diff options
| author | Jonathan Wakely <jwakely@redhat.com> | 2024-03-13 21:19:54 +0000 |
|---|---|---|
| committer | Jonathan Wakely <jwakely@redhat.com> | 2024-03-14 16:58:15 +0000 |
| commit | f89cfdb2f2e9b4fe517b1e00511c4d70a7014cbc (patch) | |
| tree | 67f1c557476d23df6e42eaa80f009ba6ae43cc8f /libstdc++-v3 | |
| parent | df483ebd24689a3bebfae2089637a00eca0e5a12 (diff) | |
libstdc++: Fix std::format("{}", negative_integer) [PR114325]
The fast path for "{}" format strings has a bug for negative integers
where the length passed to std::to_chars is too long.
libstdc++-v3/ChangeLog:
PR libstdc++/114325
* include/std/format (_Scanner::_M_scan): Pass correct length to
__to_chars_10_impl.
* testsuite/std/format/functions/format.cc: Check negative
integers with empty format-spec.
Diffstat (limited to 'libstdc++-v3')
| -rw-r--r-- | libstdc++-v3/include/std/format | 7 | ||||
| -rw-r--r-- | libstdc++-v3/testsuite/std/format/functions/format.cc | 5 |
2 files changed, 9 insertions, 3 deletions
diff --git a/libstdc++-v3/include/std/format b/libstdc++-v3/include/std/format index 1e839e88db4..613016d1a10 100644 --- a/libstdc++-v3/include/std/format +++ b/libstdc++-v3/include/std/format @@ -4091,6 +4091,7 @@ namespace __format __sink_out = __sink.out(); if constexpr (is_same_v<_CharT, char>) + // Fast path for "{}" format strings and simple format arg types. if (__fmt.size() == 2 && __fmt[0] == '{' && __fmt[1] == '}') { bool __done = false; @@ -4124,14 +4125,14 @@ namespace __format __uval = make_unsigned_t<_Tp>(~__arg) + 1u; else __uval = __arg; - const auto __n = __detail::__to_chars_len(__uval) + __neg; - if (auto __res = __sink_out._M_reserve(__n)) + const auto __n = __detail::__to_chars_len(__uval); + if (auto __res = __sink_out._M_reserve(__n + __neg)) { auto __ptr = __res.get(); *__ptr = '-'; __detail::__to_chars_10_impl(__ptr + (int)__neg, __n, __uval); - __res._M_bump(__n); + __res._M_bump(__n + __neg); __done = true; } } diff --git a/libstdc++-v3/testsuite/std/format/functions/format.cc b/libstdc++-v3/testsuite/std/format/functions/format.cc index a27fbe74631..4499397aaf9 100644 --- a/libstdc++-v3/testsuite/std/format/functions/format.cc +++ b/libstdc++-v3/testsuite/std/format/functions/format.cc @@ -157,6 +157,11 @@ test_std_examples() // Restore std::locale::global(std::locale::classic()); + + string s5 = format("{}", -100); // PR libstdc++/114325 + VERIFY(s5 == "-100"); + string s6 = format("{:d} {:d}", -123, 999); + VERIFY(s6 == "-123 999"); } } |