1 //===- ObjectFile.cpp - File format independent object file ---------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file defines a file format independent ObjectFile class. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "llvm/Object/ObjectFile.h" 14 #include "llvm/ADT/StringRef.h" 15 #include "llvm/BinaryFormat/Magic.h" 16 #include "llvm/Object/Binary.h" 17 #include "llvm/Object/COFF.h" 18 #include "llvm/Object/Error.h" 19 #include "llvm/Object/MachO.h" 20 #include "llvm/Object/Wasm.h" 21 #include "llvm/Support/Error.h" 22 #include "llvm/Support/ErrorHandling.h" 23 #include "llvm/Support/ErrorOr.h" 24 #include "llvm/Support/FileSystem.h" 25 #include "llvm/Support/MemoryBuffer.h" 26 #include "llvm/Support/raw_ostream.h" 27 #include <algorithm> 28 #include <cstdint> 29 #include <memory> 30 #include <system_error> 31 32 using namespace llvm; 33 using namespace object; 34 35 raw_ostream &object::operator<<(raw_ostream &OS, const SectionedAddress &Addr) { 36 OS << "SectionedAddress{" << format_hex(Addr.Address, 10); 37 if (Addr.SectionIndex != SectionedAddress::UndefSection) 38 OS << ", " << Addr.SectionIndex; 39 return OS << "}"; 40 } 41 42 void ObjectFile::anchor() {} 43 44 ObjectFile::ObjectFile(unsigned int Type, MemoryBufferRef Source) 45 : SymbolicFile(Type, Source) {} 46 47 bool SectionRef::containsSymbol(SymbolRef S) const { 48 Expected<section_iterator> SymSec = S.getSection(); 49 if (!SymSec) { 50 // TODO: Actually report errors helpfully. 51 consumeError(SymSec.takeError()); 52 return false; 53 } 54 return *this == **SymSec; 55 } 56 57 Expected<uint64_t> ObjectFile::getSymbolValue(DataRefImpl Ref) const { 58 if (Expected<uint32_t> FlagsOrErr = getSymbolFlags(Ref)) { 59 if (*FlagsOrErr & SymbolRef::SF_Undefined) 60 return 0; 61 if (*FlagsOrErr & SymbolRef::SF_Common) 62 return getCommonSymbolSize(Ref); 63 } else 64 // TODO: Test this error. 65 return FlagsOrErr.takeError(); 66 return getSymbolValueImpl(Ref); 67 } 68 69 Error ObjectFile::printSymbolName(raw_ostream &OS, DataRefImpl Symb) const { 70 Expected<StringRef> Name = getSymbolName(Symb); 71 if (!Name) 72 return Name.takeError(); 73 OS << *Name; 74 return Error::success(); 75 } 76 77 uint32_t ObjectFile::getSymbolAlignment(DataRefImpl DRI) const { return 0; } 78 79 bool ObjectFile::isSectionBitcode(DataRefImpl Sec) const { 80 Expected<StringRef> NameOrErr = getSectionName(Sec); 81 if (NameOrErr) 82 return *NameOrErr == ".llvmbc"; 83 consumeError(NameOrErr.takeError()); 84 return false; 85 } 86 87 bool ObjectFile::isSectionStripped(DataRefImpl Sec) const { return false; } 88 89 bool ObjectFile::isBerkeleyText(DataRefImpl Sec) const { 90 return isSectionText(Sec); 91 } 92 93 bool ObjectFile::isBerkeleyData(DataRefImpl Sec) const { 94 return isSectionData(Sec); 95 } 96 97 bool ObjectFile::isDebugSection(StringRef SectionName) const { 98 return false; 99 } 100 101 Expected<section_iterator> 102 ObjectFile::getRelocatedSection(DataRefImpl Sec) const { 103 return section_iterator(SectionRef(Sec, this)); 104 } 105 106 Triple ObjectFile::makeTriple() const { 107 Triple TheTriple; 108 auto Arch = getArch(); 109 TheTriple.setArch(Triple::ArchType(Arch)); 110 111 // For ARM targets, try to use the build attributes to build determine 112 // the build target. Target features are also added, but later during 113 // disassembly. 