// Copyright 2015 the V8 project authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #ifndef V8_WASM_WASM_MODULE_H_ #define V8_WASM_WASM_MODULE_H_ #include <memory> #include "src/base/optional.h" #include "src/common/globals.h" #include "src/handles/handles.h" #include "src/utils/vector.h" #include "src/wasm/signature-map.h" #include "src/wasm/struct-types.h" #include "src/wasm/wasm-constants.h" #include "src/wasm/wasm-opcodes.h" #include "src/zone/zone-containers.h" namespace v8 { namespace internal { class WasmModuleObject; namespace wasm { using WasmName = Vector<const char>; struct AsmJsOffsets; class ErrorThrower; // Reference to a string in the wire bytes. class WireBytesRef { public: WireBytesRef() : WireBytesRef(0, 0) {} WireBytesRef(uint32_t offset, uint32_t length) : offset_(offset), length_(length) { DCHECK_IMPLIES(offset_ == 0, length_ == 0); DCHECK_LE(offset_, offset_ + length_); // no uint32_t overflow. } uint32_t offset() const { return offset_; } uint32_t length() const { return length_; } uint32_t end_offset() const { return offset_ + length_; } bool is_empty() const { return length_ == 0; } bool is_set() const { return offset_ != 0; } private: uint32_t offset_; uint32_t length_; }; // Static representation of a wasm function. struct WasmFunction { const FunctionSig* sig; // signature of the function. uint32_t func_index; // index into the function table. uint32_t sig_index; // index into the signature table. WireBytesRef code; // code of this function. bool imported; bool exported; bool declared; }; // Static representation of a wasm global variable. struct WasmGlobal { ValueType type; // type of the global. bool mutability; // {true} if mutable. WasmInitExpr init; // the initialization expression of the global. union { uint32_t index; // index of imported mutable global. uint32_t offset; // offset into global memory (if not imported & mutable). }; bool imported; // true if imported. bool exported; // true if exported. }; // Note: An exception signature only uses the params portion of a // function signature. using WasmExceptionSig = FunctionSig; // Static representation of a wasm exception type. struct WasmException { explicit WasmException(const WasmExceptionSig* sig) : sig(sig) {} const FunctionSig* ToFunctionSig() const { return sig; } const WasmExceptionSig* sig; // type signature of the exception. }; // Static representation of a wasm data segment. struct WasmDataSegment { // Construct an active segment. explicit WasmDataSegment(WasmInitExpr dest_addr) : dest_addr(dest_addr), active(true) {} // Construct a passive segment, which has no dest_addr. WasmDataSegment() : active(false) {} WasmInitExpr dest_addr; // destination memory address of the data. WireBytesRef source; // start offset in the module bytes. bool active = true; // true if copied automatically during instantiation. }; // Static representation of a wasm indirect call table. struct WasmTable { MOVE_ONLY_WITH_DEFAULT_CONSTRUCTORS(WasmTable); ValueType type = kWasmStmt; // table type. uint32_t initial_size = 0; // initial table size. uint32_t maximum_size = 0; // maximum table size. bool has_maximum_size = false; // true if there is a maximum size. bool imported = false; // true if imported. bool exported = false; // true if exported. }; // Static representation of wasm element segment (table initializer). struct WasmElemSegment { MOVE_ONLY_NO_DEFAULT_CONSTRUCTOR(WasmElemSegment); // Construct an active segment. WasmElemSegment(uint32_t table_index, WasmInitExpr offset) : type(ValueType::Ref(kHeapFunc, kNullable)), table_index(table_index), offset(offset), status(kStatusActive) {} // Construct a passive or declarative segment, which has no table index or // offset. explicit WasmElemSegment(bool declarative) : type(ValueType::Ref(kHeapFunc, kNullable)), table_index(0), status(declarative ? kStatusDeclarative : kStatusPassive) {} // Used in the {entries} vector to represent a `ref.null` entry in a passive // segment. V8_EXPORT_PRIVATE static const uint32_t kNullIndex = ~0u; ValueType type; uint32_t table_index; WasmInitExpr offset; std::vector<uint32_t> entries; enum Status { kStatusActive, // copied automatically during instantiation. kStatusPassive, // copied explicitly after instantiation. kStatusDeclarative // purely declarative and never copied. } status; }; // Static representation of a wasm import. struct WasmImport { WireBytesRef module_name; // module name. WireBytesRef field_name; // import name. ImportExportKindCode kind; // kind of the import. uint32_t index; // index into the respective space. }; // Static