ObjectFile.h revision 81a96aa6242f7b559770f5dc62316253cb8cb0d4
1//===-- ObjectFile.h --------------------------------------------*- 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#ifndef liblldb_ObjectFile_h_ 11#define liblldb_ObjectFile_h_ 12 13#include "lldb/lldb-private.h" 14#include "lldb/Core/DataExtractor.h" 15#include "lldb/Host/FileSpec.h" 16#include "lldb/Core/ModuleChild.h" 17#include "lldb/Core/PluginInterface.h" 18#include "lldb/Host/Endian.h" 19#include "lldb/Symbol/Symtab.h" 20#include "lldb/Symbol/UnwindTable.h" 21 22namespace lldb_private { 23 24//---------------------------------------------------------------------- 25/// @class ObjectFile ObjectFile.h "lldb/Symbol/ObjectFile.h" 26/// @brief A plug-in interface definition class for object file parsers. 27/// 28/// Object files belong to Module objects and know how to extract 29/// information from executable, shared library, and object (.o) files 30/// used by operating system runtime. The symbol table and section list 31/// for an object file. 32/// 33/// Object files can be represented by the entire file, or by part of a 34/// file. Examples of object files that are part of a file include 35/// object files that contain information for multiple architectures in 36/// the same file, or archive files that contain multiple objects 37/// (ranlib archives) (possibly for multiple architectures as well). 38/// 39/// Object archive files (e.g. ranlib archives) can contain 40/// multiple .o (object) files that must be selected by index or by name. 41/// The number of objects that an ObjectFile contains can be determined 42/// using the ObjectFile::GetNumObjects() const 43/// function, and followed by a call to 44/// ObjectFile::SelectObjectAtIndex (uint32_t) to change the currently 45/// selected object. Objects can also be selected by name using the 46/// ObjectFile::SelectObject(const char *) function. 47/// 48/// Once an architecture is selected (and an object is selected for 49/// for archives), the object file information can be extracted from 50/// this abstract class. 51//---------------------------------------------------------------------- 52class ObjectFile: 53 public STD_ENABLE_SHARED_FROM_THIS(ObjectFile), 54 public PluginInterface, 55 public ModuleChild 56{ 57friend class lldb_private::Module; 58 59public: 60 typedef enum 61 { 62 eTypeInvalid = 0, 63 eTypeCoreFile, /// A core file that has a checkpoint of a program's execution state 64 eTypeExecutable, /// A normal executable 65 eTypeDebugInfo, /// An object file that contains only debug information 66 eTypeDynamicLinker, /// The platform's dynamic linker executable 67 eTypeObjectFile, /// An intermediate object file 68 eTypeSharedLibrary, /// A shared library that can be used during execution 69 eTypeStubLibrary, /// A library that can be linked against but not used for execution 70 eTypeUnknown 71 } Type; 72 73 typedef enum 74 { 75 eStrataInvalid = 0, 76 eStrataUnknown, 77 eStrataUser, 78 eStrataKernel, 79 eStrataRawImage 80 } Strata; 81 82 //------------------------------------------------------------------ 83 /// Construct with a parent module, offset, and header data. 84 /// 85 /// Object files belong to modules and a valid module must be 86 /// supplied upon construction. The at an offset within a file for 87 /// objects that contain more than one architecture or object. 88 //------------------------------------------------------------------ 89 ObjectFile (const lldb::ModuleSP &module_sp, 90 const FileSpec *file_spec_ptr, 91 lldb::offset_t file_offset, 92 lldb::offset_t length, 93 lldb::DataBufferSP& data_sp, 94 lldb::offset_t data_offset); 95 96 ObjectFile (const lldb::ModuleSP &module_sp, 97 const lldb::ProcessSP &process_sp, 98 lldb::addr_t header_addr, 99 lldb::DataBufferSP& data_sp); 100 101 //------------------------------------------------------------------ 102 /// Destructor. 103 /// 104 /// The destructor is virtual since this class is designed to be 105 /// inherited from by the plug-in instance. 106 //------------------------------------------------------------------ 107 virtual 108 ~ObjectFile(); 109 110 //------------------------------------------------------------------ 111 /// Dump a description of this object to a Stream. 