Cleanup the AST code by removing unused parts and get rid of the...

src/flow-graph.cc

Index: src/flow-graph.cc
===================================================================
--- src/flow-graph.cc	(revision 5322)
+++ src/flow-graph.cc	(working copy)
@@ -1,763 +0,0 @@
-// Copyright 2010 the V8 project authors. All rights reserved.
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-//       notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-//       copyright notice, this list of conditions and the following
-//       disclaimer in the documentation and/or other materials provided
-//       with the distribution.
-//     * Neither the name of Google Inc. nor the names of its
-//       contributors may be used to endorse or promote products derived
-//       from this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-#include "flow-graph.h"
-#include "scopes.h"
-
-namespace v8 {
-namespace internal {
-
-void BasicBlock::BuildTraversalOrder(ZoneList<BasicBlock*>* preorder,
-                                     ZoneList<BasicBlock*>* postorder,
-                                     bool mark) {
-  if (mark_ == mark) return;
-  mark_ = mark;
-  preorder->Add(this);
-  if (right_successor_ != NULL) {
-    right_successor_->BuildTraversalOrder(preorder, postorder, mark);
-  }
-  if (left_successor_ != NULL) {
-    left_successor_->BuildTraversalOrder(preorder, postorder, mark);
-  }
-  postorder->Add(this);
-}
-
-
-FlowGraph* FlowGraphBuilder::Build(FunctionLiteral* lit) {
-  // Create new entry and exit nodes.  These will not change during
-  // construction.
-  entry_ = new BasicBlock(NULL);
-  exit_ = new BasicBlock(NULL);
-  // Begin accumulating instructions in the entry block.
-  current_ = entry_;
-
-  VisitDeclarations(lit->scope()->declarations());
-  VisitStatements(lit->body());
-  // In the event of stack overflow or failure to handle a syntactic
-  // construct, return an invalid flow graph.
-  if (HasStackOverflow()) return new FlowGraph(NULL, NULL);
-
-  // If current is not the exit, add a link to the exit.
-  if (current_ != exit_) {
-    // If current already has a successor (i.e., will be a branch node) and
-    // if the exit already has a predecessor, insert an empty block to
-    // maintain edge split form.
-    if (current_->HasSuccessor() && exit_->HasPredecessor()) {
-      current_ = new BasicBlock(current_);
-    }
-    Literal* undefined = new Literal(Factory::undefined_value());
-    current_->AddInstruction(new ReturnStatement(undefined));
-    exit_->AddPredecessor(current_);
-  }
-
-  FlowGraph* graph = new FlowGraph(entry_, exit_);
-  bool mark = !entry_->GetMark();
-  entry_->BuildTraversalOrder(graph->preorder(), graph->postorder(), mark);
-
-#ifdef DEBUG
-  // Number the nodes in reverse postorder.
-  int n = 0;
-  for (int i = graph->postorder()->length() - 1; i >= 0; --i) {
-    graph->postorder()->at(i)->set_number(n++);
-  }
-#endif
-
-  return graph;
-}
-
-
-void FlowGraphBuilder::VisitDeclaration(Declaration* decl) {
-  Variable* var = decl->proxy()->AsVariable();
-  Slot* slot = var->slot();
-  // We allow only declarations that do not require code generation.
-  // The following all require code generation: global variables and
-  // functions, variables with slot type LOOKUP, declarations with
-  // mode CONST, and functions.
-
-  if (var->is_global() ||
-      (slot != NULL && slot->type() == Slot::LOOKUP) ||
-      decl->mode() == Variable::CONST ||
-      decl->fun() != NULL) {
-    // Here and in the rest of the flow graph builder we indicate an
-    // unsupported syntactic construct by setting the stack overflow
-    // flag on the visitor.  This causes bailout of the visitor.
-    SetStackOverflow();
-  }
-}
-
-
-void FlowGraphBuilder::VisitBlock(Block* stmt) {
-  VisitStatements(stmt->statements());
-}
-
-
-void FlowGraphBuilder::VisitExpressionStatement(ExpressionStatement* stmt) {
-  Visit(stmt->expression());
-}
-
-
-void FlowGraphBuilder::VisitEmptyStatement(EmptyStatement* stmt) {
-  // Nothing to do.
