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 "SyntaxHighlighting.h" 11 #include "llvm/ADT/ArrayRef.h" 12 #include "llvm/ADT/None.h" 13 #include "llvm/ADT/Optional.h" 14 #include "llvm/ADT/StringRef.h" 15 #include "llvm/DebugInfo/DWARF/DWARFContext.h" 16 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h" 17 #include "llvm/DebugInfo/DWARF/DWARFRelocMap.h" 18 #include "llvm/DebugInfo/DWARF/DWARFUnit.h" 19 #include "llvm/Support/Dwarf.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 namespace { 63 64 /// A helper class that can be used in DWARFFormValue.cpp functions that need 65 /// to know the byte size of DW_FORM values that vary in size depending on the 66 /// DWARF version, address byte size, or DWARF32 or DWARF64. 67 class FormSizeHelper { 68 uint16_t Version; 69 uint8_t AddrSize; 70 llvm::dwarf::DwarfFormat Format; 71 72 public: 73 FormSizeHelper(uint16_t V, uint8_t A, llvm::dwarf::DwarfFormat F) 74 : Version(V), AddrSize(A), Format(F) {} 75 76 uint8_t getAddressByteSize() const { return AddrSize; } 77 78 uint8_t getRefAddrByteSize() const { 79 if (Version == 2) 80 return AddrSize; 81 return getDwarfOffsetByteSize(); 82 } 83 84 uint8_t getDwarfOffsetByteSize() const { 85 switch (Format) { 86 case dwarf::DwarfFormat::DWARF32: 87 return 4; 88 case dwarf::DwarfFormat::DWARF64: 89 return 8; 90 } 91 llvm_unreachable("Invalid Format value"); 92 } 93 }; 94 95 } // end anonymous namespace 96 97 template <class T> 98 static Optional<uint8_t> getFixedByteSize(dwarf::Form Form, const T *U) { 99 switch (Form) { 100 case DW_FORM_addr: 101 if (U) 102 return U->getAddressByteSize(); 103 return None; 104 105 case DW_FORM_block: // ULEB128 length L followed by L bytes. 106 case DW_FORM_block1: // 1 byte length L followed by L bytes. 107 case DW_FORM_block2: // 2 byte length L followed by L bytes. 108 case DW_FORM_block4: // 4 byte length L followed by L bytes. 109 case DW_FORM_string: // C-string with null terminator. 110 case DW_FORM_sdata: // SLEB128. 111 case DW_FORM_udata: // ULEB128. 112 case DW_FORM_ref_udata: // ULEB128. 113 case DW_FORM_indirect: // ULEB128. 114 case DW_FORM_exprloc: // ULEB128 length L followed by L bytes. 115 case DW_FORM_strx: // ULEB128. 116 case DW_FORM_addrx: // ULEB128. 117 case DW_FORM_loclistx: // ULEB128. 118 case DW_FORM_rnglistx: // ULEB128. 119 case DW_FORM_GNU_addr_index: // ULEB128. 120 case DW_FORM_GNU_str_index: // ULEB128. 121 return None; 122 123 case DW_FORM_ref_addr: 124 if (U) 125 return U->getRefAddrByteSize(); 126 return None; 127 128 case DW_FORM_flag: 129 case DW_FORM_data1: 130 case DW_FORM_ref1: 131 case DW_FORM_strx1: 132 case DW_FORM_addrx1: 133 return 1; 134 135 case DW_FORM_data2: 136 case DW_FORM_ref2: 137 case DW_FORM_strx2: 138 case DW_FORM_addrx2: 139 return 2; 140 141 case DW_FORM_data4: 142 case DW_FORM_ref4: 143 case DW_FORM_ref_sup4: 144 case DW_FORM_strx4: 145 case DW_FORM_addrx4: 146 return 4; 147 148 case DW_FORM_strp: 149 case DW_FORM_GNU_ref_alt: 150 case DW_FORM_GNU_strp_alt: 151 case DW_FORM_line_strp: 152 