ExplodedNode*
SwitchNodeBuilder::generateDefaultCaseNode(ProgramStateRef St,
bool IsSink) {
// Get the block for the default case.
assert(Src->succ_rbegin() != Src->succ_rend());
CFGBlock *DefaultBlock = *Src->succ_rbegin();
// Sanity check for default blocks that are unreachable and not caught
// by earlier stages.
if (!DefaultBlock)
return NULL;
bool IsNew;
ExplodedNode *Succ = Eng.G->getNode(BlockEdge(Src, DefaultBlock,
Pred->getLocationContext()), St,
IsSink, &IsNew);
Succ->addPredecessor(Pred, *Eng.G);
if (!IsNew)
return 0;
if (!IsSink)
Eng.WList->enqueue(Succ);
return Succ;
}
void ExprEngine::processCallEnter(NodeBuilderContext& BC, CallEnter CE,
ExplodedNode *Pred) {
// Get the entry block in the CFG of the callee.
const StackFrameContext *calleeCtx = CE.getCalleeContext();
PrettyStackTraceLocationContext CrashInfo(calleeCtx);
const CFGBlock *Entry = CE.getEntry();
// Validate the CFG.
assert(Entry->empty());
assert(Entry->succ_size() == 1);
// Get the solitary successor.
const CFGBlock *Succ = *(Entry->succ_begin());
// Construct an edge representing the starting location in the callee.
BlockEdge Loc(Entry, Succ, calleeCtx);
ProgramStateRef state = Pred->getState();
// Construct a new node, notify checkers that analysis of the function has
// begun, and add the resultant nodes to the worklist.
bool isNew;
ExplodedNode *Node = G.getNode(Loc, state, false, &isNew);
Node->addPredecessor(Pred, G);
if (isNew) {
ExplodedNodeSet DstBegin;
processBeginOfFunction(BC, Node, DstBegin, Loc);
Engine.enqueue(DstBegin);
}
}
void StmtNodeBuilder::GenerateAutoTransition(ExplodedNode *N) {
assert (!N->isSink());
// Check if this node entered a callee.
if (isa<CallEnter>(N->getLocation())) {
// Still use the index of the CallExpr. It's needed to create the callee
// StackFrameContext.
Eng.WList->enqueue(N, &B, Idx);
return;
}
// Do not create extra nodes. Move to the next CFG element.
if (isa<PostInitializer>(N->getLocation())) {
Eng.WList->enqueue(N, &B, Idx+1);
return;
}
PostStmt Loc(getStmt(), N->getLocationContext());
if (Loc == N->getLocation()) {
// Note: 'N' should be a fresh node because otherwise it shouldn't be
// a member of Deferred.
Eng.WList->enqueue(N, &B, Idx+1);
return;
}
bool IsNew;
ExplodedNode *Succ = Eng.G->getNode(Loc, N->State, &IsNew);
Succ->addPredecessor(N, *Eng.G);
if (IsNew)
Eng.WList->enqueue(Succ, &B, Idx+1);
}
ExplodedNode* GRBranchNodeBuilder::generateNode(const GRState* State,
bool branch) {
// If the branch has been marked infeasible we should not generate a node.
if (!isFeasible(branch))
return NULL;
bool IsNew;
ExplodedNode* Succ =
Eng.G->getNode(BlockEdge(Src,branch ? DstT:DstF,Pred->getLocationContext()),
State, &IsNew);
Succ->addPredecessor(Pred, *Eng.G);
if (branch)
GeneratedTrue = true;
else
GeneratedFalse = true;
if (IsNew) {
Deferred.push_back(Succ);
return Succ;
}
return NULL;
}
void ExprEngine::processCallEnter(CallEnter CE, ExplodedNode *Pred) {
// Get the entry block in the CFG of the callee.
const StackFrameContext *calleeCtx = CE.getCalleeContext();
PrettyStackTraceLocationContext CrashInfo(calleeCtx);
const CFG *CalleeCFG = calleeCtx->getCFG();
const CFGBlock *Entry = &(CalleeCFG->getEntry());
// Validate the CFG.
assert(Entry->empty());
assert(Entry->succ_size() == 1);
// Get the solitary successor.
const CFGBlock *Succ = *(Entry->succ_begin());
// Construct an edge representing the starting location in the callee.
BlockEdge Loc(Entry, Succ, calleeCtx);
ProgramStateRef state = Pred->getState();
// Construct a new node and add it to the worklist.
bool isNew;
ExplodedNode *Node = G.getNode(Loc, state, false, &isNew);
Node->addPredecessor(Pred, G);
if (isNew)
Engine.getWorkList()->enqueue(Node);
}
ExplodedNode *CoreEngine::generateCallExitBeginNode(ExplodedNode *N) {
// Create a CallExitBegin node and enqueue it.
const StackFrameContext *LocCtx
= cast<StackFrameContext>(N->getLocationContext());
// Use the the callee location context.
