Coverage Report

Created: 2019-02-15 18:59

/Users/buildslave/jenkins/workspace/clang-stage2-coverage-R/llvm/include/llvm/Analysis/CFLSteensAliasAnalysis.h
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//==- CFLSteensAliasAnalysis.h - Unification-based Alias Analysis -*- C++-*-==//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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/// \file
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/// This is the interface for LLVM's unification-based alias analysis
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/// implemented with CFL graph reachability.
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///
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_ANALYSIS_CFLSTEENSALIASANALYSIS_H
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#define LLVM_ANALYSIS_CFLSTEENSALIASANALYSIS_H
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#include "llvm/ADT/DenseMap.h"
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#include "llvm/ADT/Optional.h"
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#include "llvm/Analysis/AliasAnalysis.h"
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#include "llvm/Analysis/CFLAliasAnalysisUtils.h"
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#include "llvm/Analysis/MemoryLocation.h"
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#include "llvm/IR/PassManager.h"
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#include "llvm/Pass.h"
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#include "llvm/Support/Casting.h"
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#include <forward_list>
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#include <memory>
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namespace llvm {
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class Function;
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class TargetLibraryInfo;
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namespace cflaa {
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struct AliasSummary;
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} // end namespace cflaa
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class CFLSteensAAResult : public AAResultBase<CFLSteensAAResult> {
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  friend AAResultBase<CFLSteensAAResult>;
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  class FunctionInfo;
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public:
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  explicit CFLSteensAAResult(const TargetLibraryInfo &TLI);
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  CFLSteensAAResult(CFLSteensAAResult &&Arg);
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  ~CFLSteensAAResult();
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  /// Handle invalidation events from the new pass manager.
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  ///
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  /// By definition, this result is stateless and so remains valid.
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  bool invalidate(Function &, const PreservedAnalyses &,
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                  FunctionAnalysisManager::Invalidator &) {
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    return false;
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  }
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  /// Inserts the given Function into the cache.
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  void scan(Function *Fn);
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  void evict(Function *Fn);
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  /// Ensures that the given function is available in the cache.
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  /// Returns the appropriate entry from the cache.
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  const Optional<FunctionInfo> &ensureCached(Function *Fn);
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  /// Get the alias summary for the given function
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  /// Return nullptr if the summary is not found or not available
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  const cflaa::AliasSummary *getAliasSummary(Function &Fn);
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  AliasResult query(const MemoryLocation &LocA, const MemoryLocation &LocB);
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  AliasResult alias(const MemoryLocation &LocA, const MemoryLocation &LocB) {
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    if (LocA.Ptr == LocB.Ptr)
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      return MustAlias;
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    // Comparisons between global variables and other constants should be
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    // handled by BasicAA.
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    // CFLSteensAA may report NoAlias when comparing a GlobalValue and
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    // ConstantExpr, but every query needs to have at least one Value tied to a
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    // Function, and neither GlobalValues nor ConstantExprs are.
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    if (isa<Constant>(LocA.Ptr) && 
isa<Constant>(LocB.Ptr)51
)
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      return AAResultBase::alias(LocA, LocB);
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    AliasResult QueryResult = query(LocA, LocB);
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    if (QueryResult == MayAlias)
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      return AAResultBase::alias(LocA, LocB);
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    return QueryResult;
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  }
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private:
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  const TargetLibraryInfo &TLI;
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  /// Cached mapping of Functions to their StratifiedSets.
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  /// If a function's sets are currently being built, it is marked
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  /// in the cache as an Optional without a value. This way, if we
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  /// have any kind of recursion, it is discernable from a function
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  /// that simply has empty sets.
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  DenseMap<Function *, Optional<FunctionInfo>> Cache;
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  std::forward_list<cflaa::FunctionHandle<CFLSteensAAResult>> Handles;
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  FunctionInfo buildSetsFrom(Function *F);
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};
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/// Analysis pass providing a never-invalidated alias analysis result.
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///
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/// FIXME: We really should refactor CFL to use the analysis more heavily, and
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/// in particular to leverage invalidation to trigger re-computation of sets.
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class CFLSteensAA : public AnalysisInfoMixin<CFLSteensAA> {
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  friend AnalysisInfoMixin<CFLSteensAA>;
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  static AnalysisKey Key;
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public:
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  using Result = CFLSteensAAResult;
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  CFLSteensAAResult run(Function &F, FunctionAnalysisManager &AM);
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};
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/// Legacy wrapper pass to provide the CFLSteensAAResult object.
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class CFLSteensAAWrapperPass : public ImmutablePass {
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  std::unique_ptr<CFLSteensAAResult> Result;
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public:
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  static char ID;
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  CFLSteensAAWrapperPass();
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  CFLSteensAAResult &getResult() { return *Result; }
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  const CFLSteensAAResult &getResult() const { return *Result; }
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  void initializePass() override;
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  void getAnalysisUsage(AnalysisUsage &AU) const override;
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};
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// createCFLSteensAAWrapperPass - This pass implements a set-based approach to
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// alias analysis.
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ImmutablePass *createCFLSteensAAWrapperPass();
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} // end namespace llvm
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#endif // LLVM_ANALYSIS_CFLSTEENSALIASANALYSIS_H