Microsoft compatibility: support __super specifier to access members of base classes

[llvmbot]

Bugzilla Link	13236
Resolution	FIXED
Resolved on	Sep 25, 2014 19:33
Version	trunk
OS	Windows NT
Blocks	llvm/llvm-bugzilla-archive#13707
Reporter	LLVM Bugzilla Contributor
CC	@DougGregor

Extended Description

Official docs: http://msdn.microsoft.com/en-us/library/94dw1w7x%28v=vs.80%29.aspx

Unofficially, the grammar seems to be

qualified-id:
  '__super' '::' unqualified-id

__super can't be chained (i.e. __super::__super is invalid).

__super is only valid in member function scope (in particular, the following is invalid:

struct A { typedef int t; };
struct B: A {
    typedef __super::t u; // error
}

).

The unqualified-id is looked up in all the base classes and the results are merged.

struct A { void foo(long); };
struct B { void foo(int); };
struct C: A, B { 
    void test() {
        __super::foo(1); // OK: calls B::foo
    }
};

The result may name a type-name.

struct A { typedef int t; };
struct B: A {
    typedef long t;
    void test() {
        __super::t v; // OK: the type of 'v' is 'int'
    }
};

__super is enabled only when compiling without /Za (disable language extensions).

[llvmbot]

Initial implementation: avakar/clang@__super

[llvmbot]

Also note that the nested-name-specified may not precede __super.

struct A { void foo(); };
struct B: A {
    void test() {
        __super::foo();     // OK
        B::__super::foo();  // error: illegal token on right side of '::'
    }
};

[llvmbot]

If initial implementation below works, any possibility of it being merged into trunk?
Currently this is a blocker for me using Clang-modernize on my MS VC++ codebase.

[llvmbot]

I would also greatly appreciate if the __super extension was supported. I am trying to compile code that makes extensive use of this extension.

[llvmbot]

Fixed in r218484.

[tritao]

mentioned in issue llvm/llvm-bugzilla-archive#13707