regex_compiler.h
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// class template regex -*- C++ -*-
// Copyright (C) 2010-2023 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_compiler.h
* 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
_GLIBCXX_BEGIN_NAMESPACE_CXX11
template<typename>
class regex_traits;
_GLIBCXX_END_NAMESPACE_CXX11
namespace __detail
{
/**
* @addtogroup regex-detail
* @{
*/
template<typename, bool, bool>
struct _BracketMatcher;
/**
* @brief Builds an NFA from an input iterator range.
*
* The %_TraitsT type should fulfill requirements [28.3].
*/
template<typename _TraitsT>
class _Compiler
{
public:
typedef typename _TraitsT::char_type _CharT;
typedef _NFA<_TraitsT> _RegexT;
typedef regex_constants::syntax_option_type _FlagT;
_Compiler(const _CharT* __b, const _CharT* __e,
const typename _TraitsT::locale_type& __traits, _FlagT __flags);
shared_ptr<const _RegexT>
_M_get_nfa() noexcept
{ return std::move(_M_nfa); }
private:
typedef _Scanner<_CharT> _ScannerT;
typedef typename _TraitsT::string_type _StringT;
typedef typename _ScannerT::_TokenT _TokenT;
typedef _StateSeq<_TraitsT> _StateSeqT;
typedef std::stack<_StateSeqT> _StackT;
typedef std::ctype<_CharT> _CtypeT;
// accepts a specific token or returns false.
bool
_M_match_token(_TokenT __token);
void
_M_disjunction();
void
_M_alternative();
bool
_M_term();
bool
_M_assertion();
bool
_M_quantifier();
bool
_M_atom();
bool
_M_bracket_expression();
template<bool __icase, bool __collate>
void
_M_insert_any_matcher_ecma();
template<bool __icase, bool __collate>
void
_M_insert_any_matcher_posix();
template<bool __icase, bool __collate>
void
_M_insert_char_matcher();
template<bool __icase, bool __collate>
void
_M_insert_character_class_matcher();
template<bool __icase, bool __collate>
void
_M_insert_bracket_matcher(bool __neg);
// Cache of the last atom seen in a bracketed range expression.
struct _BracketState
{
enum class _Type : char { _None, _Char, _Class } _M_type = _Type::_None;
_CharT _M_char = _CharT();
void
set(_CharT __c) noexcept { _M_type = _Type::_Char; _M_char = __c; }
_GLIBCXX_NODISCARD _CharT
get() const noexcept { return _M_char; }
void
reset(_Type __t = _Type::_None) noexcept { _M_type = __t; }
explicit operator bool() const noexcept
{ return _M_type != _Type::_None; }
// Previous token was a single character.
_GLIBCXX_NODISCARD bool
_M_is_char() const noexcept { return _M_type == _Type::_Char; }
// Previous token was a character class, equivalent class,
// collating symbol etc.
_GLIBCXX_NODISCARD bool
_M_is_class() const noexcept { return _M_type == _Type::_Class; }
};
template<bool __icase, bool __collate>
using _BracketMatcher
= std::__detail::_BracketMatcher<_TraitsT, __icase, __collate>;
// Returns true if successfully parsed one term and should continue
// compiling a bracket expression.
// Returns false if the compiler should move on.
template<bool __icase, bool __collate>
bool
_M_expression_term(_BracketState& __last_char,
_BracketMatcher<__icase, __collate>& __matcher);
int
_M_cur_int_value(int __radix);
bool
_M_try_char();
_StateSeqT
_M_pop()
{
auto ret = _M_stack.top();
_M_stack.pop();
return ret;
}
static _FlagT
_S_validate(_FlagT __f)
{
using namespace regex_constants;
switch (__f & (ECMAScript|basic|extended|awk|grep|egrep))
{
case ECMAScript:
case basic:
case extended:
case awk:
case grep:
case egrep:
return __f;
case _FlagT(0):
return __f | ECMAScript;
default:
std::__throw_regex_error(_S_grammar, "conflicting grammar options");
}
}
_FlagT _M_flags;
_ScannerT _M_scanner;
shared_ptr<_RegexT> _M_nfa;
_StringT _M_value;
_StackT _M_stack;
const _TraitsT& _M_traits;
const _CtypeT& _M_ctype;
};
// [28.13.14]
template<typename _TraitsT, bool __icase, bool __collate>
class _RegexTranslatorBase
{
public:
typedef typename _TraitsT::char_type _CharT;
typedef typename _TraitsT::string_type _StringT;
typedef _StringT _StrTransT;
explicit
_RegexTranslatorBase(const _TraitsT& __traits)
: _M_traits(__traits)
{ }
_CharT
_M_translate(_CharT __ch) const
{
if _GLIBCXX17_CONSTEXPR (__icase)
return _M_traits.translate_nocase(__ch);
else if _GLIBCXX17_CONSTEXPR (__collate)
return _M_traits.translate(__ch);
else
return __ch;
}
_StrTransT
_M_transform(_CharT __ch) const
{
_StrTransT __str(1, __ch);
return _M_traits.transform(__str.begin(), __str.end());
}
// See LWG 523. It's not efficiently implementable when _TraitsT is not
// std::regex_traits<>, and __collate is true. See specializations for
// implementations of other cases.
