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Consumed.h
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1 //===- Consumed.h ----------------------------------------------*- 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 #ifndef LLVM_CLANG_ANALYSIS_ANALYSES_CONSUMED_H
16 #define LLVM_CLANG_ANALYSIS_ANALYSES_CONSUMED_H
17 
18 #include "clang/AST/DeclCXX.h"
19 #include "clang/AST/ExprCXX.h"
20 #include "clang/AST/StmtCXX.h"
24 
25 namespace clang {
26 namespace consumed {
27 
29  // No state information for the given variable.
31 
35  };
36 
38 
40  typedef std::pair<PartialDiagnosticAt, OptionalNotes> DelayedDiag;
41  typedef std::list<DelayedDiag> DiagList;
42 
44 
45  public:
46 
48 
49  /// \brief Emit the warnings and notes left by the analysis.
50  virtual void emitDiagnostics() {}
51 
52  /// \brief Warn that a variable's state doesn't match at the entry and exit
53  /// of a loop.
54  ///
55  /// \param Loc -- The location of the end of the loop.
56  ///
57  /// \param VariableName -- The name of the variable that has a mismatched
58  /// state.
60  StringRef VariableName) {}
61 
62  /// \brief Warn about parameter typestate mismatches upon return.
63  ///
64  /// \param Loc -- The SourceLocation of the return statement.
65  ///
66  /// \param ExpectedState -- The state the return value was expected to be
67  /// in.
68  ///
69  /// \param ObservedState -- The state the return value was observed to be
70  /// in.
72  StringRef VariableName,
73  StringRef ExpectedState,
74  StringRef ObservedState) {}
75 
76  // FIXME: Add documentation.
78  StringRef ExpectedState,
79  StringRef ObservedState) {}
80 
81  // FIXME: This can be removed when the attr propagation fix for templated
82  // classes lands.
83  /// \brief Warn about return typestates set for unconsumable types.
84  ///
85  /// \param Loc -- The location of the attributes.
86  ///
87  /// \param TypeName -- The name of the unconsumable type.
89  StringRef TypeName) {}
90 
91  /// \brief Warn about return typestate mismatches.
92  ///
93  /// \param Loc -- The SourceLocation of the return statement.
94  ///
95  /// \param ExpectedState -- The state the return value was expected to be
96  /// in.
97  ///
98  /// \param ObservedState -- The state the return value was observed to be
99  /// in.
101  StringRef ExpectedState,
102  StringRef ObservedState) {}
103 
104  /// \brief Warn about use-while-consumed errors.
105  /// \param MethodName -- The name of the method that was incorrectly
106  /// invoked.
107  ///
108  /// \param State -- The state the object was used in.
109  ///
110  /// \param Loc -- The SourceLocation of the method invocation.
111  virtual void warnUseOfTempInInvalidState(StringRef MethodName,
112  StringRef State,
113  SourceLocation Loc) {}
114 
115  /// \brief Warn about use-while-consumed errors.
116  /// \param MethodName -- The name of the method that was incorrectly
117  /// invoked.
118  ///
119  /// \param State -- The state the object was used in.
120  ///
121  /// \param VariableName -- The name of the variable that holds the unique
122  /// value.
123  ///
124  /// \param Loc -- The SourceLocation of the method invocation.
125  virtual void warnUseInInvalidState(StringRef MethodName,
126  StringRef VariableName,
127  StringRef State,
128  SourceLocation Loc) {}
129  };
130 
132 
133  typedef llvm::DenseMap<const VarDecl *, ConsumedState> VarMapType;
134  typedef llvm::DenseMap<const CXXBindTemporaryExpr *, ConsumedState>
135  TmpMapType;
136 
137  protected:
138 
139  bool Reachable;
140  const Stmt *From;
141  VarMapType VarMap;
142  TmpMapType TmpMap;
143 
144  public:
145  ConsumedStateMap() : Reachable(true), From(nullptr) {}
147  : Reachable(Other.Reachable), From(Other.From), VarMap(Other.VarMap),
148  TmpMap() {}
149 
150  /// \brief Warn if any of the parameters being tracked are not in the state
151  /// they were declared to be in upon return from a function.
