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//===-- ExprEngine.h - Path-Sensitive Expression-Level Dataflow ---*- 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 a meta-engine for path-sensitive dataflow analysis that
// is built on CoreEngine, but provides the boilerplate to execute transfer
// functions and build the ExplodedGraph at the expression level.
#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/SubEngine.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CoreEngine.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
#include "clang/AST/Type.h"
#include "clang/AST/ExprObjC.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/StmtObjC.h"
namespace clang {
class AnalysisDeclContextManager;
class ObjCForCollectionStmt;
namespace ento {
class AnalysisManager;
class CallOrObjCMessage;
class ObjCMessage;
class ExprEngine : public SubEngine {
AnalysisManager &AMgr;
AnalysisDeclContextManager &AnalysisDeclContexts;
CoreEngine Engine;
/// G - the simulation graph.
ExplodedGraph& G;
/// StateMgr - Object that manages the data for all created states.
ProgramStateManager StateMgr;
/// SymMgr - Object that manages the symbol information.
SymbolManager& SymMgr;
/// svalBuilder - SValBuilder object that creates SVals from expressions.
SValBuilder &svalBuilder;
/// EntryNode - The immediate predecessor node.
ExplodedNode *EntryNode;
/// CleanedState - The state for EntryNode "cleaned" of all dead
/// variables and symbols (as determined by a liveness analysis).
const ProgramState *CleanedState;
/// currentStmt - The current block-level statement.
const Stmt *currentStmt;
unsigned int currentStmtIdx;
const NodeBuilderContext *currentBuilderContext;
/// Obj-C Class Identifiers.
IdentifierInfo* NSExceptionII;
/// Obj-C Selectors.
Selector* NSExceptionInstanceRaiseSelectors;
Selector RaiseSel;
/// Whether or not GC is enabled in this analysis.
bool ObjCGCEnabled;
/// The BugReporter associated with this engine. It is important that
/// this object be placed at the very end of member variables so that its
/// destructor is called before the rest of the ExprEngine is destroyed.
GRBugReporter BR;
ExprEngine(AnalysisManager &mgr, bool gcEnabled);
void ExecuteWorkList(const LocationContext *L, unsigned Steps = 150000) {
Engine.ExecuteWorkList(L, Steps, 0);
/// Execute the work list with an initial state. Nodes that reaches the exit
/// of the function are added into the Dst set, which represent the exit
/// state of the function call.
void ExecuteWorkListWithInitialState(const LocationContext *L, unsigned Steps,
const ProgramState *InitState,
ExplodedNodeSet &Dst) {
Engine.ExecuteWorkListWithInitialState(L, Steps, InitState, Dst);
/// getContext - Return the ASTContext associated with this analysis.
ASTContext &getContext() const { return AMgr.getASTContext(); }
virtual AnalysisManager &getAnalysisManager() { return AMgr; }
CheckerManager &getCheckerManager() const {
return *AMgr.getCheckerManager();
SValBuilder &getSValBuilder() { return svalBuilder; }
BugReporter& getBugReporter() { return BR; }
const NodeBuilderContext &getBuilderContext() {
return *currentBuilderContext;
bool isObjCGCEnabled() { return ObjCGCEnabled; }
const Stmt *getStmt() const;
void GenerateAutoTransition(ExplodedNode *N);
void enqueueEndOfPath(ExplodedNodeSet &S);
void GenerateCallExitNode(ExplodedNode *N);
/// ViewGraph - Visualize the ExplodedGraph created by executing the
/// simulation.
void ViewGraph(bool trim = false);
void ViewGraph(ExplodedNode** Beg, ExplodedNode** End);
/// getInitialState - Return the initial state used for the root vertex
/// in the ExplodedGraph.
const ProgramState *getInitialState(const LocationContext *InitLoc);
ExplodedGraph& getGraph() { return G; }
const ExplodedGraph& getGraph() const { return G; }
/// processCFGElement - Called by CoreEngine. Used to generate new successor
/// nodes by processing the 'effects' of a CFG element.
