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//===- Wasm.h - Wasm object file implementation -----------------*- C++ -*-===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// This file declares the WasmObjectFile class, which implements the ObjectFile
// interface for Wasm files.
// See:
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/BinaryFormat/Wasm.h"
#include "llvm/Config/llvm-config.h"
#include "llvm/MC/MCSymbolWasm.h"
#include "llvm/Object/Binary.h"
#include "llvm/Object/ObjectFile.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/MemoryBuffer.h"
#include <cstddef>
#include <cstdint>
#include <vector>
namespace llvm {
namespace object {
class WasmSymbol {
WasmSymbol(const wasm::WasmSymbolInfo &Info,
const wasm::WasmGlobalType *GlobalType,
const wasm::WasmEventType *EventType,
const wasm::WasmSignature *Signature)
: Info(Info), GlobalType(GlobalType), EventType(EventType),
Signature(Signature) {}
const wasm::WasmSymbolInfo &Info;
const wasm::WasmGlobalType *GlobalType;
const wasm::WasmEventType *EventType;
const wasm::WasmSignature *Signature;
bool isTypeFunction() const {
return Info.Kind == wasm::WASM_SYMBOL_TYPE_FUNCTION;
bool isTypeData() const { return Info.Kind == wasm::WASM_SYMBOL_TYPE_DATA; }
bool isTypeGlobal() const {
return Info.Kind == wasm::WASM_SYMBOL_TYPE_GLOBAL;
bool isTypeSection() const {
return Info.Kind == wasm::WASM_SYMBOL_TYPE_SECTION;
bool isTypeEvent() const { return Info.Kind == wasm::WASM_SYMBOL_TYPE_EVENT; }
bool isDefined() const { return !isUndefined(); }
bool isUndefined() const {
return (Info.Flags & wasm::WASM_SYMBOL_UNDEFINED) != 0;
bool isBindingWeak() const {
return getBinding() == wasm::WASM_SYMBOL_BINDING_WEAK;
bool isBindingGlobal() const {
return getBinding() == wasm::WASM_SYMBOL_BINDING_GLOBAL;
bool isBindingLocal() const {
return getBinding() == wasm::WASM_SYMBOL_BINDING_LOCAL;
unsigned getBinding() const {
return Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK;
bool isHidden() const {
return getVisibility() == wasm::WASM_SYMBOL_VISIBILITY_HIDDEN;
unsigned getVisibility() const {
return Info.Flags & wasm::WASM_SYMBOL_VISIBILITY_MASK;
void print(raw_ostream &Out) const;
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
LLVM_DUMP_METHOD void dump() const;
struct WasmSection {
WasmSection() = default;
uint32_t Type = 0; // Section type (See below)
uint32_t Offset = 0; // Offset with in the file
StringRef Name; // Section name (User-defined sections only)
ArrayRef<uint8_t> Content; // Section content
std::vector<wasm::WasmRelocation> Relocations; // Relocations for this section
struct WasmSegment {
uint32_t SectionOffset;
wasm::WasmDataSegment Data;
class WasmObjectFile : public ObjectFile {
WasmObjectFile(MemoryBufferRef Object, Error &Err);
const wasm::WasmObjectHeader &getHeader() const;
const WasmSymbol &getWasmSymbol(const DataRefImpl &Symb) const;
const WasmSymbol &getWasmSymbol(const SymbolRef &Symbol) const;
const WasmSection &getWasmSection(const SectionRef &Section) const;
const wasm::WasmRelocation &getWasmRelocation(const RelocationRef &Ref) const;
static bool classof(const Binary *v) { return v->isWasm(); }
const wasm::WasmDylinkInfo &dylinkInfo() const { return DylinkInfo; }
const wasm::WasmProducerInfo &getProducerInfo() const { return ProducerInfo; }
ArrayRef<wasm::WasmFeatureEntry> getTargetFeatures() const {
return TargetFeatures;
ArrayRef<wasm::WasmSignature> types() const { return Signatures; }
ArrayRef<uint32_t> functionTypes() const { return FunctionTypes; }
ArrayRef<wasm::WasmImport> imports() const { return Imports; }
ArrayRef<wasm::WasmTable> tables() const { return Tables; }
ArrayRef<wasm::WasmLimits> memories() const { return Memories; }
ArrayRef<wasm::WasmGlobal> globals() const { return Globals; }
ArrayRef<wasm::WasmEvent> events() const { return Events; }
