1 //===- WasmObjectFile.cpp - Wasm object file implementation ---------------===// 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/ADT/ArrayRef.h" 10 #include "llvm/ADT/DenseSet.h" 11 #include "llvm/ADT/STLExtras.h" 12 #include "llvm/ADT/SmallSet.h" 13 #include "llvm/ADT/StringRef.h" 14 #include "llvm/ADT/StringSet.h" 15 #include "llvm/ADT/Triple.h" 16 #include "llvm/BinaryFormat/Wasm.h" 17 #include "llvm/MC/SubtargetFeature.h" 18 #include "llvm/Object/Binary.h" 19 #include "llvm/Object/Error.h" 20 #include "llvm/Object/ObjectFile.h" 21 #include "llvm/Object/SymbolicFile.h" 22 #include "llvm/Object/Wasm.h" 23 #include "llvm/Support/Endian.h" 24 #include "llvm/Support/Error.h" 25 #include "llvm/Support/ErrorHandling.h" 26 #include "llvm/Support/LEB128.h" 27 #include "llvm/Support/ScopedPrinter.h" 28 #include <algorithm> 29 #include <cassert> 30 #include <cstdint> 31 #include <cstring> 32 #include <system_error> 33 34 #define DEBUG_TYPE "wasm-object" 35 36 using namespace llvm; 37 using namespace object; 38 39 void WasmSymbol::print(raw_ostream &Out) const { 40 Out << "Name=" << Info.Name 41 << ", Kind=" << toString(wasm::WasmSymbolType(Info.Kind)) 42 << ", Flags=" << Info.Flags; 43 if (!isTypeData()) { 44 Out << ", ElemIndex=" << Info.ElementIndex; 45 } else if (isDefined()) { 46 Out << ", Segment=" << Info.DataRef.Segment; 47 Out << ", Offset=" << Info.DataRef.Offset; 48 Out << ", Size=" << Info.DataRef.Size; 49 } 50 } 51 52 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 53 LLVM_DUMP_METHOD void WasmSymbol::dump() const { print(dbgs()); } 54 #endif 55 56 Expected<std::unique_ptr<WasmObjectFile>> 57 ObjectFile::createWasmObjectFile(MemoryBufferRef Buffer) { 58 Error Err = Error::success(); 59 auto ObjectFile = std::make_unique<WasmObjectFile>(Buffer, Err); 60 if (Err) 61 return std::move(Err); 62 63 return std::move(ObjectFile); 64 } 65 66 #define VARINT7_MAX ((1 << 7) - 1) 67 #define VARINT7_MIN (-(1 << 7)) 68 #define VARUINT7_MAX (1 << 7) 69 #define VARUINT1_MAX (1) 70 71 static uint8_t readUint8(WasmObjectFile::ReadContext &Ctx) { 72 if (Ctx.Ptr == Ctx.End) 73 report_fatal_error("EOF while reading uint8"); 74 return *Ctx.Ptr++; 75 } 76 77 static uint32_t readUint32(WasmObjectFile::ReadContext &Ctx) { 78 if (Ctx.Ptr + 4 > Ctx.End) 79 report_fatal_error("EOF while reading uint32"); 80 uint32_t Result = support::endian::read32le(Ctx.Ptr); 81 Ctx.Ptr += 4; 82 return Result; 83 } 84 85 static int32_t readFloat32(WasmObjectFile::ReadContext &Ctx) { 86 if (Ctx.Ptr + 4 > Ctx.End) 87 report_fatal_error("EOF while reading float64"); 88 int32_t Result = 0; 89 memcpy(&Result, Ctx.Ptr, sizeof(Result)); 90 Ctx.Ptr += sizeof(Result); 91 return Result; 92 } 93 94 static int64_t readFloat64(WasmObjectFile::ReadContext &Ctx) { 95 if (Ctx.Ptr + 8 > Ctx.End) 96 report_fatal_error("EOF while reading float64"); 97 int64_t Result = 0; 98 memcpy(&Result, Ctx.Ptr, sizeof(Result)); 99 Ctx.Ptr += sizeof(Result); 100 return Result; 101 } 102 103 static uint64_t readULEB128(WasmObjectFile::ReadContext &Ctx) { 104 unsigned Count; 105 const char *Error = nullptr; 106 uint64_t Result = decodeULEB128(Ctx.Ptr, &Count, Ctx.End, &Error); 107 if (Error) 108 report_fatal_error(Error); 109 Ctx.Ptr += Count; 110 return Result; 111 } 112 113 static StringRef readString(WasmObjectFile::ReadContext &Ctx) { 114 uint32_t StringLen = readULEB128(Ctx); 115 if (Ctx.Ptr + StringLen > Ctx.End) 116 report_fatal_error("EOF while reading string"); 117 StringRef Return = 118 StringRef(reinterpret_cast<const char *>(Ctx.Ptr), StringLen); 119 Ctx.Ptr += StringLen; 120 return Return; 121 } 122 123 static int64_t readLEB128(WasmObjectFile::ReadContext &Ctx) { 124 unsigned Count; 125 const char *Error = nullptr; 126 uint64_t Result = decodeSLEB128(Ctx.Ptr, &Count, Ctx.End, &Error); 127 if (Error) 128 report_fatal_error(Error); 129 Ctx.Ptr += Count; 130 return Result; 131 } 132 133 static uint8_t readVaruint1(WasmObjectFile::ReadContext &Ctx) { 134 int64_t Result = readLEB128(Ctx); 135 if (Result > VARUINT1_MAX || Result < 0) 136 report_fatal_error("LEB is outside Varuint1 range"); 137 return Result; 138 } 139 140 static int32_t readVarint32(WasmObjectFile::ReadContext &Ctx) { 141 int64_t Result = readLEB128(Ctx); 142 if (Result > INT32_MAX || Result < INT32_MIN) 143 report_fatal_error("LEB is outside Varint32 range"); 144 return Result; 145 } 146 147 static uint32_t readVaruint32(WasmObjectFile::ReadContext &Ctx) { 148 uint64_t Result = readULEB128(Ctx); 149 if (Result > UINT32_MAX) 150 report_fatal_error("LEB is outside Varuint32 range"); 151 return Result; 152 } 153 154 static int64_t readVarint64(WasmObjectFile::ReadContext &Ctx) { 155 return readLEB128(Ctx); 156 } 157 158 static uint8_t readOpcode(WasmObjectFile::ReadContext &Ctx) { 159 return readUint8(Ctx); 160 } 161 162 static Error readInitExpr(wasm::WasmInitExpr &Expr, 163 WasmObjectFile::ReadContext &Ctx) { 164 Expr.Opcode = readOpcode(Ctx); 165 166 switch (Expr.Opcode) { 167 case wasm::WASM_OPCODE_I32_CONST: 168 Expr.Value.Int32 = readVarint32(Ctx); 169 break; 170 case wasm::WASM_OPCODE_I64_CONST: 171 Expr.Value.Int64 = readVarint64(Ctx); 172 break; 173 case wasm::WASM_OPCODE_F32_CONST: 174 Expr.Value.Float32 = readFloat32(Ctx); 175 break; 176 case wasm::WASM_OPCODE_F64_CONST: 177 Expr.Value.Float64 = readFloat64(Ctx); 178 break; 179 case wasm::WASM_OPCODE_GLOBAL_GET: 180 Expr.Value.Global = readULEB128(Ctx); 181 break; 182 default: 183 return make_error<GenericBinaryError>("Invalid opcode in init_expr", 184 object_error::parse_failed); 185 } 186 187 uint8_t EndOpcode = readOpcode(Ctx); 188 if (EndOpcode != wasm::WASM_OPCODE_END) { 189 return make_error<GenericBinaryError>("Invalid init_expr", 190 object_error::parse_failed); 191 } 192 return Error::success(); 193 } 194 195 static wasm::WasmLimits readLimits(WasmObjectFile::ReadContext &Ctx) { 196 wasm::WasmLimits Result; 197 Result.Flags = readVaruint32(Ctx); 198 Result.Initial = readVaruint32(Ctx); 199 if (Result.Flags & wasm::WASM_LIMITS_FLAG_HAS_MAX) 200 Result.Maximum = readVaruint32(Ctx); 201 return Result; 202 } 203 204 static wasm::WasmTable readTable(WasmObjectFile::ReadContext &Ctx) { 205 wasm::WasmTable Table; 206 Table.ElemType = readUint8(Ctx); 207 Table.Limits = readLimits(Ctx); 208 return Table; 209 } 210 211 static Error readSection(WasmSection &Section, WasmObjectFile::ReadContext &Ctx, 212 WasmSectionOrderChecker &Checker) { 213 Section.Offset = Ctx.Ptr - Ctx.Start; 214 Section.Type = readUint8(Ctx); 215 LLVM_DEBUG(dbgs() << "readSection type=" << Section.Type << "\n"); 216 uint32_t Size = readVaruint32(Ctx); 217 if (Size == 0) 218 return make_error<StringError>("Zero length section", 219 object_error::parse_failed); 220 if (Ctx.Ptr + Size > Ctx.End) 221 return make_error<StringError>("Section too large", 222 object_error::parse_failed); 223 if (Section.Type == wasm::WASM_SEC_CUSTOM) { 224 WasmObjectFile::ReadContext SectionCtx; 225 SectionCtx.Start = Ctx.Ptr; 226 SectionCtx.Ptr = Ctx.Ptr; 227 SectionCtx.End = Ctx.Ptr + Size; 228 229 Section.Name = readString(SectionCtx); 230 231 uint32_t SectionNameSize = SectionCtx.Ptr - SectionCtx.Start; 232 Ctx.Ptr += SectionNameSize; 233 Size -= SectionNameSize; 234 } 235 236 if (!Checker.isValidSectionOrder(Section.Type, Section.Name)) { 237 return make_error<StringError>("Out of order section type: " + 238 llvm::to_string(Section.Type), 239 object_error::parse_failed); 240 } 241 242 Section.Content = ArrayRef<uint8_t>(Ctx.Ptr, Size); 243 Ctx.Ptr += Size; 244 return Error::success(); 245 } 246 247 WasmObjectFile::WasmObjectFile(MemoryBufferRef Buffer, Error &Err) 248 : ObjectFile(Binary::ID_Wasm, Buffer) { 249 ErrorAsOutParameter ErrAsOutParam(&Err); 250 Header.Magic = getData().substr(0, 4); 251 if (Header.Magic != StringRef("\0asm", 4)) { 252 Err = 253 make_error<StringError>("Bad magic number", object_error::parse_failed); 254 return; 255 } 256 257 ReadContext Ctx; 258 Ctx.Start = getData().bytes_begin(); 259 Ctx.Ptr = Ctx.Start + 4; 260 Ctx.End = Ctx.Start + getData().size(); 261 262 if (Ctx.Ptr + 4 > Ctx.End) { 263 Err = make_error<StringError>("Missing version number", 264 object_error::parse_failed); 265 return; 266 } 267 268 Header.Version = readUint32(Ctx); 269 if (Header.Version != wasm::WasmVersion) { 270 Err = make_error<StringError>("Bad version number", 271 object_error::parse_failed); 272 return; 273 } 274 275 WasmSection Sec; 276 WasmSectionOrderChecker Checker; 277 while (Ctx.Ptr < Ctx.End) { 278 if ((Err = readSection(Sec, Ctx, Checker))) 279 return; 280 if ((Err = parseSection(Sec))) 281 return; 282 283 Sections.push_back(Sec); 284 } 285 } 286 287 Error WasmObjectFile::parseSection(WasmSection &Sec) { 288 ReadContext Ctx; 289 Ctx.Start = Sec.Content.data(); 290 Ctx.End = Ctx.Start + Sec.Content.size(); 291 Ctx.Ptr = Ctx.Start; 292 switch (Sec.Type) { 293 case wasm::WASM_SEC_CUSTOM: 294 return parseCustomSection(Sec, Ctx); 295 case wasm::WASM_SEC_TYPE: 296 return parseTypeSection(Ctx); 297 case wasm::WASM_SEC_IMPORT: 298 return parseImportSection(Ctx); 299 case wasm::WASM_SEC_FUNCTION: 300 return parseFunctionSection(Ctx); 301 case wasm::WASM_SEC_TABLE: 302 return parseTableSection(Ctx); 303 case wasm::WASM_SEC_MEMORY: 304 return parseMemorySection(Ctx); 305 case wasm::WASM_SEC_GLOBAL: 306 return parseGlobalSection(Ctx); 307 case wasm::WASM_SEC_EVENT: 308 return parseEventSection(Ctx); 309 case wasm::WASM_SEC_EXPORT: 310 return parseExportSection(Ctx); 311 case wasm::WASM_SEC_START: 312 return parseStartSection(Ctx); 313 case wasm::WASM_SEC_ELEM: 314 return parseElemSection(Ctx); 315 case wasm::WASM_SEC_CODE: 316 return parseCodeSection(Ctx); 317 case wasm::WASM_SEC_DATA: 318 return parseDataSection(Ctx); 319 case wasm::WASM_SEC_DATACOUNT: 320 return parseDataCountSection(Ctx); 321 default: 322 return make_error<GenericBinaryError>( 323 "Invalid section type: " + Twine(Sec.Type), object_error::parse_failed); 324 } 325 } 326 327 Error WasmObjectFile::parseDylinkSection(ReadContext &Ctx) { 328 // See https://github.com/WebAssembly/tool-conventions/blob/master/DynamicLinking.md 329 HasDylinkSection = true; 330 DylinkInfo.MemorySize = readVaruint32(Ctx); 331 DylinkInfo.MemoryAlignment = readVaruint32(Ctx); 332 DylinkInfo.TableSize = readVaruint32(Ctx); 333 DylinkInfo.TableAlignment = readVaruint32(Ctx); 334 uint32_t Count = readVaruint32(Ctx); 335 while (Count--) { 336 DylinkInfo.Needed.push_back(readString(Ctx)); 337 } 338 if (Ctx.Ptr != Ctx.End) 339 return make_error<GenericBinaryError>("dylink section ended prematurely", 340 object_error::parse_failed); 341 return Error::success(); 342 } 343 344 Error WasmObjectFile::parseNameSection(ReadContext &Ctx) { 345 llvm::DenseSet<uint64_t> Seen; 346 if (Functions.size() != FunctionTypes.size()) { 347 return make_error<GenericBinaryError>("Names must come after code section", 348 object_error::parse_failed); 349 } 350 351 while (Ctx.Ptr < Ctx.End) { 352 uint8_t Type = readUint8(Ctx); 353 uint32_t Size = readVaruint32(Ctx); 354 const uint8_t *SubSectionEnd = Ctx.Ptr + Size; 355 switch (Type) { 356 case wasm::WASM_NAMES_FUNCTION: { 357 uint32_t Count = readVaruint32(Ctx); 358 while (Count--) { 359 uint32_t Index = readVaruint32(Ctx); 360 if (!Seen.insert(Index).second) 361 return make_error<GenericBinaryError>("Function named more than once", 362 object_error::parse_failed); 363 StringRef Name = readString(Ctx); 364 if (!isValidFunctionIndex(Index) || Name.empty()) 365 return make_error<GenericBinaryError>("Invalid name entry", 366 object_error::parse_failed); 367 DebugNames.push_back(wasm::WasmFunctionName{Index, Name}); 368 if (isDefinedFunctionIndex(Index)) 369 getDefinedFunction(Index).DebugName = Name; 370 } 371 break; 372 } 373 // Ignore local names for now 374 case wasm::WASM_NAMES_LOCAL: 375 default: 376 Ctx.Ptr += Size; 377 break; 378 } 379 if (Ctx.Ptr != SubSectionEnd) 380 return make_error<GenericBinaryError>( 381 "Name sub-section ended prematurely", object_error::parse_failed); 382 } 383 384 if (Ctx.Ptr != Ctx.End) 385 return make_error<GenericBinaryError>("Name section ended prematurely", 386 object_error::parse_failed); 387 return Error::success(); 388 } 389 390 Error WasmObjectFile::parseLinkingSection(ReadContext &Ctx) { 391 HasLinkingSection = true; 392 if (Functions.size() != FunctionTypes.size()) { 393 return make_error<GenericBinaryError>( 394 "Linking data must come after code section", 395 object_error::parse_failed); 396 } 397 398 LinkingData.Version = readVaruint32(Ctx); 399 if (LinkingData.Version != wasm::WasmMetadataVersion) { 400 return make_error<GenericBinaryError>( 401 "Unexpected metadata version: " + Twine(LinkingData.Version) + 402 " (Expected: " + Twine(wasm::WasmMetadataVersion) + ")", 403 object_error::parse_failed); 404 } 405 406 const uint8_t *OrigEnd = Ctx.End; 407 while (Ctx.Ptr < OrigEnd) { 408 Ctx.End = OrigEnd; 409 uint8_t Type = readUint8(Ctx); 410 uint32_t Size = readVaruint32(Ctx); 411 LLVM_DEBUG(dbgs() << "readSubsection type=" << int(Type) << " size=" << Size 412 << "\n"); 413 Ctx.End = Ctx.Ptr + Size; 414 switch (Type) { 415 case wasm::WASM_SYMBOL_TABLE: 416 if (Error Err = parseLinkingSectionSymtab(Ctx)) 417 return Err; 418 break; 419 case wasm::WASM_SEGMENT_INFO: { 420 uint32_t Count = readVaruint32(Ctx); 421 if (Count > DataSegments.size()) 422 return make_error<GenericBinaryError>("Too many segment names", 423 object_error::parse_failed); 424 for (uint32_t I = 0; I < Count; I++) { 425 DataSegments[I].Data.Name = readString(Ctx); 426 DataSegments[I].Data.Alignment = readVaruint32(Ctx); 427 DataSegments[I].Data.LinkerFlags = readVaruint32(Ctx); 428 } 429 break; 430 } 431 case wasm::WASM_INIT_FUNCS: { 432 uint32_t Count = readVaruint32(Ctx); 433 LinkingData.InitFunctions.reserve(Count); 434 for (uint32_t I = 0; I < Count; I++) { 435 wasm::WasmInitFunc Init; 436 Init.Priority = readVaruint32(Ctx); 437 Init.Symbol = readVaruint32(Ctx); 438 if (!isValidFunctionSymbol(Init.Symbol)) 439 return make_error<GenericBinaryError>("Invalid function symbol: " + 440 Twine(Init.Symbol), 441 object_error::parse_failed); 442 LinkingData.InitFunctions.emplace_back(Init); 443 } 444 break; 445 } 446 case wasm::WASM_COMDAT_INFO: 447 if (Error Err = parseLinkingSectionComdat(Ctx)) 448 return Err; 449 break; 450 default: 451 Ctx.Ptr += Size; 452 break; 453 } 454 if (Ctx.Ptr != Ctx.End) 455 return make_error<GenericBinaryError>( 456 "Linking sub-section ended prematurely", object_error::parse_failed); 457 } 458 if (Ctx.Ptr != OrigEnd) 