clang  8.0.0svn
CFGReachabilityAnalysis.h
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1 //===- CFGReachabilityAnalysis.h - Basic reachability analysis --*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines a flow-sensitive, (mostly) path-insensitive reachability
11 // analysis based on Clang's CFGs. Clients can query if a given basic block
12 // is reachable within the CFG.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #ifndef LLVM_CLANG_ANALYSIS_ANALYSES_CFGREACHABILITYANALYSIS_H
17 #define LLVM_CLANG_ANALYSIS_ANALYSES_CFGREACHABILITYANALYSIS_H
18 
19 #include "llvm/ADT/BitVector.h"
20 #include "llvm/ADT/DenseMap.h"
21 
22 namespace clang {
23 
24 class CFG;
25 class CFGBlock;
26 
27 // A class that performs reachability queries for CFGBlocks. Several internal
28 // checks in this checker require reachability information. The requests all
29 // tend to have a common destination, so we lazily do a predecessor search
30 // from the destination node and cache the results to prevent work
31 // duplication.
33  using ReachableSet = llvm::BitVector;
34  using ReachableMap = llvm::DenseMap<unsigned, ReachableSet>;
35 
36  ReachableSet analyzed;
37  ReachableMap reachable;
38 
39 public:
41 
42  /// Returns true if the block 'Dst' can be reached from block 'Src'.
43  bool isReachable(const CFGBlock *Src, const CFGBlock *Dst);
44 
45 private:
46  void mapReachability(const CFGBlock *Dst);
47 };
48 
49 } // namespace clang
50 
51 #endif // LLVM_CLANG_ANALYSIS_ANALYSES_CFGREACHABILITYANALYSIS_H
Represents a single basic block in a source-level CFG.
Definition: CFG.h:552
Represents a source-level, intra-procedural CFG that represents the control-flow of a Stmt...
Definition: CFG.h:1003
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.