[Lldb-commits] [PATCH] D134066: [LLDB][NativePDB] Forcefully complete a record type it has incomplete type debug info.

Mon Oct 17 18:18:11 PDT 2022

zequanwu added inline comments.

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Comment at: lldb/source/Plugins/SymbolFile/NativePDB/PdbAstBuilder.cpp:681
+        auto &ts = llvm::cast<TypeSystemClang>(*ct.GetTypeSystem());
+        ts.GetMetadata(&tag)->SetIsForcefullyCompleted();
+      }
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zequanwu wrote:
> labath wrote:
> > zequanwu wrote:
> > > rnk wrote:
> > > > Is this what we do for DWARF? The same kind of situation seems like it can arise, where clang requires a type to be complete, but the information is missing, and we still try to proceed with evaluation.
> > > I think it's here: https://github.com/llvm/llvm-project/blob/main/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp#L221-L250, relevant: https://reviews.llvm.org/D85968.
> > The trick is to do the forced completion only when the type is used within contexts where the c++ rules require it to be complete. something like `class A; A* a;` is perfectly legal c++. `class A; class B : A {};` is not. You can't do this from within the completion callback. In DWARF code, we check for this when we're parsing the enclosing entity (so, when we're parsing `B`, we'd check, and if needed, "forcefully complete" the class `A`.
> What does dwarf plugin do in this case that we don't have debug info for class A: `class A; class B : A {};`? The problem I'm trying to fix is when the base class has no debug info to complete it.
@labath, Do you see anything would go wrong if we forcefully complete a class that has no debug info? It seems fine, for the chrome crash report I was checking.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D134066/new/

https://reviews.llvm.org/D134066