llvm/llvm/include/llvm/MC/MCFixup.h

//===-- llvm/MC/MCFixup.h - Instruction Relocation and Patching -*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_MC_MCFIXUP_H
#define LLVM_MC_MCFIXUP_H

#include "llvm/Support/DataTypes.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/SMLoc.h"
#include <cassert>

namespace llvm {
class MCExpr;

/// Extensible enumeration to represent the type of a fixup.
enum MCFixupKind { … };

/// Encode information on a single operation to perform on a byte
/// sequence (e.g., an encoded instruction) which requires assemble- or run-
/// time patching.
///
/// Fixups are used any time the target instruction encoder needs to represent
/// some value in an instruction which is not yet concrete. The encoder will
/// encode the instruction assuming the value is 0, and emit a fixup which
/// communicates to the assembler backend how it should rewrite the encoded
/// value.
///
/// During the process of relaxation, the assembler will apply fixups as
/// symbolic values become concrete. When relaxation is complete, any remaining
/// fixups become relocations in the object file (or errors, if the fixup cannot
/// be encoded on the target).
class MCFixup { … };

} // End llvm namespace

#endif