Update clang to r84119.vendor/clang/clang-r84119

1 files changed, 2084 insertions, 0 deletions

diff --git a/lib/Analysis/CFG.cpp b/lib/Analysis/CFG.cpp
new file mode 100644
index 000000000000..7b1d50cb3aee
--- /dev/null
+++ b/lib/Analysis/CFG.cpp
@@ -0,0 +1,2084 @@
+//===--- CFG.cpp - Classes for representing and building CFGs----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines the CFG and CFGBuilder classes for representing and
+//  building Control-Flow Graphs (CFGs) from ASTs.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Analysis/Support/SaveAndRestore.h"
+#include "clang/Analysis/CFG.h"
+#include "clang/AST/StmtVisitor.h"
+#include "clang/AST/PrettyPrinter.h"
+#include "llvm/Support/GraphWriter.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/Allocator.h"
+#include "llvm/Support/Format.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallPtrSet.h"
+
+using namespace clang;
+
+namespace {
+
+static SourceLocation GetEndLoc(Decl* D) {
+  if (VarDecl* VD = dyn_cast<VarDecl>(D))
+    if (Expr* Ex = VD->getInit())
+      return Ex->getSourceRange().getEnd();
+
+  return D->getLocation();
+}
+
+/// CFGBuilder - This class implements CFG construction from an AST.
+///   The builder is stateful: an instance of the builder should be used to only
+///   construct a single CFG.
+///
+///   Example usage:
+///
+///     CFGBuilder builder;
+///     CFG* cfg = builder.BuildAST(stmt1);
+///
+///  CFG construction is done via a recursive walk of an AST.  We actually parse
+///  the AST in reverse order so that the successor of a basic block is
+///  constructed prior to its predecessor.  This allows us to nicely capture
+///  implicit fall-throughs without extra basic blocks.
+///
+class VISIBILITY_HIDDEN CFGBuilder {
+  ASTContext *Context;
+  CFG* cfg;
+
+  CFGBlock* Block;
+  CFGBlock* Succ;
+  CFGBlock* ContinueTargetBlock;
+  CFGBlock* BreakTargetBlock;
+  CFGBlock* SwitchTerminatedBlock;
+  CFGBlock* DefaultCaseBlock;
+
+  // LabelMap records the mapping from Label expressions to their blocks.
+  typedef llvm::DenseMap<LabelStmt*,CFGBlock*> LabelMapTy;
+  LabelMapTy LabelMap;
+
+  // A list of blocks that end with a "goto" that must be backpatched to their
+  // resolved targets upon completion of CFG construction.
+  typedef std::vector<CFGBlock*> BackpatchBlocksTy;
+  BackpatchBlocksTy BackpatchBlocks;
+
+  // A list of labels whose address has been taken (for indirect gotos).
+  typedef llvm::SmallPtrSet<LabelStmt*,5> LabelSetTy;
+  LabelSetTy AddressTakenLabels;
+
+public:
+  explicit CFGBuilder() : cfg(new CFG()), // crew a new CFG
+                          Block(NULL), Succ(NULL),
+                          ContinueTargetBlock(NULL), BreakTargetBlock(NULL),
+                          SwitchTerminatedBlock(NULL), DefaultCaseBlock(NULL) {}
+
+  ~CFGBuilder() { delete cfg; }
+
+  // buildCFG - Used by external clients to construct the CFG.
+  CFG* buildCFG(Stmt *Statement, ASTContext *C);
+
+private:
+  // Visitors to walk an AST and construct the CFG.
+  CFGBlock *VisitAddrLabelExpr(AddrLabelExpr *A, bool alwaysAdd);
+  CFGBlock *VisitBinaryOperator(BinaryOperator *B, bool alwaysAdd);
+  CFGBlock *VisitBlockExpr(BlockExpr* E, bool alwaysAdd);
+  CFGBlock *VisitBlockDeclRefExpr(BlockDeclRefExpr* E, bool alwaysAdd);
+  CFGBlock *VisitBreakStmt(BreakStmt *B);
+  CFGBlock *VisitCallExpr(CallExpr *C, bool alwaysAdd);
+  CFGBlock *VisitCaseStmt(CaseStmt *C);
+  CFGBlock *VisitChooseExpr(ChooseExpr *C);
+  CFGBlock *VisitCompoundStmt(CompoundStmt *C);
+  CFGBlock *VisitConditionalOperator(ConditionalOperator *C);
+  CFGBlock *VisitContinueStmt(ContinueStmt *C);
+  CFGBlock *VisitCXXThrowExpr(CXXThrowExpr *T);
+  CFGBlock *VisitDeclStmt(DeclStmt *DS);
+  CFGBlock *VisitDeclSubExpr(Decl* D);
+  CFGBlock *VisitDefaultStmt(DefaultStmt *D);
+  CFGBlock *VisitDoStmt(DoStmt *D);
+  CFGBlock *VisitForStmt(ForStmt *F);
+  CFGBlock *VisitGotoStmt(GotoStmt* G);
+  CFGBlock *VisitIfStmt(IfStmt *I);
+  CFGBlock *VisitIndirectGotoStmt(IndirectGotoStmt *I);
+  CFGBlock *VisitLabelStmt(LabelStmt *L);
+  CFGBlock *VisitObjCAtCatchStmt(ObjCAtCatchStmt *S);
+  CFGBlock *VisitObjCAtSynchronizedStmt(ObjCAtSynchronizedStmt *S);
+  CFGBlock *VisitObjCAtThrowStmt(ObjCAtThrowStmt *S);
+  CFGBlock *VisitObjCAtTryStmt(ObjCAtTryStmt *S);
+  CFGBlock *VisitObjCForCollectionStmt(ObjCForCollectionStmt *S);
+  CFGBlock *VisitReturnStmt(ReturnStmt* R);
+  CFGBlock *VisitSizeOfAlignOfExpr(SizeOfAlignOfExpr *E, bool alwaysAdd);
+  CFGBlock *VisitStmtExpr(StmtExpr *S, bool alwaysAdd);
+  CFGBlock *VisitSwitchStmt(SwitchStmt *S);
+  CFGBlock *VisitWhileStmt(WhileStmt *W);
+
+  CFGBlock *Visit(Stmt *S, bool alwaysAdd = false);
+  CFGBlock *VisitStmt(Stmt *S, bool alwaysAdd);
+  CFGBlock *VisitChildren(Stmt* S);
+
+  // NYS == Not Yet Supported
+  CFGBlock* NYS() {
+    badCFG = true;
+    return Block;
+  }
+
+  void autoCreateBlock() { if (!Block) Block = createBlock(); }
+  CFGBlock *createBlock(bool add_successor = true);
+  bool FinishBlock(CFGBlock* B);
+  CFGBlock *addStmt(Stmt *S) { return Visit(S, true); }
+  
+  void AppendStmt(CFGBlock *B, Stmt *S) {
+    B->appendStmt(S, cfg->getBumpVectorContext());
+  }
+  
+  void AddSuccessor(CFGBlock *B, CFGBlock *S) {
+    B->addSuccessor(S, cfg->getBumpVectorContext());
+  }
+
+  /// TryResult - a class representing a variant over the values
+  ///  'true', 'false', or 'unknown'.  This is returned by TryEvaluateBool,
+  ///  and is used by the CFGBuilder to decide if a branch condition
+  ///  can be decided up front during CFG construction.
+  class TryResult {
+    int X;
+  public:
+    TryResult(bool b) : X(b ? 1 : 0) {}
+    TryResult() : X(-1) {}
+
+    bool isTrue() const { return X == 1; }
+    bool isFalse() const { return X == 0; }
+    bool isKnown() const { return X >= 0; }
+    void negate() {
+      assert(isKnown());
+      X ^= 0x1;
+    }
+  };
+
+  /// TryEvaluateBool - Try and evaluate the Stmt and return 0 or 1
+  /// if we can evaluate to a known value, otherwise return -1.
+  TryResult TryEvaluateBool(Expr *S) {
+    Expr::EvalResult Result;
+    if (!S->isTypeDependent() && !S->isValueDependent() &&
+        S->Evaluate(Result, *Context) && Result.Val.isInt())
+      return Result.Val.getInt().getBoolValue();
+
+    return TryResult();
+  }
+
+  bool badCFG;
+};
+
+// FIXME: Add support for dependent-sized array types in C++?
+// Does it even make sense to build a CFG for an uninstantiated template?
+static VariableArrayType* FindVA(Type* t) {
+  while (ArrayType* vt = dyn_cast<ArrayType>(t)) {
+    if (VariableArrayType* vat = dyn_cast<VariableArrayType>(vt))
+      if (vat->getSizeExpr())
+        return vat;
+
+    t = vt->getElementType().getTypePtr();
+  }
+
+  return 0;
+}
+
+/// BuildCFG - Constructs a CFG from an AST (a Stmt*).  The AST can represent an
+///  arbitrary statement.  Examples include a single expression or a function
+///  body (compound statement).  The ownership of the returned CFG is
+///  transferred to the caller.  If CFG construction fails, this method returns
+///  NULL.
+CFG* CFGBuilder::buildCFG(Stmt* Statement, ASTContext* C) {
+  Context = C;
+  assert(cfg);
+  if (!Statement)
+    return NULL;
+
+  badCFG = false;
+
+  // Create an empty block that will serve as the exit block for the CFG.  Since
+  // this is the first block added to the CFG, it will be implicitly registered
+  // as the exit block.
+  Succ = createBlock();
+  assert(Succ == &cfg->getExit());
+  Block = NULL;  // the EXIT block is empty.  Create all other blocks lazily.
+
+  // Visit the statements and create the CFG.
+  CFGBlock* B = addStmt(Statement);
+  if (!B) B = Succ;
+
+  if (B) {
+    // Finalize the last constructed block.  This usually involves reversing the
+    // order of the statements in the block.
