* libc/stdio/fflush.c (fflush): On seekable streams, always flush

        read but unused data.
        * libc/stdio/fclose.c (_fclose_r): Always flush streams, since
        even read streams may have side effects that must happen.

3 files changed, 290 insertions, 0 deletions

diff --git a/newlib/ChangeLog b/newlib/ChangeLog
index f7105e00677..1433fbe7305 100644
--- a/newlib/ChangeLog
+++ b/newlib/ChangeLog
@@ -1,3 +1,11 @@
+2006-12-14  Jeff Johnston  <jjohnstn@redhat.com>
+            Eric Blake  <ebb9@byu.net>
+
+        * libc/stdio/fflush.c (fflush): On seekable streams, always flush
+        read but unused data.
+        * libc/stdio/fclose.c (_fclose_r): Always flush streams, since
+        even read streams may have side effects that must happen.
+
 2006-11-30  Lev Bishop  <lev.bishop@gmail.com>
 
 	* libc/include/math.h: Allow C99 functions/macros to be
diff --git a/newlib/libc/stdio/fclose.c b/newlib/libc/stdio/fclose.c
new file mode 100644
index 00000000000..76f4140d611
--- /dev/null
+++ b/newlib/libc/stdio/fclose.c
@@ -0,0 +1,122 @@
+/*
+ * Copyright (c) 1990 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that the above copyright notice and this paragraph are
+ * duplicated in all such forms and that any documentation,
+ * advertising materials, and other materials related to such
+ * distribution and use acknowledge that the software was developed
+ * by the University of California, Berkeley.  The name of the
+ * University may not be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+/*
+FUNCTION
+<<fclose>>---close a file
+
+INDEX
+	fclose
+INDEX
+	_fclose_r
+
+ANSI_SYNOPSIS
+	#include <stdio.h>
+	int fclose(FILE *<[fp]>);
+	int _fclose_r(struct _reent *<[reent]>, FILE *<[fp]>);
+
+TRAD_SYNOPSIS
+	#include <stdio.h>
+	int fclose(<[fp]>)
+	FILE *<[fp]>;
+        
+	int fclose(<[fp]>)
+        struct _reent *<[reent]>
+	FILE *<[fp]>;
+
+DESCRIPTION
+If the file or stream identified by <[fp]> is open, <<fclose>> closes
+it, after first ensuring that any pending data is written (by calling
+<<fflush(<[fp]>)>>).
+
+The alternate function <<_fclose_r>> is a reentrant version.
+The extra argument <[reent]> is a pointer to a reentrancy structure.
+
+RETURNS
+<<fclose>> returns <<0>> if successful (including when <[fp]> is
+<<NULL>> or not an open file); otherwise, it returns <<EOF>>.
+
+PORTABILITY
+<<fclose>> is required by ANSI C.
+
+Required OS subroutines: <<close>>, <<fstat>>, <<isatty>>, <<lseek>>,
+<<read>>, <<sbrk>>, <<write>>.
+*/
+
+#include <_ansi.h>
+#include <reent.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/lock.h>
+#include "local.h"
+
+int
+_DEFUN(_fclose_r, (rptr, fp),
+      struct _reent *rptr _AND
+      register FILE * fp)
+{
+  int r;
+
+  if (fp == NULL)
+    return (0);			/* on NULL */
+
+  __sfp_lock_acquire ();
+
+  CHECK_INIT (rptr);
+
+  _flockfile (fp);
+  
+  if (fp->_flags == 0)		/* not open! */
+    {
+      _funlockfile (fp);
+      __sfp_lock_release ();
+      return (0);
+    }
+  /* Unconditionally flush to allow special handling for seekable read
+     files to reposition file to last byte processed as opposed to
+     last byte read ahead into the buffer.  */
+  r = fflush (fp);
+  if (fp->_close != NULL && (*fp->_close) (fp->_cookie) < 0)
+    r = EOF;
+  if (fp->_flags & __SMBF)
+    _free_r (rptr, (char *) fp->_bf._base);
+  if (HASUB (fp))
+    FREEUB (fp);
+  if (HASLB (fp))
+    FREELB (fp);
+  fp->_flags = 0;		/* release this FILE for reuse */
+  _funlockfile (fp);
+#ifndef __SINGLE_THREAD__
+  __lock_close_recursive (fp->_lock);
+#endif
+
+  __sfp_lock_release ();
+
+  return (r);
+}
+
+#ifndef _REENT_ONLY
+
+int
+_DEFUN(fclose, (fp),
+       register FILE * fp)
+{
+  return _fclose_r(_REENT, fp);
+}
+
+#endif
+
diff --git a/newlib/libc/stdio/fflush.c b/newlib/libc/stdio/fflush.c
new file mode 100644
index 00000000000..f88d49cc598
--- /dev/null
+++ b/newlib/libc/stdio/fflush.c
@@ -0,0 +1,160 @@
+/*
+ * Copyright (c) 1990, 2006 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that the above copyright notice and this paragraph are
+ * duplicated in all such forms and that any documentation,
+ * advertising materials, and other materials related to such