ArrayRef<wasm::WasmExport> exports() const { return Exports; }
ArrayRef<WasmSymbol> syms() const { return Symbols; }
const wasm::WasmLinkingData &linkingData() const { return LinkingData; }
uint32_t getNumberOfSymbols() const { return Symbols.size(); }
ArrayRef<wasm::WasmElemSegment> elements() const { return ElemSegments; }
ArrayRef<WasmSegment> dataSegments() const { return DataSegments; }
ArrayRef<wasm::WasmFunction> functions() const { return Functions; }
ArrayRef<wasm::WasmFunctionName> debugNames() const { return DebugNames; }
uint32_t startFunction() const { return StartFunction; }
uint32_t getNumImportedGlobals() const { return NumImportedGlobals; }
uint32_t getNumImportedFunctions() const { return NumImportedFunctions; }
uint32_t getNumImportedEvents() const { return NumImportedEvents; }
void moveSymbolNext(DataRefImpl &Symb) const override;
uint32_t getSymbolFlags(DataRefImpl Symb) const override;
basic_symbol_iterator symbol_begin() const override;
basic_symbol_iterator symbol_end() const override;
Expected<StringRef> getSymbolName(DataRefImpl Symb) const override;
Expected<uint64_t> getSymbolAddress(DataRefImpl Symb) const override;
uint64_t getWasmSymbolValue(const WasmSymbol &Sym) const;
uint64_t getSymbolValueImpl(DataRefImpl Symb) const override;
uint32_t getSymbolAlignment(DataRefImpl Symb) const override;
uint64_t getCommonSymbolSizeImpl(DataRefImpl Symb) const override;
Expected<SymbolRef::Type> getSymbolType(DataRefImpl Symb) const override;
Expected<section_iterator> getSymbolSection(DataRefImpl Symb) const override;
// Overrides from SectionRef.
void moveSectionNext(DataRefImpl &Sec) const override;
std::error_code getSectionName(DataRefImpl Sec,
StringRef &Res) const override;
uint64_t getSectionAddress(DataRefImpl Sec) const override;
uint64_t getSectionIndex(DataRefImpl Sec) const override;
uint64_t getSectionSize(DataRefImpl Sec) const override;
std::error_code getSectionContents(DataRefImpl Sec,
StringRef &Res) const override;
uint64_t getSectionAlignment(DataRefImpl Sec) const override;
bool isSectionCompressed(DataRefImpl Sec) const override;
bool isSectionText(DataRefImpl Sec) const override;
bool isSectionData(DataRefImpl Sec) const override;
bool isSectionBSS(DataRefImpl Sec) const override;
bool isSectionVirtual(DataRefImpl Sec) const override;
bool isSectionBitcode(DataRefImpl Sec) const override;
relocation_iterator section_rel_begin(DataRefImpl Sec) const override;
relocation_iterator section_rel_end(DataRefImpl Sec) const override;
// Overrides from RelocationRef.
void moveRelocationNext(DataRefImpl &Rel) const override;
uint64_t getRelocationOffset(DataRefImpl Rel) const override;
symbol_iterator getRelocationSymbol(DataRefImpl Rel) const override;
uint64_t getRelocationType(DataRefImpl Rel) const override;
void getRelocationTypeName(DataRefImpl Rel,
SmallVectorImpl<char> &Result) const override;
section_iterator section_begin() const override;
section_iterator section_end() const override;
uint8_t getBytesInAddress() const override;
StringRef getFileFormatName() const override;
Triple::ArchType getArch() const override;
SubtargetFeatures getFeatures() const override;
bool isRelocatableObject() const override;
bool isSharedObject() const;
struct ReadContext {
const uint8_t *Start;
const uint8_t *Ptr;
const uint8_t *End;
bool isValidFunctionIndex(uint32_t Index) const;
bool isDefinedFunctionIndex(uint32_t Index) const;
bool isValidGlobalIndex(uint32_t Index) const;
bool isDefinedGlobalIndex(uint32_t Index) const;
bool isValidEventIndex(uint32_t Index) const;
bool isDefinedEventIndex(uint32_t Index) const;
bool isValidFunctionSymbol(uint32_t Index) const;
bool isValidGlobalSymbol(uint32_t Index) const;
bool isValidEventSymbol(uint32_t Index) const;
bool isValidDataSymbol(uint32_t Index) const;
