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/MC/SubtargetFeature.h"
19 #include "llvm/Object/SymbolicFile.h"
20 #include "llvm/Support/DataTypes.h"
21 #include "llvm/Support/ErrorHandling.h"
22 #include "llvm/Support/FileSystem.h"
23 #include "llvm/Support/MemoryBuffer.h"
24 #include <cstring>
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 isCompressed() const;
94 bool isText() const;
95 bool isData() const;
96 bool isBSS() const;
97 bool isVirtual() const;
98 bool isBitcode() const;
99
100 bool containsSymbol(SymbolRef S) const;
101
102 relocation_iterator relocation_begin() const;
103 relocation_iterator relocation_end() const;
relocations()104 iterator_range<relocation_iterator> relocations() const {
105 return make_range(relocation_begin(), relocation_end());
106 }
107 section_iterator getRelocatedSection() const;
108
109 DataRefImpl getRawDataRefImpl() const;
110 const ObjectFile *getObject() const;
111 };
112
113 /// This is a value type class that represents a single symbol in the list of
114 /// symbols in the object file.
115 class SymbolRef : public BasicSymbolRef {
116 friend class SectionRef;
117
118 public:
SymbolRef()119 SymbolRef() : BasicSymbolRef() {}
120
121 enum Type {
122 ST_Unknown, // Type not specified
123 ST_Data,
124 ST_Debug,
125 ST_File,
126 ST_Function,
127 ST_Other
128 };
129
130 SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner);
SymbolRef(const BasicSymbolRef & B)131 SymbolRef(const BasicSymbolRef &B) : BasicSymbolRef(B) {
132 assert(isa<ObjectFile>(BasicSymbolRef::getObject()));
133 }
134
135 Expected<StringRef> getName() const;
136 /// Returns the symbol virtual address (i.e. address at which it will be
137 /// mapped).
138 Expected<uint64_t> getAddress() const;
139
140 /// Return the value of the symbol depending on the object this can be an
141 /// offset or a virtual address.
142 uint64_t getValue() const;
143
144 /// @brief Get the alignment of this symbol as the actual value (not log 2).
145 uint32_t getAlignment() const;
146 uint64_t getCommonSize() const;
147 Expected<SymbolRef::Type> getType() const;
148
149 /// @brief Get section this symbol is defined in reference to. Result is
150 /// end_sections() if it is undefined or is an absolute symbol.
151 Expected<section_iterator> getSection() const;
152
153 const ObjectFile *getObject() const;
154 };
155
156 class symbol_iterator : public basic_symbol_iterator {
157 public:
symbol_iterator(SymbolRef Sym)158 symbol_iterator(SymbolRef Sym) : basic_symbol_iterator(Sym) {}
symbol_iterator(const basic_symbol_iterator & B)159 symbol_iterator(const basic_symbol_iterator &B)
160 : basic_symbol_iterator(SymbolRef(B->getRawDataRefImpl(),
161 cast<ObjectFile>(B->getObject()))) {}
162
163 const SymbolRef *operator->() const {
164 const BasicSymbolRef &P = basic_symbol_iterator::operator *();
165 return static_cast<const SymbolRef*>(&P);
166 }
167
168 const SymbolRef &operator*() const {
169 const BasicSymbolRef &P = basic_symbol_iterator::operator *();
170 return static_cast<const SymbolRef&>(P);
171 }
172 };
173
174 /// This class is the base class for all object file types. Concrete instances
175 /// of this object are created by createObjectFile, which figures out which type
176 /// to create.
177 class ObjectFile : public SymbolicFile {
178 virtual void anchor();
179 ObjectFile() = delete;
180 ObjectFile(const ObjectFile &other) = delete;
181
182 protected:
183 ObjectFile(unsigned int Type, MemoryBufferRef Source);
184
base()185 const uint8_t *base() const {
186 return reinterpret_cast<const uint8_t *>(Data.getBufferStart());
187 }
188
189 // These functions are for SymbolRef to call internally. The main goal of
190 // this is to allow SymbolRef::SymbolPimpl to point directly to the symbol
191 // entry in the memory mapped object file. SymbolPimpl cannot contain any
192 // virtual functions because then it could not point into the memory mapped
193 // file.
