BugReporter.cpp source code [clang_source_code/lib/StaticAnalyzer/Core/BugReporter.cpp]

1	//===- BugReporter.cpp - Generate PathDiagnostics for bugs ----------------===//
2	//
3	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4	// See https://llvm.org/LICENSE.txt for license information.
5	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6	//
7	//===----------------------------------------------------------------------===//
8	//
9	// This file defines BugReporter, a utility class for generating
10	// PathDiagnostics.
11	//
12	//===----------------------------------------------------------------------===//
13
14	#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
15	#include "clang/AST/Decl.h"
16	#include "clang/AST/DeclBase.h"
17	#include "clang/AST/DeclObjC.h"
18	#include "clang/AST/Expr.h"
19	#include "clang/AST/ExprCXX.h"
20	#include "clang/AST/ParentMap.h"
21	#include "clang/AST/Stmt.h"
22	#include "clang/AST/StmtCXX.h"
23	#include "clang/AST/StmtObjC.h"
24	#include "clang/Analysis/AnalysisDeclContext.h"
25	#include "clang/Analysis/CFG.h"
26	#include "clang/Analysis/CFGStmtMap.h"
27	#include "clang/Analysis/ProgramPoint.h"
28	#include "clang/Basic/LLVM.h"
29	#include "clang/Basic/SourceLocation.h"
30	#include "clang/Basic/SourceManager.h"
31	#include "clang/StaticAnalyzer/Core/AnalyzerOptions.h"
32	#include "clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitors.h"
33	#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
34	#include "clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h"
35	#include "clang/StaticAnalyzer/Core/Checker.h"
36	#include "clang/StaticAnalyzer/Core/CheckerManager.h"
37	#include "clang/StaticAnalyzer/Core/PathSensitive/ExplodedGraph.h"
38	#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
39	#include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
40	#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
41	#include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
42	#include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
43	#include "llvm/ADT/ArrayRef.h"
44	#include "llvm/ADT/DenseMap.h"
45	#include "llvm/ADT/DenseSet.h"
46	#include "llvm/ADT/FoldingSet.h"
47	#include "llvm/ADT/None.h"
48	#include "llvm/ADT/Optional.h"
49	#include "llvm/ADT/STLExtras.h"
50	#include "llvm/ADT/SmallPtrSet.h"
51	#include "llvm/ADT/SmallString.h"
52	#include "llvm/ADT/SmallVector.h"
53	#include "llvm/ADT/Statistic.h"
54	#include "llvm/ADT/StringRef.h"
55	#include "llvm/ADT/iterator_range.h"
56	#include "llvm/Support/Casting.h"
57	#include "llvm/Support/Compiler.h"
58	#include "llvm/Support/ErrorHandling.h"
59	#include "llvm/Support/MemoryBuffer.h"
60	#include "llvm/Support/raw_ostream.h"
61	#include <algorithm>
62	#include <cassert>
63	#include <cstddef>
64	#include <iterator>
65	#include <memory>
66	#include <queue>
67	#include <string>
68	#include <tuple>
69	#include <utility>
70	#include <vector>
71
72	using namespace clang;
73	using namespace ento;
74
75	#define DEBUG_TYPE "BugReporter"
76
77	STATISTIC(MaxBugClassSize,
78	"The maximum number of bug reports in the same equivalence class");
79	STATISTIC(MaxValidBugClassSize,
80	"The maximum number of bug reports in the same equivalence class "
81	"where at least one report is valid (not suppressed)");
82
83	BugReporterVisitor::~BugReporterVisitor() = default;
84
85	void BugReporterContext::anchor() {}
86
87	//===----------------------------------------------------------------------===//
88	// Helper routines for walking the ExplodedGraph and fetching statements.
89	//===----------------------------------------------------------------------===//
90
91	static const Stmt GetPreviousStmt(const ExplodedNode N) {
92	for (N = N->getFirstPred(); N; N = N->getFirstPred())
93	if (const Stmt *S = PathDiagnosticLocation::getStmt(N))
94	return S;
95
96	return nullptr;
97	}
98
99	static inline const Stmt*
100	GetCurrentOrPreviousStmt(const ExplodedNode *N) {
101	if (const Stmt *S = PathDiagnosticLocation::getStmt(N))
102	return S;
103
104	return GetPreviousStmt(N);
105	}
106
107	//===----------------------------------------------------------------------===//
108	// Diagnostic cleanup.
109	//===----------------------------------------------------------------------===//
110
111	static PathDiagnosticEventPiece *
112	eventsDescribeSameCondition(PathDiagnosticEventPiece *X,
113	PathDiagnosticEventPiece *Y) {
114	// Prefer diagnostics that come from ConditionBRVisitor over
115	// those that came from TrackConstraintBRVisitor,
116	// unless the one from ConditionBRVisitor is
117	// its generic fallback diagnostic.
118	const void *tagPreferred = ConditionBRVisitor::getTag();
119	const void *tagLesser = TrackConstraintBRVisitor::getTag();
120
121	if (X->getLocation() != Y->getLocation())
122	return nullptr;
123
124	if (X->getTag() == tagPreferred && Y->getTag() == tagLesser)
125	return ConditionBRVisitor::isPieceMessageGeneric(X) ? Y : X;
126
127	if (Y->getTag() == tagPreferred && X->getTag() == tagLesser)
128	return ConditionBRVisitor::isPieceMessageGeneric(Y) ? X : Y;
129
130	return nullptr;
131	}
132
133	/// An optimization pass over PathPieces that removes redundant diagnostics
134	/// generated by both ConditionBRVisitor and TrackConstraintBRVisitor. Both
135	/// BugReporterVisitors use different methods to generate diagnostics, with
136	/// one capable of emitting diagnostics in some cases but not in others. This
137	/// can lead to redundant diagnostic pieces at the same point in a path.
138	static void removeRedundantMsgs(PathPieces &path) {
139	unsigned N = path.size();
140	if (N < 2)
141	return;
142	// NOTE: this loop intentionally is not using an iterator. Instead, we
143	// are streaming the path and modifying it in place. This is done by
144	// grabbing the front, processing it, and if we decide to keep it append
145	// it to the end of the path. The entire path is processed in this way.
146	for (unsigned i = 0; i < N; ++i) {
147	auto piece = std::move(path.front());
148	path.pop_front();
149
150	switch (piece->getKind()) {
151	case PathDiagnosticPiece::Call:
152	removeRedundantMsgs(cast<PathDiagnosticCallPiece>(*piece).path);
153	break;
154	case PathDiagnosticPiece::Macro:
155	removeRedundantMsgs(cast<PathDiagnosticMacroPiece>(*piece).subPieces);
156	break;
157	case PathDiagnosticPiece::ControlFlow:
158	break;
159	case PathDiagnosticPiece::Event: {
160	if (i == N-1)
161	break;
162
163	if (auto *nextEvent =
164	dyn_cast<PathDiagnosticEventPiece>(path.front().get())) {
165	auto *event = cast<PathDiagnosticEventPiece>(piece.get());
166	// Check to see if we should keep one of the two pieces. If we
167	// come up with a preference, record which piece to keep, and consume
168	// another piece from the path.
169	if (auto *pieceToKeep =
170	eventsDescribeSameCondition(event, nextEvent)) {
171	piece = std::move(pieceToKeep == event ? piece : path.front());
172	path.pop_front();
173	++i;
174	}
175	}
176	break;
177	}
178	case PathDiagnosticPiece::Note:
179	break;
180	}
181	path.push_back(std::move(piece));
182	}
183	}
184
185	/// A map from PathDiagnosticPiece to the LocationContext of the inlined
186	/// function call it represents.
187	using LocationContextMap =
188	llvm::DenseMap<const PathPieces , const LocationContext >;
189
190	/// Recursively scan through a path and prune out calls and macros pieces
191	/// that aren't needed. Return true if afterwards the path contains
192	/// "interesting stuff" which means it shouldn't be pruned from the parent path.
193	static bool removeUnneededCalls(PathPieces &pieces, BugReport *R,
194	LocationContextMap &LCM,
195	bool IsInteresting = false) {
196	bool containsSomethingInteresting = IsInteresting;
197	const unsigned N = pieces.size();
198
199	for (unsigned i = 0 ; i < N ; ++i) {
200	// Remove the front piece from the path. If it is still something we
201	// want to keep once we are done, we will push it back on the end.
202	auto piece = std::move(pieces.front());
203	pieces.pop_front();
204
205	switch (piece->getKind()) {
206	case PathDiagnosticPiece::Call: {
207	auto &call = cast<PathDiagnosticCallPiece>(*piece);
208	// Check if the location context is interesting.
209	assert(LCM.count(&call.path));
210	if (!removeUnneededCalls(call.path, R, LCM,
211	R->isInteresting(LCM[&call.path])))
212	continue;
213
214	containsSomethingInteresting = true;
215	break;
216	}
217	case PathDiagnosticPiece::Macro: {
218	auto &macro = cast<PathDiagnosticMacroPiece>(*piece);
219	if (!removeUnneededCalls(macro.subPieces, R, LCM, IsInteresting))
220	continue;
221	containsSomethingInteresting = true;
222	break;
223	}
224	case PathDiagnosticPiece::Event: {
225	auto &event = cast<PathDiagnosticEventPiece>(*piece);
226
227	// We never throw away an event, but we do throw it away wholesale
228	// as part of a path if we throw the entire path away.
229	containsSomethingInteresting \|= !event.isPrunable();
230	break;
231	}
232	case PathDiagnosticPiece::ControlFlow:
233	break;
234
235	case PathDiagnosticPiece::Note:
236	break;
237	}
238
239	pieces.push_back(std::move(piece));
240	}
241
242	return containsSomethingInteresting;
243	}
244
245	/// Returns true if the given decl has been implicitly given a body, either by
246	/// the analyzer or by the compiler proper.
247	static bool hasImplicitBody(const Decl *D) {
248	assert(D);
249	return D->isImplicit() \|\| !D->hasBody();
250	}
251
252	/// Recursively scan through a path and make sure that all call pieces have
253	/// valid locations.
254	static void
255	adjustCallLocations(PathPieces &Pieces,
256	PathDiagnosticLocation *LastCallLocation = nullptr) {
257	for (const auto &I : Pieces) {
258	auto *Call = dyn_cast<PathDiagnosticCallPiece>(I.get());
259
260	if (!Call)
261	continue;
262
263	if (LastCallLocation) {
264	bool CallerIsImplicit = hasImplicitBody(Call->getCaller());
265	if (CallerIsImplicit \|\| !Call->callEnter.asLocation().isValid())
266	Call->callEnter = *LastCallLocation;
267	if (CallerIsImplicit \|\| !Call->callReturn.asLocation().isValid())
268	Call->callReturn = *LastCallLocation;
269	}
270
271	// Recursively clean out the subclass. Keep this call around if
272	// it contains any informative diagnostics.
273	PathDiagnosticLocation *ThisCallLocation;
274	if (Call->callEnterWithin.asLocation().isValid() &&
275	!hasImplicitBody(Call->getCallee()))
276	ThisCallLocation = &Call->callEnterWithin;
277	else
278	ThisCallLocation = &Call->callEnter;
279
280	(0) . __assert_fail ("ThisCallLocation && \"Outermost call has an invalid location\"", "/home/seafit/code_projects/clang_source/clang/lib/StaticAnalyzer/Core/BugReporter.cpp", 280, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(ThisCallLocation && "Outermost call has an invalid location");
281	adjustCallLocations(Call->path, ThisCallLocation);
282	}
283	}
284
285	/// Remove edges in and out of C++ default initializer expressions. These are
286	/// for fields that have in-class initializers, as opposed to being initialized
287	/// explicitly in a constructor or braced list.
288	static void removeEdgesToDefaultInitializers(PathPieces &Pieces) {
289	for (PathPieces::iterator I = Pieces.begin(), E = Pieces.end(); I != E;) {
290	if (auto *C = dyn_cast<PathDiagnosticCallPiece>(I->get()))
291	removeEdgesToDefaultInitializers(C->path);
292
293	if (auto *M = dyn_cast<PathDiagnosticMacroPiece>(I->get()))
294	removeEdgesToDefaultInitializers(M->subPieces);
295
296	if (auto *CF = dyn_cast<PathDiagnosticControlFlowPiece>(I->get())) {
297	const Stmt *Start = CF->getStartLocation().asStmt();
298	const Stmt *End = CF->getEndLocation().asStmt();
299	if (Start && isa<CXXDefaultInitExpr>(Start)) {
300	I = Pieces.erase(I);
301	continue;
302	} else if (End && isa<CXXDefaultInitExpr>(End)) {
303	PathPieces::iterator Next = std::next(I);
304	if (Next != E) {
305	if (auto *NextCF =
306	dyn_cast<PathDiagnosticControlFlowPiece>(Next->get())) {
307	NextCF->setStartLocation(CF->getStartLocation());
308	}
309	}
310	I = Pieces.erase(I);
311	continue;
312	}
313	}
314
315	I++;
316	}
317	}
318
319	/// Remove all pieces with invalid locations as these cannot be serialized.
320	/// We might have pieces with invalid locations as a result of inlining Body
321	/// Farm generated functions.
322	static void removePiecesWithInvalidLocations(PathPieces &Pieces) {
323	for (PathPieces::iterator I = Pieces.begin(), E = Pieces.end(); I != E;) {
324	if (auto *C = dyn_cast<PathDiagnosticCallPiece>(I->get()))
325	removePiecesWithInvalidLocations(C->path);
326
327	if (auto *M = dyn_cast<PathDiagnosticMacroPiece>(I->get()))
328	removePiecesWithInvalidLocations(M->subPieces);
329
330	if (!(*I)->getLocation().isValid() \|\|
331	!(*I)->getLocation().asLocation().isValid()) {
332	I = Pieces.erase(I);
333	continue;
334	}
335	I++;
336	}
337	}
338
339	//===----------------------------------------------------------------------===//
340	// PathDiagnosticBuilder and its associated routines and helper objects.
341	//===----------------------------------------------------------------------===//
342
343	namespace {
344
345	class PathDiagnosticBuilder : public BugReporterContext {
346	BugReport *R;
347	PathDiagnosticConsumer *PDC;
348
349	public:
350	const LocationContext *LC;
351
352	PathDiagnosticBuilder(GRBugReporter &br,
353	BugReport *r, InterExplodedGraphMap &Backmap,
354	PathDiagnosticConsumer *pdc)
355	: BugReporterContext(br, Backmap), R(r), PDC(pdc),
356	LC(r->getErrorNode()->getLocationContext()) {}
357
358	PathDiagnosticLocation ExecutionContinues(const ExplodedNode *N);
359
360	PathDiagnosticLocation ExecutionContinues(llvm::raw_string_ostream &os,
361	const ExplodedNode *N);
362
363	BugReport *getBugReport() { return R; }
364
365	Decl const &getCodeDecl() { return R->getErrorNode()->getCodeDecl(); }
366
367	ParentMap& getParentMap() { return LC->getParentMap(); }
368
369	const Stmt getParent(const Stmt S) {
370	return getParentMap().getParent(S);
371	}
372
373	PathDiagnosticLocation getEnclosingStmtLocation(const Stmt *S);
374
375	PathDiagnosticConsumer::PathGenerationScheme getGenerationScheme() const {
376	return PDC ? PDC->getGenerationScheme() : PathDiagnosticConsumer::Minimal;
377	}
378
379	bool supportsLogicalOpControlFlow() const {
380	return PDC ? PDC->supportsLogicalOpControlFlow() : true;
381	}
382	};
383
384	} // namespace
385
386	PathDiagnosticLocation
387	PathDiagnosticBuilder::ExecutionContinues(const ExplodedNode *N) {
388	if (const Stmt *S = PathDiagnosticLocation::getNextStmt(N))
389	return PathDiagnosticLocation(S, getSourceManager(), LC);
390
391	return PathDiagnosticLocation::createDeclEnd(N->getLocationContext(),
392	getSourceManager());
393	}
394
395	PathDiagnosticLocation
396	PathDiagnosticBuilder::ExecutionContinues(llvm::raw_string_ostream &os,
397	const ExplodedNode *N) {
398	// Slow, but probably doesn't matter.
