libiberty/vasprintf.c

   1 /* Like vsprintf but provides a pointer to malloc'd storage, which must
   2    be freed by the caller.
   3    Copyright (C) 1994, 2003, 2011, 2013 Free Software Foundation, Inc.
   4
   5 This file is part of the libiberty library.
   6 Libiberty is free software; you can redistribute it and/or
   7 modify it under the terms of the GNU Library General Public
   8 License as published by the Free Software Foundation; either
   9 version 2 of the License, or (at your option) any later version.
  10
  11 Libiberty is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 Library General Public License for more details.
  15
  16 You should have received a copy of the GNU Library General Public
  17 License along with libiberty; see the file COPYING.LIB.  If
  18 not, write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
  19 Boston, MA 02110-1301, USA.  */
  20
  21 #ifdef HAVE_CONFIG_H
  22 #include "config.h"
  23 #endif
  24 #include <ansidecl.h>
  25 #include <stdarg.h>
  26 #if !defined (va_copy) && defined (__va_copy)
  27 # define va_copy(d,s)  __va_copy((d),(s))
  28 #endif
  29 #include <stdio.h>
  30 #ifdef HAVE_STRING_H
  31 #include <string.h>
  32 #endif
  33 #ifdef HAVE_STDLIB_H
  34 #include <stdlib.h>
  35 #else
  36 extern unsigned long strtoul ();
  37 extern PTR malloc ();
  38 #endif
  39 #include "libiberty.h"
  40
  41 #ifdef TEST
  42 int global_total_width;
  43 #endif
  44
  45 /*
  46
  47 @deftypefn Extension int vasprintf (char **@var{resptr}, @
  48   const char *@var{format}, va_list @var{args})
  49
  50 Like @code{vsprintf}, but instead of passing a pointer to a buffer,
  51 you pass a pointer to a pointer.  This function will compute the size
  52 of the buffer needed, allocate memory with @code{malloc}, and store a
  53 pointer to the allocated memory in @code{*@var{resptr}}.  The value
  54 returned is the same as @code{vsprintf} would return.  If memory could
  55 not be allocated, minus one is returned and @code{NULL} is stored in
  56 @code{*@var{resptr}}.
  57
  58 @end deftypefn
  59
  60 */
  61
  62 static int int_vasprintf (char **, const char *, va_list);
  63
  64 static int
  65 int_vasprintf (char **result, const char *format, va_list args)
  66 {
  67   const char *p = format;
  68   /* Add one to make sure that it is never zero, which might cause malloc
  69      to return NULL.  */
  70   int total_width = strlen (format) + 1;
  71   va_list ap;
  72
  73 #ifdef va_copy
  74   va_copy (ap, args);
  75 #else
  76   memcpy ((PTR) &ap, (PTR) &args, sizeof (va_list));
  77 #endif
  78
  79   while (*p != '\0')
  80     {
  81       if (*p++ == '%')
  82         {
  83           while (strchr ("-+ #0", *p))
  84             ++p;
  85           if (*p == '*')
  86             {
  87               ++p;
  88               total_width += abs (va_arg (ap, int));
  89             }
  90           else
  91             total_width += strtoul (p, (char **) &p, 10);
  92           if (*p == '.')
  93             {
  94               ++p;
  95               if (*p == '*')
  96                 {
  97                   ++p;
  98                   total_width += abs (va_arg (ap, int));
  99                 }
 100               else
 101               total_width += strtoul (p, (char **) &p, 10);
 102             }
 103           while (strchr ("hlL", *p))
 104             ++p;
 105           /* Should be big enough for any format specifier except %s and floats.  */
 106           total_width += 30;
 107           switch (*p)
 108             {
 109             case 'd':
 110             case 'i':
 111             case 'o':
 112             case 'u':
 113             case 'x':
 114             case 'X':
 115             case 'c':
 116               (void) va_arg (ap, int);
 117               break;
 118             case 'f':
 119             case 'e':
 120             case 'E':
 121             case 'g':
 122             case 'G':
 123               (void) va_arg (ap, double);
 124               /* Since an ieee double can have an exponent of 307, we'll
 125                  make the buffer wide enough to cover the gross case. */
 126               total_width += 307;
 127               break;
 128             case 's':
 129               total_width += strlen (va_arg (ap, char *));
 130               break;
 131             case 'p':
 132             case 'n':
 133               (void) va_arg (ap, char *);
 134               break;
 135             }
 136           p++;
 137         }
 138     }
 139 #ifdef va_copy
 140   va_end (ap);
 141 #endif
 142 #ifdef TEST
 143   global_total_width = total_width;
 144 #endif
 145   *result = (char *) malloc (total_width);
 146   if (*result != NULL)
 147     return vsprintf (*result, format, args);
 148   else
 149     return -1;
 150 }
 151
 152 int
 153 vasprintf (char **result, const char *format,
 154 #if defined (_BSD_VA_LIST_) && defined (__FreeBSD__)
 155            _BSD_VA_LIST_ args)
 156 #else
 157            va_list args)
 158 #endif
 159 {
 160   return int_vasprintf (result, format, args);
 161 }
 162
 163 #ifdef TEST
 164 static void ATTRIBUTE_PRINTF_1
 165 checkit (const char *format, ...)
 166 {
 167   char *result;
 168   va_list args;
 169   va_start (args, format);
 170   vasprintf (&result, format, args);
 171   va_end (args);
 172
 173   if (strlen (result) < (size_t) global_total_width)
 174     printf ("PASS: ");
 175   else
 176     printf ("FAIL: ");
 177   printf ("%d %s\n", global_total_width, result);
 178
 179   free (result);
 180 }
 181
 182 extern int main (void);
 183
 184 int
 185 main (void)
 186 {
 187   checkit ("%d", 0x12345678);
 188   checkit ("%200d", 5);
 189   checkit ("%.300d", 6);
 190   checkit ("%100.150d", 7);
 191   checkit ("%s", "jjjjjjjjjiiiiiiiiiiiiiiioooooooooooooooooppppppppppppaa\n\
 192 777777777777777777333333333333366666666666622222222222777777777777733333");
 193   checkit ("%f%s%d%s", 1.0, "foo", 77, "asdjffffffffffffffiiiiiiiiiiixxxxx");
 194
 195   return 0;
 196 }
 197 #endif /* TEST */