|  | //===- WasmObjectFile.cpp - Wasm object file implementation ---------------===// | 
|  | // | 
|  | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | 
|  | // See https://llvm.org/LICENSE.txt for license information. | 
|  | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | 
|  | // | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | #include "llvm/ADT/ArrayRef.h" | 
|  | #include "llvm/ADT/DenseSet.h" | 
|  | #include "llvm/ADT/STLExtras.h" | 
|  | #include "llvm/ADT/SmallSet.h" | 
|  | #include "llvm/ADT/StringRef.h" | 
|  | #include "llvm/ADT/StringSet.h" | 
|  | #include "llvm/ADT/StringSwitch.h" | 
|  | #include "llvm/ADT/Triple.h" | 
|  | #include "llvm/BinaryFormat/Wasm.h" | 
|  | #include "llvm/MC/SubtargetFeature.h" | 
|  | #include "llvm/Object/Binary.h" | 
|  | #include "llvm/Object/Error.h" | 
|  | #include "llvm/Object/ObjectFile.h" | 
|  | #include "llvm/Object/SymbolicFile.h" | 
|  | #include "llvm/Object/Wasm.h" | 
|  | #include "llvm/Support/Endian.h" | 
|  | #include "llvm/Support/Error.h" | 
|  | #include "llvm/Support/ErrorHandling.h" | 
|  | #include "llvm/Support/LEB128.h" | 
|  | #include "llvm/Support/ScopedPrinter.h" | 
|  | #include <algorithm> | 
|  | #include <cassert> | 
|  | #include <cstdint> | 
|  | #include <cstring> | 
|  | #include <system_error> | 
|  |  | 
|  | #define DEBUG_TYPE "wasm-object" | 
|  |  | 
|  | using namespace llvm; | 
|  | using namespace object; | 
|  |  | 
|  | void WasmSymbol::print(raw_ostream &Out) const { | 
|  | Out << "Name=" << Info.Name | 
|  | << ", Kind=" << toString(wasm::WasmSymbolType(Info.Kind)) << ", Flags=0x" | 
|  | << Twine::utohexstr(Info.Flags); | 
|  | if (!isTypeData()) { | 
|  | Out << ", ElemIndex=" << Info.ElementIndex; | 
|  | } else if (isDefined()) { | 
|  | Out << ", Segment=" << Info.DataRef.Segment; | 
|  | Out << ", Offset=" << Info.DataRef.Offset; | 
|  | Out << ", Size=" << Info.DataRef.Size; | 
|  | } | 
|  | } | 
|  |  | 
|  | #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) | 
|  | LLVM_DUMP_METHOD void WasmSymbol::dump() const { print(dbgs()); } | 
|  | #endif | 
|  |  | 
|  | Expected<std::unique_ptr<WasmObjectFile>> | 
|  | ObjectFile::createWasmObjectFile(MemoryBufferRef Buffer) { | 
|  | Error Err = Error::success(); | 
|  | auto ObjectFile = std::make_unique<WasmObjectFile>(Buffer, Err); | 
|  | if (Err) | 
|  | return std::move(Err); | 
|  |  | 
|  | return std::move(ObjectFile); | 
|  | } | 
|  |  | 
|  | #define VARINT7_MAX ((1 << 7) - 1) | 
|  | #define VARINT7_MIN (-(1 << 7)) | 
|  | #define VARUINT7_MAX (1 << 7) | 
|  | #define VARUINT1_MAX (1) | 
|  |  | 
|  | static uint8_t readUint8(WasmObjectFile::ReadContext &Ctx) { | 
|  | if (Ctx.Ptr == Ctx.End) | 
|  | report_fatal_error("EOF while reading uint8"); | 
|  | return *Ctx.Ptr++; | 
|  | } | 
|  |  | 
|  | static uint32_t readUint32(WasmObjectFile::ReadContext &Ctx) { | 
|  | if (Ctx.Ptr + 4 > Ctx.End) | 
|  | report_fatal_error("EOF while reading uint32"); | 
|  | uint32_t Result = support::endian::read32le(Ctx.Ptr); | 
|  | Ctx.Ptr += 4; | 
|  | return Result; | 
|  | } | 
|  |  | 
|  | static int32_t readFloat32(WasmObjectFile::ReadContext &Ctx) { | 
|  | if (Ctx.Ptr + 4 > Ctx.End) | 
|  | report_fatal_error("EOF while reading float64"); | 
|  | int32_t Result = 0; | 
|  | memcpy(&Result, Ctx.Ptr, sizeof(Result)); | 
|  | Ctx.Ptr += sizeof(Result); | 
|  | return Result; | 
|  | } | 
|  |  | 
|  | static int64_t readFloat64(WasmObjectFile::ReadContext &Ctx) { | 
|  | if (Ctx.Ptr + 8 > Ctx.End) | 
|  | report_fatal_error("EOF while reading float64"); | 
|  | int64_t Result = 0; | 
|  | memcpy(&Result, Ctx.Ptr, sizeof(Result)); | 
|  | Ctx.Ptr += sizeof(Result); | 
|  | return Result; | 
|  | } | 
|  |  | 
|  | static uint64_t readULEB128(WasmObjectFile::ReadContext &Ctx) { | 
|  | unsigned Count; | 
|  | const char *Error = nullptr; | 
|  | uint64_t Result = decodeULEB128(Ctx.Ptr, &Count, Ctx.End, &Error); | 
|  | if (Error) | 
|  | report_fatal_error(Error); | 
|  | Ctx.Ptr += Count; | 
|  | return Result; | 
|  | } | 
|  |  | 
|  | static StringRef readString(WasmObjectFile::ReadContext &Ctx) { | 
|  | uint32_t StringLen = readULEB128(Ctx); | 
|  | if (Ctx.Ptr + StringLen > Ctx.End) | 
|  | report_fatal_error("EOF while reading string"); | 
|  | StringRef Return = | 
|  | StringRef(reinterpret_cast<const char *>(Ctx.Ptr), StringLen); | 
|  | Ctx.Ptr += StringLen; | 
|  | return Return; | 
|  | } | 
|  |  | 
|  | static int64_t readLEB128(WasmObjectFile::ReadContext &Ctx) { | 
|  | unsigned Count; | 
|  | const char *Error = nullptr; | 
|  | uint64_t Result = decodeSLEB128(Ctx.Ptr, &Count, Ctx.End, &Error); | 
|  | if (Error) | 
|  | report_fatal_error(Error); | 
|  | Ctx.Ptr += Count; | 
|  | return Result; | 
|  | } | 
|  |  | 
|  | static uint8_t readVaruint1(WasmObjectFile::ReadContext &Ctx) { | 
|  | int64_t Result = readLEB128(Ctx); | 
|  | if (Result > VARUINT1_MAX || Result < 0) | 
|  | report_fatal_error("LEB is outside Varuint1 range"); | 
|  | return Result; | 
|  | } | 
|  |  | 
|  | static int32_t readVarint32(WasmObjectFile::ReadContext &Ctx) { | 
|  | int64_t Result = readLEB128(Ctx); | 
|  | if (Result > INT32_MAX || Result < INT32_MIN) | 
|  | report_fatal_error("LEB is outside Varint32 range"); | 
|  | return Result; | 
|  | } | 
|  |  | 
|  | static uint32_t readVaruint32(WasmObjectFile::ReadContext &Ctx) { | 
|  | uint64_t Result = readULEB128(Ctx); | 
|  | if (Result > UINT32_MAX) | 
|  | report_fatal_error("LEB is outside Varuint32 range"); | 
|  | return Result; | 
|  | } | 
|  |  | 
|  | static int64_t readVarint64(WasmObjectFile::ReadContext &Ctx) { | 
|  | return readLEB128(Ctx); | 
|  | } | 
|  |  | 
|  | static uint64_t readVaruint64(WasmObjectFile::ReadContext &Ctx) { | 
|  | return readULEB128(Ctx); | 
|  | } | 
|  |  | 
|  | static uint8_t readOpcode(WasmObjectFile::ReadContext &Ctx) { | 
|  | return readUint8(Ctx); | 
|  | } | 
|  |  | 
|  | static Error readInitExpr(wasm::WasmInitExpr &Expr, | 
|  | WasmObjectFile::ReadContext &Ctx) { | 
|  | Expr.Opcode = readOpcode(Ctx); | 
|  |  | 
|  | switch (Expr.Opcode) { | 
|  | case wasm::WASM_OPCODE_I32_CONST: | 
|  | Expr.Value.Int32 = readVarint32(Ctx); | 
|  | break; | 
|  | case wasm::WASM_OPCODE_I64_CONST: | 
|  | Expr.Value.Int64 = readVarint64(Ctx); | 
|  | break; | 
|  | case wasm::WASM_OPCODE_F32_CONST: | 
|  | Expr.Value.Float32 = readFloat32(Ctx); | 
|  | break; | 
|  | case wasm::WASM_OPCODE_F64_CONST: | 
|  | Expr.Value.Float64 = readFloat64(Ctx); | 
|  | break; | 
|  | case wasm::WASM_OPCODE_GLOBAL_GET: | 
|  | Expr.Value.Global = readULEB128(Ctx); | 
|  | break; | 
|  | case wasm::WASM_OPCODE_REF_NULL: { | 
|  | wasm::ValType Ty = static_cast<wasm::ValType>(readULEB128(Ctx)); | 
|  | if (Ty != wasm::ValType::EXTERNREF) { | 
|  | return make_error<GenericBinaryError>("invalid type for ref.null", | 
|  | object_error::parse_failed); | 
|  | } | 
|  | break; | 
|  | } | 
|  | default: | 
|  | return make_error<GenericBinaryError>("invalid opcode in init_expr", | 
|  | object_error::parse_failed); | 
|  | } | 
|  |  | 
|  | uint8_t EndOpcode = readOpcode(Ctx); | 
|  | if (EndOpcode != wasm::WASM_OPCODE_END) { | 
|  | return make_error<GenericBinaryError>("invalid init_expr", | 
|  | object_error::parse_failed); | 
|  | } | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | static wasm::WasmLimits readLimits(WasmObjectFile::ReadContext &Ctx) { | 
|  | wasm::WasmLimits Result; | 
|  | Result.Flags = readVaruint32(Ctx); | 
|  | Result.Minimum = readVaruint64(Ctx); | 
|  | if (Result.Flags & wasm::WASM_LIMITS_FLAG_HAS_MAX) | 
|  | Result.Maximum = readVaruint64(Ctx); | 
|  | return Result; | 
|  | } | 
|  |  | 
|  | static wasm::WasmTableType readTableType(WasmObjectFile::ReadContext &Ctx) { | 
|  | wasm::WasmTableType TableType; | 
|  | TableType.ElemType = readUint8(Ctx); | 
|  | TableType.Limits = readLimits(Ctx); | 
|  | return TableType; | 
|  | } | 
|  |  | 
|  | static Error readSection(WasmSection &Section, WasmObjectFile::ReadContext &Ctx, | 
|  | WasmSectionOrderChecker &Checker) { | 
|  | Section.Offset = Ctx.Ptr - Ctx.Start; | 
|  | Section.Type = readUint8(Ctx); | 
|  | LLVM_DEBUG(dbgs() << "readSection type=" << Section.Type << "\n"); | 
|  | uint32_t Size = readVaruint32(Ctx); | 
|  | if (Size == 0) | 
|  | return make_error<StringError>("zero length section", | 
|  | object_error::parse_failed); | 
|  | if (Ctx.Ptr + Size > Ctx.End) | 
|  | return make_error<StringError>("section too large", | 
|  | object_error::parse_failed); | 
|  | if (Section.Type == wasm::WASM_SEC_CUSTOM) { | 
|  | WasmObjectFile::ReadContext SectionCtx; | 
|  | SectionCtx.Start = Ctx.Ptr; | 
|  | SectionCtx.Ptr = Ctx.Ptr; | 
|  | SectionCtx.End = Ctx.Ptr + Size; | 
|  |  | 
|  | Section.Name = readString(SectionCtx); | 
|  |  | 
|  | uint32_t SectionNameSize = SectionCtx.Ptr - SectionCtx.Start; | 
|  | Ctx.Ptr += SectionNameSize; | 
|  | Size -= SectionNameSize; | 
|  | } | 
|  |  | 
|  | if (!Checker.isValidSectionOrder(Section.Type, Section.Name)) { | 
|  | return make_error<StringError>("out of order section type: " + | 
|  | llvm::to_string(Section.Type), | 
|  | object_error::parse_failed); | 
|  | } | 
|  |  | 
|  | Section.Content = ArrayRef<uint8_t>(Ctx.Ptr, Size); | 
