[gcc/devel/omp/gcc-9] Define C11 macros such as FLT_DECIMAL_DIG for C++17

[Tobias Burnus]

https://gcc.gnu.org/g:20ac9d2b38132d612b21ad1a454e7171c6b14d52

commit 20ac9d2b38132d612b21ad1a454e7171c6b14d52
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Wed Jul 31 20:56:16 2019 +0100

    Define C11 macros such as FLT_DECIMAL_DIG for C++17
    
    Backport from mainline
    2019-06-24  Jonathan Wakely  <jwakely@redhat.com>
    
    	* 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.
    
    Backport from mainline
    2019-06-24  Jonathan Wakely  <jwakely@redhat.com>
    
    	* testsuite/18_support/headers/cfloat/values_c++17.cc: New test.
    
    From-SVN: r273949

Diff:
---
 gcc/ChangeLog                                      |  9 ++++++
 gcc/ginclude/float.h                               |  3 +-
 libstdc++-v3/ChangeLog                             |  7 ++++
 .../18_support/headers/cfloat/values_c++17.cc      | 37 ++++++++++++++++++++++
 4 files changed, 55 insertions(+), 1 deletion(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index bd8fc67..f837f7d 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2019-07-31  Jonathan Wakely  <jwakely@redhat.com>
+
+	Backport from mainline
+	2019-06-24  Jonathan Wakely  <jwakely@redhat.com>
+
+	* 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.
+
 2019-07-31  Richard Biener  <rguenther@suse.de>
 
 	Backport from mainline
diff --git a/gcc/ginclude/float.h b/gcc/ginclude/float.h
index 9ebae05..4767d7b 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/ChangeLog b/libstdc++-v3/ChangeLog
index 78504c9..04aefd3 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,6 +1,13 @@
 2019-07-31  Jonathan Wakely  <jwakely@redhat.com>
 
 	Backport from mainline
+	2019-06-24  Jonathan Wakely  <jwakely@redhat.com>
+
+	* testsuite/18_support/headers/cfloat/values_c++17.cc: New test.
+
+2019-07-31  Jonathan Wakely  <jwakely@redhat.com>
+
+	Backport from mainline
 	2019-07-31  Jonathan Wakely  <jwakely@redhat.com>
 
 	* include/std/memory (make_obj_using_allocator): Qualify call to
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 0000000..f3efd20
--- /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;
+}