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
32using namespace llvm;
33using namespace object;
34
35raw_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
42void ObjectFile::anchor() {}
43
44ObjectFile::ObjectFile(unsigned int Type, MemoryBufferRef Source)
45    : SymbolicFile(Type, Source) {}
46
47bool 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
57Expected<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
69Error 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
77uint32_t ObjectFile::getSymbolAlignment(DataRefImpl DRI) const { return 0; }
78
79bool 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
87bool ObjectFile::isSectionStripped(DataRefImpl Sec) const { return false; }
88
89bool ObjectFile::isBerkeleyText(DataRefImpl Sec) const {
90  return isSectionText(Sec);
91}
92
93bool ObjectFile::isBerkeleyData(DataRefImpl Sec) const {
94  return isSectionData(Sec);
95}
96
97bool ObjectFile::isDebugSection(StringRef SectionName) const {
98  return false;
99}
100
101Expected<section_iterator>
102ObjectFile::getRelocatedSection(DataRefImpl Sec) const {
103  return section_iterator(SectionRef(Sec, this));
104}
105
106Triple 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
134Expected<std::unique_ptr<ObjectFile>>
135ObjectFile::createObjectFile(MemoryBufferRef Object, file_magic Type) {
136  StringRef Data = Object.getBuffer();
137  if (Type == file_magic::unknown)
138    Type = identify_magic(Data);
139
140  switch (Type) {
141  case file_magic::unknown:
142  case file_magic::bitcode:
143  case file_magic::coff_cl_gl_object:
144  case file_magic::archive:
145  case file_magic::macho_universal_binary:
146  case file_magic::windows_resource:
147  case file_magic::pdb:
148  case file_magic::minidump:
149    return errorCodeToError(object_error::invalid_file_type);
150  case file_magic::tapi_file:
151    return errorCodeToError(object_error::invalid_file_type);
152  case file_magic::elf:
153  case file_magic::elf_relocatable:
154  case file_magic::elf_executable:
155  case file_magic::elf_shared_object:
156  case file_magic::elf_core:
157    return createELFObjectFile(Object);
158  case file_magic::macho_object:
159  case file_magic::macho_executable:
160  case file_magic::macho_fixed_virtual_memory_shared_lib:
161  case file_magic::macho_core:
162  case file_magic::macho_preload_executable:
163  case file_magic::macho_dynamically_linked_shared_lib:
164  case file_magic::macho_dynamic_linker:
165  case file_magic::macho_bundle:
166  case file_magic::macho_dynamically_linked_shared_lib_stub:
167  case file_magic::macho_dsym_companion:
168  case file_magic::macho_kext_bundle:
169    return createMachOObjectFile(Object);
170  case file_magic::coff_object:
171  case file_magic::coff_import_library:
172  case file_magic::pecoff_executable:
173    return createCOFFObjectFile(Object);
174  case file_magic::xcoff_object_32:
175    return createXCOFFObjectFile(Object, Binary::ID_XCOFF32);
176  case file_magic::xcoff_object_64:
177    return createXCOFFObjectFile(Object, Binary::ID_XCOFF64);
178  case file_magic::wasm_object:
179    return createWasmObjectFile(Object);
180  }
181  llvm_unreachable("Unexpected Object File Type");
182}
183
184Expected<OwningBinary<ObjectFile>>
185ObjectFile::createObjectFile(StringRef ObjectPath) {
186  ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr =
187      MemoryBuffer::getFile(ObjectPath);
188  if (std::error_code EC = FileOrErr.getError())
189    return errorCodeToError(EC);
190  std::unique_ptr<MemoryBuffer> Buffer = std::move(FileOrErr.get());
191
192  Expected<std::unique_ptr<ObjectFile>> ObjOrErr =
193      createObjectFile(Buffer->getMemBufferRef());
194  if (Error Err = ObjOrErr.takeError())
195    return std::move(Err);
196  std::unique_ptr<ObjectFile> Obj = std::move(ObjOrErr.get());
197
198  return OwningBinary<ObjectFile>(std::move(Obj), std::move(Buffer));
199}
200