194 //
195 // Implementations assume that the DataRefImpl is valid and has not been
196 // modified externally. It's UB otherwise.
197 friend class SymbolRef;
198 virtual Expected<StringRef> getSymbolName(DataRefImpl Symb) const = 0;
199 std::error_code printSymbolName(raw_ostream &OS,
200 DataRefImpl Symb) const override;
201 virtual Expected<uint64_t> getSymbolAddress(DataRefImpl Symb) const = 0;
202 virtual uint64_t getSymbolValueImpl(DataRefImpl Symb) const = 0;
203 virtual uint32_t getSymbolAlignment(DataRefImpl Symb) const;
204 virtual uint64_t getCommonSymbolSizeImpl(DataRefImpl Symb) const = 0;
205 virtual Expected<SymbolRef::Type> getSymbolType(DataRefImpl Symb) const = 0;
206 virtual Expected<section_iterator>
207 getSymbolSection(DataRefImpl Symb) const = 0;
208
209 // Same as above for SectionRef.
210 friend class SectionRef;
211 virtual void moveSectionNext(DataRefImpl &Sec) const = 0;
212 virtual std::error_code getSectionName(DataRefImpl Sec,
213 StringRef &Res) const = 0;
214 virtual uint64_t getSectionAddress(DataRefImpl Sec) const = 0;
215 virtual uint64_t getSectionSize(DataRefImpl Sec) const = 0;
216 virtual std::error_code getSectionContents(DataRefImpl Sec,
217 StringRef &Res) const = 0;
218 virtual uint64_t getSectionAlignment(DataRefImpl Sec) const = 0;
219 virtual bool isSectionCompressed(DataRefImpl Sec) const = 0;
220 virtual bool isSectionText(DataRefImpl Sec) const = 0;
221 virtual bool isSectionData(DataRefImpl Sec) const = 0;
222 virtual bool isSectionBSS(DataRefImpl Sec) const = 0;
223 // A section is 'virtual' if its contents aren't present in the object image.
224 virtual bool isSectionVirtual(DataRefImpl Sec) const = 0;
225 virtual bool isSectionBitcode(DataRefImpl Sec) const;
226 virtual relocation_iterator section_rel_begin(DataRefImpl Sec) const = 0;
227 virtual relocation_iterator section_rel_end(DataRefImpl Sec) const = 0;
228 virtual section_iterator getRelocatedSection(DataRefImpl Sec) const;
229
230 // Same as above for RelocationRef.
231 friend class RelocationRef;
232 virtual void moveRelocationNext(DataRefImpl &Rel) const = 0;
233 virtual uint64_t getRelocationOffset(DataRefImpl Rel) const = 0;
234 virtual symbol_iterator getRelocationSymbol(DataRefImpl Rel) const = 0;
235 virtual uint64_t getRelocationType(DataRefImpl Rel) const = 0;
236 virtual void getRelocationTypeName(DataRefImpl Rel,
237 SmallVectorImpl<char> &Result) const = 0;
238
239 uint64_t getSymbolValue(DataRefImpl Symb) const;
240
241 public:
getCommonSymbolSize(DataRefImpl Symb)242 uint64_t getCommonSymbolSize(DataRefImpl Symb) const {
243 assert(getSymbolFlags(Symb) & SymbolRef::SF_Common);
244 return getCommonSymbolSizeImpl(Symb);
245 }
246
247 typedef iterator_range<symbol_iterator> symbol_iterator_range;
symbols()248 symbol_iterator_range symbols() const {
249 return symbol_iterator_range(symbol_begin(), symbol_end());
250 }
251
252 virtual section_iterator section_begin() const = 0;
253 virtual section_iterator section_end() const = 0;
254
255 typedef iterator_range<section_iterator> section_iterator_range;
sections()256 section_iterator_range sections() const {
257 return section_iterator_range(section_begin(), section_end());
258 }
259
260 /// @brief The number of bytes used to represent an address in this object
261 /// file format.
