gdb/ui-file.c

/* UI_FILE - a generic STDIO like output stream.

   Copyright (C) 1999, 2000, 2001, 2002, 2007, 2008, 2009, 2010, 2011
   Free Software Foundation, Inc.

   This file is part of GDB.

   This program 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 3 of the License, or
   (at your option) any later version.

   This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.  */

/* Implement the ``struct ui_file'' object.  */

#include "defs.h"
#include "ui-file.h"
#include "gdb_obstack.h"
#include "gdb_string.h"
#include "gdb_select.h"

#include <errno.h>

static ui_file_isatty_ftype null_file_isatty;
static ui_file_write_ftype null_file_write;
static ui_file_write_ftype null_file_write_async_safe;
static ui_file_fputs_ftype null_file_fputs;
static ui_file_read_ftype null_file_read;
static ui_file_flush_ftype null_file_flush;
static ui_file_delete_ftype null_file_delete;
static ui_file_rewind_ftype null_file_rewind;
static ui_file_put_ftype null_file_put;

struct ui_file
  {
    int *magic;
    ui_file_flush_ftype *to_flush;
    ui_file_write_ftype *to_write;
    ui_file_write_async_safe_ftype *to_write_async_safe;
    ui_file_fputs_ftype *to_fputs;
    ui_file_read_ftype *to_read;
    ui_file_delete_ftype *to_delete;
    ui_file_isatty_ftype *to_isatty;
    ui_file_rewind_ftype *to_rewind;
    ui_file_put_ftype *to_put;
    void *to_data;
  };
int ui_file_magic;

struct ui_file *
ui_file_new (void)
{
  struct ui_file *file = xmalloc (sizeof (struct ui_file));

  file->magic = &ui_file_magic;
  set_ui_file_data (file, NULL, null_file_delete);
  set_ui_file_flush (file, null_file_flush);
  set_ui_file_write (file, null_file_write);
  set_ui_file_write_async_safe (file, null_file_write_async_safe);
  set_ui_file_fputs (file, null_file_fputs);
  set_ui_file_read (file, null_file_read);
  set_ui_file_isatty (file, null_file_isatty);
  set_ui_file_rewind (file, null_file_rewind);
  set_ui_file_put (file, null_file_put);
  return file;
}

void
ui_file_delete (struct ui_file *file)
{
  file->to_delete (file);
  xfree (file);
}

static int
null_file_isatty (struct ui_file *file)
{
  return 0;
}

static void
null_file_rewind (struct ui_file *file)
{
  return;
}

static void
null_file_put (struct ui_file *file,
	       ui_file_put_method_ftype *write,
	       void *dest)
{
  return;
}

static void
null_file_flush (struct ui_file *file)
{
  return;
}

static void
null_file_write (struct ui_file *file,
		 const char *buf,
		 long sizeof_buf)
{
  if (file->to_fputs == null_file_fputs)
    /* Both the write and fputs methods are null.  Discard the
       request.  */
    return;
  else
    {
      /* The fputs method isn't null, slowly pass the write request
         onto that.  FYI, this isn't as bad as it may look - the
         current (as of 1999-11-07) printf_* function calls fputc and
         fputc does exactly the below.  By having a write function it
         is possible to clean up that code.  */
      int i;
      char b[2];

      b[1] = '\0';
      for (i = 0; i < sizeof_buf; i++)
	{
	  b[0] = buf[i];
	  file->to_fputs (b, file);
	}
      return;
    }
}

static long
null_file_read (struct ui_file *file,
		char *buf,
		long sizeof_buf)
{
  errno = EBADF;
  return 0;
}

static void
null_file_fputs (const char *buf, struct ui_file *file)
{
  if (file->to_write == null_file_write)
    /* Both the write and fputs methods are null.  Discard the
       request.  */
    return;
  else
    {
      /* The write method was implemented, use that.  */
      file->to_write (file, buf, strlen (buf));
    }
}

static void
null_file_write_async_safe (struct ui_file *file,
			    const char *buf,
			    long sizeof_buf)
{
  return;
}