399	if (os.str().empty())
400	os << ' ';
401
402	const PathDiagnosticLocation &Loc = ExecutionContinues(N);
403
404	if (Loc.asStmt())
405	os << "Execution continues on line "
406	<< getSourceManager().getExpansionLineNumber(Loc.asLocation())
407	<< '.';
408	else {
409	os << "Execution jumps to the end of the ";
410	const Decl *D = N->getLocationContext()->getDecl();
411	if (isa<ObjCMethodDecl>(D))
412	os << "method";
413	else if (isa<FunctionDecl>(D))
414	os << "function";
415	else {
416	(D)", "/home/seafit/code_projects/clang_source/clang/lib/StaticAnalyzer/Core/BugReporter.cpp", 416, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(isa<BlockDecl>(D));
417	os << "anonymous block";
418	}
419	os << '.';
420	}
421
422	return Loc;
423	}
424
425	static const Stmt getEnclosingParent(const Stmt S, const ParentMap &PM) {
426	if (isa<Expr>(S) && PM.isConsumedExpr(cast<Expr>(S)))
427	return PM.getParentIgnoreParens(S);
428
429	const Stmt *Parent = PM.getParentIgnoreParens(S);
430	if (!Parent)
431	return nullptr;
432
433	switch (Parent->getStmtClass()) {
434	case Stmt::ForStmtClass:
435	case Stmt::DoStmtClass:
436	case Stmt::WhileStmtClass:
437	case Stmt::ObjCForCollectionStmtClass:
438	case Stmt::CXXForRangeStmtClass:
439	return Parent;
440	default:
441	break;
442	}
443
444	return nullptr;
445	}
446
447	static PathDiagnosticLocation
448	getEnclosingStmtLocation(const Stmt *S, SourceManager &SMgr, const ParentMap &P,
449	const LocationContext *LC, bool allowNestedContexts) {
450	if (!S)
451	return {};
452
453	while (const Stmt *Parent = getEnclosingParent(S, P)) {
454	switch (Parent->getStmtClass()) {
455	case Stmt::BinaryOperatorClass: {
456	const auto *B = cast<BinaryOperator>(Parent);
457	if (B->isLogicalOp())
458	return PathDiagnosticLocation(allowNestedContexts ? B : S, SMgr, LC);
459	break;
460	}
461	case Stmt::CompoundStmtClass:
462	case Stmt::StmtExprClass:
463	return PathDiagnosticLocation(S, SMgr, LC);
464	case Stmt::ChooseExprClass:
465	// Similar to '?' if we are referring to condition, just have the edge
466	// point to the entire choose expression.
467	if (allowNestedContexts \|\| cast<ChooseExpr>(Parent)->getCond() == S)
468	return PathDiagnosticLocation(Parent, SMgr, LC);
469	else
470	return PathDiagnosticLocation(S, SMgr, LC);
471	case Stmt::BinaryConditionalOperatorClass:
472	case Stmt::ConditionalOperatorClass:
473	// For '?', if we are referring to condition, just have the edge point
474	// to the entire '?' expression.
475	if (allowNestedContexts \|\|
476	cast<AbstractConditionalOperator>(Parent)->getCond() == S)
477	return PathDiagnosticLocation(Parent, SMgr, LC);
478	else
479	return PathDiagnosticLocation(S, SMgr, LC);
480	case Stmt::CXXForRangeStmtClass:
481	if (cast<CXXForRangeStmt>(Parent)->getBody() == S)
482	return PathDiagnosticLocation(S, SMgr, LC);
483	break;
484	case Stmt::DoStmtClass:
485	return PathDiagnosticLocation(S, SMgr, LC);
486	case Stmt::ForStmtClass:
487	if (cast<ForStmt>(Parent)->getBody() == S)
488	return PathDiagnosticLocation(S, SMgr, LC);
489	break;
490	case Stmt::IfStmtClass:
491	if (cast<IfStmt>(Parent)->getCond() != S)
492	return PathDiagnosticLocation(S, SMgr, LC);
493	break;
494	case Stmt::ObjCForCollectionStmtClass:
495	if (cast<ObjCForCollectionStmt>(Parent)->getBody() == S)
496	return PathDiagnosticLocation(S, SMgr, LC);
497	break;
498	case Stmt::WhileStmtClass:
499	if (cast<WhileStmt>(Parent)->getCond() != S)
500	return PathDiagnosticLocation(S, SMgr, LC);
501	break;
502	default:
503	break;
504	}
505
506	S = Parent;
507	}
508
509	(0) . __assert_fail ("S && \"Cannot have null Stmt for PathDiagnosticLocation\"", "/home/seafit/code_projects/clang_source/clang/lib/StaticAnalyzer/Core/BugReporter.cpp", 509, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(S && "Cannot have null Stmt for PathDiagnosticLocation");
510
511	return PathDiagnosticLocation(S, SMgr, LC);
512	}
513
514	PathDiagnosticLocation
515	PathDiagnosticBuilder::getEnclosingStmtLocation(const Stmt *S) {
516	(0) . __assert_fail ("S && \"Null Stmt passed to getEnclosingStmtLocation\"", "/home/seafit/code_projects/clang_source/clang/lib/StaticAnalyzer/Core/BugReporter.cpp", 516, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(S && "Null Stmt passed to getEnclosingStmtLocation");
517	return ::getEnclosingStmtLocation(S, getSourceManager(), getParentMap(), LC,
518	/allowNestedContexts=/false);
519	}
520
521	//===----------------------------------------------------------------------===//
522	// "Minimal" path diagnostic generation algorithm.
523	//===----------------------------------------------------------------------===//
524	using StackDiagPair =
525	std::pair<PathDiagnosticCallPiece , const ExplodedNode >;
526	using StackDiagVector = SmallVector<StackDiagPair, 6>;
527
528	static void updateStackPiecesWithMessage(PathDiagnosticPiece &P,
529	StackDiagVector &CallStack) {
530	// If the piece contains a special message, add it to all the call
531	// pieces on the active stack.
532	if (auto *ep = dyn_cast<PathDiagnosticEventPiece>(&P)) {
533	if (ep->hasCallStackHint())
534	for (const auto &I : CallStack) {
535	PathDiagnosticCallPiece *CP = I.first;
536	const ExplodedNode *N = I.second;
537	std::string stackMsg = ep->getCallStackMessage(N);
538
539	// The last message on the path to final bug is the most important
540	// one. Since we traverse the path backwards, do not add the message
541	// if one has been previously added.
542	if (!CP->hasCallStackMessage())
543	CP->setCallStackMessage(stackMsg);
544	}
545	}
546	}
547
548	static void CompactMacroExpandedPieces(PathPieces &path,
549	const SourceManager& SM);
550
551
552	std::shared_ptr<PathDiagnosticControlFlowPiece> generateDiagForSwitchOP(
553	const ExplodedNode *N,
554	const CFGBlock *Dst,
555	const SourceManager &SM,
556	const LocationContext *LC,
557	PathDiagnosticBuilder &PDB,
558	PathDiagnosticLocation &Start
559	) {
560	// Figure out what case arm we took.
561	std::string sbuf;
562	llvm::raw_string_ostream os(sbuf);
563	PathDiagnosticLocation End;
564
565	if (const Stmt *S = Dst->getLabel()) {
566	End = PathDiagnosticLocation(S, SM, LC);
567
568	switch (S->getStmtClass()) {
569	default:
570	os << "No cases match in the switch statement. "
571	"Control jumps to line "
572	<< End.asLocation().getExpansionLineNumber();
573	break;
574	case Stmt::DefaultStmtClass:
575	os << "Control jumps to the 'default' case at line "
576	<< End.asLocation().getExpansionLineNumber();
577	break;
578
579	case Stmt::CaseStmtClass: {
580	os << "Control jumps to 'case ";
581	const auto *Case = cast<CaseStmt>(S);
582	const Expr *LHS = Case->getLHS()->IgnoreParenCasts();
583
584	// Determine if it is an enum.
585	bool GetRawInt = true;
586
587	if (const auto *DR = dyn_cast<DeclRefExpr>(LHS)) {
588	// FIXME: Maybe this should be an assertion. Are there cases
589	// were it is not an EnumConstantDecl?
590	const auto *D = dyn_cast<EnumConstantDecl>(DR->getDecl());
591
592	if (D) {
593	GetRawInt = false;
594	os << *D;
595	}
596	}
597
598	if (GetRawInt)
599	os << LHS->EvaluateKnownConstInt(PDB.getASTContext());
600
601	os << ":' at line " << End.asLocation().getExpansionLineNumber();
602	break;
603	}
604	}
605	} else {
606	os << "'Default' branch taken. ";
607	End = PDB.ExecutionContinues(os, N);
608	}
609	return std::make_shared<PathDiagnosticControlFlowPiece>(Start, End,
610	os.str());
611	}
612
613
614	std::shared_ptr<PathDiagnosticControlFlowPiece> generateDiagForGotoOP(
615	const Stmt *S,
616	PathDiagnosticBuilder &PDB,
617	PathDiagnosticLocation &Start) {
618	std::string sbuf;
619	llvm::raw_string_ostream os(sbuf);
620	const PathDiagnosticLocation &End = PDB.getEnclosingStmtLocation(S);
621	os << "Control jumps to line " << End.asLocation().getExpansionLineNumber();
622	return std::make_shared<PathDiagnosticControlFlowPiece>(Start, End, os.str());
623
624	}
625
626	std::shared_ptr<PathDiagnosticControlFlowPiece> generateDiagForBinaryOP(
627	const ExplodedNode *N,
628	const Stmt *T,
629	const CFGBlock *Src,
630	const CFGBlock *Dst,
631	const SourceManager &SM,
632	PathDiagnosticBuilder &PDB,
633	const LocationContext *LC) {
634	const auto *B = cast<BinaryOperator>(T);
635	std::string sbuf;
636	llvm::raw_string_ostream os(sbuf);
637	os << "Left side of '";
638	PathDiagnosticLocation Start, End;
639
640	if (B->getOpcode() == BO_LAnd) {
641	os << "&&"
642	<< "' is ";
643
644	if (*(Src->succ_begin() + 1) == Dst) {
645	os << "false";
646	End = PathDiagnosticLocation(B->getLHS(), SM, LC);
647	Start =
648	PathDiagnosticLocation::createOperatorLoc(B, SM);
649	} else {
650	os << "true";
651	Start = PathDiagnosticLocation(B->getLHS(), SM, LC);
652	End = PDB.ExecutionContinues(N);
653	}
654	} else {
655	getOpcode() == BO_LOr", "/home/seafit/code_projects/clang_source/clang/lib/StaticAnalyzer/Core/BugReporter.cpp", 655, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(B->getOpcode() == BO_LOr);
656	os << "\|\|"
657	<< "' is ";
658
659	if (*(Src->succ_begin() + 1) == Dst) {
660	os << "false";
661	Start = PathDiagnosticLocation(B->getLHS(), SM, LC);
662	End = PDB.ExecutionContinues(N);
663	} else {
664	os << "true";
665	End = PathDiagnosticLocation(B->getLHS(), SM, LC);
666	Start =
667	PathDiagnosticLocation::createOperatorLoc(B, SM);
668	}
669	}
670	return std::make_shared<PathDiagnosticControlFlowPiece>(Start, End,
671	os.str());
672	}
673
674	void generateMinimalDiagForBlockEdge(const ExplodedNode *N, BlockEdge BE,
675	const SourceManager &SM,
676	PathDiagnosticBuilder &PDB,
677	PathDiagnostic &PD) {
678	const LocationContext *LC = N->getLocationContext();
679	const CFGBlock *Src = BE.getSrc();
680	const CFGBlock *Dst = BE.getDst();
681	const Stmt *T = Src->getTerminator();
682	if (!T)
683	return;
684
685	auto Start = PathDiagnosticLocation::createBegin(T, SM, LC);
686	switch (T->getStmtClass()) {
687	default:
688	break;
689
690	case Stmt::GotoStmtClass:
691	case Stmt::IndirectGotoStmtClass: {
692	if (const Stmt *S = PathDiagnosticLocation::getNextStmt(N))
693	PD.getActivePath().push_front(generateDiagForGotoOP(S, PDB, Start));
694	break;
695	}
696
697	case Stmt::SwitchStmtClass: {
698	PD.getActivePath().push_front(
699	generateDiagForSwitchOP(N, Dst, SM, LC, PDB, Start));
700	break;
701	}
702
703	case Stmt::BreakStmtClass:
704	case Stmt::ContinueStmtClass: {
705	std::string sbuf;
706	llvm::raw_string_ostream os(sbuf);
707	PathDiagnosticLocation End = PDB.ExecutionContinues(os, N);
708	PD.getActivePath().push_front(
709	std::make_shared<PathDiagnosticControlFlowPiece>(Start, End, os.str()));
710	break;
711	}
712
713	// Determine control-flow for ternary '?'.
714	case Stmt::BinaryConditionalOperatorClass:
715	case Stmt::ConditionalOperatorClass: {
716	std::string sbuf;
717	llvm::raw_string_ostream os(sbuf);
718	os << "'?' condition is ";
719
720	if (*(Src->succ_begin() + 1) == Dst)
721	os << "false";
722	else
723	os << "true";
724
725	PathDiagnosticLocation End = PDB.ExecutionContinues(N);
726
727	if (const Stmt *S = End.asStmt())
728	End = PDB.getEnclosingStmtLocation(S);
729
730	PD.getActivePath().push_front(
731	std::make_shared<PathDiagnosticControlFlowPiece>(Start, End, os.str()));
732	break;
733	}
734
735	// Determine control-flow for short-circuited '&&' and '\|\|'.
736	case Stmt::BinaryOperatorClass: {
737	if (!PDB.supportsLogicalOpControlFlow())
738	break;
739
740	std::shared_ptr<PathDiagnosticControlFlowPiece> Diag =
741	generateDiagForBinaryOP(N, T, Src, Dst, SM, PDB, LC);
742	PD.getActivePath().push_front(Diag);
743	break;
744	}
745
746	case Stmt::DoStmtClass:
747	if (*(Src->succ_begin()) == Dst) {
748	std::string sbuf;
749	llvm::raw_string_ostream os(sbuf);
750
751	os << "Loop condition is true. ";
752	PathDiagnosticLocation End = PDB.ExecutionContinues(os, N);
753
754	if (const Stmt *S = End.asStmt())
755	End = PDB.getEnclosingStmtLocation(S);
756
757	PD.getActivePath().push_front(
758	std::make_shared<PathDiagnosticControlFlowPiece>(Start, End,
759	os.str()));
760	} else {
761	PathDiagnosticLocation End = PDB.ExecutionContinues(N);
762
763	if (const Stmt *S = End.asStmt())
764	End = PDB.getEnclosingStmtLocation(S);
765
766	PD.getActivePath().push_front(
767	std::make_shared<PathDiagnosticControlFlowPiece>(
768	Start, End, "Loop condition is false. Exiting loop"));
769	}
770	break;
771
772	case Stmt::WhileStmtClass:
773	case Stmt::ForStmtClass:
774	if (*(Src->succ_begin() + 1) == Dst) {
775	std::string sbuf;
776	llvm::raw_string_ostream os(sbuf);
777
778	os << "Loop condition is false. ";
779	PathDiagnosticLocation End = PDB.ExecutionContinues(os, N);
780	if (const Stmt *S = End.asStmt())
781	End = PDB.getEnclosingStmtLocation(S);
782
783	PD.getActivePath().push_front(
784	std::make_shared<PathDiagnosticControlFlowPiece>(Start, End,
785	os.str()));
786	} else {
787	PathDiagnosticLocation End = PDB.ExecutionContinues(N);
788	if (const Stmt *S = End.asStmt())
789	End = PDB.getEnclosingStmtLocation(S);
790
791	PD.getActivePath().push_front(
792	std::make_shared<PathDiagnosticControlFlowPiece>(
793	Start, End, "Loop condition is true. Entering loop body"));
794	}
795
796	break;
797
798	case Stmt::IfStmtClass: {
799	PathDiagnosticLocation End = PDB.ExecutionContinues(N);
800
801	if (const Stmt *S = End.asStmt())
802	End = PDB.getEnclosingStmtLocation(S);
803
804	if (*(Src->succ_begin() + 1) == Dst)
805	PD.getActivePath().push_front(
806	std::make_shared<PathDiagnosticControlFlowPiece>(
807	Start, End, "Taking false branch"));
808	else
809	PD.getActivePath().push_front(
810	std::make_shared<PathDiagnosticControlFlowPiece>(
811	Start, End, "Taking true branch"));
812
813	break;
814	}
815	}
816	}
817
818	// Cone-of-influence: support the reverse propagation of "interesting" symbols
819	// and values by tracing interesting calculations backwards through evaluated
820	// expressions along a path. This is probably overly complicated, but the idea
821	// is that if an expression computed an "interesting" value, the child
822	// expressions are also likely to be "interesting" as well (which then
823	// propagates to the values they in turn compute). This reverse propagation
824	// is needed to track interesting correlations across function call boundaries,
825	// where formal arguments bind to actual arguments, etc. This is also needed
826	// because the constraint solver sometimes simplifies certain symbolic values
827	// into constants when appropriate, and this complicates reasoning about
828	// interesting values.
