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llvm-6502/lib/Object/ELFObjectFile.cpp
Eric Christopher 539d8d8a72 Assorted bugfixes in object file handling: 
- Adds support for sniffing PE/COFF files on win32 (.exe and .dll)
   which are COFF files that have an MS-DOS compatibility stub on
   the front of them.

 - Fixes a bug in the COFFObjectFile's support for the Microsoft COFF
   extension for long symbol names, wherein it was attempting to parse
   the leading '/' in an extended symbol name reference as part of the
   integer offset.

 - Fixes bugs in COFFObjectFile and ELFObjectFile wherein section
   and symbol iterators were being returned with uninitialized bytes;
   the type DataRefImpl is a union between 2 32-bit words (d.a and d.b)
   and a single intptr_t word (p). Only p was being initialized, so in
   32-bit builds the result would be iterators with random upper 32-bit
   words in their DataRefImpls. This caused random failures when
   seeking around in object files.

Patch by Graydon Hoare!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128799 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-03 22:53:19 +00:00

689 lines
26 KiB
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//===- ELFObjectFile.cpp - ELF object file implementation -------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the ELFObjectFile class.
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Object/ObjectFile.h"
#include "llvm/Support/ELF.h"
#include "llvm/Support/Endian.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MemoryBuffer.h"
#include <limits>
#include <utility>
using namespace llvm;
using namespace object;
// Templates to choose Elf_Addr and Elf_Off depending on is64Bits.
namespace {
template<support::endianness target_endianness>
struct ELFDataTypeTypedefHelperCommon {
typedef support::detail::packed_endian_specific_integral
<uint16_t, target_endianness, support::aligned> Elf_Half;
typedef support::detail::packed_endian_specific_integral
<uint32_t, target_endianness, support::aligned> Elf_Word;
typedef support::detail::packed_endian_specific_integral
<int32_t, target_endianness, support::aligned> Elf_Sword;
typedef support::detail::packed_endian_specific_integral
<uint64_t, target_endianness, support::aligned> Elf_Xword;
typedef support::detail::packed_endian_specific_integral
<int64_t, target_endianness, support::aligned> Elf_Sxword;
};
}
namespace {
template<support::endianness target_endianness, bool is64Bits>
struct ELFDataTypeTypedefHelper;
/// ELF 32bit types.
template<support::endianness target_endianness>
struct ELFDataTypeTypedefHelper<target_endianness, false>
: ELFDataTypeTypedefHelperCommon<target_endianness> {
typedef support::detail::packed_endian_specific_integral
<uint32_t, target_endianness, support::aligned> Elf_Addr;
typedef support::detail::packed_endian_specific_integral
<uint32_t, target_endianness, support::aligned> Elf_Off;
};
/// ELF 64bit types.
template<support::endianness target_endianness>
struct ELFDataTypeTypedefHelper<target_endianness, true>
: ELFDataTypeTypedefHelperCommon<target_endianness>{
typedef support::detail::packed_endian_specific_integral
<uint64_t, target_endianness, support::aligned> Elf_Addr;
typedef support::detail::packed_endian_specific_integral
<uint64_t, target_endianness, support::aligned> Elf_Off;
};
}
// I really don't like doing this, but the alternative is copypasta.
#define LLVM_ELF_IMPORT_TYPES(target_endianness, is64Bits) \
typedef typename \
ELFDataTypeTypedefHelper<target_endianness, is64Bits>::Elf_Addr Elf_Addr; \
typedef typename \
ELFDataTypeTypedefHelper<target_endianness, is64Bits>::Elf_Off Elf_Off; \
typedef typename \
ELFDataTypeTypedefHelper<target_endianness, is64Bits>::Elf_Half Elf_Half; \
typedef typename \
ELFDataTypeTypedefHelper<target_endianness, is64Bits>::Elf_Word Elf_Word; \
typedef typename \
ELFDataTypeTypedefHelper<target_endianness, is64Bits>::Elf_Sword Elf_Sword; \
typedef typename \
ELFDataTypeTypedefHelper<target_endianness, is64Bits>::Elf_Xword Elf_Xword; \
typedef typename \
ELFDataTypeTypedefHelper<target_endianness, is64Bits>::Elf_Sxword Elf_Sxword;
// Section header.
