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: doInitialization(Module &)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: MachineFunctionPass(char & ID)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 getRequiredProperties()56 virtual MachineFunctionProperties getRequiredProperties() const { 57 return MachineFunctionProperties(); 58 } getSetProperties()59 virtual MachineFunctionProperties getSetProperties() const { 60 return MachineFunctionProperties(); 61 } getClearedProperties()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 81