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//==- CFLAndersAliasAnalysis.h - Unification-based 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 is the interface for LLVM's inclusion-based alias analysis
/// implemented with CFL graph reachability.
///
//===----------------------------------------------------------------------===//
#ifndef LLVM_ANALYSIS_CFLANDERSALIASANALYSIS_H
#define LLVM_ANALYSIS_CFLANDERSALIASANALYSIS_H
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/Optional.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/CFLAliasAnalysisUtils.h"
#include "llvm/IR/PassManager.h"
#include "llvm/Pass.h"
#include <forward_list>
#include <memory>
namespace llvm {
class Function;
class MemoryLocation;
class TargetLibraryInfo;
namespace cflaa {
struct AliasSummary;
} // end namespace cflaa
class CFLAndersAAResult : public AAResultBase<CFLAndersAAResult> {
friend AAResultBase<CFLAndersAAResult>;
class FunctionInfo;
public:
explicit CFLAndersAAResult(const TargetLibraryInfo &TLI);
CFLAndersAAResult(CFLAndersAAResult &&RHS);
~CFLAndersAAResult();
/// 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;
}
/// Evict the given function from cache
void evict(const Function *Fn);
/// Get the alias summary for the given function
/// Return nullptr if the summary is not found or not available
const cflaa::AliasSummary *getAliasSummary(const Function &);
AliasResult query(const MemoryLocation &, const MemoryLocation &);
AliasResult alias(const MemoryLocation &, const MemoryLocation &);
private:
/// Ensures that the given function is available in the cache.
/// Returns the appropriate entry from the cache.
const Optional<FunctionInfo> &ensureCached(const Function &);
/// Inserts the given Function into the cache.
void scan(const Function &);
/// Build summary for a given function
FunctionInfo buildInfoFrom(const Function &);
const TargetLibraryInfo &TLI;
/// Cached mapping of Functions to their StratifiedSets.
/// If a function's sets are currently being built, it is marked
/// in the cache as an Optional without a value. This way, if we
/// have any kind of recursion, it is discernable from a function
/// that simply has empty sets.
DenseMap<const Function *, Optional<FunctionInfo>> Cache;
std::forward_list<cflaa::FunctionHandle<CFLAndersAAResult>> Handles;
};
/// Analysis pass providing a never-invalidated alias analysis result.
///
/// FIXME: We really should refactor CFL to use the analysis more heavily, and
/// in particular to leverage invalidation to trigger re-computation.
class CFLAndersAA : public AnalysisInfoMixin<CFLAndersAA> {
friend AnalysisInfoMixin<CFLAndersAA>;
static AnalysisKey Key;
public:
using Result = CFLAndersAAResult;
CFLAndersAAResult run(Function &F, FunctionAnalysisManager &AM);
};
/// Legacy wrapper pass to provide the CFLAndersAAResult object.
class CFLAndersAAWrapperPass : public ImmutablePass {
std::unique_ptr<CFLAndersAAResult> Result;
public:
static char ID;
CFLAndersAAWrapperPass();
CFLAndersAAResult &getResult() { return *Result; }
const CFLAndersAAResult &getResult() const { return *Result; }
void initializePass() override;
void getAnalysisUsage(AnalysisUsage &AU) const override;
};
// createCFLAndersAAWrapperPass - This pass implements a set-based approach to
// alias analysis.
ImmutablePass *createCFLAndersAAWrapperPass();
} // end namespace llvm
#endif // LLVM_ANALYSIS_CFLANDERSALIASANALYSIS_H