ObjectFile.h revision ac725afac61b48d1dc0e38370d824fe45c52c3b7
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::tr1::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 (Module* module, 90 const FileSpec *file_spec_ptr, 91 lldb::addr_t offset, 92 lldb::addr_t length, 93 lldb::DataBufferSP& headerDataSP); 94 95 ObjectFile (Module* module, 96 const lldb::ProcessSP &process_sp, 97 lldb::addr_t header_addr, 98 lldb::DataBufferSP& headerDataSP); 99 100 //------------------------------------------------------------------ 101 /// Destructor. 102 /// 103 /// The destructor is virtual since this class is designed to be 104 /// inherited from by the plug-in instance. 105 //------------------------------------------------------------------ 106 virtual 107 ~ObjectFile(); 108 109 //------------------------------------------------------------------ 110 /// Dump a description of this object to a Stream. 111 /// 112 /// Dump a description of the current contents of this object 113 /// to the supplied stream \a s. The dumping should include the 114 /// section list if it has been parsed, and the symbol table 115 /// if it has been parsed. 116 /// 117 /// @param[in] s 118 /// The stream to which to dump the object descripton. 119 //------------------------------------------------------------------ 120 virtual void 121 Dump (Stream *s) = 0; 122 123 //------------------------------------------------------------------ 124 /// Find a ObjectFile plug-in that can parse \a file_spec. 125 /// 126 /// Scans all loaded plug-in interfaces that implement versions of 127 /// the ObjectFile plug-in interface and returns the first 128 /// instance that can parse the file. 129 /// 130 /// @param[in] module 131 /// The parent module that owns this object file. 132 /// 133 /// @param[in] file_spec 134 /// A file specification that indicates which file to use as the 135 /// object file. 136 /// 137 /// @param[in] file_offset 138 /// The offset into the file at which to start parsing the 139 /// object. This is for files that contain multiple 140 /// architectures or objects. 141 /// 142 /// @param[in] file_size 143 /// The size of the current object file if it can be determined 144 /// or if it is known. This can be zero. 145 /// 146 /// @see ObjectFile::ParseHeader() 147 //------------------------------------------------------------------ 148 static lldb::ObjectFileSP 149 FindPlugin (Module* module, 150 const FileSpec* file_spec, 151 lldb::addr_t file_offset, 152 lldb::addr_t file_size, 153 lldb::DataBufferSP &data_sp); 154 155 //------------------------------------------------------------------ 156 /// Find a ObjectFile plug-in that can parse a file in memory. 157 /// 158 /// Scans all loaded plug-in interfaces that implement versions of 159 /// the ObjectFile plug-in interface and returns the first 160 /// instance that can parse the file. 161 /// 162 /// @param[in] module 163 /// The parent module that owns this object file. 164 /// 165 /// @param[in] process_sp 166 /// A shared pointer to the process whose memory space contains 167 /// an object file. This will be stored as a std::weak_ptr. 168 /// 169 /// @param[in] header_addr 170 /// The address of the header for the object file in memory. 171 //------------------------------------------------------------------ 172 static lldb::ObjectFileSP 173 FindPlugin (Module* module, 174 const lldb::ProcessSP &process_sp, 175 lldb::addr_t header_addr, 176 lldb::DataBufferSP &file_data_sp); 177 178 //------------------------------------------------------------------ 179 /// Gets the address size in bytes for the current object file. 180 /// 181 /// @return 182 /// The size of an address in bytes for the currently selected 183 /// architecture (and object for archives). Returns zero if no 184 /// architecture or object has been selected. 185 //------------------------------------------------------------------ 186 virtual size_t 187 GetAddressByteSize () const = 0; 188 189 //------------------------------------------------------------------ 190 /// Get the address type given a file address in an object file. 191 /// 192 /// Many binary file formats know what kinds 193 /// This is primarily for ARM binaries, though it can be applied to 194 /// any executable file format that supports different opcode types 195 /// within the same binary. ARM binaries support having both ARM and 196 /// Thumb within the same executable container. We need to be able 197 /// to get 198 /// @return 199 /// The size of an address in bytes for the currently selected 200 /// architecture (and object for archives). Returns zero if no 201 /// architecture or object has been selected. 