1 //===- TypeBasedAliasAnalysis.h - Type-Based Alias 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 /// \file
10 /// This is the interface for a metadata-based TBAA. See the source file for
11 /// details on the algorithm.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_ANALYSIS_TYPEBASEDALIASANALYSIS_H
16 #define LLVM_ANALYSIS_TYPEBASEDALIASANALYSIS_H
17 
18 #include "llvm/Analysis/AliasAnalysis.h"
19 #include "llvm/IR/PassManager.h"
20 #include "llvm/Pass.h"
21 #include <memory>
22 
23 namespace llvm {
24 
25 class CallBase;
26 class Function;
27 class MDNode;
28 class MemoryLocation;
29 
30 /// A simple AA result that uses TBAA metadata to answer queries.
31 class TypeBasedAAResult : public AAResultBase<TypeBasedAAResult> {
32   friend AAResultBase<TypeBasedAAResult>;
33 
34 public:
35   /// Handle invalidation events from the new pass manager.
36   ///
37   /// By definition, this result is stateless and so remains valid.
38   bool invalidate(Function &, const PreservedAnalyses &,
39                   FunctionAnalysisManager::Invalidator &) {
40     return false;
41   }
42 
43   AliasResult alias(const MemoryLocation &LocA, const MemoryLocation &LocB,
44                     AAQueryInfo &AAQI);
45   bool pointsToConstantMemory(const MemoryLocation &Loc, AAQueryInfo &AAQI,
46                               bool OrLocal);
47   FunctionModRefBehavior getModRefBehavior(const CallBase *Call);
48   FunctionModRefBehavior getModRefBehavior(const Function *F);
49   ModRefInfo getModRefInfo(const CallBase *Call, const MemoryLocation &Loc,
50                            AAQueryInfo &AAQI);
51   ModRefInfo getModRefInfo(const CallBase *Call1, const CallBase *Call2,
52                            AAQueryInfo &AAQI);
53 
54 private:
55   bool Aliases(const MDNode *A, const MDNode *B) const;
56 };
57 
58 /// Analysis pass providing a never-invalidated alias analysis result.
59 class TypeBasedAA : public AnalysisInfoMixin<TypeBasedAA> {
60   friend AnalysisInfoMixin<TypeBasedAA>;
61 
62   static AnalysisKey Key;
63 
64 public:
65   using Result = TypeBasedAAResult;
66 
67   TypeBasedAAResult run(Function &F, FunctionAnalysisManager &AM);
68 };
69 
70 /// Legacy wrapper pass to provide the TypeBasedAAResult object.
71 class TypeBasedAAWrapperPass : public ImmutablePass {
72   std::unique_ptr<TypeBasedAAResult> Result;
73 
74 public:
75   static char ID;
76 
77   TypeBasedAAWrapperPass();
78 
79   TypeBasedAAResult &getResult() { return *Result; }
80   const TypeBasedAAResult &getResult() const { return *Result; }
81 
82   bool doInitialization(Module &M) override;
83   bool doFinalization(Module &M) override;
84   void getAnalysisUsage(AnalysisUsage &AU) const override;
85 };
86 
87 //===--------------------------------------------------------------------===//
88 //
89 // createTypeBasedAAWrapperPass - This pass implements metadata-based
90 // type-based alias analysis.
91 //
92 ImmutablePass *createTypeBasedAAWrapperPass();
93 
94 } // end namespace llvm
95 
96 #endif // LLVM_ANALYSIS_TYPEBASEDALIASANALYSIS_H
97