memcheck/mc_replace_strmem.c

/*--------------------------------------------------------------------*/
/*--- Replacements for strcpy(), memcpy() et al, which run on the  ---*/
/*--- simulated CPU.                                               ---*/
/*---                                          mc_replace_strmem.c ---*/
/*--------------------------------------------------------------------*/

/*
   This file is part of MemCheck, a heavyweight Valgrind tool for
   detecting memory errors.

   Copyright (C) 2000-2010 Julian Seward 
      jseward@acm.org

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   This program 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
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307, USA.

   The GNU General Public License is contained in the file COPYING.
*/

#include "pub_tool_basics.h"
#include "pub_tool_hashtable.h"
#include "pub_tool_redir.h"
#include "pub_tool_tooliface.h"
#include "valgrind.h"

#include "mc_include.h"
#include "memcheck.h"

/* ---------------------------------------------------------------------
   We have our own versions of these functions for two reasons:
   (a) it allows us to do overlap checking
   (b) some of the normal versions are hyper-optimised, which fools
       Memcheck and cause spurious value warnings.  Our versions are
       simpler.

   Note that overenthusiastic use of PLT bypassing by the glibc people also
   means that we need to patch multiple versions of some of the functions to
   our own implementations.

   THEY RUN ON THE SIMD CPU!
   ------------------------------------------------------------------ */

/* Assignment of behavioural equivalence class tags: 2NNNP is intended
   to be reserved for Memcheck.  Current usage:

   20010 STRRCHR
   20020 STRCHR
   20030 STRCAT
   20040 STRNCAT
   20050 STRLCAT
   20060 STRNLEN
   20070 STRLEN
   20080 STRCPY
   20090 STRNCPY
   20100 STRLCPY
   20110 STRNCMP
   20120 STRCASECMP
   20130 STRNCASECMP
   20140 STRCASECMP_L
   20150 STRNCASECMP_L
   20160 STRCMP
   20170 MEMCHR

   20180 MEMCPY    if there's a conflict between memcpy and
   20181 MEMMOVE   memmove, prefer memmove

   20190 MEMCMP
   20200 STPCPY
   20210 MEMSET
   2022P unused (was previously MEMMOVE)
   20230 BCOPY
   20240 GLIBC25___MEMMOVE_CHK
   20250 GLIBC232_STRCHRNUL
   20260 GLIBC232_RAWMEMCHR
   20270 GLIBC25___STRCPY_CHK
   20280 GLIBC25___STPCPY_CHK
   20290 GLIBC25_MEMPCPY
   20300 GLIBC26___MEMCPY_CHK
   20310 STRSTR
   20320 STRPBRK
   20330 STRCSPN
   20340 STRSPN
*/


/* Figure out if [dst .. dst+dstlen-1] overlaps with 
                 [src .. src+srclen-1].
   We assume that the address ranges do not wrap around
   (which is safe since on Linux addresses >= 0xC0000000
   are not accessible and the program will segfault in this
   circumstance, presumably).
*/
static inline
Bool is_overlap ( void* dst, const void* src, SizeT dstlen, SizeT srclen )
{
   Addr loS, hiS, loD, hiD;

   if (dstlen == 0 || srclen == 0)
      return False;

   loS = (Addr)src;
   loD = (Addr)dst;
   hiS = loS + srclen - 1;
   hiD = loD + dstlen - 1;

   /* So figure out if [loS .. hiS] overlaps with [loD .. hiD]. */
   if (loS < loD) {
      return !(hiS < loD);
   }
   else if (loD < loS) {
      return !(hiD < loS);
   }
   else { 
      /* They start at same place.  Since we know neither of them has
         zero length, they must overlap. */
      return True;
   }
}


/* Call here to exit if we can't continue.  On Android we can't call
   _exit for some reason, so we have to blunt-instrument it. */
__attribute__ ((__noreturn__))
static inline void my_exit ( int x )
{
#  if defined(VGPV_arm_linux_android)
   __asm__ __volatile__(".word 0xFFFFFFFF");
   while (1) {}
#  else
   extern void _exit(int status);
   _exit(x);
#  endif
}


// This is a macro rather than a function because we don't want to have an
// extra function in the stack trace.
#define RECORD_OVERLAP_ERROR(s, src, dst, len)                  \
  VALGRIND_DO_CLIENT_REQUEST_EXPR(0,                            \
                  _VG_USERREQ__MEMCHECK_RECORD_OVERLAP_ERROR,   \
                  s, src, dst, len, 0)


/*---------------------- strrchr ----------------------*/

#define STRRCHR(soname, fnname) \
   char* VG_REPLACE_FUNCTION_EZU(20010,soname,fnname)( const char* s, int c ); \
   char* VG_REPLACE_FUNCTION_EZU(20010,soname,fnname)( const char* s, int c ) \
   { \
      UChar  ch   = (UChar)((UInt)c); \
      UChar* p    = (UChar*)s; \
      UChar* last = NULL; \
      while (True) { \
         if (*p == ch) last = p; \
         if (*p == 0) return last; \
         p++; \
      } \
   }

// Apparently rindex() is the same thing as strrchr()
#if defined(VGO_linux)
 STRRCHR(VG_Z_LIBC_SONAME,   strrchr)
 STRRCHR(VG_Z_LIBC_SONAME,   rindex)
 STRRCHR(VG_Z_LIBC_SONAME,   __GI_strrchr)
 STRRCHR(VG_Z_LD_LINUX_SO_2, rindex)

#elif defined(VGO_darwin)
 STRRCHR(VG_Z_LIBC_SONAME,   strrchr)
 STRRCHR(VG_Z_LIBC_SONAME,   rindex)
 STRRCHR(VG_Z_DYLD,          strrchr)
 STRRCHR(VG_Z_DYLD,          rindex)

#endif
   

/*---------------------- strchr ----------------------*/

#define STRCHR(soname, fnname) \
   char* VG_REPLACE_FUNCTION_EZU(20020,soname,fnname) ( const char* s, int c ); \
   char* VG_REPLACE_FUNCTION_EZU(20020,soname,fnname) ( const char* s, int c ) \
   { \
      UChar  ch = (UChar)((UInt)c); \
      UChar* p  = (UChar*)s; \
      while (True) { \
         if (*p == ch) return p; \
         if (*p == 0) return NULL; \
         p++; \
      } \
   }

// Apparently index() is the same thing as strchr()
#if defined(VGO_linux)
 STRCHR(VG_Z_LIBC_SONAME,          strchr)
 STRCHR(VG_Z_LIBC_SONAME,          index)
 STRCHR(VG_Z_LIBC_SONAME,          __GI_strchr)
# if !defined(VGP_x86_linux)
  STRCHR(VG_Z_LD_LINUX_SO_2,        strchr)
  STRCHR(VG_Z_LD_LINUX_SO_2,        index)
  STRCHR(VG_Z_LD_LINUX_X86_64_SO_2, strchr)
  STRCHR(VG_Z_LD_LINUX_X86_64_SO_2, index)
# endif