CallExitBegin Loc(LocCtx);
bool isNew;
ExplodedNode *Node = G->getNode(Loc, N->getState(), false, &isNew);
Node->addPredecessor(N, *G);
return isNew ? Node : 0;
}
ExplodedNode*
SwitchNodeBuilder::generateCaseStmtNode(const iterator &I,
ProgramStateRef St) {
bool IsNew;
ExplodedNode *Succ =
Eng.G.getNode(BlockEdge(Src, I.getBlock(), Pred->getLocationContext()),
St, false, &IsNew);
Succ->addPredecessor(Pred, Eng.G);
if (!IsNew)
return nullptr;
Eng.WList->enqueue(Succ);
return Succ;
}
void CallExitNodeBuilder::generateNode(const ProgramState *state) {
// Get the callee's location context.
const StackFrameContext *LocCtx
= cast<StackFrameContext>(Pred->getLocationContext());
// When exiting an implicit automatic obj dtor call, the callsite is the Stmt
// that triggers the dtor.
PostStmt Loc(LocCtx->getCallSite(), LocCtx->getParent());
bool isNew;
ExplodedNode *Node = Eng.G->getNode(Loc, state, &isNew);
Node->addPredecessor(const_cast<ExplodedNode*>(Pred), *Eng.G);
if (isNew)
Eng.WList->enqueue(Node, LocCtx->getCallSiteBlock(),
LocCtx->getIndex() + 1);
}
void ExprEngine::processCallExit(ExplodedNode *Pred) {
ProgramStateRef state = Pred->getState();
const StackFrameContext *calleeCtx =
Pred->getLocationContext()->getCurrentStackFrame();
const LocationContext *callerCtx = calleeCtx->getParent();
const Stmt *CE = calleeCtx->getCallSite();
// If the callee returns an expression, bind its value to CallExpr.
if (const ReturnStmt *RS = getReturnStmt(Pred)) {
const LocationContext *LCtx = Pred->getLocationContext();
SVal V = state->getSVal(RS, LCtx);
state = state->BindExpr(CE, callerCtx, V);
}
// Bind the constructed object value to CXXConstructExpr.
if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(CE)) {
const CXXThisRegion *ThisR =
getCXXThisRegion(CCE->getConstructor()->getParent(), calleeCtx);
SVal ThisV = state->getSVal(ThisR);
// Always bind the region to the CXXConstructExpr.
state = state->BindExpr(CCE, Pred->getLocationContext(), ThisV);
}
static SimpleProgramPointTag returnTag("ExprEngine : Call Return");
PostStmt Loc(CE, callerCtx, &returnTag);
bool isNew;
ExplodedNode *N = G.getNode(Loc, state, false, &isNew);
N->addPredecessor(Pred, G);
if (!isNew)
return;
// Perform the post-condition check of the CallExpr.
ExplodedNodeSet Dst;
NodeBuilderContext Ctx(Engine, calleeCtx->getCallSiteBlock(), N);
SaveAndRestore<const NodeBuilderContext*> NBCSave(currentBuilderContext,
&Ctx);
SaveAndRestore<unsigned> CBISave(currentStmtIdx, calleeCtx->getIndex());
getCheckerManager().runCheckersForPostStmt(Dst, N, CE, *this,
/* wasInlined */ true);
// Enqueue the next element in the block.
for (ExplodedNodeSet::iterator I = Dst.begin(), E = Dst.end(); I != E; ++I) {
Engine.getWorkList()->enqueue(*I,
calleeCtx->getCallSiteBlock(),
calleeCtx->getIndex()+1);
}
}
void CoreEngine::enqueueStmtNode(ExplodedNode *N,
const CFGBlock *Block, unsigned Idx) {
assert(Block);
assert(!N->isSink());
// Check if this node entered a callee.
if (N->getLocation().getAs<CallEnter>()) {
// Still use the index of the CallExpr. It's needed to create the callee
// StackFrameContext.
WList->enqueue(N, Block, Idx);
return;
}
// Do not create extra nodes. Move to the next CFG element.
if (N->getLocation().getAs<PostInitializer>() ||
N->getLocation().getAs<PostImplicitCall>()||
N->getLocation().getAs<LoopExit>()) {
WList->enqueue(N, Block, Idx+1);
return;
}
if (N->getLocation().getAs<EpsilonPoint>()) {
WList->enqueue(N, Block, Idx);
return;
}
if ((*Block)[Idx].getKind() == CFGElement::NewAllocator) {
WList->enqueue(N, Block, Idx+1);
return;
}
// At this point, we know we're processing a normal statement.
CFGStmt CS = (*Block)[Idx].castAs<CFGStmt>();
PostStmt Loc(CS.getStmt(), N->getLocationContext());
if (Loc == N->getLocation().withTag(nullptr)) {
// Note: 'N' should be a fresh node because otherwise it shouldn't be
// a member of Deferred.
WList->enqueue(N, Block, Idx+1);
return;
}
bool IsNew;
ExplodedNode *Succ = G.getNode(Loc, N->getState(), false, &IsNew);
Succ->addPredecessor(N, G);
if (IsNew)
WList->enqueue(Succ, Block, Idx+1);
}
ExplodedNode*
SwitchNodeBuilder::generateCaseStmtNode(const iterator &I,
const ProgramState *St) {
bool IsNew;
ExplodedNode *Succ = Eng.G->getNode(BlockEdge(Src, I.getBlock(),
Pred->getLocationContext()),
St, &IsNew);
Succ->addPredecessor(Pred, *Eng.G);
if (IsNew) {
Eng.WList->enqueue(Succ);
return Succ;
}
return NULL;
}
ExplodedNode*
StmtNodeBuilder::generateNodeInternal(const ProgramPoint &Loc,
const ProgramState *State,
ExplodedNode *Pred) {
bool IsNew;
ExplodedNode *N = Eng.G->getNode(Loc, State, &IsNew);
N->addPredecessor(Pred, *Eng.G);
Deferred.erase(Pred);
if (IsNew) {
Deferred.insert(N);
return N;
}
return NULL;
}
/// GenerateNode - Utility method to generate nodes, hook up successors,
/// and add nodes to the worklist.
void GRCoreEngine::GenerateNode(const ProgramPoint& Loc,
const GRState* State, ExplodedNode* Pred) {
bool IsNew;
ExplodedNode* Node = G->getNode(Loc, State, &IsNew);
if (Pred)
Node->addPredecessor(Pred, *G); // Link 'Node' with its predecessor.
else {
assert (IsNew);
G->addRoot(Node); // 'Node' has no predecessor. Make it a root.
}
// Only add 'Node' to the worklist if it was freshly generated.
if (IsNew) WList->Enqueue(Node);
}
void EndOfFunctionNodeBuilder::GenerateCallExitNode(const ProgramState *state) {
hasGeneratedNode = true;
// Create a CallExit node and enqueue it.
const StackFrameContext *LocCtx
= cast<StackFrameContext>(Pred->getLocationContext());
const Stmt *CE = LocCtx->getCallSite();
// Use the the callee location context.
CallExit Loc(CE, LocCtx);
bool isNew;
ExplodedNode *Node = Eng.G->getNode(Loc, state, &isNew);
Node->addPredecessor(Pred, *Eng.G);
if (isNew)
Eng.WList->enqueue(Node);
}
// This function generate a new ExplodedNode but not a new branch(block edge).
ExplodedNode *BranchNodeBuilder::generateNode(const Stmt *Condition,
const ProgramState *State) {
bool IsNew;
ExplodedNode *Succ
= Eng.G->getNode(PostCondition(Condition, Pred->getLocationContext()), State,
&IsNew);
Succ->addPredecessor(Pred, *Eng.G);
Pred = Succ;
if (IsNew)
return Succ;
return NULL;
}
ExplodedNode* NodeBuilder::generateNodeImpl(const ProgramPoint &Loc,
ProgramStateRef State,
ExplodedNode *FromN,
bool MarkAsSink) {
HasGeneratedNodes = true;
bool IsNew;
ExplodedNode *N = C.Eng.G->getNode(Loc, State, MarkAsSink, &IsNew);
N->addPredecessor(FromN, *C.Eng.G);
Frontier.erase(FromN);
if (!IsNew)
return 0;
if (!MarkAsSink)
Frontier.Add(N);
return N;
}
ExplodedNode*
GREndPathNodeBuilder::generateNode(const GRState* State, const void *tag,
ExplodedNode* P) {
HasGeneratedNode = true;
bool IsNew;
ExplodedNode* Node = Eng.G->getNode(BlockEntrance(&B,
Pred->getLocationContext(), tag), State, &IsNew);
Node->addPredecessor(P ? P : Pred, *Eng.G);
if (IsNew) {
Eng.G->addEndOfPath(Node);
return Node;
}
return NULL;
}
ExplodedNode*
IndirectGotoNodeBuilder::generateNode(const iterator &I,
ProgramStateRef St,
bool IsSink) {
bool IsNew;
ExplodedNode *Succ = Eng.G->getNode(BlockEdge(Src, I.getBlock(),
Pred->getLocationContext()), St,
IsSink, &IsNew);
Succ->addPredecessor(Pred, *Eng.G);
if (!IsNew)
return 0;
if (!IsSink)
Eng.WList->enqueue(Succ);
return Succ;
}
void GRStmtNodeBuilder::GenerateAutoTransition(ExplodedNode* N) {
assert (!N->isSink());
PostStmt Loc(getStmt(), N->getLocationContext());
if (Loc == N->getLocation()) {
// Note: 'N' should be a fresh node because otherwise it shouldn't be
// a member of Deferred.
Eng.WList->Enqueue(N, B, Idx+1);
return;
}
bool IsNew;
ExplodedNode* Succ = Eng.G->getNode(Loc, N->State, &IsNew);
Succ->addPredecessor(N, *Eng.G);
if (IsNew)
Eng.WList->Enqueue(Succ, B, Idx+1);
}
void CoreEngine::enqueueStmtNode(ExplodedNode *N,
const CFGBlock *Block, unsigned Idx) {
assert(Block);
assert (!N->isSink());
// Check if this node entered a callee.
if (isa<CallEnter>(N->getLocation())) {
// Still use the index of the CallExpr. It's needed to create the callee
// StackFrameContext.
WList->enqueue(N, Block, Idx);
return;
}
// Do not create extra nodes. Move to the next CFG element.
if (isa<PostInitializer>(N->getLocation())) {
WList->enqueue(N, Block, Idx+1);
return;
}
if (isa<EpsilonPoint>(N->getLocation())) {
WList->enqueue(N, Block, Idx);
return;
}
const CFGStmt *CS = (*Block)[Idx].getAs<CFGStmt>();
const Stmt *St = CS ? CS->getStmt() : 0;
PostStmt Loc(St, N->getLocationContext());
if (Loc == N->getLocation()) {
// Note: 'N' should be a fresh node because otherwise it shouldn't be
// a member of Deferred.
WList->enqueue(N, Block, Idx+1);
return;
}
bool IsNew;
ExplodedNode *Succ = G->getNode(Loc, N->getState(), false, &IsNew);
Succ->addPredecessor(N, *G);
if (IsNew)
WList->enqueue(Succ, Block, Idx+1);
}
ExplodedNode *
GenericNodeBuilderImpl::generateNodeImpl(const ProgramState *state,
ExplodedNode *pred,
ProgramPoint programPoint,
bool asSink) {
hasGeneratedNode = true;
bool isNew;
ExplodedNode *node = engine.getGraph().getNode(programPoint, state, &isNew);
if (pred)
node->addPredecessor(pred, engine.getGraph());
if (isNew) {
if (asSink) {
node->markAsSink();
sinksGenerated.push_back(node);
}
return node;
}
return 0;
}
ExplodedNode*
EndOfFunctionNodeBuilder::generateNode(const ProgramState *State,
ExplodedNode *P,
const ProgramPointTag *tag) {
hasGeneratedNode = true;
bool IsNew;
ExplodedNode *Node = Eng.G->getNode(BlockEntrance(&B,
Pred->getLocationContext(), tag ? tag : Tag),
State, &IsNew);
Node->addPredecessor(P ? P : Pred, *Eng.G);
if (IsNew) {
Eng.G->addEndOfPath(Node);
return Node;
}
return NULL;
}
ExplodedNode*
GRIndirectGotoNodeBuilder::generateNode(const iterator& I, const GRState* St,
bool isSink) {
bool IsNew;
ExplodedNode* Succ = Eng.G->getNode(BlockEdge(Src, I.getBlock(),
Pred->getLocationContext()), St, &IsNew);
Succ->addPredecessor(Pred, *Eng.G);
if (IsNew) {
if (isSink)
Succ->markAsSink();
else
Eng.WList->Enqueue(Succ);
return Succ;
}
return NULL;
}
void CallInliner::EvalCall(ExplodedNodeSet& Dst, GRExprEngine& Engine,
GRStmtNodeBuilder& Builder, CallExpr* CE, SVal L,
ExplodedNode* Pred) {
FunctionDecl const *FD = L.getAsFunctionDecl();
if (!FD)
return; // GRExprEngine is responsible for the autotransition.
// Make a new LocationContext.
StackFrameContext const *LocCtx =
Engine.getAnalysisManager().getStackFrame(FD, Pred->getLocationContext(), CE);
CFGBlock const *Entry = &(LocCtx->getCFG()->getEntry());
assert (Entry->empty() && "Entry block must be empty.");
assert (Entry->succ_size() == 1 && "Entry block must have 1 successor.");
// Get the solitary successor.
CFGBlock const *SuccB = *(Entry->succ_begin());
// Construct an edge representing the starting location in the function.
BlockEdge Loc(Entry, SuccB, LocCtx);
GRState const *state = Builder.GetState(Pred);
state = Engine.getStoreManager().EnterStackFrame(state, LocCtx);
bool isNew;
ExplodedNode *SuccN = Engine.getGraph().getNode(Loc, state, &isNew);
SuccN->addPredecessor(Pred, Engine.getGraph());
Builder.Deferred.erase(Pred);
// This is a hack. We really should not use the GRStmtNodeBuilder.
if (isNew)
Builder.getWorkList()->Enqueue(SuccN);
Builder.HasGeneratedNode = true;
}
ExplodedNode*
GRSwitchNodeBuilder::generateDefaultCaseNode(const GRState* St, bool isSink) {
// Get the block for the default case.
assert (Src->succ_rbegin() != Src->succ_rend());
CFGBlock* DefaultBlock = *Src->succ_rbegin();
bool IsNew;
ExplodedNode* Succ = Eng.G->getNode(BlockEdge(Src, DefaultBlock,
Pred->getLocationContext()), St, &IsNew);
Succ->addPredecessor(Pred, *Eng.G);
if (IsNew) {
if (isSink)
Succ->markAsSink();
else
Eng.WList->Enqueue(Succ);
return Succ;
}
return NULL;
}
ExplodedGraph*
ExplodedGraph::TrimInternal(const ExplodedNode* const* BeginSources,
const ExplodedNode* const* EndSources,
InterExplodedGraphMap* M,
llvm::DenseMap<const void*, const void*> *InverseMap) const {
typedef llvm::DenseSet<const ExplodedNode*> Pass1Ty;
Pass1Ty Pass1;
typedef llvm::DenseMap<const ExplodedNode*, ExplodedNode*> Pass2Ty;
Pass2Ty& Pass2 = M->M;
SmallVector<const ExplodedNode*, 10> WL1, WL2;
// ===- Pass 1 (reverse DFS) -===
for (const ExplodedNode* const* I = BeginSources; I != EndSources; ++I) {
assert(*I);
WL1.push_back(*I);
}
// Process the first worklist until it is empty. Because it is a std::list
// it acts like a FIFO queue.
while (!WL1.empty()) {
const ExplodedNode *N = WL1.back();
WL1.pop_back();
// Have we already visited this node? If so, continue to the next one.
if (Pass1.count(N))
continue;
// Otherwise, mark this node as visited.
Pass1.insert(N);
// If this is a root enqueue it to the second worklist.
if (N->Preds.empty()) {
WL2.push_back(N);
continue;
}
// Visit our predecessors and enqueue them.
for (ExplodedNode::pred_iterator I = N->Preds.begin(), E = N->Preds.end();
I != E; ++I)
WL1.push_back(*I);
}
// We didn't hit a root? Return with a null pointer for the new graph.
if (WL2.empty())
return 0;
// Create an empty graph.
ExplodedGraph* G = MakeEmptyGraph();
// ===- Pass 2 (forward DFS to construct the new graph) -===
while (!WL2.empty()) {
const ExplodedNode *N = WL2.back();
WL2.pop_back();
// Skip this node if we have already processed it.
if (Pass2.find(N) != Pass2.end())
continue;
// Create the corresponding node in the new graph and record the mapping
// from the old node to the new node.
ExplodedNode *NewN = G->getNode(N->getLocation(), N->State, N->isSink(), 0);
Pass2[N] = NewN;
// Also record the reverse mapping from the new node to the old node.
if (InverseMap) (*InverseMap)[NewN] = N;
// If this node is a root, designate it as such in the graph.
if (N->Preds.empty())
G->addRoot(NewN);
// In the case that some of the intended predecessors of NewN have already
// been created, we should hook them up as predecessors.
// Walk through the predecessors of 'N' and hook up their corresponding
// nodes in the new graph (if any) to the freshly created node.
for (ExplodedNode::pred_iterator I = N->Preds.begin(), E = N->Preds.end();
I != E; ++I) {
Pass2Ty::iterator PI = Pass2.find(*I);
if (PI == Pass2.end())
continue;
NewN->addPredecessor(PI->second, *G);
}
// In the case that some of the intended successors of NewN have already
// been created, we should hook them up as successors. Otherwise, enqueue
// the new nodes from the original graph that should have nodes created
// in the new graph.
for (ExplodedNode::succ_iterator I = N->Succs.begin(), E = N->Succs.end();
I != E; ++I) {
Pass2Ty::iterator PI = Pass2.find(*I);
if (PI != Pass2.end()) {
PI->second->addPredecessor(NewN, *G);
continue;
}
// Enqueue nodes to the worklist that were marked during pass 1.
if (Pass1.count(*I))
WL2.push_back(*I);
}
}
return G;
}
/// The call exit is simulated with a sequence of nodes, which occur between
/// CallExitBegin and CallExitEnd. The following operations occur between the
/// two program points:
/// 1. CallExitBegin (triggers the start of call exit sequence)
/// 2. Bind the return value
/// 3. Run Remove dead bindings to clean up the dead symbols from the callee.
/// 4. CallExitEnd (switch to the caller context)
/// 5. PostStmt<CallExpr>
void ExprEngine::processCallExit(ExplodedNode *CEBNode) {
// Step 1 CEBNode was generated before the call.
PrettyStackTraceLocationContext CrashInfo(CEBNode->getLocationContext());
const StackFrameContext *calleeCtx =
CEBNode->getLocationContext()->getCurrentStackFrame();
// The parent context might not be a stack frame, so make sure we
// look up the first enclosing stack frame.
const StackFrameContext *callerCtx =
calleeCtx->getParent()->getCurrentStackFrame();
const Stmt *CE = calleeCtx->getCallSite();
ProgramStateRef state = CEBNode->getState();
// Find the last statement in the function and the corresponding basic block.
const Stmt *LastSt = nullptr;
const CFGBlock *Blk = nullptr;
std::tie(LastSt, Blk) = getLastStmt(CEBNode);
// Generate a CallEvent /before/ cleaning the state, so that we can get the
// correct value for 'this' (if necessary).
CallEventManager &CEMgr = getStateManager().getCallEventManager();
CallEventRef<> Call = CEMgr.getCaller(calleeCtx, state);
// Step 2: generate node with bound return value: CEBNode -> BindedRetNode.
