MachineFunctionPass.h revision 321369 
1//===-- MachineFunctionPass.h - Pass for MachineFunctions --------*-C++ -*-===//
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 MachineFunctionPass class.  MachineFunctionPass's are
11// just FunctionPass's, except they operate on machine code as part of a code
12// generator.  Because they operate on machine code, not the LLVM
13// representation, MachineFunctionPass's are not allowed to modify the LLVM
14// representation.  Due to this limitation, the MachineFunctionPass class takes
15// care of declaring that no LLVM passes are invalidated.
16//
17//===----------------------------------------------------------------------===//
18
19#ifndef LLVM_CODEGEN_MACHINEFUNCTIONPASS_H
20#define LLVM_CODEGEN_MACHINEFUNCTIONPASS_H
21
22#include "llvm/CodeGen/MachineFunction.h"
23#include "llvm/Pass.h"
24
25namespace llvm {
26
27/// MachineFunctionPass - This class adapts the FunctionPass interface to
28/// allow convenient creation of passes that operate on the MachineFunction
29/// representation. Instead of overriding runOnFunction, subclasses
30/// override runOnMachineFunction.
31class MachineFunctionPass : public FunctionPass {
32public:
33  bool doInitialization(Module&) override {
34    // Cache the properties info at module-init time so we don't have to
35    // construct them for every function.
36    RequiredProperties = getRequiredProperties();
37    SetProperties = getSetProperties();
38    ClearedProperties = getClearedProperties();
39    return false;
40  }
41protected:
42  explicit MachineFunctionPass(char &ID) : FunctionPass(ID) {}
43
44  /// runOnMachineFunction - This method must be overloaded to perform the
45  /// desired machine code transformation or analysis.
46  ///
47  virtual bool runOnMachineFunction(MachineFunction &MF) = 0;
48
49  /// getAnalysisUsage - Subclasses that override getAnalysisUsage
50  /// must call this.
51  ///
52  /// For MachineFunctionPasses, calling AU.preservesCFG() indicates that
53  /// the pass does not modify the MachineBasicBlock CFG.
54  ///
55  void getAnalysisUsage(AnalysisUsage &AU) const override;
56
57  virtual MachineFunctionProperties getRequiredProperties() const {
58    return MachineFunctionProperties();
59  }
60  virtual MachineFunctionProperties getSetProperties() const {
61    return MachineFunctionProperties();
62  }
63  virtual MachineFunctionProperties getClearedProperties() const {
64    return MachineFunctionProperties();
65  }
66
67private:
68  MachineFunctionProperties RequiredProperties;
69  MachineFunctionProperties SetProperties;
70  MachineFunctionProperties ClearedProperties;
71
72  /// createPrinterPass - Get a machine function printer pass.
73  Pass *createPrinterPass(raw_ostream &O,
74                          const std::string &Banner) const override;
75
76  bool runOnFunction(Function &F) override;
77};
78
79} // End llvm namespace
80
81#endif
82