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Diffstat (limited to 'clang-r353983e/include/llvm/Analysis/GlobalsModRef.h')
| -rw-r--r-- | clang-r353983e/include/llvm/Analysis/GlobalsModRef.h | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/clang-r353983e/include/llvm/Analysis/GlobalsModRef.h b/clang-r353983e/include/llvm/Analysis/GlobalsModRef.h new file mode 100644 index 00000000..14b20971 --- /dev/null +++ b/clang-r353983e/include/llvm/Analysis/GlobalsModRef.h @@ -0,0 +1,155 @@ +//===- GlobalsModRef.h - Simple Mod/Ref AA for Globals ----------*- 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 is the interface for a simple mod/ref and alias analysis over globals. +/// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_ANALYSIS_GLOBALSMODREF_H +#define LLVM_ANALYSIS_GLOBALSMODREF_H + +#include "llvm/Analysis/AliasAnalysis.h" +#include "llvm/Analysis/CallGraph.h" +#include "llvm/IR/Constants.h" +#include "llvm/IR/Function.h" +#include "llvm/IR/Module.h" +#include "llvm/IR/ValueHandle.h" +#include "llvm/Pass.h" +#include <list> + +namespace llvm { + +/// An alias analysis result set for globals. +/// +/// This focuses on handling aliasing properties of globals and interprocedural +/// function call mod/ref information. +class GlobalsAAResult : public AAResultBase<GlobalsAAResult> { + friend AAResultBase<GlobalsAAResult>; + + class FunctionInfo; + + const DataLayout &DL; + const TargetLibraryInfo &TLI; + + /// The globals that do not have their addresses taken. + SmallPtrSet<const GlobalValue *, 8> NonAddressTakenGlobals; + + /// IndirectGlobals - The memory pointed to by this global is known to be + /// 'owned' by the global. + SmallPtrSet<const GlobalValue *, 8> IndirectGlobals; + + /// AllocsForIndirectGlobals - If an instruction allocates memory for an + /// indirect global, this map indicates which one. + DenseMap<const Value *, const GlobalValue *> AllocsForIndirectGlobals; + + /// For each function, keep track of what globals are modified or read. + DenseMap<const Function *, FunctionInfo> FunctionInfos; + + /// A map of functions to SCC. The SCCs are described by a simple integer + /// ID that is only useful for comparing for equality (are two functions + /// in the same SCC or not?) + DenseMap<const Function *, unsigned> FunctionToSCCMap; + + /// Handle to clear this analysis on deletion of values. + struct DeletionCallbackHandle final : CallbackVH { + GlobalsAAResult *GAR; + std::list<DeletionCallbackHandle>::iterator I; + + DeletionCallbackHandle(GlobalsAAResult &GAR, Value *V) + : CallbackVH(V), GAR(&GAR) {} + + void deleted() override; + }; + + /// List of callbacks for globals being tracked by this analysis. Note that + /// these objects are quite large, but we only anticipate having one per + /// global tracked by this analysis. There are numerous optimizations we + /// could perform to the memory utilization here if this becomes a problem. + std::list<DeletionCallbackHandle> Handles; + + explicit GlobalsAAResult(const DataLayout &DL, const TargetLibraryInfo &TLI); + +public: + GlobalsAAResult(GlobalsAAResult &&Arg); + ~GlobalsAAResult(); + + static GlobalsAAResult analyzeModule(Module &M, const TargetLibraryInfo &TLI, + CallGraph &CG); + + //------------------------------------------------ + // Implement the AliasAnalysis API + // + AliasResult alias(const MemoryLocation &LocA, const MemoryLocation &LocB); + + using AAResultBase::getModRefInfo; + ModRefInfo getModRefInfo(const CallBase *Call, const MemoryLocation &Loc); + + /// getModRefBehavior - Return the behavior of the specified function if + /// called from the specified call site. The call site may be null in which + /// case the most generic behavior of this function should be returned. + FunctionModRefBehavior getModRefBehavior(const Function *F); + + /// getModRefBehavior - Return the behavior of the specified function if + /// called from the specified call site. The call site may be null in which + /// case the most generic behavior of this function should be returned. + FunctionModRefBehavior getModRefBehavior(const CallBase *Call); + +private: + FunctionInfo *getFunctionInfo(const Function *F); + + void AnalyzeGlobals(Module &M); + void AnalyzeCallGraph(CallGraph &CG, Module &M); + bool AnalyzeUsesOfPointer(Value *V, + SmallPtrSetImpl<Function *> *Readers = nullptr, + SmallPtrSetImpl<Function *> *Writers = nullptr, + GlobalValue *OkayStoreDest = nullptr); + bool AnalyzeIndirectGlobalMemory(GlobalVariable *GV); + void CollectSCCMembership(CallGraph &CG); + + bool isNonEscapingGlobalNoAlias(const GlobalValue *GV, const Value *V); + ModRefInfo getModRefInfoForArgument(const CallBase *Call, + const GlobalValue *GV); +}; + +/// Analysis pass providing a never-invalidated alias analysis result. +class GlobalsAA : public AnalysisInfoMixin<GlobalsAA> { + friend AnalysisInfoMixin<GlobalsAA>; + static AnalysisKey Key; + +public: + typedef GlobalsAAResult Result; + + GlobalsAAResult run(Module &M, ModuleAnalysisManager &AM); +}; + +/// Legacy wrapper pass to provide the GlobalsAAResult object. +class GlobalsAAWrapperPass : public ModulePass { + std::unique_ptr<GlobalsAAResult> Result; + +public: + static char ID; + + GlobalsAAWrapperPass(); + + GlobalsAAResult &getResult() { return *Result; } + const GlobalsAAResult &getResult() const { return *Result; } + + bool runOnModule(Module &M) override; + bool doFinalization(Module &M) override; + void getAnalysisUsage(AnalysisUsage &AU) const override; +}; + +//===--------------------------------------------------------------------===// +// +// createGlobalsAAWrapperPass - This pass provides alias and mod/ref info for +// global values that do not have their addresses taken. +// +ModulePass *createGlobalsAAWrapperPass(); +} + +#endif |