-}
-
-
-void FlowGraphBuilder::VisitIfStatement(IfStatement* stmt) {
-  // Build a diamond in the flow graph.  First accumulate the instructions
-  // of the test in the current basic block.
-  Visit(stmt->condition());
-
-  // Remember the branch node and accumulate the true branch as its left
-  // successor.  This relies on the successors being added left to right.
-  BasicBlock* branch = current_;
-  current_ = new BasicBlock(branch);
-  Visit(stmt->then_statement());
-
-  // Construct a join node and then accumulate the false branch in a fresh
-  // successor of the branch node.
-  BasicBlock* join = new BasicBlock(current_);
-  current_ = new BasicBlock(branch);
-  Visit(stmt->else_statement());
-  join->AddPredecessor(current_);
-
-  current_ = join;
-}
-
-
-void FlowGraphBuilder::VisitContinueStatement(ContinueStatement* stmt) {
-  SetStackOverflow();
-}
-
-
-void FlowGraphBuilder::VisitBreakStatement(BreakStatement* stmt) {
-  SetStackOverflow();
-}
-
-
-void FlowGraphBuilder::VisitReturnStatement(ReturnStatement* stmt) {
-  SetStackOverflow();
-}
-
-
-void FlowGraphBuilder::VisitWithEnterStatement(WithEnterStatement* stmt) {
-  SetStackOverflow();
-}
-
-
-void FlowGraphBuilder::VisitWithExitStatement(WithExitStatement* stmt) {
-  SetStackOverflow();
-}
-
-
-void FlowGraphBuilder::VisitSwitchStatement(SwitchStatement* stmt) {
-  SetStackOverflow();
-}
-
-
-void FlowGraphBuilder::VisitDoWhileStatement(DoWhileStatement* stmt) {
-  SetStackOverflow();
-}
-
-
-void FlowGraphBuilder::VisitWhileStatement(WhileStatement* stmt) {
-  SetStackOverflow();
-}
-
-
-void FlowGraphBuilder::VisitForStatement(ForStatement* stmt) {
-  // Build a loop in the flow graph.  First accumulate the instructions of
-  // the initializer in the current basic block.
-  if (stmt->init() != NULL) Visit(stmt->init());
-
-  // Create a new basic block for the test.  This will be the join node.
-  BasicBlock* join = new BasicBlock(current_);
-  current_ = join;
-  if (stmt->cond() != NULL) Visit(stmt->cond());
-
-  // The current node is the branch node.  Create a new basic block to begin
-  // the body.
-  BasicBlock* branch = current_;
-  current_ = new BasicBlock(branch);
-  Visit(stmt->body());
-  if (stmt->next() != NULL) Visit(stmt->next());
-
-  // Add the backward edge from the end of the body and continue with the
-  // false arm of the branch.
-  join->AddPredecessor(current_);
-  current_ = new BasicBlock(branch);
-}
-
-
-void FlowGraphBuilder::VisitForInStatement(ForInStatement* stmt) {
-  SetStackOverflow();
-}
-
-
-void FlowGraphBuilder::VisitTryCatchStatement(TryCatchStatement* stmt) {
-  SetStackOverflow();
-}
-
-
-void FlowGraphBuilder::VisitTryFinallyStatement(TryFinallyStatement* stmt) {
-  SetStackOverflow();
-}
-
-
-void FlowGraphBuilder::VisitDebuggerStatement(DebuggerStatement* stmt) {
-  SetStackOverflow();
-}
-
-
-void FlowGraphBuilder::VisitFunctionLiteral(FunctionLiteral* expr) {
-  SetStackOverflow();
-}
-
-
-void FlowGraphBuilder::VisitSharedFunctionInfoLiteral(
-    SharedFunctionInfoLiteral* expr) {
-  SetStackOverflow();
-}
-
-
-void FlowGraphBuilder::VisitConditional(Conditional* expr) {
-  SetStackOverflow();
-}
-
-
-void FlowGraphBuilder::VisitSlot(Slot* expr) {
-  // Slots do not appear in the AST.
