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/StringSwitch.h" 16 #include "llvm/ADT/Triple.h" 17 #include "llvm/BinaryFormat/Wasm.h" 18 #include "llvm/MC/SubtargetFeature.h" 19 #include "llvm/Object/Binary.h" 20 #include "llvm/Object/Error.h" 21 #include "llvm/Object/ObjectFile.h" 22 #include "llvm/Object/SymbolicFile.h" 23 #include "llvm/Object/Wasm.h" 24 #include "llvm/Support/Endian.h" 25 #include "llvm/Support/Error.h" 26 #include "llvm/Support/ErrorHandling.h" 27 #include "llvm/Support/LEB128.h" 28 #include "llvm/Support/ScopedPrinter.h" 29 #include <algorithm> 30 #include <cassert> 31 #include <cstdint> 32 #include <cstring> 33 #include <system_error> 34 35 #define DEBUG_TYPE "wasm-object" 36 37 using namespace llvm; 38 using namespace object; 39 40 void WasmSymbol::print(raw_ostream &Out) const { 41 Out << "Name=" << Info.Name 42 << ", Kind=" << toString(wasm::WasmSymbolType(Info.Kind)) 43 << ", Flags=" << Info.Flags; 44 if (!isTypeData()) { 45 Out << ", ElemIndex=" << Info.ElementIndex; 46 } else if (isDefined()) { 47 Out << ", Segment=" << Info.DataRef.Segment; 48 Out << ", Offset=" << Info.DataRef.Offset; 49 Out << ", Size=" << Info.DataRef.Size; 50 } 51 } 52 53 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 54 LLVM_DUMP_METHOD void WasmSymbol::dump() const { print(dbgs()); } 55 #endif 56 57 Expected<std::unique_ptr<WasmObjectFile>> 58 ObjectFile::createWasmObjectFile(MemoryBufferRef Buffer) { 59 Error Err = Error::success(); 60 auto ObjectFile = std::make_unique<WasmObjectFile>(Buffer, Err); 61 if (Err) 62 return std::move(Err); 63 64 return std::move(ObjectFile); 65 } 66 67 #define VARINT7_MAX ((1 << 7) - 1) 68 #define VARINT7_MIN (-(1 << 7)) 69 #define VARUINT7_MAX (1 << 7) 70 #define VARUINT1_MAX (1) 71 72 static uint8_t readUint8(WasmObjectFile::ReadContext &Ctx) { 73 if (Ctx.Ptr == Ctx.End) 74 report_fatal_error("EOF while reading uint8"); 75 return *Ctx.Ptr++; 76 } 77 78 static uint32_t readUint32(WasmObjectFile::ReadContext &Ctx) { 79 if (Ctx.Ptr + 4 > Ctx.End) 80 report_fatal_error("EOF while reading uint32"); 81 uint32_t Result = support::endian::read32le(Ctx.Ptr); 82 Ctx.Ptr += 4; 83 return Result; 84 } 85 86 static int32_t readFloat32(WasmObjectFile::ReadContext &Ctx) { 87 if (Ctx.Ptr + 4 > Ctx.End) 88 report_fatal_error("EOF while reading float64"); 89 int32_t Result = 0; 90 memcpy(&Result, Ctx.Ptr, sizeof(Result)); 91 Ctx.Ptr += sizeof(Result); 92 return Result; 93 } 94 95 static int64_t readFloat64(WasmObjectFile::ReadContext &Ctx) { 96 if (Ctx.Ptr + 8 > Ctx.End) 97 report_fatal_error("EOF while reading float64"); 98 int64_t Result = 0; 99 memcpy(&Result, Ctx.Ptr, sizeof(Result)); 100 Ctx.Ptr += sizeof(Result); 101 return Result; 102 } 103 104 static uint64_t readULEB128(WasmObjectFile::ReadContext &Ctx) { 105 unsigned Count; 106 const char *Error = nullptr; 107 uint64_t Result = decodeULEB128(Ctx.Ptr, &Count, Ctx.End, &Error); 108 if (Error) 109 report_fatal_error(Error); 110 Ctx.Ptr += Count; 111 return Result; 112 } 113 114 static StringRef readString(WasmObjectFile::ReadContext &Ctx) { 115 uint32_t StringLen = readULEB128(Ctx); 116 if (Ctx.Ptr + StringLen > Ctx.End) 117 report_fatal_error("EOF while reading string"); 118 StringRef Return = 119 StringRef(reinterpret_cast<const char *>(Ctx.Ptr), StringLen); 120 Ctx.Ptr += StringLen; 121 return Return; 122 } 123 124 static int64_t readLEB128(WasmObjectFile::ReadContext &Ctx) { 125 unsigned Count; 126 const char *Error = nullptr; 127 uint64_t Result = decodeSLEB128(Ctx.Ptr, &Count, Ctx.End, &Error); 128 if (Error) 129 report_fatal_error(Error); 130 Ctx.Ptr += Count; 131 return Result; 132 } 133 134 static uint8_t readVaruint1(WasmObjectFile::ReadContext &Ctx) { 135 int64_t Result = readLEB128(Ctx); 136 if (Result > VARUINT1_MAX || Result < 0) 137 report_fatal_error("LEB is outside Varuint1 range"); 138 return Result; 139 } 140 141 static int32_t readVarint32(WasmObjectFile::ReadContext &Ctx) { 142 int64_t Result = readLEB128(Ctx); 143 if (Result > INT32_MAX || Result < INT32_MIN) 144 report_fatal_error("LEB is outside Varint32 range"); 145 return Result; 146 } 147 148 static uint32_t readVaruint32(WasmObjectFile::ReadContext &Ctx) { 149 uint64_t Result = readULEB128(Ctx); 150 if (Result > UINT32_MAX) 151 report_fatal_error("LEB is outside Varuint32 range"); 152 return Result; 153 } 154 155 static int64_t readVarint64(WasmObjectFile::ReadContext &Ctx) { 156 return readLEB128(Ctx); 157 } 158 159 static uint64_t readVaruint64(WasmObjectFile::ReadContext &Ctx) { 160 return readULEB128(Ctx); 161 } 162 163 static uint8_t readOpcode(WasmObjectFile::ReadContext &Ctx) { 164 return readUint8(Ctx); 165 } 166 167 static Error readInitExpr(wasm::WasmInitExpr &Expr, 168 WasmObjectFile::ReadContext &Ctx) { 169 Expr.Opcode = readOpcode(Ctx); 170 171 switch (Expr.Opcode) { 172 case wasm::WASM_OPCODE_I32_CONST: 173 Expr.Value.Int32 = readVarint32(Ctx); 174 break; 175 case wasm::WASM_OPCODE_I64_CONST: 176 Expr.Value.Int64 = readVarint64(Ctx); 177 break; 178 case wasm::WASM_OPCODE_F32_CONST: 179 Expr.Value.Float32 = readFloat32(Ctx); 180 break; 181 case wasm::WASM_OPCODE_F64_CONST: 182 Expr.Value.Float64 = readFloat64(Ctx); 183 break; 184 case wasm::WASM_OPCODE_GLOBAL_GET: 185 Expr.Value.Global = readULEB128(Ctx); 186 break; 187 case wasm::WASM_OPCODE_REF_NULL: { 188 wasm::ValType Ty = static_cast<wasm::ValType>(readULEB128(Ctx)); 189 if (Ty != wasm::ValType::EXTERNREF) { 190 return make_error<GenericBinaryError>("Invalid type for ref.null", 191 object_error::parse_failed); 192 } 193 break; 194 } 195 default: 196 return make_error<GenericBinaryError>("Invalid opcode in init_expr", 197 object_error::parse_failed); 198 } 199 200 uint8_t EndOpcode = readOpcode(Ctx); 201 if (EndOpcode != wasm::WASM_OPCODE_END) { 202 return make_error<GenericBinaryError>("Invalid init_expr", 203 object_error::parse_failed); 204 } 205 return Error::success(); 206 } 207 208 static wasm::WasmLimits readLimits(WasmObjectFile::ReadContext &Ctx) { 209 wasm::WasmLimits Result; 210 Result.Flags = readVaruint32(Ctx); 211 Result.Initial = readVaruint64(Ctx); 212 if (Result.Flags & wasm::WASM_LIMITS_FLAG_HAS_MAX) 213 Result.Maximum = readVaruint64(Ctx); 214 return Result; 215 } 216 217 static wasm::WasmTable readTable(WasmObjectFile::ReadContext &Ctx) { 218 wasm::WasmTable Table; 219 Table.ElemType = readUint8(Ctx); 220 Table.Limits = readLimits(Ctx); 221 return Table; 222 } 223 224 static Error readSection(WasmSection &Section, WasmObjectFile::ReadContext &Ctx, 225 WasmSectionOrderChecker &Checker) { 226 Section.Offset = Ctx.Ptr - Ctx.Start; 227 Section.Type = readUint8(Ctx); 228 LLVM_DEBUG(dbgs() << "readSection type=" << Section.Type << "\n"); 229 uint32_t Size = readVaruint32(Ctx); 230 if (Size == 0) 231 return make_error<StringError>("Zero length section", 232 object_error::parse_failed); 233 if (Ctx.Ptr + Size > Ctx.End) 234 return make_error<StringError>("Section too large", 235 object_error::parse_failed); 236 if (Section.Type == wasm::WASM_SEC_CUSTOM) { 237 WasmObjectFile::ReadContext SectionCtx; 238 SectionCtx.Start = Ctx.Ptr; 239 SectionCtx.Ptr = Ctx.Ptr; 240 SectionCtx.End = Ctx.Ptr + Size; 241 242 Section.Name = readString(SectionCtx); 243 244 uint32_t SectionNameSize = SectionCtx.Ptr - SectionCtx.Start; 245 Ctx.Ptr += SectionNameSize; 246 Size -= SectionNameSize; 247 } 248 249 if (!Checker.isValidSectionOrder(Section.Type, Section.Name)) { 250 return make_error<StringError>("Out of order section type: " + 251 