[GLIBC][PATCH] Remove strdup inlines

[Wilco Dijkstra]

Remove the str(n)dup inlines from string/bits/string2.h.  Although inlining
calls with constant strings shows a small (~10%) performance gain, strdup is
typically used in error reporting code, so not performance critical.

Avoid linknamespace and localplt failures by redirecting str(n)dup to GCC
builtins.

ChangeLog:
2015-12-12  Wilco Dijkstra  <wdijkstr@arm.com>

	* string/string.h (strdup): Use builtin.
	(strndup): Likewise.
	* string/bits/string2.h (__strdup): Remove define.
	(strdup): Likewise.
	(__strndup): Likewise.
	(strndup): Likewise.
--

diff --git a/string/bits/string2.h b/string/bits/string2.h
index 03af22cc27a33c81f36d56ddc52fce0a5ea81ece..b0be5f6a49024a0bedfc37e9ec2c0356e0e4fa09 100644
--- a/string/bits/string2.h
+++ b/string/bits/string2.h
@@ -118,58 +118,6 @@
 #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
-
-# define __need_malloc_and_calloc
-# include <stdlib.h>
-
-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
-
-
-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 /* Use misc. or use GNU.  */
-
 #ifndef _FORCE_INLINES
 # undef __STRING_INLINE
 #endif
diff --git a/string/string.h b/string/string.h
index b103e64912fe1904098e229ccb845bb2c5c10835..c251cc603a1dbb5bef469d4b71f90037612d36f0 100644
--- a/string/string.h
+++ b/string/string.h
@@ -636,6 +636,15 @@ extern char *basename (const char *__filename) __THROW __nonnull ((1));
 # endif
 #endif
 
+#if (defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8     \
+     || __GLIBC_USE (LIB_EXT2))
+# define strdup(s) __builtin_strdup (s)
+#endif
+
+#if defined __USE_XOPEN2K8 || __GLIBC_USE (LIB_EXT2)
+# define strndup(s,n) __builtin_strndup (s, n)
+#endif
+
 #if defined __USE_GNU && defined __OPTIMIZE__ \
     && defined __extern_always_inline && __GNUC_PREREQ (3,2)
 # if !defined _FORCE_INLINES && !defined _HAVE_STRING_ARCH_mempcpy