459 return make_error<GenericBinaryError>("Linking section ended prematurely", 460 object_error::parse_failed); 461 return Error::success(); 462 } 463 464 Error WasmObjectFile::parseLinkingSectionSymtab(ReadContext &Ctx) { 465 uint32_t Count = readVaruint32(Ctx); 466 LinkingData.SymbolTable.reserve(Count); 467 Symbols.reserve(Count); 468 StringSet<> SymbolNames; 469 470 std::vector<wasm::WasmImport *> ImportedGlobals; 471 std::vector<wasm::WasmImport *> ImportedFunctions; 472 std::vector<wasm::WasmImport *> ImportedEvents; 473 ImportedGlobals.reserve(Imports.size()); 474 ImportedFunctions.reserve(Imports.size()); 475 ImportedEvents.reserve(Imports.size()); 476 for (auto &I : Imports) { 477 if (I.Kind == wasm::WASM_EXTERNAL_FUNCTION) 478 ImportedFunctions.emplace_back(&I); 479 else if (I.Kind == wasm::WASM_EXTERNAL_GLOBAL) 480 ImportedGlobals.emplace_back(&I); 481 else if (I.Kind == wasm::WASM_EXTERNAL_EVENT) 482 ImportedEvents.emplace_back(&I); 483 } 484 485 while (Count--) { 486 wasm::WasmSymbolInfo Info; 487 const wasm::WasmSignature *Signature = nullptr; 488 const wasm::WasmGlobalType *GlobalType = nullptr; 489 const wasm::WasmEventType *EventType = nullptr; 490 491 Info.Kind = readUint8(Ctx); 492 Info.Flags = readVaruint32(Ctx); 493 bool IsDefined = (Info.Flags & wasm::WASM_SYMBOL_UNDEFINED) == 0; 494 495 switch (Info.Kind) { 496 case wasm::WASM_SYMBOL_TYPE_FUNCTION: 497 Info.ElementIndex = readVaruint32(Ctx); 498 if (!isValidFunctionIndex(Info.ElementIndex) || 499 IsDefined != isDefinedFunctionIndex(Info.ElementIndex)) 500 return make_error<GenericBinaryError>("invalid function symbol index", 501 object_error::parse_failed); 502 if (IsDefined) { 503 Info.Name = readString(Ctx); 504 unsigned FuncIndex = Info.ElementIndex - NumImportedFunctions; 505 Signature = &Signatures[FunctionTypes[FuncIndex]]; 506 wasm::WasmFunction &Function = Functions[FuncIndex]; 507 if (Function.SymbolName.empty()) 508 Function.SymbolName = Info.Name; 509 } else { 510 wasm::WasmImport &Import = *ImportedFunctions[Info.ElementIndex]; 511 if ((Info.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) 512 Info.Name = readString(Ctx); 513 else 514 Info.Name = Import.Field; 515 Signature = &Signatures[Import.SigIndex]; 516 Info.ImportName = Import.Field; 517 Info.ImportModule = Import.Module; 518 } 519 break; 520 521 case wasm::WASM_SYMBOL_TYPE_GLOBAL: 522 Info.ElementIndex = readVaruint32(Ctx); 523 if (!isValidGlobalIndex(Info.ElementIndex) || 524 IsDefined != isDefinedGlobalIndex(Info.ElementIndex)) 525 return make_error<GenericBinaryError>("invalid global symbol index", 526 object_error::parse_failed); 527 if (!IsDefined && (Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) == 528 wasm::WASM_SYMBOL_BINDING_WEAK) 529 return make_error<GenericBinaryError>("undefined weak global symbol", 530 object_error::parse_failed); 531 if (IsDefined) { 532 Info.Name = readString(Ctx); 533 unsigned GlobalIndex = Info.ElementIndex - NumImportedGlobals; 534 wasm::WasmGlobal &Global = Globals[GlobalIndex]; 535 GlobalType = &Global.Type; 536 if (Global.SymbolName.empty()) 537 Global.SymbolName = Info.Name; 538 } else { 539 wasm::WasmImport &Import = *ImportedGlobals[Info.ElementIndex]; 540 if ((Info.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) 541 Info.Name = readString(Ctx); 542 else 543 Info.Name = Import.Field; 544 GlobalType = &Import.Global; 545 Info.ImportName = Import.Field; 546 Info.ImportModule = Import.Module; 547 } 548 break; 549 550 case wasm::WASM_SYMBOL_TYPE_DATA: 551 Info.Name = readString(Ctx); 552 if (IsDefined) { 553 uint32_t Index = readVaruint32(Ctx); 554 if (Index >= DataSegments.size()) 555 return make_error<GenericBinaryError>("invalid data symbol index", 556 object_error::parse_failed); 557 uint32_t Offset = readVaruint32(Ctx); 558 uint32_t Size = readVaruint32(Ctx); 559 if (Offset + Size > DataSegments[Index].Data.Content.size()) 560 return make_error<GenericBinaryError>("invalid data symbol offset", 561 object_error::parse_failed); 562 Info.DataRef = wasm::WasmDataReference{Index, Offset, Size}; 563 } 564 break; 565 566 case wasm::WASM_SYMBOL_TYPE_SECTION: { 567 if ((Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) != 568 wasm::WASM_SYMBOL_BINDING_LOCAL) 569 return make_error<GenericBinaryError>( 570 "Section symbols must have local binding", 571 object_error::parse_failed); 572 Info.ElementIndex = readVaruint32(Ctx); 573 // Use somewhat unique section name as symbol name. 574 StringRef SectionName = Sections[Info.ElementIndex].Name; 575 Info.Name = SectionName; 576 break; 577 } 578 579 case wasm::WASM_SYMBOL_TYPE_EVENT: { 580 Info.ElementIndex = readVaruint32(Ctx); 581 if (!isValidEventIndex(Info.ElementIndex) || 582 IsDefined != isDefinedEventIndex(Info.ElementIndex)) 583 return make_error<GenericBinaryError>("invalid event symbol index", 584 object_error::parse_failed); 585 if (!IsDefined && (Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) == 586 wasm::WASM_SYMBOL_BINDING_WEAK) 587 return make_error<GenericBinaryError>("undefined weak global symbol", 588 object_error::parse_failed); 589 if (IsDefined) { 590 Info.Name = readString(Ctx); 591 unsigned EventIndex = Info.ElementIndex - NumImportedEvents; 592 wasm::WasmEvent &Event = Events[EventIndex]; 593 Signature = &Signatures[Event.Type.SigIndex]; 594 EventType = &Event.Type; 595 if (Event.SymbolName.empty()) 596 Event.SymbolName = Info.Name; 597 598 } else { 599 wasm::WasmImport &Import = *ImportedEvents[Info.ElementIndex]; 600 if ((Info.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) 601 Info.Name = readString(Ctx); 602 else 603 Info.Name = Import.Field; 604 EventType = &Import.Event; 605 Signature = &Signatures[EventType->SigIndex]; 606 Info.ImportName = Import.Field; 607 Info.ImportModule = Import.Module; 608 } 609 break; 610 } 611 612 default: 613 return make_error<GenericBinaryError>("Invalid symbol type", 614 object_error::parse_failed); 615 } 616 617 if ((Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) != 618 wasm::WASM_SYMBOL_BINDING_LOCAL && 619 !SymbolNames.insert(Info.Name).second) 620 return make_error<GenericBinaryError>("Duplicate symbol name " + 621 Twine(Info.Name), 622 object_error::parse_failed); 623 LinkingData.SymbolTable.emplace_back(Info); 624 Symbols.emplace_back(LinkingData.SymbolTable.back(), GlobalType, EventType, 625 Signature); 626 LLVM_DEBUG(dbgs() << "Adding symbol: " << Symbols.back() << "\n"); 627 } 628 629 return Error::success(); 630 } 631 632 Error WasmObjectFile::parseLinkingSectionComdat(ReadContext &Ctx) { 633 uint32_t ComdatCount = readVaruint32(Ctx); 634 StringSet<> ComdatSet; 635 for (unsigned ComdatIndex = 0; ComdatIndex < ComdatCount; ++ComdatIndex) { 636 StringRef Name = readString(Ctx); 637 if (Name.empty() || !ComdatSet.insert(Name).second) 638 return make_error<GenericBinaryError>("Bad/duplicate COMDAT name " + 639 Twine(Name), 640 object_error::parse_failed); 641 LinkingData.Comdats.emplace_back(Name); 642 uint32_t Flags = readVaruint32(Ctx); 643 if (Flags != 0) 644 return make_error<GenericBinaryError>("Unsupported COMDAT flags", 645 object_error::parse_failed); 646 647 uint32_t EntryCount = readVaruint32(Ctx); 648 while (EntryCount--) { 649 unsigned Kind = readVaruint32(Ctx); 650 unsigned