1 //===- DWARFFormValue.cpp -------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h" 10 #include "llvm/ADT/ArrayRef.h" 11 #include "llvm/ADT/None.h" 12 #include "llvm/ADT/Optional.h" 13 #include "llvm/ADT/StringRef.h" 14 #include "llvm/BinaryFormat/Dwarf.h" 15 #include "llvm/DebugInfo/DWARF/DWARFContext.h" 16 #include "llvm/DebugInfo/DWARF/DWARFRelocMap.h" 17 #include "llvm/DebugInfo/DWARF/DWARFUnit.h" 18 #include "llvm/Support/ErrorHandling.h" 19 #include "llvm/Support/Format.h" 20 #include "llvm/Support/WithColor.h" 21 #include "llvm/Support/raw_ostream.h" 22 #include <cinttypes> 23 #include <cstdint> 24 #include <limits> 25 26 using namespace llvm; 27 using namespace dwarf; 28 29 static const DWARFFormValue::FormClass DWARF5FormClasses[] = { 30 DWARFFormValue::FC_Unknown, // 0x0 31 DWARFFormValue::FC_Address, // 0x01 DW_FORM_addr 32 DWARFFormValue::FC_Unknown, // 0x02 unused 33 DWARFFormValue::FC_Block, // 0x03 DW_FORM_block2 34 DWARFFormValue::FC_Block, // 0x04 DW_FORM_block4 35 DWARFFormValue::FC_Constant, // 0x05 DW_FORM_data2 36 // --- These can be FC_SectionOffset in DWARF3 and below: 37 DWARFFormValue::FC_Constant, // 0x06 DW_FORM_data4 38 DWARFFormValue::FC_Constant, // 0x07 DW_FORM_data8 39 // --- 40 DWARFFormValue::FC_String, // 0x08 DW_FORM_string 41 DWARFFormValue::FC_Block, // 0x09 DW_FORM_block 42 DWARFFormValue::FC_Block, // 0x0a DW_FORM_block1 43 DWARFFormValue::FC_Constant, // 0x0b DW_FORM_data1 44 DWARFFormValue::FC_Flag, // 0x0c DW_FORM_flag 45 DWARFFormValue::FC_Constant, // 0x0d DW_FORM_sdata 46 DWARFFormValue::FC_String, // 0x0e DW_FORM_strp 47 DWARFFormValue::FC_Constant, // 0x0f DW_FORM_udata 48 DWARFFormValue::FC_Reference, // 0x10 DW_FORM_ref_addr 49 DWARFFormValue::FC_Reference, // 0x11 DW_FORM_ref1 50 DWARFFormValue::FC_Reference, // 0x12 DW_FORM_ref2 51 DWARFFormValue::FC_Reference, // 0x13 DW_FORM_ref4 52 DWARFFormValue::FC_Reference, // 0x14 DW_FORM_ref8 53 DWARFFormValue::FC_Reference, // 0x15 DW_FORM_ref_udata 54 DWARFFormValue::FC_Indirect, // 0x16 DW_FORM_indirect 55 DWARFFormValue::FC_SectionOffset, // 0x17 DW_FORM_sec_offset 56 DWARFFormValue::FC_Exprloc, // 0x18 DW_FORM_exprloc 57 DWARFFormValue::FC_Flag, // 0x19 DW_FORM_flag_present 58 DWARFFormValue::FC_String, // 0x1a DW_FORM_strx 59 DWARFFormValue::FC_Address, // 0x1b DW_FORM_addrx 60 DWARFFormValue::FC_Reference, // 0x1c DW_FORM_ref_sup4 61 DWARFFormValue::FC_String, // 0x1d DW_FORM_strp_sup 62 DWARFFormValue::FC_Constant, // 0x1e DW_FORM_data16 63 DWARFFormValue::FC_String, // 0x1f DW_FORM_line_strp 64 DWARFFormValue::FC_Reference, // 0x20 DW_FORM_ref_sig8 65 DWARFFormValue::FC_Constant, // 0x21 DW_FORM_implicit_const 66 DWARFFormValue::FC_SectionOffset, // 0x22 DW_FORM_loclistx 67 DWARFFormValue::FC_SectionOffset, // 0x23 DW_FORM_rnglistx 68 DWARFFormValue::FC_Reference, // 0x24 DW_FORM_ref_sup8 69 DWARFFormValue::FC_String, // 0x25 DW_FORM_strx1 70 DWARFFormValue::FC_String, // 0x26 DW_FORM_strx2 71 DWARFFormValue::FC_String, // 0x27 DW_FORM_strx3 72 DWARFFormValue::FC_String, // 0x28 