Viewing file:  MCSectionELF.h (3.93 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
//===- MCSectionELF.h - ELF 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 MCSectionELF class.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_MC_MCSECTIONELF_H
#define LLVM_MC_MCSECTIONELF_H
#include "llvm/ADT/PointerIntPair.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/BinaryFormat/ELF.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSymbolELF.h"
#include "llvm/MC/SectionKind.h"
namespace llvm {
/// This represents a section on linux, lots of unix variants and some bare
/// metal systems.
class MCSectionELF final : public MCSection {
/// This is the sh_type field of a section, drawn from the enums below.
unsigned Type;
/// This is the sh_flags field of a section, drawn from the enums below.
unsigned Flags;
unsigned UniqueID;
/// The size of each entry in this section. This size only makes sense for
/// sections that contain fixed-sized entries. If a section does not contain
/// fixed-sized entries 'EntrySize' will be 0.
unsigned EntrySize;
/// The section group signature symbol (if not null) and a bool indicating
/// whether this is a GRP_COMDAT group.
const PointerIntPair<const MCSymbolELF *, 1, bool> Group;
/// Used by SHF_LINK_ORDER. If non-null, the sh_link field will be set to the
/// section header index of the section where LinkedToSym is defined.
const MCSymbol *LinkedToSym;
/// Start/end offset in file, used by ELFWriter.
uint64_t StartOffset;
uint64_t EndOffset;
private:
friend class MCContext;
// The storage of Name is owned by MCContext's ELFUniquingMap.
MCSectionELF(StringRef Name, unsigned type, unsigned flags,
unsigned entrySize, const MCSymbolELF *group, bool IsComdat,
unsigned UniqueID, MCSymbol *Begin,
const MCSymbolELF *LinkedToSym)
: MCSection(SV_ELF, Name, flags & ELF::SHF_EXECINSTR,
type == ELF::SHT_NOBITS, Begin),
Type(type), Flags(flags), UniqueID(UniqueID), EntrySize(entrySize),
Group(group, IsComdat), LinkedToSym(LinkedToSym) {
if (Group.getPointer())
Group.getPointer()->setIsSignature();
}
// TODO Delete after we stop supporting generation of GNU-style .zdebug_*
// sections.
void setSectionName(StringRef Name) { this->Name = Name; }
public:
/// Decides whether a '.section' directive should be printed before the
/// section name
bool shouldOmitSectionDirective(StringRef Name, const MCAsmInfo &MAI) const;
unsigned getType() const { return Type; }
unsigned getFlags() const { return Flags; }
unsigned getEntrySize() const { return EntrySize; }
void setFlags(unsigned F) { Flags = F; }
const MCSymbolELF *getGroup() const { return Group.getPointer(); }
bool isComdat() const { return Group.getInt(); }
void printSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
raw_ostream &OS,
uint32_t Subsection) const override;
bool useCodeAlign() const override;
StringRef getVirtualSectionKind() const override;
bool isUnique() const { return UniqueID != NonUniqueID; }
unsigned getUniqueID() const { return UniqueID; }
const MCSection *getLinkedToSection() const {
return &LinkedToSym->getSection();
}
const MCSymbol *getLinkedToSymbol() const { return LinkedToSym; }
void setOffsets(uint64_t Start, uint64_t End) {
StartOffset = Start;
EndOffset = End;
}
std::pair<uint64_t, uint64_t> getOffsets() const {
return std::make_pair(StartOffset, EndOffset);
}
static bool classof(const MCSection *S) {
return S->getVariant() == SV_ELF;
}
};
} // end namespace llvm
#endif // LLVM_MC_MCSECTIONELF_H
|