Google Git
Sign in
llvm / clang / 55c8788102d8fd203270fabd6513247b2d7fbd87 / . / lib / StaticAnalyzer / Core / BugReporter.cpp
blob: fd7f53210490cacddc794b38e5fddefddb4138e2 [file] [log] [blame]
//===- BugReporter.cpp - Generate PathDiagnostics for bugs ----------------===//
//
// 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/AST/Decl.h"
#include "clang/AST/DeclBase.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/ParentMap.h"
#include "clang/AST/Stmt.h"
#include "clang/AST/StmtCXX.h"
#include "clang/AST/StmtObjC.h"
#include "clang/Analysis/AnalysisDeclContext.h"
#include "clang/Analysis/CFG.h"
#include "clang/Analysis/CFGStmtMap.h"
#include "clang/Analysis/ProgramPoint.h"
#include "clang/Basic/LLVM.h"
#include "clang/Basic/SourceLocation.h"
#include "clang/Basic/SourceManager.h"
#include "clang/StaticAnalyzer/Core/AnalyzerOptions.h"
#include "clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitors.h"
#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
#include "clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h"
#include "clang/StaticAnalyzer/Core/Checker.h"
#include "clang/StaticAnalyzer/Core/CheckerManager.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ExplodedGraph.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/ADT/None.h"
#include "llvm/ADT/Optional.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/iterator_range.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cassert>
#include <cstddef>
#include <iterator>
#include <memory>
#include <queue>
#include <string>
#include <tuple>
#include <utility>
#include <vector>
using namespace clang;
using namespace ento;
#define DEBUG_TYPE "BugReporter"
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() = default;
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 nullptr;
}
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,
// unless the one from ConditionBRVisitor is
// its generic fallback diagnostic.
const void *tagPreferred = ConditionBRVisitor::getTag();
const void *tagLesser = TrackConstraintBRVisitor::getTag();
if (X->getLocation() != Y->getLocation())
return nullptr;
if (X->getTag() == tagPreferred && Y->getTag() == tagLesser)
return ConditionBRVisitor::isPieceMessageGeneric(X) ? Y : X;
if (Y->getTag() == tagPreferred && X->getTag() == tagLesser)
return ConditionBRVisitor::isPieceMessageGeneric(Y) ? X : Y;
return nullptr;
}
/// 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) {
auto piece = std::move(path.front());
path.pop_front();
switch (piece->getKind()) {
case PathDiagnosticPiece::Call:
removeRedundantMsgs(cast<PathDiagnosticCallPiece>(*piece).path);
break;
case PathDiagnosticPiece::Macro:
removeRedundantMsgs(cast<PathDiagnosticMacroPiece>(*piece).subPieces);
break;
case PathDiagnosticPiece::ControlFlow:
break;
case PathDiagnosticPiece::Event: {
if (i == N-1)
break;
if (auto *nextEvent =
dyn_cast<PathDiagnosticEventPiece>(path.front().get())) {
auto *event = cast<PathDiagnosticEventPiece>(piece.get());
// 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 (auto *pieceToKeep =
eventsDescribeSameCondition(event, nextEvent)) {
piece = std::move(pieceToKeep == event ? piece : path.front());
path.pop_front();
++i;
}
}
break;
}
case PathDiagnosticPiece::Note:
break;
}
path.push_back(std::move(piece));
}
}
/// A map from PathDiagnosticPiece to the LocationContext of the inlined
/// function call it represents.
using LocationContextMap =
llvm::DenseMap<const PathPieces *, const LocationContext *>;
/// 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 IsInteresting = false) {
bool containsSomethingInteresting = IsInteresting;
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.
auto piece = std::move(pieces.front());
pieces.pop_front();
switch (piece->getKind()) {
case PathDiagnosticPiece::Call: {
auto &call = cast<PathDiagnosticCallPiece>(*piece);
// Check if the location context is interesting.
assert(LCM.count(&call.path));
if (!removeUnneededCalls(call.path, R, LCM,
R->isInteresting(LCM[&call.path])))
continue;
containsSomethingInteresting = true;
break;
}
case PathDiagnosticPiece::Macro: {
auto &macro = cast<PathDiagnosticMacroPiece>(*piece);
if (!removeUnneededCalls(macro.subPieces, R, LCM, IsInteresting))
continue;
containsSomethingInteresting = true;
break;
}
case PathDiagnosticPiece::Event: {
auto &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;
case PathDiagnosticPiece::Note:
break;
}
pieces.push_back(std::move(piece));
}
return containsSomethingInteresting;
}
/// Returns true if the given decl has been implicitly given a body, either by
/// the analyzer or by the compiler proper.
static bool hasImplicitBody(const Decl *D) {
assert(D);
return D->isImplicit() || !D->hasBody();
}
/// Recursively scan through a path and make sure that all call pieces have
/// valid locations.
static void
adjustCallLocations(PathPieces &Pieces,
PathDiagnosticLocation *LastCallLocation = nullptr) {
for (const auto &I : Pieces) {
auto *Call = dyn_cast<PathDiagnosticCallPiece>(I.get());
if (!Call)
continue;
if (LastCallLocation) {
bool CallerIsImplicit = hasImplicitBody(Call->getCaller());
if (CallerIsImplicit || !Call->callEnter.asLocation().isValid())
Call->callEnter = *LastCallLocation;
if (CallerIsImplicit || !Call->callReturn.asLocation().isValid())
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() &&
!hasImplicitBody(Call->getCallee()))
ThisCallLocation = &Call->callEnterWithin;
else
ThisCallLocation = &Call->callEnter;
assert(ThisCallLocation && "Outermost call has an invalid location");
adjustCallLocations(Call->path, ThisCallLocation);
}
}
/// Remove edges in and out of C++ default initializer expressions. These are
/// for fields that have in-class initializers, as opposed to being initialized
/// explicitly in a constructor or braced list.
static void removeEdgesToDefaultInitializers(PathPieces &Pieces) {
for (PathPieces::iterator I = Pieces.begin(), E = Pieces.end(); I != E;) {
if (auto *C = dyn_cast<PathDiagnosticCallPiece>(I->get()))
removeEdgesToDefaultInitializers(C->path);
if (auto *M = dyn_cast<PathDiagnosticMacroPiece>(I->get()))
removeEdgesToDefaultInitializers(M->subPieces);
if (auto *CF = dyn_cast<PathDiagnosticControlFlowPiece>(I->get())) {
const Stmt *Start = CF->getStartLocation().asStmt();
const Stmt *End = CF->getEndLocation().asStmt();
if (Start && isa<CXXDefaultInitExpr>(Start)) {
I = Pieces.erase(I);
continue;
} else if (End && isa<CXXDefaultInitExpr>(End)) {
PathPieces::iterator Next = std::next(I);
if (Next != E) {
if (auto *NextCF =
dyn_cast<PathDiagnosticControlFlowPiece>(Next->get())) {
NextCF->setStartLocation(CF->getStartLocation());
}
}
I = Pieces.erase(I);
continue;
}
}
I++;
}
}
/// Remove all pieces with invalid locations as these cannot be serialized.
/// We might have pieces with invalid locations as a result of inlining Body
/// Farm generated functions.
static void removePiecesWithInvalidLocations(PathPieces &Pieces) {
for (PathPieces::iterator I = Pieces.begin(), E = Pieces.end(); I != E;) {
if (auto *C = dyn_cast<PathDiagnosticCallPiece>(I->get()))
removePiecesWithInvalidLocations(C->path);
if (auto *M = dyn_cast<PathDiagnosticMacroPiece>(I->get()))
removePiecesWithInvalidLocations(M->subPieces);
if (!(*I)->getLocation().isValid() ||
!(*I)->getLocation().asLocation().isValid()) {
I = Pieces.erase(I);
continue;
}
I++;
}
}
//===----------------------------------------------------------------------===//
// PathDiagnosticBuilder and its associated routines and helper objects.
//===----------------------------------------------------------------------===//
namespace {
class PathDiagnosticBuilder : public BugReporterContext {
BugReport *R;
PathDiagnosticConsumer *PDC;
public:
const LocationContext *LC;
PathDiagnosticBuilder(GRBugReporter &br,
BugReport *r, InterExplodedGraphMap &Backmap,
PathDiagnosticConsumer *pdc)
: BugReporterContext(br, Backmap), R(r), PDC(pdc),
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);
}
PathDiagnosticLocation getEnclosingStmtLocation(const Stmt *S);
PathDiagnosticConsumer::PathGenerationScheme getGenerationScheme() const {
return PDC ? PDC->getGenerationScheme() : PathDiagnosticConsumer::Minimal;
}
bool supportsLogicalOpControlFlow() const {
return PDC ? PDC->supportsLogicalOpControlFlow() : true;
}
};
} // 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 const Stmt *getEnclosingParent(const Stmt *S, const ParentMap &PM) {
if (isa<Expr>(S) && PM.isConsumedExpr(cast<Expr>(S)))
return PM.getParentIgnoreParens(S);
const Stmt *Parent = PM.getParentIgnoreParens(S);
if (!Parent)
return nullptr;
switch (Parent->getStmtClass()) {
case Stmt::ForStmtClass:
case Stmt::DoStmtClass:
case Stmt::WhileStmtClass:
case Stmt::ObjCForCollectionStmtClass:
case Stmt::CXXForRangeStmtClass:
return Parent;
default:
break;
}
return nullptr;
}
static PathDiagnosticLocation
getEnclosingStmtLocation(const Stmt *S, SourceManager &SMgr, const ParentMap &P,
const LocationContext *LC, bool allowNestedContexts) {
if (!S)
return {};
while (const Stmt *Parent = getEnclosingParent(S, P)) {
switch (Parent->getStmtClass()) {
case Stmt::BinaryOperatorClass: {
const auto *B = cast<BinaryOperator>(Parent);
if (B->isLogicalOp())
return PathDiagnosticLocation(allowNestedContexts ? B : 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 (allowNestedContexts || 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 (allowNestedContexts ||
cast<AbstractConditionalOperator>(Parent)->getCond() == S)
return PathDiagnosticLocation(Parent, SMgr, LC);
else
return PathDiagnosticLocation(S, SMgr, LC);
case Stmt::CXXForRangeStmtClass:
if (cast<CXXForRangeStmt>(Parent)->getBody() == S)
return PathDiagnosticLocation(S, SMgr, LC);
break;
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");
return PathDiagnosticLocation(S, SMgr, LC);
}
PathDiagnosticLocation
PathDiagnosticBuilder::getEnclosingStmtLocation(const Stmt *S) {
assert(S && "Null Stmt passed to getEnclosingStmtLocation");
return ::getEnclosingStmtLocation(S, getSourceManager(), getParentMap(), LC,
/*allowNestedContexts=*/false);
}
//===----------------------------------------------------------------------===//
// "Minimal" path diagnostic generation algorithm.
