As someone who can remember when you might not be able to include both
string.h and strings.h at the same time, it annoys me that strings.h
still exists and is the only standard source for str(n)casecmp(_l) and
ffs.  I think it’s right that we expose those functions from string.h.
However, there’s no reason we need to keep exposing the other obsolete
functions that strings.h declares from string.h.

This patch creates <bits/strings_x2k8.h>, which declares the
non-obsolete functions whose official home is strings.h.  strings.h
includes it unconditionally, and string.h includes it under
__USE_MISC, instead of strings.h.

Two tests of the obsolete strings.h functions had to be adjusted.

	* string/strings.h (strcasecmp, strncasecmp, strcasecmp_l)
	(strncasecmp_l, ffs, ffsl, ffsll): Move declarations to...
	* string/bits/strings_x2k8.h: ... this new file.
	* string/Makefile: Install bits/strings_x2k8.h.
	* include/bits/strings_x2k8h: New wrapper.
	* string/string.h: Include bits/strings_x2k8.h instead of
	strings.h.

	* debug/tst-chk1.c, string/test-string.h: Include strings.h.
	* scripts/check-obsolete-constructs.py: string.h is no longer
	expected to include strings.h.

	* sysdeps/i386/i686/multiarch/bcopy.c
	* sysdeps/i386/i686/multiarch/bzero.c
	* sysdeps/i386/i686/multiarch/ifunc-impl-list.c
	* sysdeps/powerpc/powerpc32/power4/multiarch/ifunc-impl-list.c
	* sysdeps/powerpc/powerpc64/multiarch/bcopy-ppc64.c
	* sysdeps/powerpc/powerpc64/multiarch/bcopy.c
	* sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
	* sysdeps/s390/bzero.c
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	* sysdeps/sparc/sparc64/multiarch/bzero.c
	* sysdeps/sparc/sparc64/multiarch/ifunc-impl-list.c:
        Include strings.h.

With only two exceptions (sys/types.h and sys/param.h, both of which
historically might have defined BYTE_ORDER) the public headers that
include <endian.h> only want to be able to test __BYTE_ORDER against
__*_ENDIAN.

This patch creates a new bits/endian.h that can be included by any
header that wants to be able to test __BYTE_ORDER and/or
__FLOAT_WORD_ORDER against the __*_ENDIAN constants, or needs
__LONG_LONG_PAIR.  It only defines macros in the implementation
namespace.

The existing bits/endian.h (which could not be included independently
of endian.h, and only defines __BYTE_ORDER and maybe __FLOAT_WORD_ORDER)
is renamed to bits/endianness.h.  I also took the opportunity to
canonicalize the form of this header, which we are stuck with having
one copy of per architecture.  Since they are so short, this means git
doesn’t understand that they were renamed from existing headers, sigh.

endian.h itself is a nonstandard header and its only remaining use
from a standard header is guarded by __USE_MISC, so I dropped the
__USE_MISC conditionals from around all of the public-namespace things
it defines.  (This means, an application that requests strict library
conformance but includes endian.h will still see the definition of
BYTE_ORDER.)

A few changes to specific bits/endian(ness).h variants deserve
mention:

 - sysdeps/unix/sysv/linux/ia64/bits/endian.h is moved to
   sysdeps/ia64/bits/endianness.h.  If I remember correctly, ia64 did
   have selectable endianness, but we have assembly code in
   sysdeps/ia64 that assumes it’s little-endian, so there is no reason
   to treat the ia64 endianness.h as linux-specific.

 - The C-SKY port does not fully support big-endian mode, the compile
   will error out if __CSKYBE__ is defined.

 - The PowerPC port had extra logic in its bits/endian.h to detect a
   broken compiler, which strikes me as unnecessary, so I removed it.

 - The only files that defined __FLOAT_WORD_ORDER always defined it to
   the same value as __BYTE_ORDER, so I removed those definitions.
   The SH bits/endian(ness).h had comments inconsistent with the
   actual setting of __FLOAT_WORD_ORDER, which I also removed.

 - I *removed* copyright boilerplate from the few bits/endian(ness).h
   headers that had it; these files record a single fact in a fashion
   dictated by an external spec, so I do not think they are copyrightable.

As long as I was changing every copy of ieee754.h in the tree, I
noticed that only the MIPS variant includes float.h, because it uses
LDBL_MANT_DIG to decide among three different versions of
ieee854_long_double.  This patch makes it not include float.h when
GCC’s intrinsic __LDBL_MANT_DIG__ is available.

