// Copyright 2016 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 #include #include "src/wasm/wasm-interpreter.h" #include "src/assembler-inl.h" #include "src/boxed-float.h" #include "src/compiler/wasm-compiler.h" #include "src/conversions.h" #include "src/identity-map.h" #include "src/objects-inl.h" #include "src/trap-handler/trap-handler.h" #include "src/utils.h" #include "src/wasm/decoder.h" #include "src/wasm/function-body-decoder-impl.h" #include "src/wasm/function-body-decoder.h" #include "src/wasm/memory-tracing.h" #include "src/wasm/wasm-external-refs.h" #include "src/wasm/wasm-limits.h" #include "src/wasm/wasm-module.h" #include "src/wasm/wasm-objects-inl.h" #include "src/zone/accounting-allocator.h" #include "src/zone/zone-containers.h" namespace v8 { namespace internal { namespace wasm { #if DEBUG #define TRACE(...) \ do { \ if (FLAG_trace_wasm_interpreter) PrintF(__VA_ARGS__); \ } while (false) #else #define TRACE(...) #endif #define FOREACH_INTERNAL_OPCODE(V) V(Breakpoint, 0xFF) #define WASM_CTYPES(V) \ V(I32, int32_t) V(I64, int64_t) V(F32, float) V(F64, double) #define FOREACH_SIMPLE_BINOP(V) \ V(I32Add, uint32_t, +) \ V(I32Sub, uint32_t, -) \ V(I32Mul, uint32_t, *) \ V(I32And, uint32_t, &) \ V(I32Ior, uint32_t, |) \ V(I32Xor, uint32_t, ^) \ V(I32Eq, uint32_t, ==) \ V(I32Ne, uint32_t, !=) \ V(I32LtU, uint32_t, <) \ V(I32LeU, uint32_t, <=) \ V(I32GtU, uint32_t, >) \ V(I32GeU, uint32_t, >=) \ V(I32LtS, int32_t, <) \ V(I32LeS, int32_t, <=) \ V(I32GtS, int32_t, >) \ V(I32GeS, int32_t, >=) \ V(I64Add, uint64_t, +) \ V(I64Sub, uint64_t, -) \ V(I64Mul, uint64_t, *) \ V(I64And, uint64_t, &) \ V(I64Ior, uint64_t, |) \ V(I64Xor, uint64_t, ^) \ V(I64Eq, uint64_t, ==) \ V(I64Ne, uint64_t, !=) \ V(I64LtU, uint64_t, <) \ V(I64LeU, uint64_t, <=) \ V(I64GtU, uint64_t, >) \ V(I64GeU, uint64_t, >=) \ V(I64LtS, int64_t, <) \ V(I64LeS, int64_t, <=) \ V(I64GtS, int64_t, >) \ V(I64GeS, int64_t, >=) \ V(F32Add, float, +) \ V(F32Sub, float, -) \ V(F32Eq, float, ==) \ V(F32Ne, float, !=) \ V(F32Lt, float, <) \ V(F32Le, float, <=) \ V(F32Gt, float, >) \ V(F32Ge, float, >=) \ V(F64Add, double, +) \ V(F64Sub, double, -) \ V(F64Eq, double, ==) \ V(F64Ne, double, !=) \ V(F64Lt, double, <) \ V(F64Le, double, <=) \ V(F64Gt, double, >) \ V(F64Ge, double, >=) \ V(F32Mul, float, *) \ V(F64Mul, double, *) \ V(F32Div, float, /) \ V(F64Div, double, /) #define FOREACH_OTHER_BINOP(V) \ V(I32DivS, int32_t) \ V(I32DivU, uint32_t) \ V(I32RemS, int32_t) \ V(I32RemU, uint32_t) \ V(I32Shl, uint32_t) \ V(I32ShrU, uint32_t) \ V(I32ShrS, int32_t) \ V(I64DivS, int64_t) \ V(I64DivU, uint64_t) \ V(I64RemS, int64_t) \ V(I64RemU, uint64_t) \ V(I64Shl, uint64_t) \ V(I64ShrU, uint64_t) \ V(I64ShrS, int64_t) \ V(I32Ror, int32_t) \ V(I32Rol, int32_t) \ V(I64Ror, int64_t) \ V(I64Rol, int64_t) \ V(F32Min, float) \ V(F32Max, float) \ V(F64Min, double) \ V(F64Max, double) \ V(I32AsmjsDivS, int32_t) \ V(I32AsmjsDivU, uint32_t) \ V(I32AsmjsRemS, int32_t) \ V(I32AsmjsRemU, uint32_t) \ V(F32CopySign, Float32) \ V(F64CopySign, Float64) #define FOREACH_OTHER_UNOP(V) \ V(I32Clz, uint32_t) \ V(I32Ctz, uint32_t) \ V(I32Popcnt, uint32_t) \ V(I32Eqz, uint32_t) \ V(I64Clz, uint64_t) \ V(I64Ctz, uint64_t) \ V(I64Popcnt, uint64_t) \ V(I64Eqz, uint64_t) \ V(F32Abs, Float32) \ V(F32Neg, Float32) \ V(F32Ceil, float) \ V(F32Floor, float) \ V(F32Trunc, float) \ V(F32NearestInt, float) \ V(F64Abs, Float64) \ V(F64Neg, Float64) \ V(F64Ceil, double) \ V(F64Floor, double) \ V(F64Trunc, double) \ V(F64NearestInt, double) \ V(I32SConvertF32, float) \ V(I32SConvertF64, double) \ V(I32UConvertF32, float) \ V(I32UConvertF64, double) \ V(I32ConvertI64, int64_t) \ V(I64SConvertF32, float) \ V(I64SConvertF64, double) \ V(I64UConvertF32, float) \ V(I64UConvertF64, double) \ V(I64SConvertI32, int32_t) \ V(I64UConvertI32, uint32_t) \ V(F32SConvertI32, int32_t) \ V(F32UConvertI32, uint32_t) \ V(F32SConvertI64, int64_t) \ V(F32UConvertI64, uint64_t) \ V(F32ConvertF64, double) \ V(F32ReinterpretI32, int32_t) \ V(F64SConvertI32, int32_t) \ V(F64UConvertI32, uint32_t) \ V(F64SConvertI64, int64_t) \ V(F64UConvertI64, uint64_t) \ V(F64ConvertF32, float) \ V(F64ReinterpretI64, int64_t) \ V(I32AsmjsSConvertF32, float) \ V(I32AsmjsUConvertF32, float) \ V(I32AsmjsSConvertF64, double) \ V(I32AsmjsUConvertF64, double) \ V(F32Sqrt, float) \ V(F64Sqrt, double) namespace { constexpr uint32_t kFloat32SignBitMask = uint32_t{1} << 31; constexpr uint64_t kFloat64SignBitMask = uint64_t{1} << 63; inline int32_t ExecuteI32DivS(int32_t a, int32_t b, TrapReason* trap) { if (b == 0) { *trap = kTrapDivByZero; return 0; } if (b == -1 && a == std::numeric_limits::min()) { *trap = kTrapDivUnrepresentable; return 0; } return a / b; } inline uint32_t ExecuteI32DivU(uint32_t a, uint32_t b, TrapReason* trap) { if (b == 0) { *trap = kTrapDivByZero; return 0; } return a / b; } inline int32_t ExecuteI32RemS(int32_t a, int32_t b, TrapReason* trap) { if (b == 0) { *trap = kTrapRemByZero; return 0; } if (b == -1) return 0; return a % b; } inline uint32_t ExecuteI32RemU(uint32_t a, uint32_t b, TrapReason* trap) { if (b == 0) { *trap = kTrapRemByZero; return 0; } return a % b; } inline uint32_t ExecuteI32Shl(uint32_t a, uint32_t b, TrapReason* trap) { return a << (b & 0x1f); } inline uint32_t ExecuteI32ShrU(uint32_t a, uint32_t b, TrapReason* trap) { return a >> (b & 0x1f); } inline int32_t ExecuteI32ShrS(int32_t a, int32_t b, TrapReason* trap) { return a >> (b & 0x1f); } inline int64_t ExecuteI64DivS(int64_t a, int64_t b, TrapReason* trap) { if (b == 0) { *trap = kTrapDivByZero; return 0; } if (b == -1 && a == std::numeric_limits::min()) { *trap = kTrapDivUnrepresentable; return 0; } return a / b; } inline uint64_t ExecuteI64DivU(uint64_t a, uint64_t b, TrapReason* trap) { if (b == 0) { *trap = kTrapDivByZero; return 0; } return a / b; } inline int64_t ExecuteI64RemS(int64_t a, int64_t b, TrapReason* trap) { if (b == 0) { *trap = kTrapRemByZero; return 0; } if (b == -1) return 0; return a % b; } inline uint64_t ExecuteI64RemU(uint64_t a, uint64_t b, TrapReason* trap) { if (b == 0) { *trap = kTrapRemByZero; return 0; } return a % b; } inline uint64_t ExecuteI64Shl(uint64_t a, uint64_t b, TrapReason* trap) { return a << (b & 0x3f); } inline uint64_t ExecuteI64ShrU(uint64_t a, uint64_t b, TrapReason* trap) { return a >> (b & 0x3f); } inline int64_t ExecuteI64ShrS(int64_t a, int64_t b, TrapReason* trap) { return a >> (b & 0x3f); } inline uint32_t ExecuteI32Ror(uint32_t a, uint32_t b, TrapReason* trap) { uint32_t shift = (b & 0x1f); return (a >> shift) | (a << (32 - shift)); } inline uint32_t ExecuteI32Rol(uint32_t a, uint32_t b, TrapReason* trap) { uint32_t shift = (b & 0x1f); return (a << shift) | (a >> (32 - shift)); } inline uint64_t ExecuteI64Ror(uint64_t a, uint64_t b, TrapReason* trap) { uint32_t shift = (b & 0x3f); return (a >> shift) | (a << (64 - shift)); } inline uint64_t ExecuteI64Rol(uint64_t a, uint64_t b, TrapReason* trap) { uint32_t shift = (b & 0x3f); return (a << shift) | (a >> (64 - shift)); } inline float ExecuteF32Min(float a, float b, TrapReason* trap) { return JSMin(a, b); } inline float ExecuteF32Max(float a, float b, TrapReason* trap) { return JSMax(a, b); } inline Float32 ExecuteF32CopySign(Float32 a, Float32 b, TrapReason* trap) { return Float32::FromBits((a.get_bits() & ~kFloat32SignBitMask) | (b.get_bits() & kFloat32SignBitMask)); } inline double ExecuteF64Min(double a, double b, TrapReason* trap) { return JSMin(a, b); } inline double ExecuteF64Max(double a, double b, TrapReason* trap) { return JSMax(a, b); } inline Float64 ExecuteF64CopySign(Float64 a, Float64 b, TrapReason* trap) { return Float64::FromBits((a.get_bits() & ~kFloat64SignBitMask) | (b.get_bits() & kFloat64SignBitMask)); } inline int32_t ExecuteI32AsmjsDivS(int32_t a, int32_t b, TrapReason* trap) { if (b == 0) return 0; if (b == -1 && a == std::numeric_limits::min()) { return std::numeric_limits::min(); } return a / b; } inline uint32_t ExecuteI32AsmjsDivU(uint32_t a, uint32_t b, TrapReason* trap) { if (b == 0) return 0; return a / b; } inline int32_t ExecuteI32AsmjsRemS(int32_t a, int32_t b, TrapReason* trap) { if (b == 0) return 0; if (b == -1) return 0; return a % b; } inline uint32_t ExecuteI32AsmjsRemU(uint32_t a, uint32_t b, TrapReason* trap) { if (b == 0) return 0; return a % b; } inline int32_t ExecuteI32AsmjsSConvertF32(float a, TrapReason* trap) { return DoubleToInt32(a); } inline uint32_t ExecuteI32AsmjsUConvertF32(float a, TrapReason* trap) { return DoubleToUint32(a); } inline int32_t ExecuteI32AsmjsSConvertF64(double a, TrapReason* trap) { return DoubleToInt32(a); } inline uint32_t ExecuteI32AsmjsUConvertF64(double a, TrapReason* trap) { return DoubleToUint32(a); } int32_t ExecuteI32Clz(uint32_t val, TrapReason* trap) { return base::bits::CountLeadingZeros(val); } uint32_t ExecuteI32Ctz(uint32_t val, TrapReason* trap) { return base::bits::CountTrailingZeros(val); } uint32_t ExecuteI32Popcnt(uint32_t val, TrapReason* trap) { return word32_popcnt_wrapper(&val); } inline uint32_t ExecuteI32Eqz(uint32_t val, TrapReason* trap) { return val == 0 ? 