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Diffstat (limited to 'lib/Object/ELFObjectFile.cpp')
| -rw-r--r-- | lib/Object/ELFObjectFile.cpp | 686 |
1 files changed, 686 insertions, 0 deletions
diff --git a/lib/Object/ELFObjectFile.cpp b/lib/Object/ELFObjectFile.cpp new file mode 100644 index 000000000000..682be770f48f --- /dev/null +++ b/lib/Object/ELFObjectFile.cpp @@ -0,0 +1,686 @@ +//===- 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; + 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; + 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 |