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llvm / llvm-archive / 9ee4ded126524dc671b998a7c57f4d2433ee9d20 / . / safecode / tools / clang / lib / StaticAnalyzer / Core / BugReporter.cpp
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// 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.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "BugReporter"
#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ParentMap.h"
#include "clang/AST/StmtObjC.h"
#include "clang/Analysis/CFG.h"
#include "clang/Analysis/ProgramPoint.h"
#include "clang/Basic/SourceManager.h"
#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
#include "clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/IntrusiveRefCntPtr.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Support/raw_ostream.h"
#include <queue>
using namespace clang;
using namespace ento;
STATISTIC(MaxBugClassSize,
"The maximum number of bug reports in the same equivalence class");
STATISTIC(MaxValidBugClassSize,
"The maximum number of bug reports in the same equivalence class "
"where at least one report is valid (not suppressed)");
BugReporterVisitor::~BugReporterVisitor() {}
void BugReporterContext::anchor() {}
//===----------------------------------------------------------------------===//
// Helper routines for walking the ExplodedGraph and fetching statements.
//===----------------------------------------------------------------------===//
static const Stmt *GetPreviousStmt(const ExplodedNode *N) {
for (N = N->getFirstPred(); N; N = N->getFirstPred())
if (const Stmt *S = PathDiagnosticLocation::getStmt(N))
return S;
return 0;
}
static inline const Stmt*
GetCurrentOrPreviousStmt(const ExplodedNode *N) {
if (const Stmt *S = PathDiagnosticLocation::getStmt(N))
return S;
return GetPreviousStmt(N);
}
//===----------------------------------------------------------------------===//
// Diagnostic cleanup.
//===----------------------------------------------------------------------===//
static PathDiagnosticEventPiece *
eventsDescribeSameCondition(PathDiagnosticEventPiece *X,
PathDiagnosticEventPiece *Y) {
// Prefer diagnostics that come from ConditionBRVisitor over
// those that came from TrackConstraintBRVisitor.
const void *tagPreferred = ConditionBRVisitor::getTag();
const void *tagLesser = TrackConstraintBRVisitor::getTag();
if (X->getLocation() != Y->getLocation())
return 0;
if (X->getTag() == tagPreferred && Y->getTag() == tagLesser)
return X;
if (Y->getTag() == tagPreferred && X->getTag() == tagLesser)
return Y;
return 0;
}
/// An optimization pass over PathPieces that removes redundant diagnostics
/// generated by both ConditionBRVisitor and TrackConstraintBRVisitor. Both
/// BugReporterVisitors use different methods to generate diagnostics, with
/// one capable of emitting diagnostics in some cases but not in others. This
/// can lead to redundant diagnostic pieces at the same point in a path.
static void removeRedundantMsgs(PathPieces &path) {
unsigned N = path.size();
if (N < 2)
return;
// NOTE: this loop intentionally is not using an iterator. Instead, we
// are streaming the path and modifying it in place. This is done by
// grabbing the front, processing it, and if we decide to keep it append
// it to the end of the path. The entire path is processed in this way.
for (unsigned i = 0; i < N; ++i) {
IntrusiveRefCntPtr<PathDiagnosticPiece> piece(path.front());
path.pop_front();
switch (piece->getKind()) {
case clang::ento::PathDiagnosticPiece::Call:
removeRedundantMsgs(cast<PathDiagnosticCallPiece>(piece)->path);
break;
case clang::ento::PathDiagnosticPiece::Macro:
removeRedundantMsgs(cast<PathDiagnosticMacroPiece>(piece)->subPieces);
break;
case clang::ento::PathDiagnosticPiece::ControlFlow:
break;
case clang::ento::PathDiagnosticPiece::Event: {
if (i == N-1)
break;
if (PathDiagnosticEventPiece *nextEvent =
dyn_cast<PathDiagnosticEventPiece>(path.front().getPtr())) {
PathDiagnosticEventPiece *event =
cast<PathDiagnosticEventPiece>(piece);
// Check to see if we should keep one of the two pieces. If we
// come up with a preference, record which piece to keep, and consume
// another piece from the path.
if (PathDiagnosticEventPiece *pieceToKeep =
eventsDescribeSameCondition(event, nextEvent)) {
piece = pieceToKeep;
path.pop_front();
++i;
}
}
break;
}
}
path.push_back(piece);
}
}
/// A map from PathDiagnosticPiece to the LocationContext of the inlined
/// function call it represents.
typedef llvm::DenseMap<const PathPieces *, const LocationContext *>
LocationContextMap;
/// 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 shouldn't be pruned from the parent path.
static bool removeUnneededCalls(PathPieces &pieces, BugReport *R,
LocationContextMap &LCM) {
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();
// Throw away pieces with invalid locations. Note that we can't throw away
// calls just yet because they might have something interesting inside them.
// If so, their locations will be adjusted as necessary later.
if (piece->getKind() != PathDiagnosticPiece::Call &&
piece->getLocation().asLocation().isInvalid())
continue;
switch (piece->getKind()) {
case PathDiagnosticPiece::Call: {
PathDiagnosticCallPiece *call = cast<PathDiagnosticCallPiece>(piece);
// Check if the location context is interesting.
assert(LCM.count(&call->path));
if (R->isInteresting(LCM[&call->path])) {
containsSomethingInteresting = true;
break;
}
if (!removeUnneededCalls(call->path, R, LCM))
continue;
containsSomethingInteresting = true;
break;
}
case PathDiagnosticPiece::Macro: {
PathDiagnosticMacroPiece *macro = cast<PathDiagnosticMacroPiece>(piece);
if (!removeUnneededCalls(macro->subPieces, R, LCM))
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.
containsSomethingInteresting |= !event->isPrunable();
break;
}
case PathDiagnosticPiece::ControlFlow:
break;
}
pieces.push_back(piece);
}
return containsSomethingInteresting;
}
/// Recursively scan through a path and make sure that all call pieces have
/// valid locations. Note that all other pieces with invalid locations should
/// have already been pruned out.
static void adjustCallLocations(PathPieces &Pieces,
PathDiagnosticLocation *LastCallLocation = 0) {
for (PathPieces::iterator I = Pieces.begin(), E = Pieces.end(); I != E; ++I) {
PathDiagnosticCallPiece *Call = dyn_cast<PathDiagnosticCallPiece>(*I);
if (!Call) {
assert((*I)->getLocation().asLocation().isValid());
continue;
}
if (LastCallLocation) {
if (!Call->callEnter.asLocation().isValid() ||
Call->getCaller()->isImplicit())
Call->callEnter = *LastCallLocation;
if (!Call->callReturn.asLocation().isValid() ||
Call->getCaller()->isImplicit())
Call->callReturn = *LastCallLocation;
}
// Recursively clean out the subclass. Keep this call around if
// it contains any informative diagnostics.
