1 //===- Consumed.cpp --------------------------------------------*- C++ --*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // A intra-procedural analysis for checking consumed properties. This is based,
11 // in part, on research on linear types.
12 //
13 //===----------------------------------------------------------------------===//
14
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"
33 #include <memory>
34
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
41 // identifiers.
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.
47 // (Deferred)
48 // TODO: Test nested conditionals: A) Checking the same value multiple times,
49 // and 2) Checking different values. (Deferred)
50
51 using namespace clang;
52 using namespace consumed;
53
54 // Key method definition
~ConsumedWarningsHandlerBase()55 ConsumedWarningsHandlerBase::~ConsumedWarningsHandlerBase() {}
56
getFirstStmtLoc(const CFGBlock * Block)57 static SourceLocation getFirstStmtLoc(const CFGBlock *Block) {
58 // Find the source location of the first statement in the block, if the block
59 // is not empty.
60 for (const auto &B : *Block)
61 if (Optional<CFGStmt> CS = B.getAs<CFGStmt>())
62 return CS->getStmt()->getLocStart();
63
64 // Block is empty.
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());
68
69 return SourceLocation();
70 }
71
getLastStmtLoc(const CFGBlock * Block)72 static SourceLocation getLastStmtLoc(const CFGBlock *Block) {
73 // Find the source location of the last statement in the block, if the block
74 // is not empty.
75 if (const Stmt *StmtNode = Block->getTerminator()) {
76 return StmtNode->getLocStart();
77 } else {
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();
82 }
83 }
84
85 // If we have one successor, return the first statement in that block
86 SourceLocation Loc;
87 if (Block->succ_size() == 1 && *Block->succ_begin())
88 Loc = getFirstStmtLoc(*Block->succ_begin());
89 if (Loc.isValid())
90 return Loc;
91
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());
95
96 return Loc;
97 }
98
invertConsumedUnconsumed(ConsumedState State)99 static ConsumedState invertConsumedUnconsumed(ConsumedState State) {
100 switch (State) {
101 case CS_Unconsumed:
102 return CS_Consumed;
103 case CS_Consumed:
104 return CS_Unconsumed;
105 case CS_None:
106 return CS_None;
107 case CS_Unknown:
108 return CS_Unknown;
109 }
110 llvm_unreachable("invalid enum");
111 }
112
isCallableInState(const CallableWhenAttr * CWAttr,ConsumedState State)113 static bool isCallableInState(const CallableWhenAttr *CWAttr,
114 ConsumedState State) {
115
116 for (const auto &S : CWAttr->callableStates()) {
117 ConsumedState MappedAttrState = CS_None;
118
119 switch (S) {
120 case CallableWhenAttr::Unknown:
121 MappedAttrState = CS_Unknown;
122 break;
123
124 case CallableWhenAttr::Unconsumed:
125 MappedAttrState = CS_Unconsumed;
126 break;
127
128 case CallableWhenAttr::Consumed:
129 MappedAttrState = CS_Consumed;
130 break;
131 }
132
133 if (MappedAttrState == State)
134 return true;
135 }
136
137 return false;
138 }
139
140
isConsumableType(const QualType & QT)141 static bool isConsumableType(const QualType &QT) {
142 if (QT->isPointerType() || QT->isReferenceType())
143 return false;
144
145 if (const CXXRecordDecl *RD = QT->getAsCXXRecordDecl())
146 return RD->hasAttr<ConsumableAttr>();
147
148 return false;
149 }
150
isAutoCastType(const QualType & QT)151 static bool isAutoCastType(const QualType &QT) {
152 if (QT->isPointerType() || QT->isReferenceType())
153 return false;
154
155 if (const CXXRecordDecl *RD = QT->getAsCXXRecordDecl())
156 return RD->hasAttr<ConsumableAutoCastAttr>();
157
158 return false;
159 }
160
isSetOnReadPtrType(const QualType & QT)161 static bool isSetOnReadPtrType(const QualType &QT) {
162 if (const CXXRecordDecl *RD = QT->getPointeeCXXRecordDecl())
163 return RD->hasAttr<ConsumableSetOnReadAttr>();
164 return false;
165 }
166
167
isKnownState(ConsumedState State)168 static bool isKnownState(ConsumedState State) {
169 switch (State) {
170 case CS_Unconsumed:
171 case CS_Consumed:
172 return true;
173 case CS_None:
174 case CS_Unknown:
175 return false;
176 }
177 llvm_unreachable("invalid enum");
178 }
179
isRValueRef(QualType ParamType)180 static bool isRValueRef(QualType ParamType) {
181 return ParamType->isRValueReferenceType();
182 }
183
isTestingFunction(const FunctionDecl * FunDecl)184 static bool isTestingFunction(const FunctionDecl *FunDecl) {
185 return FunDecl->hasAttr<TestTypestateAttr>();
186 }
187
isPointerOrRef(QualType ParamType)188 static bool isPointerOrRef(QualType ParamType) {
189 return ParamType->isPointerType() || ParamType->isReferenceType();
190 }
191
mapConsumableAttrState(const QualType QT)192 static ConsumedState mapConsumableAttrState(const QualType QT) {
193 assert(isConsumableType(QT));
194
195 const ConsumableAttr *CAttr =
196 QT->getAsCXXRecordDecl()->getAttr<ConsumableAttr>();
197
198 switch (CAttr->getDefaultState()) {
199 case ConsumableAttr::Unknown:
200 return CS_Unknown;
201 case ConsumableAttr::Unconsumed:
202 return CS_Unconsumed;
203 case ConsumableAttr::Consumed:
204 return CS_Consumed;
205 }
206 llvm_unreachable("invalid enum");
207 }
208
209 static ConsumedState
mapParamTypestateAttrState(const ParamTypestateAttr * PTAttr)210 mapParamTypestateAttrState(const ParamTypestateAttr *PTAttr) {
211 switch (PTAttr->getParamState()) {
212 case ParamTypestateAttr::Unknown:
213 return CS_Unknown;
214 case ParamTypestateAttr::Unconsumed:
215 return CS_Unconsumed;
216 case ParamTypestateAttr::Consumed:
