1 //===- DWARFFormValue.cpp -------------------------------------------------===// 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 "llvm/DebugInfo/DWARF/DWARFFormValue.h" 11 #include "SyntaxHighlighting.h" 12 #include "llvm/ADT/ArrayRef.h" 13 #include "llvm/ADT/None.h" 14 #include "llvm/ADT/Optional.h" 15 #include "llvm/ADT/StringRef.h" 16 #include "llvm/BinaryFormat/Dwarf.h" 17 #include "llvm/DebugInfo/DWARF/DWARFContext.h" 18 #include "llvm/DebugInfo/DWARF/DWARFRelocMap.h" 19 #include "llvm/DebugInfo/DWARF/DWARFUnit.h" 20 #include "llvm/Support/ErrorHandling.h" 21 #include "llvm/Support/Format.h" 22 #include "llvm/Support/raw_ostream.h" 23 #include <cinttypes> 24 #include <cstdint> 25 #include <limits> 26 27 using namespace llvm; 28 using namespace dwarf; 29 using namespace syntax; 30 31 static const DWARFFormValue::FormClass DWARF4FormClasses[] = { 32 DWARFFormValue::FC_Unknown, // 0x0 33 DWARFFormValue::FC_Address, // 0x01 DW_FORM_addr 34 DWARFFormValue::FC_Unknown, // 0x02 unused 35 DWARFFormValue::FC_Block, // 0x03 DW_FORM_block2 36 DWARFFormValue::FC_Block, // 0x04 DW_FORM_block4 37 DWARFFormValue::FC_Constant, // 0x05 DW_FORM_data2 38 // --- These can be FC_SectionOffset in DWARF3 and below: 39 DWARFFormValue::FC_Constant, // 0x06 DW_FORM_data4 40 DWARFFormValue::FC_Constant, // 0x07 DW_FORM_data8 41 // --- 42 DWARFFormValue::FC_String, // 0x08 DW_FORM_string 43 DWARFFormValue::FC_Block, // 0x09 DW_FORM_block 44 DWARFFormValue::FC_Block, // 0x0a DW_FORM_block1 45 DWARFFormValue::FC_Constant, // 0x0b DW_FORM_data1 46 DWARFFormValue::FC_Flag, // 0x0c DW_FORM_flag 47 DWARFFormValue::FC_Constant, // 0x0d DW_FORM_sdata 48 DWARFFormValue::FC_String, // 0x0e DW_FORM_strp 49 DWARFFormValue::FC_Constant, // 0x0f DW_FORM_udata 50 DWARFFormValue::FC_Reference, // 0x10 DW_FORM_ref_addr 51 DWARFFormValue::FC_Reference, // 0x11 DW_FORM_ref1 52 DWARFFormValue::FC_Reference, // 0x12 DW_FORM_ref2 53 DWARFFormValue::FC_Reference, // 0x13 DW_FORM_ref4 54 DWARFFormValue::FC_Reference, // 0x14 DW_FORM_ref8 55 DWARFFormValue::FC_Reference, // 0x15 DW_FORM_ref_udata 56 DWARFFormValue::FC_Indirect, // 0x16 DW_FORM_indirect 57 DWARFFormValue::FC_SectionOffset, // 0x17 DW_FORM_sec_offset 58 DWARFFormValue::FC_Exprloc, // 0x18 DW_FORM_exprloc 59 DWARFFormValue::FC_Flag, // 0x19 DW_FORM_flag_present 60 }; 61 62 Optional<uint8_t> 63 DWARFFormValue::getFixedByteSize(dwarf::Form Form, 64 const DWARFFormParams &Params) { 65 switch (Form) { 66 case DW_FORM_addr: 67 assert(Params.Version && Params.AddrSize && "Invalid Params for form"); 68 return Params.AddrSize; 69 70 case DW_FORM_block: // ULEB128 length L followed by L bytes. 71 case DW_FORM_block1: // 1 byte length L followed by L bytes. 72 case DW_FORM_block2: // 2 byte length L followed by L bytes. 73 case DW_FORM_block4: // 4 byte length L followed by L bytes. 74 case DW_FORM_string: // C-string with null terminator. 75 case DW_FORM_sdata: // SLEB128. 76 case DW_FORM_udata: // ULEB128. 77 case DW_FORM_ref_udata: // ULEB128. 78 case DW_FORM_indirect: // ULEB128. 79 case DW_FORM_exprloc: // ULEB128 length L followed by L bytes. 80 case DW_FORM_strx: // ULEB128. 