PathDiagnosticLocation *ThisCallLocation;
if (Call->callEnterWithin.asLocation().isValid() &&
!Call->getCallee()->isImplicit())
ThisCallLocation = &Call->callEnterWithin;
else
ThisCallLocation = &Call->callEnter;
assert(ThisCallLocation && "Outermost call has an invalid location");
adjustCallLocations(Call->path, ThisCallLocation);
}
}
//===----------------------------------------------------------------------===//
// PathDiagnosticBuilder and its associated routines and helper objects.
//===----------------------------------------------------------------------===//
namespace {
class NodeMapClosure : public BugReport::NodeResolver {
InterExplodedGraphMap &M;
public:
NodeMapClosure(InterExplodedGraphMap &m) : M(m) {}
const ExplodedNode *getOriginalNode(const ExplodedNode *N) {
return M.lookup(N);
}
};
class PathDiagnosticBuilder : public BugReporterContext {
BugReport *R;
PathDiagnosticConsumer *PDC;
NodeMapClosure NMC;
public:
const LocationContext *LC;
PathDiagnosticBuilder(GRBugReporter &br,
BugReport *r, InterExplodedGraphMap &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 = PathDiagnosticLocation::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);
}
//===----------------------------------------------------------------------===//
// "Visitors only" path diagnostic generation algorithm.
//===----------------------------------------------------------------------===//
static bool GenerateVisitorsOnlyPathDiagnostic(PathDiagnostic &PD,
PathDiagnosticBuilder &PDB,
const ExplodedNode *N,
ArrayRef<BugReporterVisitor *> visitors) {
// All path generation skips the very first node (the error node).
// This is because there is special handling for the end-of-path note.
N = N->getFirstPred();
if (!N)
return true;
BugReport *R = PDB.getBugReport();
while (const ExplodedNode *Pred = N->getFirstPred()) {
for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(),
E = visitors.end();
I != E; ++I) {
// Visit all the node pairs, but throw the path pieces away.
PathDiagnosticPiece *Piece = (*I)->VisitNode(N, Pred, PDB, *R);
delete Piece;
}
N = Pred;
}
return R->isValid();
}
//===----------------------------------------------------------------------===//
// "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 bool GenerateMinimalPathDiagnostic(PathDiagnostic& PD,
PathDiagnosticBuilder &PDB,
const ExplodedNode *N,
LocationContextMap &LCM,
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 = N->getFirstPred();
ProgramPoint P = N->getLocation();
do {
if (Optional<CallExitEnd> CE = P.getAs<CallExitEnd>()) {
PathDiagnosticCallPiece *C =
PathDiagnosticCallPiece::construct(N, *CE, SMgr);
// Record the mapping from call piece to LocationContext.
LCM[&C->path] = CE->getCalleeContext();
PD.getActivePath().push_front(C);
PD.pushActivePath(&C->path);
CallStack.push_back(StackDiagPair(C, N));
break;
}
if (Optional<CallEnter> CE = P.getAs<CallEnter>()) {
// Flush all locations, and pop the active path.
bool VisitedEntireCall = PD.isWithinCall();
PD.popActivePath();
// Either we just added a bunch of stuff to the top-level path, or
// we have a previous CallExitEnd. If the former, 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;
if (VisitedEntireCall) {
C = cast<PathDiagnosticCallPiece>(PD.getActivePath().front());
} else {
const Decl *Caller = CE->getLocationContext()->getDecl();
C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller);
// Record the mapping from call piece to LocationContext.
LCM[&C->path] = CE->getCalleeContext();
}
C->setCallee(*CE, SMgr);
if (!CallStack.empty()) {
assert(CallStack.back().first == C);
CallStack.pop_back();
}
break;
}
if (Optional<BlockEdge> BE = P.getAs<BlockEdge>()) {
const CFGBlock *Src = BE->getSrc();
const CFGBlock *Dst = BE->getDst();
const Stmt *T = Src->getTerminator();
if (!T)
break;
PathDiagnosticLocation Start =
PathDiagnosticLocation::createBegin(T, SMgr,
N->getLocationContext());
switch (T->getStmtClass()) {
default:
break;
case Stmt::GotoStmtClass:
case Stmt::IndirectGotoStmtClass: {
const Stmt *S = PathDiagnosticLocation::getNextStmt(N);
if (!S)
break;
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;
}
}
}
} while(0);
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);
}
}
}
}
if (!PDB.getBugReport()->isValid())
return false;
// After constructing the full PathDiagnostic, do a pass over it to compact
// PathDiagnosticPieces that occur within a macro.
CompactPathDiagnostic(PD.getMutablePieces(), PDB.getSourceManager());
return true;
}
//===----------------------------------------------------------------------===//
// "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; }
};
static PathDiagnosticLocation cleanUpLocation(PathDiagnosticLocation L,
const LocationContext *LC,
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(), LC);
}
if (firstCharOnly)
L = PathDiagnosticLocation::createSingleLocation(L);
return L;
}
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);
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(), PDB.LC, 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,
bool IsPostJump = false);
void rawAddEdge(PathDiagnosticLocation NewLoc);
void addContext(const Stmt *S);
void addContext(const PathDiagnosticLocation &L);
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, PDB.LC);
const PathDiagnosticLocation &PrevLocClean = cleanUpLocation(PrevLoc, PDB.LC);
if (PrevLocClean.asLocation().isInvalid()) {
PrevLoc = NewLoc;
return;
}
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,
bool IsPostJump) {
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))
TopContextLoc.markDead();
rawAddEdge(NewLoc);
}
if (IsPostJump)
TopContextLoc.markDead();
return;
}
if (containsLocation(TopContextLoc, CLoc)) {
if (alwaysAdd) {
rawAddEdge(NewLoc);
if (IsConsumedExpr(CLoc)) {
CLocs.push_back(ContextLocation(CLoc, /*IsDead=*/true));
return;
}
}
CLocs.push_back(ContextLocation(CLoc, /*IsDead=*/IsPostJump));
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);
addContext(L);
}
void EdgeBuilder::addContext(const PathDiagnosticLocation &L) {
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);
}
// Cone-of-influence: support the reverse propagation of "interesting" symbols
// and values by tracing interesting calculations backwards through evaluated
// expressions along a path. This is probably overly complicated, but the idea
// is that if an expression computed an "interesting" value, the child
// expressions are are also likely to be "interesting" as well (which then
// propagates to the values they in turn compute). This reverse propagation
// is needed to track interesting correlations across function call boundaries,
// where formal arguments bind to actual arguments, etc. This is also needed
// because the constraint solver sometimes simplifies certain symbolic values
// into constants when appropriate, and this complicates reasoning about
// interesting values.
