1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
|
/* Machine-independant string function optimizations.
Copyright (C) 1997-2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#ifndef _STRING_H
# error "Never use <bits/string2.h> directly; include <string.h> instead."
#endif
#ifndef __NO_STRING_INLINES
/* Unlike the definitions in the header <bits/string.h> the
definitions contained here are not optimized down to assembler
level. Those optimizations are not always a good idea since this
means the code size increases a lot. Instead the definitions here
optimize some functions in a way which do not dramatically
increase the code size and which do not use assembler. The main
trick is to use GCC's `__builtin_constant_p' function.
Every function XXX which has a defined version in
<bits/string.h> must be accompanied by a symbol _HAVE_STRING_ARCH_XXX
to make sure we don't get redefinitions.
We must use here macros instead of inline functions since the
trick won't work with the latter. */
#ifndef __STRING_INLINE
# ifdef __cplusplus
# define __STRING_INLINE inline
# else
# define __STRING_INLINE __extern_inline
# endif
#endif
/* Dereferencing a pointer arg to run sizeof on it fails for the void
pointer case, so we use this instead.
Note that __x is evaluated twice. */
#define __string2_1bptr_p(__x) \
((size_t)(const void *)((__x) + 1) - (size_t)(const void *)(__x) == 1)
/* Set N bytes of S to 0. */
#if !defined _HAVE_STRING_ARCH_memset
# define __bzero(s, n) __builtin_memset (s, '\0', n)
#endif
/* Copy SRC to DEST, returning pointer to final NUL byte. */
#ifdef __USE_GNU
# ifndef _HAVE_STRING_ARCH_stpcpy
# define __stpcpy(dest, src) __builtin_stpcpy (dest, src)
/* In glibc we use this function frequently but for namespace reasons
we have to use the name `__stpcpy'. */
# define stpcpy(dest, src) __stpcpy (dest, src)
# endif
#endif
/* Copy no more than N characters of SRC to DEST. */
#ifndef _HAVE_STRING_ARCH_strncpy
# define strncpy(dest, src, n) __builtin_strncpy (dest, src, n)
#endif
/* Append no more than N characters from SRC onto DEST. */
#ifndef _HAVE_STRING_ARCH_strncat
# ifdef _USE_STRING_ARCH_strchr
# define strncat(dest, src, n) \
(__extension__ ({ char *__dest = (dest); \
__builtin_constant_p (src) && __builtin_constant_p (n) \
? (strlen (src) < ((size_t) (n)) \
? strcat (__dest, src) \
: (*((char *) __mempcpy (strchr (__dest, '\0'), \
src, n)) = '\0', __dest)) \
: strncat (dest, src, n); }))
# else
# define strncat(dest, src, n) __builtin_strncat (dest, src, n)
# endif
#endif
/* Return the length of the initial segment of S which
consists entirely of characters not in REJECT. */
#ifndef _HAVE_STRING_ARCH_strcspn
# define strcspn(s, reject) __builtin_strcspn (s, reject)
#endif
/* Return the length of the initial segment of S which
consists entirely of characters in ACCEPT. */
#ifndef _HAVE_STRING_ARCH_strspn
# define strspn(s, accept) __builtin_strspn (s, accept)
#endif
/* Find the first occurrence in S of any character in ACCEPT. */
#ifndef _HAVE_STRING_ARCH_strpbrk
# define strpbrk(s, accept) __builtin_strpbrk (s, accept)
#endif
/* We need the memory allocation functions for inline strdup().
Referring to stdlib.h (even minimally) is not allowed
in any of the tight standards compliant modes. */
#ifdef __USE_MISC
# if !defined _HAVE_STRING_ARCH_strdup || !defined _HAVE_STRING_ARCH_strndup
# define __need_malloc_and_calloc
# include <stdlib.h>
# endif
# ifndef _HAVE_STRING_ARCH_strdup
extern char *__strdup (const char *__string) __THROW __attribute_malloc__;
# define __strdup(s) \
(__extension__ (__builtin_constant_p (s) && __string2_1bptr_p (s) \
? (((const char *) (s))[0] == '\0' \
? (char *) calloc ((size_t) 1, (size_t) 1) \
: ({ size_t __len = strlen (s) + 1; \
char *__retval = (char *) malloc (__len); \
if (__retval != NULL) \
__retval = (char *) memcpy (__retval, s, __len); \
__retval; })) \
: __strdup (s)))
# if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
# define strdup(s) __strdup (s)
# endif
# endif
# ifndef _HAVE_STRING_ARCH_strndup
extern char *__strndup (const char *__string, size_t __n)
__THROW __attribute_malloc__;
# define __strndup(s, n) \
(__extension__ (__builtin_constant_p (s) && __string2_1bptr_p (s) \
? (((const char *) (s))[0] == '\0' \
? (char *) calloc ((size_t) 1, (size_t) 1) \
: ({ size_t __len = strlen (s) + 1; \
size_t __n = (n); \
char *__retval; \
if (__n < __len) \
__len = __n + 1; \
__retval = (char *) malloc (__len); \
if (__retval != NULL) \
{ \
__retval[__len - 1] = '\0'; \
__retval = (char *) memcpy (__retval, s, \
__len - 1); \
} \
__retval; })) \
: __strndup (s, n)))
# ifdef __USE_XOPEN2K8
# define strndup(s, n) __strndup (s, n)
# endif
# endif
#endif /* Use misc. or use GNU. */
#ifndef _FORCE_INLINES
# undef __STRING_INLINE
#endif
#endif /* No string inlines. */
|
