+        v_import->mutate()->assign_src_file(imported);
       }
     }
   }

tolk/pipe-find-unused-symbols.cpp

@@ -24,51 +24,41 @@
     from all source files in the program, then also delete it here.
 */
 #include "tolk.h"
-#include "src-file.h"
 #include "compiler-state.h"
 
 /*
- *   Here we find unused symbols (global functions and variables) to strip them off codegen.
- *   Note, that currently it's implemented as a standalone step after AST has been transformed to legacy Expr/Op.
- * The reason why it's not done on AST level is that symbol resolving is done too late. For instance,
- * having `beginCell()` there is not enough information in AST whether if points to a global function
- * or it's a local variable application.
- *   In the future, this should be done on AST level.
+ *   This pipe finds unused symbols (global functions and variables) to strip them off codegen.
+ *   It happens after converting AST to Op, so it does not traverse AST.
+ *   In the future, when control flow graph is introduced, this should be done at AST level.
  */
 
 namespace tolk {
 
 static void mark_function_used_dfs(const std::unique_ptr<Op>& op);
 
-static void mark_function_used(SymValCodeFunc* func_val) {
-  if (!func_val->code || func_val->is_really_used) { // already handled
+static void mark_function_used(const FunctionData* fun_ref) {
+  if (!fun_ref->is_regular_function() || fun_ref->is_really_used()) { // already handled
     return;
   }
 
-  func_val->is_really_used = true;
-  mark_function_used_dfs(func_val->code->ops);
+  fun_ref->mutate()->assign_is_really_used();
+  mark_function_used_dfs(std::get<FunctionBodyCode*>(fun_ref->body)->code->ops);
 }
 
-static void mark_global_var_used(SymValGlobVar* glob_val) {
-  glob_val->is_really_used = true;
+static void mark_global_var_used(const GlobalVarData* glob_ref) {
+  glob_ref->mutate()->assign_is_really_used();
 }
 
 static void mark_function_used_dfs(const std::unique_ptr<Op>& op) {
   if (!op) {
     return;
   }
-  // op->fun_ref, despite its name, may actually ref global var
-  // note, that for non-calls, e.g. `var a = some_fn` (Op::_Let), some_fn is Op::_GlobVar
-  // (in other words, fun_ref exists not only for direct Op::_Call, but for non-call references also)
-  if (op->fun_ref) {
-    if (auto* func_val = dynamic_cast<SymValCodeFunc*>(op->fun_ref->value)) {
-      mark_function_used(func_val);
-    } else if (auto* glob_val = dynamic_cast<SymValGlobVar*>(op->fun_ref->value)) {
-      mark_global_var_used(glob_val);
-    } else if (auto* asm_val = dynamic_cast<SymValAsmFunc*>(op->fun_ref->value)) {
-    } else {
-      tolk_assert(false);
+
+  if (op->f_sym) {  // for Op::_Call
+    mark_function_used(op->f_sym);
   }
+  if (op->g_sym) {  // for Op::_GlobVar
+    mark_global_var_used(op->g_sym);
   }
   mark_function_used_dfs(op->next);
   mark_function_used_dfs(op->block0);
@@ -76,11 +66,9 @@ static void mark_function_used_dfs(const std::unique_ptr<Op>& op) {
 }
 
 void pipeline_find_unused_symbols() {
-  for (SymDef* func_sym : G.all_code_functions) {
-    auto* func_val = dynamic_cast<SymValCodeFunc*>(func_sym->value);
-    std::string name = G.symbols.get_name(func_sym->sym_idx);
-    if (func_val->method_id.not_null() || func_val->is_entrypoint()) {
-      mark_function_used(func_val);
+  for (const FunctionData* fun_ref : G.all_code_functions) {
+    if (fun_ref->is_method_id_not_empty()) {    // get methods, main and other entrypoints, regular functions with @method_id
+      mark_function_used(fun_ref);
     }
   }
 }

tolk/pipe-generate-fif-output.cpp

@@ -1,5 +1,5 @@
 /*
-    This file is part of TON Blockchain source code.
+    This file is part of TON Blockchain source code->
 
     TON Blockchain is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
@@ -30,107 +30,87 @@
 
 namespace tolk {
 
-bool SymValCodeFunc::does_need_codegen() const {
-  // when a function is declared, but not referenced from code in any way, don't generate its body
-  if (!is_really_used && G.settings.remove_unused_functions) {
-    return false;
-  }
-  // when a function is referenced like `var a = some_fn;` (or in some other non-call way), its continuation should exist
-  if (flags & flagUsedAsNonCall) {
-    return true;
-  }
-  // currently, there is no inlining, all functions are codegenerated
-  // (but actually, unused ones are later removed by Fift)
-  // in the future, we may want to implement a true AST inlining for "simple" functions
-  return true;
-}
-
-void SymValCodeFunc::set_code(CodeBlob* code) {
+void FunctionBodyCode::set_code(CodeBlob* code) {
   this->code = code;
 }
 
-void SymValAsmFunc::set_code(std::vector<AsmOp> code) {
-  this->ext_compile = make_ext_compile(std::move(code));
+void FunctionBodyAsm::set_code(std::vector<AsmOp>&& code) {
+  this->ops = std::move(code);
 }
 
 
-static void generate_output_func(SymDef* func_sym) {
-  SymValCodeFunc* func_val = dynamic_cast<SymValCodeFunc*>(func_sym->value);
-  tolk_assert(func_val);
-  std::string name = G.symbols.get_name(func_sym->sym_idx);
+static void generate_output_func(const FunctionData* fun_ref) {
+  tolk_assert(fun_ref->is_regular_function());
   if (G.is_verbosity(2)) {
-    std::cerr << "\n\n=========================\nfunction " << name << " : " << func_val->get_type() << std::endl;
+    std::cerr << "\n\n=========================\nfunction " << fun_ref->name << " : " << fun_ref->full_type << std::endl;
   }
-  if (!func_val->code) {
-    throw ParseError(func_sym->loc, "function `" + name + "` is just declared, not implemented");
-  } else {
-    CodeBlob& code = *(func_val->code);
+
+  CodeBlob* code = std::get<FunctionBodyCode*>(fun_ref->body)->code;
   if (G.is_verbosity(3)) {
-      code.print(std::cerr, 9);
+    code->print(std::cerr, 9);
   }
-    code.simplify_var_types();
+  code->simplify_var_types();
   if (G.is_verbosity(5)) {
     std::cerr << "after simplify_var_types: \n";
-      code.print(std::cerr, 0);
+    code->print(std::cerr, 0);
   }
-    code.prune_unreachable_code();
+  code->prune_unreachable_code();
   if (G.is_verbosity(5)) {
     std::cerr << "after prune_unreachable: \n";
-      code.print(std::cerr, 0);
+    code->print(std::cerr, 0);
   }
-    code.split_vars(true);
+  code->split_vars(true);
   if (G.is_verbosity(5)) {
     std::cerr << "after split_vars: \n";
-      code.print(std::cerr, 0);
+    code->print(std::cerr, 0);
   }
   for (int i = 0; i < 8; i++) {
-      code.compute_used_code_vars();
+    code->compute_used_code_vars();
     if (G.is_verbosity(4)) {
       std::cerr << "after compute_used_vars: \n";
-        code.print(std::cerr, 6);
+      code->print(std::cerr, 6);
     }
-      code.fwd_analyze();
+    code->fwd_analyze();
     if (G.is_verbosity(5)) {
       std::cerr << "after fwd_analyze: \n";
-        code.print(std::cerr, 6);
+      code->print(std::cerr, 6);
     }
-      code.prune_unreachable_code();
+    code->prune_unreachable_code();
     if (G.is_verbosity(5)) {
       std::cerr << "after prune_unreachable: \n";
-        code.print(std::cerr, 6);
+      code->print(std::cerr, 6);
     }
   }
-    code.mark_noreturn();
+  code->mark_noreturn();
   if (G.is_verbosity(3)) {
-      code.print(std::cerr, 15);
+    code->print(std::cerr, 15);
   }
   if (G.is_verbosity(2)) {
-      std::cerr << "\n---------- resulting code for " << name << " -------------\n";
+    std::cerr << "\n---------- resulting code for " << fun_ref->name << " -------------\n";
   }
   const char* modifier = "";
-    if (func_val->is_inline()) {
+  if (fun_ref->is_inline()) {
     modifier = "INLINE";
-    } else if (func_val->is_inline_ref()) {
+  } else if (fun_ref->is_inline_ref()) {
     modifier = "REF";
   }
-    std::cout << std::string(2, ' ') << name << " PROC" << modifier << ":<{\n";
+  std::cout << std::string(2, ' ') << fun_ref->name << " PROC" << modifier << ":<{\n";
   int mode = 0;
   if (G.settings.stack_layout_comments) {
     mode |= Stack::_StkCmt | Stack::_CptStkCmt;
   }
-    if (func_val->is_inline() && code.ops->noreturn()) {
+  if (fun_ref->is_inline() && code->ops->noreturn()) {
     mode |= Stack::_InlineFunc;
   }
-    if (func_val->is_inline() || func_val->is_inline_ref()) {
+  if (fun_ref->is_inline() || fun_ref->is_inline_ref()) {
     mode |= Stack::_InlineAny;
   }
-    code.generate_code(std::cout, mode, 2);
+  code->generate_code(std::cout, mode, 2);
   std::cout << std::string(2, ' ') << "}>\n";
   if (G.is_verbosity(2)) {
     std::cerr << "--------------\n";
   }
 }
-}
 
 void pipeline_generate_fif_output_to_std_cout(const AllSrcFiles& all_src_files) {
   std::cout << "\"Asm.fif\" include\n";
@@ -149,26 +129,23 @@ void pipeline_generate_fif_output_to_std_cout(const AllSrcFiles& all_src_files)
   std::cout << "PROGRAM{\n";
 
   bool has_main_procedure = false;
-  for (SymDef* func_sym : G.all_code_functions) {
-    SymValCodeFunc* func_val = dynamic_cast<SymValCodeFunc*>(func_sym->value);
-    tolk_assert(func_val);
-    if (!func_val->does_need_codegen()) {
+  for (const FunctionData* fun_ref : G.all_code_functions) {
+    if (!fun_ref->does_need_codegen()) {
       if (G.is_verbosity(2)) {
-        std::cerr << func_sym->name() << ": code not generated, function does not need codegen\n";
+        std::cerr << fun_ref->name << ": code not generated, function does not need codegen\n";
       }
       continue;
     }
 
-    std::string name = G.symbols.get_name(func_sym->sym_idx);
-    if (func_val->is_entrypoint() && (name == "main" || name == "onInternalMessage")) {
+    if (fun_ref->is_entrypoint() && (fun_ref->name == "main" || fun_ref->name == "onInternalMessage")) {
       has_main_procedure = true;
     }
 
     std::cout << std::string(2, ' ');
-    if (func_val->method_id.is_null()) {
-      std::cout << "DECLPROC " << name << "\n";
+    if (fun_ref->is_method_id_not_empty()) {
+      std::cout << fun_ref->method_id << " DECLMETHOD " << fun_ref->name << "\n";
     } else {
-      std::cout << func_val->method_id << " DECLMETHOD " << name << "\n";
+      std::cout << "DECLPROC " << fun_ref->name << "\n";
     }
   }
 
@@ -176,25 +153,22 @@ void pipeline_generate_fif_output_to_std_cout(const AllSrcFiles& all_src_files)
     throw Fatal("the contract has no entrypoint; forgot `fun onInternalMessage(...)`?");
   }
 
-  for (SymDef* gvar_sym : G.all_global_vars) {
-    auto* glob_val = dynamic_cast<SymValGlobVar*>(gvar_sym->value);
-    tolk_assert(glob_val);
-    if (!glob_val->is_really_used && G.settings.remove_unused_functions) {
+  for (const GlobalVarData* var_ref : G.all_global_vars) {
+    if (!var_ref->is_really_used() && G.settings.remove_unused_functions) {
       if (G.is_verbosity(2)) {
-        std::cerr << gvar_sym->name() << ": variable not generated, it's unused\n";
+        std::cerr << var_ref->name << ": variable not generated, it's unused\n";
       }
       continue;
     }
-    std::string name = G.symbols.get_name(gvar_sym->sym_idx);
-    std::cout << std::string(2, ' ') << "DECLGLOBVAR " << name << "\n";
-  }
 
-  for (SymDef* func_sym : G.all_code_functions) {
-    SymValCodeFunc* func_val = dynamic_cast<SymValCodeFunc*>(func_sym->value);
-    if (!func_val->does_need_codegen()) {
+    std::cout << std::string(2, ' ') << "DECLGLOBVAR " << var_ref->name << "\n";
+  }
+
+  for (const FunctionData* fun_ref : G.all_code_functions) {
+    if (!fun_ref->does_need_codegen()) {
       continue;
     }
-    generate_output_func(func_sym);
+    generate_output_func(fun_ref);
   }
 
   std::cout << "}END>c\n";