typedef llvm::DenseSet<const Expr *> InterestingExprs;
static void reversePropagateIntererstingSymbols(BugReport &R,
InterestingExprs &IE,
const ProgramState *State,
const Expr *Ex,
const LocationContext *LCtx) {
SVal V = State->getSVal(Ex, LCtx);
if (!(R.isInteresting(V) || IE.count(Ex)))
return;
switch (Ex->getStmtClass()) {
default:
if (!isa<CastExpr>(Ex))
break;
// Fall through.
case Stmt::BinaryOperatorClass:
case Stmt::UnaryOperatorClass: {
for (Stmt::const_child_iterator CI = Ex->child_begin(),
CE = Ex->child_end();
CI != CE; ++CI) {
if (const Expr *child = dyn_cast_or_null<Expr>(*CI)) {
IE.insert(child);
SVal ChildV = State->getSVal(child, LCtx);
R.markInteresting(ChildV);
}
break;
}
}
}
R.markInteresting(V);
}
static void reversePropagateInterestingSymbols(BugReport &R,
InterestingExprs &IE,
const ProgramState *State,
const LocationContext *CalleeCtx,
const LocationContext *CallerCtx)
{
// FIXME: Handle non-CallExpr-based CallEvents.
const StackFrameContext *Callee = CalleeCtx->getCurrentStackFrame();
const Stmt *CallSite = Callee->getCallSite();
if (const CallExpr *CE = dyn_cast_or_null<CallExpr>(CallSite)) {
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CalleeCtx->getDecl())) {
FunctionDecl::param_const_iterator PI = FD->param_begin(),
PE = FD->param_end();
CallExpr::const_arg_iterator AI = CE->arg_begin(), AE = CE->arg_end();
for (; AI != AE && PI != PE; ++AI, ++PI) {
if (const Expr *ArgE = *AI) {
if (const ParmVarDecl *PD = *PI) {
Loc LV = State->getLValue(PD, CalleeCtx);
if (R.isInteresting(LV) || R.isInteresting(State->getRawSVal(LV)))
IE.insert(ArgE);
}
}
}
}
}
}
//===----------------------------------------------------------------------===//
// Functions for determining if a loop was executed 0 times.
//===----------------------------------------------------------------------===//
/// Return true if the terminator is a loop and the destination is the
/// false branch.
static bool isLoopJumpPastBody(const Stmt *Term, const BlockEdge *BE) {
switch (Term->getStmtClass()) {
case Stmt::ForStmtClass:
case Stmt::WhileStmtClass:
case Stmt::ObjCForCollectionStmtClass:
break;
default:
// Note that we intentionally do not include do..while here.
return false;
}
// Did we take the false branch?
const CFGBlock *Src = BE->getSrc();
assert(Src->succ_size() == 2);
return (*(Src->succ_begin()+1) == BE->getDst());
}
static bool isContainedByStmt(ParentMap &PM, const Stmt *S, const Stmt *SubS) {
while (SubS) {
if (SubS == S)
return true;
SubS = PM.getParent(SubS);
}
return false;
}
static const Stmt *getStmtBeforeCond(ParentMap &PM, const Stmt *Term,
const ExplodedNode *N) {
while (N) {
Optional<StmtPoint> SP = N->getLocation().getAs<StmtPoint>();
if (SP) {
const Stmt *S = SP->getStmt();
if (!isContainedByStmt(PM, Term, S))
return S;
}
N = N->getFirstPred();
}
return 0;
}
static bool isInLoopBody(ParentMap &PM, const Stmt *S, const Stmt *Term) {
const Stmt *LoopBody = 0;
switch (Term->getStmtClass()) {
case Stmt::ForStmtClass: {
const ForStmt *FS = cast<ForStmt>(Term);
if (isContainedByStmt(PM, FS->getInc(), S))
return true;
LoopBody = FS->getBody();
break;
}
case Stmt::ObjCForCollectionStmtClass: {
const ObjCForCollectionStmt *FC = cast<ObjCForCollectionStmt>(Term);
LoopBody = FC->getBody();
break;
}
case Stmt::WhileStmtClass:
LoopBody = cast<WhileStmt>(Term)->getBody();
break;
default:
return false;
}
return isContainedByStmt(PM, LoopBody, S);
}
//===----------------------------------------------------------------------===//
// Top-level logic for generating extensive path diagnostics.
//===----------------------------------------------------------------------===//
static bool GenerateExtensivePathDiagnostic(PathDiagnostic& PD,
PathDiagnosticBuilder &PDB,
const ExplodedNode *N,
LocationContextMap &LCM,
ArrayRef<BugReporterVisitor *> visitors) {
EdgeBuilder EB(PD, PDB);
const SourceManager& SM = PDB.getSourceManager();
StackDiagVector CallStack;
InterestingExprs IE;
const ExplodedNode *NextNode = N->pred_empty() ? NULL : *(N->pred_begin());
while (NextNode) {
N = NextNode;
NextNode = N->getFirstPred();
ProgramPoint P = N->getLocation();
do {
if (Optional<PostStmt> PS = P.getAs<PostStmt>()) {
if (const Expr *Ex = PS->getStmtAs<Expr>())
reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE,
N->getState().getPtr(), Ex,
N->getLocationContext());
}
if (Optional<CallExitEnd> CE = P.getAs<CallExitEnd>()) {
const Stmt *S = CE->getCalleeContext()->getCallSite();
if (const Expr *Ex = dyn_cast_or_null<Expr>(S)) {
reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE,
N->getState().getPtr(), Ex,
N->getLocationContext());
}
PathDiagnosticCallPiece *C =
PathDiagnosticCallPiece::construct(N, *CE, SM);
LCM[&C->path] = CE->getCalleeContext();
EB.addEdge(C->callReturn, /*AlwaysAdd=*/true, /*IsPostJump=*/true);
EB.flushLocations();
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 (Optional<CallEnter> CE = P.getAs<CallEnter>()) {
// 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.