static void
null_file_delete (struct ui_file *file)
{
  return;
}

void *
ui_file_data (struct ui_file *file)
{
  if (file->magic != &ui_file_magic)
    internal_error (__FILE__, __LINE__,
		    _("ui_file_data: bad magic number"));
  return file->to_data;
}

void
gdb_flush (struct ui_file *file)
{
  file->to_flush (file);
}

int
ui_file_isatty (struct ui_file *file)
{
  return file->to_isatty (file);
}

void
ui_file_rewind (struct ui_file *file)
{
  file->to_rewind (file);
}

void
ui_file_put (struct ui_file *file,
	      ui_file_put_method_ftype *write,
	      void *dest)
{
  file->to_put (file, write, dest);
}

void
ui_file_write (struct ui_file *file,
		const char *buf,
		long length_buf)
{
  file->to_write (file, buf, length_buf);
}

void
ui_file_write_async_safe (struct ui_file *file,
			  const char *buf,
			  long length_buf)
{
  file->to_write_async_safe (file, buf, length_buf);
}

long
ui_file_read (struct ui_file *file, char *buf, long length_buf)
{
  return file->to_read (file, buf, length_buf); 
}

void
fputs_unfiltered (const char *buf, struct ui_file *file)
{
  file->to_fputs (buf, file);
}

void
set_ui_file_flush (struct ui_file *file, ui_file_flush_ftype *flush)
{
  file->to_flush = flush;
}

void
set_ui_file_isatty (struct ui_file *file, ui_file_isatty_ftype *isatty)
{
  file->to_isatty = isatty;
}

void
set_ui_file_rewind (struct ui_file *file, ui_file_rewind_ftype *rewind)
{
  file->to_rewind = rewind;
}

void
set_ui_file_put (struct ui_file *file, ui_file_put_ftype *put)
{
  file->to_put = put;
}

void
set_ui_file_write (struct ui_file *file,
		    ui_file_write_ftype *write)
{
  file->to_write = write;
}

void
set_ui_file_write_async_safe (struct ui_file *file,
			      ui_file_write_async_safe_ftype *write_async_safe)
{
  file->to_write_async_safe = write_async_safe;
}

void
set_ui_file_read (struct ui_file *file, ui_file_read_ftype *read)
{
  file->to_read = read;
}

void
set_ui_file_fputs (struct ui_file *file, ui_file_fputs_ftype *fputs)
{
  file->to_fputs = fputs;
}

void
set_ui_file_data (struct ui_file *file, void *data,
		  ui_file_delete_ftype *delete)
{
  file->to_data = data;
  file->to_delete = delete;
}

/* ui_file utility function for converting a ``struct ui_file'' into
   a memory buffer.  */

struct accumulated_ui_file
{
  char *buffer;
  long length;
};

static void
do_ui_file_xstrdup (void *context, const char *buffer, long length)
{
  struct accumulated_ui_file *acc = context;

  if (acc->buffer == NULL)
    acc->buffer = xmalloc (length + 1);
  else
    acc->buffer = xrealloc (acc->buffer, acc->length + length + 1);
  memcpy (acc->buffer + acc->length, buffer, length);
  acc->length += length;
  acc->buffer[acc->length] = '\0';
}

char *
ui_file_xstrdup (struct ui_file *file, long *length)
{
  struct accumulated_ui_file acc;

  acc.buffer = NULL;
  acc.length = 0;
  ui_file_put (file, do_ui_file_xstrdup, &acc);
  if (acc.buffer == NULL)
    acc.buffer = xstrdup ("");
  if (length != NULL)
    *length = acc.length;
  return acc.buffer;
}

static void
do_ui_file_obsavestring (void *context, const char *buffer, long length)
{
  struct obstack *obstack = (struct obstack *) context;

  obstack_grow (obstack, buffer, length);
}

char *
ui_file_obsavestring (struct ui_file *file, struct obstack *obstack,
		      long *length)
{
  ui_file_put (file, do_ui_file_obsavestring, obstack);
  *length = obstack_object_size (obstack);
  obstack_1grow (obstack, '\0');
  return obstack_finish (obstack);
}

