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 case DW_FORM_implicit_const: 172 if (Optional<uint8_t> FixedSize = 173 dwarf::getFixedFormByteSize(Form, Params)) { 174 *OffsetPtr += *FixedSize; 175 return true; 176 } 177 return false; 178 179 // signed or unsigned LEB 128 values. 180 case DW_FORM_sdata: 181 DebugInfoData.getSLEB128(OffsetPtr); 182 return true; 183 184 case DW_FORM_udata: 185 case DW_FORM_ref_udata: 186 case DW_FORM_strx: 187 case DW_FORM_addrx: 188 case DW_FORM_loclistx: 189 case DW_FORM_rnglistx: 190 case DW_FORM_GNU_addr_index: 191 case DW_FORM_GNU_str_index: 192 DebugInfoData.getULEB128(OffsetPtr); 193 return true; 194 195 case DW_FORM_indirect: 196 Indirect = true; 197 Form = static_cast<dwarf::Form>(DebugInfoData.getULEB128(OffsetPtr)); 198 break; 199 200 default: 201 return false; 202 } 203 } while (Indirect); 204 return true; 205 } 206 207 bool DWARFFormValue::isFormClass(DWARFFormValue::FormClass FC) const { 208 // First, check DWARF5 form classes. 209 if (Form < makeArrayRef(DWARF5FormClasses).size() && 210 DWARF5FormClasses[Form] == FC) 211 return true; 212 // Check more forms from extensions and proposals. 213 switch (Form) { 214 case DW_FORM_GNU_ref_alt: 215 return (FC == FC_Reference); 216 case DW_FORM_GNU_addr_index: 217 return (FC == FC_Address); 218 case DW_FORM_GNU_str_index: 219 case DW_FORM_GNU_strp_alt: 220 return (FC == FC_String); 221 default: 222 break; 223 } 224 225 if (FC == FC_SectionOffset) { 226 if (Form == DW_FORM_strp || Form == DW_FORM_line_strp) 227 return true; 228 // In DWARF3 DW_FORM_data4 and DW_FORM_data8 served also as a section 229 // offset. If we don't have a DWARFUnit, default to the old behavior. 230 if (Form == DW_FORM_data4 || Form == DW_FORM_data8) 231 return !U || U->getVersion() <= 3; 232 } 233 234 return false; 235 } 236 237 bool DWARFFormValue::extractValue(const DWARFDataExtractor &Data, 238 uint64_t *OffsetPtr, dwarf::FormParams FP, 239 const DWARFContext *Ctx, 240 const DWARFUnit *CU) { 241 if (!Ctx && CU) 242 Ctx = &CU->getContext(); 243 C = Ctx; 244 U = CU; 245 Format = FP.Format; 246 bool Indirect = false; 247 bool IsBlock = false; 248 Value.data = nullptr; 249 // Read the value for the form into value and follow and DW_FORM_indirect 250 // instances we run into 251 Error Err = Error::success(); 252 do { 253 Indirect = false; 254 switch (Form) { 255 case DW_FORM_addr: 256 case DW_FORM_ref_addr: { 257 uint16_t Size = 258 (Form == DW_FORM_addr) ? FP.AddrSize : FP.getRefAddrByteSize(); 259 Value.uval = 260 Data.getRelocatedValue(Size, OffsetPtr, &Value.SectionIndex, &Err); 261 break; 262 } 263 case DW_FORM_exprloc: 264 case DW_FORM_block: 265 Value.uval = Data.getULEB128(OffsetPtr, &Err); 266 IsBlock = true; 267 break; 268 case DW_FORM_block1: 269 Value.uval = Data.getU8(OffsetPtr, &Err); 270 IsBlock = true; 271 break; 272 case DW_FORM_block2: 273 Value.uval = Data.getU16(OffsetPtr, &Err); 274 IsBlock = true; 275 break; 276 case DW_FORM_block4: 277 Value.uval = Data.getU32(OffsetPtr, &Err); 278 IsBlock = true; 279 break; 280 case DW_FORM_data1: 281 case DW_FORM_ref1: 282 case DW_FORM_flag: 283 case DW_FORM_strx1: 284 case DW_FORM_addrx1: 285 Value.uval = Data.getU8(OffsetPtr, &Err); 286 