Make min_of_type_ macros function-like.

math_private.h uses __MATH_TG in defining the min_of_type macro used
within libm, with min_of_type_<suffix> macros for each type.  This
runs into problems with __MATH_TG expansions used with additional
_FloatN and _FloatNx type support, because those can end up
macro-expanding the FUNC argument to __MATH_TG before it gets
concatenated with a suffix - meaning that min_of_type_ can't
simultaneously be the macro name for double, and a prefix to other
macro names, since the latter case requires such premature macro
expansion not to occur.  (This is not a problem for the uses of
__MATH_TG in installed headers because FUNC there is a function name
in the implementation namespace, and the suffixes themselves don't get
macro-expanded.)

This patch fixes the problem by making min_of_type_<suffix> macros
function-like, so no macro expansion occurs when min_of_type_ is
expanded on its own as a macro argument, only later when followed by
() after expansion.

Tested for x86_64, including in conjunction with _Float64x support
patches.

	* sysdeps/generic/math_private.h (min_of_type_f): Make into a
	function-like macro.
	(min_of_type_): Likewise.
	(min_of_type_l): Likewise.
	(min_of_type_f128): Likewise.
	(min_of_type): Pass () as last argument of __MATH_TG.

1 files changed, 7 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index be9ed44..3da496d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 2017-11-24  Joseph Myers  <joseph@codesourcery.com>
 
+	* sysdeps/generic/math_private.h (min_of_type_f): Make into a
+	function-like macro.
+	(min_of_type_): Likewise.
+	(min_of_type_l): Likewise.
+	(min_of_type_f128): Likewise.
+	(min_of_type): Pass () as last argument of __MATH_TG.
+
 	* stdlib/tst-strtod-round-skeleton.c
 	(__STDC_WANT_IEC_60559_TYPES_EXT__): Define before including
 	headers.