llvm-6502/include/llvm/CodeGen/MachineFunctionPass.h
Dan Gohman d1ad72f54f Add a comment about the additional meaning of setPreservesCFG() for
MachineFunctionPass passes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78669 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-11 15:50:56 +00:00

56 lines
2.0 KiB
C++

//===-- MachineFunctionPass.h - Pass for MachineFunctions --------*-C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the MachineFunctionPass class. MachineFunctionPass's are
// just FunctionPass's, except they operate on machine code as part of a code
// generator. Because they operate on machine code, not the LLVM
// representation, MachineFunctionPass's are not allowed to modify the LLVM
// representation. Due to this limitation, the MachineFunctionPass class takes
// care of declaring that no LLVM passes are invalidated.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_MACHINE_FUNCTION_PASS_H
#define LLVM_CODEGEN_MACHINE_FUNCTION_PASS_H
#include "llvm/Pass.h"
#include "llvm/CodeGen/MachineFunction.h"
namespace llvm {
/// MachineFunctionPass - This class adapts the FunctionPass interface to
/// allow convenient creation of passes that operate on the MachineFunction
/// representation. Instead of overriding runOnFunction, subclasses
/// override runOnMachineFunction.
class MachineFunctionPass : public FunctionPass {
protected:
explicit MachineFunctionPass(intptr_t ID) : FunctionPass(ID) {}
explicit MachineFunctionPass(void *ID) : FunctionPass(ID) {}
/// runOnMachineFunction - This method must be overloaded to perform the
/// desired machine code transformation or analysis.
///
virtual bool runOnMachineFunction(MachineFunction &MF) = 0;
/// getAnalysisUsage - Subclasses that override getAnalysisUsage
/// must call this.
///
/// For MachineFunctionPasses, calling AU.preservesCFG() indicates that
/// the pass does not modify the MachineBasicBlock CFG.
///
virtual void getAnalysisUsage(AnalysisUsage &AU) const;
private:
bool runOnFunction(Function &F);
};
} // End llvm namespace
#endif