break; 287 case DW_FORM_data2: 288 case DW_FORM_ref2: 289 case DW_FORM_strx2: 290 case DW_FORM_addrx2: 291 Value.uval = Data.getU16(OffsetPtr, &Err); 292 break; 293 case DW_FORM_strx3: 294 Value.uval = Data.getU24(OffsetPtr, &Err); 295 break; 296 case DW_FORM_data4: 297 case DW_FORM_ref4: 298 case DW_FORM_ref_sup4: 299 case DW_FORM_strx4: 300 case DW_FORM_addrx4: 301 Value.uval = Data.getRelocatedValue(4, OffsetPtr, nullptr, &Err); 302 break; 303 case DW_FORM_data8: 304 case DW_FORM_ref8: 305 case DW_FORM_ref_sup8: 306 Value.uval = Data.getRelocatedValue(8, OffsetPtr, nullptr, &Err); 307 break; 308 case DW_FORM_data16: 309 // Treat this like a 16-byte block. 310 Value.uval = 16; 311 IsBlock = true; 312 break; 313 case DW_FORM_sdata: 314 Value.sval = Data.getSLEB128(OffsetPtr, &Err); 315 break; 316 case DW_FORM_udata: 317 case DW_FORM_ref_udata: 318 case DW_FORM_rnglistx: 319 case DW_FORM_loclistx: 320 case DW_FORM_GNU_addr_index: 321 case DW_FORM_GNU_str_index: 322 case DW_FORM_addrx: 323 case DW_FORM_strx: 324 Value.uval = Data.getULEB128(OffsetPtr, &Err); 325 break; 326 case DW_FORM_string: 327 Value.cstr = Data.getCStr(OffsetPtr, &Err); 328 break; 329 case DW_FORM_indirect: 330 Form = static_cast<dwarf::Form>(Data.getULEB128(OffsetPtr, &Err)); 331 Indirect = true; 332 break; 333 case DW_FORM_strp: 334 case DW_FORM_sec_offset: 335 case DW_FORM_GNU_ref_alt: 336 case DW_FORM_GNU_strp_alt: 337 case DW_FORM_line_strp: 338 case DW_FORM_strp_sup: { 339 Value.uval = Data.getRelocatedValue(FP.getDwarfOffsetByteSize(), 340 OffsetPtr, nullptr, &Err); 341 break; 342 } 343 case DW_FORM_flag_present: 344 Value.uval = 1; 345 break; 346 case DW_FORM_ref_sig8: 347 Value.uval = Data.getU64(OffsetPtr, &Err); 348 break; 349 case DW_FORM_implicit_const: 350 // Value has been already set by DWARFFormValue::createFromSValue. 351 break; 352 default: 353 // DWARFFormValue::skipValue() will have caught this and caused all 354 // DWARF DIEs to fail to be parsed, so this code is not be reachable. 355 llvm_unreachable("unsupported form"); 356 } 357 } while (Indirect && !Err); 358 359 if (IsBlock) 360 Value.data = Data.getBytes(OffsetPtr, Value.uval, &Err).bytes_begin(); 361 362 return !errorToBool(std::move(Err)); 363 } 364 365 void DWARFFormValue::dumpAddress(raw_ostream &OS, uint8_t AddressSize, 366 uint64_t Address) { 367 uint8_t HexDigits = AddressSize * 2; 368 OS << format("0x%*.*" PRIx64, HexDigits, HexDigits, Address); 369 } 370 371 void DWARFFormValue::dumpSectionedAddress(raw_ostream &OS, 372 DIDumpOptions DumpOpts, 373 object::SectionedAddress SA) const { 374 dumpAddress(OS, U->getAddressByteSize(), SA.Address); 375 dumpAddressSection(U->getContext().getDWARFObj(), OS, DumpOpts, 376 SA.SectionIndex); 377 } 378 379 void DWARFFormValue::dumpAddressSection(const DWARFObject &Obj, raw_ostream &OS, 380 DIDumpOptions DumpOpts, 381 uint64_t SectionIndex) { 382 if (!DumpOpts.Verbose || SectionIndex == -1ULL) 383 return; 384 ArrayRef<SectionName> SectionNames = Obj.getSectionNames(); 385 const auto &SecRef = SectionNames[SectionIndex]; 386 387 OS << " \"" << SecRef.Name << '\"'; 388 389 // Print section index if name is not unique. 