1//===- ExprEngine.h - Path-Sensitive Expression-Level Dataflow --*- C++ -*-===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines a meta-engine for path-sensitive dataflow analysis that
11// is built on CoreEngine, but provides the boilerplate to execute transfer
12// functions and build the ExplodedGraph at the expression level.
13//
14//===----------------------------------------------------------------------===//
15
16#ifndef LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_EXPRENGINE_H
17#define LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_EXPRENGINE_H
18
19#include "clang/AST/Expr.h"
20#include "clang/AST/Type.h"
21#include "clang/Analysis/CFG.h"
22#include "clang/Analysis/DomainSpecific/ObjCNoReturn.h"
23#include "clang/Analysis/ProgramPoint.h"
24#include "clang/Basic/LLVM.h"
25#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
26#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
27#include "clang/StaticAnalyzer/Core/PathSensitive/CoreEngine.h"
28#include "clang/StaticAnalyzer/Core/PathSensitive/FunctionSummary.h"
29#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
30#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
31#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState_Fwd.h"
32#include "clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h"
33#include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
34#include "clang/StaticAnalyzer/Core/PathSensitive/SubEngine.h"
35#include "clang/StaticAnalyzer/Core/PathSensitive/WorkList.h"
36#include "llvm/ADT/ArrayRef.h"
37#include <cassert>
38#include <utility>
39
40namespace clang {
41
42class AnalysisDeclContextManager;
43class AnalyzerOptions;
44class ASTContext;
45class ConstructionContext;
46class CXXBindTemporaryExpr;
47class CXXCatchStmt;
48class CXXConstructExpr;
49class CXXDeleteExpr;
50class CXXNewExpr;
51class CXXThisExpr;
52class Decl;
53class DeclStmt;
54class GCCAsmStmt;
55class LambdaExpr;
56class LocationContext;
57class MaterializeTemporaryExpr;
58class MSAsmStmt;
59class NamedDecl;
60class ObjCAtSynchronizedStmt;
61class ObjCForCollectionStmt;
62class ObjCIvarRefExpr;
63class ObjCMessageExpr;
64class ReturnStmt;
65class Stmt;
66
67namespace cross_tu {
68
69class CrossTranslationUnitContext;
70
71} // namespace cross_tu
72
73namespace ento {
74
75class BasicValueFactory;
76class CallEvent;
77class CheckerManager;
78class ConstraintManager;
79class CXXTempObjectRegion;
80class MemRegion;
81class RegionAndSymbolInvalidationTraits;
82class SymbolManager;
83
84class ExprEngine : public SubEngine {
85public:
86 /// The modes of inlining, which override the default analysis-wide settings.
87 enum InliningModes {
88 /// Follow the default settings for inlining callees.
89 Inline_Regular = 0,
90
91 /// Do minimal inlining of callees.
92 Inline_Minimal = 0x1
93 };
94
95 /// Hints for figuring out of a call should be inlined during evalCall().
96 struct EvalCallOptions {
97 /// This call is a constructor or a destructor for which we do not currently
98 /// compute the this-region correctly.
99 bool IsCtorOrDtorWithImproperlyModeledTargetRegion = false;
100
101 /// This call is a constructor or a destructor for a single element within
102 /// an array, a part of array construction or destruction.
103 bool IsArrayCtorOrDtor = false;
104
105 /// This call is a constructor or a destructor of a temporary value.
106 bool IsTemporaryCtorOrDtor = false;
107
108 /// This call is a constructor for a temporary that is lifetime-extended
109 /// by binding it to a reference-type field within an aggregate,
110 /// for example 'A { const C &c; }; A a = { C() };'
111 bool IsTemporaryLifetimeExtendedViaAggregate = false;
112
113 EvalCallOptions() {}
114 };
115
116private:
117 cross_tu::CrossTranslationUnitContext &CTU;
118
119 AnalysisManager &AMgr;
120
121 AnalysisDeclContextManager &AnalysisDeclContexts;
122
123 CoreEngine Engine;
124
125 /// G - the simulation graph.
126 ExplodedGraph &G;
127
128 /// StateMgr - Object that manages the data for all created states.
129 ProgramStateManager StateMgr;
130
131 /// SymMgr - Object that manages the symbol information.
132 SymbolManager &SymMgr;
133
134 /// svalBuilder - SValBuilder object that creates SVals from expressions.
135 SValBuilder &svalBuilder;
136
137 unsigned int currStmtIdx = 0;
138 const NodeBuilderContext *currBldrCtx = nullptr;
139
140 /// Helper object to determine if an Objective-C message expression
141 /// implicitly never returns.
142 ObjCNoReturn ObjCNoRet;
143
144 /// The BugReporter associated with this engine. It is important that
145 /// this object be placed at the very end of member variables so that its
146 /// destructor is called before the rest of the ExprEngine is destroyed.
