1 // Copyright 2012 Google Inc.
2 // All rights reserved.
3 //
4 // Redistribution and use in source and binary forms, with or without
5 // modification, are permitted provided that the following conditions are
6 // met:
7 //
8 // * Redistributions of source code must retain the above copyright
9 // notice, this list of conditions and the following disclaimer.
10 // * Redistributions in binary form must reproduce the above copyright
11 // notice, this list of conditions and the following disclaimer in the
12 // documentation and/or other materials provided with the distribution.
13 // * Neither the name of Google Inc. nor the names of its contributors
14 // may be used to endorse or promote products derived from this software
15 // without specific prior written permission.
16 //
17 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28
29 #include "text.h"
30
31 #include <assert.h>
32 #include <errno.h>
33 #include <stdarg.h>
34 #include <stdlib.h>
35 #include <stdio.h>
36
37 #include "error.h"
38
39
40 /// Calculates the length of a formatting string with its replacements.
41 ///
42 /// \param format The formatting string.
43 /// \param ap List of arguments to apply to the formatting string.
44 ///
45 /// \return -1 if there is an error; or the final length otherwise.
46 static int
calculate_length(const char * format,va_list ap)47 calculate_length(const char* format, va_list ap)
48 {
49 va_list ap2;
50
51 char buffer[1];
52 va_copy(ap2, ap);
53 const int needed = vsnprintf(buffer, sizeof(buffer), format, ap);
54 va_end(ap2);
55 return needed;
56 }
57
58
59 /// Generates a string from a format string and its replacements.
60 ///
61 /// \param [out] output Pointer to the dynamically-allocated string with the
62 /// result of the operation. The caller must release this with free().
63 /// \param format The formatting string.
64 /// \param ... Arguments to apply to the formatting string.
65 ///
66 /// \return OK if the string could be formatted; an error otherwise.
67 kyua_error_t
kyua_text_printf(char ** output,const char * format,...)68 kyua_text_printf(char** output, const char* format, ...)
69 {
70 kyua_error_t error;
71 va_list ap;
72
73 va_start(ap, format);
74 error = kyua_text_vprintf(output, format, ap);
75 va_end(ap);
76
77 return error;
78 }
79
80
81 /// Generates a string from a format string and its replacements.
82 ///
83 /// \param [out] output Pointer to the dynamically-allocated string with the
84 /// result of the operation. The caller must release this with free().
85 /// \param format The formatting string.
86 /// \param ap List of to apply to the formatting string.
87 ///
88 /// \return OK if the string could be formatted; an error otherwise.
89 kyua_error_t
kyua_text_vprintf(char ** output,const char * format,va_list ap)90 kyua_text_vprintf(char** output, const char* format, va_list ap)
91 {
92 va_list ap2;
93
94 va_copy(ap2, ap);
95 const int length = calculate_length(format, ap2);
96 va_end(ap2);
97 if (length < 0)
98 return kyua_libc_error_new(errno, "Could not calculate length of "
99 "string with format '%s'", format);
100
101 char* buffer = (char*)malloc(length + 1);
102 if (buffer == NULL)
103 return kyua_oom_error_new();
104
105 va_copy(ap2, ap);
106 const int printed_length = vsnprintf(buffer, length + 1, format, ap2);
107 va_end(ap2);
108 assert(printed_length == length);
109 if (printed_length < 0) {
110 free(buffer);
111 return kyua_libc_error_new(errno, "Could generate string with format "
112 "'%s'", format);
113 }
114
115 *output = buffer;
116 return kyua_error_ok();
117 }
118