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/SmallSet.h" 12 #include "llvm/ADT/StringRef.h" 13 #include "llvm/ADT/StringSet.h" 14 #include "llvm/ADT/StringSwitch.h" 15 #include "llvm/BinaryFormat/Wasm.h" 16 #include "llvm/Object/Binary.h" 17 #include "llvm/Object/Error.h" 18 #include "llvm/Object/ObjectFile.h" 19 #include "llvm/Object/SymbolicFile.h" 20 #include "llvm/Object/Wasm.h" 21 #include "llvm/Support/Endian.h" 22 #include "llvm/Support/Error.h" 23 #include "llvm/Support/ErrorHandling.h" 24 #include "llvm/Support/Format.h" 25 #include "llvm/Support/LEB128.h" 26 #include "llvm/Support/ScopedPrinter.h" 27 #include "llvm/TargetParser/SubtargetFeature.h" 28 #include "llvm/TargetParser/Triple.h" 29 #include <algorithm> 30 #include <cassert> 31 #include <cstdint> 32 #include <cstring> 33 #include <limits> 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)) << ", Flags=0x" 43 << Twine::utohexstr(Info.Flags) << " ["; 44 switch (getBinding()) { 45 case wasm::WASM_SYMBOL_BINDING_GLOBAL: Out << "global"; break; 46 case wasm::WASM_SYMBOL_BINDING_LOCAL: Out << "local"; break; 47 case wasm::WASM_SYMBOL_BINDING_WEAK: Out << "weak"; break; 48 } 49 if (isHidden()) { 50 Out << ", hidden"; 51 } else { 52 Out << ", default"; 53 } 54 Out << "]"; 55 if (!isTypeData()) { 56 Out << ", ElemIndex=" << Info.ElementIndex; 57 } else if (isDefined()) { 58 Out << ", Segment=" << Info.DataRef.Segment; 59 Out << ", Offset=" << Info.DataRef.Offset; 60 Out << ", Size=" << Info.DataRef.Size; 61 } 62 } 63 64 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 65 LLVM_DUMP_METHOD void WasmSymbol::dump() const { print(dbgs()); } 66 #endif 67 68 Expected<std::unique_ptr<WasmObjectFile>> 69 ObjectFile::createWasmObjectFile(MemoryBufferRef Buffer) { 70 Error Err = Error::success(); 71 auto ObjectFile = std::make_unique<WasmObjectFile>(Buffer, Err); 72 if (Err) 73 return std::move(Err); 74 75 return std::move(ObjectFile); 76 } 77 78 #define VARINT7_MAX ((1 << 7) - 1) 79 #define VARINT7_MIN (-(1 << 7)) 80 #define VARUINT7_MAX (1 << 7) 81 #define VARUINT1_MAX (1) 82 83 static uint8_t readUint8(WasmObjectFile::ReadContext &Ctx) { 84 if (Ctx.Ptr == Ctx.End) 85 report_fatal_error("EOF while reading uint8"); 86 return *Ctx.Ptr++; 87 } 88 89 static uint32_t readUint32(WasmObjectFile::ReadContext &Ctx) { 90 if (Ctx.Ptr + 4 > Ctx.End) 91 report_fatal_error("EOF while reading uint32"); 92 uint32_t Result = support::endian::read32le(Ctx.Ptr); 93 Ctx.Ptr += 4; 94 return Result; 95 } 96 97 static int32_t readFloat32(WasmObjectFile::ReadContext &Ctx) { 98 if (Ctx.Ptr + 4 > Ctx.End) 99 report_fatal_error("EOF while reading float64"); 100 int32_t Result = 0; 101 memcpy(&Result, Ctx.Ptr, sizeof(Result)); 102 Ctx.Ptr += sizeof(Result); 103 return Result; 104 } 105 106 static int64_t readFloat64(WasmObjectFile::ReadContext &Ctx) { 107 if (Ctx.Ptr + 8 > Ctx.End) 108 report_fatal_error("EOF while reading float64"); 109 int64_t Result = 0; 110 memcpy(&Result, Ctx.Ptr, sizeof(Result)); 111 Ctx.Ptr += sizeof(Result); 112 return Result; 113 } 114 115 static uint64_t readULEB128(WasmObjectFile::ReadContext &Ctx) { 116 unsigned Count; 117 const char *Error = nullptr; 118 uint64_t Result = decodeULEB128(Ctx.Ptr, &Count, Ctx.End, &Error); 119 if (Error) 120 report_fatal_error(Error); 121 Ctx.Ptr += Count; 122 return Result; 123 } 124 125 static StringRef readString(WasmObjectFile::ReadContext &Ctx) { 126 uint32_t StringLen = readULEB128(Ctx); 127 if (Ctx.Ptr + StringLen > Ctx.End) 128 report_fatal_error("EOF while reading string"); 129 StringRef Return = 130 StringRef(reinterpret_cast<const char *>(Ctx.Ptr), StringLen); 131 Ctx.Ptr += StringLen; 132 return Return; 133 } 134 135 static int64_t readLEB128(WasmObjectFile::ReadContext &Ctx) { 136 unsigned Count; 137 const char *Error = nullptr; 138 uint64_t Result = decodeSLEB128(Ctx.Ptr, &Count, Ctx.End, &Error); 139 if (Error) 140 report_fatal_error(Error); 141 Ctx.Ptr += Count; 142 return Result; 143 } 144 145 static uint8_t readVaruint1(WasmObjectFile::ReadContext &Ctx) { 146 int64_t Result = readLEB128(Ctx); 147 if (Result > VARUINT1_MAX || Result < 0) 148 report_fatal_error("LEB is outside Varuint1 range"); 149 return Result; 150 } 151 152 static int32_t readVarint32(WasmObjectFile::ReadContext &Ctx) { 153 int64_t Result = readLEB128(Ctx); 154 if (Result > INT32_MAX || Result < INT32_MIN) 155 report_fatal_error("LEB is outside Varint32 range"); 156 return Result; 157 } 158 159 static uint32_t readVaruint32(WasmObjectFile::ReadContext &Ctx) { 160 uint64_t Result = readULEB128(Ctx); 161 if (Result > UINT32_MAX) 162 report_fatal_error("LEB is outside Varuint32 range"); 163 return Result; 164 } 165 166 static int64_t readVarint64(WasmObjectFile::ReadContext &Ctx) { 167 return readLEB128(Ctx); 168 } 169 170 static uint64_t readVaruint64(WasmObjectFile::ReadContext &Ctx) { 171 return readULEB128(Ctx); 172 } 173 174 static uint8_t readOpcode(WasmObjectFile::ReadContext &Ctx) { 175 return readUint8(Ctx); 176 } 177 178 static wasm::ValType parseValType(WasmObjectFile::ReadContext &Ctx, 179 uint32_t Code) { 180 // only directly encoded FUNCREF/EXTERNREF/EXNREF are supported 181 // (not ref null func, ref null extern, or ref null exn) 182 switch (Code) { 183 case wasm::WASM_TYPE_I32: 184 case wasm::WASM_TYPE_I64: 185 case wasm::WASM_TYPE_F32: 186 case wasm::WASM_TYPE_F64: 187 case wasm::WASM_TYPE_V128: 188 case wasm::WASM_TYPE_FUNCREF: 189 case wasm::WASM_TYPE_EXTERNREF: 190 case wasm::WASM_TYPE_EXNREF: 191 return wasm::ValType(Code); 192 } 193 if (Code == wasm::WASM_TYPE_NULLABLE || Code == wasm::WASM_TYPE_NONNULLABLE) { 194 /* Discard HeapType */ readVarint64(Ctx); 195 } 196 return wasm::ValType(wasm::ValType::OTHERREF); 197 } 198 199 static Error readInitExpr(wasm::WasmInitExpr &Expr, 200 WasmObjectFile::ReadContext &Ctx) { 201 auto Start = Ctx.Ptr; 202 203 Expr.Extended = false; 204 Expr.Inst.Opcode = readOpcode(Ctx); 205 switch (Expr.Inst.Opcode) { 206 case wasm::WASM_OPCODE_I32_CONST: 207 Expr.Inst.Value.Int32 = readVarint32(Ctx); 208 break; 209 case wasm::WASM_OPCODE_I64_CONST: 210 Expr.Inst.Value.Int64 = readVarint64(Ctx); 211 break; 212 case wasm::WASM_OPCODE_F32_CONST: 213 Expr.Inst.Value.Float32 = readFloat32(Ctx); 214 break; 215 case wasm::WASM_OPCODE_F64_CONST: 216 Expr.Inst.Value.Float64 = readFloat64(Ctx); 217 break; 218 case wasm::WASM_OPCODE_GLOBAL_GET: 219 Expr.Inst.Value.Global = readULEB128(Ctx); 220 break; 221 case wasm::WASM_OPCODE_REF_NULL: { 222 /* Discard type */ parseValType(Ctx, readVaruint32(Ctx)); 223 break; 224 } 225 default: 226 Expr.Extended = true; 227 } 228 229 if (!Expr.Extended) { 230 uint8_t EndOpcode = readOpcode(Ctx); 231 if (EndOpcode != wasm::WASM_OPCODE_END) 232 Expr.Extended = true; 233 } 234 235 if (Expr.Extended) { 236 Ctx.Ptr = Start; 237 while (true) { 238 uint8_t Opcode = readOpcode(Ctx); 239 switch (Opcode) { 240 case wasm::WASM_OPCODE_I32_CONST: 241 case wasm::WASM_OPCODE_GLOBAL_GET: 242 case wasm::WASM_OPCODE_REF_NULL: 243 case wasm::WASM_OPCODE_REF_FUNC: 244 case wasm::WASM_OPCODE_I64_CONST: 245 readULEB128(Ctx); 246 break; 247 case wasm::WASM_OPCODE_F32_CONST: 248 readFloat32(Ctx); 249 break; 250 case wasm::WASM_OPCODE_F64_CONST: 251 readFloat64(Ctx); 252 break; 253 case wasm::WASM_OPCODE_I32_ADD: 254 case wasm::WASM_OPCODE_I32_SUB: 255 case wasm::WASM_OPCODE_I32_MUL: 256 case wasm::WASM_OPCODE_I64_ADD: 257 case wasm::WASM_OPCODE_I64_SUB: 258 case wasm::WASM_OPCODE_I64_MUL: 259 break; 260 case wasm::WASM_OPCODE_GC_PREFIX: 261 break; 262 // The GC opcodes are in a separate (prefixed space). This flat switch 263 // structure works as long as there is no overlap between the GC and 264 // general opcodes used in init exprs. 265 case wasm::WASM_OPCODE_STRUCT_NEW: 266 case wasm::WASM_OPCODE_STRUCT_NEW_DEFAULT: 267 case wasm::WASM_OPCODE_ARRAY_NEW: 268 case wasm::WASM_OPCODE_ARRAY_NEW_DEFAULT: 269 readULEB128(Ctx); // heap type index 270 break; 271 case wasm::WASM_OPCODE_ARRAY_NEW_FIXED: 272 readULEB128(Ctx); // heap type index 273 readULEB128(Ctx); // array size 274 break; 275 case wasm::WASM_OPCODE_REF_I31: 276 break; 277 case wasm::WASM_OPCODE_END: 278 Expr.Body = ArrayRef<uint8_t>(Start, Ctx.Ptr - Start); 279 return Error::success(); 280 default: 281 return make_error<GenericBinaryError>( 282 Twine("invalid opcode in init_expr: ") + Twine(unsigned(Opcode)), 283 object_error::parse_failed); 284 } 285 } 286 } 287 288 return Error::success(); 289 } 290 291 static wasm::WasmLimits readLimits(WasmObjectFile::ReadContext &Ctx) { 292 wasm::WasmLimits Result; 293 Result.Flags = readVaruint32(Ctx); 294 Result.Minimum = readVaruint64(Ctx); 295 if (Result.Flags & wasm::WASM_LIMITS_FLAG_HAS_MAX) 296 Result.Maximum = readVaruint64(Ctx); 297 return Result; 298 } 299 300 static wasm::WasmTableType readTableType(WasmObjectFile::ReadContext &Ctx) { 301 wasm::WasmTableType TableType; 302 auto ElemType = parseValType(Ctx, readVaruint32(Ctx)); 303 TableType.ElemType = ElemType; 304 TableType.Limits = readLimits(Ctx); 305 return TableType; 306 } 307 308 static Error readSection(WasmSection &Section, WasmObjectFile::ReadContext &Ctx, 309 WasmSectionOrderChecker &Checker) { 310 Section.Type = readUint8(Ctx); 311 LLVM_DEBUG(dbgs() << "readSection type=" << Section.Type << "\n"); 312 // When reading the section's size, store the size of the LEB used to encode 313 // it. This allows objcopy/strip to reproduce the binary identically. 