81 case DW_FORM_addrx: // ULEB128. 82 case DW_FORM_loclistx: // ULEB128. 83 case DW_FORM_rnglistx: // ULEB128. 84 case DW_FORM_GNU_addr_index: // ULEB128. 85 case DW_FORM_GNU_str_index: // ULEB128. 86 return None; 87 88 case DW_FORM_ref_addr: 89 assert(Params.Version && Params.AddrSize && "Invalid Params for form"); 90 return Params.getRefAddrByteSize(); 91 92 case DW_FORM_flag: 93 case DW_FORM_data1: 94 case DW_FORM_ref1: 95 case DW_FORM_strx1: 96 case DW_FORM_addrx1: 97 return 1; 98 99 case DW_FORM_data2: 100 case DW_FORM_ref2: 101 case DW_FORM_strx2: 102 case DW_FORM_addrx2: 103 return 2; 104 105 case DW_FORM_strx3: 106 return 3; 107 108 case DW_FORM_data4: 109 case DW_FORM_ref4: 110 case DW_FORM_ref_sup4: 111 case DW_FORM_strx4: 112 case DW_FORM_addrx4: 113 return 4; 114 115 case DW_FORM_strp: 116 case DW_FORM_GNU_ref_alt: 117 case DW_FORM_GNU_strp_alt: 118 case DW_FORM_line_strp: 119 case DW_FORM_sec_offset: 120 case DW_FORM_strp_sup: 121 assert(Params.Version && Params.AddrSize && "Invalid Params for form"); 122 return Params.getDwarfOffsetByteSize(); 123 124 case DW_FORM_data8: 125 case DW_FORM_ref8: 126 case DW_FORM_ref_sig8: 127 case DW_FORM_ref_sup8: 128 return 8; 129 130 case DW_FORM_flag_present: 131 return 0; 132 133 case DW_FORM_data16: 134 return 16; 135 136 case DW_FORM_implicit_const: 137 // The implicit value is stored in the abbreviation as a SLEB128, and 138 // there no data in debug info. 139 return 0; 140 141 default: 142 llvm_unreachable("Handle this form in this switch statement"); 143 } 144 return None; 145 } 146 147 bool DWARFFormValue::skipValue(dwarf::Form Form, DataExtractor DebugInfoData, 148 uint32_t *OffsetPtr, 149 const DWARFFormParams &Params) { 150 bool Indirect = false; 151 do { 152 switch (Form) { 153 // Blocks of inlined data that have a length field and the data bytes 154 // inlined in the .debug_info. 155 case DW_FORM_exprloc: 156 case DW_FORM_block: { 157 uint64_t size = DebugInfoData.getULEB128(OffsetPtr); 158 *OffsetPtr += size; 159 return true; 160 } 161 case DW_FORM_block1: { 162 uint8_t size = DebugInfoData.getU8(OffsetPtr); 163 *OffsetPtr += size; 164 return true; 165 } 166 case DW_FORM_block2: { 167 uint16_t size = DebugInfoData.getU16(OffsetPtr); 168 *OffsetPtr += size; 169 return true; 170 } 171 case DW_FORM_block4: { 172 uint32_t size = DebugInfoData.getU32(OffsetPtr); 173 *OffsetPtr += size; 174 return true; 175 } 176 177 // Inlined NULL terminated C-strings. 178 case DW_FORM_string: 179 DebugInfoData.getCStr(OffsetPtr); 180 return true; 181 182 case DW_FORM_addr: 183 case DW_FORM_ref_addr: 184 case DW_FORM_flag_present: 185 case DW_FORM_data1: 186 case DW_FORM_data2: 187 case DW_FORM_data4: 188 case DW_FORM_data8: 189 case DW_FORM_flag: 190 case DW_FORM_ref1: 191 case DW_FORM_ref2: 192 case DW_FORM_ref4: 193 case DW_FORM_ref8: 194 case DW_FORM_ref_sig8: 195 case DW_FORM_ref_sup4: 196 case DW_FORM_ref_sup8: 197 case DW_FORM_strx1: 198 case DW_FORM_strx2: 199 case DW_FORM_strx4: 200 case DW_FORM_addrx1: 201 case DW_FORM_addrx2: 202 case DW_FORM_addrx4: 203 case DW_FORM_sec_offset: 204 case DW_FORM_strp: 205 case DW_FORM_strp_sup: 206 case DW_FORM_line_strp: 207 case DW_FORM_GNU_ref_alt: 208 case DW_FORM_GNU_strp_alt: 209 if (Optional<uint8_t> FixedSize = 210 DWARFFormValue::getFixedByteSize(Form, Params)) { 211 *OffsetPtr += *FixedSize; 212 return true; 213 } 214 return false; 215 216 // signed or unsigned LEB 128 values. 