PR 43839

[pf3gnuchains/gcc-fork.git] / libgfortran / io / file_pos.c

diff --git a/libgfortran/io/file_pos.c b/libgfortran/io/file_pos.c
index 085921b..f7d9499 100644 (file)
--- a/libgfortran/io/file_pos.c
+++ b/libgfortran/io/file_pos.c
@@ -1,36 +1,31 @@
-/* Copyright (C) 2002-2003, 2005, 2006 Free Software Foundation, Inc.
+/* Copyright (C) 2002-2003, 2005, 2006, 2007, 2009 Free Software Foundation, Inc.

    Contributed by Andy Vaught and Janne Blomqvist
 
 This file is part of the GNU Fortran runtime library (libgfortran).
 
 Libgfortran is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
    Contributed by Andy Vaught and Janne Blomqvist
 
 This file is part of the GNU Fortran runtime library (libgfortran).
 
 Libgfortran is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by

-the Free Software Foundation; either version 2, or (at your option)
+the Free Software Foundation; either version 3, or (at your option)

 any later version.
 
 any later version.
 

-In addition to the permissions in the GNU General Public License, the
-Free Software Foundation gives you unlimited permission to link the
-compiled version of this file into combinations with other programs,
-and to distribute those combinations without any restriction coming
-from the use of this file.  (The General Public License restrictions
-do apply in other respects; for example, they cover modification of
-the file, and distribution when not linked into a combine
-executable.)
-

 Libgfortran is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.
 
 Libgfortran is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.
 

-You should have received a copy of the GNU General Public License
-along with Libgfortran; see the file COPYING.  If not, write to
-the Free Software Foundation, 51 Franklin Street, Fifth Floor,
-Boston, MA 02110-1301, USA.  */
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+<http://www.gnu.org/licenses/>.  */

 
 

-#include "config.h"
-#include <string.h>
-#include "libgfortran.h"

 #include "io.h"
 #include "io.h"

+#include "fbuf.h"
+#include "unix.h"
+#include <string.h>

 
 /* file_pos.c-- Implement the file positioning statements, i.e. BACKSPACE,
    ENDFILE, and REWIND as well as the FLUSH statement.  */
 
 /* file_pos.c-- Implement the file positioning statements, i.e. BACKSPACE,
    ENDFILE, and REWIND as well as the FLUSH statement.  */


@@ -41,24 +36,24 @@ Boston, MA 02110-1301, USA.  */
    record, and we have to sift backwards to find the newline before
    that or the start of the file, whichever comes first.  */
 
    record, and we have to sift backwards to find the newline before
    that or the start of the file, whichever comes first.  */
 

-#define READ_CHUNK 4096
+static const int READ_CHUNK = 4096;

 
 static void
 formatted_backspace (st_parameter_filepos *fpp, gfc_unit *u)
 {
   gfc_offset base;
 
 static void
 formatted_backspace (st_parameter_filepos *fpp, gfc_unit *u)
 {
   gfc_offset base;

-  char *p;
-  int n;
+  char p[READ_CHUNK];
+  ssize_t n;

 
 

-  base = file_position (u->s) - 1;
+  base = stell (u->s) - 1;

 
   do
     {
       n = (base < READ_CHUNK) ? base : READ_CHUNK;
       base -= n;
 
   do
     {
       n = (base < READ_CHUNK) ? base : READ_CHUNK;
       base -= n;

-
-      p = salloc_r_at (u->s, &n, base);
-      if (p == NULL)
+      if (sseek (u->s, base, SEEK_SET) < 0)
+        goto io_error;
+      if (sread (u->s, p, n) != n)

        goto io_error;
 
       /* We have moved backwards from the current position, it should
        goto io_error;
 
       /* We have moved backwards from the current position, it should


@@ -68,15 +63,14 @@ formatted_backspace (st_parameter_filepos *fpp, gfc_unit *u)
       /* There is no memrchr() in the C library, so we have to do it
          ourselves.  */
 
       /* There is no memrchr() in the C library, so we have to do it
          ourselves.  */
 

-      n--;
-      while (n >= 0)
+      while (n > 0)