147 GRBugReporter BR;
148
149 /// The functions which have been analyzed through inlining. This is owned by
150 /// AnalysisConsumer. It can be null.
151 SetOfConstDecls *VisitedCallees;
152
153 /// The flag, which specifies the mode of inlining for the engine.
154 InliningModes HowToInline;
155
156public:
157 ExprEngine(cross_tu::CrossTranslationUnitContext &CTU, AnalysisManager &mgr,
158 SetOfConstDecls *VisitedCalleesIn,
159 FunctionSummariesTy *FS, InliningModes HowToInlineIn);
160
161 ~ExprEngine() override;
162
163 /// Returns true if there is still simulation state on the worklist.
164 bool ExecuteWorkList(const LocationContext *L, unsigned Steps = 150000) {
165 return Engine.ExecuteWorkList(L, Steps, nullptr);
166 }
167
168 /// Execute the work list with an initial state. Nodes that reaches the exit
169 /// of the function are added into the Dst set, which represent the exit
170 /// state of the function call. Returns true if there is still simulation
171 /// state on the worklist.
172 bool ExecuteWorkListWithInitialState(const LocationContext *L, unsigned Steps,
173 ProgramStateRef InitState,
174 ExplodedNodeSet &Dst) {
175 return Engine.ExecuteWorkListWithInitialState(L, Steps, InitState, Dst);
176 }
177
178 /// getContext - Return the ASTContext associated with this analysis.
179 ASTContext &getContext() const { return AMgr.getASTContext(); }
180
181 AnalysisManager &getAnalysisManager() override { return AMgr; }
182
183 CheckerManager &getCheckerManager() const {
184 return *AMgr.getCheckerManager();
185 }
186
187 SValBuilder &getSValBuilder() { return svalBuilder; }
188
189 BugReporter &getBugReporter() { return BR; }
190
191 cross_tu::CrossTranslationUnitContext *
192 getCrossTranslationUnitContext() override {
193 return &CTU;
194 }
195
196 const NodeBuilderContext &getBuilderContext() {
197 assert(currBldrCtx);
198 return *currBldrCtx;
199 }
200
201 const Stmt *getStmt() const;
202
203 void GenerateAutoTransition(ExplodedNode *N);
204 void enqueueEndOfPath(ExplodedNodeSet &S);
205 void GenerateCallExitNode(ExplodedNode *N);
206
207
208 /// Dump graph to the specified filename.
209 /// If filename is empty, generate a temporary one.
210 /// \return The filename the graph is written into.
211 std::string DumpGraph(bool trim = false, StringRef Filename="");
212
213 /// Dump the graph consisting of the given nodes to a specified filename.
214 /// Generate a temporary filename if it's not provided.
215 /// \return The filename the graph is written into.
216 std::string DumpGraph(ArrayRef<const ExplodedNode *> Nodes,
217 StringRef Filename = "");
218
219 /// Visualize the ExplodedGraph created by executing the simulation.
220 void ViewGraph(bool trim = false);
221
222 /// Visualize a trimmed ExplodedGraph that only contains paths to the given
223 /// nodes.
224 void ViewGraph(ArrayRef<const ExplodedNode *> Nodes);
225
226 /// getInitialState - Return the initial state used for the root vertex
227 /// in the ExplodedGraph.
228 ProgramStateRef getInitialState(const LocationContext *InitLoc) override;
229
230 ExplodedGraph &getGraph() { return G; }
231 const ExplodedGraph &getGraph() const { return G; }
232
233 /// Run the analyzer's garbage collection - remove dead symbols and
234 /// bindings from the state.
235 ///
236 /// Checkers can participate in this process with two callbacks:
237 /// \c checkLiveSymbols and \c checkDeadSymbols. See the CheckerDocumentation
238 /// class for more information.
239 ///
240 /// \param Node The predecessor node, from which the processing should start.
241 /// \param Out The returned set of output nodes.
242 /// \param ReferenceStmt The statement which is about to be processed.
243 /// Everything needed for this statement should be considered live.
244 /// A null statement means that everything in child LocationContexts
245 /// is dead.
246 /// \param LC The location context of the \p ReferenceStmt. A null location
247 /// context means that we have reached the end of analysis and that
248 /// all statements and local variables should be considered dead.
249 /// \param DiagnosticStmt Used as a location for any warnings that should
250 /// occur while removing the dead (e.g. leaks). By default, the
251 /// \p ReferenceStmt is used.
252 /// \param K Denotes whether this is a pre- or post-statement purge. This
253 /// must only be ProgramPoint::PostStmtPurgeDeadSymbolsKind if an
254 /// entire location context is being cleared, in which case the
255 /// \p ReferenceStmt must either be a ReturnStmt or \c NULL. Otherwise,
256 /// it must be ProgramPoint::PreStmtPurgeDeadSymbolsKind (the default)
257 /// and \p ReferenceStmt must be valid (non-null).