/* A pure memory based ``struct ui_file'' that can be used an output
   buffer.  The buffers accumulated contents are available via
   ui_file_put().  */

struct mem_file
  {
    int *magic;
    char *buffer;
    int sizeof_buffer;
    int length_buffer;
  };

static ui_file_rewind_ftype mem_file_rewind;
static ui_file_put_ftype mem_file_put;
static ui_file_write_ftype mem_file_write;
static ui_file_delete_ftype mem_file_delete;
static struct ui_file *mem_file_new (void);
static int mem_file_magic;

static struct ui_file *
mem_file_new (void)
{
  struct mem_file *stream = XMALLOC (struct mem_file);
  struct ui_file *file = ui_file_new ();

  set_ui_file_data (file, stream, mem_file_delete);
  set_ui_file_rewind (file, mem_file_rewind);
  set_ui_file_put (file, mem_file_put);
  set_ui_file_write (file, mem_file_write);
  stream->magic = &mem_file_magic;
  stream->buffer = NULL;
  stream->sizeof_buffer = 0;
  stream->length_buffer = 0;
  return file;
}

static void
mem_file_delete (struct ui_file *file)
{
  struct mem_file *stream = ui_file_data (file);

  if (stream->magic != &mem_file_magic)
    internal_error (__FILE__, __LINE__,
		    _("mem_file_delete: bad magic number"));
  if (stream->buffer != NULL)
    xfree (stream->buffer);
  xfree (stream);
}

struct ui_file *
mem_fileopen (void)
{
  return mem_file_new ();
}

static void
mem_file_rewind (struct ui_file *file)
{
  struct mem_file *stream = ui_file_data (file);

  if (stream->magic != &mem_file_magic)
    internal_error (__FILE__, __LINE__,
		    _("mem_file_rewind: bad magic number"));
  stream->length_buffer = 0;
}

static void
mem_file_put (struct ui_file *file,
	      ui_file_put_method_ftype *write,
	      void *dest)
{
  struct mem_file *stream = ui_file_data (file);

  if (stream->magic != &mem_file_magic)
    internal_error (__FILE__, __LINE__,
		    _("mem_file_put: bad magic number"));
  if (stream->length_buffer > 0)
    write (dest, stream->buffer, stream->length_buffer);
}

void
mem_file_write (struct ui_file *file,
		const char *buffer,
		long length_buffer)
{
  struct mem_file *stream = ui_file_data (file);

  if (stream->magic != &mem_file_magic)
    internal_error (__FILE__, __LINE__,
		    _("mem_file_write: bad magic number"));
  if (stream->buffer == NULL)
    {
      stream->length_buffer = length_buffer;
      stream->sizeof_buffer = length_buffer;
      stream->buffer = xmalloc (stream->sizeof_buffer);
      memcpy (stream->buffer, buffer, length_buffer);
    }
  else
    {
      int new_length = stream->length_buffer + length_buffer;

      if (new_length >= stream->sizeof_buffer)
	{
	  stream->sizeof_buffer = new_length;
	  stream->buffer = xrealloc (stream->buffer, stream->sizeof_buffer);
	}
      memcpy (stream->buffer + stream->length_buffer, buffer, length_buffer);
      stream->length_buffer = new_length;
    }
}

/* ``struct ui_file'' implementation that maps directly onto
   <stdio.h>'s FILE.  */

static ui_file_write_ftype stdio_file_write;
static ui_file_write_async_safe_ftype stdio_file_write_async_safe;
static ui_file_fputs_ftype stdio_file_fputs;
static ui_file_read_ftype stdio_file_read;
static ui_file_isatty_ftype stdio_file_isatty;
static ui_file_delete_ftype stdio_file_delete;
static struct ui_file *stdio_file_new (FILE *file, int close_p);
static ui_file_flush_ftype stdio_file_flush;

static int stdio_file_magic;