112 /// 113 /// Dump a description of the current contents of this object 114 /// to the supplied stream \a s. The dumping should include the 115 /// section list if it has been parsed, and the symbol table 116 /// if it has been parsed. 117 /// 118 /// @param[in] s 119 /// The stream to which to dump the object descripton. 120 //------------------------------------------------------------------ 121 virtual void 122 Dump (Stream *s) = 0; 123 124 //------------------------------------------------------------------ 125 /// Find a ObjectFile plug-in that can parse \a file_spec. 126 /// 127 /// Scans all loaded plug-in interfaces that implement versions of 128 /// the ObjectFile plug-in interface and returns the first 129 /// instance that can parse the file. 130 /// 131 /// @param[in] module 132 /// The parent module that owns this object file. 133 /// 134 /// @param[in] file_spec 135 /// A file specification that indicates which file to use as the 136 /// object file. 137 /// 138 /// @param[in] file_offset 139 /// The offset into the file at which to start parsing the 140 /// object. This is for files that contain multiple 141 /// architectures or objects. 142 /// 143 /// @param[in] file_size 144 /// The size of the current object file if it can be determined 145 /// or if it is known. This can be zero. 146 /// 147 /// @see ObjectFile::ParseHeader() 148 //------------------------------------------------------------------ 149 static lldb::ObjectFileSP 150 FindPlugin (const lldb::ModuleSP &module_sp, 151 const FileSpec* file_spec, 152 lldb::offset_t file_offset, 153 lldb::offset_t file_size, 154 lldb::DataBufferSP &data_sp, 155 lldb::offset_t &data_offset); 156 157 //------------------------------------------------------------------ 158 /// Find a ObjectFile plug-in that can parse a file in memory. 159 /// 160 /// Scans all loaded plug-in interfaces that implement versions of 161 /// the ObjectFile plug-in interface and returns the first 162 /// instance that can parse the file. 163 /// 164 /// @param[in] module 165 /// The parent module that owns this object file. 166 /// 167 /// @param[in] process_sp 168 /// A shared pointer to the process whose memory space contains 169 /// an object file. This will be stored as a std::weak_ptr. 170 /// 171 /// @param[in] header_addr 172 /// The address of the header for the object file in memory. 173 //------------------------------------------------------------------ 174 static lldb::ObjectFileSP 175 FindPlugin (const lldb::ModuleSP &module_sp, 176 const lldb::ProcessSP &process_sp, 177 lldb::addr_t header_addr, 178 lldb::DataBufferSP &file_data_sp); 179 180 181 //------------------------------------------------------------------ 182 /// Split a path into a file path with object name. 183 /// 184 /// For paths like "/tmp/foo.a(bar.o)" we often need to split a path 185 /// up into the actual path name and into the object name so we can 186 /// make a valid object file from it. 187 /// 188 /// @param[in] path_with_object 189 /// A path that might contain an archive path with a .o file 190 /// specified in parens in the basename of the path. 191 /// 192 /// @param[out] archive_file 193 /// If \b true is returned, \a file_spec will be filled in with 194 /// the path to the archive. 195 /// 196 /// @param[out] archive_object 197 /// If \b true is returned, \a object will be filled in with 198 /// the name of the object inside the archive. 199 /// 200 /// @return 201 /// \b true if the path matches the pattern of archive + object 202 /// and \a archive_file and \a archive_object are modified, 203 /// \b false otherwise and \a archive_file and \a archive_object 204 /// are guaranteed to be remain unchanged. 205 //------------------------------------------------------------------ 206 static bool 207 SplitArchivePathWithObject (const char *path_with_object, 208 lldb_private::FileSpec &archive_file, 209 lldb_private::ConstString &archive_object, 210 bool must_exist); 211 212 //------------------------------------------------------------------ 213 /// Gets the address size in bytes for the current object file. 214 /// 215 /// @return 216 /// The size of an address in bytes for the currently selected 217 /// architecture (and object for archives). Returns zero if no 218 /// architecture or object has been selected. 