Fix GCC detection to be robust to symlinks #592
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jwnimmer-tri
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hvadehra,
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trybka
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I'm suspicious this will break somebody. Perhaps it would be more conservative to introduce this as a 2nd fallback check instead? I did confirm this pattern works with |
On Ubuntu /usr/bin/cc is a symlink to /usr/bin/gcc. Because GCC uses `argv[0]` to report its `--version`, that means if the user has set `CC=/usr/bin/cc` then `_is_gcc` will return false and the compiler will be mis-detected. Instead of relying on the binary name, we'll match how Clang detection was already done: run with `-v` and look for the compiler species in the output. Unlike clang, we'll be slightly more careful by looking for a more specific string, and only on the last line. This is safer because `clang -v` prints GCC-adjacent details and we don't want that being detected as GCC itself.
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Fair point. I've pushed that change now. |
armandomontanez
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type: bug
armandomontanez
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Feb 5, 2026
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On Ubuntu /usr/bin/cc is a symlink to /usr/bin/gcc. Because GCC uses
argv[0]to report its--version, that means if the user has setCC=/usr/bin/ccthen_is_gccwill return false and the compiler will be mis-detected.Instead of relying on the binary name, we'll match how Clang detection was already done: run with
-vand look for the compiler species in the output. Unlike clang, we'll be slightly more careful by looking for a more specific string, and only on the last line. This is safer becauseclang -vprints GCC-adjacent details and we don't want that being detected as GCC itself.On Ubuntu: