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//===- MCSectionELF.h - ELF Machine Code Sections ---------------*- C++ -*-===//
// The LLVM Compiler Infrastructure
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
// This file declares the MCSectionELF class.
#include "llvm/ADT/Twine.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ELF.h"
#include "llvm/Support/raw_ostream.h"
namespace llvm {
class MCSymbol;
/// MCSectionELF - This represents a section on linux, lots of unix variants
/// and some bare metal systems.
class MCSectionELF : public MCSection {
/// SectionName - This is the name of the section. The referenced memory is
/// owned by TargetLoweringObjectFileELF's ELFUniqueMap.
StringRef SectionName;
/// Type - This is the sh_type field of a section, drawn from the enums below.
unsigned Type;
/// Flags - This is the sh_flags field of a section, drawn from the enums.
/// below.
unsigned Flags;
/// EntrySize - 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;
const MCSymbol *Group;
friend class MCContext;
MCSectionELF(StringRef Section, unsigned type, unsigned flags,
SectionKind K, unsigned entrySize, const MCSymbol *group)
: MCSection(SV_ELF, K), SectionName(Section), Type(type), Flags(flags),
EntrySize(entrySize), Group(group) {}
void setSectionName(StringRef Name) { SectionName = Name; }
/// ShouldOmitSectionDirective - Decides whether a '.section' directive
/// should be printed before the section name
bool ShouldOmitSectionDirective(StringRef Name, const MCAsmInfo &MAI) const;
StringRef getSectionName() const { return SectionName; }
std::string getLabelBeginName() const override {
if (Group)
return (SectionName.str() + '_' + Group->getName() + "_begin").str();
return SectionName.str() + "_begin";
std::string getLabelEndName() const override {
if (Group)
return (SectionName.str() + '_' + Group->getName() + "_end").str();
return SectionName.str() + "_end";
unsigned getType() const { return Type; }
unsigned getFlags() const { return Flags; }
unsigned getEntrySize() const { return EntrySize; }
const MCSymbol *getGroup() const { return Group; }
void PrintSwitchToSection(const MCAsmInfo &MAI, raw_ostream &OS,
const MCExpr *Subsection) const override;
bool UseCodeAlign() const override;
bool isVirtualSection() const override;
/// isBaseAddressKnownZero - We know that non-allocatable sections (like
/// debug info) have a base of zero.
bool isBaseAddressKnownZero() const override {
return (getFlags() & ELF::SHF_ALLOC) == 0;
static bool classof(const MCSection *S) {
return S->getVariant() == SV_ELF;
// Return the entry size for sections with fixed-width data.
static unsigned DetermineEntrySize(SectionKind Kind);
} // end namespace llvm