+ * distribution and use acknowledge that the software was developed
+ * by the University of California, Berkeley.  The name of the
+ * University may not be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+/*
+FUNCTION
+<<fflush>>---flush buffered file output
+
+INDEX
+	fflush
+
+ANSI_SYNOPSIS
+	#include <stdio.h>
+	int fflush(FILE *<[fp]>);
+
+TRAD_SYNOPSIS
+	#include <stdio.h>
+	int fflush(<[fp]>)
+	FILE *<[fp]>;
+
+DESCRIPTION
+The <<stdio>> output functions can buffer output before delivering it
+to the host system, in order to minimize the overhead of system calls.
+
+Use <<fflush>> to deliver any such pending output (for the file
+or stream identified by <[fp]>) to the host system.
+
+If <[fp]> is <<NULL>>, <<fflush>> delivers pending output from all
+open files.
+
+RETURNS
+<<fflush>> returns <<0>> unless it encounters a write error; in that
+situation, it returns <<EOF>>.
+
+PORTABILITY
+ANSI C requires <<fflush>>.
+
+No supporting OS subroutines are required.
+*/
+
+#include <_ansi.h>
+#include <stdio.h>
+#include "local.h"
+
+/* Flush a single file, or (if fp is NULL) all files.  */
+
+int
+_DEFUN(fflush, (fp),
+       register FILE * fp)
+{
+  register unsigned char *p;
+  register int n, t;
+
+  if (fp == NULL)
+    return _fwalk (_GLOBAL_REENT, fflush);
+
+  CHECK_INIT (_REENT);
+
+  _flockfile (fp);
+
+  t = fp->_flags;
+  if ((t & __SWR) == 0)
+    {
+      _fpos_t _EXFUN((*seekfn), (_PTR, _fpos_t, int));
+
+      /* For a read stream, an fflush causes the next seek to be
+         unoptimized (i.e. forces a system-level seek).  This conforms
+         to the POSIX and SUSv3 standards.  */
+      fp->_flags |= __SNPT;
+
+      /* For a seekable stream with buffered read characters, we will attempt
+         a seek to the current position now.  A subsequent read will then get
+         the next byte from the file rather than the buffer.  This conforms
+         to the POSIX and SUSv3 standards.  Note that the standards allow
+         this seek to be deferred until necessary, but we choose to do it here
+         to make the change simpler, more contained, and less likely
+         to miss a code scenario.  */
+      if ((fp->_r > 0 || fp->_ur > 0) && (seekfn = fp->_seek) != NULL)
+        {
+          _fpos_t curoff;
+
+          /* Get the physical position we are at in the file.  */
+          if (fp->_flags & __SOFF)
+            curoff = fp->_offset;
+          else
+            {
+              /* We don't know current physical offset, so ask for it.  */
+              curoff = (*seekfn) (fp->_cookie, (_fpos_t) 0, SEEK_CUR);
+              if (curoff == -1L)
+                {
+                  _funlockfile (fp);
+                  return 0;
+                }
+            }
+          if (fp->_flags & __SRD)
+            {
+              /* Current offset is at end of buffer.  Compensate for
+                 characters not yet read.  */
+              curoff -= fp->_r;
+              if (HASUB (fp))
+                curoff -= fp->_ur;
+            }
+          /* Now physically seek to after byte last read.  */
+          if ((*seekfn)(fp->_cookie, curoff, SEEK_SET) != -1)
+            {
+              /* Seek successful.  We can clear read buffer now.  */
+              fp->_flags &= ~__SNPT;
+              fp->_r = 0;
+              fp->_p = fp->_bf._base;
+              if (fp->_flags & __SOFF)
+                fp->_offset = curoff;
+            }
+        } 
+      _funlockfile (fp);
+      return 0;
+    }
+  if ((p = fp->_bf._base) == NULL)
+    {
+      /* Nothing to flush.  */
+      _funlockfile (fp);
+      return 0;
+    }
+  n = fp->_p - p;		/* write this much */
+
+  /*
+   * Set these immediately to avoid problems with longjmp
+   * and to allow exchange buffering (via setvbuf) in user
+   * write function.
+   */
+  fp->_p = p;
+  fp->_w = t & (__SLBF | __SNBF) ? 0 : fp->_bf._size;
+
+  while (n > 0)
+    {
+      t = (*fp->_write) (fp->_cookie, (char *) p, n);
+      if (t <= 0)
+	{
+          fp->_flags |= __SERR;
+          _funlockfile (fp);
+          return EOF;
+	}
+      p += t;
+      n -= t;
+    }
+  _funlockfile (fp);
+  return 0;
+}