Filter host libstdc++ ABI flag in rustc_llvm cross builds#158808
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Rollup of 14 pull requests Successful merges: - #159307 (Improve cross-namespace name diagnostics) - #159543 (Remove extra semicolons in parsing item lists) - #157270 (ergonomic_clones_dotuse_capture_by_ref: Capture upvar by ref for `.use` in non-move closures) - #158496 (Move `check_rustc_pub_transparent` into the attribute parser) - #158547 (Move `std::io::buffered` to `alloc::io`) - #158808 (Filter host libstdc++ ABI flag in rustc_llvm cross builds) - #159362 (Add regression test for #120328) - #159472 (Support creating float constants in rustc_public mir) - #159505 (make rustdoc::bare_urls strip trailing periods from url) - #159568 (Suggest close compiler options) - #159578 (Extract coroutine closure helper functions) - #159601 (Make `TokenTreeCursor` private) - #159613 (Set the rustc lib path for unstable-book-gen) - #159616 (Clarify the comment about stage1/stage2 discrepancy in input-stats test)
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Rollup merge of #158808 - chitao1234:fix-rustc-llvm-cross-libstdcxx-abi, r=cuviper Filter host libstdc++ ABI flag in rustc_llvm cross builds `compiler/rustc_llvm/build.rs` invokes `llvm-config` for the build host machine in cross compilation scenarios. In particular, the normal LLVM configuration on Linux sets `_GLIBCXX_USE_CXX11_ABI=1` and those flags would then pollute C++ wrapper objects being compiled for the target. This patch makes `rustc_llvm` avoid propagating that macro when cross-compiling. This follows the existing pattern in `rustc_llvm/build.rs`, which already treats parts of cross `llvm-config` output as host-specific by filtering `-m*` flags and rewriting include paths. Although I think the more appropriate approach is to use a separate target LLVM C++ flags setting. This currently affects Haiku rustc cross-compilation from Linux hosts. The Haiku target currently uses the old libstdc++ string ABI by default and that creates an ABI mismatch. I currently work around this locally by setting environment variable `CXXFLAGS_x86_64_unknown_haiku=-D_GLIBCXX_USE_CXX11_ABI=0`.
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Rollup of 14 pull requests Successful merges: - rust-lang/rust#159307 (Improve cross-namespace name diagnostics) - rust-lang/rust#159543 (Remove extra semicolons in parsing item lists) - rust-lang/rust#157270 (ergonomic_clones_dotuse_capture_by_ref: Capture upvar by ref for `.use` in non-move closures) - rust-lang/rust#158496 (Move `check_rustc_pub_transparent` into the attribute parser) - rust-lang/rust#158547 (Move `std::io::buffered` to `alloc::io`) - rust-lang/rust#158808 (Filter host libstdc++ ABI flag in rustc_llvm cross builds) - rust-lang/rust#159362 (Add regression test for rust-lang/rust#120328) - rust-lang/rust#159472 (Support creating float constants in rustc_public mir) - rust-lang/rust#159505 (make rustdoc::bare_urls strip trailing periods from url) - rust-lang/rust#159568 (Suggest close compiler options) - rust-lang/rust#159578 (Extract coroutine closure helper functions) - rust-lang/rust#159601 (Make `TokenTreeCursor` private) - rust-lang/rust#159613 (Set the rustc lib path for unstable-book-gen) - rust-lang/rust#159616 (Clarify the comment about stage1/stage2 discrepancy in input-stats test)
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compiler/rustc_llvm/build.rsinvokesllvm-configfor the build host machine in cross compilation scenarios. In particular, the normal LLVM configuration on Linux sets_GLIBCXX_USE_CXX11_ABI=1and those flags would then pollute C++ wrapper objects being compiled for the target.This patch makes
rustc_llvmavoid propagating that macro when cross-compiling. This follows the existing pattern inrustc_llvm/build.rs, which already treats parts of crossllvm-configoutput as host-specific by filtering-m*flags and rewriting include paths. Although I think the more appropriate approach is to use a separate target LLVM C++ flags setting.This currently affects Haiku rustc cross-compilation from Linux hosts. The Haiku target currently uses the old libstdc++ string ABI by default and that creates an ABI mismatch. I currently work around this locally by setting environment variable
CXXFLAGS_x86_64_unknown_haiku=-D_GLIBCXX_USE_CXX11_ABI=0.