[cfe-dev] Unreachable at IdentifierResolver.cpp:78 when friend-ing a using declaration

[Stephen Lin]

Apologies, not sure why I didn't notice before but the patch I
attached seems to break a test (namespace.udecl/p12.cpp), so ignore
it.

On Sun, Mar 10, 2013 at 5:18 PM, Stephen Lin <stephenwlin at gmail.com> wrote:
> Hi,
>
> I'm new to clang development but I think I've managed to find
> and patch a small issue. I'm not sure what SOP is for this is, so I'm
> sending a message here; if this is unnecessary in the future let me
> know.
>
> The code below crashes because Sema::CheckOverload assumes that a
> function declaration is in the same semantic scope as the current
> lexical scope whenever the latter is a record and tries to use member
> using hiding rules:
>
> struct A
> {
>     void delete_foo();
> };
>
> struct B : public A
> {
>     using A::delete_foo;
> };
>
> struct Foo { friend void B::delete_foo(); private: ~Foo() { } };
>
> Similar results are obtained when "friend"-ing a using declaration
> declared at namespace scope.
>
> I added a small check to verify that the new function declaration is
> actually in the same semantic scope as the current (record) scope: as
> far as I can tell this can only affect "friend" declarations. The code
> above now triggers an error "declaration conflicts with target of
> using declaration already in scope" (I believe this is correct, g++
> errors as well) rather than a crash, and added a test for this case.
>
> Bug report at http://llvm.org/bugs/show_bug.cgi?id=15485 with patch attached.
>
> Let me know if there's anything else I can do to help with this issue.
>
> Thanks,
> Stephen