maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

[libc++] Fix wrongly non-inline basic_string::shrink_to_fit 

As explained in https://stackoverflow.com/a/70339311/627587, the fact
that shrink_to_fit wasn't defined as inline lead to issues when explicitly
instantiating basic_string. While explicit instantiations are always
somewhat brittle, this one was clearly a bug on our end.

Differential Revision: https://reviews.llvm.org/D115656
This commit is contained in:
Louis Dionne 2021-12-13 14:15:21 -05:00
parent 61bb8b5d40
commit bf39e7dc6c
2 changed files with 61 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
libcxx/include/string
View File

@ -3303,6 +3303,7 @@ basic_string<_CharT, _Traits, _Allocator>::reserve(size_type __requested_capacit
}
template <class _CharT, class _Traits, class _Allocator>
inline
void
basic_string<_CharT, _Traits, _Allocator>::shrink_to_fit() _NOEXCEPT
{
@ -3313,6 +3314,7 @@ basic_string<_CharT, _Traits, _Allocator>::shrink_to_fit() _NOEXCEPT
}
template <class _CharT, class _Traits, class _Allocator>
inline
void
basic_string<_CharT, _Traits, _Allocator>::__shrink_or_extend(size_type __target_capacity)
{

59
libcxx/test/std/strings/basic.string/string.capacity/shrink_to_fit.explicit_instantiation.sh.cpp Normal file
View File

@ -0,0 +1,59 @@
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// This test checks that we can explicitly instantiate std::string with a custom
// character type and traits and then use `shrink_to_fit`. In particular, this is
// a regression test for the bug that was reported at https://stackoverflow.com/q/69520633/627587
// and https://seedcentral.apple.com/sm/feedback_collector/radar/85053279.
// RUN: %{cxx} %{flags} %{compile_flags} %s %{link_flags} -DTU1 -c -o %t.tu1.o
// RUN: %{cxx} %{flags} %{compile_flags} %s %{link_flags} -DTU2 -c -o %t.tu2.o
// RUN: %{cxx} %{flags} %t.tu1.o %t.tu2.o %{link_flags} -o %t.exe
// UNSUPPORTED: libcpp-has-no-localization
#include <cstdint>
#include <ios>
#include <string>
typedef std::uint16_t char16;
struct string16_char_traits {
typedef char16 char_type;
typedef int int_type;
typedef std::streamoff off_type;
typedef std::mbstate_t state_type;
typedef std::fpos<state_type> pos_type;
static void assign(char_type&, const char_type&) { }
static bool eq(const char_type&, const char_type&) { return false; }
static bool lt(const char_type&, const char_type&) { return false; }
static int compare(const char_type*, const char_type*, size_t) { return 0; }
static size_t length(const char_type*) { return 0; }
static const char_type* find(const char_type*, size_t, const char_type&) { return nullptr; }
static char_type* move(char_type*, const char_type*, size_t) { return nullptr; }
static char_type* copy(char_type*, const char_type*, size_t) { return nullptr; }
static char_type* assign(char_type*, size_t, char_type) { return nullptr; }
static int_type not_eof(const int_type&) { return 0; }
static char_type to_char_type(const int_type&) { return char_type(); }
static int_type to_int_type(const char_type&) { return int_type(); }
static bool eq_int_type(const int_type&, const int_type&) { return false; }
static int_type eof() { return int_type(); }
};
#if defined(TU1)
template class std::basic_string<char16, string16_char_traits>;
#else
extern template class std::basic_string<char16, string16_char_traits>;
int main() {
std::basic_string<char16, string16_char_traits> s;
s.shrink_to_fit();
}
#endif