| //===- ExprEngineCXX.cpp - ExprEngine support for C++ -----------*- 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/StaticAnalyzer/Core/PathSensitive/ExprEngine.h" |
| #include "clang/AST/DeclCXX.h" |
| #include "clang/AST/StmtCXX.h" |
| #include "clang/Basic/PrettyStackTrace.h" |
| #include "clang/StaticAnalyzer/Core/CheckerManager.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h" |
| |
| using namespace clang; |
| using namespace ento; |
| |
| void ExprEngine::CreateCXXTemporaryObject(const MaterializeTemporaryExpr *ME, |
| ExplodedNode *Pred, |
| ExplodedNodeSet &Dst) { |
| StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx); |
| const Expr *tempExpr = ME->GetTemporaryExpr()->IgnoreParens(); |
| ProgramStateRef state = Pred->getState(); |
| const LocationContext *LCtx = Pred->getLocationContext(); |
| |
| SVal V = state->getSVal(tempExpr, LCtx); |
| |
| // If the value is already a CXXTempObjectRegion, it is fine as it is. |
| // Otherwise, create a new CXXTempObjectRegion, and copy the value into it. |
| // This is an optimization for when an rvalue is constructed and then |
| // immediately materialized. |
| const MemRegion *MR = V.getAsRegion(); |
| if (const CXXTempObjectRegion *TR = |
| dyn_cast_or_null<CXXTempObjectRegion>(MR)) { |
| if (getContext().hasSameUnqualifiedType(TR->getValueType(), ME->getType())) |
| state = state->BindExpr(ME, LCtx, V); |
| } |
| |
| if (state == Pred->getState()) |
| state = createTemporaryRegionIfNeeded(state, LCtx, tempExpr, ME); |
| Bldr.generateNode(ME, Pred, state); |
| } |
| |
| void ExprEngine::performTrivialCopy(NodeBuilder &Bldr, ExplodedNode *Pred, |
| const CXXConstructorCall &Call) { |
| const CXXConstructExpr *CtorExpr = Call.getOriginExpr(); |
| assert(CtorExpr->getConstructor()->isCopyOrMoveConstructor()); |
| assert(CtorExpr->getConstructor()->isTrivial()); |
| |
| SVal ThisVal = Call.getCXXThisVal(); |
| const LocationContext *LCtx = Pred->getLocationContext(); |
| |
| ExplodedNodeSet Dst; |
| Bldr.takeNodes(Pred); |
| |
| SVal V = Call.getArgSVal(0); |
| |
| // Make sure the value being copied is not unknown. |
| if (Optional<Loc> L = V.getAs<Loc>()) |
| V = Pred->getState()->getSVal(*L); |
| |
| evalBind(Dst, CtorExpr, Pred, ThisVal, V, true); |
| |
| PostStmt PS(CtorExpr, LCtx); |
| for (ExplodedNodeSet::iterator I = Dst.begin(), E = Dst.end(); |
| I != E; ++I) { |
| ProgramStateRef State = (*I)->getState(); |
| State = bindReturnValue(Call, LCtx, State); |
| Bldr.generateNode(PS, State, *I); |
| } |
| } |
| |
| void ExprEngine::VisitCXXConstructExpr(const CXXConstructExpr *CE, |
| ExplodedNode *Pred, |
| ExplodedNodeSet &destNodes) { |
| const LocationContext *LCtx = Pred->getLocationContext(); |
| ProgramStateRef State = Pred->getState(); |
| |
| const MemRegion *Target = 0; |
| bool IsArray = false; |
| |
| switch (CE->getConstructionKind()) { |
| case CXXConstructExpr::CK_Complete: { |
| // See if we're constructing an existing region by looking at the next |
| // element in the CFG. |
| const CFGBlock *B = currBldrCtx->getBlock(); |
| if (currStmtIdx + 1 < B->size()) { |
| CFGElement Next = (*B)[currStmtIdx+1]; |
| |
| // Is this a constructor for a local variable? |
| if (Optional<CFGStmt> StmtElem = Next.getAs<CFGStmt>()) { |
| if (const DeclStmt *DS = dyn_cast<DeclStmt>(StmtElem->getStmt())) { |
| if (const VarDecl *Var = dyn_cast<VarDecl>(DS->getSingleDecl())) { |
| if (Var->getInit()->IgnoreImplicit() == CE) { |
| QualType Ty = Var->getType(); |