namespace {
template<support::endianness target_endianness, bool is64Bits>
struct Elf_Shdr_Base;
template<support::endianness target_endianness>
struct Elf_Shdr_Base<target_endianness, false> {
LLVM_ELF_IMPORT_TYPES(target_endianness, false)
Elf_Word sh_name; // Section name (index into string table)
Elf_Word sh_type; // Section type (SHT_*)
Elf_Word sh_flags; // Section flags (SHF_*)
Elf_Addr sh_addr; // Address where section is to be loaded
Elf_Off sh_offset; // File offset of section data, in bytes
Elf_Word sh_size; // Size of section, in bytes
Elf_Word sh_link; // Section type-specific header table index link
Elf_Word sh_info; // Section type-specific extra information
Elf_Word sh_addralign;// Section address alignment
Elf_Word sh_entsize; // Size of records contained within the section
};
template<support::endianness target_endianness>
struct Elf_Shdr_Base<target_endianness, true> {
LLVM_ELF_IMPORT_TYPES(target_endianness, true)
Elf_Word sh_name; // Section name (index into string table)
Elf_Word sh_type; // Section type (SHT_*)
Elf_Xword sh_flags; // Section flags (SHF_*)
Elf_Addr sh_addr; // Address where section is to be loaded
Elf_Off sh_offset; // File offset of section data, in bytes
Elf_Xword sh_size; // Size of section, in bytes
Elf_Word sh_link; // Section type-specific header table index link
Elf_Word sh_info; // Section type-specific extra information
Elf_Xword sh_addralign;// Section address alignment
Elf_Xword sh_entsize; // Size of records contained within the section
};
template<support::endianness target_endianness, bool is64Bits>
struct Elf_Shdr_Impl : Elf_Shdr_Base<target_endianness, is64Bits> {
using Elf_Shdr_Base<target_endianness, is64Bits>::sh_entsize;
using Elf_Shdr_Base<target_endianness, is64Bits>::sh_size;
/// @brief Get the number of entities this section contains if it has any.
unsigned getEntityCount() const {
if (sh_entsize == 0)
return 0;
return sh_size / sh_entsize;
}
};
}
namespace {
template<support::endianness target_endianness, bool is64Bits>
struct Elf_Sym_Base;
template<support::endianness target_endianness>
struct Elf_Sym_Base<target_endianness, false> {
LLVM_ELF_IMPORT_TYPES(target_endianness, false)
Elf_Word st_name; // Symbol name (index into string table)
Elf_Addr st_value; // Value or address associated with the symbol
Elf_Word st_size; // Size of the symbol
unsigned char st_info; // Symbol's type and binding attributes
unsigned char st_other; // Must be zero; reserved
Elf_Half st_shndx; // Which section (header table index) it's defined in
};
template<support::endianness target_endianness>
struct Elf_Sym_Base<target_endianness, true> {
LLVM_ELF_IMPORT_TYPES(target_endianness, true)
Elf_Word st_name; // Symbol name (index into string table)
unsigned char st_info; // Symbol's type and binding attributes
unsigned char st_other; // Must be zero; reserved
Elf_Half st_shndx; // Which section (header table index) it's defined in
Elf_Addr st_value; // Value or address associated with the symbol
Elf_Xword st_size; // Size of the symbol
};
template<support::endianness target_endianness, bool is64Bits>
struct Elf_Sym_Impl : Elf_Sym_Base<target_endianness, is64Bits> {
using Elf_Sym_Base<target_endianness, is64Bits>::st_info;
// These accessors and mutators correspond to the ELF32_ST_BIND,
// ELF32_ST_TYPE, and ELF32_ST_INFO macros defined in the ELF specification:
unsigned char getBinding() const { return st_info >> 4; }
unsigned char getType() const { return st_info & 0x0f; }
void setBinding(unsigned char b) { setBindingAndType(b, getType()); }
void setType(unsigned char t) { setBindingAndType(getBinding(), t); }
