xref: /llvm-project/llvm/lib/Object/ObjectFile.cpp (revision d341c93268010ff79786d9299cd6a25b0974cfe2)
1 //===- ObjectFile.cpp - File format independent object file ---------------===//
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/ADT/StringRef.h"
15 #include "llvm/Object/Binary.h"
16 #include "llvm/Object/COFF.h"
17 #include "llvm/Object/Error.h"
18 #include "llvm/Object/MachO.h"
19 #include "llvm/Object/ObjectFile.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 
32 using namespace llvm;
33 using namespace object;
34 
35 void ObjectFile::anchor() {}
36 
37 ObjectFile::ObjectFile(unsigned int Type, MemoryBufferRef Source)
38     : SymbolicFile(Type, Source) {}
39 
40 bool SectionRef::containsSymbol(SymbolRef S) const {
41   Expected<section_iterator> SymSec = S.getSection();
42   if (!SymSec) {
43     // TODO: Actually report errors helpfully.
44     consumeError(SymSec.takeError());
45     return false;
46   }
47   return *this == **SymSec;
48 }
49 
50 uint64_t ObjectFile::getSymbolValue(DataRefImpl Ref) const {
51   uint32_t Flags = getSymbolFlags(Ref);
52   if (Flags & SymbolRef::SF_Undefined)
53     return 0;
54   if (Flags & SymbolRef::SF_Common)
55     return getCommonSymbolSize(Ref);
56   return getSymbolValueImpl(Ref);
57 }
58 
59 std::error_code ObjectFile::printSymbolName(raw_ostream &OS,
60                                             DataRefImpl Symb) const {
61   Expected<StringRef> Name = getSymbolName(Symb);
62   if (!Name)
63     return errorToErrorCode(Name.takeError());
64   OS << *Name;
65   return std::error_code();
66 }
67 
68 uint32_t ObjectFile::getSymbolAlignment(DataRefImpl DRI) const { return 0; }
69 
70 bool ObjectFile::isSectionBitcode(DataRefImpl Sec) const {
71   StringRef SectName;
72   if (!getSectionName(Sec, SectName))
73     return SectName == ".llvmbc";
74   return false;
75 }
76 
77 section_iterator ObjectFile::getRelocatedSection(DataRefImpl Sec) const {
78   return section_iterator(SectionRef(Sec, this));
79 }
80 
81 Expected<std::unique_ptr<ObjectFile>>
82 ObjectFile::createObjectFile(MemoryBufferRef Object, sys::fs::file_magic Type) {
83   StringRef Data = Object.getBuffer();
84   if (Type == sys::fs::file_magic::unknown)
85     Type = sys::fs::identify_magic(Data);
86 
87   switch (Type) {
88   case sys::fs::file_magic::unknown:
89   case sys::fs::file_magic::bitcode:
90   case sys::fs::file_magic::coff_cl_gl_object:
91   case sys::fs::file_magic::archive:
92   case sys::fs::file_magic::macho_universal_binary:
93   case sys::fs::file_magic::windows_resource:
94     return errorCodeToError(object_error::invalid_file_type);
95   case sys::fs::file_magic::elf:
96   case sys::fs::file_magic::elf_relocatable:
97   case sys::fs::file_magic::elf_executable:
98   case sys::fs::file_magic::elf_shared_object:
99   case sys::fs::file_magic::elf_core:
100     return errorOrToExpected(createELFObjectFile(Object));
101   case sys::fs::file_magic::macho_object:
102   case sys::fs::file_magic::macho_executable:
103   case sys::fs::file_magic::macho_fixed_virtual_memory_shared_lib:
104   case sys::fs::file_magic::macho_core:
105   case sys::fs::file_magic::macho_preload_executable:
106   case sys::fs::file_magic::macho_dynamically_linked_shared_lib:
107   case sys::fs::file_magic::macho_dynamic_linker:
108   case sys::fs::file_magic::macho_bundle:
109   case sys::fs::file_magic::macho_dynamically_linked_shared_lib_stub:
110   case sys::fs::file_magic::macho_dsym_companion:
111   case sys::fs::file_magic::macho_kext_bundle:
112     return createMachOObjectFile(Object);
113   case sys::fs::file_magic::coff_object:
114   case sys::fs::file_magic::coff_import_library:
115   case sys::fs::file_magic::pecoff_executable:
116     return errorOrToExpected(createCOFFObjectFile(Object));
117   case sys::fs::file_magic::wasm_object:
118     return createWasmObjectFile(Object);
119   }
120   llvm_unreachable("Unexpected Object File Type");
121 }
122 
123 Expected<OwningBinary<ObjectFile>>
124 ObjectFile::createObjectFile(StringRef ObjectPath) {
125   ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr =
126       MemoryBuffer::getFile(ObjectPath);
127   if (std::error_code EC = FileOrErr.getError())
128     return errorCodeToError(EC);
129   std::unique_ptr<MemoryBuffer> Buffer = std::move(FileOrErr.get());
130 
131   Expected<std::unique_ptr<ObjectFile>> ObjOrErr =
132       createObjectFile(Buffer->getMemBufferRef());
133   if (Error Err = ObjOrErr.takeError())
134     return std::move(Err);
135   std::unique_ptr<ObjectFile> Obj = std::move(ObjOrErr.get());
136 
137   return OwningBinary<ObjectFile>(std::move(Obj), std::move(Buffer));
138 }
139