[PATCH] Define C11 macros such as FLT_DECIMAL_DIG for C++17

Jason Merrill jason@redhat.com
Fri Jun 21 18:37:00 GMT 2019


OK.

On Fri, Jun 21, 2019 at 1:24 PM Jonathan Wakely <jwakely@redhat.com> wrote:
>
> On 13/06/19 17:09 +0100, Jonathan Wakely wrote:
> >The C++17 library was rebased on C11 by https://wg21.link/p0063r3 so
> >these nine macros are needed for C++17 conformance.
> >
> >gcc:
> >
> >       * ginclude/float.h (FLT_DECIMAL_DIG, DBL_DECIMAL_DIG, LDBL_DECIMAL_DIG)
> >       (FLT_HAS_SUBNORM, DBL_HAS_SUBNORM, LDBL_HAS_SUBNORM, FLT_TRUE_MIN)
> >       (DBL_TRUE_MIN, LDBL_TRUE_MIN): Also define for C++17.
> >
> >libstdc++-v3:
> >
> >       * testsuite/18_support/headers/cfloat/values_c++17.cc: New test.
> >
> >
> >Tested x86_64-linux and powerpc64le-linux.
> >
> >OK for trunk and gcc-9-branch?
>
> Ping.
>
>
> >commit ce40ee46ca226c102c548032184345fe9f5d352e
> >Author: Jonathan Wakely <jwakely@redhat.com>
> >Date:   Thu Jun 13 11:38:33 2019 +0100
> >
> >    Define C11 macros such as FLT_DECIMAL_DIG for C++17
> >
> >    The C++17 library was rebased on C11 by https://wg21.link/p0063r3 so
> >    these nine macros are needed for C++17 conformance.
> >
> >    gcc:
> >
> >            * ginclude/float.h (FLT_DECIMAL_DIG, DBL_DECIMAL_DIG, LDBL_DECIMAL_DIG)
> >            (FLT_HAS_SUBNORM, DBL_HAS_SUBNORM, LDBL_HAS_SUBNORM, FLT_TRUE_MIN)
> >            (DBL_TRUE_MIN, LDBL_TRUE_MIN): Also define for C++17.
> >
> >    libstdc++-v3:
> >
> >            * testsuite/18_support/headers/cfloat/values_c++17.cc: New test.
> >
> >diff --git a/gcc/ginclude/float.h b/gcc/ginclude/float.h
> >index 9ebae057d34..4767d7b9dfb 100644
> >--- a/gcc/ginclude/float.h
> >+++ b/gcc/ginclude/float.h
> >@@ -210,7 +210,8 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
> >
> > #endif /* C99 */
> >
> >-#if defined (__STDC_VERSION__) && __STDC_VERSION__ >= 201112L
> >+#if (defined (__STDC_VERSION__) && __STDC_VERSION__ >= 201112L) \
> >+     || (defined (__cplusplus) && __cplusplus >= 201703L)
> > /* Versions of DECIMAL_DIG for each floating-point type.  */
> > #undef FLT_DECIMAL_DIG
> > #undef DBL_DECIMAL_DIG
> >diff --git a/libstdc++-v3/testsuite/18_support/headers/cfloat/values_c++17.cc b/libstdc++-v3/testsuite/18_support/headers/cfloat/values_c++17.cc
> >new file mode 100644
> >index 00000000000..f3efd204d17
> >--- /dev/null
> >+++ b/libstdc++-v3/testsuite/18_support/headers/cfloat/values_c++17.cc
> >@@ -0,0 +1,37 @@
> >+// { dg-options "-std=gnu++17" }
> >+// { dg-do compile { target c++17 } }
> >+
> >+// Copyright (C) 2019 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 <cfloat>
> >+#include "values.cc"
> >+
> >+namespace gnu17
> >+{
> >+  double d1 = DBL_DECIMAL_DIG;
> >+  double d2 = DBL_HAS_SUBNORM;
> >+  double d3 = DBL_TRUE_MIN;
> >+
> >+  float f1 = FLT_DECIMAL_DIG;
> >+  float f2 = FLT_HAS_SUBNORM;
> >+  float f3 = FLT_TRUE_MIN;
> >+
> >+  long double ld1 = LDBL_DECIMAL_DIG;
> >+  long double ld2 = LDBL_HAS_SUBNORM;
> >+  long double ld3 = LDBL_TRUE_MIN;
> >+}
>



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