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//===- ELFObjectFile.h - ELF object file implementation ---------*- 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 ELFObjectFile template class.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_OBJECT_ELFOBJECTFILE_H
#define LLVM_OBJECT_ELFOBJECTFILE_H
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Triple.h"
#include "llvm/ADT/iterator_range.h"
#include "llvm/BinaryFormat/ELF.h"
#include "llvm/MC/SubtargetFeature.h"
#include "llvm/Object/Binary.h"
#include "llvm/Object/ELF.h"
#include "llvm/Object/ELFTypes.h"
#include "llvm/Object/Error.h"
#include "llvm/Object/ObjectFile.h"
#include "llvm/Object/SymbolicFile.h"
#include "llvm/Support/ARMAttributeParser.h"
#include "llvm/Support/ARMBuildAttributes.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Endian.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MemoryBuffer.h"
#include <cassert>
#include <cstdint>
#include <system_error>
namespace llvm {
namespace object {
constexpr int NumElfSymbolTypes = 16;
extern const llvm::EnumEntry<unsigned> ElfSymbolTypes[NumElfSymbolTypes];
class elf_symbol_iterator;
class ELFObjectFileBase : public ObjectFile {
friend class ELFRelocationRef;
friend class ELFSectionRef;
friend class ELFSymbolRef;
protected:
ELFObjectFileBase(unsigned int Type, MemoryBufferRef Source);
virtual uint64_t getSymbolSize(DataRefImpl Symb) const = 0;
virtual uint8_t getSymbolBinding(DataRefImpl Symb) const = 0;
virtual uint8_t getSymbolOther(DataRefImpl Symb) const = 0;
virtual uint8_t getSymbolELFType(DataRefImpl Symb) const = 0;
virtual uint32_t getSectionType(DataRefImpl Sec) const = 0;
virtual uint64_t getSectionFlags(DataRefImpl Sec) const = 0;
virtual uint64_t getSectionOffset(DataRefImpl Sec) const = 0;
virtual Expected<int64_t> getRelocationAddend(DataRefImpl Rel) const = 0;
virtual Error getBuildAttributes(ARMAttributeParser &Attributes) const = 0;
public:
using elf_symbol_iterator_range = iterator_range<elf_symbol_iterator>;
virtual elf_symbol_iterator_range getDynamicSymbolIterators() const = 0;
/// Returns platform-specific object flags, if any.
virtual unsigned getPlatformFlags() const = 0;
elf_symbol_iterator_range symbols() const;
static bool classof(const Binary *v) { return v->isELF(); }
SubtargetFeatures getFeatures() const override;
SubtargetFeatures getMIPSFeatures() const;
SubtargetFeatures getARMFeatures() const;
SubtargetFeatures getRISCVFeatures() const;
void setARMSubArch(Triple &TheTriple) const override;
virtual uint16_t getEType() const = 0;
virtual uint16_t getEMachine() const = 0;
std::vector<std::pair<DataRefImpl, uint64_t>> getPltAddresses() const;
};
class ELFSectionRef : public SectionRef {
public:
ELFSectionRef(const SectionRef &B) : SectionRef(B) {
assert(isa<ELFObjectFileBase>(SectionRef::getObject()));
}
const ELFObjectFileBase *getObject() const {
return cast<ELFObjectFileBase>(SectionRef::getObject());
}
uint32_t getType() const {
return getObject()->getSectionType(getRawDataRefImpl());
}
uint64_t getFlags() const {
return getObject()->getSectionFlags(getRawDataRefImpl());
}
uint64_t getOffset() const {
return getObject()->getSectionOffset(getRawDataRefImpl());
}
};
class elf_section_iterator : public section_iterator {
public:
elf_section_iterator(const section_iterator &B) : section_iterator(B) {
assert(isa<ELFObjectFileBase>(B->getObject()));
}
const ELFSectionRef *operator->() const {
return static_cast<const ELFSectionRef *>(section_iterator::operator->());
}
const ELFSectionRef &operator*() const {
return static_cast<const ELFSectionRef &>(section_iterator::operator*());
}
};
class ELFSymbolRef : public SymbolRef {
public:
ELFSymbolRef(const SymbolRef &B) : SymbolRef(B) {
assert(isa<ELFObjectFileBase>(SymbolRef::getObject()));
}
const ELFObjectFileBase *getObject() const {
return cast<ELFObjectFileBase>(BasicSymbolRef::getObject());
}
uint64_t getSize() const {
return getObject()->getSymbolSize(getRawDataRefImpl());
}
uint8_t getBinding() const {
return getObject()->getSymbolBinding(getRawDataRefImpl());
}
uint8_t getOther() const {
return getObject()->getSymbolOther(getRawDataRefImpl());
}
uint8_t getELFType() const {
return getObject()->getSymbolELFType(getRawDataRefImpl());
}
StringRef getELFTypeName() const {
uint8_t Type = getELFType();
for (auto &EE : ElfSymbolTypes) {
if (EE.Value == Type) {
return EE.AltName;
}
}
return "";
}
};
class elf_symbol_iterator : public symbol_iterator {
public:
elf_symbol_iterator(const basic_symbol_iterator &B)
: symbol_iterator(SymbolRef(B->getRawDataRefImpl(),
cast<ELFObjectFileBase>(B->getObject()))) {}
const ELFSymbolRef *operator->() const {
return static_cast<const ELFSymbolRef *>(symbol_iterator::operator->());
