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 std::error_code ObjectFile::printSymbolName(raw_ostream &OS, 60 DataRefImpl Symb) const { 61 Expected<StringRef> Name = getSymbolName(Symb); 62 if (!Name) 63 return errorToErrorCode(Name.takeError()); 64 OS << *Name; 65 return std::error_code(); 66 } 67 68 uint32_t ObjectFile::getSymbolAlignment(DataRefImpl DRI) const { return 0; } 69 70 bool ObjectFile::isSectionBitcode(DataRefImpl Sec) const { 71 StringRef SectName; 72 if (!getSectionName(Sec, SectName)) 73 return SectName == ".llvmbc"; 74 return false; 75 } 76 77 bool ObjectFile::isSectionStripped(DataRefImpl Sec) const { return false; } 78 79 bool ObjectFile::isBerkeleyText(DataRefImpl Sec) const { 80 return isSectionText(Sec); 81 } 82 83 bool ObjectFile::isBerkeleyData(DataRefImpl Sec) const { 84 return isSectionData(Sec); 85 } 86 87 section_iterator ObjectFile::getRelocatedSection(DataRefImpl Sec) const { 88 return section_iterator(SectionRef(Sec, this)); 89 } 90 91 Triple ObjectFile::makeTriple() const { 92 Triple TheTriple; 93 auto Arch = getArch(); 94 TheTriple.setArch(Triple::ArchType(Arch)); 95 96 // For ARM targets, try to use the build attributes to build determine 97 // the build target. Target features are also added, but later during 98 // disassembly. 99 if (Arch == Triple::arm || Arch == Triple::armeb) 100 setARMSubArch(TheTriple); 101 102 // TheTriple defaults to ELF, and COFF doesn't have an environment: 103 // the best we can do here is indicate that it is mach-o. 104 if (isMachO()) 105 TheTriple.setObjectFormat(Triple::MachO); 106 107 if (isCOFF()) { 108 const auto COFFObj = dyn_cast<COFFObjectFile>(this); 109 if (COFFObj->getArch() == Triple::thumb) 110 TheTriple.setTriple("thumbv7-windows"); 111 } 112 113 return TheTriple; 114 } 115 116 Expected<std::unique_ptr<ObjectFile>> 117 ObjectFile::createObjectFile(MemoryBufferRef Object, file_magic Type) { 118 StringRef Data = Object.getBuffer(); 119 if (Type == file_magic::unknown) 120 Type = identify_magic(Data); 121 122 switch (Type) { 123 case file_magic::unknown: 124 case file_magic::bitcode: 125 case file_magic::coff_cl_gl_object: 126 case file_magic::archive: 127 case file_magic::macho_universal_binary: 128 case file_magic::windows_resource: 129 case file_magic::pdb: 130 case file_magic::minidump: 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::wasm_object: 155 return createWasmObjectFile(Object); 156 } 157 llvm_unreachable("Unexpected Object File Type"); 158 } 159 160 Expected<OwningBinary<ObjectFile>> 161 ObjectFile::createObjectFile(StringRef ObjectPath) { 162 ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr = 163 MemoryBuffer::getFile(ObjectPath); 164 if (std::error_code EC = FileOrErr.getError()) 165 return errorCodeToError(EC); 166 std::unique_ptr<MemoryBuffer> Buffer = std::move(FileOrErr.get()); 167 168 Expected<std::unique_ptr<ObjectFile>> ObjOrErr = 169 createObjectFile(Buffer->getMemBufferRef()); 170 if (Error Err = ObjOrErr.takeError()) 171 return std::move(Err); 172 std::unique_ptr<ObjectFile> Obj = std::move(ObjOrErr.get()); 173 174 return OwningBinary<ObjectFile>(std::move(Obj), std::move(Buffer)); 175 } 176