#elif defined(VGO_darwin)
 STRCHR(VG_Z_LIBC_SONAME,          strchr)
 STRCHR(VG_Z_LIBC_SONAME,          index)
 STRCHR(VG_Z_DYLD,                 strchr)
 STRCHR(VG_Z_DYLD,                 index)

#endif


/*---------------------- strcat ----------------------*/

#define STRCAT(soname, fnname) \
   char* VG_REPLACE_FUNCTION_EZU(20030,soname,fnname) \
            ( char* dst, const char* src ); \
   char* VG_REPLACE_FUNCTION_EZU(20030,soname,fnname) \
            ( char* dst, const char* src ) \
   { \
      const Char* src_orig = src; \
            Char* dst_orig = dst; \
      while (*dst) dst++; \
      while (*src) *dst++ = *src++; \
      *dst = 0; \
      \
      /* This is a bit redundant, I think;  any overlap and the strcat will */ \
      /* go forever... or until a seg fault occurs. */ \
      if (is_overlap(dst_orig,  \
                     src_orig,  \
                     (Addr)dst-(Addr)dst_orig+1,  \
                     (Addr)src-(Addr)src_orig+1)) \
         RECORD_OVERLAP_ERROR("strcat", dst_orig, src_orig, 0); \
      \
      return dst_orig; \
   }

#if defined(VGO_linux)
 STRCAT(VG_Z_LIBC_SONAME, strcat)
 STRCAT(VG_Z_LIBC_SONAME, __GI_strcat)

#elif defined(VGO_darwin)
 STRCAT(VG_Z_LIBC_SONAME, strcat)

#endif


/*---------------------- strncat ----------------------*/

#define STRNCAT(soname, fnname) \
   char* VG_REPLACE_FUNCTION_EZU(20040,soname,fnname) \
            ( char* dst, const char* src, SizeT n ); \
   char* VG_REPLACE_FUNCTION_EZU(20040,soname,fnname) \
            ( char* dst, const char* src, SizeT n ) \
   { \
      const Char* src_orig = src; \
            Char* dst_orig = dst; \
      SizeT m = 0; \
      \
      while (*dst) dst++; \
      while (m < n && *src) { m++; *dst++ = *src++; } /* concat <= n chars */ \
      *dst = 0;                                       /* always add null   */ \
      \
      /* This checks for overlap after copying, unavoidable without */ \
      /* pre-counting lengths... should be ok */ \
      if (is_overlap(dst_orig,  \
                     src_orig,  \
                     (Addr)dst-(Addr)dst_orig+1, \
                     (Addr)src-(Addr)src_orig+1)) \
         RECORD_OVERLAP_ERROR("strncat", dst_orig, src_orig, n); \
      \
      return dst_orig; \
   }

#if defined(VGO_linux)
 STRNCAT(VG_Z_LIBC_SONAME, strncat)

#elif defined(VGO_darwin)
 STRNCAT(VG_Z_LIBC_SONAME, strncat)
 STRNCAT(VG_Z_DYLD,        strncat)

#endif


/*---------------------- strlcat ----------------------*/

/* Append src to dst. n is the size of dst's buffer. dst is guaranteed 
   to be nul-terminated after the copy, unless n <= strlen(dst_orig). 
   Returns min(n, strlen(dst_orig)) + strlen(src_orig). 
   Truncation occurred if retval >= n. 
*/
#define STRLCAT(soname, fnname) \
   SizeT VG_REPLACE_FUNCTION_EZU(20050,soname,fnname) \
        ( char* dst, const char* src, SizeT n ); \
   SizeT VG_REPLACE_FUNCTION_EZU(20050,soname,fnname) \
        ( char* dst, const char* src, SizeT n ) \
   { \
      const Char* src_orig = src; \
      Char* dst_orig = dst; \
      SizeT m = 0; \
      \
      while (m < n && *dst) { m++; dst++; } \
      if (m < n) { \
         /* Fill as far as dst_orig[n-2], then nul-terminate. */ \
         while (m < n-1 && *src) { m++; *dst++ = *src++; } \
         *dst = 0; \
      } else { \
         /* No space to copy anything to dst. m == n */ \
      } \
      /* Finish counting min(n, strlen(dst_orig)) + strlen(src_orig) */ \
      while (*src) { m++; src++; } \
      /* This checks for overlap after copying, unavoidable without */ \
      /* pre-counting lengths... should be ok */ \
      if (is_overlap(dst_orig,  \
                     src_orig,  \
                     (Addr)dst-(Addr)dst_orig+1,  \
                     (Addr)src-(Addr)src_orig+1)) \
         RECORD_OVERLAP_ERROR("strlcat", dst_orig, src_orig, n); \
      \
      return m; \
   }

#if defined(VGO_linux)

#elif defined(VGO_darwin)
 STRLCAT(VG_Z_LIBC_SONAME, strlcat)
 STRLCAT(VG_Z_DYLD,        strlcat)

#endif


/*---------------------- strnlen ----------------------*/

#define STRNLEN(soname, fnname) \
   SizeT VG_REPLACE_FUNCTION_EZU(20060,soname,fnname) \
            ( const char* str, SizeT n ); \
   SizeT VG_REPLACE_FUNCTION_EZU(20060,soname,fnname) \
            ( const char* str, SizeT n ) \
   { \
      SizeT i = 0; \
      while (i < n && str[i] != 0) i++; \
      return i; \
   }

#if defined(VGO_linux)
 STRNLEN(VG_Z_LIBC_SONAME, strnlen)
 STRNLEN(VG_Z_LIBC_SONAME, __GI_strnlen)

#elif defined(VGO_darwin)
 STRNLEN(VG_Z_LIBC_SONAME, strnlen)

#endif
   

/*---------------------- strlen ----------------------*/

// Note that this replacement often doesn't get used because gcc inlines
// calls to strlen() with its own built-in version.  This can be very
// confusing if you aren't expecting it.  Other small functions in
// this file may also be inline by gcc.