314 const uint8_t *PreSizePtr = Ctx.Ptr; 315 uint32_t Size = readVaruint32(Ctx); 316 Section.HeaderSecSizeEncodingLen = Ctx.Ptr - PreSizePtr; 317 Section.Offset = Ctx.Ptr - Ctx.Start; 318 if (Size == 0) 319 return make_error<StringError>("zero length section", 320 object_error::parse_failed); 321 if (Ctx.Ptr + Size > Ctx.End) 322 return make_error<StringError>("section too large", 323 object_error::parse_failed); 324 if (Section.Type == wasm::WASM_SEC_CUSTOM) { 325 WasmObjectFile::ReadContext SectionCtx; 326 SectionCtx.Start = Ctx.Ptr; 327 SectionCtx.Ptr = Ctx.Ptr; 328 SectionCtx.End = Ctx.Ptr + Size; 329 330 Section.Name = readString(SectionCtx); 331 332 uint32_t SectionNameSize = SectionCtx.Ptr - SectionCtx.Start; 333 Ctx.Ptr += SectionNameSize; 334 Size -= SectionNameSize; 335 } 336 337 if (!Checker.isValidSectionOrder(Section.Type, Section.Name)) { 338 return make_error<StringError>("out of order section type: " + 339 llvm::to_string(Section.Type), 340 object_error::parse_failed); 341 } 342 343 Section.Content = ArrayRef<uint8_t>(Ctx.Ptr, Size); 344 Ctx.Ptr += Size; 345 return Error::success(); 346 } 347 348 WasmObjectFile::WasmObjectFile(MemoryBufferRef Buffer, Error &Err) 349 : ObjectFile(Binary::ID_Wasm, Buffer) { 350 ErrorAsOutParameter ErrAsOutParam(&Err); 351 Header.Magic = getData().substr(0, 4); 352 if (Header.Magic != StringRef("\0asm", 4)) { 353 Err = make_error<StringError>("invalid magic number", 354 object_error::parse_failed); 355 return; 356 } 357 358 ReadContext Ctx; 359 Ctx.Start = getData().bytes_begin(); 360 Ctx.Ptr = Ctx.Start + 4; 361 Ctx.End = Ctx.Start + getData().size(); 362 363 if (Ctx.Ptr + 4 > Ctx.End) { 364 Err = make_error<StringError>("missing version number", 365 object_error::parse_failed); 366 return; 367 } 368 369 Header.Version = readUint32(Ctx); 370 if (Header.Version != wasm::WasmVersion) { 371 Err = make_error<StringError>("invalid version number: " + 372 Twine(Header.Version), 373 object_error::parse_failed); 374 return; 375 } 376 377 WasmSectionOrderChecker Checker; 378 while (Ctx.Ptr < Ctx.End) { 379 WasmSection Sec; 380 if ((Err = readSection(Sec, Ctx, Checker))) 381 return; 382 if ((Err = parseSection(Sec))) 383 return; 384 385 Sections.push_back(Sec); 386 } 387 } 388 389 Error WasmObjectFile::parseSection(WasmSection &Sec) { 390 ReadContext Ctx; 391 Ctx.Start = Sec.Content.data(); 392 Ctx.End = Ctx.Start + Sec.Content.size(); 393 Ctx.Ptr = Ctx.Start; 394 switch (Sec.Type) { 395 case wasm::WASM_SEC_CUSTOM: 396 return parseCustomSection(Sec, Ctx); 397 case wasm::WASM_SEC_TYPE: 398 return parseTypeSection(Ctx); 399 case wasm::WASM_SEC_IMPORT: 400 return parseImportSection(Ctx); 401 case wasm::WASM_SEC_FUNCTION: 402 return parseFunctionSection(Ctx); 403 case wasm::WASM_SEC_TABLE: 404 return parseTableSection(Ctx); 405 case wasm::WASM_SEC_MEMORY: 406 return parseMemorySection(Ctx); 407 case wasm::WASM_SEC_TAG: 408 return parseTagSection(Ctx); 409 case wasm::WASM_SEC_GLOBAL: 410 return parseGlobalSection(Ctx); 411 case wasm::WASM_SEC_EXPORT: 412 return parseExportSection(Ctx); 413 case wasm::WASM_SEC_START: 414 return parseStartSection(Ctx); 415 case wasm::WASM_SEC_ELEM: 416 return parseElemSection(Ctx); 417 case wasm::WASM_SEC_CODE: 418 return parseCodeSection(Ctx); 419 case wasm::WASM_SEC_DATA: 420 return parseDataSection(Ctx); 421 case wasm::WASM_SEC_DATACOUNT: 422 return parseDataCountSection(Ctx); 423 default: 424 return make_error<GenericBinaryError>( 425 "invalid section type: " + Twine(Sec.Type), object_error::parse_failed); 426 } 427 } 428 429 Error WasmObjectFile::parseDylinkSection(ReadContext &Ctx) { 430 // Legacy "dylink" section support. 431 // See parseDylink0Section for the current "dylink.0" section parsing. 432 HasDylinkSection = true; 433 DylinkInfo.MemorySize = readVaruint32(Ctx); 434 DylinkInfo.MemoryAlignment = readVaruint32(Ctx); 435 DylinkInfo.TableSize = readVaruint32(Ctx); 436 DylinkInfo.TableAlignment = readVaruint32(Ctx); 437 uint32_t Count = readVaruint32(Ctx); 438 while (Count--) { 439 DylinkInfo.Needed.push_back(readString(Ctx)); 440 } 441 442 if (Ctx.Ptr != Ctx.End) 443 return make_error<GenericBinaryError>("dylink section ended prematurely", 444 object_error::parse_failed); 445 return Error::success(); 446 } 447 448 Error WasmObjectFile::parseDylink0Section(ReadContext &Ctx) { 449 // See 450 // https://github.com/WebAssembly/tool-conventions/blob/main/DynamicLinking.md 451 HasDylinkSection = true; 452 453 const uint8_t *OrigEnd = Ctx.End; 454 while (Ctx.Ptr < OrigEnd) { 455 Ctx.End = OrigEnd; 456 uint8_t Type = readUint8(Ctx); 457 uint32_t Size = readVaruint32(Ctx); 458 LLVM_DEBUG(dbgs() << "readSubsection type=" << int(Type) << " size=" << Size 459 << "\n"); 460 Ctx.End = Ctx.Ptr + Size; 461 uint32_t Count; 462 switch (Type) { 463 case wasm::WASM_DYLINK_MEM_INFO: 464 DylinkInfo.MemorySize = readVaruint32(Ctx); 465 DylinkInfo.MemoryAlignment = readVaruint32(Ctx); 466 DylinkInfo.TableSize = readVaruint32(Ctx); 467 DylinkInfo.TableAlignment = readVaruint32(Ctx); 468 break; 469 case wasm::WASM_DYLINK_NEEDED: 470 Count = readVaruint32(Ctx); 471 while (Count--) { 472 DylinkInfo.Needed.push_back(readString(Ctx)); 473 } 474 break; 475 case wasm::WASM_DYLINK_EXPORT_INFO: { 476 uint32_t Count = readVaruint32(Ctx); 477 while (Count--) { 478 DylinkInfo.ExportInfo.push_back({readString(Ctx), readVaruint32(Ctx)}); 479 } 480 break; 481 } 482 case wasm::WASM_DYLINK_IMPORT_INFO: { 483 uint32_t Count = readVaruint32(Ctx); 484 while (Count--) { 485 DylinkInfo.ImportInfo.push_back( 486 {readString(Ctx), readString(Ctx), readVaruint32(Ctx)}); 487 } 488 break; 489 } 490 default: 491 LLVM_DEBUG(dbgs() << "unknown dylink.0 sub-section: " << Type << "\n"); 492 Ctx.Ptr += Size; 493 break; 494 } 495 if (Ctx.Ptr != Ctx.End) { 496 return make_error<GenericBinaryError>( 497 "dylink.0 sub-section ended prematurely", object_error::parse_failed); 498 } 499 } 500 501 if (Ctx.Ptr != Ctx.End) 502 return make_error<GenericBinaryError>("dylink.0 section ended prematurely", 503 object_error::parse_failed); 504 return Error::success(); 505 } 506 507 Error WasmObjectFile::parseNameSection(ReadContext &Ctx) { 508 llvm::DenseSet<uint64_t> SeenFunctions; 509 llvm::DenseSet<uint64_t> SeenGlobals; 510 llvm::DenseSet<uint64_t> SeenSegments; 511 512 // If we have linking section (symbol table) or if we are parsing a DSO 513 // then we don't use the name section for symbol information. 514 bool PopulateSymbolTable = !HasLinkingSection && !HasDylinkSection; 515 516 // If we are using the name section for symbol information then it will 517 // supersede any symbols created by the export section. 518 if (PopulateSymbolTable) 519 Symbols.clear(); 520 521 while (Ctx.Ptr < Ctx.End) { 522 uint8_t Type = readUint8(Ctx); 523 uint32_t Size = readVaruint32(Ctx); 524 const uint8_t *SubSectionEnd = Ctx.Ptr + Size; 525 526 switch (Type) { 527 case wasm::WASM_NAMES_FUNCTION: 528 case wasm::WASM_NAMES_GLOBAL: 529 case wasm::WASM_NAMES_DATA_SEGMENT: { 530 uint32_t Count = readVaruint32(Ctx); 531 while (Count--) { 532 uint32_t Index = readVaruint32(Ctx); 533 StringRef Name = readString(Ctx); 534 wasm::NameType nameType = wasm::NameType::FUNCTION; 535 wasm::WasmSymbolInfo Info{Name, 536 /*Kind */ wasm::WASM_SYMBOL_TYPE_FUNCTION, 537 /* Flags */ 0, 538 /* ImportModule */ std::nullopt, 539 /* ImportName */ std::nullopt, 540 /* ExportName */ std::nullopt, 541 {/* ElementIndex */ Index}}; 542 const wasm::WasmSignature *Signature = nullptr; 543 const wasm::WasmGlobalType *GlobalType = nullptr; 544 const wasm::WasmTableType *TableType = nullptr; 545 if (Type == wasm::WASM_NAMES_FUNCTION) { 546 if (!SeenFunctions.insert(Index).second) 547 return make_error<GenericBinaryError>( 548 "function named more than once", object_error::parse_failed); 549 if (!isValidFunctionIndex(Index) || Name.empty()) 550 return make_error<GenericBinaryError>("invalid function name entry", 551 object_error::parse_failed); 552 553 if (isDefinedFunctionIndex(Index)) { 554 wasm::WasmFunction &F = getDefinedFunction(Index); 555 F.DebugName = Name; 556 Signature = &Signatures[F.SigIndex]; 557 if (F.ExportName) { 558 Info.ExportName = F.ExportName; 559 Info.Flags |= wasm::WASM_SYMBOL_BINDING_GLOBAL; 560 } else { 561 Info.Flags |= wasm::WASM_SYMBOL_BINDING_LOCAL; 562 } 563 } else { 564 Info.Flags |= wasm::WASM_SYMBOL_UNDEFINED; 565 } 566 } else if (Type == wasm::WASM_NAMES_GLOBAL) { 567 if (!SeenGlobals.insert(Index).second) 568 return make_error<GenericBinaryError>("global named more than once", 569 object_error::parse_failed); 570 if (!isValidGlobalIndex(Index) || Name.empty()) 571 return make_error<GenericBinaryError>("invalid global name entry", 572 object_error::parse_failed); 573 nameType = wasm::NameType::GLOBAL; 574 Info.Kind = wasm::WASM_SYMBOL_TYPE_GLOBAL; 575 if (isDefinedGlobalIndex(Index)) { 576 GlobalType = &getDefinedGlobal(Index).Type; 577 } else { 578 Info.Flags |= wasm::WASM_SYMBOL_UNDEFINED; 579 } 580 } else { 581 if (!SeenSegments.insert(Index).second) 582 return make_error<GenericBinaryError>( 583 "segment named more than once", object_error::parse_failed); 584 if (Index > DataSegments.size()) 585 return make_error<GenericBinaryError>("invalid data segment name entry", 586 object_error::parse_failed); 587 nameType = wasm::NameType::DATA_SEGMENT; 588 Info.Kind = wasm::WASM_SYMBOL_TYPE_DATA; 589 Info.Flags |= wasm::WASM_SYMBOL_BINDING_LOCAL; 590 assert(Index < DataSegments.size()); 591 Info.DataRef = wasm::WasmDataReference{ 592 Index, 0, DataSegments[Index].Data.Content.size()}; 593 } 594 DebugNames.push_back(wasm::WasmDebugName{nameType, Index, Name}); 595 if (PopulateSymbolTable) 596 Symbols.emplace_back(Info, GlobalType, TableType, Signature); 597 } 598 break; 599 } 600 // Ignore local names for now 601 case wasm::WASM_NAMES_LOCAL: 602 default: 603 Ctx.Ptr += Size; 604 break; 605 } 606 if (Ctx.Ptr != SubSectionEnd) 607 return make_error<GenericBinaryError>( 608 "name sub-section ended prematurely", object_error::parse_failed); 609 } 610 611 if (Ctx.Ptr != Ctx.End) 612 return make_error<GenericBinaryError>("name section ended prematurely", 613 object_error::parse_failed); 614 return Error::success(); 615 } 616 617 Error WasmObjectFile::parseLinkingSection(ReadContext &Ctx) { 618 HasLinkingSection = true; 619 620 LinkingData.Version = readVaruint32(Ctx); 621 if (LinkingData.Version != wasm::WasmMetadataVersion) { 622 return make_error<GenericBinaryError>( 623 "unexpected metadata version: " + Twine(LinkingData.Version) + 624 " (Expected: " + Twine(wasm::WasmMetadataVersion) + ")", 625 object_error::parse_failed); 626 } 627 628 const uint8_t *OrigEnd = Ctx.End; 629 while (Ctx.Ptr < OrigEnd) { 630 Ctx.End = OrigEnd; 631 uint8_t Type = readUint8(Ctx); 632 uint32_t Size = readVaruint32(Ctx); 633 LLVM_DEBUG(dbgs() << "readSubsection type=" << int(Type) << " size=" << Size 634 << "\n"); 635 Ctx.End = Ctx.Ptr + Size; 636 switch (Type) { 637 case wasm::WASM_SYMBOL_TABLE: 638 if (Error Err = parseLinkingSectionSymtab(Ctx)) 639 return Err; 640 break; 641 case wasm::WASM_SEGMENT_INFO: { 642 uint32_t Count = readVaruint32(Ctx); 643 if (Count > DataSegments.size()) 644 return make_error<GenericBinaryError>("too many segment names", 645 object_error::parse_failed); 646 for (uint32_t I = 0; I < Count; I++) { 647 DataSegments[I].Data.Name = readString(Ctx); 648 DataSegments[I].Data.Alignment = readVaruint32(Ctx); 649 DataSegments[I].Data.LinkingFlags = readVaruint32(Ctx); 650 } 651 break; 652 } 653 case wasm::WASM_INIT_FUNCS: { 654 uint32_t Count = readVaruint32(Ctx); 655 LinkingData.InitFunctions.reserve(Count); 656 for (uint32_t I = 0; I < Count; I++) { 657 wasm::WasmInitFunc Init; 658 Init.Priority = readVaruint32(Ctx); 659 Init.Symbol = readVaruint32(Ctx); 660 if (!isValidFunctionSymbol(Init.Symbol)) 661 return make_error<GenericBinaryError>("invalid function symbol: " + 662 Twine(Init.Symbol), 663 object_error::parse_failed); 664 LinkingData.InitFunctions.emplace_back(Init); 665 } 666 break; 667 } 668 case wasm::WASM_COMDAT_INFO: 669 if (Error Err = parseLinkingSectionComdat(Ctx)) 670 return Err; 671 break; 672 default: 673 Ctx.Ptr += Size; 674 break; 675 } 676 if (Ctx.Ptr != Ctx.End) 677 return make_error<GenericBinaryError>( 678 "linking sub-section ended prematurely", object_error::parse_failed); 679 } 680 if (Ctx.Ptr != OrigEnd) 681 return make_error<GenericBinaryError>("linking section ended prematurely", 682 object_error::parse_failed); 683 return Error::success(); 684 } 685 686 Error WasmObjectFile::parseLinkingSectionSymtab(ReadContext &Ctx) { 687 uint32_t Count = readVaruint32(Ctx); 688 // Clear out any symbol information that was derived from the exports 689 // section. 690 Symbols.clear(); 691 Symbols.reserve(Count); 692 StringSet<> SymbolNames; 693 694 std::vector<wasm::WasmImport *> ImportedGlobals; 695 std::vector<wasm::WasmImport *> ImportedFunctions; 696 std::vector<wasm::WasmImport *> ImportedTags; 697 std::vector<wasm::WasmImport *> ImportedTables; 698 ImportedGlobals.reserve(Imports.size()); 699 ImportedFunctions.reserve(Imports.size()); 700 ImportedTags.reserve(Imports.size()); 701 ImportedTables.reserve(Imports.size()); 702 for (auto &I : Imports) { 703 if (I.Kind == wasm::WASM_EXTERNAL_FUNCTION) 704 ImportedFunctions.emplace_back(&I); 705 else if (I.Kind == wasm::WASM_EXTERNAL_GLOBAL) 706 ImportedGlobals.emplace_back(&I); 707 else if (I.Kind == wasm::WASM_EXTERNAL_TAG) 708 ImportedTags.emplace_back(&I); 709 else if (I.Kind == wasm::WASM_EXTERNAL_TABLE) 710 ImportedTables.emplace_back(&I); 711 } 712 713 while (Count--) { 714 wasm::WasmSymbolInfo Info; 715 const wasm::WasmSignature *Signature = nullptr; 716 const wasm::WasmGlobalType *GlobalType = nullptr; 717 const wasm::WasmTableType *TableType = nullptr; 718 719 Info.Kind = readUint8(Ctx); 720 Info.Flags = readVaruint32(Ctx); 721 bool IsDefined = (Info.Flags & wasm::WASM_SYMBOL_UNDEFINED) == 0; 722 723 switch (Info.Kind) { 724 case wasm::WASM_SYMBOL_TYPE_FUNCTION: 725 Info.ElementIndex = readVaruint32(Ctx); 726 if (!isValidFunctionIndex(Info.ElementIndex) || 727 IsDefined != isDefinedFunctionIndex(Info.ElementIndex)) 728 return make_error<GenericBinaryError>("invalid function symbol index", 729 object_error::parse_failed); 730 if (IsDefined) { 731 Info.Name = readString(Ctx); 732 unsigned FuncIndex = Info.ElementIndex - NumImportedFunctions; 733 wasm::WasmFunction &Function = Functions[FuncIndex]; 734 Signature = &Signatures[Function.SigIndex]; 735 if (Function.SymbolName.empty()) 736 Function.SymbolName = Info.Name; 737 } else { 738 wasm::WasmImport &Import = *ImportedFunctions[Info.ElementIndex]; 739 if ((Info.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) { 740 Info.Name = readString(Ctx); 741 Info.ImportName = Import.Field; 742 } else { 743 Info.Name = Import.Field; 744 } 745 Signature = &Signatures[Import.SigIndex]; 746 Info.ImportModule = Import.Module; 747 } 748 break; 749 750 case wasm::WASM_SYMBOL_TYPE_GLOBAL: 751 Info.ElementIndex = readVaruint32(Ctx); 752 if (!isValidGlobalIndex(Info.ElementIndex) || 753 IsDefined != isDefinedGlobalIndex(Info.ElementIndex)) 754 return make_error<GenericBinaryError>("invalid global symbol index", 755 object_error::parse_failed); 756 if (!IsDefined && (Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) == 757 wasm::WASM_SYMBOL_BINDING_WEAK) 758 return make_error<GenericBinaryError>("undefined weak global symbol", 759 object_error::parse_failed); 760 if (IsDefined) { 761 Info.Name = readString(Ctx); 762 unsigned GlobalIndex = Info.ElementIndex - NumImportedGlobals; 763 wasm::WasmGlobal &Global = Globals[GlobalIndex]; 764 GlobalType = &Global.Type; 765 if (Global.SymbolName.empty()) 766 Global.SymbolName = Info.Name; 767 } else { 768 wasm::WasmImport &Import = *ImportedGlobals[Info.ElementIndex]; 769 if ((Info.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) { 770 Info.Name = readString(Ctx); 771 Info.ImportName = Import.Field; 772 } else { 773 Info.Name = Import.Field; 774 } 775 GlobalType = &Import.Global; 776 Info.ImportModule = Import.Module; 777 } 778 break; 779 780 case wasm::WASM_SYMBOL_TYPE_TABLE: 781 Info.ElementIndex = readVaruint32(Ctx); 782 if (!isValidTableNumber(Info.ElementIndex) || 783 IsDefined != isDefinedTableNumber(Info.ElementIndex)) 784 return make_error<GenericBinaryError>("invalid table symbol index", 785 object_error::parse_failed); 786 if (!IsDefined && (Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) == 787 wasm::WASM_SYMBOL_BINDING_WEAK) 788 return make_error<GenericBinaryError>("undefined weak table symbol", 789 object_error::parse_failed); 790 if (IsDefined) { 791 Info.Name = readString(Ctx); 792 unsigned TableNumber = Info.ElementIndex - NumImportedTables; 793 wasm::WasmTable &Table = Tables[TableNumber]; 794 TableType = &Table.Type; 795 if (Table.SymbolName.empty()) 796 Table.SymbolName = Info.Name; 797 } else { 798 wasm::WasmImport &Import = *ImportedTables[Info.ElementIndex]; 799 if ((Info.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) { 800 Info.Name = readString(Ctx); 801 Info.ImportName = Import.Field; 802 } else { 803 Info.Name = Import.Field; 804 } 805 TableType = &Import.Table; 806 Info.ImportModule = Import.Module; 807 } 808 break; 809 810 case wasm::WASM_SYMBOL_TYPE_DATA: 811 Info.Name = readString(Ctx); 812 if (IsDefined) { 813 auto Index = readVaruint32(Ctx); 814 auto Offset = readVaruint64(Ctx); 815 auto Size = readVaruint64(Ctx); 816 if (!(Info.Flags & wasm::WASM_SYMBOL_ABSOLUTE)) { 817 if (static_cast<size_t>(Index) >= DataSegments.size()) 818 return make_error<GenericBinaryError>( 819 "invalid data segment index: " + Twine(Index), 820 object_error::parse_failed); 821 size_t SegmentSize = DataSegments[Index].Data.Content.size(); 822 if (Offset > SegmentSize) 823 return make_error<GenericBinaryError>( 824 "invalid data symbol offset: `" + Info.Name + 825 "` (offset: " + Twine(Offset) + 826 " segment size: " + Twine(SegmentSize) + ")", 827 object_error::parse_failed); 828 } 829 Info.DataRef = wasm::WasmDataReference{Index, Offset, Size}; 830 } 831 break; 832 833 case wasm::WASM_SYMBOL_TYPE_SECTION: { 834 if ((Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) != 835 wasm::WASM_SYMBOL_BINDING_LOCAL) 836 return make_error<GenericBinaryError>( 837 "section symbols must have local binding", 838 object_error::parse_failed); 839 Info.ElementIndex = readVaruint32(Ctx); 840 // Use somewhat unique section name as symbol name. 841 StringRef SectionName = Sections[Info.ElementIndex].Name; 842 Info.Name = SectionName; 843 break; 844 } 845 846 case wasm::WASM_SYMBOL_TYPE_TAG: { 847 Info.ElementIndex = readVaruint32(Ctx); 848 if (!isValidTagIndex(Info.ElementIndex) || 849 IsDefined != isDefinedTagIndex(Info.ElementIndex)) 850 return make_error<GenericBinaryError>("invalid tag symbol index", 851 object_error::parse_failed); 852 if (!IsDefined && (Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) == 853 wasm::WASM_SYMBOL_BINDING_WEAK) 854 return make_error<GenericBinaryError>("undefined weak global symbol", 855 object_error::parse_failed); 856 if (IsDefined) { 857 Info.Name = readString(Ctx); 858 unsigned TagIndex = Info.ElementIndex - NumImportedTags; 859 wasm::WasmTag &Tag = Tags[TagIndex]; 860 Signature = &Signatures[Tag.SigIndex]; 861 if (Tag.SymbolName.empty()) 862 Tag.SymbolName = Info.Name; 863 864 } else { 865 wasm::WasmImport &Import = *ImportedTags[Info.ElementIndex]; 866 if ((Info.