DW_FORM_strx4 73 DWARFFormValue::FC_Address, // 0x29 DW_FORM_addrx1 74 DWARFFormValue::FC_Address, // 0x2a DW_FORM_addrx2 75 DWARFFormValue::FC_Address, // 0x2b DW_FORM_addrx3 76 DWARFFormValue::FC_Address, // 0x2c DW_FORM_addrx4 77 78 }; 79 80 DWARFFormValue DWARFFormValue::createFromSValue(dwarf::Form F, int64_t V) { 81 return DWARFFormValue(F, ValueType(V)); 82 } 83 84 DWARFFormValue DWARFFormValue::createFromUValue(dwarf::Form F, uint64_t V) { 85 return DWARFFormValue(F, ValueType(V)); 86 } 87 88 DWARFFormValue DWARFFormValue::createFromPValue(dwarf::Form F, const char *V) { 89 return DWARFFormValue(F, ValueType(V)); 90 } 91 92 DWARFFormValue DWARFFormValue::createFromBlockValue(dwarf::Form F, 93 ArrayRef<uint8_t> D) { 94 ValueType V; 95 V.uval = D.size(); 96 V.data = D.data(); 97 return DWARFFormValue(F, V); 98 } 99 100 DWARFFormValue DWARFFormValue::createFromUnit(dwarf::Form F, const DWARFUnit *U, 101 uint64_t *OffsetPtr) { 102 DWARFFormValue FormValue(F); 103 FormValue.extractValue(U->getDebugInfoExtractor(), OffsetPtr, 104 U->getFormParams(), U); 105 return FormValue; 106 } 107 108 bool DWARFFormValue::skipValue(dwarf::Form Form, DataExtractor DebugInfoData, 109 uint64_t *OffsetPtr, 110 const dwarf::FormParams Params) { 111 bool Indirect = false; 112 do { 113 switch (Form) { 114 // Blocks of inlined data that have a length field and the data bytes 115 // inlined in the .debug_info. 116 case DW_FORM_exprloc: 117 case DW_FORM_block: { 118 uint64_t size = DebugInfoData.getULEB128(OffsetPtr); 119 *OffsetPtr += size; 120 return true; 121 } 122 case DW_FORM_block1: { 123 uint8_t size = DebugInfoData.getU8(OffsetPtr); 124 *OffsetPtr += size; 125 return true; 126 } 127 case DW_FORM_block2: { 128 uint16_t size = DebugInfoData.getU16(OffsetPtr); 129 *OffsetPtr += size; 130 return true; 131 } 132 case DW_FORM_block4: { 133 uint32_t size = DebugInfoData.getU32(OffsetPtr); 134 *OffsetPtr += size; 135 return true; 136 } 137 138 // Inlined NULL terminated C-strings. 139 case DW_FORM_string: 140 DebugInfoData.getCStr(OffsetPtr); 141 return true; 142 143 case DW_FORM_addr: 144 case DW_FORM_ref_addr: 145 case DW_FORM_flag_present: 146 case DW_FORM_data1: 147 case DW_FORM_data2: 148 case DW_FORM_data4: 149 case DW_FORM_data8: 150 case DW_FORM_data16: 151 case DW_FORM_flag: 152 case DW_FORM_ref1: 153 case DW_FORM_ref2: 154 case DW_FORM_ref4: 155 case DW_FORM_ref8: 156 case DW_FORM_ref_sig8: 157 case DW_FORM_ref_sup4: 158 case DW_FORM_ref_sup8: 159 case DW_FORM_strx1: 160 case DW_FORM_strx2: 161 case DW_FORM_strx4: 162 case DW_FORM_addrx1: 163 case DW_FORM_addrx2: 164 case DW_FORM_addrx4: 165 case DW_FORM_sec_offset: 166 case DW_FORM_strp: 167 case DW_FORM_strp_sup: 168 case DW_FORM_line_strp: 169 case DW_FORM_GNU_ref_alt: 170 case DW_FORM_GNU_strp_alt: 171 if (Optional<uint8_t> FixedSize = 172 dwarf::getFixedFormByteSize(Form, Params)) { 173 *OffsetPtr += *FixedSize; 174 return true; 175 } 176 return false; 177 178 // signed or unsigned LEB 128 values. 