llvm-project/lld/lib/ReaderWriter/ELF/Atoms.h

971 lines
27 KiB
C++

//===- lib/ReaderWriter/ELF/Atoms.h ---------------------------------------===//
//
// The LLVM Linker
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLD_READER_WRITER_ELF_ATOMS_H
#define LLD_READER_WRITER_ELF_ATOMS_H
#include "TargetHandler.h"
#include "lld/Core/LLVM.h"
#include "lld/ReaderWriter/Simple.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/StringSwitch.h"
#include <memory>
#include <vector>
namespace lld {
namespace elf {
template <class ELFT> class DynamicFile;
template <typename ELFT> class ELFFile;
/// \brief Relocation References: Defined Atoms may contain references that will
/// need to be patched before the executable is written.
///
/// Construction of ELFReferences is two pass process. ELFReferences are
/// instantiated while we are iterating over symbol tables to atomize
/// symbols. At that time we only know the index of relocation target symbol
/// (not target atom) about a relocation, so we store the index to
/// ELFREference. In the second pass, ELFReferences are revisited to update
/// target atoms by target symbol indexes.
template <class ELFT> class ELFReference : public Reference {
typedef llvm::object::Elf_Rel_Impl<ELFT, false> Elf_Rel;
typedef llvm::object::Elf_Rel_Impl<ELFT, true> Elf_Rela;
public:
ELFReference(const Elf_Rela *rela, uint64_t off, Reference::KindArch arch,
uint16_t relocType, uint32_t idx)
: Reference(Reference::KindNamespace::ELF, arch, relocType),
_target(nullptr), _targetSymbolIndex(idx), _offsetInAtom(off),
_addend(rela->r_addend) {}
ELFReference(const Elf_Rel *rel, uint64_t off, Reference::KindArch arch,
uint16_t relocType, uint32_t idx)
: Reference(Reference::KindNamespace::ELF, arch, relocType),
_target(nullptr), _targetSymbolIndex(idx), _offsetInAtom(off),
_addend(0) {}
ELFReference(uint32_t edgeKind)
: Reference(Reference::KindNamespace::all, Reference::KindArch::all,
edgeKind),
_target(nullptr), _targetSymbolIndex(0), _offsetInAtom(0), _addend(0) {}
virtual uint64_t offsetInAtom() const { return _offsetInAtom; }
virtual const Atom *target() const {
return _target;
}
/// \brief The symbol table index that contains the target reference.
uint64_t targetSymbolIndex() const {
return _targetSymbolIndex;
}
virtual Addend addend() const {
return _addend;
}
virtual void setOffset(uint64_t off) { _offsetInAtom = off; }
virtual void setAddend(Addend A) { _addend = A; }
virtual void setTarget(const Atom *newAtom) { _target = newAtom; }
private:
const Atom *_target;
uint64_t _targetSymbolIndex;
uint64_t _offsetInAtom;
Addend _addend;
};
/// \brief These atoms store symbols that are fixed to a particular address.
/// This atom has no content its address will be used by the writer to fixup
/// references that point to it.
template <class ELFT> class ELFAbsoluteAtom : public AbsoluteAtom {
typedef llvm::object::Elf_Sym_Impl<ELFT> Elf_Sym;
public:
ELFAbsoluteAtom(const ELFFile<ELFT> &file, StringRef name,
const Elf_Sym *symbol, uint64_t value)
: _owningFile(file), _name(name), _symbol(symbol), _value(value) {
}
virtual const ELFFile<ELFT> &file() const {
return _owningFile;
}
virtual Scope scope() const {
if (_symbol->st_other == llvm::ELF::STV_HIDDEN)
return scopeLinkageUnit;
if (_symbol->getBinding() == llvm::ELF::STB_LOCAL)
return scopeTranslationUnit;
else
return scopeGlobal;
}
virtual StringRef name() const {
return _name;
}
virtual uint64_t value() const {
return _value;
}
private:
const ELFFile<ELFT> &_owningFile;
StringRef _name;
const Elf_Sym *_symbol;
uint64_t _value;
};
/// \brief ELFUndefinedAtom: These atoms store undefined symbols and are place
/// holders that will be replaced by defined atoms later in the linking process.