| if (const ArrayType *AT = getContext().getAsArrayType(Ty)) { |
| // FIXME: Handle arrays, which run the same constructor for |
| // every element. This workaround will just run the first |
| // constructor (which should still invalidate the entire array). |
| SVal Base = State->getLValue(Var, LCtx); |
| Target = State->getLValue(AT->getElementType(), |
| getSValBuilder().makeZeroArrayIndex(), |
| Base).getAsRegion(); |
| IsArray = true; |
| } else { |
| Target = State->getLValue(Var, LCtx).getAsRegion(); |
| } |
| } |
| } |
| } |
| } |
| |
| // Is this a constructor for a member? |
| if (Optional<CFGInitializer> InitElem = Next.getAs<CFGInitializer>()) { |
| const CXXCtorInitializer *Init = InitElem->getInitializer(); |
| assert(Init->isAnyMemberInitializer()); |
| |
| const CXXMethodDecl *CurCtor = cast<CXXMethodDecl>(LCtx->getDecl()); |
| Loc ThisPtr = getSValBuilder().getCXXThis(CurCtor, |
| LCtx->getCurrentStackFrame()); |
| SVal ThisVal = State->getSVal(ThisPtr); |
| |
| if (Init->isIndirectMemberInitializer()) { |
| SVal Field = State->getLValue(Init->getIndirectMember(), ThisVal); |
| Target = Field.getAsRegion(); |
| } else { |
| SVal Field = State->getLValue(Init->getMember(), ThisVal); |
| Target = Field.getAsRegion(); |
| } |
| } |
| |
| // FIXME: This will eventually need to handle new-expressions as well. |
| } |
| |
| // If we couldn't find an existing region to construct into, assume we're |
| // constructing a temporary. |
| if (!Target) { |
| MemRegionManager &MRMgr = getSValBuilder().getRegionManager(); |
| Target = MRMgr.getCXXTempObjectRegion(CE, LCtx); |
| } |
| |
| break; |
| } |
| case CXXConstructExpr::CK_NonVirtualBase: |
| case CXXConstructExpr::CK_VirtualBase: |
| case CXXConstructExpr::CK_Delegating: { |
| const CXXMethodDecl *CurCtor = cast<CXXMethodDecl>(LCtx->getDecl()); |
| Loc ThisPtr = getSValBuilder().getCXXThis(CurCtor, |
| LCtx->getCurrentStackFrame()); |
| SVal ThisVal = State->getSVal(ThisPtr); |
| |
| if (CE->getConstructionKind() == CXXConstructExpr::CK_Delegating) { |
| Target = ThisVal.getAsRegion(); |
| } else { |
| // Cast to the base type. |
| bool IsVirtual = |
| (CE->getConstructionKind() == CXXConstructExpr::CK_VirtualBase); |
| SVal BaseVal = getStoreManager().evalDerivedToBase(ThisVal, CE->getType(), |
| IsVirtual); |
| Target = BaseVal.getAsRegion(); |
| } |
| break; |
| } |
| } |
| |
| CallEventManager &CEMgr = getStateManager().getCallEventManager(); |
| CallEventRef<CXXConstructorCall> Call = |
| CEMgr.getCXXConstructorCall(CE, Target, State, LCtx); |
| |
| ExplodedNodeSet DstPreVisit; |
| getCheckerManager().runCheckersForPreStmt(DstPreVisit, Pred, CE, *this); |
| ExplodedNodeSet DstPreCall; |
| getCheckerManager().runCheckersForPreCall(DstPreCall, DstPreVisit, |
| *Call, *this); |
| |
| ExplodedNodeSet DstEvaluated; |
| StmtNodeBuilder Bldr(DstPreCall, DstEvaluated, *currBldrCtx); |
| |
| if (CE->getConstructor()->isTrivial() && |
| CE->getConstructor()->isCopyOrMoveConstructor() && |
| !IsArray) { |
| // FIXME: Handle other kinds of trivial constructors as well. |
| for (ExplodedNodeSet::iterator I = DstPreCall.begin(), E = DstPreCall.end(); |
| I != E; ++I) |
| performTrivialCopy(Bldr, *I, *Call); |
| |
| } else { |
| for (ExplodedNodeSet::iterator I = DstPreCall.begin(), E = DstPreCall.end(); |
| I != E; ++I) |
| defaultEvalCall(Bldr, *I, *Call); |
| } |
| |
| ExplodedNodeSet DstPostCall; |
| getCheckerManager().runCheckersForPostCall(DstPostCall, DstEvaluated, |