258 void removeDead(ExplodedNode *Node, ExplodedNodeSet &Out,
259 const Stmt *ReferenceStmt, const LocationContext *LC,
260 const Stmt *DiagnosticStmt = nullptr,
261 ProgramPoint::Kind K = ProgramPoint::PreStmtPurgeDeadSymbolsKind);
262
263 /// processCFGElement - Called by CoreEngine. Used to generate new successor
264 /// nodes by processing the 'effects' of a CFG element.
265 void processCFGElement(const CFGElement E, ExplodedNode *Pred,
266 unsigned StmtIdx, NodeBuilderContext *Ctx) override;
267
268 void ProcessStmt(const Stmt *S, ExplodedNode *Pred);
269
270 void ProcessLoopExit(const Stmt* S, ExplodedNode *Pred);
271
272 void ProcessInitializer(const CFGInitializer I, ExplodedNode *Pred);
273
274 void ProcessImplicitDtor(const CFGImplicitDtor D, ExplodedNode *Pred);
275
276 void ProcessNewAllocator(const CXXNewExpr *NE, ExplodedNode *Pred);
277
278 void ProcessAutomaticObjDtor(const CFGAutomaticObjDtor D,
279 ExplodedNode *Pred, ExplodedNodeSet &Dst);
280 void ProcessDeleteDtor(const CFGDeleteDtor D,
281 ExplodedNode *Pred, ExplodedNodeSet &Dst);
282 void ProcessBaseDtor(const CFGBaseDtor D,
283 ExplodedNode *Pred, ExplodedNodeSet &Dst);
284 void ProcessMemberDtor(const CFGMemberDtor D,
285 ExplodedNode *Pred, ExplodedNodeSet &Dst);
286 void ProcessTemporaryDtor(const CFGTemporaryDtor D,
287 ExplodedNode *Pred, ExplodedNodeSet &Dst);
288
289 /// Called by CoreEngine when processing the entrance of a CFGBlock.
290 void processCFGBlockEntrance(const BlockEdge &L,
291 NodeBuilderWithSinks &nodeBuilder,
292 ExplodedNode *Pred) override;
293
294 /// ProcessBranch - Called by CoreEngine. Used to generate successor
295 /// nodes by processing the 'effects' of a branch condition.
296 void processBranch(const Stmt *Condition,
297 NodeBuilderContext& BuilderCtx,
298 ExplodedNode *Pred,
299 ExplodedNodeSet &Dst,
300 const CFGBlock *DstT,
301 const CFGBlock *DstF) override;
302
303 /// Called by CoreEngine.
304 /// Used to generate successor nodes for temporary destructors depending
305 /// on whether the corresponding constructor was visited.
306 void processCleanupTemporaryBranch(const CXXBindTemporaryExpr *BTE,
307 NodeBuilderContext &BldCtx,
308 ExplodedNode *Pred, ExplodedNodeSet &Dst,
309 const CFGBlock *DstT,
310 const CFGBlock *DstF) override;
311
312 /// Called by CoreEngine. Used to processing branching behavior
313 /// at static initializers.
314 void processStaticInitializer(const DeclStmt *DS,
315 NodeBuilderContext& BuilderCtx,
316 ExplodedNode *Pred,
317 ExplodedNodeSet &Dst,
318 const CFGBlock *DstT,
319 const CFGBlock *DstF) override;
320
321 /// processIndirectGoto - Called by CoreEngine. Used to generate successor
322 /// nodes by processing the 'effects' of a computed goto jump.
323 void processIndirectGoto(IndirectGotoNodeBuilder& builder) override;
324
325 /// ProcessSwitch - Called by CoreEngine. Used to generate successor
326 /// nodes by processing the 'effects' of a switch statement.
327 void processSwitch(SwitchNodeBuilder& builder) override;
328
329 /// Called by CoreEngine. Used to notify checkers that processing a
330 /// function has begun. Called for both inlined and and top-level functions.
331 void processBeginOfFunction(NodeBuilderContext &BC,
332 ExplodedNode *Pred, ExplodedNodeSet &Dst,
333 const BlockEdge &L) override;
334
335 /// Called by CoreEngine. Used to notify checkers that processing a
336 /// function has ended. Called for both inlined and and top-level functions.
337 void processEndOfFunction(NodeBuilderContext& BC,
338 ExplodedNode *Pred,
339 const ReturnStmt *RS = nullptr) override;
340
341 /// Remove dead bindings/symbols before exiting a function.
342 void removeDeadOnEndOfFunction(NodeBuilderContext& BC,
343 ExplodedNode *Pred,
344 ExplodedNodeSet &Dst);
345
346 /// Generate the entry node of the callee.
