llvm/CodeGen/MachineFunctionPass.h

0001 //===-- MachineFunctionPass.h - Pass for MachineFunctions --------*-C++ -*-===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===----------------------------------------------------------------------===//
0008 //
0009 // This file defines the MachineFunctionPass class.  MachineFunctionPass's are
0010 // just FunctionPass's, except they operate on machine code as part of a code
0011 // generator.  Because they operate on machine code, not the LLVM
0012 // representation, MachineFunctionPass's are not allowed to modify the LLVM
0013 // representation.  Due to this limitation, the MachineFunctionPass class takes
0014 // care of declaring that no LLVM passes are invalidated.
0015 //
0016 //===----------------------------------------------------------------------===//
0017
0018 #ifndef LLVM_CODEGEN_MACHINEFUNCTIONPASS_H
0019 #define LLVM_CODEGEN_MACHINEFUNCTIONPASS_H
0020
0021 #include "llvm/CodeGen/MachineFunction.h"
0022 #include "llvm/Pass.h"
0023
0024 namespace llvm {
0025
0026 /// MachineFunctionPass - This class adapts the FunctionPass interface to
0027 /// allow convenient creation of passes that operate on the MachineFunction
0028 /// representation. Instead of overriding runOnFunction, subclasses
0029 /// override runOnMachineFunction.
0030 class MachineFunctionPass : public FunctionPass {
0031 public:
0032   bool doInitialization(Module&) override {
0033     // Cache the properties info at module-init time so we don't have to
0034     // construct them for every function.
0035     RequiredProperties = getRequiredProperties();
0036     SetProperties = getSetProperties();
0037     ClearedProperties = getClearedProperties();
0038     return false;
0039   }
0040 protected:
0041   explicit MachineFunctionPass(char &ID) : FunctionPass(ID) {}
0042
0043   /// runOnMachineFunction - This method must be overloaded to perform the
0044   /// desired machine code transformation or analysis.
0045   ///
0046   virtual bool runOnMachineFunction(MachineFunction &MF) = 0;
0047
0048   /// getAnalysisUsage - Subclasses that override getAnalysisUsage
0049   /// must call this.
0050   ///
0051   /// For MachineFunctionPasses, calling AU.preservesCFG() indicates that
0052   /// the pass does not modify the MachineBasicBlock CFG.
0053   ///
0054   void getAnalysisUsage(AnalysisUsage &AU) const override;
0055
0056   virtual MachineFunctionProperties getRequiredProperties() const {
0057     return MachineFunctionProperties();
0058   }
0059   virtual MachineFunctionProperties getSetProperties() const {
0060     return MachineFunctionProperties();
0061   }
0062   virtual MachineFunctionProperties getClearedProperties() const {
0063     return MachineFunctionProperties();
0064   }
0065
0066 private:
0067   MachineFunctionProperties RequiredProperties;
0068   MachineFunctionProperties SetProperties;
0069   MachineFunctionProperties ClearedProperties;
0070
0071   /// createPrinterPass - Get a machine function printer pass.
0072   Pass *createPrinterPass(raw_ostream &O,
0073                           const std::string &Banner) const override;
0074
0075   bool runOnFunction(Function &F) override;
0076 };
0077
0078 } // End llvm namespace
0079
0080 #endif