Constify all references to Stmt* and CFGBlock* in libChecker.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@108811 91177308-0d34-0410-b5e6-96231b3b80d8

15 files changed, 320 insertions, 305 deletions

diff --git a/include/clang/Analysis/ProgramPoint.h b/include/clang/Analysis/ProgramPoint.h
index 24bbf22640..08e08f2ad0 100644
--- a/include/clang/Analysis/ProgramPoint.h
+++ b/include/clang/Analysis/ProgramPoint.h
@@ -109,16 +109,16 @@ public:
                 const void *tag = 0)
     : ProgramPoint(B, BlockEntranceKind, L, tag) {}
 
-  CFGBlock* getBlock() const {
-    return const_cast<CFGBlock*>(reinterpret_cast<const CFGBlock*>(getData1()));
+  const CFGBlock* getBlock() const {
+    return reinterpret_cast<const CFGBlock*>(getData1());
   }
 
-  CFGElement getFirstElement() const {
+  const CFGElement getFirstElement() const {
     const CFGBlock* B = getBlock();
     return B->empty() ? CFGElement() : B->front();
   }
   
-  Stmt *getFirstStmt() const {
+  const Stmt *getFirstStmt() const {
     return getFirstElement().getStmt();
   }
 
@@ -132,16 +132,16 @@ public:
   BlockExit(const CFGBlock* B, const LocationContext *L)
     : ProgramPoint(B, BlockExitKind, L) {}
 
-  CFGBlock* getBlock() const {
-    return const_cast<CFGBlock*>(reinterpret_cast<const CFGBlock*>(getData1()));
+  const CFGBlock* getBlock() const {
+    return reinterpret_cast<const CFGBlock*>(getData1());
   }
 
-  Stmt* getLastStmt() const {
+  const Stmt* getLastStmt() const {
     const CFGBlock* B = getBlock();
     return B->empty() ? CFGElement() : B->back();
   }
 
-  Stmt* getTerminator() const {
+  const Stmt* getTerminator() const {
     return getBlock()->getTerminator();
   }
 
@@ -300,12 +300,12 @@ public:
   BlockEdge(const CFGBlock* B1, const CFGBlock* B2, const LocationContext *L)
     : ProgramPoint(B1, B2, BlockEdgeKind, L) {}
 
-  CFGBlock* getSrc() const {
-    return const_cast<CFGBlock*>(static_cast<const CFGBlock*>(getData1()));
+  const CFGBlock* getSrc() const {
+    return static_cast<const CFGBlock*>(getData1());
   }
 
-  CFGBlock* getDst() const {
-    return const_cast<CFGBlock*>(static_cast<const CFGBlock*>(getData2()));
+  const CFGBlock* getDst() const {
+    return static_cast<const CFGBlock*>(getData2());
   }
 
   static bool classof(const ProgramPoint* Location) {
diff --git a/include/clang/Checker/PathSensitive/Checker.h b/include/clang/Checker/PathSensitive/Checker.h
index 49dc3fa7dc..b439205edd 100644
--- a/include/clang/Checker/PathSensitive/Checker.h
+++ b/include/clang/Checker/PathSensitive/Checker.h
@@ -269,7 +269,7 @@ public:
 
   virtual void VisitBranchCondition(GRBranchNodeBuilder &Builder,
                                     GRExprEngine &Eng,
-                                    Stmt *Condition, void *tag) {}
+                                    const Stmt *Condition, void *tag) {}
 
   virtual bool EvalNilReceiver(CheckerContext &C, const ObjCMessageExpr *ME) {
     return false;
diff --git a/include/clang/Checker/PathSensitive/GRCoreEngine.h b/include/clang/Checker/PathSensitive/GRCoreEngine.h
index acd3651eb5..efb7be6026 100644
--- a/include/clang/Checker/PathSensitive/GRCoreEngine.h
+++ b/include/clang/Checker/PathSensitive/GRCoreEngine.h
@@ -67,11 +67,11 @@ class GRCoreEngine {
 
   void HandleBlockEdge(const BlockEdge& E, ExplodedNode* Pred);
   void HandleBlockEntrance(const BlockEntrance& E, ExplodedNode* Pred);
-  void HandleBlockExit(CFGBlock* B, ExplodedNode* Pred);
-  void HandlePostStmt(const PostStmt& S, CFGBlock* B,
+  void HandleBlockExit(const CFGBlock* B, ExplodedNode* Pred);
+  void HandlePostStmt(const PostStmt& S, const CFGBlock* B,
                       unsigned StmtIdx, ExplodedNode *Pred);
 
-  void HandleBranch(Stmt* Cond, Stmt* Term, CFGBlock* B,
+  void HandleBranch(const Stmt* Cond, const Stmt* Term, const CFGBlock* B,
                     ExplodedNode* Pred);
   void HandleCallEnter(const CallEnter &L, const CFGBlock *Block,
                        unsigned Index, ExplodedNode *Pred);
@@ -84,13 +84,13 @@ class GRCoreEngine {
 
   void ProcessEndPath(GREndPathNodeBuilder& Builder);
 
