clang  10.0.0svn
Consumed.cpp
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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 
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"
25 #include "clang/Analysis/CFG.h"
26 #include "clang/Basic/LLVM.h"
29 #include "llvm/ADT/DenseMap.h"
30 #include "llvm/ADT/Optional.h"
31 #include "llvm/ADT/STLExtras.h"
32 #include "llvm/ADT/StringRef.h"
33 #include "llvm/Support/Casting.h"
34 #include "llvm/Support/ErrorHandling.h"
35 #include <cassert>
36 #include <memory>
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 
55 using namespace clang;
56 using namespace consumed;
57 
58 // Key method definition
60 
61 static 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 (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->succ_begin());
72 
73  return {};
74 }
75 
76 static 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 (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->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->pred_begin());
99 
100  return Loc;
101 }
102 
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 
117 static bool isCallableInState(const CallableWhenAttr *CWAttr,
119  for (const auto &S : CWAttr->callableStates()) {
120  ConsumedState MappedAttrState = CS_None;
121 
122  switch (S) {
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 
143 static 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 
153 static 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 
163 static bool isSetOnReadPtrType(const QualType &QT) {
164  if (const CXXRecordDecl *RD = QT->getPointeeCXXRecordDecl())
165  return RD->hasAttr<ConsumableSetOnReadAttr>();
166  return false;
167 }
168 
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 
181 static bool isRValueRef(QualType ParamType) {
182  return ParamType->isRValueReferenceType();
183 }
184 
185 static bool isTestingFunction(const FunctionDecl *FunDecl) {
186  return FunDecl->hasAttr<TestTypestateAttr>();
187 }
188 
189 static bool isPointerOrRef(QualType ParamType) {
190  return ParamType->isPointerType() || ParamType->isReferenceType();
191 }
192 
194  assert(isConsumableType(QT));
195 
196  const ConsumableAttr *CAttr =
197  QT->getAsCXXRecordDecl()->getAttr<ConsumableAttr>();
198 
199  switch (CAttr->getDefaultState()) {
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 
210 static ConsumedState
211 mapParamTypestateAttrState(const ParamTypestateAttr *PTAttr) {
212  switch (PTAttr->getParamState()) {
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 
223 static ConsumedState
224 mapReturnTypestateAttrState(const ReturnTypestateAttr *RTSAttr) {
225  switch (RTSAttr->getState()) {
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 
236 static ConsumedState mapSetTypestateAttrState(const SetTypestateAttr *STAttr) {
237  switch (STAttr->getNewState()) {
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 
248 static StringRef stateToString(ConsumedState State) {
249  switch (State) {
250  case consumed::CS_None:
251  return "none";
252 
254  return "unknown";
255 
257  return "unconsumed";
258 
260  return "consumed";
261  }
262  llvm_unreachable("invalid enum");
263 }
264 
265 static 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 
276 namespace {
277 
278 struct VarTestResult {
279  const VarDecl *Var;
280  ConsumedState TestsFor;
281 };
282 
283 } // namespace
284 
285 namespace clang {
286 namespace consumed {
287 
291 };
292 
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 {
312  VarTestResult VarTest;
313  const VarDecl *Var;
315  BinTestTy BinTest;
316  };
317 
318 public:
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 
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 
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 
351  : InfoType(IT_State), State(State) {}
352  PropagationInfo(const VarDecl *Var) : InfoType(IT_Var), Var(Var) {}
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);
391  else if (isTmp())
392  return StateMap->getState(Tmp);
393  else if (isState())
394  return State;
395  else
396  return CS_None;
397  }
398 
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 
425  assert(InfoType == IT_VarTest || InfoType == IT_BinTest);
426 
427  if (InfoType == IT_VarTest) {
428  return PropagationInfo(VarTest.Var,
429  invertConsumedUnconsumed(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(BinTest.LTest.TestsFor),
435  BinTest.RTest.Var, invertConsumedUnconsumed(BinTest.RTest.TestsFor));
436  } else {
437  return {};
438  }
439  }
440 };
441 
442 } // namespace consumed
443 } // namespace clang
444 
445 static void
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 namespace clang {
457 namespace consumed {
458 
459 class 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>(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>(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(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 
493 public:
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 
517  : Analyzer(Analyzer), StateMap(StateMap) {}
518 
519  PropagationInfo getInfo(const Expr *StmtNode) const {
520  ConstInfoEntry Entry = findInfo(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 
536 void ConsumedStmtVisitor::forwardInfo(const Expr *From, const Expr *To) {
537  InfoEntry Entry = findInfo(From);
538  if (Entry != PropagationMap.end())
539  insertInfo(To, 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.