219 //------------------------------------------------------------------ 220 virtual uint32_t 221 GetAddressByteSize () const = 0; 222 223 //------------------------------------------------------------------ 224 /// Get the address type given a file address in an object file. 225 /// 226 /// Many binary file formats know what kinds 227 /// This is primarily for ARM binaries, though it can be applied to 228 /// any executable file format that supports different opcode types 229 /// within the same binary. ARM binaries support having both ARM and 230 /// Thumb within the same executable container. We need to be able 231 /// to get 232 /// @return 233 /// The size of an address in bytes for the currently selected 234 /// architecture (and object for archives). Returns zero if no 235 /// architecture or object has been selected. 236 //------------------------------------------------------------------ 237 virtual lldb::AddressClass 238 GetAddressClass (lldb::addr_t file_addr); 239 240 //------------------------------------------------------------------ 241 /// Extract the dependent modules from an object file. 242 /// 243 /// If an object file has information about which other images it 244 /// depends on (such as shared libraries), this function will 245 /// provide the list. Since many executables or shared libraries 246 /// may depend on the same files, 247 /// FileSpecList::AppendIfUnique(const FileSpec &) should be 248 /// used to make sure any files that are added are not already in 249 /// the list. 250 /// 251 /// @param[out] file_list 252 /// A list of file specification objects that gets dependent 253 /// files appended to. 254 /// 255 /// @return 256 /// The number of new files that were appended to \a file_list. 257 /// 258 /// @see FileSpecList::AppendIfUnique(const FileSpec &) 259 //------------------------------------------------------------------ 260 virtual uint32_t 261 GetDependentModules (FileSpecList& file_list) = 0; 262 263 //------------------------------------------------------------------ 264 /// Tells whether this object file is capable of being the main executable 265 /// for a process. 266 /// 267 /// @return 268 /// \b true if it is, \b false otherwise. 269 //------------------------------------------------------------------ 270 virtual bool 271 IsExecutable () const = 0; 272 273 //------------------------------------------------------------------ 274 /// Returns the offset into a file at which this object resides. 275 /// 276 /// Some files contain many object files, and this function allows 277 /// access to an object's offset within the file. 278 /// 279 /// @return 280 /// The offset in bytes into the file. Defaults to zero for 281 /// simple object files that a represented by an entire file. 282 //------------------------------------------------------------------ 283 virtual lldb::addr_t 284 GetFileOffset () const 285 { return m_file_offset; } 286 287 virtual lldb::addr_t 288 GetByteSize () const 289 { return m_length; } 290 291 //------------------------------------------------------------------ 292 /// Get accessor to the object file specification. 293 /// 294 /// @return 295 /// The file specification object pointer if there is one, or 296 /// NULL if this object is only from memory. 297 //------------------------------------------------------------------ 298 virtual FileSpec& 299 GetFileSpec() { return m_file; } 300 301 //------------------------------------------------------------------ 302 /// Get const accessor to the object file specification. 303 /// 304 /// @return 305 /// The const file specification object pointer if there is one, 306 /// or NULL if this object is only from memory. 307 //------------------------------------------------------------------ 308 virtual const FileSpec& 309 GetFileSpec() const { return m_file; } 310 311 //------------------------------------------------------------------ 312 /// Get the name of the cpu, vendor and OS for this object file. 313 /// 314 /// This value is a string that represents the target triple where 315 /// the cpu type, the vendor and the OS are encoded into a string. 316 /// 317 /// @param[out] target_triple 318 /// The string value of the target triple. 319 /// 320 /// @return 321 /// \b True if the target triple was able to be computed, \b 322 /// false otherwise. 