217 return CS_Consumed;
218 }
219 llvm_unreachable("invalid_enum");
220 }
221
222 static ConsumedState
mapReturnTypestateAttrState(const ReturnTypestateAttr * RTSAttr)223 mapReturnTypestateAttrState(const ReturnTypestateAttr *RTSAttr) {
224 switch (RTSAttr->getState()) {
225 case ReturnTypestateAttr::Unknown:
226 return CS_Unknown;
227 case ReturnTypestateAttr::Unconsumed:
228 return CS_Unconsumed;
229 case ReturnTypestateAttr::Consumed:
230 return CS_Consumed;
231 }
232 llvm_unreachable("invalid enum");
233 }
234
mapSetTypestateAttrState(const SetTypestateAttr * STAttr)235 static ConsumedState mapSetTypestateAttrState(const SetTypestateAttr *STAttr) {
236 switch (STAttr->getNewState()) {
237 case SetTypestateAttr::Unknown:
238 return CS_Unknown;
239 case SetTypestateAttr::Unconsumed:
240 return CS_Unconsumed;
241 case SetTypestateAttr::Consumed:
242 return CS_Consumed;
243 }
244 llvm_unreachable("invalid_enum");
245 }
246
stateToString(ConsumedState State)247 static StringRef stateToString(ConsumedState State) {
248 switch (State) {
249 case consumed::CS_None:
250 return "none";
251
252 case consumed::CS_Unknown:
253 return "unknown";
254
255 case consumed::CS_Unconsumed:
256 return "unconsumed";
257
258 case consumed::CS_Consumed:
259 return "consumed";
260 }
261 llvm_unreachable("invalid enum");
262 }
263
testsFor(const FunctionDecl * FunDecl)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:
270 return CS_Consumed;
271 }
272 llvm_unreachable("invalid enum");
273 }
274
275 namespace {
276 struct VarTestResult {
277 const VarDecl *Var;
278 ConsumedState TestsFor;
279 };
280 } // end anonymous::VarTestResult
281
282 namespace clang {
283 namespace consumed {
284
285 enum EffectiveOp {
286 EO_And,
287 EO_Or
288 };
289
290 class PropagationInfo {
291 enum {
292 IT_None,
293 IT_State,
294 IT_VarTest,
295 IT_BinTest,
296 IT_Var,
297 IT_Tmp
298 } InfoType;
299
300 struct BinTestTy {
301 const BinaryOperator *Source;
302 EffectiveOp EOp;
303 VarTestResult LTest;
304 VarTestResult RTest;
305 };
306
307 union {
308 ConsumedState State;
309 VarTestResult VarTest;
310 const VarDecl *Var;
311 const CXXBindTemporaryExpr *Tmp;
312 BinTestTy BinTest;
313 };
314
315 public:
PropagationInfo()316 PropagationInfo() : InfoType(IT_None) {}
317
PropagationInfo(const VarTestResult & VarTest)318 PropagationInfo(const VarTestResult &VarTest)
319 : InfoType(IT_VarTest), VarTest(VarTest) {}
320
PropagationInfo(const VarDecl * Var,ConsumedState TestsFor)321 PropagationInfo(const VarDecl *Var, ConsumedState TestsFor)
322 : InfoType(IT_VarTest) {
323
324 VarTest.Var = Var;
325 VarTest.TestsFor = TestsFor;
326 }
327
PropagationInfo(const BinaryOperator * Source,EffectiveOp EOp,const VarTestResult & LTest,const VarTestResult & RTest)328 PropagationInfo(const BinaryOperator *Source, EffectiveOp EOp,
329 const VarTestResult <est, const VarTestResult &RTest)
330 : InfoType(IT_BinTest) {
331
332 BinTest.Source = Source;
333 BinTest.EOp = EOp;
334 BinTest.LTest = LTest;
335 BinTest.RTest = RTest;
336 }
337
PropagationInfo(const BinaryOperator * Source,EffectiveOp EOp,const VarDecl * LVar,ConsumedState LTestsFor,const VarDecl * RVar,ConsumedState RTestsFor)338 PropagationInfo(const BinaryOperator *Source, EffectiveOp EOp,
339 const VarDecl *LVar, ConsumedState LTestsFor,
340 const VarDecl *RVar, ConsumedState RTestsFor)
341 : InfoType(IT_BinTest) {
342
343 BinTest.Source = Source;
344 BinTest.EOp = EOp;
345 BinTest.LTest.Var = LVar;
346 BinTest.LTest.TestsFor = LTestsFor;
347 BinTest.RTest.Var = RVar;
348 BinTest.RTest.TestsFor = RTestsFor;
349 }
350
PropagationInfo(ConsumedState State)351 PropagationInfo(ConsumedState State)
352 : InfoType(IT_State), State(State) {}
353
PropagationInfo(const VarDecl * Var)354 PropagationInfo(const VarDecl *Var) : InfoType(IT_Var), Var(Var) {}
PropagationInfo(const CXXBindTemporaryExpr * Tmp)355 PropagationInfo(const CXXBindTemporaryExpr *Tmp)
356 : InfoType(IT_Tmp), Tmp(Tmp) {}
357
getState() const358 const ConsumedState & getState() const {
359 assert(InfoType == IT_State);
360 return State;
361 }
362
getVarTest() const363 const VarTestResult & getVarTest() const {
364 assert(InfoType == IT_VarTest);
365 return VarTest;
366 }
367
getLTest() const368 const VarTestResult & getLTest() const {
369 assert(InfoType == IT_BinTest);
370 return BinTest.LTest;
371 }
372
getRTest() const373 const VarTestResult & getRTest() const {
374 assert(InfoType == IT_BinTest);
375 return BinTest.RTest;
376 }
377
getVar() const378 const VarDecl * getVar() const {
379 assert(InfoType == IT_Var);
380 return Var;
381 }
382
getTmp() const383 const CXXBindTemporaryExpr * getTmp() const {
384 assert(InfoType == IT_Tmp);
385 return Tmp;
386 }
387
getAsState(const ConsumedStateMap * StateMap) const388 ConsumedState getAsState(const ConsumedStateMap *StateMap) const {
389 assert(isVar() || isTmp() || isState());
390
391 if (isVar())
392 return StateMap->getState(Var);
393 else if (isTmp())
394 return StateMap->getState(Tmp);
395 else if (isState())
396 return State;
397 else
398 return CS_None;
399 }
400
testEffectiveOp() const401 EffectiveOp testEffectiveOp() const {
402 assert(InfoType == IT_BinTest);
403 return BinTest.EOp;
404 }
405
testSourceNode() const406 const BinaryOperator * testSourceNode() const {
407 assert(InfoType == IT_BinTest);
408 return BinTest.Source;
409 }
410
isValid() const411 inline bool isValid() const { return InfoType != IT_None; }
isState() const412 inline bool isState() const { return InfoType == IT_State; }
