1 //===- Consumed.cpp --------------------------------------------*- C++ --*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // A intra-procedural analysis for checking consumed properties. This is based,
11 // in part, on research on linear types.
13 //===----------------------------------------------------------------------===//
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/Attr.h"
17 #include "clang/AST/DeclCXX.h"
18 #include "clang/AST/ExprCXX.h"
19 #include "clang/AST/RecursiveASTVisitor.h"
20 #include "clang/AST/StmtCXX.h"
21 #include "clang/AST/StmtVisitor.h"
22 #include "clang/AST/Type.h"
23 #include "clang/Analysis/Analyses/Consumed.h"
24 #include "clang/Analysis/Analyses/PostOrderCFGView.h"
25 #include "clang/Analysis/AnalysisContext.h"
26 #include "clang/Analysis/CFG.h"
27 #include "clang/Basic/OperatorKinds.h"
28 #include "clang/Basic/SourceLocation.h"
29 #include "llvm/ADT/DenseMap.h"
30 #include "llvm/ADT/SmallVector.h"
31 #include "llvm/Support/Compiler.h"
32 #include "llvm/Support/raw_ostream.h"
35 // TODO: Adjust states of args to constructors in the same way that arguments to
36 // function calls are handled.
37 // TODO: Use information from tests in for- and while-loop conditional.
38 // TODO: Add notes about the actual and expected state for
39 // TODO: Correctly identify unreachable blocks when chaining boolean operators.
40 // TODO: Adjust the parser and AttributesList class to support lists of
42 // TODO: Warn about unreachable code.
43 // TODO: Switch to using a bitmap to track unreachable blocks.
44 // TODO: Handle variable definitions, e.g. bool valid = x.isValid();
45 // if (valid) ...; (Deferred)
46 // TODO: Take notes on state transitions to provide better warning messages.
48 // TODO: Test nested conditionals: A) Checking the same value multiple times,
49 // and 2) Checking different values. (Deferred)
51 using namespace clang;
52 using namespace consumed;
54 // Key method definition
55 ConsumedWarningsHandlerBase::~ConsumedWarningsHandlerBase() {}
57 static SourceLocation getFirstStmtLoc(const CFGBlock *Block) {
58 // Find the source location of the first statement in the block, if the block
60 for (const auto &B : *Block)
61 if (Optional<CFGStmt> CS = B.getAs<CFGStmt>())
62 return CS->getStmt()->getLocStart();
65 // If we have one successor, return the first statement in that block
66 if (Block->succ_size() == 1 && *Block->succ_begin())
67 return getFirstStmtLoc(*Block->succ_begin());
69 return SourceLocation();
72 static SourceLocation getLastStmtLoc(const CFGBlock *Block) {
73 // Find the source location of the last statement in the block, if the block
75 if (const Stmt *StmtNode = Block->getTerminator()) {
76 return StmtNode->getLocStart();
78 for (CFGBlock::const_reverse_iterator BI = Block->rbegin(),
79 BE = Block->rend(); BI != BE; ++BI) {
80 if (Optional<CFGStmt> CS = BI->getAs<CFGStmt>())
81 return CS->getStmt()->getLocStart();
85 // If we have one successor, return the first statement in that block
87 if (Block->succ_size() == 1 && *Block->succ_begin())
88 Loc = getFirstStmtLoc(*Block->succ_begin());
92 // If we have one predecessor, return the last statement in that block
93 if (Block->pred_size() == 1 && *Block->pred_begin())
94 return getLastStmtLoc(*Block->pred_begin());
99 static ConsumedState invertConsumedUnconsumed(ConsumedState State) {
104 return CS_Unconsumed;
110 llvm_unreachable("invalid enum");
113 static bool isCallableInState(const CallableWhenAttr *CWAttr,
114 ConsumedState State) {
116 for (const auto &S : CWAttr->callableStates()) {
117 ConsumedState MappedAttrState = CS_None;
120 case CallableWhenAttr::Unknown:
121 MappedAttrState = CS_Unknown;
124 case CallableWhenAttr::Unconsumed:
125 MappedAttrState = CS_Unconsumed;
128 case CallableWhenAttr::Consumed:
129 MappedAttrState = CS_Consumed;
133 if (MappedAttrState == State)
141 static bool isConsumableType(const QualType &QT) {
142 if (QT->isPointerType() || QT->isReferenceType())
145 if (const CXXRecordDecl *RD = QT->getAsCXXRecordDecl())
146 return RD->hasAttr<ConsumableAttr>();
151 static bool isAutoCastType(const QualType &QT) {
152 if (QT->isPointerType() || QT->isReferenceType())
155 if (const CXXRecordDecl *RD = QT->getAsCXXRecordDecl())
156 return RD->hasAttr<ConsumableAutoCastAttr>();
161 static bool isSetOnReadPtrType(const QualType &QT) {
162 if (const CXXRecordDecl *RD = QT->getPointeeCXXRecordDecl())
163 return RD->hasAttr<ConsumableSetOnReadAttr>();
168 static bool isKnownState(ConsumedState State) {
177 llvm_unreachable("invalid enum");
180 static bool isRValueRef(QualType ParamType) {
181 return ParamType->isRValueReferenceType();
184 static bool isTestingFunction(const FunctionDecl *FunDecl) {
185 return FunDecl->hasAttr<TestTypestateAttr>();
188 static bool isPointerOrRef(QualType ParamType) {
189 return ParamType->isPointerType() || ParamType->isReferenceType();
192 static ConsumedState mapConsumableAttrState(const QualType QT) {
193 assert(isConsumableType(QT));
195 const ConsumableAttr *CAttr =
196 QT->getAsCXXRecordDecl()->getAttr<ConsumableAttr>();