-  void ProcessStmt(CFGElement E, GRStmtNodeBuilder& Builder);
+  void ProcessStmt(const CFGElement E, GRStmtNodeBuilder& Builder);
 
-  bool ProcessBlockEntrance(CFGBlock* Blk, const ExplodedNode *Pred,
+  bool ProcessBlockEntrance(const CFGBlock* Blk, const ExplodedNode *Pred,
                             GRBlockCounter BC);
 
 
-  void ProcessBranch(Stmt* Condition, Stmt* Terminator,
+  void ProcessBranch(const Stmt* Condition, const Stmt* Terminator,
                      GRBranchNodeBuilder& Builder);
 
 
@@ -141,7 +141,7 @@ public:
 
 class GRStmtNodeBuilder {
   GRCoreEngine& Eng;
-  CFGBlock& B;
+  const CFGBlock& B;
   const unsigned Idx;
   ExplodedNode* Pred;
   GRStateManager& Mgr;
@@ -163,7 +163,7 @@ public:
   void GenerateAutoTransition(ExplodedNode* N);
 
 public:
-  GRStmtNodeBuilder(CFGBlock* b, unsigned idx, ExplodedNode* N,
+  GRStmtNodeBuilder(const CFGBlock* b, unsigned idx, ExplodedNode* N,
                     GRCoreEngine* e, GRStateManager &mgr);
 
   ~GRStmtNodeBuilder();
@@ -222,11 +222,11 @@ public:
 
   /// getStmt - Return the current block-level expression associated with
   ///  this builder.
-  Stmt* getStmt() const { return B[Idx]; }
+  const Stmt* getStmt() const { return B[Idx]; }
 
   /// getBlock - Return the CFGBlock associated with the block-level expression
   ///  of this builder.
-  CFGBlock* getBlock() const { return &B; }
+  const CFGBlock* getBlock() const { return &B; }
 
   unsigned getIndex() const { return Idx; }
 
@@ -259,9 +259,9 @@ public:
 
 class GRBranchNodeBuilder {
   GRCoreEngine& Eng;
-  CFGBlock* Src;
-  CFGBlock* DstT;
-  CFGBlock* DstF;
+  const CFGBlock* Src;
+  const CFGBlock* DstT;
+  const CFGBlock* DstF;
   ExplodedNode* Pred;
 
   typedef llvm::SmallVector<ExplodedNode*,3> DeferredTy;
@@ -273,8 +273,8 @@ class GRBranchNodeBuilder {
   bool InFeasibleFalse;
 
 public:
-  GRBranchNodeBuilder(CFGBlock* src, CFGBlock* dstT, CFGBlock* dstF,
-                          ExplodedNode* pred, GRCoreEngine* e)
+  GRBranchNodeBuilder(const CFGBlock* src, const CFGBlock* dstT, 
+                      const CFGBlock* dstF, ExplodedNode* pred, GRCoreEngine* e)
   : Eng(*e), Src(src), DstT(dstT), DstF(dstF), Pred(pred),
     GeneratedTrue(false), GeneratedFalse(false),
     InFeasibleTrue(!DstT), InFeasibleFalse(!DstF) {}
@@ -289,7 +289,7 @@ public:
 
   ExplodedNode* generateNode(const GRState* State, bool branch);
 
-  CFGBlock* getTargetBlock(bool branch) const {
+  const CFGBlock* getTargetBlock(bool branch) const {
     return branch ? DstT : DstF;
   }
 
@@ -311,31 +311,31 @@ public:
 
 class GRIndirectGotoNodeBuilder {
   GRCoreEngine& Eng;
-  CFGBlock* Src;
-  CFGBlock& DispatchBlock;
-  Expr* E;
+  const CFGBlock* Src;
+  const CFGBlock& DispatchBlock;
+  const Expr* E;
   ExplodedNode* Pred;
 
 public:
-  GRIndirectGotoNodeBuilder(ExplodedNode* pred, CFGBlock* src, Expr* e,
-                            CFGBlock* dispatch, GRCoreEngine* eng)
-  : Eng(*eng), Src(src), DispatchBlock(*dispatch), E(e), Pred(pred) {}
+  GRIndirectGotoNodeBuilder(ExplodedNode* pred, const CFGBlock* src, 
+                    const Expr* e, const CFGBlock* dispatch, GRCoreEngine* eng)
+    : Eng(*eng), Src(src), DispatchBlock(*dispatch), E(e), Pred(pred) {}
 
   class iterator {
-    CFGBlock::succ_iterator I;
+    CFGBlock::const_succ_iterator I;
 
     friend class GRIndirectGotoNodeBuilder;
-    iterator(CFGBlock::succ_iterator i) : I(i) {}
+    iterator(CFGBlock::const_succ_iterator i) : I(i) {}
   public:
 
     iterator& operator++() { ++I; return *this; }
     bool operator!=(const iterator& X) const { return I != X.I; }
 
-    LabelStmt* getLabel() const {
+    const LabelStmt* getLabel() const {
       return llvm::cast<LabelStmt>((*I)->getLabel());
     }
 