bool VisitedEntireCall = PD.isWithinCall();
EB.flushLocations();
PD.popActivePath();
PDB.LC = N->getLocationContext();
// Either we just added a bunch of stuff to the top-level path, or
// we have a previous CallExitEnd. If the former, 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;
if (VisitedEntireCall) {
C = cast<PathDiagnosticCallPiece>(PD.getActivePath().front());
} else {
const Decl *Caller = CE->getLocationContext()->getDecl();
C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller);
LCM[&C->path] = CE->getCalleeContext();
}
C->setCallee(*CE, SM);
EB.addContext(C->getLocation());
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 (Optional<BlockEdge> BE = P.getAs<BlockEdge>()) {
// Does this represent entering a call? If so, look at propagating
// interesting symbols across call boundaries.
if (NextNode) {
const LocationContext *CallerCtx = NextNode->getLocationContext();
const LocationContext *CalleeCtx = PDB.LC;
if (CallerCtx != CalleeCtx) {
reversePropagateInterestingSymbols(*PDB.getBugReport(), IE,
N->getState().getPtr(),
CalleeCtx, CallerCtx);
}
}
// Are we jumping to the head of a loop? Add a special diagnostic.
if (const Stmt *Loop = BE->getSrc()->getLoopTarget()) {
PathDiagnosticLocation L(Loop, SM, PDB.LC);
const CompoundStmt *CS = NULL;
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);
}
}
const CFGBlock *BSrc = BE->getSrc();
ParentMap &PM = PDB.getParentMap();
if (const Stmt *Term = BSrc->getTerminator()) {
// Are we jumping past the loop body without ever executing the
// loop (because the condition was false)?
if (isLoopJumpPastBody(Term, &*BE) &&
!isInLoopBody(PM,
getStmtBeforeCond(PM,
BSrc->getTerminatorCondition(),
N),
Term)) {
PathDiagnosticLocation L(Term, SM, PDB.LC);
PathDiagnosticEventPiece *PE =
new PathDiagnosticEventPiece(L, "Loop body executed 0 times");
PE->setPrunable(true);
EB.addEdge(PE->getLocation(), true);
PD.getActivePath().push_front(PE);
}
// In any case, add the terminator as the current statement
// context for control edges.
EB.addContext(Term);
}
break;
}
if (Optional<BlockEntrance> BE = P.getAs<BlockEntrance>()) {
Optional<CFGElement> First = BE->getFirstElement();
if (Optional<CFGStmt> S = First ? First->getAs<CFGStmt>() : None) {
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());
}
}
}
return PDB.getBugReport()->isValid();
}
/// \brief Adds a sanitized control-flow diagnostic edge to a path.
static void addEdgeToPath(PathPieces &path,
PathDiagnosticLocation &PrevLoc,
PathDiagnosticLocation NewLoc,
const LocationContext *LC) {
if (!NewLoc.isValid())
return;
SourceLocation NewLocL = NewLoc.asLocation();
if (NewLocL.isInvalid() || NewLocL.isMacroID())
return;
if (!PrevLoc.isValid()) {
PrevLoc = NewLoc;
return;
}
// FIXME: ignore intra-macro edges for now.
if (NewLoc.asLocation().getExpansionLoc() ==
PrevLoc.asLocation().getExpansionLoc())
return;
path.push_front(new PathDiagnosticControlFlowPiece(NewLoc,
PrevLoc));
PrevLoc = NewLoc;
}
static bool
GenerateAlternateExtensivePathDiagnostic(PathDiagnostic& PD,
PathDiagnosticBuilder &PDB,
const ExplodedNode *N,
LocationContextMap &LCM,
ArrayRef<BugReporterVisitor *> visitors) {
BugReport *report = PDB.getBugReport();
const SourceManager& SM = PDB.getSourceManager();
StackDiagVector CallStack;
InterestingExprs IE;
// Record the last location for a given visited stack frame.
llvm::DenseMap<const StackFrameContext *, PathDiagnosticLocation>
PrevLocMap;
const ExplodedNode *NextNode = N->getFirstPred();
while (NextNode) {
N = NextNode;
NextNode = N->getFirstPred();
ProgramPoint P = N->getLocation();
const LocationContext *LC = N->getLocationContext();
assert(!LCM[&PD.getActivePath()] || LCM[&PD.getActivePath()] == LC);
LCM[&PD.getActivePath()] = LC;
PathDiagnosticLocation &PrevLoc = PrevLocMap[LC->getCurrentStackFrame()];
do {
if (Optional<PostStmt> PS = P.getAs<PostStmt>()) {
// For expressions, make sure we propagate the
// interesting symbols correctly.
if (const Expr *Ex = PS->getStmtAs<Expr>())
reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE,
N->getState().getPtr(), Ex,
N->getLocationContext());
PathDiagnosticLocation L =
PathDiagnosticLocation(PS->getStmt(), SM, LC);
addEdgeToPath(PD.getActivePath(), PrevLoc, L, LC);
break;
}
// Have we encountered an exit from a function call?
if (Optional<CallExitEnd> CE = P.getAs<CallExitEnd>()) {
const Stmt *S = CE->getCalleeContext()->getCallSite();
// Propagate the interesting symbols accordingly.
if (const Expr *Ex = dyn_cast_or_null<Expr>(S)) {
reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE,
N->getState().getPtr(), Ex,
N->getLocationContext());
}
// We are descending into a call (backwards). Construct
// a new call piece to contain the path pieces for that call.
PathDiagnosticCallPiece *C =
PathDiagnosticCallPiece::construct(N, *CE, SM);
// Record the location context for this call piece.
LCM[&C->path] = CE->getCalleeContext();
// Add the edge to the return site.
addEdgeToPath(PD.getActivePath(), PrevLoc, C->callReturn, LC);
// Make the contents of the call the active path for now.
