AuroraMiddleware/glibc
1
0
Fork 0
mirror of https://sourceware.org/git/glibc.git synced 2024-11-26 06:50:07 +00:00
Code Issues Packages Projects Releases Wiki Activity
14348aaeff
glibc/string/bits/string2.h
Zack Weinberg 9601d3ad78 Fix typo in string/bits/string2.h. 
The comment above the bzero() macro in this file appears to have been
copied verbatim from the comment above the memset() prototype in
string.h proper.  bzero() has no 'c' argument and can only set memory
contents to 0.  (The comment above the prototype of bzero() in
string.h proper does not make the same mistake.)

	* string/bits/string2.h: Fix typo in comment.
2016-11-14 12:35:10 -05:00

376 lines
12 KiB
C
Raw Blame History

/* Machine-independant string function optimizations.
Copyright (C) 1997-2016 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
#ifndef _HAVE_STRING_ARCH_strchr
extern void *__rawmemchr (const void *__s, int __c);
# define strchr(s, c) \
(__extension__ (__builtin_constant_p (c) && !__builtin_constant_p (s) \
&& (c) == '\0' \
? (char *) __rawmemchr (s, c) \
: __builtin_strchr (s, c)))
#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
/* Compare characters of S1 and S2. */
#ifndef _HAVE_STRING_ARCH_strcmp
# define strcmp(s1, s2) \
__extension__ \
({ size_t __s1_len, __s2_len; \
(__builtin_constant_p (s1) && __builtin_constant_p (s2) \
&& (__s1_len = strlen (s1), __s2_len = strlen (s2), \
(!__string2_1bptr_p (s1) || __s1_len >= 4) \
&& (!__string2_1bptr_p (s2) || __s2_len >= 4)) \
? __builtin_strcmp (s1, s2) \
: (__builtin_constant_p (s1) && __string2_1bptr_p (s1) \
&& (__s1_len = strlen (s1), __s1_len < 4) \
? (__builtin_constant_p (s2) && __string2_1bptr_p (s2) \
? __builtin_strcmp (s1, s2) \
: __strcmp_cg (s1, s2, __s1_len)) \
: (__builtin_constant_p (s2) && __string2_1bptr_p (s2) \
&& (__s2_len = strlen (s2), __s2_len < 4) \
? (__builtin_constant_p (s1) && __string2_1bptr_p (s1) \
? __builtin_strcmp (s1, s2) \
: -__strcmp_cg (s2, s1, __s2_len)) \
: __builtin_strcmp (s1, s2)))); })
# define __strcmp_cg(s1, s2, l1) \
(__extension__ ({ const unsigned char *__s2 = \
(const unsigned char *) (const char *) (s2); \
int __result = \
(((const unsigned char *) (const char *) (s1))[0] \
- __s2[0]); \
if (l1 > 0 && __result == 0) \
{ \
__result = (((const unsigned char *) \
(const char *) (s1))[1] - __s2[1]); \
if (l1 > 1 && __result == 0) \
{ \
__result = (((const unsigned char *) \
(const char *) (s1))[2] - __s2[2]); \
if (l1 > 2 && __result == 0) \
__result = (((const unsigned char *) \
(const char *) (s1))[3] \
- __s2[3]); \
} \
} \
__result; }))
#endif
/* Compare N characters of S1 and S2. */
#ifndef _HAVE_STRING_ARCH_strncmp
# define strncmp(s1, s2, n) \
(__extension__ (__builtin_constant_p (n) \
&& ((__builtin_constant_p (s1) \
&& strlen (s1) < ((size_t) (n))) \
|| (__builtin_constant_p (s2) \
&& strlen (s2) < ((size_t) (n)))) \
? strcmp (s1, s2) : strncmp (s1, s2, n)))
#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
#if !defined _HAVE_STRING_ARCH_strtok_r || defined _FORCE_INLINES
# ifndef _HAVE_STRING_ARCH_strtok_r
# define __strtok_r(s, sep, nextp) \
(__extension__ (__builtin_constant_p (sep) && __string2_1bptr_p (sep) \
&& ((const char *) (sep))[0] != '\0' \
&& ((const char *) (sep))[1] == '\0' \
? __strtok_r_1c (s, ((const char *) (sep))[0], nextp) \
: __strtok_r (s, sep, nextp)))
# endif
__STRING_INLINE char *__strtok_r_1c (char *__s, char __sep, char **__nextp);
__STRING_INLINE char *
__strtok_r_1c (char *__s, char __sep, char **__nextp)
{
char *__result;
if (__s == NULL)
__s = *__nextp;
while (*__s == __sep)
++__s;
__result = NULL;
if (*__s != '\0')
{
__result = __s++;
while (*__s != '\0')
if (*__s++ == __sep)
{
__s[-1] = '\0';
break;
}
}
*__nextp = __s;
return __result;
}
# ifdef __USE_POSIX
# define strtok_r(s, sep, nextp) __strtok_r (s, sep, nextp)
# endif
#endif
#if !defined _HAVE_STRING_ARCH_strsep || defined _FORCE_INLINES
# ifndef _HAVE_STRING_ARCH_strsep
extern char *__strsep_g (char **__stringp, const char *__delim);
# define __strsep(s, reject) \
__extension__ \
({ char __r0, __r1, __r2; \
(__builtin_constant_p (reject) && __string2_1bptr_p (reject) \
&& (__r0 = ((const char *) (reject))[0], \
((const char *) (reject))[0] != '\0') \
? ((__r1 = ((const char *) (reject))[1], \
((const char *) (reject))[1] == '\0') \
? __strsep_1c (s, __r0) \
: ((__r2 = ((const char *) (reject))[2], __r2 == '\0') \
? __strsep_2c (s, __r0, __r1) \
: (((const char *) (reject))[3] == '\0' \
? __strsep_3c (s, __r0, __r1, __r2) \
: __strsep_g (s, reject)))) \
: __strsep_g (s, reject)); })
# endif
__STRING_INLINE char *__strsep_1c (char **__s, char __reject);
__STRING_INLINE char *
__strsep_1c (char **__s, char __reject)
{
char *__retval = *__s;
if (__retval != NULL && (*__s = strchr (__retval, __reject)) != NULL)
*(*__s)++ = '\0';
return __retval;
}
__STRING_INLINE char *__strsep_2c (char **__s, char __reject1, char __reject2);
__STRING_INLINE char *
__strsep_2c (char **__s, char __reject1, char __reject2)
{
char *__retval = *__s;
if (__retval != NULL)
{
char *__cp = __retval;
while (1)
{
if (*__cp == '\0')
{
__cp = NULL;
break;
}
if (*__cp == __reject1 || *__cp == __reject2)
{
*__cp++ = '\0';
break;
}
++__cp;
}
*__s = __cp;
}
return __retval;
}
__STRING_INLINE char *__strsep_3c (char **__s, char __reject1, char __reject2,
char __reject3);
__STRING_INLINE char *
__strsep_3c (char **__s, char __reject1, char __reject2, char __reject3)
{
char *__retval = *__s;
if (__retval != NULL)
{
char *__cp = __retval;
while (1)
{
if (*__cp == '\0')
{
__cp = NULL;
break;
}
if (*__cp == __reject1 || *__cp == __reject2 || *__cp == __reject3)
{
*__cp++ = '\0';
break;
}
++__cp;
}
*__s = __cp;
}
return __retval;
}
# ifdef __USE_MISC
# define strsep(s, reject) __strsep (s, reject)
# endif
#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. */
Reference in New Issue View Git Blame Copy Permalink