-    CFGBlock*  getBlock() const {
+    const CFGBlock*  getBlock() const {
       return *I;
     }
   };
@@ -346,37 +346,37 @@ public:
   ExplodedNode* generateNode(const iterator& I, const GRState* State,
                              bool isSink = false);
 
-  Expr* getTarget() const { return E; }
+  const Expr* getTarget() const { return E; }
 
   const GRState* getState() const { return Pred->State; }
 };
 
 class GRSwitchNodeBuilder {
   GRCoreEngine& Eng;
-  CFGBlock* Src;
-  Expr* Condition;
+  const CFGBlock* Src;
+  const Expr* Condition;
   ExplodedNode* Pred;
 
 public:
-  GRSwitchNodeBuilder(ExplodedNode* pred, CFGBlock* src,
-                      Expr* condition, GRCoreEngine* eng)
+  GRSwitchNodeBuilder(ExplodedNode* pred, const CFGBlock* src,
+                      const Expr* condition, GRCoreEngine* eng)
   : Eng(*eng), Src(src), Condition(condition), Pred(pred) {}
 
   class iterator {
-    CFGBlock::succ_reverse_iterator I;
+    CFGBlock::const_succ_reverse_iterator I;
 
     friend class GRSwitchNodeBuilder;
-    iterator(CFGBlock::succ_reverse_iterator i) : I(i) {}
+    iterator(CFGBlock::const_succ_reverse_iterator i) : I(i) {}
 
   public:
     iterator& operator++() { ++I; return *this; }
     bool operator!=(const iterator& X) const { return I != X.I; }
 
-    CaseStmt* getCase() const {
+    const CaseStmt* getCase() const {
       return llvm::cast<CaseStmt>((*I)->getLabel());
     }
 
-    CFGBlock* getBlock() const {
+    const CFGBlock* getBlock() const {
       return *I;
     }
   };
@@ -389,21 +389,21 @@ public:
   ExplodedNode* generateDefaultCaseNode(const GRState* State,
                                         bool isSink = false);
 
-  Expr* getCondition() const { return Condition; }
+  const Expr* getCondition() const { return Condition; }
 
   const GRState* getState() const { return Pred->State; }
 };
 
 class GREndPathNodeBuilder {
   GRCoreEngine &Eng;
-  CFGBlock& B;
+  const CFGBlock& B;
   ExplodedNode* Pred;
 
 public:
   bool HasGeneratedNode;
 
 public:
-  GREndPathNodeBuilder(CFGBlock* b, ExplodedNode* N, GRCoreEngine* e)
+  GREndPathNodeBuilder(const CFGBlock* b, ExplodedNode* N, GRCoreEngine* e)
     : Eng(*e), B(*b), Pred(N), HasGeneratedNode(false) {}
 
   ~GREndPathNodeBuilder();
@@ -427,7 +427,7 @@ public:
 
   void GenerateCallExitNode(const GRState *state);
 
-  CFGBlock* getBlock() const { return &B; }
+  const CFGBlock* getBlock() const { return &B; }
 
   const GRState* getState() const {
     return getPredecessor()->getState();
diff --git a/include/clang/Checker/PathSensitive/GRExprEngine.h b/include/clang/Checker/PathSensitive/GRExprEngine.h
index d93c5f1e25..6a12d6304e 100644
--- a/include/clang/Checker/PathSensitive/GRExprEngine.h
+++ b/include/clang/Checker/PathSensitive/GRExprEngine.h
@@ -64,7 +64,7 @@ class GRExprEngine : public GRSubEngine {
   const GRState* CleanedState;
 
   /// CurrentStmt - The current block-level statement.
-  Stmt* CurrentStmt;
+  const Stmt* CurrentStmt;
 
   // Obj-C Class Identifiers.
   IdentifierInfo* NSExceptionII;
@@ -101,10 +101,10 @@ class GRExprEngine : public GRSubEngine {
 
   class CallExprWLItem {
   public:
-    CallExpr::arg_iterator I;
+    CallExpr::const_arg_iterator I;
     ExplodedNode *N;
 
-    CallExprWLItem(const CallExpr::arg_iterator &i, ExplodedNode *n)
+    CallExprWLItem(const CallExpr::const_arg_iterator &i, ExplodedNode *n)
       : I(i), N(n) {}
   };
 
@@ -166,17 +166,18 @@ public:
 
   /// ProcessStmt - Called by GRCoreEngine. Used to generate new successor
   ///  nodes by processing the 'effects' of a block-level statement.
-  void ProcessStmt(CFGElement E, GRStmtNodeBuilder& builder);
+  void ProcessStmt(const CFGElement E, GRStmtNodeBuilder& builder);
 
   /// ProcessBlockEntrance - Called by GRCoreEngine when start processing
   ///  a CFGBlock.  This method returns true if the analysis should continue
   ///  exploring the given path, and false otherwise.
-  bool ProcessBlockEntrance(CFGBlock* B, const ExplodedNode *Pred,
+  bool ProcessBlockEntrance(const CFGBlock* B, const ExplodedNode *Pred,
                             GRBlockCounter BC);
 
