library TVM_Disasm
// simple TVM Disassembler
"Lists.fif" include

variable 'disasm
{ 'disasm @ execute } : disasm  // disassemble a slice
// usage: x{74B0} disasm

variable @dismode  @dismode 0!
{ rot over @ and rot xor swap ! } : andxor!
{ -2 0 @dismode andxor! } : stack-disasm  // output 's1 s4 XCHG'
{ -2 1 @dismode andxor! } : std-disasm    // output 'XCHG s1, s4'
{ -3 2 @dismode andxor! } : show-vm-code
{ -3 0 @dismode andxor! } : hide-vm-code
{ @dismode @ 1 and 0= } : stack-disasm?

variable @indent  @indent 0!
{ ' space @indent @ 2* times } : .indent
{ @indent 1+! } : +indent
{ @indent 1-! } : -indent

{ " " $pos } : spc-pos
{ dup " " $pos swap "," $pos dup 0< { drop } {
  over 0< { nip } { min } cond } cond
} : spc-comma-pos
{ { dup spc-pos 0= } { 1 $| nip } while } : -leading
{ -leading -trailing dup spc-pos dup 0< {
  drop dup $len { atom single } { drop nil } cond } {
    $| swap atom swap -leading 2 { over spc-comma-pos dup 0>= } {
      swap 1+ -rot $| 1 $| nip -leading rot
    } while drop tuple
  } cond
} : parse-op
{ dup "s-1" $= { drop "s(-1)" true } {
  dup "s-2" $= { drop "s(-2)" true } {
  dup 1 $| swap "x" $= { nip "x{" swap $+ +"}" true } {
  2drop false } cond } cond } cond
} : adj-op-arg
{ over count over <= { drop } { 2dup [] adj-op-arg { swap []= } { drop } cond } cond } : adj-arg[]
{ 1 adj-arg[] 2 adj-arg[] 3 adj-arg[]
  dup first
  dup `XCHG eq? {
    drop dup count 2 = { tpop swap "s0" , swap , } if } {
  dup `LSHIFT eq? {
    drop dup count 2 = stack-disasm? and { second `LSHIFT# swap pair } if } {
  dup `RSHIFT eq? {
    drop dup count 2 = stack-disasm? and { second `RSHIFT# swap pair } if } {
  drop 
  } cond } cond } cond
} : adjust-op

variable @cp  @cp 0!
variable @curop
variable @contX  variable @contY  variable @cdict

{ atom>$ type } : .atom
{ dup first .atom dup count 1 > { space 0 over count 2- { 1+ 2dup [] type .", " } swap times 1+ [] type } { drop } cond } : std-show-op
{ 0 over count 1- { 1+ 2dup [] type space } swap times drop first .atom } : stk-show-op
{ @dismode @ 2 and { .indent ."// " @curop @ csr. } if } : .curop?
{ .curop? .indent @dismode @ 1 and ' std-show-op ' stk-show-op cond cr
} : show-simple-op
{ dup 4 u@ 9 = { 8 u@+ swap 15 and 3 << s@ } {
  dup 7 u@ 0x47 = { 7 u@+ nip 2 u@+ 7 u@+ -rot 3 << swap sr@ } {
  dup 8 u@ 0x8A = { ref@ <s } {
  abort"invalid PUSHCONT"
  } cond } cond } cond
} : get-cont-body
{ 14 u@+ nip 10 u@+ ref@ dup rot pair swap <s empty? { drop null } if } : get-const-dict
{ @contX @ @contY @ @contX ! @contY ! } : scont-swap
{ .indent swap type type cr @contY @ @contY null! @contX @ @contX null!
  +indent disasm -indent @contY !
} : show-cont-bodyx
{ ":<{" show-cont-bodyx .indent ."}>" cr } : show-cont-op
{ swap scont-swap ":<{" show-cont-bodyx scont-swap
  "" show-cont-bodyx .indent ."}>" cr } : show-cont2-op

{ @contX @ null? { "CONT" show-cont-op } ifnot
} : flush-contX
{ @contY @ null? { scont-swap "CONT" show-cont-op scont-swap } ifnot
} : flush-contY
{ flush-contY flush-contX } : flush-cont
{ @contX @ null? not } : have-cont?
{ @contY @ null? not } : have-cont2?
{ flush-contY @contY ! scont-swap } : save-cont-body

{ @cdict ! } : save-const-dict
{ @cdict null! } : flush-dict
{ @cdict @ null? not } : have-dict?