217 case DW_FORM_sdata: 218 DebugInfoData.getSLEB128(OffsetPtr); 219 return true; 220 221 case DW_FORM_udata: 222 case DW_FORM_ref_udata: 223 case DW_FORM_strx: 224 case DW_FORM_addrx: 225 case DW_FORM_loclistx: 226 case DW_FORM_rnglistx: 227 case DW_FORM_GNU_addr_index: 228 case DW_FORM_GNU_str_index: 229 DebugInfoData.getULEB128(OffsetPtr); 230 return true; 231 232 case DW_FORM_indirect: 233 Indirect = true; 234 Form = static_cast<dwarf::Form>(DebugInfoData.getULEB128(OffsetPtr)); 235 break; 236 237 default: 238 return false; 239 } 240 } while (Indirect); 241 return true; 242 } 243 244 bool DWARFFormValue::isFormClass(DWARFFormValue::FormClass FC) const { 245 // First, check DWARF4 form classes. 246 if (Form < makeArrayRef(DWARF4FormClasses).size() && 247 DWARF4FormClasses[Form] == FC) 248 return true; 249 // Check more forms from DWARF4 and DWARF5 proposals. 250 switch (Form) { 251 case DW_FORM_ref_sig8: 252 case DW_FORM_GNU_ref_alt: 253 return (FC == FC_Reference); 254 case DW_FORM_GNU_addr_index: 255 return (FC == FC_Address); 256 case DW_FORM_GNU_str_index: 257 case DW_FORM_GNU_strp_alt: 258 case DW_FORM_strx: 259 case DW_FORM_strx1: 260 case DW_FORM_strx2: 261 case DW_FORM_strx3: 262 case DW_FORM_strx4: 263 return (FC == FC_String); 264 case DW_FORM_implicit_const: 265 return (FC == FC_Constant); 266 default: 267 break; 268 } 269 // In DWARF3 DW_FORM_data4 and DW_FORM_data8 served also as a section offset. 270 // Don't check for DWARF version here, as some producers may still do this 271 // by mistake. Also accept DW_FORM_strp since this is .debug_str section 272 // offset. 273 return (Form == DW_FORM_data4 || Form == DW_FORM_data8 || 274 Form == DW_FORM_strp) && 275 FC == FC_SectionOffset; 276 } 277 278 bool DWARFFormValue::extractValue(const DataExtractor &Data, 279 uint32_t *OffsetPtr, const DWARFUnit *CU) { 280 U = CU; 281 bool Indirect = false; 282 bool IsBlock = false; 283 Value.data = nullptr; 284 // Read the value for the form into value and follow and DW_FORM_indirect 285 // instances we run into 286 do { 287 Indirect = false; 288 switch (Form) { 289 case DW_FORM_addr: 290 case DW_FORM_ref_addr: { 291 if (!U) 292 return false; 293 uint16_t AddrSize = (Form == DW_FORM_addr) ? U->getAddressByteSize() 294 : U->getRefAddrByteSize(); 295 Value.uval = getRelocatedValue(Data, AddrSize, OffsetPtr, 296 U->getRelocMap(), &Value.SectionIndex); 297 break; 298 } 299 case DW_FORM_exprloc: 300 case DW_FORM_block: 301 Value.uval = Data.getULEB128(OffsetPtr); 302 IsBlock = true; 303 break; 304 case DW_FORM_block1: 305 Value.uval = Data.getU8(OffsetPtr); 306 IsBlock = true; 307 break; 308 case DW_FORM_block2: 309 Value.uval = Data.getU16(OffsetPtr); 310 IsBlock = true; 311 break; 312 case DW_FORM_block4: 313 Value.uval = Data.getU32(OffsetPtr); 314 IsBlock = true; 315 break; 316 case DW_FORM_data1: 317 case DW_FORM_ref1: 318 case DW_FORM_flag: 