1//===- ExprEngine.h - Path-Sensitive Expression-Level Dataflow --*- C++ -*-===//
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 a meta-engine for path-sensitive dataflow analysis that
10// is built on CoreEngine, but provides the boilerplate to execute transfer
11// functions and build the ExplodedGraph at the expression level.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_EXPRENGINE_H
16#define LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_EXPRENGINE_H
17
18#include "clang/AST/Expr.h"
19#include "clang/AST/Type.h"
20#include "clang/Analysis/CFG.h"
21#include "clang/Analysis/DomainSpecific/ObjCNoReturn.h"
22#include "clang/Analysis/ProgramPoint.h"
23#include "clang/Basic/LLVM.h"
24#include "clang/StaticAnalyzer/Core/CheckerManager.h"
25#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
26#include "clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitors.h"
27#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
28#include "clang/StaticAnalyzer/Core/PathSensitive/CoreEngine.h"
29#include "clang/StaticAnalyzer/Core/PathSensitive/FunctionSummary.h"
30#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
31#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
32#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState_Fwd.h"
33#include "clang/StaticAnalyzer/Core/PathSensitive/Store.h"
34#include "clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h"
35#include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
36#include "clang/StaticAnalyzer/Core/PathSensitive/WorkList.h"
37#include "llvm/ADT/ArrayRef.h"
38#include <cassert>
39#include <utility>
40
41namespace clang {
42
43class AnalysisDeclContextManager;
44class AnalyzerOptions;
45class ASTContext;
46class CFGBlock;
47class CFGElement;
48class ConstructionContext;
49class CXXBindTemporaryExpr;
50class CXXCatchStmt;
51class CXXConstructExpr;
52class CXXDeleteExpr;
53class CXXNewExpr;
54class CXXThisExpr;
55class Decl;
56class DeclStmt;
57class GCCAsmStmt;
58class LambdaExpr;
59class LocationContext;
60class MaterializeTemporaryExpr;
61class MSAsmStmt;
62class NamedDecl;
63class ObjCAtSynchronizedStmt;
64class ObjCForCollectionStmt;
65class ObjCIvarRefExpr;
66class ObjCMessageExpr;
67class ReturnStmt;
68class Stmt;
69
70namespace cross_tu {
71
72class CrossTranslationUnitContext;
73
74} // namespace cross_tu
75
76namespace ento {
77
78class AnalysisManager;
79class BasicValueFactory;
80class BlockCounter;
81class BranchNodeBuilder;
82class CallEvent;
83class CheckerManager;
84class ConstraintManager;
85class CXXTempObjectRegion;
86class EndOfFunctionNodeBuilder;
87class ExplodedNodeSet;
88class ExplodedNode;
89class IndirectGotoNodeBuilder;
90class MemRegion;
91struct NodeBuilderContext;
92class NodeBuilderWithSinks;
93class ProgramState;
94class ProgramStateManager;
95class RegionAndSymbolInvalidationTraits;
96class SymbolManager;
97class SwitchNodeBuilder;
98
99/// Hints for figuring out of a call should be inlined during evalCall().
100struct EvalCallOptions {
101 /// This call is a constructor or a destructor for which we do not currently
102 /// compute the this-region correctly.
103 bool IsCtorOrDtorWithImproperlyModeledTargetRegion = false;
104
105 /// This call is a constructor or a destructor for a single element within
106 /// an array, a part of array construction or destruction.
107 bool IsArrayCtorOrDtor = false;
108
109 /// This call is a constructor or a destructor of a temporary value.
110 bool IsTemporaryCtorOrDtor = false;
111
112 /// This call is a constructor for a temporary that is lifetime-extended
113 /// by binding it to a reference-type field within an aggregate,
114 /// for example 'A { const C &c; }; A a = { C() };'
115 bool IsTemporaryLifetimeExtendedViaAggregate = false;
116
117 /// This call is a pre-C++17 elidable constructor that we failed to elide
118 /// because we failed to compute the target region into which
119 /// this constructor would have been ultimately elided. Analysis that
120 /// we perform in this case is still correct but it behaves differently,
121 /// as if copy elision is disabled.
122 bool IsElidableCtorThatHasNotBeenElided = false;
123
124 EvalCallOptions() {}
125};
126
127class ExprEngine {
128 void anchor();
129
130public:
131 /// The modes of inlining, which override the default analysis-wide settings.
132 enum InliningModes {
133 /// Follow the default settings for inlining callees.
134 Inline_Regular = 0,
135
136 /// Do minimal inlining of callees.
137 Inline_Minimal = 0x1
138 };
139
140private:
141 cross_tu::CrossTranslationUnitContext &CTU;
142
143 AnalysisManager &AMgr;
144
145 AnalysisDeclContextManager &AnalysisDeclContexts;
146
147 CoreEngine Engine;
148
149 /// G - the simulation graph.
150 ExplodedGraph &G;
151
152 /// StateMgr - Object that manages the data for all created states.
153 ProgramStateManager StateMgr;
154
155 /// SymMgr - Object that manages the symbol information.
156 SymbolManager &SymMgr;
157
158 /// MRMgr - MemRegionManager object that creates memory regions.
159 MemRegionManager &MRMgr;
160
161 /// svalBuilder - SValBuilder object that creates SVals from expressions.
