[PATCH] D67901: [clangd] Improve semantic highlighting in dependent contexts (fixes #154)

[Haojian Wu via Phabricator via cfe-commits]

hokein added inline comments.


================
Comment at: clang-tools-extra/clangd/SemanticHighlighting.cpp:181
+      addToken(E->getMemberLoc(), E->getQualifier()
+                                      ? HighlightingKind::StaticField
+                                      : HighlightingKind::Field);
----------------
ilya-biryukov wrote:
> nridge wrote:
> > hokein wrote:
> > > This could be member functions, a case is like
> > > 
> > > ```
> > > template<class T>
> > > class Foo {
> > > public:
> > >   void foo() {
> > >     this->foo();
> > >   }
> > > };
> > > ```
> > Thanks for the example.
> > 
> > Do you have a suggestion for how to discriminate this case? To me, it would seem logical to do it based on syntax (highlight as a member function if the expression forms the function name of a function call expression). That would require navigating from the expression to its parent node. Is there a way to do that?
> There is no way to do this in C++.
> Even if the name is followed by a pair of parenthese, this could either be a field with overloaded `operator()` (e.g. a `std::function<void()> field`) or a function with the same name.
> 
> It's much better to pick a separate highlighting kind for dependent names, this follows the actual semantics of C++.
+1, I think we should just highlight them as a dependent type.


================
Comment at: clang-tools-extra/clangd/SemanticHighlighting.cpp:159
+      addToken(E->getNameLoc(), E->getNamingClass()
+                                    ? HighlightingKind::StaticMethod
+                                    : HighlightingKind::Function);
----------------
I'm doubting we will encounter other exceptions.

```
struct X {
template<class T>
static T t;
};

template<typename T>
void f() {
  X::t<T>; // this is a `UnresolvedLookupExpr`.
}
```


================
Comment at: clang-tools-extra/clangd/unittests/SemanticHighlightingTests.cpp:54
       {HighlightingKind::StaticMethod, "StaticMethod"},
+      {HighlightingKind::Typedef, "Typedef"},
+      {HighlightingKind::DependentType, "DependentType"},
----------------
thanks for catching this!


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D67901/new/

https://reviews.llvm.org/D67901