ObjectFile.h revision 13d24fb1817faa7ccc4cfd799113ba1a2b8968eb
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 } Strata; 80 81 //------------------------------------------------------------------ 82 /// Construct with a parent module, offset, and header data. 83 /// 84 /// Object files belong to modules and a valid module must be 85 /// supplied upon construction. The at an offset within a file for 86 /// objects that contain more than one architecture or object. 87 //------------------------------------------------------------------ 88 ObjectFile (Module* module, 89 const FileSpec *file_spec_ptr, 90 lldb::addr_t offset, 91 lldb::addr_t length, 92 lldb::DataBufferSP& headerDataSP); 93 94 //------------------------------------------------------------------ 95 /// Destructor. 96 /// 97 /// The destructor is virtual since this class is designed to be 98 /// inherited from by the plug-in instance. 99 //------------------------------------------------------------------ 100 virtual 101 ~ObjectFile(); 102 103 //------------------------------------------------------------------ 104 /// Dump a description of this object to a Stream. 105 /// 106 /// Dump a description of the current contents of this object 107 /// to the supplied stream \a s. The dumping should include the 108 /// section list if it has been parsed, and the symbol table 109 /// if it has been parsed. 110 /// 111 /// @param[in] s 112 /// The stream to which to dump the object descripton. 113 //------------------------------------------------------------------ 114 virtual void 115 Dump (Stream *s) = 0; 116 117 //------------------------------------------------------------------ 118 /// Find a ObjectFile plug-in that can parse \a file_spec. 119 /// 120 /// Scans all loaded plug-in interfaces that implement versions of 121 /// the ObjectFile plug-in interface and returns the first 122 /// instance that can parse the file. 123 /// 124 /// @param[in] module 125 /// The parent module that owns this object file. 126 /// 127 /// @param[in] file_spec 128 /// A file specification that indicates which file to use as the 129 /// object file. 130 /// 131 /// @param[in] file_offset 132 /// The offset into the file at which to start parsing the 133 /// object. This is for files that contain multiple 134 /// architectures or objects. 135 /// 136 /// @param[in] file_size 137 /// The size of the current object file if it can be determined 138 /// or if it is known. This can be zero. 139 /// 140 /// @see ObjectFile::ParseHeader() 141 //------------------------------------------------------------------ 142 static lldb::ObjectFileSP 143 FindPlugin (Module* module, 144 const FileSpec* file_spec, 145 lldb::addr_t file_offset, 146 lldb::addr_t file_size, 147 lldb::DataBufferSP &data_sp); 148 149 //------------------------------------------------------------------ 150 /// Gets the address size in bytes for the current object file. 151 /// 152 /// @return 153 /// The size of an address in bytes for the currently selected 154 /// architecture (and object for archives). Returns zero if no 155 /// architecture or object has been selected. 156 //------------------------------------------------------------------ 157 virtual size_t 158 GetAddressByteSize () const = 0; 159 160 //------------------------------------------------------------------ 161 /// Get the address type given a file address in an object file. 162 /// 163 /// Many binary file formats know what kinds 164 /// This is primarily for ARM binaries, though it can be applied to 165 /// any executable file format that supports different opcode types 166 /// within the same binary. ARM binaries support having both ARM and 167 /// Thumb within the same executable container. We need to be able 168 /// to get 169 /// @return 170 /// The size of an address in bytes for the currently selected 171 /// architecture (and object for archives). Returns zero if no 172 /// architecture or object has been selected. 173 //------------------------------------------------------------------ 174 virtual AddressClass 175 GetAddressClass (lldb::addr_t file_addr); 176 177 //------------------------------------------------------------------ 178 /// Extract the dependent modules from an object file. 179 /// 180 /// If an object file has information about which other images it 181 /// depends on (such as shared libraries), this function will 182 /// provide the list. Since many executables or shared libraries 183 /// may depend on the same files, 184 /// FileSpecList::AppendIfUnique(const FileSpec &) should be 185 /// used to make sure any files that are added are not already in 186 /// the list. 187 /// 188 /// @param[out] file_list 189 /// A list of file specification objects that gets dependent 190 /// files appended to. 191 /// 192 /// @return 193 /// The number of new files that were appended to \a file_list. 194 /// 195 /// @see FileSpecList::AppendIfUnique(const FileSpec &) 196 //------------------------------------------------------------------ 197 virtual uint32_t 198 GetDependentModules (FileSpecList& file_list) = 0; 199 200 //------------------------------------------------------------------ 201 /// Tells whether this object file is capable of being the main executable 202 /// for a process. 