198 switch (CAttr->getDefaultState()) {
199 case ConsumableAttr::Unknown:
201 case ConsumableAttr::Unconsumed:
202 return CS_Unconsumed;
203 case ConsumableAttr::Consumed:
206 llvm_unreachable("invalid enum");
210 mapParamTypestateAttrState(const ParamTypestateAttr *PTAttr) {
211 switch (PTAttr->getParamState()) {
212 case ParamTypestateAttr::Unknown:
214 case ParamTypestateAttr::Unconsumed:
215 return CS_Unconsumed;
216 case ParamTypestateAttr::Consumed:
219 llvm_unreachable("invalid_enum");
223 mapReturnTypestateAttrState(const ReturnTypestateAttr *RTSAttr) {
224 switch (RTSAttr->getState()) {
225 case ReturnTypestateAttr::Unknown:
227 case ReturnTypestateAttr::Unconsumed:
228 return CS_Unconsumed;
229 case ReturnTypestateAttr::Consumed:
232 llvm_unreachable("invalid enum");
235 static ConsumedState mapSetTypestateAttrState(const SetTypestateAttr *STAttr) {
236 switch (STAttr->getNewState()) {
237 case SetTypestateAttr::Unknown:
239 case SetTypestateAttr::Unconsumed:
240 return CS_Unconsumed;
241 case SetTypestateAttr::Consumed:
244 llvm_unreachable("invalid_enum");
247 static StringRef stateToString(ConsumedState State) {
249 case consumed::CS_None:
252 case consumed::CS_Unknown:
255 case consumed::CS_Unconsumed:
258 case consumed::CS_Consumed:
261 llvm_unreachable("invalid enum");
264 static ConsumedState testsFor(const FunctionDecl *FunDecl) {
265 assert(isTestingFunction(FunDecl));
266 switch (FunDecl->getAttr<TestTypestateAttr>()->getTestState()) {
267 case TestTypestateAttr::Unconsumed:
268 return CS_Unconsumed;
269 case TestTypestateAttr::Consumed:
272 llvm_unreachable("invalid enum");
276 struct VarTestResult {
278 ConsumedState TestsFor;
280 } // end anonymous::VarTestResult
290 class PropagationInfo {
301 const BinaryOperator *Source;
309 VarTestResult VarTest;
311 const CXXBindTemporaryExpr *Tmp;
316 PropagationInfo() : InfoType(IT_None) {}
318 PropagationInfo(const VarTestResult &VarTest)
319 : InfoType(IT_VarTest), VarTest(VarTest) {}
321 PropagationInfo(const VarDecl *Var, ConsumedState TestsFor)
322 : InfoType(IT_VarTest) {
325 VarTest.TestsFor = TestsFor;
328 PropagationInfo(const BinaryOperator *Source, EffectiveOp EOp,
329 const VarTestResult <est, const VarTestResult &RTest)
330 : InfoType(IT_BinTest) {
332 BinTest.Source = Source;
334 BinTest.LTest = LTest;
335 BinTest.RTest = RTest;
338 PropagationInfo(const BinaryOperator *Source, EffectiveOp EOp,
339 const VarDecl *LVar, ConsumedState LTestsFor,
340 const VarDecl *RVar, ConsumedState RTestsFor)
341 : InfoType(IT_BinTest) {
343 BinTest.Source = Source;
345 BinTest.LTest.Var = LVar;
346 BinTest.LTest.TestsFor = LTestsFor;
347 BinTest.RTest.Var = RVar;
348 BinTest.RTest.TestsFor = RTestsFor;
351 PropagationInfo(ConsumedState State)
352 : InfoType(IT_State), State(State) {}
354 PropagationInfo(const VarDecl *Var) : InfoType(IT_Var), Var(Var) {}
355 PropagationInfo(const CXXBindTemporaryExpr *Tmp)
356 : InfoType(IT_Tmp), Tmp(Tmp) {}
358 const ConsumedState & getState() const {
359 assert(InfoType == IT_State);
363 const VarTestResult & getVarTest() const {
364 assert(InfoType == IT_VarTest);
368 const VarTestResult & getLTest() const {
369 assert(InfoType == IT_BinTest);
370 return BinTest.LTest;
373 const VarTestResult & getRTest() const {
374 assert(InfoType == IT_BinTest);
375 return BinTest.RTest;
378 const VarDecl * getVar() const {
379 assert(InfoType == IT_Var);
383 const CXXBindTemporaryExpr * getTmp() const {
384 assert(InfoType == IT_Tmp);
388 ConsumedState getAsState(const ConsumedStateMap *StateMap) const {
389 assert(isVar() || isTmp() || isState());
392 return StateMap->getState(Var);
394 return StateMap->getState(Tmp);
401 EffectiveOp testEffectiveOp() const {
402 assert(InfoType == IT_BinTest);
406 const BinaryOperator * testSourceNode() const {
407 assert(InfoType == IT_BinTest);
408 return BinTest.Source;
411 inline bool isValid() const { return InfoType != IT_None; }
412 inline bool isState() const { return InfoType == IT_State; }
413 inline bool isVarTest() const { return InfoType == IT_VarTest; }
414 inline bool isBinTest() const { return InfoType == IT_BinTest; }
415 inline bool isVar() const { return InfoType == IT_Var; }
416 inline bool isTmp() const { return InfoType == IT_Tmp; }
418 bool isTest() const {
419 return InfoType == IT_VarTest || InfoType == IT_BinTest;
422 bool isPointerToValue() const {
423 return InfoType == IT_Var || InfoType == IT_Tmp;
426 PropagationInfo invertTest() const {
427 assert(InfoType == IT_VarTest || InfoType == IT_BinTest);
429 if (InfoType == IT_VarTest) {
430 return PropagationInfo(VarTest.Var,
431 invertConsumedUnconsumed(VarTest.TestsFor));
433 } else if (InfoType == IT_BinTest) {
434 return PropagationInfo(BinTest.Source,
435 BinTest.EOp == EO_And ? EO_Or : EO_And,
436 BinTest.LTest.Var, invertConsumedUnconsumed(BinTest.LTest.TestsFor),
437 BinTest.RTest.Var, invertConsumedUnconsumed(BinTest.RTest.TestsFor));
439 return PropagationInfo();
445 setStateForVarOrTmp(ConsumedStateMap *StateMap, const PropagationInfo &PInfo,
446 ConsumedState State) {
