[PATCH] D69844: [clang][Basic] Integrate SourceLocation with FoldingSet, NFCI

[Duncan P. N. Exon Smith via Phabricator via cfe-commits]

dexonsmith accepted this revision.
dexonsmith added a comment.
This revision is now accepted and ready to land.

LGTM.



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Comment at: clang/lib/Analysis/PathDiagnostic.cpp:1088
+  ID.Add(Range.getEnd());
+  ID.Add(static_cast<const SourceLocation &>(Loc));
 }
----------------
miyuki wrote:
> dexonsmith wrote:
> > I'm surprised you need this `static_cast`, can you explain why it was necessary?
> `Loc` is an object of type `FullSourceLoc`, a class derived from `SourceLocation`. When the `FoldingSetNodeID::Add` template method is called with `Loc` it tries to instantiate `FoldingSetTrait<FullSourceLoc>` and fails (because there is no explicit specialization for `FullSourceLoc` and the default one relies on the method `FullSourceLoc::Profile` which does not exist). `FullSourceLoc` does not contain any additional information about the location itself (it just holds a pointer to the associated `SourceManager`), so there is no need to specialize `FoldingSetTrait` for it, and casting to `SourceLocation` will make `FoldingSetNodeID::Add` use the correct `FoldingSetTrait` specialization.
Right, that makes sense. Thanks for explaining!


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