libc/include/string.h

/*
 * Copyright (C) 2008 The Android Open Source Project
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
#ifndef _STRING_H_
#define _STRING_H_

#include <sys/cdefs.h>
#include <stddef.h>
#include <malloc.h>

__BEGIN_DECLS

extern void*  memccpy(void *, const void *, int, size_t);
extern void*  memchr(const void *, int, size_t) __purefunc;
extern void*  memrchr(const void *, int, size_t) __purefunc;
extern int    memcmp(const void *, const void *, size_t) __purefunc;
extern void*  memcpy(void *, const void *, size_t);
extern void*  memmove(void *, const void *, size_t);
extern void*  memset(void *, int, size_t);
extern void*  memmem(const void *, size_t, const void *, size_t) __purefunc;
extern void   memswap(void *, void *, size_t);

extern char*  index(const char *, int) __purefunc;
extern char*  rindex(const char *, int) __purefunc;
extern char*  strchr(const char *, int) __purefunc;
extern char*  strrchr(const char *, int) __purefunc;

extern size_t strlen(const char *) __purefunc;
extern int    strcmp(const char *, const char *) __purefunc;
extern char*  strcpy(char *, const char *);
extern char*  strcat(char *, const char *);

extern int    strcasecmp(const char *, const char *) __purefunc;
extern int    strncasecmp(const char *, const char *, size_t) __purefunc;
extern char*  strdup(const char *);

extern char*  strstr(const char *, const char *) __purefunc;
extern char*  strcasestr(const char *haystack, const char *needle) __purefunc;
extern char*  strtok(char *, const char *);
extern char*  strtok_r(char *, const char *, char**);

extern char*  strerror(int);
extern int    strerror_r(int errnum, char *buf, size_t n);

extern size_t strnlen(const char *, size_t) __purefunc;
extern char*  strncat(char *, const char *, size_t);
extern char*  strndup(const char *, size_t);
extern int    strncmp(const char *, const char *, size_t) __purefunc;
extern char*  strncpy(char *, const char *, size_t);

extern size_t strlcat(char *, const char *, size_t);
extern size_t strlcpy(char *, const char *, size_t);

extern size_t strcspn(const char *, const char *) __purefunc;
extern char*  strpbrk(const char *, const char *) __purefunc;
extern char*  strsep(char **, const char *);
extern size_t strspn(const char *, const char *);

extern char*  strsignal(int  sig);

extern int    strcoll(const char *, const char *) __purefunc;
extern size_t strxfrm(char *, const char *, size_t);

#if defined(__BIONIC_FORTIFY_INLINE)

extern void __memcpy_dest_size_error()
    __attribute__((__error__("memcpy called with size bigger than destination")));
extern void __memcpy_src_size_error()
    __attribute__((__error__("memcpy called with size bigger than source")));
extern void __memcpy_overlap_error()
    __attribute__((__error__("memcpy called with overlapping regions")));

__BIONIC_FORTIFY_INLINE
void *memcpy (void *dest, const void *src, size_t copy_amount) {
    char *d = (char *) dest;
    const char *s = (const char *) src;
    size_t s_len = __builtin_object_size(s, 0);
    size_t d_len = __builtin_object_size(d, 0);

    if (__builtin_constant_p(copy_amount) && (copy_amount > d_len)) {
        __memcpy_dest_size_error();
    }

    if (__builtin_constant_p(copy_amount) && (copy_amount > s_len)) {
        __memcpy_src_size_error();
    }

    if (__builtin_constant_p(d - s) && __builtin_constant_p(copy_amount)
            && (((size_t)(d - s) < copy_amount) || ((size_t)(s - d) < copy_amount))) {
        __memcpy_overlap_error();
    }

    return __builtin___memcpy_chk(dest, src, copy_amount, d_len);
}

__BIONIC_FORTIFY_INLINE
void *memmove (void *dest, const void *src, size_t len) {
    return __builtin___memmove_chk(dest, src, len, __builtin_object_size (dest, 0));
}

__BIONIC_FORTIFY_INLINE
char *strcpy(char *dest, const char *src) {
    return __builtin___strcpy_chk(dest, src, __builtin_object_size (dest, 0));
}

__BIONIC_FORTIFY_INLINE
char *strncpy(char *dest, const char *src, size_t n) {
    return __builtin___strncpy_chk(dest, src, n, __builtin_object_size (dest, 0));
}

__BIONIC_FORTIFY_INLINE
char *strcat(char *dest, const char *src) {
    return __builtin___strcat_chk(dest, src, __builtin_object_size (dest, 0));
}

