1 //===-- DWARFFormValue.cpp --------------------------------------*- 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 #include <assert.h> 11 12 #include "lldb/Core/dwarf.h" 13 #include "lldb/Core/Stream.h" 14 15 #include "DWARFFormValue.h" 16 #include "DWARFCompileUnit.h" 17 18 class DWARFCompileUnit; 19 20 using namespace lldb_private; 21 22 23 static uint8_t g_form_sizes_addr4[] = 24 { 25 0, // 0x00 unused 26 4, // 0x01 DW_FORM_addr 27 0, // 0x02 unused 28 0, // 0x03 DW_FORM_block2 29 0, // 0x04 DW_FORM_block4 30 2, // 0x05 DW_FORM_data2 31 4, // 0x06 DW_FORM_data4 32 8, // 0x07 DW_FORM_data8 33 0, // 0x08 DW_FORM_string 34 0, // 0x09 DW_FORM_block 35 0, // 0x0a DW_FORM_block1 36 1, // 0x0b DW_FORM_data1 37 1, // 0x0c DW_FORM_flag 38 0, // 0x0d DW_FORM_sdata 39 4, // 0x0e DW_FORM_strp 40 0, // 0x0f DW_FORM_udata 41 0, // 0x10 DW_FORM_ref_addr (addr size for DWARF2 and earlier, 4 bytes for DWARF32, 8 bytes for DWARF32 in DWARF 3 and later 42 1, // 0x11 DW_FORM_ref1 43 2, // 0x12 DW_FORM_ref2 44 4, // 0x13 DW_FORM_ref4 45 8, // 0x14 DW_FORM_ref8 46 0, // 0x15 DW_FORM_ref_udata 47 0, // 0x16 DW_FORM_indirect 48 4, // 0x17 DW_FORM_sec_offset 49 0, // 0x18 DW_FORM_exprloc 50 0, // 0x19 DW_FORM_flag_present 51 0, // 0x1a 52 0, // 0x1b 53 0, // 0x1c 54 0, // 0x1d 55 0, // 0x1e 56 0, // 0x1f 57 8, // 0x20 DW_FORM_ref_sig8 58 59 }; 60 61 static uint8_t 62 g_form_sizes_addr8[] = 63 { 64 0, // 0x00 unused 65 8, // 0x01 DW_FORM_addr 66 0, // 0x02 unused 67 0, // 0x03 DW_FORM_block2 68 0, // 0x04 DW_FORM_block4 69 2, // 0x05 DW_FORM_data2 70 4, // 0x06 DW_FORM_data4 71 8, // 0x07 DW_FORM_data8 72 0, // 0x08 DW_FORM_string 73 0, // 0x09 DW_FORM_block 74 0, // 0x0a DW_FORM_block1 75 1, // 0x0b DW_FORM_data1 76 1, // 0x0c DW_FORM_flag 77 0, // 0x0d DW_FORM_sdata 78 4, // 0x0e DW_FORM_strp 79 0, // 0x0f DW_FORM_udata 80 0, // 0x10 DW_FORM_ref_addr (addr size for DWARF2 and earlier, 4 bytes for DWARF32, 8 bytes for DWARF32 in DWARF 3 and later 81 1, // 0x11 DW_FORM_ref1 82 2, // 0x12 DW_FORM_ref2 83 4, // 0x13 DW_FORM_ref4 84 8, // 0x14 DW_FORM_ref8 85 0, // 0x15 DW_FORM_ref_udata 86 0, // 0x16 DW_FORM_indirect 87 4, // 0x17 DW_FORM_sec_offset 88 0, // 0x18 DW_FORM_exprloc 89 0, // 0x19 DW_FORM_flag_present 90 0, // 0x1a 91 0, // 0x1b 92 0, // 0x1c 93 0, // 0x1d 94 0, // 0x1e 95 0, // 0x1f 96 8, // 0x20 DW_FORM_ref_sig8 97 }; 98 99 // Difference with g_form_sizes_addr8: 100 // DW_FORM_strp and DW_FORM_sec_offset are 8 instead of 4 101 static uint8_t 102 g_form_sizes_addr8_dwarf64[] = 103 { 104 0, // 0x00 unused 105 8, // 0x01 DW_FORM_addr 106 0, // 0x02 unused 107 0, // 0x03 DW_FORM_block2 108 0, // 0x04 DW_FORM_block4 109 2, // 0x05 DW_FORM_data2 110 4, // 0x06 DW_FORM_data4 111 8, // 0x07 DW_FORM_data8 112 0, // 0x08 DW_FORM_string 113 0, // 0x09 DW_FORM_block 114 0, // 0x0a DW_FORM_block1 115 1, // 0x0b DW_FORM_data1 116 1, // 0x0c DW_FORM_flag 117 0, // 0x0d DW_FORM_sdata 118 8, // 0x0e DW_FORM_strp 119 0, // 0x0f DW_FORM_udata 