| // Copyright 2021 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. |
| |
| #include "src/wasm/constant-expression-interface.h" |
| |
| #include "src/execution/isolate.h" |
| #include "src/handles/handles-inl.h" |
| #include "src/objects/fixed-array-inl.h" |
| #include "src/objects/oddball.h" |
| #include "src/wasm/decoder.h" |
| #include "src/wasm/wasm-objects.h" |
| |
| namespace v8 { |
| namespace internal { |
| namespace wasm { |
| |
| void ConstantExpressionInterface::I32Const(FullDecoder* decoder, Value* result, |
| int32_t value) { |
| if (generate_value()) result->runtime_value = WasmValue(value); |
| } |
| |
| void ConstantExpressionInterface::I64Const(FullDecoder* decoder, Value* result, |
| int64_t value) { |
| if (generate_value()) result->runtime_value = WasmValue(value); |
| } |
| |
| void ConstantExpressionInterface::F32Const(FullDecoder* decoder, Value* result, |
| float value) { |
| if (generate_value()) result->runtime_value = WasmValue(value); |
| } |
| |
| void ConstantExpressionInterface::F64Const(FullDecoder* decoder, Value* result, |
| double value) { |
| if (generate_value()) result->runtime_value = WasmValue(value); |
| } |
| |
| void ConstantExpressionInterface::S128Const(FullDecoder* decoder, |
| const Simd128Immediate& imm, |
| Value* result) { |
| if (!generate_value()) return; |
| result->runtime_value = WasmValue(imm.value, kWasmS128); |
| } |
| |
| void ConstantExpressionInterface::UnOp(FullDecoder* decoder, WasmOpcode opcode, |
| const Value& input, Value* result) { |
| if (!generate_value()) return; |
| switch (opcode) { |
| case kExprExternExternalize: { |
| const char* error_message = nullptr; |
| result->runtime_value = WasmValue( |
| WasmToJSObject(isolate_, input.runtime_value.to_ref(), |
| input.type.heap_type(), &error_message) |
| .ToHandleChecked(), |
| ValueType::RefMaybeNull(HeapType::kExtern, input.type.nullability())); |
| break; |
| } |
| case kExprExternInternalize: { |
| const char* error_message = nullptr; |
| result->runtime_value = WasmValue( |
| JSToWasmObject(isolate_, input.runtime_value.to_ref(), kWasmAnyRef, |
| &error_message) |
| .ToHandleChecked(), |
| ValueType::RefMaybeNull(HeapType::kAny, input.type.nullability())); |
| break; |
| } |
| default: |
| UNREACHABLE(); |
| } |
| } |
| |
| void ConstantExpressionInterface::BinOp(FullDecoder* decoder, WasmOpcode opcode, |
| const Value& lhs, const Value& rhs, |
| Value* result) { |
| if (!generate_value()) return; |
| switch (opcode) { |
| case kExprI32Add: |
| result->runtime_value = |
| WasmValue(lhs.runtime_value.to_i32() + rhs.runtime_value.to_i32()); |
| break; |
| case kExprI32Sub: |
| result->runtime_value = |
| WasmValue(lhs.runtime_value.to_i32() - rhs.runtime_value.to_i32()); |
| break; |
| case kExprI32Mul: |
| result->runtime_value = |
| WasmValue(lhs.runtime_value.to_i32() * rhs.runtime_value.to_i32()); |
| break; |
| case kExprI64Add: |
| result->runtime_value = |
| WasmValue(lhs.runtime_value.to_i64() + rhs.runtime_value.to_i64()); |
| break; |
| case kExprI64Sub: |
| result->runtime_value = |
| WasmValue(lhs.runtime_value.to_i64() - rhs.runtime_value.to_i64()); |
| break; |
| case kExprI64Mul: |
| result->runtime_value = |
| WasmValue(lhs.runtime_value.to_i64() * rhs.runtime_value.to_i64()); |
| break; |
| default: |
| UNREACHABLE(); |
