DWARFFormValue.cpp revision 309124
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 18class DWARFCompileUnit; 19 20using namespace lldb_private; 21 22 23static 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 61static uint8_t 62g_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 101static uint8_t 102g_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 139DWARFFormValue::FixedFormSizes 140DWARFFormValue::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 156DWARFFormValue::DWARFFormValue() : 157 m_cu (NULL), 158 m_form(0), 159 m_value() 160{ 161} 162 163DWARFFormValue::DWARFFormValue(const DWARFCompileUnit* cu, dw_form_t form) : 164 m_cu (cu), 165 m_form(form), 166 m_value() 167{ 168} 169 170void 171DWARFFormValue::Clear() 172{ 173 m_cu = nullptr; 174 m_form = 0; 175 memset(&m_value, 0, sizeof(m_value)); 176} 177 178bool 179DWARFFormValue::ExtractValue(const DWARFDataExtractor& data, lldb::offset_t* offset_ptr) 180{ 181 bool indirect = false; 182 bool is_block = false; 183 m_value.data = NULL; 184 uint8_t ref_addr_size; 185 // Read the value for the form into value and follow and DW_FORM_indirect instances we run into 186 do 187 { 188 indirect = false; 189 switch (m_form) 190 { 191 case DW_FORM_addr: assert(m_cu); 192 m_value.value.uval = data.GetMaxU64(offset_ptr, DWARFCompileUnit::GetAddressByteSize(m_cu)); break; 193 case DW_FORM_block2: m_value.value.uval = data.GetU16(offset_ptr); is_block = true; break; 194 case DW_FORM_block4: m_value.value.uval = data.GetU32(offset_ptr); is_block = true; break; 195 case DW_FORM_data2: m_value.value.uval = data.GetU16(offset_ptr); break; 196 case DW_FORM_data4: m_value.value.uval = data.GetU32(offset_ptr); break; 197 case DW_FORM_data8: m_value.value.uval = data.GetU64(offset_ptr); break; 198 case DW_FORM_string: m_value.value.cstr = data.GetCStr(offset_ptr); break; 199 case DW_FORM_exprloc: 200 case DW_FORM_block: m_value.value.uval = data.GetULEB128(offset_ptr); is_block = true; break; 201 case DW_FORM_block1: m_value.value.uval = data.GetU8(offset_ptr); is_block = true; break; 202 case DW_FORM_data1: m_value.value.uval = data.GetU8(offset_ptr); break; 203 case DW_FORM_flag: m_value.value.uval = data.GetU8(offset_ptr); break; 204 case DW_FORM_sdata: m_value.value.sval = data.GetSLEB128(offset_ptr); break; 205 case DW_FORM_strp: assert(m_cu); 206 m_value.value.uval = data.GetMaxU64(offset_ptr, DWARFCompileUnit::IsDWARF64(m_cu) ? 8 : 4); break; 207 // case DW_FORM_APPLE_db_str: 208 case DW_FORM_udata: m_value.value.uval = data.GetULEB128(offset_ptr); break; 209 case DW_FORM_ref_addr: assert(m_cu); 210 ref_addr_size = 4; 211 if (m_cu->GetVersion() <= 2) 212 ref_addr_size = m_cu->GetAddressByteSize(); 213 else 214 ref_addr_size = m_cu->IsDWARF64() ? 8 : 4; 215 m_value.value.uval = data.GetMaxU64(offset_ptr, ref_addr_size); break; 216 case DW_FORM_ref1: m_value.value.uval = data.GetU8(offset_ptr); break; 217 case DW_FORM_ref2: m_value.value.uval = data.GetU16(offset_ptr); break; 218 case DW_FORM_ref4: m_value.value.uval = data.GetU32(offset_ptr); break; 219 case DW_FORM_ref8: m_value.value.uval = data.GetU64(offset_ptr); break; 220 case DW_FORM_ref_udata: m_value.value.uval = data.GetULEB128(offset_ptr); break; 221 case DW_FORM_indirect: 222 m_form = data.GetULEB128(offset_ptr); 223 indirect = true; 224 break; 225 226 case DW_FORM_sec_offset: assert(m_cu); 227 m_value.value.uval = data.GetMaxU64(offset_ptr, DWARFCompileUnit::IsDWARF64(m_cu) ? 8 : 4); break; 228 case DW_FORM_flag_present: m_value.value.uval = 1; break; 229 case DW_FORM_ref_sig8: m_value.value.uval = data.GetU64(offset_ptr); break; 230 case DW_FORM_GNU_str_index: m_value.value.uval = data.GetULEB128(offset_ptr); break; 231 case DW_FORM_GNU_addr_index: m_value.value.uval = data.GetULEB128(offset_ptr); break; 232 default: 233 return false; 234 break; 235 } 236 } while (indirect); 237 238 if (is_block) 239 { 240 m_value.data = data.PeekData(*offset_ptr, m_value.value.uval); 241 if (m_value.data != NULL) 242 { 243 *offset_ptr += m_value.value.uval; 244 } 245 } 246 247 return true; 248} 249 250bool 251DWARFFormValue::SkipValue(const DWARFDataExtractor& debug_info_data, lldb::offset_t *offset_ptr) const 252{ 253 return DWARFFormValue::SkipValue(m_form, debug_info_data, offset_ptr, m_cu); 254} 255 256bool 257DWARFFormValue::SkipValue(dw_form_t form, const DWARFDataExtractor& debug_info_data, lldb::offset_t *offset_ptr, const DWARFCompileUnit* cu) 258{ 259 uint8_t ref_addr_size; 260 switch (form) 261 { 262 // Blocks if inlined data that have a length field and the data bytes 263 // inlined in the .debug_info 264 case DW_FORM_exprloc: 265 case DW_FORM_block: { dw_uleb128_t size = debug_info_data.GetULEB128(offset_ptr); *offset_ptr += size; } return true; 266 case DW_FORM_block1: { dw_uleb128_t size = debug_info_data.GetU8(offset_ptr); *offset_ptr += size; } return true; 267 case DW_FORM_block2: { dw_uleb128_t size = debug_info_data.GetU16(offset_ptr); *offset_ptr += size; } return true; 268 case DW_FORM_block4: { dw_uleb128_t size = debug_info_data.GetU32(offset_ptr); *offset_ptr += size; } return true; 269 270 // Inlined NULL terminated C-strings 271 case DW_FORM_string: 272 debug_info_data.GetCStr(offset_ptr); 273 return true; 274 275 // Compile unit address sized values 276 case DW_FORM_addr: 277 *offset_ptr += DWARFCompileUnit::GetAddressByteSize(cu); 278 return true; 279 280 case DW_FORM_ref_addr: 281 ref_addr_size = 4; 282 assert (cu); // CU must be valid for DW_FORM_ref_addr objects or we will get this wrong 283 if (cu->GetVersion() <= 2) 284 ref_addr_size = cu->GetAddressByteSize(); 285 else 286 ref_addr_size = cu->IsDWARF64() ? 8 : 4; 287 *offset_ptr += ref_addr_size; 288 return true; 289 290 // 0 bytes values (implied from DW_FORM) 291 case DW_FORM_flag_present: 292 return true; 293 294 // 1 byte values 295 case DW_FORM_data1: 296 case DW_FORM_flag: 297 case DW_FORM_ref1: 298 *offset_ptr += 1; 299 return true; 300 301 // 2 byte values 302 case DW_FORM_data2: 303 case DW_FORM_ref2: 304 *offset_ptr += 2; 305 return true; 306 307 // 32 bit for DWARF 32, 64 for DWARF 64 308 case DW_FORM_sec_offset: 309 case DW_FORM_strp: 310 assert(cu); 311 *offset_ptr += (cu->IsDWARF64() ? 