829	using InterestingExprs = llvm::DenseSet<const Expr *>;
830
831	static void reversePropagateIntererstingSymbols(BugReport &R,
832	InterestingExprs &IE,
833	const ProgramState *State,
834	const Expr *Ex,
835	const LocationContext *LCtx) {
836	SVal V = State->getSVal(Ex, LCtx);
837	if (!(R.isInteresting(V) \|\| IE.count(Ex)))
838	return;
839
840	switch (Ex->getStmtClass()) {
841	default:
842	if (!isa<CastExpr>(Ex))
843	break;
844	LLVM_FALLTHROUGH;
845	case Stmt::BinaryOperatorClass:
846	case Stmt::UnaryOperatorClass: {
847	for (const Stmt *SubStmt : Ex->children()) {
848	if (const auto *child = dyn_cast_or_null<Expr>(SubStmt)) {
849	IE.insert(child);
850	SVal ChildV = State->getSVal(child, LCtx);
851	R.markInteresting(ChildV);
852	}
853	}
854	break;
855	}
856	}
857
858	R.markInteresting(V);
859	}
860
861	static void reversePropagateInterestingSymbols(BugReport &R,
862	InterestingExprs &IE,
863	const ProgramState *State,
864	const LocationContext *CalleeCtx)
865	{
866	// FIXME: Handle non-CallExpr-based CallEvents.
867	const StackFrameContext *Callee = CalleeCtx->getStackFrame();
868	const Stmt *CallSite = Callee->getCallSite();
869	if (const auto *CE = dyn_cast_or_null<CallExpr>(CallSite)) {
870	if (const auto *FD = dyn_cast<FunctionDecl>(CalleeCtx->getDecl())) {
871	FunctionDecl::param_const_iterator PI = FD->param_begin(),
872	PE = FD->param_end();
873	CallExpr::const_arg_iterator AI = CE->arg_begin(), AE = CE->arg_end();
874	for (; AI != AE && PI != PE; ++AI, ++PI) {
875	if (const Expr ArgE = AI) {
876	if (const ParmVarDecl PD = PI) {
877	Loc LV = State->getLValue(PD, CalleeCtx);
878	if (R.isInteresting(LV) \|\| R.isInteresting(State->getRawSVal(LV)))
879	IE.insert(ArgE);
880	}
881	}
882	}
883	}
884	}
885	}
886
887	//===----------------------------------------------------------------------===//
888	// Functions for determining if a loop was executed 0 times.
889	//===----------------------------------------------------------------------===//
890
891	static bool isLoop(const Stmt *Term) {
892	switch (Term->getStmtClass()) {
893	case Stmt::ForStmtClass:
894	case Stmt::WhileStmtClass:
895	case Stmt::ObjCForCollectionStmtClass:
896	case Stmt::CXXForRangeStmtClass:
897	return true;
898	default:
899	// Note that we intentionally do not include do..while here.
900	return false;
901	}
902	}
903
904	static bool isJumpToFalseBranch(const BlockEdge *BE) {
905	const CFGBlock *Src = BE->getSrc();
906	succ_size() == 2", "/home/seafit/code_projects/clang_source/clang/lib/StaticAnalyzer/Core/BugReporter.cpp", 906, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(Src->succ_size() == 2);
907	return (*(Src->succ_begin()+1) == BE->getDst());
908	}
909
910	static bool isContainedByStmt(ParentMap &PM, const Stmt S, const Stmt SubS) {
911	while (SubS) {
912	if (SubS == S)
913	return true;
914	SubS = PM.getParent(SubS);
915	}
916	return false;
917	}
918
919	static const Stmt getStmtBeforeCond(ParentMap &PM, const Stmt Term,
920	const ExplodedNode *N) {
921	while (N) {
922	Optional<StmtPoint> SP = N->getLocation().getAs<StmtPoint>();
923	if (SP) {
924	const Stmt *S = SP->getStmt();
925	if (!isContainedByStmt(PM, Term, S))
926	return S;
927	}
928	N = N->getFirstPred();
929	}
930	return nullptr;
931	}
932
933	static bool isInLoopBody(ParentMap &PM, const Stmt S, const Stmt Term) {
934	const Stmt *LoopBody = nullptr;
935	switch (Term->getStmtClass()) {
936	case Stmt::CXXForRangeStmtClass: {
937	const auto *FR = cast<CXXForRangeStmt>(Term);
938	if (isContainedByStmt(PM, FR->getInc(), S))
939	return true;
940	if (isContainedByStmt(PM, FR->getLoopVarStmt(), S))
941	return true;
942	LoopBody = FR->getBody();
943	break;
944	}
945	case Stmt::ForStmtClass: {
946	const auto *FS = cast<ForStmt>(Term);
947	if (isContainedByStmt(PM, FS->getInc(), S))
948	return true;
949	LoopBody = FS->getBody();
950	break;
951	}
952	case Stmt::ObjCForCollectionStmtClass: {
953	const auto *FC = cast<ObjCForCollectionStmt>(Term);
954	LoopBody = FC->getBody();
955	break;
956	}
957	case Stmt::WhileStmtClass:
958	LoopBody = cast<WhileStmt>(Term)->getBody();
959	break;
960	default:
961	return false;
962	}
963	return isContainedByStmt(PM, LoopBody, S);
964	}
965
966	/// Adds a sanitized control-flow diagnostic edge to a path.
967	static void addEdgeToPath(PathPieces &path,
968	PathDiagnosticLocation &PrevLoc,
969	PathDiagnosticLocation NewLoc) {
970	if (!NewLoc.isValid())
971	return;
972
973	SourceLocation NewLocL = NewLoc.asLocation();
974	if (NewLocL.isInvalid())
975	return;
976
977	if (!PrevLoc.isValid() \|\| !PrevLoc.asLocation().isValid()) {
978	PrevLoc = NewLoc;
979	return;
980	}
981
982	// Ignore self-edges, which occur when there are multiple nodes at the same
983	// statement.
984	if (NewLoc.asStmt() && NewLoc.asStmt() == PrevLoc.asStmt())
985	return;
986
987	path.push_front(
988	std::make_shared<PathDiagnosticControlFlowPiece>(NewLoc, PrevLoc));
989	PrevLoc = NewLoc;
990	}
991
992	/// A customized wrapper for CFGBlock::getTerminatorCondition()
993	/// which returns the element for ObjCForCollectionStmts.
994	static const Stmt getTerminatorCondition(const CFGBlock B) {
995	const Stmt *S = B->getTerminatorCondition();
996	if (const auto *FS = dyn_cast_or_null<ObjCForCollectionStmt>(S))
997	return FS->getElement();
998	return S;
999	}
1000
1001	static const char StrEnteringLoop[] = "Entering loop body";
1002	static const char StrLoopBodyZero[] = "Loop body executed 0 times";
1003	static const char StrLoopRangeEmpty[] =
1004	"Loop body skipped when range is empty";
1005	static const char StrLoopCollectionEmpty[] =
1006	"Loop body skipped when collection is empty";
1007
1008	static std::unique_ptr<FilesToLineNumsMap>
1009	findExecutedLines(SourceManager &SM, const ExplodedNode *N);
1010
1011	/// Generate diagnostics for the node \p N,
1012	/// and write it into \p PD.
1013	/// \p AddPathEdges Whether diagnostic consumer can generate path arrows
1014	/// showing both row and column.
1015	static void generatePathDiagnosticsForNode(const ExplodedNode *N,
1016	PathDiagnostic &PD,
1017	PathDiagnosticLocation &PrevLoc,
1018	PathDiagnosticBuilder &PDB,
1019	LocationContextMap &LCM,
1020	StackDiagVector &CallStack,
1021	InterestingExprs &IE,
1022	bool AddPathEdges) {
1023	ProgramPoint P = N->getLocation();
1024	const SourceManager& SM = PDB.getSourceManager();
1025
1026	// Have we encountered an entrance to a call? It may be
1027	// the case that we have not encountered a matching
1028	// call exit before this point. This means that the path
1029	// terminated within the call itself.
1030	if (auto CE = P.getAs<CallEnter>()) {
1031
1032	if (AddPathEdges) {
1033	// Add an edge to the start of the function.
1034	const StackFrameContext *CalleeLC = CE->getCalleeContext();
1035	const Decl *D = CalleeLC->getDecl();
1036	// Add the edge only when the callee has body. We jump to the beginning
1037	// of the declaration, however we expect it to be followed by the
1038	// body. This isn't the case for autosynthesized property accessors in
1039	// Objective-C. No need for a similar extra check for CallExit points
1040	// because the exit edge comes from a statement (i.e. return),
1041	// not from declaration.
1042	if (D->hasBody())
1043	addEdgeToPath(PD.getActivePath(), PrevLoc,
1044	PathDiagnosticLocation::createBegin(D, SM));
1045	}
1046
1047	// Did we visit an entire call?
1048	bool VisitedEntireCall = PD.isWithinCall();
1049	PD.popActivePath();
1050
1051	PathDiagnosticCallPiece *C;
1052	if (VisitedEntireCall) {
1053	C = cast<PathDiagnosticCallPiece>(PD.getActivePath().front().get());
1054	} else {
1055	const Decl *Caller = CE->getLocationContext()->getDecl();
1056	C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller);
1057
1058	if (AddPathEdges) {
1059	// Since we just transferred the path over to the call piece,
1060	// reset the mapping from active to location context.
1061	assert(PD.getActivePath().size() == 1 &&
1062	PD.getActivePath().front().get() == C);
1063	LCM[&PD.getActivePath()] = nullptr;
1064	}
1065
1066	// Record the location context mapping for the path within
1067	// the call.
1068	path] == nullptr \|\| LCM[&C->path] == CE->getCalleeContext()", "/home/seafit/code_projects/clang_source/clang/lib/StaticAnalyzer/Core/BugReporter.cpp", 1069, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(LCM[&C->path] == nullptr \|\|
1069	path] == nullptr \|\| LCM[&C->path] == CE->getCalleeContext()", "/home/seafit/code_projects/clang_source/clang/lib/StaticAnalyzer/Core/BugReporter.cpp", 1069, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true"> LCM[&C->path] == CE->getCalleeContext());
1070	LCM[&C->path] = CE->getCalleeContext();
1071
1072	// If this is the first item in the active path, record
1073	// the new mapping from active path to location context.
1074	const LocationContext *&NewLC = LCM[&PD.getActivePath()];
1075	if (!NewLC)
1076	NewLC = N->getLocationContext();
1077
1078	PDB.LC = NewLC;
1079	}
1080	C->setCallee(*CE, SM);
1081
1082	// Update the previous location in the active path.
1083	PrevLoc = C->getLocation();
1084
1085	if (!CallStack.empty()) {
1086	assert(CallStack.back().first == C);
1087	CallStack.pop_back();
1088	}
1089	return;
1090	}
1091
1092
1093	if (AddPathEdges) {
1094	// Query the location context here and the previous location
1095	// as processing CallEnter may change the active path.
1096	PDB.LC = N->getLocationContext();
1097
1098	// Record the mapping from the active path to the location
1099	// context.
1100	assert(!LCM[&PD.getActivePath()] \|\| LCM[&PD.getActivePath()] == PDB.LC);
1101	LCM[&PD.getActivePath()] = PDB.LC;
1102	}
1103
1104	// Have we encountered an exit from a function call?
1105	if (Optional<CallExitEnd> CE = P.getAs<CallExitEnd>()) {
1106
1107	// We are descending into a call (backwards). Construct
1108	// a new call piece to contain the path pieces for that call.
1109	auto C = PathDiagnosticCallPiece::construct(*CE, SM);
1110	// Record the mapping from call piece to LocationContext.
1111	LCM[&C->path] = CE->getCalleeContext();
1112
1113	if (AddPathEdges) {
1114	const Stmt *S = CE->getCalleeContext()->getCallSite();
1115	// Propagate the interesting symbols accordingly.
1116	if (const auto *Ex = dyn_cast_or_null<Expr>(S)) {
1117	reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE,
1118	N->getState().get(), Ex,
1119	N->getLocationContext());
1120	}
1121	// Add the edge to the return site.
1122	addEdgeToPath(PD.getActivePath(), PrevLoc, C->callReturn);
1123	PrevLoc.invalidate();
1124	}
1125
1126	auto *P = C.get();
1127	PD.getActivePath().push_front(std::move(C));
1128
1129	// Make the contents of the call the active path for now.
1130	PD.pushActivePath(&P->path);
1131	CallStack.push_back(StackDiagPair(P, N));
1132	return;
1133	}
1134
1135	if (auto PS = P.getAs<PostStmt>()) {
1136	if (!AddPathEdges)
1137	return;
1138
1139	// For expressions, make sure we propagate the
1140	// interesting symbols correctly.
1141	if (const Expr *Ex = PS->getStmtAs<Expr>())
1142	reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE,
1143	N->getState().get(), Ex,
1144	N->getLocationContext());
1145
1146	// Add an edge. If this is an ObjCForCollectionStmt do
1147	// not add an edge here as it appears in the CFG both
1148	// as a terminator and as a terminator condition.
1149	if (!isa<ObjCForCollectionStmt>(PS->getStmt())) {
1150	PathDiagnosticLocation L =
1151	PathDiagnosticLocation(PS->getStmt(), SM, PDB.LC);
1152	addEdgeToPath(PD.getActivePath(), PrevLoc, L);
1153	}
1154
1155	} else if (auto BE = P.getAs<BlockEdge>()) {
1156
1157	if (!AddPathEdges) {
1158	generateMinimalDiagForBlockEdge(N, *BE, SM, PDB, PD);
1159	return;
1160	}
1161
1162	// Does this represent entering a call? If so, look at propagating
1163	// interesting symbols across call boundaries.
1164	if (const ExplodedNode *NextNode = N->getFirstPred()) {
1165	const LocationContext *CallerCtx = NextNode->getLocationContext();
1166	const LocationContext *CalleeCtx = PDB.LC;
1167	if (CallerCtx != CalleeCtx && AddPathEdges) {
1168	reversePropagateInterestingSymbols(*PDB.getBugReport(), IE,
1169	N->getState().get(), CalleeCtx);
1170	}
1171	}
1172
1173	// Are we jumping to the head of a loop? Add a special diagnostic.
1174	if (const Stmt *Loop = BE->getSrc()->getLoopTarget()) {
1175	PathDiagnosticLocation L(Loop, SM, PDB.LC);
1176	const Stmt *Body = nullptr;
1177
1178	if (const auto *FS = dyn_cast<ForStmt>(Loop))
1179	Body = FS->getBody();
1180	else if (const auto *WS = dyn_cast<WhileStmt>(Loop))
1181	Body = WS->getBody();
1182	else if (const auto *OFS = dyn_cast<ObjCForCollectionStmt>(Loop)) {
1183	Body = OFS->getBody();
1184	} else if (const auto *FRS = dyn_cast<CXXForRangeStmt>(Loop)) {
1185	Body = FRS->getBody();
1186	}
1187	// do-while statements are explicitly excluded here
1188
1189	auto p = std::make_shared<PathDiagnosticEventPiece>(
1190	L, "Looping back to the head "
1191	"of the loop");
1192	p->setPrunable(true);
1193
1194	addEdgeToPath(PD.getActivePath(), PrevLoc, p->getLocation());
1195	PD.getActivePath().push_front(std::move(p));
1196
1197	if (const auto *CS = dyn_cast_or_null<CompoundStmt>(Body)) {
1198	addEdgeToPath(PD.getActivePath(), PrevLoc,
1199	PathDiagnosticLocation::createEndBrace(CS, SM));
1200	}
1201	}
1202
1203	const CFGBlock *BSrc = BE->getSrc();
1204	ParentMap &PM = PDB.getParentMap();
1205
1206	if (const Stmt *Term = BSrc->getTerminator()) {
1207	// Are we jumping past the loop body without ever executing the
1208	// loop (because the condition was false)?