void setBindingAndType(unsigned char b, unsigned char t) {
st_info = (b << 4) + (t & 0x0f);
}
};
}
namespace {
template<support::endianness target_endianness, bool is64Bits>
class ELFObjectFile : public ObjectFile {
LLVM_ELF_IMPORT_TYPES(target_endianness, is64Bits)
typedef Elf_Shdr_Impl<target_endianness, is64Bits> Elf_Shdr;
typedef Elf_Sym_Impl<target_endianness, is64Bits> Elf_Sym;
struct Elf_Ehdr {
unsigned char e_ident[ELF::EI_NIDENT]; // ELF Identification bytes
Elf_Half e_type; // Type of file (see ET_*)
Elf_Half e_machine; // Required architecture for this file (see EM_*)
Elf_Word e_version; // Must be equal to 1
Elf_Addr e_entry; // Address to jump to in order to start program
Elf_Off e_phoff; // Program header table's file offset, in bytes
Elf_Off e_shoff; // Section header table's file offset, in bytes
Elf_Word e_flags; // Processor-specific flags
Elf_Half e_ehsize; // Size of ELF header, in bytes
Elf_Half e_phentsize;// Size of an entry in the program header table
Elf_Half e_phnum; // Number of entries in the program header table
Elf_Half e_shentsize;// Size of an entry in the section header table
Elf_Half e_shnum; // Number of entries in the section header table
Elf_Half e_shstrndx; // Section header table index of section name
// string table
bool checkMagic() const {
return (memcmp(e_ident, ELF::ElfMagic, strlen(ELF::ElfMagic))) == 0;
}
unsigned char getFileClass() const { return e_ident[ELF::EI_CLASS]; }
unsigned char getDataEncoding() const { return e_ident[ELF::EI_DATA]; }
};
typedef SmallVector<const Elf_Shdr*, 1> SymbolTableSections_t;
const Elf_Ehdr *Header;
const Elf_Shdr *SectionHeaderTable;
const Elf_Shdr *dot_shstrtab_sec; // Section header string table.
const Elf_Shdr *dot_strtab_sec; // Symbol header string table.
SymbolTableSections_t SymbolTableSections;
void validateSymbol(DataRefImpl Symb) const;
const Elf_Sym *getSymbol(DataRefImpl Symb) const;
const Elf_Shdr *getSection(DataRefImpl index) const;
const Elf_Shdr *getSection(uint16_t index) const;
const char *getString(uint16_t section, uint32_t offset) const;
const char *getString(const Elf_Shdr *section, uint32_t offset) const;
protected:
virtual SymbolRef getSymbolNext(DataRefImpl Symb) const;
virtual StringRef getSymbolName(DataRefImpl Symb) const;
virtual uint64_t getSymbolAddress(DataRefImpl Symb) const;
virtual uint64_t getSymbolSize(DataRefImpl Symb) const;
virtual char getSymbolNMTypeChar(DataRefImpl Symb) const;
virtual bool isSymbolInternal(DataRefImpl Symb) const;
virtual SectionRef getSectionNext(DataRefImpl Sec) const;
virtual StringRef getSectionName(DataRefImpl Sec) const;
virtual uint64_t getSectionAddress(DataRefImpl Sec) const;
virtual uint64_t getSectionSize(DataRefImpl Sec) const;
virtual StringRef getSectionContents(DataRefImpl Sec) const;
virtual bool isSectionText(DataRefImpl Sec) const;
public:
ELFObjectFile(MemoryBuffer *Object);
virtual symbol_iterator begin_symbols() const;
virtual symbol_iterator end_symbols() const;
virtual section_iterator begin_sections() const;
virtual section_iterator end_sections() const;
virtual uint8_t getBytesInAddress() const;
virtual StringRef getFileFormatName() const;
virtual unsigned getArch() const;
};
} // end namespace
template<support::endianness target_endianness, bool is64Bits>
void ELFObjectFile<target_endianness, is64Bits>
::validateSymbol(DataRefImpl Symb) const {
const Elf_Sym *symb = getSymbol(Symb);
const Elf_Shdr *SymbolTableSection = SymbolTableSections[Symb.d.b];
// FIXME: We really need to do proper error handling in the case of an invalid
// input file. Because we don't use exceptions, I think we'll just pass
// an error object around.