323 //------------------------------------------------------------------ 324 virtual bool 325 GetArchitecture (ArchSpec &arch) = 0; 326 327 //------------------------------------------------------------------ 328 /// Gets the section list for the currently selected architecture 329 /// (and object for archives). 330 /// 331 /// Section list parsing can be deferred by ObjectFile instances 332 /// until this accessor is called the first time. 333 /// 334 /// @return 335 /// The list of sections contained in this object file. 336 //------------------------------------------------------------------ 337 virtual SectionList * 338 GetSectionList () = 0; 339 340 //------------------------------------------------------------------ 341 /// Gets the symbol table for the currently selected architecture 342 /// (and object for archives). 343 /// 344 /// Symbol table parsing can be deferred by ObjectFile instances 345 /// until this accessor is called the first time. 346 /// 347 /// @return 348 /// The symbol table for this object file. 349 //------------------------------------------------------------------ 350 virtual Symtab * 351 GetSymtab () = 0; 352 353 //------------------------------------------------------------------ 354 /// Frees the symbol table. 355 /// 356 /// This function should only be used when an object file is 357 /// 358 /// @return 359 /// The symbol table for this object file. 360 //------------------------------------------------------------------ 361 virtual void 362 ClearSymtab (); 363 364 //------------------------------------------------------------------ 365 /// Gets the UUID for this object file. 366 /// 367 /// If the object file format contains a UUID, the value should be 368 /// returned. Else ObjectFile instances should return the MD5 369 /// checksum of all of the bytes for the object file (or memory for 370 /// memory based object files). 371 /// 372 /// @return 373 /// Returns \b true if a UUID was successfully extracted into 374 /// \a uuid, \b false otherwise. 375 //------------------------------------------------------------------ 376 virtual bool 377 GetUUID (lldb_private::UUID* uuid) = 0; 378 379 //------------------------------------------------------------------ 380 /// Gets whether endian swapping should occur when extracting data 381 /// from this object file. 382 /// 383 /// @return 384 /// Returns \b true if endian swapping is needed, \b false 385 /// otherwise. 386 //------------------------------------------------------------------ 387 virtual lldb::ByteOrder 388 GetByteOrder () const = 0; 389 390 //------------------------------------------------------------------ 391 /// Attempts to parse the object header. 392 /// 393 /// This function is used as a test to see if a given plug-in 394 /// instance can parse the header data already contained in 395 /// ObjectFile::m_data. If an object file parser does not 396 /// recognize that magic bytes in a header, false should be returned 397 /// and the next plug-in can attempt to parse an object file. 398 /// 399 /// @return 400 /// Returns \b true if the header was parsed succesfully, \b 401 /// false otherwise. 402 //------------------------------------------------------------------ 403 virtual bool 404 ParseHeader () = 0; 405 406 //------------------------------------------------------------------ 407 /// Returns a reference to the UnwindTable for this ObjectFile 408 /// 409 /// The UnwindTable contains FuncUnwinders objects for any function in 410 /// this ObjectFile. If a FuncUnwinders object hasn't been created yet 411 /// (i.e. the function has yet to be unwound in a stack walk), it 412 /// will be created when requested. Specifically, we do not create 413 /// FuncUnwinders objects for functions until they are needed. 414 /// 415 /// @return 416 /// Returns the unwind table for this object file. 417 //------------------------------------------------------------------ 418 virtual lldb_private::UnwindTable& 419 GetUnwindTable () { return m_unwind_table; } 420 421 //------------------------------------------------------------------ 422 /// Similar to Process::GetImageInfoAddress(). 423 /// 424 /// Some platforms embed auxiliary structures useful to debuggers in the 425 /// address space of the inferior process. This method returns the address 426 /// of such a structure if the information can be resolved via entries in 427 /// the object file. ELF, for example, provides a means to hook into the 428 /// runtime linker so that a debugger may monitor the loading and unloading 429 /// of shared libraries. 