448 assert(PInfo.isVar() || PInfo.isTmp());
451 StateMap->setState(PInfo.getVar(), State);
453 StateMap->setState(PInfo.getTmp(), State);
456 class ConsumedStmtVisitor : public ConstStmtVisitor<ConsumedStmtVisitor> {
458 typedef llvm::DenseMap<const Stmt *, PropagationInfo> MapType;
459 typedef std::pair<const Stmt *, PropagationInfo> PairType;
460 typedef MapType::iterator InfoEntry;
461 typedef MapType::const_iterator ConstInfoEntry;
463 AnalysisDeclContext &AC;
464 ConsumedAnalyzer &Analyzer;
465 ConsumedStateMap *StateMap;
466 MapType PropagationMap;
468 InfoEntry findInfo(const Expr *E) {
469 return PropagationMap.find(E->IgnoreParens());
471 ConstInfoEntry findInfo(const Expr *E) const {
472 return PropagationMap.find(E->IgnoreParens());
474 void insertInfo(const Expr *E, const PropagationInfo &PI) {
475 PropagationMap.insert(PairType(E->IgnoreParens(), PI));
478 void forwardInfo(const Expr *From, const Expr *To);
479 void copyInfo(const Expr *From, const Expr *To, ConsumedState CS);
480 ConsumedState getInfo(const Expr *From);
481 void setInfo(const Expr *To, ConsumedState NS);
482 void propagateReturnType(const Expr *Call, const FunctionDecl *Fun);
485 void checkCallability(const PropagationInfo &PInfo,
486 const FunctionDecl *FunDecl,
487 SourceLocation BlameLoc);
488 bool handleCall(const CallExpr *Call, const Expr *ObjArg,
489 const FunctionDecl *FunD);
491 void VisitBinaryOperator(const BinaryOperator *BinOp);
492 void VisitCallExpr(const CallExpr *Call);
493 void VisitCastExpr(const CastExpr *Cast);
494 void VisitCXXBindTemporaryExpr(const CXXBindTemporaryExpr *Temp);
495 void VisitCXXConstructExpr(const CXXConstructExpr *Call);
496 void VisitCXXMemberCallExpr(const CXXMemberCallExpr *Call);
497 void VisitCXXOperatorCallExpr(const CXXOperatorCallExpr *Call);
498 void VisitDeclRefExpr(const DeclRefExpr *DeclRef);
499 void VisitDeclStmt(const DeclStmt *DelcS);
500 void VisitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *Temp);
501 void VisitMemberExpr(const MemberExpr *MExpr);
502 void VisitParmVarDecl(const ParmVarDecl *Param);
503 void VisitReturnStmt(const ReturnStmt *Ret);
504 void VisitUnaryOperator(const UnaryOperator *UOp);
505 void VisitVarDecl(const VarDecl *Var);
507 ConsumedStmtVisitor(AnalysisDeclContext &AC, ConsumedAnalyzer &Analyzer,
508 ConsumedStateMap *StateMap)
509 : AC(AC), Analyzer(Analyzer), StateMap(StateMap) {}
511 PropagationInfo getInfo(const Expr *StmtNode) const {
512 ConstInfoEntry Entry = findInfo(StmtNode);
514 if (Entry != PropagationMap.end())
515 return Entry->second;
517 return PropagationInfo();
520 void reset(ConsumedStateMap *NewStateMap) {
521 StateMap = NewStateMap;
526 void ConsumedStmtVisitor::forwardInfo(const Expr *From, const Expr *To) {
527 InfoEntry Entry = findInfo(From);
528 if (Entry != PropagationMap.end())
529 insertInfo(To, Entry->second);
533 // Create a new state for To, which is initialized to the state of From.
534 // If NS is not CS_None, sets the state of From to NS.
535 void ConsumedStmtVisitor::copyInfo(const Expr *From, const Expr *To,
537 InfoEntry Entry = findInfo(From);
538 if (Entry != PropagationMap.end()) {
539 PropagationInfo& PInfo = Entry->second;
540 ConsumedState CS = PInfo.getAsState(StateMap);
542 insertInfo(To, PropagationInfo(CS));
543 if (NS != CS_None && PInfo.isPointerToValue())
544 setStateForVarOrTmp(StateMap, PInfo, NS);
549 // Get the ConsumedState for From
550 ConsumedState ConsumedStmtVisitor::getInfo(const Expr *From) {
551 InfoEntry Entry = findInfo(From);
552 if (Entry != PropagationMap.end()) {
553 PropagationInfo& PInfo = Entry->second;
554 return PInfo.getAsState(StateMap);
560 // If we already have info for To then update it, otherwise create a new entry.
561 void ConsumedStmtVisitor::setInfo(const Expr *To, ConsumedState NS) {
562 InfoEntry Entry = findInfo(To);
563 if (Entry != PropagationMap.end()) {
564 PropagationInfo& PInfo = Entry->second;
565 if (PInfo.isPointerToValue())
566 setStateForVarOrTmp(StateMap, PInfo, NS);
567 } else if (NS != CS_None) {
568 insertInfo(To, PropagationInfo(NS));
574 void ConsumedStmtVisitor::checkCallability(const PropagationInfo &PInfo,
575 const FunctionDecl *FunDecl,
576 SourceLocation BlameLoc) {
577 assert(!PInfo.isTest());
579 const CallableWhenAttr *CWAttr = FunDecl->getAttr<CallableWhenAttr>();
584 ConsumedState VarState = StateMap->getState(PInfo.getVar());
586 if (VarState == CS_None || isCallableInState(CWAttr, VarState))
589 Analyzer.WarningsHandler.warnUseInInvalidState(
590 FunDecl->getNameAsString(), PInfo.getVar()->getNameAsString(),
591 stateToString(VarState), BlameLoc);
594 ConsumedState TmpState = PInfo.getAsState(StateMap);
596 if (TmpState == CS_None || isCallableInState(CWAttr, TmpState))
599 Analyzer.WarningsHandler.warnUseOfTempInInvalidState(
600 FunDecl->getNameAsString(), stateToString(TmpState), BlameLoc);
605 // Factors out common behavior for function, method, and operator calls.
606 // Check parameters and set parameter state if necessary.
607 // Returns true if the state of ObjArg is set, or false otherwise.
