Fix locale memmem namespace (bug 17585).

Locale code, brought in by ISO C functions, calls memmem, which is not
an ISO C function.  This isn't an ISO C conformance bug, because all
mem* names are reserved, but glibc practice is not to rely on that
reservation (thus, memmem is only declared in string.h if __USE_GNU
even though ISO C would allow it to be declared unconditionally, for
example).  This patch changes that code to use __memmem.

Note: there are uses of memmem elsewhere in glibc that I didn't
change, although it may turn out some of those also need to use
__memmem.

Tested for x86_64 (testsuite, and that disassembly of installed shared
libraries is unchanged by this patch).

	[BZ #17585]
	* string/memmem.c [!_LIBC] (__memmem): Define to memmem.
	(memmem): Rename to __memmem and define as weak alias of
	__memmem.  Use libc_hidden_weak.
	(__memmem): Use libc_hidden_def.
	* include/string.h (__memmem): Declare.  Use libc_hidden_proto.
	* locale/findlocale.c (valid_locale_name): Use __memmem instead of
	memmem.

1 files changed, 6 insertions, 3 deletions

diff --git a/string/memmem.c b/string/memmem.c
index b2842fe57f..bafac03df9 100644
--- a/string/memmem.c
+++ b/string/memmem.c
@@ -26,6 +26,7 @@
 
 #ifndef _LIBC
 # define __builtin_expect(expr, val)   (expr)
+# define __memmem	memmem
 #endif
 
 #define RETURN_TYPE void *
@@ -38,8 +39,8 @@
    if NEEDLE_LEN is 0, otherwise NULL if NEEDLE is not found in
    HAYSTACK.  */
 void *
-memmem (const void *haystack_start, size_t haystack_len,
-	const void *needle_start, size_t needle_len)
+__memmem (const void *haystack_start, size_t haystack_len,
+	  const void *needle_start, size_t needle_len)
 {
   /* Abstract memory is considered to be an array of 'unsigned char' values,
      not an array of 'char' values.  See ISO C 99 section 6.2.6.1.  */
@@ -73,6 +74,8 @@ memmem (const void *haystack_start, size_t haystack_len,
   else
     return two_way_long_needle (haystack, haystack_len, needle, needle_len);
 }
-libc_hidden_def (memmem)
+libc_hidden_def (__memmem)
+weak_alias (__memmem, memmem)
+libc_hidden_weak (memmem)
 
 #undef LONG_NEEDLE_THRESHOLD