202 //------------------------------------------------------------------ 203 virtual AddressClass 204 GetAddressClass (lldb::addr_t file_addr); 205 206 //------------------------------------------------------------------ 207 /// Extract the dependent modules from an object file. 208 /// 209 /// If an object file has information about which other images it 210 /// depends on (such as shared libraries), this function will 211 /// provide the list. Since many executables or shared libraries 212 /// may depend on the same files, 213 /// FileSpecList::AppendIfUnique(const FileSpec &) should be 214 /// used to make sure any files that are added are not already in 215 /// the list. 216 /// 217 /// @param[out] file_list 218 /// A list of file specification objects that gets dependent 219 /// files appended to. 220 /// 221 /// @return 222 /// The number of new files that were appended to \a file_list. 223 /// 224 /// @see FileSpecList::AppendIfUnique(const FileSpec &) 225 //------------------------------------------------------------------ 226 virtual uint32_t 227 GetDependentModules (FileSpecList& file_list) = 0; 228 229 //------------------------------------------------------------------ 230 /// Tells whether this object file is capable of being the main executable 231 /// for a process. 232 /// 233 /// @return 234 /// \b true if it is, \b false otherwise. 235 //------------------------------------------------------------------ 236 virtual bool 237 IsExecutable () const = 0; 238 239 //------------------------------------------------------------------ 240 /// Returns the offset into a file at which this object resides. 241 /// 242 /// Some files contain many object files, and this function allows 243 /// access to an object's offset within the file. 244 /// 245 /// @return 246 /// The offset in bytes into the file. Defaults to zero for 247 /// simple object files that a represented by an entire file. 248 //------------------------------------------------------------------ 249 virtual lldb::addr_t 250 GetOffset () const 251 { return m_offset; } 252 253 virtual lldb::addr_t 254 GetByteSize () const 255 { return m_length; } 256 257 //------------------------------------------------------------------ 258 /// Get accessor to the object file specification. 259 /// 260 /// @return 261 /// The file specification object pointer if there is one, or 262 /// NULL if this object is only from memory. 263 //------------------------------------------------------------------ 264 virtual FileSpec& 265 GetFileSpec() { return m_file; } 266 267 //------------------------------------------------------------------ 268 /// Get const accessor to the object file specification. 269 /// 270 /// @return 271 /// The const file specification object pointer if there is one, 272 /// or NULL if this object is only from memory. 273 //------------------------------------------------------------------ 274 virtual const FileSpec& 275 GetFileSpec() const { return m_file; } 276 277 //------------------------------------------------------------------ 278 /// Get the name of the cpu, vendor and OS for this object file. 279 /// 280 /// This value is a string that represents the target triple where 281 /// the cpu type, the vendor and the OS are encoded into a string. 282 /// 283 /// @param[out] target_triple 284 /// The string value of the target triple. 285 /// 286 /// @return 287 /// \b True if the target triple was able to be computed, \b 288 /// false otherwise. 289 //------------------------------------------------------------------ 290 virtual bool 291 GetArchitecture (ArchSpec &arch) = 0; 292 293 //------------------------------------------------------------------ 294 /// Gets the section list for the currently selected architecture 295 /// (and object for archives). 296 /// 297 /// Section list parsing can be deferred by ObjectFile instances 298 /// until this accessor is called the first time. 299 /// 300 /// @return 301 /// The list of sections contained in this object file. 302 //------------------------------------------------------------------ 303 virtual SectionList * 304 GetSectionList () = 0; 305 306 //------------------------------------------------------------------ 307 /// Gets the symbol table for the currently selected architecture 308 /// (and object for archives). 