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) { 867 Info.Name = readString(Ctx); 868 Info.ImportName = Import.Field; 869 } else { 870 Info.Name = Import.Field; 871 } 872 Signature = &Signatures[Import.SigIndex]; 873 Info.ImportModule = Import.Module; 874 } 875 break; 876 } 877 878 default: 879 return make_error<GenericBinaryError>("invalid symbol type: " + 880 Twine(unsigned(Info.Kind)), 881 object_error::parse_failed); 882 } 883 884 if ((Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) != 885 wasm::WASM_SYMBOL_BINDING_LOCAL && 886 !SymbolNames.insert(Info.Name).second) 887 return make_error<GenericBinaryError>("duplicate symbol name " + 888 Twine(Info.Name), 889 object_error::parse_failed); 890 Symbols.emplace_back(Info, GlobalType, TableType, Signature); 891 LLVM_DEBUG(dbgs() << "Adding symbol: " << Symbols.back() << "\n"); 892 } 893 894 return Error::success(); 895 } 896 897 Error WasmObjectFile::parseLinkingSectionComdat(ReadContext &Ctx) { 898 uint32_t ComdatCount = readVaruint32(Ctx); 899 StringSet<> ComdatSet; 900 for (unsigned ComdatIndex = 0; ComdatIndex < ComdatCount; ++ComdatIndex) { 901 StringRef Name = readString(Ctx); 902 if (Name.empty() || !ComdatSet.insert(Name).second) 903 return make_error<GenericBinaryError>("bad/duplicate COMDAT name " + 904 Twine(Name), 905 object_error::parse_failed); 906 LinkingData.Comdats.emplace_back(Name); 907 uint32_t Flags = readVaruint32(Ctx); 908 if (Flags != 0) 909 return make_error<GenericBinaryError>("unsupported COMDAT flags", 910 object_error::parse_failed); 911 912 uint32_t EntryCount = readVaruint32(Ctx); 913 while (EntryCount--) { 914 unsigned Kind = readVaruint32(Ctx); 915 unsigned Index = readVaruint32(Ctx); 916 switch (Kind) { 917 default: 918 return make_error<GenericBinaryError>("invalid COMDAT entry type", 919 object_error::parse_failed); 920 case wasm::WASM_COMDAT_DATA: 921 if (Index >= DataSegments.size()) 922 return make_error<GenericBinaryError>( 923 "COMDAT data index out of range", object_error::parse_failed); 924 if (DataSegments[Index].Data.Comdat != UINT32_MAX) 925 return make_error<GenericBinaryError>("data segment in two COMDATs", 926 object_error::parse_failed); 927 DataSegments[Index].Data.Comdat = ComdatIndex; 928 break; 929 case wasm::WASM_COMDAT_FUNCTION: 930 if (!isDefinedFunctionIndex(Index)) 931 return make_error<GenericBinaryError>( 932 "COMDAT function index out of range", object_error::parse_failed); 933 if (getDefinedFunction(Index).Comdat != UINT32_MAX) 934 return make_error<GenericBinaryError>("function in two COMDATs", 935 object_error::parse_failed); 936 getDefinedFunction(Index).Comdat = ComdatIndex; 937 break; 938 case wasm::WASM_COMDAT_SECTION: 939 if (Index >= Sections.size()) 940 return make_error<GenericBinaryError>( 941 "COMDAT section index out of range", object_error::parse_failed); 942 if (Sections[Index].Type != wasm::WASM_SEC_CUSTOM) 943 return make_error<GenericBinaryError>( 944 "non-custom section in a COMDAT", object_error::parse_failed); 945 Sections[Index].Comdat = ComdatIndex; 946 break; 947 } 948 } 949 } 950 return Error::success(); 951 } 952 953 Error WasmObjectFile::parseProducersSection(ReadContext &Ctx) { 954 llvm::SmallSet<StringRef, 3> FieldsSeen; 955 uint32_t Fields = readVaruint32(Ctx); 956 for (size_t I = 0; I < Fields; ++I) { 957 StringRef FieldName = readString(Ctx); 958 if (!FieldsSeen.insert(FieldName).second) 959 return make_error<GenericBinaryError>( 960 "producers section does not have unique fields", 961 object_error::parse_failed); 962 std::vector<std::pair<std::string, std::string>> *ProducerVec = nullptr; 963 if (FieldName == "language") { 964 ProducerVec = &ProducerInfo.Languages; 965 } else if (FieldName == "processed-by") { 966 ProducerVec = &ProducerInfo.Tools; 967 } else if (FieldName == "sdk") { 968 ProducerVec = &ProducerInfo.SDKs; 969 } else { 970 return make_error<GenericBinaryError>( 971 "producers section field is not named one of language, processed-by, " 972 "or sdk", 973 object_error::parse_failed); 974 } 975 uint32_t ValueCount = readVaruint32(Ctx); 976 llvm::SmallSet<StringRef, 8> ProducersSeen; 977 for (size_t J = 0; J < ValueCount; ++J) { 978 StringRef Name = readString(Ctx); 979 StringRef Version = readString(Ctx); 980 if (!ProducersSeen.insert(Name).second) { 981 return make_error<GenericBinaryError>( 982 "producers section contains repeated producer", 983 object_error::parse_failed); 984 } 985 ProducerVec->emplace_back(std::string(Name), std::string(Version)); 986 } 987 } 988 if (Ctx.Ptr != Ctx.End) 989 return make_error<GenericBinaryError>("producers section ended prematurely", 990 object_error::parse_failed); 991 return Error::success(); 992 } 993 994 Error WasmObjectFile::parseTargetFeaturesSection(ReadContext &Ctx) { 995 llvm::SmallSet<std::string, 8> FeaturesSeen; 996 uint32_t FeatureCount = readVaruint32(Ctx); 997 for (size_t I = 0; I < FeatureCount; ++I) { 998 wasm::WasmFeatureEntry Feature; 999 Feature.Prefix = readUint8(Ctx); 1000 switch (Feature.Prefix) { 1001 case wasm::WASM_FEATURE_PREFIX_USED: 1002 case wasm::WASM_FEATURE_PREFIX_DISALLOWED: 1003 break; 1004 default: 1005 return make_error<GenericBinaryError>("unknown feature policy prefix", 1006 object_error::parse_failed); 1007 } 1008 Feature.Name = std::string(readString(Ctx)); 1009 if (!FeaturesSeen.insert(Feature.Name).second) 1010 return make_error<GenericBinaryError>( 1011 "target features section contains repeated feature \"" + 1012 Feature.Name + "\"", 1013 object_error::parse_failed); 1014 TargetFeatures.push_back(Feature); 1015 } 1016 if (Ctx.Ptr != Ctx.End) 1017 return make_error<GenericBinaryError>( 1018 "target features section ended prematurely", 1019 object_error::parse_failed); 1020 return Error::success(); 1021 } 1022 1023 Error WasmObjectFile::parseRelocSection(StringRef Name, ReadContext &Ctx) { 1024 uint32_t SectionIndex = readVaruint32(Ctx); 1025 if (SectionIndex >= Sections.size()) 1026 return make_error<GenericBinaryError>("invalid section index", 1027 object_error::parse_failed); 1028 WasmSection &Section = Sections[SectionIndex]; 1029 uint32_t RelocCount = readVaruint32(Ctx); 1030 uint32_t EndOffset = Section.Content.size(); 1031 uint32_t PreviousOffset = 0; 1032 while (RelocCount--) { 1033 wasm::WasmRelocation Reloc = {}; 1034 uint32_t type = readVaruint32(Ctx); 1035 Reloc.Type = type; 1036 Reloc.Offset = readVaruint32(Ctx); 1037 if (Reloc.Offset < PreviousOffset) 1038 return make_error<GenericBinaryError>("relocations not in offset order", 1039 object_error::parse_failed); 1040 1041 auto badReloc = [&](StringRef msg) { 1042 return make_error<GenericBinaryError>( 1043 msg + ": " + Twine(Symbols[Reloc.Index].Info.Name), 1044 object_error::parse_failed); 1045 }; 1046 1047 PreviousOffset = Reloc.Offset; 1048 Reloc.Index = readVaruint32(Ctx); 1049 switch (type) { 1050 case wasm::R_WASM_FUNCTION_INDEX_LEB: 1051 case wasm::R_WASM_FUNCTION_INDEX_I32: 1052 case wasm::R_WASM_TABLE_INDEX_SLEB: 1053 case wasm::R_WASM_TABLE_INDEX_SLEB64: 1054 case wasm::R_WASM_TABLE_INDEX_I32: 1055 case wasm::R_WASM_TABLE_INDEX_I64: 1056 case wasm::R_WASM_TABLE_INDEX_REL_SLEB: 1057 case wasm::R_WASM_TABLE_INDEX_REL_SLEB64: 1058 if (!isValidFunctionSymbol(Reloc.Index)) 1059 return badReloc("invalid function relocation"); 1060 break; 1061 case wasm::R_WASM_TABLE_NUMBER_LEB: 1062 if (!isValidTableSymbol(Reloc.Index)) 1063 return badReloc("invalid table relocation"); 1064 break; 1065 case wasm::R_WASM_TYPE_INDEX_LEB: 1066 if (Reloc.Index >= Signatures.size()) 1067 return badReloc("invalid relocation type index"); 1068 break; 1069 case wasm::R_WASM_GLOBAL_INDEX_LEB: 1070 // R_WASM_GLOBAL_INDEX_LEB are can be used against function and data 1071 // symbols to refer to their GOT entries. 1072 if (!isValidGlobalSymbol(Reloc.Index) && 1073 !isValidDataSymbol(Reloc.Index) && 1074 !isValidFunctionSymbol(Reloc.Index)) 1075 return badReloc("invalid global relocation"); 1076 break; 1077 case wasm::R_WASM_GLOBAL_INDEX_I32: 1078 if (!isValidGlobalSymbol(Reloc.Index)) 1079 return badReloc("invalid global relocation"); 1080 break; 1081 case wasm::R_WASM_TAG_INDEX_LEB: 1082 if (!isValidTagSymbol(Reloc.Index)) 1083 return badReloc("invalid tag relocation"); 1084 break; 1085 case wasm::R_WASM_MEMORY_ADDR_LEB: 1086 case wasm::R_WASM_MEMORY_ADDR_SLEB: 1087 case wasm::R_WASM_MEMORY_ADDR_I32: 1088 case wasm::R_WASM_MEMORY_ADDR_REL_SLEB: 1089 case wasm::R_WASM_MEMORY_ADDR_TLS_SLEB: 1090 case wasm::R_WASM_MEMORY_ADDR_LOCREL_I32: 1091 if (!isValidDataSymbol(Reloc.Index)) 1092 return badReloc("invalid data relocation"); 1093 Reloc.Addend = readVarint32(Ctx); 1094 break; 1095 case wasm::R_WASM_MEMORY_ADDR_LEB64: 1096 case wasm::R_WASM_MEMORY_ADDR_SLEB64: 1097 case wasm::R_WASM_MEMORY_ADDR_I64: 1098 case wasm::R_WASM_MEMORY_ADDR_REL_SLEB64: 1099 case wasm::R_WASM_MEMORY_ADDR_TLS_SLEB64: 1100 if (!isValidDataSymbol(Reloc.Index)) 1101 return badReloc("invalid data relocation"); 1102 Reloc.Addend = readVarint64(Ctx); 1103 break; 1104 case wasm::R_WASM_FUNCTION_OFFSET_I32: 1105 if (!isValidFunctionSymbol(Reloc.Index)) 1106 return badReloc("invalid function relocation"); 1107 Reloc.Addend = readVarint32(Ctx); 1108 break; 1109 case wasm::R_WASM_FUNCTION_OFFSET_I64: 1110 if (!isValidFunctionSymbol(Reloc.Index)) 1111 return badReloc("invalid function relocation"); 1112 Reloc.Addend = readVarint64(Ctx); 1113 break; 1114 case wasm::R_WASM_SECTION_OFFSET_I32: 1115 if (!isValidSectionSymbol(Reloc.Index)) 1116 return badReloc("invalid section relocation"); 1117 Reloc.Addend = readVarint32(Ctx); 1118 break; 1119 default: 1120 return make_error<GenericBinaryError>("invalid relocation type: " + 1121 Twine(type), 1122 object_error::parse_failed); 1123 } 1124 1125 // Relocations must fit inside the section, and must appear in order. They 1126 // also shouldn't overlap a function/element boundary, but we don't bother 1127 // to check that. 1128 uint64_t Size = 5; 1129 if (Reloc.Type == wasm::R_WASM_MEMORY_ADDR_LEB64 || 1130 Reloc.Type == wasm::R_WASM_MEMORY_ADDR_SLEB64 || 1131 Reloc.Type == wasm::R_WASM_MEMORY_ADDR_REL_SLEB64) 1132 Size = 10; 1133 if (Reloc.Type == wasm::R_WASM_TABLE_INDEX_I32 || 1134 Reloc.Type == wasm::R_WASM_MEMORY_ADDR_I32 || 1135 Reloc.Type == wasm::R_WASM_MEMORY_ADDR_LOCREL_I32 || 1136 Reloc.Type == wasm::R_WASM_SECTION_OFFSET_I32 || 1137 Reloc.Type == wasm::R_WASM_FUNCTION_OFFSET_I32 || 1138 Reloc.Type == wasm::R_WASM_FUNCTION_INDEX_I32 || 1139 Reloc.Type == wasm::R_WASM_GLOBAL_INDEX_I32) 1140 Size = 4; 1141 if (Reloc.Type == wasm::R_WASM_TABLE_INDEX_I64 || 1142 Reloc.Type == wasm::R_WASM_MEMORY_ADDR_I64 || 1143 Reloc.Type == wasm::R_WASM_FUNCTION_OFFSET_I64) 1144 Size = 8; 1145 if (Reloc.Offset + Size > EndOffset) 1146 return make_error<GenericBinaryError>("invalid relocation offset", 1147 object_error::parse_failed); 1148 1149 Section.Relocations.push_back(Reloc); 1150 } 1151 if (Ctx.Ptr != Ctx.End) 1152 return make_error<GenericBinaryError>("reloc section ended prematurely", 1153 object_error::parse_failed); 1154 return Error::success(); 1155 } 1156 1157 Error WasmObjectFile::parseCustomSection(WasmSection &Sec, ReadContext &Ctx) { 1158 if (Sec.Name == "dylink") { 1159 if (Error Err = parseDylinkSection(Ctx)) 1160 return Err; 1161 } else if (Sec.Name == "dylink.0") { 1162 if (Error Err = parseDylink0Section(Ctx)) 1163 return Err; 1164 } else if (Sec.Name == "name") { 1165 if (Error Err = parseNameSection(Ctx)) 1166 return Err; 1167 } else if (Sec.Name == "linking") { 1168 if (Error Err = parseLinkingSection(Ctx)) 1169 return Err; 1170 } else if (Sec.Name == "producers") { 1171 if (Error Err = parseProducersSection(Ctx)) 1172 return Err; 1173 } else if (Sec.Name == "target_features") { 1174 if (Error Err = parseTargetFeaturesSection(Ctx)) 1175 return Err; 1176 } else if (Sec.Name.starts_with("reloc.")) { 1177 if (Error Err = parseRelocSection(Sec.Name, Ctx)) 1178 return Err; 1179 } 1180 return Error::success(); 1181 } 1182 1183 Error WasmObjectFile::parseTypeSection(ReadContext &Ctx) { 1184 auto parseFieldDef = [&]() { 1185 uint32_t TypeCode = readVaruint32((Ctx)); 1186 /* Discard StorageType */ parseValType(Ctx, TypeCode); 1187 /* Discard Mutability */ readVaruint32(Ctx); 1188 }; 1189 1190 uint32_t Count = readVaruint32(Ctx); 1191 Signatures.reserve(Count); 1192 while (Count--) { 1193 wasm::WasmSignature Sig; 1194 uint8_t Form = readUint8(Ctx); 1195 if (Form == wasm::WASM_TYPE_REC) { 1196 // Rec groups expand the type index space (beyond what was declared at 1197 // the top of the section, and also consume one element in that space. 1198 uint32_t RecSize = readVaruint32(Ctx); 1199 if (RecSize == 0) 1200 return make_error<GenericBinaryError>("Rec group size cannot be 0", 1201 object_error::parse_failed); 1202 Signatures.reserve(Signatures.size() + RecSize); 1203 Count += RecSize; 1204 Sig.Kind = wasm::WasmSignature::Placeholder; 1205 Signatures.push_back(std::move(Sig)); 1206 HasUnmodeledTypes = true; 1207 continue; 1208 } 1209 if (Form != wasm::WASM_TYPE_FUNC) { 1210 // Currently LLVM only models function types, and not other composite 1211 // types. Here we parse the type declarations just enough to skip past 1212 // them in the binary. 1213 if (Form == wasm::WASM_TYPE_SUB || Form == wasm::WASM_TYPE_SUB_FINAL) { 1214 uint32_t Supers = readVaruint32(Ctx); 1215 if (Supers > 0) { 1216 if (Supers != 1) 1217 return make_error<GenericBinaryError>( 1218 "Invalid number of supertypes", object_error::parse_failed); 1219 /* Discard SuperIndex */ readVaruint32(Ctx); 1220 } 1221 Form = readVaruint32(Ctx); 1222 } 1223 if (Form == wasm::WASM_TYPE_STRUCT) { 1224 uint32_t FieldCount = readVaruint32(Ctx); 1225 while (FieldCount--) { 1226 parseFieldDef(); 1227 } 1228 } else if (Form == wasm::WASM_TYPE_ARRAY) { 1229 parseFieldDef(); 1230 } else { 1231 return make_error<GenericBinaryError>("bad form", 1232 object_error::parse_failed); 1233 } 1234 Sig.Kind = wasm::WasmSignature::Placeholder; 1235 Signatures.push_back(std::move(Sig)); 1236 HasUnmodeledTypes = true; 1237 continue; 1238 } 1239 1240 uint32_t ParamCount = readVaruint32(Ctx); 1241 Sig.Params.reserve(ParamCount); 1242 while (ParamCount--) { 1243 uint32_t ParamType = readUint8(Ctx); 1244 Sig.Params.push_back(parseValType(Ctx, ParamType)); 1245 } 1246 uint32_t ReturnCount = readVaruint32(Ctx); 1247 while (ReturnCount--) { 1248 uint32_t ReturnType = readUint8(Ctx); 1249 Sig.Returns.push_back(parseValType(Ctx, ReturnType)); 1250 } 1251 1252 Signatures.push_back(std::move(Sig)); 1253 } 1254 if (Ctx.Ptr != Ctx.End) 1255 return make_error<GenericBinaryError>("type section ended prematurely", 1256 object_error::parse_failed); 1257 return Error::success(); 1258 } 1259 1260 Error WasmObjectFile::parseImportSection(ReadContext &Ctx) { 1261 uint32_t Count = readVaruint32(Ctx); 1262 uint32_t NumTypes = Signatures.size(); 1263 Imports.reserve(Count); 1264 for (uint32_t I = 0; I < Count; I++) { 1265 wasm::WasmImport Im; 1266 Im.Module = readString(Ctx); 1267 Im.Field = readString(Ctx); 1268 Im.Kind = readUint8(Ctx); 1269 switch (Im.Kind) { 1270 case wasm::WASM_EXTERNAL_FUNCTION: 1271 NumImportedFunctions++; 1272 Im.SigIndex = readVaruint32(Ctx); 1273 if (Im.SigIndex >= NumTypes) 1274 return make_error<GenericBinaryError>("invalid function type", 1275 object_error::parse_failed); 1276 break; 1277 case wasm::WASM_EXTERNAL_GLOBAL: 1278 NumImportedGlobals++; 1279 Im.Global.Type = readUint8(Ctx); 1280 Im.Global.Mutable = readVaruint1(Ctx); 1281 break; 1282 case wasm::WASM_EXTERNAL_MEMORY: 1283 Im.Memory = readLimits(Ctx); 1284 if (Im.Memory.Flags & wasm::WASM_LIMITS_FLAG_IS_64) 1285 HasMemory64 = true; 1286 break; 1287 case wasm::WASM_EXTERNAL_TABLE: { 1288 Im.Table = readTableType(Ctx); 1289 NumImportedTables++; 1290 auto ElemType = Im.Table.ElemType; 1291 if (ElemType != wasm::ValType::FUNCREF && 1292 ElemType != wasm::ValType::EXTERNREF && 1293 ElemType != wasm::ValType::EXNREF && 1294 ElemType != wasm::ValType::OTHERREF) 1295 return make_error<GenericBinaryError>("invalid table element type", 1296 object_error::parse_failed); 1297 break; 1298 } 1299 case wasm::WASM_EXTERNAL_TAG: 1300 NumImportedTags++; 1301 if (readUint8(Ctx) != 0) // Reserved 'attribute' field 1302 return make_error<GenericBinaryError>("invalid attribute", 1303 object_error::parse_failed); 1304 Im.SigIndex = readVaruint32(Ctx); 1305 if (Im.SigIndex >= NumTypes) 1306 return make_error<GenericBinaryError>("invalid tag type", 1307 object_error::parse_failed); 1308 break; 1309 default: 1310 return make_error<GenericBinaryError>("unexpected import kind", 1311 object_error::parse_failed); 1312 } 1313 Imports.push_back(Im); 1314 } 1315 if (Ctx.Ptr != Ctx.End) 1316 return make_error<GenericBinaryError>("import section ended prematurely", 1317 object_error::parse_failed); 1318 return Error::success(); 1319 } 1320 1321 Error WasmObjectFile::parseFunctionSection(ReadContext &Ctx) { 1322 uint32_t Count = readVaruint32(Ctx); 1323 Functions.reserve(Count); 1324 uint32_t NumTypes = Signatures.size(); 1325 while (Count--) { 1326 uint32_t Type = readVaruint32(Ctx); 1327 if (Type >= NumTypes) 1328 return make_error<GenericBinaryError>("invalid function type", 1329 object_error::parse_failed); 1330 wasm::WasmFunction F; 1331 F.SigIndex = Type; 1332 Functions.push_back(F); 1333 } 1334 if (Ctx.Ptr != Ctx.End) 1335 return make_error<GenericBinaryError>("function section ended prematurely", 1336 object_error::parse_failed); 1337 return Error::success(); 1338 } 1339 1340 Error WasmObjectFile::parseTableSection(ReadContext &Ctx) { 1341 TableSection = Sections.size(); 1342 uint32_t Count = readVaruint32(Ctx); 1343 Tables.reserve(Count); 1344 while (Count--) { 1345 wasm::WasmTable T; 1346 T.Type = readTableType(Ctx); 1347 T.Index = NumImportedTables + Tables.size(); 1348 Tables.push_back(T); 1349 auto ElemType = Tables.back().Type.ElemType; 1350 if (ElemType != wasm::ValType::FUNCREF && 1351 ElemType != wasm::ValType::EXTERNREF && 1352 ElemType != wasm::ValType::EXNREF && 1353 ElemType != wasm::ValType::OTHERREF) { 1354 return make_error<GenericBinaryError>("invalid table element type", 1355 object_error::parse_failed); 1356 } 1357 } 1358 if (Ctx.Ptr != Ctx.End) 1359 return make_error<GenericBinaryError>("table section ended prematurely", 1360 object_error::parse_failed); 1361 return Error::success(); 1362 } 1363 1364 Error WasmObjectFile::parseMemorySection(ReadContext &Ctx) { 1365 uint32_t Count = readVaruint32(Ctx); 1366 Memories.reserve(Count); 1367 while (Count--) { 1368 auto Limits = readLimits(Ctx); 1369 if (Limits.Flags & wasm::WASM_LIMITS_FLAG_IS_64) 1370 HasMemory64 = true; 1371 Memories.push_back(Limits); 1372 } 1373 if (Ctx.Ptr != Ctx.End) 1374 return make_error<GenericBinaryError>("memory section ended prematurely", 1375 object_error::parse_failed); 1376 return Error::success(); 1377 } 1378 1379 Error WasmObjectFile::parseTagSection(ReadContext &Ctx) { 1380 TagSection = Sections.size(); 1381 uint32_t Count = readVaruint32(Ctx); 1382 Tags.reserve(Count); 1383 uint32_t NumTypes = Signatures.size(); 1384 while (Count--) { 1385 if (readUint8(Ctx) != 0) // Reserved 'attribute' field 1386 return make_error<GenericBinaryError>("invalid attribute", 1387 object_error::parse_failed); 1388 uint32_t Type = readVaruint32(Ctx); 1389 if (Type >= NumTypes) 1390 return make_error<GenericBinaryError>("invalid tag type", 1391 object_error::parse_failed); 1392 wasm::WasmTag Tag; 1393 Tag.Index = NumImportedTags + Tags.size(); 1394 Tag.SigIndex = Type; 1395 Signatures[Type].Kind = wasm::WasmSignature::Tag; 1396 Tags.push_back(Tag); 1397 } 1398 1399 if (Ctx.Ptr != Ctx.End) 1400 return make_error<GenericBinaryError>("tag section ended prematurely", 1401 object_error::parse_failed); 1402 return Error::success(); 1403 } 1404 1405 Error WasmObjectFile::parseGlobalSection(ReadContext &Ctx) { 1406 GlobalSection = Sections.size(); 1407 const uint8_t *SectionStart = Ctx.Ptr; 1408 uint32_t Count = readVaruint32(Ctx); 1409 Globals.reserve(Count); 1410 while (Count--) { 1411 wasm::WasmGlobal Global; 1412 Global.Index = NumImportedGlobals + Globals.size(); 1413 const uint8_t *GlobalStart = Ctx.Ptr; 1414 Global.Offset = static_cast<uint32_t>(GlobalStart - SectionStart); 1415 auto GlobalOpcode = readVaruint32(Ctx); 1416 Global.Type.Type = (uint8_t)parseValType(Ctx, GlobalOpcode); 1417 Global.Type.Mutable = readVaruint1(Ctx); 1418 if (Error Err = readInitExpr(Global.InitExpr, Ctx)) 1419 return Err; 1420 Global.Size = static_cast<uint32_t>(Ctx.Ptr - GlobalStart); 1421 