390 if (!SecRef.IsNameUnique) 391 OS << format(" [%" PRIu64 "]", SectionIndex); 392 } 393 394 void DWARFFormValue::dump(raw_ostream &OS, DIDumpOptions DumpOpts) const { 395 uint64_t UValue = Value.uval; 396 bool CURelativeOffset = false; 397 raw_ostream &AddrOS = DumpOpts.ShowAddresses 398 ? WithColor(OS, HighlightColor::Address).get() 399 : nulls(); 400 int OffsetDumpWidth = 2 * dwarf::getDwarfOffsetByteSize(Format); 401 switch (Form) { 402 case DW_FORM_addr: 403 dumpSectionedAddress(AddrOS, DumpOpts, {Value.uval, Value.SectionIndex}); 404 break; 405 case DW_FORM_addrx: 406 case DW_FORM_addrx1: 407 case DW_FORM_addrx2: 408 case DW_FORM_addrx3: 409 case DW_FORM_addrx4: 410 case DW_FORM_GNU_addr_index: { 411 if (U == nullptr) { 412 OS << "<invalid dwarf unit>"; 413 break; 414 } 415 Optional<object::SectionedAddress> A = U->getAddrOffsetSectionItem(UValue); 416 if (!A || DumpOpts.Verbose) 417 AddrOS << format("indexed (%8.8x) address = ", (uint32_t)UValue); 418 if (A) 419 dumpSectionedAddress(AddrOS, DumpOpts, *A); 420 else 421 OS << "<unresolved>"; 422 break; 423 } 424 case DW_FORM_flag_present: 425 OS << "true"; 426 break; 427 case DW_FORM_flag: 428 case DW_FORM_data1: 429 OS << format("0x%02x", (uint8_t)UValue); 430 break; 431 case DW_FORM_data2: 432 OS << format("0x%04x", (uint16_t)UValue); 433 break; 434 case DW_FORM_data4: 435 OS << format("0x%08x", (uint32_t)UValue); 436 break; 437 case DW_FORM_ref_sig8: 438 AddrOS << format("0x%016" PRIx64, UValue); 439 break; 440 case DW_FORM_data8: 441 OS << format("0x%016" PRIx64, UValue); 442 break; 443 case DW_FORM_data16: 444 OS << format_bytes(ArrayRef<uint8_t>(Value.data, 16), None, 16, 16); 445 break; 446 case DW_FORM_string: 447 OS << '"'; 448 OS.write_escaped(Value.cstr); 449 OS << '"'; 450 break; 451 case DW_FORM_exprloc: 452 case DW_FORM_block: 453 case DW_FORM_block1: 454 case DW_FORM_block2: 455 case DW_FORM_block4: 456 if (UValue > 0) { 457 switch (Form) { 458 case DW_FORM_exprloc: 459 case DW_FORM_block: 460 AddrOS << format("<0x%" PRIx64 "> ", UValue); 461 break; 462 case DW_FORM_block1: 463 AddrOS << format("<0x%2.2x> ", (uint8_t)UValue); 464 break; 465 case DW_FORM_block2: 466 AddrOS << format("<0x%4.4x> ", (uint16_t)UValue); 467 break; 468 case DW_FORM_block4: 469 AddrOS << format("<0x%8.8x> ", (uint32_t)UValue); 470 break; 471 default: 472 break; 473 } 474 475 const uint8_t *DataPtr = Value.data; 476 if (DataPtr) { 477 // UValue contains size of block 478 const uint8_t *EndDataPtr = DataPtr + UValue; 479 while (DataPtr < EndDataPtr) { 480 AddrOS << format("%2.2x ", *DataPtr); 481 ++DataPtr; 482 } 483 } else 484 OS << "NULL"; 485 } 486 break; 487 488 case DW_FORM_sdata: 489 case DW_FORM_implicit_const: 490 OS << Value.sval; 491 break; 492 case DW_FORM_udata: 493 OS << Value.uval; 494 break; 495 case DW_FORM_strp: 496 if (DumpOpts.Verbose) 497 OS << format(" .debug_str[0x%0*" PRIx64 "] = ", OffsetDumpWidth, UValue); 498 dumpString(OS); 499 break; 500 case DW_FORM_line_strp: 501 if (DumpOpts.Verbose) 502 OS << format(" .debug_line_str[0x%0*" PRIx64 "] = ", OffsetDumpWidth, 503 UValue); 504 dumpString(OS); 505 break; 506 case DW_FORM_strx: 507 case DW_FORM_strx1: 508 case DW_FORM_strx2: 509 case DW_FORM_strx3: 510 case DW_FORM_strx4: 511 case