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| author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2016-01-11 13:34:52 -0200 |
|---|---|---|
| committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2016-01-11 17:13:36 -0200 |
| commit | d9b965fa56350d6eea9f7f438a0714c7ffbb183f (patch) | |
| tree | d62ed49512fbc76c0f08ff977f51735cf49586dd /math/bits | |
| parent | c83196b0df4340209f260ffaf90e787c711c268e (diff) | |
| download | glibc-d9b965fa56350d6eea9f7f438a0714c7ffbb183f.tar.gz | |
Fix isinf/isnan declaration conflict with C++11
GLIBC declares isinf and isnan as expected by Unix98 and for C99 programs
these functions are hidden by the generics inf and isnan macros.
However C++11 defines isinf and isnan with the same semantics as C99
but requires that they are functions not macros (C++11 26.8 [c.math]
paragraph 10).
This then results in a conflict for perfectly valid C++11 programs:
--
using std::isinf;
using std::isnan;
double d1 = isinf(1.0);
double d2 = isnan(1.0);
d.cc:3:12: error: ‘constexpr bool std::isinf(double)’ conflicts with a previous declaration
using std::isinf;
[...]
/usr/include/bits/mathcalls.h:201:1: note: previous declaration ‘int isinf(double)’
__MATHDECL_1 (int,isinf,, (_Mdouble_ __value)) __attribute__ ((__const__));
[...]
--
This patch fixes the prototypes by leaving the obsolete functions
defined for C++98 code (since they do not conflict with any standard
function in C++98), however preventing them on C++11.
No issues found in libstdc++ tests and check on x86_64 and i686 with
glibc testsuite.
Patch from Jonathan Wakely <jwakely.gcc@gmail.com>.
[BZ #19439]
* math/bits/mathcalls.h
[!__cplusplus || __cplusplus < 201103L] (isinf): Do not declare
prototype.
[!__cplusplus || __cplusplus < 201103L] (isnan): Likewise.
Diffstat (limited to 'math/bits')
| -rw-r--r-- | math/bits/mathcalls.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/math/bits/mathcalls.h b/math/bits/mathcalls.h index b82c37352f..a48345d916 100644 --- a/math/bits/mathcalls.h +++ b/math/bits/mathcalls.h @@ -196,9 +196,11 @@ __MATHDECL_1 (int,__finite,, (_Mdouble_ __value)) __attribute__ ((__const__)); _Mdouble_END_NAMESPACE #ifdef __USE_MISC +# if !defined __cplusplus || __cplusplus < 201103L /* Conflicts with C++11. */ /* 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__)); +# endif /* Return nonzero if VALUE is finite and not NaN. */ __MATHDECL_1 (int,finite,, (_Mdouble_ __value)) __attribute__ ((__const__)); @@ -230,8 +232,10 @@ __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. */ /* Return nonzero if VALUE is not a number. */ __MATHDECL_1 (int,isnan,, (_Mdouble_ __value)) __attribute__ ((__const__)); +# endif #endif #if defined __USE_MISC || (defined __USE_XOPEN && __MATH_DECLARING_DOUBLE) |