Fix bits/math-finite.h _MSUF_ expansion namespace (bug 22028).

The current bits/math-finite.h approach to defining functions for
different types, involving math.h defining _MSUF_ and _MSUFTO_ for the
function suffixes involved, is not namespace-clean if one of those
suffixes (f, l, f128) is defined as a macro by the user before math.h
is included; too many levels of macro expansion occur.  Instead, those
suffixes should appear directly in the expansion of the macro using ##
so they don't get expanded even if defined as macros by the user (that
is, math.h should be defining __REDIRFROM_X and __REDIRTO_X directly
to use those suffixes rather than suffixes being passed as an argument
by macro callers).  This patch makes that change.

Tested for x86_64.

	[BZ #22028]
	* math/math.h [__FINITE_MATH_ONLY__ && __FINITE_MATH_ONLY__ > 0]
	(_MSUF_): Remove macro.
	[__FINITE_MATH_ONLY__ && __FINITE_MATH_ONLY__ > 0] (_MSUFTO_):
	Likewise.
	[__FINITE_MATH_ONLY__ && __FINITE_MATH_ONLY__ > 0]
	(__REDIRFROM_X): New macro.
	[__FINITE_MATH_ONLY__ && __FINITE_MATH_ONLY__ > 0] (__REDIRTO_X):
	Likewise.
	* math/bits/math-finite.h (__REDIRFROM_X): Remove macro.
	(__REDIRTO_X): Likewise.
	(__MATH_REDIRCALL): Do not pass _MSUF_ or _MSUFTO_ macro
	arguments.
	(__MATH_REDIRCALL_2): Likewise.
	(__MATH_REDIRCALL_INTERNAL): Likewise.
	(__REDIRFROM (lgamma, , _MSUF_)): Likewise.
	(__REDIRFROM (gamma, , _MSUF_)): Likweise.
	(__REDIRFROM (__gamma, _r_finite, _MSUF_)): Likewise.
	(__REDIRFROM (tgamma, , _MSUF_)): Likewise.
	* math/test-finite-macros.c: New file.
	* math/Makefile (tests): Add test-finite-macros.
	(CFLAGS-test-finite-macros.c): New variable.

1 files changed, 14 insertions, 20 deletions

diff --git a/math/bits/math-finite.h b/math/bits/math-finite.h
index 4c8295842c..de57b504bd 100644
--- a/math/bits/math-finite.h
+++ b/math/bits/math-finite.h
@@ -20,30 +20,26 @@
 # error "Never use <bits/math-finite.h> directly; include <math.h> instead."
 #endif
 
-#define __REDIRFROM_X(function, reentrant, suffix) \
-  function ## suffix ## reentrant
 #define __REDIRFROM(...) __REDIRFROM_X(__VA_ARGS__)
 
-#define __REDIRTO_X(function, reentrant, suffix) \
-   __ ## function ## suffix ## reentrant ## _finite
 #define __REDIRTO(...) __REDIRTO_X(__VA_ARGS__)
 
 #define __MATH_REDIRCALL_X(from, args, to) \
   extern _Mdouble_ __REDIRECT_NTH (from, args, to)
 #define __MATH_REDIRCALL(function, reentrant, args) \
   __MATH_REDIRCALL_X \
-   (__REDIRFROM (function, reentrant, _MSUF_), args, \
-    __REDIRTO (function, reentrant, _MSUFTO_))
+   (__REDIRFROM (function, reentrant), args, \
+    __REDIRTO (function, reentrant))
 #define __MATH_REDIRCALL_2(from, reentrant, args, to) \
   __MATH_REDIRCALL_X \
-   (__REDIRFROM (from, reentrant, _MSUF_), args, \
-    __REDIRTO (to, reentrant, _MSUFTO_))
+   (__REDIRFROM (from, reentrant), args, \
+    __REDIRTO (to, reentrant))
 
 #define __MATH_REDIRCALL_INTERNAL(function, reentrant, args) \
   __MATH_REDIRCALL_X \
    (__REDIRFROM (__CONCAT (__, function), \
-		 __CONCAT (reentrant, _finite), _MSUF_), \
-    args, __REDIRTO (function, _r, _MSUFTO_))
+		 __CONCAT (reentrant, _finite)), \
+    args, __REDIRTO (function, _r))
 
 
 /* acos.  */
@@ -129,13 +125,13 @@ __MATH_REDIRCALL_INTERNAL (lgamma, _r, (_Mdouble_, int *));
      && defined __extern_always_inline)
 /* lgamma.  */
 __extern_always_inline _Mdouble_
-__NTH (__REDIRFROM (lgamma, , _MSUF_) (_Mdouble_ __d))
+__NTH (__REDIRFROM (lgamma, ) (_Mdouble_ __d))
 {
 # if defined __USE_MISC || defined __USE_XOPEN
-  return __REDIRTO (lgamma, _r, _MSUFTO_) (__d, &signgam);
+  return __REDIRTO (lgamma, _r) (__d, &signgam);
 # else
   int __local_signgam = 0;
-  return __REDIRTO (lgamma, _r, _MSUFTO_) (__d, &__local_signgam);
+  return __REDIRTO (lgamma, _r) (__d, &__local_signgam);
 # endif
 }
 #endif
@@ -144,9 +140,9 @@ __NTH (__REDIRFROM (lgamma, , _MSUF_) (_Mdouble_ __d))
      && defined __extern_always_inline) && !__MATH_DECLARING_FLOATN
 /* gamma.  */
 __extern_always_inline _Mdouble_
-__NTH (__REDIRFROM (gamma, , _MSUF_) (_Mdouble_ __d))
+__NTH (__REDIRFROM (gamma, ) (_Mdouble_ __d))
 {
-  return __REDIRTO (lgamma, _r, _MSUFTO_) (__d, &signgam);
+  return __REDIRTO (lgamma, _r) (__d, &signgam);
 }
 #endif
 
@@ -187,21 +183,19 @@ __MATH_REDIRCALL (sqrt, , (_Mdouble_));
 #if defined __USE_ISOC99 && defined __extern_always_inline
 /* tgamma.  */
 extern _Mdouble_
-__REDIRFROM (__gamma, _r_finite, _MSUF_) (_Mdouble_, int *);
+__REDIRFROM (__gamma, _r_finite) (_Mdouble_, int *);
 
 __extern_always_inline _Mdouble_
-__NTH (__REDIRFROM (tgamma, , _MSUF_) (_Mdouble_ __d))
+__NTH (__REDIRFROM (tgamma, ) (_Mdouble_ __d))
 {
   int __local_signgam = 0;
-  _Mdouble_ __res = __REDIRTO (gamma, _r, _MSUFTO_) (__d, &__local_signgam);
+  _Mdouble_ __res = __REDIRTO (gamma, _r) (__d, &__local_signgam);
   return __local_signgam < 0 ? -__res : __res;
 }
 #endif
 
 #undef __REDIRFROM
-#undef __REDIRFROM_X
 #undef __REDIRTO
-#undef __REDIRTO_X
 #undef __MATH_REDIRCALL
 #undef __MATH_REDIRCALL_2
 #undef __MATH_REDIRCALL_INTERNAL