DW_FORM_GNU_str_index: 512 if (DumpOpts.Verbose) 513 OS << format("indexed (%8.8x) string = ", (uint32_t)UValue); 514 dumpString(OS); 515 break; 516 case DW_FORM_GNU_strp_alt: 517 if (DumpOpts.Verbose) 518 OS << format("alt indirect string, offset: 0x%" PRIx64 "", UValue); 519 dumpString(OS); 520 break; 521 case DW_FORM_ref_addr: 522 AddrOS << format("0x%016" PRIx64, UValue); 523 break; 524 case DW_FORM_ref1: 525 CURelativeOffset = true; 526 if (DumpOpts.Verbose) 527 AddrOS << format("cu + 0x%2.2x", (uint8_t)UValue); 528 break; 529 case DW_FORM_ref2: 530 CURelativeOffset = true; 531 if (DumpOpts.Verbose) 532 AddrOS << format("cu + 0x%4.4x", (uint16_t)UValue); 533 break; 534 case DW_FORM_ref4: 535 CURelativeOffset = true; 536 if (DumpOpts.Verbose) 537 AddrOS << format("cu + 0x%4.4x", (uint32_t)UValue); 538 break; 539 case DW_FORM_ref8: 540 CURelativeOffset = true; 541 if (DumpOpts.Verbose) 542 AddrOS << format("cu + 0x%8.8" PRIx64, UValue); 543 break; 544 case DW_FORM_ref_udata: 545 CURelativeOffset = true; 546 if (DumpOpts.Verbose) 547 AddrOS << format("cu + 0x%" PRIx64, UValue); 548 break; 549 case DW_FORM_GNU_ref_alt: 550 AddrOS << format("<alt 0x%" PRIx64 ">", UValue); 551 break; 552 553 // All DW_FORM_indirect attributes should be resolved prior to calling 554 // this function 555 case DW_FORM_indirect: 556 OS << "DW_FORM_indirect"; 557 break; 558 559 case DW_FORM_rnglistx: 560 OS << format("indexed (0x%x) rangelist = ", (uint32_t)UValue); 561 break; 562 563 case DW_FORM_loclistx: 564 OS << format("indexed (0x%x) loclist = ", (uint32_t)UValue); 565 break; 566 567 case DW_FORM_sec_offset: 568 AddrOS << format("0x%0*" PRIx64, OffsetDumpWidth, UValue); 569 break; 570 571 default: 572 OS << format("DW_FORM(0x%4.4x)", Form); 573 break; 574 } 575 576 if (CURelativeOffset) { 577 if (DumpOpts.Verbose) 578 OS << " => {"; 579 if (DumpOpts.ShowAddresses) 580 WithColor(OS, HighlightColor::Address).get() 581 << format("0x%8.8" PRIx64, UValue + (U ? U->getOffset() : 0)); 582 if (DumpOpts.Verbose) 583 OS << "}"; 584 } 585 } 586 587 void DWARFFormValue::dumpString(raw_ostream &OS) const { 588 Optional<const char *> DbgStr = getAsCString(); 589 if (DbgStr.hasValue()) { 590 auto COS = WithColor(OS, HighlightColor::String); 591 COS.get() << '"'; 592 COS.get().write_escaped(DbgStr.getValue()); 593 COS.get() << '"'; 594 } 595 } 596 597 Optional<const char *> DWARFFormValue::getAsCString() const { 598 if (!isFormClass(FC_String)) 599 return None; 600 if (Form == DW_FORM_string) 601 return Value.cstr; 602 // FIXME: Add support for DW_FORM_GNU_strp_alt 603 if (Form == DW_FORM_GNU_strp_alt || C == nullptr) 604 return None; 605 uint64_t Offset = Value.uval; 606 if (Form == DW_FORM_line_strp) { 607 // .debug_line_str is tracked in the Context. 