// If the callee returns an expression, bind its value to CallExpr.
if (CE) {
if (const ReturnStmt *RS = dyn_cast_or_null<ReturnStmt>(LastSt)) {
const LocationContext *LCtx = CEBNode->getLocationContext();
SVal V = state->getSVal(RS, LCtx);
// Ensure that the return type matches the type of the returned Expr.
if (wasDifferentDeclUsedForInlining(Call, calleeCtx)) {
QualType ReturnedTy =
CallEvent::getDeclaredResultType(calleeCtx->getDecl());
if (!ReturnedTy.isNull()) {
if (const Expr *Ex = dyn_cast<Expr>(CE)) {
V = adjustReturnValue(V, Ex->getType(), ReturnedTy,
getStoreManager());
}
}
}
state = state->BindExpr(CE, callerCtx, V);
}
// Bind the constructed object value to CXXConstructExpr.
if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(CE)) {
loc::MemRegionVal This =
svalBuilder.getCXXThis(CCE->getConstructor()->getParent(), calleeCtx);
SVal ThisV = state->getSVal(This);
// If the constructed object is a temporary prvalue, get its bindings.
if (isTemporaryPRValue(CCE, ThisV))
ThisV = state->getSVal(ThisV.castAs<Loc>());
state = state->BindExpr(CCE, callerCtx, ThisV);
}
}
// Step 3: BindedRetNode -> CleanedNodes
// If we can find a statement and a block in the inlined function, run remove
// dead bindings before returning from the call. This is important to ensure
// that we report the issues such as leaks in the stack contexts in which
// they occurred.
ExplodedNodeSet CleanedNodes;
if (LastSt && Blk && AMgr.options.AnalysisPurgeOpt != PurgeNone) {
static SimpleProgramPointTag retValBind("ExprEngine", "Bind Return Value");
PostStmt Loc(LastSt, calleeCtx, &retValBind);
bool isNew;
ExplodedNode *BindedRetNode = G.getNode(Loc, state, false, &isNew);
BindedRetNode->addPredecessor(CEBNode, G);
if (!isNew)
return;
NodeBuilderContext Ctx(getCoreEngine(), Blk, BindedRetNode);
currBldrCtx = &Ctx;
// Here, we call the Symbol Reaper with 0 statement and callee location
// context, telling it to clean up everything in the callee's context
// (and its children). We use the callee's function body as a diagnostic
// statement, with which the program point will be associated.
removeDead(BindedRetNode, CleanedNodes, nullptr, calleeCtx,
calleeCtx->getAnalysisDeclContext()->getBody(),
ProgramPoint::PostStmtPurgeDeadSymbolsKind);
currBldrCtx = nullptr;
} else {
CleanedNodes.Add(CEBNode);
}
for (ExplodedNodeSet::iterator I = CleanedNodes.begin(),
E = CleanedNodes.end(); I != E; ++I) {
// Step 4: Generate the CallExit and leave the callee's context.
// CleanedNodes -> CEENode
CallExitEnd Loc(calleeCtx, callerCtx);
bool isNew;
ProgramStateRef CEEState = (*I == CEBNode) ? state : (*I)->getState();
ExplodedNode *CEENode = G.getNode(Loc, CEEState, false, &isNew);
CEENode->addPredecessor(*I, G);
if (!isNew)
return;
// Step 5: Perform the post-condition check of the CallExpr and enqueue the
// result onto the work list.
// CEENode -> Dst -> WorkList
NodeBuilderContext Ctx(Engine, calleeCtx->getCallSiteBlock(), CEENode);
SaveAndRestore<const NodeBuilderContext*> NBCSave(currBldrCtx,
&Ctx);
SaveAndRestore<unsigned> CBISave(currStmtIdx, calleeCtx->getIndex());
CallEventRef<> UpdatedCall = Call.cloneWithState(CEEState);
ExplodedNodeSet DstPostCall;
getCheckerManager().runCheckersForPostCall(DstPostCall, CEENode,
*UpdatedCall, *this,
/*WasInlined=*/true);
ExplodedNodeSet Dst;
if (const ObjCMethodCall *Msg = dyn_cast<ObjCMethodCall>(Call)) {
getCheckerManager().runCheckersForPostObjCMessage(Dst, DstPostCall, *Msg,
*this,
/*WasInlined=*/true);
} else if (CE) {
getCheckerManager().runCheckersForPostStmt(Dst, DstPostCall, CE,
*this, /*WasInlined=*/true);
} else {
Dst.insert(DstPostCall);
}
// Enqueue the next element in the block.
for (ExplodedNodeSet::iterator PSI = Dst.begin(), PSE = Dst.end();
PSI != PSE; ++PSI) {
Engine.getWorkList()->enqueue(*PSI, calleeCtx->getCallSiteBlock(),
calleeCtx->getIndex()+1);
}
}
}
void CallEnterNodeBuilder::generateNode(const ProgramState *state) {
// Check if the callee is in the same translation unit.
if (CalleeCtx->getTranslationUnit() !=
Pred->getLocationContext()->getTranslationUnit()) {
// Create a new engine. We must be careful that the new engine should not
// reference data structures owned by the old engine.
AnalysisManager &OldMgr = Eng.SubEng.getAnalysisManager();
// Get the callee's translation unit.
idx::TranslationUnit *TU = CalleeCtx->getTranslationUnit();
// Create a new AnalysisManager with components of the callee's
// TranslationUnit.
// The Diagnostic is actually shared when we create ASTUnits from AST files.
