[c++] Another question about demangler output

[Gabriel Dos Reis]

Ian Lance Taylor <ian@wasabisystems.com> writes:

| Gabriel Dos Reis <gdr@integrable-solutions.net> writes:
| 
| > Ian Lance Taylor <ian@wasabisystems.com> writes:
| > 
| > [...]
| > 
| > | This gives _ZN2BBcvPFivEEv which (currently) demangles as
| > |     BB::operator int (*)()()
| > | 
| > | But using a gcc extension, I can do this without a typedef:
| > | 
| > | class BB { operator typeof (int(*)())(); };
| > | BB::operator typeof (int(*)())() { return 0; }
| > 
| > If you do that, then you might end up accpeting two different
| > declarations as same where the token-oriented scheme (ODR) would have
| > kept them separate.  That is, you would not be able to differentiate
| > 
| > tu1.C:
| > 
| >   struct B { operator typeof(int(*)())(); };
| > 
| > from
| > 
| > tu2.C:
| > 
| >   struct B { typedef int (*foo)(); operator foo(); };
| > 
| > ODR says they are different.
| 
| I don't know who the ``you'' is in ``if you do that.''  Or else I
| don't know what the ``that'' is.
| 
| I gave two code samples, and g++ uses the same name mangling for both.
| Try it.  Is that a bug in g++?
| 
| Frankly, I don't see how g++ could do anything else.

The point is this.  "typeof" is a GNU/C++ extension.  Its use in a
function declaration should be mangled differently from any standard
C++ construction.  After all, the ABI has provided hook for vendor
extension. 

-- Gaby