if (!( symb
&& SymbolTableSection
&& symb >= (const Elf_Sym*)(base
+ SymbolTableSection->sh_offset)
&& symb < (const Elf_Sym*)(base
+ SymbolTableSection->sh_offset
+ SymbolTableSection->sh_size)))
// FIXME: Proper error handling.
report_fatal_error("Symb must point to a valid symbol!");
}
template<support::endianness target_endianness, bool is64Bits>
SymbolRef ELFObjectFile<target_endianness, is64Bits>
::getSymbolNext(DataRefImpl Symb) const {
validateSymbol(Symb);
const Elf_Shdr *SymbolTableSection = SymbolTableSections[Symb.d.b];
++Symb.d.a;
// Check to see if we are at the end of this symbol table.
if (Symb.d.a >= SymbolTableSection->getEntityCount()) {
// We are at the end. If there are other symbol tables, jump to them.
++Symb.d.b;
Symb.d.a = 1; // The 0th symbol in ELF is fake.
// Otherwise return the terminator.
if (Symb.d.b >= SymbolTableSections.size()) {
Symb.d.a = std::numeric_limits<uint32_t>::max();
Symb.d.b = std::numeric_limits<uint32_t>::max();
}
}
return SymbolRef(Symb, this);
}
template<support::endianness target_endianness, bool is64Bits>
StringRef ELFObjectFile<target_endianness, is64Bits>
::getSymbolName(DataRefImpl Symb) const {
validateSymbol(Symb);
const Elf_Sym *symb = getSymbol(Symb);
if (symb->st_name == 0) {
const Elf_Shdr *section = getSection(symb->st_shndx);
if (!section)
return "";
return getString(dot_shstrtab_sec, section->sh_name);
}
// Use the default symbol table name section.
return getString(dot_strtab_sec, symb->st_name);
}
template<support::endianness target_endianness, bool is64Bits>
uint64_t ELFObjectFile<target_endianness, is64Bits>
::getSymbolAddress(DataRefImpl Symb) const {
validateSymbol(Symb);
const Elf_Sym *symb = getSymbol(Symb);
const Elf_Shdr *Section;
switch (symb->st_shndx) {
case ELF::SHN_COMMON:
// Undefined symbols have no address yet.
case ELF::SHN_UNDEF: return UnknownAddressOrSize;
case ELF::SHN_ABS: return symb->st_value;
default: Section = getSection(symb->st_shndx);
}
switch (symb->getType()) {
case ELF::STT_SECTION: return Section ? Section->sh_addr
: UnknownAddressOrSize;
case ELF::STT_FUNC:
case ELF::STT_OBJECT:
case ELF::STT_NOTYPE:
return symb->st_value;
default: return UnknownAddressOrSize;
}
}
template<support::endianness target_endianness, bool is64Bits>
uint64_t ELFObjectFile<target_endianness, is64Bits>
::getSymbolSize(DataRefImpl Symb) const {
validateSymbol(Symb);
const Elf_Sym *symb = getSymbol(Symb);
if (symb->st_size == 0)
return UnknownAddressOrSize;
return symb->st_size;
}
template<support::endianness target_endianness, bool is64Bits>
char ELFObjectFile<target_endianness, is64Bits>
::getSymbolNMTypeChar(DataRefImpl Symb) const {
validateSymbol(Symb);
const Elf_Sym *symb = getSymbol(Symb);
const Elf_Shdr *Section = getSection(symb->st_shndx);
char ret = '?';
if (Section) {
switch (Section->sh_type) {
case ELF::SHT_PROGBITS:
case ELF::SHT_DYNAMIC:
switch (Section->sh_flags) {
case (ELF::SHF_ALLOC | ELF::SHF_EXECINSTR):
ret = 't'; break;
case (ELF::SHF_ALLOC | ELF::SHF_WRITE):
ret = 'd'; break;
case ELF::SHF_ALLOC:
case (ELF::SHF_ALLOC | ELF::SHF_MERGE):
case (ELF::SHF_ALLOC | ELF::SHF_MERGE | ELF::SHF_STRINGS):
ret = 'r'; break;
}
break;
case ELF::SHT_NOBITS: ret = 'b';
}
}
switch (symb->st_shndx) {
case ELF::SHN_UNDEF:
if (ret == '?')