+    if (Block) FinishBlock(B);
+
+    // Backpatch the gotos whose label -> block mappings we didn't know when we
+    // encountered them.
+    for (BackpatchBlocksTy::iterator I = BackpatchBlocks.begin(),
+         E = BackpatchBlocks.end(); I != E; ++I ) {
+
+      CFGBlock* B = *I;
+      GotoStmt* G = cast<GotoStmt>(B->getTerminator());
+      LabelMapTy::iterator LI = LabelMap.find(G->getLabel());
+
+      // If there is no target for the goto, then we are looking at an
+      // incomplete AST.  Handle this by not registering a successor.
+      if (LI == LabelMap.end()) continue;
+
+      AddSuccessor(B, LI->second);
+    }
+
+    // Add successors to the Indirect Goto Dispatch block (if we have one).
+    if (CFGBlock* B = cfg->getIndirectGotoBlock())
+      for (LabelSetTy::iterator I = AddressTakenLabels.begin(),
+           E = AddressTakenLabels.end(); I != E; ++I ) {
+
+        // Lookup the target block.
+        LabelMapTy::iterator LI = LabelMap.find(*I);
+
+        // If there is no target block that contains label, then we are looking
+        // at an incomplete AST.  Handle this by not registering a successor.
+        if (LI == LabelMap.end()) continue;
+
+        AddSuccessor(B, LI->second);
+      }
+
+    Succ = B;
+  }
+
+  // Create an empty entry block that has no predecessors.
+  cfg->setEntry(createBlock());
+
+  if (badCFG) {
+    delete cfg;
+    cfg = NULL;
+    return NULL;
+  }
+
+  // NULL out cfg so that repeated calls to the builder will fail and that the
+  // ownership of the constructed CFG is passed to the caller.
+  CFG* t = cfg;
+  cfg = NULL;
+  return t;
+}
+
+/// createBlock - Used to lazily create blocks that are connected
+///  to the current (global) succcessor.
+CFGBlock* CFGBuilder::createBlock(bool add_successor) {
+  CFGBlock* B = cfg->createBlock();
+  if (add_successor && Succ)
+    AddSuccessor(B, Succ);
+  return B;
+}
+
+/// FinishBlock - "Finalize" the block by checking if we have a bad CFG.
+bool CFGBuilder::FinishBlock(CFGBlock* B) {
+  if (badCFG)
+    return false;
+
+  assert(B);
+  return true;
+}
+
+/// Visit - Walk the subtree of a statement and add extra
+///   blocks for ternary operators, &&, and ||.  We also process "," and
+///   DeclStmts (which may contain nested control-flow).
+CFGBlock* CFGBuilder::Visit(Stmt * S, bool alwaysAdd) {
+tryAgain:
+  switch (S->getStmtClass()) {
+    default:
+      return VisitStmt(S, alwaysAdd);
+
+    case Stmt::AddrLabelExprClass:
+      return VisitAddrLabelExpr(cast<AddrLabelExpr>(S), alwaysAdd);
+
+    case Stmt::BinaryOperatorClass:
+      return VisitBinaryOperator(cast<BinaryOperator>(S), alwaysAdd);
+
+    case Stmt::BlockExprClass:
+      return VisitBlockExpr(cast<BlockExpr>(S), alwaysAdd);
+
+    case Stmt::BlockDeclRefExprClass:
+      return VisitBlockDeclRefExpr(cast<BlockDeclRefExpr>(S), alwaysAdd);
+
+    case Stmt::BreakStmtClass:
+      return VisitBreakStmt(cast<BreakStmt>(S));
+
+    case Stmt::CallExprClass:
+      return VisitCallExpr(cast<CallExpr>(S), alwaysAdd);
+
+    case Stmt::CaseStmtClass:
+      return VisitCaseStmt(cast<CaseStmt>(S));
+
+    case Stmt::ChooseExprClass:
+      return VisitChooseExpr(cast<ChooseExpr>(S));
+
+    case Stmt::CompoundStmtClass:
+      return VisitCompoundStmt(cast<CompoundStmt>(S));
+
+    case Stmt::ConditionalOperatorClass:
+      return VisitConditionalOperator(cast<ConditionalOperator>(S));
+
+    case Stmt::ContinueStmtClass:
+      return VisitContinueStmt(cast<ContinueStmt>(S));
+
+    case Stmt::DeclStmtClass:
+      return VisitDeclStmt(cast<DeclStmt>(S));
+
+    case Stmt::DefaultStmtClass:
+      return VisitDefaultStmt(cast<DefaultStmt>(S));
+
+    case Stmt::DoStmtClass:
+      return VisitDoStmt(cast<DoStmt>(S));
+
+    case Stmt::ForStmtClass:
+      return VisitForStmt(cast<ForStmt>(S));
+
+    case Stmt::GotoStmtClass:
+      return VisitGotoStmt(cast<GotoStmt>(S));
+
+    case Stmt::IfStmtClass:
+      return VisitIfStmt(cast<IfStmt>(S));
+
+    case Stmt::IndirectGotoStmtClass:
+      return VisitIndirectGotoStmt(cast<IndirectGotoStmt>(S));
+
+    case Stmt::LabelStmtClass:
+      return VisitLabelStmt(cast<LabelStmt>(S));
+
+    case Stmt::ObjCAtCatchStmtClass:
+      return VisitObjCAtCatchStmt(cast<ObjCAtCatchStmt>(S));
+
+  case Stmt::CXXThrowExprClass:
+    return VisitCXXThrowExpr(cast<CXXThrowExpr>(S));
+
+    case Stmt::ObjCAtSynchronizedStmtClass:
+      return VisitObjCAtSynchronizedStmt(cast<ObjCAtSynchronizedStmt>(S));
+
+    case Stmt::ObjCAtThrowStmtClass:
+      return VisitObjCAtThrowStmt(cast<ObjCAtThrowStmt>(S));
+
+    case Stmt::ObjCAtTryStmtClass:
+      return VisitObjCAtTryStmt(cast<ObjCAtTryStmt>(S));
+
+    case Stmt::ObjCForCollectionStmtClass:
+      return VisitObjCForCollectionStmt(cast<ObjCForCollectionStmt>(S));
+
+    case Stmt::ParenExprClass:
+      S = cast<ParenExpr>(S)->getSubExpr();
+      goto tryAgain;
+
+    case Stmt::NullStmtClass:
+      return Block;
+
+    case Stmt::ReturnStmtClass:
+      return VisitReturnStmt(cast<ReturnStmt>(S));
+
+    case Stmt::SizeOfAlignOfExprClass:
+      return VisitSizeOfAlignOfExpr(cast<SizeOfAlignOfExpr>(S), alwaysAdd);
+
+    case Stmt::StmtExprClass:
+      return VisitStmtExpr(cast<StmtExpr>(S), alwaysAdd);
+
+    case Stmt::SwitchStmtClass:
+      return VisitSwitchStmt(cast<SwitchStmt>(S));
+
+    case Stmt::WhileStmtClass:
+      return VisitWhileStmt(cast<WhileStmt>(S));
+  }
+}
+
+CFGBlock *CFGBuilder::VisitStmt(Stmt *S, bool alwaysAdd) {
+  if (alwaysAdd) {
+    autoCreateBlock();
+    AppendStmt(Block, S);
+  }
+
+  return VisitChildren(S);
+}
+
+/// VisitChildren - Visit the children of a Stmt.
+CFGBlock *CFGBuilder::VisitChildren(Stmt* Terminator) {
+  CFGBlock *B = Block;
+  for (Stmt::child_iterator I = Terminator->child_begin(),
+         E = Terminator->child_end(); I != E; ++I) {
+    if (*I) B = Visit(*I);
+  }
+  return B;
+}
+
+CFGBlock *CFGBuilder::VisitAddrLabelExpr(AddrLabelExpr *A, bool alwaysAdd) {
+  AddressTakenLabels.insert(A->getLabel());
+
+  if (alwaysAdd) {
+    autoCreateBlock();
+    AppendStmt(Block, A);
+  }
+
+  return Block;
+}
+
+CFGBlock *CFGBuilder::VisitBinaryOperator(BinaryOperator *B, bool alwaysAdd) {
+  if (B->isLogicalOp()) { // && or ||
+    CFGBlock* ConfluenceBlock = Block ? Block : createBlock();
+    AppendStmt(ConfluenceBlock, B);
+
+    if (!FinishBlock(ConfluenceBlock))
+      return 0;
+
+    // create the block evaluating the LHS
+    CFGBlock* LHSBlock = createBlock(false);
+    LHSBlock->setTerminator(B);
+
+    // create the block evaluating the RHS
+    Succ = ConfluenceBlock;
+    Block = NULL;
+    CFGBlock* RHSBlock = addStmt(B->getRHS());
+    if (!FinishBlock(RHSBlock))
+      return 0;
+
+    // See if this is a known constant.
+    TryResult KnownVal = TryEvaluateBool(B->getLHS());
+    if (KnownVal.isKnown() && (B->getOpcode() == BinaryOperator::LOr))
+      KnownVal.negate();
+
+    // Now link the LHSBlock with RHSBlock.
+    if (B->getOpcode() == BinaryOperator::LOr) {
+      AddSuccessor(LHSBlock, KnownVal.isTrue() ? NULL : ConfluenceBlock);
+      AddSuccessor(LHSBlock, KnownVal.isFalse() ? NULL : RHSBlock);
+    } else {
+      assert (B->getOpcode() == BinaryOperator::LAnd);
+      AddSuccessor(LHSBlock, KnownVal.isFalse() ? NULL : RHSBlock);
+      AddSuccessor(LHSBlock, KnownVal.isTrue() ? NULL : ConfluenceBlock);
+    }
+
+    // Generate the blocks for evaluating the LHS.
