re PR libstdc++/64584 (basic_regex::assign breaks *this if it throws regex_error)

	PR libstdc++/64584
	PR libstdc++/64585
	* include/bits/regex.h (basic_regex<>::basic_regex,
	basic_regex<>::assign, basic_regex<>::imbue,
	basic_regex<>::swap, basic_regex<>::mark_count): Drop NFA after
	imbuing basic_regex; Make assign() transactional against exception.
	* include/bits/regex_compiler.h (__compile_nfa<>): Add back
	__compile_nfa SFINAE.
	* include/std/regex: Adjust include order to avoid __compile_nfa
	forward declaration.
	* testsuite/28_regex/basic_regex/assign/char/string.cc: New testcase.
	* testsuite/28_regex/basic_regex/imbue/string.cc: New testcase.

From-SVN: r219865

3 files changed, 74 insertions, 39 deletions

diff --git a/libstdc++-v3/include/bits/regex.h b/libstdc++-v3/include/bits/regex.h
index 52c2384..6de883a 100644
--- a/libstdc++-v3/include/bits/regex.h
+++ b/libstdc++-v3/include/bits/regex.h
@@ -62,13 +62,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   template<typename, typename, typename, bool>
     class _Executor;
 
-  template<typename _TraitsT>
-    inline std::shared_ptr<_NFA<_TraitsT>>
-    __compile_nfa(const typename _TraitsT::char_type* __first,
-		  const typename _TraitsT::char_type* __last,
-		  const typename _TraitsT::locale_type& __loc,
-		  regex_constants::syntax_option_type __flags);
-
 _GLIBCXX_END_NAMESPACE_VERSION
 }
 
@@ -433,7 +426,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
        * character sequence.
        */
       basic_regex()
-      : _M_flags(ECMAScript), _M_loc(), _M_original_str(), _M_automaton(nullptr)
+      : _M_flags(ECMAScript), _M_loc(), _M_automaton(nullptr)
       { }
 
       /**
@@ -497,7 +490,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
 	basic_regex(const std::basic_string<_Ch_type, _Ch_traits,
 					    _Ch_alloc>& __s,
 		    flag_type __f = ECMAScript)
-	: basic_regex(__s.begin(), __s.end(), __f)
+	: basic_regex(__s.data(), __s.data() + __s.size(), __f)
 	{ }
 
       /**
@@ -516,14 +509,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
       template<typename _FwdIter>
 	basic_regex(_FwdIter __first, _FwdIter __last,
 		    flag_type __f = ECMAScript)
-	: _M_flags(__f),
-	  _M_loc(),
-	  _M_original_str(__first, __last),
-	  _M_automaton(__detail::__compile_nfa<_Rx_traits>(
-	    _M_original_str.c_str(),
-	    _M_original_str.c_str() + _M_original_str.size(),
-	    _M_loc,
-	    _M_flags))
+	: basic_regex(std::move(__first), std::move(__last), locale_type(), __f)
 	{ }
 
       /**
@@ -657,15 +643,8 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
 	assign(const basic_string<_Ch_type, _Ch_traits, _Alloc>& __s,
 	       flag_type __flags = ECMAScript)
 	{
-	  _M_flags = __flags;
-	  _M_original_str.assign(__s.begin(), __s.end());
-	  auto __p = _M_original_str.c_str();
-	  _M_automaton = __detail::__compile_nfa<_Rx_traits>(
-	    __p,
-	    __p + _M_original_str.size(),
-	    _M_loc,
-	    _M_flags);
-	  return *this;
+	  return this->assign(basic_regex(__s.data(), __s.data() + __s.size(),
+					  _M_loc, _M_flags));
 	}
 
       /**
@@ -709,7 +688,11 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
        */
       unsigned int
       mark_count() const
-      { return _M_automaton->_M_sub_count() - 1; }
+      {
+	if (_M_automaton)
+	  return _M_automaton->_M_sub_count() - 1;
+	return 0;
+      }
 
       /**
        * @brief Gets the flags used to construct the regular expression
@@ -729,8 +712,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
       imbue(locale_type __loc)
       {
 	std::swap(__loc, _M_loc);
-	if (_M_automaton != nullptr)
-	  this->assign(_M_original_str, _M_flags);
+	_M_automaton = nullptr;
 	return __loc;
       }
 
@@ -753,7 +735,6 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
       {
 	std::swap(_M_flags, __rhs._M_flags);
 	std::swap(_M_loc, __rhs._M_loc);
-	std::swap(_M_original_str, __rhs._M_original_str);
 	std::swap(_M_automaton, __rhs._M_automaton);
       }
 