1 : 0; } int64_t ExecuteI64Clz(uint64_t val, TrapReason* trap) { return base::bits::CountLeadingZeros(val); } inline uint64_t ExecuteI64Ctz(uint64_t val, TrapReason* trap) { return base::bits::CountTrailingZeros(val); } inline int64_t ExecuteI64Popcnt(uint64_t val, TrapReason* trap) { return word64_popcnt_wrapper(&val); } inline int32_t ExecuteI64Eqz(uint64_t val, TrapReason* trap) { return val == 0 ? 1 : 0; } inline Float32 ExecuteF32Abs(Float32 a, TrapReason* trap) { return Float32::FromBits(a.get_bits() & ~kFloat32SignBitMask); } inline Float32 ExecuteF32Neg(Float32 a, TrapReason* trap) { return Float32::FromBits(a.get_bits() ^ kFloat32SignBitMask); } inline float ExecuteF32Ceil(float a, TrapReason* trap) { return ceilf(a); } inline float ExecuteF32Floor(float a, TrapReason* trap) { return floorf(a); } inline float ExecuteF32Trunc(float a, TrapReason* trap) { return truncf(a); } inline float ExecuteF32NearestInt(float a, TrapReason* trap) { return nearbyintf(a); } inline float ExecuteF32Sqrt(float a, TrapReason* trap) { float result = sqrtf(a); return result; } inline Float64 ExecuteF64Abs(Float64 a, TrapReason* trap) { return Float64::FromBits(a.get_bits() & ~kFloat64SignBitMask); } inline Float64 ExecuteF64Neg(Float64 a, TrapReason* trap) { return Float64::FromBits(a.get_bits() ^ kFloat64SignBitMask); } inline double ExecuteF64Ceil(double a, TrapReason* trap) { return ceil(a); } inline double ExecuteF64Floor(double a, TrapReason* trap) { return floor(a); } inline double ExecuteF64Trunc(double a, TrapReason* trap) { return trunc(a); } inline double ExecuteF64NearestInt(double a, TrapReason* trap) { return nearbyint(a); } inline double ExecuteF64Sqrt(double a, TrapReason* trap) { return sqrt(a); } int32_t ExecuteI32SConvertF32(float a, TrapReason* trap) { // The upper bound is (INT32_MAX + 1), which is the lowest float-representable // number above INT32_MAX which cannot be represented as int32. float upper_bound = 2147483648.0f; // We use INT32_MIN as a lower bound because (INT32_MIN - 1) is not // representable as float, and no number between (INT32_MIN - 1) and INT32_MIN // is. float lower_bound = static_cast(INT32_MIN); if (a < upper_bound && a >= lower_bound) { return static_cast(a); } *trap = kTrapFloatUnrepresentable; return 0; } int32_t ExecuteI32SConvertF64(double a, TrapReason* trap) { // The upper bound is (INT32_MAX + 1), which is the lowest double- // representable number above INT32_MAX which cannot be represented as int32. double upper_bound = 2147483648.0; // The lower bound is (INT32_MIN - 1), which is the greatest double- // representable number below INT32_MIN which cannot be represented as int32. double lower_bound = -2147483649.0; if (a < upper_bound && a > lower_bound) { return static_cast(a); } *trap = kTrapFloatUnrepresentable; return 0; } uint32_t ExecuteI32UConvertF32(float a, TrapReason* trap) { // The upper bound is (UINT32_MAX + 1), which is the lowest // float-representable number above UINT32_MAX which cannot be represented as // uint32. double upper_bound = 4294967296.0f; double lower_bound = -1.0f; if (a < upper_bound && a > lower_bound) { return static_cast(a); } *trap = kTrapFloatUnrepresentable; return 0; } uint32_t ExecuteI32UConvertF64(double a, TrapReason* trap) { // The upper bound is (UINT32_MAX + 1), which is the lowest // double-representable number above UINT32_MAX which cannot be represented as // uint32. double upper_bound = 4294967296.0; double lower_bound = -1.0; if (a < upper_bound && a > lower_bound) { return static_cast(a); } *trap = kTrapFloatUnrepresentable; return 0; } inline uint32_t ExecuteI32ConvertI64(int64_t a, TrapReason* trap) { return static_cast(a & 0xFFFFFFFF); } int64_t ExecuteI64SConvertF32(float a, TrapReason* trap) { int64_t output; if (!float32_to_int64_wrapper(&a, &output)) { *trap = kTrapFloatUnrepresentable; } return output; } int64_t ExecuteI64SConvertF64(double a, TrapReason* trap) { int64_t output; if (!float64_to_int64_wrapper(&a, &output)) { *trap = kTrapFloatUnrepresentable; } return output; } uint64_t ExecuteI64UConvertF32(float a, TrapReason* trap) { uint64_t output; if (!float32_to_uint64_wrapper(&a, &output)) { *trap = kTrapFloatUnrepresentable; } return output; } uint64_t ExecuteI64UConvertF64(double a, TrapReason* trap) { uint64_t output; if (!float64_to_uint64_wrapper(&a, &output)) { *trap = kTrapFloatUnrepresentable; } return output; } inline int64_t ExecuteI64SConvertI32(int32_t a, TrapReason* trap) { return static_cast(a); } inline int64_t ExecuteI64UConvertI32(uint32_t a, TrapReason* trap) { return static_cast(a); } inline float ExecuteF32SConvertI32(int32_t a, TrapReason* trap) { return static_cast(a); } inline float ExecuteF32UConvertI32(uint32_t a, TrapReason* trap) { return static_cast(a); } inline float ExecuteF32SConvertI64(int64_t a, TrapReason* trap) { float output; int64_to_float32_wrapper(&a, &output); return output; } inline float ExecuteF32UConvertI64(uint64_t a, TrapReason* trap) { float output; uint64_to_float32_wrapper(&a, &output); return output; } inline float ExecuteF32ConvertF64(double a, TrapReason* trap) { return static_cast(a); } inline Float32 ExecuteF32ReinterpretI32(int32_t a, TrapReason* trap) { return Float32::FromBits(a); } inline double ExecuteF64SConvertI32(int32_t a, TrapReason* trap) { return static_cast(a); } inline double ExecuteF64UConvertI32(uint32_t a, TrapReason* trap) { return static_cast(a); } inline double ExecuteF64SConvertI64(int64_t a, TrapReason* trap) { double output; int64_to_float64_wrapper(&a, &output); return output; } inline double ExecuteF64UConvertI64(uint64_t a, TrapReason* trap) { double output; uint64_to_float64_wrapper(&a, &output); return output; } inline double ExecuteF64ConvertF32(float a, TrapReason* trap) { return static_cast(a); } inline Float64 ExecuteF64ReinterpretI64(int64_t a, TrapReason* trap) { return Float64::FromBits(a); } inline int32_t ExecuteI32ReinterpretF32(WasmValue a) { return a.to_f32_boxed().get_bits(); } inline int64_t ExecuteI64ReinterpretF64(WasmValue a) { return a.to_f64_boxed().get_bits(); } enum InternalOpcode { #define DECL_INTERNAL_ENUM(name, value) kInternal##name = value, FOREACH_INTERNAL_OPCODE(DECL_INTERNAL_ENUM) #undef DECL_INTERNAL_ENUM }; const char* OpcodeName(uint32_t val) { switch (val) { #define DECL_INTERNAL_CASE(name, value) \ case kInternal##name: \ return "Internal" #name; FOREACH_INTERNAL_OPCODE(DECL_INTERNAL_CASE) #undef DECL_INTERNAL_CASE } return WasmOpcodes::OpcodeName(static_cast(val)); } // Unwrap a wasm to js wrapper, return the callable heap object. // If the wrapper would throw a TypeError, return a null handle. Handle UnwrapWasmToJSWrapper(Isolate* isolate, Handle js_wrapper) { DCHECK_EQ(Code::WASM_TO_JS_FUNCTION, js_wrapper->kind()); Handle deopt_data(js_wrapper->deoptimization_data(), isolate); DCHECK_EQ(2, deopt_data->length()); intptr_t js_imports_table_loc = static_cast( HeapNumber::cast(deopt_data->get(0))->value_as_bits()); Handle js_imports_table( reinterpret_cast(js_imports_table_loc)); int index = 0; CHECK(deopt_data->get(1)->ToInt32(&index)); DCHECK_GT(js_imports_table->length(), index); Handle obj(js_imports_table->get(index), isolate); if (obj->IsCallable()) { return Handle::cast(obj); } else { // If we did not find a callable object, this is an illegal JS import and // obj must be undefined. DCHECK(obj->IsUndefined(isolate)); return Handle::null(); } } class SideTable; // Code and metadata needed to execute a function. struct InterpreterCode { const WasmFunction* function; // wasm function BodyLocalDecls locals; // local declarations const byte* orig_start; // start of original code const byte* orig_end; // end of original code byte* start; // start of (maybe altered) code byte* end; // end of (maybe altered) code SideTable* side_table; // precomputed side table for control flow. const byte* at(pc_t pc) { return start + pc; } }; // A helper class to compute the control transfers for each bytecode offset. // Control transfers allow Br, BrIf, BrTable, If, Else, and End bytecodes to // be directly executed without the need to dynamically track blocks. class SideTable : public ZoneObject { public: ControlTransferMap map_; uint32_t max_stack_height_; SideTable(Zone* zone, const