[PATCH] D43494: [Modules] Fix creating fake definition data for lambdas.

[Volodymyr Sapsai via Phabricator via cfe-commits]

vsapsai added inline comments.


================
Comment at: clang/lib/Serialization/ASTReaderDecl.cpp:2969
 
+    if (!DD && RD->isBeingDefined())
+      return nullptr;
----------------
aprantl wrote:
> Perhaps add a comment explaining what's going on in this early exit?
While I was trying to explain this early exit, I realized one of my assumptions was incorrect. Now I'm not sure returning nullptr is the right fix, maybe assigning incomplete definition data like

```lang=c++
D->DefinitionData = DD;
ReadCXXDefinitionData(*DD, D);
```
is better.

I am trying to come up with a test case showing different behaviour for these 2 different fixes. But so far nothing yet. If anybody can tell which one is correct: null context for merging or not-yet-populated definition data, that would be helpful.


https://reviews.llvm.org/D43494