[lldb-dev] RTTI does not work stable in LLDB.

[Robinson, Paul via lldb-dev]

Yes, I do get that it was just unfortunate timing.  Sorry for failing at being light-hearted.

I suspect the compiler can be persuaded to emit a name consistent with the demangling of the vtable name.  Despite being the way-things-have-worked for a long time, it still seems moderately fragile, especially in the face of various compiler-list debates about what the name actually should contain.
--paulr

From: Greg Clayton [mailto:gclayton at apple.com]
Sent: Monday, February 06, 2017 4:38 PM
To: Robinson, Paul
Cc: Zachary Turner; LLDB Dev (lldb-dev at lists.llvm.org)
Subject: Re: [lldb-dev] RTTI does not work stable in LLDB.


On Feb 6, 2017, at 3:38 PM, Robinson, Paul <paul.robinson at sony.com<mailto:paul.robinson at sony.com>> wrote:

It's not practical for the DWARF to try to identify the actual address of the vtable; that address might not be available.
it seems like we could hang onto the linkage_name of the vtable though, somewhere, so you wouldn't be relying on the demangler you have available at runtime to produce the same string that the compiler did at compile time.  The symbolic name of the vtable should be unambiguous (one hopes!) but not depend on the existence of the vtable in any particular place.
Doesn't solve the problem for today's compilers, granted.
--paulr

P.S. It would be helpful to have these things come up *before* the next rev of the spec is frozen.  Just sayin'.  :)


We had just identified this today and realized it was a problem so we had no idea there was a problem until today. Debuggers have been doing this pretty reliably for the past 15 years, so it was never anything we actually needed extra support for since it was so easy to do.

Greg



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