template <class ELFT> class ELFUndefinedAtom : public lld::UndefinedAtom {
typedef llvm::object::Elf_Sym_Impl<ELFT> Elf_Sym;
public:
ELFUndefinedAtom(const File &file, StringRef name, const Elf_Sym *symbol)
: _owningFile(file), _name(name), _symbol(symbol) {}
virtual const File &file() const { return _owningFile; }
virtual StringRef name() const { return _name; }
// FIXME: What distinguishes a symbol in ELF that can help decide if the
// symbol is undefined only during build and not runtime? This will make us
// choose canBeNullAtBuildtime and canBeNullAtRuntime.
virtual CanBeNull canBeNull() const {
if (_symbol->getBinding() == llvm::ELF::STB_WEAK)
return CanBeNull::canBeNullAtBuildtime;
else
return CanBeNull::canBeNullNever;
}
private:
const File &_owningFile;
StringRef _name;
const Elf_Sym *_symbol;
};
/// \brief This atom stores defined symbols and will contain either data or
/// code.
template <class ELFT> class ELFDefinedAtom : public DefinedAtom {
typedef llvm::object::Elf_Sym_Impl<ELFT> Elf_Sym;
typedef llvm::object::Elf_Shdr_Impl<ELFT> Elf_Shdr;
public:
ELFDefinedAtom(const ELFFile<ELFT> &file, StringRef symbolName,
StringRef sectionName, const Elf_Sym *symbol,
const Elf_Shdr *section, ArrayRef<uint8_t> contentData,
unsigned int referenceStart, unsigned int referenceEnd,
std::vector<ELFReference<ELFT> *> &referenceList)
: _owningFile(file), _symbolName(symbolName), _sectionName(sectionName),
_symbol(symbol), _section(section), _contentData(contentData),
_referenceStartIndex(referenceStart), _referenceEndIndex(referenceEnd),
_referenceList(referenceList), _contentType(typeUnknown),
_permissions(permUnknown) {}
~ELFDefinedAtom() {}
virtual const ELFFile<ELFT> &file() const {
return _owningFile;
}
virtual StringRef name() const {
return _symbolName;
}
virtual uint64_t ordinal() const {
return _ordinal;
}
const Elf_Sym *symbol() const { return _symbol; }
const Elf_Shdr *section() const { return _section; }
virtual uint64_t size() const {
// Common symbols are not allocated in object files,
// so use st_size to tell how many bytes are required.
if ((_symbol->getType() == llvm::ELF::STT_COMMON) ||
_symbol->st_shndx == llvm::ELF::SHN_COMMON)
return (uint64_t) _symbol->st_size;
return _contentData.size();
}
virtual Scope scope() const {
if (_symbol->st_other == llvm::ELF::STV_HIDDEN)
return scopeLinkageUnit;
else if (_symbol->getBinding() != llvm::ELF::STB_LOCAL)
return scopeGlobal;
else
return scopeTranslationUnit;
}
// FIXME: Need to revisit this in future.
virtual Interposable interposable() const {
return interposeNo;
}
// FIXME: What ways can we determine this in ELF?
