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      1 //===- ObjectFile.cpp - File format independent object file -----*- C++ -*-===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file defines a file format independent ObjectFile class.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #include "llvm/Object/COFF.h"
     15 #include "llvm/Object/MachO.h"
     16 #include "llvm/Object/ObjectFile.h"
     17 #include "llvm/Support/ErrorHandling.h"
     18 #include "llvm/Support/FileSystem.h"
     19 #include "llvm/Support/MemoryBuffer.h"
     20 #include "llvm/Support/raw_ostream.h"
     21 #include <system_error>
     22 
     23 using namespace llvm;
     24 using namespace object;
     25 
     26 void ObjectFile::anchor() { }
     27 
     28 ObjectFile::ObjectFile(unsigned int Type, MemoryBufferRef Source)
     29     : SymbolicFile(Type, Source) {}
     30 
     31 bool SectionRef::containsSymbol(SymbolRef S) const {
     32   ErrorOr<section_iterator> SymSec = S.getSection();
     33   if (!SymSec)
     34     return false;
     35   return *this == **SymSec;
     36 }
     37 
     38 uint64_t ObjectFile::getSymbolValue(DataRefImpl Ref) const {
     39   uint32_t Flags = getSymbolFlags(Ref);
     40   if (Flags & SymbolRef::SF_Undefined)
     41     return 0;
     42   if (Flags & SymbolRef::SF_Common)
     43     return getCommonSymbolSize(Ref);
     44   return getSymbolValueImpl(Ref);
     45 }
     46 
     47 std::error_code ObjectFile::printSymbolName(raw_ostream &OS,
     48                                             DataRefImpl Symb) const {
     49   ErrorOr<StringRef> Name = getSymbolName(Symb);
     50   if (std::error_code EC = Name.getError())
     51     return EC;
     52   OS << *Name;
     53   return std::error_code();
     54 }
     55 
     56 uint32_t ObjectFile::getSymbolAlignment(DataRefImpl DRI) const { return 0; }
     57 
     58 section_iterator ObjectFile::getRelocatedSection(DataRefImpl Sec) const {
     59   return section_iterator(SectionRef(Sec, this));
     60 }
     61 
     62 ErrorOr<std::unique_ptr<ObjectFile>>
     63 ObjectFile::createObjectFile(MemoryBufferRef Object, sys::fs::file_magic Type) {
     64   StringRef Data = Object.getBuffer();
     65   if (Type == sys::fs::file_magic::unknown)
     66     Type = sys::fs::identify_magic(Data);
     67 
     68   switch (Type) {
     69   case sys::fs::file_magic::unknown:
     70   case sys::fs::file_magic::bitcode:
     71   case sys::fs::file_magic::archive:
     72   case sys::fs::file_magic::macho_universal_binary:
     73   case sys::fs::file_magic::windows_resource:
     74     return object_error::invalid_file_type;
     75   case sys::fs::file_magic::elf:
     76   case sys::fs::file_magic::elf_relocatable:
     77   case sys::fs::file_magic::elf_executable:
     78   case sys::fs::file_magic::elf_shared_object:
     79   case sys::fs::file_magic::elf_core:
     80     return createELFObjectFile(Object);
     81   case sys::fs::file_magic::macho_object:
     82   case sys::fs::file_magic::macho_executable:
     83   case sys::fs::file_magic::macho_fixed_virtual_memory_shared_lib:
     84   case sys::fs::file_magic::macho_core:
     85   case sys::fs::file_magic::macho_preload_executable:
     86   case sys::fs::file_magic::macho_dynamically_linked_shared_lib:
     87   case sys::fs::file_magic::macho_dynamic_linker:
     88   case sys::fs::file_magic::macho_bundle:
     89   case sys::fs::file_magic::macho_dynamically_linked_shared_lib_stub:
     90   case sys::fs::file_magic::macho_dsym_companion:
     91   case sys::fs::file_magic::macho_kext_bundle:
     92     return createMachOObjectFile(Object);
     93   case sys::fs::file_magic::coff_object:
     94   case sys::fs::file_magic::coff_import_library:
     95   case sys::fs::file_magic::pecoff_executable:
     96     return createCOFFObjectFile(Object);
     97   }
     98   llvm_unreachable("Unexpected Object File Type");
     99 }
    100 
    101 ErrorOr<OwningBinary<ObjectFile>>
    102 ObjectFile::createObjectFile(StringRef ObjectPath) {
    103   ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr =
    104       MemoryBuffer::getFile(ObjectPath);
    105   if (std::error_code EC = FileOrErr.getError())
    106     return EC;
    107   std::unique_ptr<MemoryBuffer> Buffer = std::move(FileOrErr.get());
    108 
    109   ErrorOr<std::unique_ptr<ObjectFile>> ObjOrErr =
    110       createObjectFile(Buffer->getMemBufferRef());
    111   if (std::error_code EC = ObjOrErr.getError())
    112     return EC;
    113   std::unique_ptr<ObjectFile> Obj = std::move(ObjOrErr.get());
    114 
    115   return OwningBinary<ObjectFile>(std::move(Obj), std::move(Buffer));
    116 }
    117