struct stdio_file
  {
    int *magic;
    FILE *file;
    /* The associated file descriptor is extracted ahead of time for
       stdio_file_write_async_safe's benefit, in case fileno isn't async-safe.  */
    int fd;
    int close_p;
  };

static struct ui_file *
stdio_file_new (FILE *file, int close_p)
{
  struct ui_file *ui_file = ui_file_new ();
  struct stdio_file *stdio = xmalloc (sizeof (struct stdio_file));

  stdio->magic = &stdio_file_magic;
  stdio->file = file;
  stdio->fd = fileno (file);
  stdio->close_p = close_p;
  set_ui_file_data (ui_file, stdio, stdio_file_delete);
  set_ui_file_flush (ui_file, stdio_file_flush);
  set_ui_file_write (ui_file, stdio_file_write);
  set_ui_file_write_async_safe (ui_file, stdio_file_write_async_safe);
  set_ui_file_fputs (ui_file, stdio_file_fputs);
  set_ui_file_read (ui_file, stdio_file_read);
  set_ui_file_isatty (ui_file, stdio_file_isatty);
  return ui_file;
}

static void
stdio_file_delete (struct ui_file *file)
{
  struct stdio_file *stdio = ui_file_data (file);

  if (stdio->magic != &stdio_file_magic)
    internal_error (__FILE__, __LINE__,
		    _("stdio_file_delete: bad magic number"));
  if (stdio->close_p)
    {
      fclose (stdio->file);
    }
  xfree (stdio);
}

static void
stdio_file_flush (struct ui_file *file)
{
  struct stdio_file *stdio = ui_file_data (file);

  if (stdio->magic != &stdio_file_magic)
    internal_error (__FILE__, __LINE__,
		    _("stdio_file_flush: bad magic number"));
  fflush (stdio->file);
}

static long
stdio_file_read (struct ui_file *file, char *buf, long length_buf)
{
  struct stdio_file *stdio = ui_file_data (file);

  if (stdio->magic != &stdio_file_magic)
    internal_error (__FILE__, __LINE__,
		    _("stdio_file_read: bad magic number"));

  /* For the benefit of Windows, call gdb_select before reading from
     the file.  Wait until at least one byte of data is available.
     Control-C can interrupt gdb_select, but not read.  */
  {
    fd_set readfds;
    FD_ZERO (&readfds);
    FD_SET (stdio->fd, &readfds);
    if (gdb_select (stdio->fd + 1, &readfds, NULL, NULL, NULL) == -1)
      return -1;
  }

  return read (stdio->fd, buf, length_buf);
}

static void
stdio_file_write (struct ui_file *file, const char *buf, long length_buf)
{
  struct stdio_file *stdio = ui_file_data (file);

  if (stdio->magic != &stdio_file_magic)
    internal_error (__FILE__, __LINE__,
		    _("stdio_file_write: bad magic number"));
  /* Calling error crashes when we are called from the exception framework.  */
  if (fwrite (buf, length_buf, 1, stdio->file))
    ;
}

static void
stdio_file_write_async_safe (struct ui_file *file,
			     const char *buf, long length_buf)
{
  struct stdio_file *stdio = ui_file_data (file);

  if (stdio->magic != &stdio_file_magic)
    {
      /* gettext isn't necessarily async safe, so we can't use _("error message") here.
	 We could extract the correct translation ahead of time, but this is an extremely
	 rare event, and one of the other stdio_file_* routines will presumably catch
	 the problem anyway.  For now keep it simple and ignore the error here.  */
      return;
    }