319 case DW_FORM_strx1: 320 case DW_FORM_addrx1: 321 Value.uval = Data.getU8(OffsetPtr); 322 break; 323 case DW_FORM_data2: 324 case DW_FORM_ref2: 325 case DW_FORM_strx2: 326 case DW_FORM_addrx2: 327 Value.uval = Data.getU16(OffsetPtr); 328 break; 329 case DW_FORM_strx3: 330 Value.uval = Data.getU24(OffsetPtr); 331 break; 332 case DW_FORM_data4: 333 case DW_FORM_ref4: 334 case DW_FORM_ref_sup4: 335 case DW_FORM_strx4: 336 case DW_FORM_addrx4: { 337 const RelocAddrMap *RelocMap = U ? U->getRelocMap() : nullptr; 338 Value.uval = getRelocatedValue(Data, 4, OffsetPtr, RelocMap); 339 break; 340 } 341 case DW_FORM_data8: 342 case DW_FORM_ref8: 343 case DW_FORM_ref_sup8: 344 Value.uval = Data.getU64(OffsetPtr); 345 break; 346 case DW_FORM_sdata: 347 Value.sval = Data.getSLEB128(OffsetPtr); 348 break; 349 case DW_FORM_udata: 350 case DW_FORM_ref_udata: 351 Value.uval = Data.getULEB128(OffsetPtr); 352 break; 353 case DW_FORM_string: 354 Value.cstr = Data.getCStr(OffsetPtr); 355 break; 356 case DW_FORM_indirect: 357 Form = static_cast<dwarf::Form>(Data.getULEB128(OffsetPtr)); 358 Indirect = true; 359 break; 360 case DW_FORM_strp: 361 case DW_FORM_sec_offset: 362 case DW_FORM_GNU_ref_alt: 363 case DW_FORM_GNU_strp_alt: 364 case DW_FORM_line_strp: 365 case DW_FORM_strp_sup: { 366 if (!U) 367 return false; 368 Value.uval = getRelocatedValue(Data, U->getDwarfOffsetByteSize(), 369 OffsetPtr, U->getRelocMap()); 370 break; 371 } 372 case DW_FORM_flag_present: 373 Value.uval = 1; 374 break; 375 case DW_FORM_ref_sig8: 376 Value.uval = Data.getU64(OffsetPtr); 377 break; 378 case DW_FORM_GNU_addr_index: 379 case DW_FORM_GNU_str_index: 380 case DW_FORM_strx: 381 Value.uval = Data.getULEB128(OffsetPtr); 382 break; 383 default: 384 // DWARFFormValue::skipValue() will have caught this and caused all 385 // DWARF DIEs to fail to be parsed, so this code is not be reachable. 386 llvm_unreachable("unsupported form"); 387 } 388 } while (Indirect); 389 390 if (IsBlock) { 391 StringRef Str = Data.getData().substr(*OffsetPtr, Value.uval); 392 Value.data = nullptr; 393 if (!Str.empty()) { 394 Value.data = reinterpret_cast<const uint8_t *>(Str.data()); 395 *OffsetPtr += Value.uval; 396 } 397 } 398 399 return true; 400 } 401 402 void DWARFFormValue::dump(raw_ostream &OS) const { 403 uint64_t UValue = Value.uval; 404 bool CURelativeOffset = false; 405 406 switch (Form) { 407 case DW_FORM_addr: 408 OS << format("0x%016" PRIx64, UValue); 409 break; 410 case DW_FORM_GNU_addr_index: { 411 OS << format(" indexed (%8.8x) address = ", (uint32_t)UValue); 412 uint64_t Address; 413 if (U == nullptr) 414 OS << "<invalid dwarf unit>"; 415 else if (U->getAddrOffsetSectionItem(UValue, Address)) 416 OS << format("0x%016" PRIx64, Address); 417 else 418 OS << "<no .debug_addr section>"; 419 break; 420 } 421 case DW_FORM_flag_present: 422 OS << "true"; 423 break; 424 case DW_FORM_flag: 425 case DW_FORM_data1: 426 OS << format("0x%02x", (uint8_t)UValue); 427 break; 428 case DW_FORM_data2: 429 OS << format("0x%04x", (uint16_t)UValue); 430 break; 431 case DW_FORM_data4: 432 OS << format("0x%08x", (uint32_t)UValue); 433 break; 434 case DW_FORM_ref_sig8: 435 