In MachO a segment fully contains its sections and a section can only be in one segment. I don't remember how much the lldb Section nesting code enforces this. It would be weird to have two Sections at the same level overlap, I don't see any "GetSectionsForAddress(lldb::addr_t address)" API's so I don't think we're ready to handle that.
Maybe we could start marking sections as "duplicate" and only handing out the original one when doing lldb::addr_t -> Section lookups? Jim > On Dec 11, 2018, at 11:58 AM, Pavel Labath <pa...@labath.sk> wrote: > > On 11/12/2018 20:39, Jim Ingham wrote: >> Sections can have parents. In MachO the text and data sections are actually >> contained in the TEXT and DATA segments respectively. LLDB represents this >> by having an lldb_private::Section for the segment, and then all the >> sections in that segment are children of the parent Section (the MachO >> segment). All the code that looks up addresses expects to potentially >> traverse this hierarchy. >> It seems to me that what you are describing should fit in the nesting model? >> Jim >> > > Hmm.. that's an interesting idea. I'll have to think about that. > > Does MachO enforce somehow that every section is fully contained in one > segment? Because while that is true for elf in general, it is not a > requirement, and it is possible to create functional executables (though I > think I would have to use a hex editor for that) where one segment contains > only a half of some section. But that might not be a big issue, as I think > most tools will choke on files like this, so if we do something suboptimal > here, it shouldn't be too bad. > > The other hickup I can think of is that sometimes (and this happens in > perfectly valid files too) one section is present in multiple segments. For > example .eh_frame will be present in a "LOAD" segment (so it ends up in > memory), but it will also be present in a special "GNU_EH_FRAME" segment (not > sure why, but I guess it's to make it easier for someone to find it). But I > think I can get around that by only creating these "container" sections for > LOAD segments. > > > The part I know nothing about is whether something similar could be done for > PE/COFF files (and I'll need something like that there too). Adrian, Zachary, > what is the relation ship between "image base" of an object file and its > sections? Is there any way we could arrange so that the base address of a > module always belongs to one of its sections? > > pl _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
