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.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@135373 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 45 insertions, 9 deletions

diff --git a/libgfortran/io/io.h b/libgfortran/io/io.h
index 30d4051f126..e554d8cccbc 100644
--- a/libgfortran/io/io.h
+++ b/libgfortran/io/io.h
@@ -49,8 +49,7 @@ struct st_parameter_dt;
 
 typedef struct stream
 {
-  char *(*alloc_w_at) (struct stream *, int *, gfc_offset);
-  char *(*alloc_r_at) (struct stream *, int *, gfc_offset);
+  char *(*alloc_w_at) (struct stream *, int *);
   try (*sfree) (struct stream *);
   try (*close) (struct stream *);
   try (*seek) (struct stream *, gfc_offset);
@@ -70,11 +69,7 @@ io_mode;
 #define sfree(s) ((s)->sfree)(s)
 #define sclose(s) ((s)->close)(s)
 
-#define salloc_r(s, len) ((s)->alloc_r_at)(s, len, -1)
-#define salloc_w(s, len) ((s)->alloc_w_at)(s, len, -1)
-
-#define salloc_r_at(s, len, where) ((s)->alloc_r_at)(s, len, where)
-#define salloc_w_at(s, len, where) ((s)->alloc_w_at)(s, len, where)
+#define salloc_w(s, len) ((s)->alloc_w_at)(s, len)
 
 #define sseek(s, pos) ((s)->seek)(s, pos)
 #define struncate(s) ((s)->trunc)(s)
@@ -528,6 +523,25 @@ typedef struct
 unit_flags;
 
 
+/* Formatting buffer. This is a temporary scratch buffer. Currently used only
+   by formatted writes. After every
+   formatted write statement, this buffer is flushed. This buffer is needed since
+   not all devices are seekable, and T or TL edit descriptors require 
+   moving backwards in the record.  However, advance='no' complicates the
+   situation, so the buffer must only be partially flushed from the end of the
+   last flush until the current position in the record. */
+
+typedef struct fbuf
+{
+  char *buf;			/* Start of buffer.  */
+  size_t len;			/* Length of buffer.  */
+  size_t act;			/* Active bytes in buffer.  */
+  size_t flushed;		/* Flushed bytes from beginning of buffer.  */
+  char *ptr;			/* Current position in buffer.  */
+}
+fbuf;
+
+
 typedef struct gfc_unit
 {
   int unit_number;
@@ -578,6 +592,9 @@ typedef struct gfc_unit
 
   int file_len;
   char *file;
+  
+  /* Formatting buffer.  */
+  struct fbuf *fbuf;
 }
 gfc_unit;
 
@@ -812,8 +829,8 @@ internal_proto(free_format_data);
 extern const char *type_name (bt);
 internal_proto(type_name);
 
-extern void *read_block (st_parameter_dt *, int *);
-internal_proto(read_block);
+extern try read_block_form (st_parameter_dt *, void *, size_t *);
+internal_proto(read_block_form);
 
 extern char *read_sf (st_parameter_dt *, int *, int);
 internal_proto(read_sf);
@@ -931,6 +948,25 @@ internal_proto(size_from_real_kind);
 extern size_t size_from_complex_kind (int);
 internal_proto(size_from_complex_kind);
 
+/* fbuf.c */
+extern void fbuf_init (gfc_unit *, size_t);
+internal_proto(fbuf_init);
+
+extern void fbuf_destroy (gfc_unit *);
+internal_proto(fbuf_destroy);
+
+extern void fbuf_reset (gfc_unit *);
+internal_proto(fbuf_reset);
+
+extern char * fbuf_alloc (gfc_unit *, size_t);
+internal_proto(fbuf_alloc);
+
+extern int fbuf_flush (gfc_unit *, int);
+internal_proto(fbuf_flush);
+
+extern int fbuf_seek (gfc_unit *, gfc_offset);
+internal_proto(fbuf_seek);
+
 /* lock.c */
 extern void free_ionml (st_parameter_dt *);
 internal_proto(free_ionml);