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 
40 int
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 ((PTR) &ap, (PTR) &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