ret = 'U';
break;
case ELF::SHN_ABS: ret = 'a'; break;
case ELF::SHN_COMMON: ret = 'c'; break;
}
switch (symb->getBinding()) {
case ELF::STB_GLOBAL: ret = ::toupper(ret); break;
case ELF::STB_WEAK:
if (symb->st_shndx == ELF::SHN_UNDEF)
ret = 'w';
else
if (symb->getType() == ELF::STT_OBJECT)
ret = 'V';
else
ret = 'W';
}
if (ret == '?' && symb->getType() == ELF::STT_SECTION)
return StringSwitch<char>(getSymbolName(Symb))
.StartsWith(".debug", 'N')
.StartsWith(".note", 'n');
return ret;
}
template<support::endianness target_endianness, bool is64Bits>
bool ELFObjectFile<target_endianness, is64Bits>
::isSymbolInternal(DataRefImpl Symb) const {
validateSymbol(Symb);
const Elf_Sym *symb = getSymbol(Symb);
if ( symb->getType() == ELF::STT_FILE
|| symb->getType() == ELF::STT_SECTION)
return true;
return false;
}
template<support::endianness target_endianness, bool is64Bits>
SectionRef ELFObjectFile<target_endianness, is64Bits>
::getSectionNext(DataRefImpl Sec) const {
const uint8_t *sec = reinterpret_cast<const uint8_t *>(Sec.p);
sec += Header->e_shentsize;
Sec.p = reinterpret_cast<intptr_t>(sec);
return SectionRef(Sec, this);
}
template<support::endianness target_endianness, bool is64Bits>
StringRef ELFObjectFile<target_endianness, is64Bits>
::getSectionName(DataRefImpl Sec) const {
const Elf_Shdr *sec = reinterpret_cast<const Elf_Shdr *>(Sec.p);
return StringRef(getString(dot_shstrtab_sec, sec->sh_name));
}
template<support::endianness target_endianness, bool is64Bits>
uint64_t ELFObjectFile<target_endianness, is64Bits>
::getSectionAddress(DataRefImpl Sec) const {
const Elf_Shdr *sec = reinterpret_cast<const Elf_Shdr *>(Sec.p);
return sec->sh_addr;
}
template<support::endianness target_endianness, bool is64Bits>
uint64_t ELFObjectFile<target_endianness, is64Bits>
::getSectionSize(DataRefImpl Sec) const {
const Elf_Shdr *sec = reinterpret_cast<const Elf_Shdr *>(Sec.p);
return sec->sh_size;
}
template<support::endianness target_endianness, bool is64Bits>
StringRef ELFObjectFile<target_endianness, is64Bits>
::getSectionContents(DataRefImpl Sec) const {
const Elf_Shdr *sec = reinterpret_cast<const Elf_Shdr *>(Sec.p);
const char *start = (char*)base + sec->sh_offset;
return StringRef(start, sec->sh_size);
}
template<support::endianness target_endianness, bool is64Bits>
bool ELFObjectFile<target_endianness, is64Bits>
::isSectionText(DataRefImpl Sec) const {
const Elf_Shdr *sec = reinterpret_cast<const Elf_Shdr *>(Sec.p);
if (sec->sh_flags & ELF::SHF_EXECINSTR)
return true;
return false;
}
template<support::endianness target_endianness, bool is64Bits>
ELFObjectFile<target_endianness, is64Bits>::ELFObjectFile(MemoryBuffer *Object)
: ObjectFile(Object)
, SectionHeaderTable(0)
, dot_shstrtab_sec(0)
, dot_strtab_sec(0) {
Header = reinterpret_cast<const Elf_Ehdr *>(base);
if (Header->e_shoff == 0)
return;
SectionHeaderTable =
reinterpret_cast<const Elf_Shdr *>(base + Header->e_shoff);
uint32_t SectionTableSize = Header->e_shnum * Header->e_shentsize;
if (!( (const uint8_t *)SectionHeaderTable + SectionTableSize
<= base + MapFile->getBufferSize()))
// FIXME: Proper error handling.
report_fatal_error("Section table goes past end of file!");
// To find the symbol tables we walk the section table to find SHT_STMTAB.
