Chris Lattner has strong opinions about directory
layout. :)
Rename the 'EntoSA' directories to 'StaticAnalyzer'.
Internally we will still use the 'ento' namespace
for the analyzer engine (unless there are further
sabre rattlings...).
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@122514 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/StaticAnalyzer/BugReporterVisitors.cpp b/lib/StaticAnalyzer/BugReporterVisitors.cpp
new file mode 100644
index 0000000..91d7275
--- /dev/null
+++ b/lib/StaticAnalyzer/BugReporterVisitors.cpp
@@ -0,0 +1,457 @@
+// BugReporterVisitors.cpp - Helpers for reporting bugs -----------*- 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 a set of BugReporter "visitors" which can be used to
+// enhance the diagnostics reported for a bug.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/AST/Expr.h"
+#include "clang/AST/ExprObjC.h"
+#include "clang/StaticAnalyzer/BugReporter/BugReporter.h"
+#include "clang/StaticAnalyzer/BugReporter/PathDiagnostic.h"
+#include "clang/StaticAnalyzer/PathSensitive/ExplodedGraph.h"
+#include "clang/StaticAnalyzer/PathSensitive/GRState.h"
+
+using namespace clang;
+using namespace ento;
+
+//===----------------------------------------------------------------------===//
+// Utility functions.
+//===----------------------------------------------------------------------===//
+
+const Stmt *bugreporter::GetDerefExpr(const ExplodedNode *N) {
+ // Pattern match for a few useful cases (do something smarter later):
+ // a[0], p->f, *p
+ const Stmt *S = N->getLocationAs<PostStmt>()->getStmt();
+
+ if (const UnaryOperator *U = dyn_cast<UnaryOperator>(S)) {
+ if (U->getOpcode() == UO_Deref)
+ return U->getSubExpr()->IgnoreParenCasts();
+ }
+ else if (const MemberExpr *ME = dyn_cast<MemberExpr>(S)) {
+ return ME->getBase()->IgnoreParenCasts();
+ }
+ else if (const ArraySubscriptExpr *AE = dyn_cast<ArraySubscriptExpr>(S)) {
+ // Retrieve the base for arrays since BasicStoreManager doesn't know how
+ // to reason about them.
+ return AE->getBase();
+ }
+
+ return NULL;
+}
+
+const Stmt *bugreporter::GetDenomExpr(const ExplodedNode *N) {
+ const Stmt *S = N->getLocationAs<PreStmt>()->getStmt();
+ if (const BinaryOperator *BE = dyn_cast<BinaryOperator>(S))
+ return BE->getRHS();
+ return NULL;
+}
+
+const Stmt *bugreporter::GetCalleeExpr(const ExplodedNode *N) {
+ // Callee is checked as a PreVisit to the CallExpr.
+ const Stmt *S = N->getLocationAs<PreStmt>()->getStmt();
+ if (const CallExpr *CE = dyn_cast<CallExpr>(S))
+ return CE->getCallee();
+ return NULL;
+}
+
+const Stmt *bugreporter::GetRetValExpr(const ExplodedNode *N) {
+ const Stmt *S = N->getLocationAs<PostStmt>()->getStmt();
+ if (const ReturnStmt *RS = dyn_cast<ReturnStmt>(S))
+ return RS->getRetValue();
+ return NULL;
+}
+
+//===----------------------------------------------------------------------===//
+// Definitions for bug reporter visitors.
