Using Zig as C compiler for a shared library leads to undefined symbol: _DllMainCRTStartup

[nxrighthere]

The command: zig build-lib --c-source test.c --library c -dynamic -target x86_64-windows-gnu leads to lld: error: <root>: undefined symbol: _DllMainCRTStartup error. Compilation of static library seems to work fine.

[FireFox317]

Looking at all the options that can be provided for lld-link (linker for windows), I think the option -NOENTRY has to be added to the linker. This is what the help mentions:

-NOENTRY      Don't add reference to DllMainCRTStartup; only valid with /dll

Passing this option to the linker does indeed solve the issue.

Edit: According to the windows docs, that creates a resource-only DLL that contains no executable code. So probably not the correct solution then

[andrewrk]

@FireFox317 I think that's a good way to go. However I also think there is a regression. If you grep std lib for DllMainCRTStartup you can see there is something that was supposed to be provided. I think that mess can be removed in favor of comptime logic in std/special/start.zig.

[andrewrk]

Hmm I'm not sure if this is a bug actually. I think you're supposed to define DllMainCRTStartup in your C code.

[daurnimator]

Related: #3000

[nxrighthere]

@andrewrk Isn't it against using Zig as C compiler idea, if I don't need to do that with GCC/Clang/MSVC?

[zhaozg]

ref: #6482