tolk/pipe-infer-check-types.cpp

@@ -0,0 +1,524 @@
+/*
+    This file is part of TON Blockchain Library.
+
+    TON Blockchain Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 2 of the License, or
+    (at your option) any later version.
+
+    TON Blockchain Library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with TON Blockchain Library.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#include "tolk.h"
+#include "src-file.h"
+#include "ast.h"
+#include "ast-visitor.h"
+
+/*
+ *   This pipe does type inferring.
+ *   It will be fully rewritten, because current type system is based on Hindley-Milner (unifying usages),
+ * and I am going to introduce a static type system, drop TypeExpr completely, etc.
+ *   Currently, after this inferring, lots of `te_Indirect` and partially complete types still exist,
+ * whey are partially refined during converting AST to legacy.
+ */
+
+namespace tolk {
+
+class InferAndCheckTypesInsideFunctionVisitor final : public ASTVisitorFunctionBody {
+  const FunctionData* current_function = nullptr;
+
+  static bool expect_integer(TypeExpr* inferred) {
+    try {
+      TypeExpr* t_int = TypeExpr::new_atomic(TypeExpr::_Int);
+      unify(inferred, t_int);
+      return true;
+    } catch (UnifyError&) {
+      return false;
+    }
+  }
+
+  static bool expect_integer(AnyExprV v_inferred) {
+    return expect_integer(v_inferred->inferred_type);
+  }
+
+  static bool is_expr_valid_as_return_self(AnyExprV return_expr) {
+    // `return self`
+    if (return_expr->type == ast_self_keyword) {
+      return true;
+    }
+    // `return self.someMethod()`
+    if (auto v_call = return_expr->try_as<ast_dot_method_call>()) {
+      return v_call->fun_ref->does_return_self() && is_expr_valid_as_return_self(v_call->get_obj());
+    }
+    // `return cond ? ... : ...`
+    if (auto v_ternary = return_expr->try_as<ast_ternary_operator>()) {
+      return is_expr_valid_as_return_self(v_ternary->get_when_true()) && is_expr_valid_as_return_self(v_ternary->get_when_false());
+    }
+    return false;
+  }
+
+  void visit(V<ast_parenthesized_expression> v) override {
+    parent::visit(v->get_expr());
+    v->mutate()->assign_inferred_type(v->get_expr()->inferred_type);
+  }
+
+  void visit(V<ast_tensor> v) override {
+    if (v->empty()) {
+      v->mutate()->assign_inferred_type(TypeExpr::new_unit());
+      return;
+    }
+    std::vector<TypeExpr*> types_list;
+    types_list.reserve(v->get_items().size());
+    for (AnyExprV item : v->get_items()) {
+      parent::visit(item);
+      types_list.emplace_back(item->inferred_type);
+    }
+    v->mutate()->assign_inferred_type(TypeExpr::new_tensor(std::move(types_list)));
+  }
+
+  void visit(V<ast_tensor_square> v) override {
+    if (v->empty()) {
+      v->mutate()->assign_inferred_type(TypeExpr::new_tuple(TypeExpr::new_unit()));
+      return;
+    }
+    std::vector<TypeExpr*> types_list;
+    types_list.reserve(v->get_items().size());
+    for (AnyExprV item : v->get_items()) {
+      parent::visit(item);
+      types_list.emplace_back(item->inferred_type);
+    }
+    v->mutate()->assign_inferred_type(TypeExpr::new_tuple(TypeExpr::new_tensor(std::move(types_list), false)));
+  }
+
+  void visit(V<ast_identifier> v) override {
+    if (const auto* glob_ref = v->sym->try_as<GlobalVarData>()) {
+      v->mutate()->assign_inferred_type(glob_ref->declared_type);
+    } else if (const auto* const_ref = v->sym->try_as<GlobalConstData>()) {
+      v->mutate()->assign_inferred_type(const_ref->inferred_type);
+    } else if (const auto* fun_ref = v->sym->try_as<FunctionData>()) {
+      v->mutate()->assign_inferred_type(fun_ref->full_type);
+    } else if (const auto* var_ref = v->sym->try_as<LocalVarData>()) {
+      v->mutate()->assign_inferred_type(var_ref->declared_type);
+    }
+  }
+
+  void visit(V<ast_int_const> v) override {
+    v->mutate()->assign_inferred_type(TypeExpr::new_atomic(TypeExpr::_Int));
+  }
+
+  void visit(V<ast_string_const> v) override {
+    switch (v->modifier) {
+      case 0:
+      case 's':
+      case 'a':
+        v->mutate()->assign_inferred_type(TypeExpr::new_atomic(TypeExpr::_Slice));
+        break;
+      case 'u':
+      case 'h':
+      case 'H':
+      case 'c':
+        v->mutate()->assign_inferred_type(TypeExpr::new_atomic(TypeExpr::_Int));
+        break;
+      default:
+        break;
+    }
+  }
+
+  void visit(V<ast_bool_const> v) override {
+    v->mutate()->assign_inferred_type(TypeExpr::new_atomic(TypeExpr::_Int));
+  }
+
+  void visit(V<ast_null_keyword> v) override {
+    const FunctionData* fun_ref = lookup_global_symbol("__null")->as<FunctionData>();
+    TypeExpr* fun_type = TypeExpr::new_map(TypeExpr::new_unit(), TypeExpr::new_hole());
+    TypeExpr* sym_type = fun_ref->full_type;
+    try {
+      unify(fun_type, sym_type);
+    } catch (UnifyError& ue) {
+      std::ostringstream os;
+      os << "cannot apply function " << fun_ref->name << " : " << fun_ref->full_type << " to arguments of type "
+         << fun_type->args[0] << ": " << ue;
+      v->error(os.str());
+    }
+    TypeExpr* e_type = fun_type->args[1];
+    TypeExpr::remove_indirect(e_type);
+    v->mutate()->assign_inferred_type(e_type);
+  }
+
+  void visit(V<ast_self_keyword> v) override {
+    v->mutate()->assign_inferred_type(v->param_ref->declared_type);
+  }
+
+  void visit(V<ast_argument> v) override {
+    parent::visit(v->get_expr());
+    v->mutate()->assign_inferred_type(v->get_expr()->inferred_type);
+  }
+
+  void visit(V<ast_argument_list> v) override {
+    if (v->empty()) {
+      v->mutate()->assign_inferred_type(TypeExpr::new_unit());
+      return;
+    }
+    std::vector<TypeExpr*> types_list;
+    types_list.reserve(v->size());
+    for (AnyExprV item : v->get_arguments()) {
+      parent::visit(item);
+      types_list.emplace_back(item->inferred_type);
+    }
+    v->mutate()->assign_inferred_type(TypeExpr::new_tensor(std::move(types_list)));
+  }
+
+  void visit(V<ast_function_call> v) override {
+    // special error for "null()" which is a FunC syntax
+    if (v->get_called_f()->type == ast_null_keyword) {
+      v->error("null is not a function: use `null`, not `null()`");
+    }
+
+    parent::visit(v->get_called_f());
+    visit(v->get_arg_list());
+
+    // most likely it's a global function, but also may be `some_var(args)` or even `getF()(args)`
+    const FunctionData* fun_ref = v->fun_maybe;
+    if (!fun_ref) {
+      TypeExpr* arg_tensor = v->get_arg_list()->inferred_type;
+      TypeExpr* lhs_type = v->get_called_f()->inferred_type;
+      TypeExpr* fun_type = TypeExpr::new_map(arg_tensor, TypeExpr::new_hole());
+      try {
+        unify(fun_type, lhs_type);
+      } catch (UnifyError& ue) {
+        std::ostringstream os;
+        os << "cannot apply expression of type " << lhs_type << " to an expression of type " << arg_tensor
+           << ": " << ue;
+        v->error(os.str());
+      }
+      TypeExpr* e_type = fun_type->args[1];
+      TypeExpr::remove_indirect(e_type);
+      v->mutate()->assign_inferred_type(e_type);
+      return;
+    }
+
+    TypeExpr* arg_tensor = v->get_arg_list()->inferred_type;
+    TypeExpr* fun_type = TypeExpr::new_map(arg_tensor, TypeExpr::new_hole());
+    TypeExpr* sym_type = fun_ref->full_type;
+    try {
+      unify(fun_type, sym_type);
+    } catch (UnifyError& ue) {
+      std::ostringstream os;
+      os << "cannot apply function " << fun_ref->name << " : " << fun_ref->full_type << " to arguments of type "
+         << fun_type->args[0] << ": " << ue;
+      v->error(os.str());
+    }
+    TypeExpr* e_type = fun_type->args[1];
+    TypeExpr::remove_indirect(e_type);
+
+    if (fun_ref->has_mutate_params()) {
+      tolk_assert(e_type->constr == TypeExpr::te_Tensor);
+      e_type = e_type->args[e_type->args.size() - 1];
+    }
+
+    v->mutate()->assign_inferred_type(e_type);
+  }
+  
+  void visit(V<ast_dot_method_call> v) override {
+    parent::visit(v->get_obj());
+    visit(v->get_arg_list());
+    std::vector<TypeExpr*> arg_types;
+    arg_types.reserve(1 + v->get_num_args());
+    arg_types.push_back(v->get_obj()->inferred_type);
+    for (int i = 0; i < v->get_num_args(); ++i) {
+      arg_types.push_back(v->get_arg(i)->inferred_type);
+    }
+
+    TypeExpr* arg_tensor = TypeExpr::new_tensor(std::move(arg_types));
+    TypeExpr* fun_type = TypeExpr::new_map(arg_tensor, TypeExpr::new_hole());
+    TypeExpr* sym_type = v->fun_ref->full_type;
+    try {
+      unify(fun_type, sym_type);
+    } catch (UnifyError& ue) {
+      std::ostringstream os;
+      os << "cannot apply function " << v->fun_ref->name << " : " << v->fun_ref->full_type << " to arguments of type "
+         << fun_type->args[0] << ": " << ue;
+      v->error(os.str());
+    }
+    TypeExpr* e_type = fun_type->args[1];
+    TypeExpr::remove_indirect(e_type);
+
+    if (v->fun_ref->has_mutate_params()) {
+      tolk_assert(e_type->constr == TypeExpr::te_Tensor);
+      e_type = e_type->args[e_type->args.size() - 1];
+    }
+    if (v->fun_ref->does_return_self()) {
+      e_type = v->get_obj()->inferred_type;
+      TypeExpr::remove_indirect(e_type);
+    }
+
+    v->mutate()->assign_inferred_type(e_type);
+  }
+
+  void visit(V<ast_underscore> v) override {
+    v->mutate()->assign_inferred_type(TypeExpr::new_hole());
+  }
+
+  void visit(V<ast_unary_operator> v) override {
+    parent::visit(v->get_rhs());
+    if (!expect_integer(v->get_rhs())) {
+      v->error("operator `" + static_cast<std::string>(v->operator_name) + "` expects integer operand");
+    }
+    v->mutate()->assign_inferred_type(TypeExpr::new_atomic(TypeExpr::_Int));
+  }
+
+  void visit(V<ast_binary_operator> v) override {
+    parent::visit(v->get_lhs());
+    parent::visit(v->get_rhs());
+    switch (v->tok) {
+      case tok_assign: {
+        TypeExpr* lhs_type = v->get_lhs()->inferred_type;
+        TypeExpr* rhs_type = v->get_rhs()->inferred_type;
+        try {
+          unify(lhs_type, rhs_type);
+        } catch (UnifyError& ue) {
+          std::ostringstream os;
+          os << "cannot assign an expression of type " << rhs_type << " to a variable or pattern of type "
+             << lhs_type << ": " << ue;
+          v->error(os.str());
+        }
+        TypeExpr* e_type = lhs_type;
+        TypeExpr::remove_indirect(e_type);
+        v->mutate()->assign_inferred_type(e_type);
+        break;
+      }
+      case tok_eq:
+      case tok_neq:
+      case tok_spaceship: {
+        if (!expect_integer(v->get_lhs()) || !expect_integer(v->get_rhs())) {
+          v->error("comparison operators `== !=` can compare only integers");
+        }
+        v->mutate()->assign_inferred_type(TypeExpr::new_atomic(TypeExpr::_Int));
+        break;
+      }
+      case tok_logical_and:
+      case tok_logical_or: {
+        if (!expect_integer(v->get_lhs()) || !expect_integer(v->get_rhs())) {
+          v->error("logical operators `&& ||` expect integer operands");
+        }
+        v->mutate()->assign_inferred_type(TypeExpr::new_atomic(TypeExpr::_Int));
+        break;
+      }
+      default:
+        if (!expect_integer(v->get_lhs()) || !expect_integer(v->get_rhs())) {
+          v->error("operator `" + static_cast<std::string>(v->operator_name) + "` expects integer operands");
+        }
+        v->mutate()->assign_inferred_type(TypeExpr::new_atomic(TypeExpr::_Int));
+    }
+  }
+
+  void visit(V<ast_ternary_operator> v) override {
+    parent::visit(v->get_cond());
+    if (!expect_integer(v->get_cond())) {
+      v->get_cond()->error("condition of ternary ?: operator must be an integer");
+    }
+    parent::visit(v->get_when_true());
+    parent::visit(v->get_when_false());
+
+    TypeExpr* res = TypeExpr::new_hole();
+    TypeExpr *ttrue = v->get_when_true()->inferred_type;
+    TypeExpr *tfals = v->get_when_false()->inferred_type;
+    unify(res, ttrue);
+    unify(res, tfals);
+    v->mutate()->assign_inferred_type(res);
+  }
+
+  void visit(V<ast_if_statement> v) override {
+    parent::visit(v->get_cond());
+    parent::visit(v->get_if_body());
+    parent::visit(v->get_else_body());
+    TypeExpr* flag_type = TypeExpr::new_atomic(TypeExpr::_Int);
+    TypeExpr* cond_type = v->get_cond()->inferred_type;
+    try {
+      
+      unify(cond_type, flag_type);
+    } catch (UnifyError& ue) {
+      std::ostringstream os;
+      os << "`if` condition value of type " << cond_type << " is not an integer: " << ue;
+      v->get_cond()->error(os.str());
+    }
+    v->get_cond()->mutate()->assign_inferred_type(cond_type);
+  }
+
+  void visit(V<ast_repeat_statement> v) override {
+    parent::visit(v->get_cond());
+    parent::visit(v->get_body());
+    TypeExpr* cnt_type = TypeExpr::new_atomic(TypeExpr::_Int);
+    TypeExpr* cond_type = v->get_cond()->inferred_type;
+    try {
+      unify(cond_type, cnt_type);
+    } catch (UnifyError& ue) {
+      std::ostringstream os;
+      os << "repeat count value of type " << cond_type << " is not an integer: " << ue;
+      v->get_cond()->error(os.str());
+    }
+    v->get_cond()->mutate()->assign_inferred_type(cond_type);
+  }
+
+  void visit(V<ast_while_statement> v) override {
+    parent::visit(v->get_cond());
+    parent::visit(v->get_body());
+    TypeExpr* cnt_type = TypeExpr::new_atomic(TypeExpr::_Int);
+    TypeExpr* cond_type = v->get_cond()->inferred_type;
+    try {
+      unify(cond_type, cnt_type);
+    } catch (UnifyError& ue) {
+      std::ostringstream os;
+      os << "`while` condition value of type " << cond_type << " is not an integer: " << ue;
+      v->get_cond()->error(os.str());
+    }
+    v->get_cond()->mutate()->assign_inferred_type(cond_type);
+  }
+
+  void visit(V<ast_do_while_statement> v) override {
+    parent::visit(v->get_body());
+    parent::visit(v->get_cond());
+    TypeExpr* cnt_type = TypeExpr::new_atomic(TypeExpr::_Int);
+    TypeExpr* cond_type = v->get_cond()->inferred_type;
+    try {
+      unify(cond_type, cnt_type);
+    } catch (UnifyError& ue) {
+      std::ostringstream os;
+      os << "`while` condition value of type " << cond_type << " is not an integer: " << ue;
+      v->get_cond()->error(os.str());
+    }
+    v->get_cond()->mutate()->assign_inferred_type(cond_type);
+  }
+
+  void visit(V<ast_return_statement> v) override {
+    parent::visit(v->get_return_value());
+    if (current_function->does_return_self()) {
+      if (!is_expr_valid_as_return_self(v->get_return_value())) {
+        v->error("invalid return from `self` function");
+      }
+      return;
+    }
+    TypeExpr* expr_type = v->get_return_value()->inferred_type;
+    TypeExpr* ret_type = current_function->full_type;
+    if (ret_type->constr == TypeExpr::te_ForAll) {
+      ret_type = ret_type->args[0];
+    }
+    tolk_assert(ret_type->constr == TypeExpr::te_Map);
+    ret_type = ret_type->args[1];
+    if (current_function->has_mutate_params()) {
+      tolk_assert(ret_type->constr == TypeExpr::te_Tensor);
+      ret_type = ret_type->args[ret_type->args.size() - 1];
+    }
+    try {
+      unify(expr_type, ret_type);
+    } catch (UnifyError& ue) {
+      std::ostringstream os;
+      os << "previous function return type " << ret_type
+         << " cannot be unified with return statement expression type " << expr_type << ": " << ue;
+      v->error(os.str());
+    }
+  }
+
+  void visit(V<ast_local_var> v) override {
+    if (v->var_maybe) {  // not underscore
+      if (const auto* var_ref = v->var_maybe->try_as<LocalVarData>()) {
+        v->mutate()->assign_inferred_type(var_ref->declared_type);
+      } else if (const auto* glob_ref = v->var_maybe->try_as<GlobalVarData>()) {
+        v->mutate()->assign_inferred_type(glob_ref->declared_type);
+      } else {
+        tolk_assert(0);
+      }
+    } else if (v->declared_type) {  // underscore with type
+      v->mutate()->assign_inferred_type(v->declared_type);
+    } else {  // just underscore
+      v->mutate()->assign_inferred_type(TypeExpr::new_hole());
+    }
+    v->get_identifier()->mutate()->assign_inferred_type(v->inferred_type);
+  }
+
+  void visit(V<ast_local_vars_declaration> v) override {
+    parent::visit(v->get_lhs());
+    parent::visit(v->get_assigned_val());
+    TypeExpr* lhs = v->get_lhs()->inferred_type;
+    TypeExpr* rhs = v->get_assigned_val()->inferred_type;
+    try {
+      unify(lhs, rhs);
+    } catch (UnifyError& ue) {
+      std::ostringstream os;
+      os << "cannot assign an expression of type " << rhs << " to a variable or pattern of type " << lhs << ": " << ue;
+      v->error(os.str());
+    }
+  }
+
+  void visit(V<ast_try_catch_statement> v) override {
+    parent::visit(v->get_try_body());
+    parent::visit(v->get_catch_expr());
+
+    TypeExpr* tvm_error_type = TypeExpr::new_tensor(TypeExpr::new_var(), TypeExpr::new_atomic(TypeExpr::_Int));
+    tolk_assert(v->get_catch_expr()->size() == 2);
+    TypeExpr* type1 = v->get_catch_expr()->get_item(0)->inferred_type;
+    unify(type1, tvm_error_type->args[1]);
+    TypeExpr* type2 = v->get_catch_expr()->get_item(1)->inferred_type;
+    unify(type2, tvm_error_type->args[0]);
+
+    parent::visit(v->get_catch_body());
+  }
+
+  void visit(V<ast_throw_statement> v) override {
+    parent::visit(v->get_thrown_code());
+    if (!expect_integer(v->get_thrown_code())) {
+      v->get_thrown_code()->error("excNo of `throw` must be an integer");
+    }
+    if (v->has_thrown_arg()) {
+      parent::visit(v->get_thrown_arg());
+    }
+  }
+  
+  void visit(V<ast_assert_statement> v) override {
+    parent::visit(v->get_cond());
+    if (!expect_integer(v->get_cond())) {
+      v->get_cond()->error("condition of `assert` must be an integer");
+    }
+    parent::visit(v->get_thrown_code());
+  }
+
+public:
+  void start_visiting_function(V<ast_function_declaration> v_function) override {
+    current_function = v_function->fun_ref;
+    parent::visit(v_function->get_body());
+    if (current_function->is_implicit_return()) {
+      if (current_function->does_return_self()) {
+        throw ParseError(v_function->get_body()->as<ast_sequence>()->loc_end, "missing return; forgot `return self`?");
+      }
+      TypeExpr* expr_type = TypeExpr::new_unit();
+      TypeExpr* ret_type = current_function->full_type;
+      if (ret_type->constr == TypeExpr::te_ForAll) {
+        ret_type = ret_type->args[0];
+      }
+      tolk_assert(ret_type->constr == TypeExpr::te_Map);
+      ret_type = ret_type->args[1];
+      if (current_function->has_mutate_params()) {
+        ret_type = ret_type->args[ret_type->args.size() - 1];
+      }
+      try {
+        unify(expr_type, ret_type);
+      } catch (UnifyError& ue) {
+        std::ostringstream os;
+        os << "implicit function return type " << expr_type
+           << " cannot be unified with inferred return type " << ret_type << ": " << ue;
+        v_function->error(os.str());
+      }
+    }
+  }
+};
+
+void pipeline_infer_and_check_types(const AllSrcFiles& all_src_files) {
+  visit_ast_of_all_functions<InferAndCheckTypesInsideFunctionVisitor>(all_src_files);
+}
+
+} // namespace tolk