544 void ConsumedStmtVisitor::copyInfo(const Expr *From, const Expr *To,
545  ConsumedState NS) {
546  InfoEntry Entry = findInfo(From);
547  if (Entry != PropagationMap.end()) {
548  PropagationInfo& PInfo = Entry->second;
549  ConsumedState CS = PInfo.getAsState(StateMap);
550  if (CS != CS_None)
551  insertInfo(To, PropagationInfo(CS));
552  if (NS != CS_None && PInfo.isPointerToValue())
553  setStateForVarOrTmp(StateMap, PInfo, NS);
554  }
555 }
556 
557 // Get the ConsumedState for From
558 ConsumedState ConsumedStmtVisitor::getInfo(const Expr *From) {
559  InfoEntry Entry = findInfo(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.
568 void ConsumedStmtVisitor::setInfo(const Expr *To, ConsumedState NS) {
569  InfoEntry Entry = findInfo(To);
570  if (Entry != PropagationMap.end()) {
571  PropagationInfo& PInfo = Entry->second;
572  if (PInfo.isPointerToValue())
573  setStateForVarOrTmp(StateMap, PInfo, NS);
574  } else if (NS != CS_None) {
575  insertInfo(To, PropagationInfo(NS));
576  }
577 }
578 
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(PInfo.getVar());
590 
591  if (VarState == CS_None || isCallableInState(CWAttr, VarState))
592  return;
593 
594  Analyzer.WarningsHandler.warnUseInInvalidState(
595  FunDecl->getNameAsString(), PInfo.getVar()->getNameAsString(),
596  stateToString(VarState), 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  FunDecl->getNameAsString(), stateToString(TmpState), 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.
611 bool ConsumedStmtVisitor::handleCall(const CallExpr *Call, const Expr *ObjArg,
612  const FunctionDecl *FunD) {
613  unsigned Offset = 0;
614  if (isa<CXXOperatorCallExpr>(Call) && isa<CXXMethodDecl>(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(Index - Offset);
624  QualType ParamType = Param->getType();
625 
626  InfoEntry Entry = findInfo(Call->getArg(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  Call->getArg(Index)->getExprLoc(),
640  stateToString(ExpectedState), stateToString(ParamState));
641  }
642 
643  if (!(Entry->second.isVar() || Entry->second.isTmp()))
644  continue;
645 
646  // Adjust state on the caller side.
647  if (isRValueRef(ParamType))
648  setStateForVarOrTmp(StateMap, PInfo, consumed::CS_Consumed);
649  else if (ReturnTypestateAttr *RT = Param->getAttr<ReturnTypestateAttr>())
650  setStateForVarOrTmp(StateMap, PInfo, mapReturnTypestateAttrState(RT));
651  else if (isPointerOrRef(ParamType) &&
652  (!ParamType->getPointeeType().isConstQualified() ||
653  isSetOnReadPtrType(ParamType)))
654  setStateForVarOrTmp(StateMap, PInfo, consumed::CS_Unknown);
655  }
656 
657  if (!ObjArg)
658  return false;
659 
660  // check implicit 'self' parameter, if present
661  InfoEntry Entry = findInfo(ObjArg);
662  if (Entry != PropagationMap.end()) {
663  PropagationInfo PInfo = Entry->second;
664  checkCallability(PInfo, FunD, 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(FunD) && PInfo.isVar()) {
677  PropagationMap.insert(PairType(Call,
678  PropagationInfo(PInfo.getVar(), testsFor(FunD))));
679  }
680  }
681  return false;
682 }
683 
684 void 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(RetType)) {
691  ConsumedState ReturnState;
692  if (ReturnTypestateAttr *RTA = Fun->getAttr<ReturnTypestateAttr>())
693  ReturnState = mapReturnTypestateAttrState(RTA);
694  else
695  ReturnState = mapConsumableAttrState(RetType);
696 
697  PropagationMap.insert(PairType(Call, PropagationInfo(ReturnState)));
698  }
699 }
700 
702  switch (BinOp->getOpcode()) {
703  case BO_LAnd:
704  case BO_LOr : {
705  InfoEntry LEntry = findInfo(BinOp->getLHS()),
706  REntry = findInfo(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(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 
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(0), Call, CS_Consumed);
749  return;
750  }
751 
752  handleCall(Call, nullptr, FunDecl);
753  propagateReturnType(Call, FunDecl);
754 }
755 
757  forwardInfo(Cast->getSubExpr(), Cast);
758 }
759 
761  const CXXBindTemporaryExpr *Temp) {
762 
763  InfoEntry Entry = findInfo(Temp->getSubExpr());
764 
765  if (Entry != PropagationMap.end() && !Entry->second.isTest()) {
766  StateMap->setState(Temp, Entry->second.getAsState(StateMap));
767  PropagationMap.insert(PairType(Temp, PropagationInfo(Temp)));
768  }
769 }
770 
772  CXXConstructorDecl *Constructor = Call->getConstructor();
773 
774  QualType ThisType = Constructor->getThisType()->getPointeeType();
775 
776  if (!isConsumableType(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.
783  PropagationMap.insert(PairType(Call, PropagationInfo(RetState)));
784  } else if (Constructor->isDefaultConstructor()) {
785  PropagationMap.insert(PairType(Call,
787  } else if (Constructor->isMoveConstructor()) {
788  copyInfo(Call->getArg(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(Constructor->getThisType()) ?
794  copyInfo(Call->getArg(0), Call, NS);
795  } else {
796  // TODO: Adjust state of args appropriately.
