diff options
Diffstat (limited to 'clang/lib/StaticAnalyzer/Core/BugReporter.cpp')
| -rw-r--r-- | clang/lib/StaticAnalyzer/Core/BugReporter.cpp | 2056 |
1 files changed, 2056 insertions, 0 deletions
diff --git a/clang/lib/StaticAnalyzer/Core/BugReporter.cpp b/clang/lib/StaticAnalyzer/Core/BugReporter.cpp new file mode 100644 index 0000000..a264212 --- /dev/null +++ b/clang/lib/StaticAnalyzer/Core/BugReporter.cpp @@ -0,0 +1,2056 @@ +// BugReporter.cpp - Generate PathDiagnostics for 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 BugReporter, a utility class for generating +// PathDiagnostics. +// +//===----------------------------------------------------------------------===// + +#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h" +#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h" +#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h" +#include "clang/AST/ASTContext.h" +#include "clang/Analysis/CFG.h" +#include "clang/AST/DeclObjC.h" +#include "clang/AST/Expr.h" +#include "clang/AST/ParentMap.h" +#include "clang/AST/StmtObjC.h" +#include "clang/Basic/SourceManager.h" +#include "clang/Analysis/ProgramPoint.h" +#include "clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h" +#include "llvm/Support/raw_ostream.h" +#include "llvm/ADT/DenseMap.h" +#include "llvm/ADT/SmallString.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/OwningPtr.h" +#include "llvm/ADT/IntrusiveRefCntPtr.h" +#include <queue> + +using namespace clang; +using namespace ento; + +BugReporterVisitor::~BugReporterVisitor() {} + +void BugReporterContext::anchor() {} + +//===----------------------------------------------------------------------===// +// Helper routines for walking the ExplodedGraph and fetching statements. +//===----------------------------------------------------------------------===// + +static inline const Stmt *GetStmt(const ProgramPoint &P) { + if (const StmtPoint* SP = dyn_cast<StmtPoint>(&P)) + return SP->getStmt(); + else if (const BlockEdge *BE = dyn_cast<BlockEdge>(&P)) + return BE->getSrc()->getTerminator(); + + return 0; +} + +static inline const ExplodedNode* +GetPredecessorNode(const ExplodedNode *N) { + return N->pred_empty() ? NULL : *(N->pred_begin()); +} + +static inline const ExplodedNode* +GetSuccessorNode(const ExplodedNode *N) { + return N->succ_empty() ? NULL : *(N->succ_begin()); +} + +static const Stmt *GetPreviousStmt(const ExplodedNode *N) { + for (N = GetPredecessorNode(N); N; N = GetPredecessorNode(N)) + if (const Stmt *S = GetStmt(N->getLocation())) + return S; + + return 0; +} + +static const Stmt *GetNextStmt(const ExplodedNode *N) { + for (N = GetSuccessorNode(N); N; N = GetSuccessorNode(N)) + if (const Stmt *S = GetStmt(N->getLocation())) { + // Check if the statement is '?' or '&&'/'||'. These are "merges", + // not actual statement points. + switch (S->getStmtClass()) { + case Stmt::ChooseExprClass: + case Stmt::BinaryConditionalOperatorClass: continue; + case Stmt::ConditionalOperatorClass: continue; + case Stmt::BinaryOperatorClass: { + BinaryOperatorKind Op = cast<BinaryOperator>(S)->getOpcode(); + if (Op == BO_LAnd || Op == BO_LOr) + continue; + break; + } + default: + break; + } + return S; + } + + return 0; +} + +static inline const Stmt* +GetCurrentOrPreviousStmt(const ExplodedNode *N) { + if (const Stmt *S = GetStmt(N->getLocation())) + return S; + + return GetPreviousStmt(N); +} + +static inline const Stmt* +GetCurrentOrNextStmt(const ExplodedNode *N) { + if (const Stmt *S = GetStmt(N->getLocation())) + return S; + + return GetNextStmt(N); +} + +//===----------------------------------------------------------------------===// +// Diagnostic cleanup. +//===----------------------------------------------------------------------===// + +/// Recursively scan through a path and prune out calls and macros pieces +/// that aren't needed. Return true if afterwards the path contains +/// "interesting stuff" which means it should be pruned from the parent path. +static bool RemoveUneededCalls(PathPieces &pieces) { + bool containsSomethingInteresting = false; + const unsigned N = pieces.size(); + + for (unsigned i = 0 ; i < N ; ++i) { + // Remove the front piece from the path. If it is still something we + // want to keep once we are done, we will push it back on the end. + IntrusiveRefCntPtr<PathDiagnosticPiece> piece(pieces.front()); + pieces.pop_front(); + + switch (piece->getKind()) { + case PathDiagnosticPiece::Call: { + PathDiagnosticCallPiece *call = cast<PathDiagnosticCallPiece>(piece); + // Recursively clean out the subclass. Keep this call around if + // it contains any informative diagnostics. + if (!RemoveUneededCalls(call->path)) + continue; + containsSomethingInteresting = true; + break; + } + case PathDiagnosticPiece::Macro: { + PathDiagnosticMacroPiece *macro = cast<PathDiagnosticMacroPiece>(piece); + if (!RemoveUneededCalls(macro->subPieces)) + continue; + containsSomethingInteresting = true; + break; + } + case PathDiagnosticPiece::Event: { + PathDiagnosticEventPiece *event = cast<PathDiagnosticEventPiece>(piece); + // We never throw away an event, but we do throw it away wholesale + // as part of a path if we throw the entire path away. + if (event->isPrunable()) + continue; + containsSomethingInteresting = true; + break; + } + case PathDiagnosticPiece::ControlFlow: + break; + } + + pieces.push_back(piece); + } + + return containsSomethingInteresting; +} + +//===----------------------------------------------------------------------===// +// PathDiagnosticBuilder and its associated routines and helper objects. +//===----------------------------------------------------------------------===// + +typedef llvm::DenseMap<const ExplodedNode*, +const ExplodedNode*> NodeBackMap; + +namespace { +class NodeMapClosure : public BugReport::NodeResolver { + NodeBackMap& M; +public: + NodeMapClosure(NodeBackMap *m) : M(*m) {} + ~NodeMapClosure() {} + + const ExplodedNode *getOriginalNode(const ExplodedNode *N) { + NodeBackMap::iterator I = M.find(N); + return I == M.end() ? 0 : I->second; + } +}; + +class PathDiagnosticBuilder : public BugReporterContext { + BugReport *R; + PathDiagnosticConsumer *PDC; + OwningPtr<ParentMap> PM; + NodeMapClosure NMC; +public: + const LocationContext *LC; + + PathDiagnosticBuilder(GRBugReporter &br, + BugReport *r, NodeBackMap *Backmap, + PathDiagnosticConsumer *pdc) + : BugReporterContext(br), + R(r), PDC(pdc), NMC(Backmap), LC(r->getErrorNode()->getLocationContext()) + {} + + PathDiagnosticLocation ExecutionContinues(const ExplodedNode *N); + + PathDiagnosticLocation ExecutionContinues(llvm::raw_string_ostream &os, + const ExplodedNode *N); + + BugReport *getBugReport() { return R; } + + Decl const &getCodeDecl() { return R->getErrorNode()->getCodeDecl(); } + + ParentMap& getParentMap() { return LC->getParentMap(); } + + const Stmt *getParent(const Stmt *S) { + return getParentMap().getParent(S); + } + + virtual NodeMapClosure& getNodeResolver() { return NMC; } + + PathDiagnosticLocation getEnclosingStmtLocation(const Stmt *S); + + PathDiagnosticConsumer::PathGenerationScheme getGenerationScheme() const { + return PDC ? PDC->getGenerationScheme() : PathDiagnosticConsumer::Extensive; + } + + bool supportsLogicalOpControlFlow() const { + return PDC ? PDC->supportsLogicalOpControlFlow() : true; + } +}; +} // end anonymous namespace + +PathDiagnosticLocation +PathDiagnosticBuilder::ExecutionContinues(const ExplodedNode *N) { + if (const Stmt *S = GetNextStmt(N)) + return PathDiagnosticLocation(S, getSourceManager(), LC); + + return