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
27namespace llvm {
28
29class Function;
30class MemoryLocation;
31class TargetLibraryInfo;
32
33namespace cflaa {
34
35struct AliasSummary;
36
37} // end namespace cflaa
38
39class CFLAndersAAResult : public AAResultBase<CFLAndersAAResult> {
40 friend AAResultBase<CFLAndersAAResult>;
41
42 class FunctionInfo;
43
44public:
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
66private:
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.
93class CFLAndersAA : public AnalysisInfoMixin<CFLAndersAA> {
94 friend AnalysisInfoMixin<CFLAndersAA>;
95
96 static AnalysisKey Key;
97
98public:
99 using Result = CFLAndersAAResult;
100
101 CFLAndersAAResult run(Function &F, FunctionAnalysisManager &AM);
102};
103
104/// Legacy wrapper pass to provide the CFLAndersAAResult object.
105class CFLAndersAAWrapperPass : public ImmutablePass {
106 std::unique_ptr<CFLAndersAAResult> Result;
107
108public:
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.
122ImmutablePass *createCFLAndersAAWrapperPass();
123
124} // end namespace llvm
125
126#endif // LLVM_ANALYSIS_CFLANDERSALIASANALYSIS_H
127