case DW_FORM_sec_offset: 153 case DW_FORM_strp_sup: 154 if (U) 155 return U->getDwarfOffsetByteSize(); 156 return None; 157 158 case DW_FORM_data8: 159 case DW_FORM_ref8: 160 case DW_FORM_ref_sig8: 161 case DW_FORM_ref_sup8: 162 return 8; 163 164 case DW_FORM_flag_present: 165 return 0; 166 167 case DW_FORM_data16: 168 return 16; 169 170 case DW_FORM_implicit_const: 171 // The implicit value is stored in the abbreviation as a SLEB128, and 172 // there no data in debug info. 173 return 0; 174 175 default: 176 llvm_unreachable("Handle this form in this switch statement"); 177 } 178 return None; 179 } 180 181 template <class T> 182 static bool skipFormValue(dwarf::Form Form, const DataExtractor &DebugInfoData, 183 uint32_t *OffsetPtr, const T *U) { 184 bool Indirect = false; 185 do { 186 switch (Form) { 187 // Blocks of inlined data that have a length field and the data bytes 188 // inlined in the .debug_info. 189 case DW_FORM_exprloc: 190 case DW_FORM_block: { 191 uint64_t size = DebugInfoData.getULEB128(OffsetPtr); 192 *OffsetPtr += size; 193 return true; 194 } 195 case DW_FORM_block1: { 196 uint8_t size = DebugInfoData.getU8(OffsetPtr); 197 *OffsetPtr += size; 198 return true; 199 } 200 case DW_FORM_block2: { 201 uint16_t size = DebugInfoData.getU16(OffsetPtr); 202 *OffsetPtr += size; 203 return true; 204 } 205 case DW_FORM_block4: { 206 uint32_t size = DebugInfoData.getU32(OffsetPtr); 207 *OffsetPtr += size; 208 return true; 209 } 210 211 // Inlined NULL terminated C-strings. 212 case DW_FORM_string: 213 DebugInfoData.getCStr(OffsetPtr); 214 return true; 215 216 case DW_FORM_addr: 217 case DW_FORM_ref_addr: 218 case DW_FORM_flag_present: 219 case DW_FORM_data1: 220 case DW_FORM_data2: 221 case DW_FORM_data4: 222 case DW_FORM_data8: 223 case DW_FORM_flag: 224 case DW_FORM_ref1: 225 case DW_FORM_ref2: 226 case DW_FORM_ref4: 227 case DW_FORM_ref8: 228 case DW_FORM_ref_sig8: 229 case DW_FORM_ref_sup4: 230 case DW_FORM_ref_sup8: 231 case DW_FORM_strx1: 232 case DW_FORM_strx2: 233 case DW_FORM_strx4: 234 case DW_FORM_addrx1: 235 case DW_FORM_addrx2: 236 case DW_FORM_addrx4: 237 case DW_FORM_sec_offset: 238 case DW_FORM_strp: 239 case DW_FORM_strp_sup: 240 case DW_FORM_line_strp: 241 case DW_FORM_GNU_ref_alt: 242 case DW_FORM_GNU_strp_alt: 243 if (Optional<uint8_t> FixedSize = ::getFixedByteSize(Form, U)) { 244 *OffsetPtr += *FixedSize; 245 return true; 246 } 247 return false; 248 249 // signed or unsigned LEB 128 values. 250 case DW_FORM_sdata: 251 DebugInfoData.getSLEB128(OffsetPtr); 252 return true; 253 254 case DW_FORM_udata: 255 case DW_FORM_ref_udata: 256 case DW_FORM_strx: 257 case DW_FORM_addrx: 258 case DW_FORM_loclistx: 259 case DW_FORM_rnglistx: 260 case DW_FORM_GNU_addr_index: 261 case DW_FORM_GNU_str_index: 262 DebugInfoData.getULEB128(OffsetPtr); 263 return true; 264 265 case DW_FORM_indirect: 266 Indirect = true; 267 Form = static_cast<dwarf::Form>(DebugInfoData.getULEB128(OffsetPtr)); 268 break; 269 270 default: 271 return false; 272 } 273 } while (Indirect); 274 return