Re: [PATCH] Preserve ::is{inf,nan}{f,l} prototypes even for C++11 and later

[Adhemerval Zanella <adhemerval dot zanella at linaro dot org>]

On 09-02-2016 19:54, Carlos O'Donell wrote:
> On 02/09/2016 12:38 PM, Carlos O'Donell wrote:
>> On 02/09/2016 12:23 PM, Jonathan Wakely wrote:
>>> On 03/02/16 16:04 -0200, Adhemerval Zanella wrote:
>>>>
>>>>
>>>> On 03-02-2016 15:40, Mike Frysinger wrote:
>>>>> On 03 Feb 2016 14:55, Adhemerval Zanella wrote:
>>>>>> I will quote the email referenced:
>>>>>>
>>>>>>> C++11 code using isinf and isnan continues to compile after that
>>>>>>> change, because the C++11 standard library provides its own versions
>>>>>>> conforming to the C++11 requirements. However, the C++11 library
>>>>>>> doesn't provide isinff, isinfl etc. and so code using those
>>>>>>> (non-standard) functions will no longer compile if they are not
>>>>>>> declared by glibc.
>>>>>>
>>>>>> This was not clear to me, what kind of build issue are you seeing now?
>>>>>> Using isinf{f,l} by including just <cmath> along with C++11? If it is the
>>>>>> case please open a bugzilla (or update the original) and please commit
>>>>>> the fix.
>>>>>
>>>>> if the change hasn't seen a release yet, then we can just re-use the
>>>>> existing bug since it's really just a direct follow up to that ?
>>>>> -mike
>>>>>
>>>>
>>>> I do not see why not.
>>>
>>> Hi, what's the status of this then - do we need to add a testcase or
>>> can it be committed for 2.23? (or wait for 2.24?)
>>
>> Yes, we want always want a test case. It's perfectly fine to use C++
>> in  tests in glibc, and if the C++ compiler isn't present those tests
>> should become UNSUPPORTED tests, which is OK (when bootstrapping).
>>
>> In summary:
>> - Add C++ test.
>> - Use BZ #19439 and provide ChangeLog.
>> - Post v2
> 
> v2
> - Added test case which fails to compile before patch. I saw no easier
>   way to test a header inclusion issue like this than to fail the entire
>   testsuite when building that test. Adding a conform test just for this
>   is overkill and outside the scope of conformtest.
> - Regression tested on x86_64 with no regressions.
> 
> I'll commit this ASAP if nobody objects.
> 
> Adhemerval?
> 

Sorry for late response.  This is ok for 2.23, thanks!

> 2016-02-09  Jakub Jelinek  <jakub@redhat.com>
> 	    Jonathan Wakely  <jwakely@redhat.com>
> 	    Carlos O'Donell  <carlos@redhat.com>
> 
> 	[BZ 19439]
> 	* math/Makefile (tests): Add test-math-isinff.
> 	(CFLAGS-test-math-isinff.cc): Use -std=gnu++11.
> 	* math/bits/mathcalls.h [__USE_MISC]: Use
> 	'|| __MATH_DECLARING_DOUBLE == 0' to relax definition of
> 	functions not in C++11 and which don't conflict e.g. isinff,
> 	isinfl etc.
> 	* math/test-math-isinff.cc: New file.
> 
> diff --git a/math/Makefile b/math/Makefile
> index 222ee6b..7d573a0 100644
> --- a/math/Makefile
> +++ b/math/Makefile
> @@ -114,6 +114,7 @@ tests = test-matherr test-fenv atest-exp atest-sincos atest-exp2 basic-test \
>  	test-nearbyint-except-2 test-signgam-uchar test-signgam-uchar-init \
>  	test-signgam-uint test-signgam-uint-init test-signgam-ullong \
>  	test-signgam-ullong-init test-nan-overflow test-nan-payload \
> +	test-math-isinff \
>  	$(tests-static)
>  tests-static = test-fpucw-static test-fpucw-ieee-static \
>  	       test-signgam-uchar-static test-signgam-uchar-init-static \
> @@ -220,6 +221,8 @@ 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-isinff.cc = -std=gnu++11
> +
>  # The -lieee module sets the _LIB_VERSION_ switch to IEEE mode
>  # for error handling in the -lm functions.
>  install-lib += libieee.a
> diff --git a/math/bits/mathcalls.h b/math/bits/mathcalls.h
> index a48345d..9a7b3f0 100644
> --- a/math/bits/mathcalls.h
> +++ b/math/bits/mathcalls.h
> @@ -196,7 +196,9 @@ __MATHDECL_1 (int,__finite,, (_Mdouble_ __value)) __attribute__ ((__const__));
>  _Mdouble_END_NAMESPACE
>  
>  #ifdef __USE_MISC
> -# if !defined __cplusplus || __cplusplus < 201103L /* Conflicts with C++11.  */
> +# if (!defined __cplusplus \
> +      || __cplusplus < 201103L /* isinf conflicts with C++11.  */ \
> +      || __MATH_DECLARING_DOUBLE == 0) /* isinff or isinfl don't.  */
>  /* Return 0 if VALUE is finite or NaN, +1 if it
>     is +Infinity, -1 if it is -Infinity.  */
>  __MATHDECL_1 (int,isinf,, (_Mdouble_ __value)) __attribute__ ((__const__));
> @@ -232,7 +234,9 @@ __END_NAMESPACE_C99
>  __MATHDECL_1 (int,__isnan,, (_Mdouble_ __value)) __attribute__ ((__const__));
>  
>  #if defined __USE_MISC || (defined __USE_XOPEN && !defined __USE_XOPEN2K)
> -# if !defined __cplusplus || __cplusplus < 201103L /* Conflicts with C++11.  */
> +# if (!defined __cplusplus \
> +      || __cplusplus < 201103L /* isnan conflicts with C++11.  */ \
> +      || __MATH_DECLARING_DOUBLE == 0) /* isnanf or isnanl don't.  */
>  /* Return nonzero if VALUE is not a number.  */
>  __MATHDECL_1 (int,isnan,, (_Mdouble_ __value)) __attribute__ ((__const__));
>  # endif
> diff --git a/math/test-math-isinff.cc b/math/test-math-isinff.cc
> new file mode 100644
> index 0000000..195d753
> --- /dev/null
> +++ b/math/test-math-isinff.cc
> @@ -0,0 +1,48 @@
> +/* Test for bug 19439.
> +   Copyright (C) 2016 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   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/>.  */
> +
> +#define _GNU_SOURCE 1
> +#include <math.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +
> +static int
> +do_test (void)
> +{
> +  /* Verify that isinff, isinfl, isnanf, and isnanlf are defined
> +     in the header under C++11 and can be called.  Without the
> +     header fix this test will not compile.  */
> +  if (isinff (1.0f)
> +      || !isinff (INFINITY)
> +      || isinfl (1.0L)
> +      || !isinfl (INFINITY)
> +      || isnanf (2.0f)
> +      || !isnanf (NAN)
> +      || isnanl (2.0L)
> +      || !isnanl (NAN))
> +    {
> +      printf ("FAIL: Failed to call is* functions.\n");
> +      exit (1);
> +    }
> +  printf ("PASS: Able to call isinff, isinfl, isnanf, and isnanl.\n");
> +  exit (0);
> +}
> +
> +#define TEST_FUNCTION do_test ()
> +#include "../test-skeleton.c"
> ---
> 
> Cheers,
> Carlos.
> 
>