| } |
| } |
| |
| void ConstantExpressionInterface::RefNull(FullDecoder* decoder, ValueType type, |
| Value* result) { |
| if (!generate_value()) return; |
| result->runtime_value = |
| WasmValue(type == kWasmExternRef || type == kWasmNullExternRef |
| ? Handle<Object>::cast(isolate_->factory()->null_value()) |
| : Handle<Object>::cast(isolate_->factory()->wasm_null()), |
| type); |
| } |
| |
| void ConstantExpressionInterface::RefFunc(FullDecoder* decoder, |
| uint32_t function_index, |
| Value* result) { |
| if (isolate_ == nullptr) { |
| outer_module_->functions[function_index].declared = true; |
| return; |
| } |
| if (!generate_value()) return; |
| ValueType type = ValueType::Ref(module_->functions[function_index].sig_index); |
| Handle<WasmInternalFunction> internal = |
| WasmInstanceObject::GetOrCreateWasmInternalFunction(isolate_, instance_, |
| function_index); |
| result->runtime_value = WasmValue(internal, type); |
| } |
| |
| void ConstantExpressionInterface::GlobalGet(FullDecoder* decoder, Value* result, |
| const GlobalIndexImmediate& imm) { |
| if (!generate_value()) return; |
| const WasmGlobal& global = module_->globals[imm.index]; |
| DCHECK(!global.mutability); |
| result->runtime_value = |
| global.type.is_numeric() |
| ? WasmValue( |
| reinterpret_cast<byte*>( |
| instance_->untagged_globals_buffer().backing_store()) + |
| global.offset, |
| global.type) |
| : WasmValue( |
| handle(instance_->tagged_globals_buffer().get(global.offset), |
| isolate_), |
| global.type); |
| } |
| |
| void ConstantExpressionInterface::StructNew(FullDecoder* decoder, |
| const StructIndexImmediate& imm, |
| const Value& rtt, |
| const Value args[], Value* result) { |
| if (!generate_value()) return; |
| std::vector<WasmValue> field_values(imm.struct_type->field_count()); |
| for (size_t i = 0; i < field_values.size(); i++) { |
| field_values[i] = args[i].runtime_value; |
| } |
| result->runtime_value = |
| WasmValue(isolate_->factory()->NewWasmStruct( |
| imm.struct_type, field_values.data(), |
| Handle<Map>::cast(rtt.runtime_value.to_ref())), |
| ValueType::Ref(HeapType(imm.index))); |
| } |
| |
| void ConstantExpressionInterface::StringConst(FullDecoder* decoder, |
| const StringConstImmediate& imm, |
| Value* result) { |
| if (!generate_value()) return; |
| static_assert(base::IsInRange(kV8MaxWasmStringLiterals, 0, Smi::kMaxValue)); |
| |
| DCHECK_LT(imm.index, module_->stringref_literals.size()); |
| |
| const wasm::WasmStringRefLiteral& literal = |
| module_->stringref_literals[imm.index]; |
| const base::Vector<const uint8_t> module_bytes = |
| instance_->module_object().native_module()->wire_bytes(); |
| const base::Vector<const uint8_t> string_bytes = |
| module_bytes.SubVector(literal.source.offset(), |
| literal.source.offset() + literal.source.length()); |
| Handle<String> string = |
| isolate_->factory() |
| ->NewStringFromUtf8(string_bytes, unibrow::Utf8Variant::kWtf8) |
| .ToHandleChecked(); |
| result->runtime_value = WasmValue(string, kWasmStringRef.AsNonNull()); |
| } |
| |
| namespace { |
| WasmValue DefaultValueForType(ValueType type, Isolate* isolate) { |
| switch (type.kind()) { |
| case kI32: |
| case kI8: |
| case kI16: |
| return WasmValue(0); |
| case kI64: |
| return WasmValue(int64_t{0}); |
| case kF32: |
| return WasmValue(0.0f); |
