1 //===- ObjectFile.h - 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 declares a file format independent ObjectFile class.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #ifndef LLVM_OBJECT_OBJECTFILE_H
15 #define LLVM_OBJECT_OBJECTFILE_H
16
17 #include "llvm/ADT/StringRef.h"
18 #include "llvm/Object/SymbolicFile.h"
19 #include "llvm/Support/DataTypes.h"
20 #include "llvm/Support/ErrorHandling.h"
21 #include "llvm/Support/FileSystem.h"
22 #include "llvm/Support/MemoryBuffer.h"
23 #include <cstring>
24 #include <vector>
25
26 namespace llvm {
27 namespace object {
28
29 class ObjectFile;
30 class COFFObjectFile;
31 class MachOObjectFile;
32
33 class SymbolRef;
34 class symbol_iterator;
35 class SectionRef;
36 typedef content_iterator<SectionRef> section_iterator;
37
38 /// This is a value type class that represents a single relocation in the list
39 /// of relocations in the object file.
40 class RelocationRef {
41 DataRefImpl RelocationPimpl;
42 const ObjectFile *OwningObject;
43
44 public:
RelocationRef()45 RelocationRef() : OwningObject(nullptr) { }
46
47 RelocationRef(DataRefImpl RelocationP, const ObjectFile *Owner);
48
49 bool operator==(const RelocationRef &Other) const;
50
51 void moveNext();
52
53 uint64_t getOffset() const;
54 symbol_iterator getSymbol() const;
55 uint64_t getType() const;
56
57 /// @brief Get a string that represents the type of this relocation.
58 ///
59 /// This is for display purposes only.
60 void getTypeName(SmallVectorImpl<char> &Result) const;
61
62 DataRefImpl getRawDataRefImpl() const;
63 const ObjectFile *getObject() const;
64 };
65 typedef content_iterator<RelocationRef> relocation_iterator;
66
67 /// This is a value type class that represents a single section in the list of
68 /// sections in the object file.
69 class SectionRef {
70 friend class SymbolRef;
71 DataRefImpl SectionPimpl;
72 const ObjectFile *OwningObject;
73
74 public:
SectionRef()75 SectionRef() : OwningObject(nullptr) { }
76
77 SectionRef(DataRefImpl SectionP, const ObjectFile *Owner);
78
79 bool operator==(const SectionRef &Other) const;
80 bool operator!=(const SectionRef &Other) const;
81 bool operator<(const SectionRef &Other) const;
82
83 void moveNext();
84
85 std::error_code getName(StringRef &Result) const;
86 uint64_t getAddress() const;
87 uint64_t getSize() const;
88 std::error_code getContents(StringRef &Result) const;
89
90 /// @brief Get the alignment of this section as the actual value (not log 2).
91 uint64_t getAlignment() const;
92
93 bool isText() const;
94 bool isData() const;
95 bool isBSS() const;
96 bool isVirtual() const;
97
98 bool containsSymbol(SymbolRef S) const;
99
100 relocation_iterator relocation_begin() const;
101 relocation_iterator relocation_end() const;
relocations()102 iterator_range<relocation_iterator> relocations() const {
103 return iterator_range<relocation_iterator>(relocation_begin(),
104 relocation_end());
105 }
106 section_iterator getRelocatedSection() const;
107
108 DataRefImpl getRawDataRefImpl() const;
109 const ObjectFile *getObject() const;
110 };
111
112 /// This is a value type class that represents a single symbol in the list of
113 /// symbols in the object file.
114 class SymbolRef : public BasicSymbolRef {
115 friend class SectionRef;
116
117 public:
SymbolRef()118 SymbolRef() : BasicSymbolRef() {}
119
120 enum Type {
121 ST_Unknown, // Type not specified
122 ST_Data,
123 ST_Debug,
124 ST_File,
125 ST_Function,
126 ST_Other
127 };
128
129 SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner);
SymbolRef(const BasicSymbolRef & B)130 SymbolRef(const BasicSymbolRef &B) : BasicSymbolRef(B) {
131 assert(isa<ObjectFile>(BasicSymbolRef::getObject()));
132 }
133
134 ErrorOr<StringRef> getName() const;
135 /// Returns the symbol virtual address (i.e. address at which it will be
136 /// mapped).
137 ErrorOr<uint64_t> getAddress() const;
138
139 /// Return the value of the symbol depending on the object this can be an
140 /// offset or a virtual address.
141 uint64_t getValue() const;
142
143 /// @brief Get the alignment of this symbol as the actual value (not log 2).
144 uint32_t getAlignment() const;
145 uint64_t getCommonSize() const;
146 SymbolRef::Type getType() const;
147
148 /// @brief Get section this symbol is defined in reference to. Result is
149 /// end_sections() if it is undefined or is an absolute symbol.