llvm::to_string(Section.Type), 252 object_error::parse_failed); 253 } 254 255 Section.Content = ArrayRef<uint8_t>(Ctx.Ptr, Size); 256 Ctx.Ptr += Size; 257 return Error::success(); 258 } 259 260 WasmObjectFile::WasmObjectFile(MemoryBufferRef Buffer, Error &Err) 261 : ObjectFile(Binary::ID_Wasm, Buffer) { 262 ErrorAsOutParameter ErrAsOutParam(&Err); 263 Header.Magic = getData().substr(0, 4); 264 if (Header.Magic != StringRef("\0asm", 4)) { 265 Err = 266 make_error<StringError>("Bad magic number", object_error::parse_failed); 267 return; 268 } 269 270 ReadContext Ctx; 271 Ctx.Start = getData().bytes_begin(); 272 Ctx.Ptr = Ctx.Start + 4; 273 Ctx.End = Ctx.Start + getData().size(); 274 275 if (Ctx.Ptr + 4 > Ctx.End) { 276 Err = make_error<StringError>("Missing version number", 277 object_error::parse_failed); 278 return; 279 } 280 281 Header.Version = readUint32(Ctx); 282 if (Header.Version != wasm::WasmVersion) { 283 Err = make_error<StringError>("Bad version number", 284 object_error::parse_failed); 285 return; 286 } 287 288 WasmSection Sec; 289 WasmSectionOrderChecker Checker; 290 while (Ctx.Ptr < Ctx.End) { 291 if ((Err = readSection(Sec, Ctx, Checker))) 292 return; 293 if ((Err = parseSection(Sec))) 294 return; 295 296 Sections.push_back(Sec); 297 } 298 } 299 300 Error WasmObjectFile::parseSection(WasmSection &Sec) { 301 ReadContext Ctx; 302 Ctx.Start = Sec.Content.data(); 303 Ctx.End = Ctx.Start + Sec.Content.size(); 304 Ctx.Ptr = Ctx.Start; 305 switch (Sec.Type) { 306 case wasm::WASM_SEC_CUSTOM: 307 return parseCustomSection(Sec, Ctx); 308 case wasm::WASM_SEC_TYPE: 309 return parseTypeSection(Ctx); 310 case wasm::WASM_SEC_IMPORT: 311 return parseImportSection(Ctx); 312 case wasm::WASM_SEC_FUNCTION: 313 return parseFunctionSection(Ctx); 314 case wasm::WASM_SEC_TABLE: 315 return parseTableSection(Ctx); 316 case wasm::WASM_SEC_MEMORY: 317 return parseMemorySection(Ctx); 318 case wasm::WASM_SEC_EVENT: 319 return parseEventSection(Ctx); 320 case wasm::WASM_SEC_GLOBAL: 321 return parseGlobalSection(Ctx); 322 case wasm::WASM_SEC_EXPORT: 323 return parseExportSection(Ctx); 324 case wasm::WASM_SEC_START: 325 return parseStartSection(Ctx); 326 case wasm::WASM_SEC_ELEM: 327 return parseElemSection(Ctx); 328 case wasm::WASM_SEC_CODE: 329 return parseCodeSection(Ctx); 330 case wasm::WASM_SEC_DATA: 331 return parseDataSection(Ctx); 332 case wasm::WASM_SEC_DATACOUNT: 333 return parseDataCountSection(Ctx); 334 default: 335 return make_error<GenericBinaryError>( 336 "Invalid section type: " + Twine(Sec.Type), object_error::parse_failed); 337 } 338 } 339 340 Error WasmObjectFile::parseDylinkSection(ReadContext &Ctx) { 341 // See https://github.com/WebAssembly/tool-conventions/blob/master/DynamicLinking.md 342 HasDylinkSection = true; 343 DylinkInfo.MemorySize = readVaruint32(Ctx); 344 DylinkInfo.MemoryAlignment = readVaruint32(Ctx); 345 DylinkInfo.TableSize = readVaruint32(Ctx); 346 DylinkInfo.TableAlignment = readVaruint32(Ctx); 347 uint32_t Count = readVaruint32(Ctx); 348 while (Count--) { 349 DylinkInfo.Needed.push_back(readString(Ctx)); 350 } 351 if (Ctx.Ptr != Ctx.End) 352 return make_error<GenericBinaryError>("dylink section ended prematurely", 353 object_error::parse_failed); 354 return Error::success(); 355 } 356 357 Error WasmObjectFile::parseNameSection(ReadContext &Ctx) { 358 llvm::DenseSet<uint64_t> Seen; 359 if (FunctionTypes.size() && !SeenCodeSection) { 360 return make_error<GenericBinaryError>("Names must come after code section", 361 object_error::parse_failed); 362 } 363 364 while (Ctx.Ptr < Ctx.End) { 365 uint8_t Type = readUint8(Ctx); 366 uint32_t Size = readVaruint32(Ctx); 367 const uint8_t *SubSectionEnd = Ctx.Ptr + Size; 368 switch (Type) { 369 case wasm::WASM_NAMES_FUNCTION: { 370 uint32_t Count = readVaruint32(Ctx); 371 while (Count--) { 372 uint32_t Index = readVaruint32(Ctx); 373 if (!Seen.insert(Index).second) 374 return make_error<GenericBinaryError>("Function named more than once", 375 object_error::parse_failed); 376 StringRef Name = readString(Ctx); 377 if (!isValidFunctionIndex(Index) || Name.empty()) 378 return make_error<GenericBinaryError>("Invalid name entry", 379 object_error::parse_failed); 380 DebugNames.push_back(wasm::WasmFunctionName{Index, Name}); 381 if (isDefinedFunctionIndex(Index)) 382 getDefinedFunction(Index).DebugName = Name; 383 } 384 break; 385 } 386 // Ignore local names for now 387 case wasm::WASM_NAMES_LOCAL: 388 default: 389 Ctx.Ptr += Size; 390 break; 391 } 392 if (Ctx.Ptr != SubSectionEnd) 393 return make_error<GenericBinaryError>( 394 "Name sub-section ended prematurely", object_error::parse_failed); 395 } 396 397 if (Ctx.Ptr != Ctx.End) 398 return make_error<GenericBinaryError>("Name section ended prematurely", 399 object_error::parse_failed); 400 return Error::success(); 401 } 402 403 Error WasmObjectFile::parseLinkingSection(ReadContext &Ctx) { 404 HasLinkingSection = true; 405 if (FunctionTypes.size() && !SeenCodeSection) { 406 return make_error<GenericBinaryError>( 407 "Linking data must come after code section", 408 object_error::parse_failed); 409 } 410 411 LinkingData.Version = readVaruint32(Ctx); 412 if (LinkingData.Version != wasm::WasmMetadataVersion) { 413 return make_error<GenericBinaryError>( 414 "Unexpected metadata version: " + Twine(LinkingData.Version) + 415 " (Expected: " + Twine(wasm::WasmMetadataVersion) + ")", 416 object_error::parse_failed); 417 } 418 419 const uint8_t *OrigEnd = Ctx.End; 420 while (Ctx.Ptr < OrigEnd) { 421 Ctx.End = OrigEnd; 422 uint8_t Type = readUint8(Ctx); 423 uint32_t Size = readVaruint32(Ctx); 424 LLVM_DEBUG(dbgs() << "readSubsection type=" << int(Type) << " size=" << Size 425 << "\n"); 426 Ctx.End = Ctx.Ptr + Size; 427 switch (Type) { 428 case wasm::WASM_SYMBOL_TABLE: 429 if (Error Err = parseLinkingSectionSymtab(Ctx)) 430 return Err; 431 break; 432 case wasm::WASM_SEGMENT_INFO: { 433 uint32_t Count = readVaruint32(Ctx); 434 if (Count > DataSegments.size()) 435 return make_error<GenericBinaryError>("Too many segment names", 436 object_error::parse_failed); 437 for (uint32_t I = 0; I < Count; I++) { 438 DataSegments[I].Data.Name = readString(Ctx); 439 DataSegments[I].Data.Alignment = readVaruint32(Ctx); 440 DataSegments[I].Data.LinkerFlags = readVaruint32(Ctx); 441 } 442 break; 443 } 444 case wasm::WASM_INIT_FUNCS: { 445 uint32_t Count = readVaruint32(Ctx); 446 LinkingData.InitFunctions.reserve(Count); 447 for (uint32_t I = 0; I < Count; I++) { 448 wasm::WasmInitFunc Init; 449 Init.Priority = readVaruint32(Ctx); 450 Init.Symbol = readVaruint32(Ctx); 451 if (!isValidFunctionSymbol(Init.Symbol)) 452 return make_error<GenericBinaryError>("Invalid function symbol: " + 453 Twine(Init.Symbol), 454 object_error::parse_failed); 455 LinkingData.InitFunctions.emplace_back(Init); 456 } 457 break; 458 } 459 case wasm::WASM_COMDAT_INFO: 460 if (Error Err = parseLinkingSectionComdat(Ctx)) 461 return Err; 462 break; 463 default: 464 Ctx.Ptr += Size; 465 break; 466 } 467 if (Ctx.Ptr != Ctx.End) 468 return make_error<GenericBinaryError>( 469 "Linking sub-section ended prematurely", object_error::parse_failed); 470 } 471 if (Ctx.Ptr != OrigEnd) 472 return make_error<GenericBinaryError>("Linking section ended prematurely", 473 object_error::parse_failed); 474 return Error::success(); 475 } 476 477 Error WasmObjectFile::parseLinkingSectionSymtab(ReadContext &Ctx) { 478 uint32_t Count = readVaruint32(Ctx); 479 LinkingData.SymbolTable.reserve(Count); 480 Symbols.reserve(Count); 481 StringSet<> SymbolNames; 482 483 