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/StringRef.h" 12 #include "llvm/BinaryFormat/Dwarf.h" 13 #include "llvm/DebugInfo/DWARF/DWARFContext.h" 14 #include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h" 15 #include "llvm/DebugInfo/DWARF/DWARFDebugLine.h" 16 #include "llvm/DebugInfo/DWARF/DWARFObject.h" 17 #include "llvm/DebugInfo/DWARF/DWARFSection.h" 18 #include "llvm/DebugInfo/DWARF/DWARFUnit.h" 19 #include "llvm/Support/ErrorHandling.h" 20 #include "llvm/Support/Format.h" 21 #include "llvm/Support/WithColor.h" 22 #include "llvm/Support/raw_ostream.h" 23 #include <cinttypes> 24 #include <cstdint> 25 #include <limits> 26 #include <optional> 27 28 using namespace llvm; 29 using namespace dwarf; 30 31 static const DWARFFormValue::FormClass DWARF5FormClasses[] = { 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 DWARFFormValue::FC_String, // 0x1a DW_FORM_strx 61 DWARFFormValue::FC_Address, // 0x1b DW_FORM_addrx 62 DWARFFormValue::FC_Reference, // 0x1c DW_FORM_ref_sup4 63 DWARFFormValue::FC_String, // 0x1d DW_FORM_strp_sup 64 DWARFFormValue::FC_Constant, // 0x1e DW_FORM_data16 65 DWARFFormValue::FC_String, // 0x1f DW_FORM_line_strp 66 DWARFFormValue::FC_Reference, // 0x20 DW_FORM_ref_sig8 67 DWARFFormValue::FC_Constant, // 0x21 DW_FORM_implicit_const 68 DWARFFormValue::FC_SectionOffset, // 0x22 DW_FORM_loclistx 69 DWARFFormValue::FC_SectionOffset, // 0x23 DW_FORM_rnglistx 70 DWARFFormValue::FC_Reference, // 0x24 DW_FORM_ref_sup8 71 DWARFFormValue::FC_String, // 0x25 DW_FORM_strx1 72 DWARFFormValue::FC_String, // 0x26 DW_FORM_strx2 73 DWARFFormValue::FC_String, // 0x27 DW_FORM_strx3 74 DWARFFormValue::FC_String, // 0x28 DW_FORM_strx4 75 DWARFFormValue::FC_Address, // 0x29 DW_FORM_addrx1 76 DWARFFormValue::FC_Address, // 0x2a DW_FORM_addrx2 77 DWARFFormValue::FC_Address, // 0x2b DW_FORM_addrx3 78 DWARFFormValue::FC_Address, // 0x2c DW_FORM_addrx4 79 DWARFFormValue::FC_Address, // 0x2001 DW_FORM_addrx_offset 80 }; 81 82 DWARFFormValue DWARFFormValue::createFromSValue(dwarf::Form F, int64_t V) { 83 return DWARFFormValue(F, ValueType(V)); 84 } 85 86 DWARFFormValue DWARFFormValue::createFromUValue(dwarf::Form F, uint64_t V) { 87 return DWARFFormValue(F, ValueType(V)); 88 } 89 90 DWARFFormValue DWARFFormValue::createFromPValue(dwarf::Form F, const char *V) { 91 return DWARFFormValue(F, ValueType(V)); 92 } 93 94 DWARFFormValue DWARFFormValue::createFromBlockValue(dwarf::Form F, 95 ArrayRef<uint8_t> D) { 96 ValueType V; 97 V.uval = D.size(); 98 V.data = D.data(); 99 return DWARFFormValue(F, V); 100 } 101 102 DWARFFormValue DWARFFormValue::createFromUnit(dwarf::Form F, const DWARFUnit *U, 103 uint64_t *OffsetPtr) { 104 DWARFFormValue FormValue(F); 105 FormValue.extractValue(U->getDebugInfoExtractor(), OffsetPtr, 106 U->getFormParams(), U); 107 return FormValue; 108 } 109 110 bool DWARFFormValue::skipValue(dwarf::Form