150 std::error_code getSection(section_iterator &Result) const;
151
152 const ObjectFile *getObject() const;
153 };
154
155 class symbol_iterator : public basic_symbol_iterator {
156 public:
symbol_iterator(SymbolRef Sym)157 symbol_iterator(SymbolRef Sym) : basic_symbol_iterator(Sym) {}
symbol_iterator(const basic_symbol_iterator & B)158 symbol_iterator(const basic_symbol_iterator &B)
159 : basic_symbol_iterator(SymbolRef(B->getRawDataRefImpl(),
160 cast<ObjectFile>(B->getObject()))) {}
161
162 const SymbolRef *operator->() const {
163 const BasicSymbolRef &P = basic_symbol_iterator::operator *();
164 return static_cast<const SymbolRef*>(&P);
165 }
166
167 const SymbolRef &operator*() const {
168 const BasicSymbolRef &P = basic_symbol_iterator::operator *();
169 return static_cast<const SymbolRef&>(P);
170 }
171 };
172
173 /// This class is the base class for all object file types. Concrete instances
174 /// of this object are created by createObjectFile, which figures out which type
175 /// to create.
176 class ObjectFile : public SymbolicFile {
177 virtual void anchor();
178 ObjectFile() = delete;
179 ObjectFile(const ObjectFile &other) = delete;
180
181 protected:
182 ObjectFile(unsigned int Type, MemoryBufferRef Source);
183
base()184 const uint8_t *base() const {
185 return reinterpret_cast<const uint8_t *>(Data.getBufferStart());
186 }
187
188 // These functions are for SymbolRef to call internally. The main goal of
189 // this is to allow SymbolRef::SymbolPimpl to point directly to the symbol
190 // entry in the memory mapped object file. SymbolPimpl cannot contain any
191 // virtual functions because then it could not point into the memory mapped
192 // file.
193 //
194 // Implementations assume that the DataRefImpl is valid and has not been
195 // modified externally. It's UB otherwise.
196 friend class SymbolRef;
197 virtual ErrorOr<StringRef> getSymbolName(DataRefImpl Symb) const = 0;
198 std::error_code printSymbolName(raw_ostream &OS,
199 DataRefImpl Symb) const override;
200 virtual ErrorOr<uint64_t> getSymbolAddress(DataRefImpl Symb) const = 0;
201 virtual uint64_t getSymbolValueImpl(DataRefImpl Symb) const = 0;
202 virtual uint32_t getSymbolAlignment(DataRefImpl Symb) const;
203 virtual uint64_t getCommonSymbolSizeImpl(DataRefImpl Symb) const = 0;
204 virtual SymbolRef::Type getSymbolType(DataRefImpl Symb) const = 0;
205 virtual std::error_code getSymbolSection(DataRefImpl Symb,
206 section_iterator &Res) const = 0;
207
208 // Same as above for SectionRef.
209 friend class SectionRef;
210 virtual void moveSectionNext(DataRefImpl &Sec) const = 0;
211 virtual std::error_code getSectionName(DataRefImpl Sec,
212 StringRef &Res) const = 0;
213 virtual uint64_t getSectionAddress(DataRefImpl Sec) const = 0;
214 virtual uint64_t getSectionSize(DataRefImpl Sec) const = 0;
215 virtual std::error_code getSectionContents(DataRefImpl Sec,
216 StringRef &Res) const = 0;
217 virtual uint64_t getSectionAlignment(DataRefImpl Sec) const = 0;
218 virtual bool isSectionText(DataRefImpl Sec) const = 0;
219 virtual bool isSectionData(DataRefImpl Sec) const = 0;
220 virtual bool isSectionBSS(DataRefImpl Sec) const = 0;
221 // A section is 'virtual' if its contents aren't present in the object image.
222 virtual bool isSectionVirtual(DataRefImpl Sec) const = 0;
223 virtual relocation_iterator section_rel_begin(DataRefImpl Sec) const = 0;
224 virtual relocation_iterator section_rel_end(DataRefImpl Sec) const = 0;
225 virtual section_iterator getRelocatedSection(DataRefImpl Sec) const;
226
227 // Same as above for RelocationRef.