608 bool ConsumedStmtVisitor::handleCall(const CallExpr *Call, const Expr *ObjArg,
609 const FunctionDecl *FunD) {
611 if (isa<CXXOperatorCallExpr>(Call) && isa<CXXMethodDecl>(FunD))
612 Offset = 1; // first argument is 'this'
614 // check explicit parameters
615 for (unsigned Index = Offset; Index < Call->getNumArgs(); ++Index) {
616 // Skip variable argument lists.
617 if (Index - Offset >= FunD->getNumParams())
620 const ParmVarDecl *Param = FunD->getParamDecl(Index - Offset);
621 QualType ParamType = Param->getType();
623 InfoEntry Entry = findInfo(Call->getArg(Index));
625 if (Entry == PropagationMap.end() || Entry->second.isTest())
627 PropagationInfo PInfo = Entry->second;
629 // Check that the parameter is in the correct state.
630 if (ParamTypestateAttr *PTA = Param->getAttr<ParamTypestateAttr>()) {
631 ConsumedState ParamState = PInfo.getAsState(StateMap);
632 ConsumedState ExpectedState = mapParamTypestateAttrState(PTA);
634 if (ParamState != ExpectedState)
635 Analyzer.WarningsHandler.warnParamTypestateMismatch(
636 Call->getArg(Index)->getExprLoc(),
637 stateToString(ExpectedState), stateToString(ParamState));
640 if (!(Entry->second.isVar() || Entry->second.isTmp()))
643 // Adjust state on the caller side.
644 if (isRValueRef(ParamType))
645 setStateForVarOrTmp(StateMap, PInfo, consumed::CS_Consumed);
646 else if (ReturnTypestateAttr *RT = Param->getAttr<ReturnTypestateAttr>())
647 setStateForVarOrTmp(StateMap, PInfo, mapReturnTypestateAttrState(RT));
648 else if (isPointerOrRef(ParamType) &&
649 (!ParamType->getPointeeType().isConstQualified() ||
650 isSetOnReadPtrType(ParamType)))
651 setStateForVarOrTmp(StateMap, PInfo, consumed::CS_Unknown);
657 // check implicit 'self' parameter, if present
658 InfoEntry Entry = findInfo(ObjArg);
659 if (Entry != PropagationMap.end()) {
660 PropagationInfo PInfo = Entry->second;
661 checkCallability(PInfo, FunD, Call->getExprLoc());
663 if (SetTypestateAttr *STA = FunD->getAttr<SetTypestateAttr>()) {
665 StateMap->setState(PInfo.getVar(), mapSetTypestateAttrState(STA));
668 else if (PInfo.isTmp()) {
669 StateMap->setState(PInfo.getTmp(), mapSetTypestateAttrState(STA));
673 else if (isTestingFunction(FunD) && PInfo.isVar()) {
674 PropagationMap.insert(PairType(Call,
675 PropagationInfo(PInfo.getVar(), testsFor(FunD))));
682 void ConsumedStmtVisitor::propagateReturnType(const Expr *Call,
683 const FunctionDecl *Fun) {
684 QualType RetType = Fun->getCallResultType();
685 if (RetType->isReferenceType())
686 RetType = RetType->getPointeeType();
688 if (isConsumableType(RetType)) {
689 ConsumedState ReturnState;
690 if (ReturnTypestateAttr *RTA = Fun->getAttr<ReturnTypestateAttr>())
691 ReturnState = mapReturnTypestateAttrState(RTA);
693 ReturnState = mapConsumableAttrState(RetType);
695 PropagationMap.insert(PairType(Call, PropagationInfo(ReturnState)));
700 void ConsumedStmtVisitor::VisitBinaryOperator(const BinaryOperator *BinOp) {
701 switch (BinOp->getOpcode()) {
704 InfoEntry LEntry = findInfo(BinOp->getLHS()),
705 REntry = findInfo(BinOp->getRHS());
707 VarTestResult LTest, RTest;
709 if (LEntry != PropagationMap.end() && LEntry->second.isVarTest()) {
710 LTest = LEntry->second.getVarTest();
714 LTest.TestsFor = CS_None;
717 if (REntry != PropagationMap.end() && REntry->second.isVarTest()) {
718 RTest = REntry->second.getVarTest();
722 RTest.TestsFor = CS_None;
725 if (!(LTest.Var == nullptr && RTest.Var == nullptr))
726 PropagationMap.insert(PairType(BinOp, PropagationInfo(BinOp,
727 static_cast<EffectiveOp>(BinOp->getOpcode() == BO_LOr), LTest, RTest)));
734 forwardInfo(BinOp->getLHS(), BinOp);
742 void ConsumedStmtVisitor::VisitCallExpr(const CallExpr *Call) {
743 const FunctionDecl *FunDecl = Call->getDirectCallee();
747 // Special case for the std::move function.
748 // TODO: Make this more specific. (Deferred)
749 if (Call->getNumArgs() == 1 && FunDecl->getNameAsString() == "move" &&
750 FunDecl->isInStdNamespace()) {
751 copyInfo(Call->getArg(0), Call, CS_Consumed);
755 handleCall(Call, nullptr, FunDecl);
756 propagateReturnType(Call, FunDecl);
759 void ConsumedStmtVisitor::VisitCastExpr(const CastExpr *Cast) {
760 forwardInfo(Cast->getSubExpr(), Cast);
763 void ConsumedStmtVisitor::VisitCXXBindTemporaryExpr(
764 const CXXBindTemporaryExpr *Temp) {
766 InfoEntry Entry = findInfo(Temp->getSubExpr());
768 if (Entry != PropagationMap.end() && !Entry->second.isTest()) {
769 StateMap->setState(Temp, Entry->second.getAsState(StateMap));
770 PropagationMap.insert(PairType(Temp, PropagationInfo(Temp)));
774 void ConsumedStmtVisitor::VisitCXXConstructExpr(const CXXConstructExpr *Call) {
775 CXXConstructorDecl *Constructor = Call->getConstructor();
777 ASTContext &CurrContext = AC.getASTContext();
778 QualType ThisType = Constructor->getThisType(CurrContext)->getPointeeType();
780 if (!isConsumableType(ThisType))
783 // FIXME: What should happen if someone annotates the move constructor?
