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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 https://llvm.org/LICENSE.txt 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: https://github.com/WebAssembly/design/blob/main/BinaryEncoding.md
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_OBJECT_WASM_H
#define LLVM_OBJECT_WASM_H
#include "llvm/ADT/ArrayRef.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 {
public:
WasmSymbol(const wasm::WasmSymbolInfo &Info,
const wasm::WasmGlobalType *GlobalType,
const wasm::WasmTableType *TableType,
const wasm::WasmSignature *Signature)
: Info(Info), GlobalType(GlobalType), TableType(TableType),
Signature(Signature) {
assert(!Signature || Signature->Kind != wasm::WasmSignature::Placeholder);
}
// Symbol info as represented in the symbol's 'syminfo' entry of an object
// file's symbol table.
wasm::WasmSymbolInfo Info;
const wasm::WasmGlobalType *GlobalType;
const wasm::WasmTableType *TableType;
const wasm::WasmSignature *Signature;
bool isTypeFunction() const {
return Info.Kind == wasm::WASM_SYMBOL_TYPE_FUNCTION;
}
bool isTypeTable() const { return Info.Kind == wasm::WASM_SYMBOL_TYPE_TABLE; }
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 isTypeTag() const { return Info.Kind == wasm::WASM_SYMBOL_TYPE_TAG; }
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;
#endif
};
struct WasmSection {
WasmSection() = default;
uint32_t Type = 0;
uint32_t Offset = 0; // Offset within the file
StringRef Name; // Section name (User-defined sections only)
uint32_t Comdat = UINT32_MAX; // From the "comdat info" section
ArrayRef<uint8_t> Content;
std::vector<wasm::WasmRelocation> Relocations;
// Length of the LEB encoding of the section header's size field
std::optional<uint8_t> HeaderSecSizeEncodingLen;
};
struct WasmSegment {
uint32_t SectionOffset;
wasm::WasmDataSegment Data;
};
class WasmObjectFile : public ObjectFile {
public:
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<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::WasmTag> tags() const { return Tags; }
ArrayRef<wasm::WasmExport> exports() const { return Exports; }
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::WasmDebugName> debugNames() const { return DebugNames; }
uint32_t startFunction() const { return StartFunction; }
uint32_t getNumImportedGlobals() const { return NumImportedGlobals; }
uint32_t getNumImportedTables() const { return NumImportedTables; }
uint32_t getNumImportedFunctions() const { return NumImportedFunctions; }
uint32_t getNumImportedTags() const { return NumImportedTags; }
uint32_t getNumSections() const { return Sections.size(); }
void moveSymbolNext(DataRefImpl &Symb) const override;
Expected<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;
bool is64Bit() const override { return false; }
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;
uint32_t getSymbolSectionId(SymbolRef Sym) const;
uint32_t getSymbolSize(SymbolRef Sym) const;
// Overrides from SectionRef.