AnalysisManager AMgr(TU->getASTContext(), TU->getDiagnostic(),
OldMgr.getLangOptions(),
OldMgr.getPathDiagnosticClient(),
OldMgr.getStoreManagerCreator(),
OldMgr.getConstraintManagerCreator(),
OldMgr.getCheckerManager(),
OldMgr.getIndexer(),
OldMgr.getMaxNodes(), OldMgr.getMaxVisit(),
OldMgr.shouldVisualizeGraphviz(),
OldMgr.shouldVisualizeUbigraph(),
OldMgr.shouldPurgeDead(),
OldMgr.shouldEagerlyAssume(),
OldMgr.shouldTrimGraph(),
OldMgr.shouldInlineCall(),
OldMgr.getAnalysisContextManager().getUseUnoptimizedCFG(),
OldMgr.getAnalysisContextManager().
getCFGBuildOptions().AddImplicitDtors,
OldMgr.getAnalysisContextManager().
getCFGBuildOptions().AddInitializers,
OldMgr.shouldEagerlyTrimExplodedGraph());
// Create the new engine.
// FIXME: This cast isn't really safe.
bool GCEnabled = static_cast<ExprEngine&>(Eng.SubEng).isObjCGCEnabled();
ExprEngine NewEng(AMgr, GCEnabled);
// Create the new LocationContext.
AnalysisContext *NewAnaCtx = AMgr.getAnalysisContext(CalleeCtx->getDecl(),
CalleeCtx->getTranslationUnit());
const StackFrameContext *OldLocCtx = CalleeCtx;
const StackFrameContext *NewLocCtx = AMgr.getStackFrame(NewAnaCtx,
OldLocCtx->getParent(),
OldLocCtx->getCallSite(),
OldLocCtx->getCallSiteBlock(),
OldLocCtx->getIndex());
// Now create an initial state for the new engine.
const ProgramState *NewState =
NewEng.getStateManager().MarshalState(state, NewLocCtx);
ExplodedNodeSet ReturnNodes;
NewEng.ExecuteWorkListWithInitialState(NewLocCtx, AMgr.getMaxNodes(),
NewState, ReturnNodes);
return;
}
// Get the callee entry block.
const CFGBlock *Entry = &(CalleeCtx->getCFG()->getEntry());
assert(Entry->empty());
assert(Entry->succ_size() == 1);
// Get the solitary successor.
const CFGBlock *SuccB = *(Entry->succ_begin());
// Construct an edge representing the starting location in the callee.
BlockEdge Loc(Entry, SuccB, CalleeCtx);
bool isNew;
ExplodedNode *Node = Eng.G->getNode(Loc, state, &isNew);
Node->addPredecessor(const_cast<ExplodedNode*>(Pred), *Eng.G);
if (isNew)
Eng.WList->enqueue(Node);
}
std::unique_ptr<ExplodedGraph>
ExplodedGraph::trim(ArrayRef<const NodeTy *> Sinks,
InterExplodedGraphMap *ForwardMap,
InterExplodedGraphMap *InverseMap) const {
if (Nodes.empty())
return nullptr;
typedef llvm::DenseSet<const ExplodedNode*> Pass1Ty;
Pass1Ty Pass1;
typedef InterExplodedGraphMap Pass2Ty;
InterExplodedGraphMap Pass2Scratch;
Pass2Ty &Pass2 = ForwardMap ? *ForwardMap : Pass2Scratch;
SmallVector<const ExplodedNode*, 10> WL1, WL2;
// ===- Pass 1 (reverse DFS) -===
for (ArrayRef<const NodeTy *>::iterator I = Sinks.begin(), E = Sinks.end();
I != E; ++I) {
if (*I)
WL1.push_back(*I);
}
// Process the first worklist until it is empty.
while (!WL1.empty()) {
const ExplodedNode *N = WL1.pop_back_val();
// Have we already visited this node? If so, continue to the next one.
if (!Pass1.insert(N).second)
continue;
// If this is a root enqueue it to the second worklist.
if (N->Preds.empty()) {
WL2.push_back(N);
continue;
}
// Visit our predecessors and enqueue them.
WL1.append(N->Preds.begin(), N->Preds.end());
}
// We didn't hit a root? Return with a null pointer for the new graph.
if (WL2.empty())
return nullptr;
// Create an empty graph.
std::unique_ptr<ExplodedGraph> G = MakeEmptyGraph();
// ===- Pass 2 (forward DFS to construct the new graph) -===
while (!WL2.empty()) {
const ExplodedNode *N = WL2.pop_back_val();
// Skip this node if we have already processed it.
if (Pass2.find(N) != Pass2.end())
continue;
// Create the corresponding node in the new graph and record the mapping
// from the old node to the new node.
ExplodedNode *NewN = G->createUncachedNode(N->getLocation(), N->State, N->isSink());
Pass2[N] = NewN;
// Also record the reverse mapping from the new node to the old node.
if (InverseMap) (*InverseMap)[NewN] = N;
// If this node is a root, designate it as such in the graph.
if (N->Preds.empty())
G->addRoot(NewN);
// In the case that some of the intended predecessors of NewN have already
// been created, we should hook them up as predecessors.