virtual Merge merge() const {
if (_symbol->getBinding() == llvm::ELF::STB_WEAK)
return mergeAsWeak;
if ((_symbol->getType() == llvm::ELF::STT_COMMON) ||
_symbol->st_shndx == llvm::ELF::SHN_COMMON)
return mergeAsTentative;
return mergeNo;
}
virtual ContentType contentType() const {
if (_contentType != typeUnknown)
return _contentType;
ContentType ret = typeUnknown;
uint64_t flags = _section->sh_flags;
if (!(flags & llvm::ELF::SHF_ALLOC))
return _contentType = typeNoAlloc;
if (_section->sh_flags ==
(llvm::ELF::SHF_ALLOC | llvm::ELF::SHF_WRITE | llvm::ELF::SHF_TLS)) {
return _contentType = _section->sh_type == llvm::ELF::SHT_NOBITS ? typeThreadZeroFill
: typeThreadData;
}
if ((_section->sh_flags == llvm::ELF::SHF_ALLOC) &&
(_section->sh_type == llvm::ELF::SHT_PROGBITS))
return _contentType = typeConstant;
if (_symbol->getType() == llvm::ELF::STT_GNU_IFUNC)
return _contentType = typeResolver;
if (_symbol->st_shndx == llvm::ELF::SHN_COMMON)
return _contentType = typeZeroFill;
switch (_section->sh_type) {
case llvm::ELF::SHT_PROGBITS:
flags &= ~llvm::ELF::SHF_ALLOC;
flags &= ~llvm::ELF::SHF_GROUP;
switch (flags) {
case llvm::ELF::SHF_EXECINSTR:
case (llvm::ELF::SHF_WRITE|llvm::ELF::SHF_EXECINSTR):
ret = typeCode;
break;
case llvm::ELF::SHF_WRITE:
ret = typeData;
break;
case (llvm::ELF::SHF_MERGE|llvm::ELF::SHF_STRINGS):
case llvm::ELF::SHF_STRINGS:
case llvm::ELF::SHF_MERGE:
ret = typeConstant;
break;
default:
ret = typeCode;
break;
}
break;
case llvm::ELF::SHT_NOTE:
flags &= ~llvm::ELF::SHF_ALLOC;
switch (flags) {
case llvm::ELF::SHF_WRITE:
ret = typeRWNote;
break;
default:
ret = typeRONote;
break;
}
break;
case llvm::ELF::SHT_NOBITS:
ret = typeZeroFill;
break;
case llvm::ELF::SHT_NULL:
if ((_symbol->getType() == llvm::ELF::STT_COMMON)
|| _symbol->st_shndx == llvm::ELF::SHN_COMMON)
ret = typeZeroFill;
break;
case llvm::ELF::SHT_INIT_ARRAY:
case llvm::ELF::SHT_FINI_ARRAY:
ret = typeData;
break;
}
return _contentType = ret;
}
virtual Alignment alignment() const {
// Unallocated common symbols specify their alignment constraints in
// st_value.
if ((_symbol->getType() == llvm::ELF::STT_COMMON) ||
_symbol->st_shndx == llvm::ELF::SHN_COMMON) {
return Alignment(llvm::Log2_64(_symbol->st_value));
}
return Alignment(llvm::Log2_64(_section->sh_addralign),
_symbol->st_value % _section->sh_addralign);
}
// Do we have a choice for ELF? All symbols live in explicit sections.
virtual SectionChoice sectionChoice() const {
switch (contentType()) {
case typeCode:
case typeData:
case typeZeroFill:
case typeThreadZeroFill:
case typeThreadData:
case typeConstant:
if ((_sectionName == ".text") || (_sectionName == ".data") ||
(_sectionName == ".bss") || (_sectionName == ".rodata") ||
(_sectionName == ".tdata") || (_sectionName == ".tbss"))
return sectionBasedOnContent;
default:
break;
}
return sectionCustomRequired;
}
virtual StringRef customSectionName() const {
if ((contentType() == typeZeroFill) ||
(_symbol->st_shndx == llvm::ELF::SHN_COMMON))
return ".bss";
return _sectionName;
}
virtual SectionPosition sectionPosition() const {
return sectionPositionAny;
}
// It isn't clear that __attribute__((used)) is transmitted to the ELF object
// file.
virtual DeadStripKind deadStrip() const {
return deadStripNormal;
}
virtual ContentPermissions permissions() const {
if (_permissions != permUnknown)
return _permissions;
uint64_t flags = _section->sh_flags;
if (!(flags & llvm::ELF::SHF_ALLOC))
return _permissions = perm___;
switch (_section->sh_type) {
// permRW_L is for sections modified by the runtime
// loader.