//===----------------------------------------------------------------------===//
using StackDiagPair =
std::pair<PathDiagnosticCallPiece *, const ExplodedNode *>;
using StackDiagVector = SmallVector<StackDiagPair, 6>;
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 (auto *ep = dyn_cast<PathDiagnosticEventPiece>(&P)) {
if (ep->hasCallStackHint())
for (const auto &I : CallStack) {
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 CompactMacroExpandedPieces(PathPieces &path,
const SourceManager& SM);
std::shared_ptr<PathDiagnosticControlFlowPiece> generateDiagForSwitchOP(
const ExplodedNode *N,
const CFGBlock *Dst,
const SourceManager &SM,
const LocationContext *LC,
PathDiagnosticBuilder &PDB,
PathDiagnosticLocation &Start
) {
// Figure out what case arm we took.
std::string sbuf;
llvm::raw_string_ostream os(sbuf);
PathDiagnosticLocation End;
if (const Stmt *S = Dst->getLabel()) {
End = PathDiagnosticLocation(S, SM, 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 auto *Case = cast<CaseStmt>(S);
const Expr *LHS = Case->getLHS()->IgnoreParenCasts();
// Determine if it is an enum.
bool GetRawInt = true;
if (const auto *DR = dyn_cast<DeclRefExpr>(LHS)) {
// FIXME: Maybe this should be an assertion. Are there cases
// were it is not an EnumConstantDecl?
const auto *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;
}
}
} else {
os << "'Default' branch taken. ";
End = PDB.ExecutionContinues(os, N);
}
return std::make_shared<PathDiagnosticControlFlowPiece>(Start, End,
os.str());
}
std::shared_ptr<PathDiagnosticControlFlowPiece> generateDiagForGotoOP(
const Stmt *S,
PathDiagnosticBuilder &PDB,
PathDiagnosticLocation &Start) {
std::string sbuf;
llvm::raw_string_ostream os(sbuf);
const PathDiagnosticLocation &End = PDB.getEnclosingStmtLocation(S);
os << "Control jumps to line " << End.asLocation().getExpansionLineNumber();
return std::make_shared<PathDiagnosticControlFlowPiece>(Start, End, os.str());
}
std::shared_ptr<PathDiagnosticControlFlowPiece> generateDiagForBinaryOP(
const ExplodedNode *N,
const Stmt *T,
const CFGBlock *Src,
const CFGBlock *Dst,
const SourceManager &SM,
PathDiagnosticBuilder &PDB,
const LocationContext *LC) {
const auto *B = cast<BinaryOperator>(T);
std::string sbuf;
llvm::raw_string_ostream os(sbuf);
os << "Left side of '";
PathDiagnosticLocation Start, End;
if (B->getOpcode() == BO_LAnd) {
os << "&&"
<< "' is ";
if (*(Src->succ_begin() + 1) == Dst) {
os << "false";
End = PathDiagnosticLocation(B->getLHS(), SM, LC);
Start =
PathDiagnosticLocation::createOperatorLoc(B, SM);
} else {
os << "true";
Start = PathDiagnosticLocation(B->getLHS(), SM, LC);
End = PDB.ExecutionContinues(N);
}
} else {
assert(B->getOpcode() == BO_LOr);
os << "||"
<< "' is ";
if (*(Src->succ_begin() + 1) == Dst) {
os << "false";
Start = PathDiagnosticLocation(B->getLHS(), SM, LC);
End = PDB.ExecutionContinues(N);
} else {
os << "true";
End = PathDiagnosticLocation(B->getLHS(), SM, LC);
Start =
PathDiagnosticLocation::createOperatorLoc(B, SM);
}
}
return std::make_shared<PathDiagnosticControlFlowPiece>(Start, End,
os.str());
}
void generateMinimalDiagForBlockEdge(const ExplodedNode *N, BlockEdge BE,
const SourceManager &SM,
PathDiagnosticBuilder &PDB,
PathDiagnostic &PD) {
const LocationContext *LC = N->getLocationContext();
const CFGBlock *Src = BE.getSrc();
const CFGBlock *Dst = BE.getDst();
const Stmt *T = Src->getTerminator();
if (!T)
return;
auto Start = PathDiagnosticLocation::createBegin(T, SM, LC);
switch (T->getStmtClass()) {
default:
break;
case Stmt::GotoStmtClass:
case Stmt::IndirectGotoStmtClass: {
if (const Stmt *S = PathDiagnosticLocation::getNextStmt(N))
PD.getActivePath().push_front(generateDiagForGotoOP(S, PDB, Start));
break;
}
case Stmt::SwitchStmtClass: {
PD.getActivePath().push_front(
generateDiagForSwitchOP(N, Dst, SM, LC, PDB, Start));
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(
std::make_shared<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(
std::make_shared<PathDiagnosticControlFlowPiece>(Start, End, os.str()));
break;
}
// Determine control-flow for short-circuited '&&' and '||'.
case Stmt::BinaryOperatorClass: {
if (!PDB.supportsLogicalOpControlFlow())
break;
std::shared_ptr<PathDiagnosticControlFlowPiece> Diag =
generateDiagForBinaryOP(N, T, Src, Dst, SM, PDB, LC);
PD.getActivePath().push_front(Diag);
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(
std::make_shared<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(
std::make_shared<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(
std::make_shared<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(
std::make_shared<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(
std::make_shared<PathDiagnosticControlFlowPiece>(
Start, End, "Taking false branch"));
else
PD.getActivePath().push_front(
std::make_shared<PathDiagnosticControlFlowPiece>(
Start, End, "Taking true branch"));
break;
}
}
}
// 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 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.
using InterestingExprs = llvm::DenseSet<const Expr *>;
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;
LLVM_FALLTHROUGH;
case Stmt::BinaryOperatorClass:
case Stmt::UnaryOperatorClass: {
for (const Stmt *SubStmt : Ex->children()) {
if (const auto *child = dyn_cast_or_null<Expr>(SubStmt)) {
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)
{
// FIXME: Handle non-CallExpr-based CallEvents.
const StackFrameContext *Callee = CalleeCtx->getStackFrame();
const Stmt *CallSite = Callee->getCallSite();
if (const auto *CE = dyn_cast_or_null<CallExpr>(CallSite)) {
if (const auto *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.
//===----------------------------------------------------------------------===//
static bool isLoop(const Stmt *Term) {
switch (Term->getStmtClass()) {
case Stmt::ForStmtClass:
case Stmt::WhileStmtClass:
case Stmt::ObjCForCollectionStmtClass:
case Stmt::CXXForRangeStmtClass:
return true;
default:
// Note that we intentionally do not include do..while here.
return false;
}
}
static bool isJumpToFalseBranch(const BlockEdge *BE) {
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 nullptr;
}
static bool isInLoopBody(ParentMap &PM, const Stmt *S, const Stmt *Term) {
const Stmt *LoopBody = nullptr;
switch (Term->getStmtClass()) {
case Stmt::CXXForRangeStmtClass: {
const auto *FR = cast<CXXForRangeStmt>(Term);
if (isContainedByStmt(PM, FR->getInc(), S))
return true;
if (isContainedByStmt(PM, FR->getLoopVarStmt(), S))
return true;
LoopBody = FR->getBody();
break;
}
case Stmt::ForStmtClass: {
const auto *FS = cast<ForStmt>(Term);
if (isContainedByStmt(PM, FS->getInc(), S))
return true;
LoopBody = FS->getBody();
break;
}
case Stmt::ObjCForCollectionStmtClass: {
const auto *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);
}
/// Adds a sanitized control-flow diagnostic edge to a path.
static void addEdgeToPath(PathPieces &path,
PathDiagnosticLocation &PrevLoc,
PathDiagnosticLocation NewLoc) {
if (!NewLoc.isValid())
return;
SourceLocation NewLocL = NewLoc.asLocation();
if (NewLocL.isInvalid())
return;
if (!PrevLoc.isValid() || !PrevLoc.asLocation().isValid()) {
PrevLoc = NewLoc;
return;
}
// Ignore self-edges, which occur when there are multiple nodes at the same
// statement.
if (NewLoc.asStmt() && NewLoc.asStmt() == PrevLoc.asStmt())
return;
path.push_front(
std::make_shared<PathDiagnosticControlFlowPiece>(NewLoc, PrevLoc));
PrevLoc = NewLoc;
}
/// A customized wrapper for CFGBlock::getTerminatorCondition()
/// which returns the element for ObjCForCollectionStmts.
static const Stmt *getTerminatorCondition(const CFGBlock *B) {
const Stmt *S = B->getTerminatorCondition();
if (const auto *FS = dyn_cast_or_null<ObjCForCollectionStmt>(S))
return FS->getElement();
return S;
}
static const char StrEnteringLoop[] = "Entering loop body";
static const char StrLoopBodyZero[] = "Loop body executed 0 times";
static const char StrLoopRangeEmpty[] =
"Loop body skipped when range is empty";
static const char StrLoopCollectionEmpty[] =
"Loop body skipped when collection is empty";
static std::unique_ptr<FilesToLineNumsMap>
findExecutedLines(SourceManager &SM, const ExplodedNode *N);
/// Generate diagnostics for the node \p N,
/// and write it into \p PD.