tolk/pipe-refine-lvalue-for-mutate.cpp

@@ -0,0 +1,118 @@
+/*
+    This file is part of TON Blockchain source code.
+
+    TON Blockchain is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License
+    as published by the Free Software Foundation; either version 2
+    of the License, or (at your option) any later version.
+
+    TON Blockchain is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with TON Blockchain.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#include "tolk.h"
+#include "ast.h"
+#include "ast-visitor.h"
+
+/*
+ *   This pipe refines rvalue/lvalue and checks `mutate` arguments validity.
+ *   It happens after type inferring (after methods binding), because it uses fun_ref of calls.
+ *
+ *   Example: `a.increment().increment()`, the first `a.increment()` becomes lvalue (assume that increment mutates self).
+ *   Example: `increment(a)` is invalid, should be `increment(mutate a)`.
+ *
+ *   Note, that explicitly specifying `mutate` for arguments, like `increment(mutate a)` is on purpose.
+ * If we wished `increment(a)` to be valid (to work and mutate `a`, like passing by ref), it would also be done here,
+ * refining `a` to be lvalue. But to avoid unexpected mutations, `mutate` keyword for an argument is required.
+ * So, for mutated arguments, instead of setting lvalue, we check its presence.
+ */
+
+namespace tolk {
+
+GNU_ATTRIBUTE_NORETURN GNU_ATTRIBUTE_COLD
+static void fire_error_invalid_mutate_arg_passed(AnyV v, const FunctionData* fun_ref, const LocalVarData& p_sym, bool called_as_method, bool arg_passed_as_mutate, AnyV arg_expr) {
+  std::string arg_str(arg_expr->type == ast_identifier ? arg_expr->as<ast_identifier>()->name : "obj");
+
+  // case: `loadInt(cs, 32)`; suggest: `cs.loadInt(32)`
+  if (p_sym.is_mutate_parameter() && !arg_passed_as_mutate && !called_as_method && p_sym.idx == 0 && fun_ref->does_accept_self()) {
+    v->error("`" + fun_ref->name + "` is a mutating method; consider calling `" + arg_str + "." + fun_ref->name + "()`, not `" + fun_ref->name + "(" + arg_str + ")`");
+  }
+  // case: `cs.mutating_function()`; suggest: `mutating_function(mutate cs)` or make it a method
+  if (p_sym.is_mutate_parameter() && called_as_method && p_sym.idx == 0 && !fun_ref->does_accept_self()) {
+    v->error("function `" + fun_ref->name + "` mutates parameter `" + p_sym.name + "`; consider calling `" + fun_ref->name + "(mutate " + arg_str + ")`, not `" + arg_str + "." + fun_ref->name + "`(); alternatively, rename parameter to `self` to make it a method");
+  }
+  // case: `mutating_function(arg)`; suggest: `mutate arg`
+  if (p_sym.is_mutate_parameter() && !arg_passed_as_mutate) {
+    v->error("function `" + fun_ref->name + "` mutates parameter `" + p_sym.name + "`; you need to specify `mutate` when passing an argument, like `mutate " + arg_str + "`");
+  }
+  // case: `usual_function(mutate arg)`
+  if (!p_sym.is_mutate_parameter() && arg_passed_as_mutate) {
+    v->error("incorrect `mutate`, since `" + fun_ref->name + "` does not mutate this parameter");
+  }
+  throw Fatal("unreachable");
+}
+
+
+class RefineLvalueForMutateArgumentsVisitor final : public ASTVisitorFunctionBody {
+  void visit(V<ast_function_call> v) override {
+    // most likely it's a global function, but also may be `some_var(args)` or even `getF()(args)`
+    const FunctionData* fun_ref = v->fun_maybe;
+    if (!fun_ref) {
+      parent::visit(v);
+      for (int i = 0; i < v->get_num_args(); ++i) {
+        auto v_arg = v->get_arg(i);
+        if (v_arg->passed_as_mutate) {
+          v_arg->error("`mutate` used for non-mutate argument");
+        }
+      }
+      return;
+    }
+
+    tolk_assert(static_cast<int>(fun_ref->parameters.size()) == v->get_num_args());
+
+    for (int i = 0; i < v->get_num_args(); ++i) {
+      const LocalVarData& p_sym = fun_ref->parameters[i];
+      auto arg_i = v->get_arg(i);
+      if (p_sym.is_mutate_parameter() != arg_i->passed_as_mutate) {
+        fire_error_invalid_mutate_arg_passed(arg_i, fun_ref, p_sym, false, arg_i->passed_as_mutate, arg_i->get_expr());
+      }
+      parent::visit(arg_i);
+    }
+  }
+
+  void visit(V<ast_dot_method_call> v) override {
+    parent::visit(v);
+
+    const FunctionData* fun_ref = v->fun_ref;
+    tolk_assert(static_cast<int>(fun_ref->parameters.size()) == 1 + v->get_num_args());
+
+    if (fun_ref->does_mutate_self()) {
+      bool will_be_extracted_as_tmp_var = v->get_obj()->type == ast_function_call || v->get_obj()->type == ast_dot_method_call;
+      if (!will_be_extracted_as_tmp_var) {
+        v->get_obj()->mutate()->assign_lvalue_true();
+      }
+    }
+
+    if (!fun_ref->does_accept_self() && fun_ref->parameters[0].is_mutate_parameter()) {
+      fire_error_invalid_mutate_arg_passed(v, fun_ref, fun_ref->parameters[0], true, false, v->get_obj());
+    }
+
+    for (int i = 0; i < v->get_num_args(); ++i) {
+      const LocalVarData& p_sym = fun_ref->parameters[1 + i];
+      auto arg_i = v->get_arg(i);
+      if (p_sym.is_mutate_parameter() != arg_i->passed_as_mutate) {
+        fire_error_invalid_mutate_arg_passed(arg_i, fun_ref, p_sym, false, arg_i->passed_as_mutate, arg_i->get_expr());
+      }
+    }
+  }
+};
+
+void pipeline_refine_lvalue_for_mutate_arguments(const AllSrcFiles& all_src_files) {
+  visit_ast_of_all_functions<RefineLvalueForMutateArgumentsVisitor>(all_src_files);
+}
+
+} // namespace tolk

tolk/pipe-register-symbols.cpp

@@ -13,65 +13,50 @@
 
     You should have received a copy of the GNU General Public License
     along with TON Blockchain.  If not, see <http://www.gnu.org/licenses/>.
-
-    In addition, as a special exception, the copyright holders give permission
-    to link the code of portions of this program with the OpenSSL library.
-    You must obey the GNU General Public License in all respects for all
-    of the code used other than OpenSSL. If you modify file(s) with this
-    exception, you may extend this exception to your version of the file(s),
-    but you are not obligated to do so. If you do not wish to do so, delete this
-    exception statement from your version. If you delete this exception statement
-    from all source files in the program, then also delete it here.
 */
 #include "tolk.h"
 #include "platform-utils.h"
 #include "src-file.h"
 #include "ast.h"
 #include "compiler-state.h"
+#include "constant-evaluator.h"
 #include "td/utils/crypto.h"
 #include <unordered_set>
 
+/*
+ *   This pipe registers global symbols: functions, constants, global vars, etc.
+ *   It happens just after all files have been parsed to AST.
+ *
+ *   "Registering" means adding symbols to a global symbol table.
+ *   After this pass, any global symbol can be looked up.
+ *   Note, that local variables are not analyzed here, it's a later step.
+ * Before digging into locals, we need a global symtable to be filled, exactly done here.
+ */
+
 namespace tolk {
 
-Expr* process_expr(AnyV v, CodeBlob& code);
-
-GNU_ATTRIBUTE_NORETURN GNU_ATTRIBUTE_COLD
-static void fire_error_redefinition_of_symbol(V<ast_identifier> v_ident, SymDef* existing) {
-  if (existing->loc.is_stdlib()) {
-    v_ident->error("redefinition of a symbol from stdlib");
-  } else if (existing->loc.is_defined()) {
-    v_ident->error("redefinition of symbol, previous was at: " + existing->loc.to_string());
-  } else {
-    v_ident->error("redefinition of built-in symbol");
-  }
-}
-
-static int calc_sym_idx(std::string_view sym_name) {
-  return G.symbols.lookup_add(sym_name);
-}
-
-static td::RefInt256 calculate_method_id_for_entrypoint(std::string_view func_name) {
+static int calculate_method_id_for_entrypoint(std::string_view func_name) {
   if (func_name == "main" || func_name == "onInternalMessage") {
-    return td::make_refint(0);
+    return 0;
   }
   if (func_name == "onExternalMessage") {
-    return td::make_refint(-1);
+    return -1;
   }
   if (func_name == "onRunTickTock") {
-    return td::make_refint(-2);
+    return -2;
   }
   if (func_name == "onSplitPrepare") {
-    return td::make_refint(-3);
+    return -3;
   }
   if (func_name == "onSplitInstall") {
-    return td::make_refint(-4);
+    return -4;
   }
   tolk_assert(false);
 }
 