WasmModule* module, InterpreterCode* code) : map_(zone), max_stack_height_(0) { // Create a zone for all temporary objects. Zone control_transfer_zone(zone->allocator(), ZONE_NAME); // Represents a control flow label. class CLabel : public ZoneObject { explicit CLabel(Zone* zone, uint32_t target_stack_height, uint32_t arity) : target(nullptr), target_stack_height(target_stack_height), arity(arity), refs(zone) {} public: struct Ref { const byte* from_pc; const uint32_t stack_height; }; const byte* target; uint32_t target_stack_height; // Arity when branching to this label. const uint32_t arity; ZoneVector refs; static CLabel* New(Zone* zone, uint32_t stack_height, uint32_t arity) { return new (zone) CLabel(zone, stack_height, arity); } // Bind this label to the given PC. void Bind(const byte* pc) { DCHECK_NULL(target); target = pc; } // Reference this label from the given location. void Ref(const byte* from_pc, uint32_t stack_height) { // Target being bound before a reference means this is a loop. DCHECK_IMPLIES(target, *target == kExprLoop); refs.push_back({from_pc, stack_height}); } void Finish(ControlTransferMap* map, const byte* start) { DCHECK_NOT_NULL(target); for (auto ref : refs) { size_t offset = static_cast(ref.from_pc - start); auto pcdiff = static_cast(target - ref.from_pc); DCHECK_GE(ref.stack_height, target_stack_height); spdiff_t spdiff = static_cast(ref.stack_height - target_stack_height); TRACE("control transfer @%zu: Δpc %d, stack %u->%u = -%u\n", offset, pcdiff, ref.stack_height, target_stack_height, spdiff); ControlTransferEntry& entry = (*map)[offset]; entry.pc_diff = pcdiff; entry.sp_diff = spdiff; entry.target_arity = arity; } } }; // An entry in the control stack. struct Control { const byte* pc; CLabel* end_label; CLabel* else_label; // Arity (number of values on the stack) when exiting this control // structure via |end|. uint32_t exit_arity; // Track whether this block was already left, i.e. all further // instructions are unreachable. bool unreachable = false; Control(const byte* pc, CLabel* end_label, CLabel* else_label, uint32_t exit_arity) : pc(pc), end_label(end_label), else_label(else_label), exit_arity(exit_arity) {} Control(const byte* pc, CLabel* end_label, uint32_t exit_arity) : Control(pc, end_label, nullptr, exit_arity) {} void Finish(ControlTransferMap* map, const byte* start) { end_label->Finish(map, start); if (else_label) else_label->Finish(map, start); } }; // Compute the ControlTransfer map. // This algorithm maintains a stack of control constructs similar to the // AST decoder. The {control_stack} allows matching {br,br_if,br_table} // bytecodes with their target, as well as determining whether the current // bytecodes are within the true or false block of an else. ZoneVector control_stack(&control_transfer_zone); uint32_t stack_height = 0; uint32_t func_arity = static_cast(code->function->sig->return_count()); CLabel* func_label = CLabel::New(&control_transfer_zone, stack_height, func_arity); control_stack.emplace_back(code->orig_start, func_label, func_arity); auto control_parent = [&]() -> Control& { DCHECK_LE(2, control_stack.size()); return control_stack[control_stack.size() - 2]; }; auto copy_unreachable = [&] { control_stack.back().unreachable = control_parent().unreachable; }; for (BytecodeIterator i(code->orig_start, code->orig_end, &code->locals); i.has_next(); i.next()) { WasmOpcode opcode = i.current(); if (WasmOpcodes::IsPrefixOpcode(opcode)) opcode = i.prefixed_opcode(); bool unreachable = control_stack.back().unreachable; if (unreachable) { TRACE("@%u: %s (is unreachable)\n", i.pc_offset(), WasmOpcodes::OpcodeName(opcode)); } else { auto stack_effect = StackEffect(module, code->function->sig, i.pc(), i.end()); TRACE("@%u: %s (sp %d - %d + %d)\n", i.pc_offset(), WasmOpcodes::OpcodeName(opcode), stack_height, stack_effect.first, stack_effect.second); DCHECK_GE(stack_height, stack_effect.first); DCHECK_GE(kMaxUInt32, static_cast(stack_height) - stack_effect.first + stack_effect.second); stack_height = stack_height - stack_effect.first + stack_effect.second; if (stack_height > max_stack_height_) max_stack_height_ = stack_height; } switch (opcode) { case kExprBlock: case kExprLoop: { bool is_loop = opcode == kExprLoop; BlockTypeOperand operand(&i, i.pc()); if (operand.type == kWasmVar) { operand.sig = module->signatures[operand.sig_index]; } TRACE("control @%u: %s, arity %d->%d\n", i.pc_offset(), is_loop ? "Loop" : "Block", operand.in_arity(), operand.out_arity()); CLabel* label = CLabel::New(&control_transfer_zone, stack_height, is_loop ? operand.in_arity() : operand.out_arity()); control_stack.emplace_back(i.pc(), label, operand.out_arity()); copy_unreachable(); if (is_loop) label->Bind(i.pc()); break; } case kExprIf: { BlockTypeOperand operand(&i, i.pc()); if (operand.type == kWasmVar) { operand.sig = module->signatures[operand.sig_index]; } TRACE("control @%u: If, arity %d->%d\n", i.pc_offset(), operand.in_arity(), operand.out_arity()); CLabel* end_label = CLabel::New(&control_transfer_zone, stack_height, operand.out_arity()); CLabel* else_label = CLabel::New(&control_transfer_zone, stack_height, 0); control_stack.emplace_back(i.pc(), end_label, else_label, operand.out_arity()); copy_unreachable(); if (!unreachable) else_label->Ref(i.pc(), stack_height); break; } case kExprElse: { Control* c = &control_stack.back(); copy_unreachable(); TRACE("control @%u: Else\n", i.pc_offset()); if (!control_parent().unreachable) { c->end_label->Ref(i.pc(), stack_height); } DCHECK_NOT_NULL(c->else_label); c->else_label->Bind(i.pc() + 1); c->else_label->Finish(&map_, code->orig_start); c->else_label = nullptr; DCHECK_GE(stack_height, c->end_label->target_stack_height); stack_height = c->end_label->target_stack_height; break; } case kExprEnd: { Control* c = &control_stack.back(); TRACE("control @%u: End\n", i.pc_offset()); // Only loops have bound labels. DCHECK_IMPLIES(c->end_label->target, *c->pc == kExprLoop); if (!c->end_label->target) { if (c->else_label) c->else_label->Bind(i.pc()); c->end_label->Bind(i.pc() + 1); } c->Finish(&map_, code->orig_start); DCHECK_GE(stack_height, c->end_label->target_stack_height); stack_height = c->end_label->target_stack_height + c->exit_arity; control_stack.pop_back(); break; } case kExprBr: { BreakDepthOperand operand(&i, i.pc()); TRACE("control @%u: Br[depth=%u]\n", i.pc_offset(), operand.depth); Control* c = &control_stack[control_stack.size() - operand.depth - 1]; if (!unreachable) c->end_label->Ref(i.pc(), stack_height); break; } case kExprBrIf: { BreakDepthOperand operand(&i, i.pc()); TRACE("control @%u: BrIf[depth=%u]\n", i.pc_offset(), operand.depth); Control* c = &control_stack[control_stack.size() - operand.depth - 1]; if (!unreachable) c->end_label->Ref(i.pc(), stack_height); break; } case kExprBrTable: { BranchTableOperand operand(&i, i.pc()); BranchTableIterator iterator(&i, operand); TRACE("control @%u: BrTable[count=%u]\n", i.pc_offset(), operand.table_count); if (!unreachable) { while (iterator.has_next()) { uint32_t j = iterator.cur_index(); uint32_t target = iterator.next(); Control* c = &control_stack[control_stack.size() - target - 1]; c->end_label->Ref(i.pc() + j, stack_height); } } break; } default: break; } if (WasmOpcodes::IsUnconditionalJump(opcode)) { control_stack.back().unreachable = true; } } DCHECK_EQ(0, control_stack.size()); DCHECK_EQ(func_arity, stack_height); } ControlTransferEntry& Lookup(pc_t from) { auto result = map_.find(from); DCHECK(result != map_.end()); return result->second; } }; struct ExternalCallResult { enum Type { // The function should be executed inside this interpreter. INTERNAL, // For indirect calls: Table or function does not exist. INVALID_FUNC, // For indirect calls: Signature does not match expected signature. SIGNATURE_MISMATCH, // The function was executed and returned normally. EXTERNAL_RETURNED, // The function was executed, threw an exception, and the stack was unwound. EXTERNAL_UNWOUND }; Type type; // If type is INTERNAL, this field holds the function to call internally. InterpreterCode* interpreter_code; ExternalCallResult(Type type) : type(type) { // NOLINT DCHECK_NE(INTERNAL, type); } ExternalCallResult(Type type, InterpreterCode* code) : type(type), interpreter_code(code) { DCHECK_EQ(INTERNAL, type); } }; // The main storage for interpreter code. It maps {WasmFunction} to the // metadata needed to execute each function. class CodeMap { Zone* zone_; const WasmModule* module_; ZoneVector interpreter_code_; // This handle is set and reset by the SetInstanceObject() / // ClearInstanceObject() method, which is used by the HeapObjectsScope. Handle instance_; public: CodeMap(Isolate* isolate, const