representation of a wasm export. struct WasmExport { WireBytesRef name; // exported name. ImportExportKindCode kind; // kind of the export. uint32_t index; // index into the respective space. }; enum class WasmCompilationHintStrategy : uint8_t { kDefault = 0, kLazy = 1, kEager = 2, kLazyBaselineEagerTopTier = 3, }; enum class WasmCompilationHintTier : uint8_t { kDefault = 0, kBaseline = 1, kOptimized = 2, }; // Static representation of a wasm compilation hint struct WasmCompilationHint { WasmCompilationHintStrategy strategy; WasmCompilationHintTier baseline_tier; WasmCompilationHintTier top_tier; }; enum ModuleOrigin : uint8_t { kWasmOrigin, kAsmJsSloppyOrigin, kAsmJsStrictOrigin }; #define SELECT_WASM_COUNTER(counters, origin, prefix, suffix) \ ((origin) == kWasmOrigin ? (counters)->prefix##_wasm_##suffix() \ : (counters)->prefix##_asm_##suffix()) struct ModuleWireBytes; class V8_EXPORT_PRIVATE LazilyGeneratedNames { public: WireBytesRef LookupFunctionName(const ModuleWireBytes& wire_bytes, uint32_t function_index, Vector<const WasmExport> export_table) const; // For memory and global. std::pair<WireBytesRef, WireBytesRef> LookupNameFromImportsAndExports( ImportExportKindCode kind, uint32_t index, const Vector<const WasmImport> import_table, const Vector<const WasmExport> export_table) const; void AddForTesting(int function_index, WireBytesRef name); private: // {function_names_}, {global_names_}, {memory_names_} and {table_names_} are // populated lazily after decoding, and therefore need a mutex to protect // concurrent modifications from multiple {WasmModuleObject}. mutable base::Mutex mutex_; mutable std::unique_ptr<std::unordered_map<uint32_t, WireBytesRef>> function_names_; mutable std::unique_ptr< std::unordered_map<uint32_t, std::pair<WireBytesRef, WireBytesRef>>> global_names_; mutable std::unique_ptr< std::unordered_map<uint32_t, std::pair<WireBytesRef, WireBytesRef>>> memory_names_; mutable std::unique_ptr< std::unordered_map<uint32_t, std::pair<WireBytesRef, WireBytesRef>>> table_names_; }; class V8_EXPORT_PRIVATE AsmJsOffsetInformation { public: explicit AsmJsOffsetInformation(Vector<const byte> encoded_offsets); // Destructor defined in wasm-module.cc, where the definition of // {AsmJsOffsets} is available. ~AsmJsOffsetInformation(); int GetSourcePosition(int func_index, int byte_offset, bool is_at_number_conversion); std::pair<int, int> GetFunctionOffsets(int func_index); private: void EnsureDecodedOffsets(); // The offset information table is decoded lazily, hence needs to be // protected against concurrent accesses. // Exactly one of the two fields below will be set at a time. mutable base::Mutex mutex_; // Holds the encoded offset table bytes. OwnedVector<const uint8_t> encoded_offsets_; // Holds the decoded offset table. std::unique_ptr<AsmJsOffsets> decoded_offsets_; }; struct TypeDefinition { explicit TypeDefinition(const FunctionSig* sig) : function_sig(sig) {} explicit TypeDefinition(const StructType* type) : struct_type(type) {} explicit TypeDefinition(const ArrayType* type) : array_type(type) {} union { const FunctionSig* function_sig; const StructType* struct_type; const ArrayType* array_type; }; }; struct V8_EXPORT_PRIVATE WasmDebugSymbols { enum class Type { None, SourceMap, EmbeddedDWARF, ExternalDWARF }; Type type = Type::None; WireBytesRef external_url; }; // Static representation of a module. struct V8_EXPORT_PRIVATE WasmModule { std::unique_ptr<Zone> signature_zone; uint32_t initial_pages = 0; // initial size of the memory in 64k pages uint32_t maximum_pages = 0; // maximum size of the memory in 64k pages bool has_shared_memory = false; // true if memory is a SharedArrayBuffer bool has_maximum_pages = false; // true if there is a maximum memory size bool has_memory = false; // true if the memory was defined or imported bool mem_export = false; // true if the memory is exported int start_function_index = -1; // start function, >= 0 if any std::vector<WasmGlobal> globals; // Size of the buffer required for all globals that are not imported and // mutable. uint32_t untagged_globals_buffer_size = 0; uint32_t tagged_globals_buffer_size = 0; uint32_t num_imported_mutable_globals = 0; uint32_t num_imported_functions = 0; uint32_t num_imported_tables = 0; uint32_t num_declared_functions = 0; // excluding imported uint32_t num_exported_functions = 0; uint32_t num_declared_data_segments = 0; // From the DataCount section. WireBytesRef code = {0, 0}; WireBytesRef name = {0, 0}; std::vector<TypeDefinition> types; // by type index std::vector<uint8_t> type_kinds; // by type