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//===- WasmObjectFile.cpp - Wasm object file implementation ---------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/StringSet.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 <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=" << 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 = llvm::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) {
int32_t Result = 0;
memcpy(&Result, Ctx.Ptr, sizeof(Result));
Ctx.Ptr += sizeof(Result);
return Result;
}
static int64_t readFloat64(WasmObjectFile::ReadContext &Ctx) {
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 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_GET_GLOBAL:
Expr.Value.Global = readULEB128(Ctx);
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 = readVaruint1(Ctx);
Result.Initial = readVaruint32(Ctx);
if (Result.Flags & wasm::WASM_LIMITS_FLAG_HAS_MAX)
Result.Maximum = readVaruint32(Ctx);
return Result;
}
static wasm::WasmTable readTable(WasmObjectFile::ReadContext &Ctx) {
wasm::WasmTable Table;
Table.ElemType = readUint8(Ctx);
Table.Limits = readLimits(Ctx);
return Table;
}
static Error readSection(WasmSection &Section,
WasmObjectFile::ReadContext &Ctx) {
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) {
const uint8_t *NameStart = Ctx.Ptr;
Section.Name = readString(Ctx);
Size -= Ctx.Ptr - NameStart;
}
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>("Bad magic number",
object_error::parse_failed);
return;
}
ReadContext Ctx;
Ctx.Start = getPtr(0);
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>("Bad version number",
object_error::parse_failed);
return;
}
WasmSection Sec;
while (Ctx.Ptr < Ctx.End) {
if ((Err = readSection(Sec, Ctx)))
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_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);
default:
return make_error<GenericBinaryError>("Bad section type",
object_error::parse_failed);
}
}
Error WasmObjectFile::parseNameSection(ReadContext &Ctx) {
llvm::DenseSet<uint64_t> Seen;
if (Functions.size() != FunctionTypes.size()) {
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: {
uint32_t Count = readVaruint32(Ctx);
while (Count--) {
uint32_t Index = readVaruint32(Ctx);
if (!Seen.insert(Index).second)
return make_error<GenericBinaryError>("Function named more than once",
object_error::parse_failed);
StringRef Name = readString(Ctx);
if (!isValidFunctionIndex(Index) || Name.empty())
return make_error<GenericBinaryError>("Invalid name entry",
object_error::parse_failed);
DebugNames.push_back(wasm::WasmFunctionName{Index, Name});
if (isDefinedFunctionIndex(Index))
getDefinedFunction(Index).DebugName = 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 (Functions.size() != FunctionTypes.size()) {
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.Flags = 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;
ImportedGlobals.reserve(Imports.size());
ImportedFunctions.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);
}
while (Count--) {
wasm::WasmSymbolInfo Info;
const wasm::WasmSignature *FunctionType = nullptr;
const wasm::WasmGlobalType *GlobalType = 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;
FunctionType = &Signatures[FunctionTypes[FuncIndex]];
wasm::WasmFunction &Function = Functions[FuncIndex];
if (Function.SymbolName.empty())
Function.SymbolName = Info.Name;
} else {
wasm::WasmImport &Import = *ImportedFunctions[Info.ElementIndex];
FunctionType = &Signatures[Import.SigIndex];
Info.Name = Import.Field;
Info.Module = 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];
Info.Name = Import.Field;
GlobalType = &Import.Global;
}
break;
case wasm::WASM_SYMBOL_TYPE_DATA:
Info.Name = readString(Ctx);
if (IsDefined) {
uint32_t Index = readVaruint32(Ctx);
if (Index >= DataSegments.size())
return make_error<GenericBinaryError>("invalid data symbol index",
object_error::parse_failed);
uint32_t Offset = readVaruint32(Ctx);
uint32_t Size = readVaruint32(Ctx);
if (Offset + Size > DataSegments[Index].Data.Content.size())
return make_error<GenericBinaryError>("invalid data symbol offset",
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;
}
default:
return make_error<GenericBinaryError>("Invalid symbol type",
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(), FunctionType,
GlobalType);