for (const char *i = reinterpret_cast<const char *>(SectionHeaderTable),
*e = i + Header->e_shnum * Header->e_shentsize;
i != e; i += Header->e_shentsize) {
const Elf_Shdr *sh = reinterpret_cast<const Elf_Shdr*>(i);
if (sh->sh_type == ELF::SHT_SYMTAB) {
SymbolTableSections.push_back(sh);
}
}
// Get string table sections.
dot_shstrtab_sec = getSection(Header->e_shstrndx);
if (dot_shstrtab_sec) {
// Verify that the last byte in the string table in a null.
if (((const char*)base + dot_shstrtab_sec->sh_offset)
[dot_shstrtab_sec->sh_size - 1] != 0)
// FIXME: Proper error handling.
report_fatal_error("String table must end with a null terminator!");
}
// Merge this into the above loop.
for (const char *i = reinterpret_cast<const char *>(SectionHeaderTable),
*e = i + Header->e_shnum * Header->e_shentsize;
i != e; i += Header->e_shentsize) {
const Elf_Shdr *sh = reinterpret_cast<const Elf_Shdr*>(i);
if (sh->sh_type == ELF::SHT_STRTAB) {
StringRef SectionName(getString(dot_shstrtab_sec, sh->sh_name));
if (SectionName == ".strtab") {
if (dot_strtab_sec != 0)
// FIXME: Proper error handling.
report_fatal_error("Already found section named .strtab!");
dot_strtab_sec = sh;
const char *dot_strtab = (const char*)base + sh->sh_offset;
if (dot_strtab[sh->sh_size - 1] != 0)
// FIXME: Proper error handling.
report_fatal_error("String table must end with a null terminator!");
}
}
}
}
template<support::endianness target_endianness, bool is64Bits>
ObjectFile::symbol_iterator ELFObjectFile<target_endianness, is64Bits>
::begin_symbols() const {
DataRefImpl SymbolData;
memset(&SymbolData, 0, sizeof(SymbolData));
if (SymbolTableSections.size() == 0) {
SymbolData.d.a = std::numeric_limits<uint32_t>::max();
SymbolData.d.b = std::numeric_limits<uint32_t>::max();
} else {
SymbolData.d.a = 1; // The 0th symbol in ELF is fake.
SymbolData.d.b = 0;
}
return symbol_iterator(SymbolRef(SymbolData, this));
}
template<support::endianness target_endianness, bool is64Bits>
ObjectFile::symbol_iterator ELFObjectFile<target_endianness, is64Bits>
::end_symbols() const {
DataRefImpl SymbolData;
memset(&SymbolData, 0, sizeof(SymbolData));
SymbolData.d.a = std::numeric_limits<uint32_t>::max();
SymbolData.d.b = std::numeric_limits<uint32_t>::max();
return symbol_iterator(SymbolRef(SymbolData, this));
}
template<support::endianness target_endianness, bool is64Bits>
ObjectFile::section_iterator ELFObjectFile<target_endianness, is64Bits>
::begin_sections() const {
DataRefImpl ret;
memset(&ret, 0, sizeof(DataRefImpl));
ret.p = reinterpret_cast<intptr_t>(base + Header->e_shoff);
return section_iterator(SectionRef(ret, this));
}
template<support::endianness target_endianness, bool is64Bits>
ObjectFile::section_iterator ELFObjectFile<target_endianness, is64Bits>
::end_sections() const {
DataRefImpl ret;
memset(&ret, 0, sizeof(DataRefImpl));
ret.p = reinterpret_cast<intptr_t>(base
+ Header->e_shoff
+ (Header->e_shentsize * Header->e_shnum));
return section_iterator(SectionRef(ret, this));
}
template<support::endianness target_endianness, bool is64Bits>
uint8_t ELFObjectFile<target_endianness, is64Bits>::getBytesInAddress() const {
return is64Bits ? 8 : 4;
}
template<support::endianness target_endianness, bool is64Bits>
StringRef ELFObjectFile<target_endianness, is64Bits>
::getFileFormatName() const {
switch(Header->e_ident[ELF::EI_CLASS]) {
case ELF::ELFCLASS32:
switch(Header->e_machine) {
case ELF::EM_386:
return "ELF32-i386";
case ELF::EM_X86_64:
return "ELF32-x86-64";
default:
return "ELF32-unknown";
}
case ELF::ELFCLASS64:
switch(Header->e_machine) {
case ELF::EM_386:
return "ELF64-i386";
case ELF::EM_X86_64:
return "ELF64-x86-64";
default:
return "ELF64-unknown";
}
default:
// FIXME: Proper error handling.