162 SValBuilder &svalBuilder;
163
164 unsigned int currStmtIdx = 0;
165 const NodeBuilderContext *currBldrCtx = nullptr;
166
167 /// Helper object to determine if an Objective-C message expression
168 /// implicitly never returns.
169 ObjCNoReturn ObjCNoRet;
170
171 /// The BugReporter associated with this engine. It is important that
172 /// this object be placed at the very end of member variables so that its
173 /// destructor is called before the rest of the ExprEngine is destroyed.
174 PathSensitiveBugReporter BR;
175
176 /// The functions which have been analyzed through inlining. This is owned by
177 /// AnalysisConsumer. It can be null.
178 SetOfConstDecls *VisitedCallees;
179
180 /// The flag, which specifies the mode of inlining for the engine.
181 InliningModes HowToInline;
182
183public:
184 ExprEngine(cross_tu::CrossTranslationUnitContext &CTU, AnalysisManager &mgr,
185 SetOfConstDecls *VisitedCalleesIn,
186 FunctionSummariesTy *FS, InliningModes HowToInlineIn);
187
188 virtual ~ExprEngine() = default;
189
190 /// Returns true if there is still simulation state on the worklist.
191 bool ExecuteWorkList(const LocationContext *L, unsigned Steps = 150000) {
192 return Engine.ExecuteWorkList(L, Steps, nullptr);
193 }
194
195 /// Execute the work list with an initial state. Nodes that reaches the exit
196 /// of the function are added into the Dst set, which represent the exit
197 /// state of the function call. Returns true if there is still simulation
198 /// state on the worklist.
199 bool ExecuteWorkListWithInitialState(const LocationContext *L, unsigned Steps,
200 ProgramStateRef InitState,
201 ExplodedNodeSet &Dst) {
202 return Engine.ExecuteWorkListWithInitialState(L, Steps, InitState, Dst);
203 }
204
205 /// getContext - Return the ASTContext associated with this analysis.
206 ASTContext &getContext() const { return AMgr.getASTContext(); }
207
208 AnalysisManager &getAnalysisManager() { return AMgr; }
209
210 AnalysisDeclContextManager &getAnalysisDeclContextManager() {
211 return AMgr.getAnalysisDeclContextManager();
212 }
213
214 CheckerManager &getCheckerManager() const {
215 return *AMgr.getCheckerManager();
216 }
217
218 SValBuilder &getSValBuilder() { return svalBuilder; }
219
220 BugReporter &getBugReporter() { return BR; }
221
222 cross_tu::CrossTranslationUnitContext *
223 getCrossTranslationUnitContext() {
224 return &CTU;
225 }
226
227 const NodeBuilderContext &getBuilderContext() {
228 assert(currBldrCtx);
229 return *currBldrCtx;
230 }
231
232 const Stmt *getStmt() const;
233
234 void GenerateAutoTransition(ExplodedNode *N);
235 void enqueueEndOfPath(ExplodedNodeSet &S);
236 void GenerateCallExitNode(ExplodedNode *N);
237
238
239 /// Dump graph to the specified filename.
240 /// If filename is empty, generate a temporary one.
241 /// \return The filename the graph is written into.
242 std::string DumpGraph(bool trim = false, StringRef Filename="");
243
244 /// Dump the graph consisting of the given nodes to a specified filename.
245 /// Generate a temporary filename if it's not provided.
246 /// \return The filename the graph is written into.
247 std::string DumpGraph(ArrayRef<const ExplodedNode *> Nodes,
248 StringRef Filename = "");
249
250 /// Visualize the ExplodedGraph created by executing the simulation.
251 void ViewGraph(bool trim = false);
252
253 /// Visualize a trimmed ExplodedGraph that only contains paths to the given
254 /// nodes.
255 void ViewGraph(ArrayRef<const ExplodedNode *> Nodes);
256
257 /// getInitialState - Return the initial state used for the root vertex
258 /// in the ExplodedGraph.
259 ProgramStateRef getInitialState(const LocationContext *InitLoc);
260
261 ExplodedGraph &getGraph() { return G; }
262 const ExplodedGraph &getGraph() const { return G; }
263
264 /// Run the analyzer's garbage collection - remove dead symbols and
265 /// bindings from the state.
266 ///
267 /// Checkers can participate in this process with two callbacks:
268 /// \c checkLiveSymbols and \c checkDeadSymbols. See the CheckerDocumentation
269 /// class for more information.
270 ///
271 /// \param Node The predecessor node, from which the processing should start.
272 /// \param Out The returned set of output nodes.
273 /// \param ReferenceStmt The statement which is about to be processed.
274 /// Everything needed for this statement should be considered live.
275 /// A null statement means that everything in child LocationContexts
276 /// is dead.
277 /// \param LC The location context of the \p ReferenceStmt. A null location
278 /// context means that we have reached the end of analysis and that
279 /// all statements and local variables should be considered dead.
280 /// \param DiagnosticStmt Used as a location for any warnings that should
281 /// occur while removing the dead (e.g. leaks). By default, the
282 /// \p ReferenceStmt is used.
283 /// \param K Denotes whether this is a pre- or post-statement purge. This
284 /// must only be ProgramPoint::PostStmtPurgeDeadSymbolsKind if an
285 /// entire location context is being cleared, in which case the
286 /// \p ReferenceStmt must either be a ReturnStmt or \c NULL. Otherwise,
287 /// it must be ProgramPoint::PreStmtPurgeDeadSymbolsKind (the default)
288 /// and \p ReferenceStmt must be valid (non-null).
