Always read from all CFLAGS-style flags
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Reading from just one of these means that users setting different environment variables in different parts of the build process would not get flags from the other parts. Instead, we read all of the flags, but in a specific order such that more specific flags override less specific ones.
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…15245) ### What does this PR try to resolve? GitHub Runner Images 20250224.5.0+ ship Windows 11 SDK 10.0.26100+ compared to the previous Windows 11 SDK 10.0.22621, which bumped the UCRT headers. The new UCRT headers use SSE2 types. However, `cc` versions <= 1.2.15 emit `/arch:IA32` for `x86` Windows targets for `clang-cl`, which causes compilation errors since `clang-cl` can't find SSE2 types without `/arch:SSE2` specified (or defaulted). (Note that MSVC at the time of writing silently accepts and emits instruments for code using SSE2 types, as opposed to `clang-cl` hard error-ing). `cc` 1.2.16 contains a fix for this problem, rust-lang/cc-rs#1425, to correctly emit `/arch:SSE2` instead of `/arch:IA32` to enable `clang-cl` to find the SSE2 types. However, cargo's `cc` currently is still on 1.2.13. To fix this for rust-lang/rust CI, we need to bump anything that transitively relies on `cc` and tries to use `clang-cl` on `x86` Windows targets to compile any C/C++ code that transitively use functions or types that require SSE2 types, such as `<wchar.h>`. ### How should we test and review this PR? The fix was initially intended for `rustc_{codegen_ssa,llvm}` `cc`, and based on testing in rust-lang/rust#137724, I was able to successfully build `rustc_{codegen_ssa,llvm}` with a forked `cc` based on 1.2.15 which contains the fix from rust-lang/cc-rs#1425. Note that in the same PR, while the compiler build succeeded, the build of cargo itself failed since it transitively used a `cc` *without* the fix to build `curl-sys`[^dep-chain], which failed as one might expect (`curl-sys` tries to build C code that uses `<wchar.h>` which runs into the same problem). Hence, this PR is opened to bump cargo's `cc` to a `cc` version containing the fix. ### Additional information This `x86` Windows CI problem is: - Discussed in https://rust-lang.zulipchat.com/#narrow/channel/242791-t-infra/topic/spurious.20.28.3F.29.20i686.20msvc.20errors. - Tracked by rust-lang/rust#137733. #### `cc` changelog between 1.2.13 and 1.2.16 <details> <summary>`cc` changes since 1.2.13 up to and including 1.2.16</summary> ##### [1.2.16](rust-lang/cc-rs@cc-v1.2.15...cc-v1.2.16) - 2025-02-28 ###### Fixed - force windows compiler to run in `out_dir` to prevent artifacts in cwd (#1415) ###### Other - use `/arch:SSE2` for `x86` target arch (#1425) - Regenerate windows-sys binding ([#1422](rust-lang/cc-rs#1422)) - Regenerate target info ([#1418](rust-lang/cc-rs#1418)) - Add LIB var when compiling flag_check (#1417) - Change flag ordering ([#1403](rust-lang/cc-rs#1403)) - Fix archiver detection for musl cross compilation ([#1404](rust-lang/cc-rs#1404)) ##### [1.2.15](rust-lang/cc-rs@cc-v1.2.14...cc-v1.2.15) - 2025-02-21 ###### Other - Regenerate target info ([#1406](rust-lang/cc-rs#1406)) - Always read from all `CFLAGS`-style flags ([#1401](rust-lang/cc-rs#1401)) - Simplify the error output on failed `Command` invocation ([#1397](rust-lang/cc-rs#1397)) ##### [1.2.14](rust-lang/cc-rs@cc-v1.2.13...cc-v1.2.14) - 2025-02-14 ###### Other - Regenerate target info ([#1398](rust-lang/cc-rs#1398)) - Add support for setting `-gdwarf-{version}` based on RUSTFLAGS ([#1395](rust-lang/cc-rs#1395)) - Add support for alternative network stack io-sock on QNX 7.1 aarch64 and x86_64 ([#1312](rust-lang/cc-rs#1312)) </details> [^dep-chain]: I think the dep chain is something like git2 -> libgit2-sys -> curl -> curl-sys?
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…obzol
Bump `rustc_{codegen_ssa,llvm}` `cc` to 1.2.16 to fix `x86` Windows jobs on newest Windows SDK
Part of rust-lang#137733.
Bump `rustc_{codegen_ssa,llvm}` `cc` to 1.2.16 which contains rust-lang/cc-rs#1425 to help with rust-lang#137733. Previously tested in rust-lang#137724.
