1 //===- Consumed.h -----------------------------------------------*- C++ -*-===//
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
7 //===----------------------------------------------------------------------===//
9 // A intra-procedural analysis for checking consumed properties. This is based,
10 // in part, on research on linear types.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_CLANG_ANALYSIS_ANALYSES_CONSUMED_H
15 #define LLVM_CLANG_ANALYSIS_ANALYSES_CONSUMED_H
17 #include "clang/Analysis/Analyses/PostOrderCFGView.h"
18 #include "clang/Analysis/CFG.h"
19 #include "clang/Basic/LLVM.h"
20 #include "clang/Basic/PartialDiagnostic.h"
21 #include "clang/Basic/SourceLocation.h"
22 #include "llvm/ADT/DenseMap.h"
23 #include "llvm/ADT/SmallVector.h"
24 #include "llvm/ADT/StringRef.h"
32 class AnalysisDeclContext;
33 class CXXBindTemporaryExpr;
35 class PostOrderCFGView;
41 class ConsumedStmtVisitor;
44 // No state information for the given variable.
52 using OptionalNotes = SmallVector<PartialDiagnosticAt, 1>;
53 using DelayedDiag = std::pair<PartialDiagnosticAt, OptionalNotes>;
54 using DiagList = std::list<DelayedDiag>;
56 class ConsumedWarningsHandlerBase {
58 virtual ~ConsumedWarningsHandlerBase();
60 /// Emit the warnings and notes left by the analysis.
61 virtual void emitDiagnostics() {}
63 /// Warn that a variable's state doesn't match at the entry and exit
66 /// \param Loc -- The location of the end of the loop.
68 /// \param VariableName -- The name of the variable that has a mismatched
70 virtual void warnLoopStateMismatch(SourceLocation Loc,
71 StringRef VariableName) {}
73 /// Warn about parameter typestate mismatches upon return.
75 /// \param Loc -- The SourceLocation of the return statement.
77 /// \param ExpectedState -- The state the return value was expected to be
80 /// \param ObservedState -- The state the return value was observed to be
82 virtual void warnParamReturnTypestateMismatch(SourceLocation Loc,
83 StringRef VariableName,
84 StringRef ExpectedState,
85 StringRef ObservedState) {}
87 // FIXME: Add documentation.
88 virtual void warnParamTypestateMismatch(SourceLocation LOC,
89 StringRef ExpectedState,
90 StringRef ObservedState) {}
92 // FIXME: This can be removed when the attr propagation fix for templated
94 /// Warn about return typestates set for unconsumable types.
96 /// \param Loc -- The location of the attributes.
98 /// \param TypeName -- The name of the unconsumable type.
99 virtual void warnReturnTypestateForUnconsumableType(SourceLocation Loc,
100 StringRef TypeName) {}
102 /// Warn about return typestate mismatches.
104 /// \param Loc -- The SourceLocation of the return statement.
106 /// \param ExpectedState -- The state the return value was expected to be
109 /// \param ObservedState -- The state the return value was observed to be
111 virtual void warnReturnTypestateMismatch(SourceLocation Loc,
112 StringRef ExpectedState,
113 StringRef ObservedState) {}
115 /// Warn about use-while-consumed errors.
116 /// \param MethodName -- The name of the method that was incorrectly
119 /// \param State -- The state the object was used in.
121 /// \param Loc -- The SourceLocation of the method invocation.
122 virtual void warnUseOfTempInInvalidState(StringRef MethodName,
124 SourceLocation Loc) {}
126 /// Warn about use-while-consumed errors.
127 /// \param MethodName -- The name of the method that was incorrectly
130 /// \param State -- The state the object was used in.
132 /// \param VariableName -- The name of the variable that holds the unique
135 /// \param Loc -- The SourceLocation of the method invocation.
136 virtual void warnUseInInvalidState(StringRef MethodName,
137 StringRef VariableName,
139 SourceLocation Loc) {}
142 class ConsumedStateMap {
143 using VarMapType = llvm::DenseMap<const VarDecl *, ConsumedState>;
145 llvm::DenseMap<const CXXBindTemporaryExpr *, ConsumedState>;
148 bool Reachable = true;
149 const Stmt *From = nullptr;
154 ConsumedStateMap() = default;
155 ConsumedStateMap(const ConsumedStateMap &Other)
156 : Reachable(Other.Reachable), From(Other.From), VarMap(Other.VarMap),
159 /// Warn if any of the parameters being tracked are not in the state
160 /// they were declared to be in upon return from a function.