case llvm::ELF::SHT_REL:
case llvm::ELF::SHT_RELA:
return _permissions = permRW_L;
case llvm::ELF::SHT_DYNAMIC:
case llvm::ELF::SHT_PROGBITS:
case llvm::ELF::SHT_NOTE:
flags &= ~llvm::ELF::SHF_ALLOC;
flags &= ~llvm::ELF::SHF_GROUP;
switch (flags) {
// Code
case llvm::ELF::SHF_EXECINSTR:
return _permissions = permR_X;
case (llvm::ELF::SHF_WRITE|llvm::ELF::SHF_EXECINSTR):
return _permissions = permRWX;
// Data
case llvm::ELF::SHF_WRITE:
return _permissions = permRW_;
// Strings
case llvm::ELF::SHF_MERGE:
case llvm::ELF::SHF_STRINGS:
return _permissions = permR__;
default:
if (flags & llvm::ELF::SHF_WRITE)
return _permissions = permRW_;
return _permissions = permR__;
}
case llvm::ELF::SHT_NOBITS:
return _permissions = permRW_;
case llvm::ELF::SHT_INIT_ARRAY:
case llvm::ELF::SHT_FINI_ARRAY:
return _permissions = permRW_;
default:
return _permissions = perm___;
}
}
// FIXME: Not Sure if ELF supports alias atoms. Find out more.
virtual bool isAlias() const {
return false;
}
virtual ArrayRef<uint8_t> rawContent() const {
return _contentData;
}
DefinedAtom::reference_iterator begin() const {
uintptr_t index = _referenceStartIndex;
const void *it = reinterpret_cast<const void*>(index);
return reference_iterator(*this, it);
}
DefinedAtom::reference_iterator end() const {
uintptr_t index = _referenceEndIndex;
const void *it = reinterpret_cast<const void*>(index);
return reference_iterator(*this, it);
}
const Reference *derefIterator(const void *It) const {
uintptr_t index = reinterpret_cast<uintptr_t>(It);
assert(index >= _referenceStartIndex);
assert(index < _referenceEndIndex);
return ((_referenceList)[index]);
}
void incrementIterator(const void *&It) const {
uintptr_t index = reinterpret_cast<uintptr_t>(It);
++index;
It = reinterpret_cast<const void *>(index);
}
void addReference(ELFReference<ELFT> *reference) {
_referenceList.push_back(reference);
_referenceEndIndex = _referenceList.size();
}
virtual void setOrdinal(uint64_t ord) { _ordinal = ord; }
protected:
const ELFFile<ELFT> &_owningFile;
StringRef _symbolName;
StringRef _sectionName;
const Elf_Sym *_symbol;
const Elf_Shdr *_section;
/// \brief Holds the bits that make up the atom.
ArrayRef<uint8_t> _contentData;
uint64_t _ordinal;
unsigned int _referenceStartIndex;
unsigned int _referenceEndIndex;
std::vector<ELFReference<ELFT> *> &_referenceList;
mutable ContentType _contentType;
mutable ContentPermissions _permissions;
};
/// \brief This atom stores mergeable Strings
template <class ELFT> class ELFMergeAtom : public DefinedAtom {
typedef llvm::object::Elf_Shdr_Impl<ELFT> Elf_Shdr;
public:
ELFMergeAtom(const ELFFile<ELFT> &file, StringRef sectionName,
const Elf_Shdr *section, ArrayRef<uint8_t> contentData,
uint64_t offset)
: _owningFile(file), _sectionName(sectionName), _section(section),
_contentData(contentData), _offset(offset) {
}
virtual const ELFFile<ELFT> &file() const {
return _owningFile;
}
virtual StringRef name() const {
return "";
}
virtual uint64_t section() const { return _section->sh_name; }
virtual uint64_t offset() const { return _offset; }
virtual void setOrdinal(uint64_t ord) { _ordinal = ord; }
virtual uint64_t ordinal() const { return _ordinal; }
virtual uint64_t size() const { return _contentData.size(); }
virtual Scope scope() const { return scopeTranslationUnit; }
virtual Interposable interposable() const { return interposeNo; }
virtual Merge merge() const { return mergeByContent; }
virtual ContentType contentType() const { return typeConstant; }
virtual Alignment alignment() const {
return Alignment(llvm::Log2_64(_section->sh_addralign));
}
virtual SectionChoice sectionChoice() const { return sectionCustomRequired; }
virtual StringRef customSectionName() const { return _sectionName; }
virtual SectionPosition sectionPosition() const { return sectionPositionAny; }
virtual DeadStripKind deadStrip() const { return deadStripNormal; }
virtual ContentPermissions permissions() const { return permR__; }
virtual bool isThumb() const { return false; }
virtual bool isAlias() const { return false; }
virtual ArrayRef<uint8_t> rawContent() const { return _contentData; }
DefinedAtom::reference_iterator begin() const {
uintptr_t index = 0;
const void *it = reinterpret_cast<const void *>(index);
return reference_iterator(*this, it);
}
DefinedAtom::reference_iterator end() const {
uintptr_t index = 0;
const void *it = reinterpret_cast<const void *>(index);
return reference_iterator(*this, it);
}
const Reference *derefIterator(const void *It) const { return nullptr; }
void incrementIterator(const void *&It) const {}
private:
const ELFFile<ELFT> &_owningFile;
StringRef _sectionName;
const Elf_Shdr *_section;
/// \brief Holds the bits that make up the atom.