|  | Ctx.Ptr += Size; | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | WasmObjectFile::WasmObjectFile(MemoryBufferRef Buffer, Error &Err) | 
|  | : ObjectFile(Binary::ID_Wasm, Buffer) { | 
|  | ErrorAsOutParameter ErrAsOutParam(&Err); | 
|  | Header.Magic = getData().substr(0, 4); | 
|  | if (Header.Magic != StringRef("\0asm", 4)) { | 
|  | Err = make_error<StringError>("invalid magic number", | 
|  | object_error::parse_failed); | 
|  | return; | 
|  | } | 
|  |  | 
|  | ReadContext Ctx; | 
|  | Ctx.Start = getData().bytes_begin(); | 
|  | Ctx.Ptr = Ctx.Start + 4; | 
|  | Ctx.End = Ctx.Start + getData().size(); | 
|  |  | 
|  | if (Ctx.Ptr + 4 > Ctx.End) { | 
|  | Err = make_error<StringError>("missing version number", | 
|  | object_error::parse_failed); | 
|  | return; | 
|  | } | 
|  |  | 
|  | Header.Version = readUint32(Ctx); | 
|  | if (Header.Version != wasm::WasmVersion) { | 
|  | Err = make_error<StringError>("invalid version number: " + | 
|  | Twine(Header.Version), | 
|  | object_error::parse_failed); | 
|  | return; | 
|  | } | 
|  |  | 
|  | WasmSection Sec; | 
|  | WasmSectionOrderChecker Checker; | 
|  | while (Ctx.Ptr < Ctx.End) { | 
|  | if ((Err = readSection(Sec, Ctx, Checker))) | 
|  | return; | 
|  | if ((Err = parseSection(Sec))) | 
|  | return; | 
|  |  | 
|  | Sections.push_back(Sec); | 
|  | } | 
|  | } | 
|  |  | 
|  | Error WasmObjectFile::parseSection(WasmSection &Sec) { | 
|  | ReadContext Ctx; | 
|  | Ctx.Start = Sec.Content.data(); | 
|  | Ctx.End = Ctx.Start + Sec.Content.size(); | 
|  | Ctx.Ptr = Ctx.Start; | 
|  | switch (Sec.Type) { | 
|  | case wasm::WASM_SEC_CUSTOM: | 
|  | return parseCustomSection(Sec, Ctx); | 
|  | case wasm::WASM_SEC_TYPE: | 
|  | return parseTypeSection(Ctx); | 
|  | case wasm::WASM_SEC_IMPORT: | 
|  | return parseImportSection(Ctx); | 
|  | case wasm::WASM_SEC_FUNCTION: | 
|  | return parseFunctionSection(Ctx); | 
|  | case wasm::WASM_SEC_TABLE: | 
|  | return parseTableSection(Ctx); | 
|  | case wasm::WASM_SEC_MEMORY: | 
|  | return parseMemorySection(Ctx); | 
|  | case wasm::WASM_SEC_TAG: | 
|  | return parseTagSection(Ctx); | 
|  | case wasm::WASM_SEC_GLOBAL: | 
|  | return parseGlobalSection(Ctx); | 
|  | case wasm::WASM_SEC_EXPORT: | 
|  | return parseExportSection(Ctx); | 
|  | case wasm::WASM_SEC_START: | 
|  | return parseStartSection(Ctx); | 
|  | case wasm::WASM_SEC_ELEM: | 
|  | return parseElemSection(Ctx); | 
|  | case wasm::WASM_SEC_CODE: | 
|  | return parseCodeSection(Ctx); | 
|  | case wasm::WASM_SEC_DATA: | 
|  | return parseDataSection(Ctx); | 
|  | case wasm::WASM_SEC_DATACOUNT: | 
|  | return parseDataCountSection(Ctx); | 
|  | default: | 
|  | return make_error<GenericBinaryError>( | 
|  | "invalid section type: " + Twine(Sec.Type), object_error::parse_failed); | 
|  | } | 
|  | } | 
|  |  | 
|  | Error WasmObjectFile::parseDylinkSection(ReadContext &Ctx) { | 
|  | // See https://github.com/WebAssembly/tool-conventions/blob/master/DynamicLinking.md | 
|  | HasDylinkSection = true; | 
|  | DylinkInfo.MemorySize = readVaruint32(Ctx); | 
|  | DylinkInfo.MemoryAlignment = readVaruint32(Ctx); | 
|  | DylinkInfo.TableSize = readVaruint32(Ctx); | 
|  | DylinkInfo.TableAlignment = readVaruint32(Ctx); | 
|  | uint32_t Count = readVaruint32(Ctx); | 
|  | while (Count--) { | 
|  | DylinkInfo.Needed.push_back(readString(Ctx)); | 
|  | } | 
|  | if (Ctx.Ptr != Ctx.End) | 
|  | return make_error<GenericBinaryError>("dylink section ended prematurely", | 
|  | object_error::parse_failed); | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | Error WasmObjectFile::parseNameSection(ReadContext &Ctx) { | 
|  | llvm::DenseSet<uint64_t> SeenFunctions; | 
|  | llvm::DenseSet<uint64_t> SeenGlobals; | 
|  | llvm::DenseSet<uint64_t> SeenSegments; | 
|  | if (FunctionTypes.size() && !SeenCodeSection) { | 
|  | return make_error<GenericBinaryError>("names must come after code section", | 
|  | object_error::parse_failed); | 
|  | } | 
|  |  | 
|  | while (Ctx.Ptr < Ctx.End) { | 
|  | uint8_t Type = readUint8(Ctx); | 
|  | uint32_t Size = readVaruint32(Ctx); | 
|  | const uint8_t *SubSectionEnd = Ctx.Ptr + Size; | 
|  | switch (Type) { | 
|  | case wasm::WASM_NAMES_FUNCTION: | 
|  | case wasm::WASM_NAMES_GLOBAL: | 
|  | case wasm::WASM_NAMES_DATA_SEGMENT: { | 
|  | uint32_t Count = readVaruint32(Ctx); | 
|  | while (Count--) { | 
|  | uint32_t Index = readVaruint32(Ctx); | 
|  | StringRef Name = readString(Ctx); | 
|  | wasm::NameType nameType = wasm::NameType::FUNCTION; | 
|  | if (Type == wasm::WASM_NAMES_FUNCTION) { | 
|  | if (!SeenFunctions.insert(Index).second) | 
|  | return make_error<GenericBinaryError>( | 
|  | "function named more than once", object_error::parse_failed); | 
|  | if (!isValidFunctionIndex(Index) || Name.empty()) | 
|  | return make_error<GenericBinaryError>("invalid name entry", | 
|  | object_error::parse_failed); | 
|  |  | 
|  | if (isDefinedFunctionIndex(Index)) | 
|  | getDefinedFunction(Index).DebugName = Name; | 
|  | } else if (Type == wasm::WASM_NAMES_GLOBAL) { | 
|  | nameType = wasm::NameType::GLOBAL; | 
|  | if (!SeenGlobals.insert(Index).second) | 
|  | return make_error<GenericBinaryError>("global named more than once", | 
|  | object_error::parse_failed); | 
|  | if (!isValidGlobalIndex(Index) || Name.empty()) | 
|  | return make_error<GenericBinaryError>("invalid name entry", | 
|  | object_error::parse_failed); | 
|  | } else { | 
|  | nameType = wasm::NameType::DATA_SEGMENT; | 
|  | if (!SeenSegments.insert(Index).second) | 
|  | return make_error<GenericBinaryError>( | 
|  | "segment named more than once", object_error::parse_failed); | 
|  | if (Index > DataSegments.size()) | 
|  | return make_error<GenericBinaryError>("invalid named data segment", | 
|  | object_error::parse_failed); | 
|  | } | 
|  | DebugNames.push_back(wasm::WasmDebugName{nameType, Index, Name}); | 
|  | } | 
|  | break; | 
|  | } | 
|  | // Ignore local names for now | 
|  | case wasm::WASM_NAMES_LOCAL: | 
|  | default: | 
|  | Ctx.Ptr += Size; | 
|  | break; | 
|  | } | 
|  | if (Ctx.Ptr != SubSectionEnd) | 
|  | return make_error<GenericBinaryError>( | 
|  | "name sub-section ended prematurely", object_error::parse_failed); | 
|  | } | 
|  |  | 
|  | if (Ctx.Ptr != Ctx.End) | 
|  | return make_error<GenericBinaryError>("name section ended prematurely", | 
|  | object_error::parse_failed); | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | Error WasmObjectFile::parseLinkingSection(ReadContext &Ctx) { | 
|  | HasLinkingSection = true; | 
|  | if (FunctionTypes.size() && !SeenCodeSection) { | 
|  | return make_error<GenericBinaryError>( | 
|  | "linking data must come after code section", | 
|  | object_error::parse_failed); | 
|  | } | 
|  |  | 
|  | LinkingData.Version = readVaruint32(Ctx); | 
|  | if (LinkingData.Version != wasm::WasmMetadataVersion) { | 
|  | return make_error<GenericBinaryError>( | 
|  | "unexpected metadata version: " + Twine(LinkingData.Version) + | 
|  | " (Expected: " + Twine(wasm::WasmMetadataVersion) + ")", | 
|  | object_error::parse_failed); | 
|  | } | 
|  |  | 
|  | const uint8_t *OrigEnd = Ctx.End; | 
|  | while (Ctx.Ptr < OrigEnd) { | 
|  | Ctx.End = OrigEnd; | 
|  | uint8_t Type = readUint8(Ctx); | 
|  | uint32_t Size = readVaruint32(Ctx); | 
|  | LLVM_DEBUG(dbgs() << "readSubsection type=" << int(Type) << " size=" << Size | 
|  | << "\n"); | 
|  | Ctx.End = Ctx.Ptr + Size; | 
|  | switch (Type) { | 
|  | case wasm::WASM_SYMBOL_TABLE: | 
|  | if (Error Err = parseLinkingSectionSymtab(Ctx)) | 
|  | return Err; | 
|  | break; | 
|  | case wasm::WASM_SEGMENT_INFO: { | 
|  | uint32_t Count = readVaruint32(Ctx); | 
|  | if (Count > DataSegments.size()) | 
|  | return make_error<GenericBinaryError>("too many segment names", | 
|  | object_error::parse_failed); | 
|  | for (uint32_t I = 0; I < Count; I++) { | 
|  | DataSegments[I].Data.Name = readString(Ctx); | 
|  | DataSegments[I].Data.Alignment = readVaruint32(Ctx); | 
|  | DataSegments[I].Data.LinkingFlags = readVaruint32(Ctx); | 
|  | } | 
|  | break; | 
|  | } | 
|  | case wasm::WASM_INIT_FUNCS: { | 
|  | uint32_t Count = readVaruint32(Ctx); | 
|  | LinkingData.InitFunctions.reserve(Count); | 
|  | for (uint32_t I = 0; I < Count; I++) { | 
|  | wasm::WasmInitFunc Init; | 
|  | Init.Priority = readVaruint32(Ctx); | 
|  | Init.Symbol = readVaruint32(Ctx); | 
|  | if (!isValidFunctionSymbol(Init.Symbol)) | 
|  | return make_error<GenericBinaryError>("invalid function symbol: " + | 
|  | Twine(Init.Symbol), | 
|  | object_error::parse_failed); | 
|  | LinkingData.InitFunctions.emplace_back(Init); | 
|  | } | 
|  | break; | 
|  | } | 
|  | case wasm::WASM_COMDAT_INFO: | 
|  | if (Error Err = parseLinkingSectionComdat(Ctx)) | 
|  | return Err; | 
|  | break; | 
|  | default: | 
|  | Ctx.Ptr += Size; | 
|  | break; | 
|  | } | 
|  | if (Ctx.Ptr != Ctx.End) | 
|  | return make_error<GenericBinaryError>( | 
|  | "linking sub-section ended prematurely", object_error::parse_failed); | 
|  | } | 
|  | if (Ctx.Ptr != OrigEnd) | 
|  | return make_error<GenericBinaryError>("linking section ended prematurely", | 
|  | object_error::parse_failed); | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | Error WasmObjectFile::parseLinkingSectionSymtab(ReadContext &Ctx) { | 