/// \p AddPathEdges Whether diagnostic consumer can generate path arrows
/// showing both row and column.
static void generatePathDiagnosticsForNode(const ExplodedNode *N,
PathDiagnostic &PD,
PathDiagnosticLocation &PrevLoc,
PathDiagnosticBuilder &PDB,
LocationContextMap &LCM,
StackDiagVector &CallStack,
InterestingExprs &IE,
bool AddPathEdges) {
ProgramPoint P = N->getLocation();
const SourceManager& SM = PDB.getSourceManager();
// 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 (auto CE = P.getAs<CallEnter>()) {
if (AddPathEdges) {
// Add an edge to the start of the function.
const StackFrameContext *CalleeLC = CE->getCalleeContext();
const Decl *D = CalleeLC->getDecl();
// Add the edge only when the callee has body. We jump to the beginning
// of the *declaration*, however we expect it to be followed by the
// body. This isn't the case for autosynthesized property accessors in
// Objective-C. No need for a similar extra check for CallExit points
// because the exit edge comes from a statement (i.e. return),
// not from declaration.
if (D->hasBody())
addEdgeToPath(PD.getActivePath(), PrevLoc,
PathDiagnosticLocation::createBegin(D, SM));
}
// Did we visit an entire call?
bool VisitedEntireCall = PD.isWithinCall();
PD.popActivePath();
PathDiagnosticCallPiece *C;
if (VisitedEntireCall) {
C = cast<PathDiagnosticCallPiece>(PD.getActivePath().front().get());
} else {
const Decl *Caller = CE->getLocationContext()->getDecl();
C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller);
if (AddPathEdges) {
// Since we just transferred the path over to the call piece,
// reset the mapping from active to location context.
assert(PD.getActivePath().size() == 1 &&
PD.getActivePath().front().get() == C);
LCM[&PD.getActivePath()] = nullptr;
}
// Record the location context mapping for the path within
// the call.
assert(LCM[&C->path] == nullptr ||
LCM[&C->path] == CE->getCalleeContext());
LCM[&C->path] = CE->getCalleeContext();
// If this is the first item in the active path, record
// the new mapping from active path to location context.
const LocationContext *&NewLC = LCM[&PD.getActivePath()];
if (!NewLC)
NewLC = N->getLocationContext();
PDB.LC = NewLC;
}
C->setCallee(*CE, SM);
// Update the previous location in the active path.
PrevLoc = C->getLocation();
if (!CallStack.empty()) {
assert(CallStack.back().first == C);
CallStack.pop_back();
}
return;
}
if (AddPathEdges) {
// Query the location context here and the previous location
// as processing CallEnter may change the active path.
PDB.LC = N->getLocationContext();
// Record the mapping from the active path to the location
// context.
assert(!LCM[&PD.getActivePath()] || LCM[&PD.getActivePath()] == PDB.LC);
LCM[&PD.getActivePath()] = PDB.LC;
}
// Have we encountered an exit from a function call?
if (Optional<CallExitEnd> CE = P.getAs<CallExitEnd>()) {
// We are descending into a call (backwards). Construct
// a new call piece to contain the path pieces for that call.
auto C = PathDiagnosticCallPiece::construct(*CE, SM);
// Record the mapping from call piece to LocationContext.
LCM[&C->path] = CE->getCalleeContext();
if (AddPathEdges) {
const Stmt *S = CE->getCalleeContext()->getCallSite();
// Propagate the interesting symbols accordingly.
if (const auto *Ex = dyn_cast_or_null<Expr>(S)) {
reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE,
N->getState().get(), Ex,
N->getLocationContext());
}
// Add the edge to the return site.
addEdgeToPath(PD.getActivePath(), PrevLoc, C->callReturn);
PrevLoc.invalidate();
}
auto *P = C.get();
PD.getActivePath().push_front(std::move(C));
// Make the contents of the call the active path for now.
PD.pushActivePath(&P->path);
CallStack.push_back(StackDiagPair(P, N));
return;
}
if (auto PS = P.getAs<PostStmt>()) {
if (!AddPathEdges)
return;
// For expressions, make sure we propagate the
// interesting symbols correctly.
if (const Expr *Ex = PS->getStmtAs<Expr>())
reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE,
N->getState().get(), Ex,
N->getLocationContext());
// Add an edge. If this is an ObjCForCollectionStmt do
// not add an edge here as it appears in the CFG both
// as a terminator and as a terminator condition.
if (!isa<ObjCForCollectionStmt>(PS->getStmt())) {
PathDiagnosticLocation L =
PathDiagnosticLocation(PS->getStmt(), SM, PDB.LC);
addEdgeToPath(PD.getActivePath(), PrevLoc, L);
}
} else if (auto BE = P.getAs<BlockEdge>()) {
if (!AddPathEdges) {
generateMinimalDiagForBlockEdge(N, *BE, SM, PDB, PD);
return;
}
// Does this represent entering a call? If so, look at propagating
// interesting symbols across call boundaries.
if (const ExplodedNode *NextNode = N->getFirstPred()) {
const LocationContext *CallerCtx = NextNode->getLocationContext();
const LocationContext *CalleeCtx = PDB.LC;
if (CallerCtx != CalleeCtx && AddPathEdges) {
reversePropagateInterestingSymbols(*PDB.getBugReport(), IE,
N->getState().get(), CalleeCtx);
}
}
// 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 Stmt *Body = nullptr;
if (const auto *FS = dyn_cast<ForStmt>(Loop))
Body = FS->getBody();
else if (const auto *WS = dyn_cast<WhileStmt>(Loop))
Body = WS->getBody();
else if (const auto *OFS = dyn_cast<ObjCForCollectionStmt>(Loop)) {
Body = OFS->getBody();
} else if (const auto *FRS = dyn_cast<CXXForRangeStmt>(Loop)) {
Body = FRS->getBody();
}
// do-while statements are explicitly excluded here
auto p = std::make_shared<PathDiagnosticEventPiece>(
L, "Looping back to the head "
"of the loop");
p->setPrunable(true);
addEdgeToPath(PD.getActivePath(), PrevLoc, p->getLocation());
PD.getActivePath().push_front(std::move(p));
if (const auto *CS = dyn_cast_or_null<CompoundStmt>(Body)) {
addEdgeToPath(PD.getActivePath(), PrevLoc,
PathDiagnosticLocation::createEndBrace(CS, SM));
}
}
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 (isLoop(Term)) {
const Stmt *TermCond = getTerminatorCondition(BSrc);
bool IsInLoopBody =
isInLoopBody(PM, getStmtBeforeCond(PM, TermCond, N), Term);
const char *str = nullptr;
if (isJumpToFalseBranch(&*BE)) {
if (!IsInLoopBody) {
if (isa<ObjCForCollectionStmt>(Term)) {
str = StrLoopCollectionEmpty;
} else if (isa<CXXForRangeStmt>(Term)) {
str = StrLoopRangeEmpty;
} else {
str = StrLoopBodyZero;
}
}
} else {
str = StrEnteringLoop;
}
if (str) {
PathDiagnosticLocation L(TermCond ? TermCond : Term, SM, PDB.LC);
auto PE = std::make_shared<PathDiagnosticEventPiece>(L, str);
PE->setPrunable(true);
addEdgeToPath(PD.getActivePath(), PrevLoc,
PE->getLocation());
PD.getActivePath().push_front(std::move(PE));
}
} else if (isa<BreakStmt>(Term) || isa<ContinueStmt>(Term) ||
isa<GotoStmt>(Term)) {
PathDiagnosticLocation L(Term, SM, PDB.LC);
addEdgeToPath(PD.getActivePath(), PrevLoc, L);
}
}
}
}
static std::unique_ptr<PathDiagnostic>
generateEmptyDiagnosticForReport(BugReport *R, SourceManager &SM) {
BugType &BT = R->getBugType();
return llvm::make_unique<PathDiagnostic>(
R->getBugType().getCheckName(), R->getDeclWithIssue(),
R->getBugType().getName(), R->getDescription(),
R->getShortDescription(/*Fallback=*/false), BT.getCategory(),
R->getUniqueingLocation(), R->getUniqueingDecl(),
findExecutedLines(SM, R->getErrorNode()));
}
static const Stmt *getStmtParent(const Stmt *S, const ParentMap &PM) {
if (!S)
return nullptr;
while (true) {
S = PM.getParentIgnoreParens(S);
if (!S)
break;
if (isa<FullExpr>(S) ||
isa<CXXBindTemporaryExpr>(S) ||
isa<SubstNonTypeTemplateParmExpr>(S))
continue;
break;
}
return S;
}
static bool isConditionForTerminator(const Stmt *S, const Stmt *Cond) {
switch (S->getStmtClass()) {
case Stmt::BinaryOperatorClass: {
const auto *BO = cast<BinaryOperator>(S);
if (!BO->isLogicalOp())
return false;
return BO->getLHS() == Cond || BO->getRHS() == Cond;
}
case Stmt::IfStmtClass:
return cast<IfStmt>(S)->getCond() == Cond;
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: {
const auto *CO = cast<ConditionalOperator>(S);
return CO->getCond() == Cond ||
CO->getLHS() == Cond ||
CO->getRHS() == Cond;
}
case Stmt::ObjCForCollectionStmtClass:
return cast<ObjCForCollectionStmt>(S)->getElement() == Cond;
case Stmt::CXXForRangeStmtClass: {
const auto *FRS = cast<CXXForRangeStmt>(S);
return FRS->getCond() == Cond || FRS->getRangeInit() == Cond;
}
default:
return false;
}
}
static bool isIncrementOrInitInForLoop(const Stmt *S, const Stmt *FL) {
if (const auto *FS = dyn_cast<ForStmt>(FL))
return FS->getInc() == S || FS->getInit() == S;
if (const auto *FRS = dyn_cast<CXXForRangeStmt>(FL))
return FRS->getInc() == S || FRS->getRangeStmt() == S ||
FRS->getLoopVarStmt() || FRS->getRangeInit() == S;
return false;
}
using OptimizedCallsSet = llvm::DenseSet<const PathDiagnosticCallPiece *>;
/// Adds synthetic edges from top-level statements to their subexpressions.