PathDiagnosticLocation::createDeclEnd(N->getLocationContext(), + getSourceManager()); +} + +PathDiagnosticLocation +PathDiagnosticBuilder::ExecutionContinues(llvm::raw_string_ostream &os, + const ExplodedNode *N) { + + // Slow, but probably doesn't matter. + if (os.str().empty()) + os << ' '; + + const PathDiagnosticLocation &Loc = ExecutionContinues(N); + + if (Loc.asStmt()) + os << "Execution continues on line " + << getSourceManager().getExpansionLineNumber(Loc.asLocation()) + << '.'; + else { + os << "Execution jumps to the end of the "; + const Decl *D = N->getLocationContext()->getDecl(); + if (isa<ObjCMethodDecl>(D)) + os << "method"; + else if (isa<FunctionDecl>(D)) + os << "function"; + else { + assert(isa<BlockDecl>(D)); + os << "anonymous block"; + } + os << '.'; + } + + return Loc; +} + +static bool IsNested(const Stmt *S, ParentMap &PM) { + if (isa<Expr>(S) && PM.isConsumedExpr(cast<Expr>(S))) + return true; + + const Stmt *Parent = PM.getParentIgnoreParens(S); + + if (Parent) + switch (Parent->getStmtClass()) { + case Stmt::ForStmtClass: + case Stmt::DoStmtClass: + case Stmt::WhileStmtClass: + return true; + default: + break; + } + + return false; +} + +PathDiagnosticLocation +PathDiagnosticBuilder::getEnclosingStmtLocation(const Stmt *S) { + assert(S && "Null Stmt *passed to getEnclosingStmtLocation"); + ParentMap &P = getParentMap(); + SourceManager &SMgr = getSourceManager(); + + while (IsNested(S, P)) { + const Stmt *Parent = P.getParentIgnoreParens(S); + + if (!Parent) + break; + + switch (Parent->getStmtClass()) { + case Stmt::BinaryOperatorClass: { + const BinaryOperator *B = cast<BinaryOperator>(Parent); + if (B->isLogicalOp()) + return PathDiagnosticLocation(S, SMgr, LC); + break; + } + case Stmt::CompoundStmtClass: + case Stmt::StmtExprClass: + return PathDiagnosticLocation(S, SMgr, LC); + case Stmt::ChooseExprClass: + // Similar to '?' if we are referring to condition, just have the edge + // point to the entire choose expression. + if (cast<ChooseExpr>(Parent)->getCond() == S) + return PathDiagnosticLocation(Parent, SMgr, LC); + else + return PathDiagnosticLocation(S, SMgr, LC); + case Stmt::BinaryConditionalOperatorClass: + case Stmt::ConditionalOperatorClass: + // For '?', if we are referring to condition, just have the edge point + // to the entire '?' expression. + if (cast<AbstractConditionalOperator>(Parent)->getCond() == S) + return PathDiagnosticLocation(Parent, SMgr, LC); + else + return PathDiagnosticLocation(S, SMgr, LC); + case Stmt::DoStmtClass: + return PathDiagnosticLocation(S, SMgr, LC); + case Stmt::ForStmtClass: + if (cast<ForStmt>(Parent)->getBody() == S) + return PathDiagnosticLocation(S, SMgr, LC); + break; + case Stmt::IfStmtClass: + if (cast<IfStmt>(Parent)->getCond() != S) + return PathDiagnosticLocation(S, SMgr, LC); + break; + case Stmt::ObjCForCollectionStmtClass: + if (cast<ObjCForCollectionStmt>(Parent)->getBody() == S) + return PathDiagnosticLocation(S, SMgr, LC); + break; + case Stmt::WhileStmtClass: + if (cast<WhileStmt>(Parent)->getCond() != S) + return PathDiagnosticLocation(S, SMgr, LC); + break; + default: + break; + } + + S = Parent; + } + + assert(S && "Cannot have null Stmt for PathDiagnosticLocation"); + + // Special case: DeclStmts can appear in for statement declarations, in which + // case the ForStmt is the context. + if (isa<DeclStmt>(S)) { + if (const Stmt *Parent = P.getParent(S)) { + switch (Parent->getStmtClass()) { + case Stmt::ForStmtClass: + case Stmt::ObjCForCollectionStmtClass: + return PathDiagnosticLocation(Parent, SMgr, LC); + default: + break; + } + } + } + else if (isa<BinaryOperator>(S)) { + // Special case: the binary operator represents the initialization + // code in a for statement (this can happen when the variable being + // initialized is an old variable. + if (const ForStmt *FS = + dyn_cast_or_null<ForStmt>(P.getParentIgnoreParens(S))) { + if (FS->getInit() == S) + return PathDiagnosticLocation(FS, SMgr, LC); + } + } + + return PathDiagnosticLocation(S, SMgr, LC); +} + +//===----------------------------------------------------------------------===// +// "Minimal" path diagnostic generation algorithm. +//===----------------------------------------------------------------------===// +typedef std::pair<PathDiagnosticCallPiece*, const ExplodedNode*> StackDiagPair; +typedef SmallVector<StackDiagPair, 6> StackDiagVector; + +static void updateStackPiecesWithMessage(PathDiagnosticPiece *P, + StackDiagVector &CallStack) { + // If the piece contains a special message, add it to all the call + // pieces on the active stack. + if (PathDiagnosticEventPiece *ep = + dyn_cast<PathDiagnosticEventPiece>(P)) { + + if (ep->hasCallStackHint()) + for (StackDiagVector::iterator I = CallStack.begin(), + E = CallStack.end(); I != E; ++I) { + PathDiagnosticCallPiece *CP = I->first; + const ExplodedNode *N = I->second; + std::string stackMsg = ep->getCallStackMessage(N); + + // The last message on the path to final bug is the most important + // one. Since we traverse the path backwards, do not add the message + // if one has been previously added. + if (!CP->hasCallStackMessage()) + CP->setCallStackMessage(stackMsg); + } + } +} + +static void CompactPathDiagnostic(PathPieces &path, const SourceManager& SM); + +static void GenerateMinimalPathDiagnostic(PathDiagnostic& PD, + PathDiagnosticBuilder &PDB, + const ExplodedNode *N, + ArrayRef<BugReporterVisitor *> visitors) { + + SourceManager& SMgr = PDB.getSourceManager(); + const LocationContext *LC = PDB.LC; + const ExplodedNode *NextNode = N->pred_empty() + ? NULL : *(N->pred_begin()); + + StackDiagVector CallStack; + + while (NextNode) { + N = NextNode; + PDB.LC = N->getLocationContext(); + NextNode = GetPredecessorNode(N); + + ProgramPoint P = N->getLocation(); + + if (const CallExit *CE = dyn_cast<CallExit>(&P)) { + PathDiagnosticCallPiece *C = + PathDiagnosticCallPiece::construct(N, *CE, SMgr); + PD.getActivePath().push_front(C); + PD.pushActivePath(&C->path); + CallStack.push_back(StackDiagPair(C, N)); + continue; + } + + if (const CallEnter *CE = dyn_cast<CallEnter>(&P)) { + PD.popActivePath(); + // The current active path should never be empty. Either we + // just added a bunch of stuff to the top-level path, or + // we have a previous CallExit. If the front of the active + // path is not a PathDiagnosticCallPiece, it means that the + // path terminated within a function call. We must then take the + // current contents of the active path and place it within + // a new PathDiagnosticCallPiece. + assert(!PD.getActivePath().empty()); + PathDiagnosticCallPiece *C = + dyn_cast<PathDiagnosticCallPiece>(PD.getActivePath().front()); + if (!C) { + const Decl *Caller = CE->getLocationContext()->getDecl(); + C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller); + } + C->setCallee(*CE, SMgr); + if (!CallStack.empty()) { + assert(CallStack.back().first == C); + CallStack.pop_back(); + } + continue; + } + + if (const BlockEdge *BE = dyn_cast<BlockEdge>(&P)) { + const CFGBlock *Src = BE->getSrc(); + const CFGBlock *Dst = BE->getDst(); + const Stmt *T = Src->getTerminator(); + + if (!T) + continue; + + PathDiagnosticLocation Start = + PathDiagnosticLocation::createBegin(T, SMgr, + N->getLocationContext()); + + switch (T->getStmtClass()) { + default: + break; + + case Stmt::GotoStmtClass: + case Stmt::IndirectGotoStmtClass: { + const Stmt *S = GetNextStmt(N); + + if (!S) + continue; + + std::string sbuf; + llvm::raw_string_ostream os(sbuf); + const PathDiagnosticLocation &End = PDB.getEnclosingStmtLocation(S); + + os << "Control jumps to line " + << End.asLocation().getExpansionLineNumber(); + PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End, + os.str())); + break; + } + + case Stmt::SwitchStmtClass: { + // Figure out what case arm we took. + std::string sbuf; + llvm::raw_string_ostream os(sbuf); + + if (const Stmt *S = Dst->getLabel()) { + PathDiagnosticLocation End(S, SMgr, LC); + + switch (S->getStmtClass()) { + default: + os << "No cases match in the switch statement. " + "Control jumps to line " + << End.asLocation().getExpansionLineNumber(); + break; + case Stmt::DefaultStmtClass: + os << "Control jumps to the 'default' case at line " + << End.asLocation().getExpansionLineNumber(); + break; + + case Stmt::CaseStmtClass: { + os << "Control jumps to 'case "; + const CaseStmt *Case = cast<CaseStmt>(S); + const Expr *LHS = Case->getLHS()->IgnoreParenCasts(); + + // Determine if it is an enum. + bool GetRawInt = true; + + if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(LHS)) { + // FIXME: Maybe this should be an assertion. Are there cases + // were it is not an EnumConstantDecl? + const EnumConstantDecl *D = + dyn_cast<EnumConstantDecl>(DR->getDecl()); + + if (D) { + GetRawInt = false; + os << *D; + } + } + + if (GetRawInt) + os << LHS->EvaluateKnownConstInt(PDB.getASTContext()); + + os << ":' at line " + << End.asLocation().getExpansionLineNumber(); + break; + } + } + PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End, + os.str())); + } + else { + os << "'Default' branch taken. "; + const PathDiagnosticLocation &End = PDB.ExecutionContinues(os, N); + PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End, + os.str())); + } + + break; + } + + case Stmt::BreakStmtClass: + case Stmt::ContinueStmtClass: { + std::string sbuf; + llvm::raw_string_ostream os(sbuf); + PathDiagnosticLocation End = PDB.ExecutionContinues(os, N); + PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End, + os.str())); + break; + } + + // Determine control-flow for ternary '?'. + case Stmt::BinaryConditionalOperatorClass: + case Stmt::ConditionalOperatorClass: { + std::string sbuf; + llvm::raw_string_ostream os(sbuf); + os << "'?' condition is "; + + if (*(Src->succ_begin()+1) == Dst) + os << "false"; + else + os << "true"; + + PathDiagnosticLocation End = PDB.ExecutionContinues(N); + + if (const Stmt *S = End.asStmt()) + End = PDB.getEnclosingStmtLocation(S); + + PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End, + os.str())); + break; + } + + // Determine control-flow for short-circuited '&&' and '||'. + case Stmt::BinaryOperatorClass: { + if (!PDB.supportsLogicalOpControlFlow()) + break; + + const BinaryOperator *B = cast<BinaryOperator>(T); + std::string sbuf; + llvm::raw_string_ostream os(sbuf); + os << "Left side of '"; + + if (B->getOpcode() == BO_LAnd) { + os << "&&" << "' is "; + + if (*(Src->succ_begin()+1) == Dst) { + os << "false"; + PathDiagnosticLocation End(B->getLHS(), SMgr, LC); + PathDiagnosticLocation Start = + PathDiagnosticLocation::createOperatorLoc(B, SMgr); + PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End, + os.str())); + } + else { + os << "true"; + PathDiagnosticLocation Start(B->getLHS(), SMgr, LC); + PathDiagnosticLocation End = PDB.ExecutionContinues(N); + PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End, + os.str())); + } + } + else { + assert(B->getOpcode() == BO_LOr); + os << "||" << "' is "; + + if (*(Src->succ_begin()+1) == Dst) { + os << "false"; + PathDiagnosticLocation Start(B->getLHS(), SMgr, LC); + PathDiagnosticLocation End = PDB.ExecutionContinues(N); + PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End, + os.str())); + } + else { + os << "true"; + PathDiagnosticLocation End(B->getLHS(), SMgr, LC); + PathDiagnosticLocation Start = + PathDiagnosticLocation::createOperatorLoc(B, SMgr); + PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End, + os.str())); + } + } + + break; + } + + case Stmt::DoStmtClass: { + if (*(Src->succ_begin()) == Dst) { + std::string sbuf; + llvm::raw_string_ostream os(sbuf); + + os << "Loop condition is true. "; + PathDiagnosticLocation End = PDB.ExecutionContinues(os, N); + + if (const Stmt *S = End.asStmt()) + End = PDB.getEnclosingStmtLocation(S); + + PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End, + os.str())); + } + else { + PathDiagnosticLocation End = PDB.ExecutionContinues(N); + + if (const Stmt *S = End.asStmt()) + End = PDB.getEnclosingStmtLocation(S); + + PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End, + "Loop condition is false. Exiting loop")); + } + + break; + } + + case Stmt::WhileStmtClass: + case Stmt::ForStmtClass: { + if (*(Src->succ_begin()+1) == Dst) { + std::string sbuf; + llvm::raw_string_ostream os(sbuf); + + os << "Loop condition is false. "; + PathDiagnosticLocation End = PDB.ExecutionContinues(os, N); + if (const Stmt *S = End.asStmt()) + End = PDB.getEnclosingStmtLocation(S); + + PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End, + os.str())); + } + else { + PathDiagnosticLocation End = PDB.ExecutionContinues(N); + if (const Stmt *S = End.asStmt()) + End = PDB.getEnclosingStmtLocation(S); + + PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End, + "Loop condition is true. Entering loop body")); + } + + break; + } + + case Stmt::IfStmtClass: { + PathDiagnosticLocation End = PDB.ExecutionContinues(N); + + if (const Stmt *S = End.asStmt()) + End = PDB.getEnclosingStmtLocation(S); + + if (*(Src->succ_begin()+1) == Dst) + PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End, + "Taking false branch")); + else + PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End, + "Taking true branch")); + + break; + } + } + } + + if (NextNode) { + // Add diagnostic pieces from custom visitors. + BugReport *R = PDB.getBugReport(); + for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(), + E = visitors.end(); + I != E; ++I) { + if (PathDiagnosticPiece *p = (*I)->VisitNode(N, NextNode, PDB, *R)) { + PD.getActivePath().push_front(p); + updateStackPiecesWithMessage(p, CallStack); + } + } + } + } + + // After constructing the full PathDiagnostic, do a pass over it to compact + // PathDiagnosticPieces that occur within a macro. + CompactPathDiagnostic(PD.getMutablePieces(), PDB.getSourceManager()); +} + +//===----------------------------------------------------------------------===// +// "Extensive" PathDiagnostic generation. +//===----------------------------------------------------------------------===// + +static bool IsControlFlowExpr(const Stmt *S) { + const Expr *E = dyn_cast<Expr>(S); + + if (!E) + return false; + + E = E->IgnoreParenCasts(); + + if (isa<AbstractConditionalOperator>(E)) + return true; + + if (const BinaryOperator *B = dyn_cast<BinaryOperator>(E)) + if (B->isLogicalOp()) + return true; + + return false; +} + +namespace { +class ContextLocation : public PathDiagnosticLocation { + bool IsDead; +public: + ContextLocation(const PathDiagnosticLocation &L, bool isdead = false) + : PathDiagnosticLocation(L), IsDead(isdead) {} + + void markDead() { IsDead = true; } + bool isDead() const { return IsDead; } +}; + +class EdgeBuilder { + std::vector<ContextLocation> CLocs; + typedef std::vector<ContextLocation>::iterator iterator; + PathDiagnostic &PD; + PathDiagnosticBuilder &PDB; + PathDiagnosticLocation PrevLoc; + + bool IsConsumedExpr(const PathDiagnosticLocation &L); + + bool containsLocation(const PathDiagnosticLocation &Container, + const PathDiagnosticLocation &Containee); + + PathDiagnosticLocation getContextLocation(const PathDiagnosticLocation &L); + + PathDiagnosticLocation cleanUpLocation(PathDiagnosticLocation L, + bool firstCharOnly = false) { + if (const Stmt *S = L.asStmt()) { + const Stmt *Original = S; + while (1) { + // Adjust the location for some expressions that are best referenced + // by one of their subexpressions. + switch (S->getStmtClass()) { + default: + break; + case Stmt::ParenExprClass: + case Stmt::GenericSelectionExprClass: + S = cast<Expr>(S)->IgnoreParens(); + firstCharOnly = true; + continue; + case Stmt::BinaryConditionalOperatorClass: + case Stmt::ConditionalOperatorClass: + S = cast<AbstractConditionalOperator>(S)->getCond(); + firstCharOnly = true; + continue; + case Stmt::ChooseExprClass: + S = cast<ChooseExpr>(S)->getCond(); + firstCharOnly = true; + continue; + case Stmt::BinaryOperatorClass: + S = cast<BinaryOperator>(S)->getLHS(); + firstCharOnly = true; + continue; + } + + break; + } + + if (S != Original) + L = PathDiagnosticLocation(S, L.getManager(), PDB.LC); + } + + if (firstCharOnly) + L = PathDiagnosticLocation::createSingleLocation(L); + + return L; + } + + void popLocation() { + if (!CLocs.back().isDead() && CLocs.back().asLocation().isFileID()) { + // For contexts, we only one the first character as the range. + rawAddEdge(cleanUpLocation(CLocs.back(), true)); + } + CLocs.pop_back(); + } + +public: + EdgeBuilder(PathDiagnostic &pd, PathDiagnosticBuilder &pdb) + : PD(pd), PDB(pdb) { + + // If the PathDiagnostic already has pieces, add the enclosing statement + // of the first piece as a context as well. + if (!PD.path.empty()) { + PrevLoc = (*PD.path.begin())->getLocation(); + + if (const Stmt *S = PrevLoc.asStmt()) + addExtendedContext(PDB.getEnclosingStmtLocation(S).asStmt()); + } + } + + ~EdgeBuilder() { + while (!CLocs.empty()) popLocation(); + + // Finally, add an initial edge from the start location of the first + // statement (if it doesn't already exist). + PathDiagnosticLocation L = PathDiagnosticLocation::createDeclBegin( + PDB.LC, + PDB.getSourceManager()); + if (L.isValid()) + rawAddEdge(L); + } + + void flushLocations() { + while (!CLocs.empty()) + popLocation(); + PrevLoc = PathDiagnosticLocation(); + } + + void addEdge(PathDiagnosticLocation NewLoc, bool alwaysAdd = false); + + void rawAddEdge(PathDiagnosticLocation NewLoc); + + void addContext(const Stmt *S); + void addExtendedContext(const Stmt *S); +}; +} // end anonymous namespace + + +PathDiagnosticLocation +EdgeBuilder::getContextLocation(const PathDiagnosticLocation &L) { + if (const Stmt *S = L.asStmt()) { + if (IsControlFlowExpr(S)) + return L; + + return PDB.getEnclosingStmtLocation(S); + } + + return L; +} + +bool EdgeBuilder::containsLocation(const PathDiagnosticLocation &Container, + const PathDiagnosticLocation &Containee) { + + if (Container == Containee) + return true; + + if (Container.asDecl()) + return true; + + if (const Stmt *S = Containee.asStmt()) + if (const Stmt *ContainerS = Container.asStmt()) { + while (S) { + if (S == ContainerS) + return true; + S = PDB.getParent(S); + } + return false; + } + + // Less accurate: compare using source ranges. + SourceRange ContainerR = Container.asRange(); + SourceRange ContaineeR = Containee.asRange(); + + SourceManager &SM = PDB.getSourceManager(); + SourceLocation ContainerRBeg = SM.getExpansionLoc(ContainerR.getBegin()); + SourceLocation ContainerREnd = SM.getExpansionLoc(ContainerR.getEnd()); + SourceLocation ContaineeRBeg = SM.getExpansionLoc(ContaineeR.getBegin()); + SourceLocation ContaineeREnd = SM.getExpansionLoc(ContaineeR.getEnd()); + + unsigned ContainerBegLine = SM.getExpansionLineNumber(ContainerRBeg); + unsigned ContainerEndLine = SM.getExpansionLineNumber(ContainerREnd); + unsigned ContaineeBegLine = SM.getExpansionLineNumber(ContaineeRBeg); + unsigned ContaineeEndLine = SM.getExpansionLineNumber(ContaineeREnd); + + assert(ContainerBegLine <= ContainerEndLine); + assert(ContaineeBegLine <= ContaineeEndLine); + + return (ContainerBegLine <= ContaineeBegLine && + ContainerEndLine >= ContaineeEndLine && + (ContainerBegLine != ContaineeBegLine || + SM.getExpansionColumnNumber(ContainerRBeg) <= + SM.getExpansionColumnNumber(ContaineeRBeg)) && + (ContainerEndLine != ContaineeEndLine || + SM.getExpansionColumnNumber(ContainerREnd) >= + SM.getExpansionColumnNumber(ContaineeREnd))); +} + +void EdgeBuilder::rawAddEdge(PathDiagnosticLocation NewLoc) { + if (!PrevLoc.isValid()) { + PrevLoc = NewLoc; + return; + } + + const PathDiagnosticLocation &NewLocClean = cleanUpLocation(NewLoc); + const PathDiagnosticLocation &PrevLocClean = cleanUpLocation(PrevLoc); + + if (NewLocClean.asLocation() == PrevLocClean.asLocation()) + return; + + // FIXME: Ignore intra-macro edges for now. + if (NewLocClean.asLocation().getExpansionLoc() == + PrevLocClean.asLocation().getExpansionLoc()) + return; + + PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(NewLocClean, PrevLocClean)); + PrevLoc = NewLoc; +} + +void EdgeBuilder::addEdge(PathDiagnosticLocation NewLoc, bool alwaysAdd) { + + if (!alwaysAdd && NewLoc.asLocation().isMacroID()) + return; + + const PathDiagnosticLocation &CLoc = getContextLocation(NewLoc); + + while (!CLocs.empty()) { + ContextLocation &TopContextLoc = CLocs.back(); + + // Is the top location context the same as the one for the new location? + if (TopContextLoc == CLoc) { + if (alwaysAdd) { + if (IsConsumedExpr(TopContextLoc) && + !IsControlFlowExpr(TopContextLoc.asStmt())) + TopContextLoc.markDead(); + + rawAddEdge(NewLoc); + } + + return; + } + + if (containsLocation(TopContextLoc, CLoc)) { + if (alwaysAdd) { + rawAddEdge(NewLoc); + + if (IsConsumedExpr(CLoc) && !IsControlFlowExpr(CLoc.asStmt())) { + CLocs.push_back(ContextLocation(CLoc, true)); + return; + } + } + + CLocs.push_back(CLoc); + return; + } + + // Context does not contain the location. Flush it. + popLocation(); + } + + // If we reach here, there is no enclosing context. Just add the edge. + rawAddEdge(NewLoc); +} + +bool EdgeBuilder::IsConsumedExpr(const PathDiagnosticLocation &L) { + if (const Expr *X = dyn_cast_or_null<Expr>(L.asStmt())) + return PDB.getParentMap().isConsumedExpr(X) && !IsControlFlowExpr(X); + + return false; +} + +void EdgeBuilder::addExtendedContext(const Stmt *S) { + if (!S) + return; + + const Stmt *Parent = PDB.getParent(S); + while (Parent) { + if (isa<CompoundStmt>(Parent)) + Parent = PDB.getParent(Parent); + else + break; + } + + if (Parent) { + switch (Parent->getStmtClass()) { + case Stmt::DoStmtClass: + case Stmt::ObjCAtSynchronizedStmtClass: + addContext(Parent); + default: + break; + } + } + + addContext(S); +} + +void EdgeBuilder::addContext(const Stmt *S) { + if (!S) + return; + + PathDiagnosticLocation L(S, PDB.getSourceManager(), PDB.LC); + + while (!CLocs.empty()) { + const PathDiagnosticLocation &TopContextLoc = CLocs.back(); + + // Is the top location context the same as the one for the new location? + if (TopContextLoc == L) + return; + + if (containsLocation(TopContextLoc, L)) { + CLocs.push_back(L); + return; + } + + // Context does not contain the location. Flush it. + popLocation(); + } + + CLocs.push_back(L); +} + +static void GenerateExtensivePathDiagnostic(PathDiagnostic& PD, + PathDiagnosticBuilder &PDB, + const ExplodedNode *N, + ArrayRef<BugReporterVisitor *> visitors) { + EdgeBuilder EB(PD, PDB); + const SourceManager& SM = PDB.getSourceManager(); + StackDiagVector CallStack; + + const ExplodedNode *NextNode = N->pred_empty() ? NULL : *(N->pred_begin()); + while (NextNode) { + N = NextNode; + NextNode = GetPredecessorNode(N); + ProgramPoint P = N->getLocation(); + + do { + if (const CallExit *CE = dyn_cast<CallExit>(&P)) { + const StackFrameContext *LCtx = + CE->getLocationContext()->getCurrentStackFrame(); + PathDiagnosticLocation Loc(LCtx->getCallSite(), + PDB.getSourceManager(), + LCtx); + EB.addEdge(Loc, true); + EB.flushLocations(); + PathDiagnosticCallPiece *C = + PathDiagnosticCallPiece::construct(N, *CE, SM); + PD.getActivePath().push_front(C); + PD.pushActivePath(&C->path); + CallStack.push_back(StackDiagPair(C, N)); + break; + } + + // Pop the call hierarchy if we are done walking the contents + // of a function call. + if (const CallEnter *CE = dyn_cast<CallEnter>(&P)) { + // Add an edge to the start of the function. + const Decl *D = CE->getCalleeContext()->getDecl(); + PathDiagnosticLocation pos = + PathDiagnosticLocation::createBegin(D, SM); + EB.addEdge(pos); + + // Flush all locations, and pop the active path. + EB.flushLocations(); + PD.popActivePath(); + assert(!PD.getActivePath().empty()); + PDB.LC = N->getLocationContext(); + + // The current active path should never be empty. Either we + // just added a bunch of stuff to the top-level path, or + // we have a previous CallExit. If the front of the active + // path is not a PathDiagnosticCallPiece, it means that the + // path terminated within a function call. We must then take the + // current contents of the active path and place it within + // a new PathDiagnosticCallPiece. + PathDiagnosticCallPiece *C = + dyn_cast<PathDiagnosticCallPiece>(PD.getActivePath().front()); + if (!C) { + const Decl * Caller = CE->getLocationContext()->getDecl(); + C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller); + } + C->setCallee(*CE, SM); + EB.addContext(CE->getCallExpr()); + + if (!CallStack.empty()) { + assert(CallStack.back().first == C); + CallStack.pop_back(); + } + break; + } + + // Note that is important that we update the LocationContext + // after looking at CallExits. CallExit basically adds an + // edge in the *caller*, so we don't want to update the LocationContext + // too soon. + PDB.LC = N->getLocationContext(); + + // Block edges. + if (const BlockEdge *BE = dyn_cast<BlockEdge>(&P)) { + const CFGBlock &Blk = *BE->getSrc(); + const Stmt *Term = Blk.getTerminator(); + + // Are we jumping to the head of a loop? Add a special diagnostic. + if (const Stmt *Loop = BE->getDst()->getLoopTarget()) { + PathDiagnosticLocation L(Loop, SM, PDB.LC); + const CompoundStmt *CS = NULL; + + if (!Term) { + if (const ForStmt *FS = dyn_cast<ForStmt>(Loop)) + CS = dyn_cast<CompoundStmt>(FS->getBody()); + else if (const WhileStmt *WS = dyn_cast<WhileStmt>(Loop)) + CS = dyn_cast<CompoundStmt>(WS->getBody()); + } + + PathDiagnosticEventPiece *p = + new PathDiagnosticEventPiece(L, + "Looping back to the head of the loop"); + p->setPrunable(true); + + EB.addEdge(p->getLocation(), true); + PD.getActivePath().push_front(p); + + if (CS) { + PathDiagnosticLocation BL = + PathDiagnosticLocation::createEndBrace(CS, SM); + EB.addEdge(BL); + } + } + + if (Term) + EB.addContext(Term); + + break; + } + + if (const BlockEntrance *BE = dyn_cast<BlockEntrance>(&P)) { + if (const CFGStmt *S = BE->getFirstElement().getAs<CFGStmt>()) { + const Stmt *stmt = S->getStmt(); + if (IsControlFlowExpr(stmt)) { + // Add the proper context for '&&', '||', and '?'. + EB.addContext(stmt); + } + else + EB.addExtendedContext(PDB.getEnclosingStmtLocation(stmt).asStmt()); + } + + break; + } + + + } while (0); + + if (!NextNode) + continue; + + // Add pieces from custom visitors. + BugReport *R = PDB.getBugReport(); + for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(), + E = visitors.end(); + I != E; ++I) { + if (PathDiagnosticPiece *p = (*I)->VisitNode(N, NextNode, PDB, *R)) { + const PathDiagnosticLocation &Loc = p->getLocation(); + EB.addEdge(Loc, true); + PD.getActivePath().push_front(p); + updateStackPiecesWithMessage(p, CallStack); + + if (const Stmt *S = Loc.asStmt()) + EB.addExtendedContext(PDB.getEnclosingStmtLocation(S).asStmt()); + } + } + } +} + +//===----------------------------------------------------------------------===// +// Methods for BugType and subclasses. +//===----------------------------------------------------------------------===// +BugType::~BugType() { } + +void BugType::FlushReports(BugReporter &BR) {} + +void BuiltinBug::anchor() {} + +//===----------------------------------------------------------------------===// +// Methods for BugReport and subclasses. +//===----------------------------------------------------------------------===// + +void BugReport::NodeResolver::anchor() {} + +void BugReport::addVisitor(BugReporterVisitor* visitor) { + if (!visitor) + return; + + llvm::FoldingSetNodeID ID; + visitor->Profile(ID); + void *InsertPos; + + if (CallbacksSet.FindNodeOrInsertPos(ID, InsertPos)) { + delete visitor; + return; + } + + CallbacksSet.InsertNode(visitor, InsertPos); + Callbacks.push_back(visitor); + ++ConfigurationChangeToken; +} + +BugReport::~BugReport() { + for (visitor_iterator I = visitor_begin(), E = visitor_end(); I != E; ++I) { + delete *I; + } +} + +const Decl *BugReport::getDeclWithIssue() const { + if (DeclWithIssue) + return DeclWithIssue; + + const ExplodedNode *N = getErrorNode(); + if (!N) + return 0; + + const LocationContext *LC = N->getLocationContext(); + return LC->getCurrentStackFrame()->getDecl(); +} + +void BugReport::Profile(llvm::FoldingSetNodeID& hash) const { + hash.AddPointer(&BT); + hash.AddString(Description); + if (UniqueingLocation.isValid()) { + UniqueingLocation.Profile(hash); + } else if (Location.isValid()) { + Location.Profile(hash); + } else { + assert(ErrorNode); + hash.AddPointer(GetCurrentOrPreviousStmt(ErrorNode)); + } + + for (SmallVectorImpl<SourceRange>::const_iterator I = + Ranges.begin(), E = Ranges.end(); I != E; ++I) { + const SourceRange range = *I; + if (!range.isValid()) + continue; + hash.AddInteger(range.getBegin().getRawEncoding()); + hash.AddInteger(range.getEnd().getRawEncoding()); + } +} + +void BugReport::markInteresting(SymbolRef sym) { + if (!sym) + return; + + // If the symbol wasn't already in our set, note a configuration change. + if (interestingSymbols.insert(sym).second) + ++ConfigurationChangeToken; + + if (const SymbolMetadata *meta = dyn_cast<SymbolMetadata>(sym)) + interestingRegions.insert(meta->getRegion()); +} + +void BugReport::markInteresting(const MemRegion *R) { + if (!R) + return; + + // If the base region wasn't already in our set, note a configuration change. + R = R->getBaseRegion(); + if (interestingRegions.insert(R).second) + ++ConfigurationChangeToken; + + if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) + interestingSymbols.insert(SR->getSymbol()); +} + +void BugReport::markInteresting(SVal V) { + markInteresting(V.getAsRegion()); + markInteresting(V.getAsSymbol()); +} + +bool BugReport::isInteresting(SVal V) const { + return isInteresting(V.getAsRegion()) || isInteresting(V.getAsSymbol()); +} + +bool BugReport::isInteresting(SymbolRef sym) const { + if (!sym) + return false; + // We don't currently consider metadata symbols to be interesting + // even if we know their region is interesting. Is that correct behavior? + return interestingSymbols.count(sym); +} + +bool BugReport::isInteresting(const MemRegion *R) const { + if (!R) + return false; + R = R->getBaseRegion(); + bool b = interestingRegions.count(R); + if (b) + return