+    Block = LHSBlock;
+    return addStmt(B->getLHS());
+  }
+  else if (B->getOpcode() == BinaryOperator::Comma) { // ,
+    autoCreateBlock();
+    AppendStmt(Block, B);
+    addStmt(B->getRHS());
+    return addStmt(B->getLHS());
+  }
+
+  return VisitStmt(B, alwaysAdd);
+}
+
+CFGBlock *CFGBuilder::VisitBlockExpr(BlockExpr* E, bool alwaysAdd) {
+  // FIXME
+  return NYS();
+}
+
+CFGBlock *CFGBuilder::VisitBlockDeclRefExpr(BlockDeclRefExpr* E,
+                                            bool alwaysAdd) {
+  // FIXME
+  return NYS();
+}
+
+CFGBlock *CFGBuilder::VisitBreakStmt(BreakStmt *B) {
+  // "break" is a control-flow statement.  Thus we stop processing the current
+  // block.
+  if (Block && !FinishBlock(Block))
+      return 0;
+
+  // Now create a new block that ends with the break statement.
+  Block = createBlock(false);
+  Block->setTerminator(B);
+
+  // If there is no target for the break, then we are looking at an incomplete
+  // AST.  This means that the CFG cannot be constructed.
+  if (BreakTargetBlock)
+    AddSuccessor(Block, BreakTargetBlock);
+  else
+    badCFG = true;
+
+
+  return Block;
+}
+
+CFGBlock *CFGBuilder::VisitCallExpr(CallExpr *C, bool alwaysAdd) {
+  // If this is a call to a no-return function, this stops the block here.
+  bool NoReturn = false;
+  if (C->getCallee()->getType().getNoReturnAttr()) {
+    NoReturn = true;
+  }
+
+  if (FunctionDecl *FD = C->getDirectCallee())
+    if (FD->hasAttr<NoReturnAttr>())
+      NoReturn = true;
+
+  if (!NoReturn)
+    return VisitStmt(C, alwaysAdd);
+
+  if (Block && !FinishBlock(Block))
+    return 0;
+
+  // Create new block with no successor for the remaining pieces.
+  Block = createBlock(false);
+  AppendStmt(Block, C);
+
+  // Wire this to the exit block directly.
+  AddSuccessor(Block, &cfg->getExit());
+
+  return VisitChildren(C);
+}
+
+CFGBlock *CFGBuilder::VisitChooseExpr(ChooseExpr *C) {
+  CFGBlock* ConfluenceBlock = Block ? Block : createBlock();
+  AppendStmt(ConfluenceBlock, C);
+  if (!FinishBlock(ConfluenceBlock))
+    return 0;
+
+  Succ = ConfluenceBlock;
+  Block = NULL;
+  CFGBlock* LHSBlock = addStmt(C->getLHS());
+  if (!FinishBlock(LHSBlock))
+    return 0;
+
+  Succ = ConfluenceBlock;
+  Block = NULL;
+  CFGBlock* RHSBlock = addStmt(C->getRHS());
+  if (!FinishBlock(RHSBlock))
+    return 0;
+
+  Block = createBlock(false);
+  // See if this is a known constant.
+  const TryResult& KnownVal = TryEvaluateBool(C->getCond());
+  AddSuccessor(Block, KnownVal.isFalse() ? NULL : LHSBlock);
+  AddSuccessor(Block, KnownVal.isTrue() ? NULL : RHSBlock);
+  Block->setTerminator(C);
+  return addStmt(C->getCond());
+}
+
+
+CFGBlock* CFGBuilder::VisitCompoundStmt(CompoundStmt* C) {
+  CFGBlock* LastBlock = Block;
+
+  for (CompoundStmt::reverse_body_iterator I=C->body_rbegin(), E=C->body_rend();
+       I != E; ++I ) {
+    LastBlock = addStmt(*I);
+
+    if (badCFG)
+      return NULL;
+  }
+  return LastBlock;
+}
+
+CFGBlock *CFGBuilder::VisitConditionalOperator(ConditionalOperator *C) {
+  // Create the confluence block that will "merge" the results of the ternary
+  // expression.
+  CFGBlock* ConfluenceBlock = Block ? Block : createBlock();
+  AppendStmt(ConfluenceBlock, C);
+  if (!FinishBlock(ConfluenceBlock))
+    return 0;
+
+  // Create a block for the LHS expression if there is an LHS expression.  A
+  // GCC extension allows LHS to be NULL, causing the condition to be the
+  // value that is returned instead.
+  //  e.g: x ?: y is shorthand for: x ? x : y;
+  Succ = ConfluenceBlock;
+  Block = NULL;
+  CFGBlock* LHSBlock = NULL;
+  if (C->getLHS()) {
+    LHSBlock = addStmt(C->getLHS());
+    if (!FinishBlock(LHSBlock))
+      return 0;
+    Block = NULL;
+  }
+
+  // Create the block for the RHS expression.
+  Succ = ConfluenceBlock;
+  CFGBlock* RHSBlock = addStmt(C->getRHS());
+  if (!FinishBlock(RHSBlock))
+    return 0;
+
+  // Create the block that will contain the condition.
+  Block = createBlock(false);
+
+  // See if this is a known constant.
+  const TryResult& KnownVal = TryEvaluateBool(C->getCond());
+  if (LHSBlock) {
+    AddSuccessor(Block, KnownVal.isFalse() ? NULL : LHSBlock);
+  } else {
+    if (KnownVal.isFalse()) {
+      // If we know the condition is false, add NULL as the successor for
+      // the block containing the condition.  In this case, the confluence
+      // block will have just one predecessor.
+      AddSuccessor(Block, 0);
+      assert(ConfluenceBlock->pred_size() == 1);
+    } else {
+      // If we have no LHS expression, add the ConfluenceBlock as a direct
+      // successor for the block containing the condition.  Moreover, we need to
+      // reverse the order of the predecessors in the ConfluenceBlock because
+      // the RHSBlock will have been added to the succcessors already, and we
+      // want the first predecessor to the the block containing the expression
+      // for the case when the ternary expression evaluates to true.
+      AddSuccessor(Block, ConfluenceBlock);
+      assert(ConfluenceBlock->pred_size() == 2);
+      std::reverse(ConfluenceBlock->pred_begin(),
+                   ConfluenceBlock->pred_end());
+    }
+  }
+
+  AddSuccessor(Block, KnownVal.isTrue() ? NULL : RHSBlock);
+  Block->setTerminator(C);
+  return addStmt(C->getCond());
+}
+
+CFGBlock *CFGBuilder::VisitDeclStmt(DeclStmt *DS) {
+  autoCreateBlock();
+
+  if (DS->isSingleDecl()) {
+    AppendStmt(Block, DS);
+    return VisitDeclSubExpr(DS->getSingleDecl());
+  }
+
+  CFGBlock *B = 0;
+
+  // FIXME: Add a reverse iterator for DeclStmt to avoid this extra copy.
+  typedef llvm::SmallVector<Decl*,10> BufTy;
+  BufTy Buf(DS->decl_begin(), DS->decl_end());
+
+  for (BufTy::reverse_iterator I = Buf.rbegin(), E = Buf.rend(); I != E; ++I) {
+    // Get the alignment of the new DeclStmt, padding out to >=8 bytes.
+    unsigned A = llvm::AlignOf<DeclStmt>::Alignment < 8
+               ? 8 : llvm::AlignOf<DeclStmt>::Alignment;
+
+    // Allocate the DeclStmt using the BumpPtrAllocator.  It will get
+    // automatically freed with the CFG.
+    DeclGroupRef DG(*I);
+    Decl *D = *I;
+    void *Mem = cfg->getAllocator().Allocate(sizeof(DeclStmt), A);
+    DeclStmt *DSNew = new (Mem) DeclStmt(DG, D->getLocation(), GetEndLoc(D));
+
+    // Append the fake DeclStmt to block.
+    AppendStmt(Block, DSNew);
+    B = VisitDeclSubExpr(D);
+  }
+
+  return B;
+}
+
+/// VisitDeclSubExpr - Utility method to add block-level expressions for
+///  initializers in Decls.
+CFGBlock *CFGBuilder::VisitDeclSubExpr(Decl* D) {
+  assert(Block);
+
+  VarDecl *VD = dyn_cast<VarDecl>(D);
+
+  if (!VD)
+    return Block;
+
+  Expr *Init = VD->getInit();
+
+  if (Init) {
+    // Optimization: Don't create separate block-level statements for literals.
+    switch (Init->getStmtClass()) {
+      case Stmt::IntegerLiteralClass:
+      case Stmt::CharacterLiteralClass:
+      case Stmt::StringLiteralClass:
+        break;
+      default:
+        Block = addStmt(Init);
+    }
+  }
+
+  // If the type of VD is a VLA, then we must process its size expressions.
+  for (VariableArrayType* VA = FindVA(VD->getType().getTypePtr()); VA != 0;
+       VA = FindVA(VA->getElementType().getTypePtr()))
+    Block = addStmt(VA->getSizeExpr());
+
+  return Block;
+}
+
+CFGBlock* CFGBuilder::VisitIfStmt(IfStmt* I) {
+  // We may see an if statement in the middle of a basic block, or it may be the
+  // first statement we are processing.  In either case, we create a new basic
+  // block.  First, we create the blocks for the then...else statements, and
+  // then we create the block containing the if statement.  If we were in the
+  // middle of a block, we stop processing that block.  That block is then the
+  // implicit successor for the "then" and "else" clauses.
+
+  // The block we were proccessing is now finished.  Make it the successor
+  // block.
+  if (Block) {
+    Succ = Block;
+    if (!FinishBlock(Block))
+      return 0;
+  }
+
+  // Process the false branch.
