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/Format.h"
25#include "llvm/Support/MemoryBuffer.h"
26#include "llvm/Support/raw_ostream.h"
27#include <cstdint>
28#include <memory>
29#include <system_error>
30
31using namespace llvm;
32using namespace object;
33
34raw_ostream &object::operator<<(raw_ostream &OS, const SectionedAddress &Addr) {
35  OS << "SectionedAddress{" << format_hex(Addr.Address, 10);
36  if (Addr.SectionIndex != SectionedAddress::UndefSection)
37    OS << ", " << Addr.SectionIndex;
38  return OS << "}";
39}
40
41void ObjectFile::anchor() {}
42
43ObjectFile::ObjectFile(unsigned int Type, MemoryBufferRef Source)
44    : SymbolicFile(Type, Source) {}
45
46bool SectionRef::containsSymbol(SymbolRef S) const {
47  Expected<section_iterator> SymSec = S.getSection();
48  if (!SymSec) {
49    // TODO: Actually report errors helpfully.
50    consumeError(SymSec.takeError());
51    return false;
52  }
53  return *this == **SymSec;
54}
55
56Expected<uint64_t> ObjectFile::getSymbolValue(DataRefImpl Ref) const {
57  uint32_t Flags;
58  if (Error E = getSymbolFlags(Ref).moveInto(Flags))
59    // TODO: Test this error.
60    return std::move(E);
61
62  if (Flags & SymbolRef::SF_Undefined)
63    return 0;
64  if (Flags & SymbolRef::SF_Common)
65    return getCommonSymbolSize(Ref);
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(DataRefImpl Sec) const { return false; }
98
99bool ObjectFile::hasDebugInfo() const {
100  return any_of(sections(),
101                [](SectionRef Sec) { return Sec.isDebugSection(); });
102}
103
104Expected<section_iterator>
105ObjectFile::getRelocatedSection(DataRefImpl Sec) const {
106  return section_iterator(SectionRef(Sec, this));
107}
108
109Triple ObjectFile::makeTriple() const {
110  Triple TheTriple;
111  auto Arch = getArch();
112  TheTriple.setArch(Triple::ArchType(Arch));
113
114  // For ARM targets, try to use the build attributes to build determine
115  // the build target. Target features are also added, but later during
116  // disassembly.
117  if (Arch == Triple::arm || Arch == Triple::armeb)
118    setARMSubArch(TheTriple);
119
120  // TheTriple defaults to ELF, and COFF doesn't have an environment:
121  // something we can do here is indicate that it is mach-o.
122  if (isMachO()) {
123    TheTriple.setObjectFormat(Triple::MachO);
124  } else if (isCOFF()) {
125    const auto COFFObj = cast<COFFObjectFile>(this);
126    if (COFFObj->getArch() == Triple::thumb)
127      TheTriple.setTriple("thumbv7-windows");
128  } else if (isXCOFF()) {
129    // XCOFF implies AIX.
130    TheTriple.setOS(Triple::AIX);
131    TheTriple.setObjectFormat(Triple::XCOFF);
132  }
133
134  return TheTriple;
135}
136
137Expected<std::unique_ptr<ObjectFile>>
138ObjectFile::createObjectFile(MemoryBufferRef Object, file_magic Type,
139                             bool InitContent) {
140  StringRef Data = Object.getBuffer();
141  if (Type == file_magic::unknown)
142    Type = identify_magic(Data);
143
144  switch (Type) {
145  case file_magic::unknown:
146  case file_magic::bitcode:
147  case file_magic::coff_cl_gl_object:
148  case file_magic::archive:
149  case file_magic::macho_universal_binary:
150  case file_magic::windows_resource:
151  case file_magic::pdb:
152  case file_magic::minidump:
153  case file_magic::goff_object:
154  case file_magic::cuda_fatbinary:
155  case file_magic::offload_binary:
156  case file_magic::dxcontainer_object:
157    return errorCodeToError(object_error::invalid_file_type);
158  case file_magic::tapi_file:
159    return errorCodeToError(object_error::invalid_file_type);
160  case file_magic::elf:
161  case file_magic::elf_relocatable:
162  case file_magic::elf_executable:
163  case file_magic::elf_shared_object:
164  case file_magic::elf_core:
165    return createELFObjectFile(Object, InitContent);
166  case file_magic::macho_object:
167  case file_magic::macho_executable:
168  case file_magic::macho_fixed_virtual_memory_shared_lib:
169  case file_magic::macho_core:
170  case file_magic::macho_preload_executable:
171  case file_magic::macho_dynamically_linked_shared_lib:
172  case file_magic::macho_dynamic_linker:
173  case file_magic::macho_bundle:
174  case file_magic::macho_dynamically_linked_shared_lib_stub:
175  case file_magic::macho_dsym_companion:
176  case file_magic::macho_kext_bundle:
177  case file_magic::macho_file_set:
178    return createMachOObjectFile(Object);
179  case file_magic::coff_object:
180  case file_magic::coff_import_library:
181  case file_magic::pecoff_executable:
182    return createCOFFObjectFile(Object);
183  case file_magic::xcoff_object_32:
184    return createXCOFFObjectFile(Object, Binary::ID_XCOFF32);
185  case file_magic::xcoff_object_64:
186    return createXCOFFObjectFile(Object, Binary::ID_XCOFF64);
187  case file_magic::wasm_object:
188    return createWasmObjectFile(Object);
189  }
190  llvm_unreachable("Unexpected Object File Type");
191}
192
193Expected<OwningBinary<ObjectFile>>
194ObjectFile::createObjectFile(StringRef ObjectPath) {
195  ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr =
196      MemoryBuffer::getFile(ObjectPath);
197  if (std::error_code EC = FileOrErr.getError())
198    return errorCodeToError(EC);
199  std::unique_ptr<MemoryBuffer> Buffer = std::move(FileOrErr.get());
200
201  Expected<std::unique_ptr<ObjectFile>> ObjOrErr =
202      createObjectFile(Buffer->getMemBufferRef());
203  if (Error Err = ObjOrErr.takeError())
204    return std::move(Err);
205  std::unique_ptr<ObjectFile> Obj = std::move(ObjOrErr.get());
206
207  return OwningBinary<ObjectFile>(std::move(Obj), std::move(Buffer));
208}
209
210bool ObjectFile::isReflectionSectionStrippable(
211    llvm::binaryformat::Swift5ReflectionSectionKind ReflectionSectionKind)
212    const {
213  using llvm::binaryformat::Swift5ReflectionSectionKind;
214  return ReflectionSectionKind == Swift5ReflectionSectionKind::fieldmd ||
215         ReflectionSectionKind == Swift5ReflectionSectionKind::reflstr ||
216         ReflectionSectionKind == Swift5ReflectionSectionKind::assocty;
217}
218