1209	if (isLoop(Term)) {
1210	const Stmt *TermCond = getTerminatorCondition(BSrc);
1211	bool IsInLoopBody =
1212	isInLoopBody(PM, getStmtBeforeCond(PM, TermCond, N), Term);
1213
1214	const char *str = nullptr;
1215
1216	if (isJumpToFalseBranch(&*BE)) {
1217	if (!IsInLoopBody) {
1218	if (isa<ObjCForCollectionStmt>(Term)) {
1219	str = StrLoopCollectionEmpty;
1220	} else if (isa<CXXForRangeStmt>(Term)) {
1221	str = StrLoopRangeEmpty;
1222	} else {
1223	str = StrLoopBodyZero;
1224	}
1225	}
1226	} else {
1227	str = StrEnteringLoop;
1228	}
1229
1230	if (str) {
1231	PathDiagnosticLocation L(TermCond ? TermCond : Term, SM, PDB.LC);
1232	auto PE = std::make_shared<PathDiagnosticEventPiece>(L, str);
1233	PE->setPrunable(true);
1234	addEdgeToPath(PD.getActivePath(), PrevLoc,
1235	PE->getLocation());
1236	PD.getActivePath().push_front(std::move(PE));
1237	}
1238	} else if (isa<BreakStmt>(Term) \|\| isa<ContinueStmt>(Term) \|\|
1239	isa<GotoStmt>(Term)) {
1240	PathDiagnosticLocation L(Term, SM, PDB.LC);
1241	addEdgeToPath(PD.getActivePath(), PrevLoc, L);
1242	}
1243	}
1244	}
1245	}
1246
1247	static std::unique_ptr<PathDiagnostic>
1248	generateEmptyDiagnosticForReport(BugReport *R, SourceManager &SM) {
1249	const BugType &BT = R->getBugType();
1250	return llvm::make_unique<PathDiagnostic>(
1251	R->getBugType().getCheckName(), R->getDeclWithIssue(),
1252	R->getBugType().getName(), R->getDescription(),
1253	R->getShortDescription(/Fallback=/false), BT.getCategory(),
1254	R->getUniqueingLocation(), R->getUniqueingDecl(),
1255	findExecutedLines(SM, R->getErrorNode()));
1256	}
1257
1258	static const Stmt getStmtParent(const Stmt S, const ParentMap &PM) {
1259	if (!S)
1260	return nullptr;
1261
1262	while (true) {
1263	S = PM.getParentIgnoreParens(S);
1264
1265	if (!S)
1266	break;
1267
1268	if (isa<FullExpr>(S) \|\|
1269	isa<CXXBindTemporaryExpr>(S) \|\|
1270	isa<SubstNonTypeTemplateParmExpr>(S))
1271	continue;
1272
1273	break;
1274	}
1275
1276	return S;
1277	}
1278
1279	static bool isConditionForTerminator(const Stmt S, const Stmt Cond) {
1280	switch (S->getStmtClass()) {
1281	case Stmt::BinaryOperatorClass: {
1282	const auto *BO = cast<BinaryOperator>(S);
1283	if (!BO->isLogicalOp())
1284	return false;
1285	return BO->getLHS() == Cond \|\| BO->getRHS() == Cond;
1286	}
1287	case Stmt::IfStmtClass:
1288	return cast<IfStmt>(S)->getCond() == Cond;
1289	case Stmt::ForStmtClass:
1290	return cast<ForStmt>(S)->getCond() == Cond;
1291	case Stmt::WhileStmtClass:
1292	return cast<WhileStmt>(S)->getCond() == Cond;
1293	case Stmt::DoStmtClass:
1294	return cast<DoStmt>(S)->getCond() == Cond;
1295	case Stmt::ChooseExprClass:
1296	return cast<ChooseExpr>(S)->getCond() == Cond;
1297	case Stmt::IndirectGotoStmtClass:
1298	return cast<IndirectGotoStmt>(S)->getTarget() == Cond;
1299	case Stmt::SwitchStmtClass:
1300	return cast<SwitchStmt>(S)->getCond() == Cond;
1301	case Stmt::BinaryConditionalOperatorClass:
1302	return cast<BinaryConditionalOperator>(S)->getCond() == Cond;
1303	case Stmt::ConditionalOperatorClass: {
1304	const auto *CO = cast<ConditionalOperator>(S);
1305	return CO->getCond() == Cond \|\|
1306	CO->getLHS() == Cond \|\|
1307	CO->getRHS() == Cond;
1308	}
1309	case Stmt::ObjCForCollectionStmtClass:
1310	return cast<ObjCForCollectionStmt>(S)->getElement() == Cond;
1311	case Stmt::CXXForRangeStmtClass: {
1312	const auto *FRS = cast<CXXForRangeStmt>(S);
1313	return FRS->getCond() == Cond \|\| FRS->getRangeInit() == Cond;
1314	}
1315	default:
1316	return false;
1317	}
1318	}
1319
1320	static bool isIncrementOrInitInForLoop(const Stmt S, const Stmt FL) {
1321	if (const auto *FS = dyn_cast<ForStmt>(FL))
1322	return FS->getInc() == S \|\| FS->getInit() == S;
1323	if (const auto *FRS = dyn_cast<CXXForRangeStmt>(FL))
1324	return FRS->getInc() == S \|\| FRS->getRangeStmt() == S \|\|
1325	FRS->getLoopVarStmt() \|\| FRS->getRangeInit() == S;
1326	return false;
1327	}
1328
1329	using OptimizedCallsSet = llvm::DenseSet<const PathDiagnosticCallPiece *>;
1330
1331	/// Adds synthetic edges from top-level statements to their subexpressions.
1332	///
1333	/// This avoids a "swoosh" effect, where an edge from a top-level statement A
1334	/// points to a sub-expression B.1 that's not at the start of B. In these cases,
1335	/// we'd like to see an edge from A to B, then another one from B to B.1.
1336	static void addContextEdges(PathPieces &pieces, SourceManager &SM,
1337	const ParentMap &PM, const LocationContext *LCtx) {
1338	PathPieces::iterator Prev = pieces.end();
1339	for (PathPieces::iterator I = pieces.begin(), E = Prev; I != E;
1340	Prev = I, ++I) {
1341	auto *Piece = dyn_cast<PathDiagnosticControlFlowPiece>(I->get());
1342
1343	if (!Piece)
1344	continue;
1345
1346	PathDiagnosticLocation SrcLoc = Piece->getStartLocation();
1347	SmallVector<PathDiagnosticLocation, 4> SrcContexts;
1348
1349	PathDiagnosticLocation NextSrcContext = SrcLoc;
1350	const Stmt *InnerStmt = nullptr;
1351	while (NextSrcContext.isValid() && NextSrcContext.asStmt() != InnerStmt) {
1352	SrcContexts.push_back(NextSrcContext);
1353	InnerStmt = NextSrcContext.asStmt();
1354	NextSrcContext = getEnclosingStmtLocation(InnerStmt, SM, PM, LCtx,
1355	/allowNested=/true);
1356	}
1357
1358	// Repeatedly split the edge as necessary.
1359	// This is important for nested logical expressions (\|\|, &&, ?:) where we
1360	// want to show all the levels of context.
1361	while (true) {
1362	const Stmt *Dst = Piece->getEndLocation().getStmtOrNull();
1363
1364	// We are looking at an edge. Is the destination within a larger
1365	// expression?
1366	PathDiagnosticLocation DstContext =
1367	getEnclosingStmtLocation(Dst, SM, PM, LCtx, /allowNested=/true);
1368	if (!DstContext.isValid() \|\| DstContext.asStmt() == Dst)
1369	break;
1370
1371	// If the source is in the same context, we're already good.
1372	if (std::find(SrcContexts.begin(), SrcContexts.end(), DstContext) !=
1373	SrcContexts.end())
1374	break;
1375
1376	// Update the subexpression node to point to the context edge.
1377	Piece->setStartLocation(DstContext);
1378
1379	// Try to extend the previous edge if it's at the same level as the source
1380	// context.
1381	if (Prev != E) {
1382	auto *PrevPiece = dyn_cast<PathDiagnosticControlFlowPiece>(Prev->get());
1383
1384	if (PrevPiece) {
1385	if (const Stmt *PrevSrc =
1386	PrevPiece->getStartLocation().getStmtOrNull()) {
1387	const Stmt *PrevSrcParent = getStmtParent(PrevSrc, PM);
1388	if (PrevSrcParent ==
1389	getStmtParent(DstContext.getStmtOrNull(), PM)) {
1390	PrevPiece->setEndLocation(DstContext);
1391	break;
1392	}
1393	}
1394	}
1395	}
1396
1397	// Otherwise, split the current edge into a context edge and a
1398	// subexpression edge. Note that the context statement may itself have
1399	// context.
1400	auto P =
1401	std::make_shared<PathDiagnosticControlFlowPiece>(SrcLoc, DstContext);
1402	Piece = P.get();
1403	I = pieces.insert(I, std::move(P));
1404	}
1405	}
1406	}
1407
1408	/// Move edges from a branch condition to a branch target
1409	/// when the condition is simple.
1410	///
1411	/// This restructures some of the work of addContextEdges. That function
1412	/// creates edges this may destroy, but they work together to create a more
1413	/// aesthetically set of edges around branches. After the call to
1414	/// addContextEdges, we may have (1) an edge to the branch, (2) an edge from
1415	/// the branch to the branch condition, and (3) an edge from the branch
1416	/// condition to the branch target. We keep (1), but may wish to remove (2)
1417	/// and move the source of (3) to the branch if the branch condition is simple.
1418	static void simplifySimpleBranches(PathPieces &pieces) {
1419	for (PathPieces::iterator I = pieces.begin(), E = pieces.end(); I != E; ++I) {
1420	const auto *PieceI = dyn_cast<PathDiagnosticControlFlowPiece>(I->get());
1421
1422	if (!PieceI)
1423	continue;
1424
1425	const Stmt *s1Start = PieceI->getStartLocation().getStmtOrNull();
1426	const Stmt *s1End = PieceI->getEndLocation().getStmtOrNull();
1427
1428	if (!s1Start \|\| !s1End)
1429	continue;
1430
1431	PathPieces::iterator NextI = I; ++NextI;
1432	if (NextI == E)
1433	break;
1434
1435	PathDiagnosticControlFlowPiece *PieceNextI = nullptr;
1436
1437	while (true) {
1438	if (NextI == E)
1439	break;
1440
1441	const auto *EV = dyn_cast<PathDiagnosticEventPiece>(NextI->get());
1442	if (EV) {
1443	StringRef S = EV->getString();
1444	if (S == StrEnteringLoop \|\| S == StrLoopBodyZero \|\|
1445	S == StrLoopCollectionEmpty \|\| S == StrLoopRangeEmpty) {
1446	++NextI;
1447	continue;
1448	}
1449	break;
1450	}
1451
1452	PieceNextI = dyn_cast<PathDiagnosticControlFlowPiece>(NextI->get());
1453	break;
1454	}
1455
1456	if (!PieceNextI)
1457	continue;
1458
1459	const Stmt *s2Start = PieceNextI->getStartLocation().getStmtOrNull();
1460	const Stmt *s2End = PieceNextI->getEndLocation().getStmtOrNull();
1461
1462	if (!s2Start \|\| !s2End \|\| s1End != s2Start)
1463	continue;
1464
1465	// We only perform this transformation for specific branch kinds.
1466	// We don't want to do this for do..while, for example.
1467	if (!(isa<ForStmt>(s1Start) \|\| isa<WhileStmt>(s1Start) \|\|
1468	isa<IfStmt>(s1Start) \|\| isa<ObjCForCollectionStmt>(s1Start) \|\|
1469	isa<CXXForRangeStmt>(s1Start)))
1470	continue;
1471
1472	// Is s1End the branch condition?
1473	if (!isConditionForTerminator(s1Start, s1End))
1474	continue;
1475
1476	// Perform the hoisting by eliminating (2) and changing the start
1477	// location of (3).
1478	PieceNextI->setStartLocation(PieceI->getStartLocation());
1479	I = pieces.erase(I);
1480	}
1481	}
1482
1483	/// Returns the number of bytes in the given (character-based) SourceRange.
1484	///
1485	/// If the locations in the range are not on the same line, returns None.
1486	///
1487	/// Note that this does not do a precise user-visible character or column count.
1488	static Optional<size_t> getLengthOnSingleLine(SourceManager &SM,
1489	SourceRange Range) {
1490	SourceRange ExpansionRange(SM.getExpansionLoc(Range.getBegin()),
1491	SM.getExpansionRange(Range.getEnd()).getEnd());
1492
1493	FileID FID = SM.getFileID(ExpansionRange.getBegin());
1494	if (FID != SM.getFileID(ExpansionRange.getEnd()))
1495	return None;
1496
1497	bool Invalid;
1498	const llvm::MemoryBuffer *Buffer = SM.getBuffer(FID, &Invalid);
1499	if (Invalid)
1500	return None;
1501
1502	unsigned BeginOffset = SM.getFileOffset(ExpansionRange.getBegin());
1503	unsigned EndOffset = SM.getFileOffset(ExpansionRange.getEnd());
1504	StringRef Snippet = Buffer->getBuffer().slice(BeginOffset, EndOffset);
1505
1506	// We're searching the raw bytes of the buffer here, which might include
1507	// escaped newlines and such. That's okay; we're trying to decide whether the
1508	// SourceRange is covering a large or small amount of space in the user's
1509	// editor.
1510	if (Snippet.find_first_of("\r\n") != StringRef::npos)
1511	return None;
1512
1513	// This isn't Unicode-aware, but it doesn't need to be.
1514	return Snippet.size();
1515	}
1516
1517	/// \sa getLengthOnSingleLine(SourceManager, SourceRange)
1518	static Optional<size_t> getLengthOnSingleLine(SourceManager &SM,
1519	const Stmt *S) {
1520	return getLengthOnSingleLine(SM, S->getSourceRange());
1521	}
1522
1523	/// Eliminate two-edge cycles created by addContextEdges().
1524	///
1525	/// Once all the context edges are in place, there are plenty of cases where
1526	/// there's a single edge from a top-level statement to a subexpression,
1527	/// followed by a single path note, and then a reverse edge to get back out to
1528	/// the top level. If the statement is simple enough, the subexpression edges
1529	/// just add noise and make it harder to understand what's going on.
1530	///
1531	/// This function only removes edges in pairs, because removing only one edge
1532	/// might leave other edges dangling.
1533	///
1534	/// This will not remove edges in more complicated situations:
1535	/// - if there is more than one "hop" leading to or from a subexpression.
1536	/// - if there is an inlined call between the edges instead of a single event.
1537	/// - if the whole statement is large enough that having subexpression arrows
1538	/// might be helpful.
1539	static void removeContextCycles(PathPieces &Path, SourceManager &SM) {
1540	for (PathPieces::iterator I = Path.begin(), E = Path.end(); I != E; ) {
1541	// Pattern match the current piece and its successor.
1542	const auto *PieceI = dyn_cast<PathDiagnosticControlFlowPiece>(I->get());
1543
1544	if (!PieceI) {
1545	++I;
1546	continue;
1547	}
1548
1549	const Stmt *s1Start = PieceI->getStartLocation().getStmtOrNull();
1550	const Stmt *s1End = PieceI->getEndLocation().getStmtOrNull();
1551
1552	PathPieces::iterator NextI = I; ++NextI;
1553	if (NextI == E)
1554	break;
1555
1556	const auto *PieceNextI =
1557	dyn_cast<PathDiagnosticControlFlowPiece>(NextI->get());
1558
1559	if (!PieceNextI) {
1560	if (isa<PathDiagnosticEventPiece>(NextI->get())) {
1561	++NextI;
1562	if (NextI == E)
1563	break;
1564	PieceNextI = dyn_cast<PathDiagnosticControlFlowPiece>(NextI->get());
1565	}
1566
1567	if (!PieceNextI) {
1568	++I;
1569	continue;
1570	}
1571	}
1572
1573	const Stmt *s2Start = PieceNextI->getStartLocation().getStmtOrNull();
1574	const Stmt *s2End = PieceNextI->getEndLocation().getStmtOrNull();
1575
1576	if (s1Start && s2Start && s1Start == s2End && s2Start == s1End) {
1577	const size_t MAX_SHORT_LINE_LENGTH = 80;
1578	Optional<size_t> s1Length = getLengthOnSingleLine(SM, s1Start);
1579	if (s1Length && *s1Length <= MAX_SHORT_LINE_LENGTH) {
1580	Optional<size_t> s2Length = getLengthOnSingleLine(SM, s2Start);
1581	if (s2Length && *s2Length <= MAX_SHORT_LINE_LENGTH) {
1582	Path.erase(I);
1583	I = Path.erase(NextI);
1584	continue;
1585	}
1586	}
1587	}
1588
1589	++I;
1590	}
1591	}
1592
1593	/// Return true if X is contained by Y.