report_fatal_error("Invalid ELFCLASS!");
}
}
template<support::endianness target_endianness, bool is64Bits>
unsigned ELFObjectFile<target_endianness, is64Bits>::getArch() const {
switch(Header->e_machine) {
case ELF::EM_386:
return Triple::x86;
case ELF::EM_X86_64:
return Triple::x86_64;
default:
return Triple::UnknownArch;
}
}
template<support::endianness target_endianness, bool is64Bits>
const typename ELFObjectFile<target_endianness, is64Bits>::Elf_Sym *
ELFObjectFile<target_endianness, is64Bits>::getSymbol(DataRefImpl Symb) const {
const Elf_Shdr *sec = SymbolTableSections[Symb.d.b];
return reinterpret_cast<const Elf_Sym *>(
base
+ sec->sh_offset
+ (Symb.d.a * sec->sh_entsize));
}
template<support::endianness target_endianness, bool is64Bits>
const typename ELFObjectFile<target_endianness, is64Bits>::Elf_Shdr *
ELFObjectFile<target_endianness, is64Bits>::getSection(DataRefImpl Symb) const {
const Elf_Shdr *sec = getSection(Symb.d.b);
if (sec->sh_type != ELF::SHT_SYMTAB)
// FIXME: Proper error handling.
report_fatal_error("Invalid symbol table section!");
return sec;
}
template<support::endianness target_endianness, bool is64Bits>
const typename ELFObjectFile<target_endianness, is64Bits>::Elf_Shdr *
ELFObjectFile<target_endianness, is64Bits>::getSection(uint16_t index) const {
if (index == 0 || index >= ELF::SHN_LORESERVE)
return 0;
if (!SectionHeaderTable || index >= Header->e_shnum)
// FIXME: Proper error handling.
report_fatal_error("Invalid section index!");
return reinterpret_cast<const Elf_Shdr *>(
reinterpret_cast<const char *>(SectionHeaderTable)
+ (index * Header->e_shentsize));
}
template<support::endianness target_endianness, bool is64Bits>
const char *ELFObjectFile<target_endianness, is64Bits>
::getString(uint16_t section,
ELF::Elf32_Word offset) const {
return getString(getSection(section), offset);
}
template<support::endianness target_endianness, bool is64Bits>
const char *ELFObjectFile<target_endianness, is64Bits>
::getString(const Elf_Shdr *section,
ELF::Elf32_Word offset) const {
assert(section && section->sh_type == ELF::SHT_STRTAB && "Invalid section!");
if (offset >= section->sh_size)
// FIXME: Proper error handling.
report_fatal_error("Sybol name offset outside of string table!");
return (const char *)base + section->sh_offset + offset;
}
// EI_CLASS, EI_DATA.
static std::pair<unsigned char, unsigned char>
getElfArchType(MemoryBuffer *Object) {
if (Object->getBufferSize() < ELF::EI_NIDENT)
return std::make_pair((uint8_t)ELF::ELFCLASSNONE,(uint8_t)ELF::ELFDATANONE);
return std::make_pair( (uint8_t)Object->getBufferStart()[ELF::EI_CLASS]
, (uint8_t)Object->getBufferStart()[ELF::EI_DATA]);
}
namespace llvm {
ObjectFile *ObjectFile::createELFObjectFile(MemoryBuffer *Object) {
std::pair<unsigned char, unsigned char> Ident = getElfArchType(Object);
if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB)
return new ELFObjectFile<support::little, false>(Object);
else if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2MSB)
return new ELFObjectFile<support::big, false>(Object);
else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2LSB)
return new ELFObjectFile<support::little, true>(Object);
else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2MSB)
return new ELFObjectFile<support::big, true>(Object);
// FIXME: Proper error handling.
report_fatal_error("Not an ELF object file!");
}
} // end namespace llvm
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