std::vector<wasm::WasmImport *> ImportedGlobals; 484 std::vector<wasm::WasmImport *> ImportedFunctions; 485 std::vector<wasm::WasmImport *> ImportedEvents; 486 ImportedGlobals.reserve(Imports.size()); 487 ImportedFunctions.reserve(Imports.size()); 488 ImportedEvents.reserve(Imports.size()); 489 for (auto &I : Imports) { 490 if (I.Kind == wasm::WASM_EXTERNAL_FUNCTION) 491 ImportedFunctions.emplace_back(&I); 492 else if (I.Kind == wasm::WASM_EXTERNAL_GLOBAL) 493 ImportedGlobals.emplace_back(&I); 494 else if (I.Kind == wasm::WASM_EXTERNAL_EVENT) 495 ImportedEvents.emplace_back(&I); 496 } 497 498 while (Count--) { 499 wasm::WasmSymbolInfo Info; 500 const wasm::WasmSignature *Signature = nullptr; 501 const wasm::WasmGlobalType *GlobalType = nullptr; 502 const wasm::WasmEventType *EventType = nullptr; 503 504 Info.Kind = readUint8(Ctx); 505 Info.Flags = readVaruint32(Ctx); 506 bool IsDefined = (Info.Flags & wasm::WASM_SYMBOL_UNDEFINED) == 0; 507 508 switch (Info.Kind) { 509 case wasm::WASM_SYMBOL_TYPE_FUNCTION: 510 Info.ElementIndex = readVaruint32(Ctx); 511 if (!isValidFunctionIndex(Info.ElementIndex) || 512 IsDefined != isDefinedFunctionIndex(Info.ElementIndex)) 513 return make_error<GenericBinaryError>("invalid function symbol index", 514 object_error::parse_failed); 515 if (IsDefined) { 516 Info.Name = readString(Ctx); 517 unsigned FuncIndex = Info.ElementIndex - NumImportedFunctions; 518 Signature = &Signatures[FunctionTypes[FuncIndex]]; 519 wasm::WasmFunction &Function = Functions[FuncIndex]; 520 if (Function.SymbolName.empty()) 521 Function.SymbolName = Info.Name; 522 } else { 523 wasm::WasmImport &Import = *ImportedFunctions[Info.ElementIndex]; 524 if ((Info.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) { 525 Info.Name = readString(Ctx); 526 Info.ImportName = Import.Field; 527 } else { 528 Info.Name = Import.Field; 529 } 530 Signature = &Signatures[Import.SigIndex]; 531 if (!Import.Module.empty()) { 532 Info.ImportModule = Import.Module; 533 } 534 } 535 break; 536 537 case wasm::WASM_SYMBOL_TYPE_GLOBAL: 538 Info.ElementIndex = readVaruint32(Ctx); 539 if (!isValidGlobalIndex(Info.ElementIndex) || 540 IsDefined != isDefinedGlobalIndex(Info.ElementIndex)) 541 return make_error<GenericBinaryError>("invalid global symbol index", 542 object_error::parse_failed); 543 if (!IsDefined && (Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) == 544 wasm::WASM_SYMBOL_BINDING_WEAK) 545 return make_error<GenericBinaryError>("undefined weak global symbol", 546 object_error::parse_failed); 547 if (IsDefined) { 548 Info.Name = readString(Ctx); 549 unsigned GlobalIndex = Info.ElementIndex - NumImportedGlobals; 550 wasm::WasmGlobal &Global = Globals[GlobalIndex]; 551 GlobalType = &Global.Type; 552 if (Global.SymbolName.empty()) 553 Global.SymbolName = Info.Name; 554 } else { 555 wasm::WasmImport &Import = *ImportedGlobals[Info.ElementIndex]; 556 if ((Info.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) { 557 Info.Name = readString(Ctx); 558 Info.ImportName = Import.Field; 559 } else { 560 Info.Name = Import.Field; 561 } 562 GlobalType = &Import.Global; 563 Info.ImportName = Import.Field; 564 if (!Import.Module.empty()) { 565 Info.ImportModule = Import.Module; 566 } 567 } 568 break; 569 570 case wasm::WASM_SYMBOL_TYPE_DATA: 571 Info.Name = readString(Ctx); 572 if (IsDefined) { 573 auto Index = readVaruint32(Ctx); 574 if (Index >= DataSegments.size()) 575 return make_error<GenericBinaryError>("invalid data symbol index", 576 object_error::parse_failed); 577 auto Offset = readVaruint64(Ctx); 578 auto Size = readVaruint64(Ctx); 579 if (Offset + Size > DataSegments[Index].Data.Content.size()) 580 return make_error<GenericBinaryError>("invalid data symbol offset", 581 object_error::parse_failed); 582 Info.DataRef = wasm::WasmDataReference{Index, Offset, Size}; 583 } 584 break; 585 586 case wasm::WASM_SYMBOL_TYPE_SECTION: { 587 if ((Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) != 588 wasm::WASM_SYMBOL_BINDING_LOCAL) 589 return make_error<GenericBinaryError>( 590 "Section symbols must have local binding", 591 object_error::parse_failed); 592 Info.ElementIndex = readVaruint32(Ctx); 593 // Use somewhat unique section name as symbol name. 594 StringRef SectionName = Sections[Info.ElementIndex].Name; 595 Info.Name = SectionName; 596 break; 597 } 598 599 case wasm::WASM_SYMBOL_TYPE_EVENT: { 600 Info.ElementIndex = readVaruint32(Ctx); 601 if (!isValidEventIndex(Info.ElementIndex) || 602 IsDefined != isDefinedEventIndex(Info.ElementIndex)) 603 return make_error<GenericBinaryError>("invalid event symbol index", 604 object_error::parse_failed); 605 if (!IsDefined && (Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) == 606 wasm::WASM_SYMBOL_BINDING_WEAK) 607 return make_error<GenericBinaryError>("undefined weak global symbol", 608 object_error::parse_failed); 609 if (IsDefined) { 610 Info.Name = readString(Ctx); 611 unsigned EventIndex = Info.ElementIndex - NumImportedEvents; 612 wasm::WasmEvent &Event = Events[EventIndex]; 613 Signature = &Signatures[Event.Type.SigIndex]; 614 EventType = &Event.Type; 615 if (Event.SymbolName.empty()) 616 Event.SymbolName = Info.Name; 617 618 } else { 619 wasm::WasmImport &Import = *ImportedEvents[Info.ElementIndex]; 620 if ((Info.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) { 621 Info.Name = readString(Ctx); 622 Info.ImportName = Import.Field; 623 } else { 624 Info.Name = Import.Field; 625 } 626 EventType = &Import.Event; 627 Signature = &Signatures[EventType->SigIndex]; 628 if (!Import.Module.empty()) { 629 Info.ImportModule = Import.Module; 630 } 631 } 632 break; 633 } 634 635 default: 636 return make_error<GenericBinaryError>("Invalid symbol type", 637 object_error::parse_failed); 638 } 639 640 if ((Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) != 641 wasm::WASM_SYMBOL_BINDING_LOCAL && 642 !SymbolNames.insert(Info.Name).second) 643 return make_error<GenericBinaryError>("Duplicate symbol name " + 644 Twine(Info.Name), 645 object_error::parse_failed); 646 LinkingData.SymbolTable.emplace_back(Info); 647 Symbols.emplace_back(LinkingData.SymbolTable.back(), GlobalType, EventType, 648 Signature); 649 LLVM_DEBUG(dbgs() << "Adding symbol: " << Symbols.back() << "\n"); 650 } 651 652 return Error::success(); 653 } 654 655 Error WasmObjectFile::parseLinkingSectionComdat(ReadContext &Ctx) { 656 uint32_t ComdatCount = readVaruint32(Ctx); 657 StringSet<> ComdatSet; 658 for (unsigned ComdatIndex = 0; ComdatIndex < ComdatCount; ++ComdatIndex) { 659 StringRef Name = readString(Ctx); 660 if (Name.empty() || !ComdatSet.insert(Name).second) 661 return make_error<GenericBinaryError>("Bad/duplicate COMDAT name " + 662 Twine(Name), 663 object_error::parse_failed); 664 LinkingData.Comdats.emplace_back(Name); 665 uint32_t Flags = readVaruint32(Ctx); 666 if (Flags != 0) 667 return make_error<GenericBinaryError>("Unsupported COMDAT flags", 668 object_error::parse_failed); 669 670 uint32_t EntryCount = readVaruint32(Ctx); 671 while (EntryCount--) { 672 unsigned Kind = readVaruint32(Ctx); 673 unsigned Index = readVaruint32(Ctx); 674 switch (Kind) { 675 default: 676 return make_error<GenericBinaryError>("Invalid COMDAT entry type", 677 object_error::parse_failed); 678 case wasm::WASM_COMDAT_DATA: 679 if (Index >= DataSegments.size()) 680 return make_error<GenericBinaryError>( 681 "COMDAT data index out of range", object_error::parse_failed); 682 if (DataSegments[Index].Data.Comdat != UINT32_MAX) 683 return make_error<GenericBinaryError>("Data segment in two