347 void processCallEnter(NodeBuilderContext& BC, CallEnter CE,
348 ExplodedNode *Pred) override;
349
350 /// Generate the sequence of nodes that simulate the call exit and the post
351 /// visit for CallExpr.
352 void processCallExit(ExplodedNode *Pred) override;
353
354 /// Called by CoreEngine when the analysis worklist has terminated.
355 void processEndWorklist() override;
356
357 /// evalAssume - Callback function invoked by the ConstraintManager when
358 /// making assumptions about state values.
359 ProgramStateRef processAssume(ProgramStateRef state, SVal cond,
360 bool assumption) override;
361
362 /// processRegionChanges - Called by ProgramStateManager whenever a change is made
363 /// to the store. Used to update checkers that track region values.
364 ProgramStateRef
365 processRegionChanges(ProgramStateRef state,
366 const InvalidatedSymbols *invalidated,
367 ArrayRef<const MemRegion *> ExplicitRegions,
368 ArrayRef<const MemRegion *> Regions,
369 const LocationContext *LCtx,
370 const CallEvent *Call) override;
371
372 /// printState - Called by ProgramStateManager to print checker-specific data.
373 void printState(raw_ostream &Out, ProgramStateRef State, const char *NL,
374 const char *Sep,
375 const LocationContext *LCtx = nullptr) override;
376
377 ProgramStateManager &getStateManager() override { return StateMgr; }
378
379 StoreManager &getStoreManager() { return StateMgr.getStoreManager(); }
380
381 ConstraintManager &getConstraintManager() {
382 return StateMgr.getConstraintManager();
383 }
384
385 // FIXME: Remove when we migrate over to just using SValBuilder.
386 BasicValueFactory &getBasicVals() {
387 return StateMgr.getBasicVals();
388 }
389
390 // FIXME: Remove when we migrate over to just using ValueManager.
391 SymbolManager &getSymbolManager() { return SymMgr; }
392 const SymbolManager &getSymbolManager() const { return SymMgr; }
393
394 // Functions for external checking of whether we have unfinished work
395 bool wasBlocksExhausted() const { return Engine.wasBlocksExhausted(); }
396 bool hasEmptyWorkList() const { return !Engine.getWorkList()->hasWork(); }
397 bool hasWorkRemaining() const { return Engine.hasWorkRemaining(); }
398
399 const CoreEngine &getCoreEngine() const { return Engine; }
400
401public:
402 /// Visit - Transfer function logic for all statements. Dispatches to
403 /// other functions that handle specific kinds of statements.
404 void Visit(const Stmt *S, ExplodedNode *Pred, ExplodedNodeSet &Dst);
405
406 /// VisitArraySubscriptExpr - Transfer function for array accesses.
407 void VisitArraySubscriptExpr(const ArraySubscriptExpr *Ex,
408 ExplodedNode *Pred,
409 ExplodedNodeSet &Dst);
410
411 /// VisitGCCAsmStmt - Transfer function logic for inline asm.
412 void VisitGCCAsmStmt(const GCCAsmStmt *A, ExplodedNode *Pred,
413 ExplodedNodeSet &Dst);
414
415 /// VisitMSAsmStmt - Transfer function logic for MS inline asm.
416 void VisitMSAsmStmt(const MSAsmStmt *A, ExplodedNode *Pred,
417 ExplodedNodeSet &Dst);
418
419 /// VisitBlockExpr - Transfer function logic for BlockExprs.
420 void VisitBlockExpr(const BlockExpr *BE, ExplodedNode *Pred,
421 ExplodedNodeSet &Dst);
422
423 /// VisitLambdaExpr - Transfer function logic for LambdaExprs.
424 void VisitLambdaExpr(const LambdaExpr *LE, ExplodedNode *Pred,
425 ExplodedNodeSet &Dst);
426
427 /// VisitBinaryOperator - Transfer function logic for binary operators.
428 void VisitBinaryOperator(const BinaryOperator* B, ExplodedNode *Pred,
429 ExplodedNodeSet &Dst);
430
431
432 /// VisitCall - Transfer function for function calls.
433 void VisitCallExpr(const CallExpr *CE, ExplodedNode *Pred,
434 ExplodedNodeSet &Dst);
435
436 /// VisitCast - Transfer function logic for all casts (implicit and explicit).
437 void VisitCast(const CastExpr *CastE, const Expr *Ex, ExplodedNode *Pred,
438 ExplodedNodeSet &Dst);
439
440 /// VisitCompoundLiteralExpr - Transfer function logic for compound literals.
441 void VisitCompoundLiteralExpr(const CompoundLiteralExpr *CL,
442 ExplodedNode *Pred, ExplodedNodeSet &Dst);
443
444 /// Transfer function logic for DeclRefExprs and BlockDeclRefExprs.