797  ConsumedState RetState = mapConsumableAttrState(ThisType);
798  PropagationMap.insert(PairType(Call, PropagationInfo(RetState)));
799  }
800 }
801 
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 
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, Call->getArg(0), FunDecl))
820  setInfo(Call->getArg(0), CS);
821  return;
822  }
823 
824  if (const auto *MCall = dyn_cast<CXXMemberCallExpr>(Call))
825  handleCall(MCall, MCall->getImplicitObjectArgument(), FunDecl);
826  else
827  handleCall(Call, Call->getArg(0), FunDecl);
828 
829  propagateReturnType(Call, FunDecl);
830 }
831 
833  if (const auto *Var = dyn_cast_or_null<VarDecl>(DeclRef->getDecl()))
834  if (StateMap->getState(Var) != consumed::CS_None)
835  PropagationMap.insert(PairType(DeclRef, PropagationInfo(Var)));
836 }
837 
839  for (const auto *DI : DeclS->decls())
840  if (isa<VarDecl>(DI))
841  VisitVarDecl(cast<VarDecl>(DI));
842 
843  if (DeclS->isSingleDecl())
844  if (const auto *Var = dyn_cast_or_null<VarDecl>(DeclS->getSingleDecl()))
845  PropagationMap.insert(PairType(DeclS, PropagationInfo(Var)));
846 }
847 
849  const MaterializeTemporaryExpr *Temp) {
850  forwardInfo(Temp->GetTemporaryExpr(), Temp);
851 }
852 
854  forwardInfo(MExpr->getBase(), MExpr);
855 }
856 
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(ParamType))
864  ParamState = mapConsumableAttrState(ParamType);
865  else if (isRValueRef(ParamType) &&
866  isConsumableType(ParamType->getPointeeType()))
867  ParamState = mapConsumableAttrState(ParamType->getPointeeType());
868  else if (ParamType->isReferenceType() &&
869  isConsumableType(ParamType->getPointeeType()))
870  ParamState = consumed::CS_Unknown;
871 
872  if (ParamState != CS_None)
873  StateMap->setState(Param, ParamState);
874 }
875 
877  ConsumedState ExpectedState = Analyzer.getExpectedReturnState();
878 
879  if (ExpectedState != CS_None) {
880  InfoEntry Entry = findInfo(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  Ret->getReturnLoc(), stateToString(ExpectedState),
888  stateToString(RetState));
889  }
890  }
891 
892  StateMap->checkParamsForReturnTypestate(Ret->getBeginLoc(),
893  Analyzer.WarningsHandler);
894 }
895 
897  InfoEntry Entry = findInfo(UOp->getSubExpr());
898  if (Entry == PropagationMap.end()) return;
899 
900  switch (UOp->getOpcode()) {
901  case UO_AddrOf:
902  PropagationMap.insert(PairType(UOp, Entry->second));
903  break;
904 
905  case UO_LNot:
906  if (Entry->second.isTest())
907  PropagationMap.insert(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.
917  if (isConsumableType(Var->getType())) {
918  if (Var->hasInit()) {
919  MapType::iterator VIT = findInfo(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, St);
926  return;
927  }
928  }
929  }
930  // Otherwise
931  StateMap->setState(Var, consumed::CS_Unknown);
932  }
933 }
934 
935 static void splitVarStateForIf(const IfStmt *IfNode, const VarTestResult &Test,
936  ConsumedStateMap *ThenStates,
937  ConsumedStateMap *ElseStates) {
938  ConsumedState VarState = ThenStates->getState(Test.Var);
939 
940  if (VarState == CS_Unknown) {
941  ThenStates->setState(Test.Var, Test.TestsFor);
942  ElseStates->setState(Test.Var, invertConsumedUnconsumed(Test.TestsFor));
943  } else if (VarState == invertConsumedUnconsumed(Test.TestsFor)) {
944  ThenStates->markUnreachable();
945  } else if (VarState == Test.TestsFor) {
946  ElseStates->markUnreachable();
947  }
948 }
949 
950 static 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(LTest.Var) : CS_None,
957  RState = RTest.Var ? ThenStates->getState(RTest.Var) : CS_None;
958 
959  if (LTest.Var) {
960  if (PInfo.testEffectiveOp() == EO_And) {
961  if (LState == CS_Unknown) {
962  ThenStates->setState(LTest.Var, LTest.TestsFor);
963  } else if (LState == invertConsumedUnconsumed(LTest.TestsFor)) {
964  ThenStates->markUnreachable();
965  } else if (LState == LTest.TestsFor && isKnownState(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(LTest.Var,
974  invertConsumedUnconsumed(LTest.TestsFor));
975  } else if (LState == LTest.TestsFor) {
976  ElseStates->markUnreachable();
977  } else if (LState == invertConsumedUnconsumed(LTest.TestsFor) &&
978  isKnownState(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(RTest.Var, RTest.TestsFor);
991  else if (RState == invertConsumedUnconsumed(RTest.TestsFor))
992  ThenStates->markUnreachable();
993  } else {
994  if (RState == CS_Unknown)
995  ElseStates->setState(RTest.Var,
996  invertConsumedUnconsumed(RTest.TestsFor));
997  else if (RState == RTest.TestsFor)
998  ElseStates->markUnreachable();
999  }
1000  }
1001 }
1002 
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 
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(*StateMap);
1026  } else if (OwnedStateMap)
1027  Entry = std::move(OwnedStateMap);
1028  else
1029  Entry = std::make_unique<ConsumedStateMap>(*StateMap);
1030 }
1031 
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(*StateMap);
1040  } else {
1041  Entry = std::move(StateMap);
