1//===-- MachineFunctionPass.h - Pass for MachineFunctions --------*-C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file defines the MachineFunctionPass class.  MachineFunctionPass's are
10// just FunctionPass's, except they operate on machine code as part of a code
11// generator.  Because they operate on machine code, not the LLVM
12// representation, MachineFunctionPass's are not allowed to modify the LLVM
13// representation.  Due to this limitation, the MachineFunctionPass class takes
14// care of declaring that no LLVM passes are invalidated.
15//
16//===----------------------------------------------------------------------===//
17
18#ifndef LLVM_CODEGEN_MACHINEFUNCTIONPASS_H
19#define LLVM_CODEGEN_MACHINEFUNCTIONPASS_H
20
21#include "llvm/CodeGen/MachineFunction.h"
22#include "llvm/Pass.h"
23
24namespace llvm {
25
26/// MachineFunctionPass - This class adapts the FunctionPass interface to
27/// allow convenient creation of passes that operate on the MachineFunction
28/// representation. Instead of overriding runOnFunction, subclasses
29/// override runOnMachineFunction.
30class MachineFunctionPass : public FunctionPass {
31public:
32  bool doInitialization(Module&) override {
33    // Cache the properties info at module-init time so we don't have to
34    // construct them for every function.
35    RequiredProperties = getRequiredProperties();
36    SetProperties = getSetProperties();
37    ClearedProperties = getClearedProperties();
38    return false;
39  }
40protected:
41  explicit MachineFunctionPass(char &ID) : FunctionPass(ID) {}
42
43  /// runOnMachineFunction - This method must be overloaded to perform the
44  /// desired machine code transformation or analysis.
45  ///
46  virtual bool runOnMachineFunction(MachineFunction &MF) = 0;
47
48  /// getAnalysisUsage - Subclasses that override getAnalysisUsage
49  /// must call this.
50  ///
51  /// For MachineFunctionPasses, calling AU.preservesCFG() indicates that
52  /// the pass does not modify the MachineBasicBlock CFG.
53  ///
54  void getAnalysisUsage(AnalysisUsage &AU) const override;
55
56  virtual MachineFunctionProperties getRequiredProperties() const {
57    return MachineFunctionProperties();
58  }
59  virtual MachineFunctionProperties getSetProperties() const {
60    return MachineFunctionProperties();
61  }
62  virtual MachineFunctionProperties getClearedProperties() const {
63    return MachineFunctionProperties();
64  }
65
66private:
67  MachineFunctionProperties RequiredProperties;
68  MachineFunctionProperties SetProperties;
69  MachineFunctionProperties ClearedProperties;
70
71  /// createPrinterPass - Get a machine function printer pass.
72  Pass *createPrinterPass(raw_ostream &O,
73                          const std::string &Banner) const override;
74
75  bool runOnFunction(Function &F) override;
76};
77
78} // End llvm namespace
79
80#endif
81