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 { 32 /// True if type sanitizer is enabled. When TypeSanitizer is used, don't use 33 /// TBAA information for alias analysis as this might cause us to remove 34 /// memory accesses that we need to verify at runtime. 35 bool UsingTypeSanitizer; 36 37 public: 38 TypeBasedAAResult(bool UsingTypeSanitizer) 39 : UsingTypeSanitizer(UsingTypeSanitizer) {} 40 41 /// Handle invalidation events from the new pass manager. 42 /// 43 /// By definition, this result is stateless and so remains valid. 44 bool invalidate(Function &, const PreservedAnalyses &, 45 FunctionAnalysisManager::Invalidator &) { 46 return false; 47 } 48 49 AliasResult alias(const MemoryLocation &LocA, const MemoryLocation &LocB, 50 AAQueryInfo &AAQI, const Instruction *CtxI); 51 ModRefInfo getModRefInfoMask(const MemoryLocation &Loc, AAQueryInfo &AAQI, 52 bool IgnoreLocals); 53 54 MemoryEffects getMemoryEffects(const CallBase *Call, AAQueryInfo &AAQI); 55 MemoryEffects getMemoryEffects(const Function *F); 56 ModRefInfo getModRefInfo(const CallBase *Call, const MemoryLocation &Loc, 57 AAQueryInfo &AAQI); 58 ModRefInfo getModRefInfo(const CallBase *Call1, const CallBase *Call2, 59 AAQueryInfo &AAQI); 60 61 private: 62 bool Aliases(const MDNode *A, const MDNode *B) const; 63 64 /// Returns true if TBAA metadata should be used, that is if TBAA is enabled 65 /// and type sanitizer is not used. 66 bool shouldUseTBAA() const; 67 }; 68 69 /// Analysis pass providing a never-invalidated alias analysis result. 70 class TypeBasedAA : public AnalysisInfoMixin<TypeBasedAA> { 71 friend AnalysisInfoMixin<TypeBasedAA>; 72 73 static AnalysisKey Key; 74 75 public: 76 using Result = TypeBasedAAResult; 77 78 TypeBasedAAResult run(Function &F, FunctionAnalysisManager &AM); 79 }; 80 81 /// Legacy wrapper pass to provide the TypeBasedAAResult object. 82 class TypeBasedAAWrapperPass : public ImmutablePass { 83 std::unique_ptr<TypeBasedAAResult> Result; 84 85 public: 86 static char ID; 87 88 TypeBasedAAWrapperPass(); 89 90 TypeBasedAAResult &getResult() { return *Result; } 91 const TypeBasedAAResult &getResult() const { return *Result; } 92 93 bool doInitialization(Module &M) override; 94 bool doFinalization(Module &M) override; 95 void getAnalysisUsage(AnalysisUsage &AU) const override; 96 }; 97 98 //===--------------------------------------------------------------------===// 99 // 100 // createTypeBasedAAWrapperPass - This pass implements metadata-based 101 // type-based alias analysis. 102 // 103 ImmutablePass *createTypeBasedAAWrapperPass(); 104 105 } // end namespace llvm 106 107 #endif // LLVM_ANALYSIS_TYPEBASEDALIASANALYSIS_H 108