1 //
2 // Copyright 2020 Serge Martin
3 //
4 // Permission is hereby granted, free of charge, to any person obtaining a
5 // copy of this software and associated documentation files (the "Software"),
6 // to deal in the Software without restriction, including without limitation
7 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 // and/or sell copies of the Software, and to permit persons to whom the
9 // Software is furnished to do so, subject to the following conditions:
10 //
11 // The above copyright notice and this permission notice shall be included in
12 // all copies or substantial portions of the Software.
13 //
14 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
17 // THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
18 // OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19 // ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20 // OTHER DEALINGS IN THE SOFTWARE.
21 //
22 // Extract from Serge's printf clover code by airlied.
23
24 #include <assert.h>
25 #include <stdarg.h>
26 #include <string.h>
27
28 #include "macros.h"
29 #include "u_printf.h"
30
31 /* Some versions of MinGW are missing _vscprintf's declaration, although they
32 * still provide the symbol in the import library. */
33 #ifdef __MINGW32__
34 _CRTIMP int _vscprintf(const char *format, va_list argptr);
35 #endif
36
37 #ifndef va_copy
38 #ifdef __va_copy
39 #define va_copy(dest, src) __va_copy((dest), (src))
40 #else
41 #define va_copy(dest, src) (dest) = (src)
42 #endif
43 #endif
44
util_printf_next_spec_pos(const char * str,size_t pos)45 size_t util_printf_next_spec_pos(const char *str, size_t pos)
46 {
47 if (str == NULL)
48 return -1;
49
50 const char *str_found = str + pos;
51 do {
52 str_found = strchr(str_found, '%');
53 if (str_found == NULL)
54 return -1;
55
56 ++str_found;
57 if (*str_found == '%') {
58 ++str_found;
59 continue;
60 }
61
62 char *spec_pos = strpbrk(str_found, "cdieEfFgGaAosuxXp%");
63 if (spec_pos == NULL) {
64 return -1;
65 } else if (*spec_pos == '%') {
66 str_found = spec_pos;
67 } else {
68 return spec_pos - str;
69 }
70 } while (1);
71 }
72
u_printf_length(const char * fmt,va_list untouched_args)73 size_t u_printf_length(const char *fmt, va_list untouched_args)
74 {
75 int size;
76 char junk;
77
78 /* Make a copy of the va_list so the original caller can still use it */
79 va_list args;
80 va_copy(args, untouched_args);
81
82 #ifdef _WIN32
83 /* We need to use _vcsprintf to calculate the size as vsnprintf returns -1
84 * if the number of characters to write is greater than count.
85 */
86 size = _vscprintf(fmt, args);
87 (void)junk;
88 #else
89 size = vsnprintf(&junk, 1, fmt, args);
90 #endif
91 assert(size >= 0);
92
93 va_end(args);
94
95 return size;
96 }
97