228 friend class RelocationRef;
229 virtual void moveRelocationNext(DataRefImpl &Rel) const = 0;
230 virtual uint64_t getRelocationOffset(DataRefImpl Rel) const = 0;
231 virtual symbol_iterator getRelocationSymbol(DataRefImpl Rel) const = 0;
232 virtual uint64_t getRelocationType(DataRefImpl Rel) const = 0;
233 virtual void getRelocationTypeName(DataRefImpl Rel,
234 SmallVectorImpl<char> &Result) const = 0;
235
236 uint64_t getSymbolValue(DataRefImpl Symb) const;
237
238 public:
getCommonSymbolSize(DataRefImpl Symb)239 uint64_t getCommonSymbolSize(DataRefImpl Symb) const {
240 assert(getSymbolFlags(Symb) & SymbolRef::SF_Common);
241 return getCommonSymbolSizeImpl(Symb);
242 }
243
244 typedef iterator_range<symbol_iterator> symbol_iterator_range;
symbols()245 symbol_iterator_range symbols() const {
246 return symbol_iterator_range(symbol_begin(), symbol_end());
247 }
248
249 virtual section_iterator section_begin() const = 0;
250 virtual section_iterator section_end() const = 0;
251
252 typedef iterator_range<section_iterator> section_iterator_range;
sections()253 section_iterator_range sections() const {
254 return section_iterator_range(section_begin(), section_end());
255 }
256
257 /// @brief The number of bytes used to represent an address in this object
258 /// file format.
259 virtual uint8_t getBytesInAddress() const = 0;
260
261 virtual StringRef getFileFormatName() const = 0;
262 virtual /* Triple::ArchType */ unsigned getArch() const = 0;
263
264 /// Returns platform-specific object flags, if any.
getPlatformFlags(unsigned & Result)265 virtual std::error_code getPlatformFlags(unsigned &Result) const {
266 Result = 0;
267 return object_error::invalid_file_type;
268 }
269
270 /// True if this is a relocatable object (.o/.obj).
271 virtual bool isRelocatableObject() const = 0;
272
273 /// @returns Pointer to ObjectFile subclass to handle this type of object.
274 /// @param ObjectPath The path to the object file. ObjectPath.isObject must
275 /// return true.
276 /// @brief Create ObjectFile from path.
277 static ErrorOr<OwningBinary<ObjectFile>>
278 createObjectFile(StringRef ObjectPath);
279
280 static ErrorOr<std::unique_ptr<ObjectFile>>
281 createObjectFile(MemoryBufferRef Object, sys::fs::file_magic Type);
282 static ErrorOr<std::unique_ptr<ObjectFile>>
createObjectFile(MemoryBufferRef Object)283 createObjectFile(MemoryBufferRef Object) {
284 return createObjectFile(Object, sys::fs::file_magic::unknown);
285 }
286
287
classof(const Binary * v)288 static inline bool classof(const Binary *v) {
289 return v->isObject();
290 }
291
292 static ErrorOr<std::unique_ptr<COFFObjectFile>>
293 createCOFFObjectFile(MemoryBufferRef Object);
294
295 static ErrorOr<std::unique_ptr<ObjectFile>>
296 createELFObjectFile(MemoryBufferRef Object);
297
298 static ErrorOr<std::unique_ptr<MachOObjectFile>>
299 createMachOObjectFile(MemoryBufferRef Object);
300 };
301
302 // Inline function definitions.
SymbolRef(DataRefImpl SymbolP,const ObjectFile * Owner)303 inline SymbolRef::SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner)
304 : BasicSymbolRef(SymbolP, Owner) {}
305
getName()306 inline ErrorOr<StringRef> SymbolRef::getName() const {
307 return getObject()->getSymbolName(getRawDataRefImpl());
308 }
309
getAddress()310 inline ErrorOr<uint64_t> SymbolRef::getAddress() const {
311 return getObject()->getSymbolAddress(getRawDataRefImpl());
312 }
313
getValue()314 inline uint64_t SymbolRef::getValue() const {
315 return getObject()->getSymbolValue(getRawDataRefImpl());
316 }
317
getAlignment()318 inline uint32_t SymbolRef::getAlignment() const {
319 return getObject()->getSymbolAlignment(getRawDataRefImpl());
320 }
321
getCommonSize()322 inline uint64_t SymbolRef::getCommonSize() const {
323 return getObject()->getCommonSymbolSize(getRawDataRefImpl());
324 }
325
getSection(section_iterator & Result)326 inline std::error_code SymbolRef::getSection(section_iterator &Result) const {
327 return getObject()->getSymbolSection(getRawDataRefImpl(), Result);
328 }
329
getType()330 inline SymbolRef::Type SymbolRef::getType() const {
331 return getObject()->getSymbolType(getRawDataRefImpl());
332 }
333
getObject()334 inline const ObjectFile *SymbolRef::getObject() const {