1042  }
1043 }
1044 
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 
1053  StateMapsArray[Block->getBlockID()] = nullptr;
1054 }
1055 
1056 std::unique_ptr<ConsumedStateMap>
1058  assert(Block && "Block pointer must not be NULL");
1059 
1060  auto &Entry = StateMapsArray[Block->getBlockID()];
1061  return isBackEdgeTarget(Block) ? std::make_unique<ConsumedStateMap>(*Entry)
1062  : std::move(Entry);
1063 }
1064 
1065 bool 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 
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 
1090  ConsumedWarningsHandlerBase &WarningsHandler) const {
1091 
1092  for (const auto &DM : VarMap) {
1093  if (isa<ParmVarDecl>(DM.first)) {
1094  const auto *Param = cast<ParmVarDecl>(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(BlameLoc,
1103  Param->getNameAsString(), stateToString(ExpectedState),
1104  stateToString(DM.second));
1105  }
1106  }
1107 }
1108 
1110  TmpMap.clear();
1111 }
1112 
1114  VarMapType::const_iterator Entry = VarMap.find(Var);
1115 
1116  if (Entry != VarMap.end())
1117  return Entry->second;
1118 
1119  return CS_None;
1120 }
1121 
1124  TmpMapType::const_iterator Entry = TmpMap.find(Tmp);
1125 
1126  if (Entry != TmpMap.end())
1127  return Entry->second;
1128 
1129  return CS_None;
1130 }
1131 
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(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 
1152  const CFGBlock *LoopBack, const ConsumedStateMap *LoopBackStates,
1153  ConsumedWarningsHandlerBase &WarningsHandler) {
1154 
1155  ConsumedState LocalState;
1156  SourceLocation BlameLoc = getLastStmtLoc(LoopBack);
1157 
1158  for (const auto &DM : LoopBackStates->VarMap) {
1159  LocalState = this->getState(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(BlameLoc,
1167  DM.first->getNameAsString());
1168  }
1169  }
1170 }
1171 
1173  this->Reachable = false;
1174  VarMap.clear();
1175  TmpMap.clear();
1176 }
1177 
1179  VarMap[Var] = State;
1180 }
1181 
1183  ConsumedState State) {
1184  TmpMap[Tmp] = State;
1185 }
1186 
1188  TmpMap.erase(Tmp);
1189 }
1190 
1192  for (const auto &DM : Other->VarMap)
1193  if (this->getState(DM.first) != DM.second)
1194  return true;
1195  return false;
1196 }
1197 
1198 void ConsumedAnalyzer::determineExpectedReturnState(AnalysisDeclContext &AC,
1199  const FunctionDecl *D) {
1200  QualType ReturnType;
1201  if (const auto *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1202  ReturnType = Constructor->getThisType()->getPointeeType();
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  RTSAttr->getLocation(), ReturnType.getAsString());
1215  ExpectedReturnState = CS_None;
1216  } else
1217  ExpectedReturnState = mapReturnTypestateAttrState(RTSAttr);
1218  } else if (isConsumableType(ReturnType)) {
1219  if (isAutoCastType(ReturnType)) // We can auto-cast the state to the
1220  ExpectedReturnState = CS_None; // expected state.
1221  else
1222  ExpectedReturnState = mapConsumableAttrState(ReturnType);
1223  }
1224  else
1225  ExpectedReturnState = CS_None;
1226 }
1227 
1228 bool 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>(CurrBlock->getTerminator().getStmt())) {
1236  const Expr *Cond = IfNode->getCond();
1237 
1238  PInfo = Visitor.getInfo(Cond);
1239  if (!PInfo.isValid() && isa<BinaryOperator>(Cond))
1240  PInfo = Visitor.getInfo(cast<BinaryOperator>(Cond)->getRHS());
1241 
1242  if (PInfo.isVarTest()) {
1243  CurrStates->setSource(Cond);
1244  FalseStates->setSource(Cond);
1245  splitVarStateForIf(IfNode, PInfo.getVarTest(), CurrStates.get(),
1246  FalseStates.get());
1247  } else if (PInfo.isBinTest()) {
1248  CurrStates->setSource(PInfo.testSourceNode());
1249  FalseStates->setSource(PInfo.testSourceNode());
1250  splitVarStateForIfBinOp(PInfo, CurrStates.get(), FalseStates.get());
1251  } else {
1252  return false;
1253  }
1254  } else if (const auto *BinOp =
1255  dyn_cast_or_null<BinaryOperator>(CurrBlock->getTerminator().getStmt())) {
1256  PInfo = Visitor.getInfo(BinOp->getLHS());
1257  if (!PInfo.isVarTest()) {
1258  if ((BinOp = dyn_cast_or_null<BinaryOperator>(BinOp->getLHS()))) {
1259  PInfo = Visitor.getInfo(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(Test.Var);
1273 
1274  if (BinOp->getOpcode() == BO_LAnd) {
1275  if (VarState == CS_Unknown)
1276  CurrStates->setState(Test.Var, Test.TestsFor);
1277  else if (VarState == invertConsumedUnconsumed(Test.TestsFor))
1278  CurrStates->markUnreachable();
1279 
1280  } else if (BinOp->getOpcode() == BO_LOr) {
1281  if (VarState == CS_Unknown)
1282  FalseStates->setState(Test.Var,
1283  invertConsumedUnconsumed(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(*SI, std::move(CurrStates));
1295  else
1296  CurrStates = nullptr;
1297 
1298  if (*++SI)
1299  BlockInfo.addInfo(*SI, std::move(FalseStates));
1300 
1301  return true;
1302 }
1303 
1305  const auto *D = dyn_cast_or_null<FunctionDecl>(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(PI);
1326 
1327  // Visit all of the function's basic blocks.