784 if (ReturnTypestateAttr *RTA = Constructor->getAttr<ReturnTypestateAttr>()) {
785 // TODO: Adjust state of args appropriately.
786 ConsumedState RetState = mapReturnTypestateAttrState(RTA);
787 PropagationMap.insert(PairType(Call, PropagationInfo(RetState)));
788 } else if (Constructor->isDefaultConstructor()) {
789 PropagationMap.insert(PairType(Call,
790 PropagationInfo(consumed::CS_Consumed)));
791 } else if (Constructor->isMoveConstructor()) {
792 copyInfo(Call->getArg(0), Call, CS_Consumed);
793 } else if (Constructor->isCopyConstructor()) {
794 // Copy state from arg. If setStateOnRead then set arg to CS_Unknown.
796 isSetOnReadPtrType(Constructor->getThisType(CurrContext)) ?
797 CS_Unknown : CS_None;
798 copyInfo(Call->getArg(0), Call, NS);
800 // TODO: Adjust state of args appropriately.
801 ConsumedState RetState = mapConsumableAttrState(ThisType);
802 PropagationMap.insert(PairType(Call, PropagationInfo(RetState)));
807 void ConsumedStmtVisitor::VisitCXXMemberCallExpr(
808 const CXXMemberCallExpr *Call) {
809 CXXMethodDecl* MD = Call->getMethodDecl();
813 handleCall(Call, Call->getImplicitObjectArgument(), MD);
814 propagateReturnType(Call, MD);
818 void ConsumedStmtVisitor::VisitCXXOperatorCallExpr(
819 const CXXOperatorCallExpr *Call) {
821 const FunctionDecl *FunDecl =
822 dyn_cast_or_null<FunctionDecl>(Call->getDirectCallee());
823 if (!FunDecl) return;
825 if (Call->getOperator() == OO_Equal) {
826 ConsumedState CS = getInfo(Call->getArg(1));
827 if (!handleCall(Call, Call->getArg(0), FunDecl))
828 setInfo(Call->getArg(0), CS);
832 if (const CXXMemberCallExpr *MCall = dyn_cast<CXXMemberCallExpr>(Call))
833 handleCall(MCall, MCall->getImplicitObjectArgument(), FunDecl);
835 handleCall(Call, Call->getArg(0), FunDecl);
837 propagateReturnType(Call, FunDecl);
840 void ConsumedStmtVisitor::VisitDeclRefExpr(const DeclRefExpr *DeclRef) {
841 if (const VarDecl *Var = dyn_cast_or_null<VarDecl>(DeclRef->getDecl()))
842 if (StateMap->getState(Var) != consumed::CS_None)
843 PropagationMap.insert(PairType(DeclRef, PropagationInfo(Var)));
846 void ConsumedStmtVisitor::VisitDeclStmt(const DeclStmt *DeclS) {
847 for (const auto *DI : DeclS->decls())
848 if (isa<VarDecl>(DI))
849 VisitVarDecl(cast<VarDecl>(DI));
851 if (DeclS->isSingleDecl())
852 if (const VarDecl *Var = dyn_cast_or_null<VarDecl>(DeclS->getSingleDecl()))
853 PropagationMap.insert(PairType(DeclS, PropagationInfo(Var)));
856 void ConsumedStmtVisitor::VisitMaterializeTemporaryExpr(
857 const MaterializeTemporaryExpr *Temp) {
859 forwardInfo(Temp->GetTemporaryExpr(), Temp);
862 void ConsumedStmtVisitor::VisitMemberExpr(const MemberExpr *MExpr) {
863 forwardInfo(MExpr->getBase(), MExpr);
867 void ConsumedStmtVisitor::VisitParmVarDecl(const ParmVarDecl *Param) {
868 QualType ParamType = Param->getType();
869 ConsumedState ParamState = consumed::CS_None;
871 if (const ParamTypestateAttr *PTA = Param->getAttr<ParamTypestateAttr>())
872 ParamState = mapParamTypestateAttrState(PTA);
873 else if (isConsumableType(ParamType))
874 ParamState = mapConsumableAttrState(ParamType);
875 else if (isRValueRef(ParamType) &&
876 isConsumableType(ParamType->getPointeeType()))
877 ParamState = mapConsumableAttrState(ParamType->getPointeeType());
878 else if (ParamType->isReferenceType() &&
879 isConsumableType(ParamType->getPointeeType()))
880 ParamState = consumed::CS_Unknown;
882 if (ParamState != CS_None)
883 StateMap->setState(Param, ParamState);
886 void ConsumedStmtVisitor::VisitReturnStmt(const ReturnStmt *Ret) {
887 ConsumedState ExpectedState = Analyzer.getExpectedReturnState();
889 if (ExpectedState != CS_None) {
890 InfoEntry Entry = findInfo(Ret->getRetValue());
892 if (Entry != PropagationMap.end()) {
893 ConsumedState RetState = Entry->second.getAsState(StateMap);
895 if (RetState != ExpectedState)
896 Analyzer.WarningsHandler.warnReturnTypestateMismatch(
897 Ret->getReturnLoc(), stateToString(ExpectedState),
898 stateToString(RetState));
902 StateMap->checkParamsForReturnTypestate(Ret->getLocStart(),
903 Analyzer.WarningsHandler);
906 void ConsumedStmtVisitor::VisitUnaryOperator(const UnaryOperator *UOp) {
907 InfoEntry Entry = findInfo(UOp->getSubExpr());
908 if (Entry == PropagationMap.end()) return;
910 switch (UOp->getOpcode()) {
912 PropagationMap.insert(PairType(UOp, Entry->second));
916 if (Entry->second.isTest())
917 PropagationMap.insert(PairType(UOp, Entry->second.invertTest()));
925 // TODO: See if I need to check for reference types here.