isVarTest() const413 inline bool isVarTest() const { return InfoType == IT_VarTest; }
isBinTest() const414 inline bool isBinTest() const { return InfoType == IT_BinTest; }
isVar() const415 inline bool isVar() const { return InfoType == IT_Var; }
isTmp() const416 inline bool isTmp() const { return InfoType == IT_Tmp; }
417
isTest() const418 bool isTest() const {
419 return InfoType == IT_VarTest || InfoType == IT_BinTest;
420 }
421
isPointerToValue() const422 bool isPointerToValue() const {
423 return InfoType == IT_Var || InfoType == IT_Tmp;
424 }
425
invertTest() const426 PropagationInfo invertTest() const {
427 assert(InfoType == IT_VarTest || InfoType == IT_BinTest);
428
429 if (InfoType == IT_VarTest) {
430 return PropagationInfo(VarTest.Var,
431 invertConsumedUnconsumed(VarTest.TestsFor));
432
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));
438 } else {
439 return PropagationInfo();
440 }
441 }
442 };
443
444 static inline void
setStateForVarOrTmp(ConsumedStateMap * StateMap,const PropagationInfo & PInfo,ConsumedState State)445 setStateForVarOrTmp(ConsumedStateMap *StateMap, const PropagationInfo &PInfo,
446 ConsumedState State) {
447
448 assert(PInfo.isVar() || PInfo.isTmp());
449
450 if (PInfo.isVar())
451 StateMap->setState(PInfo.getVar(), State);
452 else
453 StateMap->setState(PInfo.getTmp(), State);
454 }
455
456 class ConsumedStmtVisitor : public ConstStmtVisitor<ConsumedStmtVisitor> {
457
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;
462
463 AnalysisDeclContext &AC;
464 ConsumedAnalyzer &Analyzer;
465 ConsumedStateMap *StateMap;
466 MapType PropagationMap;
467
findInfo(const Expr * E)468 InfoEntry findInfo(const Expr *E) {
469 return PropagationMap.find(E->IgnoreParens());
470 }
findInfo(const Expr * E) const471 ConstInfoEntry findInfo(const Expr *E) const {
472 return PropagationMap.find(E->IgnoreParens());
473 }
insertInfo(const Expr * E,const PropagationInfo & PI)474 void insertInfo(const Expr *E, const PropagationInfo &PI) {
475 PropagationMap.insert(PairType(E->IgnoreParens(), PI));
476 }
477
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);
483
484 public:
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);
490
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);
506
ConsumedStmtVisitor(AnalysisDeclContext & AC,ConsumedAnalyzer & Analyzer,ConsumedStateMap * StateMap)507 ConsumedStmtVisitor(AnalysisDeclContext &AC, ConsumedAnalyzer &Analyzer,
508 ConsumedStateMap *StateMap)
509 : AC(AC), Analyzer(Analyzer), StateMap(StateMap) {}
510
getInfo(const Expr * StmtNode) const511 PropagationInfo getInfo(const Expr *StmtNode) const {
512 ConstInfoEntry Entry = findInfo(StmtNode);
513
514 if (Entry != PropagationMap.end())
515 return Entry->second;
516 else
517 return PropagationInfo();
518 }
519
reset(ConsumedStateMap * NewStateMap)520 void reset(ConsumedStateMap *NewStateMap) {
521 StateMap = NewStateMap;
522 }
523 };
524
525
forwardInfo(const Expr * From,const Expr * To)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);
530 }
531
532
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.
copyInfo(const Expr * From,const Expr * To,ConsumedState NS)535 void ConsumedStmtVisitor::copyInfo(const Expr *From, const Expr *To,
536 ConsumedState NS) {
537 InfoEntry Entry = findInfo(From);
538 if (Entry != PropagationMap.end()) {
539 PropagationInfo& PInfo = Entry->second;
540 ConsumedState CS = PInfo.getAsState(StateMap);
541 if (CS != CS_None)
542 insertInfo(To, PropagationInfo(CS));
543 if (NS != CS_None && PInfo.isPointerToValue())
544 setStateForVarOrTmp(StateMap, PInfo, NS);
545 }
546 }
547
548
549 // Get the ConsumedState for From
getInfo(const Expr * 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);
555 }
556 return CS_None;
557 }
558
559
560 // If we already have info for To then update it, otherwise create a new entry.
setInfo(const Expr * To,ConsumedState NS)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));
569 }
570 }
571
572
573
checkCallability(const PropagationInfo & PInfo,const FunctionDecl * FunDecl,SourceLocation BlameLoc)574 void ConsumedStmtVisitor::checkCallability(const PropagationInfo &PInfo,
575 const FunctionDecl *FunDecl,
576 SourceLocation BlameLoc) {
577 assert(!PInfo.isTest());
578
579 const CallableWhenAttr *CWAttr = FunDecl->getAttr<CallableWhenAttr>();
580 if (!CWAttr)
581 return;
582
583 if (PInfo.isVar()) {
584 ConsumedState VarState = StateMap->getState(PInfo.getVar());
585
586 if (VarState == CS_None || isCallableInState(CWAttr, VarState))
587 return;
588
589 Analyzer.WarningsHandler.warnUseInInvalidState(
590 FunDecl->getNameAsString(), PInfo.getVar()->getNameAsString(),
591 stateToString(VarState), BlameLoc);
592
593 } else {
594 ConsumedState TmpState = PInfo.getAsState(StateMap);
595
596 if (TmpState == CS_None || isCallableInState(CWAttr, TmpState))
597 return;
598
599 Analyzer.WarningsHandler.warnUseOfTempInInvalidState(
600 FunDecl->getNameAsString(), stateToString(TmpState), BlameLoc);
601 }
602 }
603
604
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.
handleCall(const CallExpr * Call,const Expr * ObjArg,const FunctionDecl * FunD)608 bool ConsumedStmtVisitor::handleCall(const CallExpr *Call, const Expr *ObjArg,
609 const FunctionDecl *FunD) {
610 unsigned Offset = 0;
611 if (isa<CXXOperatorCallExpr>(Call) && isa<CXXMethodDecl>(FunD))
612 Offset = 1; // first argument is 'this'
613
614 // check explicit parameters
615 for (unsigned Index = Offset; Index < Call->getNumArgs(); ++Index) {
616 // Skip variable argument lists.