COMDATs", 684 object_error::parse_failed); 685 DataSegments[Index].Data.Comdat = ComdatIndex; 686 break; 687 case wasm::WASM_COMDAT_FUNCTION: 688 if (!isDefinedFunctionIndex(Index)) 689 return make_error<GenericBinaryError>( 690 "COMDAT function index out of range", object_error::parse_failed); 691 if (getDefinedFunction(Index).Comdat != UINT32_MAX) 692 return make_error<GenericBinaryError>("Function in two COMDATs", 693 object_error::parse_failed); 694 getDefinedFunction(Index).Comdat = ComdatIndex; 695 break; 696 } 697 } 698 } 699 return Error::success(); 700 } 701 702 Error WasmObjectFile::parseProducersSection(ReadContext &Ctx) { 703 llvm::SmallSet<StringRef, 3> FieldsSeen; 704 uint32_t Fields = readVaruint32(Ctx); 705 for (size_t I = 0; I < Fields; ++I) { 706 StringRef FieldName = readString(Ctx); 707 if (!FieldsSeen.insert(FieldName).second) 708 return make_error<GenericBinaryError>( 709 "Producers section does not have unique fields", 710 object_error::parse_failed); 711 std::vector<std::pair<std::string, std::string>> *ProducerVec = nullptr; 712 if (FieldName == "language") { 713 ProducerVec = &ProducerInfo.Languages; 714 } else if (FieldName == "processed-by") { 715 ProducerVec = &ProducerInfo.Tools; 716 } else if (FieldName == "sdk") { 717 ProducerVec = &ProducerInfo.SDKs; 718 } else { 719 return make_error<GenericBinaryError>( 720 "Producers section field is not named one of language, processed-by, " 721 "or sdk", 722 object_error::parse_failed); 723 } 724 uint32_t ValueCount = readVaruint32(Ctx); 725 llvm::SmallSet<StringRef, 8> ProducersSeen; 726 for (size_t J = 0; J < ValueCount; ++J) { 727 StringRef Name = readString(Ctx); 728 StringRef Version = readString(Ctx); 729 if (!ProducersSeen.insert(Name).second) { 730 return make_error<GenericBinaryError>( 731 "Producers section contains repeated producer", 732 object_error::parse_failed); 733 } 734 ProducerVec->emplace_back(std::string(Name), std::string(Version)); 735 } 736 } 737 if (Ctx.Ptr != Ctx.End) 738 return make_error<GenericBinaryError>("Producers section ended prematurely", 739 object_error::parse_failed); 740 return Error::success(); 741 } 742 743 Error WasmObjectFile::parseTargetFeaturesSection(ReadContext &Ctx) { 744 llvm::SmallSet<std::string, 8> FeaturesSeen; 745 uint32_t FeatureCount = readVaruint32(Ctx); 746 for (size_t I = 0; I < FeatureCount; ++I) { 747 wasm::WasmFeatureEntry Feature; 748 Feature.Prefix = readUint8(Ctx); 749 switch (Feature.Prefix) { 750 case wasm::WASM_FEATURE_PREFIX_USED: 751 case wasm::WASM_FEATURE_PREFIX_REQUIRED: 752 case wasm::WASM_FEATURE_PREFIX_DISALLOWED: 753 break; 754 default: 755 return make_error<GenericBinaryError>("Unknown feature policy prefix", 756 object_error::parse_failed); 757 } 758 Feature.Name = std::string(readString(Ctx)); 759 if (!FeaturesSeen.insert(Feature.Name).second) 760 return make_error<GenericBinaryError>( 761 "Target features section contains repeated feature \"" + 762 Feature.Name + "\"", 763 object_error::parse_failed); 764 TargetFeatures.push_back(Feature); 765 } 766 if (Ctx.Ptr != Ctx.End) 767 return make_error<GenericBinaryError>( 768 "Target features section ended prematurely", 769 object_error::parse_failed); 770 return Error::success(); 771 } 772 773 Error WasmObjectFile::parseRelocSection(StringRef Name, ReadContext &Ctx) { 774 uint32_t SectionIndex = readVaruint32(Ctx); 775 if (SectionIndex >= Sections.size()) 776 return make_error<GenericBinaryError>("Invalid section index", 777 object_error::parse_failed); 778 WasmSection &Section = Sections[SectionIndex]; 779 uint32_t RelocCount = readVaruint32(Ctx); 780 uint32_t EndOffset = Section.Content.size(); 781 uint32_t PreviousOffset = 0; 782 while (RelocCount--) { 783 wasm::WasmRelocation Reloc = {}; 784 Reloc.Type = readVaruint32(Ctx); 785 Reloc.Offset = readVaruint32(Ctx); 786 if (Reloc.Offset < PreviousOffset) 787 return make_error<GenericBinaryError>("Relocations not in offset order", 788 object_error::parse_failed); 789 PreviousOffset = Reloc.Offset; 790 Reloc.Index = readVaruint32(Ctx); 791 switch (Reloc.Type) { 792 case wasm::R_WASM_FUNCTION_INDEX_LEB: 793 case wasm::R_WASM_TABLE_INDEX_SLEB: 794 case wasm::R_WASM_TABLE_INDEX_I32: 795 case wasm::R_WASM_TABLE_INDEX_REL_SLEB: 796 if (!isValidFunctionSymbol(Reloc.Index)) 797 return make_error<GenericBinaryError>("Bad relocation function index", 798 object_error::parse_failed); 799 break; 800 case wasm::R_WASM_TYPE_INDEX_LEB: 801 if (Reloc.Index >= Signatures.size()) 802 return make_error<GenericBinaryError>("Bad relocation type index", 803 object_error::parse_failed); 804 break; 805 case wasm::R_WASM_GLOBAL_INDEX_LEB: 806 // R_WASM_GLOBAL_INDEX_LEB are can be used against function and data 807 // symbols to refer to their GOT entries. 808 if (!isValidGlobalSymbol(Reloc.Index) && 809 !isValidDataSymbol(Reloc.Index) && 810 !isValidFunctionSymbol(Reloc.Index)) 811 return make_error<GenericBinaryError>("Bad relocation global index", 812 object_error::parse_failed); 813 break; 814 case wasm::R_WASM_GLOBAL_INDEX_I32: 815 if (!isValidGlobalSymbol(Reloc.Index)) 816 return make_error<GenericBinaryError>("Bad relocation global index", 817 object_error::parse_failed); 818 break; 819 case wasm::R_WASM_EVENT_INDEX_LEB: 820 if (!isValidEventSymbol(Reloc.Index)) 821 return make_error<GenericBinaryError>("Bad relocation event index", 822 object_error::parse_failed); 823 break; 824 case wasm::R_WASM_MEMORY_ADDR_LEB: 825 case wasm::R_WASM_MEMORY_ADDR_SLEB: 826 case wasm::R_WASM_MEMORY_ADDR_I32: 827 case wasm::R_WASM_MEMORY_ADDR_REL_SLEB: 828 if (!isValidDataSymbol(Reloc.Index)) 829 return make_error<GenericBinaryError>("Bad relocation data index", 830 object_error::parse_failed); 831 Reloc.Addend = readVarint32(Ctx); 832 break; 833 case wasm::R_WASM_MEMORY_ADDR_LEB64: 834 case wasm::R_WASM_MEMORY_ADDR_SLEB64: 835 case wasm::R_WASM_MEMORY_ADDR_I64: 836 case wasm::R_WASM_MEMORY_ADDR_REL_SLEB64: 837 if (!isValidDataSymbol(Reloc.Index)) 838 return make_error<GenericBinaryError>("Bad relocation data index", 839 object_error::parse_failed); 840 Reloc.Addend = readVarint64(Ctx); 841 break; 842 case wasm::R_WASM_FUNCTION_OFFSET_I32: 843 if (!isValidFunctionSymbol(Reloc.Index)) 844 return make_error<GenericBinaryError>("Bad relocation function index", 845 object_error::parse_failed); 846 Reloc.Addend = readVarint32(Ctx); 847 break; 848 case wasm::R_WASM_SECTION_OFFSET_I32: 849 if (!isValidSectionSymbol(Reloc.Index)) 850 return make_error<GenericBinaryError>("Bad relocation section index", 851 object_error::parse_failed); 852 Reloc.Addend = readVarint32(Ctx); 853 break; 854 default: 855 return make_error<GenericBinaryError>("Bad relocation type: " + 856 Twine(Reloc.Type), 857 object_error::parse_failed); 858 } 859 860 // Relocations must fit inside the section, and must appear in order. They 861 // also shouldn't overlap a function/element boundary, but we don't bother 862 // to check that. 863 uint64_t Size = 5; 864 if (Reloc.Type == wasm::R_WASM_MEMORY_ADDR_LEB64 || 865 Reloc.Type == wasm::R_WASM_MEMORY_ADDR_SLEB64 || 866 Reloc.Type == wasm::R_WASM_MEMORY_ADDR_REL_SLEB64) 867 Size = 10; 868 if (Reloc.Type == wasm::R_WASM_TABLE_INDEX_I32 || 869 Reloc.Type == wasm::R_WASM_MEMORY_ADDR_I32 || 870 Reloc.Type == wasm::R_WASM_SECTION_OFFSET_I32 || 871 Reloc.Type == wasm::R_WASM_FUNCTION_OFFSET_I32 || 872 Reloc.Type == wasm::R_WASM_GLOBAL_INDEX_I32) 873 Size = 4; 874 if (Reloc.Type == wasm::R_WASM_MEMORY_ADDR_I64) 875 Size = 8; 876 if (Reloc.Offset + Size > EndOffset) 877 