ArrayRef<uint8_t> _contentData;
uint64_t _ordinal;
uint64_t _offset;
};
template <class ELFT> class ELFCommonAtom : public DefinedAtom {
typedef llvm::object::Elf_Sym_Impl<ELFT> Elf_Sym;
public:
ELFCommonAtom(const ELFFile<ELFT> &file,
StringRef symbolName,
const Elf_Sym *symbol)
: _owningFile(file),
_symbolName(symbolName),
_symbol(symbol) {}
virtual const ELFFile<ELFT> &file() const {
return _owningFile;
}
virtual StringRef name() const {
return _symbolName;
}
virtual uint64_t ordinal() const {
return _ordinal;
}
virtual void setOrdinal(uint64_t ord) { _ordinal = ord; }
virtual uint64_t size() const {
return _symbol->st_size;
}
virtual Scope scope() const {
if (_symbol->st_other == llvm::ELF::STV_HIDDEN)
return scopeLinkageUnit;
else if (_symbol->getBinding() != llvm::ELF::STB_LOCAL)
return scopeGlobal;
else
return scopeTranslationUnit;
}
virtual Interposable interposable() const {
return interposeNo;
}
virtual Merge merge() const {
return mergeAsTentative;
}
virtual ContentType contentType() const {
return typeZeroFill;
}
virtual Alignment alignment() const {
return Alignment(llvm::Log2_64(_symbol->st_value));
}
virtual SectionChoice sectionChoice() const {
return sectionBasedOnContent;
}
virtual StringRef customSectionName() const {
return ".bss";
}
virtual SectionPosition sectionPosition() const {
return sectionPositionAny;
}
virtual DeadStripKind deadStrip() const {
return deadStripNormal;
}
virtual ContentPermissions permissions() const {
return permRW_;
}
virtual bool isAlias() const {
return false;
}
virtual ArrayRef<uint8_t> rawContent() const {
return ArrayRef<uint8_t>();
}
virtual DefinedAtom::reference_iterator begin() const {
uintptr_t index = 0;
const void *it = reinterpret_cast<const void *>(index);
return reference_iterator(*this, it);
}
virtual DefinedAtom::reference_iterator end() const {
uintptr_t index = 0;
const void *it = reinterpret_cast<const void *>(index);
return reference_iterator(*this, it);
}
protected:
virtual ~ELFCommonAtom() {}
virtual const Reference *derefIterator(const void *iter) const {
return nullptr;
}
virtual void incrementIterator(const void *&iter) const {}
const ELFFile<ELFT> &_owningFile;
StringRef _symbolName;
const Elf_Sym *_symbol;
uint64_t _ordinal;
};
/// \brief An atom from a shared library.