}
const ELFSymbolRef &operator*() const {
return static_cast<const ELFSymbolRef &>(symbol_iterator::operator*());
}
};
class ELFRelocationRef : public RelocationRef {
public:
ELFRelocationRef(const RelocationRef &B) : RelocationRef(B) {
assert(isa<ELFObjectFileBase>(RelocationRef::getObject()));
}
const ELFObjectFileBase *getObject() const {
return cast<ELFObjectFileBase>(RelocationRef::getObject());
}
Expected<int64_t> getAddend() const {
return getObject()->getRelocationAddend(getRawDataRefImpl());
}
};
class elf_relocation_iterator : public relocation_iterator {
public:
elf_relocation_iterator(const relocation_iterator &B)
: relocation_iterator(RelocationRef(
B->getRawDataRefImpl(), cast<ELFObjectFileBase>(B->getObject()))) {}
const ELFRelocationRef *operator->() const {
return static_cast<const ELFRelocationRef *>(
relocation_iterator::operator->());
}
const ELFRelocationRef &operator*() const {
return static_cast<const ELFRelocationRef &>(
relocation_iterator::operator*());
}
};
inline ELFObjectFileBase::elf_symbol_iterator_range
ELFObjectFileBase::symbols() const {
return elf_symbol_iterator_range(symbol_begin(), symbol_end());
}
template <class ELFT> class ELFObjectFile : public ELFObjectFileBase {
uint16_t getEMachine() const override;
uint16_t getEType() const override;
uint64_t getSymbolSize(DataRefImpl Sym) const override;
public:
LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
using uintX_t = typename ELFT::uint;
using Elf_Sym = typename ELFT::Sym;
using Elf_Shdr = typename ELFT::Shdr;
using Elf_Ehdr = typename ELFT::Ehdr;
using Elf_Rel = typename ELFT::Rel;
using Elf_Rela = typename ELFT::Rela;
using Elf_Dyn = typename ELFT::Dyn;
SectionRef toSectionRef(const Elf_Shdr *Sec) const {
return SectionRef(toDRI(Sec), this);
}
private:
ELFObjectFile(MemoryBufferRef Object, ELFFile<ELFT> EF,
const Elf_Shdr *DotDynSymSec, const Elf_Shdr *DotSymtabSec,
ArrayRef<Elf_Word> ShndxTable);
protected:
ELFFile<ELFT> EF;
const Elf_Shdr *DotDynSymSec = nullptr; // Dynamic symbol table section.
const Elf_Shdr *DotSymtabSec = nullptr; // Symbol table section.
ArrayRef<Elf_Word> ShndxTable;
void moveSymbolNext(DataRefImpl &Symb) const override;
Expected<StringRef> getSymbolName(DataRefImpl Symb) const override;
Expected<uint64_t> getSymbolAddress(DataRefImpl Symb) const override;
uint64_t getSymbolValueImpl(DataRefImpl Symb) const override;
uint32_t getSymbolAlignment(DataRefImpl Symb) const override;
uint64_t getCommonSymbolSizeImpl(DataRefImpl Symb) const override;
uint32_t getSymbolFlags(DataRefImpl Symb) const override;
uint8_t getSymbolBinding(DataRefImpl Symb) const override;
uint8_t getSymbolOther(DataRefImpl Symb) const override;
uint8_t getSymbolELFType(DataRefImpl Symb) const override;
Expected<SymbolRef::Type> getSymbolType(DataRefImpl Symb) const override;
Expected<section_iterator> getSymbolSection(const Elf_Sym *Symb,
const Elf_Shdr *SymTab) const;
Expected<section_iterator> getSymbolSection(DataRefImpl Symb) const override;
void moveSectionNext(DataRefImpl &Sec) const override;
Expected<StringRef> getSectionName(DataRefImpl Sec) const override;
uint64_t getSectionAddress(DataRefImpl Sec) const override;
uint64_t getSectionIndex(DataRefImpl Sec) const override;
uint64_t getSectionSize(DataRefImpl Sec) const override;
Expected<ArrayRef<uint8_t>>
getSectionContents(DataRefImpl Sec) const override;
uint64_t getSectionAlignment(DataRefImpl Sec) const override;
bool isSectionCompressed(DataRefImpl Sec) const override;
bool isSectionText(DataRefImpl Sec) const override;
bool isSectionData(DataRefImpl Sec) const override;
bool isSectionBSS(DataRefImpl Sec) const override;
bool isSectionVirtual(DataRefImpl Sec) const override;
bool isBerkeleyText(DataRefImpl Sec) const override;
bool isBerkeleyData(DataRefImpl Sec) const override;
relocation_iterator section_rel_begin(DataRefImpl Sec) const override;
relocation_iterator section_rel_end(DataRefImpl Sec) const override;
std::vector<SectionRef> dynamic_relocation_sections() const override;
Expected<section_iterator>
getRelocatedSection(DataRefImpl Sec) const override;
void moveRelocationNext(DataRefImpl &Rel) const override;
uint64_t getRelocationOffset(DataRefImpl Rel) const override;
symbol_iterator getRelocationSymbol(DataRefImpl Rel) const override;
uint64_t getRelocationType(DataRefImpl Rel) const override;
void getRelocationTypeName(DataRefImpl Rel,
SmallVectorImpl<char> &Result) const override;
uint32_t getSectionType(DataRefImpl Sec) const override;
uint64_t getSectionFlags(DataRefImpl Sec) const override;
uint64_t getSectionOffset(DataRefImpl Sec) const override;
StringRef getRelocationTypeName(uint32_t Type) const;
/// Get the relocation section that contains \a Rel.
