1 | //==- CFLAndersAliasAnalysis.h - Unification-based Alias 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 | /// \file |
10 | /// This is the interface for LLVM's inclusion-based alias analysis |
11 | /// implemented with CFL graph reachability. |
12 | /// |
13 | //===----------------------------------------------------------------------===// |
14 | |
15 | #ifndef LLVM_ANALYSIS_CFLANDERSALIASANALYSIS_H |
16 | #define LLVM_ANALYSIS_CFLANDERSALIASANALYSIS_H |
17 | |
18 | #include "llvm/ADT/DenseMap.h" |
19 | #include "llvm/ADT/Optional.h" |
20 | #include "llvm/Analysis/AliasAnalysis.h" |
21 | #include "llvm/Analysis/CFLAliasAnalysisUtils.h" |
22 | #include "llvm/IR/PassManager.h" |
23 | #include "llvm/Pass.h" |
24 | #include <forward_list> |
25 | #include <memory> |
26 | |
27 | namespace llvm { |
28 | |
29 | class Function; |
30 | class MemoryLocation; |
31 | class TargetLibraryInfo; |
32 | |
33 | namespace cflaa { |
34 | |
35 | struct AliasSummary; |
36 | |
37 | } // end namespace cflaa |
38 | |
39 | class CFLAndersAAResult : public AAResultBase<CFLAndersAAResult> { |
40 | friend AAResultBase<CFLAndersAAResult>; |
41 | |
42 | class FunctionInfo; |
43 | |
44 | public: |
45 | explicit CFLAndersAAResult(const TargetLibraryInfo &TLI); |
46 | CFLAndersAAResult(CFLAndersAAResult &&RHS); |
47 | ~CFLAndersAAResult(); |
48 | |
49 | /// Handle invalidation events from the new pass manager. |
50 | /// By definition, this result is stateless and so remains valid. |
51 | bool invalidate(Function &, const PreservedAnalyses &, |
52 | FunctionAnalysisManager::Invalidator &) { |
53 | return false; |
54 | } |
55 | |
56 | /// Evict the given function from cache |
57 | void evict(const Function *Fn); |
58 | |
59 | /// Get the alias summary for the given function |
60 | /// Return nullptr if the summary is not found or not available |
61 | const cflaa::AliasSummary *getAliasSummary(const Function &); |
62 | |
63 | AliasResult query(const MemoryLocation &, const MemoryLocation &); |
64 | AliasResult alias(const MemoryLocation &, const MemoryLocation &); |
65 | |
66 | private: |
67 | /// Ensures that the given function is available in the cache. |
68 | /// Returns the appropriate entry from the cache. |
69 | const Optional<FunctionInfo> &ensureCached(const Function &); |
70 | |
71 | /// Inserts the given Function into the cache. |
72 | void scan(const Function &); |
73 | |
74 | /// Build summary for a given function |
75 | FunctionInfo buildInfoFrom(const Function &); |
76 | |
77 | const TargetLibraryInfo &TLI; |
78 | |
79 | /// Cached mapping of Functions to their StratifiedSets. |
80 | /// If a function's sets are currently being built, it is marked |
81 | /// in the cache as an Optional without a value. This way, if we |
82 | /// have any kind of recursion, it is discernable from a function |
83 | /// that simply has empty sets. |
84 | DenseMap<const Function *, Optional<FunctionInfo>> Cache; |
85 | |
86 | std::forward_list<cflaa::FunctionHandle<CFLAndersAAResult>> Handles; |
87 | }; |
88 | |
89 | /// Analysis pass providing a never-invalidated alias analysis result. |
90 | /// |
91 | /// FIXME: We really should refactor CFL to use the analysis more heavily, and |
92 | /// in particular to leverage invalidation to trigger re-computation. |
93 | class CFLAndersAA : public AnalysisInfoMixin<CFLAndersAA> { |
94 | friend AnalysisInfoMixin<CFLAndersAA>; |
95 | |
96 | static AnalysisKey Key; |
97 | |
98 | public: |
99 | using Result = CFLAndersAAResult; |
100 | |
101 | CFLAndersAAResult run(Function &F, FunctionAnalysisManager &AM); |
102 | }; |
103 | |
104 | /// Legacy wrapper pass to provide the CFLAndersAAResult object. |
105 | class CFLAndersAAWrapperPass : public ImmutablePass { |
106 | std::unique_ptr<CFLAndersAAResult> Result; |
107 | |
108 | public: |
109 | static char ID; |
110 | |
111 | CFLAndersAAWrapperPass(); |
112 | |
113 | CFLAndersAAResult &getResult() { return *Result; } |
114 | const CFLAndersAAResult &getResult() const { return *Result; } |
115 | |
116 | void initializePass() override; |
117 | void getAnalysisUsage(AnalysisUsage &AU) const override; |
118 | }; |
119 | |
120 | // createCFLAndersAAWrapperPass - This pass implements a set-based approach to |
121 | // alias analysis. |
122 | ImmutablePass *createCFLAndersAAWrapperPass(); |
123 | |
124 | } // end namespace llvm |
125 | |
126 | #endif // LLVM_ANALYSIS_CFLANDERSALIASANALYSIS_H |
127 | |