Index = readVaruint32(Ctx); 651 switch (Kind) { 652 default: 653 return make_error<GenericBinaryError>("Invalid COMDAT entry type", 654 object_error::parse_failed); 655 case wasm::WASM_COMDAT_DATA: 656 if (Index >= DataSegments.size()) 657 return make_error<GenericBinaryError>( 658 "COMDAT data index out of range", object_error::parse_failed); 659 if (DataSegments[Index].Data.Comdat != UINT32_MAX) 660 return make_error<GenericBinaryError>("Data segment in two COMDATs", 661 object_error::parse_failed); 662 DataSegments[Index].Data.Comdat = ComdatIndex; 663 break; 664 case wasm::WASM_COMDAT_FUNCTION: 665 if (!isDefinedFunctionIndex(Index)) 666 return make_error<GenericBinaryError>( 667 "COMDAT function index out of range", object_error::parse_failed); 668 if (getDefinedFunction(Index).Comdat != UINT32_MAX) 669 return make_error<GenericBinaryError>("Function in two COMDATs", 670 object_error::parse_failed); 671 getDefinedFunction(Index).Comdat = ComdatIndex; 672 break; 673 } 674 } 675 } 676 return Error::success(); 677 } 678 679 Error WasmObjectFile::parseProducersSection(ReadContext &Ctx) { 680 llvm::SmallSet<StringRef, 3> FieldsSeen; 681 uint32_t Fields = readVaruint32(Ctx); 682 for (size_t I = 0; I < Fields; ++I) { 683 StringRef FieldName = readString(Ctx); 684 if (!FieldsSeen.insert(FieldName).second) 685 return make_error<GenericBinaryError>( 686 "Producers section does not have unique fields", 687 object_error::parse_failed); 688 std::vector<std::pair<std::string, std::string>> *ProducerVec = nullptr; 689 if (FieldName == "language") { 690 ProducerVec = &ProducerInfo.Languages; 691 } else if (FieldName == "processed-by") { 692 ProducerVec = &ProducerInfo.Tools; 693 } else if (FieldName == "sdk") { 694 ProducerVec = &ProducerInfo.SDKs; 695 } else { 696 return make_error<GenericBinaryError>( 697 "Producers section field is not named one of language, processed-by, " 698 "or sdk", 699 object_error::parse_failed); 700 } 701 uint32_t ValueCount = readVaruint32(Ctx); 702 llvm::SmallSet<StringRef, 8> ProducersSeen; 703 for (size_t J = 0; J < ValueCount; ++J) { 704 StringRef Name = readString(Ctx); 705 StringRef Version = readString(Ctx); 706 if (!ProducersSeen.insert(Name).second) { 707 return make_error<GenericBinaryError>( 708 "Producers section contains repeated producer", 709 object_error::parse_failed); 710 } 711 ProducerVec->emplace_back(Name, Version); 712 } 713 } 714 if (Ctx.Ptr != Ctx.End) 715 return make_error<GenericBinaryError>("Producers section ended prematurely", 716 object_error::parse_failed); 717 return Error::success(); 718 } 719 720 Error WasmObjectFile::parseTargetFeaturesSection(ReadContext &Ctx) { 721 llvm::SmallSet<std::string, 8> FeaturesSeen; 722 uint32_t FeatureCount = readVaruint32(Ctx); 723 for (size_t I = 0; I < FeatureCount; ++I) { 724 wasm::WasmFeatureEntry Feature; 725 Feature.Prefix = readUint8(Ctx); 726 switch (Feature.Prefix) { 727 case wasm::WASM_FEATURE_PREFIX_USED: 728 case wasm::WASM_FEATURE_PREFIX_REQUIRED: 729 case wasm::WASM_FEATURE_PREFIX_DISALLOWED: 730 break; 731 default: 732 return make_error<GenericBinaryError>("Unknown feature policy prefix", 733 object_error::parse_failed); 734 } 735 Feature.Name = readString(Ctx); 736 if (!FeaturesSeen.insert(Feature.Name).second) 737 return make_error<GenericBinaryError>( 738 "Target features section contains repeated feature \"" + 739 Feature.Name + "\"", 740 object_error::parse_failed); 741 TargetFeatures.push_back(Feature); 742 } 743 if (Ctx.Ptr != Ctx.End) 744 return make_error<GenericBinaryError>( 745 "Target features section ended prematurely", 746 object_error::parse_failed); 747 return Error::success(); 748 } 749 750 Error WasmObjectFile::parseRelocSection(StringRef Name, ReadContext &Ctx) { 751 uint32_t SectionIndex = readVaruint32(Ctx); 752 if (SectionIndex >= Sections.size()) 753 return make_error<GenericBinaryError>("Invalid section index", 754 object_error::parse_failed); 755 WasmSection &Section = Sections[SectionIndex]; 756 uint32_t RelocCount = readVaruint32(Ctx); 757 uint32_t EndOffset = Section.Content.size(); 758 uint32_t PreviousOffset = 0; 759 while (RelocCount--) { 760 wasm::WasmRelocation Reloc = {}; 761 Reloc.Type = readVaruint32(Ctx); 762 Reloc.Offset = readVaruint32(Ctx); 763 if (Reloc.Offset < PreviousOffset) 764 return make_error<GenericBinaryError>("Relocations not in offset order", 765 object_error::parse_failed); 766 PreviousOffset = Reloc.Offset; 767 Reloc.Index = readVaruint32(Ctx); 768 switch (Reloc.Type) { 769 case wasm::R_WASM_FUNCTION_INDEX_LEB: 770 case wasm::R_WASM_TABLE_INDEX_SLEB: 771 case wasm::R_WASM_TABLE_INDEX_I32: 772 case wasm::R_WASM_TABLE_INDEX_REL_SLEB: 773 if (!isValidFunctionSymbol(Reloc.Index)) 774 return make_error<GenericBinaryError>("Bad relocation function index", 775 object_error::parse_failed); 776 break; 777 case wasm::R_WASM_TYPE_INDEX_LEB: 778 if (Reloc.Index >= Signatures.size()) 779 return make_error<GenericBinaryError>("Bad relocation type index", 780 object_error::parse_failed); 781 break; 782 case wasm::R_WASM_GLOBAL_INDEX_LEB: 783 // R_WASM_GLOBAL_INDEX_LEB are can be used against function and data 784 // symbols to refer to their GOT entries. 785 if (!isValidGlobalSymbol(Reloc.Index) && 786 !isValidDataSymbol(Reloc.Index) && 787 !isValidFunctionSymbol(Reloc.Index)) 788 return make_error<GenericBinaryError>("Bad relocation global index", 789 object_error::parse_failed); 790 break; 791 case wasm::R_WASM_EVENT_INDEX_LEB: 792 if (!isValidEventSymbol(Reloc.Index)) 793 return make_error<GenericBinaryError>("Bad relocation event index", 794 object_error::parse_failed); 795 break; 796 case wasm::R_WASM_MEMORY_ADDR_LEB: 797 case wasm::R_WASM_MEMORY_ADDR_SLEB: 798 case wasm::R_WASM_MEMORY_ADDR_I32: 799 case wasm::R_WASM_MEMORY_ADDR_REL_SLEB: 800 if (!isValidDataSymbol(Reloc.Index)) 801 return make_error<GenericBinaryError>("Bad relocation data index", 802 object_error::parse_failed); 803 Reloc.Addend = readVarint32(Ctx); 804 break; 805 case wasm::R_WASM_FUNCTION_OFFSET_I32: 806 if (!isValidFunctionSymbol(Reloc.Index)) 807 return make_error<GenericBinaryError>("Bad relocation function index", 808 object_error::parse_failed); 809 Reloc.Addend = readVarint32(Ctx); 810 break; 811 case wasm::R_WASM_SECTION_OFFSET_I32: 812 if (!isValidSectionSymbol(Reloc.Index)) 813 return make_error<GenericBinaryError>("Bad relocation section index", 814 object_error::parse_failed); 815 Reloc.Addend = readVarint32(Ctx); 816 break; 817 default: 818 return make_error<GenericBinaryError>("Bad relocation type: " + 819 Twine(Reloc.Type), 820 object_error::parse_failed); 821 } 822 823 // Relocations must fit inside the section, and must appear in order. They 824 // also shouldn't overlap a function/element boundary, but we don't bother 825 // to check that. 826 uint64_t Size = 5; 827 if (Reloc.Type == wasm::R_WASM_TABLE_INDEX_I32 || 828 Reloc.Type == wasm::R_WASM_MEMORY_ADDR_I32 || 829 Reloc.Type == wasm::R_WASM_SECTION_OFFSET_I32 || 830 Reloc.Type == wasm::R_WASM_FUNCTION_OFFSET_I32) 831 Size = 4; 832 if (Reloc.Offset + Size > EndOffset) 833 return make_error<GenericBinaryError>("Bad relocation offset", 834 object_error::parse_failed); 835 836 Section.Relocations.push_back(Reloc); 837 } 838 if (Ctx.Ptr != Ctx.End) 