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;
}
}
}
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();
while (RelocCount--) {
wasm::WasmRelocation Reloc = {};
Reloc.Type = readVaruint32(Ctx);
Reloc.Offset = readVaruint32(Ctx);
Reloc.Index = readVaruint32(Ctx);
switch (Reloc.Type) {
case wasm::R_WEBASSEMBLY_FUNCTION_INDEX_LEB:
case wasm::R_WEBASSEMBLY_TABLE_INDEX_SLEB:
case wasm::R_WEBASSEMBLY_TABLE_INDEX_I32:
if (!isValidFunctionSymbol(Reloc.Index))
return make_error<GenericBinaryError>("Bad relocation function index",
object_error::parse_failed);
break;
case wasm::R_WEBASSEMBLY_TYPE_INDEX_LEB:
if (Reloc.Index >= Signatures.size())
return make_error<GenericBinaryError>("Bad relocation type index",
object_error::parse_failed);
break;
case wasm::R_WEBASSEMBLY_GLOBAL_INDEX_LEB:
if (!isValidGlobalSymbol(Reloc.Index))
return make_error<GenericBinaryError>("Bad relocation global index",
object_error::parse_failed);
break;
case wasm::R_WEBASSEMBLY_MEMORY_ADDR_LEB:
case wasm::R_WEBASSEMBLY_MEMORY_ADDR_SLEB:
case wasm::R_WEBASSEMBLY_MEMORY_ADDR_I32:
if (!isValidDataSymbol(Reloc.Index))
return make_error<GenericBinaryError>("Bad relocation data index",
object_error::parse_failed);
Reloc.Addend = readVarint32(Ctx);
break;
case wasm::R_WEBASSEMBLY_FUNCTION_OFFSET_I32:
if (!isValidFunctionSymbol(Reloc.Index))
return make_error<GenericBinaryError>("Bad relocation function index",
object_error::parse_failed);
Reloc.Addend = readVarint32(Ctx);
break;
case wasm::R_WEBASSEMBLY_SECTION_OFFSET_I32:
if (!isValidSectionSymbol(Reloc.Index))
return make_error<GenericBinaryError>("Bad relocation section index",
object_error::parse_failed);
Reloc.Addend = readVarint32(Ctx);
break;
default:
return make_error<GenericBinaryError>("Bad relocation type: " +
Twine(Reloc.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_WEBASSEMBLY_TABLE_INDEX_I32 ||
Reloc.Type == wasm::R_WEBASSEMBLY_MEMORY_ADDR_I32 ||
Reloc.Type == wasm::R_WEBASSEMBLY_SECTION_OFFSET_I32 ||
Reloc.Type == wasm::R_WEBASSEMBLY_FUNCTION_OFFSET_I32)
Size = 4;
if (Reloc.Offset + Size > EndOffset)
return make_error<GenericBinaryError>("Bad 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 == "name") {
if (Error Err = parseNameSection(Ctx))
return Err;
} else if (Sec.Name == "linking") {
if (Error Err = parseLinkingSection(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;
Sig.ReturnType = wasm::WASM_TYPE_NORESULT;
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.ParamTypes.reserve(ParamCount);
while (ParamCount--) {
uint32_t ParamType = readUint8(Ctx);
Sig.ParamTypes.push_back(ParamType);
}
uint32_t ReturnCount = readVaruint32(Ctx);
if (ReturnCount) {
if (ReturnCount != 1) {
return make_error<GenericBinaryError>(
"Multiple return types not supported", object_error::parse_failed);
}
Sig.ReturnType = readUint8(Ctx);
}
Signatures.push_back(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);
break;
case wasm::WASM_EXTERNAL_TABLE:
Im.Table = readTable(Ctx);
if (Im.Table.ElemType != wasm::WASM_TYPE_ANYFUNC)
return make_error<GenericBinaryError>("Invalid table element type",
object_error::parse_failed);
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);
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) {
uint32_t Count = readVaruint32(Ctx);
Tables.reserve(Count);
while (Count--) {
Tables.push_back(readTable(Ctx));
if (Tables.back().ElemType != wasm::WASM_TYPE_ANYFUNC) {
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--) {
Memories.push_back(readLimits(Ctx));
}
if (Ctx.Ptr != Ctx.End)
return make_error<GenericBinaryError>("Memory 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 (!isValidFunctionIndex(Ex.Index))
return make_error<GenericBinaryError>("Invalid function export",
object_error::parse_failed);
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_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::isDefinedGlobalIndex(uint32_t Index) const {
return Index >= NumImportedGlobals && isValidGlobalIndex(Index);
}
bool WasmObjectFile::isValidFunctionSymbol(uint32_t Index) const {
return Index < Symbols.size() && Symbols[Index].isTypeFunction();
}
bool WasmObjectFile::isValidGlobalSymbol(uint32_t Index) const {
return Index < Symbols.size() && Symbols[Index].isTypeGlobal();
}
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];
}
