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| author | Jonathan Wakely <jwakely@redhat.com> | 2023-11-14 10:56:57 +0000 |
|---|---|---|
| committer | Jonathan Wakely <jwakely@redhat.com> | 2023-11-14 22:32:08 +0000 |
| commit | 1c15303375f7089ff985b085ab877b11ebfbc4b7 (patch) | |
| tree | b6ab3ced8878832d2fc31a4e183e6c464f497252 | |
| parent | 6f2fc42d9e52e8322e718e0154cd235d00906f99 (diff) | |
| download | gcc-1c15303375f7089ff985b085ab877b11ebfbc4b7.zip gcc-1c15303375f7089ff985b085ab877b11ebfbc4b7.tar.gz gcc-1c15303375f7089ff985b085ab877b11ebfbc4b7.tar.bz2 | |
libstdc++: Fix <charconv> uses of signed types with <bit> functions
In <charconv> we pass the int __base parameter to our internal versions
of <bit> functions, __bit_width and __countr_zero. Those functions are
only defined for unsigned types, so we need to convert the base to
unsigned. The base must be in the range [2,36] so we can mask off the
low bits and then convert that to unsigned, so that we don't need to
care about negative values becoming large unsigned values.
libstdc++-v3/ChangeLog:
* include/std/charconv (__from_chars_pow2_base): Convert base to
unsigned for call to __countr_zero.
(__from_chars_alnum): Likewise for call to __bit_width.
| -rw-r--r-- | libstdc++-v3/include/std/charconv | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/libstdc++-v3/include/std/charconv b/libstdc++-v3/include/std/charconv index 6cb7fec..5463296 100644 --- a/libstdc++-v3/include/std/charconv +++ b/libstdc++-v3/include/std/charconv @@ -465,7 +465,7 @@ namespace __detail // __glibcxx_assert((__base & (__base - 1)) == 0); // __glibcxx_assert(_DecOnly ? __base <= 8 : __base <= 32); - const int __log2_base = __countr_zero(__base); + const int __log2_base = __countr_zero(unsigned(__base & 0x3f)); const ptrdiff_t __len = __last - __first; ptrdiff_t __i = 0; @@ -517,9 +517,9 @@ namespace __detail __from_chars_alnum(const char*& __first, const char* __last, _Tp& __val, int __base) { - // __glibcxx_assert(!_DecOnly || __base <= 10); + // __glibcxx_assert(_DecOnly ? __base <= 10 : __base <= 36); - const int __bits_per_digit = __bit_width(__base); + const int __bits_per_digit = __bit_width(unsigned(__base & 0x3f)); int __unused_bits_lower_bound = __gnu_cxx::__int_traits<_Tp>::__digits; for (; __first != __last; ++__first) { |