case DW_FORM_data8: 436 OS << format("0x%016" PRIx64, UValue); 437 break; 438 case DW_FORM_string: 439 OS << '"'; 440 OS.write_escaped(Value.cstr); 441 OS << '"'; 442 break; 443 case DW_FORM_exprloc: 444 case DW_FORM_block: 445 case DW_FORM_block1: 446 case DW_FORM_block2: 447 case DW_FORM_block4: 448 if (UValue > 0) { 449 switch (Form) { 450 case DW_FORM_exprloc: 451 case DW_FORM_block: 452 OS << format("<0x%" PRIx64 "> ", UValue); 453 break; 454 case DW_FORM_block1: 455 OS << format("<0x%2.2x> ", (uint8_t)UValue); 456 break; 457 case DW_FORM_block2: 458 OS << format("<0x%4.4x> ", (uint16_t)UValue); 459 break; 460 case DW_FORM_block4: 461 OS << format("<0x%8.8x> ", (uint32_t)UValue); 462 break; 463 default: 464 break; 465 } 466 467 const uint8_t *DataPtr = Value.data; 468 if (DataPtr) { 469 // UValue contains size of block 470 const uint8_t *EndDataPtr = DataPtr + UValue; 471 while (DataPtr < EndDataPtr) { 472 OS << format("%2.2x ", *DataPtr); 473 ++DataPtr; 474 } 475 } else 476 OS << "NULL"; 477 } 478 break; 479 480 case DW_FORM_sdata: 481 OS << Value.sval; 482 break; 483 case DW_FORM_udata: 484 OS << Value.uval; 485 break; 486 case DW_FORM_strp: 487 OS << format(" .debug_str[0x%8.8x] = ", (uint32_t)UValue); 488 dumpString(OS); 489 break; 490 case DW_FORM_strx: 491 case DW_FORM_strx1: 492 case DW_FORM_strx2: 493 case DW_FORM_strx3: 494 case DW_FORM_strx4: 495 case DW_FORM_GNU_str_index: 496 OS << format(" indexed (%8.8x) string = ", (uint32_t)UValue); 497 dumpString(OS); 498 break; 499 case DW_FORM_GNU_strp_alt: 500 OS << format("alt indirect string, offset: 0x%" PRIx64 "", UValue); 501 dumpString(OS); 502 break; 503 case DW_FORM_ref_addr: 504 OS << format("0x%016" PRIx64, UValue); 505 break; 506 case DW_FORM_ref1: 507 CURelativeOffset = true; 508 OS << format("cu + 0x%2.2x", (uint8_t)UValue); 509 break; 510 case DW_FORM_ref2: 511 CURelativeOffset = true; 512 OS << format("cu + 0x%4.4x", (uint16_t)UValue); 513 break; 514 case DW_FORM_ref4: 515 CURelativeOffset = true; 516 OS << format("cu + 0x%4.4x", (uint32_t)UValue); 517 break; 518 case DW_FORM_ref8: 519 CURelativeOffset = true; 520 OS << format("cu + 0x%8.8" PRIx64, UValue); 521 break; 522 case DW_FORM_ref_udata: 523 CURelativeOffset = true; 524 OS << format("cu + 0x%" PRIx64, UValue); 525 break; 526 case DW_FORM_GNU_ref_alt: 527 OS << format("<alt 0x%" PRIx64 ">", UValue); 528 break; 529 530 // All DW_FORM_indirect attributes should be resolved prior to calling 531 // this function 532 case DW_FORM_indirect: 533 OS << "DW_FORM_indirect"; 534 break; 535 536 // Should be formatted to 64-bit for DWARF64. 537 case DW_FORM_sec_offset: 538 OS << format("0x%08x", (uint32_t)UValue); 539 break; 540 541 default: 542 OS << format("DW_FORM(0x%4.4x)", Form); 543 break; 544 } 545 546 if (CURelativeOffset) { 547 OS << " => {"; 548 WithColor(OS, syntax::Address).get() 549 << format("0x%8.8" PRIx64, UValue + (U ? U->getOffset() : 0)); 550 OS << "}"; 551 } 552 } 553 554 void DWARFFormValue::dumpString(raw_ostream &OS) const { 555 Optional<const char *> DbgStr = getAsCString(); 556 if (DbgStr.hasValue()) { 557 raw_ostream &COS = WithColor(OS, syntax::String); 558 