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 DWARFFormValue::FixedFormSizes 140 DWARFFormValue::GetFixedFormSizesForAddressSize (uint8_t addr_size, bool is_dwarf64) 141 { 142 if (!is_dwarf64) { 143 switch (addr_size) 144 { 145 case 4: return FixedFormSizes(g_form_sizes_addr4, sizeof(g_form_sizes_addr4)); 146 case 8: return FixedFormSizes(g_form_sizes_addr8, sizeof(g_form_sizes_addr8)); 147 } 148 } else { 149 if (addr_size == 8) 150 return FixedFormSizes(g_form_sizes_addr8_dwarf64, sizeof(g_form_sizes_addr8_dwarf64)); 151 // is_dwarf64 && addr_size == 4 : no provider does this. 152 } 153 return FixedFormSizes(); 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); break; 191 case DW_FORM_exprloc: 192 case DW_FORM_block: m_value.value.uval = data.GetULEB128(offset_ptr); is_block = true; break; 193 case DW_FORM_block1: m_value.value.uval = data.GetU8(offset_ptr); is_block = true; break; 194 case DW_FORM_data1: m_value.value.uval = data.GetU8(offset_ptr); break; 195 case DW_FORM_flag: m_value.value.uval = data.GetU8(offset_ptr); break; 196 case DW_FORM_sdata: m_value.value.sval = data.GetSLEB128(offset_ptr); break; 197 case DW_FORM_strp: assert(m_cu); 198 m_value.value.uval = data.GetMaxU64(offset_ptr, DWARFCompileUnit::IsDWARF64(m_cu) ? 8 : 4); break; 199 // case DW_FORM_APPLE_db_str: 200 case DW_FORM_udata: m_value.value.uval = data.GetULEB128(offset_ptr); break; 201 case DW_FORM_ref_addr: assert(m_cu); 202 ref_addr_size = 4; 203 if (m_cu->GetVersion() <= 2) 204 ref_addr_size = m_cu->GetAddressByteSize(); 205 else 206 ref_addr_size = m_cu->IsDWARF64() ? 8 : 4; 207 m_value.value.uval = data.GetMaxU64(offset_ptr, ref_addr_size); break; 208 case DW_FORM_ref1: m_value.value.uval = data.GetU8(offset_ptr); break; 209 case DW_FORM_ref2: m_value.value.uval = data.GetU16(offset_ptr); break; 210 case DW_FORM_ref4: m_value.value.uval = data.GetU32(offset_ptr); break; 211 case DW_FORM_ref8: m_value.value.uval = data.GetU64(offset_ptr); break; 212 case DW_FORM_ref_udata: m_value.value.uval = data.GetULEB128(offset_ptr); break; 213 case DW_FORM_indirect: 214 m_form = data.GetULEB128(offset_ptr); 215 indirect = true; 216 break; 217 218 case DW_FORM_sec_offset: assert(m_cu); 219 m_value.value.uval = data.GetMaxU64(offset_ptr, DWARFCompileUnit::IsDWARF64(m_cu) ? 8 : 4); break; 220 case DW_FORM_flag_present: m_value.value.uval = 1; break; 221 case DW_FORM_ref_sig8: m_value.value.uval = data.GetU64(offset_ptr); break; 222 case DW_FORM_GNU_str_index: m_value.value.uval = data.GetULEB128(offset_ptr); break; 223 case DW_FORM_GNU_addr_index: m_value.value.uval = data.GetULEB128(offset_ptr); break; 224 default: 225 return false; 226 break; 227 } 228 } while (indirect); 229 230 if (is_block) 231 { 232 m_value.data = data.PeekData(*offset_ptr, m_value.value.uval); 233 if (m_value.data != NULL) 234 { 235 *offset_ptr += m_value.value.uval; 236 } 237 } 238 239 return true; 240 } 241 242 bool 243 DWARFFormValue::SkipValue(const DWARFDataExtractor& debug_info_data, lldb::offset_t *offset_ptr) const 244 { 245 return DWARFFormValue::SkipValue(m_form, debug_info_data, offset_ptr, m_cu); 246 } 247 248 bool 249 DWARFFormValue::SkipValue(dw_form_t form, const DWARFDataExtractor& debug_info_data, lldb::offset_t *offset_ptr, const DWARFCompileUnit* cu) 250 { 251 uint8_t ref_addr_size; 252 switch (form) 253 { 254 // Blocks if inlined data that have a length field and the data bytes 255 // inlined in the .debug_info 256 case DW_FORM_exprloc: 257 case DW_FORM_block: { dw_uleb128_t size = debug_info_data.GetULEB128(offset_ptr); *offset_ptr += size; } return true; 258 case DW_FORM_block1: { dw_uleb128_t size = debug_info_data.GetU8(offset_ptr); *offset_ptr += size; } return true; 259 case DW_FORM_block2: { dw_uleb128_t size = debug_info_data.GetU16(offset_ptr); *offset_ptr += size; } return true; 260 case DW_FORM_block4: { dw_uleb128_t size = debug_info_data.GetU32(offset_ptr); *offset_ptr += size; } return true; 261 262 // Inlined NULL terminated C-strings 263 case DW_FORM_string: 264 debug_info_data.GetCStr(offset_ptr); 265 return true; 266 267 // Compile unit address sized values 268 case DW_FORM_addr: 269 *offset_ptr += DWARFCompileUnit::GetAddressByteSize(cu); 270 return true; 271 272 case DW_FORM_ref_addr: 273 ref_addr_size = 4; 274 assert (cu); // CU must be valid for DW_FORM_ref_addr objects or we will get this wrong 275 if (cu->GetVersion() <= 2) 276 ref_addr_size = cu->GetAddressByteSize(); 277 else 278 ref_addr_size = cu->IsDWARF64() ? 8 : 4; 279 *offset_ptr += ref_addr_size; 280 return true; 281 282 // 0 bytes values (implied from DW_FORM) 283 case DW_FORM_flag_present: 284 return true; 285 286 // 1 byte values 287 case DW_FORM_data1: 288 case DW_FORM_flag: 289 case DW_FORM_ref1: 290 *offset_ptr += 1; 291 return true; 292 293 // 2 byte values 294 case DW_FORM_data2: 295 case DW_FORM_ref2: 296 *offset_ptr += 2; 297 return true; 298 299 // 32 bit for DWARF 32, 64 for DWARF 64 300 case DW_FORM_sec_offset: 301 case DW_FORM_strp: 302 assert(cu); 303 *offset_ptr += (cu->IsDWARF64() ? 8 : 4); 304 return true; 305 306 // 4 byte values 307 case DW_FORM_data4: 308 case DW_FORM_ref4: 309 *offset_ptr += 4; 310 return true; 311 312 // 8 byte values 313 case DW_FORM_data8: 314 case DW_FORM_ref8: 315 case DW_FORM_ref_sig8: 316 *offset_ptr += 8; 317 return true; 318 319 // signed or unsigned LEB 128 values 320 case DW_FORM_sdata: 321 case DW_FORM_udata: 322 case DW_FORM_ref_udata: 323 case DW_FORM_GNU_addr_index: 324 case DW_FORM_GNU_str_index: 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 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()); 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 { 399 const char* dbg_str = AsCString(); 400 if (dbg_str) 401 { 402 if (verbose) 403 s.Printf(" .debug_str[0x%8.8x] = ", (uint32_t)uvalue); 404 s.QuotedCString(dbg_str); 405 } 406 else 407 { 408 s.PutHex32(uvalue); 409 } 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 448 { 449 SymbolFileDWARF* symbol_file = m_cu->GetSymbolFileDWARF(); 450 451 if (m_form == DW_FORM_string) 452 { 453 return m_value.value.cstr; 454 } 455 else if (m_form == DW_FORM_strp) 456 { 457 if (!symbol_file) 458 return nullptr; 459 460 return symbol_file->get_debug_str_data().PeekCStr(m_value.value.uval); 461 } 462 else if (m_form == DW_FORM_GNU_str_index) 463 { 464 if (!symbol_file) 465 return nullptr; 466 467 uint32_t index_size = m_cu->IsDWARF64() ? 8 : 4; 468 lldb::offset_t offset = m_value.value.uval * index_size; 469 dw_offset_t str_offset = symbol_file->get_debug_str_offsets_data().GetMaxU64(&offset, index_size); 470 return symbol_file->get_debug_str_data().PeekCStr(str_offset); 471 } 472 return nullptr; 473 } 474 475 dw_addr_t 476 DWARFFormValue::Address() const 477 { 478 SymbolFileDWARF* symbol_file = m_cu->GetSymbolFileDWARF(); 479 480 if (m_form == DW_FORM_addr) 481 return Unsigned(); 482 483 assert(m_cu); 484 assert(m_form == DW_FORM_GNU_addr_index); 485 486 if (!symbol_file) 487 return 0; 488 489 uint32_t index_size = m_cu->GetAddressByteSize(); 490 dw_offset_t addr_base = m_cu->GetAddrBase(); 491 lldb::offset_t offset = addr_base + m_value.value.uval * index_size; 492 return symbol_file->get_debug_addr_data().GetMaxU64(&offset, index_size); 493 } 494 495 uint64_t 496 DWARFFormValue::Reference() const 497 { 498 uint64_t die_offset = m_value.value.uval; 499 switch (m_form) 500 { 501 case