Merge pull request #2910 from augusto2112/ts-swift-typeref-get-instance-type

[lldb] Implement TypeSystemSwiftTypeRef::GetInstanceType

Author: augusto2112

lldb/source/Plugins/TypeSystem/Swift/TypeSystemSwiftTypeRef.cpp

@@ -2823,8 +2823,34 @@ TypeSystemSwiftTypeRef::GetReferentType(opaque_compiler_type_t type) {
 
 CompilerType
 TypeSystemSwiftTypeRef::GetInstanceType(opaque_compiler_type_t type) {
-  return m_swift_ast_context->GetInstanceType(ReconstructType(type));
+  auto impl = [&]() -> CompilerType {
+    using namespace swift::Demangle;
+    Demangler dem;
+    NodePointer node = DemangleCanonicalType(dem, type);
+
+    if (!node)
+      return {};
+    if (ContainsUnresolvedTypeAlias(node)) {
+      // If we couldn't resolve all type aliases, we might be in a REPL session
+      // where getting to the debug information necessary for resolving that
+      // type alias isn't possible, or the user might have defined the
+      // type alias in the REPL. In these cases, fallback to asking the AST
+      // for the canonical type.
+      return m_swift_ast_context->GetInstanceType(ReconstructType(type));
+    }
+
+    if (node->getKind() == Node::Kind::Metatype) {
+      for (NodePointer child : *node)
+        if (child->getKind() == Node::Kind::Type)
+          return RemangleAsType(dem, child);
+      return {};
+    }
+    return {this, type};
+  };
+  VALIDATE_AND_RETURN(impl, GetInstanceType, type, (ReconstructType(type)),
+                      (ReconstructType(type)));
 }
+
 TypeSystemSwift::TypeAllocationStrategy
 TypeSystemSwiftTypeRef::GetAllocationStrategy(opaque_compiler_type_t type) {
   return m_swift_ast_context->GetAllocationStrategy(ReconstructType(type));

lldb/unittests/Symbol/TestTypeSystemSwiftTypeRef.cpp

@@ -638,4 +638,33 @@ TEST_F(TestTypeSystemSwiftTypeRef, GetNumTemplateArguments) {
     CompilerType t = GetCompilerType(b.Mangle(n));
     ASSERT_EQ(t.GetNumTemplateArguments(), 1);
   }
-}
+}
+
+TEST_F(TestTypeSystemSwiftTypeRef, GetInstanceType) {
+  using namespace swift::Demangle;
+  Demangler dem;
+  NodeBuilder b(dem);
+  {
+    NodePointer n = b.GlobalType(
+            b.Node(Node::Kind::Metatype,
+              b.Node(Node::Kind::MetatypeRepresentation, "@thin"),
+              b.Node(Node::Kind::Type,
+                b.Node(Node::Kind::Structure,
+                  b.Node(Node::Kind::Module, "Swift"),
+                  b.Node(Node::Kind::Identifier, "String")))));
+
+    CompilerType t = GetCompilerType(b.Mangle(n));
+    CompilerType instance_type = m_swift_ts.GetInstanceType(t.GetOpaqueQualType());
+    ASSERT_EQ(instance_type.GetMangledTypeName(), "$sSSD");
+  };
+  {
+    NodePointer n = b.GlobalType(
+        b.Node(Node::Kind::Structure,
+          b.Node(Node::Kind::Module, "Swift"),
+          b.Node(Node::Kind::Identifier, "String")));
+
+    CompilerType t = GetCompilerType(b.Mangle(n));
+    CompilerType instance_type = m_swift_ts.GetInstanceType(t.GetOpaqueQualType());
+    ASSERT_EQ(instance_type.GetMangledTypeName(), "$sSSD");
+  };
+};