rustc_metadata: don't let LLVM confuse rmeta blobs for COFF object files. #66235
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rustc_metadata: don't let LLVM confuse rmeta blobs for COFF object files. This has likely been a silent issue since 1.10 but only caused trouble recently (see #65536 (comment)), when recent changes to the `rmeta` schema introduced more opportunities for COFF parse errors. To prevent any undesired interactions with old compilers, I've renamed the file inside `rlib`s from `rust.metadata.bin` to `lib.rmeta` (not strongly attached to it, suggestions welcome). Fixes #65536. <hr/> Before: ``` $ llvm-objdump -all-headers build/*/stage1-std/*/release/deps/libcore-*.rmeta build/x86_64-unknown-linux-gnu/stage1-std/x86_64-unknown-linux-gnu/release/deps/libcore-6b9e8b5a59b79a1d.rmeta: file format COFF-<unknown arch> architecture: unknown start address: 0x00000000 Sections: Idx Name Size VMA Type SYMBOL TABLE: ``` After: ``` $ llvm-objdump -all-headers build/*/stage1-std/*/release/deps/libcore-*.rmeta llvm-objdump: error: 'build/x86_64-unknown-linux-gnu/stage1-std/x86_64-unknown-linux-gnu/release/deps/libcore-6b9e8b5a59b79a1d.rmeta': The file was not recognized as a valid object file ```
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Alright, nothing too interesting going on there, I guess LLVM wasn't wasting that much time on parsing rmeta as COFF, after all. @bors r=nagisa |
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rustc_metadata: don't let LLVM confuse rmeta blobs for COFF object files. This has likely been a silent issue since 1.10 but only caused trouble recently (see rust-lang#65536 (comment)), when recent changes to the `rmeta` schema introduced more opportunities for COFF parse errors. To prevent any undesired interactions with old compilers, I've renamed the file inside `rlib`s from `rust.metadata.bin` to `lib.rmeta` (not strongly attached to it, suggestions welcome). Fixes rust-lang#65536. <hr/> Before: ``` $ llvm-objdump -all-headers build/*/stage1-std/*/release/deps/libcore-*.rmeta build/x86_64-unknown-linux-gnu/stage1-std/x86_64-unknown-linux-gnu/release/deps/libcore-6b9e8b5a59b79a1d.rmeta: file format COFF-<unknown arch> architecture: unknown start address: 0x00000000 Sections: Idx Name Size VMA Type SYMBOL TABLE: ``` After: ``` $ llvm-objdump -all-headers build/*/stage1-std/*/release/deps/libcore-*.rmeta llvm-objdump: error: 'build/x86_64-unknown-linux-gnu/stage1-std/x86_64-unknown-linux-gnu/release/deps/libcore-6b9e8b5a59b79a1d.rmeta': The file was not recognized as a valid object file ```
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Rollup of 7 pull requests Successful merges: - #65719 (Refactor sync::Once) - #65831 (Don't cast directly from &[T; N] to *const T) - #66048 (Correct error in documentation for Ipv4Addr method) - #66058 (Correct deprecated `is_global` IPv6 documentation) - #66216 ([mir-opt] Handle return place in ConstProp and improve SimplifyLocals pass) - #66217 (invalid_value lint: use diagnostic items) - #66235 (rustc_metadata: don't let LLVM confuse rmeta blobs for COFF object files.) Failed merges: r? @ghost
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This test was added in emscripten-core#10300 to check if we can handle non-objects in archives, especially rust metadata files that start with two leading zeroes. LLVM's file magic identifier thinks files with two leading zeroes are COFF files. But Rust metadata files used to start with two leading zeroes too, resulting in an error in LLVM tools. So emscripten-core#10300 bypassed use of `llvm-nm` to avoid that. We were still using `llvm-ranlib`, which also ran the LLVM magic identifier when trying to create a symbol table for an object, but `llvm-ranlib` so far has ignored those errors. But recently llvm/llvm-project@a20168d made them explicit errors, so we couldn't run `llvm-ranlib` anymore with archives containing objects that start with two leading zeroes. But this is not relevant anymore because Rust fixed their object file format in rust-lang/rust#66235, so their files are not mistaken by LLVM for COFF files anymore. So this PR fixes this test to not include a binary with two leading zeros, while still testing archival of non-object files.
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This test was added in #10300 to check if we can handle non-objects in archives, especially rust metadata files that start with two leading zeroes. LLVM's file magic identifier thinks files with two leading zeroes are COFF files. But Rust metadata files used to start with two leading zeroes too, resulting in an error in LLVM tools. So #10300 bypassed use of `llvm-nm` to avoid that. We were still using `llvm-ranlib`, which also ran the LLVM magic identifier when trying to create a symbol table for an object, but `llvm-ranlib` so far has ignored those errors. But recently llvm/llvm-project@a20168d made them explicit errors, so we couldn't run `llvm-ranlib` anymore with archives containing objects that start with two leading zeroes. But this is not relevant anymore because Rust fixed their object file format in rust-lang/rust#66235, so their files are not mistaken by LLVM for COFF files anymore. So this PR fixes this test to not include a binary with two leading zeros, while still testing archival of non-object files.
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This has likely been a silent issue since 1.10 but only caused trouble recently (see #65536 (comment)), when recent changes to the
rmetaschema introduced more opportunities for COFF parse errors.To prevent any undesired interactions with old compilers, I've renamed the file inside
rlibs fromrust.metadata.bintolib.rmeta(not strongly attached to it, suggestions welcome).Fixes #65536.
Before:
After: