On Mon, Sep 7, 2015 at 4:06 AM, Jonathan Wakely <jwak...@redhat.com> wrote:
> On 28/08/15 11:23 -0700, Tim Shen wrote:
>>
>> On Fri, Aug 28, 2015 at 8:59 AM, Jonathan Wakely <jwak...@redhat.com>
>> wrote:
>>>
>>> There seems to be no need to construct a std::string here, just pass a
>>> const char* (see below).
>>
>>
>> To be honest, I wasn't considering performance for a bit, since
>> exceptions are already considered slow by me :P. But yes, we can do
>> less allocations.
>>
>>> I wonder if we want to make this more efficient by adding a private
>>> member to regex_error that would allow information to be appended to
>>> the string, rather then creating a new regex_error with a new string.
>
>
> In case it wasn't clear, I was suggesting to add a private member
> *function* not data member.
>
>> I can add a helper function to _Scanner to construct the exception
>> object for only once. For functions that can't access this helper, use
>> return value for error handling.
>>
>>> I suggest adding another overload that takes a const char* rather than
>>> std::string. The reason is that when using the new ABI this function
>>> will take a std::__cxx11::string, so calling it will allocate memory
>>> for the string data, then that string is passed to the regex_error
>>> constructor which has to convert it internally to an old std::string,
>>> which has to allocate a second time.
>>
>>
>> First, to make it clear: due to _M_get_location_string(), we need
>> dynamic allocation.
>>
>> So is it good to have an owned raw pointer stored in runtime_error,
>> pointing to a heap allocated char chunk, which will be deallocated in
>> regex_error's dtor?
>
>
> No, adding that pointer is an ABI change.
>
> If you can't do it without an ABI change then you will have to lose
> the _M_get_location_string() functionality. It seems non-essential
> anyway.
Ok then, let's not append dynamic location information, but use a
string literal pointer only.
--
Regards,
Tim Shen
commit fc3343a2c719049620447f6dc20191e2af4895f6
Author: Tim Shen <tims...@google.com>
Date: Thu Aug 27 21:42:40 2015 -0700
PR libstdc++/67361
* include/bits/regex_error.h: Add __throw_regex_error that
supports string.
* include/bits/regex_automaton.h: Add more specific exception
messages.
* include/bits/regex_automaton.tcc: Likewise.
* include/bits/regex_compiler.h: Likewise.
* include/bits/regex_compiler.tcc: Likewise.
* include/bits/regex_scanner.h: Likewise.
* include/bits/regex_scanner.tcc: Likewise.
diff --git a/libstdc++-v3/include/bits/regex_automaton.h
b/libstdc++-v3/include/bits/regex_automaton.h
index b6ab307..1f672ee 100644
--- a/libstdc++-v3/include/bits/regex_automaton.h
+++ b/libstdc++-v3/include/bits/regex_automaton.h
@@ -327,7 +327,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{
this->push_back(std::move(__s));
if (this->size() > _GLIBCXX_REGEX_STATE_LIMIT)
- __throw_regex_error(regex_constants::error_space);
+ __throw_regex_error(
+ regex_constants::error_space,
+ "Number of NFA states exceeds limit. Please use shorter regex "
+ "string, or use smaller brace expression, or make "
+ "_GLIBCXX_REGEX_STATE_LIMIT larger.");
return this->size()-1;
}
diff --git a/libstdc++-v3/include/bits/regex_automaton.tcc
b/libstdc++-v3/include/bits/regex_automaton.tcc
index f6f63a1..9bb1164 100644
--- a/libstdc++-v3/include/bits/regex_automaton.tcc
+++ b/libstdc++-v3/include/bits/regex_automaton.tcc
@@ -149,7 +149,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_NFA<_TraitsT>::_M_insert_backref(size_t __index)
{
if (this->_M_flags & regex_constants::__polynomial)
- __throw_regex_error(regex_constants::error_complexity);
+ __throw_regex_error(regex_constants::error_complexity,
+ "Unexpected back-reference in polynomial mode.");
// To figure out whether a backref is valid, a stack is used to store
// unfinished sub-expressions. For example, when parsing
// "(a(b)(c\\1(d)))" at '\\1', _M_subexpr_count is 3, indicating that 3
@@ -158,10 +159,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// _M_paren_stack is {1, 3}, for incomplete "(a.." and "(c..". At this
// time, "\\2" is valid, but "\\1" and "\\3" are not.
if (__index >= _M_subexpr_count)
- __throw_regex_error(regex_constants::error_backref);
+ __throw_regex_error(
+ regex_constants::error_backref,
+ "Back-reference index exceeds current sub-expression count.");
for (auto __it : this->_M_paren_stack)
if (__index == __it)
- __throw_regex_error(regex_constants::error_backref);
+ __throw_regex_error(
+ regex_constants::error_backref,
+ "Back-reference referred to an opened sub-expression.");
this->_M_has_backref = true;
_StateT __tmp(_S_opcode_backref);
__tmp._M_backref_index = __index;
diff --git a/libstdc++-v3/include/bits/regex_compiler.h
b/libstdc++-v3/include/bits/regex_compiler.h
index 07a9ed3..1f6348a 100644
--- a/libstdc++-v3/include/bits/regex_compiler.h
+++ b/libstdc++-v3/include/bits/regex_compiler.h
@@ -392,7 +392,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
auto __st = _M_traits.lookup_collatename(__s.data(),
__s.data() + __s.size());
if (__st.empty())
- __throw_regex_error(regex_constants::error_collate);
+ __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;
@@ -404,7 +405,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
auto __st = _M_traits.lookup_collatename(__s.data(),
__s.data() + __s.size());
if (__st.empty())
- __throw_regex_error(regex_constants::error_collate);
+ __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);
@@ -419,7 +421,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__s.data() + __s.size(),
__icase);
if (__mask == 0)
- __throw_regex_error(regex_constants::error_ctype);
+ __throw_regex_error(regex_constants::error_collate,
+ "Invalid character class.");
if (!__neg)
_M_class_set |= __mask;
else
@@ -431,7 +434,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_M_make_range(_CharT __l, _CharT __r)
{
if (__l > __r)
- __throw_regex_error(regex_constants::error_range);
+ __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);
diff --git a/libstdc++-v3/include/bits/regex_compiler.tcc
b/libstdc++-v3/include/bits/regex_compiler.tcc
index 336a2e8..f7d52fc 100644
--- a/libstdc++-v3/include/bits/regex_compiler.tcc
+++ b/libstdc++-v3/include/bits/regex_compiler.tcc
@@ -162,7 +162,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
auto __neg = _M_value[0] == 'n';
this->_M_disjunction();
if (!_M_match_token(_ScannerT::_S_token_subexpr_end))
- __throw_regex_error(regex_constants::error_paren);
+ __throw_regex_error(regex_constants::error_paren,
+ "Parenthesis is not closed.");
auto __tmp = _M_pop();
__tmp._M_append(_M_nfa->_M_insert_accept());
_M_stack.push(
@@ -184,7 +185,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
auto __init = [this, &__neg]()
{
if (_M_stack.empty())
- __throw_regex_error(regex_constants::error_badrepeat);
+ __throw_regex_error(regex_constants::error_badrepeat,
+ "Nothing to repeat before a quantifier.");
__neg = __neg && _M_match_token(_ScannerT::_S_token_opt);
};
if (_M_match_token(_ScannerT::_S_token_closure0))
@@ -220,9 +222,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
else if (_M_match_token(_ScannerT::_S_token_interval_begin))
{
if (_M_stack.empty())
- __throw_regex_error(regex_constants::error_badrepeat);
+ __throw_regex_error(regex_constants::error_badrepeat,
+ "Nothing to repeat before a quantifier.");
if (!_M_match_token(_ScannerT::_S_token_dup_count))
- __throw_regex_error(regex_constants::error_badbrace);
+ __throw_regex_error(regex_constants::error_badbrace,
+ "Unexpected token in brace expression.");
_StateSeqT __r(_M_pop());
_StateSeqT __e(*_M_nfa, _M_nfa->_M_insert_dummy());
long __min_rep = _M_cur_int_value(10);
@@ -238,7 +242,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
else
__n = 0;
if (!_M_match_token(_ScannerT::_S_token_interval_end))
- __throw_regex_error(regex_constants::error_brace);
+ __throw_regex_error(regex_constants::error_brace,
+ "Unexpected end of brace expression.");
__neg = __neg && _M_match_token(_ScannerT::_S_token_opt);
@@ -257,7 +262,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
else
{
if (__n < 0)
- __throw_regex_error(regex_constants::error_badbrace);
+ __throw_regex_error(regex_constants::error_badbrace,
+ "Invalid range in brace expression.");
auto __end = _M_nfa->_M_insert_dummy();
// _M_alt is the "match more" branch, and _M_next is the
// "match less" one. Switch _M_alt and _M_next of all created
@@ -324,7 +330,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_StateSeqT __r(*_M_nfa, _M_nfa->_M_insert_dummy());
this->_M_disjunction();
if (!_M_match_token(_ScannerT::_S_token_subexpr_end))
- __throw_regex_error(regex_constants::error_paren);
+ __throw_regex_error(regex_constants::error_paren,
+ "Parenthesis is not closed.");
__r._M_append(_M_pop());
_M_stack.push(__r);
}
@@ -333,7 +340,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_StateSeqT __r(*_M_nfa, _M_nfa->_M_insert_subexpr_begin());
this->_M_disjunction();
if (!_M_match_token(_ScannerT::_S_token_subexpr_end))
- __throw_regex_error(regex_constants::error_paren);
+ __throw_regex_error(regex_constants::error_paren,
+ "Parenthesis is not closed.");
__r._M_append(_M_pop());
__r._M_append(_M_nfa->_M_insert_subexpr_end());
_M_stack.push(__r);
@@ -474,7 +482,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{
if (_M_match_token(_ScannerT::_S_token_bracket_end))
return false;
- __throw_regex_error(regex_constants::error_range);
+ __throw_regex_error(
+ regex_constants::error_range,
+ "Unexpected dash in bracket expression. For POSIX syntax, "
+ "a dash is not treated literally only when it is at "
+ "beginning or end.");
}
__last_char.first = true;
__last_char.second = _M_value[0];
@@ -492,7 +504,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{
if (_M_scanner._M_get_token()
!= _ScannerT::_S_token_bracket_end)
- __throw_regex_error(regex_constants::error_range);
+ __throw_regex_error(
+ regex_constants::error_range,
+ "Unexpected end of bracket expression.");
__matcher._M_add_char(_M_value[0]);
}
}
@@ -508,7 +522,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_M_ctype.is(_CtypeT::upper,
_M_value[0]));
else
- __throw_regex_error(regex_constants::error_brack);
+ __throw_regex_error(regex_constants::error_brack,
+ "Unexpected character in bracket expression.");
return true;
}
diff --git a/libstdc++-v3/include/bits/regex_error.h
b/libstdc++-v3/include/bits/regex_error.h
index 778edd5..be19fc1 100644
--- a/libstdc++-v3/include/bits/regex_error.h
+++ b/libstdc++-v3/include/bits/regex_error.h
@@ -155,6 +155,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
regex_constants::error_type
code() const
{ return _M_code; }
+
+ private:
+ regex_error(regex_constants::error_type __ecode, const char* __what)
+ : std::runtime_error(__what), _M_code(__ecode)
+ { }
+
+ friend void __throw_regex_error(regex_constants::error_type, const char*);
};
//@} // group regex
@@ -162,5 +169,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
void
__throw_regex_error(regex_constants::error_type __ecode);
+ inline void
+ __throw_regex_error(regex_constants::error_type __ecode, const char* __what)
+ { _GLIBCXX_THROW_OR_ABORT(regex_error(__ecode, __what)); }
+
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
diff --git a/libstdc++-v3/include/bits/regex_scanner.tcc
b/libstdc++-v3/include/bits/regex_scanner.tcc
index c158c65..7d24e06 100644
--- a/libstdc++-v3/include/bits/regex_scanner.tcc
+++ b/libstdc++-v3/include/bits/regex_scanner.tcc
@@ -108,7 +108,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
if (__c == '\\')
{
if (_M_current == _M_end)
- __throw_regex_error(regex_constants::error_escape);
+ __throw_regex_error(
+ regex_constants::error_escape,
+ "Unexpected end of regex when escaping.");
if (!_M_is_basic()
|| (*_M_current != '('
@@ -125,7 +127,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
if (_M_is_ecma() && *_M_current == '?')
{
if (++_M_current == _M_end)
- __throw_regex_error(regex_constants::error_paren);
+ __throw_regex_error(
+ regex_constants::error_paren,
+ "Unexpected end of regex when in an open parenthesis.");
if (*_M_current == ':')
{
@@ -145,7 +149,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_M_value.assign(1, 'n');
}
else
- __throw_regex_error(regex_constants::error_paren);
+ __throw_regex_error(
+ regex_constants::error_paren,
+ "Invalid special open parenthesis.");
}
else if (_M_flags & regex_constants::nosubs)
_M_token = _S_token_subexpr_no_group_begin;
@@ -204,14 +210,17 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_M_scan_in_bracket()
{
if (_M_current == _M_end)
- __throw_regex_error(regex_constants::error_brack);
+ __throw_regex_error(
+ regex_constants::error_brack,
+ "Unexpected end of regex when in bracket expression.");
auto __c = *_M_current++;
if (__c == '[')
{
if (_M_current == _M_end)
- __throw_regex_error(regex_constants::error_brack);
+ __throw_regex_error(regex_constants::error_brack,
+ "Unexpected character class open bracket.");
if (*_M_current == '.')
{
@@ -261,7 +270,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_M_scan_in_brace()
{
if (_M_current == _M_end)
- __throw_regex_error(regex_constants::error_brace);
+ __throw_regex_error(
+ regex_constants::error_brace,
+ "Unexpected end of regex when in brace expression.");
auto __c = *_M_current++;
@@ -285,7 +296,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
++_M_current;
}
else
- __throw_regex_error(regex_constants::error_badbrace);
+ __throw_regex_error(regex_constants::error_badbrace,
+ "Unexpected character in brace expression.");
}
else if (__c == '}')
{
@@ -293,7 +305,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_M_token = _S_token_interval_end;
}
else
- __throw_regex_error(regex_constants::error_badbrace);
+ __throw_regex_error(regex_constants::error_badbrace,
+ "Unexpected character in brace expression.");
}
template<typename _CharT>
@@ -302,7 +315,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_M_eat_escape_ecma()
{
if (_M_current == _M_end)
- __throw_regex_error(regex_constants::error_escape);
+ __throw_regex_error(regex_constants::error_escape,
+ "Unexpected end of regex when escaping.");
auto __c = *_M_current++;
auto __pos = _M_find_escape(_M_ctype.narrow(__c, '\0'));
@@ -336,7 +350,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
else if (__c == 'c')
{
if (_M_current == _M_end)
- __throw_regex_error(regex_constants::error_escape);
+ __throw_regex_error(
+ regex_constants::error_escape,
+ "Unexpected end of regex when reading control code.");
_M_token = _S_token_ord_char;
_M_value.assign(1, *_M_current++);
}
@@ -347,7 +363,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{
if (_M_current == _M_end
|| !_M_ctype.is(_CtypeT::xdigit, *_M_current))
- __throw_regex_error(regex_constants::error_escape);
+ __throw_regex_error(
+ regex_constants::error_escape,
+ "Unexpected end of regex when ascii character.");
_M_value += *_M_current++;
}
_M_token = _S_token_hex_num;
@@ -376,7 +394,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_M_eat_escape_posix()
{
if (_M_current == _M_end)
- __throw_regex_error(regex_constants::error_escape);
+ __throw_regex_error(regex_constants::error_escape,
+ "Unexpected end of regex when escaping.");
auto __c = *_M_current;
auto __pos = std::strchr(_M_spec_char, _M_ctype.narrow(__c, '\0'));
@@ -401,7 +420,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{
#ifdef __STRICT_ANSI__
// POSIX says it is undefined to escape ordinary characters
- __throw_regex_error(regex_constants::error_escape);
+ __throw_regex_error(regex_constants::error_escape,
+ "Unexpected escape character.");
#else
_M_token = _S_token_ord_char;
_M_value.assign(1, __c);
@@ -441,7 +461,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
return;
}
else
- __throw_regex_error(regex_constants::error_escape);
+ __throw_regex_error(regex_constants::error_escape,
+ "Unexpected escape character.");
}
// Eats a character class or throws an exception.
@@ -460,9 +481,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|| *_M_current++ != ']') // skip ']'
{
if (__ch == ':')
- __throw_regex_error(regex_constants::error_ctype);
+ __throw_regex_error(regex_constants::error_ctype,
+ "Unexpected end of character class.");
else
- __throw_regex_error(regex_constants::error_collate);
+ __throw_regex_error(regex_constants::error_collate,
+ "Unexpected end of character class.");
}
}
