Fix scope flags for default parameters

src/parsing/parser.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/parsing/parser.h"
 
 #include "src/api.h"
 #include "src/ast/ast.h"
 #include "src/ast/ast-expression-rewriter.h"
 #include "src/ast/ast-expression-visitor.h"
@@ skipping 4536 matching lines @@
   rewriter.Run();
 }
 
 
 Block* Parser::BuildParameterInitializationBlock(
     const ParserFormalParameters& parameters, bool* ok) {
   DCHECK(!parameters.is_simple);
   DCHECK(scope_->is_function_scope());
   Block* init_block =
       factory()->NewBlock(NULL, 1, true, RelocInfo::kNoPosition);
+  ZoneList<Scope*>* param_scopes = new (zone()) ZoneList<Scope*>(0, zone());
   for (int i = 0; i < parameters.params.length(); ++i) {
     auto parameter = parameters.params[i];
     if (parameter.is_rest && parameter.pattern->IsVariableProxy()) break;
     DeclarationDescriptor descriptor;
     descriptor.declaration_kind = DeclarationDescriptor::PARAMETER;
     descriptor.parser = this;
     descriptor.scope = scope_;
     descriptor.hoist_scope = nullptr;
     descriptor.mode = LET;
     descriptor.declaration_pos = parameter.pattern->position();
@@ skipping 21 matching lines @@
           RelocInfo::kNoPosition);
       initial_value = factory()->NewConditional(
           condition, parameter.initializer, initial_value,
           RelocInfo::kNoPosition);
       descriptor.initialization_pos = parameter.initializer->position();
       initializer_position = parameter.initializer_end_position;
     }
 
     Scope* param_scope = scope_;
     Block* param_block = init_block;
-    if (!parameter.is_simple() && scope_->calls_sloppy_eval()) {
+    if (!parameter.is_simple()) {
       param_scope = NewScope(scope_, BLOCK_SCOPE);
       param_scope->set_is_declaration_scope();
       param_scope->set_start_position(descriptor.initialization_pos);
       param_scope->set_end_position(parameter.initializer_end_position);
-      param_scope->RecordEvalCall();
+      param_scopes->Add(param_scope, zone());
+      scope_->PropagateUsageFlagsToScope(param_scope);

[adamk, 2016/06/06 18:53:36]

This is where we have to make the call, so that the call to FinalizeBlockScope
below doesn't over-eagerly remove this scope from the scope chain.

       param_block = factory()->NewBlock(NULL, 8, true, RelocInfo::kNoPosition);
       param_block->set_scope(param_scope);
       descriptor.hoist_scope = scope_;
     }
 
     {
       BlockState block_state(&scope_, param_scope);
       DeclarationParsingResult::Declaration decl(
           parameter.pattern, initializer_position, initial_value);
       PatternRewriter::DeclareAndInitializeVariables(param_block, &descriptor,
                                                      &decl, nullptr, CHECK_OK);
     }
 
-    if (!parameter.is_simple() && scope_->calls_sloppy_eval()) {
+    if (!parameter.is_simple()) {
       param_scope = param_scope->FinalizeBlockScope();
       if (param_scope != nullptr) {
         CheckConflictingVarDeclarations(param_scope, CHECK_OK);
       }
       init_block->statements()->Add(param_block, zone());
     }
   }
+  for (Scope* param_scope : *param_scopes) {
+    scope_->PropagateUsageFlagsToScope(param_scope);

[adamk, 2016/06/06 18:53:36]

This call is now redundant, right?

+  }
   return init_block;
 }
 
 Block* Parser::BuildRejectPromiseOnException(Block* block) {
   // try { <block> } catch (error) { return Promise.reject(error); }
   Block* try_block = block;
   Scope* catch_scope = NewScope(scope_, CATCH_SCOPE);
   catch_scope->set_is_hidden();
   Variable* catch_variable =
       catch_scope->DeclareLocal(ast_value_factory()->dot_catch_string(), VAR,
@@ skipping 2325 matching lines @@
                         try_block, target);
     final_loop = target;
   }
 
   return final_loop;
 }
 
 
 }  // namespace internal
 }  // namespace v8