152  void checkParamsForReturnTypestate(SourceLocation BlameLoc,
153  ConsumedWarningsHandlerBase &WarningsHandler) const;
154 
155  /// \brief Clear the TmpMap.
156  void clearTemporaries();
157 
158  /// \brief Get the consumed state of a given variable.
159  ConsumedState getState(const VarDecl *Var) const;
160 
161  /// \brief Get the consumed state of a given temporary value.
162  ConsumedState getState(const CXXBindTemporaryExpr *Tmp) const;
163 
164  /// \brief Merge this state map with another map.
165  void intersect(const ConsumedStateMap &Other);
166 
167  void intersectAtLoopHead(const CFGBlock *LoopHead, const CFGBlock *LoopBack,
168  const ConsumedStateMap *LoopBackStates,
169  ConsumedWarningsHandlerBase &WarningsHandler);
170 
171  /// \brief Return true if this block is reachable.
172  bool isReachable() const { return Reachable; }
173 
174  /// \brief Mark the block as unreachable.
175  void markUnreachable();
176 
177  /// \brief Set the source for a decision about the branching of states.
178  /// \param Source -- The statement that was the origin of a branching
179  /// decision.
180  void setSource(const Stmt *Source) { this->From = Source; }
181 
182  /// \brief Set the consumed state of a given variable.
183  void setState(const VarDecl *Var, ConsumedState State);
184 
185  /// \brief Set the consumed state of a given temporary value.
186  void setState(const CXXBindTemporaryExpr *Tmp, ConsumedState State);
187 
188  /// \brief Remove the temporary value from our state map.
189  void remove(const CXXBindTemporaryExpr *Tmp);
190 
191  /// \brief Tests to see if there is a mismatch in the states stored in two
192  /// maps.
193  ///
194  /// \param Other -- The second map to compare against.
195  bool operator!=(const ConsumedStateMap *Other) const;
196  };
197 
199  std::vector<std::unique_ptr<ConsumedStateMap>> StateMapsArray;
200  std::vector<unsigned int> VisitOrder;
201 
202  public:
203  ConsumedBlockInfo() = default;
204 
205  ConsumedBlockInfo(unsigned int NumBlocks, PostOrderCFGView *SortedGraph)
206  : StateMapsArray(NumBlocks), VisitOrder(NumBlocks, 0) {
207  unsigned int VisitOrderCounter = 0;
208  for (PostOrderCFGView::iterator BI = SortedGraph->begin(),
209  BE = SortedGraph->end(); BI != BE; ++BI) {
210  VisitOrder[(*BI)->getBlockID()] = VisitOrderCounter++;
211  }
212  }
213 
214  bool allBackEdgesVisited(const CFGBlock *CurrBlock,
215  const CFGBlock *TargetBlock);
216 
217  void addInfo(const CFGBlock *Block, ConsumedStateMap *StateMap,
218  std::unique_ptr<ConsumedStateMap> &OwnedStateMap);
219  void addInfo(const CFGBlock *Block,
220  std::unique_ptr<ConsumedStateMap> StateMap);
221 
222  ConsumedStateMap* borrowInfo(const CFGBlock *Block);
223 
224  void discardInfo(const CFGBlock *Block);
225 
226  std::unique_ptr<ConsumedStateMap> getInfo(const CFGBlock *Block);
227 
228  bool isBackEdge(const CFGBlock *From, const CFGBlock *To);
229  bool isBackEdgeTarget(const CFGBlock *Block);
230  };
231 
232  /// A class that handles the analysis of uniqueness violations.
234 
235  ConsumedBlockInfo BlockInfo;
236  std::unique_ptr<ConsumedStateMap> CurrStates;
237 
238  ConsumedState ExpectedReturnState;
239 
240  void determineExpectedReturnState(AnalysisDeclContext &AC,
241  const FunctionDecl *D);
242  bool splitState(const CFGBlock *CurrBlock,
243  const ConsumedStmtVisitor &Visitor);
244 
245  public:
246 
248 
250  : WarningsHandler(WarningsHandler) {}
251 
252  ConsumedState getExpectedReturnState() const { return ExpectedReturnState; }
253 
254  /// \brief Check a function's CFG for consumed violations.