template <class ELFT> class ELFDynamicAtom : public SharedLibraryAtom {
typedef llvm::object::Elf_Sym_Impl<ELFT> Elf_Sym;
public:
ELFDynamicAtom(const DynamicFile<ELFT> &file, StringRef symbolName,
StringRef loadName, const Elf_Sym *symbol)
: _owningFile(file), _symbolName(symbolName), _loadName(loadName),
_symbol(symbol) {
}
virtual const DynamicFile<ELFT> &file() const {
return _owningFile;
}
virtual StringRef name() const {
return _symbolName;
}
virtual Scope scope() const {
if (_symbol->st_other == llvm::ELF::STV_HIDDEN)
return scopeLinkageUnit;
else if (_symbol->getBinding() != llvm::ELF::STB_LOCAL)
return scopeGlobal;
else
return scopeTranslationUnit;
}
virtual StringRef loadName() const { return _loadName; }
virtual bool canBeNullAtRuntime() const {
return _symbol->getBinding() == llvm::ELF::STB_WEAK;
}
virtual Type type() const {
switch (_symbol->getType()) {
case llvm::ELF::STT_FUNC:
case llvm::ELF::STT_GNU_IFUNC:
return Type::Code;
case llvm::ELF::STT_OBJECT:
return Type::Data;
default:
return Type::Unknown;
}
}
virtual uint64_t size() const override {
return _symbol->st_size;
}
private:
const DynamicFile<ELFT> &_owningFile;
StringRef _symbolName;
StringRef _loadName;
const Elf_Sym *_symbol;
};
class SimpleELFDefinedAtom : public SimpleDefinedAtom {
public:
SimpleELFDefinedAtom(const File &f) : SimpleDefinedAtom(f) {}
void addReferenceELF(Reference::KindArch arch, uint16_t kindValue,
uint64_t off, const Atom *target,
Reference::Addend addend) {
this->addReference(Reference::KindNamespace::ELF, arch, kindValue, off,
target, addend);
}
void addReferenceELF_Hexagon(uint16_t relocType, uint64_t off, const Atom *t,
Reference::Addend a) {
this->addReferenceELF(Reference::KindArch::Hexagon, relocType, off, t, a);
}
void addReferenceELF_x86_64(uint16_t relocType, uint64_t off, const Atom *t,
Reference::Addend a) {
this->addReferenceELF(Reference::KindArch::x86_64, relocType, off, t, a);
}
void addReferenceELF_PowerPC(uint16_t relocType, uint64_t off, const Atom *t,
Reference::Addend a) {
this->addReferenceELF(Reference::KindArch::PowerPC, relocType, off, t, a);
}
void addReferenceELF_Mips(uint16_t relocType, uint64_t off, const Atom *t,
Reference::Addend a) {
this->addReferenceELF(Reference::KindArch::Mips, relocType, off, t, a);
}
};
/// \brief Atom which represents an object for which a COPY relocation will be
/// generated.
class ObjectAtom : public SimpleELFDefinedAtom {
public:
ObjectAtom(const File &f) : SimpleELFDefinedAtom(f) {}
virtual Scope scope() const { return scopeGlobal; }
virtual SectionChoice sectionChoice() const { return sectionBasedOnContent; }
virtual ContentType contentType() const { return typeZeroFill; }
virtual uint64_t size() const { return _size; }
virtual DynamicExport dynamicExport() const { return dynamicExportAlways; }
virtual ContentPermissions permissions() const { return permRW_; }
virtual ArrayRef<uint8_t> rawContent() const {
return ArrayRef<uint8_t>();
}
virtual Alignment alignment() const {
// The alignment should be 8 byte aligned
return Alignment(3);
}
virtual StringRef name() const { return _name; }
std::string _name;
uint64_t _size;
};
class GOTAtom : public SimpleELFDefinedAtom {
StringRef _section;
public:
GOTAtom(const File &f, StringRef secName)
: SimpleELFDefinedAtom(f), _section(secName) {}
virtual Scope scope() const { return scopeTranslationUnit; }
virtual SectionChoice sectionChoice() const { return sectionCustomRequired; }
virtual StringRef customSectionName() const { return _section; }
virtual ContentType contentType() const { return typeGOT; }
virtual uint64_t size() const { return rawContent().size(); }
virtual ContentPermissions permissions() const { return permRW_; }
virtual ArrayRef<uint8_t> rawContent() const = 0;
virtual Alignment alignment() const {
// The alignment should be 8 byte aligned
return Alignment(3);
}
#ifndef NDEBUG
virtual StringRef name() const { return _name; }
std::string _name;
#else
virtual StringRef name() const { return ""; }
#endif
};
