Define TS 18661-1 type width macros in <limits.h> and <stdint.h>.

TS 18661-1 defines <limits.h> and <stdint.h> macros for widths of
standard integer types and the typedefs defined in, or whose limits
are defined in, <stdint.h>.  (The connection to the main
floating-point subject matter of TS 18661-1 is that these are intended
to be used with the fromfp functions to convert from floating point to
integer types of any width in any rounding direction, though these
macros may be of more general use.)

This patch implements support for these macros in GCC's <limits.h> and
<stdint.h>.  To avoid needing to implement fixincludes for system
headers where GCC wraps the system libc's <stdint.h> in hosted mode,
the test for the <stdint.h> macros uses -ffreestanding (I'll add the
macros to glibc's headers separately) - but as usual for new features
in these headers, platforms (primarily OpenBSD) that use USER_H to
avoid using GCC's headers at all will have failures until the system
headers have the feature added or appropriate fixincludes are
implemented.

The header macros are implemented using appropriate new predefined
macros, with the code avoiding defining more such macros than
necessary (so one predefined macro suffices for corresponding signed
and unsigned types, while no such predefined macros are needed for the
exact-width types such as int8_t).

Bootstrapped with no regressions on x86_64-pc-linux-gnu.

gcc:
	* doc/cpp.texi (__SCHAR_WIDTH__, __SHRT_WIDTH__, __INT_WIDTH__)
	(__LONG_WIDTH__, __LONG_LONG_WIDTH__, __PTRDIFF_WIDTH__)
	(__SIG_ATOMIC_WIDTH__, __SIZE_WIDTH__, __WCHAR_WIDTH__)
	(__WINT_WIDTH__, __INT_LEAST8_WIDTH__, __INT_LEAST16_WIDTH__)
	(__INT_LEAST32_WIDTH__, __INT_LEAST64_WIDTH__)
	(__INT_FAST8_WIDTH__, __INT_FAST16_WIDTH__, __INT_FAST32_WIDTH__)
	(__INT_FAST64_WIDTH__, __INTPTR_WIDTH__, __INTMAX_WIDTH__):
	Document.
	* ginclude/stdint-gcc.h [__STDC_WANT_IEC_60559_BFP_EXT__]: Define
	width macros from TS 18661-1.
	* glimits.h [__STDC_WANT_IEC_60559_BFP_EXT__]: Likewise.

gcc/c-family:
	* c-cppbuiltin.c (builtin_define_type_width): New function.
	(builtin_define_stdint_macros, c_cpp_builtins): Define type width
	macros.

gcc/testsuite:
	* gcc.dg/limits-width-1.c, gcc.dg/stdint-width-1.c: New tests.

From-SVN: r240048

1 files changed, 26 insertions, 0 deletions

diff --git a/gcc/glimits.h b/gcc/glimits.h
index 9acd467017d..3967bfe5a0e 100644
--- a/gcc/glimits.h
+++ b/gcc/glimits.h
@@ -123,4 +123,30 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 # define ULONG_LONG_MAX (LONG_LONG_MAX * 2ULL + 1ULL)
 #endif
 
+#ifdef __STDC_WANT_IEC_60559_BFP_EXT__
+/* TS 18661-1 widths of integer types.  */
+# undef CHAR_WIDTH
+# define CHAR_WIDTH __SCHAR_WIDTH__
+# undef SCHAR_WIDTH
+# define SCHAR_WIDTH __SCHAR_WIDTH__
+# undef UCHAR_WIDTH
+# define UCHAR_WIDTH __SCHAR_WIDTH__
+# undef SHRT_WIDTH
+# define SHRT_WIDTH __SHRT_WIDTH__
+# undef USHRT_WIDTH
+# define USHRT_WIDTH __SHRT_WIDTH__
+# undef INT_WIDTH
+# define INT_WIDTH __INT_WIDTH__
+# undef UINT_WIDTH
+# define UINT_WIDTH __INT_WIDTH__
+# undef LONG_WIDTH
+# define LONG_WIDTH __LONG_WIDTH__
+# undef ULONG_WIDTH
+# define ULONG_WIDTH __LONG_WIDTH__
+# undef LLONG_WIDTH
+# define LLONG_WIDTH __LONG_LONG_WIDTH__
+# undef ULLONG_WIDTH
+# define ULLONG_WIDTH __LONG_LONG_WIDTH__
+#endif
+
 #endif /* _LIMITS_H___ */