445 void VisitCommonDeclRefExpr(const Expr *DR, const NamedDecl *D,
446 ExplodedNode *Pred, ExplodedNodeSet &Dst);
447
448 /// VisitDeclStmt - Transfer function logic for DeclStmts.
449 void VisitDeclStmt(const DeclStmt *DS, ExplodedNode *Pred,
450 ExplodedNodeSet &Dst);
451
452 /// VisitGuardedExpr - Transfer function logic for ?, __builtin_choose
453 void VisitGuardedExpr(const Expr *Ex, const Expr *L, const Expr *R,
454 ExplodedNode *Pred, ExplodedNodeSet &Dst);
455
456 void VisitInitListExpr(const InitListExpr *E, ExplodedNode *Pred,
457 ExplodedNodeSet &Dst);
458
459 /// VisitLogicalExpr - Transfer function logic for '&&', '||'
460 void VisitLogicalExpr(const BinaryOperator* B, ExplodedNode *Pred,
461 ExplodedNodeSet &Dst);
462
463 /// VisitMemberExpr - Transfer function for member expressions.
464 void VisitMemberExpr(const MemberExpr *M, ExplodedNode *Pred,
465 ExplodedNodeSet &Dst);
466
467 /// VisitAtomicExpr - Transfer function for builtin atomic expressions
468 void VisitAtomicExpr(const AtomicExpr *E, ExplodedNode *Pred,
469 ExplodedNodeSet &Dst);
470
471 /// Transfer function logic for ObjCAtSynchronizedStmts.
472 void VisitObjCAtSynchronizedStmt(const ObjCAtSynchronizedStmt *S,
473 ExplodedNode *Pred, ExplodedNodeSet &Dst);
474
475 /// Transfer function logic for computing the lvalue of an Objective-C ivar.
476 void VisitLvalObjCIvarRefExpr(const ObjCIvarRefExpr *DR, ExplodedNode *Pred,
477 ExplodedNodeSet &Dst);
478
479 /// VisitObjCForCollectionStmt - Transfer function logic for
480 /// ObjCForCollectionStmt.
481 void VisitObjCForCollectionStmt(const ObjCForCollectionStmt *S,
482 ExplodedNode *Pred, ExplodedNodeSet &Dst);
483
484 void VisitObjCMessage(const ObjCMessageExpr *ME, ExplodedNode *Pred,
485 ExplodedNodeSet &Dst);
486
487 /// VisitReturnStmt - Transfer function logic for return statements.
488 void VisitReturnStmt(const ReturnStmt *R, ExplodedNode *Pred,
489 ExplodedNodeSet &Dst);
490
491 /// VisitOffsetOfExpr - Transfer function for offsetof.
492 void VisitOffsetOfExpr(const OffsetOfExpr *Ex, ExplodedNode *Pred,
493 ExplodedNodeSet &Dst);
494
495 /// VisitUnaryExprOrTypeTraitExpr - Transfer function for sizeof.
496 void VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *Ex,
497 ExplodedNode *Pred, ExplodedNodeSet &Dst);
498
499 /// VisitUnaryOperator - Transfer function logic for unary operators.
500 void VisitUnaryOperator(const UnaryOperator* B, ExplodedNode *Pred,
501 ExplodedNodeSet &Dst);
502
503 /// Handle ++ and -- (both pre- and post-increment).
504 void VisitIncrementDecrementOperator(const UnaryOperator* U,
505 ExplodedNode *Pred,
506 ExplodedNodeSet &Dst);
507
508 void VisitCXXBindTemporaryExpr(const CXXBindTemporaryExpr *BTE,
509 ExplodedNodeSet &PreVisit,
510 ExplodedNodeSet &Dst);
511
512 void VisitCXXCatchStmt(const CXXCatchStmt *CS, ExplodedNode *Pred,
513 ExplodedNodeSet &Dst);
514
515 void VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred,
516 ExplodedNodeSet & Dst);
517
518 void VisitCXXConstructExpr(const CXXConstructExpr *E, ExplodedNode *Pred,
519 ExplodedNodeSet &Dst);
520
521 void VisitCXXDestructor(QualType ObjectType, const MemRegion *Dest,
522 const Stmt *S, bool IsBaseDtor,
523 ExplodedNode *Pred, ExplodedNodeSet &Dst,
524 const EvalCallOptions &Options);
525
526 void VisitCXXNewAllocatorCall(const CXXNewExpr *CNE,
527 ExplodedNode *Pred,
528 ExplodedNodeSet &Dst);
529
530 void VisitCXXNewExpr(const CXXNewExpr *CNE, ExplodedNode *Pred,
531 ExplodedNodeSet &Dst);
532
533 void VisitCXXDeleteExpr(const CXXDeleteExpr *CDE, ExplodedNode *Pred,
534 ExplodedNodeSet &Dst);
535
536 /// Create a C++ temporary object for an rvalue.
