1//===- Consumed.cpp -------------------------------------------------------===//
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// A intra-procedural analysis for checking consumed properties. This is based,
10// in part, on research on linear types.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/Analysis/Analyses/Consumed.h"
15#include "clang/AST/Attr.h"
16#include "clang/AST/Decl.h"
17#include "clang/AST/DeclCXX.h"
18#include "clang/AST/Expr.h"
19#include "clang/AST/ExprCXX.h"
20#include "clang/AST/Stmt.h"
21#include "clang/AST/StmtVisitor.h"
22#include "clang/AST/Type.h"
23#include "clang/Analysis/Analyses/PostOrderCFGView.h"
24#include "clang/Analysis/AnalysisDeclContext.h"
25#include "clang/Analysis/CFG.h"
26#include "clang/Basic/LLVM.h"
27#include "clang/Basic/OperatorKinds.h"
28#include "clang/Basic/SourceLocation.h"
29#include "llvm/ADT/DenseMap.h"
30#include "llvm/ADT/STLExtras.h"
31#include "llvm/ADT/StringRef.h"
32#include "llvm/Support/Casting.h"
33#include "llvm/Support/ErrorHandling.h"
34#include <cassert>
35#include <memory>
36#include <optional>
37#include <utility>
38
39// TODO: Adjust states of args to constructors in the same way that arguments to
40// function calls are handled.
41// TODO: Use information from tests in for- and while-loop conditional.
42// TODO: Add notes about the actual and expected state for
43// TODO: Correctly identify unreachable blocks when chaining boolean operators.
44// TODO: Adjust the parser and AttributesList class to support lists of
45// identifiers.
46// TODO: Warn about unreachable code.
47// TODO: Switch to using a bitmap to track unreachable blocks.
48// TODO: Handle variable definitions, e.g. bool valid = x.isValid();
49// if (valid) ...; (Deferred)
50// TODO: Take notes on state transitions to provide better warning messages.
51// (Deferred)
52// TODO: Test nested conditionals: A) Checking the same value multiple times,
53// and 2) Checking different values. (Deferred)
54
55using namespace clang;
56using namespace consumed;
57
58// Key method definition
59ConsumedWarningsHandlerBase::~ConsumedWarningsHandlerBase() = default;
60
61static SourceLocation getFirstStmtLoc(const CFGBlock *Block) {
62 // Find the source location of the first statement in the block, if the block
63 // is not empty.
64 for (const auto &B : *Block)
65 if (std::optional<CFGStmt> CS = B.getAs<CFGStmt>())
66 return CS->getStmt()->getBeginLoc();
67
68 // Block is empty.
69 // If we have one successor, return the first statement in that block
70 if (Block->succ_size() == 1 && *Block->succ_begin())
71 return getFirstStmtLoc(Block: *Block->succ_begin());
72
73 return {};
74}
75
76static SourceLocation getLastStmtLoc(const CFGBlock *Block) {
77 // Find the source location of the last statement in the block, if the block
78 // is not empty.
79 if (const Stmt *StmtNode = Block->getTerminatorStmt()) {
80 return StmtNode->getBeginLoc();
81 } else {
82 for (CFGBlock::const_reverse_iterator BI = Block->rbegin(),
83 BE = Block->rend(); BI != BE; ++BI) {
84 if (std::optional<CFGStmt> CS = BI->getAs<CFGStmt>())
85 return CS->getStmt()->getBeginLoc();
86 }
87 }
88
89 // If we have one successor, return the first statement in that block
90 SourceLocation Loc;
91 if (Block->succ_size() == 1 && *Block->succ_begin())
92 Loc = getFirstStmtLoc(Block: *Block->succ_begin());
93 if (Loc.isValid())
94 return Loc;
95
96 // If we have one predecessor, return the last statement in that block
97 if (Block->pred_size() == 1 && *Block->pred_begin())
98 return getLastStmtLoc(Block: *Block->pred_begin());
99
100 return Loc;
101}
102
103static ConsumedState invertConsumedUnconsumed(ConsumedState State) {
104 switch (State) {
105 case CS_Unconsumed:
106 return CS_Consumed;
107 case CS_Consumed:
108 return CS_Unconsumed;
109 case CS_None:
110 return CS_None;
111 case CS_Unknown:
112 return CS_Unknown;
113 }
114 llvm_unreachable("invalid enum");
115}
116
117static bool isCallableInState(const CallableWhenAttr *CWAttr,
118 ConsumedState State) {
119 for (const auto &S : CWAttr->callableStates()) {
120 ConsumedState MappedAttrState = CS_None;
121
122 switch (S) {
123 case CallableWhenAttr::Unknown:
124 MappedAttrState = CS_Unknown;
125 break;
126
127 case CallableWhenAttr::Unconsumed:
128 MappedAttrState = CS_Unconsumed;
129 break;
130
131 case CallableWhenAttr::Consumed:
132 MappedAttrState = CS_Consumed;
133 break;
134 }
135
136 if (MappedAttrState == State)
137 return true;
138 }
139
140 return false;
141}
142
143static bool isConsumableType(const QualType &QT) {
144 if (QT->isPointerType() || QT->isReferenceType())
145 return false;
146
147 if (const CXXRecordDecl *RD = QT->getAsCXXRecordDecl())
148 return RD->hasAttr<ConsumableAttr>();
149
150 return false;
151}
152
153static bool isAutoCastType(const QualType &QT) {
154 if (QT->isPointerType() || QT->isReferenceType())
155 return false;
156
157 if (const CXXRecordDecl *RD = QT->getAsCXXRecordDecl())
158 return RD->hasAttr<ConsumableAutoCastAttr>();
159
160 return false;
161}
162
163static bool isSetOnReadPtrType(const QualType &QT) {
164 if (const CXXRecordDecl *RD = QT->getPointeeCXXRecordDecl())
165 return RD->hasAttr<ConsumableSetOnReadAttr>();
166 return false;
167}
168
169static bool isKnownState(ConsumedState State) {
170 switch (State) {
171 case CS_Unconsumed:
172 case CS_Consumed:
173 return true;
174 case CS_None:
175 case CS_Unknown:
176 return false;
177 }
178 llvm_unreachable("invalid enum");
179}
180
181static bool isRValueRef(QualType ParamType) {
182 return ParamType->isRValueReferenceType();
183}
184
185static bool isTestingFunction(const FunctionDecl *FunDecl) {
186 return FunDecl->hasAttr<TestTypestateAttr>();
187}
188
189static bool isPointerOrRef(QualType ParamType) {
190 return ParamType->isPointerType() || ParamType->isReferenceType();
191}
192
193static ConsumedState mapConsumableAttrState(const QualType QT) {
194 assert(isConsumableType(QT));
195
196 const ConsumableAttr *CAttr =
197 QT->getAsCXXRecordDecl()->getAttr<ConsumableAttr>();
198
199 switch (CAttr->getDefaultState()) {
200 case ConsumableAttr::Unknown:
201 return CS_Unknown;
202 case ConsumableAttr::Unconsumed:
203 return CS_Unconsumed;
204 case ConsumableAttr::Consumed:
205 return CS_Consumed;
206 }
207 llvm_unreachable("invalid enum");
208}
209
210static ConsumedState
211mapParamTypestateAttrState(const ParamTypestateAttr *PTAttr) {
212 switch (PTAttr->getParamState()) {
213 case ParamTypestateAttr::Unknown:
214 return CS_Unknown;
215 case ParamTypestateAttr::Unconsumed:
216 return CS_Unconsumed;
217 case ParamTypestateAttr::Consumed:
218 return CS_Consumed;
219 }
220 llvm_unreachable("invalid_enum");
221}
222
223static ConsumedState
224mapReturnTypestateAttrState(const ReturnTypestateAttr *RTSAttr) {
225 switch (RTSAttr->getState()) {
226 case ReturnTypestateAttr::Unknown:
227 return CS_Unknown;
228 case ReturnTypestateAttr::Unconsumed:
229 return CS_Unconsumed;
230 case ReturnTypestateAttr::Consumed:
231 return CS_Consumed;
232 }
233 llvm_unreachable("invalid enum");
234}
235
236static ConsumedState mapSetTypestateAttrState(const SetTypestateAttr *STAttr) {
237 switch (STAttr->getNewState()) {
238 case SetTypestateAttr::Unknown:
239 return CS_Unknown;
240 case SetTypestateAttr::Unconsumed:
241 return CS_Unconsumed;
242 case SetTypestateAttr::Consumed:
243 return CS_Consumed;
244 }
245 llvm_unreachable("invalid_enum");
246}
247
248static StringRef stateToString(ConsumedState State) {
249 switch (State) {
250 case consumed::CS_None:
251 return "none";
252
253 case consumed::CS_Unknown:
254 return "unknown";
255
256 case consumed::CS_Unconsumed:
257 return "unconsumed";
258
259 case consumed::CS_Consumed:
260 return "consumed";
261 }
262 llvm_unreachable("invalid enum");
263}
264
265static ConsumedState testsFor(const FunctionDecl *FunDecl) {
266 assert(isTestingFunction(FunDecl));
267 switch (FunDecl->getAttr<TestTypestateAttr>()->getTestState()) {
268 case TestTypestateAttr::Unconsumed:
269 return CS_Unconsumed;
270 case TestTypestateAttr::Consumed:
271 return CS_Consumed;
272 }
273 llvm_unreachable("invalid enum");
274}
275
276namespace {
277
278struct VarTestResult {
279 const VarDecl *Var;
280 ConsumedState TestsFor;
281};
282
283} // namespace
284
285namespace clang {
286namespace consumed {
287
288enum EffectiveOp {
289 EO_And,
290 EO_Or
291};
292
293class PropagationInfo {
294 enum {
295 IT_None,
296 IT_State,
297 IT_VarTest,
298 IT_BinTest,
299 IT_Var,
300 IT_Tmp
301 } InfoType = IT_None;
302
303 struct BinTestTy {
304 const BinaryOperator *Source;
305 EffectiveOp EOp;
306 VarTestResult LTest;
307 VarTestResult RTest;
308 };
309
310 union {
311 ConsumedState State;
312 VarTestResult VarTest;
313 const VarDecl *Var;
314 const CXXBindTemporaryExpr *Tmp;
315 BinTestTy BinTest;
316 };
317
318public:
319 PropagationInfo() = default;
320 PropagationInfo(const VarTestResult &VarTest)
321 : InfoType(IT_VarTest), VarTest(VarTest) {}
322
323 PropagationInfo(const VarDecl *Var, ConsumedState TestsFor)
324 : InfoType(IT_VarTest) {
325 VarTest.Var = Var;
326 VarTest.TestsFor = TestsFor;
327 }
328
329 PropagationInfo(const BinaryOperator *Source, EffectiveOp EOp,
330 const VarTestResult &LTest, const VarTestResult &RTest)
331 : InfoType(IT_BinTest) {
332 BinTest.Source = Source;
333 BinTest.EOp = EOp;
334 BinTest.LTest = LTest;
335 BinTest.RTest = RTest;
336 }
337
338 PropagationInfo(const BinaryOperator *Source, EffectiveOp EOp,
339 const VarDecl *LVar, ConsumedState LTestsFor,
340 const VarDecl *RVar, ConsumedState RTestsFor)
341 : InfoType(IT_BinTest) {
342 BinTest.Source = Source;
343 BinTest.EOp = EOp;
344 BinTest.LTest.Var = LVar;
345 BinTest.LTest.TestsFor = LTestsFor;
346 BinTest.RTest.Var = RVar;
347 BinTest.RTest.TestsFor = RTestsFor;
348 }
349
350 PropagationInfo(ConsumedState State)
351 : InfoType(IT_State), State(State) {}
352 PropagationInfo(const VarDecl *Var) : InfoType(IT_Var), Var(Var) {}
353 PropagationInfo(const CXXBindTemporaryExpr *Tmp)
354 : InfoType(IT_Tmp), Tmp(Tmp) {}
355
356 const ConsumedState &getState() const {
357 assert(InfoType == IT_State);
358 return State;
359 }
360
361 const VarTestResult &getVarTest() const {
362 assert(InfoType == IT_VarTest);
363 return VarTest;
364 }
365
366 const VarTestResult &getLTest() const {
367 assert(InfoType == IT_BinTest);
368 return BinTest.LTest;
369 }
370
371 const VarTestResult &getRTest() const {
372 assert(InfoType == IT_BinTest);
373 return BinTest.RTest;
374 }
375
376 const VarDecl *getVar() const {
377 assert(InfoType == IT_Var);
378 return Var;
379 }
380
381 const CXXBindTemporaryExpr *getTmp() const {
382 assert(InfoType == IT_Tmp);
383 return Tmp;
384 }
385
386 ConsumedState getAsState(const ConsumedStateMap *StateMap) const {
387 assert(isVar() || isTmp() || isState());
388
389 if (isVar())
390 return StateMap->getState(Var: Var);
391 else if (isTmp())
392 return StateMap->getState(Tmp: Tmp);
393 else if (isState())
394 return State;
395 else
396 return CS_None;
397 }
398
399 EffectiveOp testEffectiveOp() const {
400 assert(InfoType == IT_BinTest);
401 return BinTest.EOp;
402 }
403
404 const BinaryOperator * testSourceNode() const {
405 assert(InfoType == IT_BinTest);
406 return BinTest.Source;
407 }
408
409 bool isValid() const { return InfoType != IT_None; }
410 bool isState() const { return InfoType == IT_State; }
411 bool isVarTest() const { return InfoType == IT_VarTest; }
412 bool isBinTest() const { return InfoType == IT_BinTest; }
413 bool isVar() const { return InfoType == IT_Var; }
414 bool isTmp() const { return InfoType == IT_Tmp; }
415
416 bool isTest() const {
417 return InfoType == IT_VarTest || InfoType == IT_BinTest;
418 }
419
420 bool isPointerToValue() const {
421 return InfoType == IT_Var || InfoType == IT_Tmp;
422 }
423
424 PropagationInfo invertTest() const {
425 assert(InfoType == IT_VarTest || InfoType == IT_BinTest);
426
427 if (InfoType == IT_VarTest) {
428 return PropagationInfo(VarTest.Var,
429 invertConsumedUnconsumed(State: VarTest.TestsFor));
430
431 } else if (InfoType == IT_BinTest) {
432 return PropagationInfo(BinTest.Source,
433 BinTest.EOp == EO_And ? EO_Or : EO_And,
434 BinTest.LTest.Var, invertConsumedUnconsumed(State: BinTest.LTest.TestsFor),