+//===----------------------------------------------------------------------===//
+
+namespace {
+class FindLastStoreBRVisitor : public BugReporterVisitor {
+ const MemRegion *R;
+ SVal V;
+ bool satisfied;
+ const ExplodedNode *StoreSite;
+public:
+ FindLastStoreBRVisitor(SVal v, const MemRegion *r)
+ : R(r), V(v), satisfied(false), StoreSite(0) {}
+
+ virtual void Profile(llvm::FoldingSetNodeID &ID) const {
+ static int tag = 0;
+ ID.AddPointer(&tag);
+ ID.AddPointer(R);
+ ID.Add(V);
+ }
+
+ PathDiagnosticPiece* VisitNode(const ExplodedNode *N,
+ const ExplodedNode *PrevN,
+ BugReporterContext& BRC) {
+
+ if (satisfied)
+ return NULL;
+
+ if (!StoreSite) {
+ const ExplodedNode *Node = N, *Last = NULL;
+
+ for ( ; Node ; Last = Node, Node = Node->getFirstPred()) {
+
+ if (const VarRegion *VR = dyn_cast<VarRegion>(R)) {
+ if (const PostStmt *P = Node->getLocationAs<PostStmt>())
+ if (const DeclStmt *DS = P->getStmtAs<DeclStmt>())
+ if (DS->getSingleDecl() == VR->getDecl()) {
+ Last = Node;
+ break;
+ }
+ }
+
+ if (Node->getState()->getSVal(R) != V)
+ break;
+ }
+
+ if (!Node || !Last) {
+ satisfied = true;
+ return NULL;
+ }
+
+ StoreSite = Last;
+ }
+
+ if (StoreSite != N)
+ return NULL;
+
+ satisfied = true;
+ llvm::SmallString<256> sbuf;
+ llvm::raw_svector_ostream os(sbuf);
+
+ if (const PostStmt *PS = N->getLocationAs<PostStmt>()) {
+ if (const DeclStmt *DS = PS->getStmtAs<DeclStmt>()) {
+
+ if (const VarRegion *VR = dyn_cast<VarRegion>(R)) {
+ os << "Variable '" << VR->getDecl() << "' ";
+ }
+ else
+ return NULL;
+
+ if (isa<loc::ConcreteInt>(V)) {
+ bool b = false;
+ if (R->isBoundable()) {
+ if (const TypedRegion *TR = dyn_cast<TypedRegion>(R)) {
+ if (TR->getValueType()->isObjCObjectPointerType()) {
+ os << "initialized to nil";
+ b = true;
+ }
+ }
+ }
+
+ if (!b)
+ os << "initialized to a null pointer value";
+ }
+ else if (isa<nonloc::ConcreteInt>(V)) {
+ os << "initialized to " << cast<nonloc::ConcreteInt>(V).getValue();
+ }
+ else if (V.isUndef()) {
+ if (isa<VarRegion>(R)) {
+ const VarDecl *VD = cast<VarDecl>(DS->getSingleDecl());
+ if (VD->getInit())
+ os << "initialized to a garbage value";
+ else
+ os << "declared without an initial value";
+ }
+ }
+ }
+ }
+
+ if (os.str().empty()) {
+ if (isa<loc::ConcreteInt>(V)) {
+ bool b = false;
+ if (R->isBoundable()) {
+ if (const TypedRegion *TR = dyn_cast<TypedRegion>(R)) {
+ if (TR->getValueType()->isObjCObjectPointerType()) {
+ os << "nil object reference stored to ";
+ b = true;
+ }
+ }
+ }
+
+ if (!b)
+ os << "Null pointer value stored to ";
+ }
+ else if (V.isUndef()) {
+ os << "Uninitialized value stored to ";
+ }
+ else if (isa<nonloc::ConcreteInt>(V)) {
+ os << "The value " << cast<nonloc::ConcreteInt>(V).getValue()
+ << " is assigned to ";
+ }
+ else
+ return NULL;
+
+ if (const VarRegion *VR = dyn_cast<VarRegion>(R)) {
+ os << '\'' << VR->getDecl() << '\'';
+ }
+ else
+ return NULL;
+ }
+
+ // FIXME: Refactor this into BugReporterContext.
+ const Stmt *S = 0;
+ ProgramPoint P = N->getLocation();
+
+ if (BlockEdge *BE = dyn_cast<BlockEdge>(&P)) {
+ const CFGBlock *BSrc = BE->getSrc();
+ S = BSrc->getTerminatorCondition();
+ }
+ else if (PostStmt *PS = dyn_cast<PostStmt>(&P)) {
+ S = PS->getStmt();
+ }
+
+ if (!S)
+ return NULL;
+
+ // Construct a new PathDiagnosticPiece.
