//===- COFFObjectFile.cpp - COFF 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 declares the COFFObjectFile class. // //===----------------------------------------------------------------------===// #include "llvm/Object/COFF.h" #include "llvm/ADT/SmallString.h" #include "llvm/ADT/StringSwitch.h" #include "llvm/ADT/Triple.h" using namespace llvm; using namespace object; namespace { using support::ulittle8_t; using support::ulittle16_t; using support::ulittle32_t; using support::little16_t; } namespace { // Returns false if size is greater than the buffer size. And sets ec. bool checkSize(const MemoryBuffer *m, error_code &ec, uint64_t size) { if (m->getBufferSize() < size) { ec = object_error::unexpected_eof; return false; } return true; } // Returns false if any bytes in [addr, addr + size) fall outsize of m. bool checkAddr(const MemoryBuffer *m, error_code &ec, uintptr_t addr, uint64_t size) { if (addr + size < addr || addr + size < size || addr + size > uintptr_t(m->getBufferEnd())) { ec = object_error::unexpected_eof; return false; } return true; } } const coff_symbol *COFFObjectFile::toSymb(DataRefImpl Symb) const { const coff_symbol *addr = reinterpret_cast<const coff_symbol*>(Symb.p); # ifndef NDEBUG // Verify that the symbol points to a valid entry in the symbol table. uintptr_t offset = uintptr_t(addr) - uintptr_t(base()); if (offset < Header->PointerToSymbolTable || offset >= Header->PointerToSymbolTable + (Header->NumberOfSymbols * sizeof(coff_symbol))) report_fatal_error("Symbol was outside of symbol table."); assert((offset - Header->PointerToSymbolTable) % sizeof(coff_symbol) == 0 && "Symbol did not point to the beginning of a symbol"); # endif return addr; } const coff_section *COFFObjectFile::toSec(DataRefImpl Sec) const { const coff_section *addr = reinterpret_cast<const coff_section*>(Sec.p); # ifndef NDEBUG // Verify that the section points to a valid entry in the section table. if (addr < SectionTable || addr >= (SectionTable + Header->NumberOfSections)) report_fatal_error("Section was outside of section table."); uintptr_t offset = uintptr_t(addr) - uintptr_t(SectionTable); assert(offset % sizeof(coff_section) == 0 && "Section did not point to the beginning of a section"); # endif return addr; } error_code COFFObjectFile::getSymbolNext(DataRefImpl Symb, SymbolRef &Result) const { const coff_symbol *symb = toSymb(Symb); symb += 1 + symb->NumberOfAuxSymbols; Symb.p = reinterpret_cast<uintptr_t>(symb); Result = SymbolRef(Symb, this); return object_error::success; } error_code COFFObjectFile::getSymbolName(DataRefImpl Symb, StringRef &Result) const { const coff_symbol *symb = toSymb(Symb); // Check for string table entry. First 4 bytes are 0. if (symb->Name.Offset.Zeroes == 0) { uint32_t Offset = symb->Name.Offset.Offset; if (error_code ec = getString(Offset, Result)) return ec; return object_error::success; } if (symb->Name.ShortName[7] == 0) // Null terminated, let ::strlen figure out the length. Result = StringRef(symb->Name.ShortName); else // Not null terminated, use all 8 bytes. Result = StringRef(symb->Name.ShortName, 8); return object_error::success; } error_code COFFObjectFile::getSymbolOffset(DataRefImpl Symb, uint64_t &Result) const { const coff_symbol *symb = toSymb(Symb); const coff_section *Section = NULL; if (error_code ec = getSection(symb->SectionNumber, Section)) return ec; char Type; if (error_code ec = getSymbolNMTypeChar(Symb, Type)) return ec; if (Type == 'U' || Type == 'w') Result = UnknownAddressOrSize; else if (Section) Result = Section->VirtualAddress + symb->Value; else Result = symb->Value; return object_error::success; } error_code COFFObjectFile::getSymbolAddress(DataRefImpl Symb, uint64_t &Result) const { const coff_symbol *symb = toSymb(Symb); const coff_section *Section = NULL; if (error_code ec = getSection(symb->SectionNumber, Section)) return ec; char Type; if (error_code ec = getSymbolNMTypeChar(Symb, Type)) return ec; if (Type == 'U' || Type == 'w') Result = UnknownAddressOrSize; else if (Section) Result = reinterpret_cast<uintptr_t>(base() + Section->PointerToRawData + symb->Value); else Result = reinterpret_cast<uintptr_t>(base() + symb->Value); return object_error::success; } error_code COFFObjectFile::getSymbolType(DataRefImpl Symb, SymbolRef::SymbolType &Result) const { const coff_symbol *symb = toSymb(Symb); Result = SymbolRef::ST_Other; if (symb->StorageClass == COFF::IMAGE_SYM_CLASS_EXTERNAL && symb->SectionNumber == COFF::IMAGE_SYM_UNDEFINED) { Result = SymbolRef::ST_External; } else { if (symb->Type.ComplexType == COFF::IMAGE_SYM_DTYPE_FUNCTION) { Result = SymbolRef::ST_Function; } else { char Type; if (error_code ec = getSymbolNMTypeChar(Symb, Type)) return ec; if (Type == 'r' || Type == 'R') { Result = SymbolRef::ST_Data; } } } return object_error::success; } error_code COFFObjectFile::isSymbolGlobal(DataRefImpl Symb, bool &Result) const { const coff_symbol *symb = toSymb(Symb); Result = (symb->StorageClass == COFF::IMAGE_SYM_CLASS_EXTERNAL); return object_error::success; } error_code COFFObjectFile::getSymbolSize(DataRefImpl Symb, uint64_t &Result) const { // FIXME: Return the correct size. This requires looking at all the symbols // in the same section as this symbol, and looking for either the next // symbol, or the end of the section. const coff_symbol *symb = toSymb(Symb); const coff_section *Section = NULL; if (error_code ec = getSection(symb->SectionNumber, Section)) return ec; char Type; if (error_code ec = getSymbolNMTypeChar(Symb, Type)) return ec; if (Type == 'U' || Type == 'w') Result = UnknownAddressOrSize; else if (Section) Result = Section->SizeOfRawData - symb->Value; else Result = 0; return object_error::success; } error_code COFFObjectFile::getSymbolNMTypeChar(DataRefImpl Symb, char &Result) const { const coff_symbol *symb = toSymb(Symb); StringRef name; if (error_code ec = getSymbolName(Symb, name)) return ec; char ret = StringSwitch<char>(name) .StartsWith(".debug", 'N') .StartsWith(".sxdata", 'N') .Default('?'); if (ret != '?') { Result = ret; return object_error::success; } uint32_t Characteristics = 0; if (symb->SectionNumber > 0) { const coff_section *Section = NULL; if (error_code ec = getSection(symb->SectionNumber, Section)) return ec; Characteristics = Section->Characteristics; } switch (symb->SectionNumber) { case COFF::IMAGE_SYM_UNDEFINED: // Check storage classes. if (symb->StorageClass == COFF::IMAGE_SYM_CLASS_WEAK_EXTERNAL) { Result = 'w'; return object_error::success; // Don't do ::toupper. } else ret = 'u'; break; case COFF::IMAGE_SYM_ABSOLUTE: ret = 'a'; break; case COFF::IMAGE_SYM_DEBUG: ret = 'n'; break; default: // Check section type. if (Characteristics & COFF::IMAGE_SCN_CNT_CODE) ret = 't'; else if ( Characteristics & COFF::IMAGE_SCN_MEM_READ && ~Characteristics & COFF::IMAGE_SCN_MEM_WRITE) // Read only. ret = 'r'; else if (Characteristics & COFF::IMAGE_SCN_CNT_INITIALIZED_DATA) ret = 'd'; else if (Characteristics & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA) ret = 'b'; else if (Characteristics & COFF::IMAGE_SCN_LNK_INFO) ret = 'i'; // Check for section symbol. else if ( symb->StorageClass == COFF::IMAGE_SYM_CLASS_STATIC && symb->Value == 0) ret = 's'; } if (symb->StorageClass == COFF::IMAGE_SYM_CLASS_EXTERNAL) ret = ::toupper(ret); Result = ret; return object_error::success; } error_code COFFObjectFile::isSymbolInternal(DataRefImpl Symb, bool &Result) const { Result = false; return object_error::success; } error_code COFFObjectFile::getSectionNext(DataRefImpl Sec, SectionRef &Result) const { const coff_section *sec = toSec(Sec); sec += 1; Sec.p = reinterpret_cast<uintptr_t>(sec); Result = SectionRef(Sec, this); return object_error::success; } error_code COFFObjectFile::getSectionName(DataRefImpl Sec, StringRef &Result) const { const coff_section *sec = toSec(Sec); StringRef name; if (sec->Name[7] == 0) // Null terminated, let ::strlen figure out the length. name = sec->Name; else // Not null terminated, use all 8 bytes. name = StringRef(sec->Name, 8); // Check for string table entry. First byte is '/'. if (name[0] == '/') { uint32_t