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      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_MACHINE_FUNCTION_PASS_H
     20 #define LLVM_CODEGEN_MACHINE_FUNCTION_PASS_H
     21 
     22 #include "llvm/Pass.h"
     23 
     24 namespace llvm {
     25 
     26 class MachineFunction;
     27 
     28 /// MachineFunctionPass - This class adapts the FunctionPass interface to
     29 /// allow convenient creation of passes that operate on the MachineFunction
     30 /// representation. Instead of overriding runOnFunction, subclasses
     31 /// override runOnMachineFunction.
     32 class MachineFunctionPass : public FunctionPass {
     33 protected:
     34   explicit MachineFunctionPass(char &ID) : FunctionPass(ID) {}
     35 
     36   /// runOnMachineFunction - This method must be overloaded to perform the
     37   /// desired machine code transformation or analysis.
     38   ///
     39   virtual bool runOnMachineFunction(MachineFunction &MF) = 0;
     40 
     41   /// getAnalysisUsage - Subclasses that override getAnalysisUsage
     42   /// must call this.
     43   ///
     44   /// For MachineFunctionPasses, calling AU.preservesCFG() indicates that
     45   /// the pass does not modify the MachineBasicBlock CFG.
     46   ///
     47   virtual void getAnalysisUsage(AnalysisUsage &AU) const;
     48 
     49 private:
     50   /// createPrinterPass - Get a machine function printer pass.
     51   virtual Pass *createPrinterPass(raw_ostream &O,
     52                                   const std::string &Banner) const;
     53 
     54   virtual bool runOnFunction(Function &F);
     55 };
     56 
     57 } // End llvm namespace
     58 
     59 #endif
     60