262 virtual uint8_t getBytesInAddress() const = 0;
263
264 virtual StringRef getFileFormatName() const = 0;
265 virtual /* Triple::ArchType */ unsigned getArch() const = 0;
266 virtual SubtargetFeatures getFeatures() const = 0;
267
268 /// Returns platform-specific object flags, if any.
getPlatformFlags(unsigned & Result)269 virtual std::error_code getPlatformFlags(unsigned &Result) const {
270 Result = 0;
271 return object_error::invalid_file_type;
272 }
273
274 /// True if this is a relocatable object (.o/.obj).
275 virtual bool isRelocatableObject() const = 0;
276
277 /// @returns Pointer to ObjectFile subclass to handle this type of object.
278 /// @param ObjectPath The path to the object file. ObjectPath.isObject must
279 /// return true.
280 /// @brief Create ObjectFile from path.
281 static Expected<OwningBinary<ObjectFile>>
282 createObjectFile(StringRef ObjectPath);
283
284 static Expected<std::unique_ptr<ObjectFile>>
285 createObjectFile(MemoryBufferRef Object, sys::fs::file_magic Type);
286 static Expected<std::unique_ptr<ObjectFile>>
createObjectFile(MemoryBufferRef Object)287 createObjectFile(MemoryBufferRef Object) {
288 return createObjectFile(Object, sys::fs::file_magic::unknown);
289 }
290
291
classof(const Binary * v)292 static inline bool classof(const Binary *v) {
293 return v->isObject();
294 }
295
296 static ErrorOr<std::unique_ptr<COFFObjectFile>>
297 createCOFFObjectFile(MemoryBufferRef Object);
298
299 static ErrorOr<std::unique_ptr<ObjectFile>>
300 createELFObjectFile(MemoryBufferRef Object);
301
302 static Expected<std::unique_ptr<MachOObjectFile>>
303 createMachOObjectFile(MemoryBufferRef Object);
304
305 };
306
307 // Inline function definitions.
SymbolRef(DataRefImpl SymbolP,const ObjectFile * Owner)308 inline SymbolRef::SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner)
309 : BasicSymbolRef(SymbolP, Owner) {}
310
getName()311 inline Expected<StringRef> SymbolRef::getName() const {
312 return getObject()->getSymbolName(getRawDataRefImpl());
313 }
314
getAddress()315 inline Expected<uint64_t> SymbolRef::getAddress() const {
316 return getObject()->getSymbolAddress(getRawDataRefImpl());
317 }
318
getValue()319 inline uint64_t SymbolRef::getValue() const {
320 return getObject()->getSymbolValue(getRawDataRefImpl());
321 }
322
getAlignment()323 inline uint32_t SymbolRef::getAlignment() const {
324 return getObject()->getSymbolAlignment(getRawDataRefImpl());
325 }
326
getCommonSize()327 inline uint64_t SymbolRef::getCommonSize() const {
328 return getObject()->getCommonSymbolSize(getRawDataRefImpl());
329 }
330
getSection()331 inline Expected<section_iterator> SymbolRef::getSection() const {
332 return getObject()->getSymbolSection(getRawDataRefImpl());
333 }
334
getType()335 inline Expected<SymbolRef::Type> SymbolRef::getType() const {
336 return getObject()->getSymbolType(getRawDataRefImpl());
337 }
338
getObject()339 inline const ObjectFile *SymbolRef::getObject() const {
340 const SymbolicFile *O = BasicSymbolRef::getObject();
341 return cast<ObjectFile>(O);
342 }
343
344
345 /// SectionRef
SectionRef(DataRefImpl SectionP,const ObjectFile * Owner)346 inline SectionRef::SectionRef(DataRefImpl SectionP,
347 const ObjectFile *Owner)
348 : SectionPimpl(SectionP)
349 , OwningObject(Owner) {}
350
351 inline bool SectionRef::operator==(const SectionRef &Other) const {
352 return SectionPimpl == Other.SectionPimpl;
353 }
354
355 inline bool SectionRef::operator!=(const SectionRef &Other) const {
356 return SectionPimpl != Other.SectionPimpl;
357 }
358
359 inline bool SectionRef::operator<(const SectionRef &Other) const {
360 return SectionPimpl < Other.SectionPimpl;
361 }
362
moveNext()363 inline void SectionRef::moveNext() {
