| //===- GRCXXExprEngine.cpp - C++ expr evaluation engine ---------*- 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 C++ expression evaluation engine. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "clang/GR/PathSensitive/AnalysisManager.h" |
| #include "clang/GR/PathSensitive/ExprEngine.h" |
| #include "clang/AST/DeclCXX.h" |
| |
| using namespace clang; |
| using namespace ento; |
| |
| namespace { |
| class CallExprWLItem { |
| public: |
| CallExpr::const_arg_iterator I; |
| ExplodedNode *N; |
| |
| CallExprWLItem(const CallExpr::const_arg_iterator &i, ExplodedNode *n) |
| : I(i), N(n) {} |
| }; |
| } |
| |
| void ExprEngine::evalArguments(ConstExprIterator AI, ConstExprIterator AE, |
| const FunctionProtoType *FnType, |
| ExplodedNode *Pred, ExplodedNodeSet &Dst, |
| bool FstArgAsLValue) { |
| |
| |
| llvm::SmallVector<CallExprWLItem, 20> WorkList; |
| WorkList.reserve(AE - AI); |
| WorkList.push_back(CallExprWLItem(AI, Pred)); |
| |
| while (!WorkList.empty()) { |
| CallExprWLItem Item = WorkList.back(); |
| WorkList.pop_back(); |
| |
| if (Item.I == AE) { |
| Dst.insert(Item.N); |
| continue; |
| } |
| |
| // Evaluate the argument. |
| ExplodedNodeSet Tmp; |
| bool VisitAsLvalue = FstArgAsLValue; |
| if (FstArgAsLValue) { |
| FstArgAsLValue = false; |
| } else { |
| const unsigned ParamIdx = Item.I - AI; |
| VisitAsLvalue = FnType && ParamIdx < FnType->getNumArgs() |
| ? FnType->getArgType(ParamIdx)->isReferenceType() |
| : false; |
| } |
| |
| Visit(*Item.I, Item.N, Tmp); |
| ++(Item.I); |
| for (ExplodedNodeSet::iterator NI=Tmp.begin(), NE=Tmp.end(); NI != NE; ++NI) |
| WorkList.push_back(CallExprWLItem(Item.I, *NI)); |
| } |
| } |
| |
| const CXXThisRegion *ExprEngine::getCXXThisRegion(const CXXRecordDecl *D, |
| const StackFrameContext *SFC) { |
| Type *T = D->getTypeForDecl(); |
| QualType PT = getContext().getPointerType(QualType(T, 0)); |
| return svalBuilder.getRegionManager().getCXXThisRegion(PT, SFC); |
| } |
| |
| const CXXThisRegion *ExprEngine::getCXXThisRegion(const CXXMethodDecl *decl, |
| const StackFrameContext *frameCtx) { |
| return svalBuilder.getRegionManager(). |
| getCXXThisRegion(decl->getThisType(getContext()), frameCtx); |
| } |
| |
| void ExprEngine::CreateCXXTemporaryObject(const Expr *Ex, ExplodedNode *Pred, |
| ExplodedNodeSet &Dst) { |
| ExplodedNodeSet Tmp; |
| Visit(Ex, Pred, Tmp); |
| for (ExplodedNodeSet::iterator I = Tmp.begin(), E = Tmp.end(); I != E; ++I) { |
| const GRState *state = GetState(*I); |
| |
| // Bind the temporary object to the value of the expression. Then bind |
| // the expression to the location of the object. |
| SVal V = state->getSVal(Ex); |
| |
| const MemRegion *R = |
| svalBuilder.getRegionManager().getCXXTempObjectRegion(Ex, |
| Pred->getLocationContext()); |
| |
| state = state->bindLoc(loc::MemRegionVal(R), V); |
| MakeNode(Dst, Ex, Pred, state->BindExpr(Ex, loc::MemRegionVal(R))); |
| } |
| } |
| |
| void ExprEngine::VisitCXXConstructExpr(const CXXConstructExpr *E, |
| const MemRegion *Dest, |
| ExplodedNode *Pred, |
| ExplodedNodeSet &Dst) { |
| if (!Dest) |
| Dest = svalBuilder.getRegionManager().getCXXTempObjectRegion(E, |
| Pred->getLocationContext()); |
| |
| if (E->isElidable()) { |
| VisitAggExpr(E->getArg(0), Dest, Pred, Dst); |
| return; |
| } |
| |
| const CXXConstructorDecl *CD = E->getConstructor(); |
| assert(CD); |
| |
| if (!(CD->isThisDeclarationADefinition() && AMgr.shouldInlineCall())) |
| // FIXME: invalidate the object. |
| return; |
| |
| |
| // Evaluate other arguments. |
| ExplodedNodeSet argsEvaluated; |
| const FunctionProtoType *FnType = CD->getType()->getAs<FunctionProtoType>(); |
| evalArguments(E->arg_begin(), E->arg_end(), FnType, Pred, argsEvaluated); |