435 BinTest.RTest.Var, invertConsumedUnconsumed(State: BinTest.RTest.TestsFor));
436 } else {
437 return {};
438 }
439 }
440};
441
442} // namespace consumed
443} // namespace clang
444
445static void
446setStateForVarOrTmp(ConsumedStateMap *StateMap, const PropagationInfo &PInfo,
447 ConsumedState State) {
448 assert(PInfo.isVar() || PInfo.isTmp());
449
450 if (PInfo.isVar())
451 StateMap->setState(Var: PInfo.getVar(), State);
452 else
453 StateMap->setState(Tmp: PInfo.getTmp(), State);
454}
455
456namespace clang {
457namespace consumed {
458
459class ConsumedStmtVisitor : public ConstStmtVisitor<ConsumedStmtVisitor> {
460 using MapType = llvm::DenseMap<const Stmt *, PropagationInfo>;
461 using PairType= std::pair<const Stmt *, PropagationInfo>;
462 using InfoEntry = MapType::iterator;
463 using ConstInfoEntry = MapType::const_iterator;
464
465 ConsumedAnalyzer &Analyzer;
466 ConsumedStateMap *StateMap;
467 MapType PropagationMap;
468
469 InfoEntry findInfo(const Expr *E) {
470 if (const auto Cleanups = dyn_cast<ExprWithCleanups>(Val: E))
471 if (!Cleanups->cleanupsHaveSideEffects())
472 E = Cleanups->getSubExpr();
473 return PropagationMap.find(E->IgnoreParens());
474 }
475
476 ConstInfoEntry findInfo(const Expr *E) const {
477 if (const auto Cleanups = dyn_cast<ExprWithCleanups>(Val: E))
478 if (!Cleanups->cleanupsHaveSideEffects())
479 E = Cleanups->getSubExpr();
480 return PropagationMap.find(E->IgnoreParens());
481 }
482
483 void insertInfo(const Expr *E, const PropagationInfo &PI) {
484 PropagationMap.insert(KV: PairType(E->IgnoreParens(), PI));
485 }
486
487 void forwardInfo(const Expr *From, const Expr *To);
488 void copyInfo(const Expr *From, const Expr *To, ConsumedState CS);
489 ConsumedState getInfo(const Expr *From);
490 void setInfo(const Expr *To, ConsumedState NS);
491 void propagateReturnType(const Expr *Call, const FunctionDecl *Fun);
492
493public:
494 void checkCallability(const PropagationInfo &PInfo,
495 const FunctionDecl *FunDecl,
496 SourceLocation BlameLoc);
497 bool handleCall(const CallExpr *Call, const Expr *ObjArg,
498 const FunctionDecl *FunD);
499
500 void VisitBinaryOperator(const BinaryOperator *BinOp);
501 void VisitCallExpr(const CallExpr *Call);
502 void VisitCastExpr(const CastExpr *Cast);
503 void VisitCXXBindTemporaryExpr(const CXXBindTemporaryExpr *Temp);
504 void VisitCXXConstructExpr(const CXXConstructExpr *Call);
505 void VisitCXXMemberCallExpr(const CXXMemberCallExpr *Call);
506 void VisitCXXOperatorCallExpr(const CXXOperatorCallExpr *Call);
507 void VisitDeclRefExpr(const DeclRefExpr *DeclRef);
508 void VisitDeclStmt(const DeclStmt *DelcS);
509 void VisitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *Temp);
510 void VisitMemberExpr(const MemberExpr *MExpr);
511 void VisitParmVarDecl(const ParmVarDecl *Param);
512 void VisitReturnStmt(const ReturnStmt *Ret);
513 void VisitUnaryOperator(const UnaryOperator *UOp);
514 void VisitVarDecl(const VarDecl *Var);
515
516 ConsumedStmtVisitor(ConsumedAnalyzer &Analyzer, ConsumedStateMap *StateMap)
517 : Analyzer(Analyzer), StateMap(StateMap) {}
518
519 PropagationInfo getInfo(const Expr *StmtNode) const {
520 ConstInfoEntry Entry = findInfo(E: StmtNode);
521
522 if (Entry != PropagationMap.end())
523 return Entry->second;
524 else
525 return {};
526 }
527
528 void reset(ConsumedStateMap *NewStateMap) {
529 StateMap = NewStateMap;
530 }
531};
532
533} // namespace consumed
534} // namespace clang
535
536void ConsumedStmtVisitor::forwardInfo(const Expr *From, const Expr *To) {
537 InfoEntry Entry = findInfo(E: From);
538 if (Entry != PropagationMap.end())
539 insertInfo(E: To, PI: Entry->second);
540}
541
542// Create a new state for To, which is initialized to the state of From.
543// If NS is not CS_None, sets the state of From to NS.
544void ConsumedStmtVisitor::copyInfo(const Expr *From, const Expr *To,
545 ConsumedState NS) {
546 InfoEntry Entry = findInfo(E: From);
547 if (Entry != PropagationMap.end()) {
548 PropagationInfo& PInfo = Entry->second;
549 ConsumedState CS = PInfo.getAsState(StateMap);
550 if (CS != CS_None)
551 insertInfo(E: To, PI: PropagationInfo(CS));
552 if (NS != CS_None && PInfo.isPointerToValue())
553 setStateForVarOrTmp(StateMap, PInfo, State: NS);
554 }
555}
556
557// Get the ConsumedState for From
558ConsumedState ConsumedStmtVisitor::getInfo(const Expr *From) {
559 InfoEntry Entry = findInfo(E: From);
560 if (Entry != PropagationMap.end()) {
561 PropagationInfo& PInfo = Entry->second;
562 return PInfo.getAsState(StateMap);
563 }
564 return CS_None;
565}
566
567// If we already have info for To then update it, otherwise create a new entry.
568void ConsumedStmtVisitor::setInfo(const Expr *To, ConsumedState NS) {
569 InfoEntry Entry = findInfo(E: To);
570 if (Entry != PropagationMap.end()) {
571 PropagationInfo& PInfo = Entry->second;
572 if (PInfo.isPointerToValue())
573 setStateForVarOrTmp(StateMap, PInfo, State: NS);
574 } else if (NS != CS_None) {
575 insertInfo(E: To, PI: PropagationInfo(NS));
576 }
577}
578
579void ConsumedStmtVisitor::checkCallability(const PropagationInfo &PInfo,
580 const FunctionDecl *FunDecl,
581 SourceLocation BlameLoc) {
582 assert(!PInfo.isTest());
583
584 const CallableWhenAttr *CWAttr = FunDecl->getAttr<CallableWhenAttr>();
585 if (!CWAttr)
586 return;
587
588 if (PInfo.isVar()) {
589 ConsumedState VarState = StateMap->getState(Var: PInfo.getVar());
590
591 if (VarState == CS_None || isCallableInState(CWAttr, VarState))
592 return;
593
594 Analyzer.WarningsHandler.warnUseInInvalidState(
595 MethodName: FunDecl->getNameAsString(), VariableName: PInfo.getVar()->getNameAsString(),
596 State: stateToString(State: VarState), Loc: BlameLoc);
597 } else {
598 ConsumedState TmpState = PInfo.getAsState(StateMap);
599
600 if (TmpState == CS_None || isCallableInState(CWAttr, TmpState))
601 return;
602
603 Analyzer.WarningsHandler.warnUseOfTempInInvalidState(
604 MethodName: FunDecl->getNameAsString(), State: stateToString(State: TmpState), Loc: BlameLoc);
605 }
606}
607
608// Factors out common behavior for function, method, and operator calls.
