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 
anchor()26 void ObjectFile::anchor() { }
27 
ObjectFile(unsigned int Type,MemoryBufferRef Source)28 ObjectFile::ObjectFile(unsigned int Type, MemoryBufferRef Source)
29     : SymbolicFile(Type, Source) {}
30 
containsSymbol(SymbolRef S) const31 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 
getSymbolValue(DataRefImpl Ref) const38 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 
printSymbolName(raw_ostream & OS,DataRefImpl Symb) const47 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 
getSymbolAlignment(DataRefImpl DRI) const56 uint32_t ObjectFile::getSymbolAlignment(DataRefImpl DRI) const { return 0; }
57 
getRelocatedSection(DataRefImpl Sec) const58 section_iterator ObjectFile::getRelocatedSection(DataRefImpl Sec) const {
59   return section_iterator(SectionRef(Sec, this));
60 }
61 
62 ErrorOr<std::unique_ptr<ObjectFile>>
createObjectFile(MemoryBufferRef Object,sys::fs::file_magic Type)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>>
createObjectFile(StringRef ObjectPath)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