Bug 19123 – -allinst gives undefined reference linker errors

Manjaro/Arch x86_64, dmd 2.081.1, ldc 1.10.0. run.dlang.io also shows the same behaviour "since 2.080.1". Reduced example, fails to link with -allinst but works without (dmd and ldc): void main() { import std.stdio; import std.datetime; writefln("%s", Clock.currTime); } > $ dmd -allinst test.d > /dlang/dmd/linux/bin64/../../src/phobos/std/range/primitives.d:273: error: undefined reference to '_D3std6format__T11hasToStringTSQBd8datetime7systime7SysTimeTaZ9__lambda2MFZ1S3putMFNaNbNiNfaZv' > /dlang/dmd/linux/bin64/../../src/phobos/std/range/primitives.d:273: error: undefined reference to '_D3std6format__T11hasToStringTSQBd8datetime7systime7SysTimeTaZ9__lambda2MFZ1S3putMFNaNbNiNfaZv' > /dlang/dmd/linux/bin64/../../src/phobos/std/range/primitives.d:273: error: undefined reference to '_D3std6format__T11hasToStringTSQBd8datetime7systime7SysTimeTaZ9__lambda2MFZ1S3putMFNaNbNiNfaZv' > /dlang/dmd/linux/bin64/../../src/phobos/std/range/primitives.d:273: error: undefined reference to '_D3std6format__T11hasToStringTSQBd8datetime7systime7SysTimeTaZ9__lambda2MFZ1S3putMFNaNbNiNfaZv' > collect2: error: ld returned 1 exit status > Error: linker exited with status 1

actually it's a 2.080.0 regression.

According to digger it was https://github.com/dlang/phobos/pull/6190 that caused this regression.

(In reply to Mike Franklin from comment #2) > According to digger it was https://github.com/dlang/phobos/pull/6190 that > caused this regression. ...though it may have just revealed a bug in DMD.

I've narrowed this down somewhat. What's happening is `-allinst` causes symbols to be emitted to the object file that otherwise wouldn't be. Those symbols, however, call other symbols, and it's those other symbols that aren't being emitted for some reason, resulting in linker errors.

_D3std6format__T11hasToStringTSQBd8datetime7systime7SysTimeTaZ9__lambda2MFZ1S3putMFNaNbNiNfaZv ... demangles to... pure nothrow @nogc @safe void std.format.hasToString!(std.datetime.systime.SysTime, char).__lambda2().S.put(char) When logging semantic in the compiler, I don't see it in the AST either.

I recently hit a bug similar to this one, if not the same one, with this following code: import std.variant; import std.typecons; struct S {} void main() { alias T = Typedef!(S, S.init); Variant v = T(); } > /dlang/dmd/linux/bin64/../../src/phobos/std/range/primitives.d:276: error: undefined reference to '_D3std6format__T11hasToStringTSQBd8typecons__T7TypedefTS9onlineapp1SVQoS0VAyanZQBhTaZ9__lambda1MFZQBg3putMFNaNbNiNfaZv' > /dlang/dmd/linux/bin64/../../src/phobos/std/range/primitives.d:276: error: undefined reference to '_D3std6format__T11hasToStringTSQBd8typecons__T7TypedefTS9onlineapp1SVQoS0VAyanZQBhTaZ9__lambda1MFZQBg3putMFNaNbNiNfaZv' > /dlang/dmd/linux/bin64/../../src/phobos/std/range/primitives.d:276: error: undefined reference to '_D3std6format__T11hasToStringTSQBd8typecons__T7TypedefTS9onlineapp1SVQoS0VAyanZQBhTaZ9__lambda1MFZQBg3putMFNaNbNiNfaZv' > collect2: error: ld returned 1 exit status > Error: linker exited with status 1

This has been fixed since originally reported. Can't point at what might have fixed it, changes like the PR linked below likely helped though. https://github.com/dlang/dmd/pull/13578