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//===- MCSectionXCOFF.h - XCOFF Machine Code Sections -----------*- 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 MCSectionXCOFF class.

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_MC_MCSECTIONXCOFF_H

#define LLVM_MC_MCSECTIONXCOFF_H

#include "llvm/BinaryFormat/XCOFF.h"

#include "llvm/MC/MCSection.h"

#include "llvm/MC/MCSymbolXCOFF.h"

namespace llvm {

// This class represents an XCOFF `Control Section`, more commonly referred to

// as a csect. A csect represents the smallest possible unit of data/code which

// will be relocated as a single block. A csect can either be:

// 1) Initialized: The Type will be XTY_SD, and the symbols inside the csect

//    will have a label definition representing their offset within the csect.

// 2) Uninitialized: The Type will be XTY_CM, it will contain a single symbol,

//    and may not contain label definitions.

// 3) An external reference providing a symbol table entry for a symbol

//    contained in another XCOFF object file. External reference csects are not

//    implemented yet.

class MCSectionXCOFF final : public MCSection {

  friend class MCContext;

  std::optional<XCOFF::CsectProperties> CsectProp;

  MCSymbolXCOFF *const QualName;

  StringRef SymbolTableName;

  std::optional<XCOFF::DwarfSectionSubtypeFlags> DwarfSubtypeFlags;

  bool MultiSymbolsAllowed;

  static constexpr unsigned DefaultAlignVal = 4;

  static constexpr unsigned DefaultTextAlignVal = 32;

  MCSectionXCOFF(StringRef Name, XCOFF::StorageMappingClass SMC,

                 XCOFF::SymbolType ST, SectionKind K, MCSymbolXCOFF *QualName,

                 MCSymbol *Begin, StringRef SymbolTableName,

                 bool MultiSymbolsAllowed)

      : MCSection(SV_XCOFF, Name, K, Begin),

        CsectProp(XCOFF::CsectProperties(SMC, ST)), QualName(QualName),

        SymbolTableName(SymbolTableName), DwarfSubtypeFlags(std::nullopt),

        MultiSymbolsAllowed(MultiSymbolsAllowed) {

    assert(

        (ST == XCOFF::XTY_SD || ST == XCOFF::XTY_CM || ST == XCOFF::XTY_ER) &&

        "Invalid or unhandled type for csect.");

    assert(QualName != nullptr && "QualName is needed.");

    if (SMC == XCOFF::XMC_UL)

      assert((ST == XCOFF::XTY_CM || ST == XCOFF::XTY_ER) &&

             "Invalid csect type for storage mapping class XCOFF::XMC_UL");

    QualName->setRepresentedCsect(this);

    QualName->setStorageClass(XCOFF::C_HIDEXT);

    if (ST != XCOFF::XTY_ER) {

      // For a csect for program code, set the alignment to 32 bytes by default.

      // For other csects, set the alignment to 4 bytes by default.

      if (SMC == XCOFF::XMC_PR)

        setAlignment(Align(DefaultTextAlignVal));

      else

        setAlignment(Align(DefaultAlignVal));

    }

  }

  MCSectionXCOFF(StringRef Name, SectionKind K, MCSymbolXCOFF *QualName,

                 XCOFF::DwarfSectionSubtypeFlags DwarfSubtypeFlags,

                 MCSymbol *Begin, StringRef SymbolTableName,

                 bool MultiSymbolsAllowed)

      : MCSection(SV_XCOFF, Name, K, Begin), QualName(QualName),

        SymbolTableName(SymbolTableName), DwarfSubtypeFlags(DwarfSubtypeFlags),

        MultiSymbolsAllowed(MultiSymbolsAllowed) {

    assert(QualName != nullptr && "QualName is needed.");

    // FIXME: use a more meaningful name for non csect sections.

    QualName->setRepresentedCsect(this);

    // Use default text alignment as the alignment for DWARF sections.

    setAlignment(Align(DefaultTextAlignVal));

  }

  void printCsectDirective(raw_ostream &OS) const;

public:

  ~MCSectionXCOFF();

  static bool classof(const MCSection *S) {

    return S->getVariant() == SV_XCOFF;

  }

  XCOFF::StorageMappingClass getMappingClass() const {

    assert(isCsect() && "Only csect section has mapping class property!");

    return CsectProp->MappingClass;

  }

  XCOFF::StorageClass getStorageClass() const {

    return QualName->getStorageClass();

  }

  XCOFF::VisibilityType getVisibilityType() const {

    return QualName->getVisibilityType();

  }

  XCOFF::SymbolType getCSectType() const {

    assert(isCsect() && "Only csect section has symbol type property!");

    return CsectProp->Type;

  }

  MCSymbolXCOFF *getQualNameSymbol() const { return QualName; }

  void printSwitchToSection(const MCAsmInfo &MAI, const Triple &T,

                            raw_ostream &OS,

                            const MCExpr *Subsection) const override;

  bool useCodeAlign() const override;

  bool isVirtualSection() const override;

  StringRef getSymbolTableName() const { return SymbolTableName; }

  bool isMultiSymbolsAllowed() const { return MultiSymbolsAllowed; }

  bool isCsect() const { return CsectProp.has_value(); }

  bool isDwarfSect() const { return DwarfSubtypeFlags.has_value(); }

  std::optional<XCOFF::DwarfSectionSubtypeFlags> getDwarfSubtypeFlags() const {

    return DwarfSubtypeFlags;

  }

  std::optional<XCOFF::CsectProperties> getCsectProp() const {

    return CsectProp;

  }

};

} // end namespace llvm

#endif