Form, DataExtractor DebugInfoData, 111 uint64_t *OffsetPtr, 112 const dwarf::FormParams Params) { 113 bool Indirect = false; 114 do { 115 switch (Form) { 116 // Blocks of inlined data that have a length field and the data bytes 117 // inlined in the .debug_info. 118 case DW_FORM_exprloc: 119 case DW_FORM_block: { 120 uint64_t size = DebugInfoData.getULEB128(OffsetPtr); 121 *OffsetPtr += size; 122 return true; 123 } 124 case DW_FORM_block1: { 125 uint8_t size = DebugInfoData.getU8(OffsetPtr); 126 *OffsetPtr += size; 127 return true; 128 } 129 case DW_FORM_block2: { 130 uint16_t size = DebugInfoData.getU16(OffsetPtr); 131 *OffsetPtr += size; 132 return true; 133 } 134 case DW_FORM_block4: { 135 uint32_t size = DebugInfoData.getU32(OffsetPtr); 136 *OffsetPtr += size; 137 return true; 138 } 139 140 // Inlined NULL terminated C-strings. 141 case DW_FORM_string: 142 DebugInfoData.getCStr(OffsetPtr); 143 return true; 144 145 case DW_FORM_addr: 146 case DW_FORM_ref_addr: 147 case DW_FORM_flag_present: 148 case DW_FORM_data1: 149 case DW_FORM_data2: 150 case DW_FORM_data4: 151 case DW_FORM_data8: 152 case DW_FORM_data16: 153 case DW_FORM_flag: 154 case DW_FORM_ref1: 155 case DW_FORM_ref2: 156 case DW_FORM_ref4: 157 case DW_FORM_ref8: 158 case DW_FORM_ref_sig8: 159 case DW_FORM_ref_sup4: 160 case DW_FORM_ref_sup8: 161 case DW_FORM_strx1: 162 case DW_FORM_strx2: 163 case DW_FORM_strx3: 164 case DW_FORM_strx4: 165 case DW_FORM_addrx1: 166 case DW_FORM_addrx2: 167 case DW_FORM_addrx3: 168 case DW_FORM_addrx4: 169 case DW_FORM_sec_offset: 170 case DW_FORM_strp: 171 case DW_FORM_strp_sup: 172 case DW_FORM_line_strp: 173 case DW_FORM_GNU_ref_alt: 174 case DW_FORM_GNU_strp_alt: 175 case DW_FORM_implicit_const: 176 if (std::optional<uint8_t> FixedSize = 177 dwarf::getFixedFormByteSize(Form, Params)) { 178 *OffsetPtr += *FixedSize; 179 return true; 180 } 181 return false; 182 183 // signed or unsigned LEB 128 values. 184 case DW_FORM_sdata: 185 DebugInfoData.getSLEB128(OffsetPtr); 186 return true; 187 188 case DW_FORM_udata: 189 case DW_FORM_ref_udata: 190 case DW_FORM_strx: 191 case DW_FORM_addrx: 192 case DW_FORM_loclistx: 193 case DW_FORM_rnglistx: 194 case DW_FORM_GNU_addr_index: 195 case DW_FORM_GNU_str_index: 196 DebugInfoData.getULEB128(OffsetPtr); 197 return true; 198 199 case DW_FORM_LLVM_addrx_offset: 200 DebugInfoData.getULEB128(OffsetPtr); 201 *OffsetPtr += 4; 202 return true; 203 204 case DW_FORM_indirect: 205 Indirect = true; 206 Form = static_cast<dwarf::Form>(DebugInfoData.getULEB128(OffsetPtr)); 207 break; 208 209 default: 210 return false; 211 } 212 } while (Indirect); 213 return true; 214 } 215 216 bool DWARFFormValue::isFormClass(DWARFFormValue::FormClass FC) const { 217 return doesFormBelongToClass(Form, FC, U ? U->getVersion() : 3); 218 } 219 220 bool DWARFFormValue::extractValue(const DWARFDataExtractor &Data, 221 uint64_t *OffsetPtr, dwarf::FormParams FP, 222 const DWARFContext *Ctx, 223 const DWARFUnit *CU) { 224 if (!Ctx && CU) 225 Ctx = &CU->getContext(); 226 C = Ctx; 227 U = CU; 228 Format = FP.Format; 229 bool Indirect = false; 230 bool IsBlock = false; 231 Value.data = nullptr; 232 // Read the value for the form into value and follow and DW_FORM_indirect 233 // instances we run into 234 Error Err = Error::success(); 235 do { 236 Indirect = false; 237 switch (Form) { 238 case DW_FORM_addr: 239 case DW_FORM_ref_addr: { 240 uint16_t Size = 241 (Form == DW_FORM_addr) ? FP.AddrSize : FP.getRefAddrByteSize(); 242 Value.uval = 243 Data.getRelocatedValue(Size, OffsetPtr, &Value.SectionIndex, &Err); 244 break; 245 } 246 case DW_FORM_exprloc: 247 case DW_FORM_block: 248 Value.uval = Data.getULEB128(OffsetPtr, &Err); 249 IsBlock = true; 250 break; 251 case DW_FORM_block1: 252 Value.uval = Data.getU8(OffsetPtr, &Err); 253 IsBlock = true; 254 break; 255 case DW_FORM_block2: 256 Value.uval = Data.getU16(OffsetPtr, &Err); 257 IsBlock = true; 258 break; 259 case DW_FORM_block4: 260 Value.uval = Data.getU32(OffsetPtr, &Err); 261 IsBlock = true; 262 break; 263 case DW_FORM_data1: 264 case DW_FORM_ref1: 265 case DW_FORM_flag: 266 case DW_FORM_strx1: 267 case DW_FORM_addrx1: 268 Value.uval = Data.getU8(OffsetPtr, &Err); 269 break; 270 case DW_FORM_data2: 271 case DW_FORM_ref2: 272 case DW_FORM_strx2: 273 case DW_FORM_addrx2: 274 Value.uval = Data.getU16(OffsetPtr, &Err); 275 break; 276 case DW_FORM_strx3: 277 case DW_FORM_addrx3: 278 Value.uval = Data.getU24(OffsetPtr, &Err); 279 break; 280 case DW_FORM_data4: 281 case DW_FORM_ref4: 282 case DW_FORM_ref_sup4: 283 case DW_FORM_strx4: 284 case DW_FORM_addrx4: 285 Value.uval = Data.getRelocatedValue(4, OffsetPtr, nullptr, &Err); 286 break; 287 case DW_FORM_data8: 288 case DW_FORM_ref8: 289 case DW_FORM_ref_sup8: 290 Value.uval = Data.getRelocatedValue(8, OffsetPtr, nullptr, &Err); 291 break; 292 case DW_FORM_data16: 293 // Treat this like a 16-byte block. 294 Value.uval = 16; 295 IsBlock = true; 296 break; 297 case DW_FORM_sdata: 298 Value.sval = Data.getSLEB128(OffsetPtr, &Err); 299 break; 300 case DW_FORM_udata: 301 case DW_FORM_ref_udata: 302 case DW_FORM_rnglistx: 303 case DW_FORM_loclistx: 304 case DW_FORM_GNU_addr_index: 305 case DW_FORM_GNU_str_index: 306 case DW_FORM_addrx: 307 case DW_FORM_strx: 308 Value.uval = Data.getULEB128(OffsetPtr, &Err); 309 break; 310 case DW_FORM_LLVM_addrx_offset: 311 Value.uval = Data.getULEB128(OffsetPtr, &Err) << 32; 312 Value.uval |= Data.getU32(OffsetPtr, &Err); 313 break; 314 case DW_FORM_string: 315 Value.cstr = Data.getCStr(OffsetPtr, &Err); 316 break; 317 case DW_FORM_indirect: 318 Form = static_cast<dwarf::Form>(Data.getULEB128(OffsetPtr, &Err)); 319 Indirect = true; 320 break; 321 case DW_FORM_strp: 322 case DW_FORM_sec_offset: 323 