[BZ,#21326] Ensure C99 and C11 interfaces are available for C++
Commit Message
On 22/09/17 17:59 +0000, Joseph Myers wrote:
>On Fri, 22 Sep 2017, Jonathan Wakely wrote:
>
>> +#ifdef __cplusplus
>> +/* This is to enable compatibility for ISO C++17. */
>> +#if __cplusplus >= 201703L
>> +# define __USE_ISOCXX17 1
>> +# define __USE_ISOC11 1
>> +#endif
>> /* This is to enable compatibility for ISO C++11.
>> -
>> - So far g++ does not provide a macro. Check the temporary macro for
>> - now, too. */
>> -#if ((defined __cplusplus && __cplusplus >= 201103L)
>> \
>> - || defined __GXX_EXPERIMENTAL_CXX0X__)
>> + Check the temporary macro for now, too. */
>> +#if __cplusplus >= 201103L || defined __GXX_EXPERIMENTAL_CXX0X__
>> # define __USE_ISOCXX11 1
>
>There is a comment listing all the __USE_ macros at the top of features.h.
>It should be updated to add __USE_ISOCXX17. (Actually, it needs
>__USE_ISOCXX11 added as well, but that's a preexisting condition. And I'm
>not sure __USE_ISOCXX17 should be added at all until there is something to
>condition on it.)
Good point. If there was reason to add it without anything using it
then there should be a __USE_ISOCXX14 as well. But since nothing needs
them, they can be left out.
>The existing __USE_* macros are also undefined in features.h before being
>possibly defined, including __USE_ISOCXX11. If a new __USE_ISOCXX17 is
>added, it should be added to that #undef sequence as well.
Here's a new patch without __USE_ISOCXX17 and listing __USE_ISOCXX11
in the comment at the top.
Tested x86_64-linux.
This patch ensures that the C99 and C11 features required by C++ are
defined according to the value of the __cplusplus macro, and not just
because G++ always defines _GNU_SOURCE. This will allow G++ to stop
defining _GNU_SOURCE some day, without causing the C99 and C11
interfaces to disappear for C++ programs.
[BZ #21326]
* include/features.h [__cplusplus >= 201103] (__USE_ISOC99): Define.
[__cplusplus >= 201703] (__USE_ISOCXX17, __USE_ISOC11): Define.
* math/Makefile (test-math-cxx11): New test.
* math/test-math-cxx11.cc: New file.
---
ChangeLog | 8 +++
include/features.h | 15 +++--
math/Makefile | 5 +-
math/test-math-cxx11.cc | 161 ++++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 183 insertions(+), 6 deletions(-)
create mode 100644 math/test-math-cxx11.cc
Comments
On 09/22/2017 08:16 PM, Jonathan Wakely wrote:
> +#ifdef __cplusplus
> +/* This is to enable compatibility for ISO C++17. */
> +#if __cplusplus >= 201703L
> +# define __USE_ISOC11 1
> +#endif
> /* This is to enable compatibility for ISO C++11.
The inner #if/#endif should be indented (similar to the inner #define).
> -
> - So far g++ does not provide a macro. Check the temporary macro for
> - now, too. */
> -#if ((defined __cplusplus && __cplusplus >= 201103L) \
> - || defined __GXX_EXPERIMENTAL_CXX0X__)
> + Check the temporary macro for now, too. */
> +#if __cplusplus >= 201103L || defined __GXX_EXPERIMENTAL_CXX0X__
> # define __USE_ISOCXX11 1
> +# define __USE_ISOC99 1
> +#endif
> #endif
I think there is a preexisting issue here which will trigger macro
redefinition warnings with -Wsystem-headers. But perhaps I'm mistaken.
Apart from that, the substance of the patch looks okay to me.
Thanks,
Florian
@@ -1,3 +1,11 @@
+2017-09-22 Jonathan Wakely <jwakely@redhat.com>
+
+ [BZ #21326]
+ * include/features.h [__cplusplus >= 201703] (__USE_ISOC11): Define.
+ [__cplusplus >= 201103] (__USE_ISOC99): Define.
+ * math/Makefile (test-math-cxx11): New test.
+ * math/test-math-cxx11.cc: New file.
+
2017-09-22 Joseph Myers <joseph@codesourcery.com>
* csu/Makefile (generated): Do not add version-info.h.
@@ -76,6 +76,7 @@
__USE_ISOC11 Define ISO C11 things.
__USE_ISOC99 Define ISO C99 things.
__USE_ISOC95 Define ISO C90 AMD1 (C95) things.
+ __USE_ISOCXX11 Define ISO C++11 things.
__USE_POSIX Define IEEE Std 1003.1 things.
__USE_POSIX2 Define IEEE Std 1003.2 things.
__USE_POSIX199309 Define IEEE Std 1003.1, and .1b things.
@@ -238,13 +239,17 @@
# define __USE_ISOC95 1
#endif
+#ifdef __cplusplus
+/* This is to enable compatibility for ISO C++17. */
+#if __cplusplus >= 201703L
+# define __USE_ISOC11 1
+#endif
/* This is to enable compatibility for ISO C++11.
