[Bug c++/77892] New: local function declarations don't match namespace scope declarations

[jeff.mirwaisi at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77892

            Bug ID: 77892
           Summary: local function declarations don't match namespace
                    scope declarations
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jeff.mirwaisi at gmail dot com
  Target Milestone: ---

//error: undefined reference to 'f()'
struct S{friend void f(){}}; //lexical scope of S, only discoverable via ADL,
no 
                             //argument, so not discoverable at all yet
void f(); //make f visible to ordinary qualified lookup
int main()
{
  void f(); //declaration should match the declaration at namespace scope,
instead       
            //hides the previous declaration at namespace scope
  f(); 
} 

//open question whether a local scope declaration is enough to make a class
scope 
//friend function visible to ordinary lookup
//works in clang not in gcc
struct S{friend void f(){}};
int main()
{
  void f();
  f();
}