case DW_FORM_GNU_ref_alt: 324 case DW_FORM_GNU_strp_alt: 325 case DW_FORM_line_strp: 326 case DW_FORM_strp_sup: { 327 Value.uval = Data.getRelocatedValue(FP.getDwarfOffsetByteSize(), 328 OffsetPtr, nullptr, &Err); 329 break; 330 } 331 case DW_FORM_flag_present: 332 Value.uval = 1; 333 break; 334 case DW_FORM_ref_sig8: 335 Value.uval = Data.getU64(OffsetPtr, &Err); 336 break; 337 case DW_FORM_implicit_const: 338 // Value has been already set by DWARFFormValue::createFromSValue. 339 break; 340 default: 341 // DWARFFormValue::skipValue() will have caught this and caused all 342 // DWARF DIEs to fail to be parsed, so this code is not be reachable. 343 llvm_unreachable("unsupported form"); 344 } 345 } while (Indirect && !Err); 346 347 if (IsBlock) 348 Value.data = Data.getBytes(OffsetPtr, Value.uval, &Err).bytes_begin(); 349 350 return !errorToBool(std::move(Err)); 351 } 352 353 void DWARFFormValue::dumpAddress(raw_ostream &OS, uint8_t AddressSize, 354 uint64_t Address) { 355 uint8_t HexDigits = AddressSize * 2; 356 OS << format("0x%*.*" PRIx64, HexDigits, HexDigits, Address); 357 } 358 359 void DWARFFormValue::dumpSectionedAddress(raw_ostream &OS, 360 DIDumpOptions DumpOpts, 361 object::SectionedAddress SA) const { 362 dumpAddress(OS, U->getAddressByteSize(), SA.Address); 363 dumpAddressSection(U->getContext().getDWARFObj(), OS, DumpOpts, 364 SA.SectionIndex); 365 } 366 367 void DWARFFormValue::dumpAddressSection(const DWARFObject &Obj, raw_ostream &OS, 368 DIDumpOptions DumpOpts, 369 uint64_t SectionIndex) { 370 if (!DumpOpts.Verbose || SectionIndex == -1ULL) 371 return; 372 ArrayRef<SectionName> SectionNames = Obj.getSectionNames(); 373 const auto &SecRef = SectionNames[SectionIndex]; 374 375 OS << " \"" << SecRef.Name << '\"'; 376 377 // Print section index if name is not unique. 378 if (!SecRef.IsNameUnique) 379 OS << format(" [%" PRIu64 "]", SectionIndex); 380 } 381 382 void DWARFFormValue::dump(raw_ostream &OS, DIDumpOptions DumpOpts) const { 383 uint64_t UValue = Value.uval; 384 bool CURelativeOffset = false; 385 raw_ostream &AddrOS = DumpOpts.ShowAddresses 386 ? WithColor(OS, HighlightColor::Address).get() 387 : nulls(); 388 int OffsetDumpWidth = 2 * dwarf::getDwarfOffsetByteSize(Format); 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 case DW_FORM_LLVM_addrx_offset: { 400 if (U == nullptr) { 401 OS << "<invalid dwarf unit>"; 402 break; 403 } 404 std::optional<object::SectionedAddress> A = getAsSectionedAddress(); 405 if (!A || DumpOpts.Verbose) { 406 if (Form == DW_FORM_LLVM_addrx_offset) { 407 uint32_t Index = UValue >> 32; 408 uint32_t Offset = UValue & 0xffffffff; 409 AddrOS << format("indexed (%8.8x) + 0x%x address = ", Index, Offset); 410 } else 411 AddrOS << format("indexed (%8.8x) address = ", (uint32_t)UValue); 412 } 413 if (A) 414 dumpSectionedAddress(AddrOS, DumpOpts, *A); 415 else 416 OS << "<unresolved>"; 