1594	static bool lexicalContains(ParentMap &PM, const Stmt X, const Stmt Y) {
1595	while (X) {
1596	if (X == Y)
1597	return true;
1598	X = PM.getParent(X);
1599	}
1600	return false;
1601	}
1602
1603	// Remove short edges on the same line less than 3 columns in difference.
1604	static void removePunyEdges(PathPieces &path, SourceManager &SM,
1605	ParentMap &PM) {
1606	bool erased = false;
1607
1608	for (PathPieces::iterator I = path.begin(), E = path.end(); I != E;
1609	erased ? I : ++I) {
1610	erased = false;
1611
1612	const auto *PieceI = dyn_cast<PathDiagnosticControlFlowPiece>(I->get());
1613
1614	if (!PieceI)
1615	continue;
1616
1617	const Stmt *start = PieceI->getStartLocation().getStmtOrNull();
1618	const Stmt *end = PieceI->getEndLocation().getStmtOrNull();
1619
1620	if (!start \|\| !end)
1621	continue;
1622
1623	const Stmt *endParent = PM.getParent(end);
1624	if (!endParent)
1625	continue;
1626
1627	if (isConditionForTerminator(end, endParent))
1628	continue;
1629
1630	SourceLocation FirstLoc = start->getBeginLoc();
1631	SourceLocation SecondLoc = end->getBeginLoc();
1632
1633	if (!SM.isWrittenInSameFile(FirstLoc, SecondLoc))
1634	continue;
1635	if (SM.isBeforeInTranslationUnit(SecondLoc, FirstLoc))
1636	std::swap(SecondLoc, FirstLoc);
1637
1638	SourceRange EdgeRange(FirstLoc, SecondLoc);
1639	Optional<size_t> ByteWidth = getLengthOnSingleLine(SM, EdgeRange);
1640
1641	// If the statements are on different lines, continue.
1642	if (!ByteWidth)
1643	continue;
1644
1645	const size_t MAX_PUNY_EDGE_LENGTH = 2;
1646	if (*ByteWidth <= MAX_PUNY_EDGE_LENGTH) {
1647	// FIXME: There are enough /bytes/ between the endpoints of the edge, but
1648	// there might not be enough /columns/. A proper user-visible column count
1649	// is probably too expensive, though.
1650	I = path.erase(I);
1651	erased = true;
1652	continue;
1653	}
1654	}
1655	}
1656
1657	static void removeIdenticalEvents(PathPieces &path) {
1658	for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; ++I) {
1659	const auto *PieceI = dyn_cast<PathDiagnosticEventPiece>(I->get());
1660
1661	if (!PieceI)
1662	continue;
1663
1664	PathPieces::iterator NextI = I; ++NextI;
1665	if (NextI == E)
1666	return;
1667
1668	const auto *PieceNextI = dyn_cast<PathDiagnosticEventPiece>(NextI->get());
1669
1670	if (!PieceNextI)
1671	continue;
1672
1673	// Erase the second piece if it has the same exact message text.
1674	if (PieceI->getString() == PieceNextI->getString()) {
1675	path.erase(NextI);
1676	}
1677	}
1678	}
1679
1680	static bool optimizeEdges(PathPieces &path, SourceManager &SM,
1681	OptimizedCallsSet &OCS,
1682	LocationContextMap &LCM) {
1683	bool hasChanges = false;
1684	const LocationContext *LC = LCM[&path];
1685	assert(LC);
1686	ParentMap &PM = LC->getParentMap();
1687
1688	for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; ) {
1689	// Optimize subpaths.
1690	if (auto *CallI = dyn_cast<PathDiagnosticCallPiece>(I->get())) {
1691	// Record the fact that a call has been optimized so we only do the
1692	// effort once.
1693	if (!OCS.count(CallI)) {
1694	while (optimizeEdges(CallI->path, SM, OCS, LCM)) {}
1695	OCS.insert(CallI);
1696	}
1697	++I;
1698	continue;
1699	}
1700
1701	// Pattern match the current piece and its successor.
1702	auto *PieceI = dyn_cast<PathDiagnosticControlFlowPiece>(I->get());
1703
1704	if (!PieceI) {
1705	++I;
1706	continue;
1707	}
1708
1709	const Stmt *s1Start = PieceI->getStartLocation().getStmtOrNull();
1710	const Stmt *s1End = PieceI->getEndLocation().getStmtOrNull();
1711	const Stmt *level1 = getStmtParent(s1Start, PM);
1712	const Stmt *level2 = getStmtParent(s1End, PM);
1713
1714	PathPieces::iterator NextI = I; ++NextI;
1715	if (NextI == E)
1716	break;
1717
1718	const auto *PieceNextI = dyn_cast<PathDiagnosticControlFlowPiece>(NextI->get());
1719
1720	if (!PieceNextI) {
1721	++I;
1722	continue;
1723	}
1724
1725	const Stmt *s2Start = PieceNextI->getStartLocation().getStmtOrNull();
1726	const Stmt *s2End = PieceNextI->getEndLocation().getStmtOrNull();
1727	const Stmt *level3 = getStmtParent(s2Start, PM);
1728	const Stmt *level4 = getStmtParent(s2End, PM);
1729
1730	// Rule I.
1731	//
1732	// If we have two consecutive control edges whose end/begin locations
1733	// are at the same level (e.g. statements or top-level expressions within
1734	// a compound statement, or siblings share a single ancestor expression),
1735	// then merge them if they have no interesting intermediate event.
1736	//
1737	// For example:
1738	//
1739	// (1.1 -> 1.2) -> (1.2 -> 1.3) becomes (1.1 -> 1.3) because the common
1740	// parent is '1'. Here 'x.y.z' represents the hierarchy of statements.
1741	//
1742	// NOTE: this will be limited later in cases where we add barriers
1743	// to prevent this optimization.
1744	if (level1 && level1 == level2 && level1 == level3 && level1 == level4) {
1745	PieceI->setEndLocation(PieceNextI->getEndLocation());
1746	path.erase(NextI);
1747	hasChanges = true;
1748	continue;
1749	}
1750
1751	// Rule II.
1752	//
1753	// Eliminate edges between subexpressions and parent expressions
1754	// when the subexpression is consumed.
1755	//
1756	// NOTE: this will be limited later in cases where we add barriers
1757	// to prevent this optimization.
1758	if (s1End && s1End == s2Start && level2) {
1759	bool removeEdge = false;
1760	// Remove edges into the increment or initialization of a
1761	// loop that have no interleaving event. This means that
1762	// they aren't interesting.
1763	if (isIncrementOrInitInForLoop(s1End, level2))
1764	removeEdge = true;
1765	// Next only consider edges that are not anchored on
1766	// the condition of a terminator. This are intermediate edges
1767	// that we might want to trim.
1768	else if (!isConditionForTerminator(level2, s1End)) {
1769	// Trim edges on expressions that are consumed by
1770	// the parent expression.
1771	if (isa<Expr>(s1End) && PM.isConsumedExpr(cast<Expr>(s1End))) {
1772	removeEdge = true;
1773	}
1774	// Trim edges where a lexical containment doesn't exist.
1775	// For example:
1776	//
1777	// X -> Y -> Z
1778	//
1779	// If 'Z' lexically contains Y (it is an ancestor) and
1780	// 'X' does not lexically contain Y (it is a descendant OR
1781	// it has no lexical relationship at all) then trim.
1782	//
1783	// This can eliminate edges where we dive into a subexpression
1784	// and then pop back out, etc.
1785	else if (s1Start && s2End &&
1786	lexicalContains(PM, s2Start, s2End) &&
1787	!lexicalContains(PM, s1End, s1Start)) {
1788	removeEdge = true;
1789	}
1790	// Trim edges from a subexpression back to the top level if the
1791	// subexpression is on a different line.
1792	//
1793	// A.1 -> A -> B
1794	// becomes
1795	// A.1 -> B
1796	//
1797	// These edges just look ugly and don't usually add anything.
1798	else if (s1Start && s2End &&
1799	lexicalContains(PM, s1Start, s1End)) {
1800	SourceRange EdgeRange(PieceI->getEndLocation().asLocation(),
1801	PieceI->getStartLocation().asLocation());
1802	if (!getLengthOnSingleLine(SM, EdgeRange).hasValue())
1803	removeEdge = true;
1804	}
1805	}
1806
1807	if (removeEdge) {
1808	PieceI->setEndLocation(PieceNextI->getEndLocation());
1809	path.erase(NextI);
1810	hasChanges = true;
1811	continue;
1812	}
1813	}
1814
1815	// Optimize edges for ObjC fast-enumeration loops.
1816	//
1817	// (X -> collection) -> (collection -> element)
1818	//
1819	// becomes:
1820	//
1821	// (X -> element)
1822	if (s1End == s2Start) {
1823	const auto *FS = dyn_cast_or_null<ObjCForCollectionStmt>(level3);
1824	if (FS && FS->getCollection()->IgnoreParens() == s2Start &&
1825	s2End == FS->getElement()) {
1826	PieceI->setEndLocation(PieceNextI->getEndLocation());
1827	path.erase(NextI);
1828	hasChanges = true;
1829	continue;
1830	}
1831	}
1832
1833	// No changes at this index? Move to the next one.
1834	++I;
1835	}
1836
1837	if (!hasChanges) {
1838	// Adjust edges into subexpressions to make them more uniform
1839	// and aesthetically pleasing.
1840	addContextEdges(path, SM, PM, LC);
1841	// Remove "cyclical" edges that include one or more context edges.
1842	removeContextCycles(path, SM);
1843	// Hoist edges originating from branch conditions to branches
1844	// for simple branches.
1845	simplifySimpleBranches(path);
1846	// Remove any puny edges left over after primary optimization pass.
1847	removePunyEdges(path, SM, PM);
1848	// Remove identical events.
1849	removeIdenticalEvents(path);
1850	}
1851
1852	return hasChanges;
1853	}
1854
1855	/// Drop the very first edge in a path, which should be a function entry edge.
1856	///
1857	/// If the first edge is not a function entry edge (say, because the first
1858	/// statement had an invalid source location), this function does nothing.
1859	// FIXME: We should just generate invalid edges anyway and have the optimizer
1860	// deal with them.
1861	static void dropFunctionEntryEdge(PathPieces &Path, LocationContextMap &LCM,
1862	SourceManager &SM) {
1863	const auto *FirstEdge =
1864	dyn_cast<PathDiagnosticControlFlowPiece>(Path.front().get());
1865	if (!FirstEdge)
1866	return;
1867
1868	const Decl *D = LCM[&Path]->getDecl();
1869	PathDiagnosticLocation EntryLoc = PathDiagnosticLocation::createBegin(D, SM);
1870	if (FirstEdge->getStartLocation() != EntryLoc)
1871	return;
1872
1873	Path.pop_front();
1874	}
1875
1876	using VisitorsDiagnosticsTy = llvm::DenseMap<const ExplodedNode *,
1877	std::vector<std::shared_ptr<PathDiagnosticPiece>>>;
1878
1879	/// Populate executes lines with lines containing at least one diagnostics.
1880	static void updateExecutedLinesWithDiagnosticPieces(
1881	PathDiagnostic &PD) {
1882
1883	PathPieces path = PD.path.flatten(/ShouldFlattenMacros=/true);
1884	FilesToLineNumsMap &ExecutedLines = PD.getExecutedLines();
1885
1886	for (const auto &P : path) {
1887	FullSourceLoc Loc = P->getLocation().asLocation().getExpansionLoc();
1888	FileID FID = Loc.getFileID();
1889	unsigned LineNo = Loc.getLineNumber();
1890	assert(FID.isValid());
1891	ExecutedLines[FID].insert(LineNo);
1892	}
1893	}
1894
1895	/// This function is responsible for generating diagnostic pieces that are
1896	/// not provided by bug report visitors.
1897	/// These diagnostics may differ depending on the consumer's settings,
1898	/// and are therefore constructed separately for each consumer.
1899	///
1900	/// There are two path diagnostics generation modes: with adding edges (used
1901	/// for plists) and without (used for HTML and text).
1902	/// When edges are added (\p ActiveScheme is Extensive),
1903	/// the path is modified to insert artificially generated
1904	/// edges.
1905	/// Otherwise, more detailed diagnostics is emitted for block edges, explaining
1906	/// the transitions in words.
1907	static std::unique_ptr<PathDiagnostic> generatePathDiagnosticForConsumer(
1908	PathDiagnosticConsumer::PathGenerationScheme ActiveScheme,
1909	PathDiagnosticBuilder &PDB,
1910	const ExplodedNode *ErrorNode,
1911	const VisitorsDiagnosticsTy &VisitorsDiagnostics) {
1912
1913	bool GenerateDiagnostics = (ActiveScheme != PathDiagnosticConsumer::None);
1914	bool AddPathEdges = (ActiveScheme == PathDiagnosticConsumer::Extensive);
1915	SourceManager &SM = PDB.getSourceManager();
1916	BugReport *R = PDB.getBugReport();
1917	AnalyzerOptions &Opts = PDB.getBugReporter().getAnalyzerOptions();
1918	StackDiagVector CallStack;
1919	InterestingExprs IE;
1920	LocationContextMap LCM;
1921	std::unique_ptr<PathDiagnostic> PD = generateEmptyDiagnosticForReport(R, SM);
1922
1923	if (GenerateDiagnostics) {
1924	auto EndNotes = VisitorsDiagnostics.find(ErrorNode);
1925	std::shared_ptr<PathDiagnosticPiece> LastPiece;
1926	if (EndNotes != VisitorsDiagnostics.end()) {
1927	second.empty()", "/home/seafit/code_projects/clang_source/clang/lib/StaticAnalyzer/Core/BugReporter.cpp", 1927, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(!EndNotes->second.empty());
1928	LastPiece = EndNotes->second[0];
1929	} else {
1930	LastPiece = BugReporterVisitor::getDefaultEndPath(PDB, ErrorNode, *R);
1931	}
1932	PD->setEndOfPath(LastPiece);
1933	}
1934
1935	PathDiagnosticLocation PrevLoc = PD->getLocation();
1936	const ExplodedNode *NextNode = ErrorNode->getFirstPred();
1937	while (NextNode) {
1938	if (GenerateDiagnostics)
1939	generatePathDiagnosticsForNode(
1940	NextNode, *PD, PrevLoc, PDB, LCM, CallStack, IE, AddPathEdges);
1941
1942	auto VisitorNotes = VisitorsDiagnostics.find(NextNode);
1943	NextNode = NextNode->getFirstPred();
1944	if (!GenerateDiagnostics \|\| VisitorNotes == VisitorsDiagnostics.end())
1945	continue;
1946
1947	// This is a workaround due to inability to put shared PathDiagnosticPiece
1948	// into a FoldingSet.
1949	std::set<llvm::FoldingSetNodeID> DeduplicationSet;
1950
1951	// Add pieces from custom visitors.
1952	for (const auto &Note : VisitorNotes->second) {
1953	llvm::FoldingSetNodeID ID;
1954	Note->Profile(ID);
1955	auto P = DeduplicationSet.insert(ID);
1956	if (!P.second)
1957	continue;
1958
1959	if (AddPathEdges)
1960	addEdgeToPath(PD->getActivePath(), PrevLoc, Note->getLocation());
1961	updateStackPiecesWithMessage(*Note, CallStack);
1962	PD->getActivePath().push_front(Note);
1963	}
1964	}
1965
1966	if (AddPathEdges) {
1967	// Add an edge to the start of the function.
1968	// We'll prune it out later, but it helps make diagnostics more uniform.
1969	const StackFrameContext *CalleeLC = PDB.LC->getStackFrame();
1970	const Decl *D = CalleeLC->getDecl();
1971	addEdgeToPath(PD->getActivePath(), PrevLoc,
1972	PathDiagnosticLocation::createBegin(D, SM));
1973	}
1974
1975
1976	// Finally, prune the diagnostic path of uninteresting stuff.
1977	if (!PD->path.empty()) {
1978	if (R->shouldPrunePath() && Opts.ShouldPrunePaths) {
1979	bool stillHasNotes =
1980	removeUnneededCalls(PD->getMutablePieces(), R, LCM);
1981	assert(stillHasNotes);
1982	(void)stillHasNotes;
1983	}
1984
1985	// Redirect all call pieces to have valid locations.
1986	adjustCallLocations(PD->getMutablePieces());
1987	removePiecesWithInvalidLocations(PD->getMutablePieces());
1988
1989	if (AddPathEdges) {
1990
1991	// Reduce the number of edges from a very conservative set
1992	// to an aesthetically pleasing subset that conveys the
1993	// necessary information.
1994	OptimizedCallsSet OCS;
1995	while (optimizeEdges(PD->getMutablePieces(), SM, OCS, LCM)) {}
1996
1997	// Drop the very first function-entry edge. It's not really necessary
1998	// for top-level functions.