289 void removeDead(ExplodedNode *Node, ExplodedNodeSet &Out,
290 const Stmt *ReferenceStmt, const LocationContext *LC,
291 const Stmt *DiagnosticStmt = nullptr,
292 ProgramPoint::Kind K = ProgramPoint::PreStmtPurgeDeadSymbolsKind);
293
294 /// processCFGElement - Called by CoreEngine. Used to generate new successor
295 /// nodes by processing the 'effects' of a CFG element.
296 void processCFGElement(const CFGElement E, ExplodedNode *Pred,
297 unsigned StmtIdx, NodeBuilderContext *Ctx);
298
299 void ProcessStmt(const Stmt *S, ExplodedNode *Pred);
300
301 void ProcessLoopExit(const Stmt* S, ExplodedNode *Pred);
302
303 void ProcessInitializer(const CFGInitializer I, ExplodedNode *Pred);
304
305 void ProcessImplicitDtor(const CFGImplicitDtor D, ExplodedNode *Pred);
306
307 void ProcessNewAllocator(const CXXNewExpr *NE, ExplodedNode *Pred);
308
309 void ProcessAutomaticObjDtor(const CFGAutomaticObjDtor D,
310 ExplodedNode *Pred, ExplodedNodeSet &Dst);
311 void ProcessDeleteDtor(const CFGDeleteDtor D,
312 ExplodedNode *Pred, ExplodedNodeSet &Dst);
313 void ProcessBaseDtor(const CFGBaseDtor D,
314 ExplodedNode *Pred, ExplodedNodeSet &Dst);
315 void ProcessMemberDtor(const CFGMemberDtor D,
316 ExplodedNode *Pred, ExplodedNodeSet &Dst);
317 void ProcessTemporaryDtor(const CFGTemporaryDtor D,
318 ExplodedNode *Pred, ExplodedNodeSet &Dst);
319
320 /// Called by CoreEngine when processing the entrance of a CFGBlock.
321 void processCFGBlockEntrance(const BlockEdge &L,
322 NodeBuilderWithSinks &nodeBuilder,
323 ExplodedNode *Pred);
324
325 /// ProcessBranch - Called by CoreEngine. Used to generate successor
326 /// nodes by processing the 'effects' of a branch condition.
327 void processBranch(const Stmt *Condition,
328 NodeBuilderContext& BuilderCtx,
329 ExplodedNode *Pred,
330 ExplodedNodeSet &Dst,
331 const CFGBlock *DstT,
332 const CFGBlock *DstF);
333
334 /// Called by CoreEngine.
335 /// Used to generate successor nodes for temporary destructors depending
336 /// on whether the corresponding constructor was visited.
337 void processCleanupTemporaryBranch(const CXXBindTemporaryExpr *BTE,
338 NodeBuilderContext &BldCtx,
339 ExplodedNode *Pred, ExplodedNodeSet &Dst,
340 const CFGBlock *DstT,
341 const CFGBlock *DstF);
342
343 /// Called by CoreEngine. Used to processing branching behavior
344 /// at static initializers.
345 void processStaticInitializer(const DeclStmt *DS,
346 NodeBuilderContext& BuilderCtx,
347 ExplodedNode *Pred,
348 ExplodedNodeSet &Dst,
349 const CFGBlock *DstT,
350 const CFGBlock *DstF);
351
352 /// processIndirectGoto - Called by CoreEngine. Used to generate successor
353 /// nodes by processing the 'effects' of a computed goto jump.
354 void processIndirectGoto(IndirectGotoNodeBuilder& builder);
355
356 /// ProcessSwitch - Called by CoreEngine. Used to generate successor
357 /// nodes by processing the 'effects' of a switch statement.
358 void processSwitch(SwitchNodeBuilder& builder);
359
360 /// Called by CoreEngine. Used to notify checkers that processing a
361 /// function has begun. Called for both inlined and and top-level functions.
362 void processBeginOfFunction(NodeBuilderContext &BC,
363 ExplodedNode *Pred, ExplodedNodeSet &Dst,
364 const BlockEdge &L);
365
366 /// Called by CoreEngine. Used to notify checkers that processing a
367 /// function has ended. Called for both inlined and and top-level functions.
368 void processEndOfFunction(NodeBuilderContext& BC,
369 ExplodedNode *Pred,
370 const ReturnStmt *RS = nullptr);
371
372 /// Remove dead bindings/symbols before exiting a function.
373 void removeDeadOnEndOfFunction(NodeBuilderContext& BC,
374 ExplodedNode *Pred,
375 ExplodedNodeSet &Dst);
376
377 /// Generate the entry node of the callee.
378 void processCallEnter(NodeBuilderContext& BC, CallEnter CE,
379 ExplodedNode *Pred);
380
381 /// Generate the sequence of nodes that simulate the call exit and the post
382 /// visit for CallExpr.
383 void processCallExit(ExplodedNode *Pred);
384
385 /// Called by CoreEngine when the analysis worklist has terminated.
386 void processEndWorklist();
387
388 /// evalAssume - Callback function invoked by the ConstraintManager when
389 /// making assumptions about state values.
390 ProgramStateRef processAssume(ProgramStateRef state, SVal cond,
391 bool assumption);
392
393 /// processRegionChanges - Called by ProgramStateManager whenever a change is made
394 /// to the store. Used to update checkers that track region values.
