• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 //===- TypeBasedAliasAnalysis.h - Type-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 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/Function.h"
20 #include "llvm/IR/Metadata.h"
21 #include "llvm/Pass.h"
22 
23 namespace llvm {
24 
25 /// A simple AA result that uses TBAA metadata to answer queries.
26 class TypeBasedAAResult : public AAResultBase<TypeBasedAAResult> {
27   friend AAResultBase<TypeBasedAAResult>;
28 
29 public:
TypeBasedAAResult()30   explicit TypeBasedAAResult() {}
TypeBasedAAResult(TypeBasedAAResult && Arg)31   TypeBasedAAResult(TypeBasedAAResult &&Arg) : AAResultBase(std::move(Arg)) {}
32 
33   /// Handle invalidation events from the new pass manager.
34   ///
35   /// By definition, this result is stateless and so remains valid.
invalidate(Function &,const PreservedAnalyses &)36   bool invalidate(Function &, const PreservedAnalyses &) { return false; }
37 
38   AliasResult alias(const MemoryLocation &LocA, const MemoryLocation &LocB);
39   bool pointsToConstantMemory(const MemoryLocation &Loc, bool OrLocal);
40   FunctionModRefBehavior getModRefBehavior(ImmutableCallSite CS);
41   FunctionModRefBehavior getModRefBehavior(const Function *F);
42   ModRefInfo getModRefInfo(ImmutableCallSite CS, const MemoryLocation &Loc);
43   ModRefInfo getModRefInfo(ImmutableCallSite CS1, ImmutableCallSite CS2);
44 
45 private:
46   bool Aliases(const MDNode *A, const MDNode *B) const;
47   bool PathAliases(const MDNode *A, const MDNode *B) const;
48 };
49 
50 /// Analysis pass providing a never-invalidated alias analysis result.
51 class TypeBasedAA : public AnalysisInfoMixin<TypeBasedAA> {
52   friend AnalysisInfoMixin<TypeBasedAA>;
53   static char PassID;
54 
55 public:
56   typedef TypeBasedAAResult Result;
57 
58   TypeBasedAAResult run(Function &F, AnalysisManager<Function> &AM);
59 };
60 
61 /// Legacy wrapper pass to provide the TypeBasedAAResult object.
62 class TypeBasedAAWrapperPass : public ImmutablePass {
63   std::unique_ptr<TypeBasedAAResult> Result;
64 
65 public:
66   static char ID;
67 
68   TypeBasedAAWrapperPass();
69 
getResult()70   TypeBasedAAResult &getResult() { return *Result; }
getResult()71   const TypeBasedAAResult &getResult() const { return *Result; }
72 
73   bool doInitialization(Module &M) override;
74   bool doFinalization(Module &M) override;
75   void getAnalysisUsage(AnalysisUsage &AU) const override;
76 };
77 
78 //===--------------------------------------------------------------------===//
79 //
80 // createTypeBasedAAWrapperPass - This pass implements metadata-based
81 // type-based alias analysis.
82 //
83 ImmutablePass *createTypeBasedAAWrapperPass();
84 }
85 
86 #endif
87