///
/// This avoids a "swoosh" effect, where an edge from a top-level statement A
/// points to a sub-expression B.1 that's not at the start of B. In these cases,
/// we'd like to see an edge from A to B, then another one from B to B.1.
static void addContextEdges(PathPieces &pieces, SourceManager &SM,
const ParentMap &PM, const LocationContext *LCtx) {
PathPieces::iterator Prev = pieces.end();
for (PathPieces::iterator I = pieces.begin(), E = Prev; I != E;
Prev = I, ++I) {
auto *Piece = dyn_cast<PathDiagnosticControlFlowPiece>(I->get());
if (!Piece)
continue;
PathDiagnosticLocation SrcLoc = Piece->getStartLocation();
SmallVector<PathDiagnosticLocation, 4> SrcContexts;
PathDiagnosticLocation NextSrcContext = SrcLoc;
const Stmt *InnerStmt = nullptr;
while (NextSrcContext.isValid() && NextSrcContext.asStmt() != InnerStmt) {
SrcContexts.push_back(NextSrcContext);
InnerStmt = NextSrcContext.asStmt();
NextSrcContext = getEnclosingStmtLocation(InnerStmt, SM, PM, LCtx,
/*allowNested=*/true);
}
// Repeatedly split the edge as necessary.
// This is important for nested logical expressions (||, &&, ?:) where we
// want to show all the levels of context.
while (true) {
const Stmt *Dst = Piece->getEndLocation().getStmtOrNull();
// We are looking at an edge. Is the destination within a larger
// expression?
PathDiagnosticLocation DstContext =
getEnclosingStmtLocation(Dst, SM, PM, LCtx, /*allowNested=*/true);
if (!DstContext.isValid() || DstContext.asStmt() == Dst)
break;
// If the source is in the same context, we're already good.
if (std::find(SrcContexts.begin(), SrcContexts.end(), DstContext) !=
SrcContexts.end())
break;
// Update the subexpression node to point to the context edge.
Piece->setStartLocation(DstContext);
// Try to extend the previous edge if it's at the same level as the source
// context.
if (Prev != E) {
auto *PrevPiece = dyn_cast<PathDiagnosticControlFlowPiece>(Prev->get());
if (PrevPiece) {
if (const Stmt *PrevSrc =
PrevPiece->getStartLocation().getStmtOrNull()) {
const Stmt *PrevSrcParent = getStmtParent(PrevSrc, PM);
if (PrevSrcParent ==
getStmtParent(DstContext.getStmtOrNull(), PM)) {
PrevPiece->setEndLocation(DstContext);
break;
}
}
}
}
// Otherwise, split the current edge into a context edge and a
// subexpression edge. Note that the context statement may itself have
// context.
auto P =
std::make_shared<PathDiagnosticControlFlowPiece>(SrcLoc, DstContext);
Piece = P.get();
I = pieces.insert(I, std::move(P));
}
}
}
/// Move edges from a branch condition to a branch target
/// when the condition is simple.
///
/// This restructures some of the work of addContextEdges. That function
/// creates edges this may destroy, but they work together to create a more
/// aesthetically set of edges around branches. After the call to
/// addContextEdges, we may have (1) an edge to the branch, (2) an edge from
/// the branch to the branch condition, and (3) an edge from the branch
/// condition to the branch target. We keep (1), but may wish to remove (2)
/// and move the source of (3) to the branch if the branch condition is simple.
static void simplifySimpleBranches(PathPieces &pieces) {
for (PathPieces::iterator I = pieces.begin(), E = pieces.end(); I != E; ++I) {
const auto *PieceI = dyn_cast<PathDiagnosticControlFlowPiece>(I->get());
if (!PieceI)
continue;
const Stmt *s1Start = PieceI->getStartLocation().getStmtOrNull();
const Stmt *s1End = PieceI->getEndLocation().getStmtOrNull();
if (!s1Start || !s1End)
continue;
PathPieces::iterator NextI = I; ++NextI;
if (NextI == E)
break;
PathDiagnosticControlFlowPiece *PieceNextI = nullptr;
while (true) {
if (NextI == E)
break;
const auto *EV = dyn_cast<PathDiagnosticEventPiece>(NextI->get());
if (EV) {
StringRef S = EV->getString();
if (S == StrEnteringLoop || S == StrLoopBodyZero ||
S == StrLoopCollectionEmpty || S == StrLoopRangeEmpty) {
++NextI;
continue;
}
break;
}
PieceNextI = dyn_cast<PathDiagnosticControlFlowPiece>(NextI->get());
break;
}
if (!PieceNextI)
continue;
const Stmt *s2Start = PieceNextI->getStartLocation().getStmtOrNull();
const Stmt *s2End = PieceNextI->getEndLocation().getStmtOrNull();
if (!s2Start || !s2End || s1End != s2Start)
continue;
// We only perform this transformation for specific branch kinds.
// We don't want to do this for do..while, for example.
if (!(isa<ForStmt>(s1Start) || isa<WhileStmt>(s1Start) ||
isa<IfStmt>(s1Start) || isa<ObjCForCollectionStmt>(s1Start) ||
isa<CXXForRangeStmt>(s1Start)))
continue;
// Is s1End the branch condition?
if (!isConditionForTerminator(s1Start, s1End))
continue;
// Perform the hoisting by eliminating (2) and changing the start
// location of (3).
PieceNextI->setStartLocation(PieceI->getStartLocation());
I = pieces.erase(I);
}
}
/// Returns the number of bytes in the given (character-based) SourceRange.
///
/// If the locations in the range are not on the same line, returns None.
///
/// Note that this does not do a precise user-visible character or column count.
static Optional<size_t> getLengthOnSingleLine(SourceManager &SM,
SourceRange Range) {
SourceRange ExpansionRange(SM.getExpansionLoc(Range.getBegin()),
SM.getExpansionRange(Range.getEnd()).getEnd());
FileID FID = SM.getFileID(ExpansionRange.getBegin());
if (FID != SM.getFileID(ExpansionRange.getEnd()))
return None;
bool Invalid;
const llvm::MemoryBuffer *Buffer = SM.getBuffer(FID, &Invalid);
if (Invalid)
return None;
unsigned BeginOffset = SM.getFileOffset(ExpansionRange.getBegin());
unsigned EndOffset = SM.getFileOffset(ExpansionRange.getEnd());
StringRef Snippet = Buffer->getBuffer().slice(BeginOffset, EndOffset);
// We're searching the raw bytes of the buffer here, which might include
// escaped newlines and such. That's okay; we're trying to decide whether the
// SourceRange is covering a large or small amount of space in the user's
// editor.
if (Snippet.find_first_of("\r\n") != StringRef::npos)
return None;
// This isn't Unicode-aware, but it doesn't need to be.
return Snippet.size();
}
/// \sa getLengthOnSingleLine(SourceManager, SourceRange)
static Optional<size_t> getLengthOnSingleLine(SourceManager &SM,
const Stmt *S) {
return getLengthOnSingleLine(SM, S->getSourceRange());
}
/// Eliminate two-edge cycles created by addContextEdges().
///
/// Once all the context edges are in place, there are plenty of cases where
/// there's a single edge from a top-level statement to a subexpression,
/// followed by a single path note, and then a reverse edge to get back out to
/// the top level. If the statement is simple enough, the subexpression edges
/// just add noise and make it harder to understand what's going on.
///
/// This function only removes edges in pairs, because removing only one edge
/// might leave other edges dangling.
///
/// This will not remove edges in more complicated situations:
/// - if there is more than one "hop" leading to or from a subexpression.
/// - if there is an inlined call between the edges instead of a single event.