609// Check parameters and set parameter state if necessary.
610// Returns true if the state of ObjArg is set, or false otherwise.
611bool ConsumedStmtVisitor::handleCall(const CallExpr *Call, const Expr *ObjArg,
612 const FunctionDecl *FunD) {
613 unsigned Offset = 0;
614 if (isa<CXXOperatorCallExpr>(Val: Call) && isa<CXXMethodDecl>(Val: FunD))
615 Offset = 1; // first argument is 'this'
616
617 // check explicit parameters
618 for (unsigned Index = Offset; Index < Call->getNumArgs(); ++Index) {
619 // Skip variable argument lists.
620 if (Index - Offset >= FunD->getNumParams())
621 break;
622
623 const ParmVarDecl *Param = FunD->getParamDecl(i: Index - Offset);
624 QualType ParamType = Param->getType();
625
626 InfoEntry Entry = findInfo(E: Call->getArg(Arg: Index));
627
628 if (Entry == PropagationMap.end() || Entry->second.isTest())
629 continue;
630 PropagationInfo PInfo = Entry->second;
631
632 // Check that the parameter is in the correct state.
633 if (ParamTypestateAttr *PTA = Param->getAttr<ParamTypestateAttr>()) {
634 ConsumedState ParamState = PInfo.getAsState(StateMap);
635 ConsumedState ExpectedState = mapParamTypestateAttrState(PTA);
636
637 if (ParamState != ExpectedState)
638 Analyzer.WarningsHandler.warnParamTypestateMismatch(
639 LOC: Call->getArg(Arg: Index)->getExprLoc(),
640 ExpectedState: stateToString(State: ExpectedState), ObservedState: stateToString(State: ParamState));
641 }
642
643 if (!(Entry->second.isVar() || Entry->second.isTmp()))
644 continue;
645
646 // Adjust state on the caller side.
647 if (ReturnTypestateAttr *RT = Param->getAttr<ReturnTypestateAttr>())
648 setStateForVarOrTmp(StateMap, PInfo, mapReturnTypestateAttrState(RT));
649 else if (isRValueRef(ParamType) || isConsumableType(QT: ParamType))
650 setStateForVarOrTmp(StateMap, PInfo, State: consumed::CS_Consumed);
651 else if (isPointerOrRef(ParamType) &&
652 (!ParamType->getPointeeType().isConstQualified() ||
653 isSetOnReadPtrType(QT: ParamType)))
654 setStateForVarOrTmp(StateMap, PInfo, State: consumed::CS_Unknown);
655 }
656
657 if (!ObjArg)
658 return false;
659
660 // check implicit 'self' parameter, if present
661 InfoEntry Entry = findInfo(E: ObjArg);
662 if (Entry != PropagationMap.end()) {
663 PropagationInfo PInfo = Entry->second;
664 checkCallability(PInfo, FunDecl: FunD, BlameLoc: Call->getExprLoc());
665
666 if (SetTypestateAttr *STA = FunD->getAttr<SetTypestateAttr>()) {
667 if (PInfo.isVar()) {
668 StateMap->setState(PInfo.getVar(), mapSetTypestateAttrState(STA));
669 return true;
670 }
671 else if (PInfo.isTmp()) {
672 StateMap->setState(PInfo.getTmp(), mapSetTypestateAttrState(STA));
673 return true;
674 }
675 }
676 else if (isTestingFunction(FunDecl: FunD) && PInfo.isVar()) {
677 PropagationMap.insert(KV: PairType(Call,
678 PropagationInfo(PInfo.getVar(), testsFor(FunDecl: FunD))));
679 }
680 }
681 return false;
682}
683
684void ConsumedStmtVisitor::propagateReturnType(const Expr *Call,
685 const FunctionDecl *Fun) {
686 QualType RetType = Fun->getCallResultType();
687 if (RetType->isReferenceType())
688 RetType = RetType->getPointeeType();
689
690 if (isConsumableType(QT: RetType)) {
691 ConsumedState ReturnState;
692 if (ReturnTypestateAttr *RTA = Fun->getAttr<ReturnTypestateAttr>())
693 ReturnState = mapReturnTypestateAttrState(RTA);
694 else
695 ReturnState = mapConsumableAttrState(QT: RetType);
696
697 PropagationMap.insert(KV: PairType(Call, PropagationInfo(ReturnState)));
698 }
699}
700
701void ConsumedStmtVisitor::VisitBinaryOperator(const BinaryOperator *BinOp) {
702 switch (BinOp->getOpcode()) {
703 case BO_LAnd:
704 case BO_LOr : {
705 InfoEntry LEntry = findInfo(E: BinOp->getLHS()),
706 REntry = findInfo(E: BinOp->getRHS());
707
708 VarTestResult LTest, RTest;
709
710 if (LEntry != PropagationMap.end() && LEntry->second.isVarTest()) {
711 LTest = LEntry->second.getVarTest();
712 } else {
713 LTest.Var = nullptr;
714 LTest.TestsFor = CS_None;
715 }
716
717 if (REntry != PropagationMap.end() && REntry->second.isVarTest()) {
718 RTest = REntry->second.getVarTest();
719 } else {
720 RTest.Var = nullptr;
721 RTest.TestsFor = CS_None;
722 }
723
724 if (!(LTest.Var == nullptr && RTest.Var == nullptr))
725 PropagationMap.insert(KV: PairType(BinOp, PropagationInfo(BinOp,
726 static_cast<EffectiveOp>(BinOp->getOpcode() == BO_LOr), LTest, RTest)));
727 break;
728 }
729
730 case BO_PtrMemD:
731 case BO_PtrMemI:
732 forwardInfo(BinOp->getLHS(), BinOp);
733 break;
734
735 default:
736 break;
737 }
738}
739
740void ConsumedStmtVisitor::VisitCallExpr(const CallExpr *Call) {
741 const FunctionDecl *FunDecl = Call->getDirectCallee();
742 if (!FunDecl)
743 return;
744
745 // Special case for the std::move function.
746 // TODO: Make this more specific. (Deferred)
747 if (Call->isCallToStdMove()) {
748 copyInfo(Call->getArg(Arg: 0), Call, CS_Consumed);
749 return;
750 }
751
752 handleCall(Call, ObjArg: nullptr, FunD: FunDecl);
753 propagateReturnType(Call, FunDecl);
754}
755
756void ConsumedStmtVisitor::VisitCastExpr(const CastExpr *Cast) {
757 forwardInfo(Cast->getSubExpr(), Cast);
758}
759
760void ConsumedStmtVisitor::VisitCXXBindTemporaryExpr(
761 const CXXBindTemporaryExpr *Temp) {
762
763 InfoEntry Entry = findInfo(E: Temp->getSubExpr());
764
765 if (Entry != PropagationMap.end() && !Entry->second.isTest()) {
766 StateMap->setState(Tmp: Temp, State: Entry->second.getAsState(StateMap));
767 PropagationMap.insert(KV: PairType(Temp, PropagationInfo(Temp)));
768 }
769}
770
771void ConsumedStmtVisitor::VisitCXXConstructExpr(const CXXConstructExpr *Call) {
772 CXXConstructorDecl *Constructor = Call->getConstructor();
773
774 QualType ThisType = Constructor->getFunctionObjectParameterType();
775
776 if (!isConsumableType(QT: ThisType))
777 return;
778
779 // FIXME: What should happen if someone annotates the move constructor?