255  ///
256  /// We traverse the blocks in the CFG, keeping track of the state of each
257  /// value who's type has uniquness annotations. If methods are invoked in
258  /// the wrong state a warning is issued. Each block in the CFG is traversed
259  /// exactly once.
260  void run(AnalysisDeclContext &AC);
261  };
262 }} // end namespace clang::consumed
263 
264 #endif
FunctionDecl - An instance of this class is created to represent a function declaration or definition...
Definition: Decl.h:1631
virtual void warnReturnTypestateForUnconsumableType(SourceLocation Loc, StringRef TypeName)
Warn about return typestates set for unconsumable types.
Definition: Consumed.h:88
Stmt - This represents one statement.
Definition: Stmt.h:60
virtual void warnParamReturnTypestateMismatch(SourceLocation Loc, StringRef VariableName, StringRef ExpectedState, StringRef ObservedState)
Warn about parameter typestate mismatches upon return.
Definition: Consumed.h:71
virtual void warnUseInInvalidState(StringRef MethodName, StringRef VariableName, StringRef State, SourceLocation Loc)
Warn about use-while-consumed errors.
Definition: Consumed.h:125
VarDecl - An instance of this class is created to represent a variable declaration or definition...
Definition: Decl.h:771
ConsumedState getExpectedReturnState() const
Definition: Consumed.h:252
Defines the clang::Expr interface and subclasses for C++ expressions.
LineState State
std::pair< PartialDiagnosticAt, OptionalNotes > DelayedDiag
Definition: Consumed.h:40
AnalysisDeclContext contains the context data for the function or method under analysis.
Represents binding an expression to a temporary.
Definition: ExprCXX.h:1134
CFGBlock - Represents a single basic block in a source-level CFG.
Definition: CFG.h:401
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:59
bool isReachable() const
Return true if this block is reachable.
Definition: Consumed.h:172
virtual void emitDiagnostics()
Emit the warnings and notes left by the analysis.
Definition: Consumed.h:50
Encodes a location in the source.
virtual void warnParamTypestateMismatch(SourceLocation LOC, StringRef ExpectedState, StringRef ObservedState)
Definition: Consumed.h:77
virtual void warnReturnTypestateMismatch(SourceLocation Loc, StringRef ExpectedState, StringRef ObservedState)
Warn about return typestate mismatches.
Definition: Consumed.h:100
ConsumedAnalyzer(ConsumedWarningsHandlerBase &WarningsHandler)
Definition: Consumed.h:249
Dataflow Directional Tag Classes.
SmallVector< PartialDiagnosticAt, 1 > OptionalNotes
Definition: Consumed.h:37
A class that handles the analysis of uniqueness violations.
Definition: Consumed.h:233
ConsumedBlockInfo(unsigned int NumBlocks, PostOrderCFGView *SortedGraph)
Definition: Consumed.h:205
ConsumedWarningsHandlerBase & WarningsHandler
Definition: Consumed.h:247
std::list< DelayedDiag > DiagList
Definition: Consumed.h:41
std::vector< const CFGBlock * >::reverse_iterator iterator
static const TypeInfo & getInfo(unsigned id)
Definition: Types.cpp:34
ConsumedStateMap(const ConsumedStateMap &Other)
Definition: Consumed.h:146
void setSource(const Stmt *Source)
Set the source for a decision about the branching of states.
Definition: Consumed.h:180
Defines the C++ Decl subclasses, other than those for templates (found in DeclTemplate.h) and friends (in DeclFriend.h).
Defines the clang::SourceLocation class and associated facilities.
bool operator!=(CanQual< T > x, CanQual< U > y)
virtual void warnUseOfTempInInvalidState(StringRef MethodName, StringRef State, SourceLocation Loc)
Warn about use-while-consumed errors.
Definition: Consumed.h:111
#define true
Definition: stdbool.h:32