-  UNREACHABLE();
-}
-
-
-void FlowGraphBuilder::VisitVariableProxy(VariableProxy* expr) {
-  current_->AddInstruction(expr);
-}
-
-
-void FlowGraphBuilder::VisitLiteral(Literal* expr) {
-  current_->AddInstruction(expr);
-}
-
-
-void FlowGraphBuilder::VisitRegExpLiteral(RegExpLiteral* expr) {
-  SetStackOverflow();
-}
-
-
-void FlowGraphBuilder::VisitObjectLiteral(ObjectLiteral* expr) {
-  SetStackOverflow();
-}
-
-
-void FlowGraphBuilder::VisitArrayLiteral(ArrayLiteral* expr) {
-  SetStackOverflow();
-}
-
-
-void FlowGraphBuilder::VisitCatchExtensionObject(CatchExtensionObject* expr) {
-  SetStackOverflow();
-}
-
-
-void FlowGraphBuilder::VisitAssignment(Assignment* expr) {
-  // There are three basic kinds of assignment: variable assignments,
-  // property assignments, and invalid left-hand sides (which are translated
-  // to "throw ReferenceError" by the parser).
-  Variable* var = expr->target()->AsVariableProxy()->AsVariable();
-  Property* prop = expr->target()->AsProperty();
-  ASSERT(var == NULL || prop == NULL);
-  if (var != NULL) {
-    if (expr->is_compound() && !expr->target()->IsTrivial()) {
-      Visit(expr->target());
-    }
-    if (!expr->value()->IsTrivial()) Visit(expr->value());
-    current_->AddInstruction(expr);
-
-  } else if (prop != NULL) {
-    if (!prop->obj()->IsTrivial()) Visit(prop->obj());
-    if (!prop->key()->IsPropertyName() && !prop->key()->IsTrivial()) {
-      Visit(prop->key());
-    }
-    if (!expr->value()->IsTrivial()) Visit(expr->value());
-    current_->AddInstruction(expr);
-
-  } else {
-    Visit(expr->target());
-  }
-}
-
-
-void FlowGraphBuilder::VisitThrow(Throw* expr) {
-  SetStackOverflow();
-}
-
-
-void FlowGraphBuilder::VisitProperty(Property* expr) {
-  if (!expr->obj()->IsTrivial()) Visit(expr->obj());
-  if (!expr->key()->IsPropertyName() && !expr->key()->IsTrivial()) {
-    Visit(expr->key());
-  }
-  current_->AddInstruction(expr);
-}
-
-
-void FlowGraphBuilder::VisitCall(Call* expr) {
-  Visit(expr->expression());
-  VisitExpressions(expr->arguments());
-  current_->AddInstruction(expr);
-}
-
-
-void FlowGraphBuilder::VisitCallNew(CallNew* expr) {
-  SetStackOverflow();
-}
-
-
-void FlowGraphBuilder::VisitCallRuntime(CallRuntime* expr) {
-  SetStackOverflow();
-}
-
-
-void FlowGraphBuilder::VisitUnaryOperation(UnaryOperation* 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());
-      current_->AddInstruction(expr);
-      break;
-
-    default:
-      UNREACHABLE();
-  }
-}
-
-
-void FlowGraphBuilder::VisitCountOperation(CountOperation* expr) {
-  Visit(expr->expression());
-  current_->AddInstruction(expr);
-}
-
-
-void FlowGraphBuilder::VisitBinaryOperation(BinaryOperation* expr) {
-  switch (expr->op()) {
-    case Token::COMMA:
-    case Token::OR:
-    case Token::AND:
-      SetStackOverflow();
-      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:
-      if (!expr->left()->IsTrivial()) Visit(expr->left());
-      if (!expr->right()->IsTrivial()) Visit(expr->right());
-      current_->AddInstruction(expr);
-      break;
-
-    default:
-      UNREACHABLE();
-  }
-}
-
-
-void FlowGraphBuilder::VisitCompareOperation(CompareOperation* 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:
-      if (!expr->left()->IsTrivial()) Visit(expr->left());
-      if (!expr->right()->IsTrivial()) Visit(expr->right());
-      current_->AddInstruction(expr);
-      break;
-
-    default:
-      UNREACHABLE();
-  }
-}
-
-
-void FlowGraphBuilder::VisitThisFunction(ThisFunction* expr) {
-  SetStackOverflow();
-}
-
-
-#ifdef DEBUG
-
-// Print a textual representation of an instruction in a flow graph.