617 if (Index - Offset >= FunD->getNumParams())
618 break;
619
620 const ParmVarDecl *Param = FunD->getParamDecl(Index - Offset);
621 QualType ParamType = Param->getType();
622
623 InfoEntry Entry = findInfo(Call->getArg(Index));
624
625 if (Entry == PropagationMap.end() || Entry->second.isTest())
626 continue;
627 PropagationInfo PInfo = Entry->second;
628
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);
633
634 if (ParamState != ExpectedState)
635 Analyzer.WarningsHandler.warnParamTypestateMismatch(
636 Call->getArg(Index)->getExprLoc(),
637 stateToString(ExpectedState), stateToString(ParamState));
638 }
639
640 if (!(Entry->second.isVar() || Entry->second.isTmp()))
641 continue;
642
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);
652 }
653
654 if (!ObjArg)
655 return false;
656
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());
662
663 if (SetTypestateAttr *STA = FunD->getAttr<SetTypestateAttr>()) {
664 if (PInfo.isVar()) {
665 StateMap->setState(PInfo.getVar(), mapSetTypestateAttrState(STA));
666 return true;
667 }
668 else if (PInfo.isTmp()) {
669 StateMap->setState(PInfo.getTmp(), mapSetTypestateAttrState(STA));
670 return true;
671 }
672 }
673 else if (isTestingFunction(FunD) && PInfo.isVar()) {
674 PropagationMap.insert(PairType(Call,
675 PropagationInfo(PInfo.getVar(), testsFor(FunD))));
676 }
677 }
678 return false;
679 }
680
681
propagateReturnType(const Expr * Call,const FunctionDecl * Fun)682 void ConsumedStmtVisitor::propagateReturnType(const Expr *Call,
683 const FunctionDecl *Fun) {
684 QualType RetType = Fun->getCallResultType();
685 if (RetType->isReferenceType())
686 RetType = RetType->getPointeeType();
687
688 if (isConsumableType(RetType)) {
689 ConsumedState ReturnState;
690 if (ReturnTypestateAttr *RTA = Fun->getAttr<ReturnTypestateAttr>())
691 ReturnState = mapReturnTypestateAttrState(RTA);
692 else
693 ReturnState = mapConsumableAttrState(RetType);
694
695 PropagationMap.insert(PairType(Call, PropagationInfo(ReturnState)));
696 }
697 }
698
699
VisitBinaryOperator(const BinaryOperator * BinOp)700 void ConsumedStmtVisitor::VisitBinaryOperator(const BinaryOperator *BinOp) {
701 switch (BinOp->getOpcode()) {
702 case BO_LAnd:
703 case BO_LOr : {
704 InfoEntry LEntry = findInfo(BinOp->getLHS()),
705 REntry = findInfo(BinOp->getRHS());
706
707 VarTestResult LTest, RTest;
708
709 if (LEntry != PropagationMap.end() && LEntry->second.isVarTest()) {
710 LTest = LEntry->second.getVarTest();
711
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
720 } else {
721 RTest.Var = nullptr;
722 RTest.TestsFor = CS_None;
723 }
724
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)));
728
729 break;
730 }
731
732 case BO_PtrMemD:
733 case BO_PtrMemI:
734 forwardInfo(BinOp->getLHS(), BinOp);
735 break;
736
737 default:
738 break;
739 }
740 }
741
VisitCallExpr(const CallExpr * Call)742 void ConsumedStmtVisitor::VisitCallExpr(const CallExpr *Call) {
743 const FunctionDecl *FunDecl = Call->getDirectCallee();
744 if (!FunDecl)
745 return;
746
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);
752 return;
753 }
754
755 handleCall(Call, nullptr, FunDecl);
756 propagateReturnType(Call, FunDecl);
757 }
758
VisitCastExpr(const CastExpr * Cast)759 void ConsumedStmtVisitor::VisitCastExpr(const CastExpr *Cast) {
760 forwardInfo(Cast->getSubExpr(), Cast);
761 }
762
VisitCXXBindTemporaryExpr(const CXXBindTemporaryExpr * Temp)763 void ConsumedStmtVisitor::VisitCXXBindTemporaryExpr(
764 const CXXBindTemporaryExpr *Temp) {
765
766 InfoEntry Entry = findInfo(Temp->getSubExpr());
767
768 if (Entry != PropagationMap.end() && !Entry->second.isTest()) {
769 StateMap->setState(Temp, Entry->second.getAsState(StateMap));
770 PropagationMap.insert(PairType(Temp, PropagationInfo(Temp)));
771 }
772 }
773
VisitCXXConstructExpr(const CXXConstructExpr * Call)774 void ConsumedStmtVisitor::VisitCXXConstructExpr(const CXXConstructExpr *Call) {
775 CXXConstructorDecl *Constructor = Call->getConstructor();
776
777 ASTContext &CurrContext = AC.getASTContext();
778 QualType ThisType = Constructor->getThisType(CurrContext)->getPointeeType();
779
780 if (!isConsumableType(ThisType))
781 return;
782
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.
795 ConsumedState NS =
796 isSetOnReadPtrType(Constructor->getThisType(CurrContext)) ?
797 CS_Unknown : CS_None;
798 copyInfo(Call->getArg(0), Call, NS);
799 } else {
800 // TODO: Adjust state of args appropriately.