179 case DW_FORM_sdata: 180 DebugInfoData.getSLEB128(OffsetPtr); 181 return true; 182 183 case DW_FORM_udata: 184 case DW_FORM_ref_udata: 185 case DW_FORM_strx: 186 case DW_FORM_addrx: 187 case DW_FORM_loclistx: 188 case DW_FORM_rnglistx: 189 case DW_FORM_GNU_addr_index: 190 case DW_FORM_GNU_str_index: 191 DebugInfoData.getULEB128(OffsetPtr); 192 return true; 193 194 case DW_FORM_indirect: 195 Indirect = true; 196 Form = static_cast<dwarf::Form>(DebugInfoData.getULEB128(OffsetPtr)); 197 break; 198 199 default: 200 return false; 201 } 202 } while (Indirect); 203 return true; 204 } 205 206 bool DWARFFormValue::isFormClass(DWARFFormValue::FormClass FC) const { 207 // First, check DWARF5 form classes. 208 if (Form < makeArrayRef(DWARF5FormClasses).size() && 209 DWARF5FormClasses[Form] == FC) 210 return true; 211 // Check more forms from extensions and proposals. 212 switch (Form) { 213 case DW_FORM_GNU_ref_alt: 214 return (FC == FC_Reference); 215 case DW_FORM_GNU_addr_index: 216 return (FC == FC_Address); 217 case DW_FORM_GNU_str_index: 218 case DW_FORM_GNU_strp_alt: 219 return (FC == FC_String); 220 default: 221 break; 222 } 223 224 if (FC == FC_SectionOffset) { 225 if (Form == DW_FORM_strp || Form == DW_FORM_line_strp) 226 return true; 227 // In DWARF3 DW_FORM_data4 and DW_FORM_data8 served also as a section 228 // offset. If we don't have a DWARFUnit, default to the old behavior. 229 if (Form == DW_FORM_data4 || Form == DW_FORM_data8) 230 return !U || U->getVersion() <= 3; 231 } 232 233 return false; 234 } 235 236 bool DWARFFormValue::extractValue(const DWARFDataExtractor &Data, 237 uint64_t *OffsetPtr, dwarf::FormParams FP, 238 const DWARFContext *Ctx, 239 const DWARFUnit *CU) { 240 if (!Ctx && CU) 241 Ctx = &CU->getContext(); 242 C = Ctx; 243 U = CU; 244 bool Indirect = false; 245 bool IsBlock = false; 246 Value.data = nullptr; 247 // Read the value for the form into value and follow and DW_FORM_indirect 248 // instances we run into 249 Error Err = Error::success(); 250 do { 251 Indirect = false; 252 switch (Form) { 253 case DW_FORM_addr: 254 case DW_FORM_ref_addr: { 255 uint16_t Size = 256 (Form == DW_FORM_addr) ? FP.AddrSize : FP.getRefAddrByteSize(); 257 Value.uval = 258 Data.getRelocatedValue(Size, OffsetPtr, &Value.SectionIndex, &Err); 259 break; 260 } 261 case DW_FORM_exprloc: 262 case DW_FORM_block: 263 Value.uval = Data.getULEB128(OffsetPtr, &Err); 264 IsBlock = true; 265 break; 266 case DW_FORM_block1: 267 Value.uval = Data.getU8(OffsetPtr, &Err); 268 IsBlock = true; 269 break; 270 case DW_FORM_block2: 271 Value.uval = Data.getU16(OffsetPtr, &Err); 272 IsBlock = true; 273 break; 274 case DW_FORM_block4: 275 Value.uval = Data.getU32(OffsetPtr, &Err); 276 IsBlock = true; 277 break; 278 case DW_FORM_data1: 279 case DW_FORM_ref1: 280 case DW_FORM_flag: 281 case DW_FORM_strx1: 282 case DW_FORM_addrx1: 283 Value.uval = Data.getU8(OffsetPtr, &Err); 284 break; 285 case DW_FORM_data2: 286 case DW_FORM_ref2: 287 case DW_FORM_strx2: 288 case DW_FORM_addrx2: 289 Value.uval = Data.getU16(OffsetPtr, &Err); 290 break; 291 case DW_FORM_strx3: 292 