780 if (ReturnTypestateAttr *RTA = Constructor->getAttr<ReturnTypestateAttr>()) {
781 // TODO: Adjust state of args appropriately.
782 ConsumedState RetState = mapReturnTypestateAttrState(RTA);
783 PropagationMap.insert(KV: PairType(Call, PropagationInfo(RetState)));
784 } else if (Constructor->isDefaultConstructor()) {
785 PropagationMap.insert(KV: PairType(Call,
786 PropagationInfo(consumed::CS_Consumed)));
787 } else if (Constructor->isMoveConstructor()) {
788 copyInfo(Call->getArg(Arg: 0), Call, CS_Consumed);
789 } else if (Constructor->isCopyConstructor()) {
790 // Copy state from arg. If setStateOnRead then set arg to CS_Unknown.
791 ConsumedState NS =
792 isSetOnReadPtrType(QT: Constructor->getThisType()) ?
793 CS_Unknown : CS_None;
794 copyInfo(Call->getArg(Arg: 0), Call, NS);
795 } else {
796 // TODO: Adjust state of args appropriately.
797 ConsumedState RetState = mapConsumableAttrState(QT: ThisType);
798 PropagationMap.insert(KV: PairType(Call, PropagationInfo(RetState)));
799 }
800}
801
802void ConsumedStmtVisitor::VisitCXXMemberCallExpr(
803 const CXXMemberCallExpr *Call) {
804 CXXMethodDecl* MD = Call->getMethodDecl();
805 if (!MD)
806 return;
807
808 handleCall(Call, Call->getImplicitObjectArgument(), MD);
809 propagateReturnType(Call, MD);
810}
811
812void ConsumedStmtVisitor::VisitCXXOperatorCallExpr(
813 const CXXOperatorCallExpr *Call) {
814 const auto *FunDecl = dyn_cast_or_null<FunctionDecl>(Call->getDirectCallee());
815 if (!FunDecl) return;
816
817 if (Call->getOperator() == OO_Equal) {
818 ConsumedState CS = getInfo(Call->getArg(1));
819 if (!handleCall(Call, ObjArg: Call->getArg(0), FunD: FunDecl))
820 setInfo(To: Call->getArg(0), NS: CS);
821 return;
822 }
823
824 if (const auto *MCall = dyn_cast<CXXMemberCallExpr>(Val: Call))
825 handleCall(Call: MCall, ObjArg: MCall->getImplicitObjectArgument(), FunD: FunDecl);
826 else
827 handleCall(Call, ObjArg: Call->getArg(0), FunD: FunDecl);
828
829 propagateReturnType(Call, Fun: FunDecl);
830}
831
832void ConsumedStmtVisitor::VisitDeclRefExpr(const DeclRefExpr *DeclRef) {
833 if (const auto *Var = dyn_cast_or_null<VarDecl>(Val: DeclRef->getDecl()))
834 if (StateMap->getState(Var) != consumed::CS_None)
835 PropagationMap.insert(KV: PairType(DeclRef, PropagationInfo(Var)));
836}
837
838void ConsumedStmtVisitor::VisitDeclStmt(const DeclStmt *DeclS) {
839 for (const auto *DI : DeclS->decls())
840 if (isa<VarDecl>(Val: DI))
841 VisitVarDecl(Var: cast<VarDecl>(Val: DI));
842
843 if (DeclS->isSingleDecl())
844 if (const auto *Var = dyn_cast_or_null<VarDecl>(Val: DeclS->getSingleDecl()))
845 PropagationMap.insert(KV: PairType(DeclS, PropagationInfo(Var)));
846}
847
848void ConsumedStmtVisitor::VisitMaterializeTemporaryExpr(
849 const MaterializeTemporaryExpr *Temp) {
850 forwardInfo(Temp->getSubExpr(), Temp);
851}
852
853void ConsumedStmtVisitor::VisitMemberExpr(const MemberExpr *MExpr) {
854 forwardInfo(MExpr->getBase(), MExpr);
855}
856
857void ConsumedStmtVisitor::VisitParmVarDecl(const ParmVarDecl *Param) {
858 QualType ParamType = Param->getType();
859 ConsumedState ParamState = consumed::CS_None;
860
861 if (const ParamTypestateAttr *PTA = Param->getAttr<ParamTypestateAttr>())
862 ParamState = mapParamTypestateAttrState(PTA);
863 else if (isConsumableType(QT: ParamType))
864 ParamState = mapConsumableAttrState(QT: ParamType);
865 else if (isRValueRef(ParamType) &&
866 isConsumableType(QT: ParamType->getPointeeType()))
867 ParamState = mapConsumableAttrState(QT: ParamType->getPointeeType());
868 else if (ParamType->isReferenceType() &&
869 isConsumableType(QT: ParamType->getPointeeType()))
870 ParamState = consumed::CS_Unknown;
871
872 if (ParamState != CS_None)
873 StateMap->setState(Param, ParamState);
874}
875
876void ConsumedStmtVisitor::VisitReturnStmt(const ReturnStmt *Ret) {
877 ConsumedState ExpectedState = Analyzer.getExpectedReturnState();
878
879 if (ExpectedState != CS_None) {
880 InfoEntry Entry = findInfo(E: Ret->getRetValue());
881
882 if (Entry != PropagationMap.end()) {
883 ConsumedState RetState = Entry->second.getAsState(StateMap);
884
885 if (RetState != ExpectedState)
886 Analyzer.WarningsHandler.warnReturnTypestateMismatch(
887 Loc: Ret->getReturnLoc(), ExpectedState: stateToString(State: ExpectedState),
888 ObservedState: stateToString(State: RetState));
889 }
890 }
891
892 StateMap->checkParamsForReturnTypestate(BlameLoc: Ret->getBeginLoc(),
893 WarningsHandler&: Analyzer.WarningsHandler);
894}
895
896void ConsumedStmtVisitor::VisitUnaryOperator(const UnaryOperator *UOp) {
897 InfoEntry Entry = findInfo(E: UOp->getSubExpr());
898 if (Entry == PropagationMap.end()) return;
899
900 switch (UOp->getOpcode()) {
901 case UO_AddrOf:
902 PropagationMap.insert(KV: PairType(UOp, Entry->second));
903 break;
904
905 case UO_LNot:
906 if (Entry->second.isTest())
907 PropagationMap.insert(KV: PairType(UOp, Entry->second.invertTest()));
908 break;
909
910 default:
911 break;
912 }
913}
914
915// TODO: See if I need to check for reference types here.