wasm::WasmGlobal &WasmObjectFile::getDefinedGlobal(uint32_t Index) {
assert(isDefinedGlobalIndex(Index));
return Globals[Index - NumImportedGlobals];
}
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) {
CodeSection = Sections.size();
uint32_t FunctionCount = readVaruint32(Ctx);
if (FunctionCount != FunctionTypes.size()) {
return make_error<GenericBinaryError>("Invalid function count",
object_error::parse_failed);
}
while (FunctionCount--) {
wasm::WasmFunction Function;
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 + Functions.size();
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);
Functions.push_back(Function);
}
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.TableIndex = readVaruint32(Ctx);
if (Segment.TableIndex != 0) {
return make_error<GenericBinaryError>("Invalid TableIndex",
object_error::parse_failed);
}
if (Error Err = readInitExpr(Segment.Offset, Ctx))
return Err;
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);
DataSegments.reserve(Count);
while (Count--) {
WasmSegment Segment;
Segment.Data.MemoryIndex = readVaruint32(Ctx);
if (Error Err = readInitExpr(Segment.Data.Offset, Ctx))
return Err;
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.Flags = 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();
}
const uint8_t *WasmObjectFile::getPtr(size_t Offset) const {
return reinterpret_cast<const uint8_t *>(getData().data() + Offset);
}
const wasm::WasmObjectHeader &WasmObjectFile::getHeader() const {
return Header;
}
void WasmObjectFile::moveSymbolNext(DataRefImpl &Symb) const { Symb.d.a++; }
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 = 0;
return BasicSymbolRef(Ref, this);
}
basic_symbol_iterator WasmObjectFile::symbol_end() const {
DataRefImpl Ref;
Ref.d.a = Symbols.size();
return BasicSymbolRef(Ref, this);
}
const WasmSymbol &WasmObjectFile::getWasmSymbol(const DataRefImpl &Symb) const {
return Symbols[Symb.d.a];
}
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 {
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:
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;
assert(Segment.Offset.Opcode == wasm::WASM_OPCODE_I32_CONST);
return Segment.Offset.Value.Int32 + Sym.Info.DataRef.Offset;
}
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;
}
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;
switch (Sym.Info.Kind) {
case wasm::WASM_SYMBOL_TYPE_FUNCTION:
Ref.d.a = CodeSection;
break;
case wasm::WASM_SYMBOL_TYPE_GLOBAL:
Ref.d.a = GlobalSection;
break;
case wasm::WASM_SYMBOL_TYPE_DATA:
Ref.d.a = DataSection;
break;
case wasm::WASM_SYMBOL_TYPE_SECTION: {
Ref.d.a = Sym.Info.ElementIndex;
break;
}
default:
llvm_unreachable("Unknown WasmSymbol::SymbolType");
}
return section_iterator(SectionRef(Ref, this));
}
void WasmObjectFile::moveSectionNext(DataRefImpl &Sec) const { Sec.d.a++; }
std::error_code WasmObjectFile::getSectionName(DataRefImpl Sec,
StringRef &Res) const {
const WasmSection &S = Sections[Sec.d.a];
#define ECase(X) \
case wasm::WASM_SEC_##X: \
Res = #X; \
break
switch (S.Type) {
ECase(TYPE);
ECase(IMPORT);
ECase(FUNCTION);
ECase(TABLE);
ECase(MEMORY);
ECase(GLOBAL);
ECase(EXPORT);
ECase(START);
ECase(ELEM);
ECase(CODE);
ECase(DATA);
case wasm::WASM_SEC_CUSTOM:
Res = S.Name;
break;
default:
return object_error::invalid_section_index;
}
#undef ECase
return std::error_code();
}
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();
}
std::error_code WasmObjectFile::getSectionContents(DataRefImpl Sec,
StringRef &Res) 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).
Res = StringRef(reinterpret_cast<const char *>(S.Content.data()),
S.Content.size());
return std::error_code();
}
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; }
bool WasmObjectFile::isSectionBitcode(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_WEBASSEMBLY_TYPE_INDEX_LEB)
return symbol_end();
DataRefImpl Sym;
Sym.d.a = Rel.Index;
Sym.d.b = 0;
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 4; }
StringRef WasmObjectFile::getFileFormatName() const { return "WASM"; }
Triple::ArchType WasmObjectFile::getArch() const { return Triple::wasm32; }
SubtargetFeatures WasmObjectFile::getFeatures() const {
return SubtargetFeatures();
}
bool WasmObjectFile::isRelocatableObject() const {
return HasLinkingSection;
}
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];
}