537 void CreateCXXTemporaryObject(const MaterializeTemporaryExpr *ME,
538 ExplodedNode *Pred,
539 ExplodedNodeSet &Dst);
540
541 /// evalEagerlyAssumeBinOpBifurcation - Given the nodes in 'Src', eagerly assume symbolic
542 /// expressions of the form 'x != 0' and generate new nodes (stored in Dst)
543 /// with those assumptions.
544 void evalEagerlyAssumeBinOpBifurcation(ExplodedNodeSet &Dst, ExplodedNodeSet &Src,
545 const Expr *Ex);
546
547 static std::pair<const ProgramPointTag *, const ProgramPointTag *>
548 geteagerlyAssumeBinOpBifurcationTags();
549
550 SVal evalMinus(SVal X) {
551 return X.isValid() ? svalBuilder.evalMinus(X.castAs<NonLoc>()) : X;
552 }
553
554 SVal evalComplement(SVal X) {
555 return X.isValid() ? svalBuilder.evalComplement(X.castAs<NonLoc>()) : X;
556 }
557
558 ProgramStateRef handleLValueBitCast(ProgramStateRef state, const Expr *Ex,
559 const LocationContext *LCtx, QualType T,
560 QualType ExTy, const CastExpr *CastE,
561 StmtNodeBuilder &Bldr,
562 ExplodedNode *Pred);
563
564 ProgramStateRef handleLVectorSplat(ProgramStateRef state,
565 const LocationContext *LCtx,
566 const CastExpr *CastE,
567 StmtNodeBuilder &Bldr,
568 ExplodedNode *Pred);
569
570 void handleUOExtension(ExplodedNodeSet::iterator I,
571 const UnaryOperator* U,
572 StmtNodeBuilder &Bldr);
573
574public:
575 SVal evalBinOp(ProgramStateRef state, BinaryOperator::Opcode op,
576 NonLoc L, NonLoc R, QualType T) {
577 return svalBuilder.evalBinOpNN(state, op, L, R, T);
578 }
579
580 SVal evalBinOp(ProgramStateRef state, BinaryOperator::Opcode op,
581 NonLoc L, SVal R, QualType T) {
582 return R.isValid() ? svalBuilder.evalBinOpNN(state, op, L,
583 R.castAs<NonLoc>(), T) : R;
584 }
585
586 SVal evalBinOp(ProgramStateRef ST, BinaryOperator::Opcode Op,
587 SVal LHS, SVal RHS, QualType T) {
588 return svalBuilder.evalBinOp(ST, Op, LHS, RHS, T);
589 }
590
591 /// By looking at a certain item that may be potentially part of an object's
592 /// ConstructionContext, retrieve such object's location. A particular
593 /// statement can be transparently passed as \p Item in most cases.
594 static Optional<SVal>
595 getObjectUnderConstruction(ProgramStateRef State,
596 const ConstructionContextItem &Item,
597 const LocationContext *LC);
598
599protected:
600 /// evalBind - Handle the semantics of binding a value to a specific location.
601 /// This method is used by evalStore, VisitDeclStmt, and others.
602 void evalBind(ExplodedNodeSet &Dst, const Stmt *StoreE, ExplodedNode *Pred,
603 SVal location, SVal Val, bool atDeclInit = false,
604 const ProgramPoint *PP = nullptr);
605
606 /// Call PointerEscape callback when a value escapes as a result of bind.
607 ProgramStateRef processPointerEscapedOnBind(ProgramStateRef State,
608 SVal Loc,
609 SVal Val,
610 const LocationContext *LCtx) override;
611 /// Call PointerEscape callback when a value escapes as a result of
612 /// region invalidation.
613 /// \param[in] ITraits Specifies invalidation traits for regions/symbols.
614 ProgramStateRef notifyCheckersOfPointerEscape(
615 ProgramStateRef State,
616 const InvalidatedSymbols *Invalidated,
617 ArrayRef<const MemRegion *> ExplicitRegions,
618 const CallEvent *Call,
619 RegionAndSymbolInvalidationTraits &ITraits) override;
620
621 /// A simple wrapper when you only need to notify checkers of pointer-escape
622 /// of a single value.
623 ProgramStateRef escapeValue(ProgramStateRef State, SVal V,
624 PointerEscapeKind K) const;
625
626public:
627 // FIXME: 'tag' should be removed, and a LocationContext should be used
628 // instead.
629 // FIXME: Comment on the meaning of the arguments, when 'St' may not
630 // be the same as Pred->state, and when 'location' may not be the
631 // same as state->getLValue(Ex).
