From d9b965fa56350d6eea9f7f438a0714c7ffbb183f Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Mon, 11 Jan 2016 13:34:52 -0200 Subject: [PATCH] Fix isinf/isnan declaration conflict with C++11 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 . [BZ #19439] * math/bits/mathcalls.h [!__cplusplus || __cplusplus < 201103L] (isinf): Do not declare prototype. [!__cplusplus || __cplusplus < 201103L] (isnan): Likewise. --- ChangeLog | 9 +++++++++ math/bits/mathcalls.h | 4 ++++ 2 files changed, 13 insertions(+) diff --git a/ChangeLog b/ChangeLog index 600c3dd501..08a05bfb7d 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,12 @@ +2016-01-11 Jonathan Wakely + Adhemerval Zanella + + [BZ #19439] + * math/bits/mathcalls.h + [!__cplusplus || __cplusplus < 201103L] (isinf): Do not declare + prototype. + [!__cplusplus || __cplusplus < 201103L] (isnan): Likewise. + 2016-01-11 Andreas Schwab [BZ #19253] 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)