1 /* Estimate the length of the string generated by a vprintf-like
2 function. Used by vasprintf and xvasprintf.
3 Copyright (C) 1994-2020 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 #include "vprintf-support.h"
40
41 int
libiberty_vprintf_buffer_size(const char * format,va_list args)42 libiberty_vprintf_buffer_size (const char *format, va_list args)
43 {
44 const char *p = format;
45 /* Add one to make sure that it is never zero, which might cause malloc
46 to return NULL. */
47 int total_width = strlen (format) + 1;
48 va_list ap;
49
50 #ifdef va_copy
51 va_copy (ap, args);
52 #else
53 memcpy ((PTR) &ap, (PTR) &args, sizeof (va_list));
54 #endif
55
56 while (*p != '\0')
57 {
58 if (*p++ == '%')
59 {
60 while (strchr ("-+ #0", *p))
61 ++p;
62 if (*p == '*')
63 {
64 ++p;
65 total_width += abs (va_arg (ap, int));
66 }
67 else
68 total_width += strtoul (p, (char **) &p, 10);
69 if (*p == '.')
70 {
71 ++p;
72 if (*p == '*')
73 {
74 ++p;
75 total_width += abs (va_arg (ap, int));
76 }
77 else
78 total_width += strtoul (p, (char **) &p, 10);
79 }
80 while (strchr ("hlL", *p))
81 ++p;
82 /* Should be big enough for any format specifier except %s and floats. */
83 total_width += 30;
84 switch (*p)
85 {
86 case 'd':
87 case 'i':
88 case 'o':
89 case 'u':
90 case 'x':
91 case 'X':
92 case 'c':
93 (void) va_arg (ap, int);
94 break;
95 case 'f':
96 case 'e':
97 case 'E':
98 case 'g':
99 case 'G':
100 (void) va_arg (ap, double);
101 /* Since an ieee double can have an exponent of 307, we'll
102 make the buffer wide enough to cover the gross case. */
103 total_width += 307;
104 break;
105 case 's':
106 total_width += strlen (va_arg (ap, char *));
107 break;
108 case 'p':
109 case 'n':
110 (void) va_arg (ap, char *);
111 break;
112 }
113 p++;
114 }
115 }
116 #ifdef va_copy
117 va_end (ap);
118 #endif
119 return total_width;
120 }
121