1 /* Estimate the length of the string generated by a vprintf-like
2 function. Used by vasprintf and xvasprintf.
3 Copyright (C) 1994-2024 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 not, write
18 to the Free Software Foundation, Inc., 51 Franklin Street - Fifth
19 Floor, 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 #endif
38 #include "libiberty.h"
39
40 int
libiberty_vprintf_buffer_size(const char * format,va_list args)41 libiberty_vprintf_buffer_size (const char *format, va_list args)
42 {
43 const char *p = format;
44 /* Add one to make sure that it is never zero, which might cause malloc
45 to return NULL. */
46 int total_width = strlen (format) + 1;
47 va_list ap;
48
49 #ifdef va_copy
50 va_copy (ap, args);
51 #else
52 memcpy ((void *) &ap, (void *) &args, sizeof (va_list));
53 #endif
54
55 while (*p != '\0')
56 {
57 if (*p++ == '%')
58 {
59 while (strchr ("-+ #0", *p))
60 ++p;
61 if (*p == '*')
62 {
63 ++p;
64 total_width += abs (va_arg (ap, int));
65 }
66 else
67 total_width += strtoul (p, (char **) &p, 10);
68 if (*p == '.')
69 {
70 ++p;
71 if (*p == '*')
72 {
73 ++p;
74 total_width += abs (va_arg (ap, int));
75 }
76 else
77 total_width += strtoul (p, (char **) &p, 10);
78 }
79 while (strchr ("hlL", *p))
80 ++p;
81 /* Should be big enough for any format specifier except %s and floats. */
82 total_width += 30;
83 switch (*p)
84 {
85 case 'd':
86 case 'i':
87 case 'o':
88 case 'u':
89 case 'x':
90 case 'X':
91 case 'c':
92 (void) va_arg (ap, int);
93 break;
94 case 'f':
95 case 'e':
96 case 'E':
97 case 'g':
98 case 'G':
99 (void) va_arg (ap, double);
100 /* Since an ieee double can have an exponent of 307, we'll
101 make the buffer wide enough to cover the gross case. */
102 total_width += 307;
103 break;
104 case 's':
105 total_width += strlen (va_arg (ap, char *));
106 break;
107 case 'p':
108 case 'n':
109 (void) va_arg (ap, char *);
110 break;
111 }
112 p++;
113 }
114 }
115 #ifdef va_copy
116 va_end (ap);
117 #endif
118 return total_width;
119 }
120