203 /// 204 /// @return 205 /// \b true if it is, \b false otherwise. 206 //------------------------------------------------------------------ 207 virtual bool 208 IsExecutable () const = 0; 209 210 //------------------------------------------------------------------ 211 /// Returns the offset into a file at which this object resides. 212 /// 213 /// Some files contain many object files, and this function allows 214 /// access to an object's offset within the file. 215 /// 216 /// @return 217 /// The offset in bytes into the file. Defaults to zero for 218 /// simple object files that a represented by an entire file. 219 //------------------------------------------------------------------ 220 virtual lldb::addr_t 221 GetOffset () const 222 { return m_offset; } 223 224 virtual lldb::addr_t 225 GetByteSize () const 226 { return m_length; } 227 228 //------------------------------------------------------------------ 229 /// Get accessor to the object file specification. 230 /// 231 /// @return 232 /// The file specification object pointer if there is one, or 233 /// NULL if this object is only from memory. 234 //------------------------------------------------------------------ 235 virtual FileSpec& 236 GetFileSpec() { return m_file; } 237 238 //------------------------------------------------------------------ 239 /// Get const accessor to the object file specification. 240 /// 241 /// @return 242 /// The const file specification object pointer if there is one, 243 /// or NULL if this object is only from memory. 244 //------------------------------------------------------------------ 245 virtual const FileSpec& 246 GetFileSpec() const { return m_file; } 247 248 //------------------------------------------------------------------ 249 /// Get the name of the cpu, vendor and OS for this object file. 250 /// 251 /// This value is a string that represents the target triple where 252 /// the cpu type, the vendor and the OS are encoded into a string. 253 /// 254 /// @param[out] target_triple 255 /// The string value of the target triple. 256 /// 257 /// @return 258 /// \b True if the target triple was able to be computed, \b 259 /// false otherwise. 260 //------------------------------------------------------------------ 261 virtual bool 262 GetArchitecture (ArchSpec &arch) = 0; 263 264 //------------------------------------------------------------------ 265 /// Gets the section list for the currently selected architecture 266 /// (and object for archives). 267 /// 268 /// Section list parsing can be deferred by ObjectFile instances 269 /// until this accessor is called the first time. 270 /// 271 /// @return 272 /// The list of sections contained in this object file. 273 //------------------------------------------------------------------ 274 virtual SectionList * 275 GetSectionList () = 0; 276 277 //------------------------------------------------------------------ 278 /// Gets the symbol table for the currently selected architecture 279 /// (and object for archives). 280 /// 281 /// Symbol table parsing can be deferred by ObjectFile instances 282 /// until this accessor is called the first time. 283 /// 284 /// @return 285 /// The symbol table for this object file. 286 //------------------------------------------------------------------ 287 virtual Symtab * 288 GetSymtab () = 0; 289 290 //------------------------------------------------------------------ 291 /// Gets the UUID for this object file. 292 /// 293 /// If the object file format contains a UUID, the value should be 294 /// returned. Else ObjectFile instances should return the MD5 295 /// checksum of all of the bytes for the object file (or memory for 296 /// memory based object files). 297 /// 298 /// @return 299 /// Returns \b true if a UUID was successfully extracted into 300 /// \a uuid, \b false otherwise. 301 //------------------------------------------------------------------ 302 virtual bool 303 GetUUID (lldb_private::UUID* uuid) = 0; 304 305 //------------------------------------------------------------------ 306 /// Gets whether endian swapping should occur when extracting data 307 /// from this object file. 308 /// 309 /// @return 310 /// Returns \b true if endian swapping is needed, \b false 311 /// otherwise. 312 //------------------------------------------------------------------ 313 virtual lldb::ByteOrder 314 GetByteOrder () const = 0; 315 316 //------------------------------------------------------------------ 317 /// Attempts to parse the object header. 318 /// 319 /// This function is used as a test to see if a given plug-in 320 /// instance can parse the header data already contained in 321 /// ObjectFile::m_data. If an object file parser does not 322 /// recognize that magic bytes in a header, false should be returned 323 /// and the next plug-in can attempt to parse an object file. 324 /// 325 /// @return 326 /// Returns \b true if the header was parsed succesfully, \b 327 /// false otherwise. 