void moveSectionNext(DataRefImpl &Sec) const override;
Expected<StringRef> getSectionName(DataRefImpl Sec) const override;
uint64_t getSectionAddress(DataRefImpl Sec) const override;
uint64_t getSectionIndex(DataRefImpl Sec) const override;
uint64_t getSectionSize(DataRefImpl Sec) const override;
Expected<ArrayRef<uint8_t>>
getSectionContents(DataRefImpl Sec) 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;
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;
Expected<SubtargetFeatures> getFeatures() const override;
bool isRelocatableObject() const override;
bool isSharedObject() const;
bool hasUnmodeledTypes() const { return HasUnmodeledTypes; }
struct ReadContext {
const uint8_t *Start;
const uint8_t *Ptr;
const uint8_t *End;
};
private:
bool isValidFunctionIndex(uint32_t Index) const;
bool isDefinedFunctionIndex(uint32_t Index) const;
bool isValidGlobalIndex(uint32_t Index) const;
bool isValidTableNumber(uint32_t Index) const;
bool isDefinedGlobalIndex(uint32_t Index) const;
bool isDefinedTableNumber(uint32_t Index) const;
bool isValidTagIndex(uint32_t Index) const;
bool isDefinedTagIndex(uint32_t Index) const;
bool isValidFunctionSymbol(uint32_t Index) const;
bool isValidTableSymbol(uint32_t Index) const;
bool isValidGlobalSymbol(uint32_t Index) const;
bool isValidTagSymbol(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;
const wasm::WasmGlobal &getDefinedGlobal(uint32_t Index) const;
wasm::WasmTag &getDefinedTag(uint32_t Index);
const WasmSection &getWasmSection(DataRefImpl Ref) const;
const wasm::WasmRelocation &getWasmRelocation(DataRefImpl Ref) const;
uint32_t getSymbolSectionIdImpl(const WasmSymbol &Symb) 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 parseTagSection(ReadContext &Ctx);
Error parseGlobalSection(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 parseDylink0Section(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<wasm::WasmTable> Tables;
std::vector<wasm::WasmLimits> Memories;
std::vector<wasm::WasmGlobal> Globals;
std::vector<wasm::WasmTag> Tags;
std::vector<wasm::WasmImport> Imports;
std::vector<wasm::WasmExport> Exports;
std::vector<wasm::WasmElemSegment> ElemSegments;
std::vector<WasmSegment> DataSegments;
std::optional<size_t> DataCount;
std::vector<wasm::WasmFunction> Functions;
std::vector<WasmSymbol> Symbols;
std::vector<wasm::WasmDebugName> DebugNames;
uint32_t StartFunction = -1;
bool HasLinkingSection = false;
bool HasDylinkSection = false;
bool HasMemory64 = false;
bool HasUnmodeledTypes = false;
wasm::WasmLinkingData LinkingData;
uint32_t NumImportedGlobals = 0;
uint32_t NumImportedTables = 0;
uint32_t NumImportedFunctions = 0;
uint32_t NumImportedTags = 0;
uint32_t CodeSection = 0;
uint32_t DataSection = 0;
uint32_t TagSection = 0;
uint32_t GlobalSection = 0;
uint32_t TableSection = 0;
};
class WasmSectionOrderChecker {
public:
// We define orders for all core wasm sections and known custom sections.
enum : int {
// Sentinel, must be zero
WASM_SEC_ORDER_NONE = 0,
// Core sections
WASM_SEC_ORDER_TYPE,
WASM_SEC_ORDER_IMPORT,
WASM_SEC_ORDER_FUNCTION,
WASM_SEC_ORDER_TABLE,
WASM_SEC_ORDER_MEMORY,
WASM_SEC_ORDER_TAG,
WASM_SEC_ORDER_GLOBAL,
WASM_SEC_ORDER_EXPORT,
WASM_SEC_ORDER_START,
WASM_SEC_ORDER_ELEM,
WASM_SEC_ORDER_DATACOUNT,
WASM_SEC_ORDER_CODE,
WASM_SEC_ORDER_DATA,
// Custom sections
// "dylink" should be the very first section in the module
WASM_SEC_ORDER_DYLINK,
// "linking" section requires DATA section in order to validate data symbols
WASM_SEC_ORDER_LINKING,
// Must come after "linking" section in order to validate reloc indexes.
WASM_SEC_ORDER_RELOC,
// "name" section must appear after DATA. Comes after "linking" to allow
// symbol table to set default function name.
WASM_SEC_ORDER_NAME,
// "producers" section must appear after "name" section.
WASM_SEC_ORDER_PRODUCERS,
// "target_features" section must appear after producers section
WASM_SEC_ORDER_TARGET_FEATURES,
// Must be last
WASM_NUM_SEC_ORDERS
};
// 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 = "");
private:
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) {
Sym.print(OS);
return OS;
}
} // end namespace llvm
#endif // LLVM_OBJECT_WASM_H
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