916void ConsumedStmtVisitor::VisitVarDecl(const VarDecl *Var) {
917 if (isConsumableType(Var->getType())) {
918 if (Var->hasInit()) {
919 MapType::iterator VIT = findInfo(E: Var->getInit()->IgnoreImplicit());
920 if (VIT != PropagationMap.end()) {
921 PropagationInfo PInfo = VIT->second;
922 ConsumedState St = PInfo.getAsState(StateMap);
923
924 if (St != consumed::CS_None) {
925 StateMap->setState(Var, State: St);
926 return;
927 }
928 }
929 }
930 // Otherwise
931 StateMap->setState(Var, State: consumed::CS_Unknown);
932 }
933}
934
935static void splitVarStateForIf(const IfStmt *IfNode, const VarTestResult &Test,
936 ConsumedStateMap *ThenStates,
937 ConsumedStateMap *ElseStates) {
938 ConsumedState VarState = ThenStates->getState(Var: Test.Var);
939
940 if (VarState == CS_Unknown) {
941 ThenStates->setState(Var: Test.Var, State: Test.TestsFor);
942 ElseStates->setState(Var: Test.Var, State: invertConsumedUnconsumed(State: Test.TestsFor));
943 } else if (VarState == invertConsumedUnconsumed(State: Test.TestsFor)) {
944 ThenStates->markUnreachable();
945 } else if (VarState == Test.TestsFor) {
946 ElseStates->markUnreachable();
947 }
948}
949
950static void splitVarStateForIfBinOp(const PropagationInfo &PInfo,
951 ConsumedStateMap *ThenStates,
952 ConsumedStateMap *ElseStates) {
953 const VarTestResult &LTest = PInfo.getLTest(),
954 &RTest = PInfo.getRTest();
955
956 ConsumedState LState = LTest.Var ? ThenStates->getState(Var: LTest.Var) : CS_None,
957 RState = RTest.Var ? ThenStates->getState(Var: RTest.Var) : CS_None;
958
959 if (LTest.Var) {
960 if (PInfo.testEffectiveOp() == EO_And) {
961 if (LState == CS_Unknown) {
962 ThenStates->setState(Var: LTest.Var, State: LTest.TestsFor);
963 } else if (LState == invertConsumedUnconsumed(State: LTest.TestsFor)) {
964 ThenStates->markUnreachable();
965 } else if (LState == LTest.TestsFor && isKnownState(State: RState)) {
966 if (RState == RTest.TestsFor)
967 ElseStates->markUnreachable();
968 else
969 ThenStates->markUnreachable();
970 }
971 } else {
972 if (LState == CS_Unknown) {
973 ElseStates->setState(Var: LTest.Var,
974 State: invertConsumedUnconsumed(State: LTest.TestsFor));
975 } else if (LState == LTest.TestsFor) {
976 ElseStates->markUnreachable();
977 } else if (LState == invertConsumedUnconsumed(State: LTest.TestsFor) &&
978 isKnownState(State: RState)) {
979 if (RState == RTest.TestsFor)
980 ElseStates->markUnreachable();
981 else
982 ThenStates->markUnreachable();
983 }
984 }
985 }
986
987 if (RTest.Var) {
988 if (PInfo.testEffectiveOp() == EO_And) {
989 if (RState == CS_Unknown)
990 ThenStates->setState(Var: RTest.Var, State: RTest.TestsFor);
991 else if (RState == invertConsumedUnconsumed(State: RTest.TestsFor))
992 ThenStates->markUnreachable();
993 } else {
994 if (RState == CS_Unknown)
995 ElseStates->setState(Var: RTest.Var,
996 State: invertConsumedUnconsumed(State: RTest.TestsFor));
997 else if (RState == RTest.TestsFor)
998 ElseStates->markUnreachable();
999 }
1000 }
1001}
1002
1003bool ConsumedBlockInfo::allBackEdgesVisited(const CFGBlock *CurrBlock,
1004 const CFGBlock *TargetBlock) {
1005 assert(CurrBlock && "Block pointer must not be NULL");
1006 assert(TargetBlock && "TargetBlock pointer must not be NULL");
1007
1008 unsigned int CurrBlockOrder = VisitOrder[CurrBlock->getBlockID()];
1009 for (CFGBlock::const_pred_iterator PI = TargetBlock->pred_begin(),
1010 PE = TargetBlock->pred_end(); PI != PE; ++PI) {
1011 if (*PI && CurrBlockOrder < VisitOrder[(*PI)->getBlockID()] )
1012 return false;
1013 }
1014 return true;
1015}
1016
1017void ConsumedBlockInfo::addInfo(
1018 const CFGBlock *Block, ConsumedStateMap *StateMap,
1019 std::unique_ptr<ConsumedStateMap> &OwnedStateMap) {
1020 assert(Block && "Block pointer must not be NULL");
1021
1022 auto &Entry = StateMapsArray[Block->getBlockID()];
1023
1024 if (Entry) {
1025 Entry->intersect(Other: *StateMap);
1026 } else if (OwnedStateMap)
1027 Entry = std::move(OwnedStateMap);
1028 else
1029 Entry = std::make_unique<ConsumedStateMap>(args&: *StateMap);
1030}
1031
1032void ConsumedBlockInfo::addInfo(const CFGBlock *Block,
1033 std::unique_ptr<ConsumedStateMap> StateMap) {
1034 assert(Block && "Block pointer must not be NULL");
1035
1036 auto &Entry = StateMapsArray[Block->getBlockID()];
1037
1038 if (Entry) {
1039 Entry->intersect(Other: *StateMap);
1040 } else {
1041 Entry = std::move(StateMap);
1042 }
1043}
1044
1045ConsumedStateMap* ConsumedBlockInfo::borrowInfo(const CFGBlock *Block) {
1046 assert(Block && "Block pointer must not be NULL");
1047 assert(StateMapsArray[Block->getBlockID()] && "Block has no block info");
1048
1049 return StateMapsArray[Block->getBlockID()].get();
1050}
1051
1052void ConsumedBlockInfo::discardInfo(const CFGBlock *Block) {
1053 StateMapsArray[Block->getBlockID()] = nullptr;
1054}
1055
1056std::unique_ptr<ConsumedStateMap>
1057ConsumedBlockInfo::getInfo(const CFGBlock *Block) {
1058 assert(Block && "Block pointer must not be NULL");
1059
1060 auto &Entry = StateMapsArray[Block->getBlockID()];
1061 return isBackEdgeTarget(Block) ? std::make_unique<ConsumedStateMap>(args&: *Entry)
1062 : std::move(Entry);
1063}
1064
1065bool ConsumedBlockInfo::isBackEdge(const CFGBlock *From, const CFGBlock *To) {
1066 assert(From && "From block must not be NULL");
1067 assert(To && "From block must not be NULL");
1068
1069 return VisitOrder[From->getBlockID()] > VisitOrder[To->getBlockID()];
1070}
1071
1072bool ConsumedBlockInfo::isBackEdgeTarget(const CFGBlock *Block) {
1073 assert(Block && "Block pointer must not be NULL");
1074
1075 // Anything with less than two predecessors can't be the target of a back
1076 // edge.