395 ProgramStateRef
396 processRegionChanges(ProgramStateRef state,
397 const InvalidatedSymbols *invalidated,
398 ArrayRef<const MemRegion *> ExplicitRegions,
399 ArrayRef<const MemRegion *> Regions,
400 const LocationContext *LCtx,
401 const CallEvent *Call);
402
403 inline ProgramStateRef
404 processRegionChange(ProgramStateRef state,
405 const MemRegion* MR,
406 const LocationContext *LCtx) {
407 return processRegionChanges(state, nullptr, MR, MR, LCtx, nullptr);
408 }
409
410 /// printJson - Called by ProgramStateManager to print checker-specific data.
411 void printJson(raw_ostream &Out, ProgramStateRef State,
412 const LocationContext *LCtx, const char *NL,
413 unsigned int Space, bool IsDot) const;
414
415 ProgramStateManager &getStateManager() { return StateMgr; }
416
417 StoreManager &getStoreManager() { return StateMgr.getStoreManager(); }
418
419 ConstraintManager &getConstraintManager() {
420 return StateMgr.getConstraintManager();
421 }
422
423 // FIXME: Remove when we migrate over to just using SValBuilder.
424 BasicValueFactory &getBasicVals() {
425 return StateMgr.getBasicVals();
426 }
427
428 SymbolManager &getSymbolManager() { return SymMgr; }
429 MemRegionManager &getRegionManager() { return MRMgr; }
430
431 NoteTag::Factory &getNoteTags() { return Engine.getNoteTags(); }
432
433
434 // Functions for external checking of whether we have unfinished work
435 bool wasBlocksExhausted() const { return Engine.wasBlocksExhausted(); }
436 bool hasEmptyWorkList() const { return !Engine.getWorkList()->hasWork(); }
437 bool hasWorkRemaining() const { return Engine.hasWorkRemaining(); }
438
439 const CoreEngine &getCoreEngine() const { return Engine; }
440
441public:
442 /// Visit - Transfer function logic for all statements. Dispatches to
443 /// other functions that handle specific kinds of statements.
444 void Visit(const Stmt *S, ExplodedNode *Pred, ExplodedNodeSet &Dst);
445
446 /// VisitArraySubscriptExpr - Transfer function for array accesses.
447 void VisitArraySubscriptExpr(const ArraySubscriptExpr *Ex,
448 ExplodedNode *Pred,
449 ExplodedNodeSet &Dst);
450
451 /// VisitGCCAsmStmt - Transfer function logic for inline asm.
452 void VisitGCCAsmStmt(const GCCAsmStmt *A, ExplodedNode *Pred,
453 ExplodedNodeSet &Dst);
454
455 /// VisitMSAsmStmt - Transfer function logic for MS inline asm.
456 void VisitMSAsmStmt(const MSAsmStmt *A, ExplodedNode *Pred,
457 ExplodedNodeSet &Dst);
458
459 /// VisitBlockExpr - Transfer function logic for BlockExprs.
460 void VisitBlockExpr(const BlockExpr *BE, ExplodedNode *Pred,
461 ExplodedNodeSet &Dst);
462
463 /// VisitLambdaExpr - Transfer function logic for LambdaExprs.
464 void VisitLambdaExpr(const LambdaExpr *LE, ExplodedNode *Pred,
465 ExplodedNodeSet &Dst);
466
467 /// VisitBinaryOperator - Transfer function logic for binary operators.
468 void VisitBinaryOperator(const BinaryOperator* B, ExplodedNode *Pred,
469 ExplodedNodeSet &Dst);
470
471
472 /// VisitCall - Transfer function for function calls.
473 void VisitCallExpr(const CallExpr *CE, ExplodedNode *Pred,
474 ExplodedNodeSet &Dst);
475
476 /// VisitCast - Transfer function logic for all casts (implicit and explicit).
477 void VisitCast(const CastExpr *CastE, const Expr *Ex, ExplodedNode *Pred,
478 ExplodedNodeSet &Dst);
479
480 /// VisitCompoundLiteralExpr - Transfer function logic for compound literals.
481 void VisitCompoundLiteralExpr(const CompoundLiteralExpr *CL,
482 ExplodedNode *Pred, ExplodedNodeSet &Dst);
483
484 /// Transfer function logic for DeclRefExprs and BlockDeclRefExprs.
485 void VisitCommonDeclRefExpr(const Expr *DR, const NamedDecl *D,
486 ExplodedNode *Pred, ExplodedNodeSet &Dst);
487
488 /// VisitDeclStmt - Transfer function logic for DeclStmts.
489 void VisitDeclStmt(const DeclStmt *DS, ExplodedNode *Pred,
490 ExplodedNodeSet &Dst);
491
492 /// VisitGuardedExpr - Transfer function logic for ?, __builtin_choose
493 void VisitGuardedExpr(const Expr *Ex, const Expr *L, const Expr *R,
494 ExplodedNode *Pred, ExplodedNodeSet &Dst);
495
496 void VisitInitListExpr(const InitListExpr *E, ExplodedNode *Pred,
497 ExplodedNodeSet &Dst);
498
499 /// VisitLogicalExpr - Transfer function logic for '&&', '||'
500 void VisitLogicalExpr(const BinaryOperator* B, ExplodedNode *Pred,
501 ExplodedNodeSet &Dst);
502
503 /// VisitMemberExpr - Transfer function for member expressions.
