2006-04-12 Paolo Carlini <pcarlini@suse.de>

	* include/std/std_stdexcept.h (class __exception_string): Add.
	(class logic_error, class runtime_error): Use it.
	* src/stdexcept.cc (_exception_string::_Rep::_M_destroy,
	__exception_string::__exception_string(const string&),
	__exception_string::operator=(const __exception_string&)): Define.
	* config/abi/pre/gnu.ver: Update exports.


git-svn-id: https://gcc.gnu.org/svn/gcc/branches/libstdcxx_so_7-branch@112888 138bc75d-0d04-0410-961f-82ee72b054a4

4 files changed, 111 insertions, 4 deletions

diff --git a/libstdc++-v3/ChangeLog.libstdcxx_so_7-branch b/libstdc++-v3/ChangeLog.libstdcxx_so_7-branch
index 3a4626ce3f0..b8d2f6be5ea 100644
--- a/libstdc++-v3/ChangeLog.libstdcxx_so_7-branch
+++ b/libstdc++-v3/ChangeLog.libstdcxx_so_7-branch
@@ -1,3 +1,12 @@
+2006-04-12  Paolo Carlini  <pcarlini@suse.de>
+
+	* include/std/std_stdexcept.h (class __exception_string): Add.
+	(class logic_error, class runtime_error): Use it.
+	* src/stdexcept.cc (_exception_string::_Rep::_M_destroy,
+	__exception_string::__exception_string(const string&),
+	__exception_string::operator=(const __exception_string&)): Define.
+	* config/abi/pre/gnu.ver: Update exports.
+
 2006-04-11  Paolo Carlini  <pcarlini@suse.de>
 
 	Merged to mainline at revision 112818.
diff --git a/libstdc++-v3/config/abi/pre/gnu.ver b/libstdc++-v3/config/abi/pre/gnu.ver
index f6be5e96867..0dfa152c01e 100644
--- a/libstdc++-v3/config/abi/pre/gnu.ver
+++ b/libstdc++-v3/config/abi/pre/gnu.ver
@@ -614,6 +614,8 @@ GLIBCXX_4.2 {
     _ZNK9__gnu_cxx12__sso_stringI[cw]St11char_traitsI[cw]ESaI[cw]EE*;
     _ZZN9__gnu_cxx12__sso_stringI[cw]St11char_traitsI[cw]ESaI[cw]EE*;
 
+    _ZNSt18__exception_string*;
+
   # DO NOT DELETE THIS LINE.  Port-specific symbols, if any, will be here.
 
   local:
diff --git a/libstdc++-v3/include/std/std_stdexcept.h b/libstdc++-v3/include/std/std_stdexcept.h
index 0104e54464e..a9e49cb16d5 100644
--- a/libstdc++-v3/include/std/std_stdexcept.h
+++ b/libstdc++-v3/include/std/std_stdexcept.h
@@ -1,6 +1,7 @@
 // Standard exception classes  -*- C++ -*-
 
-// Copyright (C) 2001, 2002, 2005 Free Software Foundation, Inc.
+// Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006
+// 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
@@ -42,9 +43,66 @@
 
 #include <exception>
 #include <string>
+#include <bits/atomicity.h>
 
 _GLIBCXX_BEGIN_NAMESPACE(std)
 
+  /** Reference-counted "mini-string" for internal use in the std exception
+   *  classes, needed due to the no-throw requirements for copy-constructor
+   *  and assignment operator, not fulfilled by sso_string.  */
+  class __exception_string
+  {
+    struct _Rep
+    {
+      size_t	    _M_size;
+      _Atomic_word  _M_refcount;
+
+      void
+      _M_destroy() throw();
+
+      void
+      _M_dispose() throw()
+      {
+	if (__gnu_cxx::__exchange_and_add(&_M_refcount, -1) <= 0)
+	  _M_destroy();
+      }
+
+      char*
+      _M_refdata() throw()
+      { return reinterpret_cast<char*>(this + 1); }
+
+      char*
+      _M_refcopy() throw()
+      {
+	__gnu_cxx::__atomic_add(&_M_refcount, 1);
+	return _M_refdata();
+      }
+    };
+
+    char* _M_data;
+
+    _Rep*
+    _M_rep() const throw()
+    { return &((reinterpret_cast<_Rep*>(_M_data))[-1]); }
+
+  public:
+    __exception_string(const __exception_string& __ex_str)
+    : _M_data(__ex_str._M_rep()->_M_refcopy()) { }
+
+    __exception_string(const string& __str);
+
+    ~__exception_string()
+    { _M_rep()->_M_dispose(); }
+
+    __exception_string&
+    operator=(const __exception_string& __ex_str);
+
+    const char*
+    c_str() const
+    { return _M_data; }
+  };
+
+
   /** Logic errors represent problems in the internal logic of a program;
    *  in theory, these are preventable, and even detectable before the
    *  program runs (e.g., violations of class invariants).
@@ -52,7 +110,7 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
    */
   class logic_error : public exception 
   {
-    string _M_msg;
+    __exception_string _M_msg;
 
   public:
     /** Takes a character string describing the error.  */
@@ -106,7 +164,7 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
    */
   class runtime_error : public exception 
   {
-    string _M_msg;
+    __exception_string _M_msg;
 
   public:
     /** Takes a character string describing the error.  */
diff --git a/libstdc++-v3/src/stdexcept.cc b/libstdc++-v3/src/stdexcept.cc
index 19ac5779eb5..51449ede7e1 100644
--- a/libstdc++-v3/src/stdexcept.cc
+++ b/libstdc++-v3/src/stdexcept.cc
@@ -1,6 +1,7 @@
 // Methods for Exception Support for -*- C++ -*-
 
-// Copyright (C) 1997, 1999, 2001, 2002, 2005 Free Software Foundation, Inc.
+// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
+// 2005, 2006 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
@@ -36,6 +37,43 @@
 
 _GLIBCXX_BEGIN_NAMESPACE(std)
 
+  void
+  __exception_string::_Rep::
+  _M_destroy() throw()
+  {
+    allocator<char>().deallocate(reinterpret_cast<char*>(this),
+				 sizeof(_Rep) + _M_size);
+  }
+
+  __exception_string::
+  __exception_string(const string& __str)
+  {
+    const size_t __size = __str.size() + 1;
+
+    void* __place = allocator<char>().allocate(sizeof(_Rep) + __size);
+    _Rep* __r = new (__place) _Rep;
+
+    memcpy(__r->_M_refdata(), __str.c_str(), __size);
+    __r->_M_size = __size;
+    __r->_M_refcount = 0;
+
+    _M_data = __r->_M_refdata();
+  }
+
+  __exception_string&
+  __exception_string::
+  operator=(const __exception_string& __ex_str)
+  {
+    if (_M_rep() != __ex_str._M_rep())
+      {
+	char* __tmp = __ex_str._M_rep()->_M_refcopy();
+	_M_rep()->_M_dispose();
+	_M_data = __tmp;
+      }
+    return *this;
+  }
+
+
   logic_error::logic_error(const string& __arg) 
   : exception(), _M_msg(__arg) { }