| case kF64: |
| return WasmValue(0.0); |
| case kS128: |
| return WasmValue(Simd128()); |
| case kRefNull: |
| return WasmValue(isolate->factory()->null_value(), type); |
| case kVoid: |
| case kRtt: |
| case kRef: |
| case kBottom: |
| UNREACHABLE(); |
| } |
| } |
| } // namespace |
| |
| void ConstantExpressionInterface::StructNewDefault( |
| FullDecoder* decoder, const StructIndexImmediate& imm, const Value& rtt, |
| Value* result) { |
| if (!generate_value()) return; |
| std::vector<WasmValue> field_values(imm.struct_type->field_count()); |
| for (uint32_t i = 0; i < field_values.size(); i++) { |
| field_values[i] = DefaultValueForType(imm.struct_type->field(i), isolate_); |
| } |
| result->runtime_value = |
| WasmValue(isolate_->factory()->NewWasmStruct( |
| imm.struct_type, field_values.data(), |
| Handle<Map>::cast(rtt.runtime_value.to_ref())), |
| ValueType::Ref(imm.index)); |
| } |
| |
| void ConstantExpressionInterface::ArrayNew(FullDecoder* decoder, |
| const ArrayIndexImmediate& imm, |
| const Value& length, |
| const Value& initial_value, |
| const Value& rtt, Value* result) { |
| if (!generate_value()) return; |
| if (length.runtime_value.to_u32() > |
| static_cast<uint32_t>(WasmArray::MaxLength(imm.array_type))) { |
| error_ = MessageTemplate::kWasmTrapArrayTooLarge; |
| return; |
| } |
| result->runtime_value = |
| WasmValue(isolate_->factory()->NewWasmArray( |
| imm.array_type, length.runtime_value.to_u32(), |
| initial_value.runtime_value, |
| Handle<Map>::cast(rtt.runtime_value.to_ref())), |
| ValueType::Ref(imm.index)); |
| } |
| |
| void ConstantExpressionInterface::ArrayNewDefault( |
| FullDecoder* decoder, const ArrayIndexImmediate& imm, const Value& length, |
| const Value& rtt, Value* result) { |
| if (!generate_value()) return; |
| Value initial_value(decoder->pc(), imm.array_type->element_type()); |
| initial_value.runtime_value = |
| DefaultValueForType(imm.array_type->element_type(), isolate_); |
| return ArrayNew(decoder, imm, length, initial_value, rtt, result); |
| } |
| |
| void ConstantExpressionInterface::ArrayNewFixed( |
| FullDecoder* decoder, const ArrayIndexImmediate& imm, |
| const base::Vector<Value>& elements, const Value& rtt, Value* result) { |
| if (!generate_value()) return; |
| std::vector<WasmValue> element_values; |
| for (Value elem : elements) element_values.push_back(elem.runtime_value); |
| result->runtime_value = |
| WasmValue(isolate_->factory()->NewWasmArrayFromElements( |
| imm.array_type, element_values, |
| Handle<Map>::cast(rtt.runtime_value.to_ref())), |
| ValueType::Ref(HeapType(imm.index))); |
| } |
| |
| // TODO(7748): These expressions are non-constant for now. There are plans to |
| // make them constant in the future, so we retain the required infrastructure |
| // here. |
| void ConstantExpressionInterface::ArrayNewSegment( |
| FullDecoder* decoder, const ArrayIndexImmediate& array_imm, |
| const IndexImmediate& segment_imm, const Value& offset_value, |
| const Value& length_value, const Value& rtt, Value* result) { |
| if (!generate_value()) return; |
| |
| uint32_t length = length_value.runtime_value.to_u32(); |
| uint32_t offset = offset_value.runtime_value.to_u32(); |
| if (length > |
| static_cast<uint32_t>(WasmArray::MaxLength(array_imm.array_type))) { |
| error_ = MessageTemplate::kWasmTrapArrayTooLarge; |