-
- So far g++ does not provide a macro. Check the temporary macro for
- now, too. */
-#if ((defined __cplusplus && __cplusplus >= 201103L) \
- || defined __GXX_EXPERIMENTAL_CXX0X__)
+ Check the temporary macro for now, too. */
+#if __cplusplus >= 201103L || defined __GXX_EXPERIMENTAL_CXX0X__
# define __USE_ISOCXX11 1
+# define __USE_ISOC99 1
+#endif
#endif
/* If none of the ANSI/POSIX macros are defined, or if _DEFAULT_SOURCE
@@ -207,7 +207,8 @@ tests-internal = test-matherr test-matherr-2
tests-static += atest-exp atest-sincos atest-exp2
ifneq (,$(CXX))
-tests += test-math-isinff test-math-iszero test-math-issignaling
+tests += test-math-isinff test-math-iszero test-math-issignaling \
+ test-math-cxx11
endif
ifneq (no,$(PERL))
@@ -352,6 +353,8 @@ CFLAGS-test-signgam-ullong-init.c = -std=c99
CFLAGS-test-signgam-ullong-static.c = -std=c99
CFLAGS-test-signgam-ullong-init-static.c = -std=c99
+CFLAGS-test-math-cxx11.cc = -std=c++11
+
CFLAGS-test-math-isinff.cc = -std=gnu++11
CFLAGS-test-math-iszero.cc = -std=gnu++11
CFLAGS-test-math-issignaling.cc = -std=gnu++11
new file mode 100644
@@ -0,0 +1,161 @@
+/* Test C99 math functions are available in C++11 without _GNU_SOURCE.
+ Copyright (C) 2017 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Jonathan Wakely <jwakely@redhat.com>, 2017.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#undef _GNU_SOURCE
+#undef _DEFAULT_SOURCE
+#undef _XOPEN_SOURCE
+#undef _POSIX_SOURCE
+#undef _POSIX_C_SOURCE
+// __STRICT_ANSI__ gets defined by -std=c++11 in CFLAGS
+#include <math.h>
+#include <stdio.h>
+
+static int
+do_test (void)
+{
+#ifdef _GNU_SOURCE
+ printf ("FAIL: _GNU_SOURCE is defined.\n");
+ return 1;
+#endif
+
+#if __cplusplus >= 201103L
+ /* Verify that C11 math functions and types are defined for C++11,
+ without _GNU_SOURCE being defined. [BZ #21326] */
+ (void) FP_INFINITE;
+ (void) FP_NAN;
+ (void) FP_NORMAL;
+ (void) FP_SUBNORMAL;
+ (void) FP_ZERO;
+ double_t d = 1.0;
+ (void) d;
+ float_t f = 1.0f;
+ (void) f;
+ (void) acosh;
+ (void) acoshf;
+ (void) acoshl;
+ (void) asinh;
+ (void) asinhf;
+ (void) asinhl;
+ (void) atanh;
+ (void) atanhf;
+ (void) atanhl;
+ (void) cbrt;
+ (void) cbrtf;
+ (void) cbrtl;
+ (void) copysign;
+ (void) copysignf;
+ (void) copysignl;
+ (void) erf;
+ (void) erff;
+ (void) erfl;
+ (void) erfc;
+ (void) erfcf;
+ (void) erfcl;
+ (void) exp2;
+ (void) exp2f;
+ (void) exp2l;
+ (void) expm1;
+ (void) expm1f;
+ (void) expm1l;
+ (void) fdim;
+ (void) fdimf;
+ (void) fdiml;
+ (void) fma;
+ (void) fmaf;
+ (void) fmal;
+ (void) fmax;
+ (void) fmaxf;
+ (void) fmaxl;
+ (void) fmin;
+ (void) fminf;
+ (void) fminl;
+ (void) hypot;
+ (void) hypotf;
+ (void) hypotl;
+ (void) ilogb;
+ (void) ilogbf;
+ (void) ilogbl;
+ (void) lgamma;
+ (void) lgammaf;
+ (void) lgammal;
+ (void) llrint;
+ (void) llrintf;
+ (void) llrintl;
+ (void) llround;
+ (void) llroundf;
+ (void) llroundl;
+ (void) log1p;
+ (void) log1pf;
+ (void) log1pl;
+ (void) log2;
+ (void) log2f;
+ (void) log2l;
+ (void) logb;
+ (void) logbf;
+ (void) logbl;
+ (void) lrint;
+ (void) lrintf;
+ (void) lrintl;
+ (void) lround;
+ (void) lroundf;
+ (void) lroundl;
+ (void) nan;
+ (void) nanf;
+ (void) nanl;
+ (void) nearbyint;
+ (void) nearbyintf;
+ (void) nearbyintl;
+ (void) nextafter;
+ (void) nextafterf;
+ (void) nextafterl;
+ (void) nexttoward;
+ (void) nexttowardf;
+ (void) nexttowardl;
+ (void) remainder;
+ (void) remainderf;
+ (void) remainderl;
+ (void) remquo;
+ (void) remquof;
+ (void) remquol;
+ (void) rint;
+ (void) rintf;
+ (void) rintl;
+ (void) round;
+ (void) roundf;
+ (void) roundl;
+ (void) scalbln;
+ (void) scalblnf;
+ (void) scalblnl;
+ (void) scalbn;
+ (void) scalbnf;
+ (void) scalbnl;
+ (void) tgamma;
+ (void) tgammaf;
+ (void) tgammal;
+ (void) trunc;
+ (void) truncf;
+ (void) truncl;
+ printf ("PASS: C11 math functions present in C++11 without _GNU_SOURCE.\n");
+#else
+ printf ("UNSUPPORTED: C++11 not enabled.\n");
+#endif
+ return 0;
+}
+
+#include <support/test-driver.c>