clang  9.0.0svn
CFGReachabilityAnalysis.h
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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.
32  using ReachableSet = llvm::BitVector;
33  using ReachableMap = llvm::DenseMap<unsigned, ReachableSet>;
34 
35  ReachableSet analyzed;
36  ReachableMap reachable;
37 
38 public:
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
Represents a single basic block in a source-level CFG.
Definition: CFG.h:551
Represents a source-level, intra-procedural CFG that represents the control-flow of a Stmt...
Definition: CFG.h:1002
bool isReachable(const CFGBlock *Src, const CFGBlock *Dst)
Returns true if the block &#39;Dst&#39; can be reached from block &#39;Src&#39;.
Dataflow Directional Tag Classes.