309 /// 310 /// Symbol table parsing can be deferred by ObjectFile instances 311 /// until this accessor is called the first time. 312 /// 313 /// @return 314 /// The symbol table for this object file. 315 //------------------------------------------------------------------ 316 virtual Symtab * 317 GetSymtab () = 0; 318 319 //------------------------------------------------------------------ 320 /// Gets the UUID for this object file. 321 /// 322 /// If the object file format contains a UUID, the value should be 323 /// returned. Else ObjectFile instances should return the MD5 324 /// checksum of all of the bytes for the object file (or memory for 325 /// memory based object files). 326 /// 327 /// @return 328 /// Returns \b true if a UUID was successfully extracted into 329 /// \a uuid, \b false otherwise. 330 //------------------------------------------------------------------ 331 virtual bool 332 GetUUID (lldb_private::UUID* uuid) = 0; 333 334 //------------------------------------------------------------------ 335 /// Gets whether endian swapping should occur when extracting data 336 /// from this object file. 337 /// 338 /// @return 339 /// Returns \b true if endian swapping is needed, \b false 340 /// otherwise. 341 //------------------------------------------------------------------ 342 virtual lldb::ByteOrder 343 GetByteOrder () const = 0; 344 345 //------------------------------------------------------------------ 346 /// Attempts to parse the object header. 347 /// 348 /// This function is used as a test to see if a given plug-in 349 /// instance can parse the header data already contained in 350 /// ObjectFile::m_data. If an object file parser does not 351 /// recognize that magic bytes in a header, false should be returned 352 /// and the next plug-in can attempt to parse an object file. 353 /// 354 /// @return 355 /// Returns \b true if the header was parsed succesfully, \b 356 /// false otherwise. 357 //------------------------------------------------------------------ 358 virtual bool 359 ParseHeader () = 0; 360 361 //------------------------------------------------------------------ 362 /// Returns a reference to the UnwindTable for this ObjectFile 363 /// 364 /// The UnwindTable contains FuncUnwinders objects for any function in 365 /// this ObjectFile. If a FuncUnwinders object hasn't been created yet 366 /// (i.e. the function has yet to be unwound in a stack walk), it 367 /// will be created when requested. Specifically, we do not create 368 /// FuncUnwinders objects for functions until they are needed. 369 /// 370 /// @return 371 /// Returns the unwind table for this object file. 372 //------------------------------------------------------------------ 373 virtual lldb_private::UnwindTable& 374 GetUnwindTable () { return m_unwind_table; } 375 376 //------------------------------------------------------------------ 377 /// Similar to Process::GetImageInfoAddress(). 378 /// 379 /// Some platforms embed auxiliary structures useful to debuggers in the 380 /// address space of the inferior process. This method returns the address 381 /// of such a structure if the information can be resolved via entries in 382 /// the object file. ELF, for example, provides a means to hook into the 383 /// runtime linker so that a debugger may monitor the loading and unloading 384 /// of shared libraries. 385 /// 386 /// @return 387 /// The address of any auxiliary tables, or an invalid address if this 388 /// object file format does not support or contain such information. 389 virtual lldb_private::Address 390 GetImageInfoAddress () { return Address(); } 391 392 //------------------------------------------------------------------ 393 /// Returns the address of the Entry Point in this object file - if 394 /// the object file doesn't have an entry point (because it is not an 395 /// executable file) then an invalid address is returned. 396 /// 397 /// @return 398 /// Returns the entry address for this module. 399 //------------------------------------------------------------------ 400 virtual lldb_private::Address 401 GetEntryPointAddress () { return Address();} 402 403 //------------------------------------------------------------------ 404 /// Returns the address that represents the header of this object 405 /// file. 406 /// 407 /// The header address is defined as where the header for the object 408 /// file is that describes the content of the file. If the header 409 /// doesn't appear in a section that is defined in the object file, 410 /// an address with no section is returned that has the file offset 411 /// set in the m_offset member of the lldb_private::Address object. 412 /// 413 /// @return 414 /// Returns the entry address for this module. 