true; 275 } 276 277 Optional<uint8_t> DWARFFormValue::getFixedByteSize(dwarf::Form Form, 278 const DWARFUnit *U) { 279 return ::getFixedByteSize(Form, U); 280 } 281 282 Optional<uint8_t> 283 DWARFFormValue::getFixedByteSize(dwarf::Form Form, uint16_t Version, 284 uint8_t AddrSize, 285 llvm::dwarf::DwarfFormat Format) { 286 FormSizeHelper FSH(Version, AddrSize, Format); 287 return ::getFixedByteSize(Form, &FSH); 288 } 289 290 bool DWARFFormValue::isFormClass(DWARFFormValue::FormClass FC) const { 291 // First, check DWARF4 form classes. 292 if (Form < makeArrayRef(DWARF4FormClasses).size() && 293 DWARF4FormClasses[Form] == FC) 294 return true; 295 // Check more forms from DWARF4 and DWARF5 proposals. 296 switch (Form) { 297 case DW_FORM_ref_sig8: 298 case DW_FORM_GNU_ref_alt: 299 return (FC == FC_Reference); 300 case DW_FORM_GNU_addr_index: 301 return (FC == FC_Address); 302 case DW_FORM_GNU_str_index: 303 case DW_FORM_GNU_strp_alt: 304 return (FC == FC_String); 305 case DW_FORM_implicit_const: 306 return (FC == FC_Constant); 307 default: 308 break; 309 } 310 // In DWARF3 DW_FORM_data4 and DW_FORM_data8 served also as a section offset. 311 // Don't check for DWARF version here, as some producers may still do this 312 // by mistake. 313 return (Form == DW_FORM_data4 || Form == DW_FORM_data8) && 314 FC == FC_SectionOffset; 315 } 316 317 bool DWARFFormValue::extractValue(const DataExtractor &data, 318 uint32_t *offset_ptr, 319 const DWARFUnit *cu) { 320 U = cu; 321 bool indirect = false; 322 bool is_block = false; 323 Value.data = nullptr; 324 // Read the value for the form into value and follow and DW_FORM_indirect 325 // instances we run into 326 do { 327 indirect = false; 328 switch (Form) { 329 case DW_FORM_addr: 330 case DW_FORM_ref_addr: { 331 if (!U) 332 return false; 333 uint16_t AddrSize = 334 (Form == DW_FORM_addr) 335 ? U->getAddressByteSize() 336 : U->getRefAddrByteSize(); 337 Value.uval = 338 getRelocatedValue(data, AddrSize, offset_ptr, U->getRelocMap()); 339 break; 340 } 341 case DW_FORM_exprloc: 342 case DW_FORM_block: 343 Value.uval = data.getULEB128(offset_ptr); 344 is_block = true; 345 break; 346 case DW_FORM_block1: 347 Value.uval = data.getU8(offset_ptr); 348 is_block = true; 349 break; 350 case DW_FORM_block2: 351 Value.uval = data.getU16(offset_ptr); 352 is_block = true; 353 break; 354 case DW_FORM_block4: 355 Value.uval = data.getU32(offset_ptr); 356 is_block = true; 357 break; 358 case DW_FORM_data1: 359 case DW_FORM_ref1: 360 case DW_FORM_flag: 361 case DW_FORM_strx1: 362 case DW_FORM_addrx1: 363 Value.uval = data.getU8(offset_ptr); 364 break; 365 case DW_FORM_data2: 366 case DW_FORM_ref2: 367 case DW_FORM_strx2: 368 case DW_FORM_addrx2: 369 Value.uval = data.getU16(offset_ptr); 370 break; 371 case DW_FORM_data4: 372 case DW_FORM_ref4: 373 case DW_FORM_ref_sup4: 374 case DW_FORM_strx4: 375 case DW_FORM_addrx4: { 376 const RelocAddrMap* RelocMap = U ? U->getRelocMap() : nullptr; 377 Value.uval = getRelocatedValue(data, 4, offset_ptr, RelocMap); 378 break; 379 } 