   /// ProcessBranch - Called by GRCoreEngine.  Used to generate successor
   ///  nodes by processing the 'effects' of a branch condition.
-  void ProcessBranch(Stmt* Condition, Stmt* Term, GRBranchNodeBuilder& builder);
+  void ProcessBranch(const Stmt* Condition, const Stmt* Term, 
+                     GRBranchNodeBuilder& builder);
 
   /// ProcessIndirectGoto - Called by GRCoreEngine.  Used to generate successor
   ///  nodes by processing the 'effects' of a computed goto jump.
@@ -201,7 +202,7 @@ public:
 
   /// EvalAssume - Callback function invoked by the ConstraintManager when
   ///  making assumptions about state values.
-  const GRState *ProcessAssume(const GRState *state, SVal cond, bool assumption);
+  const GRState *ProcessAssume(const GRState *state, SVal cond,bool assumption);
 
   GRStateManager& getStateManager() { return StateMgr; }
   const GRStateManager& getStateManager() const { return StateMgr; }
@@ -240,7 +241,7 @@ public:
 
   /// CheckerVisit - Dispatcher for performing checker-specific logic
   ///  at specific statements.
-  void CheckerVisit(Stmt *S, ExplodedNodeSet &Dst, ExplodedNodeSet &Src, 
+  void CheckerVisit(const Stmt *S, ExplodedNodeSet &Dst, ExplodedNodeSet &Src, 
                     bool isPrevisit);
 
   bool CheckerEvalCall(const CallExpr *CE, 
@@ -259,118 +260,124 @@ public:
 
   /// Visit - Transfer function logic for all statements.  Dispatches to
   ///  other functions that handle specific kinds of statements.
-  void Visit(Stmt* S, ExplodedNode* Pred, ExplodedNodeSet& Dst);
+  void Visit(const Stmt* S, ExplodedNode* Pred, ExplodedNodeSet& Dst);
 
   /// VisitLValue - Evaluate the lvalue of the expression. For example, if Ex is
   /// a DeclRefExpr, it evaluates to the MemRegionVal which represents its
   /// storage location. Note that not all kinds of expressions has lvalue.
-  void VisitLValue(Expr* Ex, ExplodedNode* Pred, ExplodedNodeSet& Dst);
+  void VisitLValue(const Expr* Ex, ExplodedNode* Pred, ExplodedNodeSet& Dst);
 
   /// VisitArraySubscriptExpr - Transfer function for array accesses.
-  void VisitArraySubscriptExpr(ArraySubscriptExpr* Ex, ExplodedNode* Pred,
+  void VisitArraySubscriptExpr(const ArraySubscriptExpr* Ex, ExplodedNode* Pred,
                                ExplodedNodeSet& Dst, bool asLValue);
 
   /// VisitAsmStmt - Transfer function logic for inline asm.
-  void VisitAsmStmt(AsmStmt* A, ExplodedNode* Pred, ExplodedNodeSet& Dst);
+  void VisitAsmStmt(const AsmStmt* A, ExplodedNode* Pred, ExplodedNodeSet& Dst);
 
-  void VisitAsmStmtHelperOutputs(AsmStmt* A,
-                                 AsmStmt::outputs_iterator I,
-                                 AsmStmt::outputs_iterator E,
+  void VisitAsmStmtHelperOutputs(const AsmStmt* A,
+                                 AsmStmt::const_outputs_iterator I,
+                                 AsmStmt::const_outputs_iterator E,
                                  ExplodedNode* Pred, ExplodedNodeSet& Dst);
 
-  void VisitAsmStmtHelperInputs(AsmStmt* A,
-                                AsmStmt::inputs_iterator I,
-                                AsmStmt::inputs_iterator E,
+  void VisitAsmStmtHelperInputs(const AsmStmt* A,
+                                AsmStmt::const_inputs_iterator I,
+                                AsmStmt::const_inputs_iterator E,
                                 ExplodedNode* Pred, ExplodedNodeSet& Dst);
   
   /// VisitBlockExpr - Transfer function logic for BlockExprs.
-  void VisitBlockExpr(BlockExpr *BE, ExplodedNode *Pred, ExplodedNodeSet &Dst);
+  void VisitBlockExpr(const BlockExpr *BE, ExplodedNode *Pred, 
+                      ExplodedNodeSet &Dst);
 
   /// VisitBinaryOperator - Transfer function logic for binary operators.
-  void VisitBinaryOperator(BinaryOperator* B, ExplodedNode* Pred, 
+  void VisitBinaryOperator(const BinaryOperator* B, ExplodedNode* Pred, 
                            ExplodedNodeSet& Dst, bool asLValue);
 
 
   /// VisitCall - Transfer function for function calls.
-  void VisitCall(CallExpr* CE, ExplodedNode* Pred,
-                 CallExpr::arg_iterator AI, CallExpr::arg_iterator AE,
+  void VisitCall(const CallExpr* CE, ExplodedNode* Pred,
+                 CallExpr::const_arg_iterator AI, 
+                 CallExpr::const_arg_iterator AE,
                  ExplodedNodeSet& Dst, bool asLValue);
 