-static td::RefInt256 calculate_method_id_by_func_name(std::string_view func_name) {
+static int calculate_method_id_by_func_name(std::string_view func_name) {
   unsigned int crc = td::crc16(static_cast<std::string>(func_name));
-  return td::make_refint((crc & 0xffff) | 0x10000);
+  return static_cast<int>(crc & 0xffff) | 0x10000;
 }
 
 static void calc_arg_ret_order_of_asm_function(V<ast_asm_body> v_body, V<ast_parameter_list> param_list, TypeExpr* ret_type,
@@ -89,7 +74,7 @@ static void calc_arg_ret_order_of_asm_function(V<ast_asm_body> v_body, V<ast_par
   int tot_width = 0;
   for (int i = 0; i < cnt; ++i) {
     V<ast_parameter> v_param = param_list->get_param(i);
-    int arg_width = v_param->param_type->get_width();
+    int arg_width = v_param->declared_type->get_width();
     if (arg_width < 0 || arg_width > 16) {
       v_param->error("parameters of an assembler built-in function must have a well-defined fixed width");
     }
@@ -130,102 +115,39 @@ static void calc_arg_ret_order_of_asm_function(V<ast_asm_body> v_body, V<ast_par
 }
 
 static void register_constant(V<ast_constant_declaration> v) {
-  AnyV init_value = v->get_init_value();
-  SymDef* sym_def = define_global_symbol(calc_sym_idx(v->get_identifier()->name), v->loc);
-  if (sym_def->value) {
-    fire_error_redefinition_of_symbol(v->get_identifier(), sym_def);
-  }
+  ConstantValue init_value = eval_const_init_value(v->get_init_value());
+  GlobalConstData* c_sym = new GlobalConstData(static_cast<std::string>(v->get_identifier()->name), v->loc, std::move(init_value));
 
-  // todo currently, constant value calculation is dirty and roughly: init_value is evaluated to fif code
-  // and waited to be a single expression
-  // although it works, of course it should be later rewritten using AST calculations, as well as lots of other parts
-  CodeBlob code("tmp", v->loc, nullptr, nullptr);
-  Expr* x = process_expr(init_value, code);
-  if (!x->is_rvalue()) {
-    v->get_init_value()->error("expression is not strictly Rvalue");
-  }
-  if (v->declared_type && !v->declared_type->equals_to(x->e_type)) {
+  if (v->declared_type && !v->declared_type->equals_to(c_sym->inferred_type)) {
     v->error("expression type does not match declared type");
   }
-  SymValConst* sym_val = nullptr;
-  if (x->cls == Expr::_Const) {  // Integer constant
-    sym_val = new SymValConst(static_cast<int>(G.all_constants.size()), x->intval);
-  } else if (x->cls == Expr::_SliceConst) {  // Slice constant (string)
-    sym_val = new SymValConst(static_cast<int>(G.all_constants.size()), x->strval);
-  } else if (x->cls == Expr::_Apply) {  // even "1 + 2" is Expr::_Apply (it applies `_+_`)
-    code.emplace_back(v->loc, Op::_Import, std::vector<var_idx_t>());
-    auto tmp_vars = x->pre_compile(code);
-    code.emplace_back(v->loc, Op::_Return, std::move(tmp_vars));
-    code.emplace_back(v->loc, Op::_Nop);
-    // It is REQUIRED to execute "optimizations" as in tolk.cpp
-    code.simplify_var_types();
-    code.prune_unreachable_code();
-    code.split_vars(true);
-    for (int i = 0; i < 16; i++) {
-      code.compute_used_code_vars();
-      code.fwd_analyze();
-      code.prune_unreachable_code();
-    }
-    code.mark_noreturn();
-    AsmOpList out_list(0, &code.vars);
-    code.generate_code(out_list);
-    if (out_list.list_.size() != 1) {
-      init_value->error("precompiled expression must result in single operation");
-    }
-    auto op = out_list.list_[0];
-    if (!op.is_const()) {
-      init_value->error("precompiled expression must result in compilation time constant");
-    }
-    if (op.origin.is_null() || !op.origin->is_valid()) {
-      init_value->error("precompiled expression did not result in a valid integer constant");
-    }
-    sym_val = new SymValConst(static_cast<int>(G.all_constants.size()), op.origin);
-  } else {
-    init_value->error("integer or slice literal or constant expected");
-  }
 
-  sym_def->value = sym_val;
-#ifdef TOLK_DEBUG
-  sym_def->value->sym_name = v->get_identifier()->name;
-#endif
-  G.all_constants.push_back(sym_def);
+  G.symtable.add_global_const(c_sym);
+  G.all_constants.push_back(c_sym);
+  v->mutate()->assign_const_ref(c_sym);
 }
 
 static void register_global_var(V<ast_global_var_declaration> v) {
-  SymDef* sym_def = define_global_symbol(calc_sym_idx(v->get_identifier()->name), v->loc);
-  if (sym_def->value) {
-    fire_error_redefinition_of_symbol(v->get_identifier(), sym_def);
+  GlobalVarData* g_sym = new GlobalVarData(static_cast<std::string>(v->get_identifier()->name), v->loc, v->declared_type);
+
+  G.symtable.add_global_var(g_sym);
+  G.all_global_vars.push_back(g_sym);
+  v->mutate()->assign_var_ref(g_sym);
 }
 
-  sym_def->value = new SymValGlobVar(static_cast<int>(G.all_global_vars.size()), v->declared_type);
-#ifdef TOLK_DEBUG
-  sym_def->value->sym_name = v->get_identifier()->name;
-#endif
-  G.all_global_vars.push_back(sym_def);
-}
-
-static SymDef* register_parameter(V<ast_parameter> v, int idx) {
+static LocalVarData register_parameter(V<ast_parameter> v, int idx) {
   if (v->is_underscore()) {
-    return nullptr;
-  }
-  SymDef* sym_def = define_parameter(calc_sym_idx(v->get_identifier()->name), v->loc);
-  if (sym_def->value) {
-    // todo always false now, how to detect similar parameter names? (remember about underscore)
-    v->error("redefined parameter");
+    return {"", v->loc, idx, v->declared_type};
   }
 
-  SymValVariable* sym_val = new SymValVariable(idx, v->param_type);
+  LocalVarData p_sym(static_cast<std::string>(v->param_name), v->loc, idx, v->declared_type);
   if (v->declared_as_mutate) {
-    sym_val->flags |= SymValVariable::flagMutateParameter;
+    p_sym.flags |= LocalVarData::flagMutateParameter;
   }
-  if (!v->declared_as_mutate && idx == 0 && v->get_identifier()->name == "self") {
-    sym_val->flags |= SymValVariable::flagImmutable;
+  if (!v->declared_as_mutate && idx == 0 && v->param_name == "self") {
+    p_sym.flags |= LocalVarData::flagImmutable;
   }
-  sym_def->value = sym_val;
-#ifdef TOLK_DEBUG
-  sym_def->value->sym_name = v->get_identifier()->name;
-#endif
-  return sym_def;
+  return p_sym;
 }
 
 static void register_function(V<ast_function_declaration> v) {
@@ -235,16 +157,16 @@ static void register_function(V<ast_function_declaration> v) {
   TypeExpr* params_tensor_type = nullptr;
   int n_params = v->get_num_params();
   int n_mutate_params = 0;
-  std::vector<SymDef*> parameters_syms;
+  std::vector<LocalVarData> parameters;
   if (n_params) {
     std::vector<TypeExpr*> param_tensor_items;
     param_tensor_items.reserve(n_params);
-    parameters_syms.reserve(n_params);
+    parameters.reserve(n_params);
     for (int i = 0; i < n_params; ++i) {
       auto v_param = v->get_param(i);
       n_mutate_params += static_cast<int>(v_param->declared_as_mutate);
-      param_tensor_items.emplace_back(v_param->param_type);
-      parameters_syms.emplace_back(register_parameter(v_param, i));
+      param_tensor_items.emplace_back(v_param->declared_type);
+      parameters.emplace_back(register_parameter(v_param, i));
     }
     params_tensor_type = TypeExpr::new_tensor(std::move(param_tensor_items));
   } else {
@@ -261,24 +183,20 @@ static void register_function(V<ast_function_declaration> v) {
     function_type = TypeExpr::new_forall(std::move(type_vars), function_type);
   }
   if (v->marked_as_builtin) {
-    const SymDef* builtin_func = lookup_symbol(G.symbols.lookup(func_name));
-    const SymValFunc* func_val = builtin_func ? dynamic_cast<SymValFunc*>(builtin_func->value) : nullptr;
-    if (!func_val || !func_val->is_builtin()) {
+    const Symbol* builtin_func = lookup_global_symbol(func_name);
+    const FunctionData* func_val = builtin_func ? builtin_func->as<FunctionData>() : nullptr;
+    if (!func_val || !func_val->is_builtin_function()) {
       v->error("`builtin` used for non-builtin function");
     }
 #ifdef TOLK_DEBUG
     // in release, we don't need this check, since `builtin` is used only in stdlib, which is our responsibility
-    if (!func_val->sym_type->equals_to(function_type) || func_val->is_marked_as_pure() != v->marked_as_pure) {
+    if (!func_val->full_type->equals_to(function_type) || func_val->is_marked_as_pure() != v->marked_as_pure) {
       v->error("declaration for `builtin` function doesn't match an actual one");
     }
 #endif
     return;
   }
 
-  SymDef* sym_def = define_global_symbol(calc_sym_idx(func_name), v->loc);
-  if (sym_def->value) {
-    fire_error_redefinition_of_symbol(v->get_identifier(), sym_def);
-  }
   if (G.is_verbosity(1)) {
     std::cerr << "fun " << func_name << " : " << function_type << std::endl;
   }
@@ -286,67 +204,61 @@ static void register_function(V<ast_function_declaration> v) {
     v->error("a pure function should return something, otherwise it will be optimized out anyway");
   }
 
-  SymValFunc* sym_val = nullptr;
-  if (const auto* v_seq = v->get_body()->try_as<ast_sequence>()) {
-    sym_val = new SymValCodeFunc(std::move(parameters_syms), static_cast<int>(G.all_code_functions.size()), function_type);
-  } else if (const auto* v_asm = v->get_body()->try_as<ast_asm_body>()) {
-    std::vector<int> arg_order, ret_order;
-    calc_arg_ret_order_of_asm_function(v_asm, v->get_param_list(), v->ret_type, arg_order, ret_order);
-    sym_val = new SymValAsmFunc(std::move(parameters_syms), function_type, std::move(arg_order), std::move(ret_order), 0);
-  } else {
-    v->error("Unexpected function body statement");
+  FunctionBody f_body = v->get_body()->type == ast_sequence ? static_cast<FunctionBody>(new FunctionBodyCode) : static_cast<FunctionBody>(new FunctionBodyAsm);
+  FunctionData* f_sym = new FunctionData(static_cast<std::string>(func_name), v->loc, function_type, std::move(parameters), 0, f_body);
+
+  if (const auto* v_asm = v->get_body()->try_as<ast_asm_body>()) {
+    calc_arg_ret_order_of_asm_function(v_asm, v->get_param_list(), v->ret_type, f_sym->arg_order, f_sym->ret_order);
   }
 
   if (v->method_id) {
-    sym_val->method_id = td::string_to_int256(static_cast<std::string>(v->method_id->int_val));
-    if (sym_val->method_id.is_null()) {
+    if (v->method_id->intval.is_null() || !v->method_id->intval->signed_fits_bits(32)) {
       v->method_id->error("invalid integer constant");
     }
+    f_sym->method_id = static_cast<int>(v->method_id->intval->to_long());
   } else if (v->marked_as_get_method) {
-    sym_val->method_id = calculate_method_id_by_func_name(func_name);
-    for (const SymDef* other : G.all_get_methods) {
-      if (!td::cmp(dynamic_cast<const SymValFunc*>(other->value)->method_id, sym_val->method_id)) {
-        v->error(PSTRING() << "GET methods hash collision: `" << other->name() << "` and `" << static_cast<std::string>(func_name) << "` produce the same hash. Consider renaming one of these functions.");
+    f_sym->method_id = calculate_method_id_by_func_name(func_name);
+    for (const FunctionData* other : G.all_get_methods) {
+      if (other->method_id == f_sym->method_id) {
+        v->error(PSTRING() << "GET methods hash collision: `" << other->name << "` and `" << f_sym->name << "` produce the same hash. Consider renaming one of these functions.");
       }
     }
   } else if (v->is_entrypoint) {
-    sym_val->method_id = calculate_method_id_for_entrypoint(func_name);
+    f_sym->method_id = calculate_method_id_for_entrypoint(func_name);
   }
   if (v->marked_as_pure) {
-    sym_val->flags |= SymValFunc::flagMarkedAsPure;
+    f_sym->flags |= FunctionData::flagMarkedAsPure;
   }
   if (v->marked_as_inline) {
-    sym_val->flags |= SymValFunc::flagInline;
+    f_sym->flags |= FunctionData::flagInline;
   }
   if (v->marked_as_inline_ref) {
-    sym_val->flags |= SymValFunc::flagInlineRef;
+    f_sym->flags |= FunctionData::flagInlineRef;
   }
   if (v->marked_as_get_method) {
-    sym_val->flags |= SymValFunc::flagGetMethod;
+    f_sym->flags |= FunctionData::flagGetMethod;
   }
   if (v->is_entrypoint) {
-    sym_val->flags |= SymValFunc::flagIsEntrypoint;
+    f_sym->flags |= FunctionData::flagIsEntrypoint;
   }
   if (n_mutate_params) {
-    sym_val->flags |= SymValFunc::flagHasMutateParams;
+    f_sym->flags |= FunctionData::flagHasMutateParams;
   }
   if (v->accepts_self) {
-    sym_val->flags |= SymValFunc::flagAcceptsSelf;
+    f_sym->flags |= FunctionData::flagAcceptsSelf;
   }
   if (v->returns_self) {
-    sym_val->flags |= SymValFunc::flagReturnsSelf;
+    f_sym->flags |= FunctionData::flagReturnsSelf;
   }
 