926 void ConsumedStmtVisitor::VisitVarDecl(const VarDecl *Var) {
927 if (isConsumableType(Var->getType())) {
928 if (Var->hasInit()) {
929 MapType::iterator VIT = findInfo(Var->getInit()->IgnoreImplicit());
930 if (VIT != PropagationMap.end()) {
931 PropagationInfo PInfo = VIT->second;
932 ConsumedState St = PInfo.getAsState(StateMap);
934 if (St != consumed::CS_None) {
935 StateMap->setState(Var, St);
941 StateMap->setState(Var, consumed::CS_Unknown);
944 }} // end clang::consumed::ConsumedStmtVisitor
949 static void splitVarStateForIf(const IfStmt *IfNode, const VarTestResult &Test,
950 ConsumedStateMap *ThenStates,
951 ConsumedStateMap *ElseStates) {
952 ConsumedState VarState = ThenStates->getState(Test.Var);
954 if (VarState == CS_Unknown) {
955 ThenStates->setState(Test.Var, Test.TestsFor);
956 ElseStates->setState(Test.Var, invertConsumedUnconsumed(Test.TestsFor));
958 } else if (VarState == invertConsumedUnconsumed(Test.TestsFor)) {
959 ThenStates->markUnreachable();
961 } else if (VarState == Test.TestsFor) {
962 ElseStates->markUnreachable();
966 static void splitVarStateForIfBinOp(const PropagationInfo &PInfo,
967 ConsumedStateMap *ThenStates,
968 ConsumedStateMap *ElseStates) {
969 const VarTestResult <est = PInfo.getLTest(),
970 &RTest = PInfo.getRTest();
972 ConsumedState LState = LTest.Var ? ThenStates->getState(LTest.Var) : CS_None,
973 RState = RTest.Var ? ThenStates->getState(RTest.Var) : CS_None;
976 if (PInfo.testEffectiveOp() == EO_And) {
977 if (LState == CS_Unknown) {
978 ThenStates->setState(LTest.Var, LTest.TestsFor);
980 } else if (LState == invertConsumedUnconsumed(LTest.TestsFor)) {
981 ThenStates->markUnreachable();
983 } else if (LState == LTest.TestsFor && isKnownState(RState)) {
984 if (RState == RTest.TestsFor)
985 ElseStates->markUnreachable();
987 ThenStates->markUnreachable();
991 if (LState == CS_Unknown) {
992 ElseStates->setState(LTest.Var,
993 invertConsumedUnconsumed(LTest.TestsFor));
995 } else if (LState == LTest.TestsFor) {
996 ElseStates->markUnreachable();
998 } else if (LState == invertConsumedUnconsumed(LTest.TestsFor) &&
999 isKnownState(RState)) {
1001 if (RState == RTest.TestsFor)
1002 ElseStates->markUnreachable();
1004 ThenStates->markUnreachable();
1010 if (PInfo.testEffectiveOp() == EO_And) {
1011 if (RState == CS_Unknown)
1012 ThenStates->setState(RTest.Var, RTest.TestsFor);
1013 else if (RState == invertConsumedUnconsumed(RTest.TestsFor))
1014 ThenStates->markUnreachable();
1017 if (RState == CS_Unknown)
1018 ElseStates->setState(RTest.Var,
1019 invertConsumedUnconsumed(RTest.TestsFor));
1020 else if (RState == RTest.TestsFor)
1021 ElseStates->markUnreachable();
1026 bool ConsumedBlockInfo::allBackEdgesVisited(const CFGBlock *CurrBlock,
1027 const CFGBlock *TargetBlock) {
1029 assert(CurrBlock && "Block pointer must not be NULL");
1030 assert(TargetBlock && "TargetBlock pointer must not be NULL");
1032 unsigned int CurrBlockOrder = VisitOrder[CurrBlock->getBlockID()];
1033 for (CFGBlock::const_pred_iterator PI = TargetBlock->pred_begin(),
1034 PE = TargetBlock->pred_end(); PI != PE; ++PI) {
1035 if (*PI && CurrBlockOrder < VisitOrder[(*PI)->getBlockID()] )
1041 void ConsumedBlockInfo::addInfo(const CFGBlock *Block,
1042 ConsumedStateMap *StateMap,
1043 bool &AlreadyOwned) {
1045 assert(Block && "Block pointer must not be NULL");
1047 ConsumedStateMap *Entry = StateMapsArray[Block->getBlockID()];
1050 Entry->intersect(StateMap);
1052 } else if (AlreadyOwned) {
1053 StateMapsArray[Block->getBlockID()] = new ConsumedStateMap(*StateMap);
1056 StateMapsArray[Block->getBlockID()] = StateMap;
1057 AlreadyOwned = true;
1061 void ConsumedBlockInfo::addInfo(const CFGBlock *Block,
1062 ConsumedStateMap *StateMap) {
1064 assert(Block && "Block pointer must not be NULL");
1066 ConsumedStateMap *Entry = StateMapsArray[Block->getBlockID()];
1069 Entry->intersect(StateMap);
1073 StateMapsArray[Block->getBlockID()] = StateMap;
1077 ConsumedStateMap* ConsumedBlockInfo::borrowInfo(const CFGBlock *Block) {
1078 assert(Block && "Block pointer must not be NULL");
1079 assert(StateMapsArray[Block->getBlockID()] && "Block has no block info");
1081 return StateMapsArray[Block->getBlockID()];
1084 void ConsumedBlockInfo::discardInfo(const CFGBlock *Block) {
1085 unsigned int BlockID = Block->getBlockID();
1086 delete StateMapsArray[BlockID];
1087 StateMapsArray[BlockID] = nullptr;