120 0, // 0x10 DW_FORM_ref_addr (addr size for DWARF2 and earlier, 4 bytes for DWARF32, 8 bytes for DWARF32 in DWARF 3 and later 121 1, // 0x11 DW_FORM_ref1 122 2, // 0x12 DW_FORM_ref2 123 4, // 0x13 DW_FORM_ref4 124 8, // 0x14 DW_FORM_ref8 125 0, // 0x15 DW_FORM_ref_udata 126 0, // 0x16 DW_FORM_indirect 127 8, // 0x17 DW_FORM_sec_offset 128 0, // 0x18 DW_FORM_exprloc 129 0, // 0x19 DW_FORM_flag_present 130 0, // 0x1a 131 0, // 0x1b 132 0, // 0x1c 133 0, // 0x1d 134 0, // 0x1e 135 0, // 0x1f 136 8, // 0x20 DW_FORM_ref_sig8 137 }; 138 139 const uint8_t * 140 DWARFFormValue::GetFixedFormSizesForAddressSize (uint8_t addr_size, bool is_dwarf64) 141 { 142 if (!is_dwarf64) { 143 switch (addr_size) 144 { 145 case 4: return g_form_sizes_addr4; 146 case 8: return g_form_sizes_addr8; 147 } 148 } else { 149 if (addr_size == 8) 150 return g_form_sizes_addr8_dwarf64; 151 // is_dwarf64 && addr_size == 4 : no provider does this. 152 } 153 return NULL; 154 } 155 156 DWARFFormValue::DWARFFormValue() : 157 m_cu (NULL), 158 m_form(0), 159 m_value() 160 { 161 } 162 163 DWARFFormValue::DWARFFormValue(const DWARFCompileUnit* cu, dw_form_t form) : 164 m_cu (cu), 165 m_form(form), 166 m_value() 167 { 168 } 169 170 bool 171 DWARFFormValue::ExtractValue(const DWARFDataExtractor& data, lldb::offset_t* offset_ptr) 172 { 173 bool indirect = false; 174 bool is_block = false; 175 m_value.data = NULL; 176 uint8_t ref_addr_size; 177 // Read the value for the form into value and follow and DW_FORM_indirect instances we run into 178 do 179 { 180 indirect = false; 181 switch (m_form) 182 { 183 case DW_FORM_addr: assert(m_cu); 184 m_value.value.uval = data.GetMaxU64(offset_ptr, DWARFCompileUnit::GetAddressByteSize(m_cu)); break; 185 case DW_FORM_block2: m_value.value.uval = data.GetU16(offset_ptr); is_block = true; break; 186 case DW_FORM_block4: m_value.value.uval = data.GetU32(offset_ptr); is_block = true; break; 187 case DW_FORM_data2: m_value.value.uval = data.GetU16(offset_ptr); break; 188 case DW_FORM_data4: m_value.value.uval = data.GetU32(offset_ptr); break; 189 case DW_FORM_data8: m_value.value.uval = data.GetU64(offset_ptr); break; 190 case DW_FORM_string: m_value.value.cstr = data.GetCStr(offset_ptr); 191 // Set the string value to also be the data for inlined cstr form values only 192 // so we can tell the difference between DW_FORM_string and DW_FORM_strp form 193 // values; 194 m_value.data = (uint8_t*)m_value.value.cstr; break; 195 case DW_FORM_exprloc: 196 case DW_FORM_block: m_value.value.uval = data.GetULEB128(offset_ptr); is_block = true; break; 197 case DW_FORM_block1: m_value.value.uval = data.GetU8(offset_ptr); is_block = true; break; 198 case DW_FORM_data1: m_value.value.uval = data.GetU8(offset_ptr); break; 199 case DW_FORM_flag: m_value.value.uval = data.GetU8(offset_ptr); break; 200 case DW_FORM_sdata: m_value.value.sval = data.GetSLEB128(offset_ptr); break; 201 case DW_FORM_strp: assert(m_cu); 202 m_value.value.uval = data.GetMaxU64(offset_ptr, DWARFCompileUnit::IsDWARF64(m_cu) ? 