Value.uval = Data.getU24(OffsetPtr, &Err); 293 break; 294 case DW_FORM_data4: 295 case DW_FORM_ref4: 296 case DW_FORM_ref_sup4: 297 case DW_FORM_strx4: 298 case DW_FORM_addrx4: 299 Value.uval = Data.getRelocatedValue(4, OffsetPtr, nullptr, &Err); 300 break; 301 case DW_FORM_data8: 302 case DW_FORM_ref8: 303 case DW_FORM_ref_sup8: 304 Value.uval = Data.getRelocatedValue(8, OffsetPtr, nullptr, &Err); 305 break; 306 case DW_FORM_data16: 307 // Treat this like a 16-byte block. 308 Value.uval = 16; 309 IsBlock = true; 310 break; 311 case DW_FORM_sdata: 312 Value.sval = Data.getSLEB128(OffsetPtr, &Err); 313 break; 314 case DW_FORM_udata: 315 case DW_FORM_ref_udata: 316 case DW_FORM_rnglistx: 317 case DW_FORM_loclistx: 318 case DW_FORM_GNU_addr_index: 319 case DW_FORM_GNU_str_index: 320 case DW_FORM_addrx: 321 case DW_FORM_strx: 322 Value.uval = Data.getULEB128(OffsetPtr, &Err); 323 break; 324 case DW_FORM_string: 325 Value.cstr = Data.getCStr(OffsetPtr, &Err); 326 break; 327 case DW_FORM_indirect: 328 Form = static_cast<dwarf::Form>(Data.getULEB128(OffsetPtr, &Err)); 329 Indirect = true; 330 break; 331 case DW_FORM_strp: 332 case DW_FORM_sec_offset: 333 case DW_FORM_GNU_ref_alt: 334 case DW_FORM_GNU_strp_alt: 335 case DW_FORM_line_strp: 336 case DW_FORM_strp_sup: { 337 Value.uval = Data.getRelocatedValue(FP.getDwarfOffsetByteSize(), 338 OffsetPtr, nullptr, &Err); 339 break; 340 } 341 case DW_FORM_flag_present: 342 Value.uval = 1; 343 break; 344 case DW_FORM_ref_sig8: 345 Value.uval = Data.getU64(OffsetPtr, &Err); 346 break; 347 default: 348 // DWARFFormValue::skipValue() will have caught this and caused all 349 // DWARF DIEs to fail to be parsed, so this code is not be reachable. 350 llvm_unreachable("unsupported form"); 351 } 352 } while (Indirect && !Err); 353 354 if (IsBlock) 355 Value.data = Data.getBytes(OffsetPtr, Value.uval, &Err).bytes_begin(); 356 357 return !errorToBool(std::move(Err)); 358 } 359 360 void DWARFFormValue::dumpSectionedAddress(raw_ostream &OS, 361 DIDumpOptions DumpOpts, 362 object::SectionedAddress SA) const { 363 OS << format("0x%016" PRIx64, SA.Address); 364 dumpAddressSection(U->getContext().getDWARFObj(), OS, DumpOpts, 365 SA.SectionIndex); 366 } 367 368 void DWARFFormValue::dumpAddressSection(const DWARFObject &Obj, raw_ostream &OS, 369 DIDumpOptions DumpOpts, 370 uint64_t SectionIndex) { 371 if (!DumpOpts.Verbose || SectionIndex == -1ULL) 372 return; 373 ArrayRef<SectionName> SectionNames = Obj.getSectionNames(); 374 const auto &SecRef = SectionNames[SectionIndex]; 375 376 OS << " \"" << SecRef.Name << '\"'; 377 378 // Print section index if name is not unique. 