const Elf_Shdr *getRelSection(DataRefImpl Rel) const {
auto RelSecOrErr = EF.getSection(Rel.d.a);
if (!RelSecOrErr)
report_fatal_error(errorToErrorCode(RelSecOrErr.takeError()).message());
return *RelSecOrErr;
}
DataRefImpl toDRI(const Elf_Shdr *SymTable, unsigned SymbolNum) const {
DataRefImpl DRI;
if (!SymTable) {
DRI.d.a = 0;
DRI.d.b = 0;
return DRI;
}
assert(SymTable->sh_type == ELF::SHT_SYMTAB ||
SymTable->sh_type == ELF::SHT_DYNSYM);
auto SectionsOrErr = EF.sections();
if (!SectionsOrErr) {
DRI.d.a = 0;
DRI.d.b = 0;
return DRI;
}
uintptr_t SHT = reinterpret_cast<uintptr_t>((*SectionsOrErr).begin());
unsigned SymTableIndex =
(reinterpret_cast<uintptr_t>(SymTable) - SHT) / sizeof(Elf_Shdr);
DRI.d.a = SymTableIndex;
DRI.d.b = SymbolNum;
return DRI;
}
const Elf_Shdr *toELFShdrIter(DataRefImpl Sec) const {
return reinterpret_cast<const Elf_Shdr *>(Sec.p);
}
DataRefImpl toDRI(const Elf_Shdr *Sec) const {
DataRefImpl DRI;
DRI.p = reinterpret_cast<uintptr_t>(Sec);
return DRI;
}
DataRefImpl toDRI(const Elf_Dyn *Dyn) const {
DataRefImpl DRI;
DRI.p = reinterpret_cast<uintptr_t>(Dyn);
return DRI;
}
bool isExportedToOtherDSO(const Elf_Sym *ESym) const {
unsigned char Binding = ESym->getBinding();
unsigned char Visibility = ESym->getVisibility();
// A symbol is exported if its binding is either GLOBAL or WEAK, and its
// visibility is either DEFAULT or PROTECTED. All other symbols are not
// exported.
return (
(Binding == ELF::STB_GLOBAL || Binding == ELF::STB_WEAK ||
Binding == ELF::STB_GNU_UNIQUE) &&
(Visibility == ELF::STV_DEFAULT || Visibility == ELF::STV_PROTECTED));
}
Error getBuildAttributes(ARMAttributeParser &Attributes) const override {
auto SectionsOrErr = EF.sections();
if (!SectionsOrErr)
return SectionsOrErr.takeError();
for (const Elf_Shdr &Sec : *SectionsOrErr) {
if (Sec.sh_type == ELF::SHT_ARM_ATTRIBUTES) {
auto ErrorOrContents = EF.getSectionContents(&Sec);
if (!ErrorOrContents)
return ErrorOrContents.takeError();
auto Contents = ErrorOrContents.get();
if (Contents[0] != ARMBuildAttrs::Format_Version || Contents.size() == 1)
return Error::success();
Attributes.Parse(Contents, ELFT::TargetEndianness == support::little);
break;
}
}
return Error::success();
}
// This flag is used for classof, to distinguish ELFObjectFile from
// its subclass. If more subclasses will be created, this flag will
// have to become an enum.
bool isDyldELFObject;
public:
ELFObjectFile(ELFObjectFile<ELFT> &&Other);
static Expected<ELFObjectFile<ELFT>> create(MemoryBufferRef Object);
const Elf_Rel *getRel(DataRefImpl Rel) const;
const Elf_Rela *getRela(DataRefImpl Rela) const;
const Elf_Sym *getSymbol(DataRefImpl Sym) const {
auto Ret = EF.template getEntry<Elf_Sym>(Sym.d.a, Sym.d.b);
if (!Ret)
report_fatal_error(errorToErrorCode(Ret.takeError()).message());
return *Ret;
}
const Elf_Shdr *getSection(DataRefImpl Sec) const {
return reinterpret_cast<const Elf_Shdr *>(Sec.p);
}
basic_symbol_iterator symbol_begin() const override;
basic_symbol_iterator symbol_end() const override;
elf_symbol_iterator dynamic_symbol_begin() const;
elf_symbol_iterator dynamic_symbol_end() const;
section_iterator section_begin() const override;
section_iterator section_end() const override;
Expected<int64_t> getRelocationAddend(DataRefImpl Rel) const override;
uint8_t getBytesInAddress() const override;
StringRef getFileFormatName() const override;
Triple::ArchType getArch() const override;
Expected<uint64_t> getStartAddress() const override;
unsigned getPlatformFlags() const override { return EF.getHeader()->e_flags; }
const ELFFile<ELFT> *getELFFile() const { return &EF; }
bool isDyldType() const { return isDyldELFObject; }
static bool classof(const Binary *v) {
return v->getType() == getELFType(ELFT::TargetEndianness == support::little,
ELFT::Is64Bits);
}
elf_symbol_iterator_range getDynamicSymbolIterators() const override;
bool isRelocatableObject() const override;
};
using ELF32LEObjectFile = ELFObjectFile<ELF32LE>;
using ELF64LEObjectFile = ELFObjectFile<ELF64LE>;
using ELF32BEObjectFile = ELFObjectFile<ELF32BE>;
using ELF64BEObjectFile = ELFObjectFile<ELF64BE>;
template <class ELFT>
void ELFObjectFile<ELFT>::moveSymbolNext(DataRefImpl &Sym) const {
++Sym.d.b;
}
template <class ELFT>
Expected<StringRef> ELFObjectFile<ELFT>::getSymbolName(DataRefImpl Sym) const {
const Elf_Sym *ESym = getSymbol(Sym);
auto SymTabOrErr = EF.getSection(Sym.d.a);
if (!SymTabOrErr)
return SymTabOrErr.takeError();
const Elf_Shdr *SymTableSec = *SymTabOrErr;
auto StrTabOrErr = EF.getSection(SymTableSec->sh_link);
if (!StrTabOrErr)
return StrTabOrErr.takeError();
const Elf_Shdr *StringTableSec = *StrTabOrErr;
auto SymStrTabOrErr = EF.getStringTable(StringTableSec);
if (!SymStrTabOrErr)
return SymStrTabOrErr.takeError();
Expected<StringRef> Name = ESym->getName(*SymStrTabOrErr);
if (Name && !Name->empty())
return Name;
// If the symbol name is empty use the section name.