| *Call, *this); |
| getCheckerManager().runCheckersForPostStmt(destNodes, DstPostCall, CE, *this); |
| } |
| |
| void ExprEngine::VisitCXXDestructor(QualType ObjectType, |
| const MemRegion *Dest, |
| const Stmt *S, |
| bool IsBaseDtor, |
| ExplodedNode *Pred, |
| ExplodedNodeSet &Dst) { |
| const LocationContext *LCtx = Pred->getLocationContext(); |
| ProgramStateRef State = Pred->getState(); |
| |
| // FIXME: We need to run the same destructor on every element of the array. |
| // This workaround will just run the first destructor (which will still |
| // invalidate the entire array). |
| // This is a loop because of multidimensional arrays. |
| while (const ArrayType *AT = getContext().getAsArrayType(ObjectType)) { |
| ObjectType = AT->getElementType(); |
| Dest = State->getLValue(ObjectType, getSValBuilder().makeZeroArrayIndex(), |
| loc::MemRegionVal(Dest)).getAsRegion(); |
| } |
| |
| const CXXRecordDecl *RecordDecl = ObjectType->getAsCXXRecordDecl(); |
| assert(RecordDecl && "Only CXXRecordDecls should have destructors"); |
| const CXXDestructorDecl *DtorDecl = RecordDecl->getDestructor(); |
| |
| CallEventManager &CEMgr = getStateManager().getCallEventManager(); |
| CallEventRef<CXXDestructorCall> Call = |
| CEMgr.getCXXDestructorCall(DtorDecl, S, Dest, IsBaseDtor, State, LCtx); |
| |
| PrettyStackTraceLoc CrashInfo(getContext().getSourceManager(), |
| Call->getSourceRange().getBegin(), |
| "Error evaluating destructor"); |
| |
| ExplodedNodeSet DstPreCall; |
| getCheckerManager().runCheckersForPreCall(DstPreCall, Pred, |
| *Call, *this); |
| |
| ExplodedNodeSet DstInvalidated; |
| StmtNodeBuilder Bldr(DstPreCall, DstInvalidated, *currBldrCtx); |
| for (ExplodedNodeSet::iterator I = DstPreCall.begin(), E = DstPreCall.end(); |
| I != E; ++I) |
| defaultEvalCall(Bldr, *I, *Call); |
| |
| ExplodedNodeSet DstPostCall; |
| getCheckerManager().runCheckersForPostCall(Dst, DstInvalidated, |
| *Call, *this); |
| } |
| |
| void ExprEngine::VisitCXXNewExpr(const CXXNewExpr *CNE, ExplodedNode *Pred, |
| ExplodedNodeSet &Dst) { |
| // FIXME: Much of this should eventually migrate to CXXAllocatorCall. |
| // Also, we need to decide how allocators actually work -- they're not |
| // really part of the CXXNewExpr because they happen BEFORE the |
| // CXXConstructExpr subexpression. See PR12014 for some discussion. |
| StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx); |
| |
| unsigned blockCount = currBldrCtx->blockCount(); |
| const LocationContext *LCtx = Pred->getLocationContext(); |
| DefinedOrUnknownSVal symVal = svalBuilder.conjureSymbolVal(0, CNE, LCtx, |
| CNE->getType(), |
| blockCount); |
| ProgramStateRef State = Pred->getState(); |
| |
| CallEventManager &CEMgr = getStateManager().getCallEventManager(); |
| CallEventRef<CXXAllocatorCall> Call = |
| CEMgr.getCXXAllocatorCall(CNE, State, LCtx); |
| |
| // Invalidate placement args. |
| // FIXME: Once we figure out how we want allocators to work, |
| // we should be using the usual pre-/(default-)eval-/post-call checks here. |
| State = Call->invalidateRegions(blockCount); |
| |
| // If we're compiling with exceptions enabled, and this allocation function |
| // is not declared as non-throwing, failures /must/ be signalled by |
| // exceptions, and thus the return value will never be NULL. |
| // C++11 [basic.stc.dynamic.allocation]p3. |
| FunctionDecl *FD = CNE->getOperatorNew(); |
| if (FD && getContext().getLangOpts().CXXExceptions) { |