328 //------------------------------------------------------------------ 329 virtual bool 330 ParseHeader () = 0; 331 332 //------------------------------------------------------------------ 333 /// Returns a reference to the UnwindTable for this ObjectFile 334 /// 335 /// The UnwindTable contains FuncUnwinders objects for any function in 336 /// this ObjectFile. If a FuncUnwinders object hasn't been created yet 337 /// (i.e. the function has yet to be unwound in a stack walk), it 338 /// will be created when requested. Specifically, we do not create 339 /// FuncUnwinders objects for functions until they are needed. 340 /// 341 /// @return 342 /// Returns the unwind table for this object file. 343 //------------------------------------------------------------------ 344 virtual lldb_private::UnwindTable& 345 GetUnwindTable () { return m_unwind_table; } 346 347 //------------------------------------------------------------------ 348 /// Similar to Process::GetImageInfoAddress(). 349 /// 350 /// Some platforms embed auxiliary structures useful to debuggers in the 351 /// address space of the inferior process. This method returns the address 352 /// of such a structure if the information can be resolved via entries in 353 /// the object file. ELF, for example, provides a means to hook into the 354 /// runtime linker so that a debugger may monitor the loading and unloading 355 /// of shared libraries. 356 /// 357 /// @return 358 /// The address of any auxiliary tables, or an invalid address if this 359 /// object file format does not support or contain such information. 360 virtual lldb_private::Address 361 GetImageInfoAddress () { return Address(); } 362 363 //------------------------------------------------------------------ 364 /// Returns the address of the Entry Point in this object file - if 365 /// the object file doesn't have an entry point (because it is not an 366 /// executable file) then an invalid address is returned. 367 /// 368 /// @return 369 /// Returns the entry address for this module. 370 //------------------------------------------------------------------ 371 virtual lldb_private::Address 372 GetEntryPointAddress () { return Address();} 373 374 //------------------------------------------------------------------ 375 /// The object file should be able to calculate its type by looking 376 /// at its file header and possibly the sections or other data in 377 /// the object file. The file type is used in the debugger to help 378 /// select the correct plug-ins for the job at hand, so this is 379 /// important to get right. If any eTypeXXX definitions do not match 380 /// up with the type of file you are loading, please feel free to 381 /// add a new enumeration value. 382 /// 383 /// @return 384 /// The calculated file type for the current object file. 385 //------------------------------------------------------------------ 386 virtual Type 387 CalculateType() = 0; 388 389 //------------------------------------------------------------------ 390 /// The object file should be able to calculate the strata of the 391 /// object file. 392 /// 393 /// Many object files for platforms might be for either user space 394 /// debugging or for kernel debugging. If your object file subclass 395 /// can figure this out, it will help with debugger plug-in selection 396 /// when it comes time to debug. 397 /// 398 /// @return 399 /// The calculated object file strata for the current object 400 /// file. 401 //------------------------------------------------------------------ 402 virtual Strata 403 CalculateStrata() = 0; 404 405 //------------------------------------------------------------------ 406 // Member Functions 407 //------------------------------------------------------------------ 408 Type 409 GetType () 410 { 411 if (m_type == eTypeInvalid) 412 m_type = CalculateType(); 413 return m_type; 414 } 415 416 Strata 417 GetStrata () 418 { 419 if (m_strata == eStrataInvalid) 420 m_strata = CalculateStrata(); 421 return m_strata; 422 } 423 424 size_t 425 GetData (off_t offset, size_t length, DataExtractor &data) const; 426 427 size_t 428 CopyData (off_t offset, size_t length, void *dst) const; 429 430protected: 431 //------------------------------------------------------------------ 432 // Member variables. 433 //------------------------------------------------------------------ 434 FileSpec m_file; 435 Type m_type; 436 Strata m_strata; 437 lldb::addr_t m_offset; ///< The offset in bytes into the file, or the address in memory 438 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). 439 DataExtractor m_data; ///< The data for this object file so things can be parsed lazily. 440 lldb_private::UnwindTable m_unwind_table; /// < Table of FuncUnwinders objects created for this ObjectFile's functions 441 442 //------------------------------------------------------------------ 443 /// Sets the architecture for a module. At present the architecture 444 /// can only be set if it is invalid. It is not allowed to switch from 445 /// one concrete architecture to another. 446 /// 447 /// @param[in] new_arch 448 /// The architecture this module will be set to. 449 /// 450 /// @return 451 /// Returns \b true if the architecture was changed, \b 452 /// false otherwise. 453 //------------------------------------------------------------------ 454 bool SetModulesArchitecture (const ArchSpec &new_arch); 455 456private: 457 DISALLOW_COPY_AND_ASSIGN (ObjectFile); 458}; 459 460} // namespace lldb_private 461 462#endif // liblldb_ObjectFile_h_ 463 464