if (ESym->getType() == ELF::STT_SECTION) {
if (Expected<section_iterator> SecOrErr = getSymbolSection(Sym)) {
consumeError(Name.takeError());
return (*SecOrErr)->getName();
}
}
return Name;
}
template <class ELFT>
uint64_t ELFObjectFile<ELFT>::getSectionFlags(DataRefImpl Sec) const {
return getSection(Sec)->sh_flags;
}
template <class ELFT>
uint32_t ELFObjectFile<ELFT>::getSectionType(DataRefImpl Sec) const {
return getSection(Sec)->sh_type;
}
template <class ELFT>
uint64_t ELFObjectFile<ELFT>::getSectionOffset(DataRefImpl Sec) const {
return getSection(Sec)->sh_offset;
}
template <class ELFT>
uint64_t ELFObjectFile<ELFT>::getSymbolValueImpl(DataRefImpl Symb) const {
const Elf_Sym *ESym = getSymbol(Symb);
uint64_t Ret = ESym->st_value;
if (ESym->st_shndx == ELF::SHN_ABS)
return Ret;
const Elf_Ehdr *Header = EF.getHeader();
// Clear the ARM/Thumb or microMIPS indicator flag.
if ((Header->e_machine == ELF::EM_ARM || Header->e_machine == ELF::EM_MIPS) &&
ESym->getType() == ELF::STT_FUNC)
Ret &= ~1;
return Ret;
}
template <class ELFT>
Expected<uint64_t>
ELFObjectFile<ELFT>::getSymbolAddress(DataRefImpl Symb) const {
uint64_t Result = getSymbolValue(Symb);
const Elf_Sym *ESym = getSymbol(Symb);
switch (ESym->st_shndx) {
case ELF::SHN_COMMON:
case ELF::SHN_UNDEF:
case ELF::SHN_ABS:
return Result;
}
const Elf_Ehdr *Header = EF.getHeader();
auto SymTabOrErr = EF.getSection(Symb.d.a);
if (!SymTabOrErr)
return SymTabOrErr.takeError();
const Elf_Shdr *SymTab = *SymTabOrErr;
if (Header->e_type == ELF::ET_REL) {
auto SectionOrErr = EF.getSection(ESym, SymTab, ShndxTable);
if (!SectionOrErr)
return SectionOrErr.takeError();
const Elf_Shdr *Section = *SectionOrErr;
if (Section)
Result += Section->sh_addr;
}
return Result;
}
template <class ELFT>
uint32_t ELFObjectFile<ELFT>::getSymbolAlignment(DataRefImpl Symb) const {
const Elf_Sym *Sym = getSymbol(Symb);
if (Sym->st_shndx == ELF::SHN_COMMON)
return Sym->st_value;
return 0;
}
template <class ELFT>
uint16_t ELFObjectFile<ELFT>::getEMachine() const {
return EF.getHeader()->e_machine;
}
template <class ELFT> uint16_t ELFObjectFile<ELFT>::getEType() const {
return EF.getHeader()->e_type;
}
template <class ELFT>
uint64_t ELFObjectFile<ELFT>::getSymbolSize(DataRefImpl Sym) const {
return getSymbol(Sym)->st_size;
}
template <class ELFT>
uint64_t ELFObjectFile<ELFT>::getCommonSymbolSizeImpl(DataRefImpl Symb) const {
return getSymbol(Symb)->st_size;
}
template <class ELFT>
uint8_t ELFObjectFile<ELFT>::getSymbolBinding(DataRefImpl Symb) const {
return getSymbol(Symb)->getBinding();
}
template <class ELFT>
uint8_t ELFObjectFile<ELFT>::getSymbolOther(DataRefImpl Symb) const {
return getSymbol(Symb)->st_other;
}
template <class ELFT>
uint8_t ELFObjectFile<ELFT>::getSymbolELFType(DataRefImpl Symb) const {
return getSymbol(Symb)->getType();
}
template <class ELFT>
Expected<SymbolRef::Type>
ELFObjectFile<ELFT>::getSymbolType(DataRefImpl Symb) const {
const Elf_Sym *ESym = getSymbol(Symb);
switch (ESym->getType()) {
case ELF::STT_NOTYPE:
return SymbolRef::ST_Unknown;
case ELF::STT_SECTION:
return SymbolRef::ST_Debug;
case ELF::STT_FILE:
return SymbolRef::ST_File;
case ELF::STT_FUNC:
return SymbolRef::ST_Function;
case ELF::STT_OBJECT:
case ELF::STT_COMMON:
case ELF::STT_TLS:
return SymbolRef::ST_Data;
default:
return SymbolRef::ST_Other;
}
}
template <class ELFT>
uint32_t ELFObjectFile<ELFT>::getSymbolFlags(DataRefImpl Sym) const {
const Elf_Sym *ESym = getSymbol(Sym);
uint32_t Result = SymbolRef::SF_None;
if (ESym->getBinding() != ELF::STB_LOCAL)
Result |= SymbolRef::SF_Global;
if (ESym->getBinding() == ELF::STB_WEAK)
Result |= SymbolRef::SF_Weak;
if (ESym->st_shndx == ELF::SHN_ABS)
Result |= SymbolRef::SF_Absolute;
if (ESym->getType() == ELF::STT_FILE || ESym->getType() == ELF::STT_SECTION)
Result |= SymbolRef::SF_FormatSpecific;
auto DotSymtabSecSyms = EF.symbols(DotSymtabSec);
if (DotSymtabSecSyms && ESym == (*DotSymtabSecSyms).begin())
Result |= SymbolRef::SF_FormatSpecific;
auto DotDynSymSecSyms = EF.symbols(DotDynSymSec);
if (DotDynSymSecSyms && ESym == (*DotDynSymSecSyms).begin())
Result |= SymbolRef::SF_FormatSpecific;
if (EF.getHeader()->e_machine == ELF::EM_ARM) {
if (Expected<StringRef> NameOrErr = getSymbolName(Sym)) {
StringRef Name = *NameOrErr;
if (Name.startswith("$d") || Name.startswith("$t") ||
Name.startswith("$a"))
Result |= SymbolRef::SF_FormatSpecific;
} else {
// TODO: Actually report errors helpfully.