  /* This is written the way it is to avoid a warning from gcc about not using the
     result of write (since it can be declared with attribute warn_unused_result).
     Alas casting to void doesn't work for this.  */
  if (write (stdio->fd, buf, length_buf))
    ;
}

static void
stdio_file_fputs (const char *linebuffer, struct ui_file *file)
{
  struct stdio_file *stdio = ui_file_data (file);

  if (stdio->magic != &stdio_file_magic)
    internal_error (__FILE__, __LINE__,
		    _("stdio_file_fputs: bad magic number"));
  /* Calling error crashes when we are called from the exception framework.  */
  if (fputs (linebuffer, stdio->file))
    ;
}

static int
stdio_file_isatty (struct ui_file *file)
{
  struct stdio_file *stdio = ui_file_data (file);

  if (stdio->magic != &stdio_file_magic)
    internal_error (__FILE__, __LINE__,
		    _("stdio_file_isatty: bad magic number"));
  return (isatty (stdio->fd));
}

/* Like fdopen().  Create a ui_file from a previously opened FILE.  */

struct ui_file *
stdio_fileopen (FILE *file)
{
  return stdio_file_new (file, 0);
}

struct ui_file *
gdb_fopen (char *name, char *mode)
{
  FILE *f = fopen (name, mode);

  if (f == NULL)
    return NULL;
  return stdio_file_new (f, 1);
}

/* ``struct ui_file'' implementation that maps onto two ui-file objects.  */

static ui_file_write_ftype tee_file_write;
static ui_file_fputs_ftype tee_file_fputs;
static ui_file_isatty_ftype tee_file_isatty;
static ui_file_delete_ftype tee_file_delete;
static ui_file_flush_ftype tee_file_flush;

static int tee_file_magic;

struct tee_file
  {
    int *magic;
    struct ui_file *one, *two;
    int close_one, close_two;
  };

struct ui_file *
tee_file_new (struct ui_file *one, int close_one,
	      struct ui_file *two, int close_two)
{
  struct ui_file *ui_file = ui_file_new ();
  struct tee_file *tee = xmalloc (sizeof (struct tee_file));

  tee->magic = &tee_file_magic;
  tee->one = one;
  tee->two = two;
  tee->close_one = close_one;
  tee->close_two = close_two;
  set_ui_file_data (ui_file, tee, tee_file_delete);
  set_ui_file_flush (ui_file, tee_file_flush);
  set_ui_file_write (ui_file, tee_file_write);
  set_ui_file_fputs (ui_file, tee_file_fputs);
  set_ui_file_isatty (ui_file, tee_file_isatty);
  return ui_file;
}

static void
tee_file_delete (struct ui_file *file)
{
  struct tee_file *tee = ui_file_data (file);

  if (tee->magic != &tee_file_magic)
    internal_error (__FILE__, __LINE__,
		    _("tee_file_delete: bad magic number"));
  if (tee->close_one)
    ui_file_delete (tee->one);
  if (tee->close_two)
    ui_file_delete (tee->two);

  xfree (tee);
}

static void
tee_file_flush (struct ui_file *file)
{
  struct tee_file *tee = ui_file_data (file);

  if (tee->magic != &tee_file_magic)
    internal_error (__FILE__, __LINE__,
		    _("tee_file_flush: bad magic number"));
  tee->one->to_flush (tee->one);
  tee->two->to_flush (tee->two);
}

static void
tee_file_write (struct ui_file *file, const char *buf, long length_buf)
{
  struct tee_file *tee = ui_file_data (file);

  if (tee->magic != &tee_file_magic)
    internal_error (__FILE__, __LINE__,
		    _("tee_file_write: bad magic number"));
  ui_file_write (tee->one, buf, length_buf);
  ui_file_write (tee->two, buf, length_buf);
}

static void
tee_file_fputs (const char *linebuffer, struct ui_file *file)
{
  struct tee_file *tee = ui_file_data (file);

  if (tee->magic != &tee_file_magic)
    internal_error (__FILE__, __LINE__,
		    _("tee_file_fputs: bad magic number"));
  tee->one->to_fputs (linebuffer, tee->one);
  tee->two->to_fputs (linebuffer, tee->two);
}

static int
tee_file_isatty (struct ui_file *file)
{
  struct tee_file *tee = ui_file_data (file);

  if (tee->magic != &tee_file_magic)
    internal_error (__FILE__, __LINE__,
		    _("tee_file_isatty: bad magic number"));

  return ui_file_isatty (tee->one);
}