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.

1 files changed, 139 insertions, 0 deletions

diff --git a/string/bits/string_fortified.h b/string/bits/string_fortified.h
new file mode 100644
index 0000000000..a89e757c9d
--- /dev/null
+++ b/string/bits/string_fortified.h
@@ -0,0 +1,139 @@
+/* Copyright (C) 2004-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   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/string_fortified.h> directly; include <string.h> instead."
+#endif
+
+#if !__GNUC_PREREQ (5,0)
+__warndecl (__warn_memset_zero_len,
+	    "memset used with constant zero length parameter; this could be due to transposed parameters");
+#endif
+
+__fortify_function void *
+__NTH (memcpy (void *__restrict __dest, const void *__restrict __src,
+	       size_t __len))
+{
+  return __builtin___memcpy_chk (__dest, __src, __len, __bos0 (__dest));
+}
+
+__fortify_function void *
+__NTH (memmove (void *__dest, const void *__src, size_t __len))
+{
+  return __builtin___memmove_chk (__dest, __src, __len, __bos0 (__dest));
+}
+
+#ifdef __USE_GNU
+__fortify_function void *
+__NTH (mempcpy (void *__restrict __dest, const void *__restrict __src,
+		size_t __len))
+{
+  return __builtin___mempcpy_chk (__dest, __src, __len, __bos0 (__dest));
+}
+#endif
+
+
+/* The first two tests here help to catch a somewhat common problem
+   where the second and third parameter are transposed.  This is
+   especially problematic if the intended fill value is zero.  In this
+   case no work is done at all.  We detect these problems by referring
+   non-existing functions.  */
+__fortify_function void *
+__NTH (memset (void *__dest, int __ch, size_t __len))
+{
+  /* GCC-5.0 and newer implements these checks in the compiler, so we don't
+     need them here.  */
+#if !__GNUC_PREREQ (5,0)
+  if (__builtin_constant_p (__len) && __len == 0
+      && (!__builtin_constant_p (__ch) || __ch != 0))
+    {
+      __warn_memset_zero_len ();
+      return __dest;
+    }
+#endif
+  return __builtin___memset_chk (__dest, __ch, __len, __bos0 (__dest));
+}
+
+#ifdef __USE_MISC
+# include <bits/strings_fortified.h>
+
+void __explicit_bzero_chk (void *__dest, size_t __len, size_t __destlen)
+  __THROW __nonnull ((1));
+
+__fortify_function void
+__NTH (explicit_bzero (void *__dest, size_t __len))
+{
+  __explicit_bzero_chk (__dest, __len, __bos0 (__dest));
+}
+#endif
+
+__fortify_function char *
+__NTH (strcpy (char *__restrict __dest, const char *__restrict __src))
+{
+  return __builtin___strcpy_chk (__dest, __src, __bos (__dest));
+}
+
+#ifdef __USE_GNU
+__fortify_function char *
+__NTH (stpcpy (char *__restrict __dest, const char *__restrict __src))
+{
+  return __builtin___stpcpy_chk (__dest, __src, __bos (__dest));
+}
+#endif
+
+
+__fortify_function char *
+__NTH (strncpy (char *__restrict __dest, const char *__restrict __src,
+		size_t __len))
+{
+  return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
+}
+
+/* XXX We have no corresponding builtin yet.  */
+extern char *__stpncpy_chk (char *__dest, const char *__src, size_t __n,
+			    size_t __destlen) __THROW;
+extern char *__REDIRECT_NTH (__stpncpy_alias, (char *__dest, const char *__src,
+					       size_t __n), stpncpy);
+
+__fortify_function char *
+__NTH (stpncpy (char *__dest, const char *__src, size_t __n))
+{
+  if (__bos (__dest) != (size_t) -1
+      && (!__builtin_constant_p (__n) || __n > __bos (__dest)))
+    return __stpncpy_chk (__dest, __src, __n, __bos (__dest));
+  return __stpncpy_alias (__dest, __src, __n);
+}
+
+
+__fortify_function char *
+__NTH (strcat (char *__restrict __dest, const char *__restrict __src))
+{
+  return __builtin___strcat_chk (__dest, __src, __bos (__dest));
+}
+
+
+__fortify_function char *
+__NTH (strncat (char *__restrict __dest, const char *__restrict __src,
+		size_t __len))
+{
+  return __builtin___strncat_chk (__dest, __src, __len, __bos (__dest));
+}
+
+#endif /* bits/string_fortified.h */