WasmModule* module, const uint8_t* module_start, Zone* zone) : zone_(zone), module_(module), interpreter_code_(zone) { if (module == nullptr) return; interpreter_code_.reserve(module->functions.size()); for (const WasmFunction& function : module->functions) { if (function.imported) { DCHECK(!function.code.is_set()); AddFunction(&function, nullptr, nullptr); } else { AddFunction(&function, module_start + function.code.offset(), module_start + function.code.end_offset()); } } } void SetInstanceObject(Handle instance) { DCHECK(instance_.is_null()); instance_ = instance; } void ClearInstanceObject() { instance_ = Handle::null(); } const WasmModule* module() const { return module_; } bool has_instance() const { return !instance_.is_null(); } WasmInstanceObject* instance() const { DCHECK(has_instance()); return *instance_; } MaybeHandle maybe_instance() const { return has_instance() ? handle(instance()) : MaybeHandle(); } Code* GetImportedFunction(uint32_t function_index) { DCHECK(has_instance()); DCHECK_GT(module_->num_imported_functions, function_index); FixedArray* code_table = instance()->compiled_module()->ptr_to_code_table(); return Code::cast(code_table->get(static_cast(function_index))); } InterpreterCode* GetCode(const WasmFunction* function) { InterpreterCode* code = GetCode(function->func_index); DCHECK_EQ(function, code->function); return code; } InterpreterCode* GetCode(uint32_t function_index) { DCHECK_LT(function_index, interpreter_code_.size()); return Preprocess(&interpreter_code_[function_index]); } InterpreterCode* GetIndirectCode(uint32_t table_index, uint32_t entry_index) { if (table_index >= module_->function_tables.size()) return nullptr; const WasmIndirectFunctionTable* table = &module_->function_tables[table_index]; if (entry_index >= table->values.size()) return nullptr; uint32_t index = table->values[entry_index]; if (index >= interpreter_code_.size()) return nullptr; return GetCode(index); } InterpreterCode* Preprocess(InterpreterCode* code) { DCHECK_EQ(code->function->imported, code->start == nullptr); if (!code->side_table && code->start) { // Compute the control targets map and the local declarations. code->side_table = new (zone_) SideTable(zone_, module_, code); } return code; } void AddFunction(const WasmFunction* function, const byte* code_start, const byte* code_end) { InterpreterCode code = { function, BodyLocalDecls(zone_), code_start, code_end, const_cast(code_start), const_cast(code_end), nullptr}; DCHECK_EQ(interpreter_code_.size(), function->func_index); interpreter_code_.push_back(code); } void SetFunctionCode(const WasmFunction* function, const byte* start, const byte* end) { DCHECK_LT(function->func_index, interpreter_code_.size()); InterpreterCode* code = &interpreter_code_[function->func_index]; DCHECK_EQ(function, code->function); code->orig_start = start; code->orig_end = end; code->start = const_cast(start); code->end = const_cast(end); code->side_table = nullptr; Preprocess(code); } }; Handle WasmValueToNumber(Factory* factory, WasmValue val, wasm::ValueType type) { switch (type) { case kWasmI32: return factory->NewNumberFromInt(val.to()); case kWasmI64: // wasm->js and js->wasm is illegal for i64 type. UNREACHABLE(); case kWasmF32: return factory->NewNumber(val.to()); case kWasmF64: return factory->NewNumber(val.to()); default: // TODO(wasm): Implement simd. UNIMPLEMENTED(); return Handle::null(); } } // Convert JS value to WebAssembly, spec here: // https://github.com/WebAssembly/design/blob/master/JS.md#towebassemblyvalue // Return WasmValue() (i.e. of type kWasmStmt) on failure. In that case, an // exception will be pending on the isolate. WasmValue ToWebAssemblyValue(Isolate* isolate, Handle value, wasm::ValueType type) { switch (type) { case kWasmI32: { MaybeHandle maybe_i32 = Object::ToInt32(isolate, value); if (maybe_i32.is_null()) return {}; int32_t value; CHECK(maybe_i32.ToHandleChecked()->ToInt32(&value)); return WasmValue(value); } case kWasmI64: // If the signature contains i64, a type error was thrown before. UNREACHABLE(); case kWasmF32: { MaybeHandle maybe_number = Object::ToNumber(value); if (maybe_number.is_null()) return {}; return WasmValue( static_cast(maybe_number.ToHandleChecked()->Number())); } case kWasmF64: { MaybeHandle maybe_number = Object::ToNumber(value); if (maybe_number.is_null()) return {}; return WasmValue(maybe_number.ToHandleChecked()->Number()); } default: // TODO(wasm): Handle simd. UNIMPLEMENTED(); return WasmValue(); } } // Like a static_cast from src to dst, but specialized for boxed floats. template struct converter { dst operator()(src val) const { return static_cast(val); } }; template <> struct converter { Float64 operator()(uint64_t val) const { return Float64::FromBits(val); } }; template <> struct converter { Float32 operator()(uint32_t val) const { return Float32::FromBits(val); } }; template <> struct converter { uint64_t operator()(Float64 val) const { return val.get_bits(); } }; template <> struct converter { uint32_t operator()(Float32 val) const { return val.get_bits(); } }; template V8_INLINE bool has_nondeterminism(T val) { static_assert(!std::is_floating_point::value, "missing specialization"); return false; } template <> V8_INLINE bool has_nondeterminism(float val) { return std::isnan(val); } template <> V8_INLINE bool has_nondeterminism(double val) { return std::isnan(val); } // Responsible for executing code directly. class ThreadImpl { struct Activation { uint32_t fp; sp_t sp; Activation(uint32_t fp, sp_t sp) : fp(fp), sp(sp) {} }; public: ThreadImpl(Zone* zone, CodeMap* codemap, WasmContext* wasm_context) : codemap_(codemap), wasm_context_(wasm_context), zone_(zone), frames_(zone), activations_(zone) {} //========================================================================== // Implementation of public interface for WasmInterpreter::Thread. //========================================================================== WasmInterpreter::State state() { return state_; } void InitFrame(const WasmFunction* function, WasmValue* args) { DCHECK_EQ(current_activation().fp, frames_.size()); InterpreterCode* code = codemap()->GetCode(function); size_t num_params = function->sig->parameter_count(); EnsureStackSpace(num_params); Push(args, num_params); PushFrame(code); } WasmInterpreter::State Run(int num_steps = -1) { DCHECK(state_ == WasmInterpreter::STOPPED || state_ == WasmInterpreter::PAUSED); DCHECK(num_steps == -1 || num_steps > 0); if (num_steps == -1) { TRACE(" => Run()\n"); } else if (num_steps == 1) { TRACE(" => Step()\n"); } else { TRACE(" => Run(%d)\n", num_steps); } state_ = WasmInterpreter::RUNNING; Execute(frames_.back().code, frames_.back().pc, num_steps); // If state_ is STOPPED, the current activation must be fully unwound. DCHECK_IMPLIES(state_ == WasmInterpreter::STOPPED, current_activation().fp == frames_.size()); return state_; } void Pause() { UNIMPLEMENTED(); } void Reset() { TRACE("----- RESET -----\n"); sp_ = stack_start_; frames_.clear(); state_ = WasmInterpreter::STOPPED; trap_reason_ = kTrapCount; possible_nondeterminism_ = false; } int GetFrameCount() { DCHECK_GE(kMaxInt, frames_.size()); return static_cast(frames_.size()); } WasmValue GetReturnValue(uint32_t index) { if (state_ == WasmInterpreter::TRAPPED) return WasmValue(0xdeadbeef); DCHECK_EQ(WasmInterpreter::FINISHED, state_); Activation act = current_activation(); // Current activation must be finished. DCHECK_EQ(act.fp, frames_.size()); return GetStackValue(act.sp + index); } WasmValue GetStackValue(sp_t index) { DCHECK_GT(StackHeight(), index); return stack_start_[index]; } void SetStackValue(sp_t index, WasmValue value) { DCHECK_GT(StackHeight(), index); stack_start_[index] = value; } TrapReason GetTrapReason() { return trap_reason_; } pc_t GetBreakpointPc() { return break_pc_; } bool PossibleNondeterminism() { return possible_nondeterminism_; } uint64_t NumInterpretedCalls() { return num_interpreted_calls_; } void AddBreakFlags(uint8_t flags) { break_flags_ |= flags; } void ClearBreakFlags() { break_flags_ = WasmInterpreter::BreakFlag::None; } uint32_t NumActivations() { return static_cast(activations_.size()); } uint32_t StartActivation() { TRACE("----- START ACTIVATION %zu -----\n", activations_.size()); // If you use activations, use them consistently: DCHECK_IMPLIES(activations_.empty(), frames_.empty()); DCHECK_IMPLIES(activations_.empty(), StackHeight() == 0); uint32_t activation_id = static_cast(activations_.size()); activations_.emplace_back(static_cast(frames_.size()), StackHeight()); state_ = WasmInterpreter::STOPPED; return activation_id; } void FinishActivation(uint32_t id) { TRACE("----- FINISH ACTIVATION %zu -----\n", activations_.size() - 1); DCHECK_LT(0, activations_.size()); DCHECK_EQ(activations_.size() - 1, id); // Stack height must match the start of this activation (otherwise unwind // first). DCHECK_EQ(activations_.back().fp, frames_.size()); DCHECK_LE(activations_.back().sp, StackHeight()); sp_ = stack_start_ + activations_.back().sp; activations_.pop_back(); } uint32_t ActivationFrameBase(uint32_t id) { DCHECK_GT(activations_.size(), id); return activations_[id].fp; } // Handle a thrown exception. Returns whether the exception was handled inside // the current activation. Unwinds the interpreted stack accordingly. WasmInterpreter::Thread::ExceptionHandlingResult HandleException( Isolate* isolate) { DCHECK(isolate->has_pending_exception()); // TODO(wasm): Add wasm exception handling (would return HANDLED). USE(isolate->pending_exception()); TRACE("----- UNWIND -----\n"); DCHECK_LT(0, activations_.size()); Activation& act = activations_.back(); DCHECK_LE(act.fp, frames_.size()); frames_.resize(act.fp); DCHECK_LE(act.sp, StackHeight()); sp_ = stack_start_ + act.sp; state_ = WasmInterpreter::STOPPED; return WasmInterpreter::Thread::UNWOUND; } private: // Entries on the stack of functions being evaluated. struct Frame { InterpreterCode* code; pc_t pc; sp_t sp; // Limit of parameters. sp_t plimit() { return sp + code->function->sig->parameter_count(); } // Limit of locals. sp_t llimit() { return plimit() + code->locals.type_list.size(); } }; struct Block { pc_t pc; sp_t sp; size_t fp; unsigned arity; }; friend class InterpretedFrameImpl; CodeMap* codemap_; WasmContext* wasm_context_; Zone* zone_; WasmValue* stack_start_ = nullptr; // Start of allocated stack space. WasmValue* stack_limit_ = nullptr; // End of allocated stack space. WasmValue* sp_ = nullptr; // Current stack pointer. ZoneVector frames_; WasmInterpreter::State state_ = WasmInterpreter::STOPPED; pc_t break_pc_ = kInvalidPc; TrapReason trap_reason_ = kTrapCount; bool possible_nondeterminism_ = false; uint8_t break_flags_ = 0; // a combination of WasmInterpreter::BreakFlag uint64_t num_interpreted_calls_ = 0; // Store the stack height of each activation (for unwind and frame // inspection). ZoneVector activations_; CodeMap* codemap() const { return codemap_; } const WasmModule* module() const { return codemap_->module(); } void DoTrap(TrapReason trap, pc_t pc) { state_ = WasmInterpreter::TRAPPED; trap_reason_ = trap; CommitPc(pc); } // Push a frame with arguments already on the stack. void PushFrame(InterpreterCode* code) { DCHECK_NOT_NULL(code); DCHECK_NOT_NULL(code->side_table); EnsureStackSpace(code->side_table->max_stack_height_ + code->locals.type_list.size()); ++num_interpreted_calls_; size_t arity = code->function->sig->parameter_count(); // The parameters will overlap the arguments already on the stack. DCHECK_GE(StackHeight(), arity); frames_.push_back({code, 0, StackHeight() - arity}); frames_.back().pc = InitLocals(code); TRACE(" => PushFrame #%zu (#%u @%zu)\n", frames_.size() - 1, code->function->func_index, frames_.back().pc); } pc_t InitLocals(InterpreterCode* code) { for (auto p : code->locals.type_list) { WasmValue val; switch (p) { #define CASE_TYPE(wasm, ctype) \ case kWasm##wasm: \ val = WasmValue(static_cast(0)); \ break; WASM_CTYPES(CASE_TYPE) #undef CASE_TYPE default: UNREACHABLE(); break; } Push(val); } return code->locals.encoded_size; } void CommitPc(pc_t pc) { DCHECK(!frames_.empty()); frames_.back().pc = pc; } bool SkipBreakpoint(InterpreterCode* code, pc_t pc) { if (pc == break_pc_) { // Skip the previously hit breakpoint when resuming. break_pc_ = kInvalidPc; return true; } return false; } int LookupTargetDelta(InterpreterCode* code, pc_t pc) { return static_cast(code->side_table->Lookup(pc).pc_diff); } int DoBreak(InterpreterCode* code, pc_t pc, size_t depth) { ControlTransferEntry& control_transfer_entry = code->side_table->Lookup(pc); DoStackTransfer(sp_ - control_transfer_entry.sp_diff, control_transfer_entry.target_arity); return control_transfer_entry.pc_diff; } pc_t ReturnPc(Decoder* decoder, InterpreterCode* code, pc_t pc) { switch (code->orig_start[pc]) { case kExprCallFunction: { CallFunctionOperand operand(decoder, code->at(pc)); return pc + 1 + operand.length; } case kExprCallIndirect: { CallIndirectOperand operand(decoder, code->at(pc)); return pc + 1 + operand.length; } default: UNREACHABLE(); } } bool DoReturn(Decoder* decoder, InterpreterCode** code, pc_t* pc, pc_t* limit, size_t arity) { DCHECK_GT(frames_.size(), 0); WasmValue* sp_dest = stack_start_ + frames_.back().sp; frames_.pop_back(); if (frames_.size() == current_activation().fp) { // A return from the last frame terminates the execution. state_ = WasmInterpreter::FINISHED; DoStackTransfer(sp_dest, arity); TRACE(" => finish\n"); return false; } else { // Return to caller frame. Frame* top = &frames_.back(); *code = top->code; decoder->Reset((*code)->start, (*code)->end); *pc = ReturnPc(decoder, *code, top->pc); *limit = top->code->end - top->code->start; TRACE(" => Return to #%zu (#%u @%zu)\n", frames_.size() - 1, (*code)->function->func_index, *pc); DoStackTransfer(sp_dest, arity); return true; } } // Returns true if the call was successful, false if the stack check failed // and the current activation was fully unwound. bool DoCall(Decoder* decoder, InterpreterCode* target, pc_t* pc, pc_t* limit) WARN_UNUSED_RESULT { frames_.back().pc = *pc; PushFrame(target); if (!DoStackCheck()) return false; *pc = frames_.back().pc; *limit = target->end - target->start; decoder->Reset(target->start, target->end); return true; } // Copies {arity} values on the top of the stack down the stack to {dest}, // dropping the values in-between. void DoStackTransfer(WasmValue* dest, size_t arity) { // before: |---------------| pop_count | arity | // ^ 0 ^ dest ^ sp_ // // after: |---------------| arity | // ^ 0 ^ sp_ DCHECK_LE(dest, sp_); DCHECK_LE(dest + arity, sp_); if (arity) memmove(dest, sp_ - arity, arity * sizeof(*sp_)); sp_ = dest + arity; } template inline bool BoundsCheck(uint32_t mem_size, uint32_t offset, uint32_t index) { return sizeof(mtype) <= mem_size && offset <= mem_size - sizeof(mtype) && index <= mem_size - sizeof(mtype) - offset; } template bool ExecuteLoad(Decoder* decoder, InterpreterCode* code, pc_t pc, int& len, MachineRepresentation rep) { MemoryAccessOperand operand(decoder, code->at(pc), sizeof(ctype)); uint32_t index = Pop().to(); if (!BoundsCheck(wasm_context_->mem_size, operand.offset, index)) { DoTrap(kTrapMemOutOfBounds, pc); return false; } byte* addr = wasm_context_->mem_start + operand.offset + index; WasmValue result( converter{}(ReadLittleEndianValue(addr))); Push(result); len = 1 + operand.length; if (FLAG_wasm_trace_memory) { tracing::TraceMemoryOperation( tracing::kWasmInterpreted, false, rep, operand.offset + index, code->function->func_index, static_cast(pc), wasm_context_->mem_start); } return true; } template bool ExecuteStore(Decoder* decoder, InterpreterCode* code, pc_t pc, int& len, MachineRepresentation rep) { MemoryAccessOperand operand(decoder, code->at(pc), sizeof(ctype)); ctype val = Pop().to(); uint32_t index = Pop().to(); if (!BoundsCheck(wasm_context_->mem_size, operand.offset, index)) { DoTrap(kTrapMemOutOfBounds, pc); return false; } byte* addr = wasm_context_->mem_start + operand.offset + index; WriteLittleEndianValue(addr, converter{}(val)); len = 1 + operand.length; if (FLAG_wasm_trace_memory) { tracing::TraceMemoryOperation( tracing::kWasmInterpreted, true, rep, operand.offset + index, code->function->func_index, static_cast(pc), wasm_context_->mem_start); } return true; } template bool ExtractAtomicBinOpParams(Decoder* decoder, InterpreterCode* code, Address& address, pc_t pc, type& val, int& len) { MemoryAccessOperand operand(decoder, code->at(pc + 1), sizeof(type)); val = Pop().to(); uint32_t index = Pop().to(); if (!BoundsCheck(wasm_context_->mem_size, operand.offset, index)) { DoTrap(kTrapMemOutOfBounds, pc); return false; } address = wasm_context_->mem_start + operand.offset + index; len = 2 + operand.length; return true; } bool ExecuteAtomicOp(WasmOpcode opcode, Decoder* decoder, InterpreterCode* code, pc_t pc, int& len) { WasmValue result; switch (opcode) { // TODO(gdeepti): Remove work-around when the bots are upgraded to a more // recent gcc version. The gcc bots (Android ARM, linux) currently use // gcc 4.8, in which atomics are insufficiently supported, also Bug#58016 // (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58016) #if __GNUG__ && __GNUC__ < 5 #define ATOMIC_BINOP_CASE(name, type, operation) \ case kExpr##name: { \ type val; \ Address addr; \ if (!ExtractAtomicBinOpParams(decoder, code, addr, pc, val, len)) { \ return false; \ } \ result = WasmValue( \ __##operation(reinterpret_cast(addr), val, __ATOMIC_SEQ_CST)); \ break; \ } #else #define ATOMIC_BINOP_CASE(name, type, operation) \ case kExpr##name: { \ type val; \ Address addr; \ if (!ExtractAtomicBinOpParams(decoder, code, addr, pc, val, len)) { \ return false; \ } \ static_assert(sizeof(std::atomic) == sizeof(type), \ "Size mismatch for types std::atomic, and " #type); \ result = WasmValue( \ std::operation(reinterpret_cast*>(addr), val)); \ break; \ } #endif ATOMIC_BINOP_CASE(I32AtomicAdd, uint32_t, atomic_fetch_add); ATOMIC_BINOP_CASE(I32AtomicAdd8U, uint8_t, atomic_fetch_add); ATOMIC_BINOP_CASE(I32AtomicAdd16U, uint16_t, atomic_fetch_add); ATOMIC_BINOP_CASE(I32AtomicSub, uint32_t, atomic_fetch_sub); ATOMIC_BINOP_CASE(I32AtomicSub8U, uint8_t, atomic_fetch_sub); ATOMIC_BINOP_CASE(I32AtomicSub16U, uint16_t, atomic_fetch_sub); ATOMIC_BINOP_CASE(I32AtomicAnd, uint32_t, atomic_fetch_and); ATOMIC_BINOP_CASE(I32AtomicAnd8U, uint8_t, atomic_fetch_and); ATOMIC_BINOP_CASE(I32AtomicAnd16U, uint16_t, atomic_fetch_and); ATOMIC_BINOP_CASE(I32AtomicOr, uint32_t, atomic_fetch_or); ATOMIC_BINOP_CASE(I32AtomicOr8U, uint8_t, atomic_fetch_or); ATOMIC_BINOP_CASE(I32AtomicOr16U, uint16_t, atomic_fetch_or); ATOMIC_BINOP_CASE(I32AtomicXor, uint32_t, atomic_fetch_xor); ATOMIC_BINOP_CASE(I32AtomicXor8U, uint8_t, atomic_fetch_xor); ATOMIC_BINOP_CASE(I32AtomicXor16U, uint16_t, atomic_fetch_xor); #if __GNUG__ && __GNUC__ < 5 ATOMIC_BINOP_CASE(I32AtomicExchange, uint32_t, atomic_exchange_n); ATOMIC_BINOP_CASE(I32AtomicExchange8U, uint8_t, atomic_exchange_n); ATOMIC_BINOP_CASE(I32AtomicExchange16U, uint16_t, atomic_exchange_n); #else ATOMIC_BINOP_CASE(I32AtomicExchange, uint32_t, atomic_exchange); ATOMIC_BINOP_CASE(I32AtomicExchange8U, uint8_t, atomic_exchange); ATOMIC_BINOP_CASE(I32AtomicExchange16U, uint16_t, atomic_exchange); #endif #undef ATOMIC_BINOP_CASE default: return false; } Push(result); return true; } // Check if our control stack (frames_) exceeds the limit. Trigger stack // overflow if it does, and unwinding the current frame. // Returns true if execution can continue, false if the current activation was // fully unwound. // Do call this function immediately *after* pushing a new frame. The pc of // the top frame will be reset to 0 if the stack check fails. bool DoStackCheck() WARN_UNUSED_RESULT { // The goal of this stack check is not to prevent actual stack overflows, // but to simulate stack overflows during the execution of compiled code. // That is why this function uses FLAG_stack_size, even though the value // stack actually lies in zone memory. const size_t stack_size_limit = FLAG_stack_size * KB; // Sum up the value stack size and the control stack size. const size_t current_stack_size = (sp_ - stack_start_) + frames_.size() * sizeof(Frame); if (V8_LIKELY(current_stack_size <= stack_size_limit)) { return true; } if (!codemap()->has_instance()) { // In test mode: Just abort. FATAL("wasm interpreter: stack overflow"); } // The pc of the top frame is initialized to the first instruction. We reset // it to 0 here such that we report the same position as in compiled code. frames_.back().pc = 0; Isolate* isolate = codemap()->instance()->GetIsolate(); HandleScope handle_scope(isolate); isolate->StackOverflow(); return HandleException(isolate) == WasmInterpreter::Thread::HANDLED; } void Execute(InterpreterCode* code, pc_t pc, int max) { DCHECK_NOT_NULL(code->side_table); DCHECK(!frames_.empty()); // There must be enough space on the stack to hold the arguments, locals, // and the value stack. DCHECK_LE(code->function->sig->parameter_count() + code->locals.type_list.size() + code->side_table->max_stack_height_, stack_limit_ - stack_start_ - frames_.back().sp); Decoder decoder(code->start, code->end); pc_t limit = code->end - code->start; bool hit_break = false; while (true) { #define PAUSE_IF_BREAK_FLAG(flag) \ if (V8_UNLIKELY(break_flags_ & WasmInterpreter::BreakFlag::flag)) { \ hit_break = true; \ max = 0; \ } DCHECK_GT(limit, pc); DCHECK_NOT_NULL(code->start); // Do first check for a breakpoint, in order to set hit_break correctly. const char* skip = " "; int len = 1; byte orig = code->start[pc]; WasmOpcode opcode = static_cast(orig); if (WasmOpcodes::IsPrefixOpcode(opcode)) { opcode = static_cast(opcode << 8 | code->start[pc + 1]); } if (V8_UNLIKELY(orig == kInternalBreakpoint)) { orig = code->orig_start[pc]; if (WasmOpcodes::IsPrefixOpcode(static_cast(orig))) { opcode = static_cast(orig << 8 | code->orig_start[pc + 1]); } if (SkipBreakpoint(code, pc)) { // skip breakpoint by switching on original code. skip = "[skip] "; } else { TRACE("@%-3zu: [break] %-24s:", pc, WasmOpcodes::OpcodeName(opcode)); TraceValueStack(); TRACE("\n"); hit_break = true; break; } } // If max is 0, break. If max is positive (a limit is set), decrement it. if (max == 0) break; if (max > 0) --max; USE(skip); TRACE("@%-3zu: %s%-24s:", pc, skip, WasmOpcodes::OpcodeName(opcode)); TraceValueStack(); TRACE("\n"); #ifdef DEBUG // Compute the stack effect of this opcode, and verify later that the // stack was modified accordingly. std::pair stack_effect = wasm::StackEffect( codemap_->module(), frames_.back().code->function->sig, code->orig_start + pc, code->orig_end); sp_t expected_new_stack_height = StackHeight() - stack_effect.first + stack_effect.second; #endif switch (orig) { case kExprNop: break; case kExprBlock: { BlockTypeOperand operand(&decoder, code->at(pc)); len = 1 + operand.length; break; } case kExprLoop: { BlockTypeOperand operand(&decoder, code->at(pc)); len = 1 + operand.length; break; } case kExprIf: { BlockTypeOperand operand(&decoder, code->at(pc)); WasmValue cond = Pop(); bool is_true = cond.to() != 0; if (is_true) { // fall through to the true block. len = 1 + operand.length; TRACE(" true => fallthrough\n"); } else { len = LookupTargetDelta(code, pc); TRACE(" false => @%zu\n", pc + len); } break; } case kExprElse: { len = LookupTargetDelta(code, pc); TRACE(" end => @%zu\n", pc + len); break; } case kExprSelect: { WasmValue cond = Pop(); WasmValue fval = Pop(); WasmValue tval = Pop(); Push(cond.to() != 0 ? tval : fval); break; } case kExprBr: { BreakDepthOperand operand(&decoder, code->at(pc)); len = DoBreak(code, pc, operand.depth); TRACE(" br => @%zu\n", pc + len); break; } case kExprBrIf: { BreakDepthOperand operand(&decoder, code->at(pc)); WasmValue cond = Pop(); bool is_true = cond.to() != 0; if (is_true) { len = DoBreak(code, pc, operand.depth); TRACE(" br_if => @%zu\n", pc + len); } else { TRACE(" false => fallthrough\n"); len = 1 + operand.length; } break; } case kExprBrTable: { BranchTableOperand operand(&decoder, code->at(pc)); BranchTableIterator iterator(&decoder, operand); uint32_t key = Pop().to(); uint32_t depth = 0; if (key >= operand.table_count) key = operand.table_count; for (uint32_t i = 0; i <= key; i++) { DCHECK(iterator.has_next()); depth = iterator.next(); } len = key + DoBreak(code, pc + key, static_cast(depth)); TRACE(" br[%u] => @%zu\n", key, pc + key + len); break; } case kExprReturn: { size_t arity = code->function->sig->return_count(); if (!DoReturn(&decoder, &code, &pc, &limit, arity)) return; PAUSE_IF_BREAK_FLAG(AfterReturn); continue; } case kExprUnreachable: { return DoTrap(kTrapUnreachable, pc); } case kExprEnd: { break; } case kExprI32Const: { ImmI32Operand operand(&decoder, code->at(pc)); Push(WasmValue(operand.value)); len = 1 + operand.length; break; } case kExprI64Const: { ImmI64Operand operand(&decoder, code->at(pc)); Push(WasmValue(operand.value)); len = 1 + operand.length; break; } case kExprF32Const: { ImmF32Operand operand(&decoder, code->at(pc)); Push(WasmValue(operand.value)); len = 1 + operand.length; break; } case kExprF64Const: { ImmF64Operand operand(&decoder, code->at(pc)); Push(WasmValue(operand.value)); len = 1 + operand.length; break; } case kExprGetLocal: { LocalIndexOperand operand(&decoder, code->at(pc)); Push(GetStackValue(frames_.back().sp + operand.index)); len = 1 + operand.length; break; } case kExprSetLocal: { LocalIndexOperand operand(&decoder, code->at(pc)); WasmValue val = Pop(); SetStackValue(frames_.back().sp + operand.index, val); len = 1 + operand.length; break; } case kExprTeeLocal: { LocalIndexOperand operand(&decoder, code->at(pc)); WasmValue val = Pop(); SetStackValue(frames_.back().sp + operand.index, val); Push(val); len = 1 + operand.length; break; } case kExprDrop: { Pop(); break; } case kExprCallFunction: { CallFunctionOperand operand(&decoder, code->at(pc)); InterpreterCode* target = codemap()->GetCode(operand.index); if (target->function->imported) { CommitPc(pc); ExternalCallResult result = CallImportedFunction(target->function->func_index); switch (result.type) { case ExternalCallResult::INTERNAL: // The import is a function of this instance. Call it directly. target = result.interpreter_code; DCHECK(!target->function->imported); break; case ExternalCallResult::INVALID_FUNC: case ExternalCallResult::SIGNATURE_MISMATCH: // Direct calls are checked statically. UNREACHABLE(); case ExternalCallResult::EXTERNAL_RETURNED: PAUSE_IF_BREAK_FLAG(AfterCall); len = 1 + operand.length; break; case ExternalCallResult::EXTERNAL_UNWOUND: return; } if (result.type != ExternalCallResult::INTERNAL) break; } // Execute an internal call. if (!DoCall(&decoder, target, &pc, &limit)) return; code = target; PAUSE_IF_BREAK_FLAG(AfterCall); continue; // don't bump pc } break; case kExprCallIndirect: { CallIndirectOperand operand(&decoder, code->at(pc)); uint32_t entry_index = Pop().to(); // Assume only one table for now. DCHECK_LE(module()->function_tables.size(), 1u); ExternalCallResult result = CallIndirectFunction(0, entry_index, operand.index); switch (result.type) { case ExternalCallResult::INTERNAL: // The import is a function of this instance. Call it directly. if (!DoCall(&decoder, result.interpreter_code, &pc, &limit)) return; code = result.interpreter_code; PAUSE_IF_BREAK_FLAG(AfterCall); continue; // don't bump pc case ExternalCallResult::INVALID_FUNC: return DoTrap(kTrapFuncInvalid, pc); case ExternalCallResult::SIGNATURE_MISMATCH: return DoTrap(kTrapFuncSigMismatch, pc); case ExternalCallResult::EXTERNAL_RETURNED: PAUSE_IF_BREAK_FLAG(AfterCall); len = 1 + operand.length; break; case ExternalCallResult::EXTERNAL_UNWOUND: return; } } break; case kExprGetGlobal: { GlobalIndexOperand operand(&decoder, code->at(pc)); const WasmGlobal* global = &module()->globals[operand.index]; byte* ptr = wasm_context_->globals_start + global->offset; WasmValue val; switch (global->type) { #define CASE_TYPE(wasm, ctype) \ case kWasm##wasm: \ val = WasmValue(*reinterpret_cast(ptr)); \ break; WASM_CTYPES(CASE_TYPE) #undef CASE_TYPE default: UNREACHABLE(); } Push(val); len = 1 + operand.length; break; } case kExprSetGlobal: { GlobalIndexOperand operand(&decoder, code->at(pc)); const WasmGlobal* global = &module()->globals[operand.index]; byte* ptr = wasm_context_->globals_start + global->offset; WasmValue val = Pop(); switch (global->type) { #define CASE_TYPE(wasm, ctype) \ case kWasm##wasm: \ *reinterpret_cast(ptr) = val.to(); \ break; WASM_CTYPES(CASE_TYPE) #undef CASE_TYPE default: UNREACHABLE(); } len = 1 + operand.length; break; } #define LOAD_CASE(name, ctype, mtype, rep) \ case kExpr##name: { \ if (!ExecuteLoad(&decoder, code, pc, len, \ MachineRepresentation::rep)) \ return; \ break; \ } LOAD_CASE(I32LoadMem8S, int32_t, int8_t, kWord8); LOAD_CASE(I32LoadMem8U, int32_t, uint8_t, kWord8); LOAD_CASE(I32LoadMem16S, int32_t, int16_t, kWord16); LOAD_CASE(I32LoadMem16U, int32_t, uint16_t, kWord16); LOAD_CASE(I64LoadMem8S, int64_t, int8_t, kWord8); LOAD_CASE(I64LoadMem8U, int64_t, uint8_t, kWord16); LOAD_CASE(I64LoadMem16S, int64_t, int16_t, kWord16); LOAD_CASE(I64LoadMem16U, int64_t, uint16_t, kWord16); LOAD_CASE(I64LoadMem32S, int64_t, int32_t, kWord32); LOAD_CASE(I64LoadMem32U, int64_t, uint32_t, kWord32); LOAD_CASE(I32LoadMem, int32_t, int32_t, kWord32); LOAD_CASE(I64LoadMem, int64_t, int64_t, kWord64); LOAD_CASE(F32LoadMem, Float32, uint32_t, kFloat32); LOAD_CASE(F64LoadMem, Float64, uint64_t, kFloat64); #undef LOAD_CASE #define STORE_CASE(name, ctype, mtype, rep) \ case kExpr##name: { \ if (!ExecuteStore(&decoder, code, pc, len, \ MachineRepresentation::rep)) \ return; \ break; \ } STORE_CASE(I32StoreMem8, int32_t, int8_t, kWord8); STORE_CASE(I32StoreMem16, int32_t, int16_t, kWord16); STORE_CASE(I64StoreMem8, int64_t, int8_t, kWord8); STORE_CASE(I64StoreMem16, int64_t, int16_t, kWord16); STORE_CASE(I64StoreMem32, int64_t, int32_t, kWord32); STORE_CASE(I32StoreMem, int32_t, int32_t, kWord32); STORE_CASE(I64StoreMem, int64_t, int64_t, kWord64); STORE_CASE(F32StoreMem, Float32, uint32_t, kFloat32); STORE_CASE(F64StoreMem, Float64, uint64_t, kFloat64); #undef STORE_CASE #define ASMJS_LOAD_CASE(name, ctype, mtype, defval) \ case kExpr##name: { \ uint32_t index = Pop().to(); \ ctype result; \ if (!BoundsCheck(wasm_context_->mem_size, 0, index)) { \ result = defval; \ } else { \ byte* addr = wasm_context_->mem_start + index; \ /* TODO(titzer): alignment for asmjs load mem? */ \ result = static_cast(*reinterpret_cast(addr)); \ } \ Push(WasmValue(result)); \ break; \ } ASMJS_LOAD_CASE(I32AsmjsLoadMem8S, int32_t, int8_t, 0); ASMJS_LOAD_CASE(I32AsmjsLoadMem8U, int32_t, uint8_t, 0); ASMJS_LOAD_CASE(I32AsmjsLoadMem16S, int32_t, int16_t, 0); ASMJS_LOAD_CASE(I32AsmjsLoadMem16U, int32_t, uint16_t, 0); ASMJS_LOAD_CASE(I32AsmjsLoadMem, int32_t, int32_t, 0); ASMJS_LOAD_CASE(F32AsmjsLoadMem, float, float, std::numeric_limits::quiet_NaN()); ASMJS_LOAD_CASE(F64AsmjsLoadMem, double, double, std::numeric_limits::quiet_NaN()); #undef ASMJS_LOAD_CASE #define ASMJS_STORE_CASE(name, ctype, mtype) \ case kExpr##name: { \ WasmValue val = Pop(); \ uint32_t index = Pop().to(); \ if (BoundsCheck(wasm_context_->mem_size, 0, index)) { \ byte* addr = wasm_context_->mem_start + index; \ /* TODO(titzer): alignment for asmjs store mem? */ \ *(reinterpret_cast(addr)) = static_cast(val.to()); \ } \ Push(val); \ break; \ } ASMJS_STORE_CASE(I32AsmjsStoreMem8, int32_t, int8_t); ASMJS_STORE_CASE(I32AsmjsStoreMem16, int32_t, int16_t); ASMJS_STORE_CASE(I32AsmjsStoreMem, int32_t, int32_t); ASMJS_STORE_CASE(F32AsmjsStoreMem, float, float); ASMJS_STORE_CASE(F64AsmjsStoreMem, double, double); #undef ASMJS_STORE_CASE case kExprGrowMemory: { MemoryIndexOperand operand(&decoder, code->at(pc)); uint32_t delta_pages = Pop().to(); Handle instance = codemap()->maybe_instance().ToHandleChecked(); DCHECK_EQ(wasm_context_, instance->wasm_context()->get()); Isolate* isolate = instance->GetIsolate(); int32_t result = WasmInstanceObject::GrowMemory(isolate, instance, delta_pages); Push(WasmValue(result)); len = 1 + operand.length; break; } case kExprMemorySize: { MemoryIndexOperand operand(&decoder, code->at(pc)); Push(WasmValue(static_cast(wasm_context_->mem_size / WasmModule::kPageSize))); len = 1 + operand.length; break; } // We need to treat kExprI32ReinterpretF32 and kExprI64ReinterpretF64 // specially to guarantee that the quiet bit of a NaN is preserved on // ia32 by the reinterpret casts. case kExprI32ReinterpretF32: { WasmValue val = Pop(); Push(WasmValue(ExecuteI32ReinterpretF32(val))); break; } case kExprI64ReinterpretF64: { WasmValue val = Pop(); Push(WasmValue(ExecuteI64ReinterpretF64(val))); break; } case kAtomicPrefix: { if (!ExecuteAtomicOp(opcode, &decoder, code, pc, len)) return; break; } #define EXECUTE_SIMPLE_BINOP(name, ctype, op) \ case kExpr##name: { \ WasmValue rval = Pop(); \ WasmValue lval = Pop(); \ auto result = lval.to() op rval.to(); \ possible_nondeterminism_ |= has_nondeterminism(result); \ Push(WasmValue(result)); \ break; \ } FOREACH_SIMPLE_BINOP(EXECUTE_SIMPLE_BINOP) #undef EXECUTE_SIMPLE_BINOP #define EXECUTE_OTHER_BINOP(name, ctype) \ case kExpr##name: { \ TrapReason trap = kTrapCount; \ ctype rval = Pop().to(); \ ctype lval = Pop().to(); \ auto result = Execute##name(lval, rval, &trap); \ possible_nondeterminism_ |= has_nondeterminism(result); \ if (trap != kTrapCount) return DoTrap(trap, pc); \ Push(WasmValue(result)); \ break; \ } FOREACH_OTHER_BINOP(EXECUTE_OTHER_BINOP) #undef EXECUTE_OTHER_BINOP #define EXECUTE_OTHER_UNOP(name, ctype) \ case kExpr##name: { \ TrapReason trap = kTrapCount; \ ctype val = Pop().to(); \ auto result = Execute##name(val, &trap); \ possible_nondeterminism_ |= has_nondeterminism(result); \ if (trap != kTrapCount) return DoTrap(trap, pc); \ Push(WasmValue(result)); \ break; \ } FOREACH_OTHER_UNOP(EXECUTE_OTHER_UNOP) #undef EXECUTE_OTHER_UNOP default: V8_Fatal(__FILE__, __LINE__, "Unknown or unimplemented opcode #%d:%s", code->start[pc], OpcodeName(code->start[pc])); UNREACHABLE(); } #ifdef DEBUG if (!WasmOpcodes::IsControlOpcode(opcode)) { DCHECK_EQ(expected_new_stack_height, StackHeight()); } #endif pc += len; if (pc == limit) { // Fell off end of code; do an implicit return. TRACE("@%-3zu: ImplicitReturn\n", pc); if (!DoReturn(&decoder, &code, &pc, &limit, code->function->sig->return_count())) return; PAUSE_IF_BREAK_FLAG(AfterReturn); } #undef PAUSE_IF_BREAK_FLAG } state_ = WasmInterpreter::PAUSED; break_pc_ = hit_break ? pc : kInvalidPc; CommitPc(pc); } WasmValue Pop() { DCHECK_GT(frames_.size(), 0); DCHECK_GT(StackHeight(), frames_.back().llimit()); // can't pop into locals return *--sp_; } void PopN(int n) { DCHECK_GE(StackHeight(), n); DCHECK_GT(frames_.size(), 