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- /* 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
- #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
- /* 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. */
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