Cut back the syntactic constructs handled by the flow graph builder.

While the flow graph is experimental, it's easier to be able to ignore
some problematic syntactic constructs.  Reduce the ones that can occur
in constructed flow graphs.

Review URL: http://codereview.chromium.org/790004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4084 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/data-flow.cc

@@ -239,20 +239,17 @@ void FlowGraphBuilder::VisitBreakStatement(BreakStatement* stmt) {
 
 
 void FlowGraphBuilder::VisitReturnStatement(ReturnStatement* stmt) {
-  Visit(stmt->expression());
-  graph_.AppendInstruction(stmt);
-  graph_.AppendNode(global_exit());
+  SetStackOverflow();
 }
 
 
 void FlowGraphBuilder::VisitWithEnterStatement(WithEnterStatement* stmt) {
-  Visit(stmt->expression());
-  graph_.AppendInstruction(stmt);
+  SetStackOverflow();
 }
 
 
 void FlowGraphBuilder::VisitWithExitStatement(WithExitStatement* stmt) {
-  graph_.AppendInstruction(stmt);
+  SetStackOverflow();
 }
 
 
@@ -262,44 +259,12 @@ void FlowGraphBuilder::VisitSwitchStatement(SwitchStatement* stmt) {
 
 
 void FlowGraphBuilder::VisitDoWhileStatement(DoWhileStatement* stmt) {
-  JoinNode* join = new JoinNode();
-  FlowGraph original = graph_;
-  graph_ = FlowGraph::Empty();
-  Visit(stmt->body());
-
-  FlowGraph body = graph_;
-  graph_ = FlowGraph::Empty();
-  Visit(stmt->cond());
-
-  BranchNode* branch = new BranchNode();
-
-  // Add body, condition and branch.
-  original.AppendNode(join);
-  original.AppendGraph(&body);
-  original.AppendGraph(&graph_);  // The condition.
-  original.AppendNode(branch);
-
-  // Tie the knot.
-  branch->AddSuccessor(join);
-  join->AddPredecessor(branch);
-
-  graph_ = original;
+  SetStackOverflow();
 }
 
 
 void FlowGraphBuilder::VisitWhileStatement(WhileStatement* stmt) {
-  JoinNode* join = new JoinNode();
-  FlowGraph original = graph_;
-  graph_ = FlowGraph::Empty();
-  Visit(stmt->cond());
-
-  BranchNode* branch = new BranchNode();
-  FlowGraph condition = graph_;
-  graph_ = FlowGraph::Empty();
-  Visit(stmt->body());
-
-  original.Loop(join, &condition, branch, &graph_);
-  graph_ = original;
+  SetStackOverflow();
 }
 
 
@@ -324,17 +289,7 @@ void FlowGraphBuilder::VisitForStatement(ForStatement* stmt) {
 
 
 void FlowGraphBuilder::VisitForInStatement(ForInStatement* stmt) {
-  Visit(stmt->enumerable());
-
-  JoinNode* join = new JoinNode();
-  FlowGraph empty;
-  BranchNode* branch = new BranchNode();
-  FlowGraph original = graph_;
-  graph_ = FlowGraph::Empty();
-  Visit(stmt->body());
-
-  original.Loop(join, &empty, branch, &graph_);
-  graph_ = original;
+  SetStackOverflow();
 }
 
 
@@ -349,36 +304,23 @@ void FlowGraphBuilder::VisitTryFinallyStatement(TryFinallyStatement* stmt) {
 
 
 void FlowGraphBuilder::VisitDebuggerStatement(DebuggerStatement* stmt) {
-  graph_.AppendInstruction(stmt);
+  SetStackOverflow();
 }
 
 
 void FlowGraphBuilder::VisitFunctionLiteral(FunctionLiteral* expr) {
-  graph_.AppendInstruction(expr);
+  SetStackOverflow();
 }
 
 
 void FlowGraphBuilder::VisitFunctionBoilerplateLiteral(
     FunctionBoilerplateLiteral* expr) {
-  graph_.AppendInstruction(expr);
+  SetStackOverflow();
 }
 
 
 void FlowGraphBuilder::VisitConditional(Conditional* expr) {
-  Visit(expr->condition());
-
-  BranchNode* branch = new BranchNode();
-  FlowGraph original = graph_;
-  graph_ = FlowGraph::Empty();
-  Visit(expr->then_expression());
-
-  FlowGraph left = graph_;
-  graph_ = FlowGraph::Empty();
-  Visit(expr->else_expression());
-
-  JoinNode* join = new JoinNode();
-  original.Split(branch, &left, &graph_, join);
-  graph_ = original;
+  SetStackOverflow();
 }
 