1999	dropFunctionEntryEdge(PD->getMutablePieces(), LCM, SM);
2000	}
2001
2002	// Remove messages that are basically the same, and edges that may not
2003	// make sense.
2004	// We have to do this after edge optimization in the Extensive mode.
2005	removeRedundantMsgs(PD->getMutablePieces());
2006	removeEdgesToDefaultInitializers(PD->getMutablePieces());
2007	}
2008
2009	if (GenerateDiagnostics && Opts.ShouldDisplayMacroExpansions)
2010	CompactMacroExpandedPieces(PD->getMutablePieces(), SM);
2011
2012	return PD;
2013	}
2014
2015
2016	//===----------------------------------------------------------------------===//
2017	// Methods for BugType and subclasses.
2018	//===----------------------------------------------------------------------===//
2019
2020	void BugType::anchor() {}
2021
2022	void BuiltinBug::anchor() {}
2023
2024	//===----------------------------------------------------------------------===//
2025	// Methods for BugReport and subclasses.
2026	//===----------------------------------------------------------------------===//
2027
2028	void BugReport::NodeResolver::anchor() {}
2029
2030	void BugReport::addVisitor(std::unique_ptr<BugReporterVisitor> visitor) {
2031	if (!visitor)
2032	return;
2033
2034	llvm::FoldingSetNodeID ID;
2035	visitor->Profile(ID);
2036
2037	void *InsertPos = nullptr;
2038	if (CallbacksSet.FindNodeOrInsertPos(ID, InsertPos)) {
2039	return;
2040	}
2041
2042	Callbacks.push_back(std::move(visitor));
2043	}
2044
2045	void BugReport::clearVisitors() {
2046	Callbacks.clear();
2047	}
2048
2049	BugReport::~BugReport() {
2050	while (!interestingSymbols.empty()) {
2051	popInterestingSymbolsAndRegions();
2052	}
2053	}
2054
2055	const Decl *BugReport::getDeclWithIssue() const {
2056	if (DeclWithIssue)
2057	return DeclWithIssue;
2058
2059	const ExplodedNode *N = getErrorNode();
2060	if (!N)
2061	return nullptr;
2062
2063	const LocationContext *LC = N->getLocationContext();
2064	return LC->getStackFrame()->getDecl();
2065	}
2066
2067	void BugReport::Profile(llvm::FoldingSetNodeID& hash) const {
2068	hash.AddPointer(&BT);
2069	hash.AddString(Description);
2070	PathDiagnosticLocation UL = getUniqueingLocation();
2071	if (UL.isValid()) {
2072	UL.Profile(hash);
2073	} else if (Location.isValid()) {
2074	Location.Profile(hash);
2075	} else {
2076	assert(ErrorNode);
2077	hash.AddPointer(GetCurrentOrPreviousStmt(ErrorNode));
2078	}
2079
2080	for (SourceRange range : Ranges) {
2081	if (!range.isValid())
2082	continue;
2083	hash.AddInteger(range.getBegin().getRawEncoding());
2084	hash.AddInteger(range.getEnd().getRawEncoding());
2085	}
2086	}
2087
2088	void BugReport::markInteresting(SymbolRef sym) {
2089	if (!sym)
2090	return;
2091
2092	getInterestingSymbols().insert(sym);
2093
2094	if (const auto *meta = dyn_cast<SymbolMetadata>(sym))
2095	getInterestingRegions().insert(meta->getRegion());
2096	}
2097
2098	void BugReport::markInteresting(const MemRegion *R) {
2099	if (!R)
2100	return;
2101
2102	R = R->getBaseRegion();
2103	getInterestingRegions().insert(R);
2104
2105	if (const auto *SR = dyn_cast<SymbolicRegion>(R))
2106	getInterestingSymbols().insert(SR->getSymbol());
2107	}
2108
2109	void BugReport::markInteresting(SVal V) {
2110	markInteresting(V.getAsRegion());
2111	markInteresting(V.getAsSymbol());
2112	}
2113
2114	void BugReport::markInteresting(const LocationContext *LC) {
2115	if (!LC)
2116	return;
2117	InterestingLocationContexts.insert(LC);
2118	}
2119
2120	bool BugReport::isInteresting(SVal V) {
2121	return isInteresting(V.getAsRegion()) \|\| isInteresting(V.getAsSymbol());
2122	}
2123
2124	bool BugReport::isInteresting(SymbolRef sym) {
2125	if (!sym)
2126	return false;
2127	// We don't currently consider metadata symbols to be interesting
2128	// even if we know their region is interesting. Is that correct behavior?
2129	return getInterestingSymbols().count(sym);
2130	}
2131
2132	bool BugReport::isInteresting(const MemRegion *R) {
2133	if (!R)
2134	return false;
2135	R = R->getBaseRegion();
2136	bool b = getInterestingRegions().count(R);
2137	if (b)
2138	return true;
2139	if (const auto *SR = dyn_cast<SymbolicRegion>(R))
2140	return getInterestingSymbols().count(SR->getSymbol());
2141	return false;
2142	}
2143
2144	bool BugReport::isInteresting(const LocationContext *LC) {
2145	if (!LC)
2146	return false;
2147	return InterestingLocationContexts.count(LC);
2148	}
2149
2150	void BugReport::lazyInitializeInterestingSets() {
2151	if (interestingSymbols.empty()) {
2152	interestingSymbols.push_back(new Symbols());
2153	interestingRegions.push_back(new Regions());
2154	}
2155	}
2156
2157	BugReport::Symbols &BugReport::getInterestingSymbols() {
2158	lazyInitializeInterestingSets();
2159	return *interestingSymbols.back();
2160	}
2161
2162	BugReport::Regions &BugReport::getInterestingRegions() {
2163	lazyInitializeInterestingSets();
2164	return *interestingRegions.back();
2165	}
2166
2167	void BugReport::pushInterestingSymbolsAndRegions() {
2168	interestingSymbols.push_back(new Symbols(getInterestingSymbols()));
2169	interestingRegions.push_back(new Regions(getInterestingRegions()));
2170	}
2171
2172	void BugReport::popInterestingSymbolsAndRegions() {
2173	delete interestingSymbols.pop_back_val();
2174	delete interestingRegions.pop_back_val();
2175	}
2176
2177	const Stmt *BugReport::getStmt() const {
2178	if (!ErrorNode)
2179	return nullptr;
2180
2181	ProgramPoint ProgP = ErrorNode->getLocation();
2182	const Stmt *S = nullptr;
2183
2184	if (Optional<BlockEntrance> BE = ProgP.getAs<BlockEntrance>()) {
2185	CFGBlock &Exit = ProgP.getLocationContext()->getCFG()->getExit();
2186	if (BE->getBlock() == &Exit)
2187	S = GetPreviousStmt(ErrorNode);
2188	}
2189	if (!S)
2190	S = PathDiagnosticLocation::getStmt(ErrorNode);
2191
2192	return S;
2193	}
2194
2195	llvm::iterator_range<BugReport::ranges_iterator> BugReport::getRanges() {
2196	// If no custom ranges, add the range of the statement corresponding to
2197	// the error node.
2198	if (Ranges.empty()) {
2199	if (const auto *E = dyn_cast_or_null<Expr>(getStmt()))
2200	addRange(E->getSourceRange());
2201	else
2202	return llvm::make_range(ranges_iterator(), ranges_iterator());
2203	}
2204
2205	// User-specified absence of range info.
2206	if (Ranges.size() == 1 && !Ranges.begin()->isValid())
2207	return llvm::make_range(ranges_iterator(), ranges_iterator());
2208
2209	return llvm::make_range(Ranges.begin(), Ranges.end());
2210	}
2211
2212	PathDiagnosticLocation BugReport::getLocation(const SourceManager &SM) const {
2213	if (ErrorNode) {
2214	(0) . __assert_fail ("!Location.isValid() && \"Either Location or ErrorNode should be specified but not both.\"", "/home/seafit/code_projects/clang_source/clang/lib/StaticAnalyzer/Core/BugReporter.cpp", 2215, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(!Location.isValid() &&
2215	(0) . __assert_fail ("!Location.isValid() && \"Either Location or ErrorNode should be specified but not both.\"", "/home/seafit/code_projects/clang_source/clang/lib/StaticAnalyzer/Core/BugReporter.cpp", 2215, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true"> "Either Location or ErrorNode should be specified but not both.");
2216	return PathDiagnosticLocation::createEndOfPath(ErrorNode, SM);
2217	}
2218
2219	assert(Location.isValid());
2220	return Location;
2221	}
2222
2223	//===----------------------------------------------------------------------===//
2224	// Methods for BugReporter and subclasses.
2225	//===----------------------------------------------------------------------===//
2226
2227	BugReportEquivClass::~BugReportEquivClass() = default;
2228
2229	GRBugReporter::~GRBugReporter() = default;
2230
2231	BugReporterData::~BugReporterData() = default;
2232
2233	ExplodedGraph &GRBugReporter::getGraph() { return Eng.getGraph(); }
2234
2235	ProgramStateManager&
2236	GRBugReporter::getStateManager() { return Eng.getStateManager(); }
2237
2238	BugReporter::~BugReporter() {
2239	FlushReports();
2240
2241	// Free the bug reports we are tracking.
2242	for (const auto I : EQClassesVector)
2243	delete I;
2244	}
2245
2246	void BugReporter::FlushReports() {
2247	if (BugTypes.isEmpty())
2248	return;
2249
2250	// We need to flush reports in deterministic order to ensure the order
2251	// of the reports is consistent between runs.
2252	for (const auto EQ : EQClassesVector)
2253	FlushReport(*EQ);
2254
2255	// BugReporter owns and deletes only BugTypes created implicitly through
2256	// EmitBasicReport.
2257	// FIXME: There are leaks from checkers that assume that the BugTypes they
2258	// create will be destroyed by the BugReporter.
2259	llvm::DeleteContainerSeconds(StrBugTypes);
2260
2261	// Remove all references to the BugType objects.
2262	BugTypes = F.getEmptySet();
2263	}
2264
2265	//===----------------------------------------------------------------------===//
2266	// PathDiagnostics generation.
2267	//===----------------------------------------------------------------------===//
2268
2269	namespace {
2270
2271	/// A wrapper around a report graph, which contains only a single path, and its
2272	/// node maps.
2273	class ReportGraph {
2274	public:
2275	InterExplodedGraphMap BackMap;
2276	std::unique_ptr<ExplodedGraph> Graph;
2277	const ExplodedNode *ErrorNode;
2278	size_t Index;
2279	};
2280
2281	/// A wrapper around a trimmed graph and its node maps.
2282	class TrimmedGraph {
2283	InterExplodedGraphMap InverseMap;
2284
2285	using PriorityMapTy = llvm::DenseMap<const ExplodedNode *, unsigned>;
2286
2287	PriorityMapTy PriorityMap;
2288
2289	using NodeIndexPair = std::pair<const ExplodedNode *, size_t>;
2290
2291	SmallVector<NodeIndexPair, 32> ReportNodes;
2292
2293	std::unique_ptr<ExplodedGraph> G;
2294
2295	/// A helper class for sorting ExplodedNodes by priority.
2296	template <bool Descending>
2297	class PriorityCompare {
2298	const PriorityMapTy &PriorityMap;
2299
2300	public:
2301	PriorityCompare(const PriorityMapTy &M) : PriorityMap(M) {}
2302
2303	bool operator()(const ExplodedNode LHS, const ExplodedNode RHS) const {
2304	PriorityMapTy::const_iterator LI = PriorityMap.find(LHS);
2305	PriorityMapTy::const_iterator RI = PriorityMap.find(RHS);
2306	PriorityMapTy::const_iterator E = PriorityMap.end();
2307
2308	if (LI == E)
2309	return Descending;
2310	if (RI == E)
2311	return !Descending;
2312
2313	return Descending ? LI->second > RI->second
2314	: LI->second < RI->second;
2315	}
2316
2317	bool operator()(const NodeIndexPair &LHS, const NodeIndexPair &RHS) const {
2318	return (*this)(LHS.first, RHS.first);
2319	}
2320	};
2321
2322	public:
2323	TrimmedGraph(const ExplodedGraph *OriginalGraph,
2324	ArrayRef<const ExplodedNode *> Nodes);
2325
2326	bool popNextReportGraph(ReportGraph &GraphWrapper);
2327	};
2328
2329	} // namespace
2330
2331	TrimmedGraph::TrimmedGraph(const ExplodedGraph *OriginalGraph,
2332	ArrayRef<const ExplodedNode *> Nodes) {
2333	// The trimmed graph is created in the body of the constructor to ensure
2334	// that the DenseMaps have been initialized already.
2335	InterExplodedGraphMap ForwardMap;
2336	G = OriginalGraph->trim(Nodes, &ForwardMap, &InverseMap);
2337
2338	// Find the (first) error node in the trimmed graph. We just need to consult
2339	// the node map which maps from nodes in the original graph to nodes
2340	// in the new graph.
2341	llvm::SmallPtrSet<const ExplodedNode *, 32> RemainingNodes;
2342
2343	for (unsigned i = 0, count = Nodes.size(); i < count; ++i) {
2344	if (const ExplodedNode *NewNode = ForwardMap.lookup(Nodes[i])) {
2345	ReportNodes.push_back(std::make_pair(NewNode, i));
2346	RemainingNodes.insert(NewNode);
2347	}
2348	}
2349
2350	(0) . __assert_fail ("!RemainingNodes.empty() && \"No error node found in the trimmed graph\"", "/home/seafit/code_projects/clang_source/clang/lib/StaticAnalyzer/Core/BugReporter.cpp", 2350, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(!RemainingNodes.empty() && "No error node found in the trimmed graph");
2351
2352	// Perform a forward BFS to find all the shortest paths.
2353	std::queue<const ExplodedNode *> WS;
2354
2355	num_roots() == 1", "/home/seafit/code_projects/clang_source/clang/lib/StaticAnalyzer/Core/BugReporter.cpp", 2355, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(G->num_roots() == 1);
2356	WS.push(*G->roots_begin());
2357	unsigned Priority = 0;
2358
2359	while (!WS.empty()) {
2360	const ExplodedNode *Node = WS.front();
2361	WS.pop();
2362
2363	PriorityMapTy::iterator PriorityEntry;
2364	bool IsNew;
2365	std::tie(PriorityEntry, IsNew) =
2366	PriorityMap.insert(std::make_pair(Node, Priority));
2367	++Priority;
2368
2369	if (!IsNew) {
2370	second <= Priority", "/home/seafit/code_projects/clang_source/clang/lib/StaticAnalyzer/Core/BugReporter.cpp", 2370, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(PriorityEntry->second <= Priority);
2371	continue;
2372	}
2373
2374	if (RemainingNodes.erase(Node))
2375	if (RemainingNodes.empty())
2376	break;
2377
2378	for (ExplodedNode::const_pred_iterator I = Node->succ_begin(),
2379	E = Node->succ_end();
2380	I != E; ++I)
2381	WS.push(*I);
2382	}
2383
2384	// Sort the error paths from longest to shortest.
2385	llvm::sort(ReportNodes, PriorityCompare<true>(PriorityMap));
2386	}
2387
2388	bool TrimmedGraph::popNextReportGraph(ReportGraph &GraphWrapper) {
2389	if (ReportNodes.empty())
2390	return false;
2391
2392	const ExplodedNode *OrigN;
2393	std::tie(OrigN, GraphWrapper.Index) = ReportNodes.pop_back_val();
2394	(0) . __assert_fail ("PriorityMap.find(OrigN) != PriorityMap.end() && \"error node not accessible from root\"", "/home/seafit/code_projects/clang_source/clang/lib/StaticAnalyzer/Core/BugReporter.cpp", 2395, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(PriorityMap.find(OrigN) != PriorityMap.end() &&
2395	(0) . __assert_fail ("PriorityMap.find(OrigN) != PriorityMap.end() && \"error node not accessible from root\"", "/home/seafit/code_projects/clang_source/clang/lib/StaticAnalyzer/Core/BugReporter.cpp", 2395, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true"> "error node not accessible from root");
2396
2397	// Create a new graph with a single path. This is the graph
2398	// that will be returned to the caller.
2399	auto GNew = llvm::make_unique<ExplodedGraph>();
2400	GraphWrapper.BackMap.clear();
2401
2402	// Now walk from the error node up the BFS path, always taking the
2403	// predeccessor with the lowest number.
2404	ExplodedNode *Succ = nullptr;
2405	while (true) {
2406	// Create the equivalent node in the new graph with the same state
2407	// and location.