return make_error<GenericBinaryError>("Bad relocation offset", 878 object_error::parse_failed); 879 880 Section.Relocations.push_back(Reloc); 881 } 882 if (Ctx.Ptr != Ctx.End) 883 return make_error<GenericBinaryError>("Reloc section ended prematurely", 884 object_error::parse_failed); 885 return Error::success(); 886 } 887 888 Error WasmObjectFile::parseCustomSection(WasmSection &Sec, ReadContext &Ctx) { 889 if (Sec.Name == "dylink") { 890 if (Error Err = parseDylinkSection(Ctx)) 891 return Err; 892 } else if (Sec.Name == "name") { 893 if (Error Err = parseNameSection(Ctx)) 894 return Err; 895 } else if (Sec.Name == "linking") { 896 if (Error Err = parseLinkingSection(Ctx)) 897 return Err; 898 } else if (Sec.Name == "producers") { 899 if (Error Err = parseProducersSection(Ctx)) 900 return Err; 901 } else if (Sec.Name == "target_features") { 902 if (Error Err = parseTargetFeaturesSection(Ctx)) 903 return Err; 904 } else if (Sec.Name.startswith("reloc.")) { 905 if (Error Err = parseRelocSection(Sec.Name, Ctx)) 906 return Err; 907 } 908 return Error::success(); 909 } 910 911 Error WasmObjectFile::parseTypeSection(ReadContext &Ctx) { 912 uint32_t Count = readVaruint32(Ctx); 913 Signatures.reserve(Count); 914 while (Count--) { 915 wasm::WasmSignature Sig; 916 uint8_t Form = readUint8(Ctx); 917 if (Form != wasm::WASM_TYPE_FUNC) { 918 return make_error<GenericBinaryError>("Invalid signature type", 919 object_error::parse_failed); 920 } 921 uint32_t ParamCount = readVaruint32(Ctx); 922 Sig.Params.reserve(ParamCount); 923 while (ParamCount--) { 924 uint32_t ParamType = readUint8(Ctx); 925 Sig.Params.push_back(wasm::ValType(ParamType)); 926 } 927 uint32_t ReturnCount = readVaruint32(Ctx); 928 while (ReturnCount--) { 929 uint32_t ReturnType = readUint8(Ctx); 930 Sig.Returns.push_back(wasm::ValType(ReturnType)); 931 } 932 Signatures.push_back(std::move(Sig)); 933 } 934 if (Ctx.Ptr != Ctx.End) 935 return make_error<GenericBinaryError>("Type section ended prematurely", 936 object_error::parse_failed); 937 return Error::success(); 938 } 939 940 Error WasmObjectFile::parseImportSection(ReadContext &Ctx) { 941 uint32_t Count = readVaruint32(Ctx); 942 Imports.reserve(Count); 943 for (uint32_t I = 0; I < Count; I++) { 944 wasm::WasmImport Im; 945 Im.Module = readString(Ctx); 946 Im.Field = readString(Ctx); 947 Im.Kind = readUint8(Ctx); 948 switch (Im.Kind) { 949 case wasm::WASM_EXTERNAL_FUNCTION: 950 NumImportedFunctions++; 951 Im.SigIndex = readVaruint32(Ctx); 952 break; 953 case wasm::WASM_EXTERNAL_GLOBAL: 954 NumImportedGlobals++; 955 Im.Global.Type = readUint8(Ctx); 956 Im.Global.Mutable = readVaruint1(Ctx); 957 break; 958 case wasm::WASM_EXTERNAL_MEMORY: 959 Im.Memory = readLimits(Ctx); 960 if (Im.Memory.Flags & wasm::WASM_LIMITS_FLAG_IS_64) 961 HasMemory64 = true; 962 break; 963 case wasm::WASM_EXTERNAL_TABLE: 964 Im.Table = readTable(Ctx); 965 if (Im.Table.ElemType != wasm::WASM_TYPE_FUNCREF) 966 return make_error<GenericBinaryError>("Invalid table element type", 967 object_error::parse_failed); 968 break; 969 case wasm::WASM_EXTERNAL_EVENT: 970 NumImportedEvents++; 971 Im.Event.Attribute = readVarint32(Ctx); 972 Im.Event.SigIndex = readVarint32(Ctx); 973 break; 974 default: 975 return make_error<GenericBinaryError>("Unexpected import kind", 976 object_error::parse_failed); 977 } 978 Imports.push_back(Im); 979 } 980 if (Ctx.Ptr != Ctx.End) 981 return make_error<GenericBinaryError>("Import section ended prematurely", 982 object_error::parse_failed); 983 return Error::success(); 984 } 985 986 Error WasmObjectFile::parseFunctionSection(ReadContext &Ctx) { 987 uint32_t Count = readVaruint32(Ctx); 988 FunctionTypes.reserve(Count); 989 Functions.resize(Count); 990 uint32_t NumTypes = Signatures.size(); 991 while (Count--) { 992 uint32_t Type = readVaruint32(Ctx); 993 if (Type >= NumTypes) 994 return make_error<GenericBinaryError>("Invalid function type", 995 object_error::parse_failed); 996 FunctionTypes.push_back(Type); 997 } 998 if (Ctx.Ptr != Ctx.End) 999 return make_error<GenericBinaryError>("Function section ended prematurely", 1000 object_error::parse_failed); 1001 return Error::success(); 1002 } 1003 1004 Error WasmObjectFile::parseTableSection(ReadContext &Ctx) { 1005 uint32_t Count = readVaruint32(Ctx); 1006 Tables.reserve(Count); 1007 while (Count--) { 1008 Tables.push_back(readTable(Ctx)); 1009 if (Tables.back().ElemType != wasm::WASM_TYPE_FUNCREF) { 1010 return make_error<GenericBinaryError>("Invalid table element type", 1011 object_error::parse_failed); 1012 } 1013 } 1014 if (Ctx.Ptr != Ctx.End) 1015 return make_error<GenericBinaryError>("Table section ended prematurely", 1016 object_error::parse_failed); 1017 return Error::success(); 1018 } 1019 1020 Error WasmObjectFile::parseMemorySection(ReadContext &Ctx) { 1021 uint32_t Count = readVaruint32(Ctx); 1022 Memories.reserve(Count); 1023 while (Count--) { 1024 auto Limits = readLimits(Ctx); 1025 if (Limits.Flags & wasm::WASM_LIMITS_FLAG_IS_64) 1026 HasMemory64 = true; 1027 Memories.push_back(Limits); 1028 } 1029 if (Ctx.Ptr != Ctx.End) 1030 return make_error<GenericBinaryError>("Memory section ended prematurely", 1031 object_error::parse_failed); 1032 return Error::success(); 1033 } 1034 1035 Error WasmObjectFile::parseEventSection(ReadContext &Ctx) { 1036 EventSection = Sections.size(); 1037 uint32_t Count = readVarint32(Ctx); 1038 Events.reserve(Count); 1039 while (Count--) { 1040 wasm::WasmEvent Event; 1041 Event.Index = NumImportedEvents + Events.size(); 1042 Event.Type.Attribute = readVaruint32(Ctx); 1043 Event.Type.SigIndex = readVarint32(Ctx); 1044 Events.push_back(Event); 1045 } 1046 1047 if (Ctx.Ptr != Ctx.End) 1048 return make_error<GenericBinaryError>("Event section ended prematurely", 1049 object_error::parse_failed); 1050 return Error::success(); 1051 } 1052 1053 Error WasmObjectFile::parseGlobalSection(ReadContext &Ctx) { 1054 GlobalSection = Sections.size(); 1055 uint32_t Count = readVaruint32(Ctx); 1056 Globals.reserve(Count); 1057 while (Count--) { 1058 wasm::WasmGlobal Global; 1059 Global.Index = NumImportedGlobals + Globals.size(); 1060 Global.Type.Type = readUint8(Ctx); 1061 Global.Type.Mutable = readVaruint1(Ctx); 1062 if (Error Err = readInitExpr(Global.InitExpr, Ctx)) 1063 return Err; 1064 Globals.push_back(Global); 1065 } 1066 if (Ctx.Ptr != Ctx.End) 1067 return make_error<GenericBinaryError>("Global section ended prematurely", 1068 object_error::parse_failed); 1069 return Error::success(); 1070 } 1071 1072 Error WasmObjectFile::parseExportSection(ReadContext &Ctx) { 1073 uint32_t Count = readVaruint32(Ctx); 1074 Exports.reserve(Count); 1075 for (uint32_t I = 0; I < Count; I++) { 1076 wasm::WasmExport Ex; 1077 Ex.Name = readString(Ctx); 1078 Ex.Kind = readUint8(Ctx); 1079 Ex.Index = readVaruint32(Ctx); 1080 switch (Ex.Kind) { 1081 case wasm::WASM_EXTERNAL_FUNCTION: 1082 1083 if (!isDefinedFunctionIndex(Ex.Index)) 1084 return make_error<GenericBinaryError>("Invalid function export", 1085 object_error::parse_failed); 1086 getDefinedFunction(Ex.Index).ExportName = Ex.Name; 1087 break; 1088 case wasm::WASM_EXTERNAL_GLOBAL: 1089 if (!isValidGlobalIndex(Ex.Index)) 1090 return make_error<GenericBinaryError>("Invalid global export", 1091 object_error::parse_failed); 1092 break; 1093 case wasm::WASM_EXTERNAL_EVENT: 1094 if (!isValidEventIndex(Ex.Index)) 1095 return make_error<GenericBinaryError>("Invalid event export", 1096 object_error::parse_failed); 1097 break; 1098 case wasm::WASM_EXTERNAL_MEMORY: 1099 case