Ensure isinff, isinfl, isnanf, and isnanl are defined (Bug 19439)

In ICO C++11 mode ensure that isinff, isinfl, isnanf, and isnanl
are defined.  These functions were accidentally removed from the
header as part of commit d9b965fa56,
but being GNU extensions, they should have been left in place.

ChangeLog

@@ -1,3 +1,16 @@
+2016-02-14  Jakub Jelinek  <jakub@redhat.com>
+	    Jonathan Wakely  <jwakely@redhat.com>
+	    Carlos O'Donell  <carlos@redhat.com>
+
+	[BZ 19439]
+	* math/Makefile (tests): Add test-math-isinff.
+	(CFLAGS-test-math-isinff.cc): Use -std=gnu++11.
+	* math/bits/mathcalls.h [__USE_MISC]: Use
+	'|| __MATH_DECLARING_DOUBLE == 0' to relax definition of
+	functions not in C++11 and which don't conflict e.g. isinff,
+	isinfl etc.
+	* math/test-math-isinff.cc: New file.
+
 2016-02-12  Florian Weimer  <fweimer@redhat.com>
 
 	* misc/bug18240.c (do_test): Set RLIMIT_AS.
@@ -38,7 +51,7 @@
 	* misc/Makefile (tests): Add it.
 
 2016-01-28  Steve Ellcey  <sellcey@imgtec.com>
-            Joseph Myers  <joseph@codesourcery.com>
+	    Joseph Myers  <joseph@codesourcery.com>
 
 	* sysdeps/mips/memcpy.S (MEMCPY_NAME) [USE_DOUBLE]: Avoid word
 	load in branch delay slot when less than a word of input left.

math/Makefile

@@ -114,6 +114,7 @@ tests = test-matherr test-fenv atest-exp atest-sincos atest-exp2 basic-test \
 	test-nearbyint-except-2 test-signgam-uchar test-signgam-uchar-init \
 	test-signgam-uint test-signgam-uint-init test-signgam-ullong \
 	test-signgam-ullong-init test-nan-overflow test-nan-payload \
+	test-math-isinff \
 	$(tests-static)
 tests-static = test-fpucw-static test-fpucw-ieee-static \
 	       test-signgam-uchar-static test-signgam-uchar-init-static \
@@ -220,6 +221,8 @@ CFLAGS-test-signgam-ullong-init.c = -std=c99
 CFLAGS-test-signgam-ullong-static.c = -std=c99
 CFLAGS-test-signgam-ullong-init-static.c = -std=c99
 
+CFLAGS-test-math-isinff.cc = -std=gnu++11
+
 # The -lieee module sets the _LIB_VERSION_ switch to IEEE mode
 # for error handling in the -lm functions.
 install-lib += libieee.a

math/bits/mathcalls.h

@@ -196,7 +196,9 @@ __MATHDECL_1 (int,__finite,, (_Mdouble_ __value)) __attribute__ ((__const__));
 _Mdouble_END_NAMESPACE
 
 #ifdef __USE_MISC
-# if !defined __cplusplus || __cplusplus < 201103L /* Conflicts with C++11.  */
+# if (!defined __cplusplus \
+      || __cplusplus < 201103L /* isinf conflicts with C++11.  */ \
+      || __MATH_DECLARING_DOUBLE == 0) /* isinff or isinfl don't.  */
 /* Return 0 if VALUE is finite or NaN, +1 if it
    is +Infinity, -1 if it is -Infinity.  */
 __MATHDECL_1 (int,isinf,, (_Mdouble_ __value)) __attribute__ ((__const__));
@@ -232,7 +234,9 @@ __END_NAMESPACE_C99
 __MATHDECL_1 (int,__isnan,, (_Mdouble_ __value)) __attribute__ ((__const__));
 
 #if defined __USE_MISC || (defined __USE_XOPEN && !defined __USE_XOPEN2K)
-# if !defined __cplusplus || __cplusplus < 201103L /* Conflicts with C++11.  */
+# if (!defined __cplusplus \
+      || __cplusplus < 201103L /* isnan conflicts with C++11.  */ \
+      || __MATH_DECLARING_DOUBLE == 0) /* isnanf or isnanl don't.  */
 /* Return nonzero if VALUE is not a number.  */
 __MATHDECL_1 (int,isnan,, (_Mdouble_ __value)) __attribute__ ((__const__));
 # endif

math/test-math-isinff.cc

@@ -0,0 +1,48 @@
+/* Test for bug 19439.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Marek Polacek <polacek@redhat.com>, 2012.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#define _GNU_SOURCE 1
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+static int
+do_test (void)
+{
+  /* Verify that isinff, isinfl, isnanf, and isnanlf are defined
+     in the header under C++11 and can be called.  Without the
+     header fix this test will not compile.  */
+  if (isinff (1.0f)
+      || !isinff (INFINITY)
+      || isinfl (1.0L)
+      || !isinfl (INFINITY)
+      || isnanf (2.0f)
+      || !isnanf (NAN)
+      || isnanl (2.0L)
+      || !isnanl (NAN))
+    {
+      printf ("FAIL: Failed to call is* functions.\n");
+      exit (1);
+    }
+  printf ("PASS: Able to call isinff, isinfl, isnanf, and isnanl.\n");
+  exit (0);
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"