	* string/endian.h: Unconditionally define LITTLE_ENDIAN,
	BIG_ENDIAN, PDP_ENDIAN, and BYTE_ORDER.	 Condition byteswapping
	macros only on !__ASSEMBLER__.	Move the definitions of
	__BIG_ENDIAN, __LITTLE_ENDIAN, __PDP_ENDIAN, __FLOAT_WORD_ORDER,
	and __LONG_LONG_PAIR to...
	* string/bits/endian.h: ...this new file, which includes
	the renamed header bits/endianness.h for the definition of
	__BYTE_ORDER and possibly __FLOAT_WORD_ORDER.

	* string/Makefile: Install bits/endianness.h.
	* include/bits/endian.h: New wrapper.

	* bits/endian.h: Rename to bits/endianness.h.
	Add multiple-include guard.  Rewrite the comment explaining what
	the machine-specific variants of this file should do.

	* sysdeps/unix/sysv/linux/ia64/bits/endian.h:
	Move to sysdeps/ia64.

	* sysdeps/aarch64/bits/endian.h
	* sysdeps/alpha/bits/endian.h
	* sysdeps/arm/bits/endian.h
	* sysdeps/csky/bits/endian.h
	* sysdeps/hppa/bits/endian.h
	* sysdeps/ia64/bits/endian.h
	* sysdeps/m68k/bits/endian.h
	* sysdeps/microblaze/bits/endian.h
	* sysdeps/mips/bits/endian.h
	* sysdeps/nios2/bits/endian.h
	* sysdeps/powerpc/bits/endian.h
	* sysdeps/riscv/bits/endian.h
	* sysdeps/s390/bits/endian.h
	* sysdeps/sh/bits/endian.h
	* sysdeps/sparc/bits/endian.h
	* sysdeps/x86/bits/endian.h:
	Rename to endianness.h; canonicalize form of file; remove
	redundant definitions of __FLOAT_WORD_ORDER.

	* sysdeps/powerpc/bits/endianness.h: Remove logic to check for
	broken compilers.

	* ctype/ctype.h
	* sysdeps/aarch64/nptl/bits/pthreadtypes-arch.h
	* sysdeps/arm/nptl/bits/pthreadtypes-arch.h
	* sysdeps/csky/nptl/bits/pthreadtypes-arch.h
	* sysdeps/ia64/ieee754.h
	* sysdeps/ieee754/ieee754.h
	* sysdeps/ieee754/ldbl-128/ieee754.h
	* sysdeps/ieee754/ldbl-128ibm/ieee754.h
	* sysdeps/m68k/nptl/bits/pthreadtypes-arch.h
	* sysdeps/microblaze/nptl/bits/pthreadtypes-arch.h
	* sysdeps/mips/ieee754/ieee754.h
	* sysdeps/mips/nptl/bits/pthreadtypes-arch.h
	* sysdeps/nios2/nptl/bits/pthreadtypes-arch.h
	* sysdeps/nptl/pthread.h
	* sysdeps/riscv/nptl/bits/pthreadtypes-arch.h
	* sysdeps/sh/nptl/bits/pthreadtypes-arch.h
	* sysdeps/sparc/sparc32/ieee754.h
	* sysdeps/unix/sysv/linux/generic/bits/stat.h
	* sysdeps/unix/sysv/linux/generic/bits/statfs.h
	* sysdeps/unix/sysv/linux/sys/acct.h
	* wctype/bits/wctype-wchar.h:
	Include bits/endian.h, not endian.h.

	* sysdeps/unix/sysv/linux/hppa/pthread.h: Don’t include endian.h.

	* sysdeps/mips/ieee754/ieee754.h: Use __LDBL_MANT_DIG__
	in ifdefs, instead of LDBL_MANT_DIG.  Only include float.h
	when __LDBL_MANT_DIG__ is not predefined, in which case
	define __LDBL_MANT_DIG__ to equal LDBL_MANT_DIG.