801 ConsumedState RetState = mapConsumableAttrState(ThisType);
802 PropagationMap.insert(PairType(Call, PropagationInfo(RetState)));
803 }
804 }
805
806
VisitCXXMemberCallExpr(const CXXMemberCallExpr * Call)807 void ConsumedStmtVisitor::VisitCXXMemberCallExpr(
808 const CXXMemberCallExpr *Call) {
809 CXXMethodDecl* MD = Call->getMethodDecl();
810 if (!MD)
811 return;
812
813 handleCall(Call, Call->getImplicitObjectArgument(), MD);
814 propagateReturnType(Call, MD);
815 }
816
817
VisitCXXOperatorCallExpr(const CXXOperatorCallExpr * Call)818 void ConsumedStmtVisitor::VisitCXXOperatorCallExpr(
819 const CXXOperatorCallExpr *Call) {
820
821 const FunctionDecl *FunDecl =
822 dyn_cast_or_null<FunctionDecl>(Call->getDirectCallee());
823 if (!FunDecl) return;
824
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);
829 return;
830 }
831
832 if (const CXXMemberCallExpr *MCall = dyn_cast<CXXMemberCallExpr>(Call))
833 handleCall(MCall, MCall->getImplicitObjectArgument(), FunDecl);
834 else
835 handleCall(Call, Call->getArg(0), FunDecl);
836
837 propagateReturnType(Call, FunDecl);
838 }
839
VisitDeclRefExpr(const DeclRefExpr * DeclRef)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)));
844 }
845
VisitDeclStmt(const DeclStmt * DeclS)846 void ConsumedStmtVisitor::VisitDeclStmt(const DeclStmt *DeclS) {
847 for (const auto *DI : DeclS->decls())
848 if (isa<VarDecl>(DI))
849 VisitVarDecl(cast<VarDecl>(DI));
850
851 if (DeclS->isSingleDecl())
852 if (const VarDecl *Var = dyn_cast_or_null<VarDecl>(DeclS->getSingleDecl()))
853 PropagationMap.insert(PairType(DeclS, PropagationInfo(Var)));
854 }
855
VisitMaterializeTemporaryExpr(const MaterializeTemporaryExpr * Temp)856 void ConsumedStmtVisitor::VisitMaterializeTemporaryExpr(
857 const MaterializeTemporaryExpr *Temp) {
858
859 forwardInfo(Temp->GetTemporaryExpr(), Temp);
860 }
861
VisitMemberExpr(const MemberExpr * MExpr)862 void ConsumedStmtVisitor::VisitMemberExpr(const MemberExpr *MExpr) {
863 forwardInfo(MExpr->getBase(), MExpr);
864 }
865
866
VisitParmVarDecl(const ParmVarDecl * Param)867 void ConsumedStmtVisitor::VisitParmVarDecl(const ParmVarDecl *Param) {
868 QualType ParamType = Param->getType();
869 ConsumedState ParamState = consumed::CS_None;
870
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;
881
882 if (ParamState != CS_None)
883 StateMap->setState(Param, ParamState);
884 }
885
VisitReturnStmt(const ReturnStmt * Ret)886 void ConsumedStmtVisitor::VisitReturnStmt(const ReturnStmt *Ret) {
887 ConsumedState ExpectedState = Analyzer.getExpectedReturnState();
888
889 if (ExpectedState != CS_None) {
890 InfoEntry Entry = findInfo(Ret->getRetValue());
891
892 if (Entry != PropagationMap.end()) {
893 ConsumedState RetState = Entry->second.getAsState(StateMap);
894
895 if (RetState != ExpectedState)
896 Analyzer.WarningsHandler.warnReturnTypestateMismatch(
897 Ret->getReturnLoc(), stateToString(ExpectedState),
898 stateToString(RetState));
899 }
900 }
901
902 StateMap->checkParamsForReturnTypestate(Ret->getLocStart(),
903 Analyzer.WarningsHandler);
904 }
905
VisitUnaryOperator(const UnaryOperator * UOp)906 void ConsumedStmtVisitor::VisitUnaryOperator(const UnaryOperator *UOp) {
907 InfoEntry Entry = findInfo(UOp->getSubExpr());
908 if (Entry == PropagationMap.end()) return;
909
910 switch (UOp->getOpcode()) {
911 case UO_AddrOf:
912 PropagationMap.insert(PairType(UOp, Entry->second));
913 break;
914
915 case UO_LNot:
916 if (Entry->second.isTest())
917 PropagationMap.insert(PairType(UOp, Entry->second.invertTest()));
918 break;
919
920 default:
921 break;
922 }
923 }
924
925 // TODO: See if I need to check for reference types here.
VisitVarDecl(const VarDecl * Var)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);
933
934 if (St != consumed::CS_None) {
935 StateMap->setState(Var, St);
936 return;
937 }
938 }
939 }
940 // Otherwise
941 StateMap->setState(Var, consumed::CS_Unknown);
942 }
943 }
944 }} // end clang::consumed::ConsumedStmtVisitor
945
946 namespace clang {
947 namespace consumed {
948
splitVarStateForIf(const IfStmt * IfNode,const VarTestResult & Test,ConsumedStateMap * ThenStates,ConsumedStateMap * ElseStates)949 void splitVarStateForIf(const IfStmt * IfNode, const VarTestResult &Test,
950 ConsumedStateMap *ThenStates,
951 ConsumedStateMap *ElseStates) {
952
953 ConsumedState VarState = ThenStates->getState(Test.Var);
954
955 if (VarState == CS_Unknown) {
956 ThenStates->setState(Test.Var, Test.TestsFor);
957 ElseStates->setState(Test.Var, invertConsumedUnconsumed(Test.TestsFor));
958
959 } else if (VarState == invertConsumedUnconsumed(Test.TestsFor)) {
960 ThenStates->markUnreachable();
961
962 } else if (VarState == Test.TestsFor) {
963 ElseStates->markUnreachable();
964 }
965 }
966
splitVarStateForIfBinOp(const PropagationInfo & PInfo,ConsumedStateMap * ThenStates,ConsumedStateMap * ElseStates)967 void splitVarStateForIfBinOp(const PropagationInfo &PInfo,
968 ConsumedStateMap *ThenStates, ConsumedStateMap *ElseStates) {