#define STRLEN(soname, fnname) \
   SizeT VG_REPLACE_FUNCTION_EZU(20070,soname,fnname) \
      ( const char* str ); \
   SizeT VG_REPLACE_FUNCTION_EZU(20070,soname,fnname) \
      ( const char* str )  \
   { \
      SizeT i = 0; \
      while (str[i] != 0) i++; \
      return i; \
   }

#if defined(VGO_linux)
 STRLEN(VG_Z_LIBC_SONAME,          strlen)
 STRLEN(VG_Z_LIBC_SONAME,          __GI_strlen)

#elif defined(VGO_darwin)
 STRLEN(VG_Z_LIBC_SONAME,          strlen)

#endif


/*---------------------- strcpy ----------------------*/

#define STRCPY(soname, fnname) \
   char* VG_REPLACE_FUNCTION_EZU(20080,soname,fnname) \
      ( char* dst, const char* src ); \
   char* VG_REPLACE_FUNCTION_EZU(20080,soname,fnname) \
      ( char* dst, const char* src ) \
   { \
      const Char* src_orig = src; \
            Char* dst_orig = dst; \
      \
      while (*src) *dst++ = *src++; \
      *dst = 0; \
      \
      /* This checks for overlap after copying, unavoidable without */ \
      /* pre-counting length... should be ok */ \
      if (is_overlap(dst_orig,  \
                     src_orig,  \
                     (Addr)dst-(Addr)dst_orig+1, \
                     (Addr)src-(Addr)src_orig+1)) \
         RECORD_OVERLAP_ERROR("strcpy", dst_orig, src_orig, 0); \
      \
      return dst_orig; \
   }

#if defined(VGO_linux)
 STRCPY(VG_Z_LIBC_SONAME, strcpy)
 STRCPY(VG_Z_LIBC_SONAME, __GI_strcpy)

#elif defined(VGO_darwin)
 STRCPY(VG_Z_LIBC_SONAME, strcpy)
 STRCPY(VG_Z_DYLD,        strcpy)

#endif


/*---------------------- strncpy ----------------------*/

#define STRNCPY(soname, fnname) \
   char* VG_REPLACE_FUNCTION_EZU(20090,soname,fnname) \
            ( char* dst, const char* src, SizeT n ); \
   char* VG_REPLACE_FUNCTION_EZU(20090,soname,fnname) \
            ( char* dst, const char* src, SizeT n ) \
   { \
      const Char* src_orig = src; \
            Char* dst_orig = dst; \
      SizeT m = 0; \
      \
      while (m   < n && *src) { m++; *dst++ = *src++; } \
      /* Check for overlap after copying; all n bytes of dst are relevant, */ \
      /* but only m+1 bytes of src if terminator was found */ \
      if (is_overlap(dst_orig, src_orig, n, (m < n) ? m+1 : n)) \
         RECORD_OVERLAP_ERROR("strncpy", dst, src, n); \
      while (m++ < n) *dst++ = 0;         /* must pad remainder with nulls */ \
      \
      return dst_orig; \
   }

#if defined(VGO_linux)
 STRNCPY(VG_Z_LIBC_SONAME, strncpy)
 STRNCPY(VG_Z_LIBC_SONAME, __GI_strncpy)

#elif defined(VGO_darwin)
 STRNCPY(VG_Z_LIBC_SONAME, strncpy)
 STRNCPY(VG_Z_DYLD,        strncpy)

#endif


/*---------------------- strlcpy ----------------------*/

/* Copy up to n-1 bytes from src to dst. Then nul-terminate dst if n > 0. 
   Returns strlen(src). Does not zero-fill the remainder of dst. */
#define STRLCPY(soname, fnname) \
   SizeT VG_REPLACE_FUNCTION_EZU(20100,soname,fnname) \
       ( char* dst, const char* src, SizeT n ); \
   SizeT VG_REPLACE_FUNCTION_EZU(20100,soname,fnname) \
       ( char* dst, const char* src, SizeT n ) \
   { \
      const char* src_orig = src; \
      char* dst_orig = dst; \
      SizeT m = 0; \
      \
      while (m < n-1 && *src) { m++; *dst++ = *src++; } \
      /* m non-nul bytes have now been copied, and m <= n-1. */ \
      /* Check for overlap after copying; all n bytes of dst are relevant, */ \
      /* but only m+1 bytes of src if terminator was found */ \
      if (is_overlap(dst_orig, src_orig, n, (m < n) ? m+1 : n)) \
          RECORD_OVERLAP_ERROR("strlcpy", dst, src, n); \
      /* Nul-terminate dst. */ \
      if (n > 0) *dst = 0; \
      /* Finish counting strlen(src). */ \
      while (*src) src++; \
      return src - src_orig; \
   }

#if defined(VGO_linux)

#elif defined(VGO_darwin)
 STRLCPY(VG_Z_LIBC_SONAME, strlcpy)
 STRLCPY(VG_Z_DYLD,        strlcpy)

#endif


/*---------------------- strncmp ----------------------*/

#define STRNCMP(soname, fnname) \
   int VG_REPLACE_FUNCTION_EZU(20110,soname,fnname) \
          ( const char* s1, const char* s2, SizeT nmax ); \
   int VG_REPLACE_FUNCTION_EZU(20110,soname,fnname) \
          ( const char* s1, const char* s2, SizeT nmax ) \
   { \
      SizeT n = 0; \
      while (True) { \
         if (n >= nmax) return 0; \
         if (*s1 == 0 && *s2 == 0) return 0; \
         if (*s1 == 0) return -1; \
         if (*s2 == 0) return 1; \
         \
         if (*(unsigned char*)s1 < *(unsigned char*)s2) return -1; \
         if (*(unsigned char*)s1 > *(unsigned char*)s2) return 1; \
         \
         s1++; s2++; n++; \
      } \
   }

#if defined(VGO_linux)
 STRNCMP(VG_Z_LIBC_SONAME, strncmp)
 STRNCMP(VG_Z_LIBC_SONAME, __GI_strncmp)

#elif defined(VGO_darwin)
 STRNCMP(VG_Z_LIBC_SONAME, strncmp)
 STRNCMP(VG_Z_DYLD,        strncmp)

#endif


/*---------------------- strcasecmp ----------------------*/

#define STRCASECMP(soname, fnname) \
   int VG_REPLACE_FUNCTION_EZU(20120,soname,fnname) \
          ( const char* s1, const char* s2 ); \
   int VG_REPLACE_FUNCTION_EZU(20120,soname,fnname) \
          ( const char* s1, const char* s2 ) \
   { \
      extern int tolower(int); \
      register unsigned char c1; \
      register unsigned char c2; \
      while (True) { \
         c1 = tolower(*(unsigned char *)s1); \
         c2 = tolower(*(unsigned char *)s2); \
         if (c1 != c2) break; \
         if (c1 == 0) break; \
         s1++; s2++; \
      } \
      if ((unsigned char)c1 < (unsigned char)c2) return -1; \
      if ((unsigned char)c1 > (unsigned char)c2) return 1; \
      return 0; \
   }

#if defined(VGO_linux)
# if !defined(VGPV_arm_linux_android)
  STRCASECMP(VG_Z_LIBC_SONAME, strcasecmp)
  STRCASECMP(VG_Z_LIBC_SONAME, __GI_strcasecmp)
# endif