8 : 4); 312 return true; 313 314 // 4 byte values 315 case DW_FORM_data4: 316 case DW_FORM_ref4: 317 *offset_ptr += 4; 318 return true; 319 320 // 8 byte values 321 case DW_FORM_data8: 322 case DW_FORM_ref8: 323 case DW_FORM_ref_sig8: 324 *offset_ptr += 8; 325 return true; 326 327 // signed or unsigned LEB 128 values 328 case DW_FORM_sdata: 329 case DW_FORM_udata: 330 case DW_FORM_ref_udata: 331 case DW_FORM_GNU_addr_index: 332 case DW_FORM_GNU_str_index: 333 debug_info_data.Skip_LEB128(offset_ptr); 334 return true; 335 336 case DW_FORM_indirect: 337 { 338 dw_form_t indirect_form = debug_info_data.GetULEB128(offset_ptr); 339 return DWARFFormValue::SkipValue (indirect_form, 340 debug_info_data, 341 offset_ptr, 342 cu); 343 } 344 345 default: 346 break; 347 } 348 return false; 349} 350 351 352void 353DWARFFormValue::Dump(Stream &s) const 354{ 355 uint64_t uvalue = Unsigned(); 356 bool cu_relative_offset = false; 357 358 bool verbose = s.GetVerbose(); 359 360 switch (m_form) 361 { 362 case DW_FORM_addr: s.Address(uvalue, sizeof (uint64_t)); break; 363 case DW_FORM_flag: 364 case DW_FORM_data1: s.PutHex8(uvalue); break; 365 case DW_FORM_data2: s.PutHex16(uvalue); break; 366 case DW_FORM_sec_offset: 367 case DW_FORM_data4: s.PutHex32(uvalue); break; 368 case DW_FORM_ref_sig8: 369 case DW_FORM_data8: s.PutHex64(uvalue); break; 370 case DW_FORM_string: s.QuotedCString(AsCString()); break; 371 case DW_FORM_exprloc: 372 case DW_FORM_block: 373 case DW_FORM_block1: 374 case DW_FORM_block2: 375 case DW_FORM_block4: 376 if (uvalue > 0) 377 { 378 switch (m_form) 379 { 380 case DW_FORM_exprloc: 381 case DW_FORM_block: s.Printf("<0x%" PRIx64 "> ", uvalue); break; 382 case DW_FORM_block1: s.Printf("<0x%2.2x> ", (uint8_t)uvalue); break; 383 case DW_FORM_block2: s.Printf("<0x%4.4x> ", (uint16_t)uvalue); break; 384 case DW_FORM_block4: s.Printf("<0x%8.8x> ", (uint32_t)uvalue); break; 385 default: break; 386 } 387 388 const uint8_t* data_ptr = m_value.data; 389 if (data_ptr) 390 { 391 const uint8_t* end_data_ptr = data_ptr + uvalue; // uvalue contains size of block 392 while (data_ptr < end_data_ptr) 393 { 394 s.Printf("%2.2x ", *data_ptr); 395 ++data_ptr; 396 } 397 } 398 else 399 s.PutCString("NULL"); 400 } 401 break; 402 403 case DW_FORM_sdata: s.PutSLEB128(uvalue); break; 404 case DW_FORM_udata: s.PutULEB128(uvalue); break; 405 case DW_FORM_strp: 406 { 407 const char* dbg_str = AsCString(); 408 if (dbg_str) 409 { 410 if (verbose) 411 s.Printf(" .debug_str[0x%8.8x] = ", (uint32_t)uvalue); 412 s.QuotedCString(dbg_str); 413 } 414 else 415 { 416 s.PutHex32(uvalue); 417 } 418 } 419 break; 420 421 case DW_FORM_ref_addr: 422 { 423 assert (m_cu); // CU must be valid for DW_FORM_ref_addr objects or we will get this wrong 424 if (m_cu->GetVersion() <= 2) 425 s.Address(uvalue, sizeof (uint64_t) * 2); 426 else 427 s.Address(uvalue, 4 * 2);// 4 for DWARF32, 8 for DWARF64, but we don't support DWARF64 yet 428 break; 429 } 430 case DW_FORM_ref1: cu_relative_offset = true; if (verbose) s.Printf("cu + 