true; + if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) + return interestingSymbols.count(SR->getSymbol()); + return false; +} + + +const Stmt *BugReport::getStmt() const { + if (!ErrorNode) + return 0; + + ProgramPoint ProgP = ErrorNode->getLocation(); + const Stmt *S = NULL; + + if (BlockEntrance *BE = dyn_cast<BlockEntrance>(&ProgP)) { + CFGBlock &Exit = ProgP.getLocationContext()->getCFG()->getExit(); + if (BE->getBlock() == &Exit) + S = GetPreviousStmt(ErrorNode); + } + if (!S) + S = GetStmt(ProgP); + + return S; +} + +std::pair<BugReport::ranges_iterator, BugReport::ranges_iterator> +BugReport::getRanges() { + // If no custom ranges, add the range of the statement corresponding to + // the error node. + if (Ranges.empty()) { + if (const Expr *E = dyn_cast_or_null<Expr>(getStmt())) + addRange(E->getSourceRange()); + else + return std::make_pair(ranges_iterator(), ranges_iterator()); + } + + // User-specified absence of range info. + if (Ranges.size() == 1 && !Ranges.begin()->isValid()) + return std::make_pair(ranges_iterator(), ranges_iterator()); + + return std::make_pair(Ranges.begin(), Ranges.end()); +} + +PathDiagnosticLocation BugReport::getLocation(const SourceManager &SM) const { + if (ErrorNode) { + assert(!Location.isValid() && + "Either Location or ErrorNode should be specified but not both."); + + if (const Stmt *S = GetCurrentOrPreviousStmt(ErrorNode)) { + const LocationContext *LC = ErrorNode->getLocationContext(); + + // For member expressions, return the location of the '.' or '->'. + if (const MemberExpr *ME = dyn_cast<MemberExpr>(S)) + return PathDiagnosticLocation::createMemberLoc(ME, SM); + // For binary operators, return the location of the operator. + if (const BinaryOperator *B = dyn_cast<BinaryOperator>(S)) + return PathDiagnosticLocation::createOperatorLoc(B, SM); + + return PathDiagnosticLocation::createBegin(S, SM, LC); + } + } else { + assert(Location.isValid()); + return Location; + } + + return PathDiagnosticLocation(); +} + +//===----------------------------------------------------------------------===// +// Methods for BugReporter and subclasses. +//===----------------------------------------------------------------------===// + +BugReportEquivClass::~BugReportEquivClass() { } +GRBugReporter::~GRBugReporter() { } +BugReporterData::~BugReporterData() {} + +ExplodedGraph &GRBugReporter::getGraph() { return Eng.getGraph(); } + +ProgramStateManager& +GRBugReporter::getStateManager() { return Eng.getStateManager(); } + +BugReporter::~BugReporter() { + FlushReports(); + + // Free the bug reports we are tracking. + typedef std::vector<BugReportEquivClass *> ContTy; + for (ContTy::iterator I = EQClassesVector.begin(), E = EQClassesVector.end(); + I != E; ++I) { + delete *I; + } +} + +void BugReporter::FlushReports() { + if (BugTypes.isEmpty()) + return; + + // First flush the warnings for each BugType. This may end up creating new + // warnings and new BugTypes. + // FIXME: Only NSErrorChecker needs BugType's FlushReports. + // Turn NSErrorChecker into a proper checker and remove this. + SmallVector<const BugType*, 16> bugTypes; + for (BugTypesTy::iterator I=BugTypes.begin(), E=BugTypes.end(); I!=E; ++I) + bugTypes.push_back(*I); + for (SmallVector<const BugType*, 16>::iterator + I = bugTypes.begin(), E = bugTypes.end(); I != E; ++I) + const_cast<BugType*>(*I)->FlushReports(*this); + + typedef llvm::FoldingSet<BugReportEquivClass> SetTy; + for (SetTy::iterator EI=EQClasses.begin(), EE=EQClasses.end(); EI!=EE;++EI){ + BugReportEquivClass& EQ = *EI; + FlushReport(EQ); + } + + // BugReporter owns and deletes only BugTypes created implicitly through + // EmitBasicReport. + // FIXME: There are leaks from checkers that assume that the BugTypes they + // create will be destroyed by the BugReporter. + for (llvm::StringMap<BugType*>::iterator + I = StrBugTypes.begin(), E = StrBugTypes.end(); I != E; ++I) + delete I->second; + + // Remove all references to the BugType objects. + BugTypes = F.getEmptySet(); +} + +//===----------------------------------------------------------------------===// +// PathDiagnostics generation. +//===----------------------------------------------------------------------===// + +static std::pair<std::pair<ExplodedGraph*, NodeBackMap*>, + std::pair<ExplodedNode*, unsigned> > +MakeReportGraph(const ExplodedGraph* G, + SmallVectorImpl<const ExplodedNode*> &nodes) { + + // Create the trimmed graph. It will contain the shortest paths from the + // error nodes to the root. In the new graph we should only have one + // error node unless there are two or more error nodes with the same minimum + // path length. + ExplodedGraph* GTrim; + InterExplodedGraphMap* NMap; + + llvm::DenseMap<const void*, const void*> InverseMap; + llvm::tie(GTrim, NMap) = G->Trim(nodes.data(), nodes.data() + nodes.size(), + &InverseMap); + + // Create owning pointers for GTrim and NMap just to ensure that they are + // released when this function exists. + OwningPtr<ExplodedGraph> AutoReleaseGTrim(GTrim); + OwningPtr<InterExplodedGraphMap> AutoReleaseNMap(NMap); + + // Find the (first) error node in the trimmed graph. We just need to consult + // the node map (NMap) which maps from nodes in the original graph to nodes + // in the new graph. + + std::queue<const ExplodedNode*> WS; + typedef llvm::DenseMap<const ExplodedNode*, unsigned> IndexMapTy; + IndexMapTy IndexMap; + + for (unsigned nodeIndex = 0 ; nodeIndex < nodes.size(); ++nodeIndex) { + const ExplodedNode *originalNode = nodes[nodeIndex]; + if (const ExplodedNode *N = NMap->getMappedNode(originalNode)) { + WS.push(N); + IndexMap[originalNode] = nodeIndex; + } + } + + assert(!WS.empty() && "No error node found in the trimmed graph."); + + // Create a new (third!) graph with a single path. This is the graph + // that will be returned to the caller. + ExplodedGraph *GNew = new ExplodedGraph(); + + // Sometimes the trimmed graph can contain a cycle. Perform a reverse BFS + // to the root node, and then construct a new graph that contains only + // a single path. + llvm::DenseMap<const void*,unsigned> Visited; + + unsigned cnt = 0; + const ExplodedNode *Root = 0; + + while (!WS.empty()) { + const ExplodedNode *Node = WS.front(); + WS.pop(); + + if (Visited.find(Node) != Visited.end()) + continue; + + Visited[Node] = cnt++; + + if (Node->pred_empty()) { + Root = Node; + break; + } + + for (ExplodedNode::const_pred_iterator I=Node->pred_begin(), + E=Node->pred_end(); I!