504 void VisitMemberExpr(const MemberExpr *M, ExplodedNode *Pred,
505 ExplodedNodeSet &Dst);
506
507 /// VisitAtomicExpr - Transfer function for builtin atomic expressions
508 void VisitAtomicExpr(const AtomicExpr *E, ExplodedNode *Pred,
509 ExplodedNodeSet &Dst);
510
511 /// Transfer function logic for ObjCAtSynchronizedStmts.
512 void VisitObjCAtSynchronizedStmt(const ObjCAtSynchronizedStmt *S,
513 ExplodedNode *Pred, ExplodedNodeSet &Dst);
514
515 /// Transfer function logic for computing the lvalue of an Objective-C ivar.
516 void VisitLvalObjCIvarRefExpr(const ObjCIvarRefExpr *DR, ExplodedNode *Pred,
517 ExplodedNodeSet &Dst);
518
519 /// VisitObjCForCollectionStmt - Transfer function logic for
520 /// ObjCForCollectionStmt.
521 void VisitObjCForCollectionStmt(const ObjCForCollectionStmt *S,
522 ExplodedNode *Pred, ExplodedNodeSet &Dst);
523
524 void VisitObjCMessage(const ObjCMessageExpr *ME, ExplodedNode *Pred,
525 ExplodedNodeSet &Dst);
526
527 /// VisitReturnStmt - Transfer function logic for return statements.
528 void VisitReturnStmt(const ReturnStmt *R, ExplodedNode *Pred,
529 ExplodedNodeSet &Dst);
530
531 /// VisitOffsetOfExpr - Transfer function for offsetof.
532 void VisitOffsetOfExpr(const OffsetOfExpr *Ex, ExplodedNode *Pred,
533 ExplodedNodeSet &Dst);
534
535 /// VisitUnaryExprOrTypeTraitExpr - Transfer function for sizeof.
536 void VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *Ex,
537 ExplodedNode *Pred, ExplodedNodeSet &Dst);
538
539 /// VisitUnaryOperator - Transfer function logic for unary operators.
540 void VisitUnaryOperator(const UnaryOperator* B, ExplodedNode *Pred,
541 ExplodedNodeSet &Dst);
542
543 /// Handle ++ and -- (both pre- and post-increment).
544 void VisitIncrementDecrementOperator(const UnaryOperator* U,
545 ExplodedNode *Pred,
546 ExplodedNodeSet &Dst);
547
548 void VisitCXXBindTemporaryExpr(const CXXBindTemporaryExpr *BTE,
549 ExplodedNodeSet &PreVisit,
550 ExplodedNodeSet &Dst);
551
552 void VisitCXXCatchStmt(const CXXCatchStmt *CS, ExplodedNode *Pred,
553 ExplodedNodeSet &Dst);
554
555 void VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred,
556 ExplodedNodeSet & Dst);
557
558 void VisitCXXConstructExpr(const CXXConstructExpr *E, ExplodedNode *Pred,
559 ExplodedNodeSet &Dst);
560
561 void VisitCXXInheritedCtorInitExpr(const CXXInheritedCtorInitExpr *E,
562 ExplodedNode *Pred, ExplodedNodeSet &Dst);
563
564 void VisitCXXDestructor(QualType ObjectType, const MemRegion *Dest,
565 const Stmt *S, bool IsBaseDtor,
566 ExplodedNode *Pred, ExplodedNodeSet &Dst,
567 EvalCallOptions &Options);
568
569 void VisitCXXNewAllocatorCall(const CXXNewExpr *CNE,
570 ExplodedNode *Pred,
571 ExplodedNodeSet &Dst);
572
573 void VisitCXXNewExpr(const CXXNewExpr *CNE, ExplodedNode *Pred,
574 ExplodedNodeSet &Dst);
575
576 void VisitCXXDeleteExpr(const CXXDeleteExpr *CDE, ExplodedNode *Pred,
577 ExplodedNodeSet &Dst);
578
579 /// Create a C++ temporary object for an rvalue.
580 void CreateCXXTemporaryObject(const MaterializeTemporaryExpr *ME,
581 ExplodedNode *Pred,
582 ExplodedNodeSet &Dst);
583
584 /// evalEagerlyAssumeBinOpBifurcation - Given the nodes in 'Src', eagerly assume symbolic
585 /// expressions of the form 'x != 0' and generate new nodes (stored in Dst)
586 /// with those assumptions.