#elif defined(VGO_darwin)
 STRCASECMP(VG_Z_LIBC_SONAME, strcasecmp)

#endif


/*---------------------- strncasecmp ----------------------*/

#define STRNCASECMP(soname, fnname) \
   int VG_REPLACE_FUNCTION_EZU(20130,soname,fnname) \
          ( const char* s1, const char* s2, SizeT nmax ); \
   int VG_REPLACE_FUNCTION_EZU(20130,soname,fnname) \
          ( const char* s1, const char* s2, SizeT nmax ) \
   { \
      extern int tolower(int); \
      SizeT n = 0; \
      while (True) { \
         if (n >= nmax) return 0; \
         if (*s1 == 0 && *s2 == 0) return 0; \
         if (*s1 == 0) return -1; \
         if (*s2 == 0) return 1; \
         \
         if (tolower(*(unsigned char*)s1) \
             < tolower(*(unsigned char*)s2)) return -1; \
         if (tolower(*(unsigned char*)s1) \
             > tolower(*(unsigned char*)s2)) return 1; \
         \
         s1++; s2++; n++; \
      } \
   }

#if defined(VGO_linux)
# if !defined(VGPV_arm_linux_android)
  STRNCASECMP(VG_Z_LIBC_SONAME, strncasecmp)
  STRNCASECMP(VG_Z_LIBC_SONAME, __GI_strncasecmp)
# endif

#elif defined(VGO_darwin)
 STRNCASECMP(VG_Z_LIBC_SONAME, strncasecmp)
 STRNCASECMP(VG_Z_DYLD,        strncasecmp)

#endif


/*---------------------- strcasecmp_l ----------------------*/

#define STRCASECMP_L(soname, fnname) \
   int VG_REPLACE_FUNCTION_EZU(20140,soname,fnname) \
          ( const char* s1, const char* s2, void* locale ); \
   int VG_REPLACE_FUNCTION_EZU(20140,soname,fnname) \
          ( const char* s1, const char* s2, void* locale ) \
   { \
      extern int tolower_l(int, void*) __attribute__((weak)); \
      register unsigned char c1; \
      register unsigned char c2; \
      while (True) { \
         c1 = tolower_l(*(unsigned char *)s1, locale); \
         c2 = tolower_l(*(unsigned char *)s2, locale); \
         if (c1 != c2) break; \
         if (c1 == 0) break; \
         s1++; s2++; \
      } \
      if ((unsigned char)c1 < (unsigned char)c2) return -1; \
      if ((unsigned char)c1 > (unsigned char)c2) return 1; \
      return 0; \
   }

#if defined(VGO_linux)
 STRCASECMP_L(VG_Z_LIBC_SONAME, strcasecmp_l)
 STRCASECMP_L(VG_Z_LIBC_SONAME, __GI_strcasecmp_l)
 STRCASECMP_L(VG_Z_LIBC_SONAME, __GI___strcasecmp_l)

#elif defined(VGO_darwin)
 STRCASECMP_L(VG_Z_LIBC_SONAME, strcasecmp_l)

#endif


/*---------------------- strncasecmp_l ----------------------*/

#define STRNCASECMP_L(soname, fnname) \
   int VG_REPLACE_FUNCTION_EZU(20150,soname,fnname) \
          ( const char* s1, const char* s2, SizeT nmax, void* locale ); \
   int VG_REPLACE_FUNCTION_EZU(20150,soname,fnname) \
          ( const char* s1, const char* s2, SizeT nmax, void* locale ) \
   { \
      extern int tolower_l(int, void*) __attribute__((weak));    \
      SizeT n = 0; \
      while (True) { \
         if (n >= nmax) return 0; \
         if (*s1 == 0 && *s2 == 0) return 0; \
         if (*s1 == 0) return -1; \
         if (*s2 == 0) return 1; \
         \
         if (tolower_l(*(unsigned char*)s1, locale) \
             < tolower_l(*(unsigned char*)s2, locale)) return -1; \
         if (tolower_l(*(unsigned char*)s1, locale) \
             > tolower_l(*(unsigned char*)s2, locale)) return 1; \
         \
         s1++; s2++; n++; \
      } \
   }

#if defined(VGO_linux)
 STRNCASECMP_L(VG_Z_LIBC_SONAME, strncasecmp_l)
 STRNCASECMP_L(VG_Z_LIBC_SONAME, __GI_strncasecmp_l)

#elif defined(VGO_darwin)
 STRNCASECMP_L(VG_Z_LIBC_SONAME, strncasecmp_l)
 STRNCASECMP_L(VG_Z_DYLD,        strncasecmp_l)

#endif


/*---------------------- strcmp ----------------------*/

#define STRCMP(soname, fnname) \
   int VG_REPLACE_FUNCTION_EZU(20160,soname,fnname) \
          ( const char* s1, const char* s2 ); \
   int VG_REPLACE_FUNCTION_EZU(20160,soname,fnname) \
          ( const char* s1, const char* s2 ) \
   { \
      register unsigned char c1; \
      register unsigned char c2; \
      while (True) { \
         c1 = *(unsigned char *)s1; \
         c2 = *(unsigned char *)s2; \
         if (c1 != c2) break; \
         if (c1 == 0) break; \
         s1++; s2++; \
      } \
      if ((unsigned char)c1 < (unsigned char)c2) return -1; \
      if ((unsigned char)c1 > (unsigned char)c2) return 1; \
      return 0; \
   }

#if defined(VGO_linux)
 STRCMP(VG_Z_LIBC_SONAME,          strcmp)
 STRCMP(VG_Z_LIBC_SONAME,          __GI_strcmp)
 STRCMP(VG_Z_LD_LINUX_X86_64_SO_2, strcmp)
 STRCMP(VG_Z_LD64_SO_1,            strcmp)

#elif defined(VGO_darwin)
 STRCMP(VG_Z_LIBC_SONAME,          strcmp)

#endif


/*---------------------- memchr ----------------------*/

#define MEMCHR(soname, fnname) \
   void* VG_REPLACE_FUNCTION_EZU(20170,soname,fnname) \
            (const void *s, int c, SizeT n); \
   void* VG_REPLACE_FUNCTION_EZU(20170,soname,fnname) \
            (const void *s, int c, SizeT n) \
   { \
      SizeT i; \
      UChar c0 = (UChar)c; \
      UChar* p = (UChar*)s; \
      for (i = 0; i < n; i++) \
         if (p[i] == c0) return (void*)(&p[i]); \
      return NULL; \
   }

#if defined(VGO_linux)
 MEMCHR(VG_Z_LIBC_SONAME, memchr)

#elif defined(VGO_darwin)
 MEMCHR(VG_Z_LIBC_SONAME, memchr)
 MEMCHR(VG_Z_DYLD,        memchr)