8 : 4); break; 203 // case DW_FORM_APPLE_db_str: 204 case DW_FORM_udata: m_value.value.uval = data.GetULEB128(offset_ptr); break; 205 case DW_FORM_ref_addr: assert(m_cu); 206 ref_addr_size = 4; 207 if (m_cu->GetVersion() <= 2) 208 ref_addr_size = m_cu->GetAddressByteSize(); 209 else 210 ref_addr_size = m_cu->IsDWARF64() ? 8 : 4; 211 m_value.value.uval = data.GetMaxU64(offset_ptr, ref_addr_size); break; 212 case DW_FORM_ref1: m_value.value.uval = data.GetU8(offset_ptr); break; 213 case DW_FORM_ref2: m_value.value.uval = data.GetU16(offset_ptr); break; 214 case DW_FORM_ref4: m_value.value.uval = data.GetU32(offset_ptr); break; 215 case DW_FORM_ref8: m_value.value.uval = data.GetU64(offset_ptr); break; 216 case DW_FORM_ref_udata: m_value.value.uval = data.GetULEB128(offset_ptr); break; 217 case DW_FORM_indirect: 218 m_form = data.GetULEB128(offset_ptr); 219 indirect = true; 220 break; 221 222 case DW_FORM_sec_offset: assert(m_cu); 223 m_value.value.uval = data.GetMaxU64(offset_ptr, DWARFCompileUnit::IsDWARF64(m_cu) ? 8 : 4); break; 224 case DW_FORM_flag_present: m_value.value.uval = 1; break; 225 case DW_FORM_ref_sig8: m_value.value.uval = data.GetU64(offset_ptr); break; 226 default: 227 return false; 228 break; 229 } 230 } while (indirect); 231 232 if (is_block) 233 { 234 m_value.data = data.PeekData(*offset_ptr, m_value.value.uval); 235 if (m_value.data != NULL) 236 { 237 *offset_ptr += m_value.value.uval; 238 } 239 } 240 241 return true; 242 } 243 244 bool 245 DWARFFormValue::SkipValue(const DWARFDataExtractor& debug_info_data, lldb::offset_t *offset_ptr) const 246 { 247 return DWARFFormValue::SkipValue(m_form, debug_info_data, offset_ptr, m_cu); 248 } 249 250 bool 251 DWARFFormValue::SkipValue(dw_form_t form, const DWARFDataExtractor& debug_info_data, lldb::offset_t *offset_ptr, const DWARFCompileUnit* cu) 252 { 253 uint8_t ref_addr_size; 254 switch (form) 255 { 256 // Blocks if inlined data that have a length field and the data bytes 257 // inlined in the .debug_info 258 case DW_FORM_exprloc: 259 case DW_FORM_block: { dw_uleb128_t size = debug_info_data.GetULEB128(offset_ptr); *offset_ptr += size; } return true; 260 case DW_FORM_block1: { dw_uleb128_t size = debug_info_data.GetU8(offset_ptr); *offset_ptr += size; } return true; 261 case DW_FORM_block2: { dw_uleb128_t size = debug_info_data.GetU16(offset_ptr); *offset_ptr += size; } return true; 262 case DW_FORM_block4: { dw_uleb128_t size = debug_info_data.GetU32(offset_ptr); *offset_ptr += size; } return true; 263 264 // Inlined NULL terminated C-strings 265 case DW_FORM_string: 266 debug_info_data.GetCStr(offset_ptr); 267 return true; 268 269 // Compile unit address sized values 270 case DW_FORM_addr: 271 *offset_ptr += DWARFCompileUnit::GetAddressByteSize(cu); 272 return true; 273 274 case DW_FORM_ref_addr: 275 ref_addr_size = 4; 276 assert (cu); // CU must be valid for DW_FORM_ref_addr objects or we will get this wrong 277 if (cu->GetVersion() <= 2) 278 ref_addr_size = cu->GetAddressByteSize(); 279 else 280 ref_addr_size = cu->IsDWARF64() ? 