        {
        {

+          n--;

          if (p[n] == '\n')
            {
              base += n + 1;
              goto done;
            }
          if (p[n] == '\n')
            {
              base += n + 1;
              goto done;
            }

-         n--;

        }
 
     }
        }
 
     }


@@ -84,7 +78,7 @@ formatted_backspace (st_parameter_filepos *fpp, gfc_unit *u)
 
   /* base is the new pointer.  Seek to it exactly.  */
  done:
 
   /* base is the new pointer.  Seek to it exactly.  */
  done:

-  if (sseek (u->s, base) == FAILURE)
+  if (sseek (u->s, base, SEEK_SET) < 0)

     goto io_error;
   u->last_record--;
   u->endfile = NO_ENDFILE;
     goto io_error;
   u->last_record--;
   u->endfile = NO_ENDFILE;


@@ -92,7 +86,7 @@ formatted_backspace (st_parameter_filepos *fpp, gfc_unit *u)
   return;
 
  io_error:
   return;
 
  io_error:

-  generate_error (&fpp->common, ERROR_OS, NULL);
+  generate_error (&fpp->common, LIBERROR_OS, NULL);

 }
 
 
 }
 
 


@@ -103,12 +97,12 @@ formatted_backspace (st_parameter_filepos *fpp, gfc_unit *u)
 static void
 unformatted_backspace (st_parameter_filepos *fpp, gfc_unit *u)
 {
 static void
 unformatted_backspace (st_parameter_filepos *fpp, gfc_unit *u)
 {

-  gfc_offset m, new;
+  gfc_offset m, slen;

   GFC_INTEGER_4 m4;
   GFC_INTEGER_8 m8;
   GFC_INTEGER_4 m4;
   GFC_INTEGER_8 m8;

-  int length, length_read;
+  ssize_t length;

   int continued;
   int continued;

-  char *p;
+  char p[sizeof (GFC_INTEGER_8)];

 
   if (compile_options.record_marker == 0)
     length = sizeof (GFC_INTEGER_4);
 
   if (compile_options.record_marker == 0)
     length = sizeof (GFC_INTEGER_4);


@@ -117,15 +111,14 @@ unformatted_backspace (st_parameter_filepos *fpp, gfc_unit *u)
 
   do
     {
 
   do
     {

-      length_read = length;
-
-      p = salloc_r_at (u->s, &length_read,
-                      file_position (u->s) - length);
-      if (p == NULL || length_read != length)
-       goto io_error;
-
-      /* Only CONVERT_NATIVE and CONVERT_SWAP are valid here.  */
-      if (u->flags.convert == CONVERT_NATIVE)
+      slen = - (gfc_offset) length;
+      if (sseek (u->s, slen, SEEK_CUR) < 0)
+        goto io_error;
+      if (sread (u->s, p, length) != length)
+        goto io_error;
+
+      /* Only GFC_CONVERT_NATIVE and GFC_CONVERT_SWAP are valid here.  */
+      if (likely (u->flags.convert == GFC_CONVERT_NATIVE))

        {
          switch (length)
            {
        {
          switch (length)
            {


@@ -169,10 +162,7 @@ unformatted_backspace (st_parameter_filepos *fpp, gfc_unit *u)
       if (continued)
        m = -m;
 
       if (continued)
        m = -m;
 

-      if ((new = file_position (u->s) - m - 2*length) < 0)
-       new = 0;
-
-      if (sseek (u->s, new) == FAILURE)
+      if (sseek (u->s, -m -2 * length, SEEK_CUR) < 0)

        goto io_error;
     } while (continued);
 
        goto io_error;
     } while (continued);
 


@@ -180,7 +170,7 @@ unformatted_backspace (st_parameter_filepos *fpp, gfc_unit *u)
   return;
 
  io_error:
   return;
 
  io_error:

-  generate_error (&fpp->common, ERROR_OS, NULL);
+  generate_error (&fpp->common, LIBERROR_OS, NULL);

 }
 
 
 }
 
 


@@ -197,34 +187,64 @@ st_backspace (st_parameter_filepos *fpp)
   u = find_unit (fpp->common.unit);
   if (u == NULL)
     {
   u = find_unit (fpp->common.unit);
   if (u == NULL)
     {

