Remove small window when function parameter types and names were reset to null

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 3279 matching lines @@
       ParamList discarded_params;
       ParseFormalParameterList(allow_explicit_default_values,
                                false,
                                &discarded_params);
     }
   } else {
     ParseFormalParameterList(allow_explicit_default_values, false, &params);
 
     // The number of parameters and their type are not yet set in local
     // functions, since they are not 'top-level' parsed.
-    if (func.IsLocalFunction()) {
+    // However, they are already set when the local function is compiled, since
+    // the local function was parsed when its parent was compiled.
+    if (func.parameter_types() == Object::empty_array().raw()) {
       AddFormalParamsToFunction(&params, func);
     }
     SetupDefaultsForOptionalParams(params);
     ASSERT(AbstractType::Handle(Z, func.result_type()).IsResolved());
     ASSERT(func.NumParameters() == params.parameters->length());
 
     // Check whether the function has any field initializer formal parameters,
     // which are not allowed in non-constructor functions.
     if (params.has_field_initializer) {
       for (int i = 0; i < params.parameters->length(); i++) {
@@ skipping 3969 matching lines @@
     const Script& script = Script::Handle(Class::Handle(func.Owner()).script());
     Report::MessageF(Report::kError,
                      script, func.token_pos(), Report::AtLocation,
                      "too many formal parameters");
   }
   func.set_num_fixed_parameters(params->num_fixed_parameters);
   func.SetNumOptionalParameters(params->num_optional_parameters,
                                 params->has_optional_positional_parameters);
   const int num_parameters = params->parameters->length();
   ASSERT(num_parameters == func.NumParameters());
+  ASSERT(func.parameter_types() == Object::empty_array().raw());
+  ASSERT(func.parameter_names() == Object::empty_array().raw());
   func.set_parameter_types(Array::Handle(Array::New(num_parameters,
                                                     Heap::kOld)));
   func.set_parameter_names(Array::Handle(Array::New(num_parameters,
                                                     Heap::kOld)));
   for (int i = 0; i < num_parameters; i++) {
     ParamDesc& param_desc = (*params->parameters)[i];
     func.SetParameterTypeAt(i, *param_desc.type);
     func.SetParameterNameAt(i, *param_desc.name);
   }
 }
@@ skipping 7179 matching lines @@
     const ArgumentListNode& function_args,
     const LocalVariable* temp_for_last_arg,
     bool is_super_invocation) {
   UNREACHABLE();
   return NULL;
 }
 
 }  // namespace dart
 
 #endif  // DART_PRECOMPILED_RUNTIME