415 //------------------------------------------------------------------ 416 virtual lldb_private::Address 417 GetHeaderAddress () { return Address();} 418 419 420 virtual uint32_t 421 GetNumThreadContexts () 422 { 423 return 0; 424 } 425 426 virtual lldb::RegisterContextSP 427 GetThreadContextAtIndex (uint32_t idx, lldb_private::Thread &thread) 428 { 429 return lldb::RegisterContextSP(); 430 } 431 //------------------------------------------------------------------ 432 /// The object file should be able to calculate its type by looking 433 /// at its file header and possibly the sections or other data in 434 /// the object file. The file type is used in the debugger to help 435 /// select the correct plug-ins for the job at hand, so this is 436 /// important to get right. If any eTypeXXX definitions do not match 437 /// up with the type of file you are loading, please feel free to 438 /// add a new enumeration value. 439 /// 440 /// @return 441 /// The calculated file type for the current object file. 442 //------------------------------------------------------------------ 443 virtual Type 444 CalculateType() = 0; 445 446 //------------------------------------------------------------------ 447 /// The object file should be able to calculate the strata of the 448 /// object file. 449 /// 450 /// Many object files for platforms might be for either user space 451 /// debugging or for kernel debugging. If your object file subclass 452 /// can figure this out, it will help with debugger plug-in selection 453 /// when it comes time to debug. 454 /// 455 /// @return 456 /// The calculated object file strata for the current object 457 /// file. 458 //------------------------------------------------------------------ 459 virtual Strata 460 CalculateStrata() = 0; 461 462 //------------------------------------------------------------------ 463 // Member Functions 464 //------------------------------------------------------------------ 465 Type 466 GetType () 467 { 468 if (m_type == eTypeInvalid) 469 m_type = CalculateType(); 470 return m_type; 471 } 472 473 Strata 474 GetStrata () 475 { 476 if (m_strata == eStrataInvalid) 477 m_strata = CalculateStrata(); 478 return m_strata; 479 } 480 481 // When an object file is in memory, subclasses should try and lock 482 // the process weak pointer. If the process weak pointer produces a 483 // valid ProcessSP, then subclasses can call this function to read 484 // memory. 485 static lldb::DataBufferSP 486 ReadMemory (const lldb::ProcessSP &process_sp, 487 lldb::addr_t addr, 488 size_t byte_size); 489 490 size_t 491 GetData (off_t offset, size_t length, DataExtractor &data) const; 492 493 size_t 494 CopyData (off_t offset, size_t length, void *dst) const; 495 496 size_t 497 ReadSectionData (const Section *section, 498 off_t section_offset, 499 void *dst, 500 size_t dst_len) const; 501 size_t 502 ReadSectionData (const Section *section, 503 DataExtractor& section_data) const; 504 505 size_t 506 MemoryMapSectionData (const Section *section, 507 DataExtractor& section_data) const; 508protected: 509 //------------------------------------------------------------------ 510 // Member variables. 511 //------------------------------------------------------------------ 512 FileSpec m_file; 513 Type m_type; 514 Strata m_strata; 515 lldb::addr_t m_offset; ///< The offset in bytes into the file, or the address in memory 516 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). 517 DataExtractor m_data; ///< The data for this object file so things can be parsed lazily. 518 lldb_private::UnwindTable m_unwind_table; /// < Table of FuncUnwinders objects created for this ObjectFile's functions 519 lldb::ProcessWP m_process_wp; 520 const lldb::addr_t m_memory_addr; 521 522 bool 523 IsInMemory () const 524 { 525 return m_memory_addr != LLDB_INVALID_ADDRESS; 526 } 527 //------------------------------------------------------------------ 528 /// Sets the architecture for a module. At present the architecture 529 /// can only be set if it is invalid. It is not allowed to switch from 530 /// one concrete architecture to another. 531 /// 532 /// @param[in] new_arch 533 /// The architecture this module will be set to. 534 /// 535 /// @return 536 /// Returns \b true if the architecture was changed, \b 537 /// false otherwise. 538 //------------------------------------------------------------------ 539 bool SetModulesArchitecture (const ArchSpec &new_arch); 540 541private: 542 DISALLOW_COPY_AND_ASSIGN (ObjectFile); 543}; 544 545} // namespace lldb_private 546 547#endif // liblldb_ObjectFile_h_ 548 549