-      generate_error (&fpp->common, ERROR_BAD_UNIT, NULL);
+      generate_error (&fpp->common, LIBERROR_BAD_UNIT, NULL);

       goto done;
     }
 
       goto done;
     }
 

-  /* Ignore direct access.  Non-advancing I/O is only allowed for formatted
-     sequential I/O and the next direct access transfer repositions the file 
-     anyway.  */
+  /* Direct access is prohibited, and so is unformatted stream access.  */
+

 
 

-  if (u->flags.access == ACCESS_DIRECT || u->flags.access == ACCESS_STREAM)
-    goto done;
+  if (u->flags.access == ACCESS_DIRECT)
+    {
+      generate_error (&fpp->common, LIBERROR_OPTION_CONFLICT,
+                     "Cannot BACKSPACE a file opened for DIRECT access");
+      goto done;
+    }
+
+  if (u->flags.access == ACCESS_STREAM && u->flags.form == FORM_UNFORMATTED)
+    {
+      generate_error (&fpp->common, LIBERROR_OPTION_CONFLICT,
+                      "Cannot BACKSPACE an unformatted stream file");
+      goto done;
+    }
+
+  /* Make sure format buffer is flushed and reset.  */
+  if (u->flags.form == FORM_FORMATTED)
+    {
+      int pos = fbuf_reset (u);
+      if (pos != 0)
+        sseek (u->s, pos, SEEK_CUR);
+    }

 
 

+  

   /* Check for special cases involving the ENDFILE record first.  */
 
   if (u->endfile == AFTER_ENDFILE)
     {
       u->endfile = AT_ENDFILE;
   /* Check for special cases involving the ENDFILE record first.  */
 
   if (u->endfile == AFTER_ENDFILE)
     {
       u->endfile = AT_ENDFILE;

-      flush (u->s);
-      struncate (u->s);
+      u->flags.position = POSITION_APPEND;
+      sflush (u->s);

     }
   else
     {
     }
   else
     {

-      if (file_position (u->s) == 0)
-       goto done;              /* Common special case */
+      if (stell (u->s) == 0)
+       {
+         u->flags.position = POSITION_REWIND;
+         goto done;            /* Common special case */
+       }

 
       if (u->mode == WRITING)
        {
 
       if (u->mode == WRITING)
        {

-         flush (u->s);
-         struncate (u->s);
+         /* If there are previously written bytes from a write with
+            ADVANCE="no", add a record marker before performing the
+            BACKSPACE.  */
+
+         if (u->previous_nonadvancing_write)
+           finish_last_advance_record (u);
+
+         u->previous_nonadvancing_write = 0;
+
+         unit_truncate (u, stell (u->s), &fpp->common);

          u->mode = READING;
         }
 
          u->mode = READING;
         }
 


@@ -233,6 +253,7 @@ st_backspace (st_parameter_filepos *fpp)
       else
        unformatted_backspace (fpp, u);
 
       else
        unformatted_backspace (fpp, u);
 

+      u->flags.position = POSITION_UNSPECIFIED;

       u->endfile = NO_ENDFILE;
       u->current_record = 0;
       u->bytes_left = 0;
       u->endfile = NO_ENDFILE;
       u->current_record = 0;
       u->bytes_left = 0;


@@ -259,6 +280,22 @@ st_endfile (st_parameter_filepos *fpp)
   u = find_unit (fpp->common.unit);
   if (u != NULL)
     {
   u = find_unit (fpp->common.unit);
   if (u != NULL)
     {

+      if (u->flags.access == ACCESS_DIRECT)
+       {
+         generate_error (&fpp->common, LIBERROR_OPTION_CONFLICT,
+                         "Cannot perform ENDFILE on a file opened"
+                         " for DIRECT access");
+         goto done;
+       }
+
+      /* If there are previously written bytes from a write with ADVANCE="no",
+        add a record marker before performing the ENDFILE.  */
+
+      if (u->previous_nonadvancing_write)
+       finish_last_advance_record (u);
+
+      u->previous_nonadvancing_write = 0;
+

       if (u->current_record)
        {
          st_parameter_dt dtp;
       if (u->current_record)
        {
          st_parameter_dt dtp;