/// - if the whole statement is large enough that having subexpression arrows
/// might be helpful.
static void removeContextCycles(PathPieces &Path, SourceManager &SM) {
for (PathPieces::iterator I = Path.begin(), E = Path.end(); I != E; ) {
// Pattern match the current piece and its successor.
const auto *PieceI = dyn_cast<PathDiagnosticControlFlowPiece>(I->get());
if (!PieceI) {
++I;
continue;
}
const Stmt *s1Start = PieceI->getStartLocation().getStmtOrNull();
const Stmt *s1End = PieceI->getEndLocation().getStmtOrNull();
PathPieces::iterator NextI = I; ++NextI;
if (NextI == E)
break;
const auto *PieceNextI =
dyn_cast<PathDiagnosticControlFlowPiece>(NextI->get());
if (!PieceNextI) {
if (isa<PathDiagnosticEventPiece>(NextI->get())) {
++NextI;
if (NextI == E)
break;
PieceNextI = dyn_cast<PathDiagnosticControlFlowPiece>(NextI->get());
}
if (!PieceNextI) {
++I;
continue;
}
}
const Stmt *s2Start = PieceNextI->getStartLocation().getStmtOrNull();
const Stmt *s2End = PieceNextI->getEndLocation().getStmtOrNull();
if (s1Start && s2Start && s1Start == s2End && s2Start == s1End) {
const size_t MAX_SHORT_LINE_LENGTH = 80;
Optional<size_t> s1Length = getLengthOnSingleLine(SM, s1Start);
if (s1Length && *s1Length <= MAX_SHORT_LINE_LENGTH) {
Optional<size_t> s2Length = getLengthOnSingleLine(SM, s2Start);
if (s2Length && *s2Length <= MAX_SHORT_LINE_LENGTH) {
Path.erase(I);
I = Path.erase(NextI);
continue;
}
}
}
++I;
}
}
/// Return true if X is contained by Y.
static bool lexicalContains(ParentMap &PM, const Stmt *X, const Stmt *Y) {
while (X) {
if (X == Y)
return true;
X = PM.getParent(X);
}
return false;
}
// Remove short edges on the same line less than 3 columns in difference.
static void removePunyEdges(PathPieces &path, SourceManager &SM,
ParentMap &PM) {
bool erased = false;
for (PathPieces::iterator I = path.begin(), E = path.end(); I != E;
erased ? I : ++I) {
erased = false;
const auto *PieceI = dyn_cast<PathDiagnosticControlFlowPiece>(I->get());
if (!PieceI)
continue;
const Stmt *start = PieceI->getStartLocation().getStmtOrNull();
const Stmt *end = PieceI->getEndLocation().getStmtOrNull();
if (!start || !end)
continue;
const Stmt *endParent = PM.getParent(end);
if (!endParent)
continue;
if (isConditionForTerminator(end, endParent))
continue;
SourceLocation FirstLoc = start->getBeginLoc();
SourceLocation SecondLoc = end->getBeginLoc();
if (!SM.isWrittenInSameFile(FirstLoc, SecondLoc))
continue;
if (SM.isBeforeInTranslationUnit(SecondLoc, FirstLoc))
std::swap(SecondLoc, FirstLoc);
SourceRange EdgeRange(FirstLoc, SecondLoc);
Optional<size_t> ByteWidth = getLengthOnSingleLine(SM, EdgeRange);
// If the statements are on different lines, continue.
if (!ByteWidth)
continue;
const size_t MAX_PUNY_EDGE_LENGTH = 2;
if (*ByteWidth <= MAX_PUNY_EDGE_LENGTH) {
// FIXME: There are enough /bytes/ between the endpoints of the edge, but
// there might not be enough /columns/. A proper user-visible column count
// is probably too expensive, though.
I = path.erase(I);
erased = true;
continue;
}
}
}
static void removeIdenticalEvents(PathPieces &path) {
for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; ++I) {
const auto *PieceI = dyn_cast<PathDiagnosticEventPiece>(I->get());
if (!PieceI)
continue;
PathPieces::iterator NextI = I; ++NextI;
if (NextI == E)
return;
const auto *PieceNextI = dyn_cast<PathDiagnosticEventPiece>(NextI->get());
if (!PieceNextI)
continue;
// Erase the second piece if it has the same exact message text.
if (PieceI->getString() == PieceNextI->getString()) {
path.erase(NextI);
}
}
}
static bool optimizeEdges(PathPieces &path, SourceManager &SM,
OptimizedCallsSet &OCS,
LocationContextMap &LCM) {
bool hasChanges = false;
const LocationContext *LC = LCM[&path];
assert(LC);
ParentMap &PM = LC->getParentMap();
for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; ) {
// Optimize subpaths.
if (auto *CallI = dyn_cast<PathDiagnosticCallPiece>(I->get())) {
// 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, OCS, LCM)) {}
OCS.insert(CallI);
}
++I;
continue;
}
// Pattern match the current piece and its successor.
auto *PieceI = dyn_cast<PathDiagnosticControlFlowPiece>(I->get());
if (!PieceI) {
++I;
continue;
}
const Stmt *s1Start = PieceI->getStartLocation().getStmtOrNull();
const Stmt *s1End = PieceI->getEndLocation().getStmtOrNull();
const Stmt *level1 = getStmtParent(s1Start, PM);
const Stmt *level2 = getStmtParent(s1End, PM);
PathPieces::iterator NextI = I; ++NextI;
if (NextI == E)
break;
const auto *PieceNextI = dyn_cast<PathDiagnosticControlFlowPiece>(NextI->get());
if (!PieceNextI) {
++I;
continue;
}
const Stmt *s2Start = PieceNextI->getStartLocation().getStmtOrNull();
const Stmt *s2End = PieceNextI->getEndLocation().getStmtOrNull();
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.
//
// Eliminate edges between subexpressions and parent expressions
// when the subexpression is consumed.
//
// NOTE: this will be limited later in cases where we add barriers
// to prevent this optimization.
if (s1End && s1End == s2Start && level2) {
bool removeEdge = false;
// Remove edges into the increment or initialization of a
// loop that have no interleaving event. This means that
// they aren't interesting.
if (isIncrementOrInitInForLoop(s1End, level2))
removeEdge = true;
// Next only consider edges that are not anchored on
// the condition of a terminator. This are intermediate edges
// that we might want to trim.
else if (!isConditionForTerminator(level2, s1End)) {
// Trim edges on expressions that are consumed by
// the parent expression.
if (isa<Expr>(s1End) && PM.isConsumedExpr(cast<Expr>(s1End))) {
removeEdge = true;
}
// Trim edges where a lexical containment doesn't exist.
// For example:
//
// X -> Y -> Z
//
// If 'Z' lexically contains Y (it is an ancestor) and
// 'X' does not lexically contain Y (it is a descendant OR
// it has no lexical relationship at all) then trim.
//
// This can eliminate edges where we dive into a subexpression
// and then pop back out, etc.
else if (s1Start && s2End &&
lexicalContains(PM, s2Start, s2End) &&
!lexicalContains(PM, s1End, s1Start)) {
removeEdge = true;
}
// Trim edges from a subexpression back to the top level if the
// subexpression is on a different line.
//
// A.1 -> A -> B
// becomes
// A.1 -> B
//
// These edges just look ugly and don't usually add anything.
else if (s1Start && s2End &&
lexicalContains(PM, s1Start, s1End)) {
SourceRange EdgeRange(PieceI->getEndLocation().asLocation(),
PieceI->getStartLocation().asLocation());
if (!getLengthOnSingleLine(SM, EdgeRange).hasValue())
removeEdge = true;
}
}
if (removeEdge) {
PieceI->setEndLocation(PieceNextI->getEndLocation());
path.erase(NextI);
hasChanges = true;
continue;
}
}
// Optimize edges for ObjC fast-enumeration loops.
//
// (X -> collection) -> (collection -> element)
//
// becomes:
//
// (X -> element)
if (s1End == s2Start) {
const auto *FS = dyn_cast_or_null<ObjCForCollectionStmt>(level3);
if (FS && FS->getCollection()->IgnoreParens() == s2Start &&
s2End == FS->getElement()) {
PieceI->setEndLocation(PieceNextI->getEndLocation());
path.erase(NextI);
hasChanges = true;
continue;
}
}
// No changes at this index? Move to the next one.
++I;
}
if (!hasChanges) {
// Adjust edges into subexpressions to make them more uniform
// and aesthetically pleasing.
addContextEdges(path, SM, PM, LC);
// Remove "cyclical" edges that include one or more context edges.
removeContextCycles(path, SM);
// Hoist edges originating from branch conditions to branches
// for simple branches.
simplifySimpleBranches(path);
// Remove any puny edges left over after primary optimization pass.
removePunyEdges(path, SM, PM);
// Remove identical events.
removeIdenticalEvents(path);
}
return hasChanges;
}
/// Drop the very first edge in a path, which should be a function entry edge.
///
/// If the first edge is not a function entry edge (say, because the first
/// statement had an invalid source location), this function does nothing.
// FIXME: We should just generate invalid edges anyway and have the optimizer
// deal with them.
static void dropFunctionEntryEdge(PathPieces &Path, LocationContextMap &LCM,
SourceManager &SM) {
const auto *FirstEdge =
dyn_cast<PathDiagnosticControlFlowPiece>(Path.front().get());
if (!FirstEdge)
return;
const Decl *D = LCM[&Path]->getDecl();
PathDiagnosticLocation EntryLoc = PathDiagnosticLocation::createBegin(D, SM);
if (FirstEdge->getStartLocation() != EntryLoc)
return;
Path.pop_front();
}
using VisitorsDiagnosticsTy = llvm::DenseMap<const ExplodedNode *,
std::vector<std::shared_ptr<PathDiagnosticPiece>>>;
/// Populate executes lines with lines containing at least one diagnostics.
static void updateExecutedLinesWithDiagnosticPieces(
PathDiagnostic &PD) {
PathPieces path = PD.path.flatten(/*ShouldFlattenMacros=*/true);
FilesToLineNumsMap &ExecutedLines = PD.getExecutedLines();
for (const auto &P : path) {
FullSourceLoc Loc = P->getLocation().asLocation().getExpansionLoc();
FileID FID = Loc.getFileID();
unsigned LineNo = Loc.getLineNumber();
assert(FID.isValid());
ExecutedLines[FID].insert(LineNo);
}
}
/// This function is responsible for generating diagnostic pieces that are
/// *not* provided by bug report visitors.
