[Lldb-commits] [lldb] Reapply [lldb][DWARF] Delay struct/class/union definition DIE searching when parsing declaration DIEs. (PR #92328)

[Zequan Wu via lldb-commits]

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@@ -2306,6 +2345,11 @@ bool DWARFASTParserClang::CompleteTypeFromDWARF(const DWARFDIE &die,
 
   if (!die)
     return false;
+  ParsedDWARFTypeAttributes attrs(die);
----------------
ZequanWu wrote:

> Why don't those cases lead to a crash? For example, what would happen if the name was simply not in the index?

That is specific to debug_names because the index gives us a declaration DIE when we are searching for definition DIE in 'FindDefinitionTypeForDWARFDeclContext'. Before, we didn't have the extra check, so we tries to complete the type from declaration DIE, which triggers an assertion in clang. However, it doesn't happen in manual index because we already explicitly checked `DW_AT_declaration` attributes when creating the manual index. It's guaranteed to find a definition DIE from `FindDefinitionTypeForDWARFDeclContext` or nothing (early bailout, won't try to complete it).

> So it seems perfectly reasonable to have this check somewhere. I just want to check whether this is the right place.

I assume Greg's change at https://github.com/llvm/llvm-project/pull/91808 will also fix this problem by skipping forward declaration DIE when processing it, which is earlier check  than this extra check added here.

https://github.com/llvm/llvm-project/pull/92328