bool
_M_match_range(const _StrTransT& __first, const _StrTransT& __last,
const _StrTransT& __s) const
{ return __first <= __s && __s <= __last; }
protected:
bool _M_in_range_icase(_CharT __first, _CharT __last, _CharT __ch) const
{
typedef std::ctype<_CharT> __ctype_type;
const auto& __fctyp = use_facet<__ctype_type>(this->_M_traits.getloc());
auto __lower = __fctyp.tolower(__ch);
auto __upper = __fctyp.toupper(__ch);
return (__first <= __lower && __lower <= __last)
|| (__first <= __upper && __upper <= __last);
}
const _TraitsT& _M_traits;
};
template<typename _TraitsT, bool __icase, bool __collate>
class _RegexTranslator
: public _RegexTranslatorBase<_TraitsT, __icase, __collate>
{
public:
typedef _RegexTranslatorBase<_TraitsT, __icase, __collate> _Base;
using _Base::_Base;
};
template<typename _TraitsT, bool __icase>
class _RegexTranslator<_TraitsT, __icase, false>
: public _RegexTranslatorBase<_TraitsT, __icase, false>
{
public:
typedef _RegexTranslatorBase<_TraitsT, __icase, false> _Base;
typedef typename _Base::_CharT _CharT;
typedef _CharT _StrTransT;
using _Base::_Base;
_StrTransT
_M_transform(_CharT __ch) const
{ return __ch; }
bool
_M_match_range(_CharT __first, _CharT __last, _CharT __ch) const
{
if _GLIBCXX17_CONSTEXPR (!__icase)
return __first <= __ch && __ch <= __last;
else
return this->_M_in_range_icase(__first, __last, __ch);
}
};
template<typename _CharType>
class _RegexTranslator<std::regex_traits<_CharType>, true, true>
: public _RegexTranslatorBase<std::regex_traits<_CharType>, true, true>
{
public:
typedef _RegexTranslatorBase<std::regex_traits<_CharType>, true, true>
_Base;
typedef typename _Base::_CharT _CharT;
typedef typename _Base::_StrTransT _StrTransT;
using _Base::_Base;
bool
_M_match_range(const _StrTransT& __first, const _StrTransT& __last,
const _StrTransT& __str) const
{
__glibcxx_assert(__first.size() == 1);
__glibcxx_assert(__last.size() == 1);
__glibcxx_assert(__str.size() == 1);
return this->_M_in_range_icase(__first[0], __last[0], __str[0]);
}
};
template<typename _TraitsT>
class _RegexTranslator<_TraitsT, false, false>
{
public:
typedef typename _TraitsT::char_type _CharT;
typedef _CharT _StrTransT;
explicit
_RegexTranslator(const _TraitsT&)
{ }
_CharT
_M_translate(_CharT __ch) const
{ return __ch; }
_StrTransT
_M_transform(_CharT __ch) const
{ return __ch; }
bool
_M_match_range(_CharT __first, _CharT __last, _CharT __ch) const
{ return __first <= __ch && __ch <= __last; }
};
template<typename _TraitsT, bool __is_ecma, bool __icase, bool __collate>
struct _AnyMatcher;
template<typename _TraitsT, bool __icase, bool __collate>
struct _AnyMatcher<_TraitsT, false, __icase, __collate>
{
typedef _RegexTranslator<_TraitsT, __icase, __collate> _TransT;
typedef typename _TransT::_CharT _CharT;
explicit
_AnyMatcher(const _TraitsT& __traits)
: _M_translator(__traits)
{ }
bool
operator()(_CharT __ch) const
{
static auto __nul = _M_translator._M_translate('\0');
return _M_translator._M_translate(__ch) != __nul;
}
_TransT _M_translator;
};
