On 7 November 2011 08:47, Jonathan Wakely wrote: > On 7 November 2011 00:43, Jonathan Wakely wrote: >> On 7 November 2011 00:37, Joseph S. Myers wrote: >>> On Mon, 7 Nov 2011, Jonathan Wakely wrote: >>> >>>> On 6 November 2011 23:53, Joseph S. Myers wrote: >>>> > >>>> > As with stdnoreturn.h, the contents of stdalign.h are conditioned out >>>> > for C++; I'll leave it to C++ people to work out what's most useful >>>> > there if something nonempty is wanted (stdnoreturn.h is empty for C++, >>>> > stdbool.h defines _Bool and bool to bool, true to true etc.). >>>> >>>> Thanks Joseph, that will allow use to provide <cstdalign> in libstdc++. >>>> >>>> By my reading of the C++11 standard, the __alignas_is_defined macro >>>> should still be defined in C++, and alignof isn't mentioned, was that >>>> a late addition to C1X? >>> >>> The move from alignof as a keyword to _Alignof as a keyword with alignof >>> as a macro in stdalign.h was done at the London meeting (March 2011) in >>> response to comment US20. stdnoreturn.h was also added at that meeting. >> >> Thanks for the info. I think treating alignof identically to alignas >> for C++ makes sense then - the __alignof_is_defined macro is in the >> reserved namespace so it's OK for a conforming C++11 implementation to >> define it. >> >>> It looks like what GCC defines in stdbool.h for C++ goes beyond what C++11 >>> says it should ("The header <cstdbool> and the header <stdbool.h> shall >>> not define macros named bool, true, or false.") stdint.h is another case >>> needing adjustment for C++11, though there what I've suggested is that GCC >>> should predefine __STDC_LIMIT_MACROS and __STDC_CONSTANT_MACROS in C++11 >>> mode as the best way to work with all implementations of that header that >>> follow what C99 footnotes suggest. >> >> Indeed - I was just noticing that the libstdc++ testsuite doesn't >> check that stdbool.h doesn't define those macros. > > > This patch adds <cstdalign> to libstdc++ > > * acinclude.m4: Check for <stdalign.h> > * configure: Regenerate. > * config.h.in: Likewise. > * include/Makefile.am: Add <cstdalign>. > * include/Makefile.in: Regenerate. > * include/c_global/cstdalign: New. > * testsuite/18_support/headers/cstdalign/std_c++0x_neg.cc: New. > * doc/xml/manual/backwards_compatibility.xml: Update. > * doc/xml/manual/status_cxx2011.xml: Update. > > Tested x86_64-linux, committed to trunk.
And then this adjusts <stdalign.h> and <stdbool.h> for C++11 conformance. C++11 requires stdbool.h so providing it is not a GCC extension, but defining _Bool is. I don't see the point of defining bool, true and false as macros in C++ and it's explicitly forbidden by C++11. Personally I'd prefer if _Bool was a typedef rather than a macro, but I haven't changed that. gcc/ChangeLog: * ginclude/stdalign.h (__alignas_is_defined, __alignof_is_defined): Define for C++. * ginclude/stdbool.h (bool, true, false): Do not define for C++. libstdc++-v3/ChangeLog: * testsuite/18_support/headers/cstdalign/macros.cc: New. * testsuite/18_support/headers/cstdbool/macros.cc: New. Tested x86_64-linux, OK for trunk?
Index: gcc/ginclude/stdalign.h =================================================================== --- gcc/ginclude/stdalign.h (revision 181077) +++ gcc/ginclude/stdalign.h (working copy) @@ -31,9 +31,9 @@ #define alignas _Alignas #define alignof _Alignof +#endif + #define __alignas_is_defined 1 #define __alignof_is_defined 1 -#endif - #endif /* stdalign.h */ Index: gcc/ginclude/stdbool.h =================================================================== --- gcc/ginclude/stdbool.h (revision 181077) +++ gcc/ginclude/stdbool.h (working copy) @@ -1,4 +1,4 @@ -/* Copyright (C) 1998, 1999, 2000, 2009 Free Software Foundation, Inc. +/* Copyright (C) 1998, 1999, 2000, 2009, 2011 Free Software Foundation, Inc. This file is part of GCC. @@ -36,11 +36,8 @@ #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 */ Index: libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.cc =================================================================== --- libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.cc (revision 0) +++ libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.cc (revision 0) @@ -0,0 +1,30 @@ +// { dg-do compile } +// { dg-options "-std=gnu++11" } + +// Copyright (C) 2011 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 <cstdalign> + +#ifdef alignas +# error "The header <cstdalign> defines a macro named alignas" +#endif + +#ifndef __alignas_is_defined +# error "The header <cstdalign> fails to define a macro named __alignas_is_defined" +#endif + Index: libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.cc =================================================================== --- libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.cc (revision 0) +++ libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.cc (revision 0) @@ -0,0 +1,38 @@ +// { dg-do compile } +// { dg-options "-std=gnu++11" } + +// Copyright (C) 2011 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 +