=E; ++I) + WS.push(*I); + } + + assert(Root); + + // Now walk from the root down the BFS path, always taking the successor + // with the lowest number. + ExplodedNode *Last = 0, *First = 0; + NodeBackMap *BM = new NodeBackMap(); + unsigned NodeIndex = 0; + + for ( const ExplodedNode *N = Root ;;) { + // Lookup the number associated with the current node. + llvm::DenseMap<const void*,unsigned>::iterator I = Visited.find(N); + assert(I != Visited.end()); + + // Create the equivalent node in the new graph with the same state + // and location. + ExplodedNode *NewN = GNew->getNode(N->getLocation(), N->getState()); + + // Store the mapping to the original node. + llvm::DenseMap<const void*, const void*>::iterator IMitr=InverseMap.find(N); + assert(IMitr != InverseMap.end() && "No mapping to original node."); + (*BM)[NewN] = (const ExplodedNode*) IMitr->second; + + // Link up the new node with the previous node. + if (Last) + NewN->addPredecessor(Last, *GNew); + + Last = NewN; + + // Are we at the final node? + IndexMapTy::iterator IMI = + IndexMap.find((const ExplodedNode*)(IMitr->second)); + if (IMI != IndexMap.end()) { + First = NewN; + NodeIndex = IMI->second; + break; + } + + // Find the next successor node. We choose the node that is marked + // with the lowest DFS number. + ExplodedNode::const_succ_iterator SI = N->succ_begin(); + ExplodedNode::const_succ_iterator SE = N->succ_end(); + N = 0; + + for (unsigned MinVal = 0; SI != SE; ++SI) { + + I = Visited.find(*SI); + + if (I == Visited.end()) + continue; + + if (!N || I->second < MinVal) { + N = *SI; + MinVal = I->second; + } + } + + assert(N); + } + + assert(First); + + return std::make_pair(std::make_pair(GNew, BM), + std::make_pair(First, NodeIndex)); +} + +/// CompactPathDiagnostic - This function postprocesses a PathDiagnostic object +/// and collapses PathDiagosticPieces that are expanded by macros. +static void CompactPathDiagnostic(PathPieces &path, const SourceManager& SM) { + typedef std::vector<std::pair<IntrusiveRefCntPtr<PathDiagnosticMacroPiece>, + SourceLocation> > MacroStackTy; + + typedef std::vector<IntrusiveRefCntPtr<PathDiagnosticPiece> > + PiecesTy; + + MacroStackTy MacroStack; + PiecesTy Pieces; + + for (PathPieces::const_iterator I = path.begin(), E = path.end(); + I!=E; ++I) { + + PathDiagnosticPiece *piece = I->getPtr(); + + // Recursively compact calls. + if (PathDiagnosticCallPiece *call=dyn_cast<PathDiagnosticCallPiece>(piece)){ + CompactPathDiagnostic(call->path, SM); + } + + // Get the location of the PathDiagnosticPiece. + const FullSourceLoc Loc = piece->getLocation().asLocation(); + + // Determine the instantiation location, which is the location we group + // related PathDiagnosticPieces. + SourceLocation InstantiationLoc = Loc.isMacroID() ? + SM.getExpansionLoc(Loc) : + SourceLocation(); + + if (Loc.isFileID()) { + MacroStack.clear(); + Pieces.push_back(piece); + continue; + } + + assert(Loc.isMacroID()); + + // Is the PathDiagnosticPiece within the same macro group? + if (!MacroStack.empty() && InstantiationLoc == MacroStack.back().second) { + MacroStack.back().first->subPieces.push_back(piece); + continue; + } + + // We aren't in the same group. Are we descending into a new macro + // or are part of an old one? + IntrusiveRefCntPtr<PathDiagnosticMacroPiece> MacroGroup; + + SourceLocation ParentInstantiationLoc = InstantiationLoc.isMacroID() ? + SM.getExpansionLoc(Loc) : + SourceLocation(); + + // Walk the entire macro stack. + while (!MacroStack.empty()) { + if (InstantiationLoc == MacroStack.back().second) { + MacroGroup = MacroStack.back().first; + break; + } + + if (ParentInstantiationLoc == MacroStack.back().second) { + MacroGroup = MacroStack.back().first; + break; + } + + MacroStack.pop_back(); + } + + if (!MacroGroup || ParentInstantiationLoc == MacroStack.back().second) { + // Create a new macro group and add it to the stack. + PathDiagnosticMacroPiece *NewGroup = + new PathDiagnosticMacroPiece( + PathDiagnosticLocation::createSingleLocation(piece->getLocation())); + + if (MacroGroup) + MacroGroup->subPieces.push_back(NewGroup); + else { + assert(InstantiationLoc.isFileID()); + Pieces.push_back(NewGroup); + } + + MacroGroup = NewGroup; + MacroStack.push_back(std::make_pair(MacroGroup, InstantiationLoc)); + } + + // Finally, add the PathDiagnosticPiece to the group. + MacroGroup->subPieces.push_back(piece); + } + + // Now take the pieces and construct a new PathDiagnostic. + path.clear(); + + for (PiecesTy::iterator I=Pieces.begin(), E=Pieces.end(); I!=E; ++I) + path.push_back(*I); +} + +void GRBugReporter::GeneratePathDiagnostic(PathDiagnostic& PD, + SmallVectorImpl<BugReport *> &bugReports) { + + assert(!bugReports.empty()); + SmallVector<const ExplodedNode *, 10> errorNodes; + for (SmallVectorImpl<BugReport*>::iterator I = bugReports.begin(), + E = bugReports.end(); I != E; ++I) { + errorNodes.push_back((*I)->getErrorNode()); + } + + // Construct a new graph that contains only a single path from the error + // node to a root. + const std::pair<std::pair<ExplodedGraph*, NodeBackMap*>, + std::pair<ExplodedNode*, unsigned> >& + GPair = MakeReportGraph(&getGraph(), errorNodes); + + // Find the BugReport with the original location. + assert(GPair.second.second < bugReports.size()); + BugReport *R = bugReports[GPair.second.second]; + assert(R && "No original report found for sliced graph."); + + OwningPtr<ExplodedGraph> ReportGraph(GPair.first.first); + OwningPtr<NodeBackMap> BackMap(GPair.first.second); + const ExplodedNode *N = GPair.second.first; + + // Start building the path diagnostic... + PathDiagnosticBuilder PDB(*this, R, BackMap.get(), + getPathDiagnosticConsumer()); + + // Register additional node visitors. + R->addVisitor(new NilReceiverBRVisitor()); + R->addVisitor(new ConditionBRVisitor()); + + BugReport::VisitorList visitors; + unsigned originalReportConfigToken, finalReportConfigToken; + + // While generating diagnostics, it's possible the visitors will decide + // new symbols and regions are interesting, or add other visitors based on + // the information they find. If they do, we need to regenerate the path + // based on our new report configuration. + do { + // Get a clean copy of all the visitors. + for (BugReport::visitor_iterator I = R->visitor_begin(), + E = R->visitor_end(); I != E; ++I) + visitors.push_back((*I)->clone()); + + // Clear out the active path from any previous work. + PD.getActivePath().clear(); + originalReportConfigToken = R->getConfigurationChangeToken(); + + // Generate the very last diagnostic piece - the piece is visible before + // the trace is expanded. + PathDiagnosticPiece *LastPiece = 0; + for (BugReport::visitor_iterator I = visitors.begin(), E = visitors.end(); + I != E; ++I) { + if (PathDiagnosticPiece *Piece = (*I)->getEndPath(PDB, N, *R)) { + assert (!LastPiece && + "There can only be one final piece in a diagnostic."); + LastPiece = Piece; + } + } + if (!LastPiece) + LastPiece = BugReporterVisitor::getDefaultEndPath(PDB, N, *R); + if (LastPiece) + PD.getActivePath().push_back(LastPiece); + else + return; + + switch (PDB.getGenerationScheme()) { + case PathDiagnosticConsumer::Extensive: + GenerateExtensivePathDiagnostic(PD, PDB, N, visitors); + break; + case PathDiagnosticConsumer::Minimal: + GenerateMinimalPathDiagnostic(PD, PDB, N, visitors); + break; + } + + // Clean up the visitors we used. + llvm::DeleteContainerPointers(visitors); + + // Did anything change while generating this path? + finalReportConfigToken = R->getConfigurationChangeToken(); + } while(finalReportConfigToken != originalReportConfigToken); + + // Finally, prune the diagnostic path of uninteresting stuff. + bool hasSomethingInteresting = RemoveUneededCalls(PD.getMutablePieces()); + assert(hasSomethingInteresting); + (void) hasSomethingInteresting; +} + +void BugReporter::Register(BugType *BT) { + BugTypes = F.add(BugTypes, BT); +} + +void BugReporter::EmitReport(BugReport* R) { + // Compute the bug report's hash to determine its equivalence class. + llvm::FoldingSetNodeID ID; + R->Profile(ID); + + // Lookup the equivance class. If there isn't one, create it. + BugType& BT = R->getBugType(); + Register(&BT); + void *InsertPos; + BugReportEquivClass* EQ = EQClasses.FindNodeOrInsertPos(ID, InsertPos); + + if (!EQ) { + EQ = new BugReportEquivClass(R); + EQClasses.InsertNode(EQ, InsertPos); + EQClassesVector.push_back(EQ); + } + else + EQ->AddReport(R); +} + + +//===----------------------------------------------------------------------===// +// Emitting reports in equivalence classes. +//===----------------------------------------------------------------------===// + +namespace { +struct FRIEC_WLItem { + const ExplodedNode *N; + ExplodedNode::const_succ_iterator I, E; + + FRIEC_WLItem(const ExplodedNode *n) + : N(n), I(N->succ_begin()), E(N->succ_end()) {} +}; +} + +static BugReport * +FindReportInEquivalenceClass(BugReportEquivClass& EQ, + SmallVectorImpl<BugReport*> &bugReports) { + + BugReportEquivClass::iterator I = EQ.begin(), E = EQ.end(); + assert(I != E); + BugType& BT = I->getBugType(); + + // If we don't need to suppress any of the nodes because they are + // post-dominated by a sink, simply add all the nodes in the equivalence class + // to 'Nodes'. Any of the reports will serve as a "representative" report. + if (!BT.isSuppressOnSink()) { + BugReport *R = I; + for (BugReportEquivClass::iterator I=EQ.begin(), E=EQ.end(); I!