[torque-ls] Turn parent class name for class decl into a TypeExpression

This enables "goto definition" navigation for parent types.

R=sigurds@chromium.org

Bug: v8:8880
Change-Id: I3207ec8b85f0e36cbab3519b89af98bba1666406
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1593081
Commit-Queue: Simon Zünd <szuend@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61169}

src/torque/ast.h

@@ -915,7 +915,7 @@ struct ClassDeclaration : Declaration {
   DEFINE_AST_NODE_LEAF_BOILERPLATE(ClassDeclaration)
   ClassDeclaration(SourcePosition pos, Identifier* name, bool is_extern,
                    bool generate_print, bool transient,
-                   base::Optional<std::string> super,
+                   base::Optional<TypeExpression*> super,
                    base::Optional<std::string> generates,
                    std::vector<Declaration*> methods,
                    std::vector<ClassFieldExpression> fields)
@@ -924,7 +924,7 @@ struct ClassDeclaration : Declaration {
         is_extern(is_extern),
         generate_print(generate_print),
         transient(transient),
-        super(std::move(super)),
+        super(super),
         generates(std::move(generates)),
         methods(std::move(methods)),
         fields(std::move(fields)) {}
@@ -932,7 +932,7 @@ struct ClassDeclaration : Declaration {
   bool is_extern;
   bool generate_print;
   bool transient;
-  base::Optional<std::string> super;
+  base::Optional<TypeExpression*> super;
   base::Optional<std::string> generates;
   std::vector<Declaration*> methods;
   std::vector<ClassFieldExpression> fields;

src/torque/declaration-visitor.cc

@@ -278,9 +278,7 @@ void DeclarationVisitor::Visit(ClassDeclaration* decl) {
     if (!decl->super) {
       ReportError("Extern class must extend another type.");
     }
-    // Compute the offset of the class' first member. If the class extends
-    // another class, it's the size of the extended class, otherwise zero.
-    const Type* super_type = Declarations::LookupType(*decl->super);
+    const Type* super_type = Declarations::GetType(*decl->super);
     if (super_type != TypeOracle::GetTaggedType()) {
       const ClassType* super_class = ClassType::DynamicCast(super_type);
       if (!super_class) {

src/torque/torque-parser.cc

@@ -575,7 +575,7 @@ base::Optional<ParseResult> MakeClassDeclaration(
   if (!IsValidTypeName(name->value)) {
     NamingConventionError("Type", name->value, "UpperCamelCase");
   }
-  auto extends = child_results->NextAs<base::Optional<std::string>>();
+  auto extends = child_results->NextAs<base::Optional<TypeExpression*>>();
   auto generates = child_results->NextAs<base::Optional<std::string>>();
   auto methods = child_results->NextAs<std::vector<Declaration*>>();
   auto fields = child_results->NextAs<std::vector<ClassFieldExpression>>();
@@ -1650,7 +1650,7 @@ struct TorqueGrammar : Grammar {
            MakeExternConstDeclaration),
       Rule({CheckIf(Token("@generatePrint")), CheckIf(Token("extern")),
             CheckIf(Token("transient")), Token("class"), &name,
-            Optional<std::string>(Sequence({Token("extends"), &identifier})),
+            Optional<TypeExpression*>(Sequence({Token("extends"), &type})),
             Optional<std::string>(
                 Sequence({Token("generates"), &externalString})),
             Token("{"), List<Declaration*>(&method),

test/unittests/torque/ls-server-data-unittest.cc

@@ -79,6 +79,23 @@ TEST(LanguageServer, GotoTypeDefinitionNoDataForFile) {
   EXPECT_FALSE(LanguageServerData::FindDefinition(test_id, {0, 0}));
 }
 
+TEST(LanguageServer, GotoDefinitionClassSuperType) {
+  const std::string source =
+      "type void;\n"
+      "type never;\n"
+      "type Tagged generates 'TNode<Object>' constexpr 'ObjectPtr';\n"
+      "extern class HeapObject extends Tagged {}";
+
+  TestCompiler compiler;
+  compiler.Compile(source);
+
+  // Find the definition for 'Tagged' of the 'extends' on line 3.
+  const SourceId id = SourceFileMap::GetSourceId("<torque>");
+  auto maybe_position = LanguageServerData::FindDefinition(id, {3, 33});
+  ASSERT_TRUE(maybe_position.has_value());
+  EXPECT_EQ(*maybe_position, (SourcePosition{id, {2, 5}, {2, 11}}));
+}
+
 }  // namespace torque
 }  // namespace internal
 }  // namespace v8