608 if (const char *Str = C->getLineStringExtractor().getCStr(&Offset)) 609 return Str; 610 return None; 611 } 612 if (Form == DW_FORM_GNU_str_index || Form == DW_FORM_strx || 613 Form == DW_FORM_strx1 || Form == DW_FORM_strx2 || Form == DW_FORM_strx3 || 614 Form == DW_FORM_strx4) { 615 if (!U) 616 return None; 617 Optional<uint64_t> StrOffset = U->getStringOffsetSectionItem(Offset); 618 if (!StrOffset) 619 return None; 620 Offset = *StrOffset; 621 } 622 // Prefer the Unit's string extractor, because for .dwo it will point to 623 // .debug_str.dwo, while the Context's extractor always uses .debug_str. 624 if (U) { 625 if (const char *Str = U->getStringExtractor().getCStr(&Offset)) 626 return Str; 627 return None; 628 } 629 if (const char *Str = C->getStringExtractor().getCStr(&Offset)) 630 return Str; 631 return None; 632 } 633 634 Optional<uint64_t> DWARFFormValue::getAsAddress() const { 635 if (auto SA = getAsSectionedAddress()) 636 return SA->Address; 637 return None; 638 } 639 640 Optional<object::SectionedAddress> 641 DWARFFormValue::getAsSectionedAddress() const { 642 if (!isFormClass(FC_Address)) 643 return None; 644 if (Form == DW_FORM_GNU_addr_index || Form == DW_FORM_addrx) { 645 uint32_t Index = Value.uval; 646 if (!U) 647 return None; 648 Optional<object::SectionedAddress> SA = U->getAddrOffsetSectionItem(Index); 649 if (!SA) 650 return None; 651 return SA; 652 } 653 return {{Value.uval, Value.SectionIndex}}; 654 } 655 656 Optional<uint64_t> DWARFFormValue::getAsReference() const { 657 if (auto R = getAsRelativeReference()) 658 return R->Unit ? R->Unit->getOffset() + R->Offset : R->Offset; 659 return None; 660 } 661 662 Optional<DWARFFormValue::UnitOffset> DWARFFormValue::getAsRelativeReference() const { 663 if (!isFormClass(FC_Reference)) 664 return None; 665 switch (Form) { 666 case DW_FORM_ref1: 667 case DW_FORM_ref2: 668 case DW_FORM_ref4: 669 case DW_FORM_ref8: 670 case DW_FORM_ref_udata: 671 if (!U) 672 return None; 673 return UnitOffset{const_cast<DWARFUnit*>(U), Value.uval}; 674 case DW_FORM_ref_addr: 675 case DW_FORM_ref_sig8: 676 case DW_FORM_GNU_ref_alt: 677 return UnitOffset{nullptr, Value.uval}; 678 default: 679 return None; 680 } 681 } 682 683 Optional<uint64_t> DWARFFormValue::getAsSectionOffset() const { 684 if (!isFormClass(FC_SectionOffset)) 685 return None; 686 return Value.uval; 687 } 688 689 Optional<uint64_t> DWARFFormValue::getAsUnsignedConstant() const { 690 if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag)) || 691 Form == DW_FORM_sdata) 692 return None; 693 return Value.uval; 694 } 695 696 Optional<int64_t> DWARFFormValue::getAsSignedConstant() const { 697 if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag)) || 698 (Form == DW_FORM_udata && 699 uint64_t(std::numeric_limits<int64_t>::max()) < Value.uval)) 700 return None; 701 switch (Form) { 702 case DW_FORM_data4: 703 return int32_t(Value.uval); 704 case DW_FORM_data2: 705 return int16_t(Value.uval); 706 case DW_FORM_data1: 707 return int8_t(Value.uval); 708 case DW_FORM_sdata: 709 case DW_FORM_data8: 710 default: 711 return Value.sval; 712 } 713 } 714 715 Optional<ArrayRef<uint8_t>> DWARFFormValue::getAsBlock() const { 716 if (!isFormClass(FC_Block) && !isFormClass(FC_Exprloc) && 717 Form != DW_FORM_data16) 718 return None; 719 return makeArrayRef(Value.data, Value.uval); 720 } 721 722 Optional<uint64_t> DWARFFormValue::getAsCStringOffset() const { 723 if (!isFormClass(FC_String) && Form == DW_FORM_string) 724 return None; 725 return Value.uval; 726 } 727 728 Optional<uint64_t> DWARFFormValue::getAsReferenceUVal() const { 729 if (!isFormClass(FC_Reference)) 730 return None; 731 return Value.uval; 732 } 733