PD.pushActivePath(&C->path);
CallStack.push_back(StackDiagPair(C, N));
break;
}
// Have we encountered an entrance to a call? It may be
// the case that we have not encountered a matching
// call exit before this point. This means that the path
// terminated within the call itself.
if (Optional<CallEnter> CE = P.getAs<CallEnter>()) {
// Add an edge to the start of the function.
const Decl *D = CE->getCalleeContext()->getDecl();
addEdgeToPath(PD.getActivePath(), PrevLoc,
PathDiagnosticLocation::createBegin(D, SM), LC);
// Did we visit an entire call?
bool VisitedEntireCall = PD.isWithinCall();
PD.popActivePath();
PathDiagnosticCallPiece *C;
if (VisitedEntireCall) {
C = cast<PathDiagnosticCallPiece>(PD.getActivePath().front());
} else {
const Decl *Caller = CE->getLocationContext()->getDecl();
C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller);
LCM[&C->path] = CE->getCalleeContext();
}
C->setCallee(*CE, SM);
if (!CallStack.empty()) {
assert(CallStack.back().first == C);
CallStack.pop_back();
}
break;
}
// Block edges.
if (Optional<BlockEdge> BE = P.getAs<BlockEdge>()) {
// Does this represent entering a call? If so, look at propagating
// interesting symbols across call boundaries.
if (NextNode) {
const LocationContext *CallerCtx = NextNode->getLocationContext();
const LocationContext *CalleeCtx = PDB.LC;
if (CallerCtx != CalleeCtx) {
reversePropagateInterestingSymbols(*PDB.getBugReport(), IE,
N->getState().getPtr(),
CalleeCtx, CallerCtx);
}
}
// Are we jumping to the head of a loop? Add a special diagnostic.
if (const Stmt *Loop = BE->getSrc()->getLoopTarget()) {
PathDiagnosticLocation L(Loop, SM, PDB.LC);
const CompoundStmt *CS = NULL;
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);
addEdgeToPath(PD.getActivePath(), PrevLoc, p->getLocation(), LC);
PD.getActivePath().push_front(p);
if (CS) {
addEdgeToPath(PD.getActivePath(), PrevLoc,
PathDiagnosticLocation::createEndBrace(CS, SM), LC);
}
}
const CFGBlock *BSrc = BE->getSrc();
ParentMap &PM = PDB.getParentMap();
if (const Stmt *Term = BSrc->getTerminator()) {
// Are we jumping past the loop body without ever executing the
// loop (because the condition was false)?
if (isLoopJumpPastBody(Term, &*BE) &&
!isInLoopBody(PM,
getStmtBeforeCond(PM,
BSrc->getTerminatorCondition(),
N),
Term))
{
PathDiagnosticLocation L(Term, SM, PDB.LC);
PathDiagnosticEventPiece *PE =
new PathDiagnosticEventPiece(L, "Loop body executed 0 times");
PE->setPrunable(true);
addEdgeToPath(PD.getActivePath(), PrevLoc,
PE->getLocation(), LC);
PD.getActivePath().push_front(PE);
}
}
break;
}
} while (0);
if (!NextNode)
continue;
// Add pieces from custom visitors.
for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(),
E = visitors.end();
I != E; ++I) {
if (PathDiagnosticPiece *p = (*I)->VisitNode(N, NextNode, PDB, *report)) {
addEdgeToPath(PD.getActivePath(), PrevLoc, p->getLocation(), LC);
PD.getActivePath().push_front(p);
updateStackPiecesWithMessage(p, CallStack);
}
}
}
return report->isValid();
}
const Stmt *getLocStmt(PathDiagnosticLocation L) {
if (!L.isValid())
return 0;
return L.asStmt();
}
const Stmt *getStmtParent(const Stmt *S, ParentMap &PM) {
if (!S)
return 0;
return PM.getParentIgnoreParens(S);
}
#if 0
static bool isConditionForTerminator(const Stmt *S, const Stmt *Cond) {
// Note that we intentionally to do not handle || and && here.
switch (S->getStmtClass()) {
case Stmt::ForStmtClass:
return cast<ForStmt>(S)->getCond() == Cond;
case Stmt::WhileStmtClass:
return cast<WhileStmt>(S)->getCond() == Cond;
case Stmt::DoStmtClass:
return cast<DoStmt>(S)->getCond() == Cond;
case Stmt::ChooseExprClass:
return cast<ChooseExpr>(S)->getCond() == Cond;
case Stmt::IndirectGotoStmtClass:
return cast<IndirectGotoStmt>(S)->getTarget() == Cond;
case Stmt::SwitchStmtClass:
return cast<SwitchStmt>(S)->getCond() == Cond;
case Stmt::BinaryConditionalOperatorClass:
return cast<BinaryConditionalOperator>(S)->getCond() == Cond;
case Stmt::ConditionalOperatorClass:
return cast<ConditionalOperator>(S)->getCond() == Cond;
case Stmt::ObjCForCollectionStmtClass:
return cast<ObjCForCollectionStmt>(S)->getElement() == Cond;
default:
return false;
}
}
#endif
typedef llvm::DenseSet<const PathDiagnosticControlFlowPiece *>
ControlFlowBarrierSet;
typedef llvm::DenseSet<const PathDiagnosticCallPiece *>
OptimizedCallsSet;
static bool isBarrier(ControlFlowBarrierSet &CFBS,
const PathDiagnosticControlFlowPiece *P) {
return CFBS.count(P);
}
static bool optimizeEdges(PathPieces &path, SourceManager &SM,
ControlFlowBarrierSet &CFBS,
OptimizedCallsSet &OCS,
LocationContextMap &LCM) {
bool hasChanges = false;
const LocationContext *LC = LCM[&path];
assert(LC);
bool isFirst = true;
for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; ) {
bool wasFirst = isFirst;
isFirst = false;
// Optimize subpaths.
if (PathDiagnosticCallPiece *CallI = dyn_cast<PathDiagnosticCallPiece>(*I)){
// Record the fact that a call has been optimized so we only do the
// effort once.
if (!OCS.count(CallI)) {
while (optimizeEdges(CallI->path, SM, CFBS, OCS, LCM)) {}
OCS.insert(CallI);
}
++I;
continue;
}
// Pattern match the current piece and its successor.
PathDiagnosticControlFlowPiece *PieceI =
dyn_cast<PathDiagnosticControlFlowPiece>(*I);
if (!PieceI) {
++I;
continue;
}
ParentMap &PM = LC->getParentMap();
const Stmt *s1Start = getLocStmt(PieceI->getStartLocation());
const Stmt *s1End = getLocStmt(PieceI->getEndLocation());
const Stmt *level1 = getStmtParent(s1Start, PM);
const Stmt *level2 = getStmtParent(s1End, PM);
if (wasFirst) {
#if 0
// Apply the "first edge" case for Rule V. here.
if (s1Start && level1 && isConditionForTerminator(level1, s1Start)) {
PathDiagnosticLocation NewLoc(level2, SM, LC);
PieceI->setStartLocation(NewLoc);
CFBS.insert(PieceI);
return true;
}
#endif
// Apply the "first edge" case for Rule III. here.
if (!isBarrier(CFBS, PieceI) &&
level1 && level2 && level2 == PM.getParent(level1)) {
path.erase(I);
// Since we are erasing the current edge at the start of the
// path, just return now so we start analyzing the start of the path
// again.
return true;
}
}
PathPieces::iterator NextI = I; ++NextI;
if (NextI == E)
break;
PathDiagnosticControlFlowPiece *PieceNextI =
dyn_cast<PathDiagnosticControlFlowPiece>(*NextI);
if (!PieceNextI) {
++I;
continue;
}
const Stmt *s2Start = getLocStmt(PieceNextI->getStartLocation());
const Stmt *s2End = getLocStmt(PieceNextI->getEndLocation());
const Stmt *level3 = getStmtParent(s2Start, PM);
const Stmt *level4 = getStmtParent(s2End, PM);
// Rule I.