-  sym_def->value = sym_val;
-#ifdef TOLK_DEBUG
-  sym_def->value->sym_name = func_name;
-#endif
-  if (dynamic_cast<SymValCodeFunc*>(sym_val)) {
-    G.all_code_functions.push_back(sym_def);
+  G.symtable.add_function(f_sym);
+  if (f_sym->is_regular_function()) {
+    G.all_code_functions.push_back(f_sym);
   }
-  if (sym_val->is_get_method()) {
-    G.all_get_methods.push_back(sym_def);
+  if (f_sym->is_get_method()) {
+    G.all_get_methods.push_back(f_sym);
   }
+  v->mutate()->assign_fun_ref(f_sym);
 }
 
 static void iterate_through_file_symbols(const SrcFile* file) {

tolk/pipe-resolve-symbols.cpp

@@ -0,0 +1,272 @@
+/*
+    This file is part of TON Blockchain Library.
+
+    TON Blockchain Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 2 of the License, or
+    (at your option) any later version.
+
+    TON Blockchain Library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with TON Blockchain Library.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#include "tolk.h"
+#include "platform-utils.h"
+#include "src-file.h"
+#include "ast.h"
+#include "ast-visitor.h"
+#include "compiler-state.h"
+#include <unordered_map>
+
+/*
+ *   This pipe resolves identifiers (local variables) in all functions bodies.
+ *   It happens before type inferring, but after all global symbols are registered.
+ * It means, that for any symbol `x` we can look up whether it's a global name or not.
+ *
+ *   Example: `var x = 10; x = 20;` both `x` point to one LocalVarData.
+ *   Example: `x = 20` undefined symbol `x` is also here (unless it's a global)
+ *   Variables scoping and redeclaration are also here.
+ *
+ *   As a result of this step, every V<ast_identifier>::sym is filled, pointing either to a local var/parameter,
+ * or to a global var / constant / function.
+ */
+
+namespace tolk {
+
+static void check_import_exists_when_using_sym(AnyV v_usage, const Symbol* used_sym) {
+  SrcLocation sym_loc = used_sym->loc;
+  if (!v_usage->loc.is_symbol_from_same_or_builtin_file(sym_loc)) {
+    const SrcFile* declared_in = sym_loc.get_src_file();
+    bool has_import = false;
+    for (const SrcFile::ImportStatement& import_stmt : v_usage->loc.get_src_file()->imports) {
+      if (import_stmt.imported_file == declared_in) {
+        has_import = true;
+      }
+    }
+    if (!has_import) {
+      v_usage->error("Using a non-imported symbol `" + used_sym->name + "`. Forgot to import \"" + declared_in->rel_filename + "\"?");
+    }
+  }
+}
+
+struct NameAndScopeResolver {
+  std::vector<std::unordered_map<uint64_t, const Symbol*>> scopes;
+
+  static uint64_t key_hash(std::string_view name_key) {
+    return std::hash<std::string_view>{}(name_key);
+  }
+
+  void open_scope([[maybe_unused]] SrcLocation loc) {
+    // std::cerr << "open_scope " << scopes.size() + 1 << " at " << loc << std::endl;
+    scopes.emplace_back();
+  }
+
+  void close_scope([[maybe_unused]] SrcLocation loc) {
+    // std::cerr << "close_scope " << scopes.size() << " at " << loc << std::endl;
+    if (UNLIKELY(scopes.empty())) {
+      throw Fatal{"cannot close the outer scope"};
+    }
+    scopes.pop_back();
+  }
+
+  const Symbol* lookup_symbol(std::string_view name) const {
+    uint64_t key = key_hash(name);
+    for (auto it = scopes.rbegin(); it != scopes.rend(); ++it) { // NOLINT(*-loop-convert)
+      const auto& scope = *it;
+      if (auto it_sym = scope.find(key); it_sym != scope.end()) {
+        return it_sym->second;
+      }
+    }
+    return G.symtable.lookup(name);
+  }
+
+  const Symbol* add_local_var(const LocalVarData* v_sym) {
+    if (UNLIKELY(scopes.empty())) {
+      throw Fatal("unexpected scope_level = 0");
+    }
+    if (v_sym->name.empty()) {    // underscore
+      return v_sym;
+    }
+
+    uint64_t key = key_hash(v_sym->name);
+    const auto& [_, inserted] = scopes.rbegin()->emplace(key, v_sym);
+    if (UNLIKELY(!inserted)) {
+      throw ParseError(v_sym->loc, "redeclaration of local variable `" + v_sym->name + "`");
+    }
+    return v_sym;
+  }
+};
+
+
+class AssignSymInsideFunctionVisitor final : public ASTVisitorFunctionBody {
+  // more correctly this field shouldn't be static, but currently there is no need to make it a part of state
+  static NameAndScopeResolver current_scope;
+
+  static const Symbol* create_local_var_sym(std::string_view name, SrcLocation loc, TypeExpr* var_type, bool immutable) {
+    LocalVarData* v_sym = new LocalVarData(static_cast<std::string>(name), loc, -1, var_type);
+    if (immutable) {
+      v_sym->flags |= LocalVarData::flagImmutable;
+    }
+    return current_scope.add_local_var(v_sym);
+  }
+
+  static void process_catch_variable(AnyV catch_var) {
+    if (auto v_ident = catch_var->try_as<ast_identifier>()) {
+      const Symbol* sym = create_local_var_sym(v_ident->name, catch_var->loc, TypeExpr::new_hole(), true);
+      v_ident->mutate()->assign_sym(sym);
+    }
+  }
+
+  static void process_function_arguments(const FunctionData* fun_ref, V<ast_argument_list> v, AnyExprV lhs_of_dot_call) {
+    int delta_self = lhs_of_dot_call ? 1 : 0;
+    int n_arguments = static_cast<int>(v->get_arguments().size()) + delta_self;
+    int n_parameters = static_cast<int>(fun_ref->parameters.size());
+
+    // Tolk doesn't have optional parameters currently, so just compare counts
+    if (n_parameters < n_arguments) {
+      v->error("too many arguments in call to `" + fun_ref->name + "`, expected " + std::to_string(n_parameters - delta_self) + ", have " + std::to_string(n_arguments - delta_self));
+    }
+    if (n_arguments < n_parameters) {
+      v->error("too few arguments in call to `" + fun_ref->name + "`, expected " + std::to_string(n_parameters - delta_self) + ", have " + std::to_string(n_arguments - delta_self));
+    }
+  }
+
+  void visit(V<ast_local_var> v) override {
+    if (v->marked_as_redef) {
+      auto v_ident = v->get_identifier()->as<ast_identifier>();
+      const Symbol* sym = current_scope.lookup_symbol(v_ident->name);
+      if (sym == nullptr) {
+        v->error("`redef` for unknown variable");
+      }
+      if (!sym->try_as<LocalVarData>() && !sym->try_as<GlobalVarData>()) {
+        v->error("`redef` for unknown variable");
+      }
+      v->mutate()->assign_var_ref(sym);
+      v_ident->mutate()->assign_sym(sym);
+    } else if (auto v_ident = v->get_identifier()->try_as<ast_identifier>()) {
+      TypeExpr* var_type = v->declared_type ? v->declared_type : TypeExpr::new_hole();
+      const Symbol* sym = create_local_var_sym(v_ident->name, v->loc, var_type, v->is_immutable);
+      v->mutate()->assign_var_ref(sym);
+      v_ident->mutate()->assign_sym(sym);
+    } else {
+      // underscore, do nothing, v->sym remains nullptr
+    }
+  }
+
+  void visit(V<ast_local_vars_declaration> v) override {
+    parent::visit(v->get_assigned_val());
+    parent::visit(v->get_lhs());
+  }
+
+  void visit(V<ast_identifier> v) override {
+    const Symbol* sym = current_scope.lookup_symbol(v->name);
+    if (!sym) {
+      v->error("undefined symbol `" + static_cast<std::string>(v->name) + "`");
+    }
+    v->mutate()->assign_sym(sym);
+
+    // for global functions, global vars and constants, `import` must exist
+    if (!sym->try_as<LocalVarData>()) {
+      check_import_exists_when_using_sym(v, sym);
+    }
+  }
+
+  void visit(V<ast_function_call> v) override {
+    parent::visit(v->get_called_f());
+    parent::visit(v->get_arg_list());
+
+    // most likely it's a global function, but also may be `some_var(args)` or even `getF()(args)`
+    // for such corner cases, sym remains nullptr
+    if (auto v_ident = v->get_called_f()->try_as<ast_identifier>()) {
+      if (const auto* fun_ref = v_ident->sym->try_as<FunctionData>()) {
+        v->mutate()->assign_fun_ref(fun_ref);
+        process_function_arguments(fun_ref, v->get_arg_list(), nullptr);
+      }
+    }
+    // for `some_var(args)`, if it's called with wrong arguments count, the error is not here
+    // it will be fired later, it's a type checking error
+  }
+
+  void visit(V<ast_dot_method_call> v) override {
+    const Symbol* sym = lookup_global_symbol(v->method_name);
+    if (!sym) {
+      v->error("undefined symbol `" + static_cast<std::string>(v->method_name) + "`");
+    }
+    const auto* fun_ref = sym->try_as<FunctionData>();
+    if (!fun_ref) {
+      v->error("`" + static_cast<std::string>(v->method_name) + "` is not a method");
+    }
+
+    if (fun_ref->parameters.empty()) {
+      v->error("`" + static_cast<std::string>(v->method_name) + "` has no parameters and can not be called as method");
+    }
+
+    v->mutate()->assign_fun_ref(fun_ref);
+    parent::visit(v);
+    process_function_arguments(fun_ref, v->get_arg_list(), v->get_obj());
+  }
+
+  void visit(V<ast_self_keyword> v) override {
+    const Symbol* sym = current_scope.lookup_symbol("self");
+    if (!sym) {
+      v->error("using `self` in a non-member function (it does not accept the first `self` parameter)");
+    }
+    v->mutate()->assign_param_ref(sym->as<LocalVarData>());
+  }
+
+  void visit(V<ast_sequence> v) override {
+    if (v->empty()) {
+      return;
+    }
+    current_scope.open_scope(v->loc);
+    parent::visit(v);
+    current_scope.close_scope(v->loc_end);
+  }
+
+  void visit(V<ast_do_while_statement> v) override {
+    current_scope.open_scope(v->loc);
+    parent::visit(v->get_body());
+    parent::visit(v->get_cond()); // in 'while' condition it's ok to use variables declared inside do
+    current_scope.close_scope(v->get_body()->loc_end);
+  }
+
+  void visit(V<ast_try_catch_statement> v) override {
+    visit(v->get_try_body());
+    current_scope.open_scope(v->get_catch_body()->loc);
+    const std::vector<AnyExprV>& catch_items = v->get_catch_expr()->get_items();
+    tolk_assert(catch_items.size() == 2);
+    process_catch_variable(catch_items[1]);
+    process_catch_variable(catch_items[0]);
+    parent::visit(v->get_catch_body());
+    current_scope.close_scope(v->get_catch_body()->loc_end);
+  }
+
+public:
+  void start_visiting_function(V<ast_function_declaration> v_function) override {
+    auto v_seq = v_function->get_body()->try_as<ast_sequence>();
+    tolk_assert(v_seq != nullptr);
+
+    current_scope.open_scope(v_function->loc);
+
+    for (int i = 0; i < v_function->get_num_params(); ++i) {
+      current_scope.add_local_var(&v_function->fun_ref->parameters[i]);
+      v_function->get_param(i)->mutate()->assign_param_ref(&v_function->fun_ref->parameters[i]);
+    }
+    parent::visit(v_seq);
+
+    current_scope.close_scope(v_seq->loc_end);
+    tolk_assert(current_scope.scopes.empty());
+  }
+};
+
+NameAndScopeResolver AssignSymInsideFunctionVisitor::current_scope;
+
+void pipeline_resolve_identifiers_and_assign_symbols(const AllSrcFiles& all_src_files) {
+  visit_ast_of_all_functions<AssignSymInsideFunctionVisitor>(all_src_files);
+}
+
+} // namespace tolk

tolk/pipeline.h

@@ -33,6 +33,14 @@ namespace tolk {
 AllSrcFiles pipeline_discover_and_parse_sources(const std::string& stdlib_filename, const std::string& entrypoint_filename);
 
 void pipeline_register_global_symbols(const AllSrcFiles&);
+void pipeline_resolve_identifiers_and_assign_symbols(const AllSrcFiles&);
+void pipeline_calculate_rvalue_lvalue(const AllSrcFiles&);
+void pipeline_detect_unreachable_statements(const AllSrcFiles&);
+void pipeline_infer_and_check_types(const AllSrcFiles&);
+void pipeline_refine_lvalue_for_mutate_arguments(const AllSrcFiles&);
+void pipeline_check_rvalue_lvalue(const AllSrcFiles&);
+void pipeline_check_pure_impure_operations(const AllSrcFiles&);
+void pipeline_constant_folding(const AllSrcFiles&);
 void pipeline_convert_ast_to_legacy_Expr_Op(const AllSrcFiles&);
 
 void pipeline_find_unused_symbols();

tolk/src-file.h

@@ -18,11 +18,10 @@
 
 #include <string>
 #include <vector>
+#include "fwd-declarations.h"
 
 namespace tolk {
 
-struct ASTNodeBase;
-
 struct SrcFile {
   struct SrcPosition {
     int offset;
@@ -39,7 +38,7 @@ struct SrcFile {
   std::string rel_filename;             // relative to cwd
   std::string abs_filename;             // absolute from root
   std::string text;                     // file contents loaded into memory, every Token::str_val points inside it
-  const ASTNodeBase* ast = nullptr;     // when a file has been parsed, its ast_tolk_file is kept here
+  AnyV ast = nullptr;                   // when a file has been parsed, its ast_tolk_file is kept here
   std::vector<ImportStatement> imports; // to check strictness (can't use a symbol without importing its file)
 
   SrcFile(int file_id, std::string rel_filename, std::string abs_filename, std::string&& text)

tolk/symtable.cpp

@@ -16,154 +16,85 @@
 */
 #include "symtable.h"
 #include "compiler-state.h"
+#include "platform-utils.h"
 #include <sstream>
 #include <cassert>
 
 namespace tolk {
 
+bool FunctionData::does_need_codegen() const {
+  // when a function is declared, but not referenced from code in any way, don't generate its body
+  if (!is_really_used() && G.settings.remove_unused_functions) {
+    return false;
+  }
+  // when a function is referenced like `var a = some_fn;` (or in some other non-call way), its continuation should exist
+  if (is_used_as_noncall()) {
+    return true;
+  }
+  // currently, there is no inlining, all functions are codegenerated
+  // (but actually, unused ones are later removed by Fift)
+  // in the future, we may want to implement a true AST inlining for "simple" functions
+  return true;
+}
 