/// These diagnostics may differ depending on the consumer's settings,
/// and are therefore constructed separately for each consumer.
///
/// There are two path diagnostics generation modes: with adding edges (used
/// for plists) and without (used for HTML and text).
/// When edges are added (\p ActiveScheme is Extensive),
/// the path is modified to insert artificially generated
/// edges.
/// Otherwise, more detailed diagnostics is emitted for block edges, explaining
/// the transitions in words.
static std::unique_ptr<PathDiagnostic> generatePathDiagnosticForConsumer(
PathDiagnosticConsumer::PathGenerationScheme ActiveScheme,
PathDiagnosticBuilder &PDB,
const ExplodedNode *ErrorNode,
const VisitorsDiagnosticsTy &VisitorsDiagnostics) {
bool GenerateDiagnostics = (ActiveScheme != PathDiagnosticConsumer::None);
bool AddPathEdges = (ActiveScheme == PathDiagnosticConsumer::Extensive);
SourceManager &SM = PDB.getSourceManager();
BugReport *R = PDB.getBugReport();
AnalyzerOptions &Opts = PDB.getBugReporter().getAnalyzerOptions();
StackDiagVector CallStack;
InterestingExprs IE;
LocationContextMap LCM;
std::unique_ptr<PathDiagnostic> PD = generateEmptyDiagnosticForReport(R, SM);
if (GenerateDiagnostics) {
auto EndNotes = VisitorsDiagnostics.find(ErrorNode);
std::shared_ptr<PathDiagnosticPiece> LastPiece;
if (EndNotes != VisitorsDiagnostics.end()) {
assert(!EndNotes->second.empty());
LastPiece = EndNotes->second[0];
} else {
LastPiece = BugReporterVisitor::getDefaultEndPath(PDB, ErrorNode, *R);
}
PD->setEndOfPath(LastPiece);
}
PathDiagnosticLocation PrevLoc = PD->getLocation();
const ExplodedNode *NextNode = ErrorNode->getFirstPred();
while (NextNode) {
if (GenerateDiagnostics)
generatePathDiagnosticsForNode(
NextNode, *PD, PrevLoc, PDB, LCM, CallStack, IE, AddPathEdges);
auto VisitorNotes = VisitorsDiagnostics.find(NextNode);
NextNode = NextNode->getFirstPred();
if (!GenerateDiagnostics || VisitorNotes == VisitorsDiagnostics.end())
continue;
// This is a workaround due to inability to put shared PathDiagnosticPiece
// into a FoldingSet.
std::set<llvm::FoldingSetNodeID> DeduplicationSet;
// Add pieces from custom visitors.
for (const auto &Note : VisitorNotes->second) {
llvm::FoldingSetNodeID ID;
Note->Profile(ID);
auto P = DeduplicationSet.insert(ID);
if (!P.second)
continue;
if (AddPathEdges)
addEdgeToPath(PD->getActivePath(), PrevLoc, Note->getLocation());
updateStackPiecesWithMessage(*Note, CallStack);
PD->getActivePath().push_front(Note);
}
}
if (AddPathEdges) {
// Add an edge to the start of the function.
// We'll prune it out later, but it helps make diagnostics more uniform.
const StackFrameContext *CalleeLC = PDB.LC->getStackFrame();
const Decl *D = CalleeLC->getDecl();
addEdgeToPath(PD->getActivePath(), PrevLoc,
PathDiagnosticLocation::createBegin(D, SM));
}
// Finally, prune the diagnostic path of uninteresting stuff.
if (!PD->path.empty()) {
if (R->shouldPrunePath() && Opts.ShouldPrunePaths) {
bool stillHasNotes =
removeUnneededCalls(PD->getMutablePieces(), R, LCM);
assert(stillHasNotes);
(void)stillHasNotes;
}
// Redirect all call pieces to have valid locations.
adjustCallLocations(PD->getMutablePieces());
removePiecesWithInvalidLocations(PD->getMutablePieces());
if (AddPathEdges) {
// Reduce the number of edges from a very conservative set
// to an aesthetically pleasing subset that conveys the
// necessary information.
OptimizedCallsSet OCS;
while (optimizeEdges(PD->getMutablePieces(), SM, OCS, LCM)) {}
// Drop the very first function-entry edge. It's not really necessary
// for top-level functions.
dropFunctionEntryEdge(PD->getMutablePieces(), LCM, SM);
}
// Remove messages that are basically the same, and edges that may not
// make sense.
// We have to do this after edge optimization in the Extensive mode.
removeRedundantMsgs(PD->getMutablePieces());
removeEdgesToDefaultInitializers(PD->getMutablePieces());
}
if (GenerateDiagnostics && Opts.ShouldDisplayMacroExpansions)
CompactMacroExpandedPieces(PD->getMutablePieces(), SM);
return PD;
}
//===----------------------------------------------------------------------===//
// Methods for BugType and subclasses.
//===----------------------------------------------------------------------===//
void BugType::anchor() {}
void BuiltinBug::anchor() {}
//===----------------------------------------------------------------------===//
// Methods for BugReport and subclasses.
//===----------------------------------------------------------------------===//
void BugReport::NodeResolver::anchor() {}
void BugReport::addVisitor(std::unique_ptr<BugReporterVisitor> visitor) {
if (!visitor)
return;
llvm::FoldingSetNodeID ID;
visitor->Profile(ID);
void *InsertPos = nullptr;
if (CallbacksSet.FindNodeOrInsertPos(ID, InsertPos)) {
return;
}
Callbacks.push_back(std::move(visitor));
}
void BugReport::clearVisitors() {
Callbacks.clear();
}
BugReport::~BugReport() {
while (!interestingSymbols.empty()) {
popInterestingSymbolsAndRegions();
}
}
const Decl *BugReport::getDeclWithIssue() const {
if (DeclWithIssue)
return DeclWithIssue;
const ExplodedNode *N = getErrorNode();
if (!N)
return nullptr;
const LocationContext *LC = N->getLocationContext();
return LC->getStackFrame()->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 (SourceRange range : Ranges) {
if (!range.isValid())
continue;
hash.AddInteger(range.getBegin().getRawEncoding());
hash.AddInteger(range.getEnd().getRawEncoding());
}
}
void BugReport::markInteresting(SymbolRef sym) {
if (!sym)
return;
getInterestingSymbols().insert(sym);
if (const auto *meta = dyn_cast<SymbolMetadata>(sym))
getInterestingRegions().insert(meta->getRegion());
}
void BugReport::markInteresting(const MemRegion *R) {
if (!R)
return;
R = R->getBaseRegion();
getInterestingRegions().insert(R);
if (const auto *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 auto *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.pop_back_val();
delete interestingRegions.pop_back_val();
}
const Stmt *BugReport::getStmt() const {
if (!ErrorNode)
return nullptr;
ProgramPoint ProgP = ErrorNode->getLocation();
const Stmt *S = nullptr;
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;
}
llvm::iterator_range<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 auto *E = dyn_cast_or_null<Expr>(getStmt()))
addRange(E->getSourceRange());
else
return llvm::make_range(ranges_iterator(), ranges_iterator());
}
// User-specified absence of range info.
if (Ranges.size() == 1 && !Ranges.begin()->isValid())
return llvm::make_range(ranges_iterator(), ranges_iterator());
return llvm::make_range(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);
}
assert(Location.isValid());
return Location;
}
//===----------------------------------------------------------------------===//
// Methods for BugReporter and subclasses.
//===----------------------------------------------------------------------===//
BugReportEquivClass::~BugReportEquivClass() = default;
GRBugReporter::~GRBugReporter() = default;
BugReporterData::~BugReporterData() = default;
ExplodedGraph &GRBugReporter::getGraph() { return Eng.getGraph(); }
ProgramStateManager&
GRBugReporter::getStateManager() { return Eng.getStateManager(); }
BugReporter::~BugReporter() {
FlushReports();
// Free the bug reports we are tracking.
for (const auto I : EQClassesVector)
delete I;
}
void BugReporter::FlushReports() {
if (BugTypes.isEmpty())
return;
// We need to flush reports in deterministic order to ensure the order
// of the reports is consistent between runs.
for (const auto EQ : EQClassesVector)
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.
llvm::DeleteContainerSeconds(StrBugTypes);
// 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;
std::unique_ptr<ExplodedGraph> Graph;
const ExplodedNode *ErrorNode;
size_t Index;
};
/// A wrapper around a trimmed graph and its node maps.
class TrimmedGraph {
InterExplodedGraphMap InverseMap;
using PriorityMapTy = llvm::DenseMap<const ExplodedNode *, unsigned>;
PriorityMapTy PriorityMap;
using NodeIndexPair = std::pair<const ExplodedNode *, size_t>;
SmallVector<NodeIndexPair, 32> ReportNodes;
std::unique_ptr<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);
};
} // namespace
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 = 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;
std::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.
llvm::sort(ReportNodes, PriorityCompare<true>(PriorityMap));
}
bool TrimmedGraph::popNextReportGraph(ReportGraph &GraphWrapper) {
if (ReportNodes.empty())
return false;
const ExplodedNode *OrigN;
std::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.
auto GNew = llvm::make_unique<ExplodedGraph>();
GraphWrapper.BackMap.clear();
// Now walk from the error node up the BFS path, always taking the
// predeccessor with the lowest number.
