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 void ObjectFile::anchor() {} 36 37 ObjectFile::ObjectFile(unsigned int Type, MemoryBufferRef Source) 38 : SymbolicFile(Type, Source) {} 39 40 bool SectionRef::containsSymbol(SymbolRef S) const { 41 Expected<section_iterator> SymSec = S.getSection(); 42 if (!SymSec) { 43 // TODO: Actually report errors helpfully. 44 consumeError(SymSec.takeError()); 45 return false; 46 } 47 return *this == **SymSec; 48 } 49 50 uint64_t ObjectFile::getSymbolValue(DataRefImpl Ref) const { 51 uint32_t Flags = getSymbolFlags(Ref); 52 if (Flags & SymbolRef::SF_Undefined) 53 return 0; 54 if (Flags & SymbolRef::SF_Common) 55 return getCommonSymbolSize(Ref); 56 return getSymbolValueImpl(Ref); 57 } 58 59 Error ObjectFile::printSymbolName(raw_ostream &OS, DataRefImpl Symb) const { 60 Expected<StringRef> Name = getSymbolName(Symb); 61 if (!Name) 62 return Name.takeError(); 63 OS << *Name; 64 return Error::success(); 65 } 66 67 uint32_t ObjectFile::getSymbolAlignment(DataRefImpl DRI) const { return 0; } 68 69 bool ObjectFile::isSectionBitcode(DataRefImpl Sec) const { 70 if (Expected<StringRef> NameOrErr = getSectionName(Sec)) 71 return *NameOrErr == ".llvmbc"; 72 return false; 73 } 74 75 bool ObjectFile::isSectionStripped(DataRefImpl Sec) const { return false; } 76 77 bool ObjectFile::isBerkeleyText(DataRefImpl Sec) const { 78 return isSectionText(Sec); 79 } 80 81 bool ObjectFile::isBerkeleyData(DataRefImpl Sec) const { 82 return isSectionData(Sec); 83 } 84 85 section_iterator ObjectFile::getRelocatedSection(DataRefImpl Sec) const { 86 return section_iterator(SectionRef(Sec, this)); 87 } 88 89 Triple ObjectFile::makeTriple() const { 90 Triple TheTriple; 91 auto Arch = getArch(); 92 TheTriple.setArch(Triple::ArchType(Arch)); 93 94 // For ARM targets, try to use the build attributes to build determine 95 // the build target. Target features are also added, but later during 96 // disassembly. 97 if (Arch == Triple::arm || Arch == Triple::armeb) 98 setARMSubArch(TheTriple); 99 100 // TheTriple defaults to ELF, and COFF doesn't have an environment: 101 // the best we can do here is indicate that it is mach-o. 102 if (isMachO()) 103 TheTriple.setObjectFormat(Triple::MachO); 104 105 if (isCOFF()) { 106 const auto COFFObj = dyn_cast<COFFObjectFile>(this); 107 if (COFFObj->getArch() == Triple::thumb) 108 TheTriple.setTriple("thumbv7-windows"); 109 } 110 111 return TheTriple; 112 } 113 114 Expected<std::unique_ptr<ObjectFile>> 115 ObjectFile::createObjectFile(MemoryBufferRef Object, file_magic Type) { 116 StringRef Data = Object.getBuffer(); 117 if (Type == file_magic::unknown) 118 Type = identify_magic(Data); 119 120 switch (Type) { 121 case file_magic::unknown: 122 case file_magic::bitcode: 123 case file_magic::coff_cl_gl_object: 124 case file_magic::archive: 125 case file_magic::macho_universal_binary: 126 case file_magic::windows_resource: 127 case file_magic::pdb: 128 case file_magic::minidump: 129 return errorCodeToError(object_error::invalid_file_type); 130 case file_magic::tapi_file: 131 return errorCodeToError(object_error::invalid_file_type); 132 case file_magic::elf: 133 case file_magic::elf_relocatable: 134 case file_magic::elf_executable: 135 case file_magic::elf_shared_object: 136 case file_magic::elf_core: 137 return createELFObjectFile(Object); 138 case file_magic::macho_object: 139 case file_magic::macho_executable: 140 case file_magic::macho_fixed_virtual_memory_shared_lib: 141 case file_magic::macho_core: 142 case file_magic::macho_preload_executable: 143 case file_magic::macho_dynamically_linked_shared_lib: 144 case file_magic::macho_dynamic_linker: 145 case file_magic::macho_bundle: 146 case file_magic::macho_dynamically_linked_shared_lib_stub: 147 case file_magic::macho_dsym_companion: 148 case file_magic::macho_kext_bundle: 149 return createMachOObjectFile(Object); 150 case file_magic::coff_object: 151 case file_magic::coff_import_library: 152 case file_magic::pecoff_executable: 153 return createCOFFObjectFile(Object); 154 case file_magic::xcoff_object_32: 155 return createXCOFFObjectFile(Object, Binary::ID_XCOFF32); 156 case file_magic::xcoff_object_64: 157 return createXCOFFObjectFile(Object, Binary::ID_XCOFF64); 158 case file_magic::wasm_object: 159 return createWasmObjectFile(Object); 160 } 161 llvm_unreachable("Unexpected Object File Type"); 162 } 163 164 Expected<OwningBinary<ObjectFile>> 165 ObjectFile::createObjectFile(StringRef ObjectPath) { 166 ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr = 167 MemoryBuffer::getFile(ObjectPath); 168 if (std::error_code EC = FileOrErr.getError()) 169 return errorCodeToError(EC); 170 std::unique_ptr<MemoryBuffer> Buffer = std::move(FileOrErr.get()); 171 172 Expected<std::unique_ptr<ObjectFile>> ObjOrErr = 173 createObjectFile(Buffer->getMemBufferRef()); 174 if (Error Err = ObjOrErr.takeError()) 175 return std::move(Err); 176 std::unique_ptr<ObjectFile> Obj = std::move(ObjOrErr.get()); 177 178 return OwningBinary<ObjectFile>(std::move(Obj), std::move(Buffer)); 179 } 180