839 return make_error<GenericBinaryError>("Reloc section ended prematurely", 840 object_error::parse_failed); 841 return Error::success(); 842 } 843 844 Error WasmObjectFile::parseCustomSection(WasmSection &Sec, ReadContext &Ctx) { 845 if (Sec.Name == "dylink") { 846 if (Error Err = parseDylinkSection(Ctx)) 847 return Err; 848 } else if (Sec.Name == "name") { 849 if (Error Err = parseNameSection(Ctx)) 850 return Err; 851 } else if (Sec.Name == "linking") { 852 if (Error Err = parseLinkingSection(Ctx)) 853 return Err; 854 } else if (Sec.Name == "producers") { 855 if (Error Err = parseProducersSection(Ctx)) 856 return Err; 857 } else if (Sec.Name == "target_features") { 858 if (Error Err = parseTargetFeaturesSection(Ctx)) 859 return Err; 860 } else if (Sec.Name.startswith("reloc.")) { 861 if (Error Err = parseRelocSection(Sec.Name, Ctx)) 862 return Err; 863 } 864 return Error::success(); 865 } 866 867 Error WasmObjectFile::parseTypeSection(ReadContext &Ctx) { 868 uint32_t Count = readVaruint32(Ctx); 869 Signatures.reserve(Count); 870 while (Count--) { 871 wasm::WasmSignature Sig; 872 uint8_t Form = readUint8(Ctx); 873 if (Form != wasm::WASM_TYPE_FUNC) { 874 return make_error<GenericBinaryError>("Invalid signature type", 875 object_error::parse_failed); 876 } 877 uint32_t ParamCount = readVaruint32(Ctx); 878 Sig.Params.reserve(ParamCount); 879 while (ParamCount--) { 880 uint32_t ParamType = readUint8(Ctx); 881 Sig.Params.push_back(wasm::ValType(ParamType)); 882 } 883 uint32_t ReturnCount = readVaruint32(Ctx); 884 while (ReturnCount--) { 885 uint32_t ReturnType = readUint8(Ctx); 886 Sig.Returns.push_back(wasm::ValType(ReturnType)); 887 } 888 Signatures.push_back(std::move(Sig)); 889 } 890 if (Ctx.Ptr != Ctx.End) 891 return make_error<GenericBinaryError>("Type section ended prematurely", 892 object_error::parse_failed); 893 return Error::success(); 894 } 895 896 Error WasmObjectFile::parseImportSection(ReadContext &Ctx) { 897 uint32_t Count = readVaruint32(Ctx); 898 Imports.reserve(Count); 899 for (uint32_t I = 0; I < Count; I++) { 900 wasm::WasmImport Im; 901 Im.Module = readString(Ctx); 902 Im.Field = readString(Ctx); 903 Im.Kind = readUint8(Ctx); 904 switch (Im.Kind) { 905 case wasm::WASM_EXTERNAL_FUNCTION: 906 NumImportedFunctions++; 907 Im.SigIndex = readVaruint32(Ctx); 908 break; 909 case wasm::WASM_EXTERNAL_GLOBAL: 910 NumImportedGlobals++; 911 Im.Global.Type = readUint8(Ctx); 912 Im.Global.Mutable = readVaruint1(Ctx); 913 break; 914 case wasm::WASM_EXTERNAL_MEMORY: 915 Im.Memory = readLimits(Ctx); 916 break; 917 case wasm::WASM_EXTERNAL_TABLE: 918 Im.Table = readTable(Ctx); 919 if (Im.Table.ElemType != wasm::WASM_TYPE_FUNCREF) 920 return make_error<GenericBinaryError>("Invalid table element type", 921 object_error::parse_failed); 922 break; 923 case wasm::WASM_EXTERNAL_EVENT: 924 NumImportedEvents++; 925 Im.Event.Attribute = readVarint32(Ctx); 926 Im.Event.SigIndex = readVarint32(Ctx); 927 break; 928 default: 929 return make_error<GenericBinaryError>("Unexpected import kind", 930 object_error::parse_failed); 931 } 932 Imports.push_back(Im); 933 } 934 if (Ctx.Ptr != Ctx.End) 935 return make_error<GenericBinaryError>("Import section ended prematurely", 936 object_error::parse_failed); 937 return Error::success(); 938 } 939 940 Error WasmObjectFile::parseFunctionSection(ReadContext &Ctx) { 941 uint32_t Count = readVaruint32(Ctx); 942 FunctionTypes.reserve(Count); 943 uint32_t NumTypes = Signatures.size(); 944 while (Count--) { 945 uint32_t Type = readVaruint32(Ctx); 946 if (Type >= NumTypes) 947 return make_error<GenericBinaryError>("Invalid function type", 948 object_error::parse_failed); 949 FunctionTypes.push_back(Type); 950 } 951 if (Ctx.Ptr != Ctx.End) 952 return make_error<GenericBinaryError>("Function section ended prematurely", 953 object_error::parse_failed); 954 return Error::success(); 955 } 956 957 Error WasmObjectFile::parseTableSection(ReadContext &Ctx) { 958 uint32_t Count = readVaruint32(Ctx); 959 Tables.reserve(Count); 960 while (Count--) { 961 Tables.push_back(readTable(Ctx)); 962 if (Tables.back().ElemType != wasm::WASM_TYPE_FUNCREF) { 963 return make_error<GenericBinaryError>("Invalid table element type", 964 object_error::parse_failed); 965 } 966 } 967 if (Ctx.Ptr != Ctx.End) 968 return make_error<GenericBinaryError>("Table section ended prematurely", 969 object_error::parse_failed); 970 return Error::success(); 971 } 972 973 Error WasmObjectFile::parseMemorySection(ReadContext &Ctx) { 974 uint32_t Count = readVaruint32(Ctx); 975 Memories.reserve(Count); 976 while (Count--) { 977 Memories.push_back(readLimits(Ctx)); 978 } 979 if (Ctx.Ptr != Ctx.End) 980 return make_error<GenericBinaryError>("Memory section ended prematurely", 981 object_error::parse_failed); 982 return Error::success(); 983 } 984 985 Error WasmObjectFile::parseGlobalSection(ReadContext &Ctx) { 986 GlobalSection = Sections.size(); 987 uint32_t Count = readVaruint32(Ctx); 988 Globals.reserve(Count); 989 while (Count--) { 990 wasm::WasmGlobal Global; 991 Global.Index = NumImportedGlobals + Globals.size(); 992 Global.Type.Type = readUint8(Ctx); 993 Global.Type.Mutable = readVaruint1(Ctx); 994 if (Error Err = readInitExpr(Global.InitExpr, Ctx)) 995 return Err; 996 Globals.push_back(Global); 997 } 998 if (Ctx.Ptr != Ctx.End) 999 return make_error<GenericBinaryError>("Global section ended prematurely", 1000 object_error::parse_failed); 1001 return Error::success(); 1002 } 1003 1004 Error WasmObjectFile::parseEventSection(ReadContext &Ctx) { 1005 EventSection = Sections.size(); 1006 uint32_t Count = readVarint32(Ctx); 1007 Events.reserve(Count); 1008 while (Count--) { 1009 wasm::WasmEvent Event; 1010 Event.Index = NumImportedEvents + Events.size(); 1011 Event.Type.Attribute = readVaruint32(Ctx); 1012 Event.Type.SigIndex = readVarint32(Ctx); 1013 Events.push_back(Event); 1014 } 1015 1016 if (Ctx.Ptr != Ctx.End) 1017 return make_error<GenericBinaryError>("Event section ended prematurely", 1018 object_error::parse_failed); 1019 return Error::success(); 1020 } 1021 1022 Error WasmObjectFile::parseExportSection(ReadContext &Ctx) { 1023 uint32_t Count = readVaruint32(Ctx); 1024 Exports.reserve(Count); 1025 for (uint32_t I = 0; I < Count; I++) { 1026 wasm::WasmExport Ex; 1027 Ex.Name = readString(Ctx); 1028 Ex.Kind = readUint8(Ctx); 1029 Ex.Index = readVaruint32(Ctx); 1030 switch (Ex.Kind) { 1031 case wasm::WASM_EXTERNAL_FUNCTION: 1032 if (!isValidFunctionIndex(Ex.Index)) 1033 return make_error<GenericBinaryError>("Invalid function export", 1034 object_error::parse_failed); 1035 break; 1036 case wasm::WASM_EXTERNAL_GLOBAL: 1037 if (!isValidGlobalIndex(Ex.Index)) 1038 return make_error<GenericBinaryError>("Invalid global export", 1039 object_error::parse_failed); 1040 break; 1041 case wasm::WASM_EXTERNAL_EVENT: 1042 if (!isValidEventIndex(Ex.Index)) 1043 return make_error<GenericBinaryError>("Invalid event export", 1044 object_error::parse_failed); 1045 break; 1046 case wasm::WASM_EXTERNAL_MEMORY: 1047 case wasm::WASM_EXTERNAL_TABLE: 1048 break; 1049 default: 1050 return make_error<GenericBinaryError>("Unexpected export kind", 1051 object_error::parse_failed); 1052 } 1053 Exports.push_back(Ex); 1054 } 1055 if (Ctx.Ptr != Ctx.End) 1056 return