0x%2.2x", (uint8_t)uvalue); break; 431 case DW_FORM_ref2: cu_relative_offset = true; if (verbose) s.Printf("cu + 0x%4.4x", (uint16_t)uvalue); break; 432 case DW_FORM_ref4: cu_relative_offset = true; if (verbose) s.Printf("cu + 0x%4.4x", (uint32_t)uvalue); break; 433 case DW_FORM_ref8: cu_relative_offset = true; if (verbose) s.Printf("cu + 0x%8.8" PRIx64, uvalue); break; 434 case DW_FORM_ref_udata: cu_relative_offset = true; if (verbose) s.Printf("cu + 0x%" PRIx64, uvalue); break; 435 436 // All DW_FORM_indirect attributes should be resolved prior to calling this function 437 case DW_FORM_indirect: s.PutCString("DW_FORM_indirect"); break; 438 case DW_FORM_flag_present: break; 439 default: 440 s.Printf("DW_FORM(0x%4.4x)", m_form); 441 break; 442 } 443 444 if (cu_relative_offset) 445 { 446 assert (m_cu); // CU must be valid for DW_FORM_ref forms that are compile unit relative or we will get this wrong 447 if (verbose) 448 s.PutCString(" => "); 449 450 s.Printf("{0x%8.8" PRIx64 "}", uvalue + m_cu->GetOffset()); 451 } 452} 453 454const char* 455DWARFFormValue::AsCString() const 456{ 457 SymbolFileDWARF* symbol_file = m_cu->GetSymbolFileDWARF(); 458 459 if (m_form == DW_FORM_string) 460 { 461 return m_value.value.cstr; 462 } 463 else if (m_form == DW_FORM_strp) 464 { 465 if (!symbol_file) 466 return nullptr; 467 468 return symbol_file->get_debug_str_data().PeekCStr(m_value.value.uval); 469 } 470 else if (m_form == DW_FORM_GNU_str_index) 471 { 472 if (!symbol_file) 473 return nullptr; 474 475 uint32_t index_size = m_cu->IsDWARF64() ? 8 : 4; 476 lldb::offset_t offset = m_value.value.uval * index_size; 477 dw_offset_t str_offset = symbol_file->get_debug_str_offsets_data().GetMaxU64(&offset, index_size); 478 return symbol_file->get_debug_str_data().PeekCStr(str_offset); 479 } 480 return nullptr; 481} 482 483dw_addr_t 484DWARFFormValue::Address() const 485{ 486 SymbolFileDWARF* symbol_file = m_cu->GetSymbolFileDWARF(); 487 488 if (m_form == DW_FORM_addr) 489 return Unsigned(); 490 491 assert(m_cu); 492 assert(m_form == DW_FORM_GNU_addr_index); 493 494 if (!symbol_file) 495 return 0; 496 497 uint32_t index_size = m_cu->GetAddressByteSize(); 498 dw_offset_t addr_base = m_cu->GetAddrBase(); 499 lldb::offset_t offset = addr_base + m_value.value.uval * index_size; 500 return symbol_file->get_debug_addr_data().GetMaxU64(&offset, index_size); 501} 502 503uint64_t 504DWARFFormValue::Reference() const 505{ 506 uint64_t die_offset = m_value.value.uval; 507 switch (m_form) 508 { 509 case DW_FORM_ref1: 510 case DW_FORM_ref2: 511 case DW_FORM_ref4: 512 case DW_FORM_ref8: 513 case DW_FORM_ref_udata: 514 assert (m_cu); // CU must be valid for DW_FORM_ref forms that are compile unit relative or we will get this wrong 515 die_offset += m_cu->GetOffset(); 516 break; 517 518 default: 519 break; 520 } 521 522 return die_offset; 523} 524 525uint64_t 526DWARFFormValue::Reference (dw_offset_t base_offset) const 527{ 528 uint64_t die_offset = m_value.value.uval; 529 switch (m_form) 530 { 531 case DW_FORM_ref1: 532 case DW_FORM_ref2: 533 case DW_FORM_ref4: 534 case DW_FORM_ref8: 