ExplodedNode *Succ = nullptr;
while (true) {
// Create the equivalent node in the new graph with the same state
// and location.
ExplodedNode *NewN = GNew->createUncachedNode(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));
}
GraphWrapper.Graph = std::move(GNew);
return true;
}
/// CompactMacroExpandedPieces - This function postprocesses a PathDiagnostic
/// object and collapses PathDiagosticPieces that are expanded by macros.
static void CompactMacroExpandedPieces(PathPieces &path,
const SourceManager& SM) {
using MacroStackTy =
std::vector<
std::pair<std::shared_ptr<PathDiagnosticMacroPiece>, SourceLocation>>;
using PiecesTy = std::vector<std::shared_ptr<PathDiagnosticPiece>>;
MacroStackTy MacroStack;
PiecesTy Pieces;
for (PathPieces::const_iterator I = path.begin(), E = path.end();
I != E; ++I) {
const auto &piece = *I;
// Recursively compact calls.
if (auto *call = dyn_cast<PathDiagnosticCallPiece>(&*piece)) {
CompactMacroExpandedPieces(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?
std::shared_ptr<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.
auto NewGroup = std::make_shared<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();
path.insert(path.end(), Pieces.begin(), Pieces.end());
}
/// Generate notes from all visitors.
/// Notes associated with {@code ErrorNode} are generated using
/// {@code getEndPath}, and the rest are generated with {@code VisitNode}.
static std::unique_ptr<VisitorsDiagnosticsTy>
generateVisitorsDiagnostics(BugReport *R, const ExplodedNode *ErrorNode,
BugReporterContext &BRC) {
auto Notes = llvm::make_unique<VisitorsDiagnosticsTy>();
BugReport::VisitorList visitors;
// Run visitors on all nodes starting from the node *before* the last one.
// The last node is reserved for notes generated with {@code getEndPath}.
const ExplodedNode *NextNode = ErrorNode->getFirstPred();
while (NextNode) {
// At each iteration, move all visitors from report to visitor list.
for (BugReport::visitor_iterator I = R->visitor_begin(),
E = R->visitor_end();
I != E; ++I) {
visitors.push_back(std::move(*I));
}
R->clearVisitors();
const ExplodedNode *Pred = NextNode->getFirstPred();
if (!Pred) {
std::shared_ptr<PathDiagnosticPiece> LastPiece;
for (auto &V : visitors) {
V->finalizeVisitor(BRC, ErrorNode, *R);
if (auto Piece = V->getEndPath(BRC, ErrorNode, *R)) {
assert(!LastPiece &&
"There can only be one final piece in a diagnostic.");
LastPiece = std::move(Piece);
(*Notes)[ErrorNode].push_back(LastPiece);
}
}
break;
}
for (auto &V : visitors) {
auto P = V->VisitNode(NextNode, BRC, *R);
if (P)
(*Notes)[NextNode].push_back(std::move(P));
}
if (!R->isValid())
break;
NextNode = Pred;
}
return Notes;
}
/// Find a non-invalidated report for a given equivalence class,
/// and return together with a cache of visitors notes.
/// If none found, return a nullptr paired with an empty cache.
static
std::pair<BugReport*, std::unique_ptr<VisitorsDiagnosticsTy>> findValidReport(
TrimmedGraph &TrimG,
ReportGraph &ErrorGraph,
ArrayRef<BugReport *> &bugReports,
AnalyzerOptions &Opts,
GRBugReporter &Reporter) {
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.");
const ExplodedNode *ErrorNode = ErrorGraph.ErrorNode;
// Register refutation visitors first, if they mark the bug invalid no
// further analysis is required
R->addVisitor(llvm::make_unique<LikelyFalsePositiveSuppressionBRVisitor>());
// Register additional node visitors.
R->addVisitor(llvm::make_unique<NilReceiverBRVisitor>());
R->addVisitor(llvm::make_unique<ConditionBRVisitor>());
R->addVisitor(llvm::make_unique<CXXSelfAssignmentBRVisitor>());
BugReporterContext BRC(Reporter, ErrorGraph.BackMap);
// Run all visitors on a given graph, once.
std::unique_ptr<VisitorsDiagnosticsTy> visitorNotes =
generateVisitorsDiagnostics(R, ErrorNode, BRC);
if (R->isValid()) {
if (Opts.ShouldCrosscheckWithZ3) {
// If crosscheck is enabled, remove all visitors, add the refutation
// visitor and check again
R->clearVisitors();
R->addVisitor(llvm::make_unique<FalsePositiveRefutationBRVisitor>());
// We don't overrite the notes inserted by other visitors because the
// refutation manager does not add any new note to the path
generateVisitorsDiagnostics(R, ErrorGraph.ErrorNode, BRC);
}
// Check if the bug is still valid
if (R->isValid())
return std::make_pair(R, std::move(visitorNotes));
}
}
return std::make_pair(nullptr, llvm::make_unique<VisitorsDiagnosticsTy>());
}
std::unique_ptr<DiagnosticForConsumerMapTy>
GRBugReporter::generatePathDiagnostics(
ArrayRef<PathDiagnosticConsumer *> consumers,
ArrayRef<BugReport *> &bugReports) {
assert(!bugReports.empty());
auto Out = llvm::make_unique<DiagnosticForConsumerMapTy>();
bool HasValid = false;
SmallVector<const ExplodedNode *, 32> errorNodes;
for (const auto I : bugReports) {
if (I->isValid()) {
HasValid = true;
errorNodes.push_back(I->getErrorNode());
} else {
// Keep the errorNodes list in sync with the bugReports list.
errorNodes.push_back(nullptr);
}
}
// If all the reports have been marked invalid by a previous path generation,
// we're done.
if (!HasValid)
return Out;
TrimmedGraph TrimG(&getGraph(), errorNodes);
ReportGraph ErrorGraph;
auto ReportInfo = findValidReport(TrimG, ErrorGraph, bugReports,
getAnalyzerOptions(), *this);
BugReport *R = ReportInfo.first;
if (R && R->isValid()) {
const ExplodedNode *ErrorNode = ErrorGraph.ErrorNode;
for (PathDiagnosticConsumer *PC : consumers) {
PathDiagnosticBuilder PDB(*this, R, ErrorGraph.BackMap, PC);
std::unique_ptr<PathDiagnostic> PD = generatePathDiagnosticForConsumer(
PC->getGenerationScheme(), PDB, ErrorNode, *ReportInfo.second);
(*Out)[PC] = std::move(PD);
}
}
return Out;
}
void BugReporter::Register(BugType *BT) {
BugTypes = F.add(BugTypes, BT);
}
void BugReporter::emitReport(std::unique_ptr<BugReport> R) {
if (const ExplodedNode *E = R->getErrorNode()) {
// An error node must either be a sink or have a tag, otherwise
// it could get reclaimed before the path diagnostic is created.
assert((E->isSink() || E->getLocation().getTag()) &&
"Error node must either be a sink or have a tag");
const AnalysisDeclContext *DeclCtx =
E->getLocationContext()->getAnalysisDeclContext();
// The source of autosynthesized body can be handcrafted AST or a model
// file. The locations from handcrafted ASTs have no valid source locations
// and have to be discarded. Locations from model files should be preserved
// for processing and reporting.
if (DeclCtx->isBodyAutosynthesized() &&
!DeclCtx->isBodyAutosynthesizedFromModelFile())
return;
}
bool ValidSourceLoc = R->getLocation(getSourceManager()).isValid();
assert(ValidSourceLoc);
// If we mess up in a release build, we'd still prefer to just drop the bug
// instead of trying to go on.
if (!ValidSourceLoc)
return;
// 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(std::move(R));
EQClasses.InsertNode(EQ, InsertPos);
EQClassesVector.push_back(EQ);
} else
EQ->AddReport(std::move(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()) {}
};
} // namespace
static const CFGBlock *findBlockForNode(const ExplodedNode *N) {
ProgramPoint P = N->getLocation();
if (auto BEP = P.getAs<BlockEntrance>())
return BEP->getBlock();
// Find the node's current statement in the CFG.
if (const Stmt *S = PathDiagnosticLocation::getStmt(N))
return N->getLocationContext()->getAnalysisDeclContext()
->getCFGStmtMap()->getBlock(S);
return nullptr;
}
// Returns true if by simply looking at the block, we can be sure that it
// results in a sink during analysis. This is useful to know when the analysis
// was interrupted, and we try to figure out if it would sink eventually.
// There may be many more reasons why a sink would appear during analysis
// (eg. checkers may generate sinks arbitrarily), but here we only consider
// sinks that would be obvious by looking at the CFG.
static bool isImmediateSinkBlock(const CFGBlock *Blk) {
if (Blk->hasNoReturnElement())
return true;
// FIXME: Throw-expressions are currently generating sinks during analysis:
// they're not supported yet, and also often used for actually terminating
// the program. So we should treat them as sinks in this analysis as well,
// at least for now, but once we have better support for exceptions,
// we'd need to carefully handle the case when the throw is being
// immediately caught.
if (std::any_of(Blk->begin(), Blk->end(), [](const CFGElement &Elm) {
if (Optional<CFGStmt> StmtElm = Elm.getAs<CFGStmt>())
if (isa<CXXThrowExpr>(StmtElm->getStmt()))
return true;
return false;
}))
return true;
return false;
}
// Returns true if by looking at the CFG surrounding the node's program
// point, we can be sure that any analysis starting from this point would
// eventually end with a sink. We scan the child CFG blocks in a depth-first
// manner and see if all paths eventually end up in an immediate sink block.
static bool isInevitablySinking(const ExplodedNode *N) {
const CFG &Cfg = N->getCFG();
const CFGBlock *StartBlk = findBlockForNode(N);
if (!StartBlk)
return false;
if (isImmediateSinkBlock(StartBlk))
return true;
llvm::SmallVector<const CFGBlock *, 32> DFSWorkList;
llvm::SmallPtrSet<const CFGBlock *, 32> Visited;
DFSWorkList.push_back(StartBlk);
while (!DFSWorkList.empty()) {
const CFGBlock *Blk = DFSWorkList.back();
DFSWorkList.pop_back();
Visited.insert(Blk);
// If at least one path reaches the CFG exit, it means that control is
// returned to the caller. For now, say that we are not sure what
// happens next. If necessary, this can be improved to analyze
// the parent StackFrameContext's call site in a similar manner.
if (Blk == &Cfg.getExit())
return false;
for (const auto &Succ : Blk->succs()) {
if (const CFGBlock *SuccBlk = Succ.getReachableBlock()) {
if (!isImmediateSinkBlock(SuccBlk) && !Visited.count(SuccBlk)) {
// If the block has reachable child blocks that aren't no-return,
// add them to the worklist.
