[Mesa-dev] [PATCH v2] math: Import isinf and others to global namespace

[Pierre Moreau]

Starting from C++11, several math functions, like isinf, moved into the std
namespace. Since cmath undefines those functions before redefining them inside
the namespace, and glibc 2.23 defines the C variants as macros, the C variants
in global namespace are not accessible any longer.

v2: Move the fix outside of Nouveau, as suggested by Jose Fonseca, since anyone
    might need it when GCC switches to C++14 by default with GCC 6.0.

Signed-off-by: Pierre Moreau <pierre.morrow at free.fr>
---
 include/cpp11_math.h                | 61 +++++++++++++++++++++++++++++++++++++
 src/gallium/auxiliary/util/u_math.h |  3 ++
 2 files changed, 64 insertions(+)
 create mode 100644 include/cpp11_math.h

diff --git a/include/cpp11_math.h b/include/cpp11_math.h
new file mode 100644
index 0000000..1f4aa3c
--- /dev/null
+++ b/include/cpp11_math.h
@@ -0,0 +1,61 @@
+/**************************************************************************
+ *
+ * Copyright 2016 Pierre Moreau
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
+ * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
+ * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ **************************************************************************/
+
+/**
+ * Wrapper for cmath which makes sure we maintain source compatibility with
+ * newer versions of C++.
+ */
+
+
+#ifndef _CPP11_MATH_H_
+#define _CPP11_MATH_H_
+
+
+/* Since C++11, the following functions are part of the std namespace. Their C
+ * counteparts should still exist in the global namespace, however cmath
+ * undefines those functions, which in glibc 2.23, are defined as macros rather
+ * than functions as in glibc 2.22.
+ */
+#if __cplusplus >= 201103L
+#include <cmath>
+
+using std::fpclassify;
+using std::isfinite;
+using std::isinf;
+using std::isnan;
+using std::isnormal;
+using std::signbit;
+using std::isgreater;
+using std::isgreaterequal;
+using std::isless;
+using std::islessequal;
+using std::islessgreater;
+using std::isunordered;
+#endif
+
+
+#endif /* #define _CPP11_MATH_H_ */
diff --git a/src/gallium/auxiliary/util/u_math.h b/src/gallium/auxiliary/util/u_math.h
index e92f83a..12a3780 100644
--- a/src/gallium/auxiliary/util/u_math.h
+++ b/src/gallium/auxiliary/util/u_math.h
@@ -42,6 +42,9 @@
 #include "pipe/p_compiler.h"
 
 #include "c99_math.h"
+#ifdef __cplusplus
+#include "cpp11_math.h"
+#endif
 #include <assert.h>
 #include <float.h>
 #include <stdarg.h>
-- 
2.8.0