@@ -764,7 +745,15 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
 #endif
 
     private:
-      typedef std::shared_ptr<__detail::_NFA<_Rx_traits>> _AutomatonPtr;
+      typedef std::shared_ptr<const __detail::_NFA<_Rx_traits>> _AutomatonPtr;
+
+      template<typename _FwdIter>
+	basic_regex(_FwdIter __first, _FwdIter __last, locale_type __loc,
+		    flag_type __f)
+	: _M_flags(__f), _M_loc(std::move(__loc)),
+	_M_automaton(__detail::__compile_nfa<_FwdIter, _Rx_traits>(
+	  std::move(__first), std::move(__last), _M_loc, _M_flags))
+	{ }
 
       template<typename _Bp, typename _Ap, typename _Cp, typename _Rp,
 	__detail::_RegexExecutorPolicy, bool>
@@ -778,7 +767,6 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
 
       flag_type              _M_flags;
       locale_type            _M_loc;
-      basic_string<_Ch_type> _M_original_str;
       _AutomatonPtr          _M_automaton;
     };
 
diff --git a/libstdc++-v3/include/bits/regex_compiler.h b/libstdc++-v3/include/bits/regex_compiler.h
index 81f8c8e..4472116 100644
--- a/libstdc++-v3/include/bits/regex_compiler.h
+++ b/libstdc++-v3/include/bits/regex_compiler.h
@@ -59,7 +59,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       _Compiler(_IterT __b, _IterT __e,
 		const typename _TraitsT::locale_type& __traits, _FlagT __flags);
 
-      std::shared_ptr<_RegexT>
+      shared_ptr<const _RegexT>
       _M_get_nfa()
       { return std::move(_M_nfa); }
 
@@ -145,15 +145,62 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       const _CtypeT&      _M_ctype;
     };
 
-  template<typename _TraitsT>
-    inline std::shared_ptr<_NFA<_TraitsT>>
-    __compile_nfa(const typename _TraitsT::char_type* __first,
-		  const typename _TraitsT::char_type* __last,
+  template<typename _Tp>
+    struct __has_contiguous_iter : std::false_type { };
+
+  template<typename _Ch, typename _Tr, typename _Alloc>
+    struct __has_contiguous_iter<std::basic_string<_Ch, _Tr, _Alloc>>
+    : std::true_type
+    { };
+
+  template<typename _Tp, typename _Alloc>
+    struct __has_contiguous_iter<std::vector<_Tp, _Alloc>>
+    : std::true_type
+    { };
+
+  template<typename _Tp>
+    struct __is_contiguous_normal_iter : std::false_type { };
+
+  template<typename _CharT>
+    struct __is_contiguous_normal_iter<_CharT*> : std::true_type { };
+
+  template<typename _Tp, typename _Cont>
+    struct
+    __is_contiguous_normal_iter<__gnu_cxx::__normal_iterator<_Tp, _Cont>>
+    : __has_contiguous_iter<_Cont>::type
+    { };
+
+  template<typename _Iter, typename _TraitsT>
+    using __enable_if_contiguous_normal_iter
+      = typename enable_if< __is_contiguous_normal_iter<_Iter>::value,
+                           std::shared_ptr<const _NFA<_TraitsT>> >::type;
+
+  template<typename _Iter, typename _TraitsT>
+    using __disable_if_contiguous_normal_iter
+      = typename enable_if< !__is_contiguous_normal_iter<_Iter>::value,
+                           std::shared_ptr<const _NFA<_TraitsT>> >::type;
+
+  template<typename _FwdIter, typename _TraitsT>
+    inline __enable_if_contiguous_normal_iter<_FwdIter, _TraitsT>
+    __compile_nfa(_FwdIter __first, _FwdIter __last,
 		  const typename _TraitsT::locale_type& __loc,
 		  regex_constants::syntax_option_type __flags)
     {
+      size_t __len = __last - __first;
+      const auto* __cfirst = __len ? std::__addressof(*__first) : nullptr;
       using _Cmplr = _Compiler<_TraitsT>;
-      return _Cmplr(__first, __last, __loc, __flags)._M_get_nfa();
+      return _Cmplr(__cfirst, __cfirst + __len, __loc, __flags)._M_get_nfa();
+    }
+
+  template<typename _FwdIter, typename _TraitsT>
+    inline __disable_if_contiguous_normal_iter<_FwdIter, _TraitsT>
+    __compile_nfa(_FwdIter __first, _FwdIter __last,
+		  const typename _TraitsT::locale_type& __loc,
+		  regex_constants::syntax_option_type __flags)
+    {
+      basic_string<typename _TraitsT::char_type> __str(__first, __last);
+      return __compile_nfa(__str.data(), __str.data() + __str.size(), __loc,
+          __flags);
     }
 
   // [28.13.14]
diff --git a/libstdc++-v3/include/std/regex b/libstdc++-v3/include/std/regex
index 4d0e93c..3dff372 100644
--- a/libstdc++-v3/include/std/regex
+++ b/libstdc++-v3/include/std/regex
@@ -56,9 +56,9 @@
 #include <bits/regex_constants.h>
 #include <bits/regex_error.h>
 #include <bits/regex_automaton.h>
-#include <bits/regex.h>
 #include <bits/regex_scanner.h>
 #include <bits/regex_compiler.h>
+#include <bits/regex.h>
 #include <bits/regex_executor.h>
 
 #endif // C++11