   /// VisitCast - Transfer function logic for all casts (implicit and explicit).
-  void VisitCast(CastExpr *CastE, Expr *Ex, ExplodedNode *Pred,
+  void VisitCast(const CastExpr *CastE, const Expr *Ex, ExplodedNode *Pred,
                  ExplodedNodeSet &Dst, bool asLValue);
 
   /// VisitCompoundLiteralExpr - Transfer function logic for compound literals.
-  void VisitCompoundLiteralExpr(CompoundLiteralExpr* CL, ExplodedNode* Pred,
-                                ExplodedNodeSet& Dst, bool asLValue);
+  void VisitCompoundLiteralExpr(const CompoundLiteralExpr* CL, 
+                                ExplodedNode* Pred, ExplodedNodeSet& Dst, 
+                                bool asLValue);
 
   /// VisitDeclRefExpr - Transfer function logic for DeclRefExprs.
-  void VisitDeclRefExpr(DeclRefExpr* DR, ExplodedNode* Pred,
+  void VisitDeclRefExpr(const DeclRefExpr* DR, ExplodedNode* Pred,
                         ExplodedNodeSet& Dst, bool asLValue);
 
   /// VisitBlockDeclRefExpr - Transfer function logic for BlockDeclRefExprs.
-  void VisitBlockDeclRefExpr(BlockDeclRefExpr* DR, ExplodedNode* Pred,
+  void VisitBlockDeclRefExpr(const BlockDeclRefExpr* DR, ExplodedNode* Pred,
                              ExplodedNodeSet& Dst, bool asLValue);
   
-  void VisitCommonDeclRefExpr(Expr* DR, const NamedDecl *D,ExplodedNode* Pred,
-                             ExplodedNodeSet& Dst, bool asLValue);  
+  void VisitCommonDeclRefExpr(const Expr* DR, const NamedDecl *D,
+                              ExplodedNode* Pred, ExplodedNodeSet& Dst, 
+                              bool asLValue);  
   
   /// VisitDeclStmt - Transfer function logic for DeclStmts.
-  void VisitDeclStmt(DeclStmt* DS, ExplodedNode* Pred, ExplodedNodeSet& Dst);
+  void VisitDeclStmt(const DeclStmt* DS, ExplodedNode* Pred, 
+                     ExplodedNodeSet& Dst);
 
   /// VisitGuardedExpr - Transfer function logic for ?, __builtin_choose
-  void VisitGuardedExpr(Expr* Ex, Expr* L, Expr* R, ExplodedNode* Pred,
-                        ExplodedNodeSet& Dst);
+  void VisitGuardedExpr(const Expr* Ex, const Expr* L, const Expr* R, 
+                        ExplodedNode* Pred, ExplodedNodeSet& Dst);
 
   /// VisitCondInit - Transfer function for handling the initialization
   ///  of a condition variable in an IfStmt, SwitchStmt, etc.
-  void VisitCondInit(VarDecl *VD, Stmt *S, ExplodedNode *Pred,
+  void VisitCondInit(const VarDecl *VD, const Stmt *S, ExplodedNode *Pred,
                      ExplodedNodeSet& Dst);
   
-  void VisitInitListExpr(InitListExpr* E, ExplodedNode* Pred,
+  void VisitInitListExpr(const InitListExpr* E, ExplodedNode* Pred,
                          ExplodedNodeSet& Dst);
 
   /// VisitLogicalExpr - Transfer function logic for '&&', '||'
-  void VisitLogicalExpr(BinaryOperator* B, ExplodedNode* Pred,
+  void VisitLogicalExpr(const BinaryOperator* B, ExplodedNode* Pred,
                         ExplodedNodeSet& Dst);
 
   /// VisitMemberExpr - Transfer function for member expressions.
-  void VisitMemberExpr(MemberExpr* M, ExplodedNode* Pred, ExplodedNodeSet& Dst,
-                       bool asLValue);
+  void VisitMemberExpr(const MemberExpr* M, ExplodedNode* Pred, 
+                       ExplodedNodeSet& Dst, bool asLValue);
 
   /// VisitObjCIvarRefExpr - Transfer function logic for ObjCIvarRefExprs.
-  void VisitObjCIvarRefExpr(ObjCIvarRefExpr* DR, ExplodedNode* Pred,
+  void VisitObjCIvarRefExpr(const ObjCIvarRefExpr* DR, ExplodedNode* Pred,
                             ExplodedNodeSet& Dst, bool asLValue);
 
   /// VisitObjCForCollectionStmt - Transfer function logic for
   ///  ObjCForCollectionStmt.
-  void VisitObjCForCollectionStmt(ObjCForCollectionStmt* S, ExplodedNode* Pred,
-                                  ExplodedNodeSet& Dst);
+  void VisitObjCForCollectionStmt(const ObjCForCollectionStmt* S, 
+                                  ExplodedNode* Pred, ExplodedNodeSet& Dst);
 