DW_FORM_ref1: 502 case DW_FORM_ref2: 503 case DW_FORM_ref4: 504 case DW_FORM_ref8: 505 case DW_FORM_ref_udata: 506 assert (m_cu); // CU must be valid for DW_FORM_ref forms that are compile unit relative or we will get this wrong 507 die_offset += m_cu->GetOffset(); 508 break; 509 510 default: 511 break; 512 } 513 514 return die_offset; 515 } 516 517 uint64_t 518 DWARFFormValue::Reference (dw_offset_t base_offset) const 519 { 520 uint64_t die_offset = m_value.value.uval; 521 switch (m_form) 522 { 523 case DW_FORM_ref1: 524 case DW_FORM_ref2: 525 case DW_FORM_ref4: 526 case DW_FORM_ref8: 527 case DW_FORM_ref_udata: 528 die_offset += base_offset; 529 break; 530 531 default: 532 break; 533 } 534 535 return die_offset; 536 } 537 538 539 const uint8_t* 540 DWARFFormValue::BlockData() const 541 { 542 return m_value.data; 543 } 544 545 546 bool 547 DWARFFormValue::IsBlockForm(const dw_form_t form) 548 { 549 switch (form) 550 { 551 case DW_FORM_block: 552 case DW_FORM_block1: 553 case DW_FORM_block2: 554 case DW_FORM_block4: 555 return true; 556 } 557 return false; 558 } 559 560 bool 561 DWARFFormValue::IsDataForm(const dw_form_t form) 562 { 563 switch (form) 564 { 565 case DW_FORM_sdata: 566 case DW_FORM_udata: 567 case DW_FORM_data1: 568 case DW_FORM_data2: 569 case DW_FORM_data4: 570 case DW_FORM_data8: 571 return true; 572 } 573 return false; 574 } 575 576 int 577 DWARFFormValue::Compare (const DWARFFormValue& a_value, 578 const DWARFFormValue& b_value) 579 { 580 dw_form_t a_form = a_value.Form(); 581 dw_form_t b_form = b_value.Form(); 582 if (a_form < b_form) 583 return -1; 584 if (a_form > b_form) 585 return 1; 586 switch (a_form) 587 { 588 case DW_FORM_addr: 589 case DW_FORM_flag: 590 case DW_FORM_data1: 591 case DW_FORM_data2: 592 case DW_FORM_data4: 593 case DW_FORM_data8: 594 case DW_FORM_udata: 595 case DW_FORM_ref_addr: 596 case DW_FORM_sec_offset: 597 case DW_FORM_flag_present: 598 case DW_FORM_ref_sig8: 599 case DW_FORM_GNU_addr_index: 600 { 601 uint64_t a = a_value.Unsigned(); 602 uint64_t b = b_value.Unsigned(); 603 if (a < b) 604 return -1; 605 if (a > b) 606 return 1; 607 return 0; 608 } 609 610 case DW_FORM_sdata: 611 { 612 int64_t a = a_value.Signed(); 613 int64_t b = b_value.Signed(); 614 if (a < b) 615 return -1; 616 if (a > b) 617 return 1; 618 return 0; 619 } 620 621 case DW_FORM_string: 622 case DW_FORM_strp: 623 case DW_FORM_GNU_str_index: 624 { 625 const char *a_string = a_value.AsCString(); 626 const char *b_string = b_value.AsCString(); 627 if (a_string == b_string) 628 return 0; 629 else if (a_string && b_string) 630 return strcmp(a_string, b_string); 631 else if (a_string == NULL) 632 return -1; // A string is NULL, and B is valid 633 else 634 return 1; // A string valid, and B is NULL 635 } 636 637 638 case DW_FORM_block: 639 case DW_FORM_block1: 640 case DW_FORM_block2: 641 case DW_FORM_block4: 642 case DW_FORM_exprloc: 643 { 644 uint64_t a_len = a_value.Unsigned(); 645 uint64_t b_len = b_value.Unsigned(); 646 if (a_len < b_len) 647 return -1; 648 if (a_len > b_len) 649 return 1; 650 // The block lengths are the same 651 return memcmp(a_value.BlockData(), b_value.BlockData(), a_value.Unsigned()); 652 } 653 break; 654 655 case DW_FORM_ref1: 656 case DW_FORM_ref2: 657 case DW_FORM_ref4: 658 case DW_FORM_ref8: 659 case DW_FORM_ref_udata: 660 { 661 uint64_t a = a_value.Reference(); 662 uint64_t b = b_value.Reference(); 663 if (a < b) 664 return -1; 665 if (a > b) 666 return 1; 667 return 0; 668 } 669 670 case DW_FORM_indirect: 671 assert(!"This shouldn't happen after the form has been extracted..."); 672 break; 673 674 default: 675 assert(!"Unhandled DW_FORM"); 676 break; 677 } 678 return -1; 679 } 680 681