[Bug c++/66294] New: Nonsensical warning message for address-of static member function expr through expr.B

[jengelh at inai dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66294

            Bug ID: 66294
           Summary: Nonsensical warning message for address-of static
                    member function expr through expr.B
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: trivial
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jengelh at inai dot de
  Target Milestone: ---

The following code:

struct F {
        F &self(void) { return *this; };
        static void test(void) { };
} f;
int main(void) { &f.self().test; }

yields the following compiler output:

t.cpp: In function ‘int main()’:
t.cpp:5:32: warning: right operand of comma operator has no effect
[-Wunused-value]
 int main(void) { &f.self().test; }

However, there is no comma in the source at all. The warning is misleading.
This occurs for all known versions.

gcc version 5.1.1 20150518 [gcc-5-branch revision 223286] (SUSE Linux) 
gcc version 4.9.0 (SUSE Linux) 
gcc version 4.8.3 20140627 [gcc-4_8-branch revision 212064] (SUSE Linux) 

What was expected:

[that which clang outputs, maybe?]
t.cpp:5:18: warning: expression result unused [-Wunused-value]
int main(void) { &f.self().test; }
                 ^~~~~~~~~~~~~~