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 DWARFDataExtractor &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 Size = (Form == DW_FORM_addr) ? U->getAddressByteSize() 294 : U->getRefAddrByteSize(); 295 Value.uval = Data.getRelocatedValue(Size, OffsetPtr, &Value.SectionIndex); 296 break; 297 } 298 case DW_FORM_exprloc: 299 case DW_FORM_block: 300 Value.uval = Data.getULEB128(OffsetPtr); 301 IsBlock = true; 302 break; 303 case DW_FORM_block1: 304 Value.uval = Data.getU8(OffsetPtr); 305 IsBlock = true; 306 break; 307 case DW_FORM_block2: 308 Value.uval = Data.getU16(OffsetPtr); 309 IsBlock = true; 310 break; 311 case DW_FORM_block4: 312 Value.uval = Data.getU32(OffsetPtr); 313 IsBlock = true; 314 break; 315 case DW_FORM_data1: 316 case DW_FORM_ref1: 317 case DW_FORM_flag: 318 case DW_FORM_strx1: 319 case DW_FORM_addrx1: 320 Value.uval = Data.getU8(OffsetPtr); 321 break; 322 case DW_FORM_data2: 323 case DW_FORM_ref2: 324 case DW_FORM_strx2: 325 case DW_FORM_addrx2: 326 Value.uval = Data.getU16(OffsetPtr); 327 break; 328 case DW_FORM_strx3: 329 Value.uval = Data.getU24(OffsetPtr); 330 break; 331 case DW_FORM_data4: 332 case DW_FORM_ref4: 333 case DW_FORM_ref_sup4: 334 case DW_FORM_strx4: 335 case DW_FORM_addrx4: 336 Value.uval = Data.getRelocatedValue(4, OffsetPtr); 337 break; 338 case DW_FORM_data8: 339 case DW_FORM_ref8: 340 case DW_FORM_ref_sup8: 341 Value.uval = Data.getU64(OffsetPtr); 342 break; 343 case DW_FORM_sdata: 344 Value.sval = Data.getSLEB128(OffsetPtr); 345 break; 346 case DW_FORM_udata: 347 case DW_FORM_ref_udata: 348 Value.uval = Data.getULEB128(OffsetPtr); 349 break; 350 case DW_FORM_string: 351 Value.cstr = Data.getCStr(OffsetPtr); 352 break; 353 case DW_FORM_indirect: 354 Form = static_cast<dwarf::Form>(Data.getULEB128(OffsetPtr)); 355 Indirect = true; 356 break; 357 case DW_FORM_strp: 358 case DW_FORM_sec_offset: 359 case DW_FORM_GNU_ref_alt: 360 case DW_FORM_GNU_strp_alt: 361 case DW_FORM_line_strp: 362 case DW_FORM_strp_sup: { 363 if (!U) 364 return false; 365 Value.uval = 366 Data.getRelocatedValue(U->getDwarfOffsetByteSize(), OffsetPtr); 367 break; 368 } 369 case DW_FORM_flag_present: 370 Value.uval = 1; 371 break; 372 case DW_FORM_ref_sig8: 373 Value.uval = Data.getU64(OffsetPtr); 374 break; 375 case DW_FORM_GNU_addr_index: 376 case DW_FORM_GNU_str_index: 377 case DW_FORM_strx: 378 Value.uval = Data.getULEB128(OffsetPtr); 379 break; 380 default: 381 // DWARFFormValue::skipValue() will have caught this and caused all 382 // DWARF DIEs to fail to be parsed, so this code is not be reachable. 383 llvm_unreachable("unsupported form"); 384 } 385 } while (Indirect); 386 387 if (IsBlock) { 388 StringRef Str = Data.getData().substr(*OffsetPtr, Value.uval); 389 Value.data = nullptr; 390 if (!Str.empty()) { 391 Value.data = reinterpret_cast<const uint8_t *>(Str.data()); 392 *OffsetPtr += Value.uval; 393 } 394 } 395 396 return true; 397 } 398 399 void DWARFFormValue::dump(raw_ostream &OS, DIDumpOptions DumpOpts) const { 400 uint64_t UValue = Value.uval; 401 bool CURelativeOffset = false; 402 403 switch (Form) { 404 case DW_FORM_addr: 405 OS << format("0x%016" PRIx64, UValue); 406 break; 407 case DW_FORM_GNU_addr_index: { 408 OS << format(" indexed (%8.8x) address = ", (uint32_t)UValue); 409 uint64_t Address; 410 if (U == nullptr) 411 OS << "<invalid dwarf unit>"; 412 else if (U->getAddrOffsetSectionItem(UValue, Address)) 