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//===- 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/CheckerManager.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/StmtCXX.h"
using namespace clang;
using namespace ento;
void ExprEngine::CreateCXXTemporaryObject(const MaterializeTemporaryExpr *ME,
ExplodedNode *Pred,
ExplodedNodeSet &Dst) {
StmtNodeBuilder Bldr(Pred, Dst, *currentBuilderContext);
const Expr *tempExpr = ME->GetTemporaryExpr()->IgnoreParens();
ProgramStateRef state = Pred->getState();
const LocationContext *LCtx = Pred->getLocationContext();
// Bind the temporary object to the value of the expression. Then bind
// the expression to the location of the object.
SVal V = state->getSVal(tempExpr, Pred->getLocationContext());
const MemRegion *R =
svalBuilder.getRegionManager().getCXXTempObjectRegion(ME, LCtx);
state = state->bindLoc(loc::MemRegionVal(R), V);
Bldr.generateNode(ME, Pred, state->BindExpr(ME, LCtx, loc::MemRegionVal(R)));
}
void ExprEngine::VisitCXXConstructExpr(const CXXConstructExpr *CE,
ExplodedNode *Pred,
ExplodedNodeSet &destNodes) {
const LocationContext *LCtx = Pred->getLocationContext();
ProgramStateRef State = Pred->getState();
const MemRegion *Target = 0;
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 = currentBuilderContext->getBlock();
if (currentStmtIdx + 1 < B->size()) {
CFGElement Next = (*B)[currentStmtIdx+1];
// Is this a constructor for a local variable?
if (const CFGStmt *StmtElem = dyn_cast<CFGStmt>(&Next)) {
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();
} else {
Target = State->getLValue(Var, LCtx).getAsRegion();
}
}
}
}
}
// Is this a constructor for a member?
if (const CFGInitializer *InitElem = dyn_cast<CFGInitializer>(&Next)) {
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, we'll just
// generate a symbolic region, which is fine.
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.
QualType BaseTy = CE->getType();
SVal BaseVal = getStoreManager().evalDerivedToBase(ThisVal, BaseTy);
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 DstInvalidated;
StmtNodeBuilder Bldr(DstPreCall, DstInvalidated, *currentBuilderContext);
for (ExplodedNodeSet::iterator I = DstPreCall.begin(), E = DstPreCall.end();
I != E; ++I)
defaultEvalCall(Bldr, *I, *Call);
ExplodedNodeSet DstPostCall;
getCheckerManager().runCheckersForPostCall(DstPostCall, DstInvalidated,
*Call, *this);
getCheckerManager().runCheckersForPostStmt(destNodes, DstPostCall, CE, *this);
}
void ExprEngine::VisitCXXDestructor(QualType ObjectType,
const MemRegion *Dest,
const Stmt *S,
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).
if (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, State, LCtx);
ExplodedNodeSet DstPreCall;
getCheckerManager().runCheckersForPreCall(DstPreCall, Pred,
*Call, *this);
ExplodedNodeSet DstInvalidated;
StmtNodeBuilder Bldr(DstPreCall, DstInvalidated, *currentBuilderContext);
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, *currentBuilderContext);
unsigned blockCount = currentBuilderContext->getCurrentBlockCount();
const LocationContext *LCtx = Pred->getLocationContext();
DefinedOrUnknownSVal symVal =
svalBuilder.getConjuredSymbolVal(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 (CNE->isArray()) {
// FIXME: allocating an array requires simulating the constructors.
// For now, just return a symbolicated region.
const MemRegion *NewReg = cast<loc::MemRegionVal>(symVal).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.)
FunctionDecl *FD = CNE->getOperatorNew();
if (FD && FD->isReservedGlobalPlacementOperator()) {
// Non-array placement new should always return the placement location.
SVal PlacementLoc = State->getSVal(CNE->getPlacementArg(0), LCtx);
State = State->BindExpr(CNE, LCtx, PlacementLoc);
} 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 (isa<Loc>(Location))
State = State->bindLoc(cast<Loc>(Location), State->getSVal(Init, LCtx));
}
}
Bldr.generateNode(CNE, Pred, State);
}
void ExprEngine::VisitCXXDeleteExpr(const CXXDeleteExpr *CDE,
ExplodedNode *Pred, ExplodedNodeSet &Dst) {
StmtNodeBuilder Bldr(Pred, Dst, *currentBuilderContext);
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.getConjuredSymbolVal(CS, LCtx, VD->getType(),
currentBuilderContext->getCurrentBlockCount());
ProgramStateRef state = Pred->getState();
state = state->bindLoc(state->getLValue(VD, LCtx), V);
StmtNodeBuilder Bldr(Pred, Dst, *currentBuilderContext);
Bldr.generateNode(CS, Pred, state);
}
void ExprEngine::VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred,
ExplodedNodeSet &Dst) {
StmtNodeBuilder Bldr(Pred, Dst, *currentBuilderContext);
// 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));
}