ab60910e01
Currently, built-in `char`/`wchar_t` arrays are assumed to be null-terminated sequence with the terminator being the last element in formatting. This doesn't conform to [format.arg]/6.9. > otherwise, if `decay_t<TD>` is `char_type*` or `const char_type*`, > initializes value with `static_cast<const char_type*>(v)`; The standard wording specifies that character arrays are decayed to pointers. When the null terminator is not the last element or there's no null terminator (the latter case is UB), libc++ currently produces different results. Also fixes and hardens `formatter<CharT[N], CharT>::format` in `<__format/formatter_string.h>`. These specializations are rarely used. Fixes #115935. Also checks the preconditions in this case, which fixes #116570.
174 lines
7.1 KiB
C++
174 lines
7.1 KiB
C++
// -*- C++ -*-
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// 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
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef _LIBCPP___FORMAT_FORMATTER_STRING_H
|
|
#define _LIBCPP___FORMAT_FORMATTER_STRING_H
|
|
|
|
#include <__assert>
|
|
#include <__config>
|
|
#include <__format/concepts.h>
|
|
#include <__format/format_parse_context.h>
|
|
#include <__format/formatter.h>
|
|
#include <__format/formatter_output.h>
|
|
#include <__format/parser_std_format_spec.h>
|
|
#include <__format/write_escaped.h>
|
|
#include <cstddef>
|
|
#include <string>
|
|
#include <string_view>
|
|
|
|
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
|
|
# pragma GCC system_header
|
|
#endif
|
|
|
|
_LIBCPP_BEGIN_NAMESPACE_STD
|
|
|
|
#if _LIBCPP_STD_VER >= 20
|
|
|
|
template <__fmt_char_type _CharT>
|
|
struct __formatter_string {
|
|
public:
|
|
template <class _ParseContext>
|
|
_LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
|
|
typename _ParseContext::iterator __result = __parser_.__parse(__ctx, __format_spec::__fields_string);
|
|
__format_spec::__process_display_type_string(__parser_.__type_);
|
|
return __result;
|
|
}
|
|
|
|
template <class _FormatContext>
|
|
_LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator
|
|
format(basic_string_view<_CharT> __str, _FormatContext& __ctx) const {
|
|
# if _LIBCPP_STD_VER >= 23
|
|
if (__parser_.__type_ == __format_spec::__type::__debug)
|
|
return __formatter::__format_escaped_string(__str, __ctx.out(), __parser_.__get_parsed_std_specifications(__ctx));
|
|
# endif
|
|
|
|
return __formatter::__write_string(__str, __ctx.out(), __parser_.__get_parsed_std_specifications(__ctx));
|
|
}
|
|
|
|
# if _LIBCPP_STD_VER >= 23
|
|
_LIBCPP_HIDE_FROM_ABI constexpr void set_debug_format() { __parser_.__type_ = __format_spec::__type::__debug; }
|
|
# endif
|
|
|
|
__format_spec::__parser<_CharT> __parser_{.__alignment_ = __format_spec::__alignment::__left};
|
|
};
|
|
|
|
// Formatter const char*.
|
|
template <__fmt_char_type _CharT>
|
|
struct formatter<const _CharT*, _CharT> : public __formatter_string<_CharT> {
|
|
using _Base _LIBCPP_NODEBUG = __formatter_string<_CharT>;
|
|
|
|
template <class _FormatContext>
|
|
_LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator format(const _CharT* __str, _FormatContext& __ctx) const {
|
|
_LIBCPP_ASSERT_INTERNAL(__str, "The basic_format_arg constructor should have prevented an invalid pointer.");
|
|
// Converting the input to a basic_string_view means the data is looped over twice;
|
|
// - once to determine the length, and
|
|
// - once to process the data.
|
|
//
|
|
// This sounds slower than writing the output directly. However internally
|
|
// the output algorithms have optimizations for "bulk" operations, which
|
|
// makes this faster than a single-pass character-by-character output.
|
|
return _Base::format(basic_string_view<_CharT>(__str), __ctx);
|
|
}
|
|
};
|
|
|
|
// Formatter char*.
|
|
template <__fmt_char_type _CharT>
|
|
struct formatter<_CharT*, _CharT> : public formatter<const _CharT*, _CharT> {
|
|
using _Base _LIBCPP_NODEBUG = formatter<const _CharT*, _CharT>;
|
|
|
|
template <class _FormatContext>
|
|
_LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator format(_CharT* __str, _FormatContext& __ctx) const {
|
|
return _Base::format(__str, __ctx);
|
|
}
|
|
};
|
|
|
|
// Formatter char[].
