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

[Jose Fonseca]

On 31/03/16 23:08, Pierre Moreau wrote:
> 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

I'm not sure a new header is necessary for this.

What this is doing is making C++11 math functions "appear" like C99 
ones.  It's not making things matching C++11 standard.

So IMO the right place for this is the end of c99_math.h

Jose

> @@ -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>
>