make_error<GenericBinaryError>("Export section ended prematurely", 1057 object_error::parse_failed); 1058 return Error::success(); 1059 } 1060 1061 bool WasmObjectFile::isValidFunctionIndex(uint32_t Index) const { 1062 return Index < NumImportedFunctions + FunctionTypes.size(); 1063 } 1064 1065 bool WasmObjectFile::isDefinedFunctionIndex(uint32_t Index) const { 1066 return Index >= NumImportedFunctions && isValidFunctionIndex(Index); 1067 } 1068 1069 bool WasmObjectFile::isValidGlobalIndex(uint32_t Index) const { 1070 return Index < NumImportedGlobals + Globals.size(); 1071 } 1072 1073 bool WasmObjectFile::isDefinedGlobalIndex(uint32_t Index) const { 1074 return Index >= NumImportedGlobals && isValidGlobalIndex(Index); 1075 } 1076 1077 bool WasmObjectFile::isValidEventIndex(uint32_t Index) const { 1078 return Index < NumImportedEvents + Events.size(); 1079 } 1080 1081 bool WasmObjectFile::isDefinedEventIndex(uint32_t Index) const { 1082 return Index >= NumImportedEvents && isValidEventIndex(Index); 1083 } 1084 1085 bool WasmObjectFile::isValidFunctionSymbol(uint32_t Index) const { 1086 return Index < Symbols.size() && Symbols[Index].isTypeFunction(); 1087 } 1088 1089 bool WasmObjectFile::isValidGlobalSymbol(uint32_t Index) const { 1090 return Index < Symbols.size() && Symbols[Index].isTypeGlobal(); 1091 } 1092 1093 bool WasmObjectFile::isValidEventSymbol(uint32_t Index) const { 1094 return Index < Symbols.size() && Symbols[Index].isTypeEvent(); 1095 } 1096 1097 bool WasmObjectFile::isValidDataSymbol(uint32_t Index) const { 1098 return Index < Symbols.size() && Symbols[Index].isTypeData(); 1099 } 1100 1101 bool WasmObjectFile::isValidSectionSymbol(uint32_t Index) const { 1102 return Index < Symbols.size() && Symbols[Index].isTypeSection(); 1103 } 1104 1105 wasm::WasmFunction &WasmObjectFile::getDefinedFunction(uint32_t Index) { 1106 assert(isDefinedFunctionIndex(Index)); 1107 return Functions[Index - NumImportedFunctions]; 1108 } 1109 1110 const wasm::WasmFunction & 1111 WasmObjectFile::getDefinedFunction(uint32_t Index) const { 1112 assert(isDefinedFunctionIndex(Index)); 1113 return Functions[Index - NumImportedFunctions]; 1114 } 1115 1116 wasm::WasmGlobal &WasmObjectFile::getDefinedGlobal(uint32_t Index) { 1117 assert(isDefinedGlobalIndex(Index)); 1118 return Globals[Index - NumImportedGlobals]; 1119 } 1120 1121 wasm::WasmEvent &WasmObjectFile::getDefinedEvent(uint32_t Index) { 1122 assert(isDefinedEventIndex(Index)); 1123 return Events[Index - NumImportedEvents]; 1124 } 1125 1126 Error WasmObjectFile::parseStartSection(ReadContext &Ctx) { 1127 StartFunction = readVaruint32(Ctx); 1128 if (!isValidFunctionIndex(StartFunction)) 1129 return make_error<GenericBinaryError>("Invalid start function", 1130 object_error::parse_failed); 1131 return Error::success(); 1132 } 1133 1134 Error WasmObjectFile::parseCodeSection(ReadContext &Ctx) { 1135 CodeSection = Sections.size(); 1136 uint32_t FunctionCount = readVaruint32(Ctx); 1137 if (FunctionCount != FunctionTypes.size()) { 1138 return make_error<GenericBinaryError>("Invalid function count", 1139 object_error::parse_failed); 1140 } 1141 1142 while (FunctionCount--) { 1143 wasm::WasmFunction Function; 1144 const uint8_t *FunctionStart = Ctx.Ptr; 1145 uint32_t Size = readVaruint32(Ctx); 1146 const uint8_t *FunctionEnd = Ctx.Ptr + Size; 1147 1148 Function.CodeOffset = Ctx.Ptr - FunctionStart; 1149 Function.Index = NumImportedFunctions + Functions.size(); 1150 Function.CodeSectionOffset = FunctionStart - Ctx.Start; 1151 Function.Size = FunctionEnd - FunctionStart; 1152 1153 uint32_t NumLocalDecls = readVaruint32(Ctx); 1154 Function.Locals.reserve(NumLocalDecls); 1155 while (NumLocalDecls--) { 1156 wasm::WasmLocalDecl Decl; 1157 Decl.Count = readVaruint32(Ctx); 1158 Decl.Type = readUint8(Ctx); 1159 Function.Locals.push_back(Decl); 1160 } 1161 1162 uint32_t BodySize = FunctionEnd - Ctx.Ptr; 1163 Function.Body = ArrayRef<uint8_t>(Ctx.Ptr, BodySize); 1164 // This will be set later when reading in the linking metadata section. 1165 Function.Comdat = UINT32_MAX; 1166 Ctx.Ptr += BodySize; 1167 assert(Ctx.Ptr == FunctionEnd); 1168 Functions.push_back(Function); 1169 } 1170 if (Ctx.Ptr != Ctx.End) 1171 return make_error<GenericBinaryError>("Code section ended prematurely", 1172 object_error::parse_failed); 1173 return Error::success(); 1174 } 1175 1176 Error WasmObjectFile::parseElemSection(ReadContext &Ctx) { 1177 uint32_t Count = readVaruint32(Ctx); 1178 ElemSegments.reserve(Count); 1179 while (Count--) { 1180 wasm::WasmElemSegment Segment; 1181 Segment.TableIndex = readVaruint32(Ctx); 1182 if (Segment.TableIndex != 0) { 1183 return make_error<GenericBinaryError>("Invalid TableIndex", 1184 object_error::parse_failed); 1185 } 1186 if (Error Err = readInitExpr(Segment.Offset, Ctx)) 1187 return Err; 1188 uint32_t NumElems = readVaruint32(Ctx); 1189 while (NumElems--) { 1190 Segment.Functions.push_back(readVaruint32(Ctx)); 1191 } 1192 ElemSegments.push_back(Segment); 1193 } 1194 if (Ctx.Ptr != Ctx.End) 1195 return make_error<GenericBinaryError>("Elem section ended prematurely", 1196 object_error::parse_failed); 1197 return Error::success(); 1198 } 1199 1200 Error WasmObjectFile::parseDataSection(ReadContext &Ctx) { 1201 DataSection = Sections.size(); 1202 uint32_t Count = readVaruint32(Ctx); 1203 if (DataCount && Count != DataCount.getValue()) 1204 return make_error<GenericBinaryError>( 1205 "Number of data segments does not match DataCount section"); 1206 DataSegments.reserve(Count); 1207 while (Count--) { 1208 WasmSegment Segment; 1209 Segment.Data.InitFlags = readVaruint32(Ctx); 1210 Segment.Data.MemoryIndex = (Segment.Data.InitFlags & wasm::WASM_SEGMENT_HAS_MEMINDEX) 1211 ? readVaruint32(Ctx) : 0; 1212 if ((Segment.Data.InitFlags & wasm::WASM_SEGMENT_IS_PASSIVE) == 0) { 1213 if (Error Err = readInitExpr(Segment.Data.Offset, Ctx)) 1214 return Err; 1215 } else { 1216 Segment.Data.Offset.Opcode = wasm::WASM_OPCODE_I32_CONST; 1217 Segment.Data.Offset.Value.Int32 = 0; 1218 } 1219 uint32_t Size = readVaruint32(Ctx); 1220 if (Size > (size_t)(Ctx.End - Ctx.Ptr)) 1221 return make_error<GenericBinaryError>("Invalid segment size", 1222 object_error::parse_failed); 1223 Segment.Data.Content = ArrayRef<uint8_t>(Ctx.Ptr, Size); 1224 // The rest of these Data fields are set later, when reading in the linking 1225 // metadata section. 