161 void checkParamsForReturnTypestate(SourceLocation BlameLoc,
162 ConsumedWarningsHandlerBase &WarningsHandler) const;
164 /// Clear the TmpMap.
165 void clearTemporaries();
167 /// Get the consumed state of a given variable.
168 ConsumedState getState(const VarDecl *Var) const;
170 /// Get the consumed state of a given temporary value.
171 ConsumedState getState(const CXXBindTemporaryExpr *Tmp) const;
173 /// Merge this state map with another map.
174 void intersect(const ConsumedStateMap &Other);
176 void intersectAtLoopHead(const CFGBlock *LoopHead, const CFGBlock *LoopBack,
177 const ConsumedStateMap *LoopBackStates,
178 ConsumedWarningsHandlerBase &WarningsHandler);
180 /// Return true if this block is reachable.
181 bool isReachable() const { return Reachable; }
183 /// Mark the block as unreachable.
184 void markUnreachable();
186 /// Set the source for a decision about the branching of states.
187 /// \param Source -- The statement that was the origin of a branching
189 void setSource(const Stmt *Source) { this->From = Source; }
191 /// Set the consumed state of a given variable.
192 void setState(const VarDecl *Var, ConsumedState State);
194 /// Set the consumed state of a given temporary value.
195 void setState(const CXXBindTemporaryExpr *Tmp, ConsumedState State);
197 /// Remove the temporary value from our state map.
198 void remove(const CXXBindTemporaryExpr *Tmp);
200 /// Tests to see if there is a mismatch in the states stored in two
203 /// \param Other -- The second map to compare against.
204 bool operator!=(const ConsumedStateMap *Other) const;
207 class ConsumedBlockInfo {
208 std::vector<std::unique_ptr<ConsumedStateMap>> StateMapsArray;
209 std::vector<unsigned int> VisitOrder;
212 ConsumedBlockInfo() = default;
214 ConsumedBlockInfo(unsigned int NumBlocks, PostOrderCFGView *SortedGraph)
215 : StateMapsArray(NumBlocks), VisitOrder(NumBlocks, 0) {
216 unsigned int VisitOrderCounter = 0;
217 for (const auto BI : *SortedGraph)
218 VisitOrder[BI->getBlockID()] = VisitOrderCounter++;
221 bool allBackEdgesVisited(const CFGBlock *CurrBlock,
222 const CFGBlock *TargetBlock);
224 void addInfo(const CFGBlock *Block, ConsumedStateMap *StateMap,
225 std::unique_ptr<ConsumedStateMap> &OwnedStateMap);
226 void addInfo(const CFGBlock *Block,
227 std::unique_ptr<ConsumedStateMap> StateMap);
229 ConsumedStateMap* borrowInfo(const CFGBlock *Block);
231 void discardInfo(const CFGBlock *Block);
233 std::unique_ptr<ConsumedStateMap> getInfo(const CFGBlock *Block);
235 bool isBackEdge(const CFGBlock *From, const CFGBlock *To);
236 bool isBackEdgeTarget(const CFGBlock *Block);
239 /// A class that handles the analysis of uniqueness violations.
240 class ConsumedAnalyzer {
241 ConsumedBlockInfo BlockInfo;
242 std::unique_ptr<ConsumedStateMap> CurrStates;
244 ConsumedState ExpectedReturnState;
246 void determineExpectedReturnState(AnalysisDeclContext &AC,
247 const FunctionDecl *D);
248 bool splitState(const CFGBlock *CurrBlock,
249 const ConsumedStmtVisitor &Visitor);
252 ConsumedWarningsHandlerBase &WarningsHandler;
254 ConsumedAnalyzer(ConsumedWarningsHandlerBase &WarningsHandler)
255 : WarningsHandler(WarningsHandler) {}
257 ConsumedState getExpectedReturnState() const { return ExpectedReturnState; }
259 /// Check a function's CFG for consumed violations.
261 /// We traverse the blocks in the CFG, keeping track of the state of each
262 /// value who's type has uniquness annotations. If methods are invoked in
263 /// the wrong state a warning is issued. Each block in the CFG is traversed
265 void run(AnalysisDeclContext &AC);
268 } // namespace consumed
272 #endif // LLVM_CLANG_ANALYSIS_ANALYSES_CONSUMED_H