re PR libstdc++/7744 (streambuf::in_avail() always returns 0 (zero) for cin input stream)

2003-03-09  Paolo Carlini  <pcarlini@unitus.it>
	    Nathan Myers  <ncm@cantrip.org>

	PR libstdc++/7744
	* config/io/basic_file_stdio.h (__basic_file<>::xsgetn, xsputn,
	seekoff, seekpos): Add a boolean parameter __stdio.
	* config/io/basic_file_stdio.cc (__basic_file<>::xsgetn, xsputn,
	seekoff, seekpos): If __stdio == true, use fread (fwrite, fseek/ftell,
	fseek/ftell, respectively), otherwise read (write, lseek, lseek,
	respectively).
	* include/bits/fstream.tcc (basic_filebuf<>::_M_convert_to_external,
	_M_really_overflow, seekoff): Use the boolean parameter in the calls.
	* include/std/std_fstream.h (sync): Likewise.
	* src/fstream.cc (basic_filebuf<>::_M_underflow_common): Likewise.
	* src/ios.cc (ios_base::Init::_S_ios_create(bool)): Revert libstdc++/8399
	commit involving isatty(0).
	* acinclude.m4 (GLIBCPP_CHECK_UNISTD_DECL_AND_LINKAGE_1): Remove.
        (GLIBCPP_CHECK_UNISTD_SUPPORT): Remove
  	* configure.in: Remove call.
	* aclocal.m4: Regenerate.
       	* config.h.in: Regenerate.
        * configure: Regenerate.
	* testsuite/27_io/narrow_stream_objects.cc (test11): Add.

Co-Authored-By: Nathan Myers <ncm@cantrip.org>

From-SVN: r64051

2 files changed, 57 insertions, 20 deletions

diff --git a/libstdc++-v3/config/io/basic_file_stdio.cc b/libstdc++-v3/config/io/basic_file_stdio.cc
index 961523b0dcd..881792e7f81 100644
--- a/libstdc++-v3/config/io/basic_file_stdio.cc
+++ b/libstdc++-v3/config/io/basic_file_stdio.cc
@@ -1,6 +1,6 @@
 // Wrapper of C-language FILE struct -*- C++ -*-
 
-// Copyright (C) 2000, 2001, 2002 Free Software Foundation, Inc.
+// Copyright (C) 2000, 2001, 2002, 2003 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
@@ -33,6 +33,7 @@
 
 #include <bits/basic_file.h>
 #include <fcntl.h>
+#include <errno.h>
 
 namespace std 
 {
@@ -191,33 +192,69 @@ namespace std
     return __retval;
   }
  
+  // In the next four functions we want to use stdio functions only
+  // when synced with stdio (_M_buf_size == 1): I/O primitives do not
+  // block until the asked number of bytes are available.
   streamsize 
-  __basic_file<char>::xsgetn(char* __s, streamsize __n)
-  { return fread(__s, 1, __n, _M_cfile); }
-  
+  __basic_file<char>::xsgetn(char* __s, streamsize __n, bool __stdio)
+  {
+    if (__stdio)
+      return fread(__s, 1, __n, _M_cfile);
+    else
+      {
+	streamsize __ret;
+        do
+	  __ret = read(this->fd(), __s, __n);
+	while (__ret == -1L && errno == EINTR);
+	return __ret;
+      }
+  }
+    
   streamsize 
-  __basic_file<char>::xsputn(const char* __s, streamsize __n)
-  { return fwrite(__s, 1, __n, _M_cfile); }
+  __basic_file<char>::xsputn(const char* __s, streamsize __n, bool __stdio)
+  {
+    if (__stdio)
+      return fwrite(__s, 1, __n, _M_cfile);
+    else
+      {
+	streamsize __ret;
+        do
+	  __ret = write(this->fd(), __s, __n);
+	while (__ret == -1L && errno == EINTR);
+	return __ret;
+      }
+  }
   
   streamoff
   __basic_file<char>::seekoff(streamoff __off, ios_base::seekdir __way, 
-			      ios_base::openmode /*__mode*/)
+			      bool __stdio, ios_base::openmode /*__mode*/)
   { 
-    if (!fseek(_M_cfile, __off, __way))
-      return ftell(_M_cfile); 
+    if (!__stdio)
+      return lseek(this->fd(), __off, __way);
     else
-      // Fseek failed.
-      return -1L;
+      {
+	if (!fseek(_M_cfile, __off, __way))
+	  return ftell(_M_cfile); 
+	else
+	  // Fseek failed.
+	  return -1L;
+      }
   }
 
   streamoff
-  __basic_file<char>::seekpos(streamoff __pos, ios_base::openmode /*__mode*/)
+  __basic_file<char>::seekpos(streamoff __pos, bool __stdio,
+			      ios_base::openmode /*__mode*/)
   { 
-    if (!fseek(_M_cfile, __pos, ios_base::beg))
-      return ftell(_M_cfile);
+    if (!__stdio)
+      return lseek(this->fd(), __pos, ios_base::beg);
     else
-      // Fseek failed.
-      return -1L;
+      {
+	if (!fseek(_M_cfile, __pos, ios_base::beg))
+	  return ftell(_M_cfile);
+	else
+	  // Fseek failed.
+	  return -1L;
+      }
   }
   
   int 
diff --git a/libstdc++-v3/config/io/basic_file_stdio.h b/libstdc++-v3/config/io/basic_file_stdio.h
index fe6edbb7058..b01e4a5db10 100644
--- a/libstdc++-v3/config/io/basic_file_stdio.h
+++ b/libstdc++-v3/config/io/basic_file_stdio.h
@@ -93,17 +93,17 @@ namespace std
       ~__basic_file();
 
       streamsize 
-      xsputn(const char* __s, streamsize __n);
+      xsputn(const char* __s, streamsize __n, bool __stdio);
 
       streamsize 
-      xsgetn(char* __s, streamsize __n);
+      xsgetn(char* __s, streamsize __n, bool __stdio);
 
       streamoff
-      seekoff(streamoff __off, ios_base::seekdir __way,
+      seekoff(streamoff __off, ios_base::seekdir __way, bool __stdio,
 	      ios_base::openmode __mode = ios_base::in | ios_base::out);
 
       streamoff
-      seekpos(streamoff __pos, 
+      seekpos(streamoff __pos, bool __stdio,
 	      ios_base::openmode __mode = ios_base::in | ios_base::out);
 
       int