430 /// 431 /// @return 432 /// The address of any auxiliary tables, or an invalid address if this 433 /// object file format does not support or contain such information. 434 virtual lldb_private::Address 435 GetImageInfoAddress () { return Address(); } 436 437 //------------------------------------------------------------------ 438 /// Returns the address of the Entry Point in this object file - if 439 /// the object file doesn't have an entry point (because it is not an 440 /// executable file) then an invalid address is returned. 441 /// 442 /// @return 443 /// Returns the entry address for this module. 444 //------------------------------------------------------------------ 445 virtual lldb_private::Address 446 GetEntryPointAddress () { return Address();} 447 448 //------------------------------------------------------------------ 449 /// Returns the address that represents the header of this object 450 /// file. 451 /// 452 /// The header address is defined as where the header for the object 453 /// file is that describes the content of the file. If the header 454 /// doesn't appear in a section that is defined in the object file, 455 /// an address with no section is returned that has the file offset 456 /// set in the m_file_offset member of the lldb_private::Address object. 457 /// 458 /// @return 459 /// Returns the entry address for this module. 460 //------------------------------------------------------------------ 461 virtual lldb_private::Address 462 GetHeaderAddress () { return Address(m_memory_addr);} 463 464 465 virtual uint32_t 466 GetNumThreadContexts () 467 { 468 return 0; 469 } 470 471 virtual lldb::RegisterContextSP 472 GetThreadContextAtIndex (uint32_t idx, lldb_private::Thread &thread) 473 { 474 return lldb::RegisterContextSP(); 475 } 476 //------------------------------------------------------------------ 477 /// The object file should be able to calculate its type by looking 478 /// at its file header and possibly the sections or other data in 479 /// the object file. The file type is used in the debugger to help 480 /// select the correct plug-ins for the job at hand, so this is 481 /// important to get right. If any eTypeXXX definitions do not match 482 /// up with the type of file you are loading, please feel free to 483 /// add a new enumeration value. 484 /// 485 /// @return 486 /// The calculated file type for the current object file. 487 //------------------------------------------------------------------ 488 virtual Type 489 CalculateType() = 0; 490 491 //------------------------------------------------------------------ 492 /// The object file should be able to calculate the strata of the 493 /// object file. 494 /// 495 /// Many object files for platforms might be for either user space 496 /// debugging or for kernel debugging. If your object file subclass 497 /// can figure this out, it will help with debugger plug-in selection 498 /// when it comes time to debug. 499 /// 500 /// @return 501 /// The calculated object file strata for the current object 502 /// file. 503 //------------------------------------------------------------------ 504 virtual Strata 505 CalculateStrata() = 0; 506 507 //------------------------------------------------------------------ 508 /// Get the object file version numbers. 509 /// 510 /// Many object files have a set of version numbers that describe 511 /// the version of the executable or shared library. Typically there 512 /// are major, minor and build, but there may be more. This function 513 /// will extract the versions from object files if they are available. 514 /// 515 /// If \a versions is NULL, or if \a num_versions is 0, the return 516 /// value will indicate how many version numbers are available in 517 /// this object file. Then a subsequent call can be made to this 518 /// function with a value of \a versions and \a num_versions that 519 /// has enough storage to store some or all version numbers. 520 /// 521 /// @param[out] versions 522 /// A pointer to an array of uint32_t types that is \a num_versions 523 /// long. If this value is NULL, the return value will indicate 524 /// how many version numbers are required for a subsequent call 525 /// to this function so that all versions can be retrieved. If 526 /// the value is non-NULL, then at most \a num_versions of the 527 /// existing versions numbers will be filled into \a versions. 