//
// If we have two consecutive control edges whose end/begin locations
// are at the same level (e.g. statements or top-level expressions within
// a compound statement, or siblings share a single ancestor expression),
// then merge them if they have no interesting intermediate event.
//
// For example:
//
// (1.1 -> 1.2) -> (1.2 -> 1.3) becomes (1.1 -> 1.3) because the common
// parent is '1'. Here 'x.y.z' represents the hierarchy of statements.
//
// NOTE: this will be limited later in cases where we add barriers
// to prevent this optimization.
//
if (level1 && level1 == level2 && level1 == level3 && level1 == level4) {
PieceI->setEndLocation(PieceNextI->getEndLocation());
path.erase(NextI);
hasChanges = true;
continue;
}
// Rule II.
//
// If we have two consecutive control edges where we decend to a
// subexpression and then pop out merge them.
//
// NOTE: this will be limited later in cases where we add barriers
// to prevent this optimization.
//
// For example:
//
// (1.1 -> 1.1.1) -> (1.1.1 -> 1.2) becomes (1.1 -> 1.2).
if (level1 && level2 &&
level1 == level4 &&
level2 == level3 && PM.getParentIgnoreParens(level2) == level1) {
PieceI->setEndLocation(PieceNextI->getEndLocation());
path.erase(NextI);
hasChanges = true;
continue;
}
// Rule III.
//
// Eliminate unnecessary edges where we descend to a subexpression from
// a statement at the same level as our parent.
//
// NOTE: this will be limited later in cases where we add barriers
// to prevent this optimization.
//
// For example:
//
// (1.1 -> 1.1.1) -> (1.1.1 -> X) becomes (1.1 -> X).
//
if (level1 && level2 && level1 == PM.getParentIgnoreParens(level2)) {
PieceI->setEndLocation(PieceNextI->getEndLocation());
path.erase(NextI);
hasChanges = true;
continue;
}
// Rule IV.
//
// Eliminate unnecessary edges where we ascend from a subexpression to
// a statement at the same level as our parent.
//
// NOTE: this will be limited later in cases where we add barriers
// to prevent this optimization.
//
// For example:
//
// (X -> 1.1.1) -> (1.1.1 -> 1.1) becomes (X -> 1.1).
// [first edge] (1.1.1 -> 1.1) -> eliminate
//
if (level2 && level4 && level2 == level3 && level4 == PM.getParent(level2)){
PieceI->setEndLocation(PieceNextI->getEndLocation());
path.erase(NextI);
hasChanges = true;
continue;
}
#if 0
// Rule V.
//
// Replace terminator conditions with terminators when the condition
// itself has no control-flow.
//
// For example:
//
// (X -> condition) -> (condition -> Y) becomes (X -> term) -> (term -> Y)
// [first edge] (condition -> Y) becomes (term -> Y)
//
// This applies to 'if', 'for', 'while', 'do .. while', 'switch'...
//
if (!isBarrier(CFBS, PieceNextI) &&
s1End && s1End == s2Start && level2) {
if (isConditionForTerminator(level2, s1End)) {
PathDiagnosticLocation NewLoc(level2, SM, LC);
PieceI->setEndLocation(NewLoc);
PieceNextI->setStartLocation(NewLoc);
CFBS.insert(PieceI);
hasChanges = true;
continue;
}
}
#endif
// No changes at this index? Move to the next one.
++I;
}
// No changes.
return hasChanges;
}
//===----------------------------------------------------------------------===//
// 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;
}
while (!interestingSymbols.empty()) {
popInterestingSymbolsAndRegions();
}
}
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);
PathDiagnosticLocation UL = getUniqueingLocation();
if (UL.isValid()) {
UL.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 (getInterestingSymbols().insert(sym).second)
++ConfigurationChangeToken;
if (const SymbolMetadata *meta = dyn_cast<SymbolMetadata>(sym))
getInterestingRegions().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 (getInterestingRegions().insert(R).second)
++ConfigurationChangeToken;
if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R))
getInterestingSymbols().insert(SR->getSymbol());
}
void BugReport::markInteresting(SVal V) {
markInteresting(V.getAsRegion());
markInteresting(V.getAsSymbol());
}
void BugReport::markInteresting(const LocationContext *LC) {
if (!LC)
return;
InterestingLocationContexts.insert(LC);
}
bool BugReport::isInteresting(SVal V) {
return isInteresting(V.getAsRegion()) || isInteresting(V.getAsSymbol());
}
bool BugReport::isInteresting(SymbolRef sym) {
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 getInterestingSymbols().count(sym);
}
bool BugReport::isInteresting(const MemRegion *R) {
if (!R)
return false;
R = R->getBaseRegion();
bool b = getInterestingRegions().count(R);
if (b)
return true;
if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R))
return getInterestingSymbols().count(SR->getSymbol());
return false;
}
bool BugReport::isInteresting(const LocationContext *LC) {
if (!LC)
return false;
return InterestingLocationContexts.count(LC);
}
void BugReport::lazyInitializeInterestingSets() {
if (interestingSymbols.empty()) {
interestingSymbols.push_back(new Symbols());
interestingRegions.push_back(new Regions());
}
}
BugReport::Symbols &BugReport::getInterestingSymbols() {
lazyInitializeInterestingSets();
return *interestingSymbols.back();
}
BugReport::Regions &BugReport::getInterestingRegions() {
lazyInitializeInterestingSets();
return *interestingRegions.back();
}
void BugReport::pushInterestingSymbolsAndRegions() {
interestingSymbols.push_back(new Symbols(getInterestingSymbols()));
interestingRegions.push_back(new Regions(getInterestingRegions()));
}
void BugReport::popInterestingSymbolsAndRegions() {
delete interestingSymbols.back();
interestingSymbols.pop_back();
delete interestingRegions.back();
interestingRegions.pop_back();
}
const Stmt *BugReport::getStmt() const {
if (!ErrorNode)
return 0;
ProgramPoint ProgP = ErrorNode->getLocation();
const Stmt *S = NULL;
if (Optional<BlockEntrance> BE = ProgP.getAs<BlockEntrance>()) {
CFGBlock &Exit = ProgP.getLocationContext()->getCFG()->getExit();
if (BE->getBlock() == &Exit)
S = GetPreviousStmt(ErrorNode);
}
if (!S)
S = PathDiagnosticLocation::getStmt(ErrorNode);
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.");
return PathDiagnosticLocation::createEndOfPath(ErrorNode, SM);
} 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);
// We need to flush reports in deterministic order to ensure the order
// of the reports is consistent between runs.