#endif


/*---------------------- memcpy ----------------------*/

#define MEMMOVE_OR_MEMCPY(becTag, soname, fnname, do_ol_check)  \
   void* VG_REPLACE_FUNCTION_EZZ(becTag,soname,fnname) \
            ( void *dst, const void *src, SizeT len ); \
   void* VG_REPLACE_FUNCTION_EZZ(becTag,soname,fnname) \
            ( void *dst, const void *src, SizeT len ) \
   { \
      if (do_ol_check && is_overlap(dst, src, len, len)) \
         RECORD_OVERLAP_ERROR("memcpy", dst, src, len); \
      \
      const Addr WS = sizeof(UWord); /* 8 or 4 */ \
      const Addr WM = WS - 1;        /* 7 or 3 */ \
      \
      if (len > 0) { \
         if (dst < src) { \
         \
            /* Copying backwards. */ \
            SizeT n = len; \
            Addr  d = (Addr)dst; \
            Addr  s = (Addr)src; \
            \
            if (((s^d) & WM) == 0) { \
               /* s and d have same UWord alignment. */ \
               /* Pull up to a UWord boundary. */ \
               while ((s & WM) != 0 && n >= 1) \
                  { *(UChar*)d = *(UChar*)s; s += 1; d += 1; n -= 1; } \
               /* Copy UWords. */ \
               while (n >= WS) \
                  { *(UWord*)d = *(UWord*)s; s += WS; d += WS; n -= WS; } \
               if (n == 0) \
                  return dst; \
            } \
            if (((s|d) & 1) == 0) { \
               /* Both are 16-aligned; copy what we can thusly. */ \
               while (n >= 2) \
                  { *(UShort*)d = *(UShort*)s; s += 2; d += 2; n -= 2; } \
            } \
            /* Copy leftovers, or everything if misaligned. */ \
            while (n >= 1) \
               { *(UChar*)d = *(UChar*)s; s += 1; d += 1; n -= 1; } \
         \
         } else if (dst > src) { \
         \
            SizeT n = len; \
            Addr  d = ((Addr)dst) + n; \
            Addr  s = ((Addr)src) + n; \
            \
            /* Copying forwards. */ \
            if (((s^d) & WM) == 0) { \
               /* s and d have same UWord alignment. */ \
               /* Back down to a UWord boundary. */ \
               while ((s & WM) != 0 && n >= 1) \
                  { s -= 1; d -= 1; *(UChar*)d = *(UChar*)s; n -= 1; } \
               /* Copy UWords. */ \
               while (n >= WS) \
                  { s -= WS; d -= WS; *(UWord*)d = *(UWord*)s; n -= WS; } \
               if (n == 0) \
                  return dst; \
            } \
            if (((s|d) & 1) == 0) { \
               /* Both are 16-aligned; copy what we can thusly. */ \
               while (n >= 2) \
                  { s -= 2; d -= 2; *(UShort*)d = *(UShort*)s; n -= 2; } \
            } \
            /* Copy leftovers, or everything if misaligned. */ \
            while (n >= 1) \
               { s -= 1; d -= 1; *(UChar*)d = *(UChar*)s; n -= 1; } \
            \
         } \
      } \
      \
      return dst; \
   }

#define MEMMOVE(soname, fnname)  \
   MEMMOVE_OR_MEMCPY(20181, soname, fnname, 0)

#define MEMCPY(soname, fnname) \
   MEMMOVE_OR_MEMCPY(20180, soname, fnname, 1)

#if defined(VGO_linux)
 /* For older memcpy we have to use memmove-like semantics and skip
    the overlap check; sigh; see #275284. */
 MEMMOVE(VG_Z_LIBC_SONAME, memcpyZAGLIBCZu2Zd2Zd5) /* memcpy@GLIBC_2.2.5 */
 MEMCPY(VG_Z_LIBC_SONAME,  memcpyZAZAGLIBCZu2Zd14) /* memcpy@@GLIBC_2.14 */
 MEMCPY(VG_Z_LIBC_SONAME,  memcpy) /* fallback case */
 MEMCPY(VG_Z_LD_SO_1,      memcpy) /* ld.so.1 */
 MEMCPY(VG_Z_LD64_SO_1,    memcpy) /* ld64.so.1 */
 /* icc9 blats these around all over the place.  Not only in the main
    executable but various .so's.  They are highly tuned and read
    memory beyond the source boundary (although work correctly and
    never go across page boundaries), so give errors when run
    natively, at least for misaligned source arg.  Just intercepting
    in the exe only until we understand more about the problem.  See
    http://bugs.kde.org/show_bug.cgi?id=139776
 */
 MEMCPY(NONE, ZuintelZufastZumemcpy)

#elif defined(VGO_darwin)
 MEMCPY(VG_Z_LIBC_SONAME,  memcpy)
 MEMCPY(VG_Z_DYLD,         memcpy)

#endif


/*---------------------- memcmp ----------------------*/

#define MEMCMP(soname, fnname) \
   int VG_REPLACE_FUNCTION_EZU(20190,soname,fnname)       \
          ( const void *s1V, const void *s2V, SizeT n ); \
   int VG_REPLACE_FUNCTION_EZU(20190,soname,fnname)       \
          ( const void *s1V, const void *s2V, SizeT n )  \
   { \
      int res; \
      unsigned char a0; \
      unsigned char b0; \
      unsigned char* s1 = (unsigned char*)s1V; \
      unsigned char* s2 = (unsigned char*)s2V; \
      \
      while (n != 0) { \
         a0 = s1[0]; \
         b0 = s2[0]; \
         s1 += 1; \
         s2 += 1; \
         res = ((int)a0) - ((int)b0); \
         if (res != 0) \
            return res; \
         n -= 1; \
      } \
      return 0; \
   }

#if defined(VGO_linux)
 MEMCMP(VG_Z_LIBC_SONAME, memcmp)
 MEMCMP(VG_Z_LIBC_SONAME, bcmp)
 MEMCMP(VG_Z_LD_SO_1,     bcmp)

#elif defined(VGO_darwin)
 MEMCMP(VG_Z_LIBC_SONAME, memcmp)
 MEMCMP(VG_Z_LIBC_SONAME, bcmp)
 MEMCMP(VG_Z_DYLD,        memcmp)
 MEMCMP(VG_Z_DYLD,        bcmp)