+  CFGBlock* ElseBlock = Succ;
+
+  if (Stmt* Else = I->getElse()) {
+    SaveAndRestore<CFGBlock*> sv(Succ);
+
+    // NULL out Block so that the recursive call to Visit will
+    // create a new basic block.
+    Block = NULL;
+    ElseBlock = addStmt(Else);
+
+    if (!ElseBlock) // Can occur when the Else body has all NullStmts.
+      ElseBlock = sv.get();
+    else if (Block) {
+      if (!FinishBlock(ElseBlock))
+        return 0;
+    }
+  }
+
+  // Process the true branch.
+  CFGBlock* ThenBlock;
+  {
+    Stmt* Then = I->getThen();
+    assert (Then);
+    SaveAndRestore<CFGBlock*> sv(Succ);
+    Block = NULL;
+    ThenBlock = addStmt(Then);
+
+    if (!ThenBlock) {
+      // We can reach here if the "then" body has all NullStmts.
+      // Create an empty block so we can distinguish between true and false
+      // branches in path-sensitive analyses.
+      ThenBlock = createBlock(false);
+      AddSuccessor(ThenBlock, sv.get());
+    } else if (Block) {
+      if (!FinishBlock(ThenBlock))
+        return 0;
+    }
+  }
+
+  // Now create a new block containing the if statement.
+  Block = createBlock(false);
+
+  // Set the terminator of the new block to the If statement.
+  Block->setTerminator(I);
+
+  // See if this is a known constant.
+  const TryResult &KnownVal = TryEvaluateBool(I->getCond());
+
+  // Now add the successors.
+  AddSuccessor(Block, KnownVal.isFalse() ? NULL : ThenBlock);
+  AddSuccessor(Block, KnownVal.isTrue()? NULL : ElseBlock);
+
+  // Add the condition as the last statement in the new block.  This may create
+  // new blocks as the condition may contain control-flow.  Any newly created
+  // blocks will be pointed to be "Block".
+  return addStmt(I->getCond());
+}
+
+
+CFGBlock* CFGBuilder::VisitReturnStmt(ReturnStmt* R) {
+  // If we were in the middle of a block we stop processing that block.
+  //
+  // NOTE: If a "return" appears in the middle of a block, this means that the
+  //       code afterwards is DEAD (unreachable).  We still keep a basic block
+  //       for that code; a simple "mark-and-sweep" from the entry block will be
+  //       able to report such dead blocks.
+  if (Block)
+    FinishBlock(Block);
+
+  // Create the new block.
+  Block = createBlock(false);
+
+  // The Exit block is the only successor.
+  AddSuccessor(Block, &cfg->getExit());
+
+  // Add the return statement to the block.  This may create new blocks if R
+  // contains control-flow (short-circuit operations).
+  return VisitStmt(R, true);
+}
+
+CFGBlock* CFGBuilder::VisitLabelStmt(LabelStmt* L) {
+  // Get the block of the labeled statement.  Add it to our map.
+  addStmt(L->getSubStmt());
+  CFGBlock* LabelBlock = Block;
+
+  if (!LabelBlock)              // This can happen when the body is empty, i.e.
+    LabelBlock = createBlock(); // scopes that only contains NullStmts.
+
+  assert(LabelMap.find(L) == LabelMap.end() && "label already in map");
+  LabelMap[ L ] = LabelBlock;
+
+  // Labels partition blocks, so this is the end of the basic block we were
+  // processing (L is the block's label).  Because this is label (and we have
+  // already processed the substatement) there is no extra control-flow to worry
+  // about.
+  LabelBlock->setLabel(L);
+  if (!FinishBlock(LabelBlock))
+    return 0;
+
+  // We set Block to NULL to allow lazy creation of a new block (if necessary);
+  Block = NULL;
+
+  // This block is now the implicit successor of other blocks.
+  Succ = LabelBlock;
+
+  return LabelBlock;
+}
+
+CFGBlock* CFGBuilder::VisitGotoStmt(GotoStmt* G) {
+  // Goto is a control-flow statement.  Thus we stop processing the current
+  // block and create a new one.
+  if (Block)
+    FinishBlock(Block);
+
+  Block = createBlock(false);
+  Block->setTerminator(G);
+
+  // If we already know the mapping to the label block add the successor now.
+  LabelMapTy::iterator I = LabelMap.find(G->getLabel());
+
+  if (I == LabelMap.end())
+    // We will need to backpatch this block later.
+    BackpatchBlocks.push_back(Block);
+  else
+    AddSuccessor(Block, I->second);
+
+  return Block;
+}
+
+CFGBlock* CFGBuilder::VisitForStmt(ForStmt* F) {
+  CFGBlock* LoopSuccessor = NULL;
+
+  // "for" is a control-flow statement.  Thus we stop processing the current
+  // block.
+  if (Block) {
+    if (!FinishBlock(Block))
+      return 0;
+    LoopSuccessor = Block;
+  } else
+    LoopSuccessor = Succ;
+
+  // Because of short-circuit evaluation, the condition of the loop can span
+  // multiple basic blocks.  Thus we need the "Entry" and "Exit" blocks that
+  // evaluate the condition.
+  CFGBlock* ExitConditionBlock = createBlock(false);
+  CFGBlock* EntryConditionBlock = ExitConditionBlock;
+
+  // Set the terminator for the "exit" condition block.
+  ExitConditionBlock->setTerminator(F);
+
+  // Now add the actual condition to the condition block.  Because the condition
+  // itself may contain control-flow, new blocks may be created.
+  if (Stmt* C = F->getCond()) {
+    Block = ExitConditionBlock;
+    EntryConditionBlock = addStmt(C);
+    if (Block) {
+      if (!FinishBlock(EntryConditionBlock))
+        return 0;
+    }
+  }
+
+  // The condition block is the implicit successor for the loop body as well as
+  // any code above the loop.
+  Succ = EntryConditionBlock;
+
+  // See if this is a known constant.
+  TryResult KnownVal(true);
+
+  if (F->getCond())
+    KnownVal = TryEvaluateBool(F->getCond());
+
+  // Now create the loop body.
+  {
+    assert (F->getBody());
+
+    // Save the current values for Block, Succ, and continue and break targets
+    SaveAndRestore<CFGBlock*> save_Block(Block), save_Succ(Succ),
+    save_continue(ContinueTargetBlock),
+    save_break(BreakTargetBlock);
+
+    // Create a new block to contain the (bottom) of the loop body.
+    Block = NULL;
+
+    if (Stmt* I = F->getInc()) {
+      // Generate increment code in its own basic block.  This is the target of
+      // continue statements.
+      Succ = addStmt(I);
+    } else {
+      // No increment code.  Create a special, empty, block that is used as the
+      // target block for "looping back" to the start of the loop.
+      assert(Succ == EntryConditionBlock);
+      Succ = createBlock();
+    }
+
+    // Finish up the increment (or empty) block if it hasn't been already.
+    if (Block) {
+      assert(Block == Succ);
+      if (!FinishBlock(Block))
+        return 0;
+      Block = 0;
+    }
+
+    ContinueTargetBlock = Succ;
+
+    // The starting block for the loop increment is the block that should
+    // represent the 'loop target' for looping back to the start of the loop.
+    ContinueTargetBlock->setLoopTarget(F);
+
+    // All breaks should go to the code following the loop.
+    BreakTargetBlock = LoopSuccessor;
+
+    // Now populate the body block, and in the process create new blocks as we
+    // walk the body of the loop.
+    CFGBlock* BodyBlock = addStmt(F->getBody());
+
+    if (!BodyBlock)
+      BodyBlock = ContinueTargetBlock; // can happen for "for (...;...;...) ;"
+    else if (Block && !FinishBlock(BodyBlock))
+      return 0;
+
+    // This new body block is a successor to our "exit" condition block.
+    AddSuccessor(ExitConditionBlock, KnownVal.isFalse() ? NULL : BodyBlock);
+  }
+
+  // Link up the condition block with the code that follows the loop.  (the
+  // false branch).
+  AddSuccessor(ExitConditionBlock, KnownVal.isTrue() ? NULL : LoopSuccessor);
+
+  // If the loop contains initialization, create a new block for those
+  // statements.  This block can also contain statements that precede the loop.
+  if (Stmt* I = F->getInit()) {
+    Block = createBlock();
+    return addStmt(I);
+  } else {
+    // There is no loop initialization.  We are thus basically a while loop.
+    // NULL out Block to force lazy block construction.
+    Block = NULL;
+    Succ = EntryConditionBlock;
+    return EntryConditionBlock;
+  }
+}
+
+CFGBlock* CFGBuilder::VisitObjCForCollectionStmt(ObjCForCollectionStmt* S) {
+  // Objective-C fast enumeration 'for' statements:
+  //  http://developer.apple.com/documentation/Cocoa/Conceptual/ObjectiveC
+  //
+  //  for ( Type newVariable in collection_expression ) { statements }
+  //
+  //  becomes:
+  //
+  //   prologue:
+  //     1. collection_expression
+  //     T. jump to loop_entry
+  //   loop_entry:
+  //     1. side-effects of element expression
+  //     1. ObjCForCollectionStmt [performs binding to newVariable]
+  //     T. ObjCForCollectionStmt  TB, FB  [jumps to TB if newVariable != nil]
+  //   TB:
+  //     statements
+  //     T. jump to loop_entry
+  //   FB:
+  //     what comes after
+  //
+  //  and
+  //
+  //  Type existingItem;
+  //  for ( existingItem in expression ) { statements }
+  //
+  //  becomes:
+  //
+  //   the same with newVariable replaced with existingItem; the binding works
+  //   the same except that for one ObjCForCollectionStmt::getElement() returns
+  //   a DeclStmt and the other returns a DeclRefExpr.