|  | uint32_t Count = readVaruint32(Ctx); | 
|  | LinkingData.SymbolTable.reserve(Count); | 
|  | Symbols.reserve(Count); | 
|  | StringSet<> SymbolNames; | 
|  |  | 
|  | std::vector<wasm::WasmImport *> ImportedGlobals; | 
|  | std::vector<wasm::WasmImport *> ImportedFunctions; | 
|  | std::vector<wasm::WasmImport *> ImportedTags; | 
|  | std::vector<wasm::WasmImport *> ImportedTables; | 
|  | ImportedGlobals.reserve(Imports.size()); | 
|  | ImportedFunctions.reserve(Imports.size()); | 
|  | ImportedTags.reserve(Imports.size()); | 
|  | ImportedTables.reserve(Imports.size()); | 
|  | for (auto &I : Imports) { | 
|  | if (I.Kind == wasm::WASM_EXTERNAL_FUNCTION) | 
|  | ImportedFunctions.emplace_back(&I); | 
|  | else if (I.Kind == wasm::WASM_EXTERNAL_GLOBAL) | 
|  | ImportedGlobals.emplace_back(&I); | 
|  | else if (I.Kind == wasm::WASM_EXTERNAL_TAG) | 
|  | ImportedTags.emplace_back(&I); | 
|  | else if (I.Kind == wasm::WASM_EXTERNAL_TABLE) | 
|  | ImportedTables.emplace_back(&I); | 
|  | } | 
|  |  | 
|  | while (Count--) { | 
|  | wasm::WasmSymbolInfo Info; | 
|  | const wasm::WasmSignature *Signature = nullptr; | 
|  | const wasm::WasmGlobalType *GlobalType = nullptr; | 
|  | const wasm::WasmTableType *TableType = nullptr; | 
|  | const wasm::WasmTagType *TagType = nullptr; | 
|  |  | 
|  | Info.Kind = readUint8(Ctx); | 
|  | Info.Flags = readVaruint32(Ctx); | 
|  | bool IsDefined = (Info.Flags & wasm::WASM_SYMBOL_UNDEFINED) == 0; | 
|  |  | 
|  | switch (Info.Kind) { | 
|  | case wasm::WASM_SYMBOL_TYPE_FUNCTION: | 
|  | Info.ElementIndex = readVaruint32(Ctx); | 
|  | if (!isValidFunctionIndex(Info.ElementIndex) || | 
|  | IsDefined != isDefinedFunctionIndex(Info.ElementIndex)) | 
|  | return make_error<GenericBinaryError>("invalid function symbol index", | 
|  | object_error::parse_failed); | 
|  | if (IsDefined) { | 
|  | Info.Name = readString(Ctx); | 
|  | unsigned FuncIndex = Info.ElementIndex - NumImportedFunctions; | 
|  | Signature = &Signatures[FunctionTypes[FuncIndex]]; | 
|  | wasm::WasmFunction &Function = Functions[FuncIndex]; | 
|  | if (Function.SymbolName.empty()) | 
|  | Function.SymbolName = Info.Name; | 
|  | } else { | 
|  | wasm::WasmImport &Import = *ImportedFunctions[Info.ElementIndex]; | 
|  | if ((Info.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) { | 
|  | Info.Name = readString(Ctx); | 
|  | Info.ImportName = Import.Field; | 
|  | } else { | 
|  | Info.Name = Import.Field; | 
|  | } | 
|  | Signature = &Signatures[Import.SigIndex]; | 
|  | if (!Import.Module.empty()) { | 
|  | Info.ImportModule = Import.Module; | 
|  | } | 
|  | } | 
|  | break; | 
|  |  | 
|  | case wasm::WASM_SYMBOL_TYPE_GLOBAL: | 
|  | Info.ElementIndex = readVaruint32(Ctx); | 
|  | if (!isValidGlobalIndex(Info.ElementIndex) || | 
|  | IsDefined != isDefinedGlobalIndex(Info.ElementIndex)) | 
|  | return make_error<GenericBinaryError>("invalid global symbol index", | 
|  | object_error::parse_failed); | 
|  | if (!IsDefined && (Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) == | 
|  | wasm::WASM_SYMBOL_BINDING_WEAK) | 
|  | return make_error<GenericBinaryError>("undefined weak global symbol", | 
|  | object_error::parse_failed); | 
|  | if (IsDefined) { | 
|  | Info.Name = readString(Ctx); | 
|  | unsigned GlobalIndex = Info.ElementIndex - NumImportedGlobals; | 
|  | wasm::WasmGlobal &Global = Globals[GlobalIndex]; | 
|  | GlobalType = &Global.Type; | 
|  | if (Global.SymbolName.empty()) | 
|  | Global.SymbolName = Info.Name; | 
|  | } else { | 
|  | wasm::WasmImport &Import = *ImportedGlobals[Info.ElementIndex]; | 
|  | if ((Info.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) { | 
|  | Info.Name = readString(Ctx); | 
|  | Info.ImportName = Import.Field; | 
|  | } else { | 
|  | Info.Name = Import.Field; | 
|  | } | 
|  | GlobalType = &Import.Global; | 
|  | if (!Import.Module.empty()) { | 
|  | Info.ImportModule = Import.Module; | 
|  | } | 
|  | } | 
|  | break; | 
|  |  | 
|  | case wasm::WASM_SYMBOL_TYPE_TABLE: | 
|  | Info.ElementIndex = readVaruint32(Ctx); | 
|  | if (!isValidTableNumber(Info.ElementIndex) || | 
|  | IsDefined != isDefinedTableNumber(Info.ElementIndex)) | 
|  | return make_error<GenericBinaryError>("invalid table symbol index", | 
|  | object_error::parse_failed); | 
|  | if (!IsDefined && (Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) == | 
|  | wasm::WASM_SYMBOL_BINDING_WEAK) | 
|  | return make_error<GenericBinaryError>("undefined weak table symbol", | 
|  | object_error::parse_failed); | 
|  | if (IsDefined) { | 
|  | Info.Name = readString(Ctx); | 
|  | unsigned TableNumber = Info.ElementIndex - NumImportedTables; | 
|  | wasm::WasmTable &Table = Tables[TableNumber]; | 
|  | TableType = &Table.Type; | 
|  | if (Table.SymbolName.empty()) | 
|  | Table.SymbolName = Info.Name; | 
|  | } else { | 
|  | wasm::WasmImport &Import = *ImportedTables[Info.ElementIndex]; | 
|  | if ((Info.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) { | 
|  | Info.Name = readString(Ctx); | 
|  | Info.ImportName = Import.Field; | 
|  | } else { | 
|  | Info.Name = Import.Field; | 
|  | } | 
|  | TableType = &Import.Table; | 
|  | if (!Import.Module.empty()) { | 
|  | Info.ImportModule = Import.Module; | 
|  | } | 
|  | } | 
|  | break; | 
|  |  | 
|  | case wasm::WASM_SYMBOL_TYPE_DATA: | 
|  | Info.Name = readString(Ctx); | 
|  | if (IsDefined) { | 
|  | auto Index = readVaruint32(Ctx); | 
|  | if (Index >= DataSegments.size()) | 
|  | return make_error<GenericBinaryError>("invalid data symbol index", | 
|  | object_error::parse_failed); | 
|  | auto Offset = readVaruint64(Ctx); | 
|  | auto Size = readVaruint64(Ctx); | 
|  | size_t SegmentSize = DataSegments[Index].Data.Content.size(); | 
|  | if (Offset > SegmentSize) | 
|  | return make_error<GenericBinaryError>( | 
|  | "invalid data symbol offset: `" + Info.Name + "` (offset: " + | 
|  | Twine(Offset) + " segment size: " + Twine(SegmentSize) + ")", | 
|  | object_error::parse_failed); | 
|  | Info.DataRef = wasm::WasmDataReference{Index, Offset, Size}; | 
|  | } | 
|  | break; | 
|  |  | 
|  | case wasm::WASM_SYMBOL_TYPE_SECTION: { | 
|  | if ((Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) != | 
|  | wasm::WASM_SYMBOL_BINDING_LOCAL) | 
|  | return make_error<GenericBinaryError>( | 
|  | "section symbols must have local binding", | 
|  | object_error::parse_failed); | 
|  | Info.ElementIndex = readVaruint32(Ctx); | 
|  | // Use somewhat unique section name as symbol name. | 
|  | StringRef SectionName = Sections[Info.ElementIndex].Name; | 
|  | Info.Name = SectionName; | 
|  | break; | 
|  | } | 
|  |  | 
|  | case wasm::WASM_SYMBOL_TYPE_TAG: { | 
|  | Info.ElementIndex = readVaruint32(Ctx); | 
|  | if (!isValidTagIndex(Info.ElementIndex) || | 
|  | IsDefined != isDefinedTagIndex(Info.ElementIndex)) | 
|  | return make_error<GenericBinaryError>("invalid tag symbol index", | 
|  | object_error::parse_failed); | 
|  | if (!IsDefined && (Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) == | 
|  | wasm::WASM_SYMBOL_BINDING_WEAK) | 
|  | return make_error<GenericBinaryError>("undefined weak global symbol", | 
|  | object_error::parse_failed); | 
|  | if (IsDefined) { | 
|  | Info.Name = readString(Ctx); | 
|  | unsigned TagIndex = Info.ElementIndex - NumImportedTags; | 
|  | wasm::WasmTag &Tag = Tags[TagIndex]; | 
|  | Signature = &Signatures[Tag.Type.SigIndex]; | 
|  | TagType = &Tag.Type; | 
|  | if (Tag.SymbolName.empty()) | 
|  | Tag.SymbolName = Info.Name; | 
|  |  | 
|  | } else { | 
|  | wasm::WasmImport &Import = *ImportedTags[Info.ElementIndex]; | 
|  | if ((Info.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) { | 
|  | Info.Name = readString(Ctx); | 
|  | Info.ImportName = Import.Field; | 
|  | } else { | 
|  | Info.Name = Import.Field; | 
|  | } | 
|  | TagType = &Import.Tag; | 
|  | Signature = &Signatures[TagType->SigIndex]; | 
|  | if (!Import.Module.empty()) { | 
|  | Info.ImportModule = Import.Module; | 
|  | } | 
|  | } | 
|  | break; | 
|  | } | 
|  |  | 
|  | default: | 
|  | return make_error<GenericBinaryError>("invalid symbol type: " + | 
|  | Twine(unsigned(Info.Kind)), | 
|  | object_error::parse_failed); | 
|  | } | 
|  |  | 
|  | if ((Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) != | 
|  | wasm::WASM_SYMBOL_BINDING_LOCAL && | 
|  | !SymbolNames.insert(Info.Name).second) | 
|  | return make_error<GenericBinaryError>("duplicate symbol name " + | 
|  | Twine(Info.Name), | 
|  | object_error::parse_failed); | 
|  | LinkingData.SymbolTable.emplace_back(Info); | 
|  | Symbols.emplace_back(LinkingData.SymbolTable.back(), GlobalType, TableType, | 
|  | TagType, Signature); | 
|  | LLVM_DEBUG(dbgs() << "Adding symbol: " << Symbols.back() << "\n"); | 
|  | } | 
|  |  | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | Error WasmObjectFile::parseLinkingSectionComdat(ReadContext &Ctx) { | 
|  | uint32_t ComdatCount = readVaruint32(Ctx); | 
|  | StringSet<> ComdatSet; | 
|  | for (unsigned ComdatIndex = 0; ComdatIndex < ComdatCount; ++ComdatIndex) { | 
|  | StringRef Name = readString(Ctx); | 
|  | if (Name.empty() || !ComdatSet.insert(Name).second) | 
|  | return make_error<GenericBinaryError>("bad/duplicate COMDAT name " + | 
|  | Twine(Name), | 