1328  for (const auto *CurrBlock : *SortedGraph) {
1329  if (!CurrStates)
1330  CurrStates = BlockInfo.getInfo(CurrBlock);
1331 
1332  if (!CurrStates) {
1333  continue;
1334  } else if (!CurrStates->isReachable()) {
1335  CurrStates = nullptr;
1336  continue;
1337  }
1338 
1339  Visitor.reset(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 
1349  const CFGTemporaryDtor &DTor = B.castAs<CFGTemporaryDtor>();
1350  const CXXBindTemporaryExpr *BTE = DTor.getBindTemporaryExpr();
1351 
1352  Visitor.checkCallability(PropagationInfo(BTE),
1353  DTor.getDestructorDecl(AC.getASTContext()),
1354  BTE->getExprLoc());
1355  CurrStates->remove(BTE);
1356  break;
1357  }
1358 
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(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(CurrBlock, *SI)) {
1391  BlockInfo.borrowInfo(*SI)->intersectAtLoopHead(
1392  *SI, CurrBlock, RawState, WarningsHandler);
1393 
1394  if (BlockInfo.allBackEdgesVisited(CurrBlock, *SI))
1395  BlockInfo.discardInfo(*SI);
1396  } else {
1397  BlockInfo.addInfo(*SI, RawState, CurrStates);
1398  }
1399  }
1400 
1401  CurrStates = nullptr;
1402  }
1403  }
1404 
1405  if (CurrBlock == &AC.getCFG()->getExit() &&
1406  D->getCallResultType()->isVoidType())
1407  CurrStates->checkParamsForReturnTypestate(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 }
void VisitDeclStmt(const DeclStmt *DelcS)
Definition: Consumed.cpp:838
A call to an overloaded operator written using operator syntax.
Definition: ExprCXX.h:77
bool isCallToStdMove() const
Definition: Expr.h:2769
Represents a function declaration or definition.
Definition: Decl.h:1748
const ConsumedState & getState() const
Definition: Consumed.cpp:356
SourceLocation getBeginLoc() const
Definition: Stmt.h:2669
pred_iterator pred_end()
Definition: CFG.h:924
A (possibly-)qualified type.
Definition: Type.h:643
Expr * getArg(unsigned Arg)
getArg - Return the specified argument.
Definition: Expr.h:2672
AdjacentBlocks::const_iterator const_pred_iterator
Definition: CFG.h:910
const Stmt * getStmt() const
Definition: CFG.h:132
ConstStmtVisitor - This class implements a simple visitor for Stmt subclasses.
Definition: StmtVisitor.h:192
succ_iterator succ_begin()
Definition: CFG.h:941
Stmt - This represents one statement.
Definition: Stmt.h:66
unsigned getNumArgs() const
getNumArgs - Return the number of actual arguments to this call.
Definition: Expr.h:2659
IfStmt - This represents an if/then/else.
Definition: Stmt.h:1812
QualType getPointeeType() const
If this is a pointer, ObjC object pointer, or block pointer, this returns the respective pointee...
Definition: Type.cpp:505
C Language Family Type Representation.
QualType getThisType() const
Return the type of the this pointer.
Definition: DeclCXX.cpp:2275
Expr * getBase() const
Definition: Expr.h:2883
unsigned getBlockID() const
Definition: CFG.h:1060
Expr * getImplicitObjectArgument() const
Retrieve the implicit object argument for the member call.
Definition: ExprCXX.cpp:642
virtual void warnParamReturnTypestateMismatch(SourceLocation Loc, StringRef VariableName, StringRef ExpectedState, StringRef ObservedState)
Warn about parameter typestate mismatches upon return.
Definition: Consumed.h:82
Opcode getOpcode() const
Definition: Expr.h:3439
Represents a call to a C++ constructor.
Definition: ExprCXX.h:1331
QualType getCallResultType() const
Determine the type of an expression that calls this function.
Definition: Decl.h:2359
T castAs() const
Convert to the specified CFGElement type, asserting that this CFGElement is of the desired type...
Definition: CFG.h:98
bool isBackEdge(const CFGBlock *From, const CFGBlock *To)
Definition: Consumed.cpp:1065
Represents a C++ constructor within a class.
Definition: DeclCXX.h:2574
Represents a prvalue temporary that is written into memory so that a reference can bind to it...
Definition: ExprCXX.h:4325
static ConsumedState testsFor(const FunctionDecl *FunDecl)
Definition: Consumed.cpp:265
unsigned succ_size() const
Definition: CFG.h:959
const CXXDestructorDecl * getDestructorDecl(ASTContext &astContext) const
Definition: CFG.cpp:4840
bool isDefaultConstructor() const
Whether this constructor is a default constructor (C++ [class.ctor]p5), which can be used to default-...
Definition: DeclCXX.cpp:2463
void VisitBinaryOperator(const BinaryOperator *BinOp)
Definition: Consumed.cpp:701
Represents a variable declaration or definition.
Definition: Decl.h:812
ASTContext & getASTContext() const
static void splitVarStateForIf(const IfStmt *IfNode, const VarTestResult &Test, ConsumedStateMap *ThenStates, ConsumedStateMap *ElseStates)
Definition: Consumed.cpp:935
const CXXBindTemporaryExpr * getTmp() const
Definition: Consumed.cpp:381
const Stmt * getTriggerStmt() const
Definition: CFG.h:393
void VisitParmVarDecl(const ParmVarDecl *Param)
Definition: Consumed.cpp:857
Represents a parameter to a function.