@@ -268,9 +305,11 @@ st_endfile (st_parameter_filepos *fpp)
          next_record (&dtp, 1);
        }
 
          next_record (&dtp, 1);
        }
 

-      flush (u->s);
-      struncate (u->s);
+      unit_truncate (u, stell (u->s), &fpp->common);

       u->endfile = AFTER_ENDFILE;
       u->endfile = AFTER_ENDFILE;

+      if (0 == stell (u->s))
+        u->flags.position = POSITION_REWIND;
+    done:

       unlock_unit (u);
     }
 
       unlock_unit (u);
     }
 


@@ -292,23 +331,24 @@ st_rewind (st_parameter_filepos *fpp)
   if (u != NULL)
     {
       if (u->flags.access == ACCESS_DIRECT)
   if (u != NULL)
     {
       if (u->flags.access == ACCESS_DIRECT)

-       generate_error (&fpp->common, ERROR_BAD_OPTION,
+       generate_error (&fpp->common, LIBERROR_BAD_OPTION,

                        "Cannot REWIND a file opened for DIRECT access");
       else
        {
                        "Cannot REWIND a file opened for DIRECT access");
       else
        {

-         /* Flush the buffers.  If we have been writing to the file, the last
-              written record is the last record in the file, so truncate the
-              file now.  Reset to read mode so two consecutive rewind
-              statements do not delete the file contents.  */
-         flush (u->s);
-         if (u->mode == WRITING && u->flags.access != ACCESS_STREAM)
-           struncate (u->s);
+         /* If there are previously written bytes from a write with ADVANCE="no",
+            add a record marker before performing the ENDFILE.  */
+
+         if (u->previous_nonadvancing_write)
+           finish_last_advance_record (u);
+
+         u->previous_nonadvancing_write = 0;
+
+         fbuf_reset (u);

 
 

-         u->mode = READING;

          u->last_record = 0;
 
          u->last_record = 0;
 

-         if (file_position (u->s) != 0 && sseek (u->s, 0) == FAILURE)
-           generate_error (&fpp->common, ERROR_OS, NULL);
+         if (sseek (u->s, 0, SEEK_SET) < 0)
+           generate_error (&fpp->common, LIBERROR_OS, NULL);

 
          /* Handle special files like /dev/null differently.  */
          if (!is_special (u->s))
 
          /* Handle special files like /dev/null differently.  */
          if (!is_special (u->s))


@@ -319,7 +359,7 @@ st_rewind (st_parameter_filepos *fpp)
          else
            {
              /* Set this for compatibilty with g77 for /dev/null.  */
          else
            {
              /* Set this for compatibilty with g77 for /dev/null.  */

-             if (file_length (u->s) == 0  && file_position (u->s) == 0)
+             if (file_length (u->s) == 0  && stell (u->s) == 0)

                u->endfile = AT_ENDFILE;
              /* Future refinements on special files can go here.  */
            }
                u->endfile = AT_ENDFILE;
              /* Future refinements on special files can go here.  */
            }


@@ -350,12 +390,16 @@ st_flush (st_parameter_filepos *fpp)
   u = find_unit (fpp->common.unit);
   if (u != NULL)
     {
   u = find_unit (fpp->common.unit);
   if (u != NULL)
     {

-      flush (u->s);
+      /* Make sure format buffer is flushed.  */
+      if (u->flags.form == FORM_FORMATTED)
+        fbuf_flush (u, u->mode);
+
+      sflush (u->s);

       unlock_unit (u);
     }
   else
     /* FLUSH on unconnected unit is illegal: F95 std., 9.3.5. */ 
       unlock_unit (u);
     }
   else
     /* FLUSH on unconnected unit is illegal: F95 std., 9.3.5. */ 

-    generate_error (&fpp->common, ERROR_BAD_OPTION,
+    generate_error (&fpp->common, LIBERROR_BAD_OPTION,

                        "Specified UNIT in FLUSH is not connected");
 
   library_end ();
                        "Specified UNIT in FLUSH is not connected");
 
   library_end ();