|  | object_error::parse_failed); | 
|  | LinkingData.Comdats.emplace_back(Name); | 
|  | uint32_t Flags = readVaruint32(Ctx); | 
|  | if (Flags != 0) | 
|  | return make_error<GenericBinaryError>("unsupported COMDAT flags", | 
|  | object_error::parse_failed); | 
|  |  | 
|  | uint32_t EntryCount = readVaruint32(Ctx); | 
|  | while (EntryCount--) { | 
|  | unsigned Kind = readVaruint32(Ctx); | 
|  | unsigned Index = readVaruint32(Ctx); | 
|  | switch (Kind) { | 
|  | default: | 
|  | return make_error<GenericBinaryError>("invalid COMDAT entry type", | 
|  | object_error::parse_failed); | 
|  | case wasm::WASM_COMDAT_DATA: | 
|  | if (Index >= DataSegments.size()) | 
|  | return make_error<GenericBinaryError>( | 
|  | "COMDAT data index out of range", object_error::parse_failed); | 
|  | if (DataSegments[Index].Data.Comdat != UINT32_MAX) | 
|  | return make_error<GenericBinaryError>("data segment in two COMDATs", | 
|  | object_error::parse_failed); | 
|  | DataSegments[Index].Data.Comdat = ComdatIndex; | 
|  | break; | 
|  | case wasm::WASM_COMDAT_FUNCTION: | 
|  | if (!isDefinedFunctionIndex(Index)) | 
|  | return make_error<GenericBinaryError>( | 
|  | "COMDAT function index out of range", object_error::parse_failed); | 
|  | if (getDefinedFunction(Index).Comdat != UINT32_MAX) | 
|  | return make_error<GenericBinaryError>("function in two COMDATs", | 
|  | object_error::parse_failed); | 
|  | getDefinedFunction(Index).Comdat = ComdatIndex; | 
|  | break; | 
|  | case wasm::WASM_COMDAT_SECTION: | 
|  | if (Index >= Sections.size()) | 
|  | return make_error<GenericBinaryError>( | 
|  | "COMDAT section index out of range", object_error::parse_failed); | 
|  | if (Sections[Index].Type != wasm::WASM_SEC_CUSTOM) | 
|  | return make_error<GenericBinaryError>( | 
|  | "non-custom section in a COMDAT", object_error::parse_failed); | 
|  | Sections[Index].Comdat = ComdatIndex; | 
|  | break; | 
|  | } | 
|  | } | 
|  | } | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | Error WasmObjectFile::parseProducersSection(ReadContext &Ctx) { | 
|  | llvm::SmallSet<StringRef, 3> FieldsSeen; | 
|  | uint32_t Fields = readVaruint32(Ctx); | 
|  | for (size_t I = 0; I < Fields; ++I) { | 
|  | StringRef FieldName = readString(Ctx); | 
|  | if (!FieldsSeen.insert(FieldName).second) | 
|  | return make_error<GenericBinaryError>( | 
|  | "producers section does not have unique fields", | 
|  | object_error::parse_failed); | 
|  | std::vector<std::pair<std::string, std::string>> *ProducerVec = nullptr; | 
|  | if (FieldName == "language") { | 
|  | ProducerVec = &ProducerInfo.Languages; | 
|  | } else if (FieldName == "processed-by") { | 
|  | ProducerVec = &ProducerInfo.Tools; | 
|  | } else if (FieldName == "sdk") { | 
|  | ProducerVec = &ProducerInfo.SDKs; | 
|  | } else { | 
|  | return make_error<GenericBinaryError>( | 
|  | "producers section field is not named one of language, processed-by, " | 
|  | "or sdk", | 
|  | object_error::parse_failed); | 
|  | } | 
|  | uint32_t ValueCount = readVaruint32(Ctx); | 
|  | llvm::SmallSet<StringRef, 8> ProducersSeen; | 
|  | for (size_t J = 0; J < ValueCount; ++J) { | 
|  | StringRef Name = readString(Ctx); | 
|  | StringRef Version = readString(Ctx); | 
|  | if (!ProducersSeen.insert(Name).second) { | 
|  | return make_error<GenericBinaryError>( | 
|  | "producers section contains repeated producer", | 
|  | object_error::parse_failed); | 
|  | } | 
|  | ProducerVec->emplace_back(std::string(Name), std::string(Version)); | 
|  | } | 
|  | } | 
|  | if (Ctx.Ptr != Ctx.End) | 
|  | return make_error<GenericBinaryError>("producers section ended prematurely", | 
|  | object_error::parse_failed); | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | Error WasmObjectFile::parseTargetFeaturesSection(ReadContext &Ctx) { | 
|  | llvm::SmallSet<std::string, 8> FeaturesSeen; | 
|  | uint32_t FeatureCount = readVaruint32(Ctx); | 
|  | for (size_t I = 0; I < FeatureCount; ++I) { | 
|  | wasm::WasmFeatureEntry Feature; | 
|  | Feature.Prefix = readUint8(Ctx); | 
|  | switch (Feature.Prefix) { | 
|  | case wasm::WASM_FEATURE_PREFIX_USED: | 
|  | case wasm::WASM_FEATURE_PREFIX_REQUIRED: | 
|  | case wasm::WASM_FEATURE_PREFIX_DISALLOWED: | 
|  | break; | 
|  | default: | 
|  | return make_error<GenericBinaryError>("unknown feature policy prefix", | 
|  | object_error::parse_failed); | 
|  | } | 
|  | Feature.Name = std::string(readString(Ctx)); | 
|  | if (!FeaturesSeen.insert(Feature.Name).second) | 
|  | return make_error<GenericBinaryError>( | 
|  | "target features section contains repeated feature \"" + | 
|  | Feature.Name + "\"", | 
|  | object_error::parse_failed); | 
|  | TargetFeatures.push_back(Feature); | 
|  | } | 
|  | if (Ctx.Ptr != Ctx.End) | 
|  | return make_error<GenericBinaryError>( | 
|  | "target features section ended prematurely", | 
|  | object_error::parse_failed); | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | Error WasmObjectFile::parseRelocSection(StringRef Name, ReadContext &Ctx) { | 
|  | uint32_t SectionIndex = readVaruint32(Ctx); | 
|  | if (SectionIndex >= Sections.size()) | 
|  | return make_error<GenericBinaryError>("invalid section index", | 
|  | object_error::parse_failed); | 
|  | WasmSection &Section = Sections[SectionIndex]; | 
|  | uint32_t RelocCount = readVaruint32(Ctx); | 
|  | uint32_t EndOffset = Section.Content.size(); | 
|  | uint32_t PreviousOffset = 0; | 
|  | while (RelocCount--) { | 
|  | wasm::WasmRelocation Reloc = {}; | 
|  | uint32_t type = readVaruint32(Ctx); | 
|  | Reloc.Type = type; | 
|  | Reloc.Offset = readVaruint32(Ctx); | 
|  | if (Reloc.Offset < PreviousOffset) | 
|  | return make_error<GenericBinaryError>("relocations not in offset order", | 
|  | object_error::parse_failed); | 
|  | PreviousOffset = Reloc.Offset; | 
|  | Reloc.Index = readVaruint32(Ctx); | 
|  | switch (type) { | 
|  | case wasm::R_WASM_FUNCTION_INDEX_LEB: | 
|  | case wasm::R_WASM_TABLE_INDEX_SLEB: | 
|  | case wasm::R_WASM_TABLE_INDEX_SLEB64: | 
|  | case wasm::R_WASM_TABLE_INDEX_I32: | 
|  | case wasm::R_WASM_TABLE_INDEX_I64: | 
|  | case wasm::R_WASM_TABLE_INDEX_REL_SLEB: | 
|  | case wasm::R_WASM_TABLE_INDEX_REL_SLEB64: | 
|  | if (!isValidFunctionSymbol(Reloc.Index)) | 
|  | return make_error<GenericBinaryError>( | 
|  | "invalid relocation function index", object_error::parse_failed); | 
|  | break; | 
|  | case wasm::R_WASM_TABLE_NUMBER_LEB: | 
|  | if (!isValidTableSymbol(Reloc.Index)) | 
|  | return make_error<GenericBinaryError>("invalid relocation table index", | 
|  | object_error::parse_failed); | 
|  | break; | 
|  | case wasm::R_WASM_TYPE_INDEX_LEB: | 
|  | if (Reloc.Index >= Signatures.size()) | 
|  | return make_error<GenericBinaryError>("invalid relocation type index", | 
|  | object_error::parse_failed); | 
|  | break; | 
|  | case wasm::R_WASM_GLOBAL_INDEX_LEB: | 
|  | // R_WASM_GLOBAL_INDEX_LEB are can be used against function and data | 
|  | // symbols to refer to their GOT entries. | 
|  | if (!isValidGlobalSymbol(Reloc.Index) && | 
|  | !isValidDataSymbol(Reloc.Index) && | 
|  | !isValidFunctionSymbol(Reloc.Index)) | 
|  | return make_error<GenericBinaryError>("invalid relocation global index", | 
|  | object_error::parse_failed); | 
|  | break; | 
|  | case wasm::R_WASM_GLOBAL_INDEX_I32: | 
|  | if (!isValidGlobalSymbol(Reloc.Index)) | 
|  | return make_error<GenericBinaryError>("invalid relocation global index", | 
|  | object_error::parse_failed); | 
|  | break; | 
|  | case wasm::R_WASM_TAG_INDEX_LEB: | 
|  | if (!isValidTagSymbol(Reloc.Index)) | 
|  | return make_error<GenericBinaryError>("invalid relocation tag index", | 
|  | object_error::parse_failed); | 
|  | break; | 
|  | case wasm::R_WASM_MEMORY_ADDR_LEB: | 
|  | case wasm::R_WASM_MEMORY_ADDR_SLEB: | 
|  | case wasm::R_WASM_MEMORY_ADDR_I32: | 
|  | case wasm::R_WASM_MEMORY_ADDR_REL_SLEB: | 
|  | case wasm::R_WASM_MEMORY_ADDR_TLS_SLEB: | 
|  | case wasm::R_WASM_MEMORY_ADDR_LOCREL_I32: | 
|  | if (!isValidDataSymbol(Reloc.Index)) | 
|  | return make_error<GenericBinaryError>("invalid relocation data index", | 
|  | object_error::parse_failed); | 
|  | Reloc.Addend = readVarint32(Ctx); | 
|  | break; | 
|  | case wasm::R_WASM_MEMORY_ADDR_LEB64: | 
|  | case wasm::R_WASM_MEMORY_ADDR_SLEB64: | 
|  | case wasm::R_WASM_MEMORY_ADDR_I64: | 
|  | case wasm::R_WASM_MEMORY_ADDR_REL_SLEB64: | 
|  | case wasm::R_WASM_MEMORY_ADDR_TLS_SLEB64: | 
|  | if (!isValidDataSymbol(Reloc.Index)) | 
|  | return make_error<GenericBinaryError>("invalid relocation data index", | 
|  | object_error::parse_failed); | 
|  | Reloc.Addend = readVarint64(Ctx); | 
|  | break; | 
|  | case wasm::R_WASM_FUNCTION_OFFSET_I32: | 
|  | if (!isValidFunctionSymbol(Reloc.Index)) | 
|  | return make_error<GenericBinaryError>( | 
|  | "invalid relocation function index", object_error::parse_failed); | 
|  | Reloc.Addend = readVarint32(Ctx); | 
|  | break; | 
|  | case wasm::R_WASM_FUNCTION_OFFSET_I64: | 
|  | if (!isValidFunctionSymbol(Reloc.Index)) | 
|  | return make_error<GenericBinaryError>( | 
|  | "invalid relocation function index", object_error::parse_failed); | 
|  | Reloc.Addend = readVarint64(Ctx); | 
|  | break; | 
|  | case wasm::R_WASM_SECTION_OFFSET_I32: | 
|  | if (!isValidSectionSymbol(Reloc.Index)) | 