|
|
template <__fmt_char_type _CharT, size_t _Size>
|
|
struct formatter<_CharT[_Size], _CharT> : public __formatter_string<_CharT> {
|
|
using _Base _LIBCPP_NODEBUG = __formatter_string<_CharT>;
|
|
|
|
template <class _FormatContext>
|
|
_LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator
|
|
format(const _CharT (&__str)[_Size], _FormatContext& __ctx) const {
|
|
const _CharT* const __pzero = char_traits<_CharT>::find(__str, _Size, _CharT{});
|
|
_LIBCPP_ASSERT_VALID_INPUT_RANGE(__pzero != nullptr, "formatting a non-null-terminated array");
|
|
return _Base::format(basic_string_view<_CharT>(__str, static_cast<size_t>(__pzero - __str)), __ctx);
|
|
}
|
|
};
|
|
|
|
// Formatter std::string.
|
|
template <__fmt_char_type _CharT, class _Traits, class _Allocator>
|
|
struct formatter<basic_string<_CharT, _Traits, _Allocator>, _CharT> : public __formatter_string<_CharT> {
|
|
using _Base _LIBCPP_NODEBUG = __formatter_string<_CharT>;
|
|
|
|
template <class _FormatContext>
|
|
_LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator
|
|
format(const basic_string<_CharT, _Traits, _Allocator>& __str, _FormatContext& __ctx) const {
|
|
// Drop _Traits and _Allocator to have one std::basic_string formatter.
|
|
return _Base::format(basic_string_view<_CharT>(__str.data(), __str.size()), __ctx);
|
|
}
|
|
};
|
|
|
|
// Formatter std::string_view.
|
|
template <__fmt_char_type _CharT, class _Traits>
|
|
struct formatter<basic_string_view<_CharT, _Traits>, _CharT> : public __formatter_string<_CharT> {
|
|
using _Base _LIBCPP_NODEBUG = __formatter_string<_CharT>;
|
|
|
|
template <class _FormatContext>
|
|
_LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator
|
|
format(basic_string_view<_CharT, _Traits> __str, _FormatContext& __ctx) const {
|
|
// Drop _Traits to have one std::basic_string_view formatter.
|
|
return _Base::format(basic_string_view<_CharT>(__str.data(), __str.size()), __ctx);
|
|
}
|
|
};
|
|
|
|
# if _LIBCPP_HAS_WIDE_CHARACTERS
|
|
template <>
|
|
struct formatter<char*, wchar_t> : __disabled_formatter {};
|
|
template <>
|
|
struct formatter<const char*, wchar_t> : __disabled_formatter {};
|
|
template <size_t _Size>
|
|
struct formatter<char[_Size], wchar_t> : __disabled_formatter {};
|
|
template <class _Traits, class _Allocator>
|
|
struct formatter<basic_string<char, _Traits, _Allocator>, wchar_t> : __disabled_formatter {};
|
|
template <class _Traits>
|
|
struct formatter<basic_string_view<char, _Traits>, wchar_t> : __disabled_formatter {};
|
|
# endif // _LIBCPP_HAS_WIDE_CHARACTERS
|
|
|
|
# if _LIBCPP_STD_VER >= 23
|
|
template <>
|
|
inline constexpr bool enable_nonlocking_formatter_optimization<char*> = true;
|
|
template <>
|
|
inline constexpr bool enable_nonlocking_formatter_optimization<const char*> = true;
|
|
template <size_t _Size>
|
|
inline constexpr bool enable_nonlocking_formatter_optimization<char[_Size]> = true;
|
|
template <class _Traits, class _Allocator>
|
|
inline constexpr bool enable_nonlocking_formatter_optimization<basic_string<char, _Traits, _Allocator>> = true;
|
|
template <class _Traits>
|
|
inline constexpr bool enable_nonlocking_formatter_optimization<basic_string_view<char, _Traits>> = true;
|
|
|
|
# if _LIBCPP_HAS_WIDE_CHARACTERS
|
|
template <>
|
|
inline constexpr bool enable_nonlocking_formatter_optimization<wchar_t*> = true;
|
|
template <>
|
|
inline constexpr bool enable_nonlocking_formatter_optimization<const wchar_t*> = true;
|
|
template <size_t _Size>
|
|
inline constexpr bool enable_nonlocking_formatter_optimization<wchar_t[_Size]> = true;
|
|
template <class _Traits, class _Allocator>
|
|
inline constexpr bool enable_nonlocking_formatter_optimization<basic_string<wchar_t, _Traits, _Allocator>> = true;
|
|
template <class _Traits>
|
|
inline constexpr bool enable_nonlocking_formatter_optimization<basic_string_view<wchar_t, _Traits>> = true;
|
|
# endif // _LIBCPP_HAS_WIDE_CHARACTERS
|
|
# endif // _LIBCPP_STD_VER >= 23
|
|
#endif // _LIBCPP_STD_VER >= 20
|
|
|
|
_LIBCPP_END_NAMESPACE_STD
|
|
|
|
#endif // _LIBCPP___FORMAT_FORMATTER_STRING_H
|