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      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