587 void evalEagerlyAssumeBinOpBifurcation(ExplodedNodeSet &Dst, ExplodedNodeSet &Src,
588 const Expr *Ex);
589
590 static std::pair<const ProgramPointTag *, const ProgramPointTag *>
591 geteagerlyAssumeBinOpBifurcationTags();
592
593 SVal evalMinus(SVal X) {
594 return X.isValid() ? svalBuilder.evalMinus(X.castAs<NonLoc>()) : X;
595 }
596
597 SVal evalComplement(SVal X) {
598 return X.isValid() ? svalBuilder.evalComplement(X.castAs<NonLoc>()) : X;
599 }
600
601 ProgramStateRef handleLValueBitCast(ProgramStateRef state, const Expr *Ex,
602 const LocationContext *LCtx, QualType T,
603 QualType ExTy, const CastExpr *CastE,
604 StmtNodeBuilder &Bldr,
605 ExplodedNode *Pred);
606
607 ProgramStateRef handleLVectorSplat(ProgramStateRef state,
608 const LocationContext *LCtx,
609 const CastExpr *CastE,
610 StmtNodeBuilder &Bldr,
611 ExplodedNode *Pred);
612
613 void handleUOExtension(ExplodedNodeSet::iterator I,
614 const UnaryOperator* U,
615 StmtNodeBuilder &Bldr);
616
617public:
618 SVal evalBinOp(ProgramStateRef state, BinaryOperator::Opcode op,
619 NonLoc L, NonLoc R, QualType T) {
620 return svalBuilder.evalBinOpNN(state, op, L, R, T);
621 }
622
623 SVal evalBinOp(ProgramStateRef state, BinaryOperator::Opcode op,
624 NonLoc L, SVal R, QualType T) {
625 return R.isValid() ? svalBuilder.evalBinOpNN(state, op, L,
626 R.castAs<NonLoc>(), T) : R;
627 }
628
629 SVal evalBinOp(ProgramStateRef ST, BinaryOperator::Opcode Op,
630 SVal LHS, SVal RHS, QualType T) {
631 return svalBuilder.evalBinOp(ST, Op, LHS, RHS, T);
632 }
633
634 /// By looking at a certain item that may be potentially part of an object's
635 /// ConstructionContext, retrieve such object's location. A particular
636 /// statement can be transparently passed as \p Item in most cases.
637 static Optional<SVal>
638 getObjectUnderConstruction(ProgramStateRef State,
639 const ConstructionContextItem &Item,
640 const LocationContext *LC);
641
642 /// Call PointerEscape callback when a value escapes as a result of bind.
643 ProgramStateRef processPointerEscapedOnBind(
644 ProgramStateRef State, ArrayRef<std::pair<SVal, SVal>> LocAndVals,
645 const LocationContext *LCtx, PointerEscapeKind Kind,
646 const CallEvent *Call);
647
648 /// Call PointerEscape callback when a value escapes as a result of
649 /// region invalidation.
650 /// \param[in] ITraits Specifies invalidation traits for regions/symbols.
651 ProgramStateRef notifyCheckersOfPointerEscape(
652 ProgramStateRef State,
653 const InvalidatedSymbols *Invalidated,
654 ArrayRef<const MemRegion *> ExplicitRegions,
655 const CallEvent *Call,
656 RegionAndSymbolInvalidationTraits &ITraits);
657
658private:
659 /// evalBind - Handle the semantics of binding a value to a specific location.
660 /// This method is used by evalStore, VisitDeclStmt, and others.
661 void evalBind(ExplodedNodeSet &Dst, const Stmt *StoreE, ExplodedNode *Pred,
662 SVal location, SVal Val, bool atDeclInit = false,
663 const ProgramPoint *PP = nullptr);
664
665 ProgramStateRef
666 processPointerEscapedOnBind(ProgramStateRef State,
667 SVal Loc, SVal Val,
668 const LocationContext *LCtx);
669
670 /// A simple wrapper when you only need to notify checkers of pointer-escape
671 /// of some values.
672 ProgramStateRef escapeValues(ProgramStateRef State, ArrayRef<SVal> Vs,
673 PointerEscapeKind K,
674 const CallEvent *Call = nullptr) const;
675
676public:
677 // FIXME: 'tag' should be removed, and a LocationContext should be used
678 // instead.
679 // FIXME: Comment on the meaning of the arguments, when 'St' may not
680 // be the same as Pred->state, and when 'location' may not be the
681 // same as state->getLValue(Ex).
682 /// Simulate a read of the result of Ex.
683 void evalLoad(ExplodedNodeSet &Dst,
684 const Expr *NodeEx, /* Eventually will be a CFGStmt */
685 const Expr *BoundExpr,
686 ExplodedNode *Pred,
687 ProgramStateRef St,
688 SVal location,
689 const ProgramPointTag *tag = nullptr,
690 QualType LoadTy = QualType());
691
692 // FIXME: 'tag' should be removed, and a LocationContext should be used
693 // instead.
694 void evalStore(ExplodedNodeSet &Dst, const Expr *AssignE, const Expr *StoreE,
695 ExplodedNode *Pred, ProgramStateRef St, SVal TargetLV, SVal Val,
696 const ProgramPointTag *tag = nullptr);
697
698 /// Return the CFG element corresponding to the worklist element
699 /// that is currently being processed by ExprEngine.
700 CFGElement getCurrentCFGElement() {
701 return (*currBldrCtx->getBlock())[currStmtIdx];
702 }
703
704 /// Create a new state in which the call return value is binded to the
705 /// call origin expression.
706 ProgramStateRef bindReturnValue(const CallEvent &Call,
707 const LocationContext *LCtx,
708 ProgramStateRef State);
709
710 /// Evaluate a call, running pre- and post-call checkers and allowing checkers
711 /// to be responsible for handling the evaluation of the call itself.
712 void evalCall(ExplodedNodeSet &Dst, ExplodedNode *Pred,
713 const CallEvent &Call);
714
715 /// Default implementation of call evaluation.
716 void defaultEvalCall(NodeBuilder &B, ExplodedNode *Pred,
717 const CallEvent &Call,
718 const EvalCallOptions &CallOpts = {});
719
720 /// Find location of the object that is being constructed by a given
721 /// constructor. This should ideally always succeed but due to not being
722 /// fully implemented it sometimes indicates that it failed via its
723 /// out-parameter CallOpts; in such cases a fake temporary region is
724 /// returned, which is better than nothing but does not represent
725 /// the actual behavior of the program.