8 : 4; 281 *offset_ptr += ref_addr_size; 282 return true; 283 284 // 0 bytes values (implied from DW_FORM) 285 case DW_FORM_flag_present: 286 return true; 287 288 // 1 byte values 289 case DW_FORM_data1: 290 case DW_FORM_flag: 291 case DW_FORM_ref1: 292 *offset_ptr += 1; 293 return true; 294 295 // 2 byte values 296 case DW_FORM_data2: 297 case DW_FORM_ref2: 298 *offset_ptr += 2; 299 return true; 300 301 // 32 bit for DWARF 32, 64 for DWARF 64 302 case DW_FORM_sec_offset: 303 case DW_FORM_strp: 304 assert(cu); 305 *offset_ptr += (cu->IsDWARF64() ? 8 : 4); 306 return true; 307 308 // 4 byte values 309 case DW_FORM_data4: 310 case DW_FORM_ref4: 311 *offset_ptr += 4; 312 return true; 313 314 // 8 byte values 315 case DW_FORM_data8: 316 case DW_FORM_ref8: 317 case DW_FORM_ref_sig8: 318 *offset_ptr += 8; 319 return true; 320 321 // signed or unsigned LEB 128 values 322 case DW_FORM_sdata: 323 case DW_FORM_udata: 324 case DW_FORM_ref_udata: 325 debug_info_data.Skip_LEB128(offset_ptr); 326 return true; 327 328 case DW_FORM_indirect: 329 { 330 dw_form_t indirect_form = debug_info_data.GetULEB128(offset_ptr); 331 return DWARFFormValue::SkipValue (indirect_form, 332 debug_info_data, 333 offset_ptr, 334 cu); 335 } 336 337 default: 338 break; 339 } 340 return false; 341 } 342 343 344 void 345 DWARFFormValue::Dump(Stream &s, const DWARFDataExtractor* debug_str_data) const 346 { 347 uint64_t uvalue = Unsigned(); 348 bool cu_relative_offset = false; 349 350 bool verbose = s.GetVerbose(); 351 352 switch (m_form) 353 { 354 case DW_FORM_addr: s.Address(uvalue, sizeof (uint64_t)); break; 355 case DW_FORM_flag: 356 case DW_FORM_data1: s.PutHex8(uvalue); break; 357 case DW_FORM_data2: s.PutHex16(uvalue); break; 358 case DW_FORM_sec_offset: 359 case DW_FORM_data4: s.PutHex32(uvalue); break; 360 case DW_FORM_ref_sig8: 361 case DW_FORM_data8: s.PutHex64(uvalue); break; 362 case DW_FORM_string: s.QuotedCString(AsCString(NULL)); break; 363 case DW_FORM_exprloc: 364 case DW_FORM_block: 365 case DW_FORM_block1: 366 case DW_FORM_block2: 367 case DW_FORM_block4: 368 if (uvalue > 0) 369 { 370 switch (m_form) 371 { 372 case DW_FORM_exprloc: 373 case DW_FORM_block: s.Printf("<0x%" PRIx64 "> ", uvalue); break; 374 case DW_FORM_block1: s.Printf("<0x%2.2x> ", (uint8_t)uvalue); break; 375 case DW_FORM_block2: s.Printf("<0x%4.4x> ", (uint16_t)uvalue); break; 376 case DW_FORM_block4: s.Printf("<0x%8.8x> ", (uint32_t)uvalue); break; 377 default: break; 378 } 379 380 const uint8_t* data_ptr = m_value.data; 381 if (data_ptr) 382 { 383 const uint8_t* end_data_ptr = data_ptr + uvalue; // uvalue contains size of block 384 while (data_ptr < end_data_ptr) 385 { 386 s.Printf("%2.2x ", *data_ptr); 387 ++data_ptr; 388 } 389 } 390 else 391 s.PutCString("NULL"); 392 } 393 break; 394 395 case DW_FORM_sdata: s.PutSLEB128(uvalue); break; 396 case