-class InstructionPrinter: public AstVisitor {
- public:
-  InstructionPrinter() {}
-
- private:
-  // Overridden from the base class.
-  virtual void VisitExpressions(ZoneList<Expression*>* exprs);
-
-  // AST node visit functions.
-#define DECLARE_VISIT(type) virtual void Visit##type(type* node);
-  AST_NODE_LIST(DECLARE_VISIT)
-#undef DECLARE_VISIT
-
-  DISALLOW_COPY_AND_ASSIGN(InstructionPrinter);
-};
-
-
-static void PrintSubexpression(Expression* expr) {
-  if (!expr->IsTrivial()) {
-    PrintF("@%d", expr->num());
-  } else if (expr->AsLiteral() != NULL) {
-    expr->AsLiteral()->handle()->Print();
-  } else if (expr->AsVariableProxy() != NULL) {
-    PrintF("%s", *expr->AsVariableProxy()->name()->ToCString());
-  } else {
-    UNREACHABLE();
-  }
-}
-
-
-void InstructionPrinter::VisitExpressions(ZoneList<Expression*>* exprs) {
-  for (int i = 0; i < exprs->length(); ++i) {
-    if (i != 0) PrintF(", ");
-    PrintF("@%d", exprs->at(i)->num());
-  }
-}
-
-
-// We only define printing functions for the node types that can occur as
-// instructions in a flow graph.  The rest are unreachable.
-void InstructionPrinter::VisitDeclaration(Declaration* decl) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitBlock(Block* stmt) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitExpressionStatement(ExpressionStatement* stmt) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitEmptyStatement(EmptyStatement* stmt) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitIfStatement(IfStatement* stmt) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitContinueStatement(ContinueStatement* stmt) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitBreakStatement(BreakStatement* stmt) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitReturnStatement(ReturnStatement* stmt) {
-  PrintF("return ");
-  PrintSubexpression(stmt->expression());
-}
-
-
-void InstructionPrinter::VisitWithEnterStatement(WithEnterStatement* stmt) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitWithExitStatement(WithExitStatement* stmt) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitSwitchStatement(SwitchStatement* stmt) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitDoWhileStatement(DoWhileStatement* stmt) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitWhileStatement(WhileStatement* stmt) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitForStatement(ForStatement* stmt) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitForInStatement(ForInStatement* stmt) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitTryCatchStatement(TryCatchStatement* stmt) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitTryFinallyStatement(TryFinallyStatement* stmt) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitDebuggerStatement(DebuggerStatement* stmt) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitFunctionLiteral(FunctionLiteral* expr) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitSharedFunctionInfoLiteral(
-    SharedFunctionInfoLiteral* expr) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitConditional(Conditional* expr) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitSlot(Slot* expr) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitVariableProxy(VariableProxy* expr) {
-  Variable* var = expr->AsVariable();
-  if (var != NULL) {
-    PrintF("%s", *var->name()->ToCString());
-  } else {
-    ASSERT(expr->AsProperty() != NULL);
-    Visit(expr->AsProperty());
-  }
-}
-
-
-void InstructionPrinter::VisitLiteral(Literal* expr) {
-  expr->handle()->Print();
-}
-
-
-void InstructionPrinter::VisitRegExpLiteral(RegExpLiteral* expr) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitObjectLiteral(ObjectLiteral* expr) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitArrayLiteral(ArrayLiteral* expr) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitCatchExtensionObject(
-    CatchExtensionObject* expr) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitAssignment(Assignment* expr) {
-  Variable* var = expr->target()->AsVariableProxy()->AsVariable();
-  Property* prop = expr->target()->AsProperty();
-
-  // Print the left-hand side.
-  Visit(expr->target());
-  if (var == NULL && prop == NULL) return;  // Throw reference error.