-  void VisitObjCForCollectionStmtAux(ObjCForCollectionStmt* S, 
+  void VisitObjCForCollectionStmtAux(const ObjCForCollectionStmt* S, 
                                      ExplodedNode* Pred,
                                      ExplodedNodeSet& Dst, SVal ElementV);
 
   /// VisitObjCMessageExpr - Transfer function for ObjC message expressions.
-  void VisitObjCMessageExpr(ObjCMessageExpr* ME, ExplodedNode* Pred, 
+  void VisitObjCMessageExpr(const ObjCMessageExpr* ME, ExplodedNode* Pred, 
                             ExplodedNodeSet& Dst, bool asLValue);
 
   /// VisitReturnStmt - Transfer function logic for return statements.
-  void VisitReturnStmt(ReturnStmt* R, ExplodedNode* Pred, ExplodedNodeSet& Dst);
+  void VisitReturnStmt(const ReturnStmt* R, ExplodedNode* Pred, 
+                       ExplodedNodeSet& Dst);
   
   /// VisitOffsetOfExpr - Transfer function for offsetof.
-  void VisitOffsetOfExpr(OffsetOfExpr* Ex, ExplodedNode* Pred,
+  void VisitOffsetOfExpr(const OffsetOfExpr* Ex, ExplodedNode* Pred,
                          ExplodedNodeSet& Dst);
 
   /// VisitSizeOfAlignOfExpr - Transfer function for sizeof.
-  void VisitSizeOfAlignOfExpr(SizeOfAlignOfExpr* Ex, ExplodedNode* Pred,
+  void VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr* Ex, ExplodedNode* Pred,
                               ExplodedNodeSet& Dst);
 
   /// VisitUnaryOperator - Transfer function logic for unary operators.
-  void VisitUnaryOperator(UnaryOperator* B, ExplodedNode* Pred, 
+  void VisitUnaryOperator(const UnaryOperator* B, ExplodedNode* Pred, 
                           ExplodedNodeSet& Dst, bool asLValue);
 
-  void VisitCXXThisExpr(CXXThisExpr *TE, ExplodedNode *Pred, 
+  void VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred, 
                         ExplodedNodeSet & Dst);
   
   void VisitCXXConstructExpr(const CXXConstructExpr *E, SVal Dest,
@@ -380,17 +387,17 @@ public:
   void VisitCXXMemberCallExpr(const CXXMemberCallExpr *MCE, ExplodedNode *Pred,
                               ExplodedNodeSet &Dst);
 
-  void VisitCXXNewExpr(CXXNewExpr *CNE, ExplodedNode *Pred,
+  void VisitCXXNewExpr(const CXXNewExpr *CNE, ExplodedNode *Pred,
                        ExplodedNodeSet &Dst);
 
-  void VisitCXXDeleteExpr(CXXDeleteExpr *CDE, ExplodedNode *Pred,
+  void VisitCXXDeleteExpr(const CXXDeleteExpr *CDE, ExplodedNode *Pred,
                           ExplodedNodeSet &Dst);
 
   void VisitAggExpr(const Expr *E, SVal Dest, ExplodedNode *Pred,
                     ExplodedNodeSet &Dst);
 
   /// Create a C++ temporary object for an rvalue.
-  void CreateCXXTemporaryObject(Expr *Ex, ExplodedNode *Pred, 
+  void CreateCXXTemporaryObject(const Expr *Ex, ExplodedNode *Pred, 
                                 ExplodedNodeSet &Dst);
 
   /// Synthesize CXXThisRegion.
@@ -398,14 +405,15 @@ public:
                                         const StackFrameContext *SFC);
 
   /// Evaluate arguments with a work list algorithm.
-  void EvalArguments(ExprIterator AI, ExprIterator AE,
+  void EvalArguments(ConstExprIterator AI, ConstExprIterator AE,
                      const FunctionProtoType *FnType, 
                      ExplodedNode *Pred, ExplodedNodeSet &Dst);
 
   /// EvalEagerlyAssume - Given the nodes in 'Src', eagerly assume symbolic
   ///  expressions of the form 'x != 0' and generate new nodes (stored in Dst)
   ///  with those assumptions.
-  void EvalEagerlyAssume(ExplodedNodeSet& Dst, ExplodedNodeSet& Src, Expr *Ex);
+  void EvalEagerlyAssume(ExplodedNodeSet& Dst, ExplodedNodeSet& Src, 
+                         const Expr *Ex);
 
   SVal EvalMinus(SVal X) {
     return X.isValid() ? SVator.EvalMinus(cast<NonLoc>(X)) : X;
@@ -433,13 +441,13 @@ public:
   }
   
 protected:
-  void EvalObjCMessageExpr(ExplodedNodeSet& Dst, ObjCMessageExpr* ME, 
+  void EvalObjCMessageExpr(ExplodedNodeSet& Dst, const ObjCMessageExpr* ME, 
                            ExplodedNode* Pred, const GRState *state) {
     assert (Builder && "GRStmtNodeBuilder must be defined.");
     getTF().EvalObjCMessageExpr(Dst, *this, *Builder, ME, Pred, state);
   }
 
