[Interpreter] Create ScopeInfos in ast-numbering phase.

src/ast/ast-numbering.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/ast/ast-numbering.h"
 
 #include "src/ast/ast.h"
 #include "src/ast/scopes.h"
 
 namespace v8 {
@@ skipping 215 matching lines @@
   IncrementNodeCount();
   node->set_base_id(ReserveIdRange(CountOperation::num_ids()));
   Visit(node->expression());
   ReserveFeedbackSlots(node);
 }
 
 
 void AstNumberingVisitor::VisitBlock(Block* node) {
   IncrementNodeCount();
   node->set_base_id(ReserveIdRange(Block::num_ids()));
+
+  if (FLAG_ignition && node->scope() != nullptr &&

[Michael Starzinger, 2016/08/09 07:38:26]

Just for posterity: We could consider adding Block::PrepareScopeInfo(Isolate*)
to bundle the predicate with the AST node. But for now lets stick with the
current version until the approach stabilizes.

+      node->scope()->NeedsContext()) {
+    // Create ScopeInfo while on the main thread to avoid allocation during
+    // potentially concurrent bytecode generation.
+    node->scope()->GetScopeInfo(isolate_);
+  }
+
   if (node->scope() != NULL) VisitDeclarations(node->scope()->declarations());
   VisitStatements(node->statements());
 }
 
 
 void AstNumberingVisitor::VisitFunctionDeclaration(FunctionDeclaration* node) {
   IncrementNodeCount();
   VisitVariableProxy(node->proxy());
   VisitFunctionLiteral(node->fun());
 }
@@ skipping 319 matching lines @@
   if (scope->calls_eval()) DisableOptimization(kFunctionCallsEval);
   if (scope->arguments() != NULL && !scope->arguments()->IsStackAllocated()) {
     DisableCrankshaft(kContextAllocatedArguments);
   }
 
   int rest_index;
   if (scope->rest_parameter(&rest_index)) {
     DisableCrankshaft(kRestParameter);
   }
 
+  if (FLAG_ignition && scope->NeedsContext() && scope->is_script_scope()) {
+    // Create ScopeInfo while on the main thread to avoid allocation during
+    // potentially concurrent bytecode generation.
+    node->scope()->GetScopeInfo(isolate_);
+  }
+
   if (IsGeneratorFunction(node->kind()) || IsAsyncFunction(node->kind())) {
     // TODO(neis): We may want to allow Turbofan optimization here if
     // --turbo-from-bytecode is set and we know that Ignition is used.
     // Unfortunately we can't express that here.
     DisableOptimization(kGenerator);
   }
 
   VisitDeclarations(scope->declarations());
   VisitStatements(node->body());
 
   node->set_ast_properties(&properties_);
   node->set_dont_optimize_reason(dont_optimize_reason());
   node->set_yield_count(yield_count_);
   return !HasStackOverflow();
 }
 
 
 bool AstNumbering::Renumber(Isolate* isolate, Zone* zone,
                             FunctionLiteral* function) {
   AstNumberingVisitor visitor(isolate, zone);
   return visitor.Renumber(function);
 }
 }  // namespace internal
 }  // namespace v8