#endif


/*---------------------- stpcpy ----------------------*/

/* Copy SRC to DEST, returning the address of the terminating '\0' in
   DEST. (minor variant of strcpy) */
#define STPCPY(soname, fnname) \
   char* VG_REPLACE_FUNCTION_EZU(20200,soname,fnname) \
            ( char* dst, const char* src ); \
   char* VG_REPLACE_FUNCTION_EZU(20200,soname,fnname) \
            ( char* dst, const char* src ) \
   { \
      const Char* src_orig = src; \
            Char* dst_orig = dst; \
      \
      while (*src) *dst++ = *src++; \
      *dst = 0; \
      \
      /* This checks for overlap after copying, unavoidable without */ \
      /* pre-counting length... should be ok */ \
      if (is_overlap(dst_orig,  \
                     src_orig,  \
                     (Addr)dst-(Addr)dst_orig+1,  \
                     (Addr)src-(Addr)src_orig+1)) \
         RECORD_OVERLAP_ERROR("stpcpy", dst_orig, src_orig, 0); \
      \
      return dst; \
   }

#if defined(VGO_linux)
 STPCPY(VG_Z_LIBC_SONAME,          stpcpy)
 STPCPY(VG_Z_LIBC_SONAME,          __GI_stpcpy)
 STPCPY(VG_Z_LD_LINUX_SO_2,        stpcpy)
 STPCPY(VG_Z_LD_LINUX_X86_64_SO_2, stpcpy)

#elif defined(VGO_darwin)
 STPCPY(VG_Z_LIBC_SONAME,          stpcpy)
 STPCPY(VG_Z_DYLD,                 stpcpy)

#endif


/*---------------------- memset ----------------------*/

/* Why are we bothering to intercept this?  It seems entirely
   pointless. */
#define MEMSET(soname, fnname) \
   void* VG_REPLACE_FUNCTION_EZU(20210,soname,fnname) \
            (void *s, Int c, SizeT n); \
   void* VG_REPLACE_FUNCTION_EZU(20210,soname,fnname) \
            (void *s, Int c, SizeT n) \
   { \
      Addr a  = (Addr)s;   \
      UInt c4 = (c & 0xFF); \
      c4 = (c4 << 8) | c4; \
      c4 = (c4 << 16) | c4; \
      while ((a & 3) != 0 && n >= 1) \
         { *(UChar*)a = (UChar)c; a += 1; n -= 1; } \
      while (n >= 4) \
         { *(UInt*)a = c4; a += 4; n -= 4; } \
      while (n >= 1) \
         { *(UChar*)a = (UChar)c; a += 1; n -= 1; } \
      return s; \
   }

#if defined(VGO_linux)
 MEMSET(VG_Z_LIBC_SONAME, memset)

#elif defined(VGO_darwin)
 MEMSET(VG_Z_LIBC_SONAME, memset)
 MEMSET(VG_Z_DYLD,        memset)

#endif


/*---------------------- memmove ----------------------*/

/* memmove -- use the MEMMOVE defn above. */
#if defined(VGO_linux)
 MEMMOVE(VG_Z_LIBC_SONAME, memmove)

#elif defined(VGO_darwin)
 MEMMOVE(VG_Z_LIBC_SONAME, memmove)
 MEMMOVE(VG_Z_DYLD,        memmove)

#endif


/*---------------------- bcopy ----------------------*/

#define BCOPY(soname, fnname) \
   void VG_REPLACE_FUNCTION_EZU(20230,soname,fnname) \
            (const void *srcV, void *dstV, SizeT n); \
   void VG_REPLACE_FUNCTION_EZU(20230,soname,fnname) \
            (const void *srcV, void *dstV, SizeT n) \
   { \
      SizeT i; \
      Char* dst = (Char*)dstV; \
      Char* src = (Char*)srcV; \
      if (dst < src) { \
         for (i = 0; i < n; i++) \
            dst[i] = src[i]; \
      } \
      else  \
      if (dst > src) { \
         for (i = 0; i < n; i++) \
            dst[n-i-1] = src[n-i-1]; \
      } \
   }

#if defined(VGO_linux)

#elif defined(VGO_darwin)
 BCOPY(VG_Z_LIBC_SONAME, bcopy)
 BCOPY(VG_Z_DYLD,        bcopy)

#endif


/*-------------------- memmove_chk --------------------*/

/* glibc 2.5 variant of memmove which checks the dest is big enough.
   There is no specific part of glibc that this is copied from. */
#define GLIBC25___MEMMOVE_CHK(soname, fnname) \
   void* VG_REPLACE_FUNCTION_EZU(20240,soname,fnname) \
            (void *dstV, const void *srcV, SizeT n, SizeT destlen); \
   void* VG_REPLACE_FUNCTION_EZU(20240,soname,fnname) \
            (void *dstV, const void *srcV, SizeT n, SizeT destlen) \
   { \
      SizeT i; \
      Char* dst = (Char*)dstV; \
      Char* src = (Char*)srcV; \
      if (destlen < n) \
         goto badness; \
      if (dst < src) { \
         for (i = 0; i < n; i++) \
            dst[i] = src[i]; \
      } \
      else  \
      if (dst > src) { \
         for (i = 0; i < n; i++) \
            dst[n-i-1] = src[n-i-1]; \
      } \
      return dst; \
     badness: \
      VALGRIND_PRINTF_BACKTRACE( \
         "*** memmove_chk: buffer overflow detected ***: " \
         "program terminated\n"); \
     my_exit(127); \
     /*NOTREACHED*/ \
     return NULL; \
   }

#if defined(VGO_linux)
 GLIBC25___MEMMOVE_CHK(VG_Z_LIBC_SONAME, __memmove_chk)

#elif defined(VGO_darwin)

#endif


/*-------------------- strchrnul --------------------*/

/* Find the first occurrence of C in S or the final NUL byte.  */
#define GLIBC232_STRCHRNUL(soname, fnname) \
   char* VG_REPLACE_FUNCTION_EZU(20250,soname,fnname) \
            (const char* s, int c_in); \
   char* VG_REPLACE_FUNCTION_EZU(20250,soname,fnname) \
            (const char* s, int c_in) \
   { \
      unsigned char  c        = (unsigned char) c_in; \
      unsigned char* char_ptr = (unsigned char *)s; \
      while (1) { \
         if (*char_ptr == 0) return char_ptr; \
         if (*char_ptr == c) return char_ptr; \
         char_ptr++; \
      } \
   }

#if defined(VGO_linux)
 GLIBC232_STRCHRNUL(VG_Z_LIBC_SONAME, strchrnul)

#elif defined(VGO_darwin)

#endif


/*---------------------- rawmemchr ----------------------*/

/* Find the first occurrence of C in S.  */
#define GLIBC232_RAWMEMCHR(soname, fnname) \
   char* VG_REPLACE_FUNCTION_EZU(20260,soname,fnname) \
            (const char* s, int c_in); \
   char* VG_REPLACE_FUNCTION_EZU(20260,soname,fnname) \
            (const char* s, int c_in) \
   { \
      unsigned char  c        = (unsigned char) c_in; \
      unsigned char* char_ptr = (unsigned char *)s; \
      while (1) { \
         if (*char_ptr == c) return char_ptr; \
         char_ptr++; \
      } \
   }

