[PATCH] D66516: [clangd] Added highlighting to types dependant on templates.

[Ilya Biryukov via Phabricator via cfe-commits]

ilya-biryukov added inline comments.


================
Comment at: clang-tools-extra/clangd/SemanticHighlighting.cpp:177
       return;
+    if (TP->isPointerType() || TP->isLValueReferenceType())
+      // When highlighting dependant template types the type can be a pointer or
----------------
jvikstrom wrote:
> ilya-biryukov wrote:
> > `RecursiveASTVisitor` also traverses the pointer and reference types, why does it not reach the inner `TemplateTypeParmType` in the cases you describe?
> The D in `using D = ...` `typedef ... D` does not have a TypeLoc (at least not one that is visited). Therefore we use the VisitTypedefNameDecl (line 121) to get the location of `D` to be able to highlight it. And we just send the typeLocs typeptr to addType (which is a Pointer for `using D = T*;`)...
> 
> But maybe we should get the underlying type before we call addType with TypePtr? Just a while loop on line 123 basically (can we have multiple PointerTypes nested in each other actually?)
> 
> Even if we keep it in addType the comment is actually wrong, because it obviously works when for the actual "type occurrences" for `D` (so will fix that no matter what). This recursion will just make us add more duplicate tokens...
Could we investigate why `RecursiveASTVisitor` does not visit the `TypeLoc` of a corresponding decl?
Here's the code from `RecursiveASTVisitor.h` that should do the trick:
```
DEF_TRAVERSE_DECL(TypeAliasDecl, {
  TRY_TO(TraverseTypeLoc(D->getTypeSourceInfo()->getTypeLoc()));
  // We shouldn't traverse D->getTypeForDecl(); it's a result of
  // declaring the type alias, not something that was written in the
  // source.
})
```

If it doesn't, we are probably holding it wrong.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D66516/new/

https://reviews.llvm.org/D66516