 
@@ -398,30 +340,22 @@ void FlowGraphBuilder::VisitLiteral(Literal* expr) {
 
 
 void FlowGraphBuilder::VisitRegExpLiteral(RegExpLiteral* expr) {
-  graph_.AppendInstruction(expr);
+  SetStackOverflow();
 }
 
 
 void FlowGraphBuilder::VisitObjectLiteral(ObjectLiteral* expr) {
-  ZoneList<ObjectLiteral::Property*>* properties = expr->properties();
-  for (int i = 0, len = properties->length(); i < len; i++) {
-    Visit(properties->at(i)->value());
-  }
-  graph_.AppendInstruction(expr);
+  SetStackOverflow();
 }
 
 
 void FlowGraphBuilder::VisitArrayLiteral(ArrayLiteral* expr) {
-  ZoneList<Expression*>* values = expr->values();
-  for (int i = 0, len = values->length(); i < len; i++) {
-    Visit(values->at(i));
-  }
-  graph_.AppendInstruction(expr);
+  SetStackOverflow();
 }
 
 
 void FlowGraphBuilder::VisitCatchExtensionObject(CatchExtensionObject* expr) {
-  graph_.AppendInstruction(expr);
+  SetStackOverflow();
 }
 
 
@@ -445,8 +379,7 @@ void FlowGraphBuilder::VisitAssignment(Assignment* expr) {
 
 
 void FlowGraphBuilder::VisitThrow(Throw* expr) {
-  Visit(expr->exception());
-  graph_.AppendInstruction(expr);
+  SetStackOverflow();
 }
 
 
@@ -468,27 +401,34 @@ void FlowGraphBuilder::VisitCall(Call* expr) {
 
 
 void FlowGraphBuilder::VisitCallNew(CallNew* expr) {
-  Visit(expr->expression());
-  ZoneList<Expression*>* arguments = expr->arguments();
-  for (int i = 0, len = arguments->length(); i < len; i++) {
-    Visit(arguments->at(i));
-  }
-  graph_.AppendInstruction(expr);
+  SetStackOverflow();
 }
 
 
 void FlowGraphBuilder::VisitCallRuntime(CallRuntime* expr) {
-  ZoneList<Expression*>* arguments = expr->arguments();
-  for (int i = 0, len = arguments->length(); i < len; i++) {
-    Visit(arguments->at(i));
-  }
-  graph_.AppendInstruction(expr);
+  SetStackOverflow();
 }
 
 
 void FlowGraphBuilder::VisitUnaryOperation(UnaryOperation* expr) {
-  Visit(expr->expression());
-  graph_.AppendInstruction(expr);
+  switch (expr->op()) {
+    case Token::NOT:
+    case Token::BIT_NOT:
+    case Token::DELETE:
+    case Token::TYPEOF:
+    case Token::VOID:
+      SetStackOverflow();
+      break;
+
+    case Token::ADD:
+    case Token::SUB:
+      Visit(expr->expression());
+      graph_.AppendInstruction(expr);
+      break;
+
+    default:
+      UNREACHABLE();
+  }
 }
 
 
@@ -503,48 +443,26 @@ void FlowGraphBuilder::VisitCountOperation(CountOperation* expr) {
 
 
 void FlowGraphBuilder::VisitBinaryOperation(BinaryOperation* expr) {
-  Visit(expr->left());
 
   switch (expr->op()) {
     case Token::COMMA:
-      Visit(expr->right());
+    case Token::OR:
+    case Token::AND:
+      SetStackOverflow();
       break;
 
-    case Token::OR: {
-      BranchNode* branch = new BranchNode();
-      FlowGraph original = graph_;
-      graph_ = FlowGraph::Empty();
-      Visit(expr->right());
-      FlowGraph empty;
-      JoinNode* join = new JoinNode();
-      original.Split(branch, &empty, &graph_, join);
-      graph_ = original;
-      break;
-    }
-
-    case Token::AND: {
-      BranchNode* branch = new BranchNode();
-      FlowGraph original = graph_;
-      graph_ = FlowGraph::Empty();
-      Visit(expr->right());
-      FlowGraph empty;
-      JoinNode* join = new JoinNode();
-      original.Split(branch, &graph_, &empty, join);
-      graph_ = original;
-      break;
-    }
-
     case Token::BIT_OR:
     case Token::BIT_XOR:
     case Token::BIT_AND:
     case Token::SHL:
-    case Token::SAR:
     case Token::SHR:
     case Token::ADD:
     case Token::SUB:
     case Token::MUL:
     case Token::DIV:
     case Token::MOD:
+    case Token::SAR:
+      Visit(expr->left());
       Visit(expr->right());
       graph_.AppendInstruction(expr);
       break;
@@ -556,14 +474,33 @@ void FlowGraphBuilder::VisitBinaryOperation(BinaryOperation* expr) {
 
 
 void FlowGraphBuilder::VisitCompareOperation(CompareOperation* expr) {
-  Visit(expr->left());
-  Visit(expr->right());
-  graph_.AppendInstruction(expr);
+  switch (expr->op()) {
+    case Token::EQ:
+    case Token::NE:
+    case Token::EQ_STRICT:
+    case Token::NE_STRICT:
+    case Token::INSTANCEOF:
+    case Token::IN:
+      SetStackOverflow();
+      break;
+
+    case Token::LT:
+    case Token::GT:
+    case Token::LTE:
+    case Token::GTE:
+      Visit(expr->left());
+      Visit(expr->right());
+      graph_.AppendInstruction(expr);
+      break;
+
+    default:
+      UNREACHABLE();
+  }
 }
 
 
 void FlowGraphBuilder::VisitThisFunction(ThisFunction* expr) {
-  graph_.AppendInstruction(expr);
+  SetStackOverflow();
 }