{ flush-cont .indent type .":<{" cr
  @curop @ ref@ <s +indent disasm -indent .indent ."}>" cr
} : show-ref-op
{ flush-contY .indent rot type .":<{" cr
  @curop @ ref@ <s @contX @ @contX null! rot ' swap if
  +indent disasm -indent .indent swap type cr
  +indent disasm -indent .indent ."}>" cr
} : show-cont-ref-op
{ flush-cont .indent swap type .":<{" cr
  @curop @ ref@+ <s +indent disasm -indent .indent swap type cr
  ref@ <s +indent disasm -indent .indent ."}>" cr
} : show-ref2-op

{ flush-cont first atom>$ dup 5 $| drop "DICTI" $= swap
  .indent type ." {" cr +indent @cdict @ @cdict null! unpair
  rot {
    swap .indent . ."=> <{" cr +indent disasm -indent .indent ."}>" cr true
  } swap ' idictforeach ' dictforeach cond drop 
  -indent .indent ."}" cr
} : show-const-dict-op

( `PUSHCONT `PUSHREFCONT ) constant @PushContL
( `REPEAT `UNTIL `IF `IFNOT `IFJMP `IFNOTJMP ) constant @CmdC1
( `IFREF `IFNOTREF `IFJMPREF `IFNOTJMPREF `CALLREF `JMPREF ) constant @CmdR1
( `DICTIGETJMP `DICTIGETJMPZ `DICTUGETJMP `DICTUGETJMPZ `DICTIGETEXEC `DICTUGETEXEC ) constant @JmpDictL
{ dup first `DICTPUSHCONST eq? {
    flush-cont @curop @ get-const-dict save-const-dict show-simple-op } {
  dup first @JmpDictL list-member? have-dict? and {
    flush-cont show-const-dict-op } {
  flush-dict
  dup first @PushContL list-member? {
    drop @curop @ get-cont-body save-cont-body } {
  dup first @CmdC1 list-member? have-cont? and {
    flush-contY first atom>$ .curop? show-cont-op } {
  dup first @CmdR1 list-member? {
    flush-cont first atom>$ dup $len 3 - $| drop .curop? show-ref-op } {
  dup first `WHILE eq? have-cont2? and {
    drop "WHILE" "}>DO<{" .curop? show-cont2-op } {
  dup first `IFELSE eq? have-cont2? and {
    drop "IF" "}>ELSE<{" .curop? show-cont2-op } {
  dup first dup `IFREFELSE eq? swap `IFELSEREF eq? or have-cont? and {
    first `IFREFELSE eq? "IF" "}>ELSE<{" rot .curop? show-cont-ref-op } {
  dup first `IFREFELSEREF eq? {
    drop "IF" "}>ELSE<{" .curop? show-ref2-op } {
    flush-cont show-simple-op
  } cond } cond } cond } cond } cond } cond } cond } cond } cond
} : show-op
{ dup @cp @ (vmoplen) dup 0> { 65536 /mod swap sr@+ swap dup @cp @ (vmopdump) parse-op swap s> true } { drop false } cond } : fetch-one-op
{ { fetch-one-op } { swap @curop ! adjust-op show-op } while } : disasm-slice
{ { disasm-slice dup sbitrefs 1- or 0= } { ref@ <s } while flush-dict flush-cont } : disasm-chain
{ @curop @ swap disasm-chain dup sbitrefs or { .indent ."Cannot disassemble: " csr. } { drop } cond @curop ! }
'disasm !