380 case DW_FORM_data8: 381 case DW_FORM_ref8: 382 case DW_FORM_ref_sup8: 383 Value.uval = data.getU64(offset_ptr); 384 break; 385 case DW_FORM_sdata: 386 Value.sval = data.getSLEB128(offset_ptr); 387 break; 388 case DW_FORM_udata: 389 case DW_FORM_ref_udata: 390 Value.uval = data.getULEB128(offset_ptr); 391 break; 392 case DW_FORM_string: 393 Value.cstr = data.getCStr(offset_ptr); 394 break; 395 case DW_FORM_indirect: 396 Form = static_cast<dwarf::Form>(data.getULEB128(offset_ptr)); 397 indirect = true; 398 break; 399 case DW_FORM_strp: 400 case DW_FORM_sec_offset: 401 case DW_FORM_GNU_ref_alt: 402 case DW_FORM_GNU_strp_alt: 403 case DW_FORM_line_strp: 404 case DW_FORM_strp_sup: { 405 if (!U) 406 return false; 407 Value.uval = getRelocatedValue(data, U->getDwarfOffsetByteSize(), 408 offset_ptr, U->getRelocMap()); 409 break; 410 } 411 case DW_FORM_flag_present: 412 Value.uval = 1; 413 break; 414 case DW_FORM_ref_sig8: 415 Value.uval = data.getU64(offset_ptr); 416 break; 417 case DW_FORM_GNU_addr_index: 418 case DW_FORM_GNU_str_index: 419 Value.uval = data.getULEB128(offset_ptr); 420 break; 421 default: 422 // DWARFFormValue::skipValue() will have caught this and caused all 423 // DWARF DIEs to fail to be parsed, so this code is not be reachable. 424 llvm_unreachable("unsupported form"); 425 } 426 } while (indirect); 427 428 if (is_block) { 429 StringRef str = data.getData().substr(*offset_ptr, Value.uval); 430 Value.data = nullptr; 431 if (!str.empty()) { 432 Value.data = reinterpret_cast<const uint8_t *>(str.data()); 433 *offset_ptr += Value.uval; 434 } 435 } 436 437 return true; 438 } 439 440 bool DWARFFormValue::skipValue(DataExtractor DebugInfoData, 441 uint32_t *offset_ptr, const DWARFUnit *U) const { 442 return DWARFFormValue::skipValue(Form, DebugInfoData, offset_ptr, U); 443 } 444 445 bool DWARFFormValue::skipValue(dwarf::Form form, DataExtractor DebugInfoData, 446 uint32_t *offset_ptr, const DWARFUnit *U) { 447 return skipFormValue(form, DebugInfoData, offset_ptr, U); 448 } 449 450 bool DWARFFormValue::skipValue(dwarf::Form form, DataExtractor DebugInfoData, 451 uint32_t *offset_ptr, uint16_t Version, 452 uint8_t AddrSize, 453 llvm::dwarf::DwarfFormat Format) { 454 FormSizeHelper FSH(Version, AddrSize, Format); 455 return skipFormValue(form, DebugInfoData, offset_ptr, &FSH); 456 } 457 458 void 459 DWARFFormValue::dump(raw_ostream &OS) const { 460 uint64_t uvalue = Value.uval; 461 bool cu_relative_offset = false; 462 463 switch (Form) { 464 case DW_FORM_addr: OS << format("0x%016" PRIx64, uvalue); break; 465 case DW_FORM_GNU_addr_index: { 466 OS << format(" indexed (%8.8x) address = ", (uint32_t)uvalue); 467 uint64_t Address; 468 if (U == nullptr) 469 OS << "<invalid dwarf unit>"; 470 else if (U->getAddrOffsetSectionItem(uvalue, Address)) 471 OS << format("0x%016" PRIx64, Address); 472 else 473 OS << "<no .debug_addr section>"; 474 break; 475 } 476 case DW_FORM_flag_present: OS << "true"; break; 477 case DW_FORM_flag: 478 case DW_FORM_data1: OS << format("0x%02x", (uint8_t)uvalue); break; 