2408	ExplodedNode *NewN = GNew->createUncachedNode(OrigN->getLocation(), OrigN->getState(),
2409	OrigN->isSink());
2410
2411	// Store the mapping to the original node.
2412	InterExplodedGraphMap::const_iterator IMitr = InverseMap.find(OrigN);
2413	(0) . __assert_fail ("IMitr != InverseMap.end() && \"No mapping to original node.\"", "/home/seafit/code_projects/clang_source/clang/lib/StaticAnalyzer/Core/BugReporter.cpp", 2413, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(IMitr != InverseMap.end() && "No mapping to original node.");
2414	GraphWrapper.BackMap[NewN] = IMitr->second;
2415
2416	// Link up the new node with the previous node.
2417	if (Succ)
2418	Succ->addPredecessor(NewN, *GNew);
2419	else
2420	GraphWrapper.ErrorNode = NewN;
2421
2422	Succ = NewN;
2423
2424	// Are we at the final node?
2425	if (OrigN->pred_empty()) {
2426	GNew->addRoot(NewN);
2427	break;
2428	}
2429
2430	// Find the next predeccessor node. We choose the node that is marked
2431	// with the lowest BFS number.
2432	OrigN = *std::min_element(OrigN->pred_begin(), OrigN->pred_end(),
2433	PriorityCompare<false>(PriorityMap));
2434	}
2435
2436	GraphWrapper.Graph = std::move(GNew);
2437
2438	return true;
2439	}
2440
2441	/// CompactMacroExpandedPieces - This function postprocesses a PathDiagnostic
2442	/// object and collapses PathDiagosticPieces that are expanded by macros.
2443	static void CompactMacroExpandedPieces(PathPieces &path,
2444	const SourceManager& SM) {
2445	using MacroStackTy =
2446	std::vector<
2447	std::pair<std::shared_ptr<PathDiagnosticMacroPiece>, SourceLocation>>;
2448
2449	using PiecesTy = std::vector<std::shared_ptr<PathDiagnosticPiece>>;
2450
2451	MacroStackTy MacroStack;
2452	PiecesTy Pieces;
2453
2454	for (PathPieces::const_iterator I = path.begin(), E = path.end();
2455	I != E; ++I) {
2456	const auto &piece = *I;
2457
2458	// Recursively compact calls.
2459	if (auto call = dyn_cast<PathDiagnosticCallPiece>(&piece)) {
2460	CompactMacroExpandedPieces(call->path, SM);
2461	}
2462
2463	// Get the location of the PathDiagnosticPiece.
2464	const FullSourceLoc Loc = piece->getLocation().asLocation();
2465
2466	// Determine the instantiation location, which is the location we group
2467	// related PathDiagnosticPieces.
2468	SourceLocation InstantiationLoc = Loc.isMacroID() ?
2469	SM.getExpansionLoc(Loc) :
2470	SourceLocation();
2471
2472	if (Loc.isFileID()) {
2473	MacroStack.clear();
2474	Pieces.push_back(piece);
2475	continue;
2476	}
2477
2478	assert(Loc.isMacroID());
2479
2480	// Is the PathDiagnosticPiece within the same macro group?
2481	if (!MacroStack.empty() && InstantiationLoc == MacroStack.back().second) {
2482	MacroStack.back().first->subPieces.push_back(piece);
2483	continue;
2484	}
2485
2486	// We aren't in the same group. Are we descending into a new macro
2487	// or are part of an old one?
2488	std::shared_ptr<PathDiagnosticMacroPiece> MacroGroup;
2489
2490	SourceLocation ParentInstantiationLoc = InstantiationLoc.isMacroID() ?
2491	SM.getExpansionLoc(Loc) :
2492	SourceLocation();
2493
2494	// Walk the entire macro stack.
2495	while (!MacroStack.empty()) {
2496	if (InstantiationLoc == MacroStack.back().second) {
2497	MacroGroup = MacroStack.back().first;
2498	break;
2499	}
2500
2501	if (ParentInstantiationLoc == MacroStack.back().second) {
2502	MacroGroup = MacroStack.back().first;
2503	break;
2504	}
2505
2506	MacroStack.pop_back();
2507	}
2508
2509	if (!MacroGroup \|\| ParentInstantiationLoc == MacroStack.back().second) {
2510	// Create a new macro group and add it to the stack.
2511	auto NewGroup = std::make_shared<PathDiagnosticMacroPiece>(
2512	PathDiagnosticLocation::createSingleLocation(piece->getLocation()));
2513
2514	if (MacroGroup)
2515	MacroGroup->subPieces.push_back(NewGroup);
2516	else {
2517	assert(InstantiationLoc.isFileID());
2518	Pieces.push_back(NewGroup);
2519	}
2520
2521	MacroGroup = NewGroup;
2522	MacroStack.push_back(std::make_pair(MacroGroup, InstantiationLoc));
2523	}
2524
2525	// Finally, add the PathDiagnosticPiece to the group.
2526	MacroGroup->subPieces.push_back(piece);
2527	}
2528
2529	// Now take the pieces and construct a new PathDiagnostic.
2530	path.clear();
2531
2532	path.insert(path.end(), Pieces.begin(), Pieces.end());
2533	}
2534
2535	/// Generate notes from all visitors.
2536	/// Notes associated with {@code ErrorNode} are generated using
2537	/// {@code getEndPath}, and the rest are generated with {@code VisitNode}.
2538	static std::unique_ptr<VisitorsDiagnosticsTy>
2539	generateVisitorsDiagnostics(BugReport R, const ExplodedNode ErrorNode,
2540	BugReporterContext &BRC) {
2541	auto Notes = llvm::make_unique<VisitorsDiagnosticsTy>();
2542	BugReport::VisitorList visitors;
2543
2544	// Run visitors on all nodes starting from the node before the last one.
2545	// The last node is reserved for notes generated with {@code getEndPath}.
2546	const ExplodedNode *NextNode = ErrorNode->getFirstPred();
2547	while (NextNode) {
2548
2549	// At each iteration, move all visitors from report to visitor list.
2550	for (BugReport::visitor_iterator I = R->visitor_begin(),
2551	E = R->visitor_end();
2552	I != E; ++I) {
2553	visitors.push_back(std::move(*I));
2554	}
2555	R->clearVisitors();
2556
2557	const ExplodedNode *Pred = NextNode->getFirstPred();
2558	if (!Pred) {
2559	std::shared_ptr<PathDiagnosticPiece> LastPiece;
2560	for (auto &V : visitors) {
2561	V->finalizeVisitor(BRC, ErrorNode, *R);
2562
2563	if (auto Piece = V->getEndPath(BRC, ErrorNode, *R)) {
2564	(0) . __assert_fail ("!LastPiece && \"There can only be one final piece in a diagnostic.\"", "/home/seafit/code_projects/clang_source/clang/lib/StaticAnalyzer/Core/BugReporter.cpp", 2565, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(!LastPiece &&
2565	(0) . __assert_fail ("!LastPiece && \"There can only be one final piece in a diagnostic.\"", "/home/seafit/code_projects/clang_source/clang/lib/StaticAnalyzer/Core/BugReporter.cpp", 2565, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true"> "There can only be one final piece in a diagnostic.");
2566	LastPiece = std::move(Piece);
2567	(*Notes)[ErrorNode].push_back(LastPiece);
2568	}
2569	}
2570	break;
2571	}
2572
2573	for (auto &V : visitors) {
2574	auto P = V->VisitNode(NextNode, BRC, *R);
2575	if (P)
2576	(*Notes)[NextNode].push_back(std::move(P));
2577	}
2578
2579	if (!R->isValid())
2580	break;
2581
2582	NextNode = Pred;
2583	}
2584
2585	return Notes;
2586	}
2587
2588	/// Find a non-invalidated report for a given equivalence class,
2589	/// and return together with a cache of visitors notes.
2590	/// If none found, return a nullptr paired with an empty cache.
2591	static
2592	std::pair<BugReport*, std::unique_ptr<VisitorsDiagnosticsTy>> findValidReport(
2593	TrimmedGraph &TrimG,
2594	ReportGraph &ErrorGraph,
2595	ArrayRef<BugReport *> &bugReports,
2596	AnalyzerOptions &Opts,
2597	GRBugReporter &Reporter) {
2598
2599	while (TrimG.popNextReportGraph(ErrorGraph)) {
2600	// Find the BugReport with the original location.
2601	assert(ErrorGraph.Index < bugReports.size());
2602	BugReport *R = bugReports[ErrorGraph.Index];
2603	(0) . __assert_fail ("R && \"No original report found for sliced graph.\"", "/home/seafit/code_projects/clang_source/clang/lib/StaticAnalyzer/Core/BugReporter.cpp", 2603, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(R && "No original report found for sliced graph.");
2604	(0) . __assert_fail ("R->isValid() && \"Report selected by trimmed graph marked invalid.\"", "/home/seafit/code_projects/clang_source/clang/lib/StaticAnalyzer/Core/BugReporter.cpp", 2604, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(R->isValid() && "Report selected by trimmed graph marked invalid.");
2605	const ExplodedNode *ErrorNode = ErrorGraph.ErrorNode;
2606
2607	// Register refutation visitors first, if they mark the bug invalid no
2608	// further analysis is required
2609	R->addVisitor(llvm::make_unique<LikelyFalsePositiveSuppressionBRVisitor>());
2610
2611	// Register additional node visitors.
2612	R->addVisitor(llvm::make_unique<NilReceiverBRVisitor>());
2613	R->addVisitor(llvm::make_unique<ConditionBRVisitor>());
2614	R->addVisitor(llvm::make_unique<CXXSelfAssignmentBRVisitor>());
2615
2616	BugReporterContext BRC(Reporter, ErrorGraph.BackMap);
2617
2618	// Run all visitors on a given graph, once.
2619	std::unique_ptr<VisitorsDiagnosticsTy> visitorNotes =
2620	generateVisitorsDiagnostics(R, ErrorNode, BRC);
2621
2622	if (R->isValid()) {
2623	if (Opts.ShouldCrosscheckWithZ3) {
2624	// If crosscheck is enabled, remove all visitors, add the refutation
2625	// visitor and check again
2626	R->clearVisitors();
2627	R->addVisitor(llvm::make_unique<FalsePositiveRefutationBRVisitor>());
2628
2629	// We don't overrite the notes inserted by other visitors because the
2630	// refutation manager does not add any new note to the path
2631	generateVisitorsDiagnostics(R, ErrorGraph.ErrorNode, BRC);
2632	}
2633
2634	// Check if the bug is still valid
2635	if (R->isValid())
2636	return std::make_pair(R, std::move(visitorNotes));
2637	}
2638	}
2639
2640	return std::make_pair(nullptr, llvm::make_unique<VisitorsDiagnosticsTy>());
2641	}
2642
2643	std::unique_ptr<DiagnosticForConsumerMapTy>
2644	GRBugReporter::generatePathDiagnostics(
2645	ArrayRef<PathDiagnosticConsumer *> consumers,
2646	ArrayRef<BugReport *> &bugReports) {
2647	assert(!bugReports.empty());
2648
2649	auto Out = llvm::make_unique<DiagnosticForConsumerMapTy>();
2650	bool HasValid = false;
2651	SmallVector<const ExplodedNode *, 32> errorNodes;
2652	for (const auto I : bugReports) {
2653	if (I->isValid()) {
2654	HasValid = true;
2655	errorNodes.push_back(I->getErrorNode());
2656	} else {
2657	// Keep the errorNodes list in sync with the bugReports list.
2658	errorNodes.push_back(nullptr);
2659	}
2660	}
2661
2662	// If all the reports have been marked invalid by a previous path generation,
2663	// we're done.
2664	if (!HasValid)
2665	return Out;
2666
2667	TrimmedGraph TrimG(&getGraph(), errorNodes);
2668	ReportGraph ErrorGraph;
2669	auto ReportInfo = findValidReport(TrimG, ErrorGraph, bugReports,
2670	getAnalyzerOptions(), *this);
2671	BugReport *R = ReportInfo.first;
2672
2673	if (R && R->isValid()) {
2674	const ExplodedNode *ErrorNode = ErrorGraph.ErrorNode;
2675	for (PathDiagnosticConsumer *PC : consumers) {
2676	PathDiagnosticBuilder PDB(*this, R, ErrorGraph.BackMap, PC);
2677	std::unique_ptr<PathDiagnostic> PD = generatePathDiagnosticForConsumer(
2678	PC->getGenerationScheme(), PDB, ErrorNode, *ReportInfo.second);
2679	(*Out)[PC] = std::move(PD);
2680	}
2681	}
2682
2683	return Out;
2684	}
2685
2686	void BugReporter::Register(const BugType *BT) {
2687	BugTypes = F.add(BugTypes, BT);
2688	}
2689
2690	void BugReporter::emitReport(std::unique_ptr<BugReport> R) {
2691	if (const ExplodedNode *E = R->getErrorNode()) {
2692	// An error node must either be a sink or have a tag, otherwise
2693	// it could get reclaimed before the path diagnostic is created.
2694	(0) . __assert_fail ("(E->isSink() \|\| E->getLocation().getTag()) && \"Error node must either be a sink or have a tag\"", "/home/seafit/code_projects/clang_source/clang/lib/StaticAnalyzer/Core/BugReporter.cpp", 2695, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert((E->isSink() \|\| E->getLocation().getTag()) &&
2695	(0) . __assert_fail ("(E->isSink() \|\| E->getLocation().getTag()) && \"Error node must either be a sink or have a tag\"", "/home/seafit/code_projects/clang_source/clang/lib/StaticAnalyzer/Core/BugReporter.cpp", 2695, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true"> "Error node must either be a sink or have a tag");
2696
2697	const AnalysisDeclContext *DeclCtx =
2698	E->getLocationContext()->getAnalysisDeclContext();
2699	// The source of autosynthesized body can be handcrafted AST or a model
2700	// file. The locations from handcrafted ASTs have no valid source locations
2701	// and have to be discarded. Locations from model files should be preserved
2702	// for processing and reporting.
2703	if (DeclCtx->isBodyAutosynthesized() &&
2704	!DeclCtx->isBodyAutosynthesizedFromModelFile())
2705	return;
2706	}
2707
2708	bool ValidSourceLoc = R->getLocation(getSourceManager()).isValid();
2709	assert(ValidSourceLoc);
2710	// If we mess up in a release build, we'd still prefer to just drop the bug
2711	// instead of trying to go on.
2712	if (!ValidSourceLoc)
2713	return;
2714
2715	// Compute the bug report's hash to determine its equivalence class.
2716	llvm::FoldingSetNodeID ID;
2717	R->Profile(ID);
2718
2719	// Lookup the equivance class. If there isn't one, create it.
2720	const BugType& BT = R->getBugType();
2721	Register(&BT);
2722	void *InsertPos;
2723	BugReportEquivClass* EQ = EQClasses.FindNodeOrInsertPos(ID, InsertPos);
2724
2725	if (!EQ) {
2726	EQ = new BugReportEquivClass(std::move(R));
2727	EQClasses.InsertNode(EQ, InsertPos);
2728	EQClassesVector.push_back(EQ);
2729	} else
2730	EQ->AddReport(std::move(R));
2731	}
2732
2733	//===----------------------------------------------------------------------===//
2734	// Emitting reports in equivalence classes.
2735	//===----------------------------------------------------------------------===//
2736
2737	namespace {
2738
2739	struct FRIEC_WLItem {
2740	const ExplodedNode *N;
2741	ExplodedNode::const_succ_iterator I, E;
2742
2743	FRIEC_WLItem(const ExplodedNode *n)
2744	: N(n), I(N->succ_begin()), E(N->succ_end()) {}
2745	};
2746
2747	} // namespace
2748
2749	static const CFGBlock findBlockForNode(const ExplodedNode N) {
2750	ProgramPoint P = N->getLocation();
2751	if (auto BEP = P.getAs<BlockEntrance>())
2752	return BEP->getBlock();
2753
2754	// Find the node's current statement in the CFG.
2755	if (const Stmt *S = PathDiagnosticLocation::getStmt(N))
2756	return N->getLocationContext()->getAnalysisDeclContext()
2757	->getCFGStmtMap()->getBlock(S);
2758
2759	return nullptr;
2760	}
2761
2762	// Returns true if by simply looking at the block, we can be sure that it
2763	// results in a sink during analysis. This is useful to know when the analysis
2764	// was interrupted, and we try to figure out if it would sink eventually.
2765	// There may be many more reasons why a sink would appear during analysis
2766	// (eg. checkers may generate sinks arbitrarily), but here we only consider
2767	// sinks that would be obvious by looking at the CFG.
