[PATCH] D122525: [clang][ASTImporter] Fix an import error handling related bug.

[Gabor Marton via Phabricator via cfe-commits]

martong added inline comments.


================
Comment at: clang/lib/AST/ASTImporter.cpp:8792-8794
+        if (!isa<TagDecl>(FromDi))
+          if (auto *FromDiDC = dyn_cast<DeclContext>(FromDi))
+            if (FromDiDC->containsDecl(PrevFromDi))
----------------
balazske wrote:
> martong wrote:
> > We should elevate this logic and the one in `ImportDeclContext` that uses `consumeError` into a common abstraction. I.e. making them closer to each other in a class.
> > Something like (draft, did not test it, might not compile):
> > ```
> > class ErrorHandlingStrategy {
> >   static bool accumulateChildErrors(DeclContext*);
> >   static bool accumulateChildErrors(Decl *FromDi, Decl* Parent); // Use this one when traversing through the import path!
> > public:
> >   static Error handleDeclContextError(Error Err, DeclContext* FromDC) {
> >     Error ChildErrors = Error::success();
> >             if (Err && accumulateChildErrors(FromDC))
> >               ChildErrors =  joinErrors(std::move(ChildErrors), std::move(Err));
> >             else
> >               consumeError(std::move(Err));
> >      return ChildErrors
> >   }
> >   
> > };
> > ```
> The `AccumulateChildErrors` value looks the only common thing. It can mean: Accumulate errors (or not) for declarations that are in child-relationship with the parent. The value is only dependent on the parent, true if it is a `TagDecl`. This value can be extracted into a function that is used in `importDeclContext` and at `Import(Decl *)`. At `importDeclContext` we should accumulate or discard errors for every child node. But not for possible other nodes that are imported but are not a child node (probably no such exists now but theoretically it is possible, and when using the error handling strategy for non-namespace-like nodes).
My point is to try to encapsulate the error handling logic as much as possible. It is not just about `AccumulateChildErrors`. The current change scatters the error handling logic into seemingly distant code parts. The `ErrorHandlingStrategy` class could serve this encapsulation, because that's what classes do.


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  https://reviews.llvm.org/D122525/new/

https://reviews.llvm.org/D122525