void processCFGElement(const CFGElement E, ExplodedNode *Pred,
unsigned StmtIdx, NodeBuilderContext *Ctx);
void ProcessStmt(const CFGStmt S, ExplodedNode *Pred);
void ProcessInitializer(const CFGInitializer I, ExplodedNode *Pred);
void ProcessImplicitDtor(const CFGImplicitDtor D, ExplodedNode *Pred);
void ProcessAutomaticObjDtor(const CFGAutomaticObjDtor D,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
void ProcessBaseDtor(const CFGBaseDtor D,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
void ProcessMemberDtor(const CFGMemberDtor D,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
void ProcessTemporaryDtor(const CFGTemporaryDtor D,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
/// Called by CoreEngine when processing the entrance of a CFGBlock.
virtual void processCFGBlockEntrance(NodeBuilderWithSinks &nodeBuilder);
/// ProcessBranch - Called by CoreEngine. Used to generate successor
/// nodes by processing the 'effects' of a branch condition.
void processBranch(const Stmt *Condition, const Stmt *Term,
NodeBuilderContext& BuilderCtx,
ExplodedNode *Pred,
ExplodedNodeSet &Dst,
const CFGBlock *DstT,
const CFGBlock *DstF);
/// processIndirectGoto - Called by CoreEngine. Used to generate successor
/// nodes by processing the 'effects' of a computed goto jump.
void processIndirectGoto(IndirectGotoNodeBuilder& builder);
/// ProcessSwitch - Called by CoreEngine. Used to generate successor
/// nodes by processing the 'effects' of a switch statement.
void processSwitch(SwitchNodeBuilder& builder);
/// ProcessEndPath - Called by CoreEngine. Used to generate end-of-path
/// nodes when the control reaches the end of a function.
void processEndOfFunction(NodeBuilderContext& BC);
/// Generate the entry node of the callee.
void processCallEnter(CallEnterNodeBuilder &builder);
/// Generate the first post callsite node.
void processCallExit(CallExitNodeBuilder &builder);
/// Called by CoreEngine when the analysis worklist has terminated.
void processEndWorklist(bool hasWorkRemaining);
/// evalAssume - Callback function invoked by the ConstraintManager when
/// making assumptions about state values.
const ProgramState *processAssume(const ProgramState *state, SVal cond,bool assumption);
/// wantsRegionChangeUpdate - Called by ProgramStateManager to determine if a
/// region change should trigger a processRegionChanges update.
bool wantsRegionChangeUpdate(const ProgramState *state);
/// processRegionChanges - Called by ProgramStateManager whenever a change is made
/// to the store. Used to update checkers that track region values.
const ProgramState *
processRegionChanges(const ProgramState *state,
const StoreManager::InvalidatedSymbols *invalidated,
ArrayRef<const MemRegion *> ExplicitRegions,
ArrayRef<const MemRegion *> Regions);
/// printState - Called by ProgramStateManager to print checker-specific data.
void printState(raw_ostream &Out, const ProgramState *State,
const char *NL, const char *Sep);
virtual ProgramStateManager& getStateManager() { return StateMgr; }
StoreManager& getStoreManager() { return StateMgr.getStoreManager(); }
ConstraintManager& getConstraintManager() {
return StateMgr.getConstraintManager();
// FIXME: Remove when we migrate over to just using SValBuilder.
BasicValueFactory& getBasicVals() {
return StateMgr.getBasicVals();
const BasicValueFactory& getBasicVals() const {
return StateMgr.getBasicVals();
// FIXME: Remove when we migrate over to just using ValueManager.
SymbolManager& getSymbolManager() { return SymMgr; }
const SymbolManager& getSymbolManager() const { return SymMgr; }
// Functions for external checking of whether we have unfinished work
bool wasBlocksExhausted() const { return Engine.wasBlocksExhausted(); }
bool hasEmptyWorkList() const { return !Engine.getWorkList()->hasWork(); }
bool hasWorkRemaining() const { return Engine.hasWorkRemaining(); }
const CoreEngine &getCoreEngine() const { return Engine; }
/// Visit - Transfer function logic for all statements. Dispatches to
/// other functions that handle specific kinds of statements.
