gnulib/tests/test-obstack-printf.c

/* Test of obstack_printf() and obstack_vprintf() functions.
   Copyright (C) 2008-2020 Free Software Foundation, Inc.

   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 <https://www.gnu.org/licenses/>.  */

/* Written by Eric Blake <ebb9@byu.net>, 2008.  */

#include <config.h>

#include <stdio.h>

#include "signature.h"
SIGNATURE_CHECK (obstack_printf, int, (struct obstack *, char const *, ...));
SIGNATURE_CHECK (obstack_vprintf, int, (struct obstack *, char const *,
                                        va_list));

#include "obstack.h"
#include "xalloc.h"

#include <stdarg.h>
#include <stdlib.h>
#include <string.h>

#include "macros.h"

#define obstack_chunk_alloc xmalloc
#define obstack_chunk_free free

static void
test_function (int (*my_obstack_printf) (struct obstack *, const char *, ...))
{
  struct obstack obs;
  obstack_init (&obs);
  /* In general, be careful that arguments to obstack_* don't have
     side effects, as not all compilers evaluate macro arguments only
     once.  */

  /* Grow the obstack to near its boundary, then check that short
     output longer than the obstack free space grows the obstack.  */
  {
    char *base = obstack_base (&obs);
    char *new_base;
    int result;
    int room = obstack_room (&obs) - 4;

    obstack_blank_fast (&obs, room);
    result = my_obstack_printf (&obs, "%d %s", 123, "456");
    ASSERT (result == 7);
    ASSERT (result + room == obstack_object_size (&obs));
    obstack_1grow (&obs, 0);
    new_base = obstack_finish (&obs);
    ASSERT (base != new_base);
    ASSERT (strcmp (new_base + room, "123 456") == 0);
  }

  /* Check that strings shorter than the obstack free space don't
     cause a reshuffling of the obstack.  */
  {
    char *base = obstack_base (&obs);
    char *new_base;
    int result;
    int room = obstack_room (&obs);

    ASSERT (8 < room);
    result = my_obstack_printf (&obs, "%d %s", 123, "456");
    ASSERT (result == 7);
    ASSERT (result == obstack_object_size (&obs));
    new_base = obstack_base (&obs);
    ASSERT (base == new_base);
    ASSERT (strncmp (base, "123 456", result) == 0);
    obstack_finish (&obs);
  }

  /* Check for generating much more output than a chunk size.  */
  {
    char *base = obstack_base (&obs);
    char *new_base;
    int result;
    int i;

    ASSERT (obstack_chunk_size (&obs) < 10000);
    result = my_obstack_printf (&obs, "%010000d", 0);
    ASSERT (result == 10000);
    ASSERT (result == obstack_object_size (&obs));
    new_base = obstack_base (&obs);
    ASSERT (base != new_base);
    for (i = 0; i < 10000; i++)
      ASSERT (new_base[i] == '0');
  }

  obstack_free (&obs, NULL);
}

static int
my_obstack_printf (struct obstack *obs, const char *format, ...)
{
  va_list args;
  int ret;

  va_start (args, format);
  ret = obstack_vprintf (obs, format, args);
  va_end (args);
  return ret;
}

static void
test_obstack_vprintf ()
{
  test_function (my_obstack_printf);
}

static void
test_obstack_printf ()
{
  test_function (obstack_printf);
}

int
main (int argc, char *argv[])
{
  test_obstack_vprintf ();
  test_obstack_printf ();
  return 0;
}