This is the mail archive of the dwarf2@corp.sgi.com mailing list for the dwarf2 project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]

Re: duplicate dwarf2 reduction via comdat


>>>>> "David" == David B Anderson <davea@quasar.engr.sgi.com> writes:

>>> So symbolic references are OK after all?  That's how my implementation
>>> works.

> All (well almost all) relocations are 'symbolic', right?

> Following this, the word 'offset' is the distance in bytes (or bits)
> from an external symbol. 

> But some are references to a particular symbol, and some
> are offsets from some particular symbol.  And many that are offsets
> from a symbol are offsets from a section symbol.

OK, so we should avoid optimizing symbol references into section+offset.
That seems easy enough--I believe that's the status quo, in fact.
I don't understand what the problem is.

> Jim's comment about layout is the key.

> How, in the presence of possibly multiple instances of stdio.h (for
> example) in an app, can one guarantee the layout of .debug_info (or
> other) data in a section group is byte-for-byte identical in the stdio.h
> dwarf2?  Something as simple as a different file-path to the *same*
> header will change offsets in dwarf2.

I haven't attempted to.  I refer to DIEs in a COMDAT using global symbols
(DW.something).

Jason

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]