2768	static bool isImmediateSinkBlock(const CFGBlock *Blk) {
2769	if (Blk->hasNoReturnElement())
2770	return true;
2771
2772	// FIXME: Throw-expressions are currently generating sinks during analysis:
2773	// they're not supported yet, and also often used for actually terminating
2774	// the program. So we should treat them as sinks in this analysis as well,
2775	// at least for now, but once we have better support for exceptions,
2776	// we'd need to carefully handle the case when the throw is being
2777	// immediately caught.
2778	if (std::any_of(Blk->begin(), Blk->end(), [](const CFGElement &Elm) {
2779	if (Optional<CFGStmt> StmtElm = Elm.getAs<CFGStmt>())
2780	if (isa<CXXThrowExpr>(StmtElm->getStmt()))
2781	return true;
2782	return false;
2783	}))
2784	return true;
2785
2786	return false;
2787	}
2788
2789	// Returns true if by looking at the CFG surrounding the node's program
2790	// point, we can be sure that any analysis starting from this point would
2791	// eventually end with a sink. We scan the child CFG blocks in a depth-first
2792	// manner and see if all paths eventually end up in an immediate sink block.
2793	static bool isInevitablySinking(const ExplodedNode *N) {
2794	const CFG &Cfg = N->getCFG();
2795
2796	const CFGBlock *StartBlk = findBlockForNode(N);
2797	if (!StartBlk)
2798	return false;
2799	if (isImmediateSinkBlock(StartBlk))
2800	return true;
2801
2802	llvm::SmallVector<const CFGBlock *, 32> DFSWorkList;
2803	llvm::SmallPtrSet<const CFGBlock *, 32> Visited;
2804
2805	DFSWorkList.push_back(StartBlk);
2806	while (!DFSWorkList.empty()) {
2807	const CFGBlock *Blk = DFSWorkList.back();
2808	DFSWorkList.pop_back();
2809	Visited.insert(Blk);
2810
2811	// If at least one path reaches the CFG exit, it means that control is
2812	// returned to the caller. For now, say that we are not sure what
2813	// happens next. If necessary, this can be improved to analyze
2814	// the parent StackFrameContext's call site in a similar manner.
2815	if (Blk == &Cfg.getExit())
2816	return false;
2817
2818	for (const auto &Succ : Blk->succs()) {
2819	if (const CFGBlock *SuccBlk = Succ.getReachableBlock()) {
2820	if (!isImmediateSinkBlock(SuccBlk) && !Visited.count(SuccBlk)) {
2821	// If the block has reachable child blocks that aren't no-return,
2822	// add them to the worklist.
2823	DFSWorkList.push_back(SuccBlk);
2824	}
2825	}
2826	}
2827	}
2828
2829	// Nothing reached the exit. It can only mean one thing: there's no return.
2830	return true;
2831	}
2832
2833	static BugReport *
2834	FindReportInEquivalenceClass(BugReportEquivClass& EQ,
2835	SmallVectorImpl<BugReport*> &bugReports) {
2836	BugReportEquivClass::iterator I = EQ.begin(), E = EQ.end();
2837	assert(I != E);
2838	const BugType& BT = I->getBugType();
2839
2840	// If we don't need to suppress any of the nodes because they are
2841	// post-dominated by a sink, simply add all the nodes in the equivalence class
2842	// to 'Nodes'. Any of the reports will serve as a "representative" report.
2843	if (!BT.isSuppressOnSink()) {
2844	BugReport R = &I;
2845	for (auto &I : EQ) {
2846	const ExplodedNode *N = I.getErrorNode();
2847	if (N) {
2848	R = &I;
2849	bugReports.push_back(R);
2850	}
2851	}
2852	return R;
2853	}
2854
2855	// For bug reports that should be suppressed when all paths are post-dominated
2856	// by a sink node, iterate through the reports in the equivalence class
2857	// until we find one that isn't post-dominated (if one exists). We use a
2858	// DFS traversal of the ExplodedGraph to find a non-sink node. We could write
2859	// this as a recursive function, but we don't want to risk blowing out the
2860	// stack for very long paths.
2861	BugReport *exampleReport = nullptr;
2862
2863	for (; I != E; ++I) {
2864	const ExplodedNode *errorNode = I->getErrorNode();
2865
2866	if (!errorNode)
2867	continue;
2868	if (errorNode->isSink()) {
2869	llvm_unreachable(
2870	"BugType::isSuppressSink() should not be 'true' for sink end nodes");
2871	}
2872	// No successors? By definition this nodes isn't post-dominated by a sink.
2873	if (errorNode->succ_empty()) {
2874	bugReports.push_back(&*I);
2875	if (!exampleReport)
2876	exampleReport = &*I;
2877	continue;
2878	}
2879
2880	// See if we are in a no-return CFG block. If so, treat this similarly
2881	// to being post-dominated by a sink. This works better when the analysis
2882	// is incomplete and we have never reached the no-return function call(s)
2883	// that we'd inevitably bump into on this path.
2884	if (isInevitablySinking(errorNode))
2885	continue;
2886
2887	// At this point we know that 'N' is not a sink and it has at least one
2888	// successor. Use a DFS worklist to find a non-sink end-of-path node.
2889	using WLItem = FRIEC_WLItem;
2890	using DFSWorkList = SmallVector<WLItem, 10>;
2891
2892	llvm::DenseMap<const ExplodedNode *, unsigned> Visited;
2893
2894	DFSWorkList WL;
2895	WL.push_back(errorNode);
2896	Visited[errorNode] = 1;
2897
2898	while (!WL.empty()) {
2899	WLItem &WI = WL.back();
2900	succ_empty()", "/home/seafit/code_projects/clang_source/clang/lib/StaticAnalyzer/Core/BugReporter.cpp", 2900, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(!WI.N->succ_empty());
2901
2902	for (; WI.I != WI.E; ++WI.I) {
2903	const ExplodedNode Succ = WI.I;
2904	// End-of-path node?
2905	if (Succ->succ_empty()) {
2906	// If we found an end-of-path node that is not a sink.
2907	if (!Succ->isSink()) {
2908	bugReports.push_back(&*I);
2909	if (!exampleReport)
2910	exampleReport = &*I;
2911	WL.clear();
2912	break;
2913	}
2914	// Found a sink? Continue on to the next successor.
2915	continue;
2916	}
2917	// Mark the successor as visited. If it hasn't been explored,
2918	// enqueue it to the DFS worklist.
2919	unsigned &mark = Visited[Succ];
2920	if (!mark) {
2921	mark = 1;
2922	WL.push_back(Succ);
2923	break;
2924	}
2925	}
2926
2927	// The worklist may have been cleared at this point. First
2928	// check if it is empty before checking the last item.
2929	if (!WL.empty() && &WL.back() == &WI)
2930	WL.pop_back();
2931	}
2932	}
2933
2934	// ExampleReport will be NULL if all the nodes in the equivalence class
2935	// were post-dominated by sinks.
2936	return exampleReport;
2937	}
2938
2939	void BugReporter::FlushReport(BugReportEquivClass& EQ) {
2940	SmallVector<BugReport*, 10> bugReports;
2941	BugReport *report = FindReportInEquivalenceClass(EQ, bugReports);
2942	if (!report)
2943	return;
2944
2945	ArrayRef<PathDiagnosticConsumer*> Consumers = getPathDiagnosticConsumers();
2946	std::unique_ptr<DiagnosticForConsumerMapTy> Diagnostics =
2947	generateDiagnosticForConsumerMap(report, Consumers, bugReports);
2948
2949	for (auto &P : *Diagnostics) {
2950	PathDiagnosticConsumer *Consumer = P.first;
2951	std::unique_ptr<PathDiagnostic> &PD = P.second;
2952
2953	// If the path is empty, generate a single step path with the location
2954	// of the issue.
2955	if (PD->path.empty()) {
2956	PathDiagnosticLocation L = report->getLocation(getSourceManager());
2957	auto piece = llvm::make_unique<PathDiagnosticEventPiece>(
2958	L, report->getDescription());
2959	for (SourceRange Range : report->getRanges())
2960	piece->addRange(Range);
2961	PD->setEndOfPath(std::move(piece));
2962	}
2963
2964	PathPieces &Pieces = PD->getMutablePieces();
2965	if (getAnalyzerOptions().ShouldDisplayNotesAsEvents) {
2966	// For path diagnostic consumers that don't support extra notes,
2967	// we may optionally convert those to path notes.
2968	for (auto I = report->getNotes().rbegin(),
2969	E = report->getNotes().rend(); I != E; ++I) {
2970	PathDiagnosticNotePiece *Piece = I->get();
2971	auto ConvertedPiece = std::make_shared<PathDiagnosticEventPiece>(
2972	Piece->getLocation(), Piece->getString());
2973	for (const auto &R: Piece->getRanges())
2974	ConvertedPiece->addRange(R);
2975
2976	Pieces.push_front(std::move(ConvertedPiece));
2977	}
2978	} else {
2979	for (auto I = report->getNotes().rbegin(),
2980	E = report->getNotes().rend(); I != E; ++I)
2981	Pieces.push_front(*I);
2982	}
2983
2984	// Get the meta data.
2985	const BugReport::ExtraTextList &Meta = report->getExtraText();
2986	for (const auto &i : Meta)
2987	PD->addMeta(i);
2988
2989	updateExecutedLinesWithDiagnosticPieces(*PD);
2990	Consumer->HandlePathDiagnostic(std::move(PD));
2991	}
2992	}
2993
2994	/// Insert all lines participating in the function signature \p Signature
2995	/// into \p ExecutedLines.
2996	static void populateExecutedLinesWithFunctionSignature(
2997	const Decl *Signature, SourceManager &SM,
2998	FilesToLineNumsMap &ExecutedLines) {
2999	SourceRange SignatureSourceRange;
3000	const Stmt* Body = Signature->getBody();
3001	if (const auto FD = dyn_cast<FunctionDecl>(Signature)) {
3002	SignatureSourceRange = FD->getSourceRange();
3003	} else if (const auto OD = dyn_cast<ObjCMethodDecl>(Signature)) {
3004	SignatureSourceRange = OD->getSourceRange();
3005	} else {
3006	return;
3007	}
3008	SourceLocation Start = SignatureSourceRange.getBegin();
3009	SourceLocation End = Body ? Body->getSourceRange().getBegin()
3010	: SignatureSourceRange.getEnd();
3011	if (!Start.isValid() \|\| !End.isValid())
3012	return;
3013	unsigned StartLine = SM.getExpansionLineNumber(Start);
3014	unsigned EndLine = SM.getExpansionLineNumber(End);
3015
3016	FileID FID = SM.getFileID(SM.getExpansionLoc(Start));
3017	for (unsigned Line = StartLine; Line <= EndLine; Line++)
3018	ExecutedLines[FID].insert(Line);
3019	}
3020
3021	static void populateExecutedLinesWithStmt(
3022	const Stmt *S, SourceManager &SM,
3023	FilesToLineNumsMap &ExecutedLines) {
3024	SourceLocation Loc = S->getSourceRange().getBegin();
3025	if (!Loc.isValid())
3026	return;
3027	SourceLocation ExpansionLoc = SM.getExpansionLoc(Loc);
3028	FileID FID = SM.getFileID(ExpansionLoc);
3029	unsigned LineNo = SM.getExpansionLineNumber(ExpansionLoc);
3030	ExecutedLines[FID].insert(LineNo);
3031	}
3032
3033	/// \return all executed lines including function signatures on the path
3034	/// starting from \p N.
3035	static std::unique_ptr<FilesToLineNumsMap>
3036	findExecutedLines(SourceManager &SM, const ExplodedNode *N) {
3037	auto ExecutedLines = llvm::make_unique<FilesToLineNumsMap>();
3038
3039	while (N) {
3040	if (N->getFirstPred() == nullptr) {
3041	// First node: show signature of the entrance point.
3042	const Decl *D = N->getLocationContext()->getDecl();
3043	populateExecutedLinesWithFunctionSignature(D, SM, *ExecutedLines);
3044	} else if (auto CE = N->getLocationAs<CallEnter>()) {
3045	// Inlined function: show signature.
3046	const Decl* D = CE->getCalleeContext()->getDecl();
3047	populateExecutedLinesWithFunctionSignature(D, SM, *ExecutedLines);
3048	} else if (const Stmt *S = PathDiagnosticLocation::getStmt(N)) {
3049	populateExecutedLinesWithStmt(S, SM, *ExecutedLines);
3050
3051	// Show extra context for some parent kinds.
3052	const Stmt *P = N->getParentMap().getParent(S);
3053
3054	// The path exploration can die before the node with the associated
3055	// return statement is generated, but we do want to show the whole
3056	// return.
3057	if (const auto *RS = dyn_cast_or_null<ReturnStmt>(P)) {
3058	populateExecutedLinesWithStmt(RS, SM, *ExecutedLines);
3059	P = N->getParentMap().getParent(RS);
3060	}
3061
3062	if (P && (isa<SwitchCase>(P) \|\| isa<LabelStmt>(P)))
3063	populateExecutedLinesWithStmt(P, SM, *ExecutedLines);
3064	}
3065
3066	N = N->getFirstPred();
3067	}
3068	return ExecutedLines;
3069	}
3070
3071	std::unique_ptr<DiagnosticForConsumerMapTy>
3072	BugReporter::generateDiagnosticForConsumerMap(
3073	BugReport report, ArrayRef<PathDiagnosticConsumer > consumers,
3074	ArrayRef<BugReport *> bugReports) {
3075
3076	if (!report->isPathSensitive()) {
3077	auto Out = llvm::make_unique<DiagnosticForConsumerMapTy>();
3078	for (auto *Consumer : consumers)
3079	(*Out)[Consumer] = generateEmptyDiagnosticForReport(report,
3080	getSourceManager());
3081	return Out;
3082	}
3083
3084	// Generate the full path sensitive diagnostic, using the generation scheme
3085	// specified by the PathDiagnosticConsumer. Note that we have to generate
3086	// path diagnostics even for consumers which do not support paths, because
3087	// the BugReporterVisitors may mark this bug as a false positive.
3088	assert(!bugReports.empty());
3089	MaxBugClassSize.updateMax(bugReports.size());
3090	std::unique_ptr<DiagnosticForConsumerMapTy> Out =
3091	generatePathDiagnostics(consumers, bugReports);
3092
3093	if (Out->empty())
3094	return Out;
3095
3096	MaxValidBugClassSize.updateMax(bugReports.size());
3097
3098	// Examine the report and see if the last piece is in a header. Reset the
3099	// report location to the last piece in the main source file.
3100	AnalyzerOptions &Opts = getAnalyzerOptions();
3101	for (auto const &P : *Out)
3102	if (Opts.ShouldReportIssuesInMainSourceFile && !Opts.AnalyzeAll)
3103	P.second->resetDiagnosticLocationToMainFile();
3104
3105	return Out;
3106	}
3107
3108	void BugReporter::EmitBasicReport(const Decl *DeclWithIssue,
3109	const CheckerBase *Checker,
3110	StringRef Name, StringRef Category,
3111	StringRef Str, PathDiagnosticLocation Loc,
3112	ArrayRef<SourceRange> Ranges) {
3113	EmitBasicReport(DeclWithIssue, Checker->getCheckName(), Name, Category, Str,
3114	Loc, Ranges);
3115	}
3116
3117	void BugReporter::EmitBasicReport(const Decl *DeclWithIssue,
3118	CheckName CheckName,
3119	StringRef name, StringRef category,
3120	StringRef str, PathDiagnosticLocation Loc,
3121	ArrayRef<SourceRange> Ranges) {
3122	// 'BT' is owned by BugReporter.
3123	BugType *BT = getBugTypeForName(CheckName, name, category);
3124	auto R = llvm::make_unique<BugReport>(*BT, str, Loc);
3125	R->setDeclWithIssue(DeclWithIssue);
3126	for (ArrayRef<SourceRange>::iterator I = Ranges.begin(), E = Ranges.end();
3127	I != E; ++I)
3128	R->addRange(*I);
3129	emitReport(std::move(R));
3130	}
3131
3132	BugType *BugReporter::getBugTypeForName(CheckName CheckName, StringRef name,
3133	StringRef category) {
3134	SmallString<136> fullDesc;
3135	llvm::raw_svector_ostream(fullDesc) << CheckName.getName() << ":" << name
3136	<< ":" << category;
3137	BugType *&BT = StrBugTypes[fullDesc];
3138	if (!BT)
3139	BT = new BugType(CheckName, name, category);
3140	return BT;
3141	}
3142