+  //
+
+  CFGBlock* LoopSuccessor = 0;
+
+  if (Block) {
+    if (!FinishBlock(Block))
+      return 0;
+    LoopSuccessor = Block;
+    Block = 0;
+  } else
+    LoopSuccessor = Succ;
+
+  // Build the condition blocks.
+  CFGBlock* ExitConditionBlock = createBlock(false);
+  CFGBlock* EntryConditionBlock = ExitConditionBlock;
+
+  // Set the terminator for the "exit" condition block.
+  ExitConditionBlock->setTerminator(S);
+
+  // The last statement in the block should be the ObjCForCollectionStmt, which
+  // performs the actual binding to 'element' and determines if there are any
+  // more items in the collection.
+  AppendStmt(ExitConditionBlock, S);
+  Block = ExitConditionBlock;
+
+  // Walk the 'element' expression to see if there are any side-effects.  We
+  // generate new blocks as necesary.  We DON'T add the statement by default to
+  // the CFG unless it contains control-flow.
+  EntryConditionBlock = Visit(S->getElement(), false);
+  if (Block) {
+    if (!FinishBlock(EntryConditionBlock))
+      return 0;
+    Block = 0;
+  }
+
+  // The condition block is the implicit successor for the loop body as well as
+  // any code above the loop.
+  Succ = EntryConditionBlock;
+
+  // Now create the true branch.
+  {
+    // Save the current values for Succ, continue and break targets.
+    SaveAndRestore<CFGBlock*> save_Succ(Succ),
+      save_continue(ContinueTargetBlock), save_break(BreakTargetBlock);
+
+    BreakTargetBlock = LoopSuccessor;
+    ContinueTargetBlock = EntryConditionBlock;
+
+    CFGBlock* BodyBlock = addStmt(S->getBody());
+
+    if (!BodyBlock)
+      BodyBlock = EntryConditionBlock; // can happen for "for (X in Y) ;"
+    else if (Block) {
+      if (!FinishBlock(BodyBlock))
+        return 0;
+    }
+
+    // This new body block is a successor to our "exit" condition block.
+    AddSuccessor(ExitConditionBlock, BodyBlock);
+  }
+
+  // Link up the condition block with the code that follows the loop.
+  // (the false branch).
+  AddSuccessor(ExitConditionBlock, LoopSuccessor);
+
+  // Now create a prologue block to contain the collection expression.
+  Block = createBlock();
+  return addStmt(S->getCollection());
+}
+
+CFGBlock* CFGBuilder::VisitObjCAtSynchronizedStmt(ObjCAtSynchronizedStmt* S) {
+  // FIXME: Add locking 'primitives' to CFG for @synchronized.
+
+  // Inline the body.
+  CFGBlock *SyncBlock = addStmt(S->getSynchBody());
+
+  // The sync body starts its own basic block.  This makes it a little easier
+  // for diagnostic clients.
+  if (SyncBlock) {
+    if (!FinishBlock(SyncBlock))
+      return 0;
+
+    Block = 0;
+  }
+
+  Succ = SyncBlock;
+
+  // Inline the sync expression.
+  return addStmt(S->getSynchExpr());
+}
+
+CFGBlock* CFGBuilder::VisitObjCAtTryStmt(ObjCAtTryStmt* S) {
+  // FIXME
+  return NYS();
+}
+
+CFGBlock* CFGBuilder::VisitWhileStmt(WhileStmt* W) {
+  CFGBlock* LoopSuccessor = NULL;
+
+  // "while" is a control-flow statement.  Thus we stop processing the current
+  // block.
+  if (Block) {
+    if (!FinishBlock(Block))
+      return 0;
+    LoopSuccessor = Block;
+  } else
+    LoopSuccessor = Succ;
+
+  // Because of short-circuit evaluation, the condition of the loop can span
+  // multiple basic blocks.  Thus we need the "Entry" and "Exit" blocks that
+  // evaluate the condition.
+  CFGBlock* ExitConditionBlock = createBlock(false);
+  CFGBlock* EntryConditionBlock = ExitConditionBlock;
+
+  // Set the terminator for the "exit" condition block.
+  ExitConditionBlock->setTerminator(W);
+
+  // Now add the actual condition to the condition block.  Because the condition
+  // itself may contain control-flow, new blocks may be created.  Thus we update
+  // "Succ" after adding the condition.
+  if (Stmt* C = W->getCond()) {
+    Block = ExitConditionBlock;
+    EntryConditionBlock = addStmt(C);
+    assert(Block == EntryConditionBlock);
+    if (Block) {
+      if (!FinishBlock(EntryConditionBlock))
+        return 0;
+    }
+  }
+
+  // The condition block is the implicit successor for the loop body as well as
+  // any code above the loop.
+  Succ = EntryConditionBlock;
+
+  // See if this is a known constant.
+  const TryResult& KnownVal = TryEvaluateBool(W->getCond());
+
+  // Process the loop body.
+  {
+    assert(W->getBody());
+
+    // Save the current values for Block, Succ, and continue and break targets
+    SaveAndRestore<CFGBlock*> save_Block(Block), save_Succ(Succ),
+                              save_continue(ContinueTargetBlock),
+                              save_break(BreakTargetBlock);
+
+    // Create an empty block to represent the transition block for looping back
+    // to the head of the loop.
+    Block = 0;
+    assert(Succ == EntryConditionBlock);
+    Succ = createBlock();
+    Succ->setLoopTarget(W);
+    ContinueTargetBlock = Succ;
+
+    // All breaks should go to the code following the loop.
+    BreakTargetBlock = LoopSuccessor;
+
+    // NULL out Block to force lazy instantiation of blocks for the body.
+    Block = NULL;
+
+    // Create the body.  The returned block is the entry to the loop body.
+    CFGBlock* BodyBlock = addStmt(W->getBody());
+
+    if (!BodyBlock)
+      BodyBlock = ContinueTargetBlock; // can happen for "while(...) ;"
+    else if (Block) {
+      if (!FinishBlock(BodyBlock))
+        return 0;
+    }
+
+    // Add the loop body entry as a successor to the condition.
+    AddSuccessor(ExitConditionBlock, KnownVal.isFalse() ? NULL : BodyBlock);
+  }
+
+  // Link up the condition block with the code that follows the loop.  (the
+  // false branch).
+  AddSuccessor(ExitConditionBlock, KnownVal.isTrue() ? NULL : LoopSuccessor);
+
+  // There can be no more statements in the condition block since we loop back
+  // to this block.  NULL out Block to force lazy creation of another block.
+  Block = NULL;
+
+  // Return the condition block, which is the dominating block for the loop.
+  Succ = EntryConditionBlock;
+  return EntryConditionBlock;
+}
+
+
+CFGBlock *CFGBuilder::VisitObjCAtCatchStmt(ObjCAtCatchStmt* S) {
+  // FIXME: For now we pretend that @catch and the code it contains does not
+  //  exit.
+  return Block;
+}
+
+CFGBlock* CFGBuilder::VisitObjCAtThrowStmt(ObjCAtThrowStmt* S) {
+  // FIXME: This isn't complete.  We basically treat @throw like a return
+  //  statement.
+
+  // If we were in the middle of a block we stop processing that block.
+  if (Block && !FinishBlock(Block))
+    return 0;
+
+  // Create the new block.
+  Block = createBlock(false);
+
+  // The Exit block is the only successor.
+  AddSuccessor(Block, &cfg->getExit());
+
+  // Add the statement to the block.  This may create new blocks if S contains
+  // control-flow (short-circuit operations).
+  return VisitStmt(S, true);
+}
+
+CFGBlock* CFGBuilder::VisitCXXThrowExpr(CXXThrowExpr* T) {
+  // If we were in the middle of a block we stop processing that block.
+  if (Block && !FinishBlock(Block))
+    return 0;
+
+  // Create the new block.
+  Block = createBlock(false);
+
+  // The Exit block is the only successor.
+  AddSuccessor(Block, &cfg->getExit());
+
+  // Add the statement to the block.  This may create new blocks if S contains
+  // control-flow (short-circuit operations).
+  return VisitStmt(T, true);
+}
+
+CFGBlock *CFGBuilder::VisitDoStmt(DoStmt* D) {
+  CFGBlock* LoopSuccessor = NULL;
+
+  // "do...while" is a control-flow statement.  Thus we stop processing the
+  // current block.
+  if (Block) {
+    if (!FinishBlock(Block))
+      return 0;
+    LoopSuccessor = Block;
+  } else
+    LoopSuccessor = Succ;
+
+  // Because of short-circuit evaluation, the condition of the loop can span
+  // multiple basic blocks.  Thus we need the "Entry" and "Exit" blocks that
+  // evaluate the condition.
+  CFGBlock* ExitConditionBlock = createBlock(false);
+  CFGBlock* EntryConditionBlock = ExitConditionBlock;
+
+  // Set the terminator for the "exit" condition block.
+  ExitConditionBlock->setTerminator(D);
+
+  // Now add the actual condition to the condition block.  Because the condition
+  // itself may contain control-flow, new blocks may be created.
+  if (Stmt* C = D->getCond()) {
+    Block = ExitConditionBlock;
+    EntryConditionBlock = addStmt(C);
+    if (Block) {
+      if (!FinishBlock(EntryConditionBlock))
+        return 0;
+    }
+  }
+
+  // The condition block is the implicit successor for the loop body.
+  Succ = EntryConditionBlock;
+
+  // See if this is a known constant.
+  const TryResult &KnownVal = TryEvaluateBool(D->getCond());
+
+  // Process the loop body.
+  CFGBlock* BodyBlock = NULL;
+  {
+    assert (D->getBody());
+
+    // Save the current values for Block, Succ, and continue and break targets
+    SaveAndRestore<CFGBlock*> save_Block(Block), save_Succ(Succ),
+    save_continue(ContinueTargetBlock),
+    save_break(BreakTargetBlock);
+
+    // All continues within this loop should go to the condition block
+    ContinueTargetBlock = EntryConditionBlock;
+
+    // All breaks should go to the code following the loop.