+ PathDiagnosticLocation L(S, BRC.getSourceManager());
+ return new PathDiagnosticEventPiece(L, os.str());
+ }
+};
+
+
+static void registerFindLastStore(BugReporterContext& BRC, const MemRegion *R,
+ SVal V) {
+ BRC.addVisitor(new FindLastStoreBRVisitor(V, R));
+}
+
+class TrackConstraintBRVisitor : public BugReporterVisitor {
+ DefinedSVal Constraint;
+ const bool Assumption;
+ bool isSatisfied;
+public:
+ TrackConstraintBRVisitor(DefinedSVal constraint, bool assumption)
+ : Constraint(constraint), Assumption(assumption), isSatisfied(false) {}
+
+ void Profile(llvm::FoldingSetNodeID &ID) const {
+ static int tag = 0;
+ ID.AddPointer(&tag);
+ ID.AddBoolean(Assumption);
+ ID.Add(Constraint);
+ }
+
+ PathDiagnosticPiece* VisitNode(const ExplodedNode *N,
+ const ExplodedNode *PrevN,
+ BugReporterContext& BRC) {
+ if (isSatisfied)
+ return NULL;
+
+ // Check if in the previous state it was feasible for this constraint
+ // to *not* be true.
+ if (PrevN->getState()->assume(Constraint, !Assumption)) {
+
+ isSatisfied = true;
+
+ // As a sanity check, make sure that the negation of the constraint
+ // was infeasible in the current state. If it is feasible, we somehow
+ // missed the transition point.
+ if (N->getState()->assume(Constraint, !Assumption))
+ return NULL;
+
+ // We found the transition point for the constraint. We now need to
+ // pretty-print the constraint. (work-in-progress)
+ std::string sbuf;
+ llvm::raw_string_ostream os(sbuf);
+
+ if (isa<Loc>(Constraint)) {
+ os << "Assuming pointer value is ";
+ os << (Assumption ? "non-null" : "null");
+ }
+
+ if (os.str().empty())
+ return NULL;
+
+ // FIXME: Refactor this into BugReporterContext.
+ const Stmt *S = 0;
+ ProgramPoint P = N->getLocation();
+
+ if (BlockEdge *BE = dyn_cast<BlockEdge>(&P)) {
+ const CFGBlock *BSrc = BE->getSrc();
+ S = BSrc->getTerminatorCondition();
+ }
+ else if (PostStmt *PS = dyn_cast<PostStmt>(&P)) {
+ S = PS->getStmt();
+ }
+
+ if (!S)
+ return NULL;
+
+ // Construct a new PathDiagnosticPiece.
+ PathDiagnosticLocation L(S, BRC.getSourceManager());
+ return new PathDiagnosticEventPiece(L, os.str());
+ }
+
+ return NULL;
+ }
+};
+} // end anonymous namespace
+
+static void registerTrackConstraint(BugReporterContext& BRC,
+ DefinedSVal Constraint,
+ bool Assumption) {
+ BRC.addVisitor(new TrackConstraintBRVisitor(Constraint, Assumption));
+}
+
+void bugreporter::registerTrackNullOrUndefValue(BugReporterContext& BRC,
+ const void *data,
+ const ExplodedNode* N) {
+
+ const Stmt *S = static_cast<const Stmt*>(data);
+
+ if (!S)
+ return;
+
+ GRStateManager &StateMgr = BRC.getStateManager();
+ const GRState *state = N->getState();
+
+ // Walk through lvalue-to-rvalue conversions.
+ if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(S)) {
+ if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) {
+ const VarRegion *R =
+ StateMgr.getRegionManager().getVarRegion(VD, N->getLocationContext());
+
+ // What did we load?
+ SVal V = state->getSVal(loc::MemRegionVal(R));
+
+ if (isa<loc::ConcreteInt>(V) || isa<nonloc::ConcreteInt>(V)
+ || V.isUndef()) {
+ ::registerFindLastStore(BRC, R, V);
+ }
+ }
+ }
+
+ SVal V = state->getSValAsScalarOrLoc(S);
+
+ // Uncomment this to find cases where we aren't properly getting the
+ // base value that was dereferenced.
