| 1 | //===- CFGReachabilityAnalysis.h - Basic reachability analysis --*- C++ -*-===// |
|---|---|
| 2 | // |
| 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 |
| 6 | // |
| 7 | //===----------------------------------------------------------------------===// |
| 8 | // |
| 9 | // This file defines a flow-sensitive, (mostly) path-insensitive reachability |
| 10 | // analysis based on Clang's CFGs. Clients can query if a given basic block |
| 11 | // is reachable within the CFG. |
| 12 | // |
| 13 | //===----------------------------------------------------------------------===// |
| 14 | |
| 15 | #ifndef LLVM_CLANG_ANALYSIS_ANALYSES_CFGREACHABILITYANALYSIS_H |
| 16 | #define LLVM_CLANG_ANALYSIS_ANALYSES_CFGREACHABILITYANALYSIS_H |
| 17 | |
| 18 | #include "llvm/ADT/BitVector.h" |
| 19 | #include "llvm/ADT/DenseMap.h" |
| 20 | |
| 21 | namespace clang { |
| 22 | |
| 23 | class CFG; |
| 24 | class CFGBlock; |
| 25 | |
| 26 | // A class that performs reachability queries for CFGBlocks. Several internal |
| 27 | // checks in this checker require reachability information. The requests all |
| 28 | // tend to have a common destination, so we lazily do a predecessor search |
| 29 | // from the destination node and cache the results to prevent work |
| 30 | // duplication. |
| 31 | class CFGReverseBlockReachabilityAnalysis { |
| 32 | using ReachableSet = llvm::BitVector; |
| 33 | using ReachableMap = llvm::DenseMap<unsigned, ReachableSet>; |
| 34 | |
| 35 | ReachableSet analyzed; |
| 36 | ReachableMap reachable; |
| 37 | |
| 38 | public: |
| 39 | CFGReverseBlockReachabilityAnalysis(const CFG &cfg); |
| 40 | |
| 41 | /// Returns true if the block 'Dst' can be reached from block 'Src'. |
| 42 | bool isReachable(const CFGBlock *Src, const CFGBlock *Dst); |
| 43 | |
| 44 | private: |
| 45 | void mapReachability(const CFGBlock *Dst); |
| 46 | }; |
| 47 | |
| 48 | } // namespace clang |
| 49 | |
| 50 | #endif // LLVM_CLANG_ANALYSIS_ANALYSES_CFGREACHABILITYANALYSIS_H |
| 51 |