413 OS << format("0x%016" PRIx64, Address); 414 else 415 OS << "<no .debug_addr section>"; 416 break; 417 } 418 case DW_FORM_flag_present: 419 OS << "true"; 420 break; 421 case DW_FORM_flag: 422 case DW_FORM_data1: 423 OS << format("0x%02x", (uint8_t)UValue); 424 break; 425 case DW_FORM_data2: 426 OS << format("0x%04x", (uint16_t)UValue); 427 break; 428 case DW_FORM_data4: 429 OS << format("0x%08x", (uint32_t)UValue); 430 break; 431 case DW_FORM_ref_sig8: 432 case DW_FORM_data8: 433 OS << format("0x%016" PRIx64, UValue); 434 break; 435 case DW_FORM_string: 436 OS << '"'; 437 OS.write_escaped(Value.cstr); 438 OS << '"'; 439 break; 440 case DW_FORM_exprloc: 441 case DW_FORM_block: 442 case DW_FORM_block1: 443 case DW_FORM_block2: 444 case DW_FORM_block4: 445 if (UValue > 0) { 446 switch (Form) { 447 case DW_FORM_exprloc: 448 case DW_FORM_block: 449 OS << format("<0x%" PRIx64 "> ", UValue); 450 break; 451 case DW_FORM_block1: 452 OS << format("<0x%2.2x> ", (uint8_t)UValue); 453 break; 454 case DW_FORM_block2: 455 OS << format("<0x%4.4x> ", (uint16_t)UValue); 456 break; 457 case DW_FORM_block4: 458 OS << format("<0x%8.8x> ", (uint32_t)UValue); 459 break; 460 default: 461 break; 462 } 463 464 const uint8_t *DataPtr = Value.data; 465 if (DataPtr) { 466 // UValue contains size of block 467 const uint8_t *EndDataPtr = DataPtr + UValue; 468 while (DataPtr < EndDataPtr) { 469 OS << format("%2.2x ", *DataPtr); 470 ++DataPtr; 471 } 472 } else 473 OS << "NULL"; 474 } 475 break; 476 477 case DW_FORM_sdata: 478 OS << Value.sval; 479 break; 480 case DW_FORM_udata: 481 OS << Value.uval; 482 break; 483 case DW_FORM_strp: 484 if (DumpOpts.Verbose) 485 OS << format(" .debug_str[0x%8.8x] = ", (uint32_t)UValue); 486 dumpString(OS); 487 break; 488 case DW_FORM_strx: 489 case DW_FORM_strx1: 490 case DW_FORM_strx2: 491 case DW_FORM_strx3: 492 case DW_FORM_strx4: 493 case DW_FORM_GNU_str_index: 494 OS << format(" indexed (%8.8x) string = ", (uint32_t)UValue); 495 dumpString(OS); 496 break; 497 case DW_FORM_GNU_strp_alt: 498 OS << format("alt indirect string, offset: 0x%" PRIx64 "", UValue); 499 dumpString(OS); 500 break; 501 case DW_FORM_ref_addr: 502 OS << format("0x%016" PRIx64, UValue); 503 break; 504 case DW_FORM_ref1: 505 CURelativeOffset = true; 506 OS << format("cu + 0x%2.2x", (uint8_t)UValue); 507 break; 508 case DW_FORM_ref2: 509 CURelativeOffset = true; 510 OS << format("cu + 0x%4.4x", (uint16_t)UValue); 511 break; 512 case DW_FORM_ref4: 513 CURelativeOffset = true; 514 OS << format("cu + 0x%4.4x", (uint32_t)UValue); 515 break; 516 case DW_FORM_ref8: 517 CURelativeOffset = true; 518 OS << format("cu + 0x%8.8" PRIx64, UValue); 519 break; 520 case DW_FORM_ref_udata: 521 CURelativeOffset = true; 522 OS << format("cu + 0x%" PRIx64, UValue); 523 break; 524 case DW_FORM_GNU_ref_alt: 525 OS << format("<alt 0x%" PRIx64 ">", UValue); 526 break; 527 528 // All DW_FORM_indirect attributes should be resolved prior to calling 529 // this function 530 case DW_FORM_indirect: 531 OS << "DW_FORM_indirect"; 532 break; 533 534 // Should be formatted to 64-bit for DWARF64. 