/* 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 , 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 . */ #ifndef _STRING_H # error "Never use directly; include instead." #endif #ifndef __NO_STRING_INLINES /* Unlike the definitions in the header 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 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_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 # 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. */