#if defined (VGO_linux)
 GLIBC232_RAWMEMCHR(VG_Z_LIBC_SONAME, rawmemchr)
 GLIBC232_RAWMEMCHR(VG_Z_LIBC_SONAME, __GI___rawmemchr)

#elif defined(VGO_darwin)

#endif


/*---------------------- strcpy_chk ----------------------*/

/* glibc variant of strcpy that checks the dest is big enough.
   Copied from glibc-2.5/debug/test-strcpy_chk.c. */
#define GLIBC25___STRCPY_CHK(soname,fnname) \
   char* VG_REPLACE_FUNCTION_EZU(20270,soname,fnname) \
            (char* dst, const char* src, SizeT len); \
   char* VG_REPLACE_FUNCTION_EZU(20270,soname,fnname) \
            (char* dst, const char* src, SizeT len) \
   { \
      char* ret = dst; \
      if (! len) \
         goto badness; \
      while ((*dst++ = *src++) != '\0') \
         if (--len == 0) \
            goto badness; \
      return ret; \
     badness: \
      VALGRIND_PRINTF_BACKTRACE( \
         "*** strcpy_chk: buffer overflow detected ***: " \
         "program terminated\n"); \
     my_exit(127); \
     /*NOTREACHED*/ \
     return NULL; \
   }

#if defined(VGO_linux)
 GLIBC25___STRCPY_CHK(VG_Z_LIBC_SONAME, __strcpy_chk)

#elif defined(VGO_darwin)

#endif


/*---------------------- stpcpy_chk ----------------------*/

/* glibc variant of stpcpy that checks the dest is big enough.
   Copied from glibc-2.5/debug/test-stpcpy_chk.c. */
#define GLIBC25___STPCPY_CHK(soname,fnname) \
   char* VG_REPLACE_FUNCTION_EZU(20280,soname,fnname) \
            (char* dst, const char* src, SizeT len); \
   char* VG_REPLACE_FUNCTION_EZU(20280,soname,fnname) \
            (char* dst, const char* src, SizeT len) \
   { \
      if (! len) \
         goto badness; \
      while ((*dst++ = *src++) != '\0') \
         if (--len == 0) \
            goto badness; \
      return dst - 1; \
     badness: \
      VALGRIND_PRINTF_BACKTRACE( \
         "*** stpcpy_chk: buffer overflow detected ***: " \
         "program terminated\n"); \
     my_exit(127); \
     /*NOTREACHED*/ \
     return NULL; \
   }

#if defined(VGO_linux)
 GLIBC25___STPCPY_CHK(VG_Z_LIBC_SONAME, __stpcpy_chk)

#elif defined(VGO_darwin)

#endif


/*---------------------- mempcpy ----------------------*/

/* mempcpy */
#define GLIBC25_MEMPCPY(soname, fnname) \
   void* VG_REPLACE_FUNCTION_EZU(20290,soname,fnname) \
            ( void *dst, const void *src, SizeT len ); \
   void* VG_REPLACE_FUNCTION_EZU(20290,soname,fnname) \
            ( void *dst, const void *src, SizeT len ) \
   { \
      register char *d; \
      register char *s; \
      SizeT len_saved = len; \
      \
      if (len == 0) \
         return dst; \
      \
      if (is_overlap(dst, src, len, len)) \
         RECORD_OVERLAP_ERROR("mempcpy", dst, src, len); \
      \
      if ( dst > src ) { \
         d = (char *)dst + len - 1; \
         s = (char *)src + len - 1; \
         while ( len-- ) { \
            *d-- = *s--; \
         } \
      } else if ( dst < src ) { \
         d = (char *)dst; \
         s = (char *)src; \
         while ( len-- ) { \
            *d++ = *s++; \
         } \
      } \
      return (void*)( ((char*)dst) + len_saved ); \
   }

#if defined(VGO_linux)
 GLIBC25_MEMPCPY(VG_Z_LIBC_SONAME, mempcpy)
 GLIBC25_MEMPCPY(VG_Z_LD_SO_1,     mempcpy) /* ld.so.1 */

#elif defined(VGO_darwin)
 GLIBC25_MEMPCPY(VG_Z_LIBC_SONAME, mempcpy)

#endif


/*-------------------- memcpy_chk --------------------*/

#define GLIBC26___MEMCPY_CHK(soname, fnname) \
   void* VG_REPLACE_FUNCTION_EZU(20300,soname,fnname) \
            (void* dst, const void* src, SizeT len, SizeT dstlen ); \
   void* VG_REPLACE_FUNCTION_EZU(20300,soname,fnname) \
            (void* dst, const void* src, SizeT len, SizeT dstlen ) \
   { \
      register char *d; \
      register char *s; \
      \
      if (dstlen < len) goto badness; \
      \
      if (len == 0) \
         return dst; \
      \
      if (is_overlap(dst, src, len, len)) \
         RECORD_OVERLAP_ERROR("memcpy_chk", dst, src, len); \
      \
      if ( dst > src ) { \
         d = (char *)dst + len - 1; \
         s = (char *)src + len - 1; \
         while ( len-- ) { \
            *d-- = *s--; \
         } \
      } else if ( dst < src ) { \
         d = (char *)dst; \
         s = (char *)src; \
         while ( len-- ) { \
            *d++ = *s++; \
         } \
      } \
      return dst; \
     badness: \
      VALGRIND_PRINTF_BACKTRACE( \
         "*** memcpy_chk: buffer overflow detected ***: " \
         "program terminated\n"); \
     my_exit(127); \
     /*NOTREACHED*/ \
     return NULL; \
   }

#if defined(VGO_linux)
 GLIBC26___MEMCPY_CHK(VG_Z_LIBC_SONAME, __memcpy_chk)

#elif defined(VGO_darwin)

#endif


/*---------------------- strstr ----------------------*/

#define STRSTR(soname, fnname) \
   void* VG_REPLACE_FUNCTION_EZU(20310,soname,fnname) \
         (void* haystack, void* needle); \
   void* VG_REPLACE_FUNCTION_EZU(20310,soname,fnname) \
         (void* haystack, void* needle) \
   { \
      UChar* h = (UChar*)haystack; \
      UChar* n = (UChar*)needle; \
      \
      /* find the length of n, not including terminating zero */ \
      UWord nlen = 0; \
      while (n[nlen]) nlen++; \
      \
      /* if n is the empty string, match immediately. */ \
      if (nlen == 0) return h; \
      \
      /* assert(nlen >= 1); */ \
      UChar n0 = n[0]; \
      \
      while (1) { \
         UChar hh = *h; \
         if (hh == 0) return NULL; \
         if (hh != n0) { h++; continue; } \
         \
         UWord i; \
         for (i = 0; i < nlen; i++) { \
            if (n[i] != h[i]) \
               break; \
         } \
         /* assert(i >= 0 && i <= nlen); */ \
         if (i == nlen) \
            return h; \
         \
         h++; \
      } \
   }

