| //===- ObjCARCAliasAnalysis.h - ObjC ARC Alias Analysis ---------*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| /// \file |
| /// This file declares a simple ARC-aware AliasAnalysis using special knowledge |
| /// of Objective C to enhance other optimization passes which rely on the Alias |
| /// Analysis infrastructure. |
| /// |
| /// WARNING: This file knows about certain library functions. It recognizes them |
| /// by name, and hardwires knowledge of their semantics. |
| /// |
| /// WARNING: This file knows about how certain Objective-C library functions are |
| /// used. Naive LLVM IR transformations which would otherwise be |
| /// behavior-preserving may break these assumptions. |
| /// |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_ANALYSIS_OBJCARCALIASANALYSIS_H |
| #define LLVM_ANALYSIS_OBJCARCALIASANALYSIS_H |
| |
| #include "llvm/Analysis/AliasAnalysis.h" |
| #include "llvm/Pass.h" |
| |
| namespace llvm { |
| namespace objcarc { |
| |
| /// This is a simple alias analysis implementation that uses knowledge |
| /// of ARC constructs to answer queries. |
| /// |
| /// TODO: This class could be generalized to know about other ObjC-specific |
| /// tricks. Such as knowing that ivars in the non-fragile ABI are non-aliasing |
| /// even though their offsets are dynamic. |
| class ObjCARCAAResult : public AAResultBase<ObjCARCAAResult> { |
| friend AAResultBase<ObjCARCAAResult>; |
| |
| const DataLayout &DL; |
| |
| public: |
| explicit ObjCARCAAResult(const DataLayout &DL) : DL(DL) {} |
| ObjCARCAAResult(ObjCARCAAResult &&Arg) |
| : AAResultBase(std::move(Arg)), DL(Arg.DL) {} |
| |
| /// Handle invalidation events from the new pass manager. |
| /// |
| /// By definition, this result is stateless and so remains valid. |
| bool invalidate(Function &, const PreservedAnalyses &, |
| FunctionAnalysisManager::Invalidator &) { |
| return false; |
| } |
| |
| AliasResult alias(const MemoryLocation &LocA, const MemoryLocation &LocB, |
| AAQueryInfo &AAQI); |
| bool pointsToConstantMemory(const MemoryLocation &Loc, AAQueryInfo &AAQI, |
| bool OrLocal); |
| |
| using AAResultBase::getModRefBehavior; |
| FunctionModRefBehavior getModRefBehavior(const Function *F); |
| |
| using AAResultBase::getModRefInfo; |
| ModRefInfo getModRefInfo(const CallBase *Call, const MemoryLocation &Loc, |
| AAQueryInfo &AAQI); |
| }; |
| |
| /// Analysis pass providing a never-invalidated alias analysis result. |
| class ObjCARCAA : public AnalysisInfoMixin<ObjCARCAA> { |
| friend AnalysisInfoMixin<ObjCARCAA>; |
| static AnalysisKey Key; |
| |
| public: |
| typedef ObjCARCAAResult Result; |
| |
| ObjCARCAAResult run(Function &F, FunctionAnalysisManager &AM); |
| }; |
| |
| /// Legacy wrapper pass to provide the ObjCARCAAResult object. |
| class ObjCARCAAWrapperPass : public ImmutablePass { |
| std::unique_ptr<ObjCARCAAResult> Result; |
| |
| public: |
| static char ID; |
| |
| ObjCARCAAWrapperPass(); |
| |
| ObjCARCAAResult &getResult() { return *Result; } |
| const ObjCARCAAResult &getResult() const { return *Result; } |
| |
| bool doInitialization(Module &M) override; |
| bool doFinalization(Module &M) override; |
| void getAnalysisUsage(AnalysisUsage &AU) const override; |
| }; |
| |
| } // namespace objcarc |
| } // namespace llvm |
| |
| #endif |