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.

diff --git a/ChangeLog b/ChangeLog
index be9ed44..3da496d 100644 (file)
--- 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.

diff --git a/sysdeps/generic/math_private.h b/sysdeps/generic/math_private.h
index 80c7c92..f29898c 100644 (file)
--- a/sysdeps/generic/math_private.h
+++ b/sysdeps/generic/math_private.h
@@ -298,12 +298,15 @@ extern void __docos (double __x, double __dx, double __v[]);
 
 #define fabs_tg(x) __MATH_TG ((x), (__typeof (x)) __builtin_fabs, (x))
 
-#define min_of_type_f FLT_MIN
-#define min_of_type_ DBL_MIN
-#define min_of_type_l LDBL_MIN
-#define min_of_type_f128 FLT128_MIN
-
-#define min_of_type(x) __MATH_TG ((x), (__typeof (x)) min_of_type_, )
+/* These must be function-like macros because some __MATH_TG
+   implementations macro-expand the function-name argument before
+   concatenating a suffix to it.  */
+#define min_of_type_f() FLT_MIN
+#define min_of_type_() DBL_MIN
+#define min_of_type_l() LDBL_MIN
+#define min_of_type_f128() FLT128_MIN
+
+#define min_of_type(x) __MATH_TG ((x), (__typeof (x)) min_of_type_, ())
 
 /* If X (which is not a NaN) is subnormal, force an underflow
    exception.  */