+ // assert(!V.isUnknownOrUndef());
+
+ // Is it a symbolic value?
+ if (loc::MemRegionVal *L = dyn_cast<loc::MemRegionVal>(&V)) {
+ const SubRegion *R = cast<SubRegion>(L->getRegion());
+ while (R && !isa<SymbolicRegion>(R)) {
+ R = dyn_cast<SubRegion>(R->getSuperRegion());
+ }
+
+ if (R) {
+ assert(isa<SymbolicRegion>(R));
+ registerTrackConstraint(BRC, loc::MemRegionVal(R), false);
+ }
+ }
+}
+
+void bugreporter::registerFindLastStore(BugReporterContext& BRC,
+ const void *data,
+ const ExplodedNode* N) {
+
+ const MemRegion *R = static_cast<const MemRegion*>(data);
+
+ if (!R)
+ return;
+
+ const GRState *state = N->getState();
+ SVal V = state->getSVal(R);
+
+ if (V.isUnknown())
+ return;
+
+ BRC.addVisitor(new FindLastStoreBRVisitor(V, R));
+}
+
+
+namespace {
+class NilReceiverVisitor : public BugReporterVisitor {
+public:
+ NilReceiverVisitor() {}
+
+ void Profile(llvm::FoldingSetNodeID &ID) const {
+ static int x = 0;
+ ID.AddPointer(&x);
+ }
+
+ PathDiagnosticPiece* VisitNode(const ExplodedNode *N,
+ const ExplodedNode *PrevN,
+ BugReporterContext& BRC) {
+
+ const PostStmt *P = N->getLocationAs<PostStmt>();
+ if (!P)
+ return 0;
+ const ObjCMessageExpr *ME = P->getStmtAs<ObjCMessageExpr>();
+ if (!ME)
+ return 0;
+ const Expr *Receiver = ME->getInstanceReceiver();
+ if (!Receiver)
+ return 0;
+ const GRState *state = N->getState();
+ const SVal &V = state->getSVal(Receiver);
+ const DefinedOrUnknownSVal *DV = dyn_cast<DefinedOrUnknownSVal>(&V);
+ if (!DV)
+ return 0;
+ state = state->assume(*DV, true);
+ if (state)
+ return 0;
+
+ // The receiver was nil, and hence the method was skipped.
+ // Register a BugReporterVisitor to issue a message telling us how
+ // the receiver was null.
+ bugreporter::registerTrackNullOrUndefValue(BRC, Receiver, N);
+ // Issue a message saying that the method was skipped.
+ PathDiagnosticLocation L(Receiver, BRC.getSourceManager());
+ return new PathDiagnosticEventPiece(L, "No method actually called "
+ "because the receiver is nil");
+ }
+};
+} // end anonymous namespace
+
+void bugreporter::registerNilReceiverVisitor(BugReporterContext &BRC) {
+ BRC.addVisitor(new NilReceiverVisitor());
+}
+
+// Registers every VarDecl inside a Stmt with a last store vistor.
+void bugreporter::registerVarDeclsLastStore(BugReporterContext &BRC,
+ const void *stmt,
+ const ExplodedNode *N) {
+ const Stmt *S = static_cast<const Stmt *>(stmt);
+
+ std::deque<const Stmt *> WorkList;
+
+ WorkList.push_back(S);
+
+ while (!WorkList.empty()) {
+ const Stmt *Head = WorkList.front();
+ WorkList.pop_front();
+
+ GRStateManager &StateMgr = BRC.getStateManager();
+ const GRState *state = N->getState();
+
+ if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Head)) {
+ if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) {
+ const VarRegion *R =
+ StateMgr.getRegionManager().getVarRegion(VD, N->getLocationContext());
+
+ // What did we load?
+ SVal V = state->getSVal(S);
+
+ if (isa<loc::ConcreteInt>(V) || isa<nonloc::ConcreteInt>(V)) {
+ ::registerFindLastStore(BRC, R, V);
+ }
+ }
+ }
+
+ for (Stmt::const_child_iterator I = Head->child_begin();
+ I != Head->child_end(); ++I)
+ WorkList.push_back(*I);
+ }
+}