Always evaluate BT_ASSERT(); add BT_ASSERT_DBG() for debug mode only
[babeltrace.git] / src / compat / stdio.h
1 #ifndef _BABELTRACE_COMPAT_STDIO_H
2 #define _BABELTRACE_COMPAT_STDIO_H
3
4 /*
5 * Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23 * SOFTWARE.
24 */
25
26 #include <stdio.h>
27 #include <errno.h>
28 #include <stdlib.h>
29 #include <limits.h>
30 #include "common/assert.h"
31
32 #define BT_GETLINE_MINBUFLEN 64
33
34 static inline
35 char * _bt_getline_bufalloc(char **lineptr, size_t *n, size_t linelen)
36 {
37 size_t buflen = *n;
38 char *buf = *lineptr;
39
40 if (buflen >= linelen && buf) {
41 return buf;
42 }
43 if (!buf) {
44 buflen = BT_GETLINE_MINBUFLEN;
45 } else {
46 buflen = buflen << 1;
47 if (buflen < BT_GETLINE_MINBUFLEN) {
48 buflen = BT_GETLINE_MINBUFLEN;
49 }
50 }
51 /* Check below not strictly needed, extra safety. */
52 if (buflen < linelen) {
53 buflen = linelen;
54 }
55 buf = realloc(buf, buflen);
56 if (!buf) {
57 errno = ENOMEM;
58 return NULL;
59 }
60 *n = buflen;
61 *lineptr = buf;
62 return buf;
63 }
64
65 /*
66 * Returns line length (including possible final \n, excluding final
67 * \0). On end of file, returns -1 with nonzero feof(stream) and errno
68 * set to 0. On error, returns -1 with errno set.
69 *
70 * This interface is similar to the getline(3) man page part of the
71 * Linux man-pages project, release 3.74. One major difference from the
72 * Open Group POSIX specification is that this implementation does not
73 * necessarily set the ferror() flag on error (because it is internal to
74 * libc).
75 */
76 static inline
77 ssize_t bt_getline(char **lineptr, size_t *n, FILE *stream)
78 {
79 size_t linelen = 0;
80 char *buf;
81 int found_eof = 0;
82
83 if (!lineptr || !n) {
84 errno = EINVAL;
85 return -1;
86 }
87 for (;;) {
88 char c;
89 int ret;
90
91 ret = fgetc(stream);
92 if (ret == EOF) {
93 if (ferror(stream)) {
94 /* ferror() is set, errno set by fgetc(). */
95 return -1;
96 }
97 BT_ASSERT_DBG(feof(stream));
98 found_eof = 1;
99 break;
100 }
101 c = (char) ret;
102 if (linelen == SSIZE_MAX) {
103 errno = EOVERFLOW;
104 return -1;
105 }
106 buf = _bt_getline_bufalloc(lineptr, n, ++linelen);
107 if (!buf) {
108 return -1;
109 }
110 buf[linelen - 1] = c;
111 if (c == '\n') {
112 break;
113 }
114 }
115 if (!linelen && found_eof) {
116 /* feof() is set. */
117 errno = 0;
118 return -1;
119 }
120 buf = _bt_getline_bufalloc(lineptr, n, ++linelen);
121 if (!buf) {
122 return -1;
123 }
124 buf[linelen - 1] = '\0';
125 return linelen - 1; /* Count don't include final \0. */
126 }
127
128 #endif /* _BABELTRACE_COMPAT_STDIO_H */
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