[Dwarf-discuss] Re: Dwarf-discuss Digest, Vol 8, Issue 2

[Ron 603-884-2088]

Jim,

Well, the more I hear the less I like what seem to be the available
approaches (including my own suggestions).

Your orginal proposal for a DW_AT_cplus_true_type seems perhaps
the closest to being viable, but it still has key problems:

 1) If you want to support modules with no debugging information except
    what you can infer from the link-time mangled name (and I absolutely
    applaud doing so!), then you still need debugger mechanism to
    map a name string into the underlying "language standard type"
    code.

 2) Adding a new *required* DWARF attribute for C++ language makes
    V3 not upward compatible with V2. It might provide a small lever
    to convince compilers to "upgrade" if/when they claim V3
    support (for other reasons), but in all likelyhood any debugger
    will need to cope without such an attribute for quite some time.

    Of course, if the attribute is optional (preserving upward
    compatibility) then the coping period is necessarily forever!

Seems like if the mechanism is available for handling mangled names,
then also using it at DWARF symbol table read-time, perhaps with some
kind of caching or lookaside data structure, is about as good as can
be done.

Would adding an optional attribute then be of any additional benefit?
I doubt it... 

So I am beginning to conclude that this would have been a good idea
to require way back when, but whose benefit is now forever lost.

Ron