gcc/libstdc++-v3/include/bits/regex_error.h
Jonathan Wakely 260a5334ee libstdc++: Improve std::regex_error::what() strings
This replaces the vague "regex_error" for std::regex_error::what() with
a string that corresponds to the error_type enum passed to the
constructor. This allows us to remove many of the strings passed to
__throw_regex_error, because the default string is at least as good.
When a string argument to __throw_regex_error is kept it should add some
context-specific detail absent from the default string.

Also remove full stops (periods) from the end of those strings, to make
it easier to include them in logs and other output. I've left them
starting with an upper-case letter, which is consistent with strerror
output for (at least) Glibc, Solaris and BSD. I'm ambivalent whether
that's the right choice.

This also adds the missing noreturn attribute to __throw_regex_error.

libstdc++-v3/ChangeLog:

	* include/bits/regex_compiler.tcc: Adjust all calls to
	__throw_regex_error.
	* include/bits/regex_error.h (__throw_regex_error): Add noreturn
	attribute.
	* include/bits/regex_scanner.tcc: Likewise.
	* src/c++11/regex.cc (desc): New helper function.
	(regex_error::regex_error(error_type)): Use desc to get a string
	corresponding to the error code.
2022-01-05 13:47:00 +00:00

188 lines
5.0 KiB
C++

// class template regex -*- C++ -*-
// Copyright (C) 2010-2022 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/**
* @file bits/regex_error.h
* @brief Error and exception objects for the std regex library.
*
* This is an internal header file, included by other library headers.
* Do not attempt to use it directly. @headername{regex}
*/
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
/**
* @addtogroup regex
* @{
*/
namespace regex_constants
{
/**
* @name 5.3 Error Types
*/
///@{
enum error_type
{
_S_error_collate, // XXX should have been a non-zero value
_S_error_ctype,
_S_error_escape,
_S_error_backref,
_S_error_brack,
_S_error_paren,
_S_error_brace,
_S_error_badbrace,
_S_error_range,
_S_error_space,
_S_error_badrepeat,
_S_error_complexity,
_S_error_stack,
_S_null,
_S_grammar
};
/** The expression contained an invalid collating element name. */
constexpr error_type error_collate(_S_error_collate);
/** The expression contained an invalid character class name. */
constexpr error_type error_ctype(_S_error_ctype);
/**
* The expression contained an invalid escaped character, or a trailing
* escape.
*/
constexpr error_type error_escape(_S_error_escape);
/** The expression contained an invalid back reference. */
constexpr error_type error_backref(_S_error_backref);
/** The expression contained mismatched [ and ]. */
constexpr error_type error_brack(_S_error_brack);
/** The expression contained mismatched ( and ). */
constexpr error_type error_paren(_S_error_paren);
/** The expression contained mismatched { and } */
constexpr error_type error_brace(_S_error_brace);
/** The expression contained an invalid range in a {} expression. */
constexpr error_type error_badbrace(_S_error_badbrace);
/**
* The expression contained an invalid character range,
* such as [b-a] in most encodings.
*/
constexpr error_type error_range(_S_error_range);
/**
* There was insufficient memory to convert the expression into a
* finite state machine.
*/
constexpr error_type error_space(_S_error_space);
/**
* One of <em>*?+{</em> was not preceded by a valid regular expression.
*/
constexpr error_type error_badrepeat(_S_error_badrepeat);
/**
* The complexity of an attempted match against a regular expression
* exceeded a pre-set level.
*/
constexpr error_type error_complexity(_S_error_complexity);
/**
* There was insufficient memory to determine whether the
* regular expression could match the specified character sequence.
*/
constexpr error_type error_stack(_S_error_stack);
///@}
} // namespace regex_constants
// [7.8] Class regex_error
/**
* @brief A regular expression exception class.
* @ingroup exceptions
*
* The regular expression library throws objects of this class on error.
*/
class regex_error : public std::runtime_error
{
using error_type = regex_constants::error_type;
error_type _M_code;
public:
/**
* @brief Constructs a regex_error object.
*
* @param __ecode the regex error code.
*/
explicit
regex_error(error_type __ecode);
virtual ~regex_error() throw();
/**
* @brief Gets the regex error code.
*
* @returns the regex error code.
*/
regex_constants::error_type
code() const noexcept
{ return _M_code; }
private:
regex_error(error_type __ecode, const char* __what)
: std::runtime_error(__what), _M_code(__ecode)
{ }
[[__noreturn__]]
friend void
__throw_regex_error(error_type __ecode __attribute__((__unused__)),
const char* __what __attribute__((__unused__)))
{ _GLIBCXX_THROW_OR_ABORT(regex_error(__ecode, __what)); }
};
/// @cond undocumented
[[__noreturn__]]
void
__throw_regex_error(regex_constants::error_type __ecode);
[[__noreturn__]]
inline void
__throw_regex_error(regex_constants::error_type __ecode, const char* __what);
/// @endcond
///@} // group regex
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std