index std::vector<uint32_t> signature_ids; // by signature index void add_signature(const FunctionSig* sig) { types.push_back(TypeDefinition(sig)); type_kinds.push_back(kWasmFunctionTypeCode); uint32_t canonical_id = sig ? signature_map.FindOrInsert(*sig) : 0; signature_ids.push_back(canonical_id); } const FunctionSig* signature(uint32_t index) const { DCHECK(type_kinds[index] == kWasmFunctionTypeCode); return types[index].function_sig; } bool has_signature(uint32_t index) const { return index < types.size() && type_kinds[index] == kWasmFunctionTypeCode; } void add_struct_type(const StructType* type) { types.push_back(TypeDefinition(type)); type_kinds.push_back(kWasmStructTypeCode); } const StructType* struct_type(uint32_t index) const { DCHECK(type_kinds[index] == kWasmStructTypeCode); return types[index].struct_type; } bool has_struct(uint32_t index) const { return index < types.size() && type_kinds[index] == kWasmStructTypeCode; } void add_array_type(const ArrayType* type) { types.push_back(TypeDefinition(type)); type_kinds.push_back(kWasmArrayTypeCode); } const ArrayType* array_type(uint32_t index) const { DCHECK(type_kinds[index] == kWasmArrayTypeCode); return types[index].array_type; } bool has_array(uint32_t index) const { return index < types.size() && type_kinds[index] == kWasmArrayTypeCode; } bool is_cached_subtype(uint32_t subtype, uint32_t supertype) const { return subtyping_cache->count(std::make_pair(subtype, supertype)) == 1; } void cache_subtype(uint32_t subtype, uint32_t supertype) const { subtyping_cache->emplace(subtype, supertype); } void uncache_subtype(uint32_t subtype, uint32_t supertype) const { subtyping_cache->erase(std::make_pair(subtype, supertype)); } bool is_cached_equivalent_type(uint32_t type1, uint32_t type2) const { if (type1 > type2) std::swap(type1, type2); return type_equivalence_cache->count(std::make_pair(type1, type2)) == 1; } void cache_type_equivalence(uint32_t type1, uint32_t type2) const { if (type1 > type2) std::swap(type1, type2); type_equivalence_cache->emplace(type1, type2); } void uncache_type_equivalence(uint32_t type1, uint32_t type2) const { if (type1 > type2) std::swap(type1, type2); type_equivalence_cache->erase(std::make_pair(type1, type2)); } std::vector<WasmFunction> functions; std::vector<WasmDataSegment> data_segments; std::vector<WasmTable> tables; std::vector<WasmImport> import_table; std::vector<WasmExport> export_table; std::vector<WasmException> exceptions; std::vector<WasmElemSegment> elem_segments; std::vector<WasmCompilationHint> compilation_hints; SignatureMap signature_map; // canonicalizing map for signature indexes. ModuleOrigin origin = kWasmOrigin; // origin of the module LazilyGeneratedNames lazily_generated_names; WasmDebugSymbols debug_symbols; // Asm.js source position information. Only available for modules compiled // from asm.js. std::unique_ptr<AsmJsOffsetInformation> asm_js_offset_information; explicit WasmModule(std::unique_ptr<Zone> signature_zone = nullptr); private: // Cache for discovered subtyping pairs. std::unique_ptr<ZoneUnorderedSet<std::pair<uint32_t, uint32_t>>> subtyping_cache; // Cache for discovered equivalent type pairs. // Indexes are stored in increasing order. std::unique_ptr<ZoneUnorderedSet<std::pair<uint32_t, uint32_t>>> type_equivalence_cache; DISALLOW_COPY_AND_ASSIGN(WasmModule); }; inline bool is_asmjs_module(const WasmModule* module) { return module->origin != kWasmOrigin; } size_t EstimateStoredSize(const WasmModule* module); // Returns the number of possible export wrappers for a given module. V8_EXPORT_PRIVATE int MaxNumExportWrappers(const WasmModule* module); // Returns the wrapper index for a function in {module} with signature {sig} // and origin defined by {is_import}. int GetExportWrapperIndex(const WasmModule* module, const FunctionSig* sig, bool is_import); // Return the byte offset of the function identified by the given index. // The offset will be relative to the start of the module bytes. // Returns -1 if the function index is invalid. int GetWasmFunctionOffset(const WasmModule* module, uint32_t func_index); // Returns the function containing the given byte offset. // Returns -1 if the byte offset is not contained in any // function of this module. int GetContainingWasmFunction(const WasmModule* module, uint32_t byte_offset); // Returns the function containing the given byte offset. // Will return preceding function if the byte offset is not // contained within a function. int GetNearestWasmFunction(const WasmModule* module, uint32_t byte_offset); // Interface to the storage (wire