-std::string Symbol::unknown_symbol_name(sym_idx_t i) {
-  if (!i) {
-    return "_";
-  } else {
-    std::ostringstream os;
-    os << "SYM#" << i;
-    return os.str();
+void FunctionData::assign_is_really_used() {
+  this->flags |= flagReallyUsed;
+}
+
+void FunctionData::assign_is_used_as_noncall() {
+  this->flags |= flagUsedAsNonCall;
+}
+
+void FunctionData::assign_is_implicit_return() {
+  this->flags |= flagImplicitReturn;
+}
+
+void GlobalVarData::assign_is_really_used() {
+  this->flags |= flagReallyUsed;
+}
+
+void LocalVarData::assign_idx(int idx) {
+  this->idx = idx;
+}
+
+GNU_ATTRIBUTE_NORETURN GNU_ATTRIBUTE_COLD
+static void fire_error_redefinition_of_symbol(SrcLocation loc, const Symbol* previous) {
+  SrcLocation prev_loc = previous->loc;
+  if (prev_loc.is_stdlib()) {
+    throw ParseError(loc, "redefinition of a symbol from stdlib");
+  }
+  if (prev_loc.is_defined()) {
+    throw ParseError(loc, "redefinition of symbol, previous was at: " + prev_loc.to_string());
+  }
+  throw ParseError(loc, "redefinition of built-in symbol");
+}
+
+void GlobalSymbolTable::add_function(const FunctionData* f_sym) {
+  auto key = key_hash(f_sym->name);
+  auto [it, inserted] = entries.emplace(key, f_sym);
+  if (!inserted) {
+    fire_error_redefinition_of_symbol(f_sym->loc, it->second);
   }
 }
 
-sym_idx_t SymTable::gen_lookup(std::string_view str, int mode, sym_idx_t idx) {
-  unsigned long long h1 = 1, h2 = 1;
-  for (char c : str) {
-    h1 = ((h1 * 239) + (unsigned char)(c)) % SIZE_PRIME;
-    h2 = ((h2 * 17) + (unsigned char)(c)) % (SIZE_PRIME - 1);
-  }
-  ++h2;
-  ++h1;
-  while (true) {
-    if (sym[h1]) {
-      if (sym[h1]->str == str) {
-        return (mode & 2) ? not_found : sym_idx_t(h1);
-      }
-      h1 += h2;
-      if (h1 > SIZE_PRIME) {
-        h1 -= SIZE_PRIME;
-      }
-    } else {
-      if (!(mode & 1)) {
-        return not_found;
-      }
-      if (def_sym >= ((long long)SIZE_PRIME * 3) / 4) {
-        throw SymTableOverflow{def_sym};
-      }
-      sym[h1] = std::make_unique<Symbol>(static_cast<std::string>(str), idx <= 0 ? sym_idx_t(h1) : -idx);
-      ++def_sym;
-      return sym_idx_t(h1);
-    }
+void GlobalSymbolTable::add_global_var(const GlobalVarData* g_sym) {
+  auto key = key_hash(g_sym->name);
+  auto [it, inserted] = entries.emplace(key, g_sym);
+  if (!inserted) {
+    fire_error_redefinition_of_symbol(g_sym->loc, it->second);
   }
 }
 
-std::string SymDef::name() const {
-  return G.symbols.get_name(sym_idx);
+void GlobalSymbolTable::add_global_const(const GlobalConstData* c_sym) {
+  auto key = key_hash(c_sym->name);
+  auto [it, inserted] = entries.emplace(key, c_sym);
+  if (!inserted) {
+    fire_error_redefinition_of_symbol(c_sym->loc, it->second);
+  }
 }
 
-void open_scope(SrcLocation loc) {
-  ++G.scope_level;
-  G.scope_opened_at.push_back(loc);
-}
-
-void close_scope() {
-  if (!G.scope_level) {
-    throw Fatal{"cannot close the outer scope"};
-  }
-  while (!G.symbol_stack.empty() && G.symbol_stack.back().first == G.scope_level) {
-    SymDef old_def = G.symbol_stack.back().second;
-    auto idx = old_def.sym_idx;
-    G.symbol_stack.pop_back();
-    SymDef* cur_def = G.sym_def[idx];
-    assert(cur_def);
-    assert(cur_def->level == G.scope_level && cur_def->sym_idx == idx);
-    //std::cerr << "restoring local symbol `" << old_def.name << "` of level " << scope_level << " to its previous level " << old_def.level << std::endl;
-    if (cur_def->value) {
-      //std::cerr << "deleting value of symbol " << old_def.name << ":" << old_def.level << " at " << (const void*) it->second.value << std::endl;
-      delete cur_def->value;
-    }
-    if (!old_def.level && !old_def.value) {
-      delete cur_def;  // ??? keep the definition always?
-      G.sym_def[idx] = nullptr;
-    } else {
-      cur_def->value = old_def.value;
-      cur_def->level = old_def.level;
-    }
-    old_def.value = nullptr;
-  }
-  --G.scope_level;
-  G.scope_opened_at.pop_back();
-}
-
-SymDef* lookup_symbol(sym_idx_t idx) {
-  if (!idx) {
-    return nullptr;
-  }
-  if (G.sym_def[idx]) {
-    return G.sym_def[idx];
-  }
-  if (G.global_sym_def[idx]) {
-    return G.global_sym_def[idx];
-  }
-  return nullptr;
-}
-
-SymDef* define_global_symbol(sym_idx_t name_idx, SrcLocation loc) {
-  if (SymDef* found = G.global_sym_def[name_idx]) {
-    return found;   // found->value is filled; it means, that a symbol is redefined
-  }
-
-  SymDef* registered = G.global_sym_def[name_idx] = new SymDef(0, name_idx, loc);
-#ifdef TOLK_DEBUG
-  registered->sym_name = registered->name();
-#endif
-  return registered;  // registered->value is nullptr; it means, it's just created
-}
-
-SymDef* define_parameter(sym_idx_t name_idx, SrcLocation loc) {
-  // note, that parameters (defined at function declaration) are not inserted into symtable
-  // their SymDef is registered to be inserted into SymValFunc::parameters
-  // (and later ->value is filled with SymValVariable)
-
-  SymDef* registered = new SymDef(0, name_idx, loc);
-#ifdef TOLK_DEBUG
-  registered->sym_name = registered->name();
-#endif
-  return registered;
-}
-
-SymDef* define_symbol(sym_idx_t name_idx, bool force_new, SrcLocation loc) {
-  if (!name_idx) {
-    return nullptr;
-  }
-  if (!G.scope_level) {
-    throw Fatal("unexpected scope_level = 0");
-  }
-  auto found = G.sym_def[name_idx];
-  if (found) {
-    if (found->level < G.scope_level) {
-      G.symbol_stack.emplace_back(G.scope_level, *found);
-      found->level = G.scope_level;
-    } else if (found->value && force_new) {
-      return nullptr;
-    }
-    found->value = nullptr;
-    found->loc = loc;
-    return found;
-  }
-  found = G.sym_def[name_idx] = new SymDef(G.scope_level, name_idx, loc);
-  G.symbol_stack.emplace_back(G.scope_level, SymDef{0, name_idx, loc});
-#ifdef TOLK_DEBUG
-  found->sym_name = found->name();
-  G.symbol_stack.back().second.sym_name = found->name();
-#endif
-  return found;
+const Symbol* lookup_global_symbol(std::string_view name) {
+  return G.symtable.lookup(name);
 }
 
 }  // namespace tolk

tolk/symtable.h

@@ -18,97 +18,194 @@
 
 #include "src-file.h"
 #include "type-expr.h"
-#include <functional>
-#include <memory>
+#include "constant-evaluator.h"
+#include "crypto/common/refint.h"
+#include <unordered_map>
+#include <variant>
+#include <vector>
 
 namespace tolk {
 
-typedef int var_idx_t;
-typedef int sym_idx_t;
-
-enum class SymValKind { _Var, _Func, _GlobVar, _Const };
-
-struct SymValBase {
-  SymValKind kind;
-  int idx;
-  TypeExpr* sym_type;
-#ifdef TOLK_DEBUG
-  std::string sym_name; // seeing symbol name in debugger makes it much easier to delve into Tolk sources
-#endif
-
-  SymValBase(SymValKind kind, int idx, TypeExpr* sym_type) : kind(kind), idx(idx), sym_type(sym_type) {
-  }
-  virtual ~SymValBase() = default;
-
-  TypeExpr* get_type() const {
-    return sym_type;
-  }
-};
-
-
 struct Symbol {
-  std::string str;
-  sym_idx_t idx;
-
-  Symbol(std::string str, sym_idx_t idx) : str(std::move(str)), idx(idx) {}
-
-  static std::string unknown_symbol_name(sym_idx_t i);
-};
-
-class SymTable {
-public:
-  static constexpr int SIZE_PRIME = 100003;
-
-private:
-  sym_idx_t def_sym{0};
-  std::unique_ptr<Symbol> sym[SIZE_PRIME + 1];
-  sym_idx_t gen_lookup(std::string_view str, int mode = 0, sym_idx_t idx = 0);
-
-public:
-
-  static constexpr sym_idx_t not_found = 0;
-  sym_idx_t lookup(std::string_view str) {
-    return gen_lookup(str, 0);
-  }
-  sym_idx_t lookup_add(std::string_view str) {
-    return gen_lookup(str, 1);
-  }
-  Symbol* operator[](sym_idx_t i) const {
-    return sym[i].get();
-  }
-  std::string get_name(sym_idx_t i) const {
-    return sym[i] ? sym[i]->str : Symbol::unknown_symbol_name(i);
-  }
-};
-
-struct SymTableOverflow {
-  int sym_def;
-  explicit SymTableOverflow(int x) : sym_def(x) {
-  }
-};
-
-
-struct SymDef {
-  int level;
-  sym_idx_t sym_idx;
-  SymValBase* value;
+  std::string name;
   SrcLocation loc;
-#ifdef TOLK_DEBUG
-  std::string sym_name;
-#endif
-  SymDef(int lvl, sym_idx_t idx, SrcLocation _loc, SymValBase* val = nullptr)
-      : level(lvl), sym_idx(idx), value(val), loc(_loc) {
+
+  Symbol(std::string name, SrcLocation loc)
+    : name(std::move(name))
+    , loc(loc) {
+  }
+
+  virtual ~Symbol() = default;
+
+  template<class T>
+  const T* as() const {
+#ifdef TOLK_DEBUG
+    assert(dynamic_cast<const T*>(this) != nullptr);
+#endif
+    return dynamic_cast<const T*>(this);
+  }
+
+  template<class T>
+  const T* try_as() const {
+    return dynamic_cast<const T*>(this);
   }
-  std::string name() const;
 };
 
+struct LocalVarData final : Symbol {
+  enum {
+    flagMutateParameter = 1,    // parameter was declared with `mutate` keyword
+    flagImmutable = 2,          // variable was declared via `val` (not `var`)
+  };
 
-void open_scope(SrcLocation loc);
-void close_scope();
-SymDef* lookup_symbol(sym_idx_t idx);
+  TypeExpr* declared_type;
+  int flags = 0;
+  int idx;
 
-SymDef* define_global_symbol(sym_idx_t name_idx, SrcLocation loc = {});
-SymDef* define_parameter(sym_idx_t name_idx, SrcLocation loc);
-SymDef* define_symbol(sym_idx_t name_idx, bool force_new, SrcLocation loc);
+  LocalVarData(std::string name, SrcLocation loc, int idx, TypeExpr* declared_type)
+    : Symbol(std::move(name), loc)
+    , declared_type(declared_type)
+    , idx(idx) {
+  }
+
+  bool is_underscore() const { return name.empty(); }
+  bool is_immutable() const { return flags & flagImmutable; }
+  bool is_mutate_parameter() const { return flags & flagMutateParameter; }
+
+  LocalVarData* mutate() const { return const_cast<LocalVarData*>(this); }
+  void assign_idx(int idx);
+};
+
+struct FunctionBodyCode;
+struct FunctionBodyAsm;
+struct FunctionBodyBuiltin;
+
+typedef std::variant<
+  FunctionBodyCode*,
+  FunctionBodyAsm*,
+  FunctionBodyBuiltin*
+> FunctionBody;
+
+struct FunctionData final : Symbol {
+  static constexpr int EMPTY_METHOD_ID = -10;
+
+  enum {
+    flagInline = 1,             // marked `@inline`
+    flagInlineRef = 2,          // marked `@inline_ref`
+    flagReallyUsed = 4,         // calculated via dfs from used functions; declared but unused functions are not codegenerated
+    flagUsedAsNonCall = 8,      // used not only as `f()`, but as a 1-st class function (assigned to var, pushed to tuple, etc.)
+    flagMarkedAsPure = 16,      // declared as `pure`, can't call impure and access globals, unused invocations are optimized out
+    flagImplicitReturn = 32,    // control flow reaches end of function, so it needs implicit return at the end
+    flagGetMethod = 64,         // was declared via `get func(): T`, method_id is auto-assigned
+    flagIsEntrypoint = 128,     // it's `main` / `onExternalMessage` / etc.
+    flagHasMutateParams = 256,  // has parameters declared as `mutate`
+    flagAcceptsSelf = 512,      // is a member function (has `self` first parameter)
+    flagReturnsSelf = 1024,     // return type is `self` (returns the mutated 1st argument), calls can be chainable
+  };
+
+  int method_id = EMPTY_METHOD_ID;
+  int flags;
+  TypeExpr* full_type;    // currently, TypeExpr::_Map, probably wrapped with forall
+
+  std::vector<LocalVarData> parameters;
+  std::vector<int> arg_order, ret_order;
+
+  FunctionBody body;
+
+  FunctionData(std::string name, SrcLocation loc, TypeExpr* full_type, std::vector<LocalVarData> parameters, int initial_flags, FunctionBody body)
+    : Symbol(std::move(name), loc)
+    , flags(initial_flags)
+    , full_type(full_type)
+    , parameters(std::move(parameters))
+    , body(body) {
+  }
+
+  const std::vector<int>* get_arg_order() const {
+    return arg_order.empty() ? nullptr : &arg_order;
+  }
+  const std::vector<int>* get_ret_order() const {
+    return ret_order.empty() ? nullptr : &ret_order;
+  }
+
+  bool is_regular_function() const { return std::holds_alternative<FunctionBodyCode*>(body); }
+  bool is_asm_function() const { return std::holds_alternative<FunctionBodyAsm*>(body); }
+  bool is_builtin_function() const { return std::holds_alternative<FunctionBodyBuiltin*>(body); }
+
+  bool is_inline() const { return flags & flagInline; }
+  bool is_inline_ref() const { return flags & flagInlineRef; }
+  bool is_really_used() const { return flags & flagReallyUsed; }
+  bool is_used_as_noncall() const { return flags & flagUsedAsNonCall; }
+  bool is_marked_as_pure() const { return flags & flagMarkedAsPure; }
+  bool is_implicit_return() const { return flags & flagImplicitReturn; }
+  bool is_get_method() const { return flags & flagGetMethod; }
+  bool is_method_id_not_empty() const { return method_id != EMPTY_METHOD_ID; }
+  bool is_entrypoint() const { return flags & flagIsEntrypoint; }
+  bool has_mutate_params() const { return flags & flagHasMutateParams; }
+  bool does_accept_self() const { return flags & flagAcceptsSelf; }
+  bool does_return_self() const { return flags & flagReturnsSelf; }
+  bool does_mutate_self() const { return (flags & flagAcceptsSelf) && parameters[0].is_mutate_parameter(); }
+
+  bool does_need_codegen() const;
+
+  FunctionData* mutate() const { return const_cast<FunctionData*>(this); }
+  void assign_is_really_used();
+  void assign_is_used_as_noncall();
+  void assign_is_implicit_return();
+};
+
+struct GlobalVarData final : Symbol {
+  enum {
+    flagReallyUsed = 1,          // calculated via dfs from used functions; unused globals are not codegenerated
+  };
+
+  TypeExpr* declared_type;
+  int flags = 0;
+
+  GlobalVarData(std::string name, SrcLocation loc, TypeExpr* declared_type)
+    : Symbol(std::move(name), loc)
+    , declared_type(declared_type) {
+  }
+
+  bool is_really_used() const { return flags & flagReallyUsed; }
+
+  GlobalVarData* mutate() const { return const_cast<GlobalVarData*>(this); }
+  void assign_is_really_used();
+};
+
+struct GlobalConstData final : Symbol {
+  ConstantValue value;
+  TypeExpr* inferred_type;
+
+  GlobalConstData(std::string name, SrcLocation loc, ConstantValue&& value)
+    : Symbol(std::move(name), loc)
+    , value(std::move(value))
+    , inferred_type(TypeExpr::new_atomic(this->value.is_int() ? TypeExpr::_Int : TypeExpr::_Slice)) {
+  }
+
+  bool is_int_const() const { return value.is_int(); }
+  bool is_slice_const() const { return value.is_slice(); }
+
+  td::RefInt256 as_int_const() const { return value.as_int(); }
+  const std::string& as_slice_const() const { return value.as_slice(); }
+};
+
+class GlobalSymbolTable {
+  std::unordered_map<uint64_t, const Symbol*> entries;
+
+  static uint64_t key_hash(std::string_view name_key) {
+    return std::hash<std::string_view>{}(name_key);
+  }
+
+public:
+  void add_function(const FunctionData* f_sym);
+  void add_global_var(const GlobalVarData* g_sym);
+  void add_global_const(const GlobalConstData* c_sym);
+
+  const Symbol* lookup(std::string_view name) const {
+    const auto it = entries.find(key_hash(name));
+    return it == entries.end() ? nullptr : it->second;
+  }
+};
+
+const Symbol* lookup_global_symbol(std::string_view name);
 