1077 if (Block->pred_size() < 2)
1078 return false;
1079
1080 unsigned int BlockVisitOrder = VisitOrder[Block->getBlockID()];
1081 for (CFGBlock::const_pred_iterator PI = Block->pred_begin(),
1082 PE = Block->pred_end(); PI != PE; ++PI) {
1083 if (*PI && BlockVisitOrder < VisitOrder[(*PI)->getBlockID()])
1084 return true;
1085 }
1086 return false;
1087}
1088
1089void ConsumedStateMap::checkParamsForReturnTypestate(SourceLocation BlameLoc,
1090 ConsumedWarningsHandlerBase &WarningsHandler) const {
1091
1092 for (const auto &DM : VarMap) {
1093 if (isa<ParmVarDecl>(Val: DM.first)) {
1094 const auto *Param = cast<ParmVarDecl>(Val: DM.first);
1095 const ReturnTypestateAttr *RTA = Param->getAttr<ReturnTypestateAttr>();
1096
1097 if (!RTA)
1098 continue;
1099
1100 ConsumedState ExpectedState = mapReturnTypestateAttrState(RTA);
1101 if (DM.second != ExpectedState)
1102 WarningsHandler.warnParamReturnTypestateMismatch(Loc: BlameLoc,
1103 VariableName: Param->getNameAsString(), ExpectedState: stateToString(State: ExpectedState),
1104 ObservedState: stateToString(State: DM.second));
1105 }
1106 }
1107}
1108
1109void ConsumedStateMap::clearTemporaries() {
1110 TmpMap.clear();
1111}
1112
1113ConsumedState ConsumedStateMap::getState(const VarDecl *Var) const {
1114 VarMapType::const_iterator Entry = VarMap.find(Val: Var);
1115
1116 if (Entry != VarMap.end())
1117 return Entry->second;
1118
1119 return CS_None;
1120}
1121
1122ConsumedState
1123ConsumedStateMap::getState(const CXXBindTemporaryExpr *Tmp) const {
1124 TmpMapType::const_iterator Entry = TmpMap.find(Val: Tmp);
1125
1126 if (Entry != TmpMap.end())
1127 return Entry->second;
1128
1129 return CS_None;
1130}
1131
1132void ConsumedStateMap::intersect(const ConsumedStateMap &Other) {
1133 ConsumedState LocalState;
1134
1135 if (this->From && this->From == Other.From && !Other.Reachable) {
1136 this->markUnreachable();
1137 return;
1138 }
1139
1140 for (const auto &DM : Other.VarMap) {
1141 LocalState = this->getState(Var: DM.first);
1142
1143 if (LocalState == CS_None)
1144 continue;
1145
1146 if (LocalState != DM.second)
1147 VarMap[DM.first] = CS_Unknown;
1148 }
1149}
1150
1151void ConsumedStateMap::intersectAtLoopHead(const CFGBlock *LoopHead,
1152 const CFGBlock *LoopBack, const ConsumedStateMap *LoopBackStates,
1153 ConsumedWarningsHandlerBase &WarningsHandler) {
1154
1155 ConsumedState LocalState;
1156 SourceLocation BlameLoc = getLastStmtLoc(Block: LoopBack);
1157
1158 for (const auto &DM : LoopBackStates->VarMap) {
1159 LocalState = this->getState(Var: DM.first);
1160
1161 if (LocalState == CS_None)
1162 continue;
1163
1164 if (LocalState != DM.second) {
1165 VarMap[DM.first] = CS_Unknown;
1166 WarningsHandler.warnLoopStateMismatch(Loc: BlameLoc,
1167 VariableName: DM.first->getNameAsString());
1168 }
1169 }
1170}
1171
1172void ConsumedStateMap::markUnreachable() {
1173 this->Reachable = false;
1174 VarMap.clear();
1175 TmpMap.clear();
1176}
1177
1178void ConsumedStateMap::setState(const VarDecl *Var, ConsumedState State) {
1179 VarMap[Var] = State;
1180}
1181
1182void ConsumedStateMap::setState(const CXXBindTemporaryExpr *Tmp,
1183 ConsumedState State) {
1184 TmpMap[Tmp] = State;
1185}
1186
1187void ConsumedStateMap::remove(const CXXBindTemporaryExpr *Tmp) {
1188 TmpMap.erase(Val: Tmp);
1189}
1190
1191bool ConsumedStateMap::operator!=(const ConsumedStateMap *Other) const {
1192 for (const auto &DM : Other->VarMap)
1193 if (this->getState(Var: DM.first) != DM.second)
1194 return true;
1195 return false;
1196}
1197
1198void ConsumedAnalyzer::determineExpectedReturnState(AnalysisDeclContext &AC,
1199 const FunctionDecl *D) {
1200 QualType ReturnType;
1201 if (const auto *Constructor = dyn_cast<CXXConstructorDecl>(Val: D)) {
1202 ReturnType = Constructor->getFunctionObjectParameterType();
1203 } else
1204 ReturnType = D->getCallResultType();
1205
1206 if (const ReturnTypestateAttr *RTSAttr = D->getAttr<ReturnTypestateAttr>()) {
1207 const CXXRecordDecl *RD = ReturnType->getAsCXXRecordDecl();
1208 if (!RD || !RD->hasAttr<ConsumableAttr>()) {
1209 // FIXME: This should be removed when template instantiation propagates
1210 // attributes at template specialization definition, not
1211 // declaration. When it is removed the test needs to be enabled
1212 // in SemaDeclAttr.cpp.