|  | return make_error<GenericBinaryError>( | 
|  | "invalid relocation section index", object_error::parse_failed); | 
|  | Reloc.Addend = readVarint32(Ctx); | 
|  | break; | 
|  | default: | 
|  | return make_error<GenericBinaryError>("invalid relocation type: " + | 
|  | Twine(type), | 
|  | object_error::parse_failed); | 
|  | } | 
|  |  | 
|  | // Relocations must fit inside the section, and must appear in order.  They | 
|  | // also shouldn't overlap a function/element boundary, but we don't bother | 
|  | // to check that. | 
|  | uint64_t Size = 5; | 
|  | if (Reloc.Type == wasm::R_WASM_MEMORY_ADDR_LEB64 || | 
|  | Reloc.Type == wasm::R_WASM_MEMORY_ADDR_SLEB64 || | 
|  | Reloc.Type == wasm::R_WASM_MEMORY_ADDR_REL_SLEB64) | 
|  | Size = 10; | 
|  | if (Reloc.Type == wasm::R_WASM_TABLE_INDEX_I32 || | 
|  | Reloc.Type == wasm::R_WASM_MEMORY_ADDR_I32 || | 
|  | Reloc.Type == wasm::R_WASM_MEMORY_ADDR_LOCREL_I32 || | 
|  | Reloc.Type == wasm::R_WASM_SECTION_OFFSET_I32 || | 
|  | Reloc.Type == wasm::R_WASM_FUNCTION_OFFSET_I32 || | 
|  | Reloc.Type == wasm::R_WASM_GLOBAL_INDEX_I32) | 
|  | Size = 4; | 
|  | if (Reloc.Type == wasm::R_WASM_TABLE_INDEX_I64 || | 
|  | Reloc.Type == wasm::R_WASM_MEMORY_ADDR_I64 || | 
|  | Reloc.Type == wasm::R_WASM_FUNCTION_OFFSET_I64) | 
|  | Size = 8; | 
|  | if (Reloc.Offset + Size > EndOffset) | 
|  | return make_error<GenericBinaryError>("invalid relocation offset", | 
|  | object_error::parse_failed); | 
|  |  | 
|  | Section.Relocations.push_back(Reloc); | 
|  | } | 
|  | if (Ctx.Ptr != Ctx.End) | 
|  | return make_error<GenericBinaryError>("reloc section ended prematurely", | 
|  | object_error::parse_failed); | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | Error WasmObjectFile::parseCustomSection(WasmSection &Sec, ReadContext &Ctx) { | 
|  | if (Sec.Name == "dylink") { | 
|  | if (Error Err = parseDylinkSection(Ctx)) | 
|  | return Err; | 
|  | } else if (Sec.Name == "name") { | 
|  | if (Error Err = parseNameSection(Ctx)) | 
|  | return Err; | 
|  | } else if (Sec.Name == "linking") { | 
|  | if (Error Err = parseLinkingSection(Ctx)) | 
|  | return Err; | 
|  | } else if (Sec.Name == "producers") { | 
|  | if (Error Err = parseProducersSection(Ctx)) | 
|  | return Err; | 
|  | } else if (Sec.Name == "target_features") { | 
|  | if (Error Err = parseTargetFeaturesSection(Ctx)) | 
|  | return Err; | 
|  | } else if (Sec.Name.startswith("reloc.")) { | 
|  | if (Error Err = parseRelocSection(Sec.Name, Ctx)) | 
|  | return Err; | 
|  | } | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | Error WasmObjectFile::parseTypeSection(ReadContext &Ctx) { | 
|  | uint32_t Count = readVaruint32(Ctx); | 
|  | Signatures.reserve(Count); | 
|  | while (Count--) { | 
|  | wasm::WasmSignature Sig; | 
|  | uint8_t Form = readUint8(Ctx); | 
|  | if (Form != wasm::WASM_TYPE_FUNC) { | 
|  | return make_error<GenericBinaryError>("invalid signature type", | 
|  | object_error::parse_failed); | 
|  | } | 
|  | uint32_t ParamCount = readVaruint32(Ctx); | 
|  | Sig.Params.reserve(ParamCount); | 
|  | while (ParamCount--) { | 
|  | uint32_t ParamType = readUint8(Ctx); | 
|  | Sig.Params.push_back(wasm::ValType(ParamType)); | 
|  | } | 
|  | uint32_t ReturnCount = readVaruint32(Ctx); | 
|  | while (ReturnCount--) { | 
|  | uint32_t ReturnType = readUint8(Ctx); | 
|  | Sig.Returns.push_back(wasm::ValType(ReturnType)); | 
|  | } | 
|  | Signatures.push_back(std::move(Sig)); | 
|  | } | 
|  | if (Ctx.Ptr != Ctx.End) | 
|  | return make_error<GenericBinaryError>("type section ended prematurely", | 
|  | object_error::parse_failed); | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | Error WasmObjectFile::parseImportSection(ReadContext &Ctx) { | 
|  | uint32_t Count = readVaruint32(Ctx); | 
|  | Imports.reserve(Count); | 
|  | for (uint32_t I = 0; I < Count; I++) { | 
|  | wasm::WasmImport Im; | 
|  | Im.Module = readString(Ctx); | 
|  | Im.Field = readString(Ctx); | 
|  | Im.Kind = readUint8(Ctx); | 
|  | switch (Im.Kind) { | 
|  | case wasm::WASM_EXTERNAL_FUNCTION: | 
|  | NumImportedFunctions++; | 
|  | Im.SigIndex = readVaruint32(Ctx); | 
|  | break; | 
|  | case wasm::WASM_EXTERNAL_GLOBAL: | 
|  | NumImportedGlobals++; | 
|  | Im.Global.Type = readUint8(Ctx); | 
|  | Im.Global.Mutable = readVaruint1(Ctx); | 
|  | break; | 
|  | case wasm::WASM_EXTERNAL_MEMORY: | 
|  | Im.Memory = readLimits(Ctx); | 
|  | if (Im.Memory.Flags & wasm::WASM_LIMITS_FLAG_IS_64) | 
|  | HasMemory64 = true; | 
|  | break; | 
|  | case wasm::WASM_EXTERNAL_TABLE: { | 
|  | Im.Table = readTableType(Ctx); | 
|  | NumImportedTables++; | 
|  | auto ElemType = Im.Table.ElemType; | 
|  | if (ElemType != wasm::WASM_TYPE_FUNCREF && | 
|  | ElemType != wasm::WASM_TYPE_EXTERNREF) | 
|  | return make_error<GenericBinaryError>("invalid table element type", | 
|  | object_error::parse_failed); | 
|  | break; | 
|  | } | 
|  | case wasm::WASM_EXTERNAL_TAG: | 
|  | NumImportedTags++; | 
|  | Im.Tag.Attribute = readUint8(Ctx); | 
|  | Im.Tag.SigIndex = readVarint32(Ctx); | 
|  | break; | 
|  | default: | 
|  | return make_error<GenericBinaryError>("unexpected import kind", | 
|  | object_error::parse_failed); | 
|  | } | 
|  | Imports.push_back(Im); | 
|  | } | 
|  | if (Ctx.Ptr != Ctx.End) | 
|  | return make_error<GenericBinaryError>("import section ended prematurely", | 
|  | object_error::parse_failed); | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | Error WasmObjectFile::parseFunctionSection(ReadContext &Ctx) { | 
|  | uint32_t Count = readVaruint32(Ctx); | 
|  | FunctionTypes.reserve(Count); | 
|  | Functions.resize(Count); | 
|  | uint32_t NumTypes = Signatures.size(); | 
|  | while (Count--) { | 
|  | uint32_t Type = readVaruint32(Ctx); | 
|  | if (Type >= NumTypes) | 
|  | return make_error<GenericBinaryError>("invalid function type", | 
|  | object_error::parse_failed); | 
|  | FunctionTypes.push_back(Type); | 
|  | } | 
|  | if (Ctx.Ptr != Ctx.End) | 
|  | return make_error<GenericBinaryError>("function section ended prematurely", | 
|  | object_error::parse_failed); | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | Error WasmObjectFile::parseTableSection(ReadContext &Ctx) { | 
|  | TableSection = Sections.size(); | 
|  | uint32_t Count = readVaruint32(Ctx); | 
|  | Tables.reserve(Count); | 
|  | while (Count--) { | 
|  | wasm::WasmTable T; | 
|  | T.Type = readTableType(Ctx); | 
|  | T.Index = NumImportedTables + Tables.size(); | 
|  | Tables.push_back(T); | 
|  | auto ElemType = Tables.back().Type.ElemType; | 
|  | if (ElemType != wasm::WASM_TYPE_FUNCREF && | 
|  | ElemType != wasm::WASM_TYPE_EXTERNREF) { | 
|  | return make_error<GenericBinaryError>("invalid table element type", | 
|  | object_error::parse_failed); | 
|  | } | 
|  | } | 
|  | if (Ctx.Ptr != Ctx.End) | 
|  | return make_error<GenericBinaryError>("table section ended prematurely", | 
|  | object_error::parse_failed); | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | Error WasmObjectFile::parseMemorySection(ReadContext &Ctx) { | 
|  | uint32_t Count = readVaruint32(Ctx); | 
|  | Memories.reserve(Count); | 
|  | while (Count--) { | 
|  | auto Limits = readLimits(Ctx); | 
|  | if (Limits.Flags & wasm::WASM_LIMITS_FLAG_IS_64) | 
|  | HasMemory64 = true; | 
|  | Memories.push_back(Limits); | 
|  | } | 
|  | if (Ctx.Ptr != Ctx.End) | 
|  | return make_error<GenericBinaryError>("memory section ended prematurely", | 
|  | object_error::parse_failed); | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | Error WasmObjectFile::parseTagSection(ReadContext &Ctx) { | 
|  | TagSection = Sections.size(); | 
|  | uint32_t Count = readVaruint32(Ctx); | 
|  | Tags.reserve(Count); | 
|  | while (Count--) { | 
|  | wasm::WasmTag Tag; | 
|  | Tag.Index = NumImportedTags + Tags.size(); | 
|  | Tag.Type.Attribute = readUint8(Ctx); | 
|  | Tag.Type.SigIndex = readVaruint32(Ctx); | 
|  | Tags.push_back(Tag); | 
|  | } | 
|  |  | 
|  | if (Ctx.Ptr != Ctx.End) | 
|  | return make_error<GenericBinaryError>("tag section ended prematurely", | 
|  | object_error::parse_failed); | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | Error WasmObjectFile::parseGlobalSection(ReadContext &Ctx) { | 
|  | GlobalSection = Sections.size(); | 
|  | uint32_t Count = readVaruint32(Ctx); | 
|  | Globals.reserve(Count); | 
|  | while (Count--) { | 
|  | wasm::WasmGlobal Global; | 
|  | Global.Index = NumImportedGlobals + Globals.size(); | 
|  | Global.Type.Type = readUint8(Ctx); | 
|  | Global.Type.Mutable = readVaruint1(Ctx); | 
|  | if (Error Err = readInitExpr(Global.InitExpr, Ctx)) | 
|  | return Err; | 
|  | Globals.push_back(Global); | 
|  | } | 
|  | if (Ctx.Ptr != Ctx.End) | 
|  | return make_error<GenericBinaryError>("global section ended prematurely", | 
|  | object_error::parse_failed); | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | Error WasmObjectFile::parseExportSection(ReadContext &Ctx) { | 
|  | uint32_t Count = readVaruint32(Ctx); | 
|  | Exports.reserve(Count); | 
|  | for (uint32_t I = 0; I < Count; I++) { | 
|  | wasm::WasmExport Ex; | 
|  | Ex.Name = readString(Ctx); | 
|  | Ex.Kind = readUint8(Ctx); | 
|  | Ex.Index = readVaruint32(Ctx); | 
|  | switch (Ex.Kind) { | 
|  | case wasm::WASM_EXTERNAL_FUNCTION: | 
|  |  | 
|  | if (!isDefinedFunctionIndex(Ex.Index)) | 