template<typename _TraitsT, bool __icase, bool __collate>
struct _AnyMatcher<_TraitsT, true, __icase, __collate>
{
typedef _RegexTranslator<_TraitsT, __icase, __collate> _TransT;
typedef typename _TransT::_CharT _CharT;
explicit
_AnyMatcher(const _TraitsT& __traits)
: _M_translator(__traits)
{ }
bool
operator()(_CharT __ch) const
{ return _M_apply(__ch, typename is_same<_CharT, char>::type()); }
bool
_M_apply(_CharT __ch, true_type) const
{
auto __c = _M_translator._M_translate(__ch);
auto __n = _M_translator._M_translate('\n');
auto __r = _M_translator._M_translate('\r');
return __c != __n && __c != __r;
}
bool
_M_apply(_CharT __ch, false_type) const
{
auto __c = _M_translator._M_translate(__ch);
auto __n = _M_translator._M_translate('\n');
auto __r = _M_translator._M_translate('\r');
auto __u2028 = _M_translator._M_translate(u'\u2028');
auto __u2029 = _M_translator._M_translate(u'\u2029');
return __c != __n && __c != __r && __c != __u2028 && __c != __u2029;
}
_TransT _M_translator;
};
template<typename _TraitsT, bool __icase, bool __collate>
struct _CharMatcher
{
typedef _RegexTranslator<_TraitsT, __icase, __collate> _TransT;
typedef typename _TransT::_CharT _CharT;
_CharMatcher(_CharT __ch, const _TraitsT& __traits)
: _M_translator(__traits), _M_ch(_M_translator._M_translate(__ch))
{ }
bool
operator()(_CharT __ch) const
{ return _M_ch == _M_translator._M_translate(__ch); }
_TransT _M_translator;
_CharT _M_ch;
};
/// Matches a character range (bracket expression)
template<typename _TraitsT, bool __icase, bool __collate>
struct _BracketMatcher
{
public:
typedef _RegexTranslator<_TraitsT, __icase, __collate> _TransT;
typedef typename _TransT::_CharT _CharT;
typedef typename _TransT::_StrTransT _StrTransT;
typedef typename _TraitsT::string_type _StringT;
typedef typename _TraitsT::char_class_type _CharClassT;
public:
_BracketMatcher(bool __is_non_matching,
const _TraitsT& __traits)
: _M_class_set(0), _M_translator(__traits), _M_traits(__traits),
_M_is_non_matching(__is_non_matching)
{ }
bool
operator()(_CharT __ch) const
{
_GLIBCXX_DEBUG_ASSERT(_M_is_ready);
return _M_apply(__ch, _UseCache());
}
void
_M_add_char(_CharT __c)
{
_M_char_set.push_back(_M_translator._M_translate(__c));
_GLIBCXX_DEBUG_ONLY(_M_is_ready = false);
}
_StringT
_M_add_collate_element(const _StringT& __s)
{
auto __st = _M_traits.lookup_collatename(__s.data(),
__s.data() + __s.size());
if (__st.empty())
__throw_regex_error(regex_constants::error_collate,
"Invalid collate element.");
_M_char_set.push_back(_M_translator._M_translate(__st[0]));
_GLIBCXX_DEBUG_ONLY(_M_is_ready = false);
return __st;
}
void
_M_add_equivalence_class(const _StringT& __s)
{
auto __st = _M_traits.lookup_collatename(__s.data(),
__s.data() + __s.size());
if (__st.empty())
__throw_regex_error(regex_constants::error_collate,
"Invalid equivalence class.");
__st = _M_traits.transform_primary(__st.data(),
__st.data() + __st.size());
_M_equiv_set.push_back(__st);
_GLIBCXX_DEBUG_ONLY(_M_is_ready = false);
}
// __neg should be true for \D, \S and \W only.