479 case DW_FORM_data2: OS << format("0x%04x", (uint16_t)uvalue); break; 480 case DW_FORM_data4: OS << format("0x%08x", (uint32_t)uvalue); break; 481 case DW_FORM_ref_sig8: 482 case DW_FORM_data8: OS << format("0x%016" PRIx64, uvalue); break; 483 case DW_FORM_string: 484 OS << '"'; 485 OS.write_escaped(Value.cstr); 486 OS << '"'; 487 break; 488 case DW_FORM_exprloc: 489 case DW_FORM_block: 490 case DW_FORM_block1: 491 case DW_FORM_block2: 492 case DW_FORM_block4: 493 if (uvalue > 0) { 494 switch (Form) { 495 case DW_FORM_exprloc: 496 case DW_FORM_block: OS << format("<0x%" PRIx64 "> ", uvalue); break; 497 case DW_FORM_block1: OS << format("<0x%2.2x> ", (uint8_t)uvalue); break; 498 case DW_FORM_block2: OS << format("<0x%4.4x> ", (uint16_t)uvalue); break; 499 case DW_FORM_block4: OS << format("<0x%8.8x> ", (uint32_t)uvalue); break; 500 default: break; 501 } 502 503 const uint8_t* data_ptr = Value.data; 504 if (data_ptr) { 505 // uvalue contains size of block 506 const uint8_t* end_data_ptr = data_ptr + uvalue; 507 while (data_ptr < end_data_ptr) { 508 OS << format("%2.2x ", *data_ptr); 509 ++data_ptr; 510 } 511 } 512 else 513 OS << "NULL"; 514 } 515 break; 516 517 case DW_FORM_sdata: OS << Value.sval; break; 518 case DW_FORM_udata: OS << Value.uval; break; 519 case DW_FORM_strp: 520 OS << format(" .debug_str[0x%8.8x] = ", (uint32_t)uvalue); 521 dumpString(OS); 522 break; 523 case DW_FORM_GNU_str_index: 524 OS << format(" indexed (%8.8x) string = ", (uint32_t)uvalue); 525 dumpString(OS); 526 break; 527 case DW_FORM_GNU_strp_alt: 528 OS << format("alt indirect string, offset: 0x%" PRIx64 "", uvalue); 529 dumpString(OS); 530 break; 531 case DW_FORM_ref_addr: 532 OS << format("0x%016" PRIx64, uvalue); 533 break; 534 case DW_FORM_ref1: 535 cu_relative_offset = true; 536 OS << format("cu + 0x%2.2x", (uint8_t)uvalue); 537 break; 538 case DW_FORM_ref2: 539 cu_relative_offset = true; 540 OS << format("cu + 0x%4.4x", (uint16_t)uvalue); 541 break; 542 case DW_FORM_ref4: 543 cu_relative_offset = true; 544 OS << format("cu + 0x%4.4x", (uint32_t)uvalue); 545 break; 546 case DW_FORM_ref8: 547 cu_relative_offset = true; 548 OS << format("cu + 0x%8.8" PRIx64, uvalue); 549 break; 550 case DW_FORM_ref_udata: 551 cu_relative_offset = true; 552 OS << format("cu + 0x%" PRIx64, uvalue); 553 break; 554 case DW_FORM_GNU_ref_alt: 555 OS << format("<alt 0x%" PRIx64 ">", uvalue); 556 break; 557 558 // All DW_FORM_indirect attributes should be resolved prior to calling 559 // this function 560 case DW_FORM_indirect: 561 OS << "DW_FORM_indirect"; 562 break; 563 564 // Should be formatted to 64-bit for DWARF64. 