|  | return make_error<GenericBinaryError>("invalid function export", | 
|  | object_error::parse_failed); | 
|  | getDefinedFunction(Ex.Index).ExportName = Ex.Name; | 
|  | break; | 
|  | case wasm::WASM_EXTERNAL_GLOBAL: | 
|  | if (!isValidGlobalIndex(Ex.Index)) | 
|  | return make_error<GenericBinaryError>("invalid global export", | 
|  | object_error::parse_failed); | 
|  | break; | 
|  | case wasm::WASM_EXTERNAL_TAG: | 
|  | if (!isValidTagIndex(Ex.Index)) | 
|  | return make_error<GenericBinaryError>("invalid tag export", | 
|  | object_error::parse_failed); | 
|  | break; | 
|  | case wasm::WASM_EXTERNAL_MEMORY: | 
|  | case wasm::WASM_EXTERNAL_TABLE: | 
|  | break; | 
|  | default: | 
|  | return make_error<GenericBinaryError>("unexpected export kind", | 
|  | object_error::parse_failed); | 
|  | } | 
|  | Exports.push_back(Ex); | 
|  | } | 
|  | if (Ctx.Ptr != Ctx.End) | 
|  | return make_error<GenericBinaryError>("export section ended prematurely", | 
|  | object_error::parse_failed); | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | bool WasmObjectFile::isValidFunctionIndex(uint32_t Index) const { | 
|  | return Index < NumImportedFunctions + FunctionTypes.size(); | 
|  | } | 
|  |  | 
|  | bool WasmObjectFile::isDefinedFunctionIndex(uint32_t Index) const { | 
|  | return Index >= NumImportedFunctions && isValidFunctionIndex(Index); | 
|  | } | 
|  |  | 
|  | bool WasmObjectFile::isValidGlobalIndex(uint32_t Index) const { | 
|  | return Index < NumImportedGlobals + Globals.size(); | 
|  | } | 
|  |  | 
|  | bool WasmObjectFile::isValidTableNumber(uint32_t Index) const { | 
|  | return Index < NumImportedTables + Tables.size(); | 
|  | } | 
|  |  | 
|  | bool WasmObjectFile::isDefinedGlobalIndex(uint32_t Index) const { | 
|  | return Index >= NumImportedGlobals && isValidGlobalIndex(Index); | 
|  | } | 
|  |  | 
|  | bool WasmObjectFile::isDefinedTableNumber(uint32_t Index) const { | 
|  | return Index >= NumImportedTables && isValidTableNumber(Index); | 
|  | } | 
|  |  | 
|  | bool WasmObjectFile::isValidTagIndex(uint32_t Index) const { | 
|  | return Index < NumImportedTags + Tags.size(); | 
|  | } | 
|  |  | 
|  | bool WasmObjectFile::isDefinedTagIndex(uint32_t Index) const { | 
|  | return Index >= NumImportedTags && isValidTagIndex(Index); | 
|  | } | 
|  |  | 
|  | bool WasmObjectFile::isValidFunctionSymbol(uint32_t Index) const { | 
|  | return Index < Symbols.size() && Symbols[Index].isTypeFunction(); | 
|  | } | 
|  |  | 
|  | bool WasmObjectFile::isValidTableSymbol(uint32_t Index) const { | 
|  | return Index < Symbols.size() && Symbols[Index].isTypeTable(); | 
|  | } | 
|  |  | 
|  | bool WasmObjectFile::isValidGlobalSymbol(uint32_t Index) const { | 
|  | return Index < Symbols.size() && Symbols[Index].isTypeGlobal(); | 
|  | } | 
|  |  | 
|  | bool WasmObjectFile::isValidTagSymbol(uint32_t Index) const { | 
|  | return Index < Symbols.size() && Symbols[Index].isTypeTag(); | 
|  | } | 
|  |  | 
|  | bool WasmObjectFile::isValidDataSymbol(uint32_t Index) const { | 
|  | return Index < Symbols.size() && Symbols[Index].isTypeData(); | 
|  | } | 
|  |  | 
|  | bool WasmObjectFile::isValidSectionSymbol(uint32_t Index) const { | 
|  | return Index < Symbols.size() && Symbols[Index].isTypeSection(); | 
|  | } | 
|  |  | 
|  | wasm::WasmFunction &WasmObjectFile::getDefinedFunction(uint32_t Index) { | 
|  | assert(isDefinedFunctionIndex(Index)); | 
|  | return Functions[Index - NumImportedFunctions]; | 
|  | } | 
|  |  | 
|  | const wasm::WasmFunction & | 
|  | WasmObjectFile::getDefinedFunction(uint32_t Index) const { | 
|  | assert(isDefinedFunctionIndex(Index)); | 
|  | return Functions[Index - NumImportedFunctions]; | 
|  | } | 
|  |  | 
|  | wasm::WasmGlobal &WasmObjectFile::getDefinedGlobal(uint32_t Index) { | 
|  | assert(isDefinedGlobalIndex(Index)); | 
|  | return Globals[Index - NumImportedGlobals]; | 
|  | } | 
|  |  | 
|  | wasm::WasmTag &WasmObjectFile::getDefinedTag(uint32_t Index) { | 
|  | assert(isDefinedTagIndex(Index)); | 
|  | return Tags[Index - NumImportedTags]; | 
|  | } | 
|  |  | 
|  | Error WasmObjectFile::parseStartSection(ReadContext &Ctx) { | 
|  | StartFunction = readVaruint32(Ctx); | 
|  | if (!isValidFunctionIndex(StartFunction)) | 
|  | return make_error<GenericBinaryError>("invalid start function", | 
|  | object_error::parse_failed); | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | Error WasmObjectFile::parseCodeSection(ReadContext &Ctx) { | 
|  | SeenCodeSection = true; | 
|  | CodeSection = Sections.size(); | 
|  | uint32_t FunctionCount = readVaruint32(Ctx); | 
|  | if (FunctionCount != FunctionTypes.size()) { | 
|  | return make_error<GenericBinaryError>("invalid function count", | 
|  | object_error::parse_failed); | 
|  | } | 
|  |  | 
|  | for (uint32_t i = 0; i < FunctionCount; i++) { | 
|  | wasm::WasmFunction& Function = Functions[i]; | 
|  | const uint8_t *FunctionStart = Ctx.Ptr; | 
|  | uint32_t Size = readVaruint32(Ctx); | 
|  | const uint8_t *FunctionEnd = Ctx.Ptr + Size; | 
|  |  | 
|  | Function.CodeOffset = Ctx.Ptr - FunctionStart; | 
|  | Function.Index = NumImportedFunctions + i; | 
|  | Function.CodeSectionOffset = FunctionStart - Ctx.Start; | 
|  | Function.Size = FunctionEnd - FunctionStart; | 
|  |  | 
|  | uint32_t NumLocalDecls = readVaruint32(Ctx); | 
|  | Function.Locals.reserve(NumLocalDecls); | 
|  | while (NumLocalDecls--) { | 
|  | wasm::WasmLocalDecl Decl; | 
|  | Decl.Count = readVaruint32(Ctx); | 
|  | Decl.Type = readUint8(Ctx); | 
|  | Function.Locals.push_back(Decl); | 
|  | } | 
|  |  | 
|  | uint32_t BodySize = FunctionEnd - Ctx.Ptr; | 
|  | Function.Body = ArrayRef<uint8_t>(Ctx.Ptr, BodySize); | 
|  | // This will be set later when reading in the linking metadata section. | 
|  | Function.Comdat = UINT32_MAX; | 
|  | Ctx.Ptr += BodySize; | 
|  | assert(Ctx.Ptr == FunctionEnd); | 
|  | } | 
|  | if (Ctx.Ptr != Ctx.End) | 
|  | return make_error<GenericBinaryError>("code section ended prematurely", | 
|  | object_error::parse_failed); | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | Error WasmObjectFile::parseElemSection(ReadContext &Ctx) { | 
|  | uint32_t Count = readVaruint32(Ctx); | 
|  | ElemSegments.reserve(Count); | 
|  | while (Count--) { | 
|  | wasm::WasmElemSegment Segment; | 
|  | Segment.Flags = readVaruint32(Ctx); | 
|  |  | 
|  | uint32_t SupportedFlags = wasm::WASM_ELEM_SEGMENT_HAS_TABLE_NUMBER | | 
|  | wasm::WASM_ELEM_SEGMENT_IS_PASSIVE | | 
|  | wasm::WASM_ELEM_SEGMENT_HAS_INIT_EXPRS; | 
|  | if (Segment.Flags & ~SupportedFlags) | 
|  | return make_error<GenericBinaryError>( | 
|  | "Unsupported flags for element segment", object_error::parse_failed); | 
|  |  | 
|  | if (Segment.Flags & wasm::WASM_ELEM_SEGMENT_HAS_TABLE_NUMBER) | 
|  | Segment.TableNumber = readVaruint32(Ctx); | 
|  | else | 
|  | Segment.TableNumber = 0; | 
|  | if (!isValidTableNumber(Segment.TableNumber)) | 
|  | return make_error<GenericBinaryError>("invalid TableNumber", | 
|  | object_error::parse_failed); | 
|  |  | 
|  | if (Segment.Flags & wasm::WASM_ELEM_SEGMENT_IS_PASSIVE) { | 
|  | Segment.Offset.Opcode = wasm::WASM_OPCODE_I32_CONST; | 
|  | Segment.Offset.Value.Int32 = 0; | 
|  | } else { | 
|  | if (Error Err = readInitExpr(Segment.Offset, Ctx)) | 
|  | return Err; | 
|  | } | 
|  |  | 
|  | if (Segment.Flags & wasm::WASM_ELEM_SEGMENT_MASK_HAS_ELEM_KIND) { | 
|  | Segment.ElemKind = readUint8(Ctx); | 
|  | if (Segment.Flags & wasm::WASM_ELEM_SEGMENT_HAS_INIT_EXPRS) { | 
|  | if (Segment.ElemKind != uint8_t(wasm::ValType::FUNCREF) && | 
|  | Segment.ElemKind != uint8_t(wasm::ValType::EXTERNREF)) { | 
|  | return make_error<GenericBinaryError>("invalid reference type", | 
|  | object_error::parse_failed); | 
|  | } | 
|  | } else { | 
|  | if (Segment.ElemKind != 0) | 
|  | return make_error<GenericBinaryError>("invalid elemtype", | 
|  | object_error::parse_failed); | 
|  | Segment.ElemKind = uint8_t(wasm::ValType::FUNCREF); | 
|  | } | 
|  | } else { | 
|  | Segment.ElemKind = uint8_t(wasm::ValType::FUNCREF); | 
|  | } | 
|  |  | 
|  | if (Segment.Flags & wasm::WASM_ELEM_SEGMENT_HAS_INIT_EXPRS) | 
|  | return make_error<GenericBinaryError>( | 
|  | "elem segment init expressions not yet implemented", | 
|  | object_error::parse_failed); | 
|  |  | 
|  | uint32_t NumElems = readVaruint32(Ctx); | 
|  | while (NumElems--) { | 
|  | Segment.Functions.push_back(readVaruint32(Ctx)); | 
|  | } | 
|  | ElemSegments.push_back(Segment); | 
|  | } | 
|  | if (Ctx.Ptr != Ctx.End) | 
|  | return make_error<GenericBinaryError>("elem section ended prematurely", | 
|  | object_error::parse_failed); | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | Error WasmObjectFile::parseDataSection(ReadContext &Ctx) { | 
|  | DataSection = Sections.size(); | 
|  | uint32_t Count = readVaruint32(Ctx); | 
|  | if (DataCount && Count != DataCount.getValue()) | 
|  | return make_error<GenericBinaryError>( | 
|  | "number of data segments does not match DataCount section"); | 
|  | DataSegments.reserve(Count); | 
|  | while (Count--) { | 
|  | WasmSegment Segment; | 
|  | Segment.Data.InitFlags = readVaruint32(Ctx); | 
|  | Segment.Data.MemoryIndex = | 
|  | (Segment.Data.InitFlags & wasm::WASM_DATA_SEGMENT_HAS_MEMINDEX) | 
|  | ? readVaruint32(Ctx) | 