417 break; 418 } 419 case DW_FORM_flag_present: 420 OS << "true"; 421 break; 422 case DW_FORM_flag: 423 case DW_FORM_data1: 424 OS << format("0x%02x", (uint8_t)UValue); 425 break; 426 case DW_FORM_data2: 427 OS << format("0x%04x", (uint16_t)UValue); 428 break; 429 case DW_FORM_data4: 430 OS << format("0x%08x", (uint32_t)UValue); 431 break; 432 case DW_FORM_ref_sig8: 433 AddrOS << format("0x%016" PRIx64, UValue); 434 break; 435 case DW_FORM_data8: 436 OS << format("0x%016" PRIx64, UValue); 437 break; 438 case DW_FORM_data16: 439 OS << format_bytes(ArrayRef<uint8_t>(Value.data, 16), std::nullopt, 16, 16); 440 break; 441 case DW_FORM_string: 442 OS << '"'; 443 OS.write_escaped(Value.cstr); 444 OS << '"'; 445 break; 446 case DW_FORM_exprloc: 447 case DW_FORM_block: 448 case DW_FORM_block1: 449 case DW_FORM_block2: 450 case DW_FORM_block4: 451 if (UValue > 0) { 452 switch (Form) { 453 case DW_FORM_exprloc: 454 case DW_FORM_block: 455 AddrOS << format("<0x%" PRIx64 "> ", UValue); 456 break; 457 case DW_FORM_block1: 458 AddrOS << format("<0x%2.2x> ", (uint8_t)UValue); 459 break; 460 case DW_FORM_block2: 461 AddrOS << format("<0x%4.4x> ", (uint16_t)UValue); 462 break; 463 case DW_FORM_block4: 464 AddrOS << format("<0x%8.8x> ", (uint32_t)UValue); 465 break; 466 default: 467 break; 468 } 469 470 const uint8_t *DataPtr = Value.data; 471 if (DataPtr) { 472 // UValue contains size of block 473 const uint8_t *EndDataPtr = DataPtr + UValue; 474 while (DataPtr < EndDataPtr) { 475 AddrOS << format("%2.2x ", *DataPtr); 476 ++DataPtr; 477 } 478 } else 479 OS << "NULL"; 480 } 481 break; 482 483 case DW_FORM_sdata: 484 case DW_FORM_implicit_const: 485 OS << Value.sval; 486 break; 487 case DW_FORM_udata: 488 OS << Value.uval; 489 break; 490 case DW_FORM_strp: 491 if (DumpOpts.Verbose) 492 OS << format(" .debug_str[0x%0*" PRIx64 "] = ", OffsetDumpWidth, UValue); 493 dumpString(OS); 494 break; 495 case DW_FORM_line_strp: 496 if (DumpOpts.Verbose) 497 OS << format(" .debug_line_str[0x%0*" PRIx64 "] = ", OffsetDumpWidth, 498 UValue); 499 dumpString(OS); 500 break; 501 case DW_FORM_strx: 502 case DW_FORM_strx1: 503 case DW_FORM_strx2: 504 case DW_FORM_strx3: 505 case DW_FORM_strx4: 506 case DW_FORM_GNU_str_index: 507 if (DumpOpts.Verbose) 508 OS << format("indexed (%8.8x) string = ", (uint32_t)UValue); 509 dumpString(OS); 510 break; 511 case DW_FORM_GNU_strp_alt: 512 if (DumpOpts.Verbose) 513 OS << format("alt indirect string, offset: 0x%" PRIx64 "", UValue); 514 dumpString(OS); 515 break; 516 case DW_FORM_ref_addr: 517 AddrOS << format("0x%016" PRIx64, UValue); 518 break; 519 case DW_FORM_ref1: 520 CURelativeOffset = true; 521 if (DumpOpts.Verbose) 522 AddrOS << format("cu + 0x%2.2x", (uint8_t)UValue); 523 break; 524 case DW_FORM_ref2: 525 CURelativeOffset = true; 526 if (DumpOpts.Verbose) 527 AddrOS << format("cu + 0x%4.4x", (uint16_t)UValue); 