Coverage Report

Created: 2022-07-16 07:03

/Users/buildslave/jenkins/workspace/coverage/llvm-project/clang/include/clang/Analysis/Analyses/Consumed.h
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//===- Consumed.h -----------------------------------------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// A intra-procedural analysis for checking consumed properties.  This is based,
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// in part, on research on linear types.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_CLANG_ANALYSIS_ANALYSES_CONSUMED_H
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#define LLVM_CLANG_ANALYSIS_ANALYSES_CONSUMED_H
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#include "clang/Analysis/Analyses/PostOrderCFGView.h"
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#include "clang/Analysis/CFG.h"
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#include "clang/Basic/LLVM.h"
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#include "clang/Basic/PartialDiagnostic.h"
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#include "clang/Basic/SourceLocation.h"
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#include "llvm/ADT/DenseMap.h"
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/ADT/StringRef.h"
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#include <list>
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#include <memory>
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#include <utility>
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#include <vector>
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namespace clang {
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class AnalysisDeclContext;
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class CXXBindTemporaryExpr;
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class FunctionDecl;
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class PostOrderCFGView;
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class Stmt;
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class VarDecl;
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namespace consumed {
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  class ConsumedStmtVisitor;
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  enum ConsumedState {
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    // No state information for the given variable.
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    CS_None,
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    CS_Unknown,
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    CS_Unconsumed,
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    CS_Consumed
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  };
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  using OptionalNotes = SmallVector<PartialDiagnosticAt, 1>;
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  using DelayedDiag = std::pair<PartialDiagnosticAt, OptionalNotes>;
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  using DiagList = std::list<DelayedDiag>;
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  class ConsumedWarningsHandlerBase {
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  public:
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    virtual ~ConsumedWarningsHandlerBase();
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    /// Emit the warnings and notes left by the analysis.
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    virtual void emitDiagnostics() {}
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    /// Warn that a variable's state doesn't match at the entry and exit
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    /// of a loop.
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    ///
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    /// \param Loc -- The location of the end of the loop.
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    ///
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    /// \param VariableName -- The name of the variable that has a mismatched
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    /// state.
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    virtual void warnLoopStateMismatch(SourceLocation Loc,
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                                       StringRef VariableName) {}
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    /// Warn about parameter typestate mismatches upon return.
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    ///
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    /// \param Loc -- The SourceLocation of the return statement.
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    ///
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    /// \param ExpectedState -- The state the return value was expected to be
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    /// in.
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    ///
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    /// \param ObservedState -- The state the return value was observed to be
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    /// in.
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    virtual void warnParamReturnTypestateMismatch(SourceLocation Loc,
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                                                  StringRef VariableName,
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                                                  StringRef ExpectedState,
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                                                  StringRef ObservedState) {}
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    // FIXME: Add documentation.
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    virtual void warnParamTypestateMismatch(SourceLocation LOC,
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                                            StringRef ExpectedState,
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                                            StringRef ObservedState) {}
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    // FIXME: This can be removed when the attr propagation fix for templated
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    //        classes lands.
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    /// Warn about return typestates set for unconsumable types.
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    ///
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    /// \param Loc -- The location of the attributes.
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    ///
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    /// \param TypeName -- The name of the unconsumable type.
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    virtual void warnReturnTypestateForUnconsumableType(SourceLocation Loc,
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                                                        StringRef TypeName) {}
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    /// Warn about return typestate mismatches.
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    ///
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    /// \param Loc -- The SourceLocation of the return statement.
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    ///
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    /// \param ExpectedState -- The state the return value was expected to be
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    /// in.
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    ///
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    /// \param ObservedState -- The state the return value was observed to be
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    /// in.
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    virtual void warnReturnTypestateMismatch(SourceLocation Loc,
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                                             StringRef ExpectedState,
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                                             StringRef ObservedState) {}
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    /// Warn about use-while-consumed errors.
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    /// \param MethodName -- The name of the method that was incorrectly
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    /// invoked.
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    ///
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    /// \param State -- The state the object was used in.
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    ///
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    /// \param Loc -- The SourceLocation of the method invocation.
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    virtual void warnUseOfTempInInvalidState(StringRef MethodName,
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                                             StringRef State,
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                                             SourceLocation Loc) {}
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    /// Warn about use-while-consumed errors.
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    /// \param MethodName -- The name of the method that was incorrectly
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    /// invoked.
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    ///
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    /// \param State -- The state the object was used in.
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    ///
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    /// \param VariableName -- The name of the variable that holds the unique
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    /// value.
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    ///
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    /// \param Loc -- The SourceLocation of the method invocation.