void
_M_add_character_class(const _StringT& __s, bool __neg)
{
auto __mask = _M_traits.lookup_classname(__s.data(),
__s.data() + __s.size(),
__icase);
if (__mask == 0)
__throw_regex_error(regex_constants::error_collate,
"Invalid character class.");
if (!__neg)
_M_class_set |= __mask;
else
_M_neg_class_set.push_back(__mask);
_GLIBCXX_DEBUG_ONLY(_M_is_ready = false);
}
void
_M_make_range(_CharT __l, _CharT __r)
{
if (__l > __r)
__throw_regex_error(regex_constants::error_range,
"Invalid range in bracket expression.");
_M_range_set.push_back(make_pair(_M_translator._M_transform(__l),
_M_translator._M_transform(__r)));
_GLIBCXX_DEBUG_ONLY(_M_is_ready = false);
}
void
_M_ready()
{
std::sort(_M_char_set.begin(), _M_char_set.end());
auto __end = std::unique(_M_char_set.begin(), _M_char_set.end());
_M_char_set.erase(__end, _M_char_set.end());
_M_make_cache(_UseCache());
_GLIBCXX_DEBUG_ONLY(_M_is_ready = true);
}
private:
// Currently we only use the cache for char
using _UseCache = typename std::is_same<_CharT, char>::type;
static constexpr size_t
_S_cache_size =
1ul << (sizeof(_CharT) * __CHAR_BIT__ * int(_UseCache::value));
struct _Dummy { };
using _CacheT = std::__conditional_t<_UseCache::value,
std::bitset<_S_cache_size>,
_Dummy>;
using _UnsignedCharT = typename std::make_unsigned<_CharT>::type;
bool
_M_apply(_CharT __ch, false_type) const;
bool
_M_apply(_CharT __ch, true_type) const
{ return _M_cache[static_cast<_UnsignedCharT>(__ch)]; }
void
_M_make_cache(true_type)
{
for (unsigned __i = 0; __i < _M_cache.size(); __i++)
_M_cache[__i] = _M_apply(static_cast<_CharT>(__i), false_type());
}
void
_M_make_cache(false_type)
{ }
private:
_GLIBCXX_STD_C::vector<_CharT> _M_char_set;
_GLIBCXX_STD_C::vector<_StringT> _M_equiv_set;
_GLIBCXX_STD_C::vector<pair<_StrTransT, _StrTransT>> _M_range_set;
_GLIBCXX_STD_C::vector<_CharClassT> _M_neg_class_set;
_CharClassT _M_class_set;
_TransT _M_translator;
const _TraitsT& _M_traits;
bool _M_is_non_matching;
_CacheT _M_cache;
#ifdef _GLIBCXX_DEBUG
bool _M_is_ready = false;
#endif
};
///@} regex-detail
} // namespace __detail
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
#include <bits/regex_compiler.tcc>
regex_compiler.tcc
std::true_type
integral_constant< bool, true > true_type
The type used as a compile-time boolean with true value.
Definition type_traits:82
std::false_type
integral_constant< bool, false > false_type
The type used as a compile-time boolean with false value.
Definition type_traits:85
std::make_pair
constexpr pair< typename __decay_and_strip< _T1 >::__type, typename __decay_and_strip< _T2 >::__type > make_pair(_T1 &&__x, _T2 &&__y)
A convenience wrapper for creating a pair from two objects.
Definition stl_pair.h:922
std::move
constexpr std::remove_reference< _Tp >::type && move(_Tp &&__t) noexcept
Convert a value to an rvalue.
Definition move.h:97
std::use_facet
const _Facet & use_facet(const locale &__loc)
Return a facet.
Definition locale_classes.tcc:192
std
ISO C++ entities toplevel namespace is std.
std::__detail
Implementation details not part of the namespace std interface.
std::regex_constants
ISO C++ 2011 namespace for options and flags used with std::regex.
std::regex_constants::error_range
constexpr error_type error_range(_S_error_range)
std::regex_constants::syntax_option_type
syntax_option_type
This is a bitmask type indicating how to interpret the regex.
Definition regex_constants.h:70
std::regex_constants::error_collate
constexpr error_type error_collate(_S_error_collate)
std::bitset
The bitset class represents a fixed-size sequence of bits.
Definition bitset:799
std::ctype
Primary class template ctype facet.
Definition locale_facets.h:616
std::regex_traits
Describes aspects of a regular expression.
Definition regex.h:97
std::__detail::_StateSeq
Describes a sequence of one or more _State, its current start and end(s). This structure contains fra...
Definition regex_automaton.h:355
std::__detail::_BracketMatcher
Matches a character range (bracket expression).
Definition regex_compiler.h:425
std::__detail::_Scanner
Scans an input range for regex tokens.
Definition regex_scanner.h:212
std::shared_ptr
A smart pointer with reference-counted copy semantics.
Definition bits/shared_ptr.h:176
std::set
A standard container made up of unique keys, which can be retrieved in logarithmic time.
Definition stl_set.h:97
std::stack
A standard container giving FILO behavior.
Definition stl_stack.h:100