[Lldb-commits] [PATCH] D42955: Make Module::GetSectionList output consistent

[Pavel Labath via Phabricator via lldb-commits]

labath added a comment.

I can try to split the patch up a bit if you think it will make things easier.  I'm not sure how much I will be able to do that, as the patch is not that big, it just needs to touch a bunch of files for the changed interfaces.

In https://reviews.llvm.org/D42955#1026061, @clayborg wrote:

> Looks fine, a bit hard to tell exactly what is going on so I will accept as long as the following things are still true:
>
> - each lldb_private::ObjectFile has its own section list that perfectly mirrors exactly what is in that object file and that file alone


This part is not completely true. It is true for ObjectFileELF/COFF/JIT, and is enforced by the fact that the ObjectFile::GetSections does not even have access to the unified section list. However, it is *not* true for ObjectFileMachO (but that is not because of this patch). This is the problem I've had when trying to refactor this (and it's the reason the ObjectFileMachO<->SymbolVendorMacOSX interface is a bit weird). It seems that the ObjectFileMachO sometimes takes a section from the unified list and adds it to it's own list (or at least it appears to be doing that). I don't know enough about MachO to understand why is it doing that, or how to fix it. I've highlighted the places in the code where I think this is happening. Any suggestions would be welcome here.

> - The lldb_private::Module hands out a unified section list that is populated by the symbol vendor where it uses one or more object files to create the unified section list

This part is true.



================
Comment at: source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp:1415-1416
 
           SectionSP unified_section_sp(
               unified_section_list.FindSectionByName(const_segname));
           if (is_dsym && unified_section_sp) {
----------------
Here we are grabbing a section from the unified section list.


================
Comment at: source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp:1562
               }
               m_sections_ap->AddSection(unified_section_sp);
             }
----------------
And here it gets added to the object file's section list.


https://reviews.llvm.org/D42955