__BIONIC_FORTIFY_INLINE
char *strncat(char *dest, const char *src, size_t n) {
    return __builtin___strncat_chk(dest, src, n, __builtin_object_size (dest, 0));
}

__BIONIC_FORTIFY_INLINE
void *memset (void *s, int c, size_t n) {
    return __builtin___memset_chk(s, c, n, __builtin_object_size (s, 0));
}

extern size_t __strlcpy_real(char *, const char *, size_t)
    __asm__(__USER_LABEL_PREFIX__ "strlcpy");
extern void __strlcpy_error()
    __attribute__((__error__("strlcpy called with size bigger than buffer")));
extern size_t __strlcpy_chk(char *, const char *, size_t, size_t);

__BIONIC_FORTIFY_INLINE
size_t strlcpy(char *dest, const char *src, size_t size) {
    size_t bos = __builtin_object_size(dest, 0);

    // Compiler doesn't know destination size. Don't call __strlcpy_chk
    if (bos == __BIONIC_FORTIFY_UNKNOWN_SIZE) {
        return __strlcpy_real(dest, src, size);
    }

    // Compiler can prove, at compile time, that the passed in size
    // is always <= the actual object size. Don't call __strlcpy_chk
    if (__builtin_constant_p(size) && (size <= bos)) {
        return __strlcpy_real(dest, src, size);
    }

    // Compiler can prove, at compile time, that the passed in size
    // is always > the actual object size. Force a compiler error.
    if (__builtin_constant_p(size) && (size > bos)) {
        __strlcpy_error();
    }

    return __strlcpy_chk(dest, src, size, bos);
}

extern size_t __strlcat_real(char *, const char *, size_t)
    __asm__(__USER_LABEL_PREFIX__ "strlcat");
extern void __strlcat_error()
    __attribute__((__error__("strlcat called with size bigger than buffer")));
extern size_t __strlcat_chk(char *, const char *, size_t, size_t);


__BIONIC_FORTIFY_INLINE
size_t strlcat(char *dest, const char *src, size_t size) {
    size_t bos = __builtin_object_size(dest, 0);

    // Compiler doesn't know destination size. Don't call __strlcat_chk
    if (bos == __BIONIC_FORTIFY_UNKNOWN_SIZE) {
        return __strlcat_real(dest, src, size);
    }

    // Compiler can prove, at compile time, that the passed in size
    // is always <= the actual object size. Don't call __strlcat_chk
    if (__builtin_constant_p(size) && (size <= bos)) {
        return __strlcat_real(dest, src, size);
    }

    // Compiler can prove, at compile time, that the passed in size
    // is always > the actual object size. Force a compiler error.
    if (__builtin_constant_p(size) && (size > bos)) {
        __strlcat_error();
    }

    return __strlcat_chk(dest, src, size, bos);
}

__purefunc extern size_t __strlen_real(const char *)
    __asm__(__USER_LABEL_PREFIX__ "strlen");
extern size_t __strlen_chk(const char *, size_t);

__BIONIC_FORTIFY_INLINE
size_t strlen(const char *s) {
    size_t bos = __builtin_object_size(s, 0);

    // Compiler doesn't know destination size. Don't call __strlen_chk
    if (bos == __BIONIC_FORTIFY_UNKNOWN_SIZE) {
        return __strlen_real(s);
    }

    return __strlen_chk(s, bos);
}

__purefunc extern char* __strchr_real(const char *, int)
    __asm__(__USER_LABEL_PREFIX__ "strchr");
extern char* __strchr_chk(const char *, int, size_t);

__BIONIC_FORTIFY_INLINE
char* strchr(const char *s, int c) {
    size_t bos = __builtin_object_size(s, 0);

    // Compiler doesn't know destination size. Don't call __strchr_chk
    if (bos == __BIONIC_FORTIFY_UNKNOWN_SIZE) {
        return __strchr_real(s, c);
    }

    return __strchr_chk(s, c, bos);
}

__purefunc extern char* __strrchr_real(const char *, int)
    __asm__(__USER_LABEL_PREFIX__ "strrchr");
extern char* __strrchr_chk(const char *, int, size_t);

__BIONIC_FORTIFY_INLINE
char* strrchr(const char *s, int c) {
    size_t bos = __builtin_object_size(s, 0);

    // Compiler doesn't know destination size. Don't call __strrchr_chk
    if (bos == __BIONIC_FORTIFY_UNKNOWN_SIZE) {
        return __strrchr_real(s, c);
    }

    return __strrchr_chk(s, c, bos);
}


#endif /* defined(__BIONIC_FORTIFY_INLINE) */

__END_DECLS

#endif /* _STRING_H_ */