From 3b1d33f54305c97301b3daa9ff6c39849490c86d Mon Sep 17 00:00:00 2001
From: EmelyanenkoK <emelyanenko.kirill@gmail.com>
Date: Tue, 20 Sep 2022 14:16:53 +0300
Subject: [PATCH] Allow constants with the same name and value (#462)

Co-authored-by: legaii <jgates.ardux@gmail.com>
---
 crypto/func/parse-func.cpp | 21 +++++++++++++++------
 crypto/func/test/co2.fc    | 15 +++++++++++++++
 2 files changed, 30 insertions(+), 6 deletions(-)
 create mode 100644 crypto/func/test/co2.fc

diff --git a/crypto/func/parse-func.cpp b/crypto/func/parse-func.cpp
index 439dfb88..6118a433 100644
--- a/crypto/func/parse-func.cpp
+++ b/crypto/func/parse-func.cpp
@@ -254,9 +254,7 @@ void parse_const_decl(Lexer& lex) {
   if (!sym_def) {
     lex.cur().error_at("cannot define global symbol `", "`");
   }
-  if (sym_def->value) {
-    lex.cur().error_at("global symbol `", "` already exists");
-  }
+  Lexem ident = lex.cur();
   lex.next();
   if (lex.tp() != '=') {
     lex.cur().error_at("expected = instead of ", "");
@@ -273,10 +271,11 @@ void parse_const_decl(Lexer& lex) {
   if ((wanted_type != Expr::_None) && (x->cls != wanted_type)) {
     lex.cur().error("expression type does not match wanted type");
   }
+  SymValConst* new_value = nullptr;
   if (x->cls == Expr::_Const) { // Integer constant
-    sym_def->value = new SymValConst{const_cnt++, x->intval};
+    new_value = new SymValConst{const_cnt++, x->intval};
   } else if (x->cls == Expr::_SliceConst) { // Slice constant (string)
-    sym_def->value = new SymValConst{const_cnt++, x->strval};
+    new_value = new SymValConst{const_cnt++, x->strval};
   } else if (x->cls == Expr::_Apply) {
     code.emplace_back(loc, Op::_Import, std::vector<var_idx_t>());
     auto tmp_vars = x->pre_compile(code);
@@ -304,10 +303,20 @@ void parse_const_decl(Lexer& lex) {
     if (op.origin.is_null() || !op.origin->is_valid()) {
       lex.cur().error("precompiled expression did not result in a valid integer constant");
     }
-    sym_def->value = new SymValConst{const_cnt++, op.origin};
+    new_value = new SymValConst{const_cnt++, op.origin};
   } else {
     lex.cur().error("integer or slice literal or constant expected");
   }
+  if (sym_def->value) {
+    SymValConst* old_value = dynamic_cast<SymValConst*>(sym_def->value);
+    Keyword new_type = new_value->get_type();
+    if (!old_value || old_value->get_type() != new_type ||
+        (new_type == _Int && *old_value->get_int_value() != *new_value->get_int_value()) ||
+        (new_type == _Slice && old_value->get_str_value() != new_value->get_str_value())) {
+      ident.error_at("global symbol `", "` already exists");
+    }
+  }
+  sym_def->value = new_value;
 }
 
 FormalArgList parse_formal_args(Lexer& lex) {
diff --git a/crypto/func/test/co2.fc b/crypto/func/test/co2.fc
new file mode 100644
index 00000000..f5fcb748
--- /dev/null
+++ b/crypto/func/test/co2.fc
@@ -0,0 +1,15 @@
+const int x = 5;
+const slice s = "abacaba";
+const int y = 3;
+const slice s = "abacaba";
+const int x = 5;
+const int z = 4, z = 4;
+
+int sdeq (slice s1, slice s2) asm "SDEQ";
+
+() main() {
+  throw_unless(101, x == 5);
+  throw_unless(102, y == 3);
+  throw_unless(103, z == 4);
+  throw_unless(104, sdeq(s, "abacaba"));
+}