ObjectFile.h revision e40b6424d9e49306392bec4b44060da36414c382
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 ReferenceCountedBaseVirtual<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 lldb::ObjectFileSP 104 GetSP (); 105 106 //------------------------------------------------------------------ 107 /// Dump a description of this object to a Stream. 108 /// 109 /// Dump a description of the current contents of this object 110 /// to the supplied stream \a s. The dumping should include the 111 /// section list if it has been parsed, and the symbol table 112 /// if it has been parsed. 113 /// 114 /// @param[in] s 115 /// The stream to which to dump the object descripton. 116 //------------------------------------------------------------------ 117 virtual void 118 Dump (Stream *s) = 0; 119 120 //------------------------------------------------------------------ 121 /// Find a ObjectFile plug-in that can parse \a file_spec. 122 /// 123 /// Scans all loaded plug-in interfaces that implement versions of 124 /// the ObjectFile plug-in interface and returns the first 125 /// instance that can parse the file. 126 /// 127 /// @param[in] module 128 /// The parent module that owns this object file. 129 /// 130 /// @param[in] file_spec 131 /// A file specification that indicates which file to use as the 132 /// object file. 133 /// 134 /// @param[in] file_offset 135 /// The offset into the file at which to start parsing the 136 /// object. This is for files that contain multiple 137 /// architectures or objects. 138 /// 139 /// @param[in] file_size 140 /// The size of the current object file if it can be determined 141 /// or if it is known. This can be zero. 142 /// 143 /// @see ObjectFile::ParseHeader() 144 //------------------------------------------------------------------ 145 static lldb::ObjectFileSP 146 FindPlugin (Module* module, 147 const FileSpec* file_spec, 148 lldb::addr_t file_offset, 149 lldb::addr_t file_size); 150 151 //------------------------------------------------------------------ 152 /// Gets the address size in bytes for the current object file. 153 /// 154 /// @return 155 /// The size of an address in bytes for the currently selected 156 /// architecture (and object for archives). Returns zero if no 157 /// architecture or object has been selected. 158 //------------------------------------------------------------------ 159 virtual size_t 160 GetAddressByteSize () const = 0; 161 162 //------------------------------------------------------------------ 163 /// Get the address type given a file address in an object file. 164 /// 165 /// Many binary file formats know what kinds 166 /// This is primarily for ARM binaries, though it can be applied to 167 /// any executable file format that supports different opcode types 168 /// within the same binary. ARM binaries support having both ARM and 169 /// Thumb within the same executable container. We need to be able 170 /// to get 171 /// @return 172 /// The size of an address in bytes for the currently selected 173 /// architecture (and object for archives). Returns zero if no 174 /// architecture or object has been selected. 175 //------------------------------------------------------------------ 176 virtual AddressClass 177 GetAddressClass (lldb::addr_t file_addr); 178 179 //------------------------------------------------------------------ 180 /// Extract the dependent modules from an object file. 181 /// 182 /// If an object file has information about which other images it 183 /// depends on (such as shared libraries), this function will 184 /// provide the list. Since many executables or shared libraries 185 /// may depend on the same files, 186 /// FileSpecList::AppendIfUnique(const FileSpec &) should be 187 /// used to make sure any files that are added are not already in 188 /// the list. 189 /// 190 /// @param[out] file_list 191 /// A list of file specification objects that gets dependent 192 /// files appended to. 193 /// 194 /// @return 195 /// The number of new files that were appended to \a file_list. 196 /// 197 /// @see FileSpecList::AppendIfUnique(const FileSpec &) 198 //------------------------------------------------------------------ 199 virtual uint32_t 200 GetDependentModules (FileSpecList& file_list) = 0; 201 202 //------------------------------------------------------------------ 203 /// Tells whether this object file is capable of being the main executable 204 /// for a process. 205 /// 206 /// @return 207 /// \b true if it is, \b false otherwise. 208 //------------------------------------------------------------------ 209 virtual bool 210 IsExecutable () const = 0; 211 212 //------------------------------------------------------------------ 213 /// Returns the offset into a file at which this object resides. 