bytes) of a wasm module. // It is illegal for anyone receiving a ModuleWireBytes to store pointers based // on module_bytes, as this storage is only guaranteed to be alive as long as // this struct is alive. struct V8_EXPORT_PRIVATE ModuleWireBytes { explicit ModuleWireBytes(Vector<const byte> module_bytes) : module_bytes_(module_bytes) {} ModuleWireBytes(const byte* start, const byte* end) : module_bytes_(start, static_cast<int>(end - start)) { DCHECK_GE(kMaxInt, end - start); } // Get a string stored in the module bytes representing a name. WasmName GetNameOrNull(WireBytesRef ref) const; // Get a string stored in the module bytes representing a function name. WasmName GetNameOrNull(const WasmFunction* function, const WasmModule* module) const; // Checks the given reference is contained within the module bytes. bool BoundsCheck(WireBytesRef ref) const { uint32_t size = static_cast<uint32_t>(module_bytes_.length()); return ref.offset() <= size && ref.length() <= size - ref.offset(); } Vector<const byte> GetFunctionBytes(const WasmFunction* function) const { return module_bytes_.SubVector(function->code.offset(), function->code.end_offset()); } Vector<const byte> module_bytes() const { return module_bytes_; } const byte* start() const { return module_bytes_.begin(); } const byte* end() const { return module_bytes_.end(); } size_t length() const { return module_bytes_.length(); } private: Vector<const byte> module_bytes_; }; // A helper for printing out the names of functions. struct WasmFunctionName { WasmFunctionName(const WasmFunction* function, WasmName name) : function_(function), name_(name) {} const WasmFunction* function_; const WasmName name_; }; std::ostream& operator<<(std::ostream& os, const WasmFunctionName& name); V8_EXPORT_PRIVATE bool IsWasmCodegenAllowed(Isolate* isolate, Handle<Context> context); Handle<JSObject> GetTypeForFunction(Isolate* isolate, const FunctionSig* sig); Handle<JSObject> GetTypeForGlobal(Isolate* isolate, bool is_mutable, ValueType type); Handle<JSObject> GetTypeForMemory(Isolate* isolate, uint32_t min_size, base::Optional<uint32_t> max_size); Handle<JSObject> GetTypeForTable(Isolate* isolate, ValueType type, uint32_t min_size, base::Optional<uint32_t> max_size); Handle<JSArray> GetImports(Isolate* isolate, Handle<WasmModuleObject> module); Handle<JSArray> GetExports(Isolate* isolate, Handle<WasmModuleObject> module); Handle<JSArray> GetCustomSections(Isolate* isolate, Handle<WasmModuleObject> module, Handle<String> name, ErrorThrower* thrower); // Get the source position from a given function index and byte offset, // for either asm.js or pure Wasm modules. int GetSourcePosition(const WasmModule*, uint32_t func_index, uint32_t byte_offset, bool is_at_number_conversion); // Translate function index to the index relative to the first declared (i.e. // non-imported) function. inline int declared_function_index(const WasmModule* module, int func_index) { DCHECK_LE(module->num_imported_functions, func_index); int declared_idx = func_index - module->num_imported_functions; DCHECK_GT(module->num_declared_functions, declared_idx); return declared_idx; } // TruncatedUserString makes it easy to output names up to a certain length, and // output a truncation followed by '...' if they exceed a limit. // Use like this: // TruncatedUserString<> name (pc, len); // printf("... %.*s ...", name.length(), name.start()) template <int kMaxLen = 50> class TruncatedUserString { static_assert(kMaxLen >= 4, "minimum length is 4 (length of '...' plus one)"); public: template <typename T> explicit TruncatedUserString(Vector<T> name) : TruncatedUserString(name.begin(), name.length()) {} TruncatedUserString(const byte* start, size_t len) : TruncatedUserString(reinterpret_cast<const char*>(start), len) {} TruncatedUserString(const char* start, size_t len) : start_(start), length_(std::min(kMaxLen, static_cast<int>(len))) { if (len > static_cast<size_t>(kMaxLen)) { memcpy(buffer_, start, kMaxLen - 3); memset(buffer_ + kMaxLen - 3, '.', 3); start_ = buffer_; } } const char* start() const { return start_; } int length() const { return length_; } private: const char* start_; const int length_; char buffer_[kMaxLen]; }; // Print the signature into the given {buffer}. If {buffer} is non-empty, it // will be null-terminated, even if the signature is cut off. Returns the number // of characters written, excluding the terminating null-byte. size_t PrintSignature(Vector<char> buffer, const wasm::FunctionSig*); } // namespace wasm } // namespace internal } // namespace v8 #endif // V8_WASM_WASM_MODULE_H_