-  PrintF(" = ");
-  // For compound assignments, print the left-hand side again and the
-  // corresponding binary operator.
-  if (expr->is_compound()) {
-    PrintSubexpression(expr->target());
-    PrintF(" %s ", Token::String(expr->binary_op()));
-  }
-
-  // Print the right-hand side.
-  PrintSubexpression(expr->value());
-}
-
-
-void InstructionPrinter::VisitThrow(Throw* expr) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitProperty(Property* expr) {
-  PrintSubexpression(expr->obj());
-  if (expr->key()->IsPropertyName()) {
-    PrintF(".");
-    ASSERT(expr->key()->AsLiteral() != NULL);
-    expr->key()->AsLiteral()->handle()->Print();
-  } else {
-    PrintF("[");
-    PrintSubexpression(expr->key());
-    PrintF("]");
-  }
-}
-
-
-void InstructionPrinter::VisitCall(Call* expr) {
-  PrintF("@%d(", expr->expression()->num());
-  VisitExpressions(expr->arguments());
-  PrintF(")");
-}
-
-
-void InstructionPrinter::VisitCallNew(CallNew* expr) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitCallRuntime(CallRuntime* expr) {
-  UNREACHABLE();
-}
-
-
-void InstructionPrinter::VisitUnaryOperation(UnaryOperation* expr) {
-  PrintF("%s(@%d)", Token::String(expr->op()), expr->expression()->num());
-}
-
-
-void InstructionPrinter::VisitCountOperation(CountOperation* expr) {
-  if (expr->is_prefix()) {
-    PrintF("%s@%d", Token::String(expr->op()), expr->expression()->num());
-  } else {
-    PrintF("@%d%s", expr->expression()->num(), Token::String(expr->op()));
-  }
-}
-
-
-void InstructionPrinter::VisitBinaryOperation(BinaryOperation* expr) {
-  PrintSubexpression(expr->left());
-  PrintF(" %s ", Token::String(expr->op()));
-  PrintSubexpression(expr->right());
-}
-
-
-void InstructionPrinter::VisitCompareOperation(CompareOperation* expr) {
-  PrintSubexpression(expr->left());
-  PrintF(" %s ", Token::String(expr->op()));
-  PrintSubexpression(expr->right());
-}
-
-
-void InstructionPrinter::VisitThisFunction(ThisFunction* expr) {
-  UNREACHABLE();
-}
-
-
-int BasicBlock::PrintAsText(int instruction_number) {
-  // Print a label for all blocks except the entry.
-  if (HasPredecessor()) {
-    PrintF("L%d:", number());
-  }
-
-  // Number and print the instructions.  Since AST child nodes are visited
-  // before their parents, the parent nodes can refer to them by number.
-  InstructionPrinter printer;
-  for (int i = 0; i < instructions_.length(); ++i) {
-    PrintF("\n%d ", instruction_number);
-    instructions_[i]->set_num(instruction_number++);
-    instructions_[i]->Accept(&printer);
-  }
-
-  // If this is the exit, print "exit".  If there is a single successor,
-  // print "goto" successor on a separate line.  If there are two
-  // successors, print "goto" successor on the same line as the last
-  // instruction in the block.  There is a blank line between blocks (and
-  // after the last one).
-  if (left_successor_ == NULL) {
-    PrintF("\nexit\n\n");
-  } else if (right_successor_ == NULL) {
-    PrintF("\ngoto L%d\n\n", left_successor_->number());
-  } else {
-    PrintF(", goto (L%d, L%d)\n\n",
-           left_successor_->number(),
-           right_successor_->number());
-  }
-
-  return instruction_number;
-}
-
-
-void FlowGraph::PrintAsText(Handle<String> name) {
-  PrintF("\n==== name = \"%s\" ====\n", *name->ToCString());
-  // Print nodes in reverse postorder.  Note that AST node numbers are used
-  // during printing of instructions and thus their current values are
-  // destroyed.
-  int number = 0;
-  for (int i = postorder_.length() - 1; i >= 0; --i) {
-    number = postorder_[i]->PrintAsText(number);
-  }
-}
-
-#endif  // DEBUG
-
-
-} }  // namespace v8::internal