vasprintf.c revision 89857 
1/* Like vsprintf but provides a pointer to malloc'd storage, which must
2   be freed by the caller.
3   Copyright (C) 1994 Free Software Foundation, Inc.
4
5This file is part of the libiberty library.
6Libiberty is free software; you can redistribute it and/or
7modify it under the terms of the GNU Library General Public
8License as published by the Free Software Foundation; either
9version 2 of the License, or (at your option) any later version.
10
11Libiberty is distributed in the hope that it will be useful,
12but WITHOUT ANY WARRANTY; without even the implied warranty of
13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14Library General Public License for more details.
15
16You should have received a copy of the GNU Library General Public
17License along with libiberty; see the file COPYING.LIB.  If
18not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19Boston, MA 02111-1307, USA.  */
20
21#ifdef HAVE_CONFIG_H
22#include "config.h"
23#endif
24#include <ansidecl.h>
25#ifdef ANSI_PROTOTYPES
26#include <stdarg.h>
27#else
28#include <varargs.h>
29#endif
30#include <stdio.h>
31#ifdef HAVE_STRING_H
32#include <string.h>
33#endif
34#ifdef HAVE_STDLIB_H
35#include <stdlib.h>
36#else
37extern unsigned long strtoul ();
38extern PTR malloc ();
39#endif
40#include "libiberty.h"
41
42#ifdef TEST
43int global_total_width;
44#endif
45
46/*
47
48@deftypefn Extension int vasprintf (char **@var{resptr}, const char *@var{format}, va_list @var{args})
49
50Like @code{vsprintf}, but instead of passing a pointer to a buffer,
51you pass a pointer to a pointer.  This function will compute the size
52of the buffer needed, allocate memory with @code{malloc}, and store a
53pointer to the allocated memory in @code{*@var{resptr}}.  The value
54returned is the same as @code{vsprintf} would return.  If memory could
55not be allocated, zero is returned and @code{NULL} is stored in
56@code{*@var{resptr}}.
57
58@end deftypefn
59
60*/
61
62static int int_vasprintf PARAMS ((char **, const char *, va_list *));
63
64static int
65int_vasprintf (result, format, args)
66     char **result;
67     const char *format;
68     va_list *args;
69{
70  const char *p = format;
71  /* Add one to make sure that it is never zero, which might cause malloc
72     to return NULL.  */
73  int total_width = strlen (format) + 1;
74  va_list ap;
75
76  memcpy ((PTR) &ap, (PTR) args, sizeof (va_list));
77
78  while (*p != '\0')
79    {
80      if (*p++ == '%')
81	{
82	  while (strchr ("-+ #0", *p))
83	    ++p;
84	  if (*p == '*')
85	    {
86	      ++p;
87	      total_width += abs (va_arg (ap, int));
88	    }
89	  else
90	    total_width += strtoul (p, (char **) &p, 10);
91	  if (*p == '.')
92	    {
93	      ++p;
94	      if (*p == '*')
95		{
96		  ++p;
97		  total_width += abs (va_arg (ap, int));
98		}
99	      else
100	      total_width += strtoul (p, (char **) &p, 10);
101	    }
102	  while (strchr ("hlL", *p))
103	    ++p;
104	  /* Should be big enough for any format specifier except %s and floats.  */
105	  total_width += 30;
106	  switch (*p)
107	    {
108	    case 'd':
109	    case 'i':
110	    case 'o':
111	    case 'u':
112	    case 'x':
113	    case 'X':
114	    case 'c':
115	      (void) va_arg (ap, int);
116	      break;
117	    case 'f':
118	    case 'e':
119	    case 'E':
120	    case 'g':
121	    case 'G':
122	      (void) va_arg (ap, double);
123	      /* Since an ieee double can have an exponent of 307, we'll
124		 make the buffer wide enough to cover the gross case. */
125	      total_width += 307;
126	      break;
127	    case 's':
128	      total_width += strlen (va_arg (ap, char *));
129	      break;
130	    case 'p':
131	    case 'n':
132	      (void) va_arg (ap, char *);
133	      break;
134	    }
135	  p++;
136	}
137    }
138#ifdef TEST
139  global_total_width = total_width;
140#endif
141  *result = malloc (total_width);
142  if (*result != NULL)
143    return vsprintf (*result, format, *args);
144  else
145    return 0;
146}
147
148int
149vasprintf (result, format, args)
150     char **result;
151     const char *format;
152#if defined (_BSD_VA_LIST_) && defined (__FreeBSD__)
153     _BSD_VA_LIST_ args;
154#else
155     va_list args;
156#endif
157{
158  return int_vasprintf (result, format, &args);
159}
160
161#ifdef TEST
162static void ATTRIBUTE_PRINTF_1
163checkit VPARAMS ((const char *format, ...))
164{
165  char *result;
166  VA_OPEN (args, format);
167  VA_FIXEDARG (args, const char *, format);
168  vasprintf (&result, format, args);
169  VA_CLOSE (args);
170
171  if (strlen (result) < (size_t) global_total_width)
172    printf ("PASS: ");
173  else
174    printf ("FAIL: ");
175  printf ("%d %s\n", global_total_width, result);
176
177  free (result);
178}
179
180extern int main PARAMS ((void));
181
182int
183main ()
184{
185  checkit ("%d", 0x12345678);
186  checkit ("%200d", 5);
187  checkit ("%.300d", 6);
188  checkit ("%100.150d", 7);
189  checkit ("%s", "jjjjjjjjjiiiiiiiiiiiiiiioooooooooooooooooppppppppppppaa\n\
190777777777777777777333333333333366666666666622222222222777777777777733333");
191  checkit ("%f%s%d%s", 1.0, "foo", 77, "asdjffffffffffffffiiiiiiiiiiixxxxx");
192
193  return 0;
194}
195#endif /* TEST */
196