114 if (Arch == Triple::arm || Arch == Triple::armeb) 115 setARMSubArch(TheTriple); 116 117 // TheTriple defaults to ELF, and COFF doesn't have an environment: 118 // something we can do here is indicate that it is mach-o. 119 if (isMachO()) { 120 TheTriple.setObjectFormat(Triple::MachO); 121 } else if (isCOFF()) { 122 const auto COFFObj = cast<COFFObjectFile>(this); 123 if (COFFObj->getArch() == Triple::thumb) 124 TheTriple.setTriple("thumbv7-windows"); 125 } else if (isXCOFF()) { 126 // XCOFF implies AIX. 127 TheTriple.setOS(Triple::AIX); 128 TheTriple.setObjectFormat(Triple::XCOFF); 129 } 130 131 return TheTriple; 132 } 133 134 Expected<std::unique_ptr<ObjectFile>> 135 ObjectFile::createObjectFile(MemoryBufferRef Object, file_magic Type, 136 bool InitContent) { 137 StringRef Data = Object.getBuffer(); 138 if (Type == file_magic::unknown) 139 Type = identify_magic(Data); 140 141 switch (Type) { 142 case file_magic::unknown: 143 case file_magic::bitcode: 144 case file_magic::coff_cl_gl_object: 145 case file_magic::archive: 146 case file_magic::macho_universal_binary: 147 case file_magic::windows_resource: 148 case file_magic::pdb: 149 case file_magic::minidump: 150 return errorCodeToError(object_error::invalid_file_type); 151 case file_magic::tapi_file: 152 return errorCodeToError(object_error::invalid_file_type); 153 case file_magic::elf: 154 case file_magic::elf_relocatable: 155 case file_magic::elf_executable: 156 case file_magic::elf_shared_object: 157 case file_magic::elf_core: 158 return createELFObjectFile(Object, InitContent); 159 case file_magic::macho_object: 160 case file_magic::macho_executable: 161 case file_magic::macho_fixed_virtual_memory_shared_lib: 162 case file_magic::macho_core: 163 case file_magic::macho_preload_executable: 164 case file_magic::macho_dynamically_linked_shared_lib: 165 case file_magic::macho_dynamic_linker: 166 case file_magic::macho_bundle: 167 case file_magic::macho_dynamically_linked_shared_lib_stub: 168 case file_magic::macho_dsym_companion: 169 case file_magic::macho_kext_bundle: 170 return createMachOObjectFile(Object); 171 case file_magic::coff_object: 172 case file_magic::coff_import_library: 173 case file_magic::pecoff_executable: 174 return createCOFFObjectFile(Object); 175 case file_magic::xcoff_object_32: 176 return createXCOFFObjectFile(Object, Binary::ID_XCOFF32); 177 case file_magic::xcoff_object_64: 178 return createXCOFFObjectFile(Object, Binary::ID_XCOFF64); 179 case file_magic::wasm_object: 180 return createWasmObjectFile(Object); 181 } 182 llvm_unreachable("Unexpected Object File Type"); 183 } 184 185 Expected<OwningBinary<ObjectFile>> 186 ObjectFile::createObjectFile(StringRef ObjectPath) { 187 ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr = 188 MemoryBuffer::getFile(ObjectPath); 189 if (std::error_code EC = FileOrErr.getError()) 190 return errorCodeToError(EC); 191 std::unique_ptr<MemoryBuffer> Buffer = std::move(FileOrErr.get()); 192 193 Expected<std::unique_ptr<ObjectFile>> ObjOrErr = 194 createObjectFile(Buffer->getMemBufferRef()); 195 if (Error Err = ObjOrErr.takeError()) 196 return std::move(Err); 197 std::unique_ptr<ObjectFile> Obj = std::move(ObjOrErr.get()); 198 199 return OwningBinary<ObjectFile>(std::move(Obj), std::move(Buffer)); 200 } 201