214 /// 215 /// Some files contain many object files, and this function allows 216 /// access to an object's offset within the file. 217 /// 218 /// @return 219 /// The offset in bytes into the file. Defaults to zero for 220 /// simple object files that a represented by an entire file. 221 //------------------------------------------------------------------ 222 virtual lldb::addr_t 223 GetOffset () const 224 { return m_offset; } 225 226 virtual lldb::addr_t 227 GetByteSize () const 228 { return m_length; } 229 230 //------------------------------------------------------------------ 231 /// Get accessor to the object file specification. 232 /// 233 /// @return 234 /// The file specification object pointer if there is one, or 235 /// NULL if this object is only from memory. 236 //------------------------------------------------------------------ 237 virtual FileSpec& 238 GetFileSpec() { return m_file; } 239 240 //------------------------------------------------------------------ 241 /// Get const accessor to the object file specification. 242 /// 243 /// @return 244 /// The const file specification object pointer if there is one, 245 /// or NULL if this object is only from memory. 246 //------------------------------------------------------------------ 247 virtual const FileSpec& 248 GetFileSpec() const { return m_file; } 249 250 //------------------------------------------------------------------ 251 /// Get the name of the cpu, vendor and OS for this object file. 252 /// 253 /// This value is a string that represents the target triple where 254 /// the cpu type, the vendor and the OS are encoded into a string. 255 /// 256 /// @param[out] target_triple 257 /// The string value of the target triple. 258 /// 259 /// @return 260 /// \b True if the target triple was able to be computed, \b 261 /// false otherwise. 262 //------------------------------------------------------------------ 263 virtual bool 264 GetArchitecture (ArchSpec &arch) = 0; 265 266 //------------------------------------------------------------------ 267 /// Gets the section list for the currently selected architecture 268 /// (and object for archives). 269 /// 270 /// Section list parsing can be deferred by ObjectFile instances 271 /// until this accessor is called the first time. 272 /// 273 /// @return 274 /// The list of sections contained in this object file. 275 //------------------------------------------------------------------ 276 virtual SectionList * 277 GetSectionList () = 0; 278 279 //------------------------------------------------------------------ 280 /// Gets the symbol table for the currently selected architecture 281 /// (and object for archives). 282 /// 283 /// Symbol table parsing can be deferred by ObjectFile instances 284 /// until this accessor is called the first time. 285 /// 286 /// @return 287 /// The symbol table for this object file. 288 //------------------------------------------------------------------ 289 virtual Symtab * 290 GetSymtab () = 0; 291 292 //------------------------------------------------------------------ 293 /// Gets the UUID for this object file. 294 /// 295 /// If the object file format contains a UUID, the value should be 296 /// returned. Else ObjectFile instances should return the MD5 297 /// checksum of all of the bytes for the object file (or memory for 298 /// memory based object files). 299 /// 300 /// @return 301 /// Returns \b true if a UUID was successfully extracted into 302 /// \a uuid, \b false otherwise. 303 //------------------------------------------------------------------ 304 virtual bool 305 GetUUID (lldb_private::UUID* uuid) = 0; 306 307 //------------------------------------------------------------------ 308 /// Gets whether endian swapping should occur when extracting data 309 /// from this object file. 310 /// 311 /// @return 312 /// Returns \b true if endian swapping is needed, \b false 313 /// otherwise. 314 //------------------------------------------------------------------ 315 virtual lldb::ByteOrder 316 GetByteOrder () const = 0; 317 318 //------------------------------------------------------------------ 319 /// Attempts to parse the object header. 320 /// 321 /// This function is used as a test to see if a given plug-in 322 /// instance can parse the header data already contained in 323 /// ObjectFile::m_data. If an object file parser does not 324 /// recognize that magic bytes in a header, false should be returned 325 /// and the next plug-in can attempt to parse an object file. 326 /// 327 /// @return 328 /// Returns \b true if the header was parsed succesfully, \b 329 /// false otherwise. 330 //------------------------------------------------------------------ 331 virtual bool 332 ParseHeader () = 0; 333 334 //------------------------------------------------------------------ 335 /// Returns a reference to the UnwindTable for this ObjectFile 336 /// 337 /// The UnwindTable contains FuncUnwinders objects for any function in 338 /// this ObjectFile. If a FuncUnwinders object hasn't been created yet 339 /// (i.e. the function has yet to be unwound in a stack walk), it 340 /// will be created when requested. Specifically, we do not create 341 /// FuncUnwinders objects for functions until they are needed. 