Definition: Decl.h:1564
Defines the clang::Expr interface and subclasses for C++ expressions.
PropagationInfo(const VarTestResult &VarTest)
Definition: Consumed.cpp:320
PropagationInfo(const VarDecl *Var)
Definition: Consumed.cpp:352
Expr * GetTemporaryExpr() const
Retrieve the temporary-generating subexpression whose value will be materialized into a glvalue...
Definition: ExprCXX.h:4366
LineState State
ConsumedState getState(const VarDecl *Var) const
Get the consumed state of a given variable.
Definition: Consumed.cpp:1113
AnalysisDeclContext contains the context data for the function or method under analysis.
Represents C++ object destructor implicitly generated for automatic object or temporary bound to cons...
Definition: CFG.h:383
const BinaryOperator * testSourceNode() const
Definition: Consumed.cpp:404
const VarTestResult & getRTest() const
Definition: Consumed.cpp:371
bool isReferenceType() const
Definition: Type.h:6369
PropagationInfo(const BinaryOperator *Source, EffectiveOp EOp, const VarDecl *LVar, ConsumedState LTestsFor, const VarDecl *RVar, ConsumedState RTestsFor)
Definition: Consumed.cpp:338
PropagationInfo(const CXXBindTemporaryExpr *Tmp)
Definition: Consumed.cpp:353
static ConsumedState mapReturnTypestateAttrState(const ReturnTypestateAttr *RTSAttr)
Definition: Consumed.cpp:224
Expr * getSubExpr()
Definition: Expr.h:3172
ArrayRef< ParmVarDecl * > parameters() const
Definition: Decl.h:2289
AdjacentBlocks::const_iterator const_succ_iterator
Definition: CFG.h:917
EffectiveOp testEffectiveOp() const
Definition: Consumed.cpp:399
bool operator!=(const ConsumedStateMap *Other) const
Tests to see if there is a mismatch in the states stored in two maps.
Definition: Consumed.cpp:1191
Forward-declares and imports various common LLVM datatypes that clang wants to use unqualified...
ConsumedStmtVisitor(ConsumedAnalyzer &Analyzer, ConsumedStateMap *StateMap)
Definition: Consumed.cpp:516
void intersectAtLoopHead(const CFGBlock *LoopHead, const CFGBlock *LoopBack, const ConsumedStateMap *LoopBackStates, ConsumedWarningsHandlerBase &WarningsHandler)
Definition: Consumed.cpp:1151
const CXXBindTemporaryExpr * Tmp
Definition: Consumed.cpp:314
const VarTestResult & getVarTest() const
Definition: Consumed.cpp:361
T * getAnalysis()
Return the specified analysis object, lazily running the analysis if necessary.
A builtin binary operation expression such as "x + y" or "x <= y".
Definition: Expr.h:3404
bool isRValueReferenceType() const
Definition: Type.h:6377
const VarDecl * getVarDecl() const
Definition: CFG.h:388
bool isBackEdgeTarget(const CFGBlock *Block)
Definition: Consumed.cpp:1072
CastExpr - Base class for type casts, including both implicit casts (ImplicitCastExpr) and explicit c...
Definition: Expr.h:3120
Represents binding an expression to a temporary.
Definition: ExprCXX.h:1282
void VisitCXXMemberCallExpr(const CXXMemberCallExpr *Call)
Definition: Consumed.cpp:802
reverse_iterator rend()
Definition: CFG.h:867
static void splitVarStateForIfBinOp(const PropagationInfo &PInfo, ConsumedStateMap *ThenStates, ConsumedStateMap *ElseStates)
Definition: Consumed.cpp:950
static bool isConsumableType(const QualType &QT)
Definition: Consumed.cpp:143
void remove(const CXXBindTemporaryExpr *Tmp)
Remove the temporary value from our state map.
Definition: Consumed.cpp:1187
bool hasAttr() const
Definition: DeclBase.h:542
CXXRecordDecl * getAsCXXRecordDecl() const
Retrieves the CXXRecordDecl that this type refers to, either because the type is a RecordType or beca...
Definition: Type.cpp:1636
CXXConstructorDecl * getConstructor() const
Get the constructor that this expression will (ultimately) call.
Definition: ExprCXX.h:1403
const CXXBindTemporaryExpr * getBindTemporaryExpr() const
Definition: CFG.h:481
Represents a single basic block in a source-level CFG.
Definition: CFG.h:570
unsigned Offset
Definition: Format.cpp:1749
virtual void warnLoopStateMismatch(SourceLocation Loc, StringRef VariableName)
Warn that a variable&#39;s state doesn&#39;t match at the entry and exit of a loop.
Definition: Consumed.h:70
static bool isPointerOrRef(QualType ParamType)
Definition: Consumed.cpp:189
This represents one expression.
Definition: Expr.h:108
static StringRef stateToString(ConsumedState State)
Definition: Consumed.cpp:248
void discardInfo(const CFGBlock *Block)
Definition: Consumed.cpp:1052
Represents a source-level, intra-procedural CFG that represents the control-flow of a Stmt...
Definition: CFG.h:1210
std::unique_ptr< ConsumedStateMap > getInfo(const CFGBlock *Block)
Definition: Consumed.cpp:1057
void VisitMemberExpr(const MemberExpr *MExpr)
Definition: Consumed.cpp:853
const CXXRecordDecl * getPointeeCXXRecordDecl() const
If this is a pointer or reference to a RecordType, return the CXXRecordDecl that the type refers to...