| // The callee stack frame context used to create the 'this' parameter region. |
| const StackFrameContext *SFC = AMgr.getStackFrame(CD, |
| Pred->getLocationContext(), |
| E, Builder->getBlock(), |
| Builder->getIndex()); |
| |
| const CXXThisRegion *ThisR =getCXXThisRegion(E->getConstructor()->getParent(), |
| SFC); |
| |
| CallEnter Loc(E, SFC, Pred->getLocationContext()); |
| for (ExplodedNodeSet::iterator NI = argsEvaluated.begin(), |
| NE = argsEvaluated.end(); NI != NE; ++NI) { |
| const GRState *state = GetState(*NI); |
| // Setup 'this' region, so that the ctor is evaluated on the object pointed |
| // by 'Dest'. |
| state = state->bindLoc(loc::MemRegionVal(ThisR), loc::MemRegionVal(Dest)); |
| ExplodedNode *N = Builder->generateNode(Loc, state, Pred); |
| if (N) |
| Dst.Add(N); |
| } |
| } |
| |
| void ExprEngine::VisitCXXDestructor(const CXXDestructorDecl *DD, |
| const MemRegion *Dest, |
| const Stmt *S, |
| ExplodedNode *Pred, |
| ExplodedNodeSet &Dst) { |
| if (!(DD->isThisDeclarationADefinition() && AMgr.shouldInlineCall())) |
| return; |
| // Create the context for 'this' region. |
| const StackFrameContext *SFC = AMgr.getStackFrame(DD, |
| Pred->getLocationContext(), |
| S, Builder->getBlock(), |
| Builder->getIndex()); |
| |
| const CXXThisRegion *ThisR = getCXXThisRegion(DD->getParent(), SFC); |
| |
| CallEnter PP(S, SFC, Pred->getLocationContext()); |
| |
| const GRState *state = Pred->getState(); |
| state = state->bindLoc(loc::MemRegionVal(ThisR), loc::MemRegionVal(Dest)); |
| ExplodedNode *N = Builder->generateNode(PP, state, Pred); |
| if (N) |
| Dst.Add(N); |
| } |
| |
| void ExprEngine::VisitCXXMemberCallExpr(const CXXMemberCallExpr *MCE, |
| ExplodedNode *Pred, |
| ExplodedNodeSet &Dst) { |
| // Get the method type. |
| const FunctionProtoType *FnType = |
| MCE->getCallee()->getType()->getAs<FunctionProtoType>(); |
| assert(FnType && "Method type not available"); |
| |
| // Evaluate explicit arguments with a worklist. |
| ExplodedNodeSet argsEvaluated; |
| evalArguments(MCE->arg_begin(), MCE->arg_end(), FnType, Pred, argsEvaluated); |
| |
| // Evaluate the implicit object argument. |
| ExplodedNodeSet AllargsEvaluated; |
| const MemberExpr *ME = dyn_cast<MemberExpr>(MCE->getCallee()->IgnoreParens()); |
| if (!ME) |
| return; |
| Expr *ObjArgExpr = ME->getBase(); |
| for (ExplodedNodeSet::iterator I = argsEvaluated.begin(), |
| E = argsEvaluated.end(); I != E; ++I) { |
| Visit(ObjArgExpr, *I, AllargsEvaluated); |
| } |
| |
| // Now evaluate the call itself. |
| const CXXMethodDecl *MD = cast<CXXMethodDecl>(ME->getMemberDecl()); |
| assert(MD && "not a CXXMethodDecl?"); |
| evalMethodCall(MCE, MD, ObjArgExpr, Pred, AllargsEvaluated, Dst); |
| } |
| |
| void ExprEngine::VisitCXXOperatorCallExpr(const CXXOperatorCallExpr *C, |
| ExplodedNode *Pred, |
| ExplodedNodeSet &Dst) { |
| const CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(C->getCalleeDecl()); |
| if (!MD) { |
| // If the operator doesn't represent a method call treat as regural call. |
| VisitCall(C, Pred, C->arg_begin(), C->arg_end(), Dst); |
| return; |
| } |
| |
| // Determine the type of function we're calling (if available). |
| const FunctionProtoType *Proto = NULL; |
| QualType FnType = C->getCallee()->IgnoreParens()->getType(); |
| if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) |
| Proto = FnTypePtr->getPointeeType()->getAs<FunctionProtoType>(); |
| |
| // Evaluate arguments treating the first one (object method is called on) |
| // as alvalue. |
| ExplodedNodeSet argsEvaluated; |
| evalArguments(C->arg_begin(), C->arg_end(), Proto, Pred, argsEvaluated, true); |
| |
| // Now evaluate the call itself. |
| evalMethodCall(C, MD, C->getArg(0), Pred, argsEvaluated, Dst); |
| } |
| |
| void ExprEngine::evalMethodCall(const CallExpr *MCE, const CXXMethodDecl *MD, |
