2003-05-26 Benjamin Kosnik <bkoz@redhat.com>

	PR libstdc++/9339
	* include/std/std_fstream.h (basic_filebuf::_M_overflow): Remove.
	(_M_pback): No array necessary.
	* include/bits/fstream.tcc (basic_filebuf::_M_overflow): Add
	unbuffered case, coalesec into ...
	(basic_filebuf::overflow): ...this.
	* testsuite/27_io/basic_filebuf/sputn/char/9339.cc: New.
	* testsuite/27_io/basic_filebuf/sputc/char/2.cc: Unbuffered.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@67175 138bc75d-0d04-0410-961f-82ee72b054a4

3 files changed, 45 insertions, 76 deletions

diff --git a/libstdc++-v3/include/bits/fstream.tcc b/libstdc++-v3/include/bits/fstream.tcc
index cda0bacd9f9..9bbb5cc1a52 100644
--- a/libstdc++-v3/include/bits/fstream.tcc
+++ b/libstdc++-v3/include/bits/fstream.tcc
@@ -73,7 +73,7 @@ namespace std
     basic_filebuf() : __streambuf_type(), _M_file(&_M_lock), 
     _M_state_cur(__state_type()), _M_state_beg(__state_type()), 
     _M_buf(NULL), _M_buf_size(BUFSIZ), _M_buf_allocated(false),
-    _M_last_overflowed(false), _M_pback_cur_save(0),
+    _M_last_overflowed(false), _M_filepos(0), _M_pback_cur_save(0),
     _M_pback_end_save(0), _M_pback_init(false), _M_codecvt(0)
     { 
       this->_M_buf_unified = true; 	  
@@ -125,7 +125,7 @@ namespace std
 	      const bool __testput = this->_M_out_beg < this->_M_out_lim;
 
 	      if (__testput 
-		  && traits_type::eq_int_type(_M_overflow(__eof), __eof))
+		  && traits_type::eq_int_type(this->overflow(), __eof))
 		__testfail = true;
 
 #if 0
@@ -133,7 +133,7 @@ namespace std
 	      if (_M_last_overflowed)
 		{
 		  _M_output_unshift();
-		  _M_overflow(__eof);
+		  this->overflow();
 		}
 #endif
 	    }
@@ -204,7 +204,7 @@ namespace std
 
 	  // Sync internal and external buffers.
 	  if (__testout && this->_M_out_beg < this->_M_out_lim)
-	    _M_overflow();
+	    this->overflow();
 
 	  if (_M_buf_size > 1)
 	    {
@@ -324,64 +324,46 @@ namespace std
   template<typename _CharT, typename _Traits>
     typename basic_filebuf<_CharT, _Traits>::int_type 
     basic_filebuf<_CharT, _Traits>::
-    _M_overflow(int_type __c)
-    {
-      int_type __ret = traits_type::eof();
-      const bool __testeof = traits_type::eq_int_type(__c, __ret);
-      const bool __testput = this->_M_out_beg < this->_M_out_lim;
-
-      if (__testput)
- 	{
- 	  // Need to restore current position. The position of the
- 	  // external byte sequence (_M_file) corresponds to
- 	  // _M_filepos, and we need to move it to _M_out_beg for the
- 	  // write.
-	  if (_M_filepos != this->_M_out_beg)
-	    _M_file.seekoff(this->_M_out_beg - _M_filepos, ios_base::cur);
-
-	  // If appropriate, append the overflow char.
-	  if (!__testeof)
-	    *this->_M_out_lim++ = traits_type::to_char_type(__c);
-
-	  // Convert pending sequence to external representation,
-	  // output. 
-	  if (_M_convert_to_external(this->_M_out_beg,
-				     this->_M_out_lim - this->_M_out_beg)
-	      && (!__testeof || (__testeof && !_M_file.sync())))
-	    {
-	      _M_set_buffer(0);
-	      __ret = traits_type::not_eof(__c);
-	    }
-	}
-      _M_last_overflowed = true;	
-      return __ret;
-    }
-
-  template<typename _CharT, typename _Traits>
-    typename basic_filebuf<_CharT, _Traits>::int_type 
-    basic_filebuf<_CharT, _Traits>::
     overflow(int_type __c)
     {
       int_type __ret = traits_type::eof();
-      const bool __testput = this->_M_out_cur < this->_M_out_end;
+      const bool __testeof = traits_type::eq_int_type(__c, __ret);
       const bool __testout = this->_M_mode & ios_base::out;
       
-      // Perhaps set below in _M_overflow.
-      _M_last_overflowed = false;
-
       if (__testout)
 	{
-	  if (traits_type::eq_int_type(__c, traits_type::eof()))
-	    __ret = traits_type::not_eof(__c);
-	  else if (__testput)
+	  if (this->_M_out_beg < this->_M_out_lim)
+	    {
+	      // Need to restore current position. The position of the
+	      // external byte sequence (_M_file) corresponds to
+	      // _M_filepos, and we need to move it to _M_out_beg for
+	      // the write.
+	      if (_M_filepos != this->_M_out_beg)
+		_M_file.seekoff(this->_M_out_beg - _M_filepos, ios_base::cur);
+
+	      // If appropriate, append the overflow char.
+	      if (!__testeof)
+		*this->_M_out_lim++ = traits_type::to_char_type(__c);
+	      
+	      // Convert pending sequence to external representation,
+	      // output.
+	      if (_M_convert_to_external(this->_M_out_beg,
+					 this->_M_out_lim - this->_M_out_beg)
+		  && (!__testeof || (__testeof && !_M_file.sync())))
+		{
+		  _M_set_buffer(0);
+		  __ret = traits_type::not_eof(__c);
+		}
+	    }
+	  else
 	    {
- 	      *this->_M_out_cur = traits_type::to_char_type(__c);
-	      _M_move_out_cur(1);
-	      __ret = traits_type::not_eof(__c);
+	      // Unbuffered.
+	      char_type __conv = traits_type::to_char_type(__c);
+	      if (!__testeof && _M_convert_to_external(&__conv, 1))
+		__ret = __c;
 	    }
-	  else 
-	    __ret = this->_M_overflow(__c);
 	}
+      _M_last_overflowed = true;	
       return __ret;
     }
   
