Simplify handling of stack overflows in AstGraphBuilder.

src/compiler/ast-graph-builder.cc

 // Copyright 2014 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/compiler/ast-graph-builder.h"
 
 #include "src/compiler.h"
 #include "src/compiler/ast-loop-assignment-analyzer.h"
 #include "src/compiler/control-builders.h"
 #include "src/compiler/linkage.h"
@@ skipping 433 matching lines @@
   // Initialize the incoming context.
   function_context_ = NewOuterContextParam();
   ContextScope incoming(this, scope, function_context_);
 
   // Build receiver check for sloppy mode if necessary.
   // TODO(mstarzinger/verwaest): Should this be moved back into the CallIC?
   Node* original_receiver = env.Lookup(scope->receiver());
   Node* patched_receiver = BuildPatchReceiverToGlobalProxy(original_receiver);
   env.Bind(scope->receiver(), patched_receiver);
 
-  bool ok;
+  // Build function context only if there are context allocated variables.
   int heap_slots = info()->num_heap_slots() - Context::MIN_CONTEXT_SLOTS;
   if (heap_slots > 0) {
     // Push a new inner context scope for the function.
     Node* closure = GetFunctionClosure();
     Node* inner_context = BuildLocalFunctionContext(function_context_, closure);
     ContextScope top_context(this, scope, inner_context);
-    ok = CreateGraphBody();
+    CreateGraphBody();
   } else {
     // Simply use the outer function context in building the graph.
-    ok = CreateGraphBody();
+    CreateGraphBody();
   }
 
   // Finish the basic structure of the graph.
-  if (ok) {
-    environment()->UpdateControlDependency(exit_control());
-    graph()->SetEnd(NewNode(common()->End()));
-  }
+  graph()->SetEnd(graph()->NewNode(common()->End(), exit_control()));
 
-  return ok;
+  // Failures indicated by stack overflow.
+  return !HasStackOverflow();
 }
 
 
-bool AstGraphBuilder::CreateGraphBody() {
+void AstGraphBuilder::CreateGraphBody() {
   Scope* scope = info()->scope();
+
   // Build the arguments object if it is used.
   BuildArgumentsObject(scope->arguments());
 
   // Build rest arguments array if it is used.
   int rest_index;
   Variable* rest_parameter = scope->rest_parameter(&rest_index);
   BuildRestArgumentsArray(rest_parameter, rest_index);
 
   // Emit tracing call if requested to do so.
   if (FLAG_trace) {
     NewNode(javascript()->CallRuntime(Runtime::kTraceEnter, 0));
   }
 
   // Visit implicit declaration of the function name.
   if (scope->is_function_scope() && scope->function() != NULL) {
     VisitVariableDeclaration(scope->function());
   }
 
   // Visit declarations within the function scope.
   VisitDeclarations(scope->declarations());
 
   // Build a stack-check before the body.
   Node* node = BuildStackCheck();
   PrepareFrameState(node, BailoutId::FunctionEntry());
 
   // Visit statements in the function body.
   VisitStatements(info()->function()->body());
-  if (HasStackOverflow()) return false;
 
   // Emit tracing call if requested to do so.
   if (FLAG_trace) {
     // TODO(mstarzinger): Only traces implicit return.
     Node* return_value = jsgraph()->UndefinedConstant();
     NewNode(javascript()->CallRuntime(Runtime::kTraceExit, 1), return_value);
   }
 
   // Return 'undefined' in case we can fall off the end.
   BuildReturn(jsgraph()->UndefinedConstant());
-
-  return true;
 }
 
 
 // Left-hand side can only be a property, a global or a variable slot.
 enum LhsKind { VARIABLE, NAMED_PROPERTY, KEYED_PROPERTY };
 
 
 // Determine the left-hand side kind of an assignment.
 static LhsKind DetermineLhsKind(Expression* expr) {
   Property* property = expr->AsProperty();
@@ skipping 2678 matching lines @@
     // Phi does not exist yet, introduce one.
     value = NewPhi(inputs, value, control);
     value->ReplaceInput(inputs - 1, other);
   }
   return value;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8