364 return OwningObject->moveSectionNext(SectionPimpl);
365 }
366
getName(StringRef & Result)367 inline std::error_code SectionRef::getName(StringRef &Result) const {
368 return OwningObject->getSectionName(SectionPimpl, Result);
369 }
370
getAddress()371 inline uint64_t SectionRef::getAddress() const {
372 return OwningObject->getSectionAddress(SectionPimpl);
373 }
374
getSize()375 inline uint64_t SectionRef::getSize() const {
376 return OwningObject->getSectionSize(SectionPimpl);
377 }
378
getContents(StringRef & Result)379 inline std::error_code SectionRef::getContents(StringRef &Result) const {
380 return OwningObject->getSectionContents(SectionPimpl, Result);
381 }
382
getAlignment()383 inline uint64_t SectionRef::getAlignment() const {
384 return OwningObject->getSectionAlignment(SectionPimpl);
385 }
386
isCompressed()387 inline bool SectionRef::isCompressed() const {
388 return OwningObject->isSectionCompressed(SectionPimpl);
389 }
390
isText()391 inline bool SectionRef::isText() const {
392 return OwningObject->isSectionText(SectionPimpl);
393 }
394
isData()395 inline bool SectionRef::isData() const {
396 return OwningObject->isSectionData(SectionPimpl);
397 }
398
isBSS()399 inline bool SectionRef::isBSS() const {
400 return OwningObject->isSectionBSS(SectionPimpl);
401 }
402
isVirtual()403 inline bool SectionRef::isVirtual() const {
404 return OwningObject->isSectionVirtual(SectionPimpl);
405 }
406
isBitcode()407 inline bool SectionRef::isBitcode() const {
408 return OwningObject->isSectionBitcode(SectionPimpl);
409 }
410
relocation_begin()411 inline relocation_iterator SectionRef::relocation_begin() const {
412 return OwningObject->section_rel_begin(SectionPimpl);
413 }
414
relocation_end()415 inline relocation_iterator SectionRef::relocation_end() const {
416 return OwningObject->section_rel_end(SectionPimpl);
417 }
418
getRelocatedSection()419 inline section_iterator SectionRef::getRelocatedSection() const {
420 return OwningObject->getRelocatedSection(SectionPimpl);
421 }
422
getRawDataRefImpl()423 inline DataRefImpl SectionRef::getRawDataRefImpl() const {
424 return SectionPimpl;
425 }
426
getObject()427 inline const ObjectFile *SectionRef::getObject() const {
428 return OwningObject;
429 }
430
431 /// RelocationRef
RelocationRef(DataRefImpl RelocationP,const ObjectFile * Owner)432 inline RelocationRef::RelocationRef(DataRefImpl RelocationP,
433 const ObjectFile *Owner)
434 : RelocationPimpl(RelocationP)
435 , OwningObject(Owner) {}
436
437 inline bool RelocationRef::operator==(const RelocationRef &Other) const {
438 return RelocationPimpl == Other.RelocationPimpl;
439 }
440
moveNext()441 inline void RelocationRef::moveNext() {
442 return OwningObject->moveRelocationNext(RelocationPimpl);
443 }
444
getOffset()445 inline uint64_t RelocationRef::getOffset() const {
446 return OwningObject->getRelocationOffset(RelocationPimpl);
447 }
448
getSymbol()449 inline symbol_iterator RelocationRef::getSymbol() const {
450 return OwningObject->getRelocationSymbol(RelocationPimpl);
451 }
452
getType()453 inline uint64_t RelocationRef::getType() const {
454 return OwningObject->getRelocationType(RelocationPimpl);
455 }
456
getTypeName(SmallVectorImpl<char> & Result)457 inline void RelocationRef::getTypeName(SmallVectorImpl<char> &Result) const {
458 return OwningObject->getRelocationTypeName(RelocationPimpl, Result);
459 }
460
getRawDataRefImpl()461 inline DataRefImpl RelocationRef::getRawDataRefImpl() const {
462 return RelocationPimpl;
463 }
464
getObject()465 inline const ObjectFile *RelocationRef::getObject() const {
466 return OwningObject;
467 }
468
469
470 } // end namespace object
471 } // end namespace llvm
472
473 #endif
474