MCSectionWasm.h

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//===- MCSectionWasm.h - Wasm 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 MCSectionWasm class.
//
//===----------------------------------------------------------------------===//
 
#ifndef LLVM_MC_MCSECTIONWASM_H
#define LLVM_MC_MCSECTIONWASM_H
 
#include "llvm/MC/MCSection.h"
 
namespace llvm {
 
class MCSymbol;
class MCSymbolWasm;
class StringRef;
class raw_ostream;
 
/// This represents a section on wasm.
class MCSectionWasm final : public MCSection {
  unsigned UniqueID;
 
  const MCSymbolWasm *Group;
 
  // The offset of the MC function/data section in the wasm code/data section.
  // For data relocations the offset is relative to start of the data payload
  // itself and does not include the size of the section header.
  uint64_t SectionOffset = 0;
 
  // For data sections, this is the index of the corresponding wasm data
  // segment
  uint32_t SegmentIndex = 0;
 
  // For data sections, whether to use a passive segment
  bool IsPassive = false;
 
  bool IsWasmData;
 
  bool IsMetadata;
 
  // For data sections, bitfield of WasmSegmentFlag
  unsigned SegmentFlags;
 
  // The storage of Name is owned by MCContext's WasmUniquingMap.
  friend class MCContext;
  MCSectionWasm(StringRef Name, SectionKind K, unsigned SegmentFlags,
                const MCSymbolWasm *Group, unsigned UniqueID, MCSymbol *Begin)
      : MCSection(SV_Wasm, Name, K.isText(), /*IsVirtual=*/false, Begin),
        UniqueID(UniqueID), Group(Group),
        IsWasmData(K.isReadOnly() || K.isWriteable()),
        IsMetadata(K.isMetadata()), SegmentFlags(SegmentFlags) {}
 
public:
  /// Decides whether a '.section' directive should be printed before the
  /// section name
  bool shouldOmitSectionDirective(StringRef Name, const MCAsmInfo &MAI) const;
 
  const MCSymbolWasm *getGroup() const { return Group; }
  unsigned getSegmentFlags() const { return SegmentFlags; }
 
  void printSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
                            raw_ostream &OS,
                            uint32_t Subsection) const override;
  bool useCodeAlign() const override;
 
  bool isWasmData() const { return IsWasmData; }
  bool isMetadata() const { return IsMetadata; }
 
  bool isUnique() const { return UniqueID != ~0U; }
  unsigned getUniqueID() const { return UniqueID; }
 
  uint64_t getSectionOffset() const { return SectionOffset; }
  void setSectionOffset(uint64_t Offset) { SectionOffset = Offset; }
 
  uint32_t getSegmentIndex() const { return SegmentIndex; }
  void setSegmentIndex(uint32_t Index) { SegmentIndex = Index; }
 
  bool getPassive() const {
    assert(isWasmData());
    return IsPassive;
  }
  void setPassive(bool V = true) {
    assert(isWasmData());
    IsPassive = V;
  }
  static bool classof(const MCSection *S) { return S->getVariant() == SV_Wasm; }
};
 
} // end namespace llvm
 
#endif