Bug 23387 – ImportC: identical structs defined in two C files lead to duplicate .init symbol on macOS

This bug report is a little weird as it is contingent on an unmerged PR (https://github.com/dlang/dmd/pull/14509), but I am filing it here before I forget. C structs will now be in the same module so the .init for structs collides across different object files. From https://github.com/dlang/dmd/pull/14509#issuecomment-1266355604 // Dummy function definitions to make the example compile. // freer.i typedef struct Foo3 *FooRef3; struct Foo3 { int x; }; void free_foo3(FooRef3 foo){} // maker.i typedef struct Foo3 *FooRef3; struct Foo3 { int x; }; FooRef3 make_foo3(void){return 0;} // do_foo.d import maker; import freer; void main(){ FooRef3 f = make_foo3(); free_foo3(f); } # Separate compilation makes # the issue obvious. $ dmd maker.i -c $ dmd freer.i -c $ dmd do_foo.d -c $ dmd do_foo.o freer.o maker.o duplicate symbol '__D3__C4Foo36__initZ' in: freer.o maker.o ld: 1 duplicate symbol for architecture x86_64 clang: error: linker command failed with exit code 1 (use -v to see invocation) Error: linker exited with status 1 $ nm freer.o 0000000000000010 B __D3__C4Foo36__initZ 0000000000000000 S _free_foo3 $ nm maker.o 0000000000000010 B __D3__C4Foo36__initZ 0000000000000000 S _make_foo3 $ echo "__D3__C4Foo36__initZ" | ddemangle __C.Foo3.__init Walter responded: WalterBright commented 15 hours ago The cause of the problem is a workaround for a linker problem: https://github.com/dlang/dmd/blob/master/compiler/src/dmd/toobj.d#L524

The above PR has been merged so the issue is now in master.

@WalterBright updated dlang/dmd pull request #14541 "fix Issue 23387 - ImportC: identical structs defined in two C files l…" fixing this issue: - fix Issue 23387 - ImportC: identical structs defined in two C files lead to duplicate .init symbol on macOS https://github.com/dlang/dmd/pull/14541

dlang/dmd pull request #14541 "fix Issue 23387 - ImportC: identical structs defined in two C files l…" was merged into master: - 7fe0aee2a4ed8775e8f55e02d2ca6696cf30ef43 by Walter Bright: fix Issue 23387 - ImportC: identical structs defined in two C files lead to duplicate .init symbol on macOS https://github.com/dlang/dmd/pull/14541