528 /// If there is no version information available, \a versions 529 /// will be filled with \a num_versions UINT32_MAX values 530 /// and zero will be returned. 531 /// 532 /// @param[in] num_versions 533 /// The maximum number of entries to fill into \a versions. If 534 /// this value is zero, then the return value will indicate 535 /// how many version numbers there are in total so another call 536 /// to this function can be make with adequate storage in 537 /// \a versions to get all of the version numbers. If \a 538 /// num_versions is less than the actual number of version 539 /// numbers in this object file, only \a num_versions will be 540 /// filled into \a versions (if \a versions is non-NULL). 541 /// 542 /// @return 543 /// This function always returns the number of version numbers 544 /// that this object file has regardless of the number of 545 /// version numbers that were copied into \a versions. 546 //------------------------------------------------------------------ 547 virtual uint32_t 548 GetVersion (uint32_t *versions, uint32_t num_versions) 549 { 550 if (versions && num_versions) 551 { 552 for (uint32_t i=0; i<num_versions; ++i) 553 versions[i] = UINT32_MAX; 554 } 555 return 0; 556 } 557 558 //------------------------------------------------------------------ 559 // Member Functions 560 //------------------------------------------------------------------ 561 Type 562 GetType () 563 { 564 if (m_type == eTypeInvalid) 565 m_type = CalculateType(); 566 return m_type; 567 } 568 569 Strata 570 GetStrata () 571 { 572 if (m_strata == eStrataInvalid) 573 m_strata = CalculateStrata(); 574 return m_strata; 575 } 576 577 // When an object file is in memory, subclasses should try and lock 578 // the process weak pointer. If the process weak pointer produces a 579 // valid ProcessSP, then subclasses can call this function to read 580 // memory. 581 static lldb::DataBufferSP 582 ReadMemory (const lldb::ProcessSP &process_sp, 583 lldb::addr_t addr, 584 size_t byte_size); 585 586 size_t 587 GetData (off_t offset, size_t length, DataExtractor &data) const; 588 589 size_t 590 CopyData (off_t offset, size_t length, void *dst) const; 591 592 size_t 593 ReadSectionData (const Section *section, 594 off_t section_offset, 595 void *dst, 596 size_t dst_len) const; 597 size_t 598 ReadSectionData (const Section *section, 599 DataExtractor& section_data) const; 600 601 size_t 602 MemoryMapSectionData (const Section *section, 603 DataExtractor& section_data) const; 604 605 bool 606 IsInMemory () const 607 { 608 return m_memory_addr != LLDB_INVALID_ADDRESS; 609 } 610 611protected: 612 //------------------------------------------------------------------ 613 // Member variables. 614 //------------------------------------------------------------------ 615 FileSpec m_file; 616 Type m_type; 617 Strata m_strata; 618 lldb::addr_t m_file_offset; ///< The offset in bytes into the file, or the address in memory 619 lldb::addr_t m_length; ///< The length of this object file if it is known (can be zero if length is unknown or can't be determined). 620 DataExtractor m_data; ///< The data for this object file so things can be parsed lazily. 621 lldb_private::UnwindTable m_unwind_table; /// < Table of FuncUnwinders objects created for this ObjectFile's functions 622 lldb::ProcessWP m_process_wp; 623 const lldb::addr_t m_memory_addr; 624 STD_UNIQUE_PTR(lldb_private::SectionList) m_sections_ap; 625 STD_UNIQUE_PTR(lldb_private::Symtab) m_symtab_ap; 626 627 //------------------------------------------------------------------ 628 /// Sets the architecture for a module. At present the architecture 629 /// can only be set if it is invalid. It is not allowed to switch from 630 /// one concrete architecture to another. 631 /// 632 /// @param[in] new_arch 633 /// The architecture this module will be set to. 634 /// 635 /// @return 636 /// Returns \b true if the architecture was changed, \b 637 /// false otherwise. 638 //------------------------------------------------------------------ 639 bool SetModulesArchitecture (const ArchSpec &new_arch); 640 641private: 642 DISALLOW_COPY_AND_ASSIGN (ObjectFile); 643}; 644 645} // namespace lldb_private 646 647#endif // liblldb_ObjectFile_h_ 648 649