include/llvm/CodeGen/MachineFunctionPass.h

   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
  24 namespace 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.
  30 class MachineFunctionPass : public FunctionPass {
  31 public:
  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   }
  40 protected:
  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
  66 private:
  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