COS << '"'; 559 COS.write_escaped(DbgStr.getValue()); 560 COS << '"'; 561 } 562 } 563 564 Optional<const char *> DWARFFormValue::getAsCString() const { 565 if (!isFormClass(FC_String)) 566 return None; 567 if (Form == DW_FORM_string) 568 return Value.cstr; 569 // FIXME: Add support for DW_FORM_GNU_strp_alt 570 if (Form == DW_FORM_GNU_strp_alt || U == nullptr) 571 return None; 572 uint32_t Offset = Value.uval; 573 if (Form == DW_FORM_GNU_str_index || Form == DW_FORM_strx || 574 Form == DW_FORM_strx1 || Form == DW_FORM_strx2 || Form == DW_FORM_strx3 || 575 Form == DW_FORM_strx4) { 576 uint64_t StrOffset; 577 if (!U->getStringOffsetSectionItem(Offset, StrOffset)) 578 return None; 579 StrOffset += U->getStringOffsetSectionRelocation(Offset); 580 Offset = StrOffset; 581 } 582 if (const char *Str = U->getStringExtractor().getCStr(&Offset)) { 583 return Str; 584 } 585 return None; 586 } 587 588 Optional<uint64_t> DWARFFormValue::getAsAddress() const { 589 if (!isFormClass(FC_Address)) 590 return None; 591 if (Form == DW_FORM_GNU_addr_index) { 592 uint32_t Index = Value.uval; 593 uint64_t Result; 594 if (!U || !U->getAddrOffsetSectionItem(Index, Result)) 595 return None; 596 return Result; 597 } 598 return Value.uval; 599 } 600 601 Optional<uint64_t> DWARFFormValue::getAsReference() const { 602 if (!isFormClass(FC_Reference)) 603 return None; 604 switch (Form) { 605 case DW_FORM_ref1: 606 case DW_FORM_ref2: 607 case DW_FORM_ref4: 608 case DW_FORM_ref8: 609 case DW_FORM_ref_udata: 610 if (!U) 611 return None; 612 return Value.uval + U->getOffset(); 613 case DW_FORM_ref_addr: 614 case DW_FORM_ref_sig8: 615 case DW_FORM_GNU_ref_alt: 616 return Value.uval; 617 default: 618 return None; 619 } 620 } 621 622 Optional<uint64_t> DWARFFormValue::getAsSectionOffset() const { 623 if (!isFormClass(FC_SectionOffset)) 624 return None; 625 return Value.uval; 626 } 627 628 Optional<uint64_t> DWARFFormValue::getAsUnsignedConstant() const { 629 if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag)) || 630 Form == DW_FORM_sdata) 631 return None; 632 return Value.uval; 633 } 634 635 Optional<int64_t> DWARFFormValue::getAsSignedConstant() const { 636 if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag)) || 637 (Form == DW_FORM_udata && 638 uint64_t(std::numeric_limits<int64_t>::max()) < Value.uval)) 639 return None; 640 switch (Form) { 641 case DW_FORM_data4: 642 return int32_t(Value.uval); 643 case DW_FORM_data2: 644 return int16_t(Value.uval); 645 case DW_FORM_data1: 646 return int8_t(Value.uval); 647 case DW_FORM_sdata: 648 case DW_FORM_data8: 649 default: 650 return Value.sval; 651 } 652 } 653 654 Optional<ArrayRef<uint8_t>> DWARFFormValue::getAsBlock() const { 655 if (!isFormClass(FC_Block) && !isFormClass(FC_Exprloc)) 656 return None; 657 return makeArrayRef(Value.data, Value.uval); 658 } 659 660 Optional<uint64_t> DWARFFormValue::getAsCStringOffset() const { 661 if (!isFormClass(FC_String) && Form == DW_FORM_string) 662 return None; 663 return Value.uval; 664 } 665 666 Optional<uint64_t> DWARFFormValue::getAsReferenceUVal() const { 667 if (!isFormClass(FC_Reference)) 668 return None; 669 return Value.uval; 670 } 671