| 1 | //===- CFGReachabilityAnalysis.h - Basic reachability analysis --*- C++ -*-===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | // |
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| 9 | // This file defines a flow-sensitive, (mostly) path-insensitive reachability |
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| 10 | // analysis based on Clang's CFGs. Clients can query if a given basic block |
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| 11 | // is reachable within the CFG. |
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| 12 | // |
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| 13 | //===----------------------------------------------------------------------===// |
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| 14 | |
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| 15 | #ifndef LLVM_CLANG_ANALYSIS_ANALYSES_CFGREACHABILITYANALYSIS_H |
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| 16 | #define LLVM_CLANG_ANALYSIS_ANALYSES_CFGREACHABILITYANALYSIS_H |
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| 17 | |
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| 18 | #include "llvm/ADT/BitVector.h" |
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| 19 | #include "llvm/ADT/DenseMap.h" |
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| 20 | |
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| 21 | namespace clang { |
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| 22 | |
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| 23 | class CFG; |
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| 24 | class CFGBlock; |
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| 25 | |
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| 26 | // A class that performs reachability queries for CFGBlocks. Several internal |
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| 27 | // checks in this checker require reachability information. The requests all |
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| 28 | // tend to have a common destination, so we lazily do a predecessor search |
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| 29 | // from the destination node and cache the results to prevent work |
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| 30 | // duplication. |
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| 31 | class CFGReverseBlockReachabilityAnalysis { |
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| 32 | using ReachableSet = llvm::BitVector; |
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| 33 | using ReachableMap = llvm::DenseMap<unsigned, ReachableSet>; |
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| 34 | |
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| 35 | ReachableSet analyzed; |
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| 36 | ReachableMap reachable; |
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| 37 | |
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| 38 | public: |
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| 39 | CFGReverseBlockReachabilityAnalysis(const CFG &cfg); |
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| 40 | |
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| 41 | /// Returns true if the block 'Dst' can be reached from block 'Src'. |
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| 42 | bool isReachable(const CFGBlock *Src, const CFGBlock *Dst); |
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| 43 | |
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| 44 | private: |
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| 45 | void mapReachability(const CFGBlock *Dst); |
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| 46 | }; |
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| 47 | |
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| 48 | } // namespace clang |
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| 49 | |
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| 50 | #endif // LLVM_CLANG_ANALYSIS_ANALYSES_CFGREACHABILITYANALYSIS_H |
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| 51 | |
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