+    BreakTargetBlock = LoopSuccessor;
+
+    // NULL out Block to force lazy instantiation of blocks for the body.
+    Block = NULL;
+
+    // Create the body.  The returned block is the entry to the loop body.
+    BodyBlock = addStmt(D->getBody());
+
+    if (!BodyBlock)
+      BodyBlock = EntryConditionBlock; // can happen for "do ; while(...)"
+    else if (Block) {
+      if (!FinishBlock(BodyBlock))
+        return 0;
+    }
+
+    // Add an intermediate block between the BodyBlock and the
+    // ExitConditionBlock to represent the "loop back" transition.  Create an
+    // empty block to represent the transition block for looping back to the
+    // head of the loop.
+    // FIXME: Can we do this more efficiently without adding another block?
+    Block = NULL;
+    Succ = BodyBlock;
+    CFGBlock *LoopBackBlock = createBlock();
+    LoopBackBlock->setLoopTarget(D);
+
+    // Add the loop body entry as a successor to the condition.
+    AddSuccessor(ExitConditionBlock, KnownVal.isFalse() ? NULL : LoopBackBlock);
+  }
+
+  // Link up the condition block with the code that follows the loop.
+  // (the false branch).
+  AddSuccessor(ExitConditionBlock, KnownVal.isTrue() ? NULL : LoopSuccessor);
+
+  // There can be no more statements in the body block(s) since we loop back to
+  // the body.  NULL out Block to force lazy creation of another block.
+  Block = NULL;
+
+  // Return the loop body, which is the dominating block for the loop.
+  Succ = BodyBlock;
+  return BodyBlock;
+}
+
+CFGBlock* CFGBuilder::VisitContinueStmt(ContinueStmt* C) {
+  // "continue" is a control-flow statement.  Thus we stop processing the
+  // current block.
+  if (Block && !FinishBlock(Block))
+      return 0;
+
+  // Now create a new block that ends with the continue statement.
+  Block = createBlock(false);
+  Block->setTerminator(C);
+
+  // If there is no target for the continue, then we are looking at an
+  // incomplete AST.  This means the CFG cannot be constructed.
+  if (ContinueTargetBlock)
+    AddSuccessor(Block, ContinueTargetBlock);
+  else
+    badCFG = true;
+
+  return Block;
+}
+
+CFGBlock *CFGBuilder::VisitSizeOfAlignOfExpr(SizeOfAlignOfExpr *E,
+                                             bool alwaysAdd) {
+
+  if (alwaysAdd) {
+    autoCreateBlock();
+    AppendStmt(Block, E);
+  }
+
+  // VLA types have expressions that must be evaluated.
+  if (E->isArgumentType()) {
+    for (VariableArrayType* VA = FindVA(E->getArgumentType().getTypePtr());
+         VA != 0; VA = FindVA(VA->getElementType().getTypePtr()))
+      addStmt(VA->getSizeExpr());
+  }
+
+  return Block;
+}
+
+/// VisitStmtExpr - Utility method to handle (nested) statement
+///  expressions (a GCC extension).
+CFGBlock* CFGBuilder::VisitStmtExpr(StmtExpr *SE, bool alwaysAdd) {
+  if (alwaysAdd) {
+    autoCreateBlock();
+    AppendStmt(Block, SE);
+  }
+  return VisitCompoundStmt(SE->getSubStmt());
+}
+
+CFGBlock* CFGBuilder::VisitSwitchStmt(SwitchStmt* Terminator) {
+  // "switch" is a control-flow statement.  Thus we stop processing the current
+  // block.
+  CFGBlock* SwitchSuccessor = NULL;
+
+  if (Block) {
+    if (!FinishBlock(Block))
+      return 0;
+    SwitchSuccessor = Block;
+  } else SwitchSuccessor = Succ;
+
+  // Save the current "switch" context.
+  SaveAndRestore<CFGBlock*> save_switch(SwitchTerminatedBlock),
+                            save_break(BreakTargetBlock),
+                            save_default(DefaultCaseBlock);
+
+  // Set the "default" case to be the block after the switch statement.  If the
+  // switch statement contains a "default:", this value will be overwritten with
+  // the block for that code.
+  DefaultCaseBlock = SwitchSuccessor;
+
+  // Create a new block that will contain the switch statement.
+  SwitchTerminatedBlock = createBlock(false);
+
+  // Now process the switch body.  The code after the switch is the implicit
+  // successor.
+  Succ = SwitchSuccessor;
+  BreakTargetBlock = SwitchSuccessor;
+
+  // When visiting the body, the case statements should automatically get linked
+  // up to the switch.  We also don't keep a pointer to the body, since all
+  // control-flow from the switch goes to case/default statements.
+  assert (Terminator->getBody() && "switch must contain a non-NULL body");
+  Block = NULL;
+  CFGBlock *BodyBlock = addStmt(Terminator->getBody());
+  if (Block) {
+    if (!FinishBlock(BodyBlock))
+      return 0;
+  }
+
+  // If we have no "default:" case, the default transition is to the code
+  // following the switch body.
+  AddSuccessor(SwitchTerminatedBlock, DefaultCaseBlock);
+
+  // Add the terminator and condition in the switch block.
+  SwitchTerminatedBlock->setTerminator(Terminator);
+  assert (Terminator->getCond() && "switch condition must be non-NULL");
+  Block = SwitchTerminatedBlock;
+
+  return addStmt(Terminator->getCond());
+}
+
+CFGBlock* CFGBuilder::VisitCaseStmt(CaseStmt* CS) {
+  // CaseStmts are essentially labels, so they are the first statement in a
+  // block.
+
+  if (CS->getSubStmt())
+    addStmt(CS->getSubStmt());
+
+  CFGBlock* CaseBlock = Block;
+  if (!CaseBlock)
+    CaseBlock = createBlock();
+
+  // Cases statements partition blocks, so this is the top of the basic block we
+  // were processing (the "case XXX:" is the label).
+  CaseBlock->setLabel(CS);
+
+  if (!FinishBlock(CaseBlock))
+    return 0;
+
+  // Add this block to the list of successors for the block with the switch
+  // statement.
+  assert(SwitchTerminatedBlock);
+  AddSuccessor(SwitchTerminatedBlock, CaseBlock);
+
+  // We set Block to NULL to allow lazy creation of a new block (if necessary)
+  Block = NULL;
+
+  // This block is now the implicit successor of other blocks.
+  Succ = CaseBlock;
+
+  return CaseBlock;
+}
+
+CFGBlock* CFGBuilder::VisitDefaultStmt(DefaultStmt* Terminator) {
+  if (Terminator->getSubStmt())
+    addStmt(Terminator->getSubStmt());
+
+  DefaultCaseBlock = Block;
+
+  if (!DefaultCaseBlock)
+    DefaultCaseBlock = createBlock();
+
+  // Default statements partition blocks, so this is the top of the basic block
+  // we were processing (the "default:" is the label).
+  DefaultCaseBlock->setLabel(Terminator);
+
+  if (!FinishBlock(DefaultCaseBlock))
+    return 0;
+
+  // Unlike case statements, we don't add the default block to the successors
+  // for the switch statement immediately.  This is done when we finish
+  // processing the switch statement.  This allows for the default case
+  // (including a fall-through to the code after the switch statement) to always
+  // be the last successor of a switch-terminated block.
+
+  // We set Block to NULL to allow lazy creation of a new block (if necessary)
+  Block = NULL;
+
+  // This block is now the implicit successor of other blocks.
+  Succ = DefaultCaseBlock;
+
+  return DefaultCaseBlock;
+}
+
+CFGBlock* CFGBuilder::VisitIndirectGotoStmt(IndirectGotoStmt* I) {
+  // Lazily create the indirect-goto dispatch block if there isn't one already.
+  CFGBlock* IBlock = cfg->getIndirectGotoBlock();
+
+  if (!IBlock) {
+    IBlock = createBlock(false);
+    cfg->setIndirectGotoBlock(IBlock);
+  }
+
+  // IndirectGoto is a control-flow statement.  Thus we stop processing the
+  // current block and create a new one.
+  if (Block && !FinishBlock(Block))
+    return 0;
+
+  Block = createBlock(false);
+  Block->setTerminator(I);
+  AddSuccessor(Block, IBlock);
+  return addStmt(I->getTarget());
+}
+
+} // end anonymous namespace
+
+/// createBlock - Constructs and adds a new CFGBlock to the CFG.  The block has
+///  no successors or predecessors.  If this is the first block created in the
+///  CFG, it is automatically set to be the Entry and Exit of the CFG.
+CFGBlock* CFG::createBlock() {
+  bool first_block = begin() == end();
+
+  // Create the block.
+  CFGBlock *Mem = getAllocator().Allocate<CFGBlock>();
+  new (Mem) CFGBlock(NumBlockIDs++, BlkBVC);
+  Blocks.push_back(Mem, BlkBVC);
+
+  // If this is the first block, set it as the Entry and Exit.
+  if (first_block)
+    Entry = Exit = &back();
+
+  // Return the block.
+  return &back();
+}
+
+/// buildCFG - Constructs a CFG from an AST.  Ownership of the returned
+///  CFG is returned to the caller.
+CFG* CFG::buildCFG(Stmt* Statement, ASTContext *C) {
+  CFGBuilder Builder;
+  return Builder.buildCFG(Statement, C);
+}
+
+//===----------------------------------------------------------------------===//
+// CFG: Queries for BlkExprs.
