[clangd] Config: handle Index block

[ArcsinX]

Summary

Without this patch config parser ignores Index block and reports warning "Unknown Config key Index".

[ArcsinX]

Sorry, it's already here https://reviews.llvm.org/D87710

[sammccall]

Thanks for catching this! Lucky coincidence it was spotted twice just before rc3!

clang-tools-extra/clangd/ConfigYAML.cpp

public:
   Parser(llvm::SourceMgr &SM) : SM(SM) {}
 
   // Tries to parse N into F, returning false if it failed and we couldn't
   // meaningfully recover (YAML syntax error, or hard semantic error).
   bool parse(Fragment &F, Node &N) {
     DictParser Dict("Config", this);
     Dict.handle("If", [&](Node &N) { parse(F.If, N); });
     Dict.handle("CompileFlags", [&](Node &N) { parse(F.CompileFlags, N); });
+    Dict.handle("Index", [&](Node &N) { parse(F.Index, N); });
     Dict.parse(N);
     return !(N.failed() || HadError);
   }
 
 private:
   void parse(Fragment::IfBlock &F, Node &N) {
     DictParser Dict("If", this);
     Dict.unrecognized(

clang-tools-extra/clangd/unittests/ConfigYAMLTests.cpp

- 1
   )yaml";
   auto Results = Fragment::parseYAML(YAML, "config.yaml", Diags.callback());
   EXPECT_THAT(Diags.Diagnostics,
               ElementsAre(DiagMessage("If should be a dictionary"),
                           DiagMessage("Config should be a dictionary")));
   ASSERT_THAT(Results, IsEmpty());
 }
 
+TEST(ParseYAML, Index) {
+  CapturedDiags Diags;
+  const char *YAML = R"yaml(
+Index:
+  Background: Skip
+  )yaml";
+  auto Results = Fragment::parseYAML(YAML, "config.yaml", Diags.callback());
+  EXPECT_THAT(Diags.Diagnostics, IsEmpty());
+}
+
 } // namespace
 } // namespace config
 } // namespace clangd
 } // namespace clang