1226 Segment.Data.Alignment = 0; 1227 Segment.Data.LinkerFlags = 0; 1228 Segment.Data.Comdat = UINT32_MAX; 1229 Segment.SectionOffset = Ctx.Ptr - Ctx.Start; 1230 Ctx.Ptr += Size; 1231 DataSegments.push_back(Segment); 1232 } 1233 if (Ctx.Ptr != Ctx.End) 1234 return make_error<GenericBinaryError>("Data section ended prematurely", 1235 object_error::parse_failed); 1236 return Error::success(); 1237 } 1238 1239 Error WasmObjectFile::parseDataCountSection(ReadContext &Ctx) { 1240 DataCount = readVaruint32(Ctx); 1241 return Error::success(); 1242 } 1243 1244 const wasm::WasmObjectHeader &WasmObjectFile::getHeader() const { 1245 return Header; 1246 } 1247 1248 void WasmObjectFile::moveSymbolNext(DataRefImpl &Symb) const { Symb.d.b++; } 1249 1250 uint32_t WasmObjectFile::getSymbolFlags(DataRefImpl Symb) const { 1251 uint32_t Result = SymbolRef::SF_None; 1252 const WasmSymbol &Sym = getWasmSymbol(Symb); 1253 1254 LLVM_DEBUG(dbgs() << "getSymbolFlags: ptr=" << &Sym << " " << Sym << "\n"); 1255 if (Sym.isBindingWeak()) 1256 Result |= SymbolRef::SF_Weak; 1257 if (!Sym.isBindingLocal()) 1258 Result |= SymbolRef::SF_Global; 1259 if (Sym.isHidden()) 1260 Result |= SymbolRef::SF_Hidden; 1261 if (!Sym.isDefined()) 1262 Result |= SymbolRef::SF_Undefined; 1263 if (Sym.isTypeFunction()) 1264 Result |= SymbolRef::SF_Executable; 1265 return Result; 1266 } 1267 1268 basic_symbol_iterator WasmObjectFile::symbol_begin() const { 1269 DataRefImpl Ref; 1270 Ref.d.a = 1; // Arbitrary non-zero value so that Ref.p is non-null 1271 Ref.d.b = 0; // Symbol index 1272 return BasicSymbolRef(Ref, this); 1273 } 1274 1275 basic_symbol_iterator WasmObjectFile::symbol_end() const { 1276 DataRefImpl Ref; 1277 Ref.d.a = 1; // Arbitrary non-zero value so that Ref.p is non-null 1278 Ref.d.b = Symbols.size(); // Symbol index 1279 return BasicSymbolRef(Ref, this); 1280 } 1281 1282 const WasmSymbol &WasmObjectFile::getWasmSymbol(const DataRefImpl &Symb) const { 1283 return Symbols[Symb.d.b]; 1284 } 1285 1286 const WasmSymbol &WasmObjectFile::getWasmSymbol(const SymbolRef &Symb) const { 1287 return getWasmSymbol(Symb.getRawDataRefImpl()); 1288 } 1289 1290 Expected<StringRef> WasmObjectFile::getSymbolName(DataRefImpl Symb) const { 1291 return getWasmSymbol(Symb).Info.Name; 1292 } 1293 1294 Expected<uint64_t> WasmObjectFile::getSymbolAddress(DataRefImpl Symb) const { 1295 auto &Sym = getWasmSymbol(Symb); 1296 if (Sym.Info.Kind == wasm::WASM_SYMBOL_TYPE_FUNCTION && 1297 isDefinedFunctionIndex(Sym.Info.ElementIndex)) 1298 return getDefinedFunction(Sym.Info.ElementIndex).CodeSectionOffset; 1299 else 1300 return getSymbolValue(Symb); 1301 } 1302 1303 uint64_t WasmObjectFile::getWasmSymbolValue(const WasmSymbol &Sym) const { 1304 switch (Sym.Info.Kind) { 1305 case wasm::WASM_SYMBOL_TYPE_FUNCTION: 1306 case wasm::WASM_SYMBOL_TYPE_GLOBAL: 1307 case wasm::WASM_SYMBOL_TYPE_EVENT: 1308 return Sym.Info.ElementIndex; 1309 case wasm::WASM_SYMBOL_TYPE_DATA: { 1310 // The value of a data symbol is the segment offset, plus the symbol 1311 // offset within the segment. 1312 uint32_t SegmentIndex = Sym.Info.DataRef.Segment; 1313 const wasm::WasmDataSegment &Segment = DataSegments[SegmentIndex].Data; 1314 assert(Segment.Offset.Opcode == wasm::WASM_OPCODE_I32_CONST); 1315 return Segment.Offset.Value.Int32 + Sym.Info.DataRef.Offset; 1316 } 1317 case wasm::WASM_SYMBOL_TYPE_SECTION: 1318 return 0; 1319 } 1320 llvm_unreachable("invalid symbol type"); 1321 } 1322 1323 uint64_t WasmObjectFile::getSymbolValueImpl(DataRefImpl Symb) const { 1324 return getWasmSymbolValue(getWasmSymbol(Symb)); 1325 } 1326 1327 uint32_t WasmObjectFile::getSymbolAlignment(DataRefImpl Symb) const { 1328 llvm_unreachable("not yet implemented"); 1329 return 0; 1330 } 1331 1332 uint64_t WasmObjectFile::getCommonSymbolSizeImpl(DataRefImpl Symb) const { 1333 llvm_unreachable("not yet implemented"); 1334 return 0; 1335 } 1336 1337 Expected<SymbolRef::Type> 1338 WasmObjectFile::getSymbolType(DataRefImpl Symb) const { 1339 const WasmSymbol &Sym = getWasmSymbol(Symb); 1340 1341 switch (Sym.Info.Kind) { 1342 case wasm::WASM_SYMBOL_TYPE_FUNCTION: 1343 return SymbolRef::ST_Function; 1344 case wasm::WASM_SYMBOL_TYPE_GLOBAL: 1345 return SymbolRef::ST_Other; 1346 case wasm::WASM_SYMBOL_TYPE_DATA: 1347 return SymbolRef::ST_Data; 1348 case wasm::WASM_SYMBOL_TYPE_SECTION: 1349 return SymbolRef::ST_Debug; 1350 case wasm::WASM_SYMBOL_TYPE_EVENT: 1351 return SymbolRef::ST_Other; 1352 } 1353 1354 llvm_unreachable("Unknown WasmSymbol::SymbolType"); 1355 return SymbolRef::ST_Other; 1356 } 1357 1358 Expected<section_iterator> 1359 WasmObjectFile::getSymbolSection(DataRefImpl Symb) const { 1360 const WasmSymbol &Sym = getWasmSymbol(Symb); 1361 if (Sym.isUndefined()) 1362 return section_end(); 1363 1364 DataRefImpl Ref; 1365 switch (Sym.Info.Kind) { 1366 case wasm::WASM_SYMBOL_TYPE_FUNCTION: 1367 Ref.d.a = CodeSection; 1368 break; 1369 case wasm::WASM_SYMBOL_TYPE_GLOBAL: 1370 Ref.d.a = GlobalSection; 1371 break; 1372 case wasm::WASM_SYMBOL_TYPE_DATA: 1373 Ref.d.a = DataSection; 1374 break; 1375 case wasm::WASM_SYMBOL_TYPE_SECTION: 1376 Ref.d.a = Sym.Info.ElementIndex; 1377 break; 1378 case wasm::WASM_SYMBOL_TYPE_EVENT: 1379 Ref.d.a = EventSection; 1380 break; 1381 default: 1382 llvm_unreachable("Unknown WasmSymbol::SymbolType"); 1383 } 1384 return section_iterator(SectionRef(Ref, this)); 1385 } 1386 1387 void WasmObjectFile::moveSectionNext(DataRefImpl &Sec) const { Sec.d.a++; } 1388 1389 Expected<StringRef> WasmObjectFile::getSectionName(DataRefImpl Sec) const { 1390 const WasmSection &S = Sections[Sec.d.a]; 1391 #define ECase(X) \ 1392 case wasm::WASM_SEC_##X: \ 1393 return #X; 1394 switch (S.Type) { 1395 ECase(TYPE); 1396 ECase(IMPORT); 1397 ECase(FUNCTION); 1398 ECase(TABLE); 1399 ECase(MEMORY); 1400 ECase(GLOBAL); 1401 ECase(EVENT); 1402 ECase(EXPORT); 1403 ECase(START); 1404 ECase(ELEM); 1405 ECase(CODE); 1406 ECase(DATA); 1407 ECase(DATACOUNT); 1408 case wasm::WASM_SEC_CUSTOM: 1409 return S.Name; 1410 default: 1411 return createStringError(object_error::invalid_section_index, ""); 1412 } 1413 #undef ECase 1414 } 1415 1416 uint64_t WasmObjectFile::getSectionAddress(DataRefImpl Sec) const { return 0; } 1417 1418 uint64_t WasmObjectFile::getSectionIndex(DataRefImpl Sec) const { 1419 return Sec.d.a; 1420 } 1421 1422 uint64_t WasmObjectFile::getSectionSize(DataRefImpl Sec) const { 1423 const WasmSection &S = Sections[Sec.d.a]; 1424 return S.Content.size(); 1425 } 1426 1427 Expected<ArrayRef<uint8_t>> 1428 WasmObjectFile::getSectionContents(DataRefImpl Sec) const { 1429 const WasmSection &S = Sections[Sec.d.a]; 1430 // This will never fail since wasm sections can never be empty (user-sections 1431 // must have a name and non-user sections each have a defined structure). 1432 return S.Content; 1433 } 1434 1435 uint64_t WasmObjectFile::getSectionAlignment(DataRefImpl Sec) const { 1436 return 1; 1437 } 1438 1439 bool WasmObjectFile::isSectionCompressed(DataRefImpl Sec) const { 1440 return false; 1441 } 1442 1443 bool WasmObjectFile::isSectionText(DataRefImpl Sec) const { 1444 return getWasmSection(Sec).Type == wasm::WASM_SEC_CODE; 1445 } 1446 1447 bool WasmObjectFile::isSectionData(DataRefImpl Sec) const { 1448 return getWasmSection(Sec).Type == wasm::WASM_SEC_DATA; 1449 } 1450 1451 bool WasmObjectFile::isSectionBSS(DataRefImpl Sec) const { return false; } 1452 1453 bool WasmObjectFile::isSectionVirtual(DataRefImpl Sec) const { return false; } 1454 1455 bool WasmObjectFile::isSectionBitcode(DataRefImpl Sec) const { return false; } 1456 1457 relocation_iterator WasmObjectFile::section_rel_begin(DataRefImpl Ref) const { 1458 DataRefImpl RelocRef; 1459 RelocRef.d.a = Ref.d.a; 1460 RelocRef.d.b = 0; 1461 return relocation_iterator(RelocationRef(RelocRef, this)); 1462 } 1463 1464 relocation_iterator WasmObjectFile::section_rel_end(DataRefImpl Ref) const { 1465 const WasmSection &Sec = getWasmSection(Ref); 1466 DataRefImpl RelocRef; 1467 RelocRef.d.a = Ref.d.a; 1468 RelocRef.d.b = Sec.Relocations.size(); 1469 return relocation_iterator(RelocationRef(RelocRef, this)); 1470 } 1471 1472 void WasmObjectFile::moveRelocationNext(DataRefImpl &Rel) const { Rel.d.b++; } 1473 1474 uint64_t WasmObjectFile::getRelocationOffset(DataRefImpl Ref) const { 1475 const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); 1476 return Rel.Offset; 1477 } 1478 1479 symbol_iterator WasmObjectFile::getRelocationSymbol(DataRefImpl Ref) const { 1480 const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); 1481 if (Rel.Type == wasm::R_WASM_TYPE_INDEX_LEB) 1482 return symbol_end(); 1483 DataRefImpl Sym; 1484 Sym.d.a = 1; 1485 Sym.d.b = Rel.Index; 1486 return symbol_iterator(SymbolRef(Sym, this)); 1487 } 1488 1489 uint64_t WasmObjectFile::getRelocationType(DataRefImpl Ref) const { 1490 const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); 1491 return Rel.Type; 1492 } 1493 1494 void WasmObjectFile::getRelocationTypeName( 1495 DataRefImpl Ref, SmallVectorImpl<char> &Result) const { 1496 const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); 1497 StringRef Res = "Unknown"; 1498 1499 #define WASM_RELOC(name, value) \ 1500 case wasm::name: \ 1501 Res = #name; \ 1502 break; 1503 1504 switch (Rel.Type) { 1505 #include "llvm/BinaryFormat/WasmRelocs.def" 1506 } 1507 1508 #undef WASM_RELOC 1509 1510 Result.append(Res.begin(), Res.end()); 1511 } 1512 1513 section_iterator WasmObjectFile::section_begin() const { 1514 DataRefImpl Ref; 1515 Ref.d.a = 0; 1516 return section_iterator(SectionRef(Ref, this)); 1517 } 1518 1519 section_iterator WasmObjectFile::section_end() const { 1520 DataRefImpl Ref; 1521 Ref.d.a = Sections.size(); 1522 return section_iterator(SectionRef(Ref, this)); 1523 } 1524 1525 uint8_t WasmObjectFile::getBytesInAddress() const { return 4; } 1526 1527 StringRef WasmObjectFile::getFileFormatName() const { return "WASM"; } 1528 1529 Triple::ArchType WasmObjectFile::getArch() const { return Triple::wasm32; } 1530 1531 SubtargetFeatures WasmObjectFile::getFeatures() const { 1532 return SubtargetFeatures(); 1533 } 1534 1535 bool WasmObjectFile::isRelocatableObject() const { return HasLinkingSection; } 1536 1537 bool WasmObjectFile::isSharedObject() const { return HasDylinkSection; } 1538 1539 const WasmSection &WasmObjectFile::getWasmSection(DataRefImpl Ref) const { 1540 assert(Ref.d.a < Sections.size()); 1541 return Sections[Ref.d.a]; 1542 } 1543 1544 const WasmSection & 1545 WasmObjectFile::getWasmSection(const SectionRef &Section) const { 1546 return getWasmSection(Section.getRawDataRefImpl()); 1547 } 1548 1549 const wasm::WasmRelocation & 1550 WasmObjectFile::getWasmRelocation(const RelocationRef &Ref) const { 1551 return getWasmRelocation(Ref.getRawDataRefImpl()); 1552 } 1553 1554 const wasm::WasmRelocation & 1555 WasmObjectFile::getWasmRelocation(DataRefImpl Ref) const { 1556 assert(Ref.d.a < Sections.size()); 1557 const WasmSection &Sec = Sections[Ref.d.a]; 1558 assert(Ref.d.b < Sec.Relocations.size()); 1559 return Sec.Relocations[Ref.d.b]; 1560 } 1561 1562 int WasmSectionOrderChecker::getSectionOrder(unsigned ID, 1563 StringRef CustomSectionName) { 1564 switch (ID) { 1565 case wasm::WASM_SEC_CUSTOM: 1566 return StringSwitch<unsigned>(CustomSectionName) 1567 .Case("dylink", WASM_SEC_ORDER_DYLINK) 1568 .Case("linking", WASM_SEC_ORDER_LINKING) 1569 .StartsWith("reloc.", WASM_SEC_ORDER_RELOC) 1570 .Case("name", WASM_SEC_ORDER_NAME) 1571 .Case("producers", WASM_SEC_ORDER_PRODUCERS) 1572 .Case("target_features", WASM_SEC_ORDER_TARGET_FEATURES) 1573 .Default(WASM_SEC_ORDER_NONE); 1574 case wasm::WASM_SEC_TYPE: 1575 return WASM_SEC_ORDER_TYPE; 1576 case wasm::WASM_SEC_IMPORT: 1577 return WASM_SEC_ORDER_IMPORT; 1578 case wasm::WASM_SEC_FUNCTION: 1579 return WASM_SEC_ORDER_FUNCTION; 1580 case wasm::WASM_SEC_TABLE: 1581 return WASM_SEC_ORDER_TABLE; 1582 case wasm::WASM_SEC_MEMORY: 1583 return WASM_SEC_ORDER_MEMORY; 1584 case wasm::WASM_SEC_GLOBAL: 1585 return WASM_SEC_ORDER_GLOBAL; 1586 case wasm::WASM_SEC_EXPORT: 1587 return WASM_SEC_ORDER_EXPORT; 1588 case wasm::WASM_SEC_START: 1589 return WASM_SEC_ORDER_START; 1590 case wasm::WASM_SEC_ELEM: 1591 return WASM_SEC_ORDER_ELEM; 1592 case wasm::WASM_SEC_CODE: 1593 return WASM_SEC_ORDER_CODE; 1594 case wasm::WASM_SEC_DATA: 1595 return WASM_SEC_ORDER_DATA; 1596 case wasm::WASM_SEC_DATACOUNT: 1597 return WASM_SEC_ORDER_DATACOUNT; 1598 case wasm::WASM_SEC_EVENT: 1599 return WASM_SEC_ORDER_EVENT; 1600 default: 1601 return WASM_SEC_ORDER_NONE; 1602 } 1603 } 1604 1605 // Represents the edges in a directed graph where any node B reachable from node 1606 // A is not allowed to appear before A in the section ordering, but may appear 1607 // afterward. 1608 int WasmSectionOrderChecker::DisallowedPredecessors[WASM_NUM_SEC_ORDERS][WASM_NUM_SEC_ORDERS] = { 1609 {}, // WASM_SEC_ORDER_NONE 1610 {WASM_SEC_ORDER_TYPE, WASM_SEC_ORDER_IMPORT}, // WASM_SEC_ORDER_TYPE, 1611 {WASM_SEC_ORDER_IMPORT, WASM_SEC_ORDER_FUNCTION}, // WASM_SEC_ORDER_IMPORT, 1612 {WASM_SEC_ORDER_FUNCTION, WASM_SEC_ORDER_TABLE}, // WASM_SEC_ORDER_FUNCTION, 1613 {WASM_SEC_ORDER_TABLE, WASM_SEC_ORDER_MEMORY}, // WASM_SEC_ORDER_TABLE, 1614 {WASM_SEC_ORDER_MEMORY, WASM_SEC_ORDER_GLOBAL}, // WASM_SEC_ORDER_MEMORY, 1615 {WASM_SEC_ORDER_GLOBAL, WASM_SEC_ORDER_EVENT}, // WASM_SEC_ORDER_GLOBAL, 1616 {WASM_SEC_ORDER_EVENT, WASM_SEC_ORDER_EXPORT}, // WASM_SEC_ORDER_EVENT, 1617 {WASM_SEC_ORDER_EXPORT, WASM_SEC_ORDER_START}, // WASM_SEC_ORDER_EXPORT, 1618 {WASM_SEC_ORDER_START, WASM_SEC_ORDER_ELEM}, // WASM_SEC_ORDER_START, 1619 {WASM_SEC_ORDER_ELEM, WASM_SEC_ORDER_DATACOUNT}, // WASM_SEC_ORDER_ELEM, 1620 {WASM_SEC_ORDER_DATACOUNT, WASM_SEC_ORDER_CODE}, // WASM_SEC_ORDER_DATACOUNT, 1621 {WASM_SEC_ORDER_CODE, WASM_SEC_ORDER_DATA}, // WASM_SEC_ORDER_CODE, 1622 {WASM_SEC_ORDER_DATA, WASM_SEC_ORDER_LINKING}, // WASM_SEC_ORDER_DATA, 1623 1624 // Custom Sections 1625 {WASM_SEC_ORDER_DYLINK, WASM_SEC_ORDER_TYPE}, // WASM_SEC_ORDER_DYLINK, 1626 {WASM_SEC_ORDER_LINKING, WASM_SEC_ORDER_RELOC, WASM_SEC_ORDER_NAME}, // WASM_SEC_ORDER_LINKING, 1627 {}, // WASM_SEC_ORDER_RELOC (can be repeated), 1628 {WASM_SEC_ORDER_NAME, WASM_SEC_ORDER_PRODUCERS}, // WASM_SEC_ORDER_NAME, 1629 {WASM_SEC_ORDER_PRODUCERS, WASM_SEC_ORDER_TARGET_FEATURES}, // WASM_SEC_ORDER_PRODUCERS, 1630 {WASM_SEC_ORDER_TARGET_FEATURES} // WASM_SEC_ORDER_TARGET_FEATURES 1631 }; 1632 1633 bool WasmSectionOrderChecker::isValidSectionOrder(unsigned ID, 1634 StringRef CustomSectionName) { 1635 int Order = getSectionOrder(ID, CustomSectionName); 1636 if (Order == WASM_SEC_ORDER_NONE) 1637 return true; 1638 1639 // Disallowed predecessors we need to check for 1640 SmallVector<int, WASM_NUM_SEC_ORDERS> WorkList; 1641 1642 // Keep track of completed checks to avoid repeating work 1643 bool Checked[WASM_NUM_SEC_ORDERS] = {}; 1644 1645 int Curr = Order; 1646 while (true) { 1647 // Add new disallowed predecessors to work list 1648 for (size_t I = 0;; ++I) { 1649 int Next = DisallowedPredecessors[Curr][I]; 1650 if (Next == WASM_SEC_ORDER_NONE) 1651 break; 1652 if (Checked[Next]) 1653 continue; 1654 WorkList.push_back(Next); 1655 Checked[Next] = true; 1656 } 1657 1658 if (WorkList.empty()) 1659 break; 1660 1661 // Consider next disallowed predecessor 1662 Curr = WorkList.pop_back_val(); 1663 if (Seen[Curr]) 1664 return false; 1665 } 1666 1667 // Have not seen any disallowed predecessors 1668 Seen[Order] = true; 1669 return true; 1670 } 1671