1090 ConsumedStateMap* ConsumedBlockInfo::getInfo(const CFGBlock *Block) {
1091 assert(Block && "Block pointer must not be NULL");
1093 ConsumedStateMap *StateMap = StateMapsArray[Block->getBlockID()];
1094 if (isBackEdgeTarget(Block)) {
1095 return new ConsumedStateMap(*StateMap);
1097 StateMapsArray[Block->getBlockID()] = nullptr;
1102 bool ConsumedBlockInfo::isBackEdge(const CFGBlock *From, const CFGBlock *To) {
1103 assert(From && "From block must not be NULL");
1104 assert(To && "From block must not be NULL");
1106 return VisitOrder[From->getBlockID()] > VisitOrder[To->getBlockID()];
1109 bool ConsumedBlockInfo::isBackEdgeTarget(const CFGBlock *Block) {
1110 assert(Block && "Block pointer must not be NULL");
1112 // Anything with less than two predecessors can't be the target of a back
1114 if (Block->pred_size() < 2)
1117 unsigned int BlockVisitOrder = VisitOrder[Block->getBlockID()];
1118 for (CFGBlock::const_pred_iterator PI = Block->pred_begin(),
1119 PE = Block->pred_end(); PI != PE; ++PI) {
1120 if (*PI && BlockVisitOrder < VisitOrder[(*PI)->getBlockID()])
1126 void ConsumedStateMap::checkParamsForReturnTypestate(SourceLocation BlameLoc,
1127 ConsumedWarningsHandlerBase &WarningsHandler) const {
1129 for (const auto &DM : VarMap) {
1130 if (isa<ParmVarDecl>(DM.first)) {
1131 const ParmVarDecl *Param = cast<ParmVarDecl>(DM.first);
1132 const ReturnTypestateAttr *RTA = Param->getAttr<ReturnTypestateAttr>();
1137 ConsumedState ExpectedState = mapReturnTypestateAttrState(RTA);
1138 if (DM.second != ExpectedState)
1139 WarningsHandler.warnParamReturnTypestateMismatch(BlameLoc,
1140 Param->getNameAsString(), stateToString(ExpectedState),
1141 stateToString(DM.second));
1146 void ConsumedStateMap::clearTemporaries() {
1150 ConsumedState ConsumedStateMap::getState(const VarDecl *Var) const {
1151 VarMapType::const_iterator Entry = VarMap.find(Var);
1153 if (Entry != VarMap.end())
1154 return Entry->second;
1160 ConsumedStateMap::getState(const CXXBindTemporaryExpr *Tmp) const {
1161 TmpMapType::const_iterator Entry = TmpMap.find(Tmp);
1163 if (Entry != TmpMap.end())
1164 return Entry->second;
1169 void ConsumedStateMap::intersect(const ConsumedStateMap *Other) {
1170 ConsumedState LocalState;
1172 if (this->From && this->From == Other->From && !Other->Reachable) {
1173 this->markUnreachable();
1177 for (const auto &DM : Other->VarMap) {
1178 LocalState = this->getState(DM.first);
1180 if (LocalState == CS_None)
1183 if (LocalState != DM.second)
1184 VarMap[DM.first] = CS_Unknown;
1188 void ConsumedStateMap::intersectAtLoopHead(const CFGBlock *LoopHead,
1189 const CFGBlock *LoopBack, const ConsumedStateMap *LoopBackStates,
1190 ConsumedWarningsHandlerBase &WarningsHandler) {
1192 ConsumedState LocalState;
1193 SourceLocation BlameLoc = getLastStmtLoc(LoopBack);
1195 for (const auto &DM : LoopBackStates->VarMap) {
1196 LocalState = this->getState(DM.first);
1198 if (LocalState == CS_None)
1201 if (LocalState != DM.second) {
1202 VarMap[DM.first] = CS_Unknown;
1203 WarningsHandler.warnLoopStateMismatch(BlameLoc,
1204 DM.first->getNameAsString());
1209 void ConsumedStateMap::markUnreachable() {
1210 this->Reachable = false;
1215 void ConsumedStateMap::setState(const VarDecl *Var, ConsumedState State) {
1216 VarMap[Var] = State;
1219 void ConsumedStateMap::setState(const CXXBindTemporaryExpr *Tmp,
1220 ConsumedState State) {
1221 TmpMap[Tmp] = State;
1224 void ConsumedStateMap::remove(const CXXBindTemporaryExpr *Tmp) {
1228 bool ConsumedStateMap::operator!=(const ConsumedStateMap *Other) const {
1229 for (const auto &DM : Other->VarMap)
1230 if (this->getState(DM.first) != DM.second)
1235 void ConsumedAnalyzer::determineExpectedReturnState(AnalysisDeclContext &AC,
1236 const FunctionDecl *D) {
1237 QualType ReturnType;
1238 if (const CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1239 ASTContext &CurrContext = AC.getASTContext();
1240 ReturnType = Constructor->getThisType(CurrContext)->getPointeeType();
1242 ReturnType = D->getCallResultType();
1244 if (const ReturnTypestateAttr *RTSAttr = D->getAttr<ReturnTypestateAttr>()) {
1245 const CXXRecordDecl *RD = ReturnType->getAsCXXRecordDecl();
1246 if (!RD || !RD->hasAttr<ConsumableAttr>()) {
1247 // FIXME: This should be removed when template instantiation propagates
1248 // attributes at template specialization definition, not
1249 // declaration. When it is removed the test needs to be enabled
1250 // in SemaDeclAttr.cpp.
