Remove bits/string.h.

These machine-dependent inline string functions have never been on by
default, and even if they were a good idea at the time they were
introduced, they haven't really been touched in ten to fifteen years
and probably aren't a good idea on current-gen processors.  Current
thinking is that this class of optimization is best left to the
compiler.

	* bits/string.h, string/bits/string.h
	* sysdeps/aarch64/bits/string.h
	* sysdeps/m68k/m680x0/m68020/bits/string.h
	* sysdeps/s390/bits/string.h, sysdeps/sparc/bits/string.h
	* sysdeps/x86/bits/string.h: Delete file.

	* string/string.h: Don't include bits/string.h.
	* string/bits/string3.h: Rename to bits/string_fortified.h.
	No need to undef various symbols that the removed headers
	might have defined as macros.
	* string/Makefile (headers): Remove bits/string.h, change
	bits/string3.h to bits/string_fortified.h.
	* string/string-inlines.c: Update commentary.  Remove definitions
	of various macros that nothing looks at anymore.  Don't directly
	include bits/string.h. Set _STRING_INLINE_unaligned here, based on
	compiler-predefined macros.
	* string/strncat.c: If STRNCAT is not defined, or STRNCAT_PRIMARY
	_is_ defined, provide internal hidden alias __strncat.
	* include/string.h: Declare internal hidden alias __strncat.
	Only forward __stpcpy to __builtin_stpcpy if __NO_STRING_INLINES is
	not defined.
	* include/bits/string3.h: Rename to bits/string_fortified.h,
	update to match above.

	* sysdeps/i386/string-inlines.c: Define compat symbols for
	everything formerly defined by sysdeps/x86/bits/string.h.
	Make existing definitions into compat symbols as well.
	Remove some no-longer-necessary messing around with macros.

	* sysdeps/powerpc/powerpc32/power4/multiarch/mempcpy.c
	* sysdeps/powerpc/powerpc64/multiarch/mempcpy.c
	* sysdeps/powerpc/powerpc64/multiarch/stpcpy.c
	* sysdeps/s390/multiarch/mempcpy.c
	No need to define _HAVE_STRING_ARCH_mempcpy.
	Do define __NO_STRING_INLINES and NO_MEMPCPY_STPCPY_REDIRECT.

	* sysdeps/i386/i686/multiarch/strncat-c.c
	* sysdeps/s390/multiarch/strncat-c.c
	* sysdeps/x86_64/multiarch/strncat-c.c
	Define STRNCAT_PRIMARY.  Don't change definition of libc_hidden_def.

string/Makefile

@@ -22,10 +22,11 @@ subdir	:= string
 
 include ../Makeconfig
 
-headers	:= string.h strings.h memory.h endian.h bits/endian.h \
-	   argz.h envz.h byteswap.h bits/byteswap.h bits/byteswap-16.h \
-	   bits/string.h bits/string3.h bits/strings_fortified.h \
-	   bits/uintn-identity.h
+headers		:= string.h bits/string_fortified.h			\
+		   strings.h bits/strings_fortified.h			\
+		   byteswap.h bits/byteswap.h bits/byteswap-16.h	\
+		   endian.h bits/endian.h bits/uintn-identity.h		\
+		   memory.h argz.h envz.h
 
 routines	:= strcat strchr strcmp strcoll strcpy strcspn		\
 		   strverscmp strdup strndup				\

string/bits/string_fortified.h

@@ -15,8 +15,11 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
+#ifndef _BITS_STRING_FORTIFIED_H
+#define _BITS_STRING_FORTIFIED_H 1
+
 #ifndef _STRING_H
-# error "Never use <bits/string3.h> directly; include <string.h> instead."
+# error "Never use <bits/string_fortified.h> directly; include <string.h> instead."
 #endif
 
 #if !__GNUC_PREREQ (5,0)
@@ -24,28 +27,6 @@ __warndecl (__warn_memset_zero_len,
 	    "memset used with constant zero length parameter; this could be due to transposed parameters");
 #endif
 
-#ifndef __cplusplus
-/* XXX This is temporarily.  We should not redefine any of the symbols
-   and instead integrate the error checking into the original
-   definitions.  */
-# undef memcpy
-# undef memmove
-# undef memset
-# undef strcat
-# undef strcpy
-# undef strncat
-# undef strncpy
-# ifdef __USE_GNU
-#  undef mempcpy
-#  undef stpcpy
-# endif
-# ifdef __USE_MISC
-#  undef bcopy
-#  undef bzero
-# endif
-#endif
-
-
 __fortify_function void *
 __NTH (memcpy (void *__restrict __dest, const void *__restrict __src,
 	       size_t __len))
@@ -154,3 +135,5 @@ __NTH (strncat (char *__restrict __dest, const char *__restrict __src,
 {
   return __builtin___strncat_chk (__dest, __src, __len, __bos (__dest));
 }
+
+#endif /* bits/string_fortified.h */

string/string-inlines.c

@@ -15,28 +15,17 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-/*  <bits/string.h> may declare some extern inline functions.
-    These functions are defined here if inlining is not possible.  */
-
-#undef __USE_STRING_INLINES
-#define __USE_STRING_INLINES
-#define _FORCE_INLINES
-#define __STRING_INLINE /* empty */
-#define __NO_INLINE__
+/* This file contains compatibility definitions of functions that were
+   formerly defined as "extern inline" in string.h; it's conceivable
+   that old binaries contain references to them.  */
 