1213 WarningsHandler.warnReturnTypestateForUnconsumableType(
1214 Loc: RTSAttr->getLocation(), TypeName: ReturnType.getAsString());
1215 ExpectedReturnState = CS_None;
1216 } else
1217 ExpectedReturnState = mapReturnTypestateAttrState(RTSAttr);
1218 } else if (isConsumableType(QT: ReturnType)) {
1219 if (isAutoCastType(QT: ReturnType)) // We can auto-cast the state to the
1220 ExpectedReturnState = CS_None; // expected state.
1221 else
1222 ExpectedReturnState = mapConsumableAttrState(QT: ReturnType);
1223 }
1224 else
1225 ExpectedReturnState = CS_None;
1226}
1227
1228bool ConsumedAnalyzer::splitState(const CFGBlock *CurrBlock,
1229 const ConsumedStmtVisitor &Visitor) {
1230 std::unique_ptr<ConsumedStateMap> FalseStates(
1231 new ConsumedStateMap(*CurrStates));
1232 PropagationInfo PInfo;
1233
1234 if (const auto *IfNode =
1235 dyn_cast_or_null<IfStmt>(Val: CurrBlock->getTerminator().getStmt())) {
1236 const Expr *Cond = IfNode->getCond();
1237
1238 PInfo = Visitor.getInfo(StmtNode: Cond);
1239 if (!PInfo.isValid() && isa<BinaryOperator>(Val: Cond))
1240 PInfo = Visitor.getInfo(StmtNode: cast<BinaryOperator>(Val: Cond)->getRHS());
1241
1242 if (PInfo.isVarTest()) {
1243 CurrStates->setSource(Cond);
1244 FalseStates->setSource(Cond);
1245 splitVarStateForIf(IfNode, Test: PInfo.getVarTest(), ThenStates: CurrStates.get(),
1246 ElseStates: FalseStates.get());
1247 } else if (PInfo.isBinTest()) {
1248 CurrStates->setSource(PInfo.testSourceNode());
1249 FalseStates->setSource(PInfo.testSourceNode());
1250 splitVarStateForIfBinOp(PInfo, ThenStates: CurrStates.get(), ElseStates: FalseStates.get());
1251 } else {
1252 return false;
1253 }
1254 } else if (const auto *BinOp =
1255 dyn_cast_or_null<BinaryOperator>(Val: CurrBlock->getTerminator().getStmt())) {
1256 PInfo = Visitor.getInfo(StmtNode: BinOp->getLHS());
1257 if (!PInfo.isVarTest()) {
1258 if ((BinOp = dyn_cast_or_null<BinaryOperator>(Val: BinOp->getLHS()))) {
1259 PInfo = Visitor.getInfo(StmtNode: BinOp->getRHS());
1260
1261 if (!PInfo.isVarTest())
1262 return false;
1263 } else {
1264 return false;
1265 }
1266 }
1267
1268 CurrStates->setSource(BinOp);
1269 FalseStates->setSource(BinOp);
1270
1271 const VarTestResult &Test = PInfo.getVarTest();
1272 ConsumedState VarState = CurrStates->getState(Var: Test.Var);
1273
1274 if (BinOp->getOpcode() == BO_LAnd) {
1275 if (VarState == CS_Unknown)
1276 CurrStates->setState(Var: Test.Var, State: Test.TestsFor);
1277 else if (VarState == invertConsumedUnconsumed(State: Test.TestsFor))
1278 CurrStates->markUnreachable();
1279
1280 } else if (BinOp->getOpcode() == BO_LOr) {
1281 if (VarState == CS_Unknown)
1282 FalseStates->setState(Var: Test.Var,
1283 State: invertConsumedUnconsumed(State: Test.TestsFor));
1284 else if (VarState == Test.TestsFor)
1285 FalseStates->markUnreachable();
1286 }
1287 } else {
1288 return false;
1289 }
1290
1291 CFGBlock::const_succ_iterator SI = CurrBlock->succ_begin();
1292
1293 if (*SI)
1294 BlockInfo.addInfo(Block: *SI, StateMap: std::move(CurrStates));
1295 else
1296 CurrStates = nullptr;
1297
1298 if (*++SI)
1299 BlockInfo.addInfo(Block: *SI, StateMap: std::move(FalseStates));
1300
1301 return true;
1302}
1303
1304void ConsumedAnalyzer::run(AnalysisDeclContext &AC) {
1305 const auto *D = dyn_cast_or_null<FunctionDecl>(Val: AC.getDecl());
1306 if (!D)
1307 return;
1308
1309 CFG *CFGraph = AC.getCFG();
1310 if (!CFGraph)
1311 return;
1312
1313 determineExpectedReturnState(AC, D);
1314
1315 PostOrderCFGView *SortedGraph = AC.getAnalysis<PostOrderCFGView>();
1316 // AC.getCFG()->viewCFG(LangOptions());
1317
1318 BlockInfo = ConsumedBlockInfo(CFGraph->getNumBlockIDs(), SortedGraph);
1319
1320 CurrStates = std::make_unique<ConsumedStateMap>();
1321 ConsumedStmtVisitor Visitor(*this, CurrStates.get());
1322
1323 // Add all trackable parameters to the state map.
1324 for (const auto *PI : D->parameters())
1325 Visitor.VisitParmVarDecl(Param: PI);
1326
1327 // Visit all of the function's basic blocks.
1328 for (const auto *CurrBlock : *SortedGraph) {
1329 if (!CurrStates)
1330 CurrStates = BlockInfo.getInfo(Block: CurrBlock);
1331
1332 if (!CurrStates) {
1333 continue;
1334 } else if (!CurrStates->isReachable()) {
1335 CurrStates = nullptr;
1336 continue;
1337 }
1338
1339 Visitor.reset(NewStateMap: CurrStates.get());
1340
1341 // Visit all of the basic block's statements.
1342 for (const auto &B : *CurrBlock) {
1343 switch (B.getKind()) {
1344 case CFGElement::Statement:
1345 Visitor.Visit(B.castAs<CFGStmt>().getStmt());
1346 break;
1347
1348 case CFGElement::TemporaryDtor: {
1349 const CFGTemporaryDtor &DTor = B.castAs<CFGTemporaryDtor>();
1350 const CXXBindTemporaryExpr *BTE = DTor.getBindTemporaryExpr();
1351
1352 Visitor.checkCallability(PInfo: PropagationInfo(BTE),
1353 FunDecl: DTor.getDestructorDecl(astContext&: AC.getASTContext()),
1354 BlameLoc: BTE->getExprLoc());
1355 CurrStates->remove(Tmp: BTE);
1356 break;
1357 }
1358
1359 case CFGElement::AutomaticObjectDtor: {
1360 const CFGAutomaticObjDtor &DTor = B.castAs<CFGAutomaticObjDtor>();
1361 SourceLocation Loc = DTor.getTriggerStmt()->getEndLoc();
1362 const VarDecl *Var = DTor.getVarDecl();
1363
1364 Visitor.checkCallability(PropagationInfo(Var),
1365 DTor.getDestructorDecl(astContext&: AC.getASTContext()),
1366 Loc);
1367 break;
1368 }
1369
1370 default:
1371 break;
1372 }
1373 }
1374
1375 // TODO: Handle other forms of branching with precision, including while-
1376 // and for-loops. (Deferred)
1377 if (!splitState(CurrBlock, Visitor)) {
1378 CurrStates->setSource(nullptr);
1379
1380 if (CurrBlock->succ_size() > 1 ||
1381 (CurrBlock->succ_size() == 1 &&
1382 (*CurrBlock->succ_begin())->pred_size() > 1)) {
1383
1384 auto *RawState = CurrStates.get();
1385
1386 for (CFGBlock::const_succ_iterator SI = CurrBlock->succ_begin(),
1387 SE = CurrBlock->succ_end(); SI != SE; ++SI) {
1388 if (*SI == nullptr) continue;
1389
1390 if (BlockInfo.isBackEdge(From: CurrBlock, To: *SI)) {
1391 BlockInfo.borrowInfo(Block: *SI)->intersectAtLoopHead(
1392 LoopHead: *SI, LoopBack: CurrBlock, LoopBackStates: RawState, WarningsHandler);
1393
1394 if (BlockInfo.allBackEdgesVisited(CurrBlock, TargetBlock: *SI))
1395 BlockInfo.discardInfo(Block: *SI);
1396 } else {
1397 BlockInfo.addInfo(Block: *SI, StateMap: RawState, OwnedStateMap&: CurrStates);
1398 }
1399 }
1400
1401 CurrStates = nullptr;
1402 }
1403 }
1404
1405 if (CurrBlock == &AC.getCFG()->getExit() &&
1406 D->getCallResultType()->isVoidType())
1407 CurrStates->checkParamsForReturnTypestate(BlameLoc: D->getLocation(),
1408 WarningsHandler);
1409 } // End of block iterator.
1410
1411 // Delete the last existing state map.
1412 CurrStates = nullptr;
1413
1414 WarningsHandler.emitDiagnostics();
1415}
1416

source code of clang/lib/Analysis/Consumed.cpp