Subversion Repositories QNX 8.QNX8 LLVM/Clang compiler suite

//===- CFGReachabilityAnalysis.h - Basic reachability analysis --*- 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

//

//===----------------------------------------------------------------------===//

//

// This file defines a flow-sensitive, (mostly) path-insensitive reachability

// analysis based on Clang's CFGs.  Clients can query if a given basic block

// is reachable within the CFG.

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_ANALYSIS_ANALYSES_CFGREACHABILITYANALYSIS_H

#define LLVM_CLANG_ANALYSIS_ANALYSES_CFGREACHABILITYANALYSIS_H

#include "llvm/ADT/BitVector.h"

#include "llvm/ADT/DenseMap.h"

namespace clang {

class CFG;

class CFGBlock;

// A class that performs reachability queries for CFGBlocks. Several internal

// checks in this checker require reachability information. The requests all

// tend to have a common destination, so we lazily do a predecessor search

// from the destination node and cache the results to prevent work

// duplication.

class CFGReverseBlockReachabilityAnalysis {

  using ReachableSet = llvm::BitVector;

  using ReachableMap = llvm::DenseMap<unsigned, ReachableSet>;

  ReachableSet analyzed;

  ReachableMap reachable;

public:

  CFGReverseBlockReachabilityAnalysis(const CFG &cfg);

  /// Returns true if the block 'Dst' can be reached from block 'Src'.

  bool isReachable(const CFGBlock *Src, const CFGBlock *Dst);

private:

  void mapReachability(const CFGBlock *Dst);

};

} // namespace clang

#endif // LLVM_CLANG_ANALYSIS_ANALYSES_CFGREACHABILITYANALYSIS_H