1251 WarningsHandler.warnReturnTypestateForUnconsumableType(
1252 RTSAttr->getLocation(), ReturnType.getAsString());
1253 ExpectedReturnState = CS_None;
1255 ExpectedReturnState = mapReturnTypestateAttrState(RTSAttr);
1256 } else if (isConsumableType(ReturnType)) {
1257 if (isAutoCastType(ReturnType)) // We can auto-cast the state to the
1258 ExpectedReturnState = CS_None; // expected state.
1260 ExpectedReturnState = mapConsumableAttrState(ReturnType);
1263 ExpectedReturnState = CS_None;
1266 bool ConsumedAnalyzer::splitState(const CFGBlock *CurrBlock,
1267 const ConsumedStmtVisitor &Visitor) {
1269 std::unique_ptr<ConsumedStateMap> FalseStates(
1270 new ConsumedStateMap(*CurrStates));
1271 PropagationInfo PInfo;
1273 if (const IfStmt *IfNode =
1274 dyn_cast_or_null<IfStmt>(CurrBlock->getTerminator().getStmt())) {
1276 const Expr *Cond = IfNode->getCond();
1278 PInfo = Visitor.getInfo(Cond);
1279 if (!PInfo.isValid() && isa<BinaryOperator>(Cond))
1280 PInfo = Visitor.getInfo(cast<BinaryOperator>(Cond)->getRHS());
1282 if (PInfo.isVarTest()) {
1283 CurrStates->setSource(Cond);
1284 FalseStates->setSource(Cond);
1285 splitVarStateForIf(IfNode, PInfo.getVarTest(), CurrStates,
1288 } else if (PInfo.isBinTest()) {
1289 CurrStates->setSource(PInfo.testSourceNode());
1290 FalseStates->setSource(PInfo.testSourceNode());
1291 splitVarStateForIfBinOp(PInfo, CurrStates, FalseStates.get());
1297 } else if (const BinaryOperator *BinOp =
1298 dyn_cast_or_null<BinaryOperator>(CurrBlock->getTerminator().getStmt())) {
1300 PInfo = Visitor.getInfo(BinOp->getLHS());
1301 if (!PInfo.isVarTest()) {
1302 if ((BinOp = dyn_cast_or_null<BinaryOperator>(BinOp->getLHS()))) {
1303 PInfo = Visitor.getInfo(BinOp->getRHS());
1305 if (!PInfo.isVarTest())
1313 CurrStates->setSource(BinOp);
1314 FalseStates->setSource(BinOp);
1316 const VarTestResult &Test = PInfo.getVarTest();
1317 ConsumedState VarState = CurrStates->getState(Test.Var);
1319 if (BinOp->getOpcode() == BO_LAnd) {
1320 if (VarState == CS_Unknown)
1321 CurrStates->setState(Test.Var, Test.TestsFor);
1322 else if (VarState == invertConsumedUnconsumed(Test.TestsFor))
1323 CurrStates->markUnreachable();
1325 } else if (BinOp->getOpcode() == BO_LOr) {
1326 if (VarState == CS_Unknown)
1327 FalseStates->setState(Test.Var,
1328 invertConsumedUnconsumed(Test.TestsFor));
1329 else if (VarState == Test.TestsFor)
1330 FalseStates->markUnreachable();
1337 CFGBlock::const_succ_iterator SI = CurrBlock->succ_begin();
1340 BlockInfo.addInfo(*SI, CurrStates);
1345 BlockInfo.addInfo(*SI, FalseStates.release());
1347 CurrStates = nullptr;
1351 void ConsumedAnalyzer::run(AnalysisDeclContext &AC) {
1352 const FunctionDecl *D = dyn_cast_or_null<FunctionDecl>(AC.getDecl());
1356 CFG *CFGraph = AC.getCFG();
1360 determineExpectedReturnState(AC, D);
1362 PostOrderCFGView *SortedGraph = AC.getAnalysis<PostOrderCFGView>();
1363 // AC.getCFG()->viewCFG(LangOptions());
1365 BlockInfo = ConsumedBlockInfo(CFGraph->getNumBlockIDs(), SortedGraph);
1367 CurrStates = new ConsumedStateMap();
1368 ConsumedStmtVisitor Visitor(AC, *this, CurrStates);
1370 // Add all trackable parameters to the state map.
1371 for (const auto *PI : D->params())
1372 Visitor.VisitParmVarDecl(PI);
1374 // Visit all of the function's basic blocks.
1375 for (const auto *CurrBlock : *SortedGraph) {
1377 CurrStates = BlockInfo.getInfo(CurrBlock);
1382 } else if (!CurrStates->isReachable()) {
1384 CurrStates = nullptr;
1388 Visitor.reset(CurrStates);
1390 // Visit all of the basic block's statements.
1391 for (const auto &B : *CurrBlock) {
1392 switch (B.getKind()) {
1393 case CFGElement::Statement:
1394 Visitor.Visit(B.castAs<CFGStmt>().getStmt());
1397 case CFGElement::TemporaryDtor: {
1398 const CFGTemporaryDtor &DTor = B.castAs<CFGTemporaryDtor>();
1399 const CXXBindTemporaryExpr *BTE = DTor.getBindTemporaryExpr();
1401 Visitor.checkCallability(PropagationInfo(BTE),
1402 DTor.getDestructorDecl(AC.getASTContext()),
1404 CurrStates->remove(BTE);
1408 case CFGElement::AutomaticObjectDtor: {
1409 const CFGAutomaticObjDtor &DTor = B.castAs<CFGAutomaticObjDtor>();
1410 SourceLocation Loc = DTor.getTriggerStmt()->getLocEnd();
1411 const VarDecl *Var = DTor.getVarDecl();
1413 Visitor.checkCallability(PropagationInfo(Var),
1414 DTor.getDestructorDecl(AC.getASTContext()),
1424 // TODO: Handle other forms of branching with precision, including while-
1425 // and for-loops. (Deferred)
1426 if (!splitState(CurrBlock, Visitor)) {
1427 CurrStates->setSource(nullptr);
1429 if (CurrBlock->succ_size() > 1 ||
1430 (CurrBlock->succ_size() == 1 &&
1431 (*CurrBlock->succ_begin())->pred_size() > 1)) {
1433 bool OwnershipTaken = false;
1435 for (CFGBlock::const_succ_iterator SI = CurrBlock->succ_begin(),
1436 SE = CurrBlock->succ_end(); SI != SE; ++SI) {
1438 if (*SI == nullptr) continue;
1440 if (BlockInfo.isBackEdge(CurrBlock, *SI)) {
1441 BlockInfo.borrowInfo(*SI)->intersectAtLoopHead(*SI, CurrBlock,
1445 if (BlockInfo.allBackEdgesVisited(CurrBlock, *SI))
1446 BlockInfo.discardInfo(*SI);
1448 BlockInfo.addInfo(*SI, CurrStates, OwnershipTaken);
1452 if (!OwnershipTaken)
1455 CurrStates = nullptr;
1459 if (CurrBlock == &AC.getCFG()->getExit() &&
1460 D->getCallResultType()->isVoidType())
1461 CurrStates->checkParamsForReturnTypestate(D->getLocation(),
1463 } // End of block iterator.
1465 // Delete the last existing state map.
1468 WarningsHandler.emitDiagnostics();
1470 }} // end namespace clang::consumed