Also, change sources.redhat.com to sourceware.org.
This patch was automatically generated by running the following shell
script, which uses GNU sed, and which avoids modifying files imported
from upstream:

sed -ri '
  s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g
  s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g
' \
  $(find $(git ls-files) -prune -type f \
      ! -name '*.po' \
      ! -name 'ChangeLog*' \
      ! -path COPYING ! -path COPYING.LIB \
      ! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \
      ! -path manual/texinfo.tex ! -path scripts/config.guess \
      ! -path scripts/config.sub ! -path scripts/install-sh \
      ! -path scripts/mkinstalldirs ! -path scripts/move-if-change \
      ! -path INSTALL ! -path  locale/programs/charmap-kw.h \
      ! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \
      ! '(' -name configure \
            -execdir test -f configure.ac -o -f configure.in ';' ')' \
      ! '(' -name preconfigure \
            -execdir test -f preconfigure.ac ';' ')' \
      -print)

and then by running 'make dist-prepare' to regenerate files built
from the altered files, and then executing the following to cleanup:

  chmod a+x sysdeps/unix/sysv/linux/riscv/configure
  # Omit irrelevant whitespace and comment-only changes,
  # perhaps from a slightly-different Autoconf version.
  git checkout -f \
    sysdeps/csky/configure \
    sysdeps/hppa/configure \
    sysdeps/riscv/configure \
    sysdeps/unix/sysv/linux/csky/configure
  # Omit changes that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines
  git checkout -f \
    sysdeps/powerpc/powerpc64/ppc-mcount.S \
    sysdeps/unix/sysv/linux/s390/s390-64/syscall.S
  # Omit change that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline
  git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S

Commit 1294b1892e ("Add support for sqrt asm redirects") added the
-fno-math-errno flag to build most of the glibc in order to enable GCC
to inline math functions. Due to GCC bug #88576, saving and restoring
errno around calls to malloc are optimized-out. In turn this causes
strerror to set errno to ENOMEM if it get passed an invalid error number
and if malloc sets errno to ENOMEM (which might happen even if it
succeeds). This is not allowed by POSIX.

This patch changes the build flags, building only libm with
-fno-math-errno and all the remaining code with -fno-math-errno. This
should be safe as libm doesn't contain any code saving and restoring
errno around malloc. This patch can probably be reverted once the GCC
bug is fixed and available in stable releases.

Tested on x86-64, no regression in the testsuite.

Changelog:
	[BZ #24024]
	* Makeconfig: Build libm with -fno-math-errno but build the remaining
	code with -fmath-errno.
	* string/Makefile [$(build-shared)] (tests): Add test-strerror-errno.
	[$(build-shared)] (LDLIBS-test-strerror-errno): New variable.
	* string/test-strerror-errno.c: New file.

	* All files with FSF copyright notices: Update copyright dates
	using scripts/update-copyrights.
	* locale/programs/charmap-kw.h: Regenerated.
	* locale/programs/locfile-kw.h: Likewise.

We have a general principle of preferring optimizations for library
facilities to use compiler built-in functions rather than being
located in library headers, where the compiler can reasonably optimize
code without needing to know glibc implementation details.

This patch applies this principle to bits/byteswap.h, eliminating all
the architecture-specific variants and bits/byteswap-16.h.  The
__bswap_16, __bswap_32 and __bswap_64 interfaces all become inline
functions, never macros, using the GCC built-in functions where
available and otherwise a single architecture-independent definition
using shifts and masking (which compilers may well be able to detect
and optimize; GCC has detection of various byte-swapping idioms).

The __bswap_constant_32 macro needs to stay around because of uses in
static initializers within glibc and its tests, and so for consistency
all __bswap_constant_* are kept rather than just being inlined into
the old-GCC-or-non-GCC parts of the __bswap_* inline function
definitions.

Various open bugs are addressed by this cleanup, with caveats about
exactly what is covered by those bugs and when the bugs applied at
all.

Bug 14508 reports -Wformat warnings building glibc because __bswap_*
sometimes returned the wrong types.  Obviously we already don't have
such warnings any more or the build would be failing, given -Werror,
and I suspect that bug was originally for wrong types for x86_64, as
fixed by commit d394eb742a3565d7fe7a4b02710a60b5f219ee64 (glibc 2.17).
The only case I saw removed by this patch where the types would still
have been wrong was the non-__GNUC__ case of __bswap_64 in the s390
header (using unsigned long long int, but uint64_t would be unsigned
long int for 64-bit).  In any case, the single header consistently
uses __uintN_t types after this patch, thereby eliminating all such
bugs.  The existing string/test-endian-types.c test already suffices
to verify that the types are correct with the compiler used to build
glibc and its tests.

Bug 15512 reports an error from __bswap_constant_16 with -Werror
-Wsign-conversion.  I am unable to reproduce this with any GCC version
supporting -Wsign-conversion - all seem to be able to avoid warning
for ((x) >> 8) & 0xffu, where x is uint16_t, which while it formally
does involve an implicit conversion from int to unsigned int, is also
a case where it should be easy for the compiler to see that the value
converted is never negative.  But in this patch __bswap_constant_16 is
changed to use signed 0xff so that no such implicit conversion occurs
at all, and a test with -Werror -Wsign-conversion is added.

