[lldb] Replace usage of remote AST with reflection on GetDynamicTypeAndAddress_Protocol.

Author: augusto2112

lldb/source/Plugins/LanguageRuntime/Swift/SwiftLanguageRuntimeDynamicTypeResolution.cpp

@@ -1808,18 +1808,128 @@ bool SwiftLanguageRuntimeImpl::IsValidErrorValue(ValueObject &in_value) {
 
   return true;
 }
+/// Digs into the protocols inside a protocol composition and checks if 
+/// any of them belong to the LLDB module.
+static bool
+IsDeclaredInLLDBExpr(const swift::reflection::TypeRef *typeref) {
+  using swift::Demangle::Node;
+
+  const auto *protocol_typeref = llvm::dyn_cast_or_null<
+      const swift::reflection::ProtocolCompositionTypeRef>(typeref);
+
+  if (!protocol_typeref)
+    return false;
+
+  swift::Demangle::Demangler dem;
+
+  NodePointer type = protocol_typeref->getDemangling(dem);
+  if (!type || type->getKind() != Node::Kind::Type ||
+      type->getNumChildren() == 0)
+    return false;
+
+  NodePointer maybe_protocol_list = type->getFirstChild();
+  NodePointer protocol_list;
+
+  if (!maybe_protocol_list)
+    return false;
+
+  switch (maybe_protocol_list->getKind()) {
+  case Node::Kind::ProtocolList:
+    protocol_list = maybe_protocol_list;
+    break;
+  case Node::Kind::ProtocolListWithAnyObject:
+  case Node::Kind::ProtocolListWithClass:
+    if (maybe_protocol_list->getNumChildren() == 0)
+      return false;
+    protocol_list = maybe_protocol_list->getFirstChild();
+    break;
+  default:
+    return false;
+  }
+
+  if (!protocol_list || protocol_list->getKind() != Node::Kind::ProtocolList ||
+      protocol_list->getNumChildren() == 0)
+    return false;
+
+  NodePointer type_list = protocol_list->getFirstChild();
+  if (!type_list || type_list->getKind() != Node::Kind::TypeList)
+    return false;
+
+  for (NodePointer internal_type : *type_list) {
+    if (!internal_type || internal_type->getKind() != Node::Kind::Type ||
+        internal_type->getNumChildren() == 0)
+      continue;
+
+    NodePointer protocol = internal_type->getFirstChild();
+    if (!protocol || protocol->getKind() != Node::Kind::Protocol ||
+        protocol->getNumChildren() == 0)
+      continue;
+
+    NodePointer module = protocol->getFirstChild();
+    if (!module || module->getKind() != Node::Kind::Module ||
+        !module->hasText())
+      continue;
+
+    if (module->getText().startswith("__lldb_expr_"))
+      return true;
+  }
+  return false;
+}
 
 bool SwiftLanguageRuntimeImpl::GetDynamicTypeAndAddress_Protocol(
     ValueObject &in_value, CompilerType protocol_type,
     SwiftASTContextForExpressions &scratch_ctx,
     lldb::DynamicValueType use_dynamic, TypeAndOrName &class_type_or_name,
     Address &address) {
+  auto remote_ast_impl = [&](bool use_local_buffer,
+                             lldb::addr_t existential_address)
+      -> llvm::Optional<std::pair<CompilerType, Address>> {
+    swift::remote::RemoteAddress remote_existential(existential_address);
+    auto &remote_ast = GetRemoteASTContext(scratch_ctx);
+    auto swift_type = GetSwiftType(protocol_type);
+    if (!swift_type)
+      return {};
+    if (use_local_buffer)
+      PushLocalBuffer(existential_address,
+                      in_value.GetByteSize().getValueOr(0));
+
+    auto result = remote_ast.getDynamicTypeAndAddressForExistential(
+        remote_existential, swift_type);
+    if (use_local_buffer)
+      PopLocalBuffer();
+
+    if (!result.isSuccess())
+      return {};
+
+    auto type_and_address = result.getValue();
+
+    CompilerType type = ToCompilerType(type_and_address.InstanceType);
+    Address address;
+    address.SetRawAddress(type_and_address.PayloadAddress.getAddressData());
+    return {{type, address}};
+  };
+
   Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_TYPES));
 
   auto &target = m_process.GetTarget();
   assert(IsScratchContextLocked(target) &&
          "Swift scratch context not locked ahead");
-  auto &remote_ast = GetRemoteASTContext(scratch_ctx);
+
+  auto *tss =
+      llvm::dyn_cast_or_null<TypeSystemSwift>(protocol_type.GetTypeSystem());
+  if (!tss) {
+    if (log)
+      log->Printf("Could not get type system swift");
+    return false;
+  }
+
+  const swift::reflection::TypeRef *protocol_typeref =
+      GetTypeRef(protocol_type, tss->GetSwiftASTContext());
+  if (!protocol_typeref) {
+    if (log)
+      log->Printf("Could not get protocol typeref");
+    return false;
+  }
 
   lldb::addr_t existential_address;
   bool use_local_buffer = false;
@@ -1844,29 +1954,65 @@ bool SwiftLanguageRuntimeImpl::GetDynamicTypeAndAddress_Protocol(
   if (log)
     log->Printf("existential address is 0x%llx", existential_address);
 