-  const GRState* MarkBranch(const GRState* St, Stmt* Terminator,
+  const GRState* MarkBranch(const GRState* St, const Stmt* Terminator,
                             bool branchTaken);
 
   /// EvalBind - Handle the semantics of binding a value to a specific location.
diff --git a/include/clang/Checker/PathSensitive/GRSubEngine.h b/include/clang/Checker/PathSensitive/GRSubEngine.h
index 90a41d7c09..535ffe288c 100644
--- a/include/clang/Checker/PathSensitive/GRSubEngine.h
+++ b/include/clang/Checker/PathSensitive/GRSubEngine.h
@@ -43,17 +43,17 @@ public:
 
   /// Called by GRCoreEngine. Used to generate new successor
   /// nodes by processing the 'effects' of a block-level statement.
-  virtual void ProcessStmt(CFGElement E, GRStmtNodeBuilder& builder) = 0;
+  virtual void ProcessStmt(const CFGElement E, GRStmtNodeBuilder& builder) = 0;
 
   /// Called by GRCoreEngine when start processing
   /// a CFGBlock.  This method returns true if the analysis should continue
   /// exploring the given path, and false otherwise.
-  virtual bool ProcessBlockEntrance(CFGBlock* B, const ExplodedNode *Pred,
+  virtual bool ProcessBlockEntrance(const CFGBlock* B, const ExplodedNode *Pred,
                                     GRBlockCounter BC) = 0;
 
   /// Called by GRCoreEngine.  Used to generate successor
   ///  nodes by processing the 'effects' of a branch condition.
-  virtual void ProcessBranch(Stmt* Condition, Stmt* Term,
+  virtual void ProcessBranch(const Stmt* Condition, const Stmt* Term,
                              GRBranchNodeBuilder& builder) = 0;
 
   /// Called by GRCoreEngine.  Used to generate successor
diff --git a/include/clang/Checker/PathSensitive/GRTransferFuncs.h b/include/clang/Checker/PathSensitive/GRTransferFuncs.h
index 374f99820b..320b7f7b8a 100644
--- a/include/clang/Checker/PathSensitive/GRTransferFuncs.h
+++ b/include/clang/Checker/PathSensitive/GRTransferFuncs.h
@@ -42,13 +42,13 @@ public:
   virtual void EvalCall(ExplodedNodeSet& Dst,
                         GRExprEngine& Engine,
                         GRStmtNodeBuilder& Builder,
-                        CallExpr* CE, SVal L,
+                        const CallExpr* CE, SVal L,
                         ExplodedNode* Pred) {}
 
   virtual void EvalObjCMessageExpr(ExplodedNodeSet& Dst,
                                    GRExprEngine& Engine,
                                    GRStmtNodeBuilder& Builder,
-                                   ObjCMessageExpr* ME,
+                                   const ObjCMessageExpr* ME,
                                    ExplodedNode* Pred,
                                    const GRState *state) {}
 
@@ -73,7 +73,7 @@ public:
   virtual void EvalReturn(ExplodedNodeSet& Dst,
                           GRExprEngine& Engine,
                           GRStmtNodeBuilder& Builder,
-                          ReturnStmt* S,
+                          const ReturnStmt* S,
                           ExplodedNode* Pred) {}
 
   // Assumptions.
diff --git a/include/clang/Checker/PathSensitive/GRWorkList.h b/include/clang/Checker/PathSensitive/GRWorkList.h
index b8f90fa1ee..315b614043 100644
--- a/include/clang/Checker/PathSensitive/GRWorkList.h
+++ b/include/clang/Checker/PathSensitive/GRWorkList.h
@@ -27,12 +27,12 @@ class ExplodedNodeImpl;
 class GRWorkListUnit {
   ExplodedNode* Node;
   GRBlockCounter Counter;
-  CFGBlock* Block;
+  const CFGBlock* Block;
   unsigned BlockIdx; // This is the index of the next statement.
 
 public:
   GRWorkListUnit(ExplodedNode* N, GRBlockCounter C,
-                 CFGBlock* B, unsigned idx)
+                 const CFGBlock* B, unsigned idx)
   : Node(N),
     Counter(C),
     Block(B),
@@ -46,7 +46,7 @@ public:
 
   ExplodedNode* getNode()         const { return Node; }
   GRBlockCounter    getBlockCounter() const { return Counter; }
-  CFGBlock*         getBlock()        const { return Block; }
+  const CFGBlock*   getBlock()        const { return Block; }
   unsigned          getIndex()        const { return BlockIdx; }
 };
 
@@ -58,8 +58,8 @@ public:
 
   virtual void Enqueue(const GRWorkListUnit& U) = 0;
 
