| Message ID | CAH6eHdQ4xWLYJEfYJ2ha-uebqGYZtWEsQkuFWQbp=eYFqDXQaA@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
I've just seen Richard's status email, so I guess this should wait for 4.8 On 9 January 2012 08:48, Jonathan Wakely wrote: > GCC's implementation of <stdbool.h> is not valid for C++11 because > [support.runtime] p8 says "The header <cstdbool> and the header > <stdbool.h> shall not define macros named bool, true, or false." > > This patch adds a libstdc++ test for that requirement and adjusts > stdbool.h to meet it. I've left _Bool defined in C++ as a GNU > extension. > > It's conceivable someone is relying on these macros being defined in > C++, in which case we could only define them when __cplusplus < > 201103L, but IMHO it's better to not define them at all. > > Tested x86_64-linux, OK for trunk? > > gcc/ > * ginclude/stdbool.h (true, false, bool): Do not define for C++. > > libstdc++/ > * testsuite/18_support/headers/cstdbool/macros.cc: New.
For what it's worth, I strongly suggest that you only define those when __cpluplus is pre-C++11. There is simply too much software out there which will run into this and being aggressive in breaking (admittedly non-standard confirming programs) gives GCC a bad reputation and is not nice to our users to begin with. Gerald On Mon, 9 Jan 2012, Jonathan Wakely wrote: > I've just seen Richard's status email, so I guess this should wait for 4.8 > > > On 9 January 2012 08:48, Jonathan Wakely wrote: >> GCC's implementation of <stdbool.h> is not valid for C++11 because >> [support.runtime] p8 says "The header <cstdbool> and the header >> <stdbool.h> shall not define macros named bool, true, or false." >> >> This patch adds a libstdc++ test for that requirement and adjusts >> stdbool.h to meet it. I've left _Bool defined in C++ as a GNU >> extension. >> >> It's conceivable someone is relying on these macros being defined in >> C++, in which case we could only define them when __cplusplus < >> 201103L, but IMHO it's better to not define them at all. >> >> Tested x86_64-linux, OK for trunk? >> >> gcc/ >> * ginclude/stdbool.h (true, false, bool): Do not define for C++. >> >> libstdc++/ >> * testsuite/18_support/headers/cstdbool/macros.cc: New.
--- a/gcc/ginclude/stdbool.h +++ b/gcc/ginclude/stdbool.h @@ -1,4 +1,4 @@ -/* Copyright (C) 1998, 1999, 2000, 2009 Free Software Foundation, Inc. +/* Copyright (C) 1998, 1999, 2000, 2009, 2012 Free Software Foundation, Inc. This file is part of GCC. @@ -36,11 +36,8 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see #else /* __cplusplus */ -/* Supporting <stdbool.h> in C++ is a GCC extension. */ +/* Supporting _Bool in C++ is a GCC extension. */ #define _Bool bool -#define bool bool -#define false false -#define true true #endif /* __cplusplus */ --- /dev/null +++ b/libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.cc @@ -0,0 +1,38 @@ +// { dg-do compile } +// { dg-options "-std=gnu++11" } + +// Copyright (C) 2012 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. + +// This 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 General Public License for more details. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// <http://www.gnu.org/licenses/>. + +#include <cstdbool> + +#ifndef __bool_true_false_are_defined +# error "The header <cstdbool> fails to define a macro named __bool_true_false_are_defined" +#endif + +#ifdef bool +# error "The header <cstdbool> defines a macro named bool" +#endif + +#ifdef true +# error "The header <cstdbool> defines a macro named true" +#endif + +#ifdef false +# error "The header <cstdbool> defines a macro named false" +#endif +
GCC's implementation of <stdbool.h> is not valid for C++11 because [support.runtime] p8 says "The header <cstdbool> and the header <stdbool.h> shall not define macros named bool, true, or false." This patch adds a libstdc++ test for that requirement and adjusts stdbool.h to meet it. I've left _Bool defined in C++ as a GNU extension. It's conceivable someone is relying on these macros being defined in C++, in which case we could only define them when __cplusplus < 201103L, but IMHO it's better to not define them at all. Tested x86_64-linux, OK for trunk? gcc/ * ginclude/stdbool.h (true, false, bool): Do not define for C++. libstdc++/ * testsuite/18_support/headers/cstdbool/macros.cc: New.