Remove C++ namespace handling from glibc headers.

glibc headers include some code (not particularly consistent or
systematic) to put various declarations in C++ namespaces std and
__c99, if _GLIBCPP_USE_NAMESPACES is defined.

As noted in <https://gcc.gnu.org/ml/libstdc++/2017-03/msg00025.html>,
this macro was removed from libstdc++ in 2000.  I don't expect
compilation with such old versions of libstdc++ to work with current
glibc headers anyway (whereas old *binaries* are expected to stay
working with current glibc); this patch (which should be a no-op with
any libstdc++ version postdating that removal) removes all this code
from the glibc headers.

The begin-end-check.pl test, whose comments say it is about checking
these namespace macro calls, is also removed.  The code in that test
would have covered __BEGIN_DECLS / __END_DECLS as well, but if those
weren't properly matched it would show up with the
check-installed-headers-cxx tests, so I don't think there is an actual
use for keeping begin-end-check.pl with the namespace code removed.

Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).

	* misc/sys/cdefs.h (__BEGIN_NAMESPACE_STD): Remove macro.
	(__END_NAMESPACE_STD): Likewise.
	(__USING_NAMESPACE_STD): Likewise.
	(__BEGIN_NAMESPACE_C99): Likewise.
	(__END_NAMESPACE_C99): Likewise.
	(__USING_NAMESPACE_C99): Likewise.
	* math/math.h (_Mdouble_BEGIN_NAMESPACE): Do not define and
	undefine macro.
	(_Mdouble_END_NAMESPACE): Likewise.
	* ctype/ctype.h: Do not handle C++ namespaces.
	* libio/bits/stdio-ldbl.h: Likewise.
	* libio/stdio.h: Likewise.
	* locale/locale.h: Likewise.
	* math/bits/mathcalls.h: Likewise.
	* setjmp/setjmp.h: Likewise.
	* signal/signal.h: Likewise.
	* stdlib/bits/stdlib-float.h: Likewise.
	* stdlib/bits/stdlib-ldbl.h: Likewise.
	* stdlib/stdlib.h: Likewise.
	* string/string.h: Likewise.
	* sysdeps/x86/fpu/bits/mathinline.h: Likewise.
	* time/bits/types/clock_t.h: Likewise.
	* time/bits/types/struct_tm.h: Likewise.
	* time/bits/types/time_t.h: Likewise.
	* time/time.h: Likewise.
	* wcsmbs/bits/wchar-ldbl.h: Likewise.
	* wcsmbs/uchar.h: Likewise.
	* wcsmbs/wchar.h: Likewise.
	[_GLIBCPP_USE_NAMESPACES] (wint_t): Remove conditional definition.
	* wctype/wctype.h: Do not handle C++ namespaces.
	* scripts/begin-end-check.pl: Remove.
	* Makefile (installed-headers): Likewise.
	(tests-special): Do not add $(objpfx)begin-end-check.out.
	($(objpfx)begin-end-check.out): Remove.

1 files changed, 0 insertions, 25 deletions

diff --git a/misc/sys/cdefs.h b/misc/sys/cdefs.h
index e5fe4f89d9..b03ebda22f 100644
--- a/misc/sys/cdefs.h
+++ b/misc/sys/cdefs.h
@@ -112,31 +112,6 @@
 #endif
 
 
-/* The standard library needs the functions from the ISO C90 standard
-   in the std namespace.  At the same time we want to be safe for
-   future changes and we include the ISO C99 code in the non-standard
-   namespace __c99.  The C++ wrapper header take case of adding the
-   definitions to the global namespace.  */
-#if defined __cplusplus && defined _GLIBCPP_USE_NAMESPACES
-# define __BEGIN_NAMESPACE_STD	namespace std {
-# define __END_NAMESPACE_STD	}
-# define __USING_NAMESPACE_STD(name) using std::name;
-# define __BEGIN_NAMESPACE_C99	namespace __c99 {
-# define __END_NAMESPACE_C99	}
-# define __USING_NAMESPACE_C99(name) using __c99::name;
-#else
-/* For compatibility we do not add the declarations into any
-   namespace.  They will end up in the global namespace which is what
-   old code expects.  */
-# define __BEGIN_NAMESPACE_STD
-# define __END_NAMESPACE_STD
-# define __USING_NAMESPACE_STD(name)
-# define __BEGIN_NAMESPACE_C99
-# define __END_NAMESPACE_C99
-# define __USING_NAMESPACE_C99(name)
-#endif
-
-
 /* Fortify support.  */
 #define __bos(ptr) __builtin_object_size (ptr, __USE_FORTIFY_LEVEL > 1)
 #define __bos0(ptr) __builtin_object_size (ptr, 0)