632 /// Simulate a read of the result of Ex.
633 void evalLoad(ExplodedNodeSet &Dst,
634 const Expr *NodeEx, /* Eventually will be a CFGStmt */
635 const Expr *BoundExpr,
636 ExplodedNode *Pred,
637 ProgramStateRef St,
638 SVal location,
639 const ProgramPointTag *tag = nullptr,
640 QualType LoadTy = QualType());
641
642 // FIXME: 'tag' should be removed, and a LocationContext should be used
643 // instead.
644 void evalStore(ExplodedNodeSet &Dst, const Expr *AssignE, const Expr *StoreE,
645 ExplodedNode *Pred, ProgramStateRef St, SVal TargetLV, SVal Val,
646 const ProgramPointTag *tag = nullptr);
647
648 /// Return the CFG element corresponding to the worklist element
649 /// that is currently being processed by ExprEngine.
650 CFGElement getCurrentCFGElement() {
651 return (*currBldrCtx->getBlock())[currStmtIdx];
652 }
653
654 /// Create a new state in which the call return value is binded to the
655 /// call origin expression.
656 ProgramStateRef bindReturnValue(const CallEvent &Call,
657 const LocationContext *LCtx,
658 ProgramStateRef State);
659
660 /// Evaluate a call, running pre- and post-call checks and allowing checkers
661 /// to be responsible for handling the evaluation of the call itself.
662 void evalCall(ExplodedNodeSet &Dst, ExplodedNode *Pred,
663 const CallEvent &Call);
664
665 /// Default implementation of call evaluation.
666 void defaultEvalCall(NodeBuilder &B, ExplodedNode *Pred,
667 const CallEvent &Call,
668 const EvalCallOptions &CallOpts = {});
669
670private:
671 ProgramStateRef finishArgumentConstruction(ProgramStateRef State,
672 const CallEvent &Call);
673 void finishArgumentConstruction(ExplodedNodeSet &Dst, ExplodedNode *Pred,
674 const CallEvent &Call);
675
676 void evalLoadCommon(ExplodedNodeSet &Dst,
677 const Expr *NodeEx, /* Eventually will be a CFGStmt */
678 const Expr *BoundEx,
679 ExplodedNode *Pred,
680 ProgramStateRef St,
681 SVal location,
682 const ProgramPointTag *tag,
683 QualType LoadTy);
684
685 void evalLocation(ExplodedNodeSet &Dst,
686 const Stmt *NodeEx, /* This will eventually be a CFGStmt */
687 const Stmt *BoundEx,
688 ExplodedNode *Pred,
689 ProgramStateRef St,
690 SVal location,
691 bool isLoad);
692
693 /// Count the stack depth and determine if the call is recursive.
694 void examineStackFrames(const Decl *D, const LocationContext *LCtx,
695 bool &IsRecursive, unsigned &StackDepth);
696
697 enum CallInlinePolicy {
698 CIP_Allowed,
699 CIP_DisallowedOnce,
700 CIP_DisallowedAlways
701 };
702
703 /// See if a particular call should be inlined, by only looking
704 /// at the call event and the current state of analysis.
705 CallInlinePolicy mayInlineCallKind(const CallEvent &Call,
706 const ExplodedNode *Pred,
707 AnalyzerOptions &Opts,
708 const EvalCallOptions &CallOpts);
709
710 /// Checks our policies and decides weither the given call should be inlined.
711 bool shouldInlineCall(const CallEvent &Call, const Decl *D,
712 const ExplodedNode *Pred,
713 const EvalCallOptions &CallOpts = {});
714
715 bool inlineCall(const CallEvent &Call, const Decl *D, NodeBuilder &Bldr,
716 ExplodedNode *Pred, ProgramStateRef State);
717
718 /// Conservatively evaluate call by invalidating regions and binding
719 /// a conjured return value.
720 void conservativeEvalCall(const CallEvent &Call, NodeBuilder &Bldr,
721 ExplodedNode *Pred, ProgramStateRef State);
722
723 /// Either inline or process the call conservatively (or both), based
724 /// on DynamicDispatchBifurcation data.
725 void BifurcateCall(const MemRegion *BifurReg,
726 const CallEvent &Call, const Decl *D, NodeBuilder &Bldr,
727 ExplodedNode *Pred);
728
729 bool replayWithoutInlining(ExplodedNode *P, const LocationContext *CalleeLC);
730
731 /// Models a trivial copy or move constructor or trivial assignment operator
732 /// call with a simple bind.
733 void performTrivialCopy(NodeBuilder &Bldr, ExplodedNode *Pred,
734 const CallEvent &Call);
735
736 /// If the value of the given expression \p InitWithAdjustments is a NonLoc,
737 /// copy it into a new temporary object region, and replace the value of the
738 /// expression with that.