528 break; 529 case DW_FORM_ref4: 530 CURelativeOffset = true; 531 if (DumpOpts.Verbose) 532 AddrOS << format("cu + 0x%4.4x", (uint32_t)UValue); 533 break; 534 case DW_FORM_ref8: 535 CURelativeOffset = true; 536 if (DumpOpts.Verbose) 537 AddrOS << format("cu + 0x%8.8" PRIx64, UValue); 538 break; 539 case DW_FORM_ref_udata: 540 CURelativeOffset = true; 541 if (DumpOpts.Verbose) 542 AddrOS << format("cu + 0x%" PRIx64, UValue); 543 break; 544 case DW_FORM_GNU_ref_alt: 545 AddrOS << format("<alt 0x%" PRIx64 ">", UValue); 546 break; 547 548 // All DW_FORM_indirect attributes should be resolved prior to calling 549 // this function 550 case DW_FORM_indirect: 551 OS << "DW_FORM_indirect"; 552 break; 553 554 case DW_FORM_rnglistx: 555 OS << format("indexed (0x%x) rangelist = ", (uint32_t)UValue); 556 break; 557 558 case DW_FORM_loclistx: 559 OS << format("indexed (0x%x) loclist = ", (uint32_t)UValue); 560 break; 561 562 case DW_FORM_sec_offset: 563 AddrOS << format("0x%0*" PRIx64, OffsetDumpWidth, UValue); 564 break; 565 566 default: 567 OS << format("DW_FORM(0x%4.4x)", Form); 568 break; 569 } 570 571 if (CURelativeOffset) { 572 if (DumpOpts.Verbose) 573 OS << " => {"; 574 if (DumpOpts.ShowAddresses) 575 WithColor(OS, HighlightColor::Address).get() 576 << format("0x%8.8" PRIx64, UValue + (U ? U->getOffset() : 0)); 577 if (DumpOpts.Verbose) 578 OS << "}"; 579 } 580 } 581 582 void DWARFFormValue::dumpString(raw_ostream &OS) const { 583 if (auto DbgStr = dwarf::toString(*this)) { 584 auto COS = WithColor(OS, HighlightColor::String); 585 COS.get() << '"'; 586 COS.get().write_escaped(*DbgStr); 587 COS.get() << '"'; 588 } 589 } 590 591 Expected<const char *> DWARFFormValue::getAsCString() const { 592 if (!isFormClass(FC_String)) 593 return make_error<StringError>("Invalid form for string attribute", 594 inconvertibleErrorCode()); 595 if (Form == DW_FORM_string) 596 return Value.cstr; 597 // FIXME: Add support for DW_FORM_GNU_strp_alt 598 if (Form == DW_FORM_GNU_strp_alt || C == nullptr) 599 return make_error<StringError>("Unsupported form for string attribute", 600 inconvertibleErrorCode()); 601 uint64_t Offset = Value.uval; 602 std::optional<uint32_t> Index; 603 if (Form == DW_FORM_GNU_str_index || Form == DW_FORM_strx || 604 Form == DW_FORM_strx1 || Form == DW_FORM_strx2 || Form == DW_FORM_strx3 || 605 Form == DW_FORM_strx4) { 606 if (!U) 607 return make_error<StringError>("API limitation - string extraction not " 608 "available without a DWARFUnit", 609 inconvertibleErrorCode()); 610 Expected<uint64_t> StrOffset = U->getStringOffsetSectionItem(Offset); 611 Index = Offset; 612 if (!StrOffset) 613 return StrOffset.takeError(); 614 Offset = *StrOffset; 615 } 616 // Prefer the Unit's string extractor, because for .dwo it will point to 617 // .debug_str.dwo, while the Context's extractor always uses .debug_str. 618 bool