Bug 9834 – incorrect detection of lambda locality.

This code makes AccessViolation on git master head: ------------------- struct Event() { void delegate() dg; void set(void delegate() handler) { dg = handler; } void call() { dg(); } } void main() { Event!() ev; auto a = new class { Object o; this() { o = new Object; ev.set((){o.toString();}); } }; ev.call(); } ------------------- $ dmd -run main object.Error: Access Violation ---------------- 0x004020A5 0x00402128 0x00402057 0x004029EC 0x00402A27 0x00402625 0x00402140 0x769133AA in BaseThreadInitThunk 0x774E9EF2 in RtlInitializeExceptionChain 0x774E9EC5 in RtlInitializeExceptionChain And, following is git bisect result: $ git bisect bad 67fbf5753e9d4a276c354e952ed2f888efcb714c is the first bad commit

(In reply to comment #0) > And, following is git bisect result: > $ git bisect bad > 67fbf5753e9d4a276c354e952ed2f888efcb714c is the first bad commit The commit is not a root cause. If change Event struct to non-template, and add pure to set method, AV still occurs. struct Event { void delegate() dg; //void set(void delegate() h) { dg = h; } // no AV void set(void delegate() h) pure { dg = h; } // AV occurs void call() { dg(); } } void main() { Event ev; auto a = new class { Object o; this() { o = new Object; ev.set((){ o.toString(); }); } }; ev.call(); }

Ok, I found the root cause. version(bad) void set(void delegate() h) pure { dg = h; } // AV occurs else void set(void delegate() h) { dg = h; } // no AV // -version=bad c:\d\test.d:14 this() { 004020ec: 55 push ebp 004020ed: 8bec mov ebp, esp 004020ef: 83ec04 sub esp, 0x4 004020f2: 53 push ebx 004020f3: 56 push esi 004020f4: 8945fc mov [ebp-0x4], eax c:\d\test.d:15 o = new Object; 004020f7: b880f34100 mov eax, 0x41f380 004020fc: 50 push eax 004020fd: e87e020000 call 0x402380 __d_newclass 00402102: 8b4dfc mov ecx, [ebp-0x4] 00402105: 894108 mov [ecx+0x8], eax c:\d\test.d:16 ev.set((){ 00402108: ba2c214000 mov edx, 0x40212c 0040210d: 52 push edx 0040210e: 8d5dfc lea ebx, [ebp-0x4] 00402111: 53 push ebx 00402112: 8b75fc mov esi, [ebp-0x4] 00402115: 8b460c mov eax, [esi+0xc] 00402118: 83c004 add eax, 0x4 0040211b: e8f0feffff call 0x402010 test.Event.set c:\d\test.d:6 00402120: 8b45fc mov eax, [ebp-0x4] 00402123: 83c404 add esp, 0x4 c:\d\test.d:19 } 00402126: 5e pop esi 00402127: 5b pop ebx 00402128: c9 leave 00402129: c3 ret c:\d\test.d:14 this() { 004020ec: 55 push ebp 004020ed: 8bec mov ebp, esp 004020ef: 83ec08 sub esp, 0x8 004020f2: 53 push ebx 004020f3: 56 push esi 004020f4: 8945fc mov [ebp-0x4], eax 004020f7: 6a08 push 0x8 <-- 004020f9: e8ee020000 call 0x4023ec __d_allocmemory <-- 004020fe: 8945f8 mov [ebp-0x8], eax <-- 00402101: 8b4dfc mov ecx, [ebp-0x4] <-- 00402104: 8908 mov [eax], ecx <-- 00402106: 8b55fc mov edx, [ebp-0x4] <-- 00402109: 895004 mov [eax+0x4], edx <-- c:\d\test.d:15 o = new Object; 0040210c: bb80f34100 mov ebx, 0x41f380 00402111: 53 push ebx 00402112: e87d020000 call 0x402394 __d_newclass 00402117: 8b75fc mov esi, [ebp-0x4] 0040211a: 894608 mov [esi+0x8], eax c:\d\test.d:16 ev.set((){ 0040211d: b840214000 mov eax, 0x402140 00402122: 50 push eax 00402123: ff75f8 push dword [ebp-0x8] 00402126: 8b4dfc mov ecx, [ebp-0x4] 00402129: 8b410c mov eax, [ecx+0xc] 0040212c: 83c004 add eax, 0x4 0040212f: e8dcfeffff call 0x402010 test.Event.set c:\d\test.d:7 00402134: 8b45fc mov eax, [ebp-0x4] 00402137: 83c408 add esp, 0x8 c:\d\test.d:19 } 0040213a: 5e pop esi 0040213b: 5b pop ebx 0040213c: c9 leave 0040213d: c3 ret With -version=bad, heap allocation for closure variable does not performed. Therefore, compiler wrongly judges that the lambda (){o.toString();} is "scope delegate".

https://github.com/D-Programming-Language/dmd/pull/1817 This is a regression happened in 2.063a.

Commits pushed to master at https://github.com/D-Programming-Language/dmd https://github.com/D-Programming-Language/dmd/commit/ac859ee5103f9204bf22373f429c67f3fe286697 fix Issue 9834 - incorrect detection of lambda locality. https://github.com/D-Programming-Language/dmd/commit/767a0293429fbeed6f812e5a514c028b5ecb2cca Merge pull request #1817 from 9rnsr/fix9834 [REG2.063] Issue 9834 - incorrect detection of lambda locality.

*** Issue 8999 has been marked as a duplicate of this issue. ***