// Walk through the predecessors of 'N' and hook up their corresponding
// nodes in the new graph (if any) to the freshly created node.
for (ExplodedNode::pred_iterator I = N->Preds.begin(), E = N->Preds.end();
I != E; ++I) {
Pass2Ty::iterator PI = Pass2.find(*I);
if (PI == Pass2.end())
continue;
NewN->addPredecessor(const_cast<ExplodedNode *>(PI->second), *G);
}
// In the case that some of the intended successors of NewN have already
// been created, we should hook them up as successors. Otherwise, enqueue
// the new nodes from the original graph that should have nodes created
// in the new graph.
for (ExplodedNode::succ_iterator I = N->Succs.begin(), E = N->Succs.end();
I != E; ++I) {
Pass2Ty::iterator PI = Pass2.find(*I);
if (PI != Pass2.end()) {
const_cast<ExplodedNode *>(PI->second)->addPredecessor(NewN, *G);
continue;
}
// Enqueue nodes to the worklist that were marked during pass 1.
if (Pass1.count(*I))
WL2.push_back(*I);
}
}
return G;
}
/// The call exit is simulated with a sequence of nodes, which occur between
/// CallExitBegin and CallExitEnd. The following operations occur between the
/// two program points:
/// 1. CallExitBegin (triggers the start of call exit sequence)
/// 2. Bind the return value
/// 3. Run Remove dead bindings to clean up the dead symbols from the callee.
/// 4. CallExitEnd (switch to the caller context)
/// 5. PostStmt<CallExpr>
void ExprEngine::processCallExit(ExplodedNode *CEBNode) {
// Step 1 CEBNode was generated before the call.
const StackFrameContext *calleeCtx =
CEBNode->getLocationContext()->getCurrentStackFrame();
const LocationContext *callerCtx = calleeCtx->getParent();
const Stmt *CE = calleeCtx->getCallSite();
ProgramStateRef state = CEBNode->getState();
// Find the last statement in the function and the corresponding basic block.
const Stmt *LastSt = 0;
const CFGBlock *Blk = 0;
llvm::tie(LastSt, Blk) = getLastStmt(CEBNode);
// Step 2: generate node with binded return value: CEBNode -> BindedRetNode.
// If the callee returns an expression, bind its value to CallExpr.
if (const ReturnStmt *RS = dyn_cast_or_null<ReturnStmt>(LastSt)) {
const LocationContext *LCtx = CEBNode->getLocationContext();
SVal V = state->getSVal(RS, LCtx);
state = state->BindExpr(CE, callerCtx, V);
}
// Bind the constructed object value to CXXConstructExpr.
if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(CE)) {
const CXXThisRegion *ThisR =
getCXXThisRegion(CCE->getConstructor()->getParent(), calleeCtx);
SVal ThisV = state->getSVal(ThisR);
// Always bind the region to the CXXConstructExpr.
state = state->BindExpr(CCE, CEBNode->getLocationContext(), ThisV);
}
static SimpleProgramPointTag retValBindTag("ExprEngine : Bind Return Value");
PostStmt Loc(LastSt, calleeCtx, &retValBindTag);
bool isNew;
ExplodedNode *BindedRetNode = G.getNode(Loc, state, false, &isNew);
BindedRetNode->addPredecessor(CEBNode, G);
if (!isNew)
return;
// Step 3: BindedRetNode -> CleanedNodes
// If we can find a statement and a block in the inlined function, run remove
// dead bindings before returning from the call. This is important to ensure
// that we report the issues such as leaks in the stack contexts in which
// they occurred.
ExplodedNodeSet CleanedNodes;
if (LastSt && Blk) {
NodeBuilderContext Ctx(getCoreEngine(), Blk, BindedRetNode);
currentBuilderContext = &Ctx;
// Here, we call the Symbol Reaper with 0 statement and caller location
// context, telling it to clean up everything in the callee's context
// (and it's children). We use LastStmt as a diagnostic statement, which
// which the PreStmtPurge Dead point will be associated.
removeDead(BindedRetNode, CleanedNodes, 0, callerCtx, LastSt,
ProgramPoint::PostStmtPurgeDeadSymbolsKind);
currentBuilderContext = 0;
}
for (ExplodedNodeSet::iterator I = CleanedNodes.begin(),
E = CleanedNodes.end(); I != E; ++I) {
// Step 4: Generate the CallExit and leave the callee's context.
// CleanedNodes -> CEENode
CallExitEnd Loc(CE, callerCtx);
bool isNew;
ExplodedNode *CEENode = G.getNode(Loc, (*I)->getState(), false, &isNew);
CEENode->addPredecessor(*I, G);
if (!isNew)
return;
// Step 5: Perform the post-condition check of the CallExpr and enqueue the
// result onto the work list.
// CEENode -> Dst -> WorkList
ExplodedNodeSet Dst;
NodeBuilderContext Ctx(Engine, calleeCtx->getCallSiteBlock(), CEENode);
SaveAndRestore<const NodeBuilderContext*> NBCSave(currentBuilderContext,
&Ctx);
SaveAndRestore<unsigned> CBISave(currentStmtIdx, calleeCtx->getIndex());
getCheckerManager().runCheckersForPostStmt(Dst, CEENode, CE, *this, true);
// Enqueue the next element in the block.
for (ExplodedNodeSet::iterator PSI = Dst.begin(), PSE = Dst.end();
PSI != PSE; ++PSI) {
Engine.getWorkList()->enqueue(*PSI, calleeCtx->getCallSiteBlock(),
calleeCtx->getIndex()+1);
}
}
}