Globals.push_back(Global); 1422 } 1423 if (Ctx.Ptr != Ctx.End) 1424 return make_error<GenericBinaryError>("global section ended prematurely", 1425 object_error::parse_failed); 1426 return Error::success(); 1427 } 1428 1429 Error WasmObjectFile::parseExportSection(ReadContext &Ctx) { 1430 uint32_t Count = readVaruint32(Ctx); 1431 Exports.reserve(Count); 1432 Symbols.reserve(Count); 1433 for (uint32_t I = 0; I < Count; I++) { 1434 wasm::WasmExport Ex; 1435 Ex.Name = readString(Ctx); 1436 Ex.Kind = readUint8(Ctx); 1437 Ex.Index = readVaruint32(Ctx); 1438 const wasm::WasmSignature *Signature = nullptr; 1439 const wasm::WasmGlobalType *GlobalType = nullptr; 1440 const wasm::WasmTableType *TableType = nullptr; 1441 wasm::WasmSymbolInfo Info; 1442 Info.Name = Ex.Name; 1443 Info.Flags = 0; 1444 switch (Ex.Kind) { 1445 case wasm::WASM_EXTERNAL_FUNCTION: { 1446 if (!isDefinedFunctionIndex(Ex.Index)) 1447 return make_error<GenericBinaryError>("invalid function export", 1448 object_error::parse_failed); 1449 getDefinedFunction(Ex.Index).ExportName = Ex.Name; 1450 Info.Kind = wasm::WASM_SYMBOL_TYPE_FUNCTION; 1451 Info.ElementIndex = Ex.Index; 1452 unsigned FuncIndex = Info.ElementIndex - NumImportedFunctions; 1453 wasm::WasmFunction &Function = Functions[FuncIndex]; 1454 Signature = &Signatures[Function.SigIndex]; 1455 break; 1456 } 1457 case wasm::WASM_EXTERNAL_GLOBAL: { 1458 if (!isValidGlobalIndex(Ex.Index)) 1459 return make_error<GenericBinaryError>("invalid global export", 1460 object_error::parse_failed); 1461 Info.Kind = wasm::WASM_SYMBOL_TYPE_DATA; 1462 uint64_t Offset = 0; 1463 if (isDefinedGlobalIndex(Ex.Index)) { 1464 auto Global = getDefinedGlobal(Ex.Index); 1465 if (!Global.InitExpr.Extended) { 1466 auto Inst = Global.InitExpr.Inst; 1467 if (Inst.Opcode == wasm::WASM_OPCODE_I32_CONST) { 1468 Offset = Inst.Value.Int32; 1469 } else if (Inst.Opcode == wasm::WASM_OPCODE_I64_CONST) { 1470 Offset = Inst.Value.Int64; 1471 } 1472 } 1473 } 1474 Info.DataRef = wasm::WasmDataReference{0, Offset, 0}; 1475 break; 1476 } 1477 case wasm::WASM_EXTERNAL_TAG: 1478 if (!isValidTagIndex(Ex.Index)) 1479 return make_error<GenericBinaryError>("invalid tag export", 1480 object_error::parse_failed); 1481 Info.Kind = wasm::WASM_SYMBOL_TYPE_TAG; 1482 Info.ElementIndex = Ex.Index; 1483 break; 1484 case wasm::WASM_EXTERNAL_MEMORY: 1485 break; 1486 case wasm::WASM_EXTERNAL_TABLE: 1487 Info.Kind = wasm::WASM_SYMBOL_TYPE_TABLE; 1488 Info.ElementIndex = Ex.Index; 1489 break; 1490 default: 1491 return make_error<GenericBinaryError>("unexpected export kind", 1492 object_error::parse_failed); 1493 } 1494 Exports.push_back(Ex); 1495 if (Ex.Kind != wasm::WASM_EXTERNAL_MEMORY) { 1496 Symbols.emplace_back(Info, GlobalType, TableType, Signature); 1497 LLVM_DEBUG(dbgs() << "Adding symbol: " << Symbols.back() << "\n"); 1498 } 1499 } 1500 if (Ctx.Ptr != Ctx.End) 1501 return make_error<GenericBinaryError>("export section ended prematurely", 1502 object_error::parse_failed); 1503 return Error::success(); 1504 } 1505 1506 bool WasmObjectFile::isValidFunctionIndex(uint32_t Index) const { 1507 return Index < NumImportedFunctions + Functions.size(); 1508 } 1509 1510 bool WasmObjectFile::isDefinedFunctionIndex(uint32_t Index) const { 1511 return Index >= NumImportedFunctions && isValidFunctionIndex(Index); 1512 } 1513 1514 bool WasmObjectFile::isValidGlobalIndex(uint32_t Index) const { 1515 return Index < NumImportedGlobals + Globals.size(); 1516 } 1517 1518 bool WasmObjectFile::isValidTableNumber(uint32_t Index) const { 1519 return Index < NumImportedTables + Tables.size(); 1520 } 1521 1522 bool WasmObjectFile::isDefinedGlobalIndex(uint32_t Index) const { 1523 return Index >= NumImportedGlobals && isValidGlobalIndex(Index); 1524 } 1525 1526 bool WasmObjectFile::isDefinedTableNumber(uint32_t Index) const { 1527 return Index >= NumImportedTables && isValidTableNumber(Index); 1528 } 1529 1530 bool WasmObjectFile::isValidTagIndex(uint32_t Index) const { 1531 return Index < NumImportedTags + Tags.size(); 1532 } 1533 1534 bool WasmObjectFile::isDefinedTagIndex(uint32_t Index) const { 1535 return Index >= NumImportedTags && isValidTagIndex(Index); 1536 } 1537 1538 bool WasmObjectFile::isValidFunctionSymbol(uint32_t Index) const { 1539 return Index < Symbols.size() && Symbols[Index].isTypeFunction(); 1540 } 1541 1542 bool WasmObjectFile::isValidTableSymbol(uint32_t Index) const { 1543 return Index < Symbols.size() && Symbols[Index].isTypeTable(); 1544 } 1545 1546 bool WasmObjectFile::isValidGlobalSymbol(uint32_t Index) const { 1547 return Index < Symbols.size() && Symbols[Index].isTypeGlobal(); 1548 } 1549 1550 bool WasmObjectFile::isValidTagSymbol(uint32_t Index) const { 1551 return Index < Symbols.size() && Symbols[Index].isTypeTag(); 1552 } 1553 1554 bool WasmObjectFile::isValidDataSymbol(uint32_t Index) const { 1555 return Index < Symbols.size() && Symbols[Index].isTypeData(); 1556 } 1557 1558 bool WasmObjectFile::isValidSectionSymbol(uint32_t Index) const { 1559 return Index < Symbols.size() && Symbols[Index].isTypeSection(); 1560 } 1561 1562 wasm::WasmFunction &WasmObjectFile::getDefinedFunction(uint32_t Index) { 1563 assert(isDefinedFunctionIndex(Index)); 1564 return Functions[Index - NumImportedFunctions]; 1565 } 1566 1567 const wasm::WasmFunction & 1568 WasmObjectFile::getDefinedFunction(uint32_t Index) const { 1569 assert(isDefinedFunctionIndex(Index)); 1570 return Functions[Index - NumImportedFunctions]; 1571 } 1572 1573 const wasm::WasmGlobal &WasmObjectFile::getDefinedGlobal(uint32_t Index) const { 1574 assert(isDefinedGlobalIndex(Index)); 1575 return Globals[Index - NumImportedGlobals]; 1576 } 1577 1578 wasm::WasmTag &WasmObjectFile::getDefinedTag(uint32_t Index) { 1579 assert(isDefinedTagIndex(Index)); 1580 return Tags[Index - NumImportedTags]; 1581 } 1582 1583 Error WasmObjectFile::parseStartSection(ReadContext &Ctx) { 1584 StartFunction = readVaruint32(Ctx); 1585 if (!isValidFunctionIndex(StartFunction)) 1586 return make_error<GenericBinaryError>("invalid start function", 1587 object_error::parse_failed); 1588 return Error::success(); 1589 } 1590 1591 Error WasmObjectFile::parseCodeSection(ReadContext &Ctx) { 1592 CodeSection = Sections.size(); 1593 uint32_t FunctionCount = readVaruint32(Ctx); 1594 if (FunctionCount != Functions.size()) { 1595 return make_error<GenericBinaryError>("invalid function count", 1596 object_error::parse_failed); 1597 } 1598 1599 for (uint32_t i = 0; i < FunctionCount; i++) { 1600 wasm::WasmFunction& Function = Functions[i]; 1601 const uint8_t *FunctionStart = Ctx.Ptr; 1602 uint32_t Size = readVaruint32(Ctx); 1603 const uint8_t *FunctionEnd = Ctx.Ptr + Size; 1604 1605 Function.CodeOffset = Ctx.Ptr - FunctionStart; 1606 Function.Index = NumImportedFunctions + i; 1607 Function.CodeSectionOffset = FunctionStart - Ctx.Start; 1608 Function.Size = FunctionEnd - FunctionStart; 1609 1610 uint32_t NumLocalDecls = readVaruint32(Ctx); 1611 Function.Locals.reserve(NumLocalDecls); 1612 while (NumLocalDecls--) { 1613 wasm::WasmLocalDecl Decl; 1614 Decl.Count = readVaruint32(Ctx); 1615 Decl.Type = readUint8(Ctx); 1616 Function.Locals.push_back(Decl); 1617 } 1618 1619 uint32_t BodySize = FunctionEnd - Ctx.Ptr; 1620 // Ensure that Function is within Ctx's buffer. 1621 if (Ctx.Ptr + BodySize > Ctx.End) { 1622 return make_error<GenericBinaryError>("Function extends beyond buffer", 1623 object_error::parse_failed); 1624 } 1625 Function.Body = ArrayRef<uint8_t>(Ctx.Ptr, BodySize); 1626 // This will be set later when reading in the linking metadata section. 1627 Function.Comdat = UINT32_MAX; 1628 Ctx.Ptr += BodySize; 1629 assert(Ctx.Ptr == FunctionEnd); 1630 } 1631 if (Ctx.Ptr != Ctx.End) 1632 return make_error<GenericBinaryError>("code section ended prematurely", 1633 object_error::parse_failed); 1634 return Error::success(); 1635 } 1636 1637 Error WasmObjectFile::parseElemSection(ReadContext &Ctx) { 1638 uint32_t Count = readVaruint32(Ctx); 1639 ElemSegments.reserve(Count); 1640 while (Count--) { 1641 wasm::WasmElemSegment Segment; 1642 Segment.Flags = readVaruint32(Ctx); 1643 1644 uint32_t SupportedFlags = wasm::WASM_ELEM_SEGMENT_HAS_TABLE_NUMBER | 1645 wasm::WASM_ELEM_SEGMENT_IS_PASSIVE | 1646 wasm::WASM_ELEM_SEGMENT_HAS_INIT_EXPRS; 1647 if (Segment.Flags & ~SupportedFlags) 1648 return make_error<GenericBinaryError>( 1649 "Unsupported flags for element segment", object_error::parse_failed); 1650 1651 bool IsPassive = (Segment.Flags & wasm::WASM_ELEM_SEGMENT_IS_PASSIVE) != 0; 1652 bool IsDeclarative = 1653 IsPassive && (Segment.Flags & wasm::WASM_ELEM_SEGMENT_IS_DECLARATIVE); 1654 bool HasTableNumber = 1655 !IsPassive && 1656 (Segment.Flags & wasm::WASM_ELEM_SEGMENT_HAS_TABLE_NUMBER); 1657 bool HasInitExprs = 1658 (Segment.Flags & wasm::WASM_ELEM_SEGMENT_HAS_INIT_EXPRS); 1659 bool HasElemKind = 1660 (Segment.Flags & wasm::WASM_ELEM_SEGMENT_MASK_HAS_ELEM_KIND) && 1661 !HasInitExprs; 1662 1663 if (HasTableNumber) 1664 Segment.TableNumber = readVaruint32(Ctx); 1665 else 1666 Segment.TableNumber = 0; 1667 1668 if (!isValidTableNumber(Segment.TableNumber)) 1669 return make_error<GenericBinaryError>("invalid TableNumber", 1670 object_error::parse_failed); 1671 1672 if (IsPassive || IsDeclarative) { 1673 Segment.Offset.Extended = false; 1674 Segment.Offset.Inst.Opcode = wasm::WASM_OPCODE_I32_CONST; 1675 Segment.Offset.Inst.Value.Int32 = 0; 1676 } else { 1677 if (Error Err = readInitExpr(Segment.Offset, Ctx)) 1678 return Err; 1679 } 1680 1681 if (HasElemKind) { 1682 auto ElemKind = readVaruint32(Ctx); 1683 if (Segment.Flags & wasm::WASM_ELEM_SEGMENT_HAS_INIT_EXPRS) { 1684 Segment.ElemKind = parseValType(Ctx, ElemKind); 1685 if (Segment.ElemKind != wasm::ValType::FUNCREF && 1686 Segment.ElemKind != wasm::ValType::EXTERNREF && 1687 Segment.ElemKind != wasm::ValType::EXNREF && 1688 Segment.ElemKind != wasm::ValType::OTHERREF) { 1689 