DW_FORM_udata: s.PutULEB128(uvalue); break; 397 case DW_FORM_strp: 398 if (debug_str_data) 399 { 400 if (verbose) 401 s.Printf(" .debug_str[0x%8.8x] = ", (uint32_t)uvalue); 402 403 const char* dbg_str = AsCString(debug_str_data); 404 if (dbg_str) 405 s.QuotedCString(dbg_str); 406 } 407 else 408 { 409 s.PutHex32(uvalue); 410 } 411 break; 412 413 case DW_FORM_ref_addr: 414 { 415 assert (m_cu); // CU must be valid for DW_FORM_ref_addr objects or we will get this wrong 416 if (m_cu->GetVersion() <= 2) 417 s.Address(uvalue, sizeof (uint64_t) * 2); 418 else 419 s.Address(uvalue, 4 * 2);// 4 for DWARF32, 8 for DWARF64, but we don't support DWARF64 yet 420 break; 421 } 422 case DW_FORM_ref1: cu_relative_offset = true; if (verbose) s.Printf("cu + 0x%2.2x", (uint8_t)uvalue); break; 423 case DW_FORM_ref2: cu_relative_offset = true; if (verbose) s.Printf("cu + 0x%4.4x", (uint16_t)uvalue); break; 424 case DW_FORM_ref4: cu_relative_offset = true; if (verbose) s.Printf("cu + 0x%4.4x", (uint32_t)uvalue); break; 425 case DW_FORM_ref8: cu_relative_offset = true; if (verbose) s.Printf("cu + 0x%8.8" PRIx64, uvalue); break; 426 case DW_FORM_ref_udata: cu_relative_offset = true; if (verbose) s.Printf("cu + 0x%" PRIx64, uvalue); break; 427 428 // All DW_FORM_indirect attributes should be resolved prior to calling this function 429 case DW_FORM_indirect: s.PutCString("DW_FORM_indirect"); break; 430 case DW_FORM_flag_present: break; 431 default: 432 s.Printf("DW_FORM(0x%4.4x)", m_form); 433 break; 434 } 435 436 if (cu_relative_offset) 437 { 438 assert (m_cu); // CU must be valid for DW_FORM_ref forms that are compile unit relative or we will get this wrong 439 if (verbose) 440 s.PutCString(" => "); 441 442 s.Printf("{0x%8.8" PRIx64 "}", uvalue + m_cu->GetOffset()); 443 } 444 } 445 446 const char* 447 DWARFFormValue::AsCString(const DWARFDataExtractor* debug_str_data_ptr) const 448 { 449 if (IsInlinedCStr()) 450 return m_value.value.cstr; 451 else if (debug_str_data_ptr) 452 return debug_str_data_ptr->PeekCStr(m_value.value.uval); 453 return NULL; 454 } 455 456 uint64_t 457 DWARFFormValue::Reference() const 458 { 459 uint64_t die_offset = m_value.value.uval; 460 switch (m_form) 461 { 462 case DW_FORM_ref1: 463 case DW_FORM_ref2: 464 case DW_FORM_ref4: 465 case DW_FORM_ref8: 466 case DW_FORM_ref_udata: 467 assert (m_cu); // CU must be valid for DW_FORM_ref forms that are compile unit relative or we will get this wrong 468 die_offset += m_cu->GetOffset(); 469 break; 470 471 default: 472 break; 473 } 474 475 return die_offset; 476 } 477 478 uint64_t 479 DWARFFormValue::Reference (dw_offset_t base_offset) const 480 { 481 uint64_t die_offset = m_value.value.uval; 482 switch (m_form) 483 { 484 case DW_FORM_ref1: 485 case DW_FORM_ref2: 486 case DW_FORM_ref4: 487 case DW_FORM_ref8: 488 case DW_FORM_ref_udata: 489 die_offset += base_offset; 490 break; 491 492 default: 493 break; 494 } 495 496 return die_offset; 497 } 498 499 500 const uint8_t* 501 