DFSWorkList.push_back(SuccBlk);
}
}
}
}
// Nothing reached the exit. It can only mean one thing: there's no return.
return true;
}
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 (auto &I : EQ) {
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 = nullptr;
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;
}
// See if we are in a no-return CFG block. If so, treat this similarly
// to being post-dominated by a sink. This works better when the analysis
// is incomplete and we have never reached the no-return function call(s)
// that we'd inevitably bump into on this path.
if (isInevitablySinking(errorNode))
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.
using WLItem = FRIEC_WLItem;
using DFSWorkList = SmallVector<WLItem, 10>;
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 *report = FindReportInEquivalenceClass(EQ, bugReports);
if (!report)
return;
ArrayRef<PathDiagnosticConsumer*> Consumers = getPathDiagnosticConsumers();
std::unique_ptr<DiagnosticForConsumerMapTy> Diagnostics =
generateDiagnosticForConsumerMap(report, Consumers, bugReports);
for (auto &P : *Diagnostics) {
PathDiagnosticConsumer *Consumer = P.first;
std::unique_ptr<PathDiagnostic> &PD = P.second;
// If the path is empty, generate a single step path with the location
// of the issue.
if (PD->path.empty()) {
PathDiagnosticLocation L = report->getLocation(getSourceManager());
auto piece = llvm::make_unique<PathDiagnosticEventPiece>(
L, report->getDescription());
for (SourceRange Range : report->getRanges())
piece->addRange(Range);
PD->setEndOfPath(std::move(piece));
}
PathPieces &Pieces = PD->getMutablePieces();
if (getAnalyzerOptions().ShouldDisplayNotesAsEvents) {
// For path diagnostic consumers that don't support extra notes,
// we may optionally convert those to path notes.
for (auto I = report->getNotes().rbegin(),
E = report->getNotes().rend(); I != E; ++I) {
PathDiagnosticNotePiece *Piece = I->get();
auto ConvertedPiece = std::make_shared<PathDiagnosticEventPiece>(
Piece->getLocation(), Piece->getString());
for (const auto &R: Piece->getRanges())
ConvertedPiece->addRange(R);
Pieces.push_front(std::move(ConvertedPiece));
}
} else {
for (auto I = report->getNotes().rbegin(),
E = report->getNotes().rend(); I != E; ++I)
Pieces.push_front(*I);
}
// Get the meta data.
const BugReport::ExtraTextList &Meta = report->getExtraText();
for (const auto &i : Meta)
PD->addMeta(i);
updateExecutedLinesWithDiagnosticPieces(*PD);
Consumer->HandlePathDiagnostic(std::move(PD));
}
}
/// Insert all lines participating in the function signature \p Signature
/// into \p ExecutedLines.
static void populateExecutedLinesWithFunctionSignature(
const Decl *Signature, SourceManager &SM,
FilesToLineNumsMap &ExecutedLines) {
SourceRange SignatureSourceRange;
const Stmt* Body = Signature->getBody();
if (const auto FD = dyn_cast<FunctionDecl>(Signature)) {
SignatureSourceRange = FD->getSourceRange();
} else if (const auto OD = dyn_cast<ObjCMethodDecl>(Signature)) {
SignatureSourceRange = OD->getSourceRange();
} else {
return;
}
SourceLocation Start = SignatureSourceRange.getBegin();
SourceLocation End = Body ? Body->getSourceRange().getBegin()
: SignatureSourceRange.getEnd();
if (!Start.isValid() || !End.isValid())
return;
unsigned StartLine = SM.getExpansionLineNumber(Start);
unsigned EndLine = SM.getExpansionLineNumber(End);
FileID FID = SM.getFileID(SM.getExpansionLoc(Start));
for (unsigned Line = StartLine; Line <= EndLine; Line++)
ExecutedLines[FID].insert(Line);
}
static void populateExecutedLinesWithStmt(
const Stmt *S, SourceManager &SM,
FilesToLineNumsMap &ExecutedLines) {
SourceLocation Loc = S->getSourceRange().getBegin();
if (!Loc.isValid())
return;
SourceLocation ExpansionLoc = SM.getExpansionLoc(Loc);
FileID FID = SM.getFileID(ExpansionLoc);
unsigned LineNo = SM.getExpansionLineNumber(ExpansionLoc);
ExecutedLines[FID].insert(LineNo);
}
/// \return all executed lines including function signatures on the path
/// starting from \p N.
static std::unique_ptr<FilesToLineNumsMap>
findExecutedLines(SourceManager &SM, const ExplodedNode *N) {
auto ExecutedLines = llvm::make_unique<FilesToLineNumsMap>();
while (N) {
if (N->getFirstPred() == nullptr) {
// First node: show signature of the entrance point.
const Decl *D = N->getLocationContext()->getDecl();
populateExecutedLinesWithFunctionSignature(D, SM, *ExecutedLines);
} else if (auto CE = N->getLocationAs<CallEnter>()) {
// Inlined function: show signature.
const Decl* D = CE->getCalleeContext()->getDecl();
populateExecutedLinesWithFunctionSignature(D, SM, *ExecutedLines);
} else if (const Stmt *S = PathDiagnosticLocation::getStmt(N)) {
populateExecutedLinesWithStmt(S, SM, *ExecutedLines);
// Show extra context for some parent kinds.
const Stmt *P = N->getParentMap().getParent(S);
// The path exploration can die before the node with the associated
// return statement is generated, but we do want to show the whole
// return.
if (const auto *RS = dyn_cast_or_null<ReturnStmt>(P)) {
populateExecutedLinesWithStmt(RS, SM, *ExecutedLines);
P = N->getParentMap().getParent(RS);
}
if (P && (isa<SwitchCase>(P) || isa<LabelStmt>(P)))
populateExecutedLinesWithStmt(P, SM, *ExecutedLines);
}
N = N->getFirstPred();
}
return ExecutedLines;
}
std::unique_ptr<DiagnosticForConsumerMapTy>
BugReporter::generateDiagnosticForConsumerMap(
BugReport *report, ArrayRef<PathDiagnosticConsumer *> consumers,
ArrayRef<BugReport *> bugReports) {
if (!report->isPathSensitive()) {
auto Out = llvm::make_unique<DiagnosticForConsumerMapTy>();
for (auto *Consumer : consumers)
(*Out)[Consumer] = generateEmptyDiagnosticForReport(report,
getSourceManager());
return Out;
}
// Generate the full path sensitive 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.
assert(!bugReports.empty());
MaxBugClassSize.updateMax(bugReports.size());
std::unique_ptr<DiagnosticForConsumerMapTy> Out =
generatePathDiagnostics(consumers, bugReports);
if (Out->empty())
return Out;
MaxValidBugClassSize.updateMax(bugReports.size());
// Examine the report and see if the last piece is in a header. Reset the
// report location to the last piece in the main source file.
AnalyzerOptions &Opts = getAnalyzerOptions();
for (auto const &P : *Out)
if (Opts.ShouldReportIssuesInMainSourceFile && !Opts.AnalyzeAll)
P.second->resetDiagnosticLocationToMainFile();
return Out;
}
void BugReporter::EmitBasicReport(const Decl *DeclWithIssue,
const CheckerBase *Checker,
StringRef Name, StringRef Category,
StringRef Str, PathDiagnosticLocation Loc,
ArrayRef<SourceRange> Ranges) {
EmitBasicReport(DeclWithIssue, Checker->getCheckName(), Name, Category, Str,
Loc, Ranges);
}
void BugReporter::EmitBasicReport(const Decl *DeclWithIssue,
CheckName CheckName,
StringRef name, StringRef category,
StringRef str, PathDiagnosticLocation Loc,
ArrayRef<SourceRange> Ranges) {
// 'BT' is owned by BugReporter.
BugType *BT = getBugTypeForName(CheckName, name, category);
auto R = llvm::make_unique<BugReport>(*BT, str, Loc);
R->setDeclWithIssue(DeclWithIssue);
for (ArrayRef<SourceRange>::iterator I = Ranges.begin(), E = Ranges.end();
I != E; ++I)
R->addRange(*I);
emitReport(std::move(R));
}
BugType *BugReporter::getBugTypeForName(CheckName CheckName, StringRef name,
StringRef category) {
SmallString<136> fullDesc;
llvm::raw_svector_ostream(fullDesc) << CheckName.getName() << ":" << name
<< ":" << category;
BugType *&BT = StrBugTypes[fullDesc];
if (!BT)
BT = new BugType(CheckName, name, category);
return BT;
}