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
operator <<(raw_ostream & OS,const SectionedAddress & Addr)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
anchor()42 void ObjectFile::anchor() {}
43
ObjectFile(unsigned int Type,MemoryBufferRef Source)44 ObjectFile::ObjectFile(unsigned int Type, MemoryBufferRef Source)
45 : SymbolicFile(Type, Source) {}
46
containsSymbol(SymbolRef S) const47 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
getSymbolValue(DataRefImpl Ref) const57 uint64_t ObjectFile::getSymbolValue(DataRefImpl Ref) const {
58 uint32_t Flags = getSymbolFlags(Ref);
59 if (Flags & SymbolRef::SF_Undefined)
60 return 0;
61 if (Flags & SymbolRef::SF_Common)
62 return getCommonSymbolSize(Ref);
63 return getSymbolValueImpl(Ref);
64 }
65
printSymbolName(raw_ostream & OS,DataRefImpl Symb) const66 Error ObjectFile::printSymbolName(raw_ostream &OS, DataRefImpl Symb) const {
67 Expected<StringRef> Name = getSymbolName(Symb);
68 if (!Name)
69 return Name.takeError();
70 OS << *Name;
71 return Error::success();
72 }
73
getSymbolAlignment(DataRefImpl DRI) const74 uint32_t ObjectFile::getSymbolAlignment(DataRefImpl DRI) const { return 0; }
75
isSectionBitcode(DataRefImpl Sec) const76 bool ObjectFile::isSectionBitcode(DataRefImpl Sec) const {
77 Expected<StringRef> NameOrErr = getSectionName(Sec);
78 if (NameOrErr)
79 return *NameOrErr == ".llvmbc";
80 consumeError(NameOrErr.takeError());
81 return false;
82 }
83
isSectionStripped(DataRefImpl Sec) const84 bool ObjectFile::isSectionStripped(DataRefImpl Sec) const { return false; }
85
isBerkeleyText(DataRefImpl Sec) const86 bool ObjectFile::isBerkeleyText(DataRefImpl Sec) const {
87 return isSectionText(Sec);
88 }
89
isBerkeleyData(DataRefImpl Sec) const90 bool ObjectFile::isBerkeleyData(DataRefImpl Sec) const {
91 return isSectionData(Sec);
92 }
93
94 Expected<section_iterator>
getRelocatedSection(DataRefImpl Sec) const95 ObjectFile::getRelocatedSection(DataRefImpl Sec) const {
96 return section_iterator(SectionRef(Sec, this));
97 }
98
makeTriple() const99 Triple ObjectFile::makeTriple() const {
100 Triple TheTriple;
101 auto Arch = getArch();
102 TheTriple.setArch(Triple::ArchType(Arch));
103
104 // For ARM targets, try to use the build attributes to build determine
105 // the build target. Target features are also added, but later during
106 // disassembly.
107 if (Arch == Triple::arm || Arch == Triple::armeb)
108 setARMSubArch(TheTriple);
109
110 // TheTriple defaults to ELF, and COFF doesn't have an environment:
111 // the best we can do here is indicate that it is mach-o.
112 if (isMachO())
113 TheTriple.setObjectFormat(Triple::MachO);
114
115 if (isCOFF()) {
116 const auto COFFObj = cast<COFFObjectFile>(this);
117 if (COFFObj->getArch() == Triple::thumb)
118 TheTriple.setTriple("thumbv7-windows");
119 }
120
121 return TheTriple;
122 }
123
124 Expected<std::unique_ptr<ObjectFile>>
createObjectFile(MemoryBufferRef Object,file_magic Type)125 ObjectFile::createObjectFile(MemoryBufferRef Object, file_magic Type) {
126 StringRef Data = Object.getBuffer();
127 if (Type == file_magic::unknown)
128 Type = identify_magic(Data);
129
130 switch (Type) {
131 case file_magic::unknown:
132 case file_magic::bitcode:
133 case file_magic::coff_cl_gl_object:
134 case file_magic::archive:
135 case file_magic::macho_universal_binary:
136 case file_magic::windows_resource:
137 case file_magic::pdb:
138 case file_magic::minidump:
139 return errorCodeToError(object_error::invalid_file_type);
140 case file_magic::tapi_file:
141 return errorCodeToError(object_error::invalid_file_type);
142 case file_magic::elf:
143 case file_magic::elf_relocatable:
144 case file_magic::elf_executable:
145 case file_magic::elf_shared_object:
146 case file_magic::elf_core:
147 return createELFObjectFile(Object);
148 case file_magic::macho_object:
149 case file_magic::macho_executable:
150 case file_magic::macho_fixed_virtual_memory_shared_lib:
151 case file_magic::macho_core:
152 case file_magic::macho_preload_executable:
153 case file_magic::macho_dynamically_linked_shared_lib:
154 case file_magic::macho_dynamic_linker:
155 case file_magic::macho_bundle:
156 case file_magic::macho_dynamically_linked_shared_lib_stub:
157 case file_magic::macho_dsym_companion:
158 case file_magic::macho_kext_bundle:
159 return createMachOObjectFile(Object);
160 case file_magic::coff_object:
161 case file_magic::coff_import_library:
162 case file_magic::pecoff_executable:
163 return createCOFFObjectFile(Object);
164 case file_magic::xcoff_object_32:
165 return createXCOFFObjectFile(Object, Binary::ID_XCOFF32);
166 case file_magic::xcoff_object_64:
167 return createXCOFFObjectFile(Object, Binary::ID_XCOFF64);
168 case file_magic::wasm_object:
169 return createWasmObjectFile(Object);
170 }
171 llvm_unreachable("Unexpected Object File Type");
172 }
173
174 Expected<OwningBinary<ObjectFile>>
createObjectFile(StringRef ObjectPath)175 ObjectFile::createObjectFile(StringRef ObjectPath) {
176 ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr =
177 MemoryBuffer::getFile(ObjectPath);
178 if (std::error_code EC = FileOrErr.getError())
179 return errorCodeToError(EC);
180 std::unique_ptr<MemoryBuffer> Buffer = std::move(FileOrErr.get());
181
182 Expected<std::unique_ptr<ObjectFile>> ObjOrErr =
183 createObjectFile(Buffer->getMemBufferRef());
184 if (Error Err = ObjOrErr.takeError())
185 return std::move(Err);
186 std::unique_ptr<ObjectFile> Obj = std::move(ObjOrErr.get());
187
188 return OwningBinary<ObjectFile>(std::move(Obj), std::move(Buffer));
189 }
190