DWARFFormValue::BlockData() const 502 { 503 if (!IsInlinedCStr()) 504 return m_value.data; 505 return NULL; 506 } 507 508 509 bool 510 DWARFFormValue::IsBlockForm(const dw_form_t form) 511 { 512 switch (form) 513 { 514 case DW_FORM_block: 515 case DW_FORM_block1: 516 case DW_FORM_block2: 517 case DW_FORM_block4: 518 return true; 519 } 520 return false; 521 } 522 523 bool 524 DWARFFormValue::IsDataForm(const dw_form_t form) 525 { 526 switch (form) 527 { 528 case DW_FORM_sdata: 529 case DW_FORM_udata: 530 case DW_FORM_data1: 531 case DW_FORM_data2: 532 case DW_FORM_data4: 533 case DW_FORM_data8: 534 return true; 535 } 536 return false; 537 } 538 539 int 540 DWARFFormValue::Compare (const DWARFFormValue& a_value, const DWARFFormValue& b_value, const DWARFDataExtractor* debug_str_data_ptr) 541 { 542 dw_form_t a_form = a_value.Form(); 543 dw_form_t b_form = b_value.Form(); 544 if (a_form < b_form) 545 return -1; 546 if (a_form > b_form) 547 return 1; 548 switch (a_form) 549 { 550 case DW_FORM_addr: 551 case DW_FORM_flag: 552 case DW_FORM_data1: 553 case DW_FORM_data2: 554 case DW_FORM_data4: 555 case DW_FORM_data8: 556 case DW_FORM_udata: 557 case DW_FORM_ref_addr: 558 case DW_FORM_sec_offset: 559 case DW_FORM_flag_present: 560 case DW_FORM_ref_sig8: 561 { 562 uint64_t a = a_value.Unsigned(); 563 uint64_t b = b_value.Unsigned(); 564 if (a < b) 565 return -1; 566 if (a > b) 567 return 1; 568 return 0; 569 } 570 571 case DW_FORM_sdata: 572 { 573 int64_t a = a_value.Signed(); 574 int64_t b = b_value.Signed(); 575 if (a < b) 576 return -1; 577 if (a > b) 578 return 1; 579 return 0; 580 } 581 582 case DW_FORM_string: 583 case DW_FORM_strp: 584 { 585 const char *a_string = a_value.AsCString(debug_str_data_ptr); 586 const char *b_string = b_value.AsCString(debug_str_data_ptr); 587 if (a_string == b_string) 588 return 0; 589 else if (a_string && b_string) 590 return strcmp(a_string, b_string); 591 else if (a_string == NULL) 592 return -1; // A string is NULL, and B is valid 593 else 594 return 1; // A string valid, and B is NULL 595 } 596 597 598 case DW_FORM_block: 599 case DW_FORM_block1: 600 case DW_FORM_block2: 601 case DW_FORM_block4: 602 case DW_FORM_exprloc: 603 { 604 uint64_t a_len = a_value.Unsigned(); 605 uint64_t b_len = b_value.Unsigned(); 606 if (a_len < b_len) 607 return -1; 608 if (a_len > b_len) 609 return 1; 610 // The block lengths are the same 611 return memcmp(a_value.BlockData(), b_value.BlockData(), a_value.Unsigned()); 612 } 613 break; 614 615 case DW_FORM_ref1: 616 case DW_FORM_ref2: 617 case DW_FORM_ref4: 618 case DW_FORM_ref8: 619 case DW_FORM_ref_udata: 620 { 621 uint64_t a = a_value.Reference(); 622 uint64_t b = b_value.Reference(); 623 if (a < b) 624 return -1; 625 if (a > b) 626 return 1; 627 return 0; 628 } 629 630 case DW_FORM_indirect: 631 assert(!"This shouldn't happen after the form has been extracted..."); 632 break; 633 634 default: 635 assert(!"Unhandled DW_FORM"); 636 break; 637 } 638 return -1; 639 } 640 641