726 SVal computeObjectUnderConstruction(
727 const Expr *E, ProgramStateRef State, const LocationContext *LCtx,
728 const ConstructionContext *CC, EvalCallOptions &CallOpts);
729
730 /// Update the program state with all the path-sensitive information
731 /// that's necessary to perform construction of an object with a given
732 /// syntactic construction context. V and CallOpts have to be obtained from
733 /// computeObjectUnderConstruction() invoked with the same set of
734 /// the remaining arguments (E, State, LCtx, CC).
735 ProgramStateRef updateObjectsUnderConstruction(
736 SVal V, const Expr *E, ProgramStateRef State, const LocationContext *LCtx,
737 const ConstructionContext *CC, const EvalCallOptions &CallOpts);
738
739 /// A convenient wrapper around computeObjectUnderConstruction
740 /// and updateObjectsUnderConstruction.
741 std::pair<ProgramStateRef, SVal> handleConstructionContext(
742 const Expr *E, ProgramStateRef State, const LocationContext *LCtx,
743 const ConstructionContext *CC, EvalCallOptions &CallOpts) {
744 SVal V = computeObjectUnderConstruction(E, State, LCtx, CC, CallOpts);
745 return std::make_pair(
746 updateObjectsUnderConstruction(V, E, State, LCtx, CC, CallOpts), V);
747 }
748
749private:
750 ProgramStateRef finishArgumentConstruction(ProgramStateRef State,
751 const CallEvent &Call);
752 void finishArgumentConstruction(ExplodedNodeSet &Dst, ExplodedNode *Pred,
753 const CallEvent &Call);
754
755 void evalLoadCommon(ExplodedNodeSet &Dst,
756 const Expr *NodeEx, /* Eventually will be a CFGStmt */
757 const Expr *BoundEx,
758 ExplodedNode *Pred,
759 ProgramStateRef St,
760 SVal location,
761 const ProgramPointTag *tag,
762 QualType LoadTy);
763
764 void evalLocation(ExplodedNodeSet &Dst,
765 const Stmt *NodeEx, /* This will eventually be a CFGStmt */
766 const Stmt *BoundEx,
767 ExplodedNode *Pred,
768 ProgramStateRef St,
769 SVal location,
770 bool isLoad);
771
772 /// Count the stack depth and determine if the call is recursive.
773 void examineStackFrames(const Decl *D, const LocationContext *LCtx,
774 bool &IsRecursive, unsigned &StackDepth);
775
776 enum CallInlinePolicy {
777 CIP_Allowed,
778 CIP_DisallowedOnce,
779 CIP_DisallowedAlways
780 };
781
782 /// See if a particular call should be inlined, by only looking
783 /// at the call event and the current state of analysis.
784 CallInlinePolicy mayInlineCallKind(const CallEvent &Call,
785 const ExplodedNode *Pred,
786 AnalyzerOptions &Opts,
787 const EvalCallOptions &CallOpts);
788
789 /// See if the given AnalysisDeclContext is built for a function that we
790 /// should always inline simply because it's small enough.
791 /// Apart from "small" functions, we also have "large" functions
792 /// (cf. isLarge()), some of which are huge (cf. isHuge()), and we classify
793 /// the remaining functions as "medium".
794 bool isSmall(AnalysisDeclContext *ADC) const;
795
796 /// See if the given AnalysisDeclContext is built for a function that we
797 /// should inline carefully because it looks pretty large.
798 bool isLarge(AnalysisDeclContext *ADC) const;
799
800 /// See if the given AnalysisDeclContext is built for a function that we
801 /// should never inline because it's legit gigantic.
802 bool isHuge(AnalysisDeclContext *ADC) const;
803
804 /// See if the given AnalysisDeclContext is built for a function that we
805 /// should inline, just by looking at the declaration of the function.
806 bool mayInlineDecl(AnalysisDeclContext *ADC) const;
807
808 /// Checks our policies and decides weither the given call should be inlined.
809 bool shouldInlineCall(const CallEvent &Call, const Decl *D,
810 const ExplodedNode *Pred,
811 const EvalCallOptions &CallOpts = {});
812
813 bool inlineCall(const CallEvent &Call, const Decl *D, NodeBuilder &Bldr,
814 ExplodedNode *Pred, ProgramStateRef State);
815
816 /// Conservatively evaluate call by invalidating regions and binding
817 /// a conjured return value.
818 void conservativeEvalCall(const CallEvent &Call, NodeBuilder &Bldr,
819 ExplodedNode *Pred, ProgramStateRef State);
820
821 /// Either inline or process the call conservatively (or both), based
822 /// on DynamicDispatchBifurcation data.
823 void BifurcateCall(const MemRegion *BifurReg,
824 const CallEvent &Call, const Decl *D, NodeBuilder &Bldr,
825 ExplodedNode *Pred);
826
827 bool replayWithoutInlining(ExplodedNode *P, const LocationContext *CalleeLC);
828
829 /// Models a trivial copy or move constructor or trivial assignment operator
830 /// call with a simple bind.