+//===----------------------------------------------------------------------===//
+
+namespace {
+  typedef llvm::DenseMap<const Stmt*,unsigned> BlkExprMapTy;
+}
+
+static void FindSubExprAssignments(Stmt* Terminator, llvm::SmallPtrSet<Expr*,50>& Set) {
+  if (!Terminator)
+    return;
+
+  for (Stmt::child_iterator I=Terminator->child_begin(), E=Terminator->child_end(); I!=E; ++I) {
+    if (!*I) continue;
+
+    if (BinaryOperator* B = dyn_cast<BinaryOperator>(*I))
+      if (B->isAssignmentOp()) Set.insert(B);
+
+    FindSubExprAssignments(*I, Set);
+  }
+}
+
+static BlkExprMapTy* PopulateBlkExprMap(CFG& cfg) {
+  BlkExprMapTy* M = new BlkExprMapTy();
+
+  // Look for assignments that are used as subexpressions.  These are the only
+  // assignments that we want to *possibly* register as a block-level
+  // expression.  Basically, if an assignment occurs both in a subexpression and
+  // at the block-level, it is a block-level expression.
+  llvm::SmallPtrSet<Expr*,50> SubExprAssignments;
+
+  for (CFG::iterator I=cfg.begin(), E=cfg.end(); I != E; ++I)
+    for (CFGBlock::iterator BI=(*I)->begin(), EI=(*I)->end(); BI != EI; ++BI)
+      FindSubExprAssignments(*BI, SubExprAssignments);
+
+  for (CFG::iterator I=cfg.begin(), E=cfg.end(); I != E; ++I) {
+
+    // Iterate over the statements again on identify the Expr* and Stmt* at the
+    // block-level that are block-level expressions.
+
+    for (CFGBlock::iterator BI=(*I)->begin(), EI=(*I)->end(); BI != EI; ++BI)
+      if (Expr* Exp = dyn_cast<Expr>(*BI)) {
+
+        if (BinaryOperator* B = dyn_cast<BinaryOperator>(Exp)) {
+          // Assignment expressions that are not nested within another
+          // expression are really "statements" whose value is never used by
+          // another expression.
+          if (B->isAssignmentOp() && !SubExprAssignments.count(Exp))
+            continue;
+        } else if (const StmtExpr* Terminator = dyn_cast<StmtExpr>(Exp)) {
+          // Special handling for statement expressions.  The last statement in
+          // the statement expression is also a block-level expr.
+          const CompoundStmt* C = Terminator->getSubStmt();
+          if (!C->body_empty()) {
+            unsigned x = M->size();
+            (*M)[C->body_back()] = x;
+          }
+        }
+
+        unsigned x = M->size();
+        (*M)[Exp] = x;
+      }
+
+    // Look at terminators.  The condition is a block-level expression.
+
+    Stmt* S = (*I)->getTerminatorCondition();
+
+    if (S && M->find(S) == M->end()) {
+        unsigned x = M->size();
+        (*M)[S] = x;
+    }
+  }
+
+  return M;
+}
+
+CFG::BlkExprNumTy CFG::getBlkExprNum(const Stmt* S) {
+  assert(S != NULL);
+  if (!BlkExprMap) { BlkExprMap = (void*) PopulateBlkExprMap(*this); }
+
+  BlkExprMapTy* M = reinterpret_cast<BlkExprMapTy*>(BlkExprMap);
+  BlkExprMapTy::iterator I = M->find(S);
+
+  if (I == M->end()) return CFG::BlkExprNumTy();
+  else return CFG::BlkExprNumTy(I->second);
+}
+
+unsigned CFG::getNumBlkExprs() {
+  if (const BlkExprMapTy* M = reinterpret_cast<const BlkExprMapTy*>(BlkExprMap))
+    return M->size();
+  else {
+    // We assume callers interested in the number of BlkExprs will want
+    // the map constructed if it doesn't already exist.
+    BlkExprMap = (void*) PopulateBlkExprMap(*this);
+    return reinterpret_cast<BlkExprMapTy*>(BlkExprMap)->size();
+  }
+}
+
+//===----------------------------------------------------------------------===//
+// Cleanup: CFG dstor.
+//===----------------------------------------------------------------------===//
+
+CFG::~CFG() {
+  delete reinterpret_cast<const BlkExprMapTy*>(BlkExprMap);
+}
+
+//===----------------------------------------------------------------------===//
+// CFG pretty printing
+//===----------------------------------------------------------------------===//
+
+namespace {
+
+class VISIBILITY_HIDDEN StmtPrinterHelper : public PrinterHelper  {
+
+  typedef llvm::DenseMap<Stmt*,std::pair<unsigned,unsigned> > StmtMapTy;
+  StmtMapTy StmtMap;
+  signed CurrentBlock;
+  unsigned CurrentStmt;
+  const LangOptions &LangOpts;
+public:
+
+  StmtPrinterHelper(const CFG* cfg, const LangOptions &LO)
+    : CurrentBlock(0), CurrentStmt(0), LangOpts(LO) {
+    for (CFG::const_iterator I = cfg->begin(), E = cfg->end(); I != E; ++I ) {
+      unsigned j = 1;
+      for (CFGBlock::const_iterator BI = (*I)->begin(), BEnd = (*I)->end() ;
+           BI != BEnd; ++BI, ++j )
+        StmtMap[*BI] = std::make_pair((*I)->getBlockID(),j);
+      }
+  }
+
+  virtual ~StmtPrinterHelper() {}
+
+  const LangOptions &getLangOpts() const { return LangOpts; }
+  void setBlockID(signed i) { CurrentBlock = i; }
+  void setStmtID(unsigned i) { CurrentStmt = i; }
+
+  virtual bool handledStmt(Stmt* Terminator, llvm::raw_ostream& OS) {
+
+    StmtMapTy::iterator I = StmtMap.find(Terminator);
+
+    if (I == StmtMap.end())
+      return false;
+
+    if (CurrentBlock >= 0 && I->second.first == (unsigned) CurrentBlock
+                          && I->second.second == CurrentStmt)
+      return false;
+
+      OS << "[B" << I->second.first << "." << I->second.second << "]";
+    return true;
+  }
+};
+} // end anonymous namespace
+
+
+namespace {
+class VISIBILITY_HIDDEN CFGBlockTerminatorPrint
+  : public StmtVisitor<CFGBlockTerminatorPrint,void> {
+
+  llvm::raw_ostream& OS;
+  StmtPrinterHelper* Helper;
+  PrintingPolicy Policy;
+
+public:
+  CFGBlockTerminatorPrint(llvm::raw_ostream& os, StmtPrinterHelper* helper,
+                          const PrintingPolicy &Policy)
+    : OS(os), Helper(helper), Policy(Policy) {}
+
+  void VisitIfStmt(IfStmt* I) {
+    OS << "if ";
+    I->getCond()->printPretty(OS,Helper,Policy);
+  }
+
+  // Default case.
+  void VisitStmt(Stmt* Terminator) {
+    Terminator->printPretty(OS, Helper, Policy);
+  }
+
+  void VisitForStmt(ForStmt* F) {
+    OS << "for (" ;
+    if (F->getInit()) OS << "...";
+    OS << "; ";
+    if (Stmt* C = F->getCond()) C->printPretty(OS, Helper, Policy);
+    OS << "; ";
+    if (F->getInc()) OS << "...";
+    OS << ")";
+  }
+
+  void VisitWhileStmt(WhileStmt* W) {
+    OS << "while " ;
+    if (Stmt* C = W->getCond()) C->printPretty(OS, Helper, Policy);
+  }
+
+  void VisitDoStmt(DoStmt* D) {
+    OS << "do ... while ";
+    if (Stmt* C = D->getCond()) C->printPretty(OS, Helper, Policy);
+  }
+
+  void VisitSwitchStmt(SwitchStmt* Terminator) {
+    OS << "switch ";
+    Terminator->getCond()->printPretty(OS, Helper, Policy);
+  }
+
+  void VisitConditionalOperator(ConditionalOperator* C) {
+    C->getCond()->printPretty(OS, Helper, Policy);
+    OS << " ? ... : ...";
+  }
+
+  void VisitChooseExpr(ChooseExpr* C) {
+    OS << "__builtin_choose_expr( ";
+    C->getCond()->printPretty(OS, Helper, Policy);
+    OS << " )";
+  }
+
+  void VisitIndirectGotoStmt(IndirectGotoStmt* I) {
+    OS << "goto *";
+    I->getTarget()->printPretty(OS, Helper, Policy);
+  }
+
+  void VisitBinaryOperator(BinaryOperator* B) {
+    if (!B->isLogicalOp()) {
+      VisitExpr(B);
+      return;
+    }
+
+    B->getLHS()->printPretty(OS, Helper, Policy);
+
+    switch (B->getOpcode()) {
+      case BinaryOperator::LOr:
+        OS << " || ...";
+        return;
+      case BinaryOperator::LAnd:
+        OS << " && ...";
+        return;
+      default:
+        assert(false && "Invalid logical operator.");
+    }
+  }
+
+  void VisitExpr(Expr* E) {
+    E->printPretty(OS, Helper, Policy);
+  }
+};
+} // end anonymous namespace
+
+
+static void print_stmt(llvm::raw_ostream &OS, StmtPrinterHelper* Helper,
+                       Stmt* Terminator) {
+  if (Helper) {
+    // special printing for statement-expressions.
+    if (StmtExpr* SE = dyn_cast<StmtExpr>(Terminator)) {
+      CompoundStmt* Sub = SE->getSubStmt();
+
+      if (Sub->child_begin() != Sub->child_end()) {
+        OS << "({ ... ; ";
+        Helper->handledStmt(*SE->getSubStmt()->body_rbegin(),OS);
+        OS << " })\n";
+        return;
+      }
+    }
+
+    // special printing for comma expressions.