| return; |
| } |
| ValueType element_type = array_imm.array_type->element_type(); |
| ValueType result_type = ValueType::Ref(HeapType(array_imm.index)); |
| if (element_type.is_numeric()) { |
| const WasmDataSegment& data_segment = |
| module_->data_segments[segment_imm.index]; |
| uint32_t length_in_bytes = |
| length * array_imm.array_type->element_type().value_kind_size(); |
| |
| if (!base::IsInBounds<uint32_t>(offset, length_in_bytes, |
| data_segment.source.length())) { |
| error_ = MessageTemplate::kWasmTrapDataSegmentOutOfBounds; |
| return; |
| } |
| |
| Address source = |
| instance_->data_segment_starts().get(segment_imm.index) + offset; |
| Handle<WasmArray> array_value = isolate_->factory()->NewWasmArrayFromMemory( |
| length, Handle<Map>::cast(rtt.runtime_value.to_ref()), source); |
| result->runtime_value = WasmValue(array_value, result_type); |
| } else { |
| const wasm::WasmElemSegment* elem_segment = |
| &decoder->module_->elem_segments[segment_imm.index]; |
| // A constant expression should not observe if a passive segment is dropped. |
| // However, it should consider active and declarative segments as empty. |
| if (!base::IsInBounds<size_t>( |
| offset, length, |
| elem_segment->status == WasmElemSegment::kStatusPassive |
| ? elem_segment->element_count |
| : 0)) { |
| error_ = MessageTemplate::kWasmTrapElementSegmentOutOfBounds; |
| return; |
| } |
| |
| Handle<Object> array_object = |
| isolate_->factory()->NewWasmArrayFromElementSegment( |
| instance_, segment_imm.index, offset, length, |
| Handle<Map>::cast(rtt.runtime_value.to_ref())); |
| if (array_object->IsSmi()) { |
| // A smi result stands for an error code. |
| error_ = static_cast<MessageTemplate>(array_object->ToSmi().value()); |
| } else { |
| result->runtime_value = WasmValue(array_object, result_type); |
| } |
| } |
| } |
| |
| void ConstantExpressionInterface::RttCanon(FullDecoder* decoder, |
| uint32_t type_index, Value* result) { |
| if (!generate_value()) return; |
| result->runtime_value = WasmValue( |
| handle(instance_->managed_object_maps().get(type_index), isolate_), |
| ValueType::Rtt(type_index)); |
| } |
| |
| void ConstantExpressionInterface::I31New(FullDecoder* decoder, |
| const Value& input, Value* result) { |
| if (!generate_value()) return; |
| Address raw = input.runtime_value.to_i32(); |
| // We have to craft the Smi manually because we accept out-of-bounds inputs. |
| // For 32-bit Smi builds, set the topmost bit to sign-extend the second bit. |
| // This way, interpretation in JS (if this value escapes there) will be the |
| // same as i31.get_s. |
| intptr_t shifted = |
| static_cast<intptr_t>(raw << (kSmiTagSize + kSmiShiftSize + 1)) >> 1; |
| result->runtime_value = |
| WasmValue(handle(Smi(shifted), isolate_), wasm::kWasmI31Ref.AsNonNull()); |
| } |
| |
| void ConstantExpressionInterface::DoReturn(FullDecoder* decoder, |
| uint32_t /*drop_values*/) { |
| end_found_ = true; |
| // End decoding on "end". Note: We need this because we do not know the length |
| // of a constant expression while decoding it. |
| decoder->set_end(decoder->pc() + 1); |
| if (generate_value()) { |
| computed_value_ = decoder->stack_value(1)->runtime_value; |
| } |
| } |
| |
| } // namespace wasm |
| } // namespace internal |
| } // namespace v8 |
