Part 1 of PR 25561.

2008-05-15  Janne Blomqvist  <jb@gcc.gnu.org>

	PR libfortran/25561
	* Makefile.am: Add fbuf.c to gfor_io_src.
	* Makefile.in: Regenerate.
	* io/io.h (read_block): Remove.
	(struct stream): Remove alloc_r_at function pointer.
	(salloc_r): Remove.
	(salloc_r_at): Remove.
	(salloc_w_at): Remove.
	(salloc_w): Remove offset argument.
	(struct fbuf): New struct for format buffer.
	(struct gfc_unit): Add fbuf.
	(read_block_form): New prototype.
	(fbuf_init): Likewise.
	(fbuf_destroy): Likewise.
	(fbuf_reset): Likewise.
	(fbuf_alloc): Likewise.
	(fbuf_flush): Likewise.
	(fbuf_seek): Likewise.
	* io/file_pos.c (formatted_backspace): Change to use sread.
	(unformatted_backspace): Likewise.
	(st_backspace): Flush format buffer.
	(st_rewind): Likewise.
	* io/list_read.c (next_char): Likewise.
	(nml_query): Tidying, flush format buffer.
	* io/open.c (new_unit): Init format buffer.
	* io/read.c (read_l): Change to use read_block_form.
	(read_a): Likewise.
	(read_decimal): Likewise.
	(read_radix): Likewise.
	(read_f): Likewise.
	(read_x): Empty reads also for stream I/O.
	* io/transfer.c (read_sf): Change to use sread.
	(read_block): Rename to read_block_form, change prototype, use sread.
	(read_block_direct): Don't seek stream files.
	(write_block): Change to use fbuf if external file, don't seek stream
	files.
	(write_buf): Don't seek stream files.
	(formatted_transfer_scalar): Use fbuf for external files.
	(us_read): Change to use sread.
	(pre_position): Do nothing for stream I/O.
	(data_transfer_init): Flush fbuf when switching from write to read, if
	POS is specified, seek stream file to correct offset.
	(skip_record): Change to use sread.
	(min_off): New function.
	(next_record_r): Change to use sread.
	(next_record_w): Change to use sset/sseek, flush fbuf.
	(finalize_transfer): Flush fbuf.
	* io/unit.c (init_units): Init fbuf for stdout, stderr.
	(close_unit_1): Destroy fbuf.
	(finish_last_advance_record): Flush fbuf, no need to seek.
	* io/unix.c (fd_alloc_r_at): Remove unused where argument.
	(fd_alloc_w_at): Likewise.
	(fd_read): Remove third argument to fd_alloc_r_at.
	(fd_write): Remove third argument to fd_alloc_w_at.
	(fd_sset): Likewise.
	(fd_open): Don't set alloc_r_at.
	(mem_alloc_r_at): Remove unused where argument.
	(mem_alloc_w_at): Likewise.
	(mem_read): Don't incorrectly return previous errno, remove unused
	third argument to alloc function.
	(mem_write): Likewise.
	(mem_set): Likewise.
	(open_internal): Don't set alloc_r_at pointer.
	* io/fbuf.c: New file.

From-SVN: r135373

1 files changed, 17 insertions, 17 deletions

diff --git a/libgfortran/io/file_pos.c b/libgfortran/io/file_pos.c
index 94e29899fb1..f4864884f33 100644
--- a/libgfortran/io/file_pos.c
+++ b/libgfortran/io/file_pos.c
@@ -39,14 +39,14 @@ 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.  */
 
-#define READ_CHUNK 4096
+static const unsigned int READ_CHUNK = 4096;
 
 static void
 formatted_backspace (st_parameter_filepos *fpp, gfc_unit *u)
 {
   gfc_offset base;
-  char *p;
-  int n;
+  char p[READ_CHUNK];
+  size_t n;
 
   base = file_position (u->s) - 1;
 
@@ -54,9 +54,9 @@ formatted_backspace (st_parameter_filepos *fpp, gfc_unit *u)
     {
       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) == FAILURE)
+        goto io_error;
+      if (sread (u->s, p, &n) != 0)
 	goto io_error;
 
       /* We have moved backwards from the current position, it should
@@ -66,15 +66,14 @@ formatted_backspace (st_parameter_filepos *fpp, gfc_unit *u)
       /* There is no memrchr() in the C library, so we have to do it
          ourselves.  */
 
-      n--;
-      while (n >= 0)
+      while (n > 0)
 	{
+          n--;
 	  if (p[n] == '\n')
 	    {
 	      base += n + 1;
 	      goto done;
 	    }
-	  n--;
 	}
 
     }
@@ -104,9 +103,9 @@ unformatted_backspace (st_parameter_filepos *fpp, gfc_unit *u)
   gfc_offset m, new;
   GFC_INTEGER_4 m4;
   GFC_INTEGER_8 m8;
-  int length, length_read;
+  size_t length;
   int continued;
-  char *p;
+  char p[sizeof (GFC_INTEGER_8)];
 
   if (compile_options.record_marker == 0)
     length = sizeof (GFC_INTEGER_4);
@@ -115,12 +114,10 @@ unformatted_backspace (st_parameter_filepos *fpp, gfc_unit *u)
 
   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;
+      if (sseek (u->s, file_position (u->s) - length) == FAILURE)
+        goto io_error;
+      if (sread (u->s, p, &length) != 0)
+        goto io_error;
 
       /* Only GFC_CONVERT_NATIVE and GFC_CONVERT_SWAP are valid here.  */
       if (u->flags.convert == GFC_CONVERT_NATIVE)
@@ -216,6 +213,9 @@ st_backspace (st_parameter_filepos *fpp)
 	goto done;
       }
 
+  /* Make sure format buffer is flushed.  */
+  fbuf_flush (u, 1);
+  
   /* Check for special cases involving the ENDFILE record first.  */
 
   if (u->endfile == AFTER_ENDFILE)