969
970 const VarTestResult <est = PInfo.getLTest(),
971 &RTest = PInfo.getRTest();
972
973 ConsumedState LState = LTest.Var ? ThenStates->getState(LTest.Var) : CS_None,
974 RState = RTest.Var ? ThenStates->getState(RTest.Var) : CS_None;
975
976 if (LTest.Var) {
977 if (PInfo.testEffectiveOp() == EO_And) {
978 if (LState == CS_Unknown) {
979 ThenStates->setState(LTest.Var, LTest.TestsFor);
980
981 } else if (LState == invertConsumedUnconsumed(LTest.TestsFor)) {
982 ThenStates->markUnreachable();
983
984 } else if (LState == LTest.TestsFor && isKnownState(RState)) {
985 if (RState == RTest.TestsFor)
986 ElseStates->markUnreachable();
987 else
988 ThenStates->markUnreachable();
989 }
990
991 } else {
992 if (LState == CS_Unknown) {
993 ElseStates->setState(LTest.Var,
994 invertConsumedUnconsumed(LTest.TestsFor));
995
996 } else if (LState == LTest.TestsFor) {
997 ElseStates->markUnreachable();
998
999 } else if (LState == invertConsumedUnconsumed(LTest.TestsFor) &&
1000 isKnownState(RState)) {
1001
1002 if (RState == RTest.TestsFor)
1003 ElseStates->markUnreachable();
1004 else
1005 ThenStates->markUnreachable();
1006 }
1007 }
1008 }
1009
1010 if (RTest.Var) {
1011 if (PInfo.testEffectiveOp() == EO_And) {
1012 if (RState == CS_Unknown)
1013 ThenStates->setState(RTest.Var, RTest.TestsFor);
1014 else if (RState == invertConsumedUnconsumed(RTest.TestsFor))
1015 ThenStates->markUnreachable();
1016
1017 } else {
1018 if (RState == CS_Unknown)
1019 ElseStates->setState(RTest.Var,
1020 invertConsumedUnconsumed(RTest.TestsFor));
1021 else if (RState == RTest.TestsFor)
1022 ElseStates->markUnreachable();
1023 }
1024 }
1025 }
1026
allBackEdgesVisited(const CFGBlock * CurrBlock,const CFGBlock * TargetBlock)1027 bool ConsumedBlockInfo::allBackEdgesVisited(const CFGBlock *CurrBlock,
1028 const CFGBlock *TargetBlock) {
1029
1030 assert(CurrBlock && "Block pointer must not be NULL");
1031 assert(TargetBlock && "TargetBlock pointer must not be NULL");
1032
1033 unsigned int CurrBlockOrder = VisitOrder[CurrBlock->getBlockID()];
1034 for (CFGBlock::const_pred_iterator PI = TargetBlock->pred_begin(),
1035 PE = TargetBlock->pred_end(); PI != PE; ++PI) {
1036 if (*PI && CurrBlockOrder < VisitOrder[(*PI)->getBlockID()] )
1037 return false;
1038 }
1039 return true;
1040 }
1041
addInfo(const CFGBlock * Block,ConsumedStateMap * StateMap,bool & AlreadyOwned)1042 void ConsumedBlockInfo::addInfo(const CFGBlock *Block,
1043 ConsumedStateMap *StateMap,
1044 bool &AlreadyOwned) {
1045
1046 assert(Block && "Block pointer must not be NULL");
1047
1048 ConsumedStateMap *Entry = StateMapsArray[Block->getBlockID()];
1049
1050 if (Entry) {
1051 Entry->intersect(StateMap);
1052
1053 } else if (AlreadyOwned) {
1054 StateMapsArray[Block->getBlockID()] = new ConsumedStateMap(*StateMap);
1055
1056 } else {
1057 StateMapsArray[Block->getBlockID()] = StateMap;
1058 AlreadyOwned = true;
1059 }
1060 }
1061
addInfo(const CFGBlock * Block,ConsumedStateMap * StateMap)1062 void ConsumedBlockInfo::addInfo(const CFGBlock *Block,
1063 ConsumedStateMap *StateMap) {
1064
1065 assert(Block && "Block pointer must not be NULL");
1066
1067 ConsumedStateMap *Entry = StateMapsArray[Block->getBlockID()];
1068
1069 if (Entry) {
1070 Entry->intersect(StateMap);
1071 delete StateMap;
1072
1073 } else {
1074 StateMapsArray[Block->getBlockID()] = StateMap;
1075 }
1076 }
1077
borrowInfo(const CFGBlock * Block)1078 ConsumedStateMap* ConsumedBlockInfo::borrowInfo(const CFGBlock *Block) {
1079 assert(Block && "Block pointer must not be NULL");
1080 assert(StateMapsArray[Block->getBlockID()] && "Block has no block info");
1081
1082 return StateMapsArray[Block->getBlockID()];
1083 }
1084
discardInfo(const CFGBlock * Block)1085 void ConsumedBlockInfo::discardInfo(const CFGBlock *Block) {
1086 unsigned int BlockID = Block->getBlockID();
1087 delete StateMapsArray[BlockID];
1088 StateMapsArray[BlockID] = nullptr;
1089 }
1090
getInfo(const CFGBlock * Block)1091 ConsumedStateMap* ConsumedBlockInfo::getInfo(const CFGBlock *Block) {
1092 assert(Block && "Block pointer must not be NULL");
1093
1094 ConsumedStateMap *StateMap = StateMapsArray[Block->getBlockID()];
1095 if (isBackEdgeTarget(Block)) {
1096 return new ConsumedStateMap(*StateMap);
1097 } else {
1098 StateMapsArray[Block->getBlockID()] = nullptr;
1099 return StateMap;
1100 }
1101 }
1102
isBackEdge(const CFGBlock * From,const CFGBlock * To)1103 bool ConsumedBlockInfo::isBackEdge(const CFGBlock *From, const CFGBlock *To) {
1104 assert(From && "From block must not be NULL");
1105 assert(To && "From block must not be NULL");
1106
1107 return VisitOrder[From->getBlockID()] > VisitOrder[To->getBlockID()];
1108 }
1109
isBackEdgeTarget(const CFGBlock * Block)1110 bool ConsumedBlockInfo::isBackEdgeTarget(const CFGBlock *Block) {
1111 assert(Block && "Block pointer must not be NULL");
1112
1113 // Anything with less than two predecessors can't be the target of a back
1114 // edge.
