[PATCH] D101554: [clangd] Add support for the `defaultLibrary` semantic token modifier

[Kadir Cetinkaya via Phabricator via cfe-commits]

kadircet added inline comments.


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Comment at: clang-tools-extra/clangd/SemanticHighlighting.cpp:413
+  /// different heuristics may be used in the future (e.g. sysroot paths).
+  bool inDefaultLibrary(SourceLocation Loc) const {
+    if (!Loc.isValid())
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you can make this a free function by accepting a decl instead. as sourcemanager is accessible via `D->getASTContext().getSourceManager()`. this way you don't need to modify signatures for `scopeModifier` overloads (and get rid of the duplicate in `CollectExtraHighlightings`).


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Comment at: clang-tools-extra/clangd/SemanticHighlighting.cpp:433
+scopeModifier(const NamedDecl *D, const HighlightingsBuilder &HB) {
+  if (!D)
+    return llvm::None;
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why the null check now?


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Comment at: clang-tools-extra/clangd/SemanticHighlighting.cpp:436
+  if (HB.inDefaultLibrary(D->getLocation()))
+    return HighlightingModifier::DefaultLibrary;
   const DeclContext *DC = D->getDeclContext();
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I don't use semantic highlighting enough to judge whether it is more useful to say `DefaultLibrary` than `{Class,Function}Scope`. (i.e. having the check here vs at the end of the function as a fallback). Can you provide some rationale about the decision (probably as comments in code)?

By looking at the testcase, I suppose you are trying to indicate "overriden"/"extended" attribute of a symbol, which makes sense but would be nice to know if there's more. I am just worried that this is very obj-c specific and won't really generalize to c/c++. As most of the system headers only provide platform specific structs (e.g. posix) and they are almost never extended. So it might be confusing for user to see different colors on some memberexprs.


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Comment at: clang-tools-extra/clangd/SemanticHighlighting.cpp:474
+    return scopeModifier(TD, HB);
+  if (auto *OT = dyn_cast<ObjCObjectType>(T))
+    return scopeModifier(OT->getInterface(), HB);
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should this be put in a separate patch?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D101554/new/

https://reviews.llvm.org/D101554