llvm/lib/Object/ObjectFile.cpp

   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
  31 using namespace llvm;
  32 using namespace object;
  33
  34 raw_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
  41 void ObjectFile::anchor() {}
  42
  43 ObjectFile::ObjectFile(unsigned int Type, MemoryBufferRef Source)
  44     : SymbolicFile(Type, Source) {}
  45
  46 bool 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
  56 Expected<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
  69 Error 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
  77 uint32_t ObjectFile::getSymbolAlignment(DataRefImpl DRI) const { return 0; }
  78
  79 bool ObjectFile::isSectionBitcode(DataRefImpl Sec) const {
  80   Expected<StringRef> NameOrErr = getSectionName(Sec);
  81   if (NameOrErr)
  82     return *NameOrErr == ".llvm.lto";
  83   consumeError(NameOrErr.takeError());
  84   return false;
  85 }
  86
  87 bool ObjectFile::isSectionStripped(DataRefImpl Sec) const { return false; }
  88
  89 bool ObjectFile::isBerkeleyText(DataRefImpl Sec) const {
  90   return isSectionText(Sec);
  91 }
  92
  93 bool ObjectFile::isBerkeleyData(DataRefImpl Sec) const {
  94   return isSectionData(Sec);
  95 }
  96
  97 bool ObjectFile::isDebugSection(DataRefImpl Sec) const { return false; }
  98
  99 bool ObjectFile::hasDebugInfo() const {
 100   return any_of(sections(),
 101                 [](SectionRef Sec) { return Sec.isDebugSection(); });
 102 }
 103
 104 Expected<section_iterator>
 105 ObjectFile::getRelocatedSection(DataRefImpl Sec) const {
 106   return section_iterator(SectionRef(Sec, this));
 107 }
 108
 109 Triple 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   else if (isGOFF()) {
 134     TheTriple.setOS(Triple::ZOS);
 135     TheTriple.setObjectFormat(Triple::GOFF);
 136   }
 137
 138   return TheTriple;
 139 }
 140
 141 Expected<std::unique_ptr<ObjectFile>>
 142 ObjectFile::createObjectFile(MemoryBufferRef Object, file_magic Type,
 143                              bool InitContent) {
 144   StringRef Data = Object.getBuffer();
 145   if (Type == file_magic::unknown)
 146     Type = identify_magic(Data);
 147
 148   switch (Type) {
 149   case file_magic::unknown:
 150   case file_magic::bitcode:
 151   case file_magic::coff_cl_gl_object:
 152   case file_magic::archive:
 153   case file_magic::macho_universal_binary:
 154   case file_magic::windows_resource:
 155   case file_magic::pdb:
 156   case file_magic::minidump:
 157   case file_magic::goff_object:
 158   case file_magic::cuda_fatbinary:
 159   case file_magic::offload_binary:
 160   case file_magic::dxcontainer_object:
 161   case file_magic::offload_bundle:
 162   case file_magic::offload_bundle_compressed:
 163     return errorCodeToError(object_error::invalid_file_type);
 164   case file_magic::tapi_file:
 165     return errorCodeToError(object_error::invalid_file_type);
 166   case file_magic::elf:
 167   case file_magic::elf_relocatable:
 168   case file_magic::elf_executable:
 169   case file_magic::elf_shared_object:
 170   case file_magic::elf_core:
 171     return createELFObjectFile(Object, InitContent);
 172   case file_magic::macho_object:
 173   case file_magic::macho_executable:
 174   case file_magic::macho_fixed_virtual_memory_shared_lib:
 175   case file_magic::macho_core:
 176   case file_magic::macho_preload_executable:
 177   case file_magic::macho_dynamically_linked_shared_lib:
 178   case file_magic::macho_dynamic_linker:
 179   case file_magic::macho_bundle:
 180   case file_magic::macho_dynamically_linked_shared_lib_stub:
 181   case file_magic::macho_dsym_companion:
 182   case file_magic::macho_kext_bundle:
 183   case file_magic::macho_file_set:
 184     return createMachOObjectFile(Object);
 185   case file_magic::coff_object:
 186   case file_magic::coff_import_library:
 187   case file_magic::pecoff_executable:
 188     return createCOFFObjectFile(Object);
 189   case file_magic::xcoff_object_32:
 190     return createXCOFFObjectFile(Object, Binary::ID_XCOFF32);
 191   case file_magic::xcoff_object_64:
 192     return createXCOFFObjectFile(Object, Binary::ID_XCOFF64);
 193   case file_magic::wasm_object:
 194     return createWasmObjectFile(Object);
 195   }
 196   llvm_unreachable("Unexpected Object File Type");
 197 }
 198
 199 Expected<OwningBinary<ObjectFile>>
 200 ObjectFile::createObjectFile(StringRef ObjectPath) {
 201   ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr =
 202       MemoryBuffer::getFile(ObjectPath);
 203   if (std::error_code EC = FileOrErr.getError())
 204     return errorCodeToError(EC);
 205   std::unique_ptr<MemoryBuffer> Buffer = std::move(FileOrErr.get());
 206
 207   Expected<std::unique_ptr<ObjectFile>> ObjOrErr =
 208       createObjectFile(Buffer->getMemBufferRef());
 209   if (Error Err = ObjOrErr.takeError())
 210     return std::move(Err);
 211   std::unique_ptr<ObjectFile> Obj = std::move(ObjOrErr.get());
 212
 213   return OwningBinary<ObjectFile>(std::move(Obj), std::move(Buffer));
 214 }
 215
 216 bool ObjectFile::isReflectionSectionStrippable(
 217     llvm::binaryformat::Swift5ReflectionSectionKind ReflectionSectionKind)
 218     const {
 219   using llvm::binaryformat::Swift5ReflectionSectionKind;
 220   return ReflectionSectionKind == Swift5ReflectionSectionKind::fieldmd ||
 221          ReflectionSectionKind == Swift5ReflectionSectionKind::reflstr ||
 222          ReflectionSectionKind == Swift5ReflectionSectionKind::assocty;
 223 }