wasm::WASM_EXTERNAL_TABLE: 1100 break; 1101 default: 1102 return make_error<GenericBinaryError>("Unexpected export kind", 1103 object_error::parse_failed); 1104 } 1105 Exports.push_back(Ex); 1106 } 1107 if (Ctx.Ptr != Ctx.End) 1108 return make_error<GenericBinaryError>("Export section ended prematurely", 1109 object_error::parse_failed); 1110 return Error::success(); 1111 } 1112 1113 bool WasmObjectFile::isValidFunctionIndex(uint32_t Index) const { 1114 return Index < NumImportedFunctions + FunctionTypes.size(); 1115 } 1116 1117 bool WasmObjectFile::isDefinedFunctionIndex(uint32_t Index) const { 1118 return Index >= NumImportedFunctions && isValidFunctionIndex(Index); 1119 } 1120 1121 bool WasmObjectFile::isValidGlobalIndex(uint32_t Index) const { 1122 return Index < NumImportedGlobals + Globals.size(); 1123 } 1124 1125 bool WasmObjectFile::isDefinedGlobalIndex(uint32_t Index) const { 1126 return Index >= NumImportedGlobals && isValidGlobalIndex(Index); 1127 } 1128 1129 bool WasmObjectFile::isValidEventIndex(uint32_t Index) const { 1130 return Index < NumImportedEvents + Events.size(); 1131 } 1132 1133 bool WasmObjectFile::isDefinedEventIndex(uint32_t Index) const { 1134 return Index >= NumImportedEvents && isValidEventIndex(Index); 1135 } 1136 1137 bool WasmObjectFile::isValidFunctionSymbol(uint32_t Index) const { 1138 return Index < Symbols.size() && Symbols[Index].isTypeFunction(); 1139 } 1140 1141 bool WasmObjectFile::isValidGlobalSymbol(uint32_t Index) const { 1142 return Index < Symbols.size() && Symbols[Index].isTypeGlobal(); 1143 } 1144 1145 bool WasmObjectFile::isValidEventSymbol(uint32_t Index) const { 1146 return Index < Symbols.size() && Symbols[Index].isTypeEvent(); 1147 } 1148 1149 bool WasmObjectFile::isValidDataSymbol(uint32_t Index) const { 1150 return Index < Symbols.size() && Symbols[Index].isTypeData(); 1151 } 1152 1153 bool WasmObjectFile::isValidSectionSymbol(uint32_t Index) const { 1154 return Index < Symbols.size() && Symbols[Index].isTypeSection(); 1155 } 1156 1157 wasm::WasmFunction &WasmObjectFile::getDefinedFunction(uint32_t Index) { 1158 assert(isDefinedFunctionIndex(Index)); 1159 return Functions[Index - NumImportedFunctions]; 1160 } 1161 1162 const wasm::WasmFunction & 1163 WasmObjectFile::getDefinedFunction(uint32_t Index) const { 1164 assert(isDefinedFunctionIndex(Index)); 1165 return Functions[Index - NumImportedFunctions]; 1166 } 1167 1168 wasm::WasmGlobal &WasmObjectFile::getDefinedGlobal(uint32_t Index) { 1169 assert(isDefinedGlobalIndex(Index)); 1170 return Globals[Index - NumImportedGlobals]; 1171 } 1172 1173 wasm::WasmEvent &WasmObjectFile::getDefinedEvent(uint32_t Index) { 1174 assert(isDefinedEventIndex(Index)); 1175 return Events[Index - NumImportedEvents]; 1176 } 1177 1178 Error WasmObjectFile::parseStartSection(ReadContext &Ctx) { 1179 StartFunction = readVaruint32(Ctx); 1180 if (!isValidFunctionIndex(StartFunction)) 1181 return make_error<GenericBinaryError>("Invalid start function", 1182 object_error::parse_failed); 1183 return Error::success(); 1184 } 1185 1186 Error WasmObjectFile::parseCodeSection(ReadContext &Ctx) { 1187 SeenCodeSection = true; 1188 CodeSection = Sections.size(); 1189 uint32_t FunctionCount = readVaruint32(Ctx); 1190 if (FunctionCount != FunctionTypes.size()) { 1191 return make_error<GenericBinaryError>("Invalid function count", 1192 object_error::parse_failed); 1193 } 1194 1195 for (uint32_t i = 0; i < FunctionCount; i++) { 1196 wasm::WasmFunction& Function = Functions[i]; 1197 const uint8_t *FunctionStart = Ctx.Ptr; 1198 uint32_t Size = readVaruint32(Ctx); 1199 const uint8_t *FunctionEnd = Ctx.Ptr + Size; 1200 1201 Function.CodeOffset = Ctx.Ptr - FunctionStart; 1202 Function.Index = NumImportedFunctions + i; 1203 Function.CodeSectionOffset = FunctionStart - Ctx.Start; 1204 Function.Size = FunctionEnd - FunctionStart; 1205 1206 uint32_t NumLocalDecls = readVaruint32(Ctx); 1207 Function.Locals.reserve(NumLocalDecls); 1208 while (NumLocalDecls--) { 1209 wasm::WasmLocalDecl Decl; 1210 Decl.Count = readVaruint32(Ctx); 1211 Decl.Type = readUint8(Ctx); 1212 Function.Locals.push_back(Decl); 1213 } 1214 1215 uint32_t BodySize = FunctionEnd - Ctx.Ptr; 1216 Function.Body = ArrayRef<uint8_t>(Ctx.Ptr, BodySize); 1217 // This will be set later when reading in the linking metadata section. 1218 Function.Comdat = UINT32_MAX; 1219 Ctx.Ptr += BodySize; 1220 assert(Ctx.Ptr == FunctionEnd); 1221 } 1222 if (Ctx.Ptr != Ctx.End) 1223 return make_error<GenericBinaryError>("Code section ended prematurely", 1224 object_error::parse_failed); 1225 return Error::success(); 1226 } 1227 1228 Error WasmObjectFile::parseElemSection(ReadContext &Ctx) { 1229 uint32_t Count = readVaruint32(Ctx); 1230 ElemSegments.reserve(Count); 1231 while (Count--) { 1232 wasm::WasmElemSegment Segment; 1233 Segment.TableIndex = readVaruint32(Ctx); 1234 if (Segment.TableIndex != 0) { 1235 return make_error<GenericBinaryError>("Invalid TableIndex", 1236 object_error::parse_failed); 1237 } 1238 if (Error Err = readInitExpr(Segment.Offset, Ctx)) 1239 return Err; 1240 uint32_t NumElems = readVaruint32(Ctx); 1241 while (NumElems--) { 1242 Segment.Functions.push_back(readVaruint32(Ctx)); 1243 } 1244 ElemSegments.push_back(Segment); 1245 } 1246 if (Ctx.Ptr != Ctx.End) 1247 return make_error<GenericBinaryError>("Elem section ended prematurely", 1248 object_error::parse_failed); 1249 return Error::success(); 1250 } 1251 1252 Error WasmObjectFile::parseDataSection(ReadContext &Ctx) { 1253 DataSection = Sections.size(); 1254 uint32_t Count = readVaruint32(Ctx); 1255 if (DataCount && Count != DataCount.getValue()) 1256 return make_error<GenericBinaryError>( 1257 "Number of data segments does not match DataCount section"); 1258 DataSegments.reserve(Count); 1259 while (Count--) { 1260 WasmSegment Segment; 1261 Segment.Data.InitFlags = readVaruint32(Ctx); 1262 Segment.Data.MemoryIndex = (Segment.Data.InitFlags & wasm::WASM_SEGMENT_HAS_MEMINDEX) 1263 ? readVaruint32(Ctx) : 0; 1264 if ((Segment.Data.InitFlags & wasm::WASM_SEGMENT_IS_PASSIVE) == 0) { 1265 if (Error Err = readInitExpr(Segment.Data.Offset, Ctx)) 1266 return Err; 1267 } else { 1268 Segment.Data.Offset.Opcode = wasm::WASM_OPCODE_I32_CONST; 1269 Segment.Data.Offset.Value.Int32 = 0; 1270 } 1271 uint32_t Size = readVaruint32(Ctx); 1272 if (Size > (size_t)(Ctx.End - Ctx.Ptr)) 1273 return make_error<GenericBinaryError>("Invalid segment size", 1274 object_error::parse_failed); 1275 Segment.Data.Content = ArrayRef<uint8_t>(Ctx.Ptr, Size); 1276 // The rest of these Data fields are set later, when reading in the linking 1277 // metadata section. 