Bug 17082 objects to the use of ({}) statement expressions in these
macros preventing use at file scope (in C, that's in sizeof etc.; in
C++, more generally in static initializers).  The particular case of
these interfaces is fixed by this patch as it changes them to inline
functions, eliminating all uses of ({}) in bits/byteswap.h, and a
corresponding testcase is added.  The bug tries to raise a more
general policy question about use of ({}) in macros in installed
headers, referring to "many other libc functions" (unspecified which
functions are being considered).

Since such policy questions belong on libc-alpha, and since there
*are* macros in installed headers which can't really avoid using ({})
(where they are type-generic, so can't use an inline function, but
need a temporary variable, and a few where the interface involves
returning memory from alloca so can't use an inline function either),
I propose to consider that bug fixed with this change.  That is
without prejudice to any other new bugs anyone wishes to file *for
precisely defined sets of macros* requesting moving away from ({})
*where it is clearly possible for those interfaces*.  Where ({}) can
be avoided, typically by use of an inline function, I think that's a
good idea - that inline functions are typically to be preferred to
({}) for header interfaces where such optimizations are useful but the
interface is suited to being defined using an inline function.

Bug 20530 requests use of __builtin_bswap16 when available (GCC 4.8
and later), which this patch implements.

Tested for x86_64, and with build-many-glibcs.py.  Also did an x86_64
test with the __GNUC_PREREQ conditionals changed to "#if 0" to verify
the old-GCC/non-GCC case in the headers.  (There are already existing
tests for correctness of results of these interfaces.)

	[BZ #14508]
	[BZ #15512]
	[BZ #17082]
	[BZ #20530]
	* bits/byteswap.h: Update file comment.  Do not include
	<bits/byteswap-16.h>.
	(__bswap_constant_16): Cast result to __uint16_t.  Use signed 0xff
	constant.
	(__bswap_16): Define as inline function.
	(__bswap_constant_32): Reformat definition.
	(__bswap_32): Always define as inline function, not macro, using
	__uint32_t.  Use __builtin_bswap32 if [__GNUC_PREREQ (4, 3)],
	otherwise __bswap_constant_32.
	(__bswap_constant_64): Reformat definition.  Do not use
	__extension__ here.
	(__bswap_64): Always define as inline function, not macro.  Use
	__extension__ on function definition.  Use __builtin_bswap64 if
	[__GNUC_PREREQ (4, 3)], otherwise __bswap_constant_64.
	* string/test-endian-file-scope.c: New file.
	* string/test-endian-sign-conversion.c: Likewise.
	* string/Makefile (headers): Remove bits/byteswap-16.h.
	(tests): Add test-endian-file-scope and
	test-endian-sign-conversion.
	(CFLAGS-test-endian-sign-conversion.c): New variable.
	* bits/byteswap-16.h: Remove file.
	* sysdeps/ia64/bits/byteswap-16.h: Likewise.
	* sysdeps/ia64/bits/byteswap.h: Likewise.
	* sysdeps/m68k/bits/byteswap.h: Likewise.
	* sysdeps/s390/bits/byteswap-16.h: Likewise.
	* sysdeps/s390/bits/byteswap.h: Likewise.
	* sysdeps/tile/bits/byteswap.h: Likewise.
	* sysdeps/x86/bits/byteswap-16.h: Likewise.
	* sysdeps/x86/bits/byteswap.h: Likewise.

	* All files with FSF copyright notices: Update copyright dates
	using scripts/update-copyrights.
	* locale/programs/charmap-kw.h: Regenerated.
	* locale/programs/locfile-kw.h: Likewise.

Replace = with += in CFLAGS-xxx.c to allow Makefile under sysdeps to
define CFLAGS-xx.c.

	* string/Makefile (CFLAGS-inl-tester.c): Replace = with +=.
	(CFLAGS-noinl-tester.c): Likewise.
	(CFLAGS-tst-strlen.c): Likewise.
	(CFLAGS-stratcliff.c): Likewise.
	(CFLAGS-test-ffs.c): Likewise.
	(CFLAGS-tst-inlcall.c): Likewise.
	(CFLAGS-tst-xbzero-opt.c): Likewise.
	(CFLAGS-memcpy.c): Likewise.
	(CFLAGS-wordcopy.c): Likewise.

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.