1115 if (Block->pred_size() < 2)
1116 return false;
1117
1118 unsigned int BlockVisitOrder = VisitOrder[Block->getBlockID()];
1119 for (CFGBlock::const_pred_iterator PI = Block->pred_begin(),
1120 PE = Block->pred_end(); PI != PE; ++PI) {
1121 if (*PI && BlockVisitOrder < VisitOrder[(*PI)->getBlockID()])
1122 return true;
1123 }
1124 return false;
1125 }
1126
checkParamsForReturnTypestate(SourceLocation BlameLoc,ConsumedWarningsHandlerBase & WarningsHandler) const1127 void ConsumedStateMap::checkParamsForReturnTypestate(SourceLocation BlameLoc,
1128 ConsumedWarningsHandlerBase &WarningsHandler) const {
1129
1130 for (const auto &DM : VarMap) {
1131 if (isa<ParmVarDecl>(DM.first)) {
1132 const ParmVarDecl *Param = cast<ParmVarDecl>(DM.first);
1133 const ReturnTypestateAttr *RTA = Param->getAttr<ReturnTypestateAttr>();
1134
1135 if (!RTA)
1136 continue;
1137
1138 ConsumedState ExpectedState = mapReturnTypestateAttrState(RTA);
1139 if (DM.second != ExpectedState)
1140 WarningsHandler.warnParamReturnTypestateMismatch(BlameLoc,
1141 Param->getNameAsString(), stateToString(ExpectedState),
1142 stateToString(DM.second));
1143 }
1144 }
1145 }
1146
clearTemporaries()1147 void ConsumedStateMap::clearTemporaries() {
1148 TmpMap.clear();
1149 }
1150
getState(const VarDecl * Var) const1151 ConsumedState ConsumedStateMap::getState(const VarDecl *Var) const {
1152 VarMapType::const_iterator Entry = VarMap.find(Var);
1153
1154 if (Entry != VarMap.end())
1155 return Entry->second;
1156
1157 return CS_None;
1158 }
1159
1160 ConsumedState
getState(const CXXBindTemporaryExpr * Tmp) const1161 ConsumedStateMap::getState(const CXXBindTemporaryExpr *Tmp) const {
1162 TmpMapType::const_iterator Entry = TmpMap.find(Tmp);
1163
1164 if (Entry != TmpMap.end())
1165 return Entry->second;
1166
1167 return CS_None;
1168 }
1169
intersect(const ConsumedStateMap * Other)1170 void ConsumedStateMap::intersect(const ConsumedStateMap *Other) {
1171 ConsumedState LocalState;
1172
1173 if (this->From && this->From == Other->From && !Other->Reachable) {
1174 this->markUnreachable();
1175 return;
1176 }
1177
1178 for (const auto &DM : Other->VarMap) {
1179 LocalState = this->getState(DM.first);
1180
1181 if (LocalState == CS_None)
1182 continue;
1183
1184 if (LocalState != DM.second)
1185 VarMap[DM.first] = CS_Unknown;
1186 }
1187 }
1188
intersectAtLoopHead(const CFGBlock * LoopHead,const CFGBlock * LoopBack,const ConsumedStateMap * LoopBackStates,ConsumedWarningsHandlerBase & WarningsHandler)1189 void ConsumedStateMap::intersectAtLoopHead(const CFGBlock *LoopHead,
1190 const CFGBlock *LoopBack, const ConsumedStateMap *LoopBackStates,
1191 ConsumedWarningsHandlerBase &WarningsHandler) {
1192
1193 ConsumedState LocalState;
1194 SourceLocation BlameLoc = getLastStmtLoc(LoopBack);
1195
1196 for (const auto &DM : LoopBackStates->VarMap) {
1197 LocalState = this->getState(DM.first);
1198
1199 if (LocalState == CS_None)
1200 continue;
1201
1202 if (LocalState != DM.second) {
1203 VarMap[DM.first] = CS_Unknown;
1204 WarningsHandler.warnLoopStateMismatch(BlameLoc,
1205 DM.first->getNameAsString());
1206 }
1207 }
1208 }
1209
markUnreachable()1210 void ConsumedStateMap::markUnreachable() {
1211 this->Reachable = false;
1212 VarMap.clear();
1213 TmpMap.clear();
1214 }
1215
setState(const VarDecl * Var,ConsumedState State)1216 void ConsumedStateMap::setState(const VarDecl *Var, ConsumedState State) {
1217 VarMap[Var] = State;
1218 }
1219
setState(const CXXBindTemporaryExpr * Tmp,ConsumedState State)1220 void ConsumedStateMap::setState(const CXXBindTemporaryExpr *Tmp,
1221 ConsumedState State) {
1222 TmpMap[Tmp] = State;
1223 }
1224
remove(const CXXBindTemporaryExpr * Tmp)1225 void ConsumedStateMap::remove(const CXXBindTemporaryExpr *Tmp) {
1226 TmpMap.erase(Tmp);
1227 }
1228
operator !=(const ConsumedStateMap * Other) const1229 bool ConsumedStateMap::operator!=(const ConsumedStateMap *Other) const {
1230 for (const auto &DM : Other->VarMap)
1231 if (this->getState(DM.first) != DM.second)
1232 return true;
1233 return false;
1234 }
1235
determineExpectedReturnState(AnalysisDeclContext & AC,const FunctionDecl * D)1236 void ConsumedAnalyzer::determineExpectedReturnState(AnalysisDeclContext &AC,
1237 const FunctionDecl *D) {
1238 QualType ReturnType;
1239 if (const CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1240 ASTContext &CurrContext = AC.getASTContext();
1241 ReturnType = Constructor->getThisType(CurrContext)->getPointeeType();
1242 } else
1243 ReturnType = D->getCallResultType();
1244
1245 if (const ReturnTypestateAttr *RTSAttr = D->getAttr<ReturnTypestateAttr>()) {
1246 const CXXRecordDecl *RD = ReturnType->getAsCXXRecordDecl();
1247 if (!RD || !RD->hasAttr<ConsumableAttr>()) {
1248 // FIXME: This should be removed when template instantiation propagates
1249 // attributes at template specialization definition, not
1250 // declaration. When it is removed the test needs to be enabled
1251 // in SemaDeclAttr.cpp.
