1//===- LibCallAliasAnalysis.h - Implement AliasAnalysis for libcalls ------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines the LibCallAliasAnalysis class.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_ANALYSIS_LIBCALLALIASANALYSIS_H
15#define LLVM_ANALYSIS_LIBCALLALIASANALYSIS_H
16
17#include "llvm/Analysis/AliasAnalysis.h"
18#include "llvm/Pass.h"
19
20namespace llvm {
21  class LibCallInfo;
22  struct LibCallFunctionInfo;
23
24  /// LibCallAliasAnalysis - Alias analysis driven from LibCallInfo.
25  struct LibCallAliasAnalysis : public FunctionPass, public AliasAnalysis {
26    static char ID; // Class identification
27
28    LibCallInfo *LCI;
29
30    explicit LibCallAliasAnalysis(LibCallInfo *LC = nullptr)
31        : FunctionPass(ID), LCI(LC) {
32      initializeLibCallAliasAnalysisPass(*PassRegistry::getPassRegistry());
33    }
34    explicit LibCallAliasAnalysis(char &ID, LibCallInfo *LC)
35        : FunctionPass(ID), LCI(LC) {
36      initializeLibCallAliasAnalysisPass(*PassRegistry::getPassRegistry());
37    }
38    ~LibCallAliasAnalysis();
39
40    ModRefResult getModRefInfo(ImmutableCallSite CS,
41                               const Location &Loc) override;
42
43    ModRefResult getModRefInfo(ImmutableCallSite CS1,
44                               ImmutableCallSite CS2) override {
45      // TODO: Could compare two direct calls against each other if we cared to.
46      return AliasAnalysis::getModRefInfo(CS1, CS2);
47    }
48
49    void getAnalysisUsage(AnalysisUsage &AU) const override;
50
51    bool runOnFunction(Function &F) override {
52      InitializeAliasAnalysis(this);                 // set up super class
53      return false;
54    }
55
56    /// getAdjustedAnalysisPointer - This method is used when a pass implements
57    /// an analysis interface through multiple inheritance.  If needed, it
58    /// should override this to adjust the this pointer as needed for the
59    /// specified pass info.
60    void *getAdjustedAnalysisPointer(const void *PI) override {
61      if (PI == &AliasAnalysis::ID)
62        return (AliasAnalysis*)this;
63      return this;
64    }
65
66  private:
67    ModRefResult AnalyzeLibCallDetails(const LibCallFunctionInfo *FI,
68                                       ImmutableCallSite CS,
69                                       const Location &Loc);
70  };
71}  // End of llvm namespace
72
73#endif
74