831 void performTrivialCopy(NodeBuilder &Bldr, ExplodedNode *Pred,
832 const CallEvent &Call);
833
834 /// If the value of the given expression \p InitWithAdjustments is a NonLoc,
835 /// copy it into a new temporary object region, and replace the value of the
836 /// expression with that.
837 ///
838 /// If \p Result is provided, the new region will be bound to this expression
839 /// instead of \p InitWithAdjustments.
840 ///
841 /// Returns the temporary region with adjustments into the optional
842 /// OutRegionWithAdjustments out-parameter if a new region was indeed needed,
843 /// otherwise sets it to nullptr.
844 ProgramStateRef createTemporaryRegionIfNeeded(
845 ProgramStateRef State, const LocationContext *LC,
846 const Expr *InitWithAdjustments, const Expr *Result = nullptr,
847 const SubRegion **OutRegionWithAdjustments = nullptr);
848
849 /// Returns a region representing the first element of a (possibly
850 /// multi-dimensional) array, for the purposes of element construction or
851 /// destruction.
852 ///
853 /// On return, \p Ty will be set to the base type of the array.
854 ///
855 /// If the type is not an array type at all, the original value is returned.
856 /// Otherwise the "IsArray" flag is set.
857 static SVal makeZeroElementRegion(ProgramStateRef State, SVal LValue,
858 QualType &Ty, bool &IsArray);
859
860 /// For a DeclStmt or CXXInitCtorInitializer, walk backward in the current CFG
861 /// block to find the constructor expression that directly constructed into
862 /// the storage for this statement. Returns null if the constructor for this
863 /// statement created a temporary object region rather than directly
864 /// constructing into an existing region.
865 const CXXConstructExpr *findDirectConstructorForCurrentCFGElement();
866
867 /// Common code that handles either a CXXConstructExpr or a
868 /// CXXInheritedCtorInitExpr.
869 void handleConstructor(const Expr *E, ExplodedNode *Pred,
870 ExplodedNodeSet &Dst);
871
872public:
873 /// Note whether this loop has any more iteratios to model. These methods are
874 /// essentially an interface for a GDM trait. Further reading in
875 /// ExprEngine::VisitObjCForCollectionStmt().
876 LLVM_NODISCARD static ProgramStateRef
877 setWhetherHasMoreIteration(ProgramStateRef State,
878 const ObjCForCollectionStmt *O,
879 const LocationContext *LC, bool HasMoreIteraton);
880
881 LLVM_NODISCARD static ProgramStateRef
882 removeIterationState(ProgramStateRef State, const ObjCForCollectionStmt *O,
883 const LocationContext *LC);
884
885 LLVM_NODISCARD static bool hasMoreIteration(ProgramStateRef State,
886 const ObjCForCollectionStmt *O,
887 const LocationContext *LC);
888private:
889 /// Store the location of a C++ object corresponding to a statement
890 /// until the statement is actually encountered. For example, if a DeclStmt
891 /// has CXXConstructExpr as its initializer, the object would be considered
892 /// to be "under construction" between CXXConstructExpr and DeclStmt.
893 /// This allows, among other things, to keep bindings to variable's fields
894 /// made within the constructor alive until its declaration actually
895 /// goes into scope.
896 static ProgramStateRef
897 addObjectUnderConstruction(ProgramStateRef State,
898 const ConstructionContextItem &Item,
899 const LocationContext *LC, SVal V);
900
901 /// Mark the object sa fully constructed, cleaning up the state trait
902 /// that tracks objects under construction.
903 static ProgramStateRef
904 finishObjectConstruction(ProgramStateRef State,
905 const ConstructionContextItem &Item,
906 const LocationContext *LC);
907
908 /// If the given expression corresponds to a temporary that was used for
909 /// passing into an elidable copy/move constructor and that constructor
910 /// was actually elided, track that we also need to elide the destructor.
911 static ProgramStateRef elideDestructor(ProgramStateRef State,
912 const CXXBindTemporaryExpr *BTE,
913 const LocationContext *LC);
914
915 /// Stop tracking the destructor that corresponds to an elided constructor.
916 static ProgramStateRef
917 cleanupElidedDestructor(ProgramStateRef State,
918 const CXXBindTemporaryExpr *BTE,
919 const LocationContext *LC);
920
921 /// Returns true if the given expression corresponds to a temporary that
922 /// was constructed for passing into an elidable copy/move constructor
923 /// and that constructor was actually elided.
924 static bool isDestructorElided(ProgramStateRef State,
925 const CXXBindTemporaryExpr *BTE,
926 const LocationContext *LC);
927
928 /// Check if all objects under construction have been fully constructed
929 /// for the given context range (including FromLC, not including ToLC).
930 /// This is useful for assertions. Also checks if elided destructors
931 /// were cleaned up.
932 static bool areAllObjectsFullyConstructed(ProgramStateRef State,
933 const LocationContext *FromLC,
934 const LocationContext *ToLC);
935};
936
937/// Traits for storing the call processing policy inside GDM.
938/// The GDM stores the corresponding CallExpr pointer.
939// FIXME: This does not use the nice trait macros because it must be accessible
940// from multiple translation units.
941struct ReplayWithoutInlining{};
942template <>
943struct ProgramStateTrait<ReplayWithoutInlining> :
944 public ProgramStatePartialTrait<const void*> {
945 static void *GDMIndex();
946};
947
948} // namespace ento
949
950} // namespace clang
951
952#endif // LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_EXPRENGINE_H
953