-  if (!existential_address || existential_address == LLDB_INVALID_ADDRESS)
+  if (!existential_address || existential_address == LLDB_INVALID_ADDRESS) {
+    if (log)
+      log->Printf("Existential address is invalid");
     return false;
+  }
+
+  // If the protocol list contains any types declared in LLDB,
+  // we use the remote AST implementation since we currently
+  // don't register the metadata generated by LLDB.
+  if (IsDeclaredInLLDBExpr(protocol_typeref)) {
+    auto pair = remote_ast_impl(use_local_buffer, existential_address);
+    if (!pair)
+      return false;
+    class_type_or_name.SetCompilerType(std::get<CompilerType>(*pair));
+    address = std::get<Address>(*pair);
+    return true;
+  }
 
   if (use_local_buffer)
     PushLocalBuffer(existential_address, in_value.GetByteSize().getValueOr(0));
 
   swift::remote::RemoteAddress remote_existential(existential_address);
-  auto result = remote_ast.getDynamicTypeAndAddressForExistential(
-      remote_existential, GetSwiftType(protocol_type));
 
+  auto *reflection_ctx = GetReflectionContext();
+  auto pair = reflection_ctx->projectExistentialAndUnwrapClass(
+      remote_existential, *protocol_typeref);
   if (use_local_buffer)
     PopLocalBuffer();
 
-  if (!result.isSuccess()) {
+  if (!pair) {
     if (log)
-      log->Printf("RemoteAST failed to get dynamic type of existential");
+      log->Printf("Runtime failed to get dynamic type of existential");
     return false;
   }
 
-  auto type_and_address = result.getValue();
-  class_type_or_name.SetCompilerType(
-      ToCompilerType(type_and_address.InstanceType));
-  address.SetRawAddress(type_and_address.PayloadAddress.getAddressData());
+  const swift::reflection::TypeRef *typeref;
+  swift::remote::RemoteAddress out_address(nullptr);
+  std::tie(typeref, out_address) = *pair;
+  auto &ts = tss->GetTypeSystemSwiftTypeRef();
+  swift::Demangle::Demangler dem;
+  swift::Demangle::NodePointer node = typeref->getDemangling(dem);
+  class_type_or_name.SetCompilerType(ts.RemangleAsType(dem, node));
+  address.SetRawAddress(out_address.getAddressData());
+
+#ifndef NDEBUG
+  auto reference_pair = remote_ast_impl(use_local_buffer, existential_address);
+  assert(pair.hasValue() >= reference_pair.hasValue() &&
+         "RemoteAST and runtime diverge");
+
+  if (reference_pair) {
+    CompilerType ref_type = std::get<CompilerType>(*reference_pair);
+    Address ref_address = std::get<Address>(*reference_pair);
+    ConstString a = class_type_or_name.GetCompilerType().GetMangledTypeName();
+    ConstString b = ref_type.GetMangledTypeName();
+    if (a != b)
+      llvm::dbgs() << "RemoteAST and runtime diverge " << a << " != " << b
+                   << "\n";
+  }
+#endif
   return true;
 }
 

lldb/source/Plugins/TypeSystem/Swift/SwiftASTContext.h

@@ -166,6 +166,10 @@ class SwiftASTContext : public TypeSystemSwift {
                   Target *target = nullptr);
 
   SwiftASTContext(const SwiftASTContext &rhs) = delete;
+  
+  TypeSystemSwiftTypeRef &GetTypeSystemSwiftTypeRef() override {
+    return m_typeref_typesystem;
+  }
 
   ~SwiftASTContext();
 

lldb/source/Plugins/TypeSystem/Swift/TypeSystemSwift.h

@@ -28,7 +28,7 @@ class Decl;
 namespace lldb_private {
 class TypeSystemClang;
 class SwiftASTContext;
-
+class TypeSystemSwiftTypeRef;
 /// The implementation of lldb::Type's m_payload field for TypeSystemSwift.
 class TypePayloadSwift {
   /// Layout: bit 1 ... IsFixedValueBuffer.
@@ -109,6 +109,7 @@ class TypeSystemSwift : public TypeSystem {
 
   static LanguageSet GetSupportedLanguagesForTypes();
   virtual SwiftASTContext *GetSwiftASTContext() = 0;
+  virtual TypeSystemSwiftTypeRef &GetTypeSystemSwiftTypeRef() = 0;
   virtual Module *GetModule() const = 0;
   virtual lldb::TypeSP GetCachedType(ConstString mangled) = 0;
   virtual void SetCachedType(ConstString mangled,

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

@@ -50,6 +50,7 @@ class TypeSystemSwiftTypeRef : public TypeSystemSwift {
 
   TypeSystemSwiftTypeRef(SwiftASTContext *swift_ast_context);
   SwiftASTContext *GetSwiftASTContext() override { return m_swift_ast_context; }
+  TypeSystemSwiftTypeRef &GetTypeSystemSwiftTypeRef() override { return *this; }
 
   Module *GetModule() const override;
   swift::CanType GetCanonicalSwiftType(CompilerType compiler_type);

lldb/test/API/lang/swift/clangimporter/dynamic_type_resolution_import_conflict/TestSwiftDynamicTypeResolutionImportConflict.py

@@ -69,4 +69,4 @@ def test(self):
         self.expect("fr v -d run-target -- input",
                     substrs=['(Dylib.LibraryProtocol) input'])
         self.expect("expr -d run-target -- input",
-                    substrs=['(Dylib.LibraryProtocol)'])
+                    substrs=['(a.FromMainModule)'])

lldb/test/API/lang/swift/private_import/TestSwiftPrivateImport.py

@@ -33,7 +33,6 @@ def test_private_import(self):
         lldbutil.run_to_source_breakpoint(
             self, 'break here', lldb.SBFileSpec('main.swift'),
             extra_images=['Library'])
-        # We should not be able to resolve the types.
-        self.expect("fr var -d run -- x", substrs=["(Any)"])
+        self.expect("fr var -d run -- x", substrs=["(Invisible.InvisibleStruct)"])
         # FIXME: This crashes LLDB with a Swift DESERIALIZATION FAILURE.
         # self.expect("fr var -d run -- y", substrs=["(Any)"])