[PATCH] D65510: [clangd] Fix implicit template instatiations appearing as topLevelDecls.

[Ilya Biryukov via Phabricator via cfe-commits]

ilya-biryukov added inline comments.


================
Comment at: clang-tools-extra/clangd/ClangdUnit.cpp:68
+  if (const auto *TD = dyn_cast<T>(D))
+    return TD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation;
+  return false;
----------------
jvikstrom wrote:
> ilya-biryukov wrote:
> > hokein wrote:
> > > ilya-biryukov wrote:
> > > > We also want to skip `TSK_ExplicitInstantiationDeclaration` and  `TSK_ExplicitInstantiationDefinition` here.
> > > > This covers cases like (not sure which one of the two enum values we get, though):
> > > > ```
> > > > template <class T>
> > > > int foo(T) { ... }
> > > > 
> > > > template int foo(int); // we'd rather not traverse these, highlightings will run into the same problems.
> > > > ```
> > > > 
> > > > Semantics I'm describing are roughly similar to `isImplicitInstatiation(D) == !isExplicitInstantion(D)`, where `isExplicitInstantiation` is taken from `CodeComplete.cpp`. (If we ignore `TSK_Undeclared`, which, I believe, should never be encountered in decls passed to HandleTopLevelDecl).
> > > > 
> > > > Please extract the helper from code complete and this one into a separate file (e.g. `clangd/AST.h`) and possibly implement one through the other
> > > > Semantics I'm describing are roughly similar to isImplicitInstatiation(D) == !isExplicitInstantion(D), 
> > > 
> > > I think there is a typo here, I believe you mean `isImplicitInstantiation(D) == !isExplicitSpecialization(D) ` (in CodeComplete.cpp, it checks whether a Decl is an explicit **specialization**).
> > Yes, there's a typo thanks!
> Still want me to move this and the helper from CodeComplete to `AST.h` as it isn't used anywhere else? (esp. when we can't implement them through of each other)
Yes, it's better to share this code between `codeComplete` and `ClangdUnit`. It might pop up in more places and it's not trivial.


================
Comment at: clang-tools-extra/clangd/ClangdUnit.cpp:82
         continue;
+      if (isImplicitTemplateInstantiation<FunctionDecl>(D) ||
+          isImplicitTemplateInstantiation<CXXRecordDecl>(D) ||
----------------
Could we expose the following non-template function instead?
```
bool isImplicitTemplateInstantiation(NamedDecl *);
```

So that the users don't need to specify which `Decl` they are interested in (I believe there's no use for it anyway)


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D65510/new/

https://reviews.llvm.org/D65510