|  | : 0; | 
|  | if ((Segment.Data.InitFlags & wasm::WASM_DATA_SEGMENT_IS_PASSIVE) == 0) { | 
|  | if (Error Err = readInitExpr(Segment.Data.Offset, Ctx)) | 
|  | return Err; | 
|  | } else { | 
|  | Segment.Data.Offset.Opcode = wasm::WASM_OPCODE_I32_CONST; | 
|  | Segment.Data.Offset.Value.Int32 = 0; | 
|  | } | 
|  | uint32_t Size = readVaruint32(Ctx); | 
|  | if (Size > (size_t)(Ctx.End - Ctx.Ptr)) | 
|  | return make_error<GenericBinaryError>("invalid segment size", | 
|  | object_error::parse_failed); | 
|  | Segment.Data.Content = ArrayRef<uint8_t>(Ctx.Ptr, Size); | 
|  | // The rest of these Data fields are set later, when reading in the linking | 
|  | // metadata section. | 
|  | Segment.Data.Alignment = 0; | 
|  | Segment.Data.LinkingFlags = 0; | 
|  | Segment.Data.Comdat = UINT32_MAX; | 
|  | Segment.SectionOffset = Ctx.Ptr - Ctx.Start; | 
|  | Ctx.Ptr += Size; | 
|  | DataSegments.push_back(Segment); | 
|  | } | 
|  | if (Ctx.Ptr != Ctx.End) | 
|  | return make_error<GenericBinaryError>("data section ended prematurely", | 
|  | object_error::parse_failed); | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | Error WasmObjectFile::parseDataCountSection(ReadContext &Ctx) { | 
|  | DataCount = readVaruint32(Ctx); | 
|  | return Error::success(); | 
|  | } | 
|  |  | 
|  | const wasm::WasmObjectHeader &WasmObjectFile::getHeader() const { | 
|  | return Header; | 
|  | } | 
|  |  | 
|  | void WasmObjectFile::moveSymbolNext(DataRefImpl &Symb) const { Symb.d.b++; } | 
|  |  | 
|  | Expected<uint32_t> WasmObjectFile::getSymbolFlags(DataRefImpl Symb) const { | 
|  | uint32_t Result = SymbolRef::SF_None; | 
|  | const WasmSymbol &Sym = getWasmSymbol(Symb); | 
|  |  | 
|  | LLVM_DEBUG(dbgs() << "getSymbolFlags: ptr=" << &Sym << " " << Sym << "\n"); | 
|  | if (Sym.isBindingWeak()) | 
|  | Result |= SymbolRef::SF_Weak; | 
|  | if (!Sym.isBindingLocal()) | 
|  | Result |= SymbolRef::SF_Global; | 
|  | if (Sym.isHidden()) | 
|  | Result |= SymbolRef::SF_Hidden; | 
|  | if (!Sym.isDefined()) | 
|  | Result |= SymbolRef::SF_Undefined; | 
|  | if (Sym.isTypeFunction()) | 
|  | Result |= SymbolRef::SF_Executable; | 
|  | return Result; | 
|  | } | 
|  |  | 
|  | basic_symbol_iterator WasmObjectFile::symbol_begin() const { | 
|  | DataRefImpl Ref; | 
|  | Ref.d.a = 1; // Arbitrary non-zero value so that Ref.p is non-null | 
|  | Ref.d.b = 0; // Symbol index | 
|  | return BasicSymbolRef(Ref, this); | 
|  | } | 
|  |  | 
|  | basic_symbol_iterator WasmObjectFile::symbol_end() const { | 
|  | DataRefImpl Ref; | 
|  | Ref.d.a = 1; // Arbitrary non-zero value so that Ref.p is non-null | 
|  | Ref.d.b = Symbols.size(); // Symbol index | 
|  | return BasicSymbolRef(Ref, this); | 
|  | } | 
|  |  | 
|  | const WasmSymbol &WasmObjectFile::getWasmSymbol(const DataRefImpl &Symb) const { | 
|  | return Symbols[Symb.d.b]; | 
|  | } | 
|  |  | 
|  | const WasmSymbol &WasmObjectFile::getWasmSymbol(const SymbolRef &Symb) const { | 
|  | return getWasmSymbol(Symb.getRawDataRefImpl()); | 
|  | } | 
|  |  | 
|  | Expected<StringRef> WasmObjectFile::getSymbolName(DataRefImpl Symb) const { | 
|  | return getWasmSymbol(Symb).Info.Name; | 
|  | } | 
|  |  | 
|  | Expected<uint64_t> WasmObjectFile::getSymbolAddress(DataRefImpl Symb) const { | 
|  | auto &Sym = getWasmSymbol(Symb); | 
|  | if (Sym.Info.Kind == wasm::WASM_SYMBOL_TYPE_FUNCTION && | 
|  | isDefinedFunctionIndex(Sym.Info.ElementIndex)) | 
|  | return getDefinedFunction(Sym.Info.ElementIndex).CodeSectionOffset; | 
|  | else | 
|  | return getSymbolValue(Symb); | 
|  | } | 
|  |  | 
|  | uint64_t WasmObjectFile::getWasmSymbolValue(const WasmSymbol &Sym) const { | 
|  | switch (Sym.Info.Kind) { | 
|  | case wasm::WASM_SYMBOL_TYPE_FUNCTION: | 
|  | case wasm::WASM_SYMBOL_TYPE_GLOBAL: | 
|  | case wasm::WASM_SYMBOL_TYPE_TAG: | 
|  | case wasm::WASM_SYMBOL_TYPE_TABLE: | 
|  | return Sym.Info.ElementIndex; | 
|  | case wasm::WASM_SYMBOL_TYPE_DATA: { | 
|  | // The value of a data symbol is the segment offset, plus the symbol | 
|  | // offset within the segment. | 
|  | uint32_t SegmentIndex = Sym.Info.DataRef.Segment; | 
|  | const wasm::WasmDataSegment &Segment = DataSegments[SegmentIndex].Data; | 
|  | if (Segment.Offset.Opcode == wasm::WASM_OPCODE_I32_CONST) { | 
|  | return Segment.Offset.Value.Int32 + Sym.Info.DataRef.Offset; | 
|  | } else if (Segment.Offset.Opcode == wasm::WASM_OPCODE_I64_CONST) { | 
|  | return Segment.Offset.Value.Int64 + Sym.Info.DataRef.Offset; | 
|  | } else { | 
|  | llvm_unreachable("unknown init expr opcode"); | 
|  | } | 
|  | } | 
|  | case wasm::WASM_SYMBOL_TYPE_SECTION: | 
|  | return 0; | 
|  | } | 
|  | llvm_unreachable("invalid symbol type"); | 
|  | } | 
|  |  | 
|  | uint64_t WasmObjectFile::getSymbolValueImpl(DataRefImpl Symb) const { | 
|  | return getWasmSymbolValue(getWasmSymbol(Symb)); | 
|  | } | 
|  |  | 
|  | uint32_t WasmObjectFile::getSymbolAlignment(DataRefImpl Symb) const { | 
|  | llvm_unreachable("not yet implemented"); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | uint64_t WasmObjectFile::getCommonSymbolSizeImpl(DataRefImpl Symb) const { | 
|  | llvm_unreachable("not yet implemented"); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | Expected<SymbolRef::Type> | 
|  | WasmObjectFile::getSymbolType(DataRefImpl Symb) const { | 
|  | const WasmSymbol &Sym = getWasmSymbol(Symb); | 
|  |  | 
|  | switch (Sym.Info.Kind) { | 
|  | case wasm::WASM_SYMBOL_TYPE_FUNCTION: | 
|  | return SymbolRef::ST_Function; | 
|  | case wasm::WASM_SYMBOL_TYPE_GLOBAL: | 
|  | return SymbolRef::ST_Other; | 
|  | case wasm::WASM_SYMBOL_TYPE_DATA: | 
|  | return SymbolRef::ST_Data; | 
|  | case wasm::WASM_SYMBOL_TYPE_SECTION: | 
|  | return SymbolRef::ST_Debug; | 
|  | case wasm::WASM_SYMBOL_TYPE_TAG: | 
|  | return SymbolRef::ST_Other; | 
|  | case wasm::WASM_SYMBOL_TYPE_TABLE: | 
|  | return SymbolRef::ST_Other; | 
|  | } | 
|  |  | 
|  | llvm_unreachable("unknown WasmSymbol::SymbolType"); | 
|  | return SymbolRef::ST_Other; | 
|  | } | 
|  |  | 
|  | Expected<section_iterator> | 
|  | WasmObjectFile::getSymbolSection(DataRefImpl Symb) const { | 
|  | const WasmSymbol &Sym = getWasmSymbol(Symb); | 
|  | if (Sym.isUndefined()) | 
|  | return section_end(); | 
|  |  | 
|  | DataRefImpl Ref; | 
|  | Ref.d.a = getSymbolSectionIdImpl(Sym); | 
|  | return section_iterator(SectionRef(Ref, this)); | 
|  | } | 
|  |  | 
|  | uint32_t WasmObjectFile::getSymbolSectionId(SymbolRef Symb) const { | 
|  | const WasmSymbol &Sym = getWasmSymbol(Symb); | 
|  | return getSymbolSectionIdImpl(Sym); | 
|  | } | 
|  |  | 
|  | uint32_t WasmObjectFile::getSymbolSectionIdImpl(const WasmSymbol &Sym) const { | 
|  | switch (Sym.Info.Kind) { | 
|  | case wasm::WASM_SYMBOL_TYPE_FUNCTION: | 
|  | return CodeSection; | 
|  | case wasm::WASM_SYMBOL_TYPE_GLOBAL: | 
|  | return GlobalSection; | 
|  | case wasm::WASM_SYMBOL_TYPE_DATA: | 
|  | return DataSection; | 
|  | case wasm::WASM_SYMBOL_TYPE_SECTION: | 
|  | return Sym.Info.ElementIndex; | 
|  | case wasm::WASM_SYMBOL_TYPE_TAG: | 
|  | return TagSection; | 
|  | case wasm::WASM_SYMBOL_TYPE_TABLE: | 
|  | return TableSection; | 
|  | default: | 
|  | llvm_unreachable("unknown WasmSymbol::SymbolType"); | 
|  | } | 
|  | } | 
|  |  | 
|  | void WasmObjectFile::moveSectionNext(DataRefImpl &Sec) const { Sec.d.a++; } | 
|  |  | 
|  | Expected<StringRef> WasmObjectFile::getSectionName(DataRefImpl Sec) const { | 
|  | const WasmSection &S = Sections[Sec.d.a]; | 
|  | #define ECase(X)                                                               \ | 
|  | case wasm::WASM_SEC_##X:                                                     \ | 
|  | return #X; | 
|  | switch (S.Type) { | 
|  | ECase(TYPE); | 
|  | ECase(IMPORT); | 
|  | ECase(FUNCTION); | 
|  | ECase(TABLE); | 
|  | ECase(MEMORY); | 
|  | ECase(GLOBAL); | 
|  | ECase(TAG); | 
|  | ECase(EXPORT); | 
|  | ECase(START); | 
|  | ECase(ELEM); | 
|  | ECase(CODE); | 
|  | ECase(DATA); | 
|  | ECase(DATACOUNT); | 
|  | case wasm::WASM_SEC_CUSTOM: | 
|  | return S.Name; | 
|  | default: | 
|  | return createStringError(object_error::invalid_section_index, ""); | 
|  | } | 
|  | #undef ECase | 
|  | } | 
|  |  | 
|  | uint64_t WasmObjectFile::getSectionAddress(DataRefImpl Sec) const { return 0; } | 
|  |  | 
|  | uint64_t WasmObjectFile::getSectionIndex(DataRefImpl Sec) const { | 
|  | return Sec.d.a; | 
|  | } | 
|  |  | 
|  | uint64_t WasmObjectFile::getSectionSize(DataRefImpl Sec) const { | 
|  | const WasmSection &S = Sections[Sec.d.a]; | 
|  | return S.Content.size(); | 
|  | } | 
|  |  | 
|  | Expected<ArrayRef<uint8_t>> | 
|  | WasmObjectFile::getSectionContents(DataRefImpl Sec) const { | 
|  | const WasmSection &S = Sections[Sec.d.a]; | 
|  | // This will never fail since wasm sections can never be empty (user-sections | 
|  | // must have a name and non-user sections each have a defined structure). | 
|  | return S.Content; | 
|  | } | 
|  |  | 
|  | uint64_t WasmObjectFile::getSectionAlignment(DataRefImpl Sec) const { | 
|  | return 1; | 
|  | } | 
|  |  | 
|  | bool WasmObjectFile::isSectionCompressed(DataRefImpl Sec) const { | 
|  | return false; | 
|  | } | 
|  |  | 
|  | bool WasmObjectFile::isSectionText(DataRefImpl Sec) const { | 
|  | return getWasmSection(Sec).Type == wasm::WASM_SEC_CODE; | 