Definition: Type.cpp:1621
const VarDecl * getVar() const
Definition: Consumed.cpp:376
Defines an enumeration for C++ overloaded operators.
bool allBackEdgesVisited(const CFGBlock *CurrBlock, const CFGBlock *TargetBlock)
Definition: Consumed.cpp:1003
void setState(const VarDecl *Var, ConsumedState State)
Set the consumed state of a given variable.
Definition: Consumed.cpp:1178
FunctionDecl * getDirectCallee()
If the callee is a FunctionDecl, return it. Otherwise return null.
Definition: Expr.h:2651
void VisitCastExpr(const CastExpr *Cast)
Definition: Consumed.cpp:756
PropagationInfo(ConsumedState State)
Definition: Consumed.cpp:350
ReturnStmt - This represents a return, optionally of an expression: return; return 4;...
Definition: Stmt.h:2610
UnaryOperator - This represents the unary-expression&#39;s (except sizeof and alignof), the postinc/postdec operators from postfix-expression, and various extensions.
Definition: Expr.h:2016
CXXMethodDecl * getMethodDecl() const
Retrieve the declaration of the called method.
Definition: ExprCXX.cpp:661
void VisitReturnStmt(const ReturnStmt *Ret)
Definition: Consumed.cpp:876
ValueDecl * getDecl()
Definition: Expr.h:1217
const Expr * getSubExpr() const
Definition: ExprCXX.h:1305
reverse_iterator rbegin()
Definition: CFG.h:866
SourceLocation getEndLoc() const LLVM_READONLY
Definition: Stmt.cpp:276
bool isConstQualified() const
Determine whether this type is const-qualified.
Definition: Type.h:6192
void addInfo(const CFGBlock *Block, ConsumedStateMap *StateMap, std::unique_ptr< ConsumedStateMap > &OwnedStateMap)
Definition: Consumed.cpp:1017
static ConsumedState mapConsumableAttrState(const QualType QT)
Definition: Consumed.cpp:193
static void setStateForVarOrTmp(ConsumedStateMap *StateMap, const PropagationInfo &PInfo, ConsumedState State)
Definition: Consumed.cpp:446
PropagationInfo invertTest() const
Definition: Consumed.cpp:424
void checkParamsForReturnTypestate(SourceLocation BlameLoc, ConsumedWarningsHandlerBase &WarningsHandler) const
Warn if any of the parameters being tracked are not in the state they were declared to be in upon ret...
Definition: Consumed.cpp:1089
Encodes a location in the source.
Expr * getRetValue()
Definition: Stmt.h:2643
Expr * getSubExpr() const
Definition: Expr.h:2046
void VisitDeclRefExpr(const DeclRefExpr *DeclRef)
Definition: Consumed.cpp:832
std::string getNameAsString() const
Get a human-readable name for the declaration, even if it is one of the special kinds of names (C++ c...
Definition: Decl.h:291
Represents a call to a member function that may be written either with member call syntax (e...
Definition: ExprCXX.h:170
DeclStmt - Adaptor class for mixing declarations with statements and expressions. ...
Definition: Stmt.h:1203
Represents a static or instance method of a struct/union/class.
Definition: DeclCXX.h:2114
static bool isTestingFunction(const FunctionDecl *FunDecl)
Definition: Consumed.cpp:185
static bool isKnownState(ConsumedState State)
Definition: Consumed.cpp:169
const ParmVarDecl * getParamDecl(unsigned i) const
Definition: Decl.h:2312
PropagationInfo(const BinaryOperator *Source, EffectiveOp EOp, const VarTestResult &LTest, const VarTestResult &RTest)
Definition: Consumed.cpp:329
const Decl * getDecl() const
void VisitUnaryOperator(const UnaryOperator *UOp)
Definition: Consumed.cpp:896
static bool isSetOnReadPtrType(const QualType &QT)
Definition: Consumed.cpp:163
unsigned getNumBlockIDs() const
Returns the total number of BlockIDs allocated (which start at 0).
Definition: CFG.h:1377
const VarTestResult & getLTest() const
Definition: Consumed.cpp:366
void intersect(const ConsumedStateMap &Other)
Merge this state map with another map.
Definition: Consumed.cpp:1132
void VisitVarDecl(const VarDecl *Var)
Definition: Consumed.cpp:916
SourceLocation getExprLoc() const LLVM_READONLY
getExprLoc - Return the preferred location for the arrow when diagnosing a problem with a generic exp...
Definition: Expr.cpp:215
Expr * getLHS() const
Definition: Expr.h:3444
void VisitCXXOperatorCallExpr(const CXXOperatorCallExpr *Call)
Definition: Consumed.cpp:812
pred_iterator pred_begin()
Definition: CFG.h:923
void checkCallability(const PropagationInfo &PInfo, const FunctionDecl *FunDecl, SourceLocation BlameLoc)
Definition: Consumed.cpp:579
void reset(ConsumedStateMap *NewStateMap)
Definition: Consumed.cpp:528
Dataflow Directional Tag Classes.
bool isValid() const
Return true if this is a valid SourceLocation object.
void clearTemporaries()
Clear the TmpMap.
Definition: Consumed.cpp:1109
OverloadedOperatorKind getOperator() const
Returns the kind of overloaded operator that this expression refers to.