=E; ++I) { + const ExplodedNode *N = I->getErrorNode(); + if (N) { + R = I; + bugReports.push_back(R); + } + } + return R; + } + + // For bug reports that should be suppressed when all paths are post-dominated + // by a sink node, iterate through the reports in the equivalence class + // until we find one that isn't post-dominated (if one exists). We use a + // DFS traversal of the ExplodedGraph to find a non-sink node. We could write + // this as a recursive function, but we don't want to risk blowing out the + // stack for very long paths. + BugReport *exampleReport = 0; + + for (; I != E; ++I) { + const ExplodedNode *errorNode = I->getErrorNode(); + + if (!errorNode) + continue; + if (errorNode->isSink()) { + llvm_unreachable( + "BugType::isSuppressSink() should not be 'true' for sink end nodes"); + } + // No successors? By definition this nodes isn't post-dominated by a sink. + if (errorNode->succ_empty()) { + bugReports.push_back(I); + if (!exampleReport) + exampleReport = I; + continue; + } + + // At this point we know that 'N' is not a sink and it has at least one + // successor. Use a DFS worklist to find a non-sink end-of-path node. + typedef FRIEC_WLItem WLItem; + typedef SmallVector<WLItem, 10> DFSWorkList; + llvm::DenseMap<const ExplodedNode *, unsigned> Visited; + + DFSWorkList WL; + WL.push_back(errorNode); + Visited[errorNode] = 1; + + while (!WL.empty()) { + WLItem &WI = WL.back(); + assert(!WI.N->succ_empty()); + + for (; WI.I != WI.E; ++WI.I) { + const ExplodedNode *Succ = *WI.I; + // End-of-path node? + if (Succ->succ_empty()) { + // If we found an end-of-path node that is not a sink. + if (!Succ->isSink()) { + bugReports.push_back(I); + if (!exampleReport) + exampleReport = I; + WL.clear(); + break; + } + // Found a sink? Continue on to the next successor. + continue; + } + // Mark the successor as visited. If it hasn't been explored, + // enqueue it to the DFS worklist. + unsigned &mark = Visited[Succ]; + if (!mark) { + mark = 1; + WL.push_back(Succ); + break; + } + } + + // The worklist may have been cleared at this point. First + // check if it is empty before checking the last item. + if (!WL.empty() && &WL.back() == &WI) + WL.pop_back(); + } + } + + // ExampleReport will be NULL if all the nodes in the equivalence class + // were post-dominated by sinks. + return exampleReport; +} + +//===----------------------------------------------------------------------===// +// DiagnosticCache. This is a hack to cache analyzer diagnostics. It +// uses global state, which eventually should go elsewhere. +//===----------------------------------------------------------------------===// +namespace { +class DiagCacheItem : public llvm::FoldingSetNode { + llvm::FoldingSetNodeID ID; +public: + DiagCacheItem(BugReport *R, PathDiagnostic *PD) { + R->Profile(ID); + PD->Profile(ID); + } + + void Profile(llvm::FoldingSetNodeID &id) { + id = ID; + } + + llvm::FoldingSetNodeID &getID() { return ID; } +}; +} + +static bool IsCachedDiagnostic(BugReport *R, PathDiagnostic *PD) { + // FIXME: Eventually this diagnostic cache should reside in something + // like AnalysisManager instead of being a static variable. This is + // really unsafe in the long term. + typedef llvm::FoldingSet<DiagCacheItem> DiagnosticCache; + static DiagnosticCache DC; + + void *InsertPos; + DiagCacheItem *Item = new DiagCacheItem(R, PD); + + if (DC.FindNodeOrInsertPos(Item->getID(), InsertPos)) { + delete Item; + return true; + } + + DC.InsertNode(Item, InsertPos); + return false; +} + +void BugReporter::FlushReport(BugReportEquivClass& EQ) { + SmallVector<BugReport*, 10> bugReports; + BugReport *exampleReport = FindReportInEquivalenceClass(EQ, bugReports); + if (!exampleReport) + return; + + PathDiagnosticConsumer* PD = getPathDiagnosticConsumer(); + + // FIXME: Make sure we use the 'R' for the path that was actually used. + // Probably doesn't make a difference in practice. + BugType& BT = exampleReport->getBugType(); + + OwningPtr<PathDiagnostic> + D(new PathDiagnostic(exampleReport->getDeclWithIssue(), + exampleReport->getBugType().getName(), + !PD || PD->useVerboseDescription() + ? exampleReport->getDescription() + : exampleReport->getShortDescription(), + BT.getCategory())); + + if (!bugReports.empty()) + GeneratePathDiagnostic(*D.get(), bugReports); + + // Get the meta data. + const BugReport::ExtraTextList &Meta = + exampleReport->getExtraText(); + for (BugReport::ExtraTextList::const_iterator i = Meta.begin(), + e = Meta.end(); i != e; ++i) { + D->addMeta(*i); + } + + // Emit a summary diagnostic to the regular Diagnostics engine. + BugReport::ranges_iterator Beg, End; + llvm::tie(Beg, End) = exampleReport->getRanges(); + DiagnosticsEngine &Diag = getDiagnostic(); + + if (!IsCachedDiagnostic(exampleReport, D.get())) { + // Search the description for '%', as that will be interpretted as a + // format character by FormatDiagnostics. + StringRef desc = exampleReport->getShortDescription(); + + SmallString<512> TmpStr; + llvm::raw_svector_ostream Out(TmpStr); + for (StringRef::iterator I=desc.begin(), E=desc.end(); I!=E; ++I) { + if (*I == '%') + Out << "%%"; + else + Out << *I; + } + + Out.flush(); + unsigned ErrorDiag = Diag.getCustomDiagID(DiagnosticsEngine::Warning, TmpStr); + + DiagnosticBuilder diagBuilder = Diag.Report( + exampleReport->getLocation(getSourceManager()).asLocation(), ErrorDiag); + for (BugReport::ranges_iterator I = Beg; I != End; ++I) + diagBuilder << *I; + } + + // Emit a full diagnostic for the path if we have a PathDiagnosticConsumer. + if (!PD) + return; + + if (D->path.empty()) { + PathDiagnosticPiece *piece = new PathDiagnosticEventPiece( + exampleReport->getLocation(getSourceManager()), + exampleReport->getDescription()); + for ( ; Beg != End; ++Beg) + piece->addRange(*Beg); + + D->getActivePath().push_back(piece); + } + + PD->HandlePathDiagnostic(D.take()); +} + +void BugReporter::EmitBasicReport(const Decl *DeclWithIssue, + StringRef name, + StringRef category, + StringRef str, PathDiagnosticLocation Loc, + SourceRange* RBeg, unsigned NumRanges) { + + // 'BT' is owned by BugReporter. + BugType *BT = getBugTypeForName(name, category); + BugReport *R = new BugReport(*BT, str, Loc); + R->setDeclWithIssue(DeclWithIssue); + for ( ; NumRanges > 0 ; --NumRanges, ++RBeg) R->addRange(*RBeg); + EmitReport(R); +} + +BugType *BugReporter::getBugTypeForName(StringRef name, + StringRef category) { + SmallString<136> fullDesc; + llvm::raw_svector_ostream(fullDesc) << name << ":" << category; + llvm::StringMapEntry<BugType *> & + entry = StrBugTypes.GetOrCreateValue(fullDesc); + BugType *BT = entry.getValue(); + if (!BT) { + BT = new BugType(name, category); + entry.setValue(BT); + } + return BT; +} |