|  | } | 
|  |  | 
|  | bool WasmObjectFile::isSectionData(DataRefImpl Sec) const { | 
|  | return getWasmSection(Sec).Type == wasm::WASM_SEC_DATA; | 
|  | } | 
|  |  | 
|  | bool WasmObjectFile::isSectionBSS(DataRefImpl Sec) const { return false; } | 
|  |  | 
|  | bool WasmObjectFile::isSectionVirtual(DataRefImpl Sec) const { return false; } | 
|  |  | 
|  | relocation_iterator WasmObjectFile::section_rel_begin(DataRefImpl Ref) const { | 
|  | DataRefImpl RelocRef; | 
|  | RelocRef.d.a = Ref.d.a; | 
|  | RelocRef.d.b = 0; | 
|  | return relocation_iterator(RelocationRef(RelocRef, this)); | 
|  | } | 
|  |  | 
|  | relocation_iterator WasmObjectFile::section_rel_end(DataRefImpl Ref) const { | 
|  | const WasmSection &Sec = getWasmSection(Ref); | 
|  | DataRefImpl RelocRef; | 
|  | RelocRef.d.a = Ref.d.a; | 
|  | RelocRef.d.b = Sec.Relocations.size(); | 
|  | return relocation_iterator(RelocationRef(RelocRef, this)); | 
|  | } | 
|  |  | 
|  | void WasmObjectFile::moveRelocationNext(DataRefImpl &Rel) const { Rel.d.b++; } | 
|  |  | 
|  | uint64_t WasmObjectFile::getRelocationOffset(DataRefImpl Ref) const { | 
|  | const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); | 
|  | return Rel.Offset; | 
|  | } | 
|  |  | 
|  | symbol_iterator WasmObjectFile::getRelocationSymbol(DataRefImpl Ref) const { | 
|  | const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); | 
|  | if (Rel.Type == wasm::R_WASM_TYPE_INDEX_LEB) | 
|  | return symbol_end(); | 
|  | DataRefImpl Sym; | 
|  | Sym.d.a = 1; | 
|  | Sym.d.b = Rel.Index; | 
|  | return symbol_iterator(SymbolRef(Sym, this)); | 
|  | } | 
|  |  | 
|  | uint64_t WasmObjectFile::getRelocationType(DataRefImpl Ref) const { | 
|  | const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); | 
|  | return Rel.Type; | 
|  | } | 
|  |  | 
|  | void WasmObjectFile::getRelocationTypeName( | 
|  | DataRefImpl Ref, SmallVectorImpl<char> &Result) const { | 
|  | const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); | 
|  | StringRef Res = "Unknown"; | 
|  |  | 
|  | #define WASM_RELOC(name, value)                                                \ | 
|  | case wasm::name:                                                             \ | 
|  | Res = #name;                                                               \ | 
|  | break; | 
|  |  | 
|  | switch (Rel.Type) { | 
|  | #include "llvm/BinaryFormat/WasmRelocs.def" | 
|  | } | 
|  |  | 
|  | #undef WASM_RELOC | 
|  |  | 
|  | Result.append(Res.begin(), Res.end()); | 
|  | } | 
|  |  | 
|  | section_iterator WasmObjectFile::section_begin() const { | 
|  | DataRefImpl Ref; | 
|  | Ref.d.a = 0; | 
|  | return section_iterator(SectionRef(Ref, this)); | 
|  | } | 
|  |  | 
|  | section_iterator WasmObjectFile::section_end() const { | 
|  | DataRefImpl Ref; | 
|  | Ref.d.a = Sections.size(); | 
|  | return section_iterator(SectionRef(Ref, this)); | 
|  | } | 
|  |  | 
|  | uint8_t WasmObjectFile::getBytesInAddress() const { | 
|  | return HasMemory64 ? 8 : 4; | 
|  | } | 
|  |  | 
|  | StringRef WasmObjectFile::getFileFormatName() const { return "WASM"; } | 
|  |  | 
|  | Triple::ArchType WasmObjectFile::getArch() const { | 
|  | return HasMemory64 ? Triple::wasm64 : Triple::wasm32; | 
|  | } | 
|  |  | 
|  | SubtargetFeatures WasmObjectFile::getFeatures() const { | 
|  | return SubtargetFeatures(); | 
|  | } | 
|  |  | 
|  | bool WasmObjectFile::isRelocatableObject() const { return HasLinkingSection; } | 
|  |  | 
|  | bool WasmObjectFile::isSharedObject() const { return HasDylinkSection; } | 
|  |  | 
|  | const WasmSection &WasmObjectFile::getWasmSection(DataRefImpl Ref) const { | 
|  | assert(Ref.d.a < Sections.size()); | 
|  | return Sections[Ref.d.a]; | 
|  | } | 
|  |  | 
|  | const WasmSection & | 
|  | WasmObjectFile::getWasmSection(const SectionRef &Section) const { | 
|  | return getWasmSection(Section.getRawDataRefImpl()); | 
|  | } | 
|  |  | 
|  | const wasm::WasmRelocation & | 
|  | WasmObjectFile::getWasmRelocation(const RelocationRef &Ref) const { | 
|  | return getWasmRelocation(Ref.getRawDataRefImpl()); | 
|  | } | 
|  |  | 
|  | const wasm::WasmRelocation & | 
|  | WasmObjectFile::getWasmRelocation(DataRefImpl Ref) const { | 
|  | assert(Ref.d.a < Sections.size()); | 
|  | const WasmSection &Sec = Sections[Ref.d.a]; | 
|  | assert(Ref.d.b < Sec.Relocations.size()); | 
|  | return Sec.Relocations[Ref.d.b]; | 
|  | } | 
|  |  | 
|  | int WasmSectionOrderChecker::getSectionOrder(unsigned ID, | 
|  | StringRef CustomSectionName) { | 
|  | switch (ID) { | 
|  | case wasm::WASM_SEC_CUSTOM: | 
|  | return StringSwitch<unsigned>(CustomSectionName) | 
|  | .Case("dylink", WASM_SEC_ORDER_DYLINK) | 
|  | .Case("linking", WASM_SEC_ORDER_LINKING) | 
|  | .StartsWith("reloc.", WASM_SEC_ORDER_RELOC) | 
|  | .Case("name", WASM_SEC_ORDER_NAME) | 
|  | .Case("producers", WASM_SEC_ORDER_PRODUCERS) | 
|  | .Case("target_features", WASM_SEC_ORDER_TARGET_FEATURES) | 
|  | .Default(WASM_SEC_ORDER_NONE); | 
|  | case wasm::WASM_SEC_TYPE: | 
|  | return WASM_SEC_ORDER_TYPE; | 
|  | case wasm::WASM_SEC_IMPORT: | 
|  | return WASM_SEC_ORDER_IMPORT; | 
|  | case wasm::WASM_SEC_FUNCTION: | 
|  | return WASM_SEC_ORDER_FUNCTION; | 
|  | case wasm::WASM_SEC_TABLE: | 
|  | return WASM_SEC_ORDER_TABLE; | 
|  | case wasm::WASM_SEC_MEMORY: | 
|  | return WASM_SEC_ORDER_MEMORY; | 
|  | case wasm::WASM_SEC_GLOBAL: | 
|  | return WASM_SEC_ORDER_GLOBAL; | 
|  | case wasm::WASM_SEC_EXPORT: | 
|  | return WASM_SEC_ORDER_EXPORT; | 
|  | case wasm::WASM_SEC_START: | 
|  | return WASM_SEC_ORDER_START; | 
|  | case wasm::WASM_SEC_ELEM: | 
|  | return WASM_SEC_ORDER_ELEM; | 
|  | case wasm::WASM_SEC_CODE: | 
|  | return WASM_SEC_ORDER_CODE; | 
|  | case wasm::WASM_SEC_DATA: | 
|  | return WASM_SEC_ORDER_DATA; | 
|  | case wasm::WASM_SEC_DATACOUNT: | 
|  | return WASM_SEC_ORDER_DATACOUNT; | 
|  | case wasm::WASM_SEC_TAG: | 
|  | return WASM_SEC_ORDER_TAG; | 
|  | default: | 
|  | return WASM_SEC_ORDER_NONE; | 
|  | } | 
|  | } | 
|  |  | 
|  | // Represents the edges in a directed graph where any node B reachable from node | 
|  | // A is not allowed to appear before A in the section ordering, but may appear | 
|  | // afterward. | 
|  | int WasmSectionOrderChecker::DisallowedPredecessors | 
|  | [WASM_NUM_SEC_ORDERS][WASM_NUM_SEC_ORDERS] = { | 
|  | // WASM_SEC_ORDER_NONE | 
|  | {}, | 
|  | // WASM_SEC_ORDER_TYPE | 
|  | {WASM_SEC_ORDER_TYPE, WASM_SEC_ORDER_IMPORT}, | 
|  | // WASM_SEC_ORDER_IMPORT | 
|  | {WASM_SEC_ORDER_IMPORT, WASM_SEC_ORDER_FUNCTION}, | 
|  | // WASM_SEC_ORDER_FUNCTION | 
|  | {WASM_SEC_ORDER_FUNCTION, WASM_SEC_ORDER_TABLE}, | 
|  | // WASM_SEC_ORDER_TABLE | 
|  | {WASM_SEC_ORDER_TABLE, WASM_SEC_ORDER_MEMORY}, | 
|  | // WASM_SEC_ORDER_MEMORY | 
|  | {WASM_SEC_ORDER_MEMORY, WASM_SEC_ORDER_TAG}, | 
|  | // WASM_SEC_ORDER_TAG | 
|  | {WASM_SEC_ORDER_TAG, WASM_SEC_ORDER_GLOBAL}, | 
|  | // WASM_SEC_ORDER_GLOBAL | 
|  | {WASM_SEC_ORDER_GLOBAL, WASM_SEC_ORDER_EXPORT}, | 
|  | // WASM_SEC_ORDER_EXPORT | 
|  | {WASM_SEC_ORDER_EXPORT, WASM_SEC_ORDER_START}, | 
|  | // WASM_SEC_ORDER_START | 
|  | {WASM_SEC_ORDER_START, WASM_SEC_ORDER_ELEM}, | 
|  | // WASM_SEC_ORDER_ELEM | 
|  | {WASM_SEC_ORDER_ELEM, WASM_SEC_ORDER_DATACOUNT}, | 
|  | // WASM_SEC_ORDER_DATACOUNT | 
|  | {WASM_SEC_ORDER_DATACOUNT, WASM_SEC_ORDER_CODE}, | 
|  | // WASM_SEC_ORDER_CODE | 
|  | {WASM_SEC_ORDER_CODE, WASM_SEC_ORDER_DATA}, | 
|  | // WASM_SEC_ORDER_DATA | 
|  | {WASM_SEC_ORDER_DATA, WASM_SEC_ORDER_LINKING}, | 
|  |  | 
|  | // Custom Sections | 
|  | // WASM_SEC_ORDER_DYLINK | 
|  | {WASM_SEC_ORDER_DYLINK, WASM_SEC_ORDER_TYPE}, | 
|  | // WASM_SEC_ORDER_LINKING | 
|  | {WASM_SEC_ORDER_LINKING, WASM_SEC_ORDER_RELOC, WASM_SEC_ORDER_NAME}, | 
|  | // WASM_SEC_ORDER_RELOC (can be repeated) | 
|  | {}, | 
|  | // WASM_SEC_ORDER_NAME | 
|  | {WASM_SEC_ORDER_NAME, WASM_SEC_ORDER_PRODUCERS}, | 
|  | // WASM_SEC_ORDER_PRODUCERS | 
|  | {WASM_SEC_ORDER_PRODUCERS, WASM_SEC_ORDER_TARGET_FEATURES}, | 
|  | // WASM_SEC_ORDER_TARGET_FEATURES | 
|  | {WASM_SEC_ORDER_TARGET_FEATURES}}; | 
|  |  | 
|  | bool WasmSectionOrderChecker::isValidSectionOrder(unsigned ID, | 
|  | StringRef CustomSectionName) { | 
|  | int Order = getSectionOrder(ID, CustomSectionName); | 
|  | if (Order == WASM_SEC_ORDER_NONE) | 
|  | return true; | 
|  |  | 
|  | // Disallowed predecessors we need to check for | 
|  | SmallVector<int, WASM_NUM_SEC_ORDERS> WorkList; | 
|  |  | 
|  | // Keep track of completed checks to avoid repeating work | 
|  | bool Checked[WASM_NUM_SEC_ORDERS] = {}; | 
|  |  | 
|  | int Curr = Order; | 
|  | while (true) { | 
|  | // Add new disallowed predecessors to work list | 
|  | for (size_t I = 0;; ++I) { | 
|  | int Next = DisallowedPredecessors[Curr][I]; | 
|  | if (Next == WASM_SEC_ORDER_NONE) | 
|  | break; | 
|  | if (Checked[Next]) | 
|  | continue; | 
|  | WorkList.push_back(Next); | 
|  | Checked[Next] = true; | 
|  | } | 
|  |  | 
|  | if (WorkList.empty()) | 
|  | break; | 
|  |  | 
|  | // Consider next disallowed predecessor | 
|  | Curr = WorkList.pop_back_val(); | 
|  | if (Seen[Curr]) | 
|  | return false; | 
|  | } | 
|  |  | 
|  | // Have not seen any disallowed predecessors | 
|  | Seen[Order] = true; | 
|  | return true; | 
|  | } |