On 2/21/19 6:10 PM, Jonathan Wakely wrote:
On 20/02/19 09:07 +0100, Jakub Jelinek wrote:
Hi!
The following patch fixes a warning when building on targets where long
double switched from being the same as double to something wider,
like e.g. powerpc*-linux, alpha*-linux, s390*-linux etc.
Fixed thusly, bootstrapped/regtested on {x86_64,i686,s390x}-linux and
bootstrapped on powerpc64le-linux, on both s390x and powerpc64le it
removed
all
../../../../libstdc++-v3/src/c++98/compatibility-ldbl.cc:77:17:
warning: 'void _ZNKSt4hashIeEclEe()' specifies less restrictive
attribute than its target 'std::size_t
std::tr1::hash<_Tp>::operator()(_Tp) const [with _Tp = long double]':
'pure' [-Wmissing-attributes]
warnings from the build log. Preapproved by Jonathan in the PR,
committed
to trunk.
Now I see:
/home/jwakely/src/gcc/libstdc++-v3/src/c++98/compatibility-ldbl.cc:78:65: warning:
‘pure’ attribute on function returning ‘void’ [-Wattributes]
78 | _GLIBCXX_PURE __attribute__((alias ("_ZNKSt3tr14hashIeEclEe")));
| ^
Are the attributes on this alias ever considered in calls to it?
If not (and assuming there's a way to tell, which I think there
should be but haven't verified it) the warning could be relaxed
to only trigger for those that are. I think those would be
either aliases declared in headers, or those with the TREE_USED
bit set.
Martin
We can disable that with a diagnostic pragma.
2019-02-20 Jakub Jelinek <ja...@redhat.com>
PR libstdc++/89402
* src/c++98/compatibility-ldbl.cc (_ZNKSt4hashIeEclEe): Add
_GLIBCXX_PURE to the alias declaration.
--- libstdc++-v3/src/c++98/compatibility-ldbl.cc.jj 2019-01-01
12:39:41.530606161 +0100
+++ libstdc++-v3/src/c++98/compatibility-ldbl.cc 2019-02-19
16:12:52.402123217 +0100
@@ -75,6 +75,6 @@ namespace std _GLIBCXX_VISIBILITY(defaul
// and std::hash<long double>::operator()
// are the same, no need to duplicate them.
extern "C" void _ZNKSt4hashIeEclEe (void)
- __attribute__((alias ("_ZNKSt3tr14hashIeEclEe")));
+ _GLIBCXX_PURE __attribute__((alias ("_ZNKSt3tr14hashIeEclEe")));
#endif
Jakub
