Mark class as typedef class before parsing its function type when using the new

runtime/vm/parser.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/parser.h"
 #include "vm/flags.h"
 
 #ifndef DART_PRECOMPILED_RUNTIME
 
 #include "lib/invocation_mirror.h"
@@ skipping 5453 matching lines @@
 
   // Create the function type alias scope class. It will be linked to its
   // signature function after it has been parsed. The type parameters, in order
   // to be properly finalized, need to be associated to this scope class as
   // they are parsed.
   const Class& function_type_alias = Class::Handle(
       Z, Class::New(library_, *alias_name, script_, declaration_pos));
   function_type_alias.set_is_synthesized_class();
   function_type_alias.set_is_abstract();
   function_type_alias.set_is_prefinalized();
+  // Make sure the function type alias can be recognized as a typedef class by
+  // setting its signature function. When use_function_type_syntax is true, this
+  // temporary signature function is replaced while parsing the function type.
+  Function& signature_function = Function::Handle(
+      Z, Function::NewSignatureFunction(function_type_alias,
+                                        Function::Handle(Z), alias_name_pos));
+  function_type_alias.set_signature_function(signature_function);
   library_.AddClass(function_type_alias);

[rmacnak, 2017/06/29 21:11:09]

ASSERT(function_type_alias.IsTypedefClass());

[regis, 2017/06/29 21:30:47]

Done.

   ASSERT(current_class().IsTopLevel());
   set_current_class(function_type_alias);
   // Parse the type parameters of the typedef class.
   ParseTypeParameters(true);  // Parameterizing current class.
-  Function& signature_function = Function::Handle(Z);
   ASSERT(innermost_function().IsNull());
   if (use_function_type_syntax) {
     ExpectToken(Token::kASSIGN);
     ASSERT(result_type.IsNull());  // Not parsed yet.
-    // Do not resolve types before the function type alias can be recognized as
-    // a typedef class, so that correct promotion of function types can occur.
     const Type& function_type = Type::Handle(
         Z, ParseFunctionType(result_type, ClassFinalizer::kDoNotResolve));
     signature_function = function_type.signature();
   } else {
-    signature_function = Function::NewSignatureFunction(
-        function_type_alias, Function::Handle(Z), alias_name_pos);
     innermost_function_ = signature_function.raw();
     ParamList params;
     // Parse the formal parameters of the function type.
     CheckToken(Token::kLPAREN, "formal parameter list expected");
     // Add implicit closure object parameter.
     params.AddFinalParameter(TokenPos(), &Symbols::ClosureParameter(),
                              &Object::dynamic_type());
     const bool allow_explicit_default_values = false;
     const bool evaluate_metadata = false;
     ParseFormalParameterList(use_function_type_syntax,
                              allow_explicit_default_values, evaluate_metadata,
                              &params);
     if (result_type.IsNull()) {
       result_type = Type::DynamicType();
     }
     signature_function.set_result_type(result_type);
     AddFormalParamsToFunction(&params, signature_function);
     ASSERT(innermost_function().raw() == signature_function.raw());
     innermost_function_ = Function::null();
   }
   ExpectSemicolon();
   ASSERT(innermost_function().IsNull());
-
-  // Set the signature function in the function type alias class.
-  function_type_alias.set_signature_function(signature_function);
+  ASSERT(function_type_alias.signature_function() == signature_function.raw());
 
   // At this point, all function type parameters have been parsed and the class
   // function_type_alias is recognized as a typedef, so we can resolve all type
   // parameters in the signature type defined by the typedef.
   AbstractType& function_type =
       Type::Handle(Z, signature_function.SignatureType());
   ASSERT(current_class().raw() == function_type_alias.raw());
   ResolveType(&function_type);
   // Resolving does not replace type or signature.
   ASSERT(function_type_alias.signature_function() ==
@@ skipping 7868 matching lines @@
                              &Object::dynamic_type());
 
     const bool use_function_type_syntax = true;
     const bool allow_explicit_default_values = false;
     const bool evaluate_metadata = false;
     ParseFormalParameterList(use_function_type_syntax,
                              allow_explicit_default_values, evaluate_metadata,
                              &params);
     AddFormalParamsToFunction(&params, signature_function);
     innermost_function_ = innermost_function_.parent_function();
+    if (innermost_function().IsNull() && current_class().IsTypedefClass() &&
+        !IsFunctionTypeSymbol()) {
+      // The last parsed signature function is the typedef signature function.
+      // Set it in the typedef class before building the signature type.
+      current_class().set_signature_function(signature_function);
+    }
     type = signature_function.SignatureType();
   } while (IsFunctionTypeSymbol());
   // At this point, all type parameters have been parsed, resolve the type.
   if (finalization == ClassFinalizer::kIgnore) {
     return Type::DynamicType();
   }
   if (finalization >= ClassFinalizer::kResolveTypeParameters) {
     ResolveType(&type);
     if (finalization >= ClassFinalizer::kCanonicalize) {
       type ^= CanonicalizeType(type);
@@ skipping 1999 matching lines @@
                                                 TokenPosition* start,
                                                 TokenPosition* end) {
   UNREACHABLE();
   return false;
 }
 
 
 }  // namespace dart
 
 #endif  // DART_PRECOMPILED_RUNTIME