diff options
authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2016-01-11 13:34:52 -0200
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2016-01-11 17:13:36 -0200
commitd9b965fa56350d6eea9f7f438a0714c7ffbb183f (patch)
parentc83196b0df4340209f260ffaf90e787c711c268e (diff)
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.
2 files changed, 13 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog
index 600c3dd501a..08a05bfb7d0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2016-01-11 Jonathan Wakely <jwakely.gcc@gmail.com>
+ Adhemerval Zanella <adhemerval.zanella@linaro.org>
+ [BZ #19439]
+ * math/bits/mathcalls.h
+ [!__cplusplus || __cplusplus < 201103L] (isinf): Do not declare
+ prototype.
+ [!__cplusplus || __cplusplus < 201103L] (isnan): Likewise.
2016-01-11 Andreas Schwab <schwab@suse.de>
[BZ #19253]
diff --git a/math/bits/mathcalls.h b/math/bits/mathcalls.h
index b82c37352fc..a48345d916d 100644
--- a/math/bits/mathcalls.h
+++ b/math/bits/mathcalls.h
@@ -196,9 +196,11 @@ __MATHDECL_1 (int,__finite,, (_Mdouble_ __value)) __attribute__ ((__const__));
#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
#if defined __USE_MISC || (defined __USE_XOPEN && __MATH_DECLARING_DOUBLE)