typedef std::vector<BugReportEquivClass *> ContVecTy;
for (ContVecTy::iterator EI=EQClassesVector.begin(), EE=EQClassesVector.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.
//===----------------------------------------------------------------------===//
namespace {
/// A wrapper around a report graph, which contains only a single path, and its
/// node maps.
class ReportGraph {
public:
InterExplodedGraphMap BackMap;
OwningPtr<ExplodedGraph> Graph;
const ExplodedNode *ErrorNode;
size_t Index;
};
/// A wrapper around a trimmed graph and its node maps.
class TrimmedGraph {
InterExplodedGraphMap InverseMap;
typedef llvm::DenseMap<const ExplodedNode *, unsigned> PriorityMapTy;
PriorityMapTy PriorityMap;
typedef std::pair<const ExplodedNode *, size_t> NodeIndexPair;
SmallVector<NodeIndexPair, 32> ReportNodes;
OwningPtr<ExplodedGraph> G;
/// A helper class for sorting ExplodedNodes by priority.
template <bool Descending>
class PriorityCompare {
const PriorityMapTy &PriorityMap;
public:
PriorityCompare(const PriorityMapTy &M) : PriorityMap(M) {}
bool operator()(const ExplodedNode *LHS, const ExplodedNode *RHS) const {
PriorityMapTy::const_iterator LI = PriorityMap.find(LHS);
PriorityMapTy::const_iterator RI = PriorityMap.find(RHS);
PriorityMapTy::const_iterator E = PriorityMap.end();
if (LI == E)
return Descending;
if (RI == E)
return !Descending;
return Descending ? LI->second > RI->second
: LI->second < RI->second;
}
bool operator()(const NodeIndexPair &LHS, const NodeIndexPair &RHS) const {
return (*this)(LHS.first, RHS.first);
}
};
public:
TrimmedGraph(const ExplodedGraph *OriginalGraph,
ArrayRef<const ExplodedNode *> Nodes);
bool popNextReportGraph(ReportGraph &GraphWrapper);
};
}
TrimmedGraph::TrimmedGraph(const ExplodedGraph *OriginalGraph,
ArrayRef<const ExplodedNode *> Nodes) {
// The trimmed graph is created in the body of the constructor to ensure
// that the DenseMaps have been initialized already.
InterExplodedGraphMap ForwardMap;
G.reset(OriginalGraph->trim(Nodes, &ForwardMap, &InverseMap));
// Find the (first) error node in the trimmed graph. We just need to consult
// the node map which maps from nodes in the original graph to nodes
// in the new graph.
llvm::SmallPtrSet<const ExplodedNode *, 32> RemainingNodes;
for (unsigned i = 0, count = Nodes.size(); i < count; ++i) {
if (const ExplodedNode *NewNode = ForwardMap.lookup(Nodes[i])) {
ReportNodes.push_back(std::make_pair(NewNode, i));
RemainingNodes.insert(NewNode);
}
}
assert(!RemainingNodes.empty() && "No error node found in the trimmed graph");
// Perform a forward BFS to find all the shortest paths.
std::queue<const ExplodedNode *> WS;
assert(G->num_roots() == 1);
WS.push(*G->roots_begin());
unsigned Priority = 0;
while (!WS.empty()) {
const ExplodedNode *Node = WS.front();
WS.pop();
PriorityMapTy::iterator PriorityEntry;
bool IsNew;
llvm::tie(PriorityEntry, IsNew) =
PriorityMap.insert(std::make_pair(Node, Priority));
++Priority;
if (!IsNew) {
assert(PriorityEntry->second <= Priority);
continue;
}
if (RemainingNodes.erase(Node))
if (RemainingNodes.empty())
break;
for (ExplodedNode::const_pred_iterator I = Node->succ_begin(),
E = Node->succ_end();
I != E; ++I)
WS.push(*I);
}
// Sort the error paths from longest to shortest.
std::sort(ReportNodes.begin(), ReportNodes.end(),
PriorityCompare<true>(PriorityMap));
}
bool TrimmedGraph::popNextReportGraph(ReportGraph &GraphWrapper) {
if (ReportNodes.empty())
return false;
const ExplodedNode *OrigN;
llvm::tie(OrigN, GraphWrapper.Index) = ReportNodes.pop_back_val();
assert(PriorityMap.find(OrigN) != PriorityMap.end() &&
"error node not accessible from root");
// Create a new graph with a single path. This is the graph
// that will be returned to the caller.
ExplodedGraph *GNew = new ExplodedGraph();
GraphWrapper.Graph.reset(GNew);
GraphWrapper.BackMap.clear();
// Now walk from the error node up the BFS path, always taking the
// predeccessor with the lowest number.
ExplodedNode *Succ = 0;
while (true) {
// Create the equivalent node in the new graph with the same state
// and location.
ExplodedNode *NewN = GNew->getNode(OrigN->getLocation(), OrigN->getState(),
OrigN->isSink());
// Store the mapping to the original node.
InterExplodedGraphMap::const_iterator IMitr = InverseMap.find(OrigN);
assert(IMitr != InverseMap.end() && "No mapping to original node.");
GraphWrapper.BackMap[NewN] = IMitr->second;
// Link up the new node with the previous node.
if (Succ)
Succ->addPredecessor(NewN, *GNew);
else
GraphWrapper.ErrorNode = NewN;
Succ = NewN;
// Are we at the final node?
if (OrigN->pred_empty()) {
GNew->addRoot(NewN);
break;
}
// Find the next predeccessor node. We choose the node that is marked
// with the lowest BFS number.