return make_error<GenericBinaryError>("invalid elem type", 1690 object_error::parse_failed); 1691 } 1692 } else { 1693 if (ElemKind != 0) 1694 return make_error<GenericBinaryError>("invalid elem type", 1695 object_error::parse_failed); 1696 Segment.ElemKind = wasm::ValType::FUNCREF; 1697 } 1698 } else if (HasInitExprs) { 1699 auto ElemType = parseValType(Ctx, readVaruint32(Ctx)); 1700 Segment.ElemKind = ElemType; 1701 } else { 1702 Segment.ElemKind = wasm::ValType::FUNCREF; 1703 } 1704 1705 uint32_t NumElems = readVaruint32(Ctx); 1706 1707 if (HasInitExprs) { 1708 while (NumElems--) { 1709 wasm::WasmInitExpr Expr; 1710 if (Error Err = readInitExpr(Expr, Ctx)) 1711 return Err; 1712 } 1713 } else { 1714 while (NumElems--) { 1715 Segment.Functions.push_back(readVaruint32(Ctx)); 1716 } 1717 } 1718 ElemSegments.push_back(Segment); 1719 } 1720 if (Ctx.Ptr != Ctx.End) 1721 return make_error<GenericBinaryError>("elem section ended prematurely", 1722 object_error::parse_failed); 1723 return Error::success(); 1724 } 1725 1726 Error WasmObjectFile::parseDataSection(ReadContext &Ctx) { 1727 DataSection = Sections.size(); 1728 uint32_t Count = readVaruint32(Ctx); 1729 if (DataCount && Count != *DataCount) 1730 return make_error<GenericBinaryError>( 1731 "number of data segments does not match DataCount section"); 1732 DataSegments.reserve(Count); 1733 while (Count--) { 1734 WasmSegment Segment; 1735 Segment.Data.InitFlags = readVaruint32(Ctx); 1736 Segment.Data.MemoryIndex = 1737 (Segment.Data.InitFlags & wasm::WASM_DATA_SEGMENT_HAS_MEMINDEX) 1738 ? readVaruint32(Ctx) 1739 : 0; 1740 if ((Segment.Data.InitFlags & wasm::WASM_DATA_SEGMENT_IS_PASSIVE) == 0) { 1741 if (Error Err = readInitExpr(Segment.Data.Offset, Ctx)) 1742 return Err; 1743 } else { 1744 Segment.Data.Offset.Extended = false; 1745 Segment.Data.Offset.Inst.Opcode = wasm::WASM_OPCODE_I32_CONST; 1746 Segment.Data.Offset.Inst.Value.Int32 = 0; 1747 } 1748 uint32_t Size = readVaruint32(Ctx); 1749 if (Size > (size_t)(Ctx.End - Ctx.Ptr)) 1750 return make_error<GenericBinaryError>("invalid segment size", 1751 object_error::parse_failed); 1752 Segment.Data.Content = ArrayRef<uint8_t>(Ctx.Ptr, Size); 1753 // The rest of these Data fields are set later, when reading in the linking 1754 // metadata section. 1755 Segment.Data.Alignment = 0; 1756 Segment.Data.LinkingFlags = 0; 1757 Segment.Data.Comdat = UINT32_MAX; 1758 Segment.SectionOffset = Ctx.Ptr - Ctx.Start; 1759 Ctx.Ptr += Size; 1760 DataSegments.push_back(Segment); 1761 } 1762 if (Ctx.Ptr != Ctx.End) 1763 return make_error<GenericBinaryError>("data section ended prematurely", 1764 object_error::parse_failed); 1765 return Error::success(); 1766 } 1767 1768 Error WasmObjectFile::parseDataCountSection(ReadContext &Ctx) { 1769 DataCount = readVaruint32(Ctx); 1770 return Error::success(); 1771 } 1772 1773 const wasm::WasmObjectHeader &WasmObjectFile::getHeader() const { 1774 return Header; 1775 } 1776 1777 void WasmObjectFile::moveSymbolNext(DataRefImpl &Symb) const { Symb.d.b++; } 1778 1779 Expected<uint32_t> WasmObjectFile::getSymbolFlags(DataRefImpl Symb) const { 1780 uint32_t Result = SymbolRef::SF_None; 1781 const WasmSymbol &Sym = getWasmSymbol(Symb); 1782 1783 LLVM_DEBUG(dbgs() << "getSymbolFlags: ptr=" << &Sym << " " << Sym << "\n"); 1784 if (Sym.isBindingWeak()) 1785 Result |= SymbolRef::SF_Weak; 1786 if (!Sym.isBindingLocal()) 1787 Result |= SymbolRef::SF_Global; 1788 if (Sym.isHidden()) 1789 Result |= SymbolRef::SF_Hidden; 1790 if (!Sym.isDefined()) 1791 Result |= SymbolRef::SF_Undefined; 1792 if (Sym.isTypeFunction()) 1793 Result |= SymbolRef::SF_Executable; 1794 return Result; 1795 } 1796 1797 basic_symbol_iterator WasmObjectFile::symbol_begin() const { 1798 DataRefImpl Ref; 1799 Ref.d.a = 1; // Arbitrary non-zero value so that Ref.p is non-null 1800 Ref.d.b = 0; // Symbol index 1801 return BasicSymbolRef(Ref, this); 1802 } 1803 1804 basic_symbol_iterator WasmObjectFile::symbol_end() const { 1805 DataRefImpl Ref; 1806 Ref.d.a = 1; // Arbitrary non-zero value so that Ref.p is non-null 1807 Ref.d.b = Symbols.size(); // Symbol index 1808 return BasicSymbolRef(Ref, this); 1809 } 1810 1811 const WasmSymbol &WasmObjectFile::getWasmSymbol(const DataRefImpl &Symb) const { 1812 return Symbols[Symb.d.b]; 1813 } 1814 1815 const WasmSymbol &WasmObjectFile::getWasmSymbol(const SymbolRef &Symb) const { 1816 return getWasmSymbol(Symb.getRawDataRefImpl()); 1817 } 1818 1819 Expected<StringRef> WasmObjectFile::getSymbolName(DataRefImpl Symb) const { 1820 return getWasmSymbol(Symb).Info.Name; 1821 } 1822 1823 Expected<uint64_t> WasmObjectFile::getSymbolAddress(DataRefImpl Symb) const { 1824 auto &Sym = getWasmSymbol(Symb); 1825 if (!Sym.isDefined()) 1826 return 0; 1827 Expected<section_iterator> Sec = getSymbolSection(Symb); 1828 if (!Sec) 1829 return Sec.takeError(); 1830 uint32_t SectionAddress = getSectionAddress(Sec.get()->getRawDataRefImpl()); 1831 if (Sym.Info.Kind == wasm::WASM_SYMBOL_TYPE_FUNCTION && 1832 isDefinedFunctionIndex(Sym.Info.ElementIndex)) { 1833 return getDefinedFunction(Sym.Info.ElementIndex).CodeSectionOffset + 1834 SectionAddress; 1835 } 1836 if (Sym.Info.Kind == wasm::WASM_SYMBOL_TYPE_GLOBAL && 1837 isDefinedGlobalIndex(Sym.Info.ElementIndex)) { 1838 return getDefinedGlobal(Sym.Info.ElementIndex).Offset + SectionAddress; 1839 } 1840 1841 return getSymbolValue(Symb); 1842 } 1843 1844 uint64_t WasmObjectFile::getWasmSymbolValue(const WasmSymbol &Sym) const { 1845 switch (Sym.Info.Kind) { 1846 case wasm::WASM_SYMBOL_TYPE_FUNCTION: 1847 case wasm::WASM_SYMBOL_TYPE_GLOBAL: 1848 case wasm::WASM_SYMBOL_TYPE_TAG: 1849 case wasm::WASM_SYMBOL_TYPE_TABLE: 1850 return Sym.Info.ElementIndex; 1851 case wasm::WASM_SYMBOL_TYPE_DATA: { 1852 // The value of a data symbol is the segment offset, plus the symbol 1853 // offset within the segment. 1854 uint32_t SegmentIndex = Sym.Info.DataRef.Segment; 1855 const wasm::WasmDataSegment &Segment = DataSegments[SegmentIndex].Data; 1856 if (Segment.Offset.Extended) { 1857 llvm_unreachable("extended init exprs not supported"); 1858 } else if (Segment.Offset.Inst.Opcode == wasm::WASM_OPCODE_I32_CONST) { 1859 return Segment.Offset.Inst.Value.Int32 + Sym.Info.DataRef.Offset; 1860 } else if (Segment.Offset.Inst.Opcode == wasm::WASM_OPCODE_I64_CONST) { 1861 return Segment.Offset.Inst.Value.Int64 + Sym.Info.DataRef.Offset; 1862 } else if (Segment.Offset.Inst.Opcode == wasm::WASM_OPCODE_GLOBAL_GET) { 1863 return Sym.Info.DataRef.Offset; 1864 } else { 1865 llvm_unreachable("unknown init expr opcode"); 1866 } 1867 } 1868 case wasm::WASM_SYMBOL_TYPE_SECTION: 1869 return 0; 1870 } 1871 llvm_unreachable("invalid symbol type"); 1872 } 1873 1874 uint64_t WasmObjectFile::getSymbolValueImpl(DataRefImpl Symb) const { 1875 return getWasmSymbolValue(getWasmSymbol(Symb)); 1876 } 1877 1878 uint32_t WasmObjectFile::getSymbolAlignment(DataRefImpl Symb) const { 1879 llvm_unreachable("not yet implemented"); 1880 return 0; 1881 } 1882 1883 uint64_t WasmObjectFile::getCommonSymbolSizeImpl(DataRefImpl Symb) const { 1884 llvm_unreachable("not yet implemented"); 1885 return 0; 1886 } 1887 1888 Expected<SymbolRef::Type> 1889 WasmObjectFile::getSymbolType(DataRefImpl Symb) const { 1890 const WasmSymbol &Sym = getWasmSymbol(Symb); 1891 1892 switch (Sym.Info.Kind) { 1893 case wasm::WASM_SYMBOL_TYPE_FUNCTION: 1894 return SymbolRef::ST_Function; 1895 case wasm::WASM_SYMBOL_TYPE_GLOBAL: 1896 return SymbolRef::ST_Other; 1897 case wasm::WASM_SYMBOL_TYPE_DATA: 1898 return SymbolRef::ST_Data; 1899 case wasm::WASM_SYMBOL_TYPE_SECTION: 1900 return SymbolRef::ST_Debug; 1901 case wasm::WASM_SYMBOL_TYPE_TAG: 1902 return SymbolRef::ST_Other; 1903 case wasm::WASM_SYMBOL_TYPE_TABLE: 1904 return SymbolRef::ST_Other; 1905 } 1906 1907 llvm_unreachable("unknown WasmSymbol::SymbolType"); 1908 return SymbolRef::ST_Other; 1909 } 1910 1911 Expected<section_iterator> 1912 WasmObjectFile::getSymbolSection(DataRefImpl Symb) const { 1913 const WasmSymbol &Sym = getWasmSymbol(Symb); 1914 if (Sym.isUndefined()) 1915 return section_end(); 1916 1917 DataRefImpl Ref; 1918 Ref.d.a = getSymbolSectionIdImpl(Sym); 1919 return section_iterator(SectionRef(Ref, this)); 1920 } 1921 1922 uint32_t WasmObjectFile::getSymbolSectionId(SymbolRef Symb) const { 1923 const WasmSymbol &Sym = getWasmSymbol(Symb); 1924 return getSymbolSectionIdImpl(Sym); 1925 } 1926 1927 uint32_t WasmObjectFile::getSymbolSectionIdImpl(const WasmSymbol &Sym) const { 1928 switch (Sym.Info.Kind) { 1929 case wasm::WASM_SYMBOL_TYPE_FUNCTION: 1930 return CodeSection; 1931 case wasm::WASM_SYMBOL_TYPE_GLOBAL: 1932 return GlobalSection; 1933 case wasm::WASM_SYMBOL_TYPE_DATA: 1934 return DataSection; 1935 case wasm::WASM_SYMBOL_TYPE_SECTION: 1936 return Sym.Info.ElementIndex; 1937 case wasm::WASM_SYMBOL_TYPE_TAG: 1938 return TagSection; 1939 case wasm::WASM_SYMBOL_TYPE_TABLE: 1940 return TableSection; 1941 default: 1942 llvm_unreachable("unknown WasmSymbol::SymbolType"); 1943 } 1944 } 1945 1946 uint32_t WasmObjectFile::getSymbolSize(SymbolRef Symb) const { 1947 const WasmSymbol &Sym = getWasmSymbol(Symb); 1948 if (!Sym.isDefined()) 1949 return 0; 1950 if (Sym.isTypeGlobal()) 1951 return getDefinedGlobal(Sym.Info.ElementIndex).Size; 1952 if (Sym.isTypeData()) 1953 return Sym.Info.DataRef.Size; 1954 if (Sym.isTypeFunction()) 1955 return functions()[Sym.Info.ElementIndex - getNumImportedFunctions()].Size; 1956 // Currently symbol size is only tracked for data segments and functions. In 1957 // principle we could also track size (e.g. binary size) for tables, globals 1958 // and element segments etc too. 1959 return 0; 1960 } 1961 1962 void WasmObjectFile::moveSectionNext(DataRefImpl &Sec) const { Sec.d.a++; } 1963 1964 Expected<StringRef> WasmObjectFile::getSectionName(DataRefImpl Sec) const { 1965 const WasmSection &S = Sections[Sec.d.a]; 1966 if (S.Type == wasm::WASM_SEC_CUSTOM) 1967 return S.Name; 1968 if (S.Type > wasm::WASM_SEC_LAST_KNOWN) 1969 return createStringError(object_error::invalid_section_index, ""); 1970 return wasm::sectionTypeToString(S.Type); 1971 } 1972 1973 uint64_t WasmObjectFile::getSectionAddress(DataRefImpl Sec) const { 1974 // For object files, use 0 for section addresses, and section offsets for 1975 // symbol addresses. For linked files, use file offsets. 