+#define __NO_STRING_INLINES
 #include <string.h>
-#undef index
-#undef rindex
-#undef __stpcpy
 
-#undef __NO_INLINE__
-#include <bits/string.h>
 #include "shlib-compat.h"
 
 #if SHLIB_COMPAT (libc, GLIBC_2_1_1, GLIBC_2_25)
-/* The inline functions are not used from GLIBC 2.25 and forward, however
-   they are required to provide the symbols through string-inlines.c
-   (if inlining is not possible for compatibility reasons).  */
+/* These functions were removed from string.h in glibc 2.25.  */
 
 char *
 __old_strtok_r_1c (char *__s, char __sep, char **__nextp)
@@ -128,9 +117,8 @@ compat_symbol (libc, __old_strsep_3c, __strsep_3c, GLIBC_2_1_1);
 #endif
 
 #if SHLIB_COMPAT (libc, GLIBC_2_1_1, GLIBC_2_24)
-/* The inline functions are not used from GLIBC 2.24 and forward, however
-   they are required to provide the symbols through string-inlines.c
-   (if inlining is not possible for compatibility reasons).  */
+/* These functions were removed from string.h in glibc 2.24.  */
+
 size_t
 __old_strcspn_c1 (const char *__s, int __reject)
 {
@@ -220,9 +208,13 @@ __old_strpbrk_c3 (const char *__s, int __accept1, int __accept2, int __accept3)
 }
 compat_symbol (libc, __old_strpbrk_c3, __strpbrk_c3, GLIBC_2_1_1);
 
+# if defined __mc68020__ || defined __s390__ || defined __i386__
+#  define _STRING_INLINE_unaligned 1
+# else
+#  define _STRING_INLINE_unaligned 0
 /* These are a few types we need for the optimizations if we cannot
    use unaligned memory accesses.  */
-# define __STRING2_COPY_TYPE(N) \
+#  define __STRING2_COPY_TYPE(N) \
   typedef struct { unsigned char __arr[N]; }				      \
     __attribute__ ((__packed__)) __STRING2_COPY_ARR##N
 __STRING2_COPY_TYPE (2);
@@ -232,8 +224,8 @@ __STRING2_COPY_TYPE (5);
 __STRING2_COPY_TYPE (6);
 __STRING2_COPY_TYPE (7);
 __STRING2_COPY_TYPE (8);
-# undef __STRING2_COPY_TYPE
-
+#  undef __STRING2_COPY_TYPE
+# endif
 
 # if _STRING_INLINE_unaligned
 void *

string/string.h

@@ -487,30 +487,10 @@ extern char *basename (const char *__filename) __THROW __nonnull ((1));
 # endif
 #endif
 
-
 #if __GNUC_PREREQ (3,4)
-# if defined __OPTIMIZE__ && !defined __OPTIMIZE_SIZE__ \
-     && !defined __NO_INLINE__ && !defined __cplusplus
-/* When using GNU CC we provide some optimized versions of selected
-   functions from this header.  There are two kinds of optimizations:
-
-   - machine-dependent optimizations, most probably using inline
-     assembler code; these might be quite expensive since the code
-     size can increase significantly.
-     These optimizations are not used unless the symbol
-	__USE_STRING_INLINES
-     is defined before including this header.
-
-   One can inhibit all optimizations by defining __NO_STRING_INLINES.  */
-
-/* Get the machine-dependent optimizations (if any).  */
-#  include <bits/string.h>
-
-# endif
-
 # if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function
 /* Functions with security checks.  */
-#  include <bits/string3.h>
+#  include <bits/string_fortified.h>
 # endif
 #endif
 

string/strncat.c

@@ -20,6 +20,7 @@
 #ifndef STRNCAT
 # undef strncat
 # define STRNCAT  strncat
+# define STRNCAT_PRIMARY
 #endif
 
 char *
@@ -37,3 +38,7 @@ STRNCAT (char *s1, const char *s2, size_t n)
 
   return s;
 }
+#ifdef STRNCAT_PRIMARY
+strong_alias (STRNCAT, __strncat)
+libc_hidden_def (__strncat)
+#endif