335 const SymbolicFile *O = BasicSymbolRef::getObject();
336 return cast<ObjectFile>(O);
337 }
338
339
340 /// SectionRef
SectionRef(DataRefImpl SectionP,const ObjectFile * Owner)341 inline SectionRef::SectionRef(DataRefImpl SectionP,
342 const ObjectFile *Owner)
343 : SectionPimpl(SectionP)
344 , OwningObject(Owner) {}
345
346 inline bool SectionRef::operator==(const SectionRef &Other) const {
347 return SectionPimpl == Other.SectionPimpl;
348 }
349
350 inline bool SectionRef::operator!=(const SectionRef &Other) const {
351 return SectionPimpl != Other.SectionPimpl;
352 }
353
354 inline bool SectionRef::operator<(const SectionRef &Other) const {
355 return SectionPimpl < Other.SectionPimpl;
356 }
357
moveNext()358 inline void SectionRef::moveNext() {
359 return OwningObject->moveSectionNext(SectionPimpl);
360 }
361
getName(StringRef & Result)362 inline std::error_code SectionRef::getName(StringRef &Result) const {
363 return OwningObject->getSectionName(SectionPimpl, Result);
364 }
365
getAddress()366 inline uint64_t SectionRef::getAddress() const {
367 return OwningObject->getSectionAddress(SectionPimpl);
368 }
369
getSize()370 inline uint64_t SectionRef::getSize() const {
371 return OwningObject->getSectionSize(SectionPimpl);
372 }
373
getContents(StringRef & Result)374 inline std::error_code SectionRef::getContents(StringRef &Result) const {
375 return OwningObject->getSectionContents(SectionPimpl, Result);
376 }
377
getAlignment()378 inline uint64_t SectionRef::getAlignment() const {
379 return OwningObject->getSectionAlignment(SectionPimpl);
380 }
381
isText()382 inline bool SectionRef::isText() const {
383 return OwningObject->isSectionText(SectionPimpl);
384 }
385
isData()386 inline bool SectionRef::isData() const {
387 return OwningObject->isSectionData(SectionPimpl);
388 }
389
isBSS()390 inline bool SectionRef::isBSS() const {
391 return OwningObject->isSectionBSS(SectionPimpl);
392 }
393
isVirtual()394 inline bool SectionRef::isVirtual() const {
395 return OwningObject->isSectionVirtual(SectionPimpl);
396 }
397
relocation_begin()398 inline relocation_iterator SectionRef::relocation_begin() const {
399 return OwningObject->section_rel_begin(SectionPimpl);
400 }
401
relocation_end()402 inline relocation_iterator SectionRef::relocation_end() const {
403 return OwningObject->section_rel_end(SectionPimpl);
404 }
405
getRelocatedSection()406 inline section_iterator SectionRef::getRelocatedSection() const {
407 return OwningObject->getRelocatedSection(SectionPimpl);
408 }
409
getRawDataRefImpl()410 inline DataRefImpl SectionRef::getRawDataRefImpl() const {
411 return SectionPimpl;
412 }
413
getObject()414 inline const ObjectFile *SectionRef::getObject() const {
415 return OwningObject;
416 }
417
418 /// RelocationRef
RelocationRef(DataRefImpl RelocationP,const ObjectFile * Owner)419 inline RelocationRef::RelocationRef(DataRefImpl RelocationP,
420 const ObjectFile *Owner)
421 : RelocationPimpl(RelocationP)
422 , OwningObject(Owner) {}
423
424 inline bool RelocationRef::operator==(const RelocationRef &Other) const {
425 return RelocationPimpl == Other.RelocationPimpl;
426 }
427
moveNext()428 inline void RelocationRef::moveNext() {
429 return OwningObject->moveRelocationNext(RelocationPimpl);
430 }
431
getOffset()432 inline uint64_t RelocationRef::getOffset() const {
433 return OwningObject->getRelocationOffset(RelocationPimpl);
434 }
435
getSymbol()436 inline symbol_iterator RelocationRef::getSymbol() const {
437 return OwningObject->getRelocationSymbol(RelocationPimpl);
438 }
439
getType()440 inline uint64_t RelocationRef::getType() const {
441 return OwningObject->getRelocationType(RelocationPimpl);
442 }
443
getTypeName(SmallVectorImpl<char> & Result)444 inline void RelocationRef::getTypeName(SmallVectorImpl<char> &Result) const {
445 return OwningObject->getRelocationTypeName(RelocationPimpl, Result);
446 }
447
getRawDataRefImpl()448 inline DataRefImpl RelocationRef::getRawDataRefImpl() const {
449 return RelocationPimpl;
450 }
451
getObject()452 inline const ObjectFile *RelocationRef::getObject() const {
453 return OwningObject;
454 }
455
456
457 } // end namespace object
458 } // end namespace llvm
459
460 #endif
461