| const Expr *ThisExpr, ExplodedNode *Pred, |
| ExplodedNodeSet &Src, ExplodedNodeSet &Dst) { |
| // Allow checkers to pre-visit the member call. |
| ExplodedNodeSet PreVisitChecks; |
| CheckerVisit(MCE, PreVisitChecks, Src, PreVisitStmtCallback); |
| |
| if (!(MD->isThisDeclarationADefinition() && AMgr.shouldInlineCall())) { |
| // FIXME: conservative method call evaluation. |
| CheckerVisit(MCE, Dst, PreVisitChecks, PostVisitStmtCallback); |
| return; |
| } |
| |
| const StackFrameContext *SFC = AMgr.getStackFrame(MD, |
| Pred->getLocationContext(), |
| MCE, |
| Builder->getBlock(), |
| Builder->getIndex()); |
| const CXXThisRegion *ThisR = getCXXThisRegion(MD, SFC); |
| CallEnter Loc(MCE, SFC, Pred->getLocationContext()); |
| for (ExplodedNodeSet::iterator I = PreVisitChecks.begin(), |
| E = PreVisitChecks.end(); I != E; ++I) { |
| // Set up 'this' region. |
| const GRState *state = GetState(*I); |
| state = state->bindLoc(loc::MemRegionVal(ThisR), state->getSVal(ThisExpr)); |
| Dst.Add(Builder->generateNode(Loc, state, *I)); |
| } |
| } |
| |
| void ExprEngine::VisitCXXNewExpr(const CXXNewExpr *CNE, ExplodedNode *Pred, |
| ExplodedNodeSet &Dst) { |
| if (CNE->isArray()) { |
| // FIXME: allocating an array has not been handled. |
| return; |
| } |
| |
| unsigned Count = Builder->getCurrentBlockCount(); |
| DefinedOrUnknownSVal symVal = |
| svalBuilder.getConjuredSymbolVal(NULL, CNE, CNE->getType(), Count); |
| const MemRegion *NewReg = cast<loc::MemRegionVal>(symVal).getRegion(); |
| |
| QualType ObjTy = CNE->getType()->getAs<PointerType>()->getPointeeType(); |
| |
| const ElementRegion *EleReg = |
| getStoreManager().GetElementZeroRegion(NewReg, ObjTy); |
| |
| // Evaluate constructor arguments. |
| const FunctionProtoType *FnType = NULL; |
| const CXXConstructorDecl *CD = CNE->getConstructor(); |
| if (CD) |
| FnType = CD->getType()->getAs<FunctionProtoType>(); |
| ExplodedNodeSet argsEvaluated; |
| evalArguments(CNE->constructor_arg_begin(), CNE->constructor_arg_end(), |
| FnType, Pred, argsEvaluated); |
| |
| // Initialize the object region and bind the 'new' expression. |
| for (ExplodedNodeSet::iterator I = argsEvaluated.begin(), |
| E = argsEvaluated.end(); I != E; ++I) { |
| const GRState *state = GetState(*I); |
| |
| if (ObjTy->isRecordType()) { |
| state = state->InvalidateRegion(EleReg, CNE, Count); |
| } else { |
| if (CNE->hasInitializer()) { |
| SVal V = state->getSVal(*CNE->constructor_arg_begin()); |
| state = state->bindLoc(loc::MemRegionVal(EleReg), V); |
| } else { |
| // Explicitly set to undefined, because currently we retrieve symbolic |
| // value from symbolic region. |
| state = state->bindLoc(loc::MemRegionVal(EleReg), UndefinedVal()); |
| } |
| } |
| state = state->BindExpr(CNE, loc::MemRegionVal(EleReg)); |
| MakeNode(Dst, CNE, *I, state); |
| } |
| } |
| |
| void ExprEngine::VisitCXXDeleteExpr(const CXXDeleteExpr *CDE, |
| ExplodedNode *Pred,ExplodedNodeSet &Dst) { |
| // Should do more checking. |
| ExplodedNodeSet Argevaluated; |
| Visit(CDE->getArgument(), Pred, Argevaluated); |
| for (ExplodedNodeSet::iterator I = Argevaluated.begin(), |
| E = Argevaluated.end(); I != E; ++I) { |
| const GRState *state = GetState(*I); |
| MakeNode(Dst, CDE, *I, state); |
| } |
| } |
| |
| void ExprEngine::VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred, |
| ExplodedNodeSet &Dst) { |
| // Get the this object region from StoreManager. |
| const MemRegion *R = |
| svalBuilder.getRegionManager().getCXXThisRegion( |
| getContext().getCanonicalType(TE->getType()), |
| Pred->getLocationContext()); |
| |
| const GRState *state = GetState(Pred); |
| SVal V = state->getSVal(loc::MemRegionVal(R)); |
| MakeNode(Dst, TE, Pred, state->BindExpr(TE, V)); |
| } |