vasprintf.c revision 130561 
1/* Like vsprintf but provides a pointer to malloc'd storage, which must
2   be freed by the caller.
3   Copyright (C) 1994, 2003 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, minus one 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#ifdef va_copy
77  va_copy (ap, args);
78#else
79  memcpy ((PTR) &ap, (PTR) &args, sizeof (va_list));
80#endif
81
82  while (*p != '\0')
83    {
84      if (*p++ == '%')
85	{
86	  while (strchr ("-+ #0", *p))
87	    ++p;
88	  if (*p == '*')
89	    {
90	      ++p;
91	      total_width += abs (va_arg (ap, int));
92	    }
93	  else
94	    total_width += strtoul (p, (char **) &p, 10);
95	  if (*p == '.')
96	    {
97	      ++p;
98	      if (*p == '*')
99		{
100		  ++p;
101		  total_width += abs (va_arg (ap, int));
102		}
103	      else
104	      total_width += strtoul (p, (char **) &p, 10);
105	    }
106	  while (strchr ("hlL", *p))
107	    ++p;
108	  /* Should be big enough for any format specifier except %s and floats.  */
109	  total_width += 30;
110	  switch (*p)
111	    {
112	    case 'd':
113	    case 'i':
114	    case 'o':
115	    case 'u':
116	    case 'x':
117	    case 'X':
118	    case 'c':
119	      (void) va_arg (ap, int);
120	      break;
121	    case 'f':
122	    case 'e':
123	    case 'E':
124	    case 'g':
125	    case 'G':
126	      (void) va_arg (ap, double);
127	      /* Since an ieee double can have an exponent of 307, we'll
128		 make the buffer wide enough to cover the gross case. */
129	      total_width += 307;
130	      break;
131	    case 's':
132	      total_width += strlen (va_arg (ap, char *));
133	      break;
134	    case 'p':
135	    case 'n':
136	      (void) va_arg (ap, char *);
137	      break;
138	    }
139	  p++;
140	}
141    }
142#ifdef va_copy
143  va_end (ap);
144#endif
145#ifdef TEST
146  global_total_width = total_width;
147#endif
148  *result = (char *) malloc (total_width);
149  if (*result != NULL)
150    return vsprintf (*result, format, args);
151  else
152    return -1;
153}
154
155int
156vasprintf (result, format, args)
157     char **result;
158     const char *format;
159#if defined (_BSD_VA_LIST_) && defined (__FreeBSD__)
160     _BSD_VA_LIST_ args;
161#else
162     va_list args;
163#endif
164{
165  return int_vasprintf (result, format, args);
166}
167
168#ifdef TEST
169static void ATTRIBUTE_PRINTF_1
170checkit VPARAMS ((const char *format, ...))
171{
172  char *result;
173  VA_OPEN (args, format);
174  VA_FIXEDARG (args, const char *, format);
175  vasprintf (&result, format, args);
176  VA_CLOSE (args);
177
178  if (strlen (result) < (size_t) global_total_width)
179    printf ("PASS: ");
180  else
181    printf ("FAIL: ");
182  printf ("%d %s\n", global_total_width, result);
183
184  free (result);
185}
186
187extern int main PARAMS ((void));
188
189int
190main ()
191{
192  checkit ("%d", 0x12345678);
193  checkit ("%200d", 5);
194  checkit ("%.300d", 6);
195  checkit ("%100.150d", 7);
196  checkit ("%s", "jjjjjjjjjiiiiiiiiiiiiiiioooooooooooooooooppppppppppppaa\n\
197777777777777777777333333333333366666666666622222222222777777777777733333");
198  checkit ("%f%s%d%s", 1.0, "foo", 77, "asdjffffffffffffffiiiiiiiiiiixxxxx");
199
200  return 0;
201}
202#endif /* TEST */
203