IsDebugLineString = Form == DW_FORM_line_strp; 619 DataExtractor StrData = 620 IsDebugLineString ? C->getLineStringExtractor() 621 : U ? U->getStringExtractor() : C->getStringExtractor(); 622 if (const char *Str = StrData.getCStr(&Offset)) 623 return Str; 624 std::string Msg = FormEncodingString(Form).str(); 625 if (Index) 626 Msg += (" uses index " + Twine(*Index) + ", but the referenced string").str(); 627 Msg += (" offset " + Twine(Offset) + " is beyond " + 628 (IsDebugLineString ? ".debug_line_str" : ".debug_str") + " bounds") 629 .str(); 630 return make_error<StringError>(Msg, 631 inconvertibleErrorCode()); 632 } 633 634 std::optional<uint64_t> DWARFFormValue::getAsAddress() const { 635 if (auto SA = getAsSectionedAddress()) 636 return SA->Address; 637 return std::nullopt; 638 } 639 640 std::optional<object::SectionedAddress> DWARFFormValue::getAsSectionedAddress( 641 const ValueType &Value, const dwarf::Form Form, const DWARFUnit *U) { 642 if (!doesFormBelongToClass(Form, FC_Address, U ? U->getVersion() : 3)) 643 return std::nullopt; 644 bool AddrOffset = Form == dwarf::DW_FORM_LLVM_addrx_offset; 645 if (Form == DW_FORM_GNU_addr_index || Form == DW_FORM_addrx || 646 Form == DW_FORM_addrx1 || Form == DW_FORM_addrx2 || 647 Form == DW_FORM_addrx3 || Form == DW_FORM_addrx4 || AddrOffset) { 648 649 uint32_t Index = AddrOffset ? (Value.uval >> 32) : Value.uval; 650 if (!U) 651 return std::nullopt; 652 std::optional<object::SectionedAddress> SA = 653 U->getAddrOffsetSectionItem(Index); 654 if (!SA) 655 return std::nullopt; 656 if (AddrOffset) 657 SA->Address += (Value.uval & 0xffffffff); 658 return SA; 659 } 660 return {{Value.uval, Value.SectionIndex}}; 661 } 662 663 std::optional<object::SectionedAddress> 664 DWARFFormValue::getAsSectionedAddress() const { 665 return getAsSectionedAddress(Value, Form, U); 666 } 667 668 std::optional<uint64_t> DWARFFormValue::getAsReference() const { 669 if (auto R = getAsRelativeReference()) 670 return R->Unit ? R->Unit->getOffset() + R->Offset : R->Offset; 671 return std::nullopt; 672 } 673 674 std::optional<DWARFFormValue::UnitOffset> 675 DWARFFormValue::getAsRelativeReference() const { 676 if (!isFormClass(FC_Reference)) 677 return std::nullopt; 678 switch (Form) { 679 case DW_FORM_ref1: 680 case DW_FORM_ref2: 681 case DW_FORM_ref4: 682 case DW_FORM_ref8: 683 case DW_FORM_ref_udata: 684 if (!U) 685 return std::nullopt; 686 return UnitOffset{const_cast<DWARFUnit*>(U), Value.uval}; 687 case DW_FORM_ref_addr: 688 case DW_FORM_ref_sig8: 689 case DW_FORM_GNU_ref_alt: 690 return UnitOffset{nullptr, Value.uval}; 691 default: 692 return std::nullopt; 693 } 694 } 695 696 std::optional<uint64_t> DWARFFormValue::getAsSectionOffset() const { 697 if (!isFormClass(FC_SectionOffset)) 698 return std::nullopt; 699 return Value.uval; 700 } 701 702 std::optional<uint64_t> DWARFFormValue::getAsUnsignedConstant() const { 703 if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag)) || 704 Form == DW_FORM_sdata) 705 return std::nullopt; 706 return Value.uval; 707 } 708 709 std::optional<int64_t> DWARFFormValue::getAsSignedConstant() const { 710 if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag)) || 711 (Form == DW_FORM_udata && 712 uint64_t(std::numeric_limits<int64_t>::max()) < Value.uval)) 713 return std::nullopt; 714 switch (Form) { 715 case DW_FORM_data4: 716 return int32_t(Value.uval); 717 case DW_FORM_data2: 718 return int16_t(Value.uval); 719 case DW_FORM_data1: 720 return int8_t(Value.uval); 721 case DW_FORM_sdata: 722 case DW_FORM_data8: 723 default: 724 return Value.sval; 725 } 726 } 727 728 std::optional<ArrayRef<uint8_t>> DWARFFormValue::getAsBlock() const { 729 if (!isFormClass(FC_Block) && !isFormClass(FC_Exprloc) && 730 Form != DW_FORM_data16) 731 return std::nullopt; 732 return ArrayRef(Value.data, Value.uval); 733 } 734 735 std::optional<uint64_t> DWARFFormValue::getAsCStringOffset() const { 736 if (!isFormClass(FC_String) && Form == DW_FORM_string) 737 return std::nullopt; 738 return Value.uval; 739 } 740 741 std::optional<uint64_t> DWARFFormValue::getAsReferenceUVal() const { 742 if (!isFormClass(FC_Reference)) 743 return std::nullopt; 744 return Value.uval; 745 } 746 747 std::optional<std::string> 748 DWARFFormValue::getAsFile(DILineInfoSpecifier::FileLineInfoKind Kind) const { 749 if (U == nullptr || !isFormClass(FC_Constant)) 750 return std::nullopt; 751 DWARFUnit *DLU = const_cast<DWARFUnit *>(U)->getLinkedUnit(); 752 if (auto *LT = DLU->getContext().getLineTableForUnit(DLU)) { 753 std::string FileName; 754 if (LT->getFileNameByIndex(Value.uval, DLU->getCompilationDir(), Kind, 755 FileName)) 756 return FileName; 757 } 758 return std::nullopt; 759 } 760 761 bool llvm::dwarf::doesFormBelongToClass(dwarf::Form Form, DWARFFormValue::FormClass FC, 762 uint16_t DwarfVersion) { 763 // First, check DWARF5 form classes. 764 if (Form < ArrayRef(DWARF5FormClasses).size() && 765 DWARF5FormClasses[Form] == FC) 766 return true; 767 // Check more forms from extensions and proposals. 768 switch (Form) { 769 case DW_FORM_GNU_ref_alt: 770 return (FC == DWARFFormValue::FC_Reference); 771 case DW_FORM_GNU_addr_index: 772 return (FC == DWARFFormValue::FC_Address); 773 case DW_FORM_GNU_str_index: 774 case DW_FORM_GNU_strp_alt: 775 return (FC == DWARFFormValue::FC_String); 776 case DW_FORM_LLVM_addrx_offset: 777 return (FC == DWARFFormValue::FC_Address); 778 case DW_FORM_strp: 779 case DW_FORM_line_strp: 780 return (FC == DWARFFormValue::FC_SectionOffset); 781 case DW_FORM_data4: 782 case DW_FORM_data8: 783 // In DWARF3 DW_FORM_data4 and DW_FORM_data8 served also as a section 784 // offset. 785 return (FC == DWARFFormValue::FC_SectionOffset) && (DwarfVersion <= 3); 786 default: 787 return false; 788 } 789 } 790