Definition: ExprCXX.h:106
void VisitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *Temp)
Definition: Consumed.cpp:848
bool isCopyConstructor(unsigned &TypeQuals) const
Whether this constructor is a copy constructor (C++ [class.copy]p2, which can be used to copy the cla...
Definition: DeclCXX.cpp:2472
const Expr * getInit() const
Definition: Decl.h:1219
unsigned pred_size() const
Definition: CFG.h:962
static std::string getAsString(SplitQualType split, const PrintingPolicy &Policy)
Definition: Type.h:979
bool isMoveConstructor(unsigned &TypeQuals) const
Determine whether this constructor is a move constructor (C++11 [class.copy]p3), which can be used to...
Definition: DeclCXX.cpp:2477
const Decl * getSingleDecl() const
Definition: Stmt.h:1218
Stmt * getTerminatorStmt()
Definition: CFG.h:1036
A class that handles the analysis of uniqueness violations.
Definition: Consumed.h:240
ConsumedStateMap * borrowInfo(const CFGBlock *Block)
Definition: Consumed.cpp:1045
bool isSingleDecl() const
isSingleDecl - This method returns true if this DeclStmt refers to a single Decl. ...
Definition: Stmt.h:1216
Stmt * getStmt()
Definition: CFG.h:529
static bool isRValueRef(QualType ParamType)
Definition: Consumed.cpp:181
void markUnreachable()
Mark the block as unreachable.
Definition: Consumed.cpp:1172
Expr * IgnoreImplicit() LLVM_READONLY
Skip past any implicit AST nodes which might surround this expression until reaching a fixed point...
Definition: Expr.cpp:2952
static const TypeInfo & getInfo(unsigned id)
Definition: Types.cpp:38
PropagationInfo getInfo(const Expr *StmtNode) const
Definition: Consumed.cpp:519
T * getAttr() const
Definition: DeclBase.h:538
PropagationInfo(const VarDecl *Var, ConsumedState TestsFor)
Definition: Consumed.cpp:323
Opcode getOpcode() const
Definition: Expr.h:2041
Expr * getArg(unsigned Arg)
Return the specified argument.
Definition: ExprCXX.h:1482
void VisitCallExpr(const CallExpr *Call)
Definition: Consumed.cpp:740
decl_range decls()
Definition: Stmt.h:1251
ConsumedState getAsState(const ConsumedStateMap *StateMap) const
Definition: Consumed.cpp:386
Defines the C++ Decl subclasses, other than those for templates (found in DeclTemplate.h) and friends (in DeclFriend.h).
static SourceLocation getFirstStmtLoc(const CFGBlock *Block)
Definition: Consumed.cpp:61
MemberExpr - [C99 6.5.2.3] Structure and Union Members.
Definition: Expr.h:2806
Defines the clang::SourceLocation class and associated facilities.
void VisitCXXConstructExpr(const CXXConstructExpr *Call)
Definition: Consumed.cpp:771
Represents a C++ struct/union/class.
Definition: DeclCXX.h:300
bool handleCall(const CallExpr *Call, const Expr *ObjArg, const FunctionDecl *FunD)
Definition: Consumed.cpp:611
bool isVoidType() const
Definition: Type.h:6616
static bool isAutoCastType(const QualType &QT)
Definition: Consumed.cpp:153
void run(AnalysisDeclContext &AC)
Check a function&#39;s CFG for consumed violations.
Definition: Consumed.cpp:1304
Represents a top-level expression in a basic block.
Definition: CFG.h:55
CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
Definition: Expr.h:2516
RetTy Visit(PTR(Stmt) S, ParamTys... P)
Definition: StmtVisitor.h:42
static ConsumedState mapParamTypestateAttrState(const ParamTypestateAttr *PTAttr)
Definition: Consumed.cpp:211
static bool isCallableInState(const CallableWhenAttr *CWAttr, ConsumedState State)
Definition: Consumed.cpp:117
A reference to a declared variable, function, enum, etc.
Definition: Expr.h:1141
Expr * getRHS() const
Definition: Expr.h:3446
bool isPointerType() const
Definition: Type.h:6357
static SourceLocation getLastStmtLoc(const CFGBlock *Block)
Definition: Consumed.cpp:76
QualType getType() const
Definition: Decl.h:647
static ConsumedState mapSetTypestateAttrState(const SetTypestateAttr *STAttr)
Definition: Consumed.cpp:236
CFGTerminator getTerminator() const
Definition: CFG.h:1034
unsigned getNumParams() const
Return the number of parameters this function must have based on its FunctionType.
Definition: Decl.cpp:3138
bool hasInit() const
Definition: Decl.cpp:2198
Represents C++ object destructor implicitly generated at the end of full expression for temporary obj...
Definition: CFG.h:476
SourceLocation getReturnLoc() const
Definition: Stmt.h:2666
SourceLocation getLocation() const
Definition: DeclBase.h:429
static ConsumedState invertConsumedUnconsumed(ConsumedState State)
Definition: Consumed.cpp:103
Expr * IgnoreParens() LLVM_READONLY
Skip past any parentheses which might surround this expression until reaching a fixed point...
Definition: Expr.cpp:2956
void VisitCXXBindTemporaryExpr(const CXXBindTemporaryExpr *Temp)
Definition: Consumed.cpp:760
CFGBlock & getExit()
Definition: CFG.h:1303