https://gcc.gnu.org/bugzilla/show_bug.cgi?id=72865
Bug ID: 72865
Summary: Adding __may_alias__ attribute triggers a compilation
error
Product: gcc
Version: 5.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: root at zta dot lk
Target Milestone: ---
The following (correct) code triggers a compilation error when compiled with
gcc. It does compiles under clang.
Removing __attribute__((__may_alias__)) clause fixes the problem.
$ cat sf.cpp
template <class T>
class rv: public T
{
rv();
~rv() throw();
rv(rv const&);
void operator=(rv const&);
} __attribute__((__may_alias__));
class A
{
A(A &);
A& operator=(A &);
public:
explicit A(rv<A>& safetyCamera);
A& operator=(rv<A>& safetyCamera);
operator const rv<A>&() const { return *static_cast<const rv<A>*>(this); }
};
A::A(rv<A>&) {}
A& A::operator=(rv<A>&) { return *this; }
The error message
=================
$ g++ -c sf.cpp
sf.cpp:20:1: error: prototype for ‘A::A(rv<A>&)’ does not match any in class
‘A’
A::A(rv<A>&) {}
^
sf.cpp:15:12: error: candidates are: A::A(rv<A>&)
explicit A(rv<A>& safetyCamera);
^
sf.cpp:12:3: error: A::A(A&)
A(A &);
^
sf.cpp:21:4: error: prototype for ‘A& A::operator=(rv<A>&)’ does not match any
in class ‘A’
A& A::operator=(rv<A>&) { return *this; }
^
sf.cpp:16:6: error: candidates are: A& A::operator=(rv<A>&)
A& operator=(rv<A>& safetyCamera);
^
sf.cpp:13:6: error: A& A::operator=(A&)
A& operator=(A &);
^
