[Triple] Ignore the vendor field for MinGW, wrt LTO/IR compatibility #122801
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For MinGW environments, the regular C/C++ toolchains usually use "w64" for the vendor field in triples, while Rust toolchains usually use "pc" in the vendor field. The differences in the vendor field have no bearing on whether the IR is compatible on this platform. (This probably goes for most other OSes as well, but limiting the scope of the change to the specific case.) Add a unit test for the isCompatibleWith, including some existing test cases found in existing tests.
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This fixes an issue brought up in mstorsjo/llvm-mingw#469 (comment); CC @Andarwinux @mati865. |
| // On MinGW, C code is usually built with a "w64" vendor, while Rust | ||
| // often uses a "pc" vendor. |
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Is uwp-windows-gnu compatible the other two mentioned variants? I think so but wanted to double-check.
Not sure if it's even a real triple in LLVM. Rust has it, but the GNU env is unmaintained: https://doc.rust-lang.org/rustc/platform-support.html
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Ah, thanks for pointing it out!
On an LTO/IR level, there's nothing there that would be incompatible. Of course, on functional level, code that doesn't target UWP may or may not work correct if code is linked in that isn't written with a UWP target in mind (but this issue is the same even if not involving LTO).
Also, thanks for pointing out the Rust use of uwp for the vendor field here; going that way would help using Clang config files for the UWP targets in llvm-mingw. (Currently we use the environment name mingw32uwp, but that gets normalized into the same windows-gnu as non-UWP.)
Not sure if it's even a real triple in LLVM.
The vendor field is pretty much freeform and not really used by anything as far as I'm aware. Sure, there are a couple of known ones and an enum for them, but neither w64 nor uwp map to any of the known enum values: https://github.com/llvm/llvm-project/blob/llvmorg-19.1.6/llvm/lib/TargetParser/Triple.cpp#L627-L644
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Yeah, I wasn't sure if there are any differences other than headers and libraries. We're good then.
For MinGW environments, the regular C/C++ toolchains usually use "w64" for the vendor field in triples, while Rust toolchains usually use "pc" in the vendor field.
The differences in the vendor field have no bearing on whether the IR is compatible on this platform. (This probably goes for most other OSes as well, but limiting the scope of the change to the specific case.)
Add a unit test for the isCompatibleWith, including some existing test cases found in existing tests.