void Visit(const Stmt *S, ExplodedNode *Pred, ExplodedNodeSet &Dst);
/// VisitArraySubscriptExpr - Transfer function for array accesses.
void VisitLvalArraySubscriptExpr(const ArraySubscriptExpr *Ex,
ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitAsmStmt - Transfer function logic for inline asm.
void VisitAsmStmt(const AsmStmt *A, ExplodedNode *Pred, ExplodedNodeSet &Dst);
void VisitAsmStmtHelperOutputs(const AsmStmt *A,
AsmStmt::const_outputs_iterator I,
AsmStmt::const_outputs_iterator E,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
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(const BlockExpr *BE, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitBinaryOperator - Transfer function logic for binary operators.
void VisitBinaryOperator(const BinaryOperator* B, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitCall - Transfer function for function calls.
void VisitCallExpr(const CallExpr *CE, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitCast - Transfer function logic for all casts (implicit and explicit).
void VisitCast(const CastExpr *CastE, const Expr *Ex, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitCompoundLiteralExpr - Transfer function logic for compound literals.
void VisitCompoundLiteralExpr(const CompoundLiteralExpr *CL,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
/// Transfer function logic for DeclRefExprs and BlockDeclRefExprs.
void VisitCommonDeclRefExpr(const Expr *DR, const NamedDecl *D,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
/// VisitDeclStmt - Transfer function logic for DeclStmts.
void VisitDeclStmt(const DeclStmt *DS, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitGuardedExpr - Transfer function logic for ?, __builtin_choose
void VisitGuardedExpr(const Expr *Ex, const Expr *L, const Expr *R,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
void VisitInitListExpr(const InitListExpr *E, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitLogicalExpr - Transfer function logic for '&&', '||'
void VisitLogicalExpr(const BinaryOperator* B, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitMemberExpr - Transfer function for member expressions.
void VisitMemberExpr(const MemberExpr *M, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// Transfer function logic for ObjCAtSynchronizedStmts.
void VisitObjCAtSynchronizedStmt(const ObjCAtSynchronizedStmt *S,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
/// Transfer function logic for computing the lvalue of an Objective-C ivar.
void VisitLvalObjCIvarRefExpr(const ObjCIvarRefExpr *DR, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitObjCForCollectionStmt - Transfer function logic for
/// ObjCForCollectionStmt.
void VisitObjCForCollectionStmt(const ObjCForCollectionStmt *S,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
void VisitObjCMessage(const ObjCMessage &msg, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitReturnStmt - Transfer function logic for return statements.
void VisitReturnStmt(const ReturnStmt *R, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitOffsetOfExpr - Transfer function for offsetof.
void VisitOffsetOfExpr(const OffsetOfExpr *Ex, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitUnaryExprOrTypeTraitExpr - Transfer function for sizeof.
void VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *Ex,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
/// VisitUnaryOperator - Transfer function logic for unary operators.
void VisitUnaryOperator(const UnaryOperator* B, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// Handle ++ and -- (both pre- and post-increment).
void VisitIncrementDecrementOperator(const UnaryOperator* U,
ExplodedNode *Pred,
ExplodedNodeSet &Dst);
void VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred,
ExplodedNodeSet & Dst);
void VisitCXXTemporaryObjectExpr(const CXXTemporaryObjectExpr *expr,
ExplodedNode *Pred, ExplodedNodeSet &Dst) {
VisitCXXConstructExpr(expr, 0, Pred, Dst);
void VisitCXXConstructExpr(const CXXConstructExpr *E, const MemRegion *Dest,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
void VisitCXXDestructor(const CXXDestructorDecl *DD,
const MemRegion *Dest, const Stmt *S,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
void VisitCXXNewExpr(const CXXNewExpr *CNE, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
void VisitCXXDeleteExpr(const CXXDeleteExpr *CDE, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
void VisitAggExpr(const Expr *E, const MemRegion *Dest, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// Create a C++ temporary object for an rvalue.
void CreateCXXTemporaryObject(const MaterializeTemporaryExpr *ME,
ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// Synthesize CXXThisRegion.