-  void Enqueue(ExplodedNode* N, CFGBlock& B, unsigned idx) {
-    Enqueue(GRWorkListUnit(N, CurrentCounter, &B, idx));
+  void Enqueue(ExplodedNode* N, const CFGBlock* B, unsigned idx) {
+    Enqueue(GRWorkListUnit(N, CurrentCounter, B, idx));
   }
 
   void Enqueue(ExplodedNode* N) {
diff --git a/include/clang/Checker/PathSensitive/SVals.h b/include/clang/Checker/PathSensitive/SVals.h
index 55fd3ea5c9..cdb338a3f2 100644
--- a/include/clang/Checker/PathSensitive/SVals.h
+++ b/include/clang/Checker/PathSensitive/SVals.h
@@ -45,15 +45,14 @@ public:
   enum { BaseBits = 2, BaseMask = 0x3 };
 
 protected:
-  void* Data;
+  const void* Data;
   unsigned Kind;
 
 protected:
   SVal(const void* d, bool isLoc, unsigned ValKind)
-  : Data(const_cast<void*>(d)),
-    Kind((isLoc ? LocKind : NonLocKind) | (ValKind << BaseBits)) {}
+  : Data(d), Kind((isLoc ? LocKind : NonLocKind) | (ValKind << BaseBits)) {}
 
-  explicit SVal(BaseKind k, void* D = NULL)
+  explicit SVal(BaseKind k, const void* D = NULL)
     : Data(D), Kind(k) {}
 
 public:
@@ -69,7 +68,7 @@ public:
 
   inline void Profile(llvm::FoldingSetNodeID& ID) const {
     ID.AddInteger((unsigned) getRawKind());
-    ID.AddPointer(reinterpret_cast<void*>(Data));
+    ID.AddPointer(Data);
   }
 
   inline bool operator==(const SVal& R) const {
@@ -163,13 +162,13 @@ public:
 class UndefinedVal : public SVal {
 public:
   UndefinedVal() : SVal(UndefinedKind) {}
-  UndefinedVal(void* D) : SVal(UndefinedKind, D) {}
+  UndefinedVal(const void* D) : SVal(UndefinedKind, D) {}
 
   static inline bool classof(const SVal* V) {
     return V->getBaseKind() == UndefinedKind;
   }
 
-  void* getData() const { return Data; }
+  const void* getData() const { return Data; }
 };
 
 class DefinedOrUnknownSVal : public SVal {
@@ -287,7 +286,7 @@ public:
     : NonLoc(SymExprValKind, reinterpret_cast<const void*>(SE)) {}
 
   const SymExpr *getSymbolicExpression() const {
-    return reinterpret_cast<SymExpr*>(Data);
+    return reinterpret_cast<const SymExpr*>(Data);
   }
 
   static inline bool classof(const SVal* V) {
@@ -305,7 +304,7 @@ public:
   ConcreteInt(const llvm::APSInt& V) : NonLoc(ConcreteIntKind, &V) {}
 
   const llvm::APSInt& getValue() const {
-    return *static_cast<llvm::APSInt*>(Data);
+    return *static_cast<const llvm::APSInt*>(Data);
   }
 
   // Transfer functions for binary/unary operations on ConcreteInts.
@@ -368,7 +367,7 @@ class CompoundVal : public NonLoc {
 
 public:
   const CompoundValData* getValue() const {
-    return static_cast<CompoundValData*>(Data);
+    return static_cast<const CompoundValData*>(Data);
   }
 
   typedef llvm::ImmutableList<SVal>::iterator iterator;
@@ -419,8 +418,8 @@ class GotoLabel : public Loc {
 public:
   GotoLabel(LabelStmt* Label) : Loc(GotoLabelKind, Label) {}
 
-  LabelStmt* getLabel() const {
-    return static_cast<LabelStmt*>(Data);
+  const LabelStmt* getLabel() const {
+    return static_cast<const LabelStmt*>(Data);
   }
 
   static inline bool classof(const SVal* V) {
@@ -439,7 +438,7 @@ public:
   MemRegionVal(const MemRegion* r) : Loc(MemRegionKind, r) {}
 
   const MemRegion* getRegion() const {
-    return static_cast<MemRegion*>(Data);
+    return static_cast<const MemRegion*>(Data);
   }
 
   const MemRegion* StripCasts() const;
@@ -473,7 +472,7 @@ public:
   ConcreteInt(const llvm::APSInt& V) : Loc(ConcreteIntKind, &V) {}
 
   const llvm::APSInt& getValue() const {
-    return *static_cast<llvm::APSInt*>(Data);
+    return *static_cast<const llvm::APSInt*>(Data);
   }
 
   // Transfer functions for binary/unary operations on ConcreteInts.
diff --git a/lib/Checker/BugReporter.cpp b/lib/Checker/BugReporter.cpp
index 0422d80ae2..90ae459e64 100644
--- a/lib/Checker/BugReporter.cpp
+++ b/lib/Checker/BugReporter.cpp
@@ -541,9 +541,9 @@ static void GenerateMinimalPathDiagnostic(PathDiagnostic& PD,
     ProgramPoint P = N->getLocation();
 
     if (const BlockEdge* BE = dyn_cast<BlockEdge>(&P)) {
-      CFGBlock* Src = BE->getSrc();
-      C