 }  // namespace tolk

tolk/tolk.cpp

@@ -54,6 +54,14 @@ int tolk_proceed(const std::string &entrypoint_filename) {
     AllSrcFiles all_files = pipeline_discover_and_parse_sources("@stdlib/common.tolk", entrypoint_filename);
 
     pipeline_register_global_symbols(all_files);
+    pipeline_resolve_identifiers_and_assign_symbols(all_files);
+    pipeline_calculate_rvalue_lvalue(all_files);
+    pipeline_detect_unreachable_statements(all_files);
+    pipeline_infer_and_check_types(all_files);
+    pipeline_refine_lvalue_for_mutate_arguments(all_files);
+    pipeline_check_rvalue_lvalue(all_files);
+    pipeline_check_pure_impure_operations(all_files);
+    pipeline_constant_folding(all_files);
     pipeline_convert_ast_to_legacy_Expr_Op(all_files);
 
     pipeline_find_unused_symbols();

tolk/tolk.h

@@ -22,6 +22,7 @@
 #include "symtable.h"
 #include "crypto/common/refint.h"
 #include "td/utils/Status.h"
+#include <functional>
 #include <vector>
 #include <string>
 #include <stack>
@@ -64,22 +65,27 @@ void unify(TypeExpr*& te1, TypeExpr*& te2);
  * 
  */
 
-using const_idx_t = int;
+typedef int var_idx_t;
+typedef int const_idx_t;
 
 struct TmpVar {
   TypeExpr* v_type;
   var_idx_t idx;
-  sym_idx_t sym_idx;
+  const LocalVarData* v_sym;  // points to var defined in code; nullptr for implicitly created tmp vars
   int coord;
   SrcLocation where;
   std::vector<std::function<void(SrcLocation)>> on_modification;
 
-  TmpVar(var_idx_t _idx, TypeExpr* _type, sym_idx_t sym_idx, SrcLocation loc);
-  bool is_unnamed() const { return sym_idx == 0; }
+  TmpVar(var_idx_t _idx, TypeExpr* _type, const LocalVarData* v_sym, SrcLocation loc)
+    : v_type(_type)
+    , idx(_idx)
+    , v_sym(v_sym)
+    , coord(0)
+    , where(loc) {
+  }
 
   void show(std::ostream& os, int omit_idx = 0) const;
   void dump(std::ostream& os) const;
-  void set_location(SrcLocation loc);
 };
 
 struct VarDescr {
@@ -171,7 +177,6 @@ struct VarDescr {
   void set_const(long long value);
   void set_const(td::RefInt256 value);
   void set_const(std::string value);
-  void set_const_nan();
   void operator+=(const VarDescr& y) {
     flags &= y.flags;
   }
@@ -303,7 +308,8 @@ struct Op {
   enum { _Disabled = 1, _NoReturn = 4, _Impure = 24 };
   int flags;
   std::unique_ptr<Op> next;
-  SymDef* fun_ref;   // despite its name, it may actually ref global var; applicable not only to Op::_Call, but for other kinds also
+  const FunctionData* f_sym = nullptr;
+  const GlobalVarData* g_sym = nullptr;
   SrcLocation where;
   VarDescrList var_info;
   std::vector<VarDescr> args;
@@ -311,27 +317,41 @@ struct Op {
   std::unique_ptr<Op> block0, block1;
   td::RefInt256 int_const;
   std::string str_const;
-  Op(SrcLocation _where = {}, OpKind _cl = _Undef) : cl(_cl), flags(0), fun_ref(nullptr), where(_where) {
+  Op(SrcLocation _where = {}, OpKind _cl = _Undef) : cl(_cl), flags(0), f_sym(nullptr), where(_where) {
   }
   Op(SrcLocation _where, OpKind _cl, const std::vector<var_idx_t>& _left)
-      : cl(_cl), flags(0), fun_ref(nullptr), where(_where), left(_left) {
+      : cl(_cl), flags(0), f_sym(nullptr), where(_where), left(_left) {
   }
   Op(SrcLocation _where, OpKind _cl, std::vector<var_idx_t>&& _left)
-      : cl(_cl), flags(0), fun_ref(nullptr), where(_where), left(std::move(_left)) {
+      : cl(_cl), flags(0), f_sym(nullptr), where(_where), left(std::move(_left)) {
   }
   Op(SrcLocation _where, OpKind _cl, const std::vector<var_idx_t>& _left, td::RefInt256 _const)
-      : cl(_cl), flags(0), fun_ref(nullptr), where(_where), left(_left), int_const(_const) {
+      : cl(_cl), flags(0), f_sym(nullptr), where(_where), left(_left), int_const(_const) {
   }
   Op(SrcLocation _where, OpKind _cl, const std::vector<var_idx_t>& _left, std::string _const)
-      : cl(_cl), flags(0), fun_ref(nullptr), where(_where), left(_left), str_const(_const) {
+      : cl(_cl), flags(0), f_sym(nullptr), where(_where), left(_left), str_const(_const) {
+  }
+  Op(SrcLocation _where, OpKind _cl, const std::vector<var_idx_t>& _left, const std::vector<var_idx_t>& _right)
+      : cl(_cl), flags(0), f_sym(nullptr), where(_where), left(_left), right(_right) {
+  }
+  Op(SrcLocation _where, OpKind _cl, std::vector<var_idx_t>&& _left, std::vector<var_idx_t>&& _right)
+      : cl(_cl), flags(0), f_sym(nullptr), where(_where), left(std::move(_left)), right(std::move(_right)) {
   }
   Op(SrcLocation _where, OpKind _cl, const std::vector<var_idx_t>& _left, const std::vector<var_idx_t>& _right,
-     SymDef* _fun = nullptr)
-      : cl(_cl), flags(0), fun_ref(_fun), where(_where), left(_left), right(_right) {
+     const FunctionData* _fun)
+      : cl(_cl), flags(0), f_sym(_fun), where(_where), left(_left), right(_right) {
   }
   Op(SrcLocation _where, OpKind _cl, std::vector<var_idx_t>&& _left, std::vector<var_idx_t>&& _right,
-     SymDef* _fun = nullptr)
-      : cl(_cl), flags(0), fun_ref(_fun), where(_where), left(std::move(_left)), right(std::move(_right)) {
+     const FunctionData* _fun)
+      : cl(_cl), flags(0), f_sym(_fun), where(_where), left(std::move(_left)), right(std::move(_right)) {
+  }
+  Op(SrcLocation _where, OpKind _cl, const std::vector<var_idx_t>& _left, const std::vector<var_idx_t>& _right,
+     const GlobalVarData* _gvar)
+      : cl(_cl), flags(0), g_sym(_gvar), where(_where), left(_left), right(_right) {
+  }
+  Op(SrcLocation _where, OpKind _cl, std::vector<var_idx_t>&& _left, std::vector<var_idx_t>&& _right,
+     const GlobalVarData* _gvar)
+      : cl(_cl), flags(0), g_sym(_gvar), where(_where), left(std::move(_left)), right(std::move(_right)) {
   }
 
   bool disabled() const { return flags & _Disabled; }
@@ -343,8 +363,7 @@ struct Op {
   bool set_noreturn(bool flag);
 
   bool impure() const { return flags & _Impure; }
-  void set_impure(const CodeBlob &code);
-  void set_impure(const CodeBlob &code, bool flag);
+  void set_impure_flag();
 
   void show(std::ostream& os, const std::vector<TmpVar>& vars, std::string pfx = "", int mode = 0) const;
   void show_var_list(std::ostream& os, const std::vector<var_idx_t>& idx_list, const std::vector<TmpVar>& vars) const;
@@ -391,247 +410,16 @@ inline ListIterator<const Op> end(const Op* op_list) {
   return ListIterator<const Op>{};
 }
 
-typedef std::tuple<TypeExpr*, SymDef*, SrcLocation> FormalArg;
+typedef std::tuple<TypeExpr*, const LocalVarData*, SrcLocation> FormalArg;
 typedef std::vector<FormalArg> FormalArgList;
 
 struct AsmOpList;
 
-/*
- *
- *   SYMBOL VALUES
- * 
- */
-
-struct SymValVariable : SymValBase {
-  enum SymValFlag {
-    flagMutateParameter = 1,    // parameter was declared with `mutate` keyword
-    flagImmutable = 2,          // variable was declared via `val` (not `var`)
-  };
-  int flags{0};
-
-  ~SymValVariable() override = default;
-  SymValVariable(int val, TypeExpr* sym_type)
-      : SymValBase(SymValKind::_Var, val, sym_type) {}
-
-  bool is_function_parameter() const {
-    return idx >= 0;
-  }
-  bool is_mutate_parameter() const {
-    return flags & flagMutateParameter;
-  }
-  bool is_local_var() const {
-    return idx == -1;
-  }
-  bool is_immutable() const {
-    return flags & flagImmutable;
-  }
-};
-
-struct SymValFunc : SymValBase {
-  enum SymValFlag {
-    flagInline = 1,             // marked `@inline`
-    flagInlineRef = 2,          // marked `@inline_ref`
-    flagUsedAsNonCall = 8,      // used not only as `f()`, but as a 1-st class function (assigned to var, pushed to tuple, etc.)
-    flagMarkedAsPure = 16,      // declared as `pure`, can't call impure and access globals, unused invocations are optimized out
-    flagBuiltinFunction = 32,   // was created via `define_builtin_func()`, not from source code
-    flagGetMethod = 64,         // was declared via `get func(): T`, method_id is auto-assigned
-    flagIsEntrypoint = 128,     // it's `main` / `onExternalMessage` / etc.
-    flagHasMutateParams = 256,  // has parameters declared as `mutate`
-    flagAcceptsSelf = 512,      // is a member function (has `self` first parameter)
-    flagReturnsSelf = 1024,     // return type is `self` (returns the mutated 1st argument), calls can be chainable
-  };
-
-  td::RefInt256 method_id;  // todo why int256? it's small
-  int flags{0};
-  std::vector<SymDef*> parameters;  // [i]-th may be nullptr for underscore; if not, its val is SymValVariable
-  std::vector<int> arg_order, ret_order;
-
-  ~SymValFunc() override = default;
-  SymValFunc(std::vector<SymDef*> parameters, int val, TypeExpr* sym_type, int flags)
-      : SymValBase(SymValKind::_Func, val, sym_type), flags(flags), parameters(std::move(parameters)) {
-  }
-  SymValFunc(std::vector<SymDef*> parameters, int val, TypeExpr* sym_type, int flags, std::initializer_list<int> arg_order, std::initializer_list<int> ret_order)
-      : SymValBase(SymValKind::_Func, val, sym_type), flags(flags), parameters(std::move(parameters)), arg_order(arg_order), ret_order(ret_order) {
-  }
-
-  const std::vector<int>* get_arg_order() const {
-    return arg_order.empty() ? nullptr : &arg_order;
-  }
-  const std::vector<int>* get_ret_order() const {
-    return ret_order.empty() ? nullptr : &ret_order;
-  }
-
-  bool is_inline() const {
-    return flags & flagInline;
-  }
-  bool is_inline_ref() const {
-    return flags & flagInlineRef;
-  }
-  bool is_marked_as_pure() const {
-    return flags & flagMarkedAsPure;
-  }
-  bool is_builtin() const {
-    return flags & flagBuiltinFunction;
-  }
-  bool is_get_method() const {
-    return flags & flagGetMethod;
-  }
-  bool is_entrypoint() const {
-    return flags & flagIsEntrypoint;
-  }
-  bool has_mutate_params() const {
-    return flags & flagHasMutateParams;
-  }
-  bool does_accept_self() const {
-    return flags & flagAcceptsSelf;
-  }
-  bool does_return_self() const {
-    return flags & flagReturnsSelf;
-  }
-};
-
-struct SymValCodeFunc : SymValFunc {
+struct FunctionBodyCode {
   CodeBlob* code;
-  bool is_really_used{false};   // calculated via dfs; unused functions are not codegenerated
-  ~SymValCodeFunc() override = default;
-  SymValCodeFunc(std::vector<SymDef*> parameters, int val, TypeExpr* _ft)
-    : SymValFunc(std::move(parameters), val, _ft, 0), code(nullptr) {
-  }
-  bool does_need_codegen() const;
   void set_code(CodeBlob* code);
 };
 