1278 Segment.Data.Alignment = 0; 1279 Segment.Data.LinkerFlags = 0; 1280 Segment.Data.Comdat = UINT32_MAX; 1281 Segment.SectionOffset = Ctx.Ptr - Ctx.Start; 1282 Ctx.Ptr += Size; 1283 DataSegments.push_back(Segment); 1284 } 1285 if (Ctx.Ptr != Ctx.End) 1286 return make_error<GenericBinaryError>("Data section ended prematurely", 1287 object_error::parse_failed); 1288 return Error::success(); 1289 } 1290 1291 Error WasmObjectFile::parseDataCountSection(ReadContext &Ctx) { 1292 DataCount = readVaruint32(Ctx); 1293 return Error::success(); 1294 } 1295 1296 const wasm::WasmObjectHeader &WasmObjectFile::getHeader() const { 1297 return Header; 1298 } 1299 1300 void WasmObjectFile::moveSymbolNext(DataRefImpl &Symb) const { Symb.d.b++; } 1301 1302 Expected<uint32_t> WasmObjectFile::getSymbolFlags(DataRefImpl Symb) const { 1303 uint32_t Result = SymbolRef::SF_None; 1304 const WasmSymbol &Sym = getWasmSymbol(Symb); 1305 1306 LLVM_DEBUG(dbgs() << "getSymbolFlags: ptr=" << &Sym << " " << Sym << "\n"); 1307 if (Sym.isBindingWeak()) 1308 Result |= SymbolRef::SF_Weak; 1309 if (!Sym.isBindingLocal()) 1310 Result |= SymbolRef::SF_Global; 1311 if (Sym.isHidden()) 1312 Result |= SymbolRef::SF_Hidden; 1313 if (!Sym.isDefined()) 1314 Result |= SymbolRef::SF_Undefined; 1315 if (Sym.isTypeFunction()) 1316 Result |= SymbolRef::SF_Executable; 1317 return Result; 1318 } 1319 1320 basic_symbol_iterator WasmObjectFile::symbol_begin() const { 1321 DataRefImpl Ref; 1322 Ref.d.a = 1; // Arbitrary non-zero value so that Ref.p is non-null 1323 Ref.d.b = 0; // Symbol index 1324 return BasicSymbolRef(Ref, this); 1325 } 1326 1327 basic_symbol_iterator WasmObjectFile::symbol_end() const { 1328 DataRefImpl Ref; 1329 Ref.d.a = 1; // Arbitrary non-zero value so that Ref.p is non-null 1330 Ref.d.b = Symbols.size(); // Symbol index 1331 return BasicSymbolRef(Ref, this); 1332 } 1333 1334 const WasmSymbol &WasmObjectFile::getWasmSymbol(const DataRefImpl &Symb) const { 1335 return Symbols[Symb.d.b]; 1336 } 1337 1338 const WasmSymbol &WasmObjectFile::getWasmSymbol(const SymbolRef &Symb) const { 1339 return getWasmSymbol(Symb.getRawDataRefImpl()); 1340 } 1341 1342 Expected<StringRef> WasmObjectFile::getSymbolName(DataRefImpl Symb) const { 1343 return getWasmSymbol(Symb).Info.Name; 1344 } 1345 1346 Expected<uint64_t> WasmObjectFile::getSymbolAddress(DataRefImpl Symb) const { 1347 auto &Sym = getWasmSymbol(Symb); 1348 if (Sym.Info.Kind == wasm::WASM_SYMBOL_TYPE_FUNCTION && 1349 isDefinedFunctionIndex(Sym.Info.ElementIndex)) 1350 return getDefinedFunction(Sym.Info.ElementIndex).CodeSectionOffset; 1351 else 1352 return getSymbolValue(Symb); 1353 } 1354 1355 uint64_t WasmObjectFile::getWasmSymbolValue(const WasmSymbol &Sym) const { 1356 switch (Sym.Info.Kind) { 1357 case wasm::WASM_SYMBOL_TYPE_FUNCTION: 1358 case wasm::WASM_SYMBOL_TYPE_GLOBAL: 1359 case wasm::WASM_SYMBOL_TYPE_EVENT: 1360 return Sym.Info.ElementIndex; 1361 case wasm::WASM_SYMBOL_TYPE_DATA: { 1362 // The value of a data symbol is the segment offset, plus the symbol 1363 // offset within the segment. 1364 uint32_t SegmentIndex = Sym.Info.DataRef.Segment; 1365 const wasm::WasmDataSegment &Segment = DataSegments[SegmentIndex].Data; 1366 if (Segment.Offset.Opcode == wasm::WASM_OPCODE_I32_CONST) { 1367 return Segment.Offset.Value.Int32 + Sym.Info.DataRef.Offset; 1368 } else if (Segment.Offset.Opcode == wasm::WASM_OPCODE_I64_CONST) { 1369 return Segment.Offset.Value.Int64 + Sym.Info.DataRef.Offset; 1370 } else { 1371 llvm_unreachable("unknown init expr opcode"); 1372 } 1373 } 1374 case wasm::WASM_SYMBOL_TYPE_SECTION: 1375 return 0; 1376 } 1377 llvm_unreachable("invalid symbol type"); 1378 } 1379 1380 uint64_t WasmObjectFile::getSymbolValueImpl(DataRefImpl Symb) const { 1381 return getWasmSymbolValue(getWasmSymbol(Symb)); 1382 } 1383 1384 uint32_t WasmObjectFile::getSymbolAlignment(DataRefImpl Symb) const { 1385 llvm_unreachable("not yet implemented"); 1386 return 0; 1387 } 1388 1389 uint64_t WasmObjectFile::getCommonSymbolSizeImpl(DataRefImpl Symb) const { 1390 llvm_unreachable("not yet implemented"); 1391 return 0; 1392 } 1393 1394 Expected<SymbolRef::Type> 1395 WasmObjectFile::getSymbolType(DataRefImpl Symb) const { 1396 const WasmSymbol &Sym = getWasmSymbol(Symb); 1397 1398 switch (Sym.Info.Kind) { 1399 case wasm::WASM_SYMBOL_TYPE_FUNCTION: 1400 return SymbolRef::ST_Function; 1401 case wasm::WASM_SYMBOL_TYPE_GLOBAL: 1402 return SymbolRef::ST_Other; 1403 case wasm::WASM_SYMBOL_TYPE_DATA: 1404 return SymbolRef::ST_Data; 1405 case wasm::WASM_SYMBOL_TYPE_SECTION: 1406 return SymbolRef::ST_Debug; 1407 case wasm::WASM_SYMBOL_TYPE_EVENT: 1408 return SymbolRef::ST_Other; 1409 } 1410 1411 llvm_unreachable("Unknown WasmSymbol::SymbolType"); 1412 return SymbolRef::ST_Other; 1413 } 1414 1415 Expected<section_iterator> 1416 WasmObjectFile::getSymbolSection(DataRefImpl Symb) const { 1417 const WasmSymbol &Sym = getWasmSymbol(Symb); 1418 if (Sym.isUndefined()) 1419 return section_end(); 1420 1421 DataRefImpl Ref; 1422 Ref.d.a = getSymbolSectionIdImpl(Sym); 1423 return section_iterator(SectionRef(Ref, this)); 1424 } 1425 1426 uint32_t WasmObjectFile::getSymbolSectionId(SymbolRef Symb) const { 1427 const WasmSymbol &Sym = getWasmSymbol(Symb); 1428 return getSymbolSectionIdImpl(Sym); 1429 } 1430 1431 uint32_t WasmObjectFile::getSymbolSectionIdImpl(const WasmSymbol &Sym) const { 1432 switch (Sym.Info.Kind) { 1433 case wasm::WASM_SYMBOL_TYPE_FUNCTION: 1434 return CodeSection; 1435 case wasm::WASM_SYMBOL_TYPE_GLOBAL: 1436 return GlobalSection; 1437 case wasm::WASM_SYMBOL_TYPE_DATA: 1438 return DataSection; 1439 case wasm::WASM_SYMBOL_TYPE_SECTION: 1440 return Sym.Info.ElementIndex; 1441 case wasm::WASM_SYMBOL_TYPE_EVENT: 1442 return EventSection; 1443 default: 1444 llvm_unreachable("Unknown WasmSymbol::SymbolType"); 1445 } 1446 } 1447 1448 void WasmObjectFile::moveSectionNext(DataRefImpl &Sec) const { Sec.d.a++; } 1449 1450 Expected<StringRef> WasmObjectFile::getSectionName(DataRefImpl Sec) const { 1451 const WasmSection &S = Sections[Sec.d.a]; 1452 #define ECase(X) \ 1453 case wasm::WASM_SEC_##X: \ 1454 return #X; 1455 switch (S.Type) { 1456 ECase(TYPE); 1457 ECase(IMPORT); 1458 ECase(FUNCTION); 1459 ECase(TABLE); 1460 ECase(MEMORY); 1461 ECase(GLOBAL); 1462 ECase(EVENT); 1463 ECase(EXPORT); 1464 ECase(START); 1465 ECase(ELEM); 1466 ECase(CODE); 1467 ECase(DATA); 1468 ECase(DATACOUNT); 1469 case wasm::WASM_SEC_CUSTOM: 1470 return S.Name; 1471 default: 1472 return createStringError(object_error::invalid_section_index, ""); 1473 } 1474 #undef ECase 1475 } 1476 1477 uint64_t WasmObjectFile::getSectionAddress(DataRefImpl Sec) const { return 0; } 1478 1479 uint64_t WasmObjectFile::getSectionIndex(DataRefImpl Sec) const { 1480 return Sec.d.a; 1481 } 1482 1483 uint64_t WasmObjectFile::getSectionSize(DataRefImpl Sec) const { 1484 const WasmSection &S = Sections[Sec.d.a]; 1485 return S.Content.size(); 1486 } 1487 1488 Expected<ArrayRef<uint8_t>> 1489 WasmObjectFile::getSectionContents(DataRefImpl Sec) const { 1490 const WasmSection &S = Sections[Sec.d.a]; 1491 // This will never fail since wasm sections can never be empty (user-sections 1492 // must have a name and non-user sections each have a defined structure). 1493 return S.Content; 1494 } 1495 1496 uint64_t WasmObjectFile::getSectionAlignment(DataRefImpl Sec) const { 1497 return 1; 1498 } 1499 1500 bool WasmObjectFile::isSectionCompressed(DataRefImpl Sec) const { 1501 return false; 1502 } 1503 1504 bool WasmObjectFile::isSectionText(DataRefImpl Sec) const { 1505 return getWasmSection(Sec).Type == wasm::WASM_SEC_CODE; 1506 } 1507 1508 bool WasmObjectFile::isSectionData(DataRefImpl Sec) const { 1509 return getWasmSection(Sec).Type == wasm::WASM_SEC_DATA; 1510 } 1511 1512 bool WasmObjectFile::isSectionBSS(DataRefImpl Sec) const { return false; } 1513 1514 bool WasmObjectFile::isSectionVirtual(DataRefImpl Sec) const { return false; } 1515 1516 relocation_iterator WasmObjectFile::section_rel_begin(DataRefImpl Ref) const { 1517 DataRefImpl RelocRef; 1518 RelocRef.d.a = Ref.d.a; 1519 RelocRef.d.b = 0; 1520 return relocation_iterator(RelocationRef(RelocRef, this)); 1521 } 1522 1523 relocation_iterator WasmObjectFile::section_rel_end(DataRefImpl Ref) const { 1524 const WasmSection &Sec = getWasmSection(Ref); 1525 DataRefImpl RelocRef; 1526 RelocRef.d.a = Ref.d.a; 1527 RelocRef.d.b = Sec.Relocations.size(); 1528 return