#### `cc` changelog between 1.2.13 and 1.2.16
<details>
<summary>`cc` changes since 1.2.13 up to and including 1.2.16</summary>
##### [1.2.16](rust-lang/cc-rs@cc-v1.2.15...cc-v1.2.16) - 2025-02-28
###### Fixed
- force windows compiler to run in `out_dir` to prevent artifacts in cwd (rust-lang#1415)
###### Other
- use `/arch:SSE2` for `x86` target arch (rust-lang#1425)
- Regenerate windows-sys binding ([rust-lang#1422](rust-lang/cc-rs#1422))
- Regenerate target info ([rust-lang#1418](rust-lang/cc-rs#1418))
- Add LIB var when compiling flag_check (rust-lang#1417)
- Change flag ordering ([rust-lang#1403](rust-lang/cc-rs#1403))
- Fix archiver detection for musl cross compilation ([rust-lang#1404](rust-lang/cc-rs#1404))
##### [1.2.15](rust-lang/cc-rs@cc-v1.2.14...cc-v1.2.15) - 2025-02-21
###### Other
- Regenerate target info ([rust-lang#1406](rust-lang/cc-rs#1406))
- Always read from all `CFLAGS`-style flags ([rust-lang#1401](rust-lang/cc-rs#1401))
- Simplify the error output on failed `Command` invocation ([rust-lang#1397](rust-lang/cc-rs#1397))
##### [1.2.14](rust-lang/cc-rs@cc-v1.2.13...cc-v1.2.14) - 2025-02-14
###### Other
- Regenerate target info ([rust-lang#1398](rust-lang/cc-rs#1398))
- Add support for setting `-gdwarf-{version}` based on RUSTFLAGS ([rust-lang#1395](rust-lang/cc-rs#1395))
- Add support for alternative network stack io-sock on QNX 7.1 aarch64 and x86_64 ([rust-lang#1312](rust-lang/cc-rs#1312))
</details>
r? `@Kobzol`
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Rollup merge of rust-lang#137788 - jieyouxu:bump-compiler-cc, r=lqd,Kobzol Bump `rustc_{codegen_ssa,llvm}` `cc` to 1.2.16 to fix `x86` Windows jobs on newest Windows SDK Part of rust-lang#137733. Bump `rustc_{codegen_ssa,llvm}` `cc` to 1.2.16 which contains rust-lang/cc-rs#1425 to help with rust-lang#137733. Previously tested in rust-lang#137724. #### `cc` changelog between 1.2.13 and 1.2.16 <details> <summary>`cc` changes since 1.2.13 up to and including 1.2.16</summary> ##### [1.2.16](rust-lang/cc-rs@cc-v1.2.15...cc-v1.2.16) - 2025-02-28 ###### Fixed - force windows compiler to run in `out_dir` to prevent artifacts in cwd (rust-lang#1415) ###### Other - use `/arch:SSE2` for `x86` target arch (rust-lang#1425) - Regenerate windows-sys binding ([rust-lang#1422](rust-lang/cc-rs#1422)) - Regenerate target info ([rust-lang#1418](rust-lang/cc-rs#1418)) - Add LIB var when compiling flag_check (rust-lang#1417) - Change flag ordering ([rust-lang#1403](rust-lang/cc-rs#1403)) - Fix archiver detection for musl cross compilation ([rust-lang#1404](rust-lang/cc-rs#1404)) ##### [1.2.15](rust-lang/cc-rs@cc-v1.2.14...cc-v1.2.15) - 2025-02-21 ###### Other - Regenerate target info ([rust-lang#1406](rust-lang/cc-rs#1406)) - Always read from all `CFLAGS`-style flags ([rust-lang#1401](rust-lang/cc-rs#1401)) - Simplify the error output on failed `Command` invocation ([rust-lang#1397](rust-lang/cc-rs#1397)) ##### [1.2.14](rust-lang/cc-rs@cc-v1.2.13...cc-v1.2.14) - 2025-02-14 ###### Other - Regenerate target info ([rust-lang#1398](rust-lang/cc-rs#1398)) - Add support for setting `-gdwarf-{version}` based on RUSTFLAGS ([rust-lang#1395](rust-lang/cc-rs#1395)) - Add support for alternative network stack io-sock on QNX 7.1 aarch64 and x86_64 ([rust-lang#1312](rust-lang/cc-rs#1312)) </details> r? `@Kobzol`
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Reading from just one of these means that users setting different environment variables in different parts of the build process would not get flags from the other parts.
This tripped me up in rust-lang/rust#133092 / rust-lang/rust#136984, where I thought that since I was extending
CFLAGS_*instead of overwriting it, I was allowingcc-rsto also read fromCFLAGS.Instead, we now read all of the flags, but in order such that more specific flags override less specific ones.
So e.g. when users set
CFLAGS=-flag1 CFLAGS_aarch64_apple_darwin=-flag2 cargo build, we end up passing-flag1 -flag2to the compiler (in that order specifically).NOTE: This has the slight chance of breaking builds where users assume that
CFLAGS_$TARGEToverwritesCFLAGS. I will argue that that is likely to be the minority, relative to users that do want flags from allCFLAGS*env vars.To fix such cases, users should pass the negative flag in
CFLAGS_$TARGETthat they don't wantCFLAGSto set (e.g. ifCFLAGScontains-pthread, users should passCFLAGS_$TARGET=-no-pthread).