const CXXThisRegion *getCXXThisRegion(const CXXRecordDecl *RD,
const StackFrameContext *SFC);
const CXXThisRegion *getCXXThisRegion(const CXXMethodDecl *decl,
const StackFrameContext *frameCtx);
/// Evaluate arguments with a work list algorithm.
void evalArguments(ConstExprIterator AI, ConstExprIterator AE,
const FunctionProtoType *FnType,
ExplodedNode *Pred, ExplodedNodeSet &Dst,
bool FstArgAsLValue = false);
/// Evaluate callee expression (for a function call).
void evalCallee(const CallExpr *callExpr, const ExplodedNodeSet &src,
ExplodedNodeSet &dest);
/// 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,
const Expr *Ex);
std::pair<const ProgramPointTag *, const ProgramPointTag*>
SVal evalMinus(SVal X) {
return X.isValid() ? svalBuilder.evalMinus(cast<NonLoc>(X)) : X;
SVal evalComplement(SVal X) {
return X.isValid() ? svalBuilder.evalComplement(cast<NonLoc>(X)) : X;
SVal evalBinOp(const ProgramState *state, BinaryOperator::Opcode op,
NonLoc L, NonLoc R, QualType T) {
return svalBuilder.evalBinOpNN(state, op, L, R, T);
SVal evalBinOp(const ProgramState *state, BinaryOperator::Opcode op,
NonLoc L, SVal R, QualType T) {
return R.isValid() ? svalBuilder.evalBinOpNN(state,op,L, cast<NonLoc>(R), T) : R;
SVal evalBinOp(const ProgramState *ST, BinaryOperator::Opcode Op,
SVal LHS, SVal RHS, QualType T) {
return svalBuilder.evalBinOp(ST, Op, LHS, RHS, T);
void evalObjCMessage(StmtNodeBuilder &Bldr, const ObjCMessage &msg,
ExplodedNode *Pred, const ProgramState *state,
bool GenSink);
const ProgramState *invalidateArguments(const ProgramState *State,
const CallOrObjCMessage &Call,
const LocationContext *LC);
const ProgramState *MarkBranch(const ProgramState *St, const Stmt *Terminator,
bool branchTaken);
/// evalBind - Handle the semantics of binding a value to a specific location.
/// This method is used by evalStore, VisitDeclStmt, and others.
void evalBind(ExplodedNodeSet &Dst, const Stmt *StoreE, ExplodedNode *Pred,
SVal location, SVal Val, bool atDeclInit = false,
ProgramPoint::Kind PP = ProgramPoint::PostStmtKind);
// FIXME: 'tag' should be removed, and a LocationContext should be used
// instead.
// FIXME: Comment on the meaning of the arguments, when 'St' may not
// be the same as Pred->state, and when 'location' may not be the
// same as state->getLValue(Ex).
/// Simulate a read of the result of Ex.
void evalLoad(ExplodedNodeSet &Dst, const Expr *Ex, ExplodedNode *Pred,
const ProgramState *St, SVal location, const ProgramPointTag *tag = 0,
QualType LoadTy = QualType());
// FIXME: 'tag' should be removed, and a LocationContext should be used
// instead.
void evalStore(ExplodedNodeSet &Dst, const Expr *AssignE, const Expr *StoreE,
ExplodedNode *Pred, const ProgramState *St, SVal TargetLV, SVal Val,
const ProgramPointTag *tag = 0);
void evalLoadCommon(ExplodedNodeSet &Dst, const Expr *Ex, ExplodedNode *Pred,
const ProgramState *St, SVal location, const ProgramPointTag *tag,
QualType LoadTy);
// FIXME: 'tag' should be removed, and a LocationContext should be used
// instead.
void evalLocation(ExplodedNodeSet &Dst, const Stmt *S, ExplodedNode *Pred,
const ProgramState *St, SVal location,
const ProgramPointTag *tag, bool isLoad);
bool InlineCall(ExplodedNodeSet &Dst, const CallExpr *CE, ExplodedNode *Pred);
/// Returns true if calling the specific function or method would possibly
/// cause global variables to be invalidated.
bool doesInvalidateGlobals(const CallOrObjCMessage &callOrMessage) const;
} // end ento namespace
} // end clang namespace