+    if (BinaryOperator* B = dyn_cast<BinaryOperator>(Terminator)) {
+      if (B->getOpcode() == BinaryOperator::Comma) {
+        OS << "... , ";
+        Helper->handledStmt(B->getRHS(),OS);
+        OS << '\n';
+        return;
+      }
+    }
+  }
+
+  Terminator->printPretty(OS, Helper, PrintingPolicy(Helper->getLangOpts()));
+
+  // Expressions need a newline.
+  if (isa<Expr>(Terminator)) OS << '\n';
+}
+
+static void print_block(llvm::raw_ostream& OS, const CFG* cfg,
+                        const CFGBlock& B,
+                        StmtPrinterHelper* Helper, bool print_edges) {
+
+  if (Helper) Helper->setBlockID(B.getBlockID());
+
+  // Print the header.
+  OS << "\n [ B" << B.getBlockID();
+
+  if (&B == &cfg->getEntry())
+    OS << " (ENTRY) ]\n";
+  else if (&B == &cfg->getExit())
+    OS << " (EXIT) ]\n";
+  else if (&B == cfg->getIndirectGotoBlock())
+    OS << " (INDIRECT GOTO DISPATCH) ]\n";
+  else
+    OS << " ]\n";
+
+  // Print the label of this block.
+  if (Stmt* Terminator = const_cast<Stmt*>(B.getLabel())) {
+
+    if (print_edges)
+      OS << "    ";
+
+    if (LabelStmt* L = dyn_cast<LabelStmt>(Terminator))
+      OS << L->getName();
+    else if (CaseStmt* C = dyn_cast<CaseStmt>(Terminator)) {
+      OS << "case ";
+      C->getLHS()->printPretty(OS, Helper,
+                               PrintingPolicy(Helper->getLangOpts()));
+      if (C->getRHS()) {
+        OS << " ... ";
+        C->getRHS()->printPretty(OS, Helper,
+                                 PrintingPolicy(Helper->getLangOpts()));
+      }
+    } else if (isa<DefaultStmt>(Terminator))
+      OS << "default";
+    else
+      assert(false && "Invalid label statement in CFGBlock.");
+
+    OS << ":\n";
+  }
+
+  // Iterate through the statements in the block and print them.
+  unsigned j = 1;
+
+  for (CFGBlock::const_iterator I = B.begin(), E = B.end() ;
+       I != E ; ++I, ++j ) {
+
+    // Print the statement # in the basic block and the statement itself.
+    if (print_edges)
+      OS << "    ";
+
+    OS << llvm::format("%3d", j) << ": ";
+
+    if (Helper)
+      Helper->setStmtID(j);
+
+    print_stmt(OS,Helper,*I);
+  }
+
+  // Print the terminator of this block.
+  if (B.getTerminator()) {
+    if (print_edges)
+      OS << "    ";
+
+    OS << "  T: ";
+
+    if (Helper) Helper->setBlockID(-1);
+
+    CFGBlockTerminatorPrint TPrinter(OS, Helper,
+                                     PrintingPolicy(Helper->getLangOpts()));
+    TPrinter.Visit(const_cast<Stmt*>(B.getTerminator()));
+    OS << '\n';
+  }
+
+  if (print_edges) {
+    // Print the predecessors of this block.
+    OS << "    Predecessors (" << B.pred_size() << "):";
+    unsigned i = 0;
+
+    for (CFGBlock::const_pred_iterator I = B.pred_begin(), E = B.pred_end();
+         I != E; ++I, ++i) {
+
+      if (i == 8 || (i-8) == 0)
+        OS << "\n     ";
+
+      OS << " B" << (*I)->getBlockID();
+    }
+
+    OS << '\n';
+
+    // Print the successors of this block.
+    OS << "    Successors (" << B.succ_size() << "):";
+    i = 0;
+
+    for (CFGBlock::const_succ_iterator I = B.succ_begin(), E = B.succ_end();
+         I != E; ++I, ++i) {
+
+      if (i == 8 || (i-8) % 10 == 0)
+        OS << "\n    ";
+
+      if (*I)
+        OS << " B" << (*I)->getBlockID();
+      else
+        OS  << " NULL";
+    }
+
+    OS << '\n';
+  }
+}
+
+
+/// dump - A simple pretty printer of a CFG that outputs to stderr.
+void CFG::dump(const LangOptions &LO) const { print(llvm::errs(), LO); }
+
+/// print - A simple pretty printer of a CFG that outputs to an ostream.
+void CFG::print(llvm::raw_ostream &OS, const LangOptions &LO) const {
+  StmtPrinterHelper Helper(this, LO);
+
+  // Print the entry block.
+  print_block(OS, this, getEntry(), &Helper, true);
+
+  // Iterate through the CFGBlocks and print them one by one.
+  for (const_iterator I = Blocks.begin(), E = Blocks.end() ; I != E ; ++I) {
+    // Skip the entry block, because we already printed it.
+    if (&(**I) == &getEntry() || &(**I) == &getExit())
+      continue;
+
+    print_block(OS, this, **I, &Helper, true);
+  }
+
+  // Print the exit block.
+  print_block(OS, this, getExit(), &Helper, true);
+  OS.flush();
+}
+
+/// dump - A simply pretty printer of a CFGBlock that outputs to stderr.
+void CFGBlock::dump(const CFG* cfg, const LangOptions &LO) const {
+  print(llvm::errs(), cfg, LO);
+}
+
+/// print - A simple pretty printer of a CFGBlock that outputs to an ostream.
+///   Generally this will only be called from CFG::print.
+void CFGBlock::print(llvm::raw_ostream& OS, const CFG* cfg,
+                     const LangOptions &LO) const {
+  StmtPrinterHelper Helper(cfg, LO);
+  print_block(OS, cfg, *this, &Helper, true);
+}
+
+/// printTerminator - A simple pretty printer of the terminator of a CFGBlock.
+void CFGBlock::printTerminator(llvm::raw_ostream &OS,
+                               const LangOptions &LO) const {
+  CFGBlockTerminatorPrint TPrinter(OS, NULL, PrintingPolicy(LO));
+  TPrinter.Visit(const_cast<Stmt*>(getTerminator()));
+}
+
+Stmt* CFGBlock::getTerminatorCondition() {
+
+  if (!Terminator)
+    return NULL;
+
+  Expr* E = NULL;
+
+  switch (Terminator->getStmtClass()) {
+    default:
+      break;
+
+    case Stmt::ForStmtClass:
+      E = cast<ForStmt>(Terminator)->getCond();
+      break;
+
+    case Stmt::WhileStmtClass:
+      E = cast<WhileStmt>(Terminator)->getCond();
+      break;
+
+    case Stmt::DoStmtClass:
+      E = cast<DoStmt>(Terminator)->getCond();
+      break;
+
+    case Stmt::IfStmtClass:
+      E = cast<IfStmt>(Terminator)->getCond();
+      break;
+
+    case Stmt::ChooseExprClass:
+      E = cast<ChooseExpr>(Terminator)->getCond();
+      break;
+
+    case Stmt::IndirectGotoStmtClass:
+      E = cast<IndirectGotoStmt>(Terminator)->getTarget();
+      break;
+
+    case Stmt::SwitchStmtClass:
+      E = cast<SwitchStmt>(Terminator)->getCond();
+      break;
+
+    case Stmt::ConditionalOperatorClass:
+      E = cast<ConditionalOperator>(Terminator)->getCond();
+      break;
+
+    case Stmt::BinaryOperatorClass: // '&&' and '||'
+      E = cast<BinaryOperator>(Terminator)->getLHS();
+      break;
+
+    case Stmt::ObjCForCollectionStmtClass:
+      return Terminator;
+  }
+
+  return E ? E->IgnoreParens() : NULL;
+}
+
+bool CFGBlock::hasBinaryBranchTerminator() const {
+
+  if (!Terminator)
+    return false;
+
+  Expr* E = NULL;
+
+  switch (Terminator->getStmtClass()) {
+    default:
+      return false;
+
+    case Stmt::ForStmtClass:
+    case Stmt::WhileStmtClass:
+    case Stmt::DoStmtClass:
+    case Stmt::IfStmtClass:
+    case Stmt::ChooseExprClass:
+    case Stmt::ConditionalOperatorClass:
+    case Stmt::BinaryOperatorClass:
+      return true;
+  }
+
+  return E ? E->IgnoreParens() : NULL;
+}
+
+
+//===----------------------------------------------------------------------===//
+// CFG Graphviz Visualization
+//===----------------------------------------------------------------------===//
+
+
+#ifndef NDEBUG
+static StmtPrinterHelper* GraphHelper;
+#endif
+
+void CFG::viewCFG(const LangOptions &LO) const {
+#ifndef NDEBUG
+  StmtPrinterHelper H(this, LO);
+  GraphHelper = &H;
+  llvm::ViewGraph(this,"CFG");
+  GraphHelper = NULL;
+#endif
+}
+
+namespace llvm {
+template<>
+struct DOTGraphTraits<const CFG*> : public DefaultDOTGraphTraits {
+  static std::string getNodeLabel(const CFGBlock* Node, const CFG* Graph,
+                                  bool ShortNames) {
+
+#ifndef NDEBUG
+    std::string OutSStr;
+    llvm::raw_string_ostream Out(OutSStr);
+    print_block(Out,Graph, *Node, GraphHelper, false);
+    std::string& OutStr = Out.str();
+
+    if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
+
+    // Process string output to make it nicer...
+    for (unsigned i = 0; i != OutStr.length(); ++i)
+      if (OutStr[i] == '\n') {                            // Left justify
+        OutStr[i] = '\\';
+        OutStr.insert(OutStr.begin()+i+1, 'l');
+      }
+
+    return OutStr;
+#else
+    return "";
+#endif
+  }
+};
+} // end namespace llvm