diff --git a/libstdc++-v3/include/bits/streambuf.tcc b/libstdc++-v3/include/bits/streambuf.tcc
index f80a815aa42..5b76c40f928 100644
--- a/libstdc++-v3/include/bits/streambuf.tcc
+++ b/libstdc++-v3/include/bits/streambuf.tcc
@@ -115,7 +115,7 @@ namespace std
       while (__ret < __n)
 	{
 	  const size_t __buf_len = _M_in_end - _M_in_cur;
-	  if (__buf_len > 0)
+	  if (__buf_len)
 	    {
 	      const size_t __remaining = __n - __ret;
 	      const size_t __len = std::min(__buf_len, __remaining);
@@ -149,7 +149,7 @@ namespace std
       while (__ret < __n)
 	{
 	  const size_t __buf_len = _M_out_end - _M_out_cur;
-	  if (__buf_len > 0)
+	  if (__buf_len)
 	    {
 	      const size_t __remaining = __n - __ret;
 	      const size_t __len = std::min(__buf_len, __remaining);
@@ -161,7 +161,7 @@ namespace std
 
 	  if (__ret < __n)
 	    {
-	      const int_type __c = this->overflow(traits_type::to_int_type(*__s));
+	      int_type __c = this->overflow(traits_type::to_int_type(*__s));
 	      if (!traits_type::eq_int_type(__c, traits_type::eof()))
 		{
 		  ++__ret;
diff --git a/libstdc++-v3/include/std/std_fstream.h b/libstdc++-v3/include/std/std_fstream.h
index 27794881c75..9faf7373006 100644
--- a/libstdc++-v3/include/std/std_fstream.h
+++ b/libstdc++-v3/include/std/std_fstream.h
@@ -158,7 +158,7 @@ namespace std
        *  @note pbacks of over one character are not currently supported.
        *  @endif
       */
-      char_type			_M_pback[1]; 
+      char_type			_M_pback; 
       char_type*		_M_pback_cur_save;
       char_type*		_M_pback_end_save;
       bool			_M_pback_init; 
@@ -177,7 +177,7 @@ namespace std
 	  {
 	    _M_pback_cur_save = this->_M_in_cur;
 	    _M_pback_end_save = this->_M_in_end;
-	    this->setg(_M_pback, _M_pback, _M_pback + 1);
+	    this->setg(&_M_pback, &_M_pback, &_M_pback + 1);
 	    _M_pback_init = true;
 	  }
       }
@@ -191,8 +191,8 @@ namespace std
 	if (_M_pback_init)
 	  {
 	    // Length _M_in_cur moved in the pback buffer.
-	    const size_t __off_cur = this->_M_in_cur - _M_pback;
-	    this->setg(this->_M_buf, _M_pback_cur_save + __off_cur, 
+	    const size_t __off = this->_M_in_cur == &_M_pback ? 0 : 1;
+	    this->setg(this->_M_buf, _M_pback_cur_save + __off, 
 		       _M_pback_end_save);
 	    _M_pback_init = false;
 	  }
@@ -311,19 +311,6 @@ namespace std
       virtual int_type
       pbackfail(int_type __c = _Traits::eof());
 
-      // NB: For what the standard expects of the overflow function,
-      // see _M_overflow(), below. Because basic_streambuf's
-      // sputc/sputn call overflow directly, and the complications of
-      // this implementation's setting of the initial pointers all
-      // equal to _M_buf when initializing, it seems essential to have
-      // this in actuality be a helper function that checks for the
-      // eccentricities of this implementation, and then call
-      // overflow() if indeed the buffer is full.
-
-      // [documentation is inherited]
-      virtual int_type
-      overflow(int_type __c = _Traits::eof());
-
       // Stroustrup, 1998, p 648
       // The overflow() function is called to transfer characters to the
       // real output destination when the buffer is full. A call to
@@ -336,8 +323,8 @@ namespace std
        *  @doctodo
        *  @endif
       */
-      int_type
-      _M_overflow(int_type __c = _Traits::eof());
+      virtual int_type
+      overflow(int_type __c = _Traits::eof());
 
       // Convert internal byte sequence to external, char-based
       // sequence via codecvt.
@@ -389,7 +376,7 @@ namespace std
 	    off_type __off = this->_M_out_cur - this->_M_out_lim;
 
 	    // _M_file.sync() will be called within
-	    if (traits_type::eq_int_type(_M_overflow(), traits_type::eof()))
+	    if (traits_type::eq_int_type(this->overflow(), traits_type::eof()))
 	      __ret = -1;
 	    else if (__off)
 	      _M_file.seekoff(__off, ios_base::cur);
@@ -444,7 +431,7 @@ namespace std
 
       // This function sets the pointers of the internal buffer, both get
       // and put areas. Typically, __off == _M_in_end - _M_in_beg upon
-      // _M_underflow; __off == 0 upon _M_overflow, seekoff, open, setbuf.
+      // _M_underflow; __off == 0 upon overflow, seekoff, open, setbuf.
       // 
       // NB: _M_out_end - _M_out_beg == _M_buf_size - 1, since _M_buf_size
       // reflects the actual allocated memory and the last cell is reserved