consumeError(NameOrErr.takeError());
}
if (ESym->getType() == ELF::STT_FUNC && (ESym->st_value & 1) == 1)
Result |= SymbolRef::SF_Thumb;
}
if (ESym->st_shndx == ELF::SHN_UNDEF)
Result |= SymbolRef::SF_Undefined;
if (ESym->getType() == ELF::STT_COMMON || ESym->st_shndx == ELF::SHN_COMMON)
Result |= SymbolRef::SF_Common;
if (isExportedToOtherDSO(ESym))
Result |= SymbolRef::SF_Exported;
if (ESym->getVisibility() == ELF::STV_HIDDEN)
Result |= SymbolRef::SF_Hidden;
return Result;
}
template <class ELFT>
Expected<section_iterator>
ELFObjectFile<ELFT>::getSymbolSection(const Elf_Sym *ESym,
const Elf_Shdr *SymTab) const {
auto ESecOrErr = EF.getSection(ESym, SymTab, ShndxTable);
if (!ESecOrErr)
return ESecOrErr.takeError();
const Elf_Shdr *ESec = *ESecOrErr;
if (!ESec)
return section_end();
DataRefImpl Sec;
Sec.p = reinterpret_cast<intptr_t>(ESec);
return section_iterator(SectionRef(Sec, this));
}
template <class ELFT>
Expected<section_iterator>
ELFObjectFile<ELFT>::getSymbolSection(DataRefImpl Symb) const {
const Elf_Sym *Sym = getSymbol(Symb);
auto SymTabOrErr = EF.getSection(Symb.d.a);
if (!SymTabOrErr)
return SymTabOrErr.takeError();
const Elf_Shdr *SymTab = *SymTabOrErr;
return getSymbolSection(Sym, SymTab);
}
template <class ELFT>
void ELFObjectFile<ELFT>::moveSectionNext(DataRefImpl &Sec) const {
const Elf_Shdr *ESec = getSection(Sec);
Sec = toDRI(++ESec);
}
template <class ELFT>
Expected<StringRef> ELFObjectFile<ELFT>::getSectionName(DataRefImpl Sec) const {
return EF.getSectionName(&*getSection(Sec));
}
template <class ELFT>
uint64_t ELFObjectFile<ELFT>::getSectionAddress(DataRefImpl Sec) const {
return getSection(Sec)->sh_addr;
}
template <class ELFT>
uint64_t ELFObjectFile<ELFT>::getSectionIndex(DataRefImpl Sec) const {
auto SectionsOrErr = EF.sections();
handleAllErrors(std::move(SectionsOrErr.takeError()),
[](const ErrorInfoBase &) {
llvm_unreachable("unable to get section index");
});
const Elf_Shdr *First = SectionsOrErr->begin();
return getSection(Sec) - First;
}
template <class ELFT>
uint64_t ELFObjectFile<ELFT>::getSectionSize(DataRefImpl Sec) const {
return getSection(Sec)->sh_size;
}
template <class ELFT>
Expected<ArrayRef<uint8_t>>
ELFObjectFile<ELFT>::getSectionContents(DataRefImpl Sec) const {
const Elf_Shdr *EShdr = getSection(Sec);
if (EShdr->sh_type == ELF::SHT_NOBITS)
return makeArrayRef((const uint8_t *)base(), 0);
if (std::error_code EC =
checkOffset(getMemoryBufferRef(),
(uintptr_t)base() + EShdr->sh_offset, EShdr->sh_size))
return errorCodeToError(EC);
return makeArrayRef((const uint8_t *)base() + EShdr->sh_offset,
EShdr->sh_size);
}
template <class ELFT>
uint64_t ELFObjectFile<ELFT>::getSectionAlignment(DataRefImpl Sec) const {
return getSection(Sec)->sh_addralign;
}
template <class ELFT>
bool ELFObjectFile<ELFT>::isSectionCompressed(DataRefImpl Sec) const {
return getSection(Sec)->sh_flags & ELF::SHF_COMPRESSED;
}
template <class ELFT>
bool ELFObjectFile<ELFT>::isSectionText(DataRefImpl Sec) const {
return getSection(Sec)->sh_flags & ELF::SHF_EXECINSTR;
}
template <class ELFT>
bool ELFObjectFile<ELFT>::isSectionData(DataRefImpl Sec) const {
const Elf_Shdr *EShdr = getSection(Sec);
return EShdr->sh_type == ELF::SHT_PROGBITS &&
EShdr->sh_flags & ELF::SHF_ALLOC &&
!(EShdr->sh_flags & ELF::SHF_EXECINSTR);
}
template <class ELFT>
bool ELFObjectFile<ELFT>::isSectionBSS(DataRefImpl Sec) const {
const Elf_Shdr *EShdr = getSection(Sec);
return EShdr->sh_flags & (ELF::SHF_ALLOC | ELF::SHF_WRITE) &&
EShdr->sh_type == ELF::SHT_NOBITS;
}
template <class ELFT>
std::vector<SectionRef>
ELFObjectFile<ELFT>::dynamic_relocation_sections() const {
std::vector<SectionRef> Res;
std::vector<uintptr_t> Offsets;
auto SectionsOrErr = EF.sections();
if (!SectionsOrErr)
return Res;
for (const Elf_Shdr &Sec : *SectionsOrErr) {
if (Sec.sh_type != ELF::SHT_DYNAMIC)
continue;
Elf_Dyn *Dynamic =
reinterpret_cast<Elf_Dyn *>((uintptr_t)base() + Sec.sh_offset);
for (; Dynamic->d_tag != ELF::DT_NULL; Dynamic++) {