342 /// 343 /// @return 344 /// Returns the unwind table for this object file. 345 //------------------------------------------------------------------ 346 virtual lldb_private::UnwindTable& 347 GetUnwindTable () { return m_unwind_table; } 348 349 //------------------------------------------------------------------ 350 /// Similar to Process::GetImageInfoAddress(). 351 /// 352 /// Some platforms embed auxiliary structures useful to debuggers in the 353 /// address space of the inferior process. This method returns the address 354 /// of such a structure if the information can be resolved via entries in 355 /// the object file. ELF, for example, provides a means to hook into the 356 /// runtime linker so that a debugger may monitor the loading and unloading 357 /// of shared libraries. 358 /// 359 /// @return 360 /// The address of any auxiliary tables, or an invalid address if this 361 /// object file format does not support or contain such information. 362 virtual lldb_private::Address 363 GetImageInfoAddress () { return Address(); } 364 365 //------------------------------------------------------------------ 366 /// Returns the address of the Entry Point in this object file - if 367 /// the object file doesn't have an entry point (because it is not an 368 /// executable file) then an invalid address is returned. 369 /// 370 /// @return 371 /// Returns the entry address for this module. 372 //------------------------------------------------------------------ 373 virtual lldb_private::Address 374 GetEntryPointAddress () { return Address();} 375 376 //------------------------------------------------------------------ 377 /// The object file should be able to calculate its type by looking 378 /// at its file header and possibly the sections or other data in 379 /// the object file. The file type is used in the debugger to help 380 /// select the correct plug-ins for the job at hand, so this is 381 /// important to get right. If any eTypeXXX definitions do not match 382 /// up with the type of file you are loading, please feel free to 383 /// add a new enumeration value. 384 /// 385 /// @return 386 /// The calculated file type for the current object file. 387 //------------------------------------------------------------------ 388 virtual Type 389 CalculateType() = 0; 390 391 //------------------------------------------------------------------ 392 /// The object file should be able to calculate the strata of the 393 /// object file. 394 /// 395 /// Many object files for platforms might be for either user space 396 /// debugging or for kernel debugging. If your object file subclass 397 /// can figure this out, it will help with debugger plug-in selection 398 /// when it comes time to debug. 399 /// 400 /// @return 401 /// The calculated object file strata for the current object 402 /// file. 403 //------------------------------------------------------------------ 404 virtual Strata 405 CalculateStrata() = 0; 406 407 //------------------------------------------------------------------ 408 // Member Functions 409 //------------------------------------------------------------------ 410 Type 411 GetType () 412 { 413 if (m_type == eTypeInvalid) 414 m_type = CalculateType(); 415 return m_type; 416 } 417 418 Strata 419 GetStrata () 420 { 421 if (m_strata == eStrataInvalid) 422 m_strata = CalculateStrata(); 423 return m_strata; 424 } 425 426 427protected: 428 //------------------------------------------------------------------ 429 // Member variables. 430 //------------------------------------------------------------------ 431 FileSpec m_file; 432 Type m_type; 433 Strata m_strata; 434 lldb::addr_t m_offset; ///< The offset in bytes into the file, or the address in memory 435 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). 436 DataExtractor m_data; ///< The data for this object file so things can be parsed lazily. 437 lldb_private::UnwindTable m_unwind_table; /// < Table of FuncUnwinders objects created for this ObjectFile's functions 438 439 //------------------------------------------------------------------ 440 /// Sets the architecture for a module. At present the architecture 441 /// can only be set if it is invalid. It is not allowed to switch from 442 /// one concrete architecture to another. 443 /// 444 /// @param[in] new_arch 445 /// The architecture this module will be set to. 446 /// 447 /// @return 448 /// Returns \b true if the architecture was changed, \b 449 /// false otherwise. 450 //------------------------------------------------------------------ 451 bool SetModulesArchitecture (const ArchSpec &new_arch); 452 453private: 454 DISALLOW_COPY_AND_ASSIGN (ObjectFile); 455}; 456 457} // namespace lldb_private 458 459#endif // liblldb_ObjectFile_h_ 460 461