535 case DW_FORM_ref_udata: 536 die_offset += base_offset; 537 break; 538 539 default: 540 break; 541 } 542 543 return die_offset; 544} 545 546 547const uint8_t* 548DWARFFormValue::BlockData() const 549{ 550 return m_value.data; 551} 552 553 554bool 555DWARFFormValue::IsBlockForm(const dw_form_t form) 556{ 557 switch (form) 558 { 559 case DW_FORM_block: 560 case DW_FORM_block1: 561 case DW_FORM_block2: 562 case DW_FORM_block4: 563 return true; 564 } 565 return false; 566} 567 568bool 569DWARFFormValue::IsDataForm(const dw_form_t form) 570{ 571 switch (form) 572 { 573 case DW_FORM_sdata: 574 case DW_FORM_udata: 575 case DW_FORM_data1: 576 case DW_FORM_data2: 577 case DW_FORM_data4: 578 case DW_FORM_data8: 579 return true; 580 } 581 return false; 582} 583 584int 585DWARFFormValue::Compare (const DWARFFormValue& a_value, 586 const DWARFFormValue& b_value) 587{ 588 dw_form_t a_form = a_value.Form(); 589 dw_form_t b_form = b_value.Form(); 590 if (a_form < b_form) 591 return -1; 592 if (a_form > b_form) 593 return 1; 594 switch (a_form) 595 { 596 case DW_FORM_addr: 597 case DW_FORM_flag: 598 case DW_FORM_data1: 599 case DW_FORM_data2: 600 case DW_FORM_data4: 601 case DW_FORM_data8: 602 case DW_FORM_udata: 603 case DW_FORM_ref_addr: 604 case DW_FORM_sec_offset: 605 case DW_FORM_flag_present: 606 case DW_FORM_ref_sig8: 607 case DW_FORM_GNU_addr_index: 608 { 609 uint64_t a = a_value.Unsigned(); 610 uint64_t b = b_value.Unsigned(); 611 if (a < b) 612 return -1; 613 if (a > b) 614 return 1; 615 return 0; 616 } 617 618 case DW_FORM_sdata: 619 { 620 int64_t a = a_value.Signed(); 621 int64_t b = b_value.Signed(); 622 if (a < b) 623 return -1; 624 if (a > b) 625 return 1; 626 return 0; 627 } 628 629 case DW_FORM_string: 630 case DW_FORM_strp: 631 case DW_FORM_GNU_str_index: 632 { 633 const char *a_string = a_value.AsCString(); 634 const char *b_string = b_value.AsCString(); 635 if (a_string == b_string) 636 return 0; 637 else if (a_string && b_string) 638 return strcmp(a_string, b_string); 639 else if (a_string == NULL) 640 return -1; // A string is NULL, and B is valid 641 else 642 return 1; // A string valid, and B is NULL 643 } 644 645 646 case DW_FORM_block: 647 case DW_FORM_block1: 648 case DW_FORM_block2: 649 case DW_FORM_block4: 650 case DW_FORM_exprloc: 651 { 652 uint64_t a_len = a_value.Unsigned(); 653 uint64_t b_len = b_value.Unsigned(); 654 if (a_len < b_len) 655 return -1; 656 if (a_len > b_len) 657 return 1; 658 // The block lengths are the same 659 return memcmp(a_value.BlockData(), b_value.BlockData(), a_value.Unsigned()); 660 } 661 break; 662 663 case DW_FORM_ref1: 664 case DW_FORM_ref2: 665 case DW_FORM_ref4: 666 case DW_FORM_ref8: 667 case DW_FORM_ref_udata: 668 { 669 uint64_t a = a_value.Reference(); 670 uint64_t b = b_value.Reference(); 671 if (a < b) 672 return -1; 673 if (a > b) 674 return 1; 675 return 0; 676 } 677 678 case DW_FORM_indirect: 679 assert(!"This shouldn't happen after the form has been extracted..."); 680 break; 681 682 default: 683 assert(!"Unhandled DW_FORM"); 684 break; 685 } 686 return -1; 687} 688 689