379 if (!SecRef.IsNameUnique) 380 OS << format(" [%" PRIu64 "]", SectionIndex); 381 } 382 383 void DWARFFormValue::dump(raw_ostream &OS, DIDumpOptions DumpOpts) const { 384 uint64_t UValue = Value.uval; 385 bool CURelativeOffset = false; 386 raw_ostream &AddrOS = DumpOpts.ShowAddresses 387 ? WithColor(OS, HighlightColor::Address).get() 388 : nulls(); 389 switch (Form) { 390 case DW_FORM_addr: 391 dumpSectionedAddress(AddrOS, DumpOpts, {Value.uval, Value.SectionIndex}); 392 break; 393 case DW_FORM_addrx: 394 case DW_FORM_addrx1: 395 case DW_FORM_addrx2: 396 case DW_FORM_addrx3: 397 case DW_FORM_addrx4: 398 case DW_FORM_GNU_addr_index: { 399 if (U == nullptr) { 400 OS << "<invalid dwarf unit>"; 401 break; 402 } 403 Optional<object::SectionedAddress> A = U->getAddrOffsetSectionItem(UValue); 404 if (!A || DumpOpts.Verbose) 405 AddrOS << format("indexed (%8.8x) address = ", (uint32_t)UValue); 406 if (A) 407 dumpSectionedAddress(AddrOS, DumpOpts, *A); 408 else 409 OS << "<unresolved>"; 410 break; 411 } 412 case DW_FORM_flag_present: 413 OS << "true"; 414 break; 415 case DW_FORM_flag: 416 case DW_FORM_data1: 417 OS << format("0x%02x", (uint8_t)UValue); 418 break; 419 case DW_FORM_data2: 420 OS << format("0x%04x", (uint16_t)UValue); 421 break; 422 case DW_FORM_data4: 423 OS << format("0x%08x", (uint32_t)UValue); 424 break; 425 case DW_FORM_ref_sig8: 426 AddrOS << format("0x%016" PRIx64, UValue); 427 break; 428 case DW_FORM_data8: 429 OS << format("0x%016" PRIx64, UValue); 430 break; 431 case DW_FORM_data16: 432 OS << format_bytes(ArrayRef<uint8_t>(Value.data, 16), None, 16, 16); 433 break; 434 case DW_FORM_string: 435 OS << '"'; 436 OS.write_escaped(Value.cstr); 437 OS << '"'; 438 break; 439 case DW_FORM_exprloc: 440 case DW_FORM_block: 441 case DW_FORM_block1: 442 case DW_FORM_block2: 443 case DW_FORM_block4: 444 if (UValue > 0) { 445 switch (Form) { 446 case DW_FORM_exprloc: 447 case DW_FORM_block: 448 AddrOS << format("<0x%" PRIx64 "> ", UValue); 449 break; 450 case DW_FORM_block1: 451 AddrOS << format("<0x%2.2x> ", (uint8_t)UValue); 452 break; 453 case DW_FORM_block2: 454 AddrOS << format("<0x%4.4x> ", (uint16_t)UValue); 455 break; 456 case DW_FORM_block4: 457 AddrOS << format("<0x%8.8x> ", (uint32_t)UValue); 458 break; 459 default: 460 break; 461 } 462 463 const uint8_t *DataPtr = Value.data; 464 if (DataPtr) { 465 // UValue contains size of block 466 const uint8_t *EndDataPtr = DataPtr + UValue; 467 while (DataPtr < EndDataPtr) { 468 AddrOS << format("%2.2x ", *DataPtr); 469 ++DataPtr; 470 } 471 } else 472 OS << "NULL"; 473 } 474 break; 475 476 case DW_FORM_sdata: 477 OS << Value.sval; 478 break; 479 case DW_FORM_udata: 480 OS << Value.uval; 481 break; 482 case DW_FORM_strp: 483 if (DumpOpts.Verbose) 484 OS << format(" .debug_str[0x%8.8" PRIx64 "] = ", UValue); 485 dumpString(OS); 486 break; 487 case DW_FORM_line_strp: 488 if (DumpOpts.Verbose) 489 OS << format(" .debug_line_str[0x%8.8" PRIx64 "] = ", UValue); 490 dumpString(OS); 491 break; 492 case DW_FORM_strx: 493 case DW_FORM_strx1: 494 case DW_FORM_strx2: 495 case DW_FORM_strx3: 496 case DW_FORM_strx4: 497 case DW_FORM_GNU_str_index: 498 if (DumpOpts.Verbose) 499 OS << format("indexed (%8.8x) string = ", (uint32_t)UValue); 500 dumpString(OS); 501 break; 502 case DW_FORM_GNU_strp_alt: 503 if (DumpOpts.Verbose) 504 OS << format("alt indirect string, offset: 0x%" PRIx64 "", UValue); 505 dumpString(OS); 506 break; 507 case DW_FORM_ref_addr: 508 