| QualType Ty = FD->getType(); |
| if (const FunctionProtoType *ProtoType = Ty->getAs<FunctionProtoType>()) |
| if (!ProtoType->isNothrow(getContext())) |
| State = State->assume(symVal, true); |
| } |
| |
| if (CNE->isArray()) { |
| // FIXME: allocating an array requires simulating the constructors. |
| // For now, just return a symbolicated region. |
| const MemRegion *NewReg = symVal.castAs<loc::MemRegionVal>().getRegion(); |
| QualType ObjTy = CNE->getType()->getAs<PointerType>()->getPointeeType(); |
| const ElementRegion *EleReg = |
| getStoreManager().GetElementZeroRegion(NewReg, ObjTy); |
| State = State->BindExpr(CNE, Pred->getLocationContext(), |
| loc::MemRegionVal(EleReg)); |
| Bldr.generateNode(CNE, Pred, State); |
| return; |
| } |
| |
| // FIXME: Once we have proper support for CXXConstructExprs inside |
| // CXXNewExpr, we need to make sure that the constructed object is not |
| // immediately invalidated here. (The placement call should happen before |
| // the constructor call anyway.) |
| if (FD && FD->isReservedGlobalPlacementOperator()) { |
| // Non-array placement new should always return the placement location. |
| SVal PlacementLoc = State->getSVal(CNE->getPlacementArg(0), LCtx); |
| SVal Result = svalBuilder.evalCast(PlacementLoc, CNE->getType(), |
| CNE->getPlacementArg(0)->getType()); |
| State = State->BindExpr(CNE, LCtx, Result); |
| } else { |
| State = State->BindExpr(CNE, LCtx, symVal); |
| } |
| |
| // If the type is not a record, we won't have a CXXConstructExpr as an |
| // initializer. Copy the value over. |
| if (const Expr *Init = CNE->getInitializer()) { |
| if (!isa<CXXConstructExpr>(Init)) { |
| QualType ObjTy = CNE->getType()->getAs<PointerType>()->getPointeeType(); |
| (void)ObjTy; |
| assert(!ObjTy->isRecordType()); |
| SVal Location = State->getSVal(CNE, LCtx); |
| if (Optional<Loc> LV = Location.getAs<Loc>()) |
| State = State->bindLoc(*LV, State->getSVal(Init, LCtx)); |
| } |
| } |
| |
| Bldr.generateNode(CNE, Pred, State); |
| } |
| |
| void ExprEngine::VisitCXXDeleteExpr(const CXXDeleteExpr *CDE, |
| ExplodedNode *Pred, ExplodedNodeSet &Dst) { |
| StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx); |
| ProgramStateRef state = Pred->getState(); |
| Bldr.generateNode(CDE, Pred, state); |
| } |
| |
| void ExprEngine::VisitCXXCatchStmt(const CXXCatchStmt *CS, |
| ExplodedNode *Pred, |
| ExplodedNodeSet &Dst) { |
| const VarDecl *VD = CS->getExceptionDecl(); |
| if (!VD) { |
| Dst.Add(Pred); |
| return; |
| } |
| |
| const LocationContext *LCtx = Pred->getLocationContext(); |
| SVal V = svalBuilder.conjureSymbolVal(CS, LCtx, VD->getType(), |
| currBldrCtx->blockCount()); |
| ProgramStateRef state = Pred->getState(); |
| state = state->bindLoc(state->getLValue(VD, LCtx), V); |
| |
| StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx); |
| Bldr.generateNode(CS, Pred, state); |
| } |
| |
| void ExprEngine::VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred, |
| ExplodedNodeSet &Dst) { |
| StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx); |
| |
| // Get the this object region from StoreManager. |
| const LocationContext *LCtx = Pred->getLocationContext(); |
| const MemRegion *R = |
| svalBuilder.getRegionManager().getCXXThisRegion( |
| getContext().getCanonicalType(TE->getType()), |
| LCtx); |
| |
| ProgramStateRef state = Pred->getState(); |
| SVal V = state->getSVal(loc::MemRegionVal(R)); |
| Bldr.generateNode(TE, Pred, state->BindExpr(TE, LCtx, V)); |
| } |