-struct SymValGlobVar : SymValBase {
-  bool is_really_used{false};   // calculated via dfs from used functions; unused globals are not codegenerated
-
-  SymValGlobVar(int val, TypeExpr* gvtype)
-      : SymValBase(SymValKind::_GlobVar, val, gvtype) {
-  }
-  ~SymValGlobVar() override = default;
-};
-
-struct SymValConst : SymValBase {
-  enum ConstKind { IntConst, SliceConst };
-
-  td::RefInt256 intval;
-  std::string strval;
-  ConstKind kind;
-
-  SymValConst(int idx, td::RefInt256 value)
-      : SymValBase(SymValKind::_Const, idx, TypeExpr::new_atomic(TypeExpr::_Int)), intval(std::move(value)), kind(IntConst) {
-  }
-  SymValConst(int idx, std::string value)
-      : SymValBase(SymValKind::_Const, idx, TypeExpr::new_atomic(TypeExpr::_Slice)), strval(std::move(value)), kind(SliceConst) {
-  }
-  ~SymValConst() override = default;
-  td::RefInt256 get_int_value() const {
-    return intval;
-  }
-  std::string get_str_value() const {
-    return strval;
-  }
-  ConstKind get_kind() const {
-    return kind;
-  }
-};
-
-
-/*
- * 
- *   EXPRESSIONS
- * 
- */
-
-struct Expr {
-  enum ExprCls {
-    _Apply,
-    _VarApply,
-    _GrabMutatedVars,
-    _ReturnSelf,
-    _MkTuple,
-    _Tensor,
-    _Const,
-    _Var,
-    _GlobFunc,
-    _GlobVar,
-    _Letop,
-    _Hole,
-    _CondExpr,
-    _SliceConst,
-  };
-  ExprCls cls;
-  int val{0};
-  enum { _IsRvalue = 2, _IsLvalue = 4, _IsImmutable = 8, _IsImpure = 32 };
-  int flags{0};
-  SrcLocation here;
-  td::RefInt256 intval;
-  std::string strval;
-  SymDef* sym{nullptr};
-  TypeExpr* e_type{nullptr};
-  std::vector<Expr*> args;
-  Expr(ExprCls c, SrcLocation loc) : cls(c), here(loc) {
-  }
-  Expr(ExprCls c, std::vector<Expr*> _args) : cls(c), args(std::move(_args)) {
-  }
-  Expr(ExprCls c, std::initializer_list<Expr*> _arglist) : cls(c), args(std::move(_arglist)) {
-  }
-  Expr(ExprCls c, SymDef* _sym, std::initializer_list<Expr*> _arglist) : cls(c), sym(_sym), args(std::move(_arglist)) {
-  }
-  Expr(ExprCls c, SymDef* _sym, std::vector<Expr*> _arglist) : cls(c), sym(_sym), args(std::move(_arglist)) {
-  }
-  Expr(ExprCls c, sym_idx_t name_idx, std::initializer_list<Expr*> _arglist);
-  ~Expr() {
-    for (auto& arg_ptr : args) {
-      delete arg_ptr;
-    }
-  }
-  Expr* copy() const;
-  void pb_arg(Expr* expr) {
-    args.push_back(expr);
-  }
-  void set_val(int _val) {
-    val = _val;
-  }
-  bool is_rvalue() const {
-    return flags & _IsRvalue;
-  }
-  bool is_lvalue() const {
-    return flags & _IsLvalue;
-  }
-  bool is_immutable() const {
-    return flags & _IsImmutable;
-  }
-  bool is_mktuple() const {
-    return cls == _MkTuple;
-  }
-  void chk_rvalue() const {
-    if (!is_rvalue()) {
-      fire_error_rvalue_expected();
-    }
-  }
-  void deduce_type();
-  void set_location(SrcLocation loc) {
-    here = loc;
-  }
-  SrcLocation get_location() const {
-    return here;
-  }
-  void define_new_vars(CodeBlob& code);
-  void predefine_vars();
-  std::vector<var_idx_t> pre_compile(CodeBlob& code, std::vector<std::pair<SymDef*, var_idx_t>>* lval_globs = nullptr) const;
-  var_idx_t new_tmp(CodeBlob& code) const;
-  std::vector<var_idx_t> new_tmp_vect(CodeBlob& code) const {
-    return {new_tmp(code)};
-  }
-
-  GNU_ATTRIBUTE_COLD GNU_ATTRIBUTE_NORETURN
-  void fire_error_rvalue_expected() const;
-  GNU_ATTRIBUTE_COLD GNU_ATTRIBUTE_NORETURN
-  void fire_error_lvalue_expected(const std::string& details) const;
-  GNU_ATTRIBUTE_COLD GNU_ATTRIBUTE_NORETURN
-  void fire_error_modifying_immutable(const std::string& details) const;
-};
-
 /*
  * 
  *   GENERATE CODE
@@ -651,7 +439,6 @@ struct AsmOp {
   int a, b;
   bool gconst{false};
   std::string op;
-  td::RefInt256 origin;
   struct SReg {
     int idx;
     SReg(int _idx) : idx(_idx) {
@@ -671,9 +458,6 @@ struct AsmOp {
   AsmOp(Type _t, int _a, int _b, std::string _op) : t(_t), a(_a), b(_b), op(std::move(_op)) {
     compute_gconst();
   }
-  AsmOp(Type _t, int _a, int _b, std::string _op, td::RefInt256 x) : t(_t), a(_a), b(_b), op(std::move(_op)), origin(x) {
-    compute_gconst();
-  }
   void out(std::ostream& os) const;
   void out_indent_nl(std::ostream& os, bool no_nl = false) const;
   std::string to_string() const;
@@ -786,20 +570,20 @@ struct AsmOp {
   static AsmOp BlkReverse(int a, int b);
   static AsmOp make_stk2(int a, int b, const char* str, int delta);
   static AsmOp make_stk3(int a, int b, int c, const char* str, int delta);
-  static AsmOp IntConst(td::RefInt256 value);
+  static AsmOp IntConst(const td::RefInt256& x);
   static AsmOp BoolConst(bool f);
-  static AsmOp Const(std::string push_op, td::RefInt256 origin = {}) {
-    return AsmOp(a_const, 0, 1, std::move(push_op), origin);
+  static AsmOp Const(std::string push_op) {
+    return AsmOp(a_const, 0, 1, std::move(push_op));
   }
-  static AsmOp Const(int arg, std::string push_op, td::RefInt256 origin = {});
-  static AsmOp Comment(std::string comment) {
+  static AsmOp Const(int arg, const std::string& push_op);
+  static AsmOp Comment(const std::string& comment) {
     return AsmOp(a_none, std::string{"// "} + comment);
   }
-  static AsmOp Custom(std::string custom_op) {
+  static AsmOp Custom(const std::string& custom_op) {
     return AsmOp(a_custom, 255, 255, custom_op);
   }
-  static AsmOp Parse(std::string custom_op);
-  static AsmOp Custom(std::string custom_op, int args, int retv = 1) {
+  static AsmOp Parse(const std::string& custom_op);
+  static AsmOp Custom(const std::string& custom_op, int args, int retv = 1) {
     return AsmOp(a_custom, args, retv, custom_op);
   }
   static AsmOp Parse(std::string custom_op, int args, int retv = 1);
@@ -887,18 +671,6 @@ inline std::ostream& operator<<(std::ostream& os, const AsmOpList& op_list) {
   return os;
 }
 
-class IndentGuard {
-  AsmOpList& aol_;
-
- public:
-  IndentGuard(AsmOpList& aol) : aol_(aol) {
-    aol.indent();
-  }
-  ~IndentGuard() {
-    aol_.undent();
-  }
-};
-
 struct AsmOpCons {
   std::unique_ptr<AsmOp> car;
   std::unique_ptr<AsmOpCons> cdr;
@@ -1321,71 +1093,57 @@ struct Stack {
  */
 
 typedef std::function<AsmOp(std::vector<VarDescr>&, std::vector<VarDescr>&, SrcLocation)> simple_compile_func_t;
-typedef std::function<bool(AsmOpList&, std::vector<VarDescr>&, std::vector<VarDescr>&)> compile_func_t;
 
 inline simple_compile_func_t make_simple_compile(AsmOp op) {
   return [op](std::vector<VarDescr>& out, std::vector<VarDescr>& in, SrcLocation) -> AsmOp { return op; };
 }
 
-inline compile_func_t make_ext_compile(std::vector<AsmOp>&& ops) {
-  return [ops = std::move(ops)](AsmOpList& dest, std::vector<VarDescr>& out, std::vector<VarDescr>& in)->bool {
-    return dest.append(ops);
-  };
-}
-
-inline compile_func_t make_ext_compile(AsmOp op) {
-  return
-      [op](AsmOpList& dest, std::vector<VarDescr>& out, std::vector<VarDescr>& in) -> bool { return dest.append(op); };
-}
-
-struct SymValAsmFunc : SymValFunc {
+struct FunctionBodyBuiltin {
   simple_compile_func_t simple_compile;
-  compile_func_t ext_compile;
-  ~SymValAsmFunc() override = default;
-  SymValAsmFunc(std::vector<SymDef*> parameters, TypeExpr* ft, std::vector<int>&& arg_order, std::vector<int>&& ret_order, int flags)
-      : SymValFunc(std::move(parameters), -1, ft, flags) {
-    this->arg_order = std::move(arg_order);
-    this->ret_order = std::move(ret_order);
-  }
-  SymValAsmFunc(std::vector<SymDef*> parameters, TypeExpr* ft, simple_compile_func_t _compile, int flags)
-      : SymValFunc(std::move(parameters), -1, ft, flags), simple_compile(std::move(_compile)) {
-  }
-  SymValAsmFunc(std::vector<SymDef*> parameters, TypeExpr* ft, simple_compile_func_t _compile, int flags,
-                std::initializer_list<int> arg_order, std::initializer_list<int> ret_order)
-      : SymValFunc(std::move(parameters), -1, ft, flags, arg_order, ret_order), simple_compile(std::move(_compile)) {
-  }
-  void set_code(std::vector<AsmOp> code);
-  bool compile(AsmOpList& dest, std::vector<VarDescr>& out, std::vector<VarDescr>& in, SrcLocation where) const;
+
+  explicit FunctionBodyBuiltin(simple_compile_func_t compile)
+    : simple_compile(std::move(compile)) {}
+
+  void compile(AsmOpList& dest, std::vector<VarDescr>& out, std::vector<VarDescr>& in, SrcLocation where) const;
+};
+
+struct FunctionBodyAsm {
+  std::vector<AsmOp> ops;
+
+  void set_code(std::vector<AsmOp>&& code);
+  void compile(AsmOpList& dest) const;
 };
 
 struct CodeBlob {
-  enum { _ForbidImpure = 4 };
   int var_cnt, in_var_cnt;
   TypeExpr* ret_type;
-  const SymValCodeFunc* func_val;
+  const FunctionData* fun_ref;
   std::string name;
   SrcLocation loc;
   std::vector<TmpVar> vars;
   std::unique_ptr<Op> ops;
   std::unique_ptr<Op>* cur_ops;
-  std::vector<Op*> debug_ttt;
+#ifdef TOLK_DEBUG
+  std::vector<Op*> _vector_of_ops;  // to see it in debugger instead of nested pointers
+#endif
   std::stack<std::unique_ptr<Op>*> cur_ops_stack;
-  int flags = 0;
   bool require_callxargs = false;
-  CodeBlob(std::string name, SrcLocation loc, const SymValCodeFunc* func_val, TypeExpr* ret_type)
-    : var_cnt(0), in_var_cnt(0), ret_type(ret_type), func_val(func_val), name(std::move(name)), loc(loc), cur_ops(&ops) {
+  CodeBlob(std::string name, SrcLocation loc, const FunctionData* fun_ref, TypeExpr* ret_type)
+    : var_cnt(0), in_var_cnt(0), ret_type(ret_type), fun_ref(fun_ref), name(std::move(name)), loc(loc), cur_ops(&ops) {
   }
   template <typename... Args>
   Op& emplace_back(Args&&... args) {
     Op& res = *(*cur_ops = std::make_unique<Op>(args...));
     cur_ops = &(res.next);
-    debug_ttt.push_back(&res);
+#ifdef TOLK_DEBUG
+    _vector_of_ops.push_back(&res);
+#endif
     return res;
   }
-  bool import_params(FormalArgList arg_list);
-  var_idx_t create_var(TypeExpr* var_type, var_idx_t sym_idx, SrcLocation loc);
+  bool import_params(FormalArgList&& arg_list);
+  var_idx_t create_var(TypeExpr* var_type, const LocalVarData* v_sym, SrcLocation loc);
   var_idx_t create_tmp_var(TypeExpr* var_type, SrcLocation loc) {
-    return create_var(var_type, 0, loc);
+    return create_var(var_type, nullptr, loc);
   }
   int split_vars(bool strict = false);
   bool compute_used_code_vars();
@@ -1413,11 +1171,13 @@ struct CodeBlob {
   void generate_code(AsmOpList& out_list, int mode = 0);
   void generate_code(std::ostream& os, int mode = 0, int indent = 0);
 
-  void on_var_modification(var_idx_t idx, SrcLocation here) const {
-    for (auto& f : vars.at(idx).on_modification) {
+  void on_var_modification(const std::vector<var_idx_t>& left_lval_indices, SrcLocation here) const {
+    for (var_idx_t ir_idx : left_lval_indices) {
+      for (auto& f : vars.at(ir_idx).on_modification) {
         f(here);
       }
     }
+  }
 };
 
 // defined in builtins.cpp

tolk/unify-types.cpp

@@ -121,7 +121,7 @@ bool TypeExpr::equals_to(const TypeExpr *rhs) const {
   while (r->constr == te_Indirect)
     r = r->args[0];
 
-  bool eq = l->constr == r->constr && l->value == r->value &&
+  bool eq = l->constr == r->constr && (l->constr == te_Unknown || l->value == r->value) &&
             l->minw == r->minw && l->maxw == r->maxw &&
             l->was_forall_var == r->was_forall_var &&
             l->args.size() == r->args.size();