From fd035e6496665b1f1197868e21cb0a4594e8db6e Mon Sep 17 00:00:00 2001
From: rdivacky <rdivacky@FreeBSD.org>
Date: Tue, 16 Feb 2010 09:31:36 +0000
Subject: Update clang to r96341.
---
lib/Checker/BugReporterVisitors.cpp | 367 ++++++++++++++++++++++++++++++++++++
1 file changed, 367 insertions(+)
create mode 100644 lib/Checker/BugReporterVisitors.cpp
(limited to 'lib/Checker/BugReporterVisitors.cpp')
diff --git a/lib/Checker/BugReporterVisitors.cpp b/lib/Checker/BugReporterVisitors.cpp
new file mode 100644
index 0000000..6cf41b1
--- /dev/null
+++ b/lib/Checker/BugReporterVisitors.cpp
@@ -0,0 +1,367 @@
+// 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/Checker/BugReporter/BugReporter.h"
+#include "clang/Checker/BugReporter/PathDiagnostic.h"
+#include "clang/Checker/PathSensitive/GRState.h"
+
+using namespace clang;
+
+//===----------------------------------------------------------------------===//
+// Utility functions.
+//===----------------------------------------------------------------------===//
+
+const Stmt *clang::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() == UnaryOperator::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*
+clang::bugreporter::GetReceiverExpr(const ExplodedNode *N){
+ const Stmt *S = N->getLocationAs<PostStmt>()->getStmt();
+ if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(S))
+ return ME->getReceiver();
+ return NULL;
+}
+
+const Stmt*
+clang::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*
+clang::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*
+clang::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) {}
+
+ 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;
+ std::string sbuf;
+ llvm::raw_string_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()->getNameAsString() << "' ";
+ }
+ else
+ return NULL;
+
+ if (isa<loc::ConcreteInt>(V)) {
+ bool b = false;
+ ASTContext &C = BRC.getASTContext();
+ if (R->isBoundable()) {
+ if (const TypedRegion *TR = dyn_cast<TypedRegion>(R)) {
+ if (TR->getValueType(C)->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;
+ ASTContext &C = BRC.getASTContext();
+ if (R->isBoundable()) {
+ if (const TypedRegion *TR = dyn_cast<TypedRegion>(R)) {
+ if (TR->getValueType(C)->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()->getNameAsString() << '\'';
+ }
+ else
+ return NULL;
+ }
+
+ // FIXME: Refactor this into BugReporterContext.
+ const Stmt *S = 0;
+ ProgramPoint P = N->getLocation();
+
+ if (BlockEdge *BE = dyn_cast<BlockEdge>(&P)) {
+ 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) {}
+
+ 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)) {
+ 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 clang::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();
+
+ 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(S);
+
+ 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 clang::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));
+}
--
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