565 case DW_FORM_sec_offset: 566 OS << format("0x%08x", (uint32_t)uvalue); 567 break; 568 569 default: 570 OS << format("DW_FORM(0x%4.4x)", Form); 571 break; 572 } 573 574 if (cu_relative_offset) { 575 OS << " => {"; 576 WithColor(OS, syntax::Address).get() 577 << format("0x%8.8" PRIx64, uvalue + (U ? U->getOffset() : 0)); 578 OS << "}"; 579 } 580 } 581 582 void DWARFFormValue::dumpString(raw_ostream &OS) const { 583 Optional<const char *> DbgStr = getAsCString(); 584 if (DbgStr.hasValue()) { 585 raw_ostream &COS = WithColor(OS, syntax::String); 586 COS << '"'; 587 COS.write_escaped(DbgStr.getValue()); 588 COS << '"'; 589 } 590 } 591 592 Optional<const char *> DWARFFormValue::getAsCString() const { 593 if (!isFormClass(FC_String)) 594 return None; 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 || U == nullptr) 599 return None; 600 uint32_t Offset = Value.uval; 601 if (Form == DW_FORM_GNU_str_index) { 602 uint32_t StrOffset; 603 if (!U->getStringOffsetSectionItem(Offset, StrOffset)) 604 return None; 605 Offset = StrOffset; 606 } 607 if (const char *Str = U->getStringExtractor().getCStr(&Offset)) { 608 return Str; 609 } 610 return None; 611 } 612 613 Optional<uint64_t> DWARFFormValue::getAsAddress() const { 614 if (!isFormClass(FC_Address)) 615 return None; 616 if (Form == DW_FORM_GNU_addr_index) { 617 uint32_t Index = Value.uval; 618 uint64_t Result; 619 if (!U || !U->getAddrOffsetSectionItem(Index, Result)) 620 return None; 621 return Result; 622 } 623 return Value.uval; 624 } 625 626 Optional<uint64_t> DWARFFormValue::getAsReference() const { 627 if (!isFormClass(FC_Reference)) 628 return None; 629 switch (Form) { 630 case DW_FORM_ref1: 631 case DW_FORM_ref2: 632 case DW_FORM_ref4: 633 case DW_FORM_ref8: 634 case DW_FORM_ref_udata: 635 if (!U) 636 return None; 637 return Value.uval + U->getOffset(); 638 case DW_FORM_ref_addr: 639 case DW_FORM_ref_sig8: 640 case DW_FORM_GNU_ref_alt: 641 return Value.uval; 642 default: 643 return None; 644 } 645 } 646 647 Optional<uint64_t> DWARFFormValue::getAsSectionOffset() const { 648 if (!isFormClass(FC_SectionOffset)) 649 return None; 650 return Value.uval; 651 } 652 653 Optional<uint64_t> DWARFFormValue::getAsUnsignedConstant() const { 654 if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag)) 655 || Form == DW_FORM_sdata) 656 return None; 657 return Value.uval; 658 } 659 660 Optional<int64_t> DWARFFormValue::getAsSignedConstant() const { 661 if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag)) || 662 (Form == DW_FORM_udata && uint64_t(std::numeric_limits<int64_t>::max()) < Value.uval)) 663 return None; 664 switch (Form) { 665 case DW_FORM_data4: 666 return int32_t(Value.uval); 667 case DW_FORM_data2: 668 return int16_t(Value.uval); 669 case DW_FORM_data1: 670 return int8_t(Value.uval); 671 case DW_FORM_sdata: 672 case DW_FORM_data8: 673 default: 674 return Value.sval; 675 } 676 } 677 678 Optional<ArrayRef<uint8_t>> DWARFFormValue::getAsBlock() const { 679 if (!isFormClass(FC_Block) && !isFormClass(FC_Exprloc)) 680 return None; 681 return makeArrayRef(Value.data, Value.uval); 682 } 683 684 Optional<uint64_t> DWARFFormValue::getAsCStringOffset() const { 685 if (!isFormClass(FC_String) && Form == DW_FORM_string) 686 return None; 687 return Value.uval; 688 } 689 690 Optional<uint64_t> DWARFFormValue::getAsReferenceUVal() const { 691 if (!isFormClass(FC_Reference)) 692 return None; 693 return Value.uval; 694 } 695