class PLTAtom : public SimpleELFDefinedAtom {
StringRef _section;
public:
PLTAtom(const File &f, StringRef secName)
: SimpleELFDefinedAtom(f), _section(secName) {}
virtual Scope scope() const { return scopeTranslationUnit; }
virtual SectionChoice sectionChoice() const { return sectionCustomRequired; }
virtual StringRef customSectionName() const { return _section; }
virtual ContentType contentType() const { return typeStub; }
virtual uint64_t size() const { return rawContent().size(); }
virtual ContentPermissions permissions() const { return permR_X; }
virtual ArrayRef<uint8_t> rawContent() const = 0;
virtual Alignment alignment() const {
return Alignment(4); // 16
}
#ifndef NDEBUG
virtual StringRef name() const { return _name; }
std::string _name;
#else
virtual StringRef name() const { return ""; }
#endif
};
class PLT0Atom : public PLTAtom {
public:
PLT0Atom(const File &f) : PLTAtom(f, ".plt") {
#ifndef NDEBUG
_name = ".PLT0";
#endif
}
};
class GLOBAL_OFFSET_TABLEAtom : public SimpleELFDefinedAtom {
public:
GLOBAL_OFFSET_TABLEAtom(const File &f) : SimpleELFDefinedAtom(f) {}
virtual StringRef name() const { return "_GLOBAL_OFFSET_TABLE_"; }
virtual Scope scope() const { return scopeGlobal; }
virtual SectionChoice sectionChoice() const { return sectionCustomRequired; }
virtual StringRef customSectionName() const { return ".got.plt"; }
virtual ContentType contentType() const { return typeGOT; }
virtual uint64_t size() const { return 0; }
virtual ContentPermissions permissions() const { return permRW_; }
virtual Alignment alignment() const {
// Needs 8 byte alignment
return Alignment(3);
}
virtual ArrayRef<uint8_t> rawContent() const {
return ArrayRef<uint8_t>();
}
};
class TLSGETADDRAtom : public SimpleELFDefinedAtom {
public:
TLSGETADDRAtom(const File &f) : SimpleELFDefinedAtom(f) {}
virtual StringRef name() const { return "__tls_get_addr"; }
virtual Scope scope() const { return scopeGlobal; }
virtual Merge merge() const { return mergeAsWeak; }
virtual SectionChoice sectionChoice() const { return sectionCustomRequired; }
virtual StringRef customSectionName() const { return ".text"; }
virtual ContentType contentType() const { return typeCode; }
virtual uint64_t size() const { return 0; }
virtual ContentPermissions permissions() const { return permR_X; }
virtual Alignment alignment() const { return Alignment(0); }
virtual ArrayRef<uint8_t> rawContent() const { return ArrayRef<uint8_t>(); }
};
class DYNAMICAtom : public SimpleELFDefinedAtom {
public:
DYNAMICAtom(const File &f) : SimpleELFDefinedAtom(f) {}
virtual StringRef name() const { return "_DYNAMIC"; }
virtual Scope scope() const { return scopeLinkageUnit; }
virtual Merge merge() const { return mergeNo; }
virtual SectionChoice sectionChoice() const { return sectionCustomRequired; }
virtual StringRef customSectionName() const { return ".dynamic"; }
virtual ContentType contentType() const { return typeData; }
virtual uint64_t size() const { return 0; }
virtual ContentPermissions permissions() const { return permRW_; }
virtual Alignment alignment() const { return Alignment(0); }
virtual ArrayRef<uint8_t> rawContent() const { return ArrayRef<uint8_t>(); }
};
class InitFiniAtom : public SimpleELFDefinedAtom {
StringRef _section;
public:
InitFiniAtom(const File &f, StringRef secName)
: SimpleELFDefinedAtom(f), _section(secName) {}
virtual Scope scope() const { return scopeGlobal; }
virtual SectionChoice sectionChoice() const { return sectionCustomRequired; }
virtual StringRef customSectionName() const { return _section; }
virtual ContentType contentType() const { return typeData; }
virtual uint64_t size() const { return rawContent().size(); }
virtual ContentPermissions permissions() const { return permRW_; }
virtual ArrayRef<uint8_t> rawContent() const = 0;
virtual Alignment alignment() const { return size(); }
#ifndef NDEBUG
virtual StringRef name() const { return _name; }
std::string _name;
#else
virtual StringRef name() const { return ""; }
#endif
};
} // end namespace elf
} // end namespace lld
#endif