OrigN = *std::min_element(OrigN->pred_begin(), OrigN->pred_end(),
PriorityCompare<false>(PriorityMap));
}
return true;
}
/// 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);
}
bool GRBugReporter::generatePathDiagnostic(PathDiagnostic& PD,
PathDiagnosticConsumer &PC,
ArrayRef<BugReport *> &bugReports) {
assert(!bugReports.empty());
bool HasValid = false;
bool HasInvalid = false;
SmallVector<const ExplodedNode *, 32> errorNodes;
for (ArrayRef<BugReport*>::iterator I = bugReports.begin(),
E = bugReports.end(); I != E; ++I) {
if ((*I)->isValid()) {
HasValid = true;
errorNodes.push_back((*I)->getErrorNode());
} else {
// Keep the errorNodes list in sync with the bugReports list.
HasInvalid = true;
errorNodes.push_back(0);
}
}
// If all the reports have been marked invalid by a previous path generation,
// we're done.
if (!HasValid)
return false;
typedef PathDiagnosticConsumer::PathGenerationScheme PathGenerationScheme;
PathGenerationScheme ActiveScheme = PC.getGenerationScheme();
if (ActiveScheme == PathDiagnosticConsumer::Extensive) {
AnalyzerOptions &options = getEngine().getAnalysisManager().options;
if (options.getBooleanOption("path-diagnostics-alternate", false)) {
ActiveScheme = PathDiagnosticConsumer::AlternateExtensive;
}
}
TrimmedGraph TrimG(&getGraph(), errorNodes);
ReportGraph ErrorGraph;
while (TrimG.popNextReportGraph(ErrorGraph)) {
// Find the BugReport with the original location.
assert(ErrorGraph.Index < bugReports.size());
BugReport *R = bugReports[ErrorGraph.Index];
assert(R && "No original report found for sliced graph.");
assert(R->isValid() && "Report selected by trimmed graph marked invalid.");
// Start building the path diagnostic...
PathDiagnosticBuilder PDB(*this, R, ErrorGraph.BackMap, &PC);
const ExplodedNode *N = ErrorGraph.ErrorNode;
// Register additional node visitors.
R->addVisitor(new NilReceiverBRVisitor());
R->addVisitor(new ConditionBRVisitor());
R->addVisitor(new LikelyFalsePositiveSuppressionBRVisitor());
BugReport::VisitorList visitors;
unsigned origReportConfigToken, finalReportConfigToken;
LocationContextMap LCM;
// 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.resetPath();
origReportConfigToken = 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 (ActiveScheme != PathDiagnosticConsumer::None) {
if (!LastPiece)
LastPiece = BugReporterVisitor::getDefaultEndPath(PDB, N, *R);
assert(LastPiece);
PD.setEndOfPath(LastPiece);
}
// Make sure we get a clean location context map so we don't
// hold onto old mappings.
LCM.clear();
switch (ActiveScheme) {
case PathDiagnosticConsumer::AlternateExtensive:
GenerateAlternateExtensivePathDiagnostic(PD, PDB, N, LCM, visitors);
break;
case PathDiagnosticConsumer::Extensive:
GenerateExtensivePathDiagnostic(PD, PDB, N, LCM, visitors);
break;
case PathDiagnosticConsumer::Minimal:
GenerateMinimalPathDiagnostic(PD, PDB, N, LCM, visitors);
break;
case PathDiagnosticConsumer::None:
GenerateVisitorsOnlyPathDiagnostic(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 != origReportConfigToken);
if (!R->isValid())
continue;
// Finally, prune the diagnostic path of uninteresting stuff.
if (!PD.path.empty()) {
// Remove messages that are basically the same.
removeRedundantMsgs(PD.getMutablePieces());
if (R->shouldPrunePath() &&
getEngine().getAnalysisManager().options.shouldPrunePaths()) {
bool stillHasNotes = removeUnneededCalls(PD.getMutablePieces(), R, LCM);
assert(stillHasNotes);
(void)stillHasNotes;
}
adjustCallLocations(PD.getMutablePieces());
if (ActiveScheme == PathDiagnosticConsumer::AlternateExtensive) {
ControlFlowBarrierSet CFBS;
OptimizedCallsSet OCS;
while (optimizeEdges(PD.getMutablePieces(), getSourceManager(), CFBS,
OCS, LCM)) {}
}
}
// We found a report and didn't suppress it.
return true;
}
// We suppressed all the reports in this equivalence class.
assert(!HasInvalid && "Inconsistent suppression");
(void)HasInvalid;
return false;
}
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;
}
void BugReporter::FlushReport(BugReportEquivClass& EQ) {
SmallVector<BugReport*, 10> bugReports;
BugReport *exampleReport = FindReportInEquivalenceClass(EQ, bugReports);
if (exampleReport) {
const PathDiagnosticConsumers &C = getPathDiagnosticConsumers();
for (PathDiagnosticConsumers::const_iterator I=C.begin(),
E=C.end(); I != E; ++I) {
FlushReport(exampleReport, **I, bugReports);
}
}
}
void BugReporter::FlushReport(BugReport *exampleReport,
PathDiagnosticConsumer &PD,
ArrayRef<BugReport*> bugReports) {
// 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(),
exampleReport->getDescription(),
exampleReport->getShortDescription(/*Fallback=*/false),
BT.getCategory(),
exampleReport->getUniqueingLocation(),
exampleReport->getUniqueingDecl()));
MaxBugClassSize = std::max(bugReports.size(),
static_cast<size_t>(MaxBugClassSize));
// Generate the full path diagnostic, using the generation scheme
// specified by the PathDiagnosticConsumer. Note that we have to generate
// path diagnostics even for consumers which do not support paths, because
// the BugReporterVisitors may mark this bug as a false positive.
if (!bugReports.empty())
if (!generatePathDiagnostic(*D.get(), PD, bugReports))
return;
MaxValidBugClassSize = std::max(bugReports.size(),
static_cast<size_t>(MaxValidBugClassSize));
// If the path is empty, generate a single step path with the location
// of the issue.
if (D->path.empty()) {
PathDiagnosticLocation L = exampleReport->getLocation(getSourceManager());
PathDiagnosticPiece *piece =
new PathDiagnosticEventPiece(L, exampleReport->getDescription());
BugReport::ranges_iterator Beg, End;
llvm::tie(Beg, End) = exampleReport->getRanges();
for ( ; Beg != End; ++Beg)
piece->addRange(*Beg);
D->setEndOfPath(piece);
}
// 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);
}
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;
}