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| author | Jonathan Wakely <jwakely@redhat.com> | 2024-11-27 12:28:30 +0000 |
|---|---|---|
| committer | Jonathan Wakely <redi@gcc.gnu.org> | 2024-11-27 21:36:14 +0000 |
| commit | 73e5d2f87c257c2c12ee72fd4de9bdbb6a8e1aa9 (patch) | |
| tree | aec2a9832f4cf9e620bb8077997299fa25291b66 | |
| parent | 17db5742a555d4f8fd5fa324adb6d1e5c55374be (diff) | |
| download | gcc-73e5d2f87c257c2c12ee72fd4de9bdbb6a8e1aa9.zip gcc-73e5d2f87c257c2c12ee72fd4de9bdbb6a8e1aa9.tar.gz gcc-73e5d2f87c257c2c12ee72fd4de9bdbb6a8e1aa9.tar.bz2 | |
libstdc++: Remove __builtin_expect from consteval assertion
libstdc++-v3/ChangeLog:
* include/bits/c++config (__glibcxx_assert): Remove useless
__builtin_expect from constexpr-only assertion. Improve
comments.
| -rw-r--r-- | libstdc++-v3/include/bits/c++config | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/libstdc++-v3/include/bits/c++config b/libstdc++-v3/include/bits/c++config index c74b030..a5001d0 100644 --- a/libstdc++-v3/include/bits/c++config +++ b/libstdc++-v3/include/bits/c++config @@ -626,14 +626,17 @@ namespace std #endif #if defined(_GLIBCXX_ASSERTIONS) -// Enable runtime assertion checks, and also check in constant expressions. +// When _GLIBCXX_ASSERTIONS is defined we enable runtime assertion checks. +// These checks will also be done during constant evaluation. # define __glibcxx_assert(cond) \ do { \ if (__builtin_expect(!bool(cond), false)) \ _GLIBCXX_ASSERT_FAIL(cond); \ } while (false) #elif _GLIBCXX_HAVE_IS_CONSTANT_EVALUATED -// Only check assertions during constant evaluation. +// _GLIBCXX_ASSERTIONS is not defined, so assertions checks are only enabled +// during constant evaluation. This ensures we diagnose undefined behaviour +// in constant expressions. namespace std { __attribute__((__always_inline__,__visibility__("default"))) @@ -643,12 +646,12 @@ namespace std } # define __glibcxx_assert(cond) \ do { \ - if (std::__is_constant_evaluated()) \ - if (__builtin_expect(!bool(cond), false)) \ - std::__glibcxx_assert_fail(); \ + if (std::__is_constant_evaluated() && !bool(cond)) \ + std::__glibcxx_assert_fail(); \ } while (false) #else -// Don't check any assertions. +// _GLIBCXX_ASSERTIONS is not defined and __is_constant_evaluated() doesn't +// work so don't check any assertions. # define __glibcxx_assert(cond) #endif |