AddrOS << format("0x%016" PRIx64, UValue); 509 break; 510 case DW_FORM_ref1: 511 CURelativeOffset = true; 512 if (DumpOpts.Verbose) 513 AddrOS << format("cu + 0x%2.2x", (uint8_t)UValue); 514 break; 515 case DW_FORM_ref2: 516 CURelativeOffset = true; 517 if (DumpOpts.Verbose) 518 AddrOS << format("cu + 0x%4.4x", (uint16_t)UValue); 519 break; 520 case DW_FORM_ref4: 521 CURelativeOffset = true; 522 if (DumpOpts.Verbose) 523 AddrOS << format("cu + 0x%4.4x", (uint32_t)UValue); 524 break; 525 case DW_FORM_ref8: 526 CURelativeOffset = true; 527 if (DumpOpts.Verbose) 528 AddrOS << format("cu + 0x%8.8" PRIx64, UValue); 529 break; 530 case DW_FORM_ref_udata: 531 CURelativeOffset = true; 532 if (DumpOpts.Verbose) 533 AddrOS << format("cu + 0x%" PRIx64, UValue); 534 break; 535 case DW_FORM_GNU_ref_alt: 536 AddrOS << format("<alt 0x%" PRIx64 ">", UValue); 537 break; 538 539 // All DW_FORM_indirect attributes should be resolved prior to calling 540 // this function 541 case DW_FORM_indirect: 542 OS << "DW_FORM_indirect"; 543 break; 544 545 case DW_FORM_rnglistx: 546 OS << format("indexed (0x%x) rangelist = ", (uint32_t)UValue); 547 break; 548 549 case DW_FORM_loclistx: 550 OS << format("indexed (0x%x) loclist = ", (uint32_t)UValue); 551 break; 552 553 case DW_FORM_sec_offset: 554 AddrOS << format("0x%08" PRIx64, UValue); 555 break; 556 557 default: 558 OS << format("DW_FORM(0x%4.4x)", Form); 559 break; 560 } 561 562 if (CURelativeOffset) { 563 if (DumpOpts.Verbose) 564 OS << " => {"; 565 if (DumpOpts.ShowAddresses) 566 WithColor(OS, HighlightColor::Address).get() 567 << format("0x%8.8" PRIx64, UValue + (U ? U->getOffset() : 0)); 568 if (DumpOpts.Verbose) 569 OS << "}"; 570 } 571 } 572 573 void DWARFFormValue::dumpString(raw_ostream &OS) const { 574 Optional<const char *> DbgStr = getAsCString(); 575 if (DbgStr.hasValue()) { 576 auto COS = WithColor(OS, HighlightColor::String); 577 COS.get() << '"'; 578 COS.get().write_escaped(DbgStr.getValue()); 579 COS.get() << '"'; 580 } 581 } 582 583 Optional<const char *> DWARFFormValue::getAsCString() const { 584 if (!isFormClass(FC_String)) 585 return None; 586 if (Form == DW_FORM_string) 587 return Value.cstr; 588 // FIXME: Add support for DW_FORM_GNU_strp_alt 589 if (Form == DW_FORM_GNU_strp_alt || C == nullptr) 590 return None; 591 uint64_t Offset = Value.uval; 592 if (Form == DW_FORM_line_strp) { 593 // .debug_line_str is tracked in the Context. 594 if (const char *Str = C->getLineStringExtractor().getCStr(&Offset)) 595 return Str; 596 return None; 597 } 598 if (Form == DW_FORM_GNU_str_index || Form == DW_FORM_strx || 599 Form == DW_FORM_strx1 || Form == DW_FORM_strx2 || Form == DW_FORM_strx3 || 600 Form == DW_FORM_strx4) { 601 if (!U) 602 return None; 603 Optional<uint64_t> StrOffset = U->getStringOffsetSectionItem(Offset); 604 if (!StrOffset) 605 return None; 606 Offset = *StrOffset; 607 } 608 // Prefer the Unit's string extractor, because for .dwo it will point to 609 // .debug_str.dwo, while the Context's extractor always uses .debug_str. 610 if (U) { 611 if (const char *Str = U->getStringExtractor().getCStr(&Offset)) 612 return Str; 613 return None; 614 } 615 if (const char *Str = C->getStringExtractor().getCStr(&Offset)) 616 return Str; 617 return None; 618 } 619 620 Optional<uint64_t> DWARFFormValue::getAsAddress() const { 621 if (auto SA = getAsSectionedAddress()) 622 return SA->Address; 623 return None; 624 } 625 626 Optional<object::SectionedAddress> 627 DWARFFormValue::getAsSectionedAddress() const { 628 if (!isFormClass(FC_Address)) 629 return None; 630 if (Form == DW_FORM_GNU_addr_index || Form == DW_FORM_addrx) { 631 uint32_t Index = Value.uval; 632 if (!U) 633 return None; 634 Optional<object::SectionedAddress> SA = U->getAddrOffsetSectionItem(Index); 635 if (!SA) 636 return None; 637 return SA; 638 } 639 return {{Value.uval, Value.SectionIndex}}; 640 } 641 642 Optional<uint64_t> DWARFFormValue::getAsReference() const { 643 if (auto R = getAsRelativeReference()) 644 return R->Unit ? R->Unit->getOffset() + R->Offset : R->Offset; 645 return None; 646 } 647 648 Optional<DWARFFormValue::UnitOffset> DWARFFormValue::getAsRelativeReference() const { 649 if (!isFormClass(FC_Reference)) 650 return None; 651 switch (Form) { 652 case DW_FORM_ref1: 653 case DW_FORM_ref2: 654 case DW_FORM_ref4: 655 case DW_FORM_ref8: 656 case DW_FORM_ref_udata: 657 if (!U) 658 return None; 659 return UnitOffset{const_cast<DWARFUnit*>(U), Value.uval}; 660 case DW_FORM_ref_addr: 661 case DW_FORM_ref_sig8: 662 case DW_FORM_GNU_ref_alt: 663 return UnitOffset{nullptr, Value.uval}; 664 default: 665 return None; 666 } 667 } 668 669 Optional<uint64_t> DWARFFormValue::getAsSectionOffset() const { 670 if (!isFormClass(FC_SectionOffset)) 671 return None; 672 return Value.uval; 673 } 674 675 Optional<uint64_t> DWARFFormValue::getAsUnsignedConstant() const { 676 if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag)) || 677 Form == DW_FORM_sdata) 678 return None; 679 return Value.uval; 680 } 681 682 Optional<int64_t> DWARFFormValue::getAsSignedConstant() const { 683 if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag)) || 684 (Form == DW_FORM_udata && 685 uint64_t(std::numeric_limits<int64_t>::max()) < Value.uval)) 686 return None; 687 switch (Form) { 688 case DW_FORM_data4: 689 return int32_t(Value.uval); 690 case DW_FORM_data2: 691 return int16_t(Value.uval); 692 case DW_FORM_data1: 693 return int8_t(Value.uval); 694 case DW_FORM_sdata: 695 case DW_FORM_data8: 696 default: 697 return Value.sval; 698 } 699 } 700 701 Optional<ArrayRef<uint8_t>> DWARFFormValue::getAsBlock() const { 702 if (!isFormClass(FC_Block) && !isFormClass(FC_Exprloc) && 703 Form != DW_FORM_data16) 704 return None; 705 return makeArrayRef(Value.data, Value.uval); 706 } 707 708 Optional<uint64_t> DWARFFormValue::getAsCStringOffset() const { 709 if (!isFormClass(FC_String) && Form == DW_FORM_string) 710 return None; 711 return Value.uval; 712 } 713 714 Optional<uint64_t> DWARFFormValue::getAsReferenceUVal() const { 715 if (!isFormClass(FC_Reference)) 716 return None; 717 return Value.uval; 718 } 719