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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/ObjCMessage.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) {
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;
if (FstArgAsLValue) {
FstArgAsLValue = 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));
}
}
void ExprEngine::evalCallee(const CallExpr *callExpr,
const ExplodedNodeSet &src,
ExplodedNodeSet &dest) {
const Expr *callee = 0;
switch (callExpr->getStmtClass()) {
case Stmt::CXXMemberCallExprClass: {
// Evaluate the implicit object argument that is the recipient of the
// call.
callee = cast<CXXMemberCallExpr>(callExpr)->getImplicitObjectArgument();
// FIXME: handle member pointers.
if (!callee)
return;
break;
}
default: {
callee = callExpr->getCallee()->IgnoreParens();
break;
}
}
for (ExplodedNodeSet::iterator i = src.begin(), e = src.end(); i != e; ++i)
Visit(callee, *i, dest);
}
const CXXThisRegion *ExprEngine::getCXXThisRegion(const CXXRecordDecl *D,
const StackFrameContext *SFC) {
const 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 MaterializeTemporaryExpr *ME,
ExplodedNode *Pred,
ExplodedNodeSet &Dst) {
StmtNodeBuilder Bldr(Pred, Dst, *currentBuilderContext);
const Expr *tempExpr = ME->GetTemporaryExpr()->IgnoreParens();
const ProgramState *state = Pred->getState();
// 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);
const MemRegion *R =
svalBuilder.getRegionManager().getCXXTempObjectRegion(ME,
Pred->getLocationContext());
state = state->bindLoc(loc::MemRegionVal(R), V);
Bldr.generateNode(ME, Pred, state->BindExpr(ME, loc::MemRegionVal(R)));
}
void ExprEngine::VisitCXXConstructExpr(const CXXConstructExpr *E,
const MemRegion *Dest,
ExplodedNode *Pred,
ExplodedNodeSet &destNodes) {
const CXXConstructorDecl *CD = E->getConstructor();
assert(CD);
#if 0
if (!(CD->doesThisDeclarationHaveABody() && AMgr.shouldInlineCall()))
// FIXME: invalidate the object.
return;
#endif
// Evaluate other arguments.
ExplodedNodeSet argsEvaluated;
const FunctionProtoType *FnType = CD->getType()->getAs<FunctionProtoType>();
evalArguments(E->arg_begin(), E->arg_end(), FnType, Pred, argsEvaluated);
#if 0
// Is the constructor elidable?
if (E->isElidable()) {
VisitAggExpr(E->getArg(0), destNodes, Pred, Dst);
// FIXME: this is here to force propagation if VisitAggExpr doesn't
if (destNodes.empty())
destNodes.Add(Pred);
return;
}
#endif
// Perform the previsit of the constructor.
ExplodedNodeSet destPreVisit;
getCheckerManager().runCheckersForPreStmt(destPreVisit, argsEvaluated, E,
*this);
// Evaluate the constructor. Currently we don't now allow checker-specific
// implementations of specific constructors (as we do with ordinary
// function calls. We can re-evaluate this in the future.
#if 0
// Inlining currently isn't fully implemented.
if (AMgr.shouldInlineCall()) {
if (!Dest)
Dest =
svalBuilder.getRegionManager().getCXXTempObjectRegion(E,
Pred->getLocationContext());
// The callee stack frame context used to create the 'this'
// parameter region.
const StackFrameContext *SFC =
AMgr.getStackFrame(CD, Pred->getLocationContext(),
E, currentBuilderContext->getBlock(),
currentStmtIdx);
// Create the 'this' region.
const CXXThisRegion *ThisR =
getCXXThisRegion(E->getConstructor()->getParent(), SFC);
CallEnter Loc(E, SFC, Pred->getLocationContext());
StmtNodeBuilder Bldr(argsEvaluated, destNodes, *currentBuilderContext);
for (ExplodedNodeSet::iterator NI = argsEvaluated.begin(),
NE = argsEvaluated.end(); NI != NE; ++NI) {
const ProgramState *state = (*NI)->getState();
// Setup 'this' region, so that the ctor is evaluated on the object pointed
// by 'Dest'.
state = state->bindLoc(loc::MemRegionVal(ThisR), loc::MemRegionVal(Dest));
Bldr.generateNode(Loc, *NI, state);
}
}
#endif
// Default semantics: invalidate all regions passed as arguments.
ExplodedNodeSet destCall;
{
StmtNodeBuilder Bldr(destPreVisit, destCall, *currentBuilderContext);
for (ExplodedNodeSet::iterator
i = destPreVisit.begin(), e = destPreVisit.end();
i != e; ++i)
{
ExplodedNode *Pred = *i;
const LocationContext *LC = Pred->getLocationContext();
const ProgramState *state = Pred->getState();
state = invalidateArguments(state, CallOrObjCMessage(E, state), LC);
Bldr.generateNode(E, Pred, state);
}
}
// Do the post visit.
getCheckerManager().runCheckersForPostStmt(destNodes, destCall, E, *this);
}
void ExprEngine::VisitCXXDestructor(const CXXDestructorDecl *DD,
const MemRegion *Dest,
const Stmt *S,
ExplodedNode *Pred,
ExplodedNodeSet &Dst) {
StmtNodeBuilder Bldr(Pred, Dst, *currentBuilderContext);
if (!(DD->doesThisDeclarationHaveABody() && AMgr.shouldInlineCall()))
return;
// Create the context for 'this' region.
const StackFrameContext *SFC =
AnalysisDeclContexts.getContext(DD)->
getStackFrame(Pred->getLocationContext(), S,
currentBuilderContext->getBlock(), currentStmtIdx);
const CXXThisRegion *ThisR = getCXXThisRegion(DD->getParent(), SFC);
CallEnter PP(S, SFC, Pred->getLocationContext());
const ProgramState *state = Pred->getState();
state = state->bindLoc(loc::MemRegionVal(ThisR), loc::MemRegionVal(Dest));
Bldr.generateNode(PP, Pred, state);
}
void ExprEngine::VisitCXXNewExpr(const CXXNewExpr *CNE, ExplodedNode *Pred,
ExplodedNodeSet &Dst) {
StmtNodeBuilder Bldr(Pred, Dst, *currentBuilderContext);
unsigned blockCount = currentBuilderContext->getCurrentBlockCount();
DefinedOrUnknownSVal symVal =
svalBuilder.getConjuredSymbolVal(NULL, CNE, CNE->getType(), blockCount);
const MemRegion *NewReg = cast<loc::MemRegionVal>(symVal).getRegion();
QualType ObjTy = CNE->getType()->getAs<PointerType>()->getPointeeType();
const ElementRegion *EleReg =
getStoreManager().GetElementZeroRegion(NewReg, ObjTy);
if (CNE->isArray()) {
// FIXME: allocating an array requires simulating the constructors.
// For now, just return a symbolicated region.
const ProgramState *state = Pred->getState();
state = state->BindExpr(CNE, loc::MemRegionVal(EleReg));
Bldr.generateNode(CNE, Pred, state);
return;
}
// Evaluate constructor arguments.
const FunctionProtoType *FnType = NULL;
const CXXConstructorDecl *CD = CNE->getConstructor();
if (CD)
FnType = CD->getType()->getAs<FunctionProtoType>();
ExplodedNodeSet argsEvaluated;
Bldr.takeNodes(Pred);
evalArguments(CNE->constructor_arg_begin(), CNE->constructor_arg_end(),
FnType, Pred, argsEvaluated);
Bldr.addNodes(argsEvaluated);
// Initialize the object region and bind the 'new' expression.
for (ExplodedNodeSet::iterator I = argsEvaluated.begin(),
E = argsEvaluated.end(); I != E; ++I) {
const ProgramState *state = (*I)->getState();
// Accumulate list of regions that are invalidated.
// FIXME: Eventually we should unify the logic for constructor
// processing in one place.
SmallVector<const MemRegion*, 10> regionsToInvalidate;
for (CXXNewExpr::const_arg_iterator
ai = CNE->constructor_arg_begin(), ae = CNE->constructor_arg_end();
ai != ae; ++ai)
{
SVal val = state->getSVal(*ai);
if (const MemRegion *region = val.getAsRegion())
regionsToInvalidate.push_back(region);
}
if (ObjTy->isRecordType()) {
regionsToInvalidate.push_back(EleReg);
// Invalidate the regions.
// TODO: Pass the call to new information as the last argument, to limit
// the globals which will get invalidated.
state = state->invalidateRegions(regionsToInvalidate,
CNE, blockCount, 0, 0);
} else {
// Invalidate the regions.
// TODO: Pass the call to new information as the last argument, to limit
// the globals which will get invalidated.
state = state->invalidateRegions(regionsToInvalidate,
CNE, blockCount, 0, 0);
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));
Bldr.generateNode(CNE, *I, state);
}
}
void ExprEngine::VisitCXXDeleteExpr(const CXXDeleteExpr *CDE,
ExplodedNode *Pred, ExplodedNodeSet &Dst) {
// Should do more checking.
ExplodedNodeSet Argevaluated;
Visit(CDE->getArgument(), Pred, Argevaluated);
StmtNodeBuilder Bldr(Argevaluated, Dst, *currentBuilderContext);
for (ExplodedNodeSet::iterator I = Argevaluated.begin(),
E = Argevaluated.end(); I != E; ++I) {
const ProgramState *state = (*I)->getState();
Bldr.generateNode(CDE, *I, state);
}
}
void ExprEngine::VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred,
ExplodedNodeSet &Dst) {
StmtNodeBuilder Bldr(Pred, Dst, *currentBuilderContext);
// Get the this object region from StoreManager.
const MemRegion *R =
svalBuilder.getRegionManager().getCXXThisRegion(
getContext().getCanonicalType(TE->getType()),
Pred->getLocationContext());
const ProgramState *state = Pred->getState();
SVal V = state->getSVal(loc::MemRegionVal(R));
Bldr.generateNode(TE, Pred, state->BindExpr(TE, V));
}