Can't statically link on Windows when building for debug about spirv_cross HOT 5 CLOSED

The original project that ran into this is meant to be a dll instead of an executable, and distributed by itself. In the future I'd like the the dll to be entirely Rust, but until then it has some C++ portions. For the time being I need to statically link the two together.

By default, Debug mode will compile using /MDd. Overriding that by compiling with /MD does resolve the linker issues, but this does put me halfway to building as Release. I also tried /MT for fun and got more linker errors than before.

I might try to play with the build.rs to build with /MDd (or possibly building as debug, I guess building as release with /MDd is just as arbitrary). How does this usually work in the Rust ecosystem? Is there a way to inform indirect dependencies of desired build configurations? I've only ever seen people read environment variables from their build.rs, but I also haven't seen too many of them.

Thank you so much for the quick reply! I can't believe I didn't think about the runtime library flags...

from spirv_cross.

Rust currently always uses the release CRT. It does not have the option to use the debug CRT. Every crate that builds C code therefore builds it with the release CRT and so trying to link the resulting staticlib into a C project using the debug CRT will cause a CRT mismatch.

from spirv_cross.

Interesting, thanks for reporting the issue!

The idea is that this crate builds the C++ library SPIRV-Cross as part if it's build. In order to do this it uses cc-rs in spirv_cross's build.rs.

I believe the default behavior when static linking on Windows would mean that /MT would be provided while building SPIRV-Cross, which statically links a particular version of the runtime library.

Could static linking be avoided in this case? (You should be able to use Rust and C++ together fine without static linking, but maybe you're considering distribution of the executable or something else)

Was the C++ executable built with /MT? I would try changing it on that side first if possible and seeing if it helps. Otherwise we can try adjusting the build.rs to pass different flags for the SPIRV-Cross (C++) portion while still building the spirv_cross (Rust) portion as a static library.

from spirv_cross.

Hmmm... after some quick experimenting it's not as simple as compiling SPIRV-Cross with /MDd. Unfortunately, I've had my fill of linker errors for the past couple of days and will probably just put up with building my dll with /MD for now. I may come back to this later.

Thanks for your help! Feel free to close this issue if you don't think it's necessary.

from spirv_cross.

Ah, that's good to know! In that case I'll close the issue.

Thanks, @retep998!

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