Offset; name.substr(1).getAsInteger(10, Offset); if (error_code ec = getString(Offset, name)) return ec; } Result = name; return object_error::success; } error_code COFFObjectFile::getSectionAddress(DataRefImpl Sec, uint64_t &Result) const { const coff_section *sec = toSec(Sec); Result = sec->VirtualAddress; return object_error::success; } error_code COFFObjectFile::getSectionSize(DataRefImpl Sec, uint64_t &Result) const { const coff_section *sec = toSec(Sec); Result = sec->SizeOfRawData; return object_error::success; } error_code COFFObjectFile::getSectionContents(DataRefImpl Sec, StringRef &Result) const { const coff_section *sec = toSec(Sec); // The only thing that we need to verify is that the contents is contained // within the file bounds. We don't need to make sure it doesn't cover other // data, as there's nothing that says that is not allowed. uintptr_t con_start = uintptr_t(base()) + sec->PointerToRawData; uintptr_t con_end = con_start + sec->SizeOfRawData; if (con_end >= uintptr_t(Data->getBufferEnd())) return object_error::parse_failed; Result = StringRef(reinterpret_cast<const char*>(con_start), sec->SizeOfRawData); return object_error::success; } error_code COFFObjectFile::getSectionAlignment(DataRefImpl Sec, uint64_t &Res) const { const coff_section *sec = toSec(Sec); if (!sec) return object_error::parse_failed; Res = uint64_t(1) << (((sec->Characteristics & 0x00F00000) >> 20) - 1); return object_error::success; } error_code COFFObjectFile::isSectionText(DataRefImpl Sec, bool &Result) const { const coff_section *sec = toSec(Sec); Result = sec->Characteristics & COFF::IMAGE_SCN_CNT_CODE; return object_error::success; } error_code COFFObjectFile::isSectionData(DataRefImpl Sec, bool &Result) const { const coff_section *sec = toSec(Sec); Result = sec->Characteristics & COFF::IMAGE_SCN_CNT_INITIALIZED_DATA; return object_error::success; } error_code COFFObjectFile::isSectionBSS(DataRefImpl Sec, bool &Result) const { const coff_section *sec = toSec(Sec); Result = sec->Characteristics & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA; return object_error::success; } error_code COFFObjectFile::sectionContainsSymbol(DataRefImpl Sec, DataRefImpl Symb, bool &Result) const { const coff_section *sec = toSec(Sec); const coff_symbol *symb = toSymb(Symb); const coff_section *symb_sec; if (error_code ec = getSection(symb->SectionNumber, symb_sec)) return ec; if (symb_sec == sec) Result = true; else Result = false; return object_error::success; } relocation_iterator COFFObjectFile::getSectionRelBegin(DataRefImpl Sec) const { const coff_section *sec = toSec(Sec); DataRefImpl ret; std::memset(&ret, 0, sizeof(ret)); if (sec->NumberOfRelocations == 0) ret.p = 0; else ret.p = reinterpret_cast<uintptr_t>(base() + sec->PointerToRelocations); return relocation_iterator(RelocationRef(ret, this)); } relocation_iterator COFFObjectFile::getSectionRelEnd(DataRefImpl Sec) const { const coff_section *sec = toSec(Sec); DataRefImpl ret; std::memset(&ret, 0, sizeof(ret)); if (sec->NumberOfRelocations == 0) ret.p = 0; else ret.p = reinterpret_cast<uintptr_t>( reinterpret_cast<const coff_relocation*>( base() + sec->PointerToRelocations) + sec->NumberOfRelocations); return relocation_iterator(RelocationRef(ret, this)); } COFFObjectFile::COFFObjectFile(MemoryBuffer *Object, error_code &ec) : ObjectFile(Binary::isCOFF, Object, ec) { // Check that we at least have enough room for a header. if (!checkSize(Data, ec, sizeof(coff_file_header))) return; // The actual starting location of the COFF header in the file. This can be // non-zero in PE/COFF files. uint64_t HeaderStart = 0; // Check if this is a PE/COFF file. if (base()[0] == 0x4d && base()[1] == 0x5a) { // PE/COFF, seek through MS-DOS compatibility stub and 4-byte // PE signature to find 'normal' COFF header. if (!checkSize(Data, ec, 0x3c + 8)) return; HeaderStart += *reinterpret_cast<const ulittle32_t *>(base() + 0x3c); // Check the PE header. ("PE\0\0") if (std::memcmp(base() + HeaderStart, "PE\0\0", 4) != 0) { ec = object_error::parse_failed; return; } HeaderStart += 4; // Skip the PE Header. } Header = reinterpret_cast<const coff_file_header *>(base() + HeaderStart); if (!checkAddr(Data, ec, uintptr_t(Header), sizeof(coff_file_header))) return; SectionTable = reinterpret_cast<const coff_section *>( base() + HeaderStart + sizeof(coff_file_header) + Header->SizeOfOptionalHeader); if (!checkAddr(Data, ec, uintptr_t(SectionTable), Header->NumberOfSections * sizeof(coff_section))) return; SymbolTable = reinterpret_cast<const coff_symbol *>(base() + Header->PointerToSymbolTable); if (!checkAddr(Data, ec, uintptr_t(SymbolTable), Header->NumberOfSymbols * sizeof(coff_symbol))) return; // Find string table. StringTable = reinterpret_cast<const char *>(base()) + Header->PointerToSymbolTable + Header->NumberOfSymbols * sizeof(coff_symbol); if (!checkAddr(Data, ec, uintptr_t(StringTable), sizeof(ulittle32_t))) return; StringTableSize = *reinterpret_cast<const ulittle32_t *>(StringTable); if (!checkAddr(Data, ec, uintptr_t(StringTable), StringTableSize)) return; // Check that the string table is null terminated if has any in it. if (StringTableSize < 4 || (StringTableSize > 4 && StringTable[StringTableSize - 1] != 0)) { ec = object_error::parse_failed; return; } ec = object_error::success; } symbol_iterator COFFObjectFile::begin_symbols() const { DataRefImpl ret; std::memset(&ret, 0, sizeof(DataRefImpl)); ret.p = reinterpret_cast<intptr_t>(SymbolTable); return symbol_iterator(SymbolRef(ret, this)); } symbol_iterator COFFObjectFile::end_symbols() const { // The symbol table ends where the string table begins. DataRefImpl ret; std::memset(&ret, 0, sizeof(DataRefImpl)); ret.p = reinterpret_cast<intptr_t>(StringTable); return symbol_iterator(SymbolRef(ret, this)); } section_iterator COFFObjectFile::begin_sections() const { DataRefImpl ret; std::memset(&ret, 0, sizeof(DataRefImpl)); ret.p = reinterpret_cast<intptr_t>(SectionTable); return section_iterator(SectionRef(ret, this)); } section_iterator COFFObjectFile::end_sections() const { DataRefImpl ret; std::memset(&ret, 0, sizeof(DataRefImpl)); ret.p = reinterpret_cast<intptr_t>(SectionTable + Header->NumberOfSections); return section_iterator(SectionRef(ret, this)); } uint8_t COFFObjectFile::getBytesInAddress() const { return getArch() == Triple::x86_64 ? 8 : 4; } StringRef COFFObjectFile::getFileFormatName() const { switch(Header->Machine) { case COFF::IMAGE_FILE_MACHINE_I386: return "COFF-i386"; case COFF::IMAGE_FILE_MACHINE_AMD64: return "COFF-x86-64"; default: return "COFF-<unknown arch>"; } } unsigned COFFObjectFile::getArch() const { switch(Header->Machine) { case COFF::IMAGE_FILE_MACHINE_I386: return Triple::x86; case COFF::IMAGE_FILE_MACHINE_AMD64: return Triple::x86_64; default: return Triple::UnknownArch; } } error_code COFFObjectFile::getSection(int32_t index, const coff_section *&Result) const { // Check for special index values. if (index == COFF::IMAGE_SYM_UNDEFINED || index == COFF::IMAGE_SYM_ABSOLUTE || index == COFF::IMAGE_SYM_DEBUG) Result = NULL; else if (index > 0 && index <= Header->NumberOfSections) // We already verified the section table data, so no need to check again. Result = SectionTable + (index - 1); else return object_error::parse_failed; return object_error::success; } error_code COFFObjectFile::getString(uint32_t offset, StringRef &Result) const { if (StringTableSize <= 4) // Tried to get a string from an empty string table. return object_error::parse_failed; if (offset >= StringTableSize) return object_error::unexpected_eof; Result = StringRef(StringTable + offset); return object_error::success; } error_code COFFObjectFile::getSymbol(uint32_t index, const coff_symbol *&Result) const { if (index > 0 && index < Header->NumberOfSymbols) Result = SymbolTable + index; else return object_error::parse_failed; return object_error::success; } const coff_relocation *COFFObjectFile::toRel(DataRefImpl Rel) const { return reinterpret_cast<const coff_relocation*>(Rel.p); } error_code COFFObjectFile::getRelocationNext(DataRefImpl Rel, RelocationRef &Res) const { Rel.p = reinterpret_cast<uintptr_t>( reinterpret_cast<const coff_relocation*>(Rel.p) + 1); Res = RelocationRef(Rel, this); return object_error::success; } error_code COFFObjectFile::getRelocationAddress(DataRefImpl Rel, uint64_t &Res) const { Res = toRel(Rel)->VirtualAddress; return object_error::success; } error_code COFFObjectFile::getRelocationSymbol(DataRefImpl Rel, SymbolRef &Res) const { const coff_relocation* R = toRel(Rel); DataRefImpl Symb; Symb.p = reinterpret_cast<uintptr_t>(SymbolTable + R->SymbolTableIndex); Res = SymbolRef(Symb, this); return object_error::success; } error_code COFFObjectFile::getRelocationType(DataRefImpl Rel, uint32_t &Res) const { const coff_relocation* R = toRel(Rel); Res = R->Type; return object_error::success; } #define LLVM_COFF_SWITCH_RELOC_TYPE_NAME(enum) \ case COFF::enum: res = #enum; break; error_code COFFObjectFile::getRelocationTypeName(DataRefImpl Rel, SmallVectorImpl<char> &Result) const { const coff_relocation *reloc = toRel(Rel); StringRef res; switch (Header->Machine) { case COFF::IMAGE_FILE_MACHINE_AMD64: switch (reloc->Type) { LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_AMD64_ABSOLUTE); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_AMD64_ADDR64); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_AMD64_ADDR32); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_AMD64_ADDR32NB); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_AMD64_REL32); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_AMD64_REL32_1); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_AMD64_REL32_2); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_AMD64_REL32_3); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_AMD64_REL32_4); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_AMD64_REL32_5); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_AMD64_SECTION); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_AMD64_SECREL); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_AMD64_SECREL7); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_AMD64_TOKEN); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_AMD64_SREL32); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_AMD64_PAIR); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_AMD64_SSPAN32); default: res = "Unknown"; } break; case COFF::IMAGE_FILE_MACHINE_I386: switch (reloc->Type) { LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_I386_ABSOLUTE); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_I386_DIR16); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_I386_REL16); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_I386_DIR32); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_I386_DIR32NB); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_I386_SEG12); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_I386_SECTION); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_I386_SECREL); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_I386_TOKEN); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_I386_SECREL7); LLVM_COFF_SWITCH_RELOC_TYPE_NAME(IMAGE_REL_I386_REL32); default: res = "Unknown"; } break; default: res = "Unknown"; } Result.append(res.begin(), res.end()); return object_error::success; } #undef LLVM_COFF_SWITCH_RELOC_TYPE_NAME error_code COFFObjectFile::getRelocationAdditionalInfo(DataRefImpl Rel, int64_t &Res) const { Res = 0; return object_error::success; } error_code COFFObjectFile::getRelocationValueString(DataRefImpl Rel, SmallVectorImpl<char> &Result) const { const coff_relocation *reloc = toRel(Rel); const coff_symbol *symb = 0; if (error_code ec = getSymbol(reloc->SymbolTableIndex, symb)) return ec; DataRefImpl sym; ::memset(&sym, 0, sizeof(sym)); sym.p = reinterpret_cast<uintptr_t>(symb); StringRef symname; if (error_code ec = getSymbolName(sym, symname)) return ec; Result.append(symname.begin(), symname.end()); return object_error::success; } namespace llvm { ObjectFile *ObjectFile::createCOFFObjectFile(MemoryBuffer *Object) { error_code ec; return new COFFObjectFile(Object, ec); } } // end namespace llvm