535 case DW_FORM_sec_offset: 536 OS << format("0x%08x", (uint32_t)UValue); 537 break; 538 539 default: 540 OS << format("DW_FORM(0x%4.4x)", Form); 541 break; 542 } 543 544 if (CURelativeOffset && DumpOpts.Verbose) { 545 OS << " => {"; 546 WithColor(OS, syntax::Address).get() 547 << format("0x%8.8" PRIx64, UValue + (U ? U->getOffset() : 0)); 548 OS << "}"; 549 } 550 } 551 552 void DWARFFormValue::dumpString(raw_ostream &OS) const { 553 Optional<const char *> DbgStr = getAsCString(); 554 if (DbgStr.hasValue()) { 555 raw_ostream &COS = WithColor(OS, syntax::String); 556 COS << '"'; 557 COS.write_escaped(DbgStr.getValue()); 558 COS << '"'; 559 } 560 } 561 562 Optional<const char *> DWARFFormValue::getAsCString() const { 563 if (!isFormClass(FC_String)) 564 return None; 565 if (Form == DW_FORM_string) 566 return Value.cstr; 567 // FIXME: Add support for DW_FORM_GNU_strp_alt 568 if (Form == DW_FORM_GNU_strp_alt || U == nullptr) 569 return None; 570 uint32_t Offset = Value.uval; 571 if (Form == DW_FORM_GNU_str_index || Form == DW_FORM_strx || 572 Form == DW_FORM_strx1 || Form == DW_FORM_strx2 || Form == DW_FORM_strx3 || 573 Form == DW_FORM_strx4) { 574 uint64_t StrOffset; 575 if (!U->getStringOffsetSectionItem(Offset, StrOffset)) 576 return None; 577 Offset = StrOffset; 578 } 579 if (const char *Str = U->getStringExtractor().getCStr(&Offset)) { 580 return Str; 581 } 582 return None; 583 } 584 585 Optional<uint64_t> DWARFFormValue::getAsAddress() const { 586 if (!isFormClass(FC_Address)) 587 return None; 588 if (Form == DW_FORM_GNU_addr_index) { 589 uint32_t Index = Value.uval; 590 uint64_t Result; 591 if (!U || !U->getAddrOffsetSectionItem(Index, Result)) 592 return None; 593 return Result; 594 } 595 return Value.uval; 596 } 597 598 Optional<uint64_t> DWARFFormValue::getAsReference() const { 599 if (!isFormClass(FC_Reference)) 600 return None; 601 switch (Form) { 602 case DW_FORM_ref1: 603 case DW_FORM_ref2: 604 case DW_FORM_ref4: 605 case DW_FORM_ref8: 606 case DW_FORM_ref_udata: 607 if (!U) 608 return None; 609 return Value.uval + U->getOffset(); 610 case DW_FORM_ref_addr: 611 case DW_FORM_ref_sig8: 612 case DW_FORM_GNU_ref_alt: 613 return Value.uval; 614 default: 615 return None; 616 } 617 } 618 619 Optional<uint64_t> DWARFFormValue::getAsSectionOffset() const { 620 if (!isFormClass(FC_SectionOffset)) 621 return None; 622 return Value.uval; 623 } 624 625 Optional<uint64_t> DWARFFormValue::getAsUnsignedConstant() const { 626 if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag)) || 627 Form == DW_FORM_sdata) 628 return None; 629 return Value.uval; 630 } 631 632 Optional<int64_t> DWARFFormValue::getAsSignedConstant() const { 633 if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag)) || 634 (Form == DW_FORM_udata && 635 uint64_t(std::numeric_limits<int64_t>::max()) < Value.uval)) 636 return None; 637 switch (Form) { 638 case DW_FORM_data4: 639 return int32_t(Value.uval); 640 case DW_FORM_data2: 641 return int16_t(Value.uval); 642 case DW_FORM_data1: 643 return int8_t(Value.uval); 644 case DW_FORM_sdata: 645 case DW_FORM_data8: 646 default: 647 return Value.sval; 648 } 649 } 650 651 Optional<ArrayRef<uint8_t>> DWARFFormValue::getAsBlock() const { 652 if (!isFormClass(FC_Block) && !isFormClass(FC_Exprloc)) 653 return None; 654 return makeArrayRef(Value.data, Value.uval); 655 } 656 657 Optional<uint64_t> DWARFFormValue::getAsCStringOffset() const { 658 if (!isFormClass(FC_String) && Form == DW_FORM_string) 659 return None; 660 return Value.uval; 661 } 662 663 Optional<uint64_t> DWARFFormValue::getAsReferenceUVal() const { 664 if (!isFormClass(FC_Reference)) 665 return None; 666 return Value.uval; 667 } 668