1252 WarningsHandler.warnReturnTypestateForUnconsumableType(
1253 RTSAttr->getLocation(), ReturnType.getAsString());
1254 ExpectedReturnState = CS_None;
1255 } else
1256 ExpectedReturnState = mapReturnTypestateAttrState(RTSAttr);
1257 } else if (isConsumableType(ReturnType)) {
1258 if (isAutoCastType(ReturnType)) // We can auto-cast the state to the
1259 ExpectedReturnState = CS_None; // expected state.
1260 else
1261 ExpectedReturnState = mapConsumableAttrState(ReturnType);
1262 }
1263 else
1264 ExpectedReturnState = CS_None;
1265 }
1266
splitState(const CFGBlock * CurrBlock,const ConsumedStmtVisitor & Visitor)1267 bool ConsumedAnalyzer::splitState(const CFGBlock *CurrBlock,
1268 const ConsumedStmtVisitor &Visitor) {
1269
1270 std::unique_ptr<ConsumedStateMap> FalseStates(
1271 new ConsumedStateMap(*CurrStates));
1272 PropagationInfo PInfo;
1273
1274 if (const IfStmt *IfNode =
1275 dyn_cast_or_null<IfStmt>(CurrBlock->getTerminator().getStmt())) {
1276
1277 const Expr *Cond = IfNode->getCond();
1278
1279 PInfo = Visitor.getInfo(Cond);
1280 if (!PInfo.isValid() && isa<BinaryOperator>(Cond))
1281 PInfo = Visitor.getInfo(cast<BinaryOperator>(Cond)->getRHS());
1282
1283 if (PInfo.isVarTest()) {
1284 CurrStates->setSource(Cond);
1285 FalseStates->setSource(Cond);
1286 splitVarStateForIf(IfNode, PInfo.getVarTest(), CurrStates,
1287 FalseStates.get());
1288
1289 } else if (PInfo.isBinTest()) {
1290 CurrStates->setSource(PInfo.testSourceNode());
1291 FalseStates->setSource(PInfo.testSourceNode());
1292 splitVarStateForIfBinOp(PInfo, CurrStates, FalseStates.get());
1293
1294 } else {
1295 return false;
1296 }
1297
1298 } else if (const BinaryOperator *BinOp =
1299 dyn_cast_or_null<BinaryOperator>(CurrBlock->getTerminator().getStmt())) {
1300
1301 PInfo = Visitor.getInfo(BinOp->getLHS());
1302 if (!PInfo.isVarTest()) {
1303 if ((BinOp = dyn_cast_or_null<BinaryOperator>(BinOp->getLHS()))) {
1304 PInfo = Visitor.getInfo(BinOp->getRHS());
1305
1306 if (!PInfo.isVarTest())
1307 return false;
1308
1309 } else {
1310 return false;
1311 }
1312 }
1313
1314 CurrStates->setSource(BinOp);
1315 FalseStates->setSource(BinOp);
1316
1317 const VarTestResult &Test = PInfo.getVarTest();
1318 ConsumedState VarState = CurrStates->getState(Test.Var);
1319
1320 if (BinOp->getOpcode() == BO_LAnd) {
1321 if (VarState == CS_Unknown)
1322 CurrStates->setState(Test.Var, Test.TestsFor);
1323 else if (VarState == invertConsumedUnconsumed(Test.TestsFor))
1324 CurrStates->markUnreachable();
1325
1326 } else if (BinOp->getOpcode() == BO_LOr) {
1327 if (VarState == CS_Unknown)
1328 FalseStates->setState(Test.Var,
1329 invertConsumedUnconsumed(Test.TestsFor));
1330 else if (VarState == Test.TestsFor)
1331 FalseStates->markUnreachable();
1332 }
1333
1334 } else {
1335 return false;
1336 }
1337
1338 CFGBlock::const_succ_iterator SI = CurrBlock->succ_begin();
1339
1340 if (*SI)
1341 BlockInfo.addInfo(*SI, CurrStates);
1342 else
1343 delete CurrStates;
1344
1345 if (*++SI)
1346 BlockInfo.addInfo(*SI, FalseStates.release());
1347
1348 CurrStates = nullptr;
1349 return true;
1350 }
1351
run(AnalysisDeclContext & AC)1352 void ConsumedAnalyzer::run(AnalysisDeclContext &AC) {
1353 const FunctionDecl *D = dyn_cast_or_null<FunctionDecl>(AC.getDecl());
1354 if (!D)
1355 return;
1356
1357 CFG *CFGraph = AC.getCFG();
1358 if (!CFGraph)
1359 return;
1360
1361 determineExpectedReturnState(AC, D);
1362
1363 PostOrderCFGView *SortedGraph = AC.getAnalysis<PostOrderCFGView>();
1364 // AC.getCFG()->viewCFG(LangOptions());
1365
1366 BlockInfo = ConsumedBlockInfo(CFGraph->getNumBlockIDs(), SortedGraph);
1367
1368 CurrStates = new ConsumedStateMap();
1369 ConsumedStmtVisitor Visitor(AC, *this, CurrStates);
1370
1371 // Add all trackable parameters to the state map.
1372 for (const auto *PI : D->params())
1373 Visitor.VisitParmVarDecl(PI);
1374
1375 // Visit all of the function's basic blocks.
1376 for (const auto *CurrBlock : *SortedGraph) {
1377 if (!CurrStates)
1378 CurrStates = BlockInfo.getInfo(CurrBlock);
1379
1380 if (!CurrStates) {
1381 continue;
1382
1383 } else if (!CurrStates->isReachable()) {
1384 delete CurrStates;
1385 CurrStates = nullptr;
1386 continue;
1387 }
1388
1389 Visitor.reset(CurrStates);
1390
1391 // Visit all of the basic block's statements.
1392 for (const auto &B : *CurrBlock) {
1393 switch (B.getKind()) {
1394 case CFGElement::Statement:
1395 Visitor.Visit(B.castAs<CFGStmt>().getStmt());
1396 break;
1397
1398 case CFGElement::TemporaryDtor: {
1399 const CFGTemporaryDtor &DTor = B.castAs<CFGTemporaryDtor>();
1400 const CXXBindTemporaryExpr *BTE = DTor.getBindTemporaryExpr();
1401
1402 Visitor.checkCallability(PropagationInfo(BTE),
1403 DTor.getDestructorDecl(AC.getASTContext()),
1404 BTE->getExprLoc());
1405 CurrStates->remove(BTE);
1406 break;
1407 }
1408
1409 case CFGElement::AutomaticObjectDtor: {
1410 const CFGAutomaticObjDtor &DTor = B.castAs<CFGAutomaticObjDtor>();
1411 SourceLocation Loc = DTor.getTriggerStmt()->getLocEnd();
1412 const VarDecl *Var = DTor.getVarDecl();
1413
1414 Visitor.checkCallability(PropagationInfo(Var),
1415 DTor.getDestructorDecl(AC.getASTContext()),
1416 Loc);
1417 break;
1418 }
1419
1420 default:
1421 break;
1422 }
1423 }
1424
1425 // TODO: Handle other forms of branching with precision, including while-
1426 // and for-loops. (Deferred)
1427 if (!splitState(CurrBlock, Visitor)) {
1428 CurrStates->setSource(nullptr);
1429
1430 if (CurrBlock->succ_size() > 1 ||
1431 (CurrBlock->succ_size() == 1 &&
1432 (*CurrBlock->succ_begin())->pred_size() > 1)) {
1433
1434 bool OwnershipTaken = false;
1435
1436 for (CFGBlock::const_succ_iterator SI = CurrBlock->succ_begin(),
1437 SE = CurrBlock->succ_end(); SI != SE; ++SI) {
1438
1439 if (*SI == nullptr) continue;
1440
1441 if (BlockInfo.isBackEdge(CurrBlock, *SI)) {
1442 BlockInfo.borrowInfo(*SI)->intersectAtLoopHead(*SI, CurrBlock,
1443 CurrStates,
1444 WarningsHandler);
1445
1446 if (BlockInfo.allBackEdgesVisited(*SI, CurrBlock))
1447 BlockInfo.discardInfo(*SI);
1448 } else {
1449 BlockInfo.addInfo(*SI, CurrStates, OwnershipTaken);
1450 }
1451 }
1452
1453 if (!OwnershipTaken)
1454 delete CurrStates;
1455
1456 CurrStates = nullptr;
1457 }
1458 }
1459
1460 if (CurrBlock == &AC.getCFG()->getExit() &&
1461 D->getCallResultType()->isVoidType())
1462 CurrStates->checkParamsForReturnTypestate(D->getLocation(),
1463 WarningsHandler);
1464 } // End of block iterator.
1465
1466 // Delete the last existing state map.
1467 delete CurrStates;
1468
1469 WarningsHandler.emitDiagnostics();
1470 }
1471 }} // end namespace clang::consumed
1472