bool isValidSectionSymbol(uint32_t Index) const;
wasm::WasmFunction &getDefinedFunction(uint32_t Index);
const wasm::WasmFunction &getDefinedFunction(uint32_t Index) const;
wasm::WasmGlobal &getDefinedGlobal(uint32_t Index);
wasm::WasmEvent &getDefinedEvent(uint32_t Index);
const WasmSection &getWasmSection(DataRefImpl Ref) const;
const wasm::WasmRelocation &getWasmRelocation(DataRefImpl Ref) const;
Error parseSection(WasmSection &Sec);
Error parseCustomSection(WasmSection &Sec, ReadContext &Ctx);
// Standard section types
Error parseTypeSection(ReadContext &Ctx);
Error parseImportSection(ReadContext &Ctx);
Error parseFunctionSection(ReadContext &Ctx);
Error parseTableSection(ReadContext &Ctx);
Error parseMemorySection(ReadContext &Ctx);
Error parseGlobalSection(ReadContext &Ctx);
Error parseEventSection(ReadContext &Ctx);
Error parseExportSection(ReadContext &Ctx);
Error parseStartSection(ReadContext &Ctx);
Error parseElemSection(ReadContext &Ctx);
Error parseCodeSection(ReadContext &Ctx);
Error parseDataSection(ReadContext &Ctx);
Error parseDataCountSection(ReadContext &Ctx);
// Custom section types
Error parseDylinkSection(ReadContext &Ctx);
Error parseNameSection(ReadContext &Ctx);
Error parseLinkingSection(ReadContext &Ctx);
Error parseLinkingSectionSymtab(ReadContext &Ctx);
Error parseLinkingSectionComdat(ReadContext &Ctx);
Error parseProducersSection(ReadContext &Ctx);
Error parseTargetFeaturesSection(ReadContext &Ctx);
Error parseRelocSection(StringRef Name, ReadContext &Ctx);
wasm::WasmObjectHeader Header;
std::vector<WasmSection> Sections;
wasm::WasmDylinkInfo DylinkInfo;
wasm::WasmProducerInfo ProducerInfo;
std::vector<wasm::WasmFeatureEntry> TargetFeatures;
std::vector<wasm::WasmSignature> Signatures;
std::vector<uint32_t> FunctionTypes;
std::vector<wasm::WasmTable> Tables;
std::vector<wasm::WasmLimits> Memories;
std::vector<wasm::WasmGlobal> Globals;
std::vector<wasm::WasmEvent> Events;
std::vector<wasm::WasmImport> Imports;
std::vector<wasm::WasmExport> Exports;
std::vector<wasm::WasmElemSegment> ElemSegments;
std::vector<WasmSegment> DataSegments;
llvm::Optional<size_t> DataCount;
std::vector<wasm::WasmFunction> Functions;
std::vector<WasmSymbol> Symbols;
std::vector<wasm::WasmFunctionName> DebugNames;
uint32_t StartFunction = -1;
bool HasLinkingSection = false;
bool HasDylinkSection = false;
wasm::WasmLinkingData LinkingData;
uint32_t NumImportedGlobals = 0;
uint32_t NumImportedFunctions = 0;
uint32_t NumImportedEvents = 0;
uint32_t CodeSection = 0;
uint32_t DataSection = 0;
uint32_t GlobalSection = 0;
uint32_t EventSection = 0;
class WasmSectionOrderChecker {
// We define orders for all core wasm sections and known custom sections.
enum : int {
// Sentinel, must be zero
// Core sections
// Custom sections
// "dylink" should be the very first section in the module
// "linking" section requires DATA section in order to validate data symbols
// Must come after "linking" section in order to validate reloc indexes.
// "name" section must appear after DATA. Comes after "linking" to allow
// symbol table to set default function name.
// "producers" section must appear after "name" section.
// "target_features" section must appear after producers section
// Must be last
// Sections that may or may not be present, but cannot be predecessors
static int DisallowedPredecessors[WASM_NUM_SEC_ORDERS][WASM_NUM_SEC_ORDERS];
bool isValidSectionOrder(unsigned ID, StringRef CustomSectionName = "");
bool Seen[WASM_NUM_SEC_ORDERS] = {}; // Sections that have been seen already
// Returns -1 for unknown sections.
int getSectionOrder(unsigned ID, StringRef CustomSectionName = "");
} // end namespace object
inline raw_ostream &operator<<(raw_ostream &OS, const object::WasmSymbol &Sym) {
return OS;
} // end namespace llvm