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    virtual void warnUseInInvalidState(StringRef MethodName,
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                                       StringRef VariableName,
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                                       StringRef State,
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                                       SourceLocation Loc) {}
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  };
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  class ConsumedStateMap {
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    using VarMapType = llvm::DenseMap<const VarDecl *, ConsumedState>;
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    using TmpMapType =
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        llvm::DenseMap<const CXXBindTemporaryExpr *, ConsumedState>;
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  protected:
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    bool Reachable = true;
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    const Stmt *From = nullptr;
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    VarMapType VarMap;
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    TmpMapType TmpMap;
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  public:
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    ConsumedStateMap() = default;
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    ConsumedStateMap(const ConsumedStateMap &Other)
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        : Reachable(Other.Reachable), From(Other.From), VarMap(Other.VarMap) {}
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    /// Warn if any of the parameters being tracked are not in the state
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    /// they were declared to be in upon return from a function.
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    void checkParamsForReturnTypestate(SourceLocation BlameLoc,
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      ConsumedWarningsHandlerBase &WarningsHandler) const;
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    /// Clear the TmpMap.
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    void clearTemporaries();
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    /// Get the consumed state of a given variable.
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    ConsumedState getState(const VarDecl *Var) const;
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    /// Get the consumed state of a given temporary value.
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    ConsumedState getState(const CXXBindTemporaryExpr *Tmp) const;
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    /// Merge this state map with another map.
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    void intersect(const ConsumedStateMap &Other);
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    void intersectAtLoopHead(const CFGBlock *LoopHead, const CFGBlock *LoopBack,
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      const ConsumedStateMap *LoopBackStates,
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      ConsumedWarningsHandlerBase &WarningsHandler);
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    /// Return true if this block is reachable.
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    bool isReachable() const { return Reachable; }
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    /// Mark the block as unreachable.
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    void markUnreachable();
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    /// Set the source for a decision about the branching of states.
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    /// \param Source -- The statement that was the origin of a branching
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    /// decision.
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    void setSource(const Stmt *Source) { this->From = Source; }
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    /// Set the consumed state of a given variable.
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    void setState(const VarDecl *Var, ConsumedState State);
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    /// Set the consumed state of a given temporary value.
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    void setState(const CXXBindTemporaryExpr *Tmp, ConsumedState State);
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    /// Remove the temporary value from our state map.
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    void remove(const CXXBindTemporaryExpr *Tmp);
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    /// Tests to see if there is a mismatch in the states stored in two
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    /// maps.
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    ///
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    /// \param Other -- The second map to compare against.
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    bool operator!=(const ConsumedStateMap *Other) const;
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  };
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  class ConsumedBlockInfo {
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    std::vector<std::unique_ptr<ConsumedStateMap>> StateMapsArray;
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    std::vector<unsigned int> VisitOrder;
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  public:
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    ConsumedBlockInfo() = default;
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    ConsumedBlockInfo(unsigned int NumBlocks, PostOrderCFGView *SortedGraph)
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        : StateMapsArray(NumBlocks), VisitOrder(NumBlocks, 0) {
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      unsigned int VisitOrderCounter = 0;
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      for (const auto BI : *SortedGraph)
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        VisitOrder[BI->getBlockID()] = VisitOrderCounter++;
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    }
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    bool allBackEdgesVisited(const CFGBlock *CurrBlock,
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                             const CFGBlock *TargetBlock);
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    void addInfo(const CFGBlock *Block, ConsumedStateMap *StateMap,
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                 std::unique_ptr<ConsumedStateMap> &OwnedStateMap);
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    void addInfo(const CFGBlock *Block,
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                 std::unique_ptr<ConsumedStateMap> StateMap);
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    ConsumedStateMap* borrowInfo(const CFGBlock *Block);
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    void discardInfo(const CFGBlock *Block);
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    std::unique_ptr<ConsumedStateMap> getInfo(const CFGBlock *Block);
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    bool isBackEdge(const CFGBlock *From, const CFGBlock *To);
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    bool isBackEdgeTarget(const CFGBlock *Block);
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  };
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  /// A class that handles the analysis of uniqueness violations.
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  class ConsumedAnalyzer {
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    ConsumedBlockInfo BlockInfo;
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    std::unique_ptr<ConsumedStateMap> CurrStates;
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    ConsumedState ExpectedReturnState;
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    void determineExpectedReturnState(AnalysisDeclContext &AC,
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                                      const FunctionDecl *D);
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    bool splitState(const CFGBlock *CurrBlock,
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                    const ConsumedStmtVisitor &Visitor);
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  public:
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    ConsumedWarningsHandlerBase &WarningsHandler;
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    ConsumedAnalyzer(ConsumedWarningsHandlerBase &WarningsHandler)
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        : WarningsHandler(WarningsHandler) {}
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    ConsumedState getExpectedReturnState() const { return ExpectedReturnState; }
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    /// Check a function's CFG for consumed violations.
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    ///
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    /// We traverse the blocks in the CFG, keeping track of the state of each
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    /// value who's type has uniquness annotations.  If methods are invoked in
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    /// the wrong state a warning is issued.  Each block in the CFG is traversed
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    /// exactly once.
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    void run(AnalysisDeclContext &AC);
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  };
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} // namespace consumed
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} // namespace clang
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#endif // LLVM_CLANG_ANALYSIS_ANALYSES_CONSUMED_H