0); // Check that we don't pop into locals. DCHECK_GE(StackHeight() - n, frames_.back().llimit()); sp_ -= n; } WasmValue PopArity(size_t arity) { if (arity == 0) return WasmValue(); CHECK_EQ(1, arity); return Pop(); } void Push(WasmValue val) { DCHECK_NE(kWasmStmt, val.type()); DCHECK_LE(1, stack_limit_ - sp_); *sp_++ = val; } void Push(WasmValue* vals, size_t arity) { DCHECK_LE(arity, stack_limit_ - sp_); for (WasmValue *val = vals, *end = vals + arity; val != end; ++val) { DCHECK_NE(kWasmStmt, val->type()); } memcpy(sp_, vals, arity * sizeof(*sp_)); sp_ += arity; } void EnsureStackSpace(size_t size) { if (V8_LIKELY(static_cast(stack_limit_ - sp_) >= size)) return; size_t old_size = stack_limit_ - stack_start_; size_t requested_size = base::bits::RoundUpToPowerOfTwo64((sp_ - stack_start_) + size); size_t new_size = Max(size_t{8}, Max(2 * old_size, requested_size)); WasmValue* new_stack = zone_->NewArray(new_size); memcpy(new_stack, stack_start_, old_size * sizeof(*sp_)); sp_ = new_stack + (sp_ - stack_start_); stack_start_ = new_stack; stack_limit_ = new_stack + new_size; } sp_t StackHeight() { return sp_ - stack_start_; } void TraceValueStack() { #ifdef DEBUG if (!FLAG_trace_wasm_interpreter) return; Frame* top = frames_.size() > 0 ? &frames_.back() : nullptr; sp_t sp = top ? top->sp : 0; sp_t plimit = top ? top->plimit() : 0; sp_t llimit = top ? top->llimit() : 0; for (size_t i = sp; i < StackHeight(); ++i) { if (i < plimit) PrintF(" p%zu:", i); else if (i < llimit) PrintF(" l%zu:", i); else PrintF(" s%zu:", i); WasmValue val = GetStackValue(i); switch (val.type()) { case kWasmI32: PrintF("i32:%d", val.to()); break; case kWasmI64: PrintF("i64:%" PRId64 "", val.to()); break; case kWasmF32: PrintF("f32:%f", val.to()); break; case kWasmF64: PrintF("f64:%lf", val.to()); break; case kWasmStmt: PrintF("void"); break; default: UNREACHABLE(); break; } } #endif // DEBUG } ExternalCallResult TryHandleException(Isolate* isolate) { if (HandleException(isolate) == WasmInterpreter::Thread::UNWOUND) { return {ExternalCallResult::EXTERNAL_UNWOUND}; } return {ExternalCallResult::EXTERNAL_RETURNED}; } // TODO(clemensh): Remove this, call JS via existing wasm-to-js wrapper, using // CallExternalWasmFunction. ExternalCallResult CallExternalJSFunction(Isolate* isolate, Handle code, FunctionSig* signature) { Handle target = UnwrapWasmToJSWrapper(isolate, code); if (target.is_null()) { isolate->Throw(*isolate->factory()->NewTypeError( MessageTemplate::kWasmTrapTypeError)); return TryHandleException(isolate); } #if DEBUG std::ostringstream oss; target->HeapObjectShortPrint(oss); TRACE(" => Calling imported function %s\n", oss.str().c_str()); #endif int num_args = static_cast(signature->parameter_count()); // Get all arguments as JS values. std::vector> args; args.reserve(num_args); WasmValue* wasm_args = sp_ - num_args; for (int i = 0; i < num_args; ++i) { args.push_back(WasmValueToNumber(isolate->factory(), wasm_args[i], signature->GetParam(i))); } // The receiver is the global proxy if in sloppy mode (default), undefined // if in strict mode. Handle receiver = isolate->global_proxy(); if (target->IsJSFunction() && is_strict(JSFunction::cast(*target)->shared()->language_mode())) { receiver = isolate->factory()->undefined_value(); } MaybeHandle maybe_retval = Execution::Call(isolate, target, receiver, num_args, args.data()); if (maybe_retval.is_null()) return TryHandleException(isolate); Handle retval = maybe_retval.ToHandleChecked(); // Pop arguments off the stack. sp_ -= num_args; // Push return values. if (signature->return_count() > 0) { // TODO(wasm): Handle multiple returns. DCHECK_EQ(1, signature->return_count()); WasmValue value = ToWebAssemblyValue(isolate, retval, signature->GetReturn()); if (value.type() == kWasmStmt) return TryHandleException(isolate); Push(value); } return {ExternalCallResult::EXTERNAL_RETURNED}; } ExternalCallResult CallExternalWasmFunction(Isolate* isolate, Handle code, FunctionSig* sig) { Handle debug_info(codemap()->instance()->debug_info(), isolate); Handle wasm_entry = WasmDebugInfo::GetCWasmEntry(debug_info, sig); TRACE(" => Calling external wasm function\n"); // Copy the arguments to one buffer. // TODO(clemensh): Introduce a helper for all argument buffer // con-/destruction. int num_args = static_cast(sig->parameter_count()); std::vector arg_buffer(num_args * 8); size_t offset = 0; WasmValue* wasm_args = sp_ - num_args; for (int i = 0; i < num_args; ++i) { uint32_t param_size = 1 << ElementSizeLog2Of(sig->GetParam(i)); if (arg_buffer.size() < offset + param_size) { arg_buffer.resize(std::max(2 * arg_buffer.size(), offset + param_size)); } switch (sig->GetParam(i)) { case kWasmI32: WriteUnalignedValue(arg_buffer.data() + offset, wasm_args[i].to()); break; case kWasmI64: WriteUnalignedValue(arg_buffer.data() + offset, wasm_args[i].to()); break; case kWasmF32: WriteUnalignedValue(arg_buffer.data() + offset, wasm_args[i].to()); break; case kWasmF64: WriteUnalignedValue(arg_buffer.data() + offset, wasm_args[i].to()); break; default: UNIMPLEMENTED(); } offset += param_size; } // Ensure that there is enough space in the arg_buffer to hold the return // value(s). uint32_t return_size = 0; for (ValueType t : sig->returns()) { return_size += 1 << ElementSizeLog2Of(t); } if (arg_buffer.size() < return_size) { arg_buffer.resize(return_size); } // Wrap the arg_buffer data pointer in a handle. As this is an aligned // pointer, to the GC it will look like a Smi. Handle arg_buffer_obj(reinterpret_cast(arg_buffer.data()), isolate); DCHECK(!arg_buffer_obj->IsHeapObject()); Handle args[compiler::CWasmEntryParameters::kNumParameters]; args[compiler::CWasmEntryParameters::kCodeObject] = code; args[compiler::CWasmEntryParameters::kArgumentsBuffer] = arg_buffer_obj; Handle receiver = isolate->factory()->undefined_value(); trap_handler::SetThreadInWasm(); MaybeHandle maybe_retval = Execution::Call(isolate, wasm_entry, receiver, arraysize(args), args); TRACE(" => External wasm function returned%s\n", maybe_retval.is_null() ? " with exception" : ""); if (maybe_retval.is_null()) { DCHECK(!trap_handler::IsThreadInWasm()); return TryHandleException(isolate); } trap_handler::ClearThreadInWasm(); // Pop arguments off the stack. sp_ -= num_args; // Push return values. if (sig->return_count() > 0) { // TODO(wasm): Handle multiple returns. DCHECK_EQ(1, sig->return_count()); switch (sig->GetReturn()) { case kWasmI32: Push(WasmValue(ReadUnalignedValue(arg_buffer.data()))); break; case kWasmI64: Push(WasmValue(ReadUnalignedValue(arg_buffer.data()))); break; case kWasmF32: Push(WasmValue(ReadUnalignedValue(arg_buffer.data()))); break; case kWasmF64: Push(WasmValue(ReadUnalignedValue(arg_buffer.data()))); break; default: UNIMPLEMENTED(); } } return {ExternalCallResult::EXTERNAL_RETURNED}; } ExternalCallResult CallCodeObject(Isolate* isolate, Handle code, FunctionSig* signature) { DCHECK(AllowHandleAllocation::IsAllowed()); DCHECK(AllowHeapAllocation::IsAllowed()); if (code->kind() == Code::WASM_FUNCTION || code->kind() == Code::WASM_TO_WASM_FUNCTION) { FixedArray* deopt_data = code->deoptimization_data(); DCHECK_EQ(2, deopt_data->length()); WasmInstanceObject* target_instance = WasmInstanceObject::cast(WeakCell::cast(deopt_data->get(0))->value()); if (target_instance != codemap()->instance()) { return CallExternalWasmFunction(isolate, code, signature); } int target_func_idx = Smi::ToInt(deopt_data->get(1)); DCHECK_LE(0, target_func_idx); return {ExternalCallResult::INTERNAL, codemap()->GetCode(target_func_idx)}; } return CallExternalJSFunction(isolate, code, signature); } ExternalCallResult CallImportedFunction(uint32_t function_index) { // Use a new HandleScope to avoid leaking / accumulating handles in the // outer scope. Isolate* isolate = codemap()->instance()->GetIsolate(); HandleScope handle_scope(isolate); Handle target(codemap()->GetImportedFunction(function_index), isolate); return CallCodeObject(isolate, target, codemap()->module()->functions[function_index].sig); } ExternalCallResult CallIndirectFunction(uint32_t table_index, uint32_t entry_index, uint32_t sig_index) { if (!codemap()->has_instance() || !codemap()->instance()->compiled_module()->has_function_tables()) { // No instance. Rely on the information stored in the WasmModule. // TODO(wasm): This is only needed for testing. Refactor testing to use // the same paths as production. InterpreterCode* code = codemap()->GetIndirectCode(table_index, entry_index); if (!code) return {ExternalCallResult::INVALID_FUNC}; if (code->function->sig_index != sig_index) { // If not an exact match, we have to do a canonical check. int function_canonical_id = module()->