Support call hierarchy for fields and non-local variables (#113900)

Fixes clangd/clangd#1308

Author: timon-ul

clang-tools-extra/clangd/XRefs.cpp

@@ -2238,7 +2238,10 @@ prepareCallHierarchy(ParsedAST &AST, Position Pos, PathRef TUPath) {
   for (const NamedDecl *Decl : getDeclAtPosition(AST, *Loc, {})) {
     if (!(isa<DeclContext>(Decl) &&
           cast<DeclContext>(Decl)->isFunctionOrMethod()) &&
-        Decl->getKind() != Decl::Kind::FunctionTemplate)
+        Decl->getKind() != Decl::Kind::FunctionTemplate &&
+        !(Decl->getKind() == Decl::Kind::Var &&
+          !cast<VarDecl>(Decl)->isLocalVarDecl()) &&
+        Decl->getKind() != Decl::Kind::Field)
       continue;
     if (auto CHI = declToCallHierarchyItem(*Decl, AST.tuPath()))
       Result.emplace_back(std::move(*CHI));

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

@@ -446,6 +446,51 @@ TEST(CallHierarchy, CallInLocalVarDecl) {
           AllOf(from(withName("caller3")), fromRanges(Source.range("call3")))));
 }
 
+TEST(CallHierarchy, HierarchyOnField) {
+  // Tests that the call hierarchy works on fields.
+  Annotations Source(R"cpp(
+    struct Vars {
+      int v^ar1 = 1;
+    };
+    void caller() {
+      Vars values;
+      values.$Callee[[var1]];
+    }
+  )cpp");
+  TestTU TU = TestTU::withCode(Source.code());
+  auto AST = TU.build();
+  auto Index = TU.index();
+
+  std::vector<CallHierarchyItem> Items =
+      prepareCallHierarchy(AST, Source.point(), testPath(TU.Filename));
+  ASSERT_THAT(Items, ElementsAre(withName("var1")));
+  auto IncomingLevel1 = incomingCalls(Items[0], Index.get());
+  ASSERT_THAT(IncomingLevel1,
+              ElementsAre(AllOf(from(withName("caller")),
+                                fromRanges(Source.range("Callee")))));
+}
+
+TEST(CallHierarchy, HierarchyOnVar) {
+  // Tests that the call hierarchy works on non-local variables.
+  Annotations Source(R"cpp(
+    int v^ar = 1;
+    void caller() {
+      $Callee[[var]];
+    }
+  )cpp");
+  TestTU TU = TestTU::withCode(Source.code());
+  auto AST = TU.build();
+  auto Index = TU.index();
+
+  std::vector<CallHierarchyItem> Items =
+      prepareCallHierarchy(AST, Source.point(), testPath(TU.Filename));
+  ASSERT_THAT(Items, ElementsAre(withName("var")));
+  auto IncomingLevel1 = incomingCalls(Items[0], Index.get());
+  ASSERT_THAT(IncomingLevel1,
+              ElementsAre(AllOf(from(withName("caller")),
+                                fromRanges(Source.range("Callee")))));
+}
+
 } // namespace
 } // namespace clangd
 } // namespace clang