relocation_iterator(RelocationRef(RelocRef, this)); 1529 } 1530 1531 void WasmObjectFile::moveRelocationNext(DataRefImpl &Rel) const { Rel.d.b++; } 1532 1533 uint64_t WasmObjectFile::getRelocationOffset(DataRefImpl Ref) const { 1534 const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); 1535 return Rel.Offset; 1536 } 1537 1538 symbol_iterator WasmObjectFile::getRelocationSymbol(DataRefImpl Ref) const { 1539 const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); 1540 if (Rel.Type == wasm::R_WASM_TYPE_INDEX_LEB) 1541 return symbol_end(); 1542 DataRefImpl Sym; 1543 Sym.d.a = 1; 1544 Sym.d.b = Rel.Index; 1545 return symbol_iterator(SymbolRef(Sym, this)); 1546 } 1547 1548 uint64_t WasmObjectFile::getRelocationType(DataRefImpl Ref) const { 1549 const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); 1550 return Rel.Type; 1551 } 1552 1553 void WasmObjectFile::getRelocationTypeName( 1554 DataRefImpl Ref, SmallVectorImpl<char> &Result) const { 1555 const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); 1556 StringRef Res = "Unknown"; 1557 1558 #define WASM_RELOC(name, value) \ 1559 case wasm::name: \ 1560 Res = #name; \ 1561 break; 1562 1563 switch (Rel.Type) { 1564 #include "llvm/BinaryFormat/WasmRelocs.def" 1565 } 1566 1567 #undef WASM_RELOC 1568 1569 Result.append(Res.begin(), Res.end()); 1570 } 1571 1572 section_iterator WasmObjectFile::section_begin() const { 1573 DataRefImpl Ref; 1574 Ref.d.a = 0; 1575 return section_iterator(SectionRef(Ref, this)); 1576 } 1577 1578 section_iterator WasmObjectFile::section_end() const { 1579 DataRefImpl Ref; 1580 Ref.d.a = Sections.size(); 1581 return section_iterator(SectionRef(Ref, this)); 1582 } 1583 1584 uint8_t WasmObjectFile::getBytesInAddress() const { 1585 return HasMemory64 ? 8 : 4; 1586 } 1587 1588 StringRef WasmObjectFile::getFileFormatName() const { return "WASM"; } 1589 1590 Triple::ArchType WasmObjectFile::getArch() const { 1591 return HasMemory64 ? Triple::wasm64 : Triple::wasm32; 1592 } 1593 1594 SubtargetFeatures WasmObjectFile::getFeatures() const { 1595 return SubtargetFeatures(); 1596 } 1597 1598 bool WasmObjectFile::isRelocatableObject() const { return HasLinkingSection; } 1599 1600 bool WasmObjectFile::isSharedObject() const { return HasDylinkSection; } 1601 1602 const WasmSection &WasmObjectFile::getWasmSection(DataRefImpl Ref) const { 1603 assert(Ref.d.a < Sections.size()); 1604 return Sections[Ref.d.a]; 1605 } 1606 1607 const WasmSection & 1608 WasmObjectFile::getWasmSection(const SectionRef &Section) const { 1609 return getWasmSection(Section.getRawDataRefImpl()); 1610 } 1611 1612 const wasm::WasmRelocation & 1613 WasmObjectFile::getWasmRelocation(const RelocationRef &Ref) const { 1614 return getWasmRelocation(Ref.getRawDataRefImpl()); 1615 } 1616 1617 const wasm::WasmRelocation & 1618 WasmObjectFile::getWasmRelocation(DataRefImpl Ref) const { 1619 assert(Ref.d.a < Sections.size()); 1620 const WasmSection &Sec = Sections[Ref.d.a]; 1621 assert(Ref.d.b < Sec.Relocations.size()); 1622 return Sec.Relocations[Ref.d.b]; 1623 } 1624 1625 int WasmSectionOrderChecker::getSectionOrder(unsigned ID, 1626 StringRef CustomSectionName) { 1627 switch (ID) { 1628 case wasm::WASM_SEC_CUSTOM: 1629 return StringSwitch<unsigned>(CustomSectionName) 1630 .Case("dylink", WASM_SEC_ORDER_DYLINK) 1631 .Case("linking", WASM_SEC_ORDER_LINKING) 1632 .StartsWith("reloc.", WASM_SEC_ORDER_RELOC) 1633 .Case("name", WASM_SEC_ORDER_NAME) 1634 .Case("producers", WASM_SEC_ORDER_PRODUCERS) 1635 .Case("target_features", WASM_SEC_ORDER_TARGET_FEATURES) 1636 .Default(WASM_SEC_ORDER_NONE); 1637 case wasm::WASM_SEC_TYPE: 1638 return WASM_SEC_ORDER_TYPE; 1639 case wasm::WASM_SEC_IMPORT: 1640 return WASM_SEC_ORDER_IMPORT; 1641 case wasm::WASM_SEC_FUNCTION: 1642 return WASM_SEC_ORDER_FUNCTION; 1643 case wasm::WASM_SEC_TABLE: 1644 return WASM_SEC_ORDER_TABLE; 1645 case wasm::WASM_SEC_MEMORY: 1646 return WASM_SEC_ORDER_MEMORY; 1647 case wasm::WASM_SEC_GLOBAL: 1648 return WASM_SEC_ORDER_GLOBAL; 1649 case wasm::WASM_SEC_EXPORT: 1650 return WASM_SEC_ORDER_EXPORT; 1651 case wasm::WASM_SEC_START: 1652 return WASM_SEC_ORDER_START; 1653 case wasm::WASM_SEC_ELEM: 1654 return WASM_SEC_ORDER_ELEM; 1655 case wasm::WASM_SEC_CODE: 1656 return WASM_SEC_ORDER_CODE; 1657 case wasm::WASM_SEC_DATA: 1658 return WASM_SEC_ORDER_DATA; 1659 case wasm::WASM_SEC_DATACOUNT: 1660 return WASM_SEC_ORDER_DATACOUNT; 1661 case wasm::WASM_SEC_EVENT: 1662 return WASM_SEC_ORDER_EVENT; 1663 default: 1664 return WASM_SEC_ORDER_NONE; 1665 } 1666 } 1667 1668 // Represents the edges in a directed graph where any node B reachable from node 1669 // A is not allowed to appear before A in the section ordering, but may appear 1670 // afterward. 1671 int WasmSectionOrderChecker::DisallowedPredecessors 1672 [WASM_NUM_SEC_ORDERS][WASM_NUM_SEC_ORDERS] = { 1673 // WASM_SEC_ORDER_NONE 1674 {}, 1675 // WASM_SEC_ORDER_TYPE 1676 {WASM_SEC_ORDER_TYPE, WASM_SEC_ORDER_IMPORT}, 1677 // WASM_SEC_ORDER_IMPORT 1678 {WASM_SEC_ORDER_IMPORT, WASM_SEC_ORDER_FUNCTION}, 1679 // WASM_SEC_ORDER_FUNCTION 1680 {WASM_SEC_ORDER_FUNCTION, WASM_SEC_ORDER_TABLE}, 1681 // WASM_SEC_ORDER_TABLE 1682 {WASM_SEC_ORDER_TABLE, WASM_SEC_ORDER_MEMORY}, 1683 // WASM_SEC_ORDER_MEMORY 1684 {WASM_SEC_ORDER_MEMORY, WASM_SEC_ORDER_EVENT}, 1685 // WASM_SEC_ORDER_EVENT 1686 {WASM_SEC_ORDER_EVENT, WASM_SEC_ORDER_GLOBAL}, 1687 // WASM_SEC_ORDER_GLOBAL 1688 {WASM_SEC_ORDER_GLOBAL, WASM_SEC_ORDER_EXPORT}, 1689 // WASM_SEC_ORDER_EXPORT 1690 {WASM_SEC_ORDER_EXPORT, WASM_SEC_ORDER_START}, 1691 // WASM_SEC_ORDER_START 1692 {WASM_SEC_ORDER_START, WASM_SEC_ORDER_ELEM}, 1693 // WASM_SEC_ORDER_ELEM 1694 {WASM_SEC_ORDER_ELEM, WASM_SEC_ORDER_DATACOUNT}, 1695 // WASM_SEC_ORDER_DATACOUNT 1696 {WASM_SEC_ORDER_DATACOUNT, WASM_SEC_ORDER_CODE}, 1697 // WASM_SEC_ORDER_CODE 1698 {WASM_SEC_ORDER_CODE, WASM_SEC_ORDER_DATA}, 1699 // WASM_SEC_ORDER_DATA 1700 {WASM_SEC_ORDER_DATA, WASM_SEC_ORDER_LINKING}, 1701 1702 // Custom Sections 1703 // WASM_SEC_ORDER_DYLINK 1704 {WASM_SEC_ORDER_DYLINK, WASM_SEC_ORDER_TYPE}, 1705 // WASM_SEC_ORDER_LINKING 1706 {WASM_SEC_ORDER_LINKING, WASM_SEC_ORDER_RELOC, WASM_SEC_ORDER_NAME}, 1707 // WASM_SEC_ORDER_RELOC (can be repeated) 1708 {}, 1709 // WASM_SEC_ORDER_NAME 1710 {WASM_SEC_ORDER_NAME, WASM_SEC_ORDER_PRODUCERS}, 1711 // WASM_SEC_ORDER_PRODUCERS 1712 {WASM_SEC_ORDER_PRODUCERS, WASM_SEC_ORDER_TARGET_FEATURES}, 1713 // WASM_SEC_ORDER_TARGET_FEATURES 1714 {WASM_SEC_ORDER_TARGET_FEATURES}}; 1715 1716 bool WasmSectionOrderChecker::isValidSectionOrder(unsigned ID, 1717 StringRef CustomSectionName) { 1718 int Order = getSectionOrder(ID, CustomSectionName); 1719 if (Order == WASM_SEC_ORDER_NONE) 1720 return true; 1721 1722 // Disallowed predecessors we need to check for 1723 SmallVector<int, WASM_NUM_SEC_ORDERS> WorkList; 1724 1725 // Keep track of completed checks to avoid repeating work 1726 bool Checked[WASM_NUM_SEC_ORDERS] = {}; 1727 1728 int Curr = Order; 1729 while (true) { 1730 // Add new disallowed predecessors to work list 1731 for (size_t I = 0;; ++I) { 1732 int Next = DisallowedPredecessors[Curr][I]; 1733 if (Next == WASM_SEC_ORDER_NONE) 1734 break; 1735 if (Checked[Next]) 1736 continue; 1737 WorkList.push_back(Next); 1738 Checked[Next] = true; 1739 } 1740 1741 if (WorkList.empty()) 1742 break; 1743 1744 // Consider next disallowed predecessor 1745 Curr = WorkList.pop_back_val(); 1746 if (Seen[Curr]) 1747 return false; 1748 } 1749 1750 // Have not seen any disallowed predecessors 1751 Seen[Order] = true; 1752 return true; 1753 } 1754