NoOwnershipChangeVisitor.h

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//===--------------------------------------------------------------*- C++ -*--//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
 
#include "clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitors.h"
#include "clang/StaticAnalyzer/Core/Checker.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState_Fwd.h"
 
namespace clang {
namespace ento {
 
class NoOwnershipChangeVisitor : public NoStateChangeFuncVisitor {
protected:
  // The symbol whose (lack of) ownership change we are interested in.
  SymbolRef Sym;
  const CheckerBackend &Checker;
 
  LLVM_DUMP_METHOD static std::string
  getFunctionName(const ExplodedNode *CallEnterN);
 
  /// Heuristically guess whether the callee intended to free the resource. This
  /// is done syntactically, because we are trying to argue about alternative
  /// paths of execution, and as a consequence we don't have path-sensitive
  /// information.
  virtual bool doesFnIntendToHandleOwnership(const Decl *Callee,
                                             ASTContext &ACtx) = 0;
 
  virtual bool hasResourceStateChanged(ProgramStateRef CallEnterState,
                                       ProgramStateRef CallExitEndState) = 0;
 
  bool wasModifiedInFunction(const ExplodedNode *CallEnterN,
                             const ExplodedNode *CallExitEndN) final;
 
  virtual PathDiagnosticPieceRef emitNote(const ExplodedNode *N) = 0;
 
  PathDiagnosticPieceRef maybeEmitNoteForObjCSelf(PathSensitiveBugReport &R,
                                                  const ObjCMethodCall &Call,
                                                  const ExplodedNode *N) final {
    // TODO: Implement.
    return nullptr;
  }
 
  PathDiagnosticPieceRef maybeEmitNoteForCXXThis(PathSensitiveBugReport &R,
                                                 const CXXConstructorCall &Call,
                                                 const ExplodedNode *N) final {
    // TODO: Implement.
    return nullptr;
  }
 
  // Set this to final, effectively dispatch to emitNote.
  PathDiagnosticPieceRef
  maybeEmitNoteForParameters(PathSensitiveBugReport &R, const CallEvent &Call,
                             const ExplodedNode *N) final;
 
public:
  using OwnerSet = llvm::SmallPtrSet<const MemRegion *, 8>;
 
private:
  OwnerSet getOwnersAtNode(const ExplodedNode *N);
 
public:
  NoOwnershipChangeVisitor(SymbolRef Sym, const CheckerBackend *Checker)
      : NoStateChangeFuncVisitor(bugreporter::TrackingKind::Thorough), Sym(Sym),
        Checker(*Checker) {}
 
  void Profile(llvm::FoldingSetNodeID &ID) const override {
    static int Tag = 0;
    ID.AddPointer(&Tag);
    ID.AddPointer(Sym);
  }
};
} // namespace ento
} // namespace clang