#if defined(VGO_linux)
 STRSTR(VG_Z_LIBC_SONAME,          strstr)

#elif defined(VGO_darwin)

#endif


/*---------------------- strpbrk ----------------------*/

#define STRPBRK(soname, fnname) \
   void* VG_REPLACE_FUNCTION_EZU(20320,soname,fnname) \
         (void* sV, void* acceptV); \
   void* VG_REPLACE_FUNCTION_EZU(20320,soname,fnname) \
         (void* sV, void* acceptV) \
   { \
      UChar* s = (UChar*)sV; \
      UChar* accept = (UChar*)acceptV; \
      \
      /*  find the length of 'accept', not including terminating zero */ \
      UWord nacc = 0; \
      while (accept[nacc]) nacc++; \
      \
      /* if n is the empty string, fail immediately. */ \
      if (nacc == 0) return NULL; \
      \
      /* assert(nacc >= 1); */ \
      while (1) { \
         UWord i; \
         UChar sc = *s; \
         if (sc == 0) \
            break; \
         for (i = 0; i < nacc; i++) { \
            if (sc == accept[i]) \
               return s; \
         } \
         s++; \
      } \
      \
      return NULL; \
   }

#if defined(VGO_linux)
 STRPBRK(VG_Z_LIBC_SONAME,          strpbrk)

#elif defined(VGO_darwin)

#endif


/*---------------------- strcspn ----------------------*/

#define STRCSPN(soname, fnname) \
   SizeT VG_REPLACE_FUNCTION_EZU(20330,soname,fnname) \
         (void* sV, void* rejectV); \
   SizeT VG_REPLACE_FUNCTION_EZU(20330,soname,fnname) \
         (void* sV, void* rejectV) \
   { \
      UChar* s = (UChar*)sV; \
      UChar* reject = (UChar*)rejectV; \
      \
      /* find the length of 'reject', not including terminating zero */ \
      UWord nrej = 0; \
      while (reject[nrej]) nrej++; \
      \
      UWord len = 0; \
      while (1) { \
         UWord i; \
         UChar sc = *s; \
         if (sc == 0) \
            break; \
         for (i = 0; i < nrej; i++) { \
            if (sc == reject[i]) \
               break; \
         } \
         /* assert(i >= 0 && i <= nrej); */ \
         if (i < nrej) \
            break; \
         s++; \
         len++; \
      } \
      \
      return len; \
   }

#if defined(VGO_linux)
 STRCSPN(VG_Z_LIBC_SONAME,          strcspn)

#elif defined(VGO_darwin)

#endif


/*---------------------- strspn ----------------------*/

#define STRSPN(soname, fnname) \
   SizeT VG_REPLACE_FUNCTION_EZU(20340,soname,fnname) \
         (void* sV, void* acceptV); \
   SizeT VG_REPLACE_FUNCTION_EZU(20340,soname,fnname) \
         (void* sV, void* acceptV) \
   { \
      UChar* s = (UChar*)sV; \
      UChar* accept = (UChar*)acceptV; \
      \
      /* find the length of 'accept', not including terminating zero */ \
      UWord nacc = 0; \
      while (accept[nacc]) nacc++; \
      if (nacc == 0) return 0; \
      \
      UWord len = 0; \
      while (1) { \
         UWord i; \
         UChar sc = *s; \
         if (sc == 0) \
            break; \
         for (i = 0; i < nacc; i++) { \
            if (sc == accept[i]) \
               break; \
         } \
         /* assert(i >= 0 && i <= nacc); */ \
         if (i == nacc) \
            break; \
         s++; \
         len++; \
      } \
      \
      return len; \
   }

#if defined(VGO_linux)
 STRSPN(VG_Z_LIBC_SONAME,          strspn)

#elif defined(VGO_darwin)

#endif


/*------------------------------------------------------------*/
/*--- Improve definedness checking of process environment  ---*/
/*------------------------------------------------------------*/

#if defined(VGO_linux)

/* If these wind up getting generated via a macro, so that multiple
   versions of each function exist (as above), use the _EZU variants
   to assign equivalance class tags. */

/*---------------------- putenv ----------------------*/

int VG_WRAP_FUNCTION_ZU(VG_Z_LIBC_SONAME, putenv) (char* string);
int VG_WRAP_FUNCTION_ZU(VG_Z_LIBC_SONAME, putenv) (char* string)
{
    OrigFn fn;
    Word result;
    const char* p = string;
    VALGRIND_GET_ORIG_FN(fn);
    /* Now by walking over the string we magically produce
       traces when hitting undefined memory. */
    if (p)
        while (*p++)
            __asm__ __volatile__("" ::: "memory");
    CALL_FN_W_W(result, fn, string);
    return result;
}


/*---------------------- unsetenv ----------------------*/

int VG_WRAP_FUNCTION_ZU(VG_Z_LIBC_SONAME, unsetenv) (const char* name);
int VG_WRAP_FUNCTION_ZU(VG_Z_LIBC_SONAME, unsetenv) (const char* name)
{
    OrigFn fn;
    Word result;
    const char* p = name;
    VALGRIND_GET_ORIG_FN(fn);
    /* Now by walking over the string we magically produce
       traces when hitting undefined memory. */
    if (p)
        while (*p++)
            __asm__ __volatile__("" ::: "memory");
    CALL_FN_W_W(result, fn, name);
    return result;
}


/*---------------------- setenv ----------------------*/

/* setenv */
int VG_WRAP_FUNCTION_ZU(VG_Z_LIBC_SONAME, setenv)
    (const char* name, const char* value, int overwrite);
int VG_WRAP_FUNCTION_ZU(VG_Z_LIBC_SONAME, setenv)
    (const char* name, const char* value, int overwrite)
{
    OrigFn fn;
    Word result;
    const char* p;
    VALGRIND_GET_ORIG_FN(fn);
    /* Now by walking over the string we magically produce
       traces when hitting undefined memory. */
    if (name)
        for (p = name; *p; p++)
            __asm__ __volatile__("" ::: "memory");
    if (value)
        for (p = value; *p; p++)
            __asm__ __volatile__("" ::: "memory");
    VALGRIND_CHECK_VALUE_IS_DEFINED (overwrite);
    CALL_FN_W_WWW(result, fn, name, value, overwrite);
    return result;
}

#endif /* defined(VGO_linux) */

/*--------------------------------------------------------------------*/
/*--- end                                                          ---*/
/*--------------------------------------------------------------------*/