1976 // See also getSymbolAddress. 1977 return isRelocatableObject() || isSharedObject() ? 0 1978 : Sections[Sec.d.a].Offset; 1979 } 1980 1981 uint64_t WasmObjectFile::getSectionIndex(DataRefImpl Sec) const { 1982 return Sec.d.a; 1983 } 1984 1985 uint64_t WasmObjectFile::getSectionSize(DataRefImpl Sec) const { 1986 const WasmSection &S = Sections[Sec.d.a]; 1987 return S.Content.size(); 1988 } 1989 1990 Expected<ArrayRef<uint8_t>> 1991 WasmObjectFile::getSectionContents(DataRefImpl Sec) const { 1992 const WasmSection &S = Sections[Sec.d.a]; 1993 // This will never fail since wasm sections can never be empty (user-sections 1994 // must have a name and non-user sections each have a defined structure). 1995 return S.Content; 1996 } 1997 1998 uint64_t WasmObjectFile::getSectionAlignment(DataRefImpl Sec) const { 1999 return 1; 2000 } 2001 2002 bool WasmObjectFile::isSectionCompressed(DataRefImpl Sec) const { 2003 return false; 2004 } 2005 2006 bool WasmObjectFile::isSectionText(DataRefImpl Sec) const { 2007 return getWasmSection(Sec).Type == wasm::WASM_SEC_CODE; 2008 } 2009 2010 bool WasmObjectFile::isSectionData(DataRefImpl Sec) const { 2011 return getWasmSection(Sec).Type == wasm::WASM_SEC_DATA; 2012 } 2013 2014 bool WasmObjectFile::isSectionBSS(DataRefImpl Sec) const { return false; } 2015 2016 bool WasmObjectFile::isSectionVirtual(DataRefImpl Sec) const { return false; } 2017 2018 relocation_iterator WasmObjectFile::section_rel_begin(DataRefImpl Ref) const { 2019 DataRefImpl RelocRef; 2020 RelocRef.d.a = Ref.d.a; 2021 RelocRef.d.b = 0; 2022 return relocation_iterator(RelocationRef(RelocRef, this)); 2023 } 2024 2025 relocation_iterator WasmObjectFile::section_rel_end(DataRefImpl Ref) const { 2026 const WasmSection &Sec = getWasmSection(Ref); 2027 DataRefImpl RelocRef; 2028 RelocRef.d.a = Ref.d.a; 2029 RelocRef.d.b = Sec.Relocations.size(); 2030 return relocation_iterator(RelocationRef(RelocRef, this)); 2031 } 2032 2033 void WasmObjectFile::moveRelocationNext(DataRefImpl &Rel) const { Rel.d.b++; } 2034 2035 uint64_t WasmObjectFile::getRelocationOffset(DataRefImpl Ref) const { 2036 const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); 2037 return Rel.Offset; 2038 } 2039 2040 symbol_iterator WasmObjectFile::getRelocationSymbol(DataRefImpl Ref) const { 2041 const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); 2042 if (Rel.Type == wasm::R_WASM_TYPE_INDEX_LEB) 2043 return symbol_end(); 2044 DataRefImpl Sym; 2045 Sym.d.a = 1; 2046 Sym.d.b = Rel.Index; 2047 return symbol_iterator(SymbolRef(Sym, this)); 2048 } 2049 2050 uint64_t WasmObjectFile::getRelocationType(DataRefImpl Ref) const { 2051 const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); 2052 return Rel.Type; 2053 } 2054 2055 void WasmObjectFile::getRelocationTypeName( 2056 DataRefImpl Ref, SmallVectorImpl<char> &Result) const { 2057 const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); 2058 StringRef Res = "Unknown"; 2059 2060 #define WASM_RELOC(name, value) \ 2061 case wasm::name: \ 2062 Res = #name; \ 2063 break; 2064 2065 switch (Rel.Type) { 2066 #include "llvm/BinaryFormat/WasmRelocs.def" 2067 } 2068 2069 #undef WASM_RELOC 2070 2071 Result.append(Res.begin(), Res.end()); 2072 } 2073 2074 section_iterator WasmObjectFile::section_begin() const { 2075 DataRefImpl Ref; 2076 Ref.d.a = 0; 2077 return section_iterator(SectionRef(Ref, this)); 2078 } 2079 2080 section_iterator WasmObjectFile::section_end() const { 2081 DataRefImpl Ref; 2082 Ref.d.a = Sections.size(); 2083 return section_iterator(SectionRef(Ref, this)); 2084 } 2085 2086 uint8_t WasmObjectFile::getBytesInAddress() const { 2087 return HasMemory64 ? 8 : 4; 2088 } 2089 2090 StringRef WasmObjectFile::getFileFormatName() const { return "WASM"; } 2091 2092 Triple::ArchType WasmObjectFile::getArch() const { 2093 return HasMemory64 ? Triple::wasm64 : Triple::wasm32; 2094 } 2095 2096 Expected<SubtargetFeatures> WasmObjectFile::getFeatures() const { 2097 return SubtargetFeatures(); 2098 } 2099 2100 bool WasmObjectFile::isRelocatableObject() const { return HasLinkingSection; } 2101 2102 bool WasmObjectFile::isSharedObject() const { return HasDylinkSection; } 2103 2104 const WasmSection &WasmObjectFile::getWasmSection(DataRefImpl Ref) const { 2105 assert(Ref.d.a < Sections.size()); 2106 return Sections[Ref.d.a]; 2107 } 2108 2109 const WasmSection & 2110 WasmObjectFile::getWasmSection(const SectionRef &Section) const { 2111 return getWasmSection(Section.getRawDataRefImpl()); 2112 } 2113 2114 const wasm::WasmRelocation & 2115 WasmObjectFile::getWasmRelocation(const RelocationRef &Ref) const { 2116 return getWasmRelocation(Ref.getRawDataRefImpl()); 2117 } 2118 2119 const wasm::WasmRelocation & 2120 WasmObjectFile::getWasmRelocation(DataRefImpl Ref) const { 2121 assert(Ref.d.a < Sections.size()); 2122 const WasmSection &Sec = Sections[Ref.d.a]; 2123 assert(Ref.d.b < Sec.Relocations.size()); 2124 return Sec.Relocations[Ref.d.b]; 2125 } 2126 2127 int WasmSectionOrderChecker::getSectionOrder(unsigned ID, 2128 StringRef CustomSectionName) { 2129 switch (ID) { 2130 case wasm::WASM_SEC_CUSTOM: 2131 return StringSwitch<unsigned>(CustomSectionName) 2132 .Case("dylink", WASM_SEC_ORDER_DYLINK) 2133 .Case("dylink.0", WASM_SEC_ORDER_DYLINK) 2134 .Case("linking", WASM_SEC_ORDER_LINKING) 2135 .StartsWith("reloc.", WASM_SEC_ORDER_RELOC) 2136 .Case("name", WASM_SEC_ORDER_NAME) 2137 .Case("producers", WASM_SEC_ORDER_PRODUCERS) 2138 .Case("target_features", WASM_SEC_ORDER_TARGET_FEATURES) 2139 .Default(WASM_SEC_ORDER_NONE); 2140 case wasm::WASM_SEC_TYPE: 2141 return WASM_SEC_ORDER_TYPE; 2142 case wasm::WASM_SEC_IMPORT: 2143 return WASM_SEC_ORDER_IMPORT; 2144 case wasm::WASM_SEC_FUNCTION: 2145 return WASM_SEC_ORDER_FUNCTION; 2146 case wasm::WASM_SEC_TABLE: 2147 return WASM_SEC_ORDER_TABLE; 2148 case wasm::WASM_SEC_MEMORY: 2149 return WASM_SEC_ORDER_MEMORY; 2150 case wasm::WASM_SEC_GLOBAL: 2151 return WASM_SEC_ORDER_GLOBAL; 2152 case wasm::WASM_SEC_EXPORT: 2153 return WASM_SEC_ORDER_EXPORT; 2154 case wasm::WASM_SEC_START: 2155 return WASM_SEC_ORDER_START; 2156 case wasm::WASM_SEC_ELEM: 2157 return WASM_SEC_ORDER_ELEM; 2158 case wasm::WASM_SEC_CODE: 2159 return WASM_SEC_ORDER_CODE; 2160 case wasm::WASM_SEC_DATA: 2161 return WASM_SEC_ORDER_DATA; 2162 case wasm::WASM_SEC_DATACOUNT: 2163 return WASM_SEC_ORDER_DATACOUNT; 2164 case wasm::WASM_SEC_TAG: 2165 return WASM_SEC_ORDER_TAG; 2166 default: 2167 return WASM_SEC_ORDER_NONE; 2168 } 2169 } 2170 2171 // Represents the edges in a directed graph where any node B reachable from node 2172 // A is not allowed to appear before A in the section ordering, but may appear 2173 // afterward. 2174 int WasmSectionOrderChecker::DisallowedPredecessors 2175 [WASM_NUM_SEC_ORDERS][WASM_NUM_SEC_ORDERS] = { 2176 // WASM_SEC_ORDER_NONE 2177 {}, 2178 // WASM_SEC_ORDER_TYPE 2179 {WASM_SEC_ORDER_TYPE, WASM_SEC_ORDER_IMPORT}, 2180 // WASM_SEC_ORDER_IMPORT 2181 {WASM_SEC_ORDER_IMPORT, WASM_SEC_ORDER_FUNCTION}, 2182 // WASM_SEC_ORDER_FUNCTION 2183 {WASM_SEC_ORDER_FUNCTION, WASM_SEC_ORDER_TABLE}, 2184 // WASM_SEC_ORDER_TABLE 2185 {WASM_SEC_ORDER_TABLE, WASM_SEC_ORDER_MEMORY}, 2186 // WASM_SEC_ORDER_MEMORY 2187 {WASM_SEC_ORDER_MEMORY, WASM_SEC_ORDER_TAG}, 2188 // WASM_SEC_ORDER_TAG 2189 {WASM_SEC_ORDER_TAG, WASM_SEC_ORDER_GLOBAL}, 2190 // WASM_SEC_ORDER_GLOBAL 2191 {WASM_SEC_ORDER_GLOBAL, WASM_SEC_ORDER_EXPORT}, 2192 // WASM_SEC_ORDER_EXPORT 2193 {WASM_SEC_ORDER_EXPORT, WASM_SEC_ORDER_START}, 2194 // WASM_SEC_ORDER_START 2195 {WASM_SEC_ORDER_START, WASM_SEC_ORDER_ELEM}, 2196 // WASM_SEC_ORDER_ELEM 2197 {WASM_SEC_ORDER_ELEM, WASM_SEC_ORDER_DATACOUNT}, 2198 // WASM_SEC_ORDER_DATACOUNT 2199 {WASM_SEC_ORDER_DATACOUNT, WASM_SEC_ORDER_CODE}, 2200 // WASM_SEC_ORDER_CODE 2201 {WASM_SEC_ORDER_CODE, WASM_SEC_ORDER_DATA}, 2202 // WASM_SEC_ORDER_DATA 2203 {WASM_SEC_ORDER_DATA, WASM_SEC_ORDER_LINKING}, 2204 2205 // Custom Sections 2206 // WASM_SEC_ORDER_DYLINK 2207 {WASM_SEC_ORDER_DYLINK, WASM_SEC_ORDER_TYPE}, 2208 // WASM_SEC_ORDER_LINKING 2209 {WASM_SEC_ORDER_LINKING, WASM_SEC_ORDER_RELOC, WASM_SEC_ORDER_NAME}, 2210 // WASM_SEC_ORDER_RELOC (can be repeated) 2211 {}, 2212 // WASM_SEC_ORDER_NAME 2213 {WASM_SEC_ORDER_NAME, WASM_SEC_ORDER_PRODUCERS}, 2214 // WASM_SEC_ORDER_PRODUCERS 2215 {WASM_SEC_ORDER_PRODUCERS, WASM_SEC_ORDER_TARGET_FEATURES}, 2216 // WASM_SEC_ORDER_TARGET_FEATURES 2217 {WASM_SEC_ORDER_TARGET_FEATURES}}; 2218 2219 bool WasmSectionOrderChecker::isValidSectionOrder(unsigned ID, 2220 StringRef CustomSectionName) { 2221 int Order = getSectionOrder(ID, CustomSectionName); 2222 if (Order == WASM_SEC_ORDER_NONE) 2223 return true; 2224 2225 // Disallowed predecessors we need to check for 2226 SmallVector<int, WASM_NUM_SEC_ORDERS> WorkList; 2227 2228 // Keep track of completed checks to avoid repeating work 2229 bool Checked[WASM_NUM_SEC_ORDERS] = {}; 2230 2231 int Curr = Order; 2232 while (true) { 2233 // Add new disallowed predecessors to work list 2234 for (size_t I = 0;; ++I) { 2235 int Next = DisallowedPredecessors[Curr][I]; 2236 if (Next == WASM_SEC_ORDER_NONE) 2237 break; 2238 if (Checked[Next]) 2239 continue; 2240 WorkList.push_back(Next); 2241 Checked[Next] = true; 2242 } 2243 2244 if (WorkList.empty()) 2245 break; 2246 2247 // Consider next disallowed predecessor 2248 Curr = WorkList.pop_back_val(); 2249 if (Seen[Curr]) 2250 return false; 2251 } 2252 2253 // Have not seen any disallowed predecessors 2254 Seen[Order] = true; 2255 return true; 2256 } 2257