llvm/llvm/include/llvm/MC/MCStreamer.h

//===- MCStreamer.h - High-level Streaming Machine Code Output --*- 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
//
//===----------------------------------------------------------------------===//
//
// This file declares the MCStreamer class.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_MC_MCSTREAMER_H
#define LLVM_MC_MCSTREAMER_H

#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/MC/MCDirectives.h"
#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MCFragment.h"
#include "llvm/MC/MCLinkerOptimizationHint.h"
#include "llvm/MC/MCPseudoProbe.h"
#include "llvm/MC/MCWinEH.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/MD5.h"
#include "llvm/Support/SMLoc.h"
#include "llvm/Support/VersionTuple.h"
#include "llvm/TargetParser/ARMTargetParser.h"
#include <cassert>
#include <cstdint>
#include <memory>
#include <optional>
#include <string>
#include <utility>
#include <vector>

namespace llvm {

class APInt;
class AssemblerConstantPools;
class MCAsmBackend;
class MCAssembler;
class MCContext;
class MCExpr;
class MCFragment;
class MCInst;
class MCInstPrinter;
class MCRegister;
class MCSection;
class MCStreamer;
class MCSubtargetInfo;
class MCSymbol;
class MCSymbolRefExpr;
class Triple;
class Twine;
class raw_ostream;

namespace codeview {
struct DefRangeRegisterRelHeader;
struct DefRangeSubfieldRegisterHeader;
struct DefRangeRegisterHeader;
struct DefRangeFramePointerRelHeader;
}

MCSectionSubPair;

/// Target specific streamer interface. This is used so that targets can
/// implement support for target specific assembly directives.
///
/// If target foo wants to use this, it should implement 3 classes:
/// * FooTargetStreamer : public MCTargetStreamer
/// * FooTargetAsmStreamer : public FooTargetStreamer
/// * FooTargetELFStreamer : public FooTargetStreamer
///
/// FooTargetStreamer should have a pure virtual method for each directive. For
/// example, for a ".bar symbol_name" directive, it should have
/// virtual emitBar(const MCSymbol &Symbol) = 0;
///
/// The FooTargetAsmStreamer and FooTargetELFStreamer classes implement the
/// method. The assembly streamer just prints ".bar symbol_name". The object
/// streamer does whatever is needed to implement .bar in the object file.
///
/// In the assembly printer and parser the target streamer can be used by
/// calling getTargetStreamer and casting it to FooTargetStreamer:
///
/// MCTargetStreamer &TS = OutStreamer.getTargetStreamer();
/// FooTargetStreamer &ATS = static_cast<FooTargetStreamer &>(TS);
///
/// The base classes FooTargetAsmStreamer and FooTargetELFStreamer should
/// *never* be treated differently. Callers should always talk to a
/// FooTargetStreamer.
class MCTargetStreamer { … };

// FIXME: declared here because it is used from
// lib/CodeGen/AsmPrinter/ARMException.cpp.
class ARMTargetStreamer : public MCTargetStreamer { … };

/// Streaming machine code generation interface.
///
/// This interface is intended to provide a programmatic interface that is very
/// similar to the level that an assembler .s file provides.  It has callbacks
/// to emit bytes, handle directives, etc.  The implementation of this interface
/// retains state to know what the current section is etc.
///
/// There are multiple implementations of this interface: one for writing out
/// a .s file, and implementations that write out .o files of various formats.
///
class MCStreamer { … };

/// Create a dummy machine code streamer, which does nothing. This is useful for
/// timing the assembler front end.
MCStreamer *createNullStreamer(MCContext &Ctx);

} // end namespace llvm

#endif // LLVM_MC_MCSTREAMER_H