739 ///
740 /// If \p Result is provided, the new region will be bound to this expression
741 /// instead of \p InitWithAdjustments.
742 ///
743 /// Returns the temporary region with adjustments into the optional
744 /// OutRegionWithAdjustments out-parameter if a new region was indeed needed,
745 /// otherwise sets it to nullptr.
746 ProgramStateRef createTemporaryRegionIfNeeded(
747 ProgramStateRef State, const LocationContext *LC,
748 const Expr *InitWithAdjustments, const Expr *Result = nullptr,
749 const SubRegion **OutRegionWithAdjustments = nullptr);
750
751 /// Returns a region representing the first element of a (possibly
752 /// multi-dimensional) array, for the purposes of element construction or
753 /// destruction.
754 ///
755 /// On return, \p Ty will be set to the base type of the array.
756 ///
757 /// If the type is not an array type at all, the original value is returned.
758 /// Otherwise the "IsArray" flag is set.
759 static SVal makeZeroElementRegion(ProgramStateRef State, SVal LValue,
760 QualType &Ty, bool &IsArray);
761
762 /// For a DeclStmt or CXXInitCtorInitializer, walk backward in the current CFG
763 /// block to find the constructor expression that directly constructed into
764 /// the storage for this statement. Returns null if the constructor for this
765 /// statement created a temporary object region rather than directly
766 /// constructing into an existing region.
767 const CXXConstructExpr *findDirectConstructorForCurrentCFGElement();
768
769 /// Update the program state with all the path-sensitive information
770 /// that's necessary to perform construction of an object with a given
771 /// syntactic construction context. If the construction context is unavailable
772 /// or unusable for any reason, a dummy temporary region is returned, and the
773 /// IsConstructorWithImproperlyModeledTargetRegion flag is set in \p CallOpts.
774 /// Returns the updated program state and the new object's this-region.
775 std::pair<ProgramStateRef, SVal> prepareForObjectConstruction(
776 const Expr *E, ProgramStateRef State, const LocationContext *LCtx,
777 const ConstructionContext *CC, EvalCallOptions &CallOpts);
778
779 /// Store the location of a C++ object corresponding to a statement
780 /// until the statement is actually encountered. For example, if a DeclStmt
781 /// has CXXConstructExpr as its initializer, the object would be considered
782 /// to be "under construction" between CXXConstructExpr and DeclStmt.
783 /// This allows, among other things, to keep bindings to variable's fields
784 /// made within the constructor alive until its declaration actually
785 /// goes into scope.
786 static ProgramStateRef
787 addObjectUnderConstruction(ProgramStateRef State,
788 const ConstructionContextItem &Item,
789 const LocationContext *LC, SVal V);
790
791 /// Mark the object sa fully constructed, cleaning up the state trait
792 /// that tracks objects under construction.
793 static ProgramStateRef
794 finishObjectConstruction(ProgramStateRef State,
795 const ConstructionContextItem &Item,
796 const LocationContext *LC);
797
798 /// If the given expression corresponds to a temporary that was used for
799 /// passing into an elidable copy/move constructor and that constructor
800 /// was actually elided, track that we also need to elide the destructor.
801 static ProgramStateRef elideDestructor(ProgramStateRef State,
802 const CXXBindTemporaryExpr *BTE,
803 const LocationContext *LC);
804
805 /// Stop tracking the destructor that corresponds to an elided constructor.
806 static ProgramStateRef
807 cleanupElidedDestructor(ProgramStateRef State,
808 const CXXBindTemporaryExpr *BTE,
809 const LocationContext *LC);
810
811 /// Returns true if the given expression corresponds to a temporary that
812 /// was constructed for passing into an elidable copy/move constructor
813 /// and that constructor was actually elided.
814 static bool isDestructorElided(ProgramStateRef State,
815 const CXXBindTemporaryExpr *BTE,
816 const LocationContext *LC);
817
818 /// Check if all objects under construction have been fully constructed
819 /// for the given context range (including FromLC, not including ToLC).
820 /// This is useful for assertions. Also checks if elided destructors
821 /// were cleaned up.
822 static bool areAllObjectsFullyConstructed(ProgramStateRef State,
823 const LocationContext *FromLC,
824 const LocationContext *ToLC);
825};
826
827/// Traits for storing the call processing policy inside GDM.
828/// The GDM stores the corresponding CallExpr pointer.
829// FIXME: This does not use the nice trait macros because it must be accessible
830// from multiple translation units.
831struct ReplayWithoutInlining{};
832template <>
833struct ProgramStateTrait<ReplayWithoutInlining> :
834 public ProgramStatePartialTrait<const void*> {
835 static void *GDMIndex();
836};
837
838} // namespace ento
839
840} // namespace clang
841
842#endif // LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_EXPRENGINE_H
843