if (Dynamic->d_tag == ELF::DT_REL || Dynamic->d_tag == ELF::DT_RELA ||
Dynamic->d_tag == ELF::DT_JMPREL) {
Offsets.push_back(Dynamic->d_un.d_val);
}
}
}
for (const Elf_Shdr &Sec : *SectionsOrErr) {
if (is_contained(Offsets, Sec.sh_addr))
Res.emplace_back(toDRI(&Sec), this);
}
return Res;
}
template <class ELFT>
bool ELFObjectFile<ELFT>::isSectionVirtual(DataRefImpl Sec) const {
return getSection(Sec)->sh_type == ELF::SHT_NOBITS;
}
template <class ELFT>
bool ELFObjectFile<ELFT>::isBerkeleyText(DataRefImpl Sec) const {
return getSection(Sec)->sh_flags & ELF::SHF_ALLOC &&
(getSection(Sec)->sh_flags & ELF::SHF_EXECINSTR ||
!(getSection(Sec)->sh_flags & ELF::SHF_WRITE));
}
template <class ELFT>
bool ELFObjectFile<ELFT>::isBerkeleyData(DataRefImpl Sec) const {
const Elf_Shdr *EShdr = getSection(Sec);
return !isBerkeleyText(Sec) && EShdr->sh_type != ELF::SHT_NOBITS &&
EShdr->sh_flags & ELF::SHF_ALLOC;
}
template <class ELFT>
relocation_iterator
ELFObjectFile<ELFT>::section_rel_begin(DataRefImpl Sec) const {
DataRefImpl RelData;
auto SectionsOrErr = EF.sections();
if (!SectionsOrErr)
return relocation_iterator(RelocationRef());
uintptr_t SHT = reinterpret_cast<uintptr_t>((*SectionsOrErr).begin());
RelData.d.a = (Sec.p - SHT) / EF.getHeader()->e_shentsize;
RelData.d.b = 0;
return relocation_iterator(RelocationRef(RelData, this));
}
template <class ELFT>
relocation_iterator
ELFObjectFile<ELFT>::section_rel_end(DataRefImpl Sec) const {
const Elf_Shdr *S = reinterpret_cast<const Elf_Shdr *>(Sec.p);
relocation_iterator Begin = section_rel_begin(Sec);
if (S->sh_type != ELF::SHT_RELA && S->sh_type != ELF::SHT_REL)
return Begin;
DataRefImpl RelData = Begin->getRawDataRefImpl();
const Elf_Shdr *RelSec = getRelSection(RelData);
// Error check sh_link here so that getRelocationSymbol can just use it.
auto SymSecOrErr = EF.getSection(RelSec->sh_link);
if (!SymSecOrErr)
report_fatal_error(errorToErrorCode(SymSecOrErr.takeError()).message());
RelData.d.b += S->sh_size / S->sh_entsize;
return relocation_iterator(RelocationRef(RelData, this));
}
template <class ELFT>
Expected<section_iterator>
ELFObjectFile<ELFT>::getRelocatedSection(DataRefImpl Sec) const {
if (EF.getHeader()->e_type != ELF::ET_REL)
return section_end();
const Elf_Shdr *EShdr = getSection(Sec);
uintX_t Type = EShdr->sh_type;
if (Type != ELF::SHT_REL && Type != ELF::SHT_RELA)
return section_end();
Expected<const Elf_Shdr *> SecOrErr = EF.getSection(EShdr->sh_info);
if (!SecOrErr)
return SecOrErr.takeError();
return section_iterator(SectionRef(toDRI(*SecOrErr), this));
}
// Relocations
template <class ELFT>
void ELFObjectFile<ELFT>::moveRelocationNext(DataRefImpl &Rel) const {
++Rel.d.b;
}
template <class ELFT>
symbol_iterator
ELFObjectFile<ELFT>::getRelocationSymbol(DataRefImpl Rel) const {
uint32_t symbolIdx;
const Elf_Shdr *sec = getRelSection(Rel);
if (sec->sh_type == ELF::SHT_REL)
symbolIdx = getRel(Rel)->getSymbol(EF.isMips64EL());
else
symbolIdx = getRela(Rel)->getSymbol(EF.isMips64EL());
if (!symbolIdx)
return symbol_end();
// FIXME: error check symbolIdx
DataRefImpl SymbolData;
SymbolData.d.a = sec->sh_link;
SymbolData.d.b = symbolIdx;
return symbol_iterator(SymbolRef(SymbolData, this));
}
template <class ELFT>
uint64_t ELFObjectFile<ELFT>::getRelocationOffset(DataRefImpl Rel) const {
const Elf_Shdr *sec = getRelSection(Rel);
if (sec->sh_type == ELF::SHT_REL)
return getRel(Rel)->r_offset;
return getRela(Rel)->r_offset;
}
template <class ELFT>
uint64_t ELFObjectFile<ELFT>::getRelocationType(DataRefImpl Rel) const {
const Elf_Shdr *sec = getRelSection(Rel);
if (sec->sh_type == ELF::SHT_REL)
return getRel(Rel)->getType(EF.isMips64EL());
else
return getRela(Rel)->getType(EF.isMips64EL());
}
template <class ELFT>
StringRef ELFObjectFile<ELFT>::getRelocationTypeName(uint32_t Type) const {
return getELFRelocationTypeName(EF.getHeader()->e_machine, Type);
}
template <class ELFT>
void ELFObjectFile<ELFT>::getRelocationTypeName(
DataRefImpl Rel, SmallVectorImpl<char> &Result) const {
uint32_t type = getRelocationType(Rel);
EF.getRelocationTypeName(type, Result);
}
template <class ELFT>
Expected<int64_t>
ELFObjectFile<ELFT>::getRelocationAddend(DataRefImpl Rel) const {
if (getRelSection(Rel)->sh_type != ELF::SHT_RELA)
return createError("Section is not SHT_RELA");
return (int64_t)getRela(Rel)->r_addend;
}
template <class ELFT>
const typename ELFObjectFile<ELFT>::Elf_Rel *
ELFObjectFile<ELFT>::getRel(DataRefImpl Rel) const {
assert(getRelSection(Rel)->sh_type == ELF::SHT_REL);
auto Ret = EF.template getEntry<Elf_Rel>(Rel.d.a, Rel.d.b);
if (!Ret)
report_fatal_error(errorToErrorCode(Ret.takeError()).message());
return *Ret;
}
template <class ELFT>
const typename ELFObjectFile<ELFT>::Elf_Rela *
ELFObjectFile<ELFT>::getRela(DataRefImpl Rela) const {
assert(getRelSection(Rela)->sh_type == ELF::SHT_RELA);
auto Ret = EF.template getEntry<Elf_Rela>(Rela.d.a, Rela.d.b);
if (!Ret)
report_fatal_error(errorToErrorCode(Ret.takeError()).message());
return *Ret;
}
template <class ELFT>
Expected<ELFObjectFile<ELFT>>
ELFObjectFile<ELFT>::create(MemoryBufferRef Object) {
auto EFOrErr = ELFFile<ELFT>::create(Object.getBuffer());
if (Error E = EFOrErr.takeError())
return std::move(E);
auto EF = std::move(*EFOrErr);
auto SectionsOrErr = EF.sections();
if (!SectionsOrErr)
return SectionsOrErr.takeError();
const Elf_Shdr *DotDynSymSec = nullptr;
const Elf_Shdr *DotSymtabSec = nullptr;
ArrayRef<Elf_Word> ShndxTable;
for (const Elf_Shdr &Sec : *SectionsOrErr) {
switch (Sec.sh_type) {
case ELF::SHT_DYNSYM: {
if (!DotDynSymSec)
DotDynSymSec = &Sec;
break;
}
case ELF::SHT_SYMTAB: {
if (!DotSymtabSec)
DotSymtabSec = &Sec;
break;
}
case ELF::SHT_SYMTAB_SHNDX: {
auto TableOrErr = EF.getSHNDXTable(Sec);
if (!TableOrErr)
return TableOrErr.takeError();
ShndxTable = *TableOrErr;
break;
}
}
}
return ELFObjectFile<ELFT>(Object, EF, DotDynSymSec, DotSymtabSec,
ShndxTable);
}
template <class ELFT>
ELFObjectFile<ELFT>::ELFObjectFile(MemoryBufferRef Object, ELFFile<ELFT> EF,
const Elf_Shdr *DotDynSymSec,
const Elf_Shdr *DotSymtabSec,
ArrayRef<Elf_Word> ShndxTable)
: ELFObjectFileBase(
getELFType(ELFT::TargetEndianness == support::little, ELFT::Is64Bits),
Object),
EF(EF), DotDynSymSec(DotDynSymSec), DotSymtabSec(DotSymtabSec),
ShndxTable(ShndxTable) {}
template <class ELFT>
ELFObjectFile<ELFT>::ELFObjectFile(ELFObjectFile<ELFT> &&Other)
: ELFObjectFile(Other.Data, Other.EF, Other.DotDynSymSec,
Other.DotSymtabSec, Other.ShndxTable) {}
template <class ELFT>
basic_symbol_iterator ELFObjectFile<ELFT>::symbol_begin() const {
DataRefImpl Sym =
toDRI(DotSymtabSec,
DotSymtabSec && DotSymtabSec->sh_size >= sizeof(Elf_Sym) ? 1 : 0);
return basic_symbol_iterator(SymbolRef(Sym, this));
}
template <class ELFT>
basic_symbol_iterator ELFObjectFile<ELFT>::symbol_end() const {
const Elf_Shdr *SymTab = DotSymtabSec;
if (!SymTab)
return symbol_begin();
DataRefImpl Sym = toDRI(SymTab, SymTab->sh_size / sizeof(Elf_Sym));
return basic_symbol_iterator(SymbolRef(Sym, this));
}
template <class ELFT>
elf_symbol_iterator ELFObjectFile<ELFT>::dynamic_symbol_begin() const {
DataRefImpl Sym = toDRI(DotDynSymSec, 0);
return symbol_iterator(SymbolRef(Sym, this));
}
template <class ELFT>
elf_symbol_iterator ELFObjectFile<ELFT>::dynamic_symbol_end() const {
const Elf_Shdr *SymTab = DotDynSymSec;
if (!SymTab)
return dynamic_symbol_begin();
DataRefImpl Sym = toDRI(SymTab, SymTab->sh_size / sizeof(Elf_Sym));
return basic_symbol_iterator(SymbolRef(Sym, this));
}
template <class ELFT>
section_iterator ELFObjectFile<ELFT>::section_begin() const {
auto SectionsOrErr = EF.sections();
if (!SectionsOrErr)
return section_iterator(SectionRef());
return section_iterator(SectionRef(toDRI((*SectionsOrErr).begin()), this));
}
template <class ELFT>
section_iterator ELFObjectFile<ELFT>::section_end() const {
auto SectionsOrErr = EF.sections();
if (!SectionsOrErr)
return section_iterator(SectionRef());
return section_iterator(SectionRef(toDRI((*SectionsOrErr).end()), this));
}
template <class ELFT>
uint8_t ELFObjectFile<ELFT>::getBytesInAddress() const {
return ELFT::Is64Bits ? 8 : 4;
}
template <class ELFT>
StringRef ELFObjectFile<ELFT>::getFileFormatName() const {
bool IsLittleEndian = ELFT::TargetEndianness == support::little;
switch (EF.getHeader()->e_ident[ELF::EI_CLASS]) {
case ELF::ELFCLASS32:
switch (EF.getHeader()->e_machine) {
case ELF::EM_386:
return "ELF32-i386";
case ELF::EM_IAMCU:
return "ELF32-iamcu";
case ELF::EM_X86_64:
return "ELF32-x86-64";
case ELF::EM_ARM:
return (IsLittleEndian ? "ELF32-arm-little" : "ELF32-arm-big");
case ELF::EM_AVR:
return "ELF32-avr";
case ELF::EM_HEXAGON:
return "ELF32-hexagon";
case ELF::EM_LANAI:
return "ELF32-lanai";
case ELF::EM_MIPS:
return "ELF32-mips";
case ELF::EM_MSP430:
return "ELF32-msp430";
case ELF::EM_PPC:
return "ELF32-ppc";
case ELF::EM_RISCV:
return "ELF32-riscv";
case ELF::EM_SPARC:
case ELF::EM_SPARC32PLUS:
return "ELF32-sparc";
case ELF::EM_AMDGPU:
return "ELF32-amdgpu";
default:
return "ELF32-unknown";
}
case ELF::ELFCLASS64:
switch (EF.getHeader()->e_machine) {
case ELF::EM_386:
return "ELF64-i386";
case ELF::EM_X86_64:
return "ELF64-x86-64";
case ELF::EM_AARCH64:
return (IsLittleEndian ? "ELF64-aarch64-little" : "ELF64-aarch64-big");
case ELF::EM_PPC64:
return "ELF64-ppc64";
case ELF::EM_RISCV:
return "ELF64-riscv";
case ELF::EM_S390:
return "ELF64-s390";
case ELF::EM_SPARCV9:
return "ELF64-sparc";
case ELF::EM_MIPS:
return "ELF64-mips";
case ELF::EM_AMDGPU:
return "ELF64-amdgpu";
case ELF::EM_BPF:
return "ELF64-BPF";
default:
return "ELF64-unknown";
}
default:
// FIXME: Proper error handling.
report_fatal_error("Invalid ELFCLASS!");
}
}
template <class ELFT> Triple::ArchType ELFObjectFile<ELFT>::getArch() const {
bool IsLittleEndian = ELFT::TargetEndianness == support::little;
switch (EF.getHeader()->e_machine) {
case ELF::EM_386:
case ELF::EM_IAMCU:
return Triple::x86;
case ELF::EM_X86_64:
return Triple::x86_64;
case ELF::EM_AARCH64:
return IsLittleEndian ? Triple::aarch64 : Triple::aarch64_be;
case ELF::EM_ARM:
return Triple::arm;
case ELF::EM_AVR:
return Triple::avr;
case ELF::EM_HEXAGON:
return Triple::hexagon;
case ELF::EM_LANAI:
return Triple::lanai;
case ELF::EM_MIPS:
switch (EF.getHeader()->e_ident[ELF::EI_CLASS]) {
case ELF::ELFCLASS32:
return IsLittleEndian ? Triple::mipsel : Triple::mips;
case ELF::ELFCLASS64:
return IsLittleEndian ? Triple::mips64el : Triple::mips64;
default:
report_fatal_error("Invalid ELFCLASS!");
}
case ELF::EM_MSP430:
return Triple::msp430;
case ELF::EM_PPC:
return Triple::ppc;
case ELF::EM_PPC64:
return IsLittleEndian ? Triple::ppc64le : Triple::ppc64;
case ELF::EM_RISCV:
switch (EF.getHeader()->e_ident[ELF::EI_CLASS]) {
case ELF::ELFCLASS32:
return Triple::riscv32;
case ELF::ELFCLASS64:
return Triple::riscv64;
default:
report_fatal_error("Invalid ELFCLASS!");
}
case ELF::EM_S390:
return Triple::systemz;
case ELF::EM_SPARC:
case ELF::EM_SPARC32PLUS:
return IsLittleEndian ? Triple::sparcel : Triple::sparc;
case ELF::EM_SPARCV9:
return Triple::sparcv9;
case ELF::EM_AMDGPU: {
if (!IsLittleEndian)
return Triple::UnknownArch;
unsigned MACH = EF.getHeader()->e_flags & ELF::EF_AMDGPU_MACH;
if (MACH >= ELF::EF_AMDGPU_MACH_R600_FIRST &&
MACH <= ELF::EF_AMDGPU_MACH_R600_LAST)
return Triple::r600;
if (MACH >= ELF::EF_AMDGPU_MACH_AMDGCN_FIRST &&
MACH <= ELF::EF_AMDGPU_MACH_AMDGCN_LAST)
return Triple::amdgcn;
return Triple::UnknownArch;
}
case ELF::EM_BPF:
return IsLittleEndian ? Triple::bpfel : Triple::bpfeb;
default:
return Triple::UnknownArch;
}
}
template <class ELFT>
Expected<uint64_t> ELFObjectFile<ELFT>::getStartAddress() const {
return EF.getHeader()->e_entry;
}
template <class ELFT>
ELFObjectFileBase::elf_symbol_iterator_range
ELFObjectFile<ELFT>::getDynamicSymbolIterators() const {
return make_range(dynamic_symbol_begin(), dynamic_symbol_end());
}
template <class ELFT> bool ELFObjectFile<ELFT>::isRelocatableObject() const {
return EF.getHeader()->e_type == ELF::ET_REL;
}
} // end namespace object
} // end namespace llvm
#endif // LLVM_OBJECT_ELFOBJECTFILE_H