libiberty/vasprintf.c

/* Like vsprintf but provides a pointer to malloc'd storage, which must
   be freed by the caller.
   Copyright (C) 1994-2026 Free Software Foundation, Inc.

This file is part of the libiberty library.
Libiberty is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.

Libiberty 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
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with libiberty; see the file COPYING.LIB.  If not, write
to the Free Software Foundation, Inc., 51 Franklin Street - Fifth
Floor, Boston, MA 02110-1301, USA.  */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <ansidecl.h>
#include <stdarg.h>
#if !defined (va_copy) && defined (__va_copy)
# define va_copy(d,s)  __va_copy((d),(s))
#endif
#include <stdio.h>
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#else
extern void *malloc ();
#endif
#include "libiberty.h"
#include "vprintf-support.h"

#ifdef TEST
int global_total_width;
#endif

/*

@deftypefn Extension int vasprintf (char **@var{resptr}, @
  const char *@var{format}, va_list @var{args})

Like @code{vsprintf}, but instead of passing a pointer to a buffer,
you pass a pointer to a pointer.  This function will compute the size
of the buffer needed, allocate memory with @code{malloc}, and store a
pointer to the allocated memory in @code{*@var{resptr}}.  The value
returned is the same as @code{vsprintf} would return.  If memory could
not be allocated, minus one is returned and @code{NULL} is stored in
@code{*@var{resptr}}.

@end deftypefn

*/

static int int_vasprintf (char **, const char *, va_list);

static int
int_vasprintf (char **result, const char *format, va_list args)
{
  int total_width = libiberty_vprintf_buffer_size (format, args);
#ifdef TEST
  global_total_width = total_width;
#endif
  *result = (char *) malloc (total_width);
  if (*result != NULL)
    return vsprintf (*result, format, args);
  else
    return -1;
}

int
vasprintf (char **result, const char *format,
#if defined (_BSD_VA_LIST_) && defined (__FreeBSD__)
           _BSD_VA_LIST_ args)
#else
           va_list args)
#endif
{
  return int_vasprintf (result, format, args);
}

#ifdef TEST
static void ATTRIBUTE_PRINTF_1
checkit (const char *format, ...)
{
  char *result;
  va_list args;
  va_start (args, format);
  vasprintf (&result, format, args);
  va_end (args);

  if (strlen (result) < (size_t) global_total_width)
    printf ("PASS: ");
  else
    printf ("FAIL: ");
  printf ("%d %s\n", global_total_width, result);

  free (result);
}

extern int main (void);

int
main (void)
{
  checkit ("%d", 0x12345678);
  checkit ("%200d", 5);
  checkit ("%.300d", 6);
  checkit ("%100.150d", 7);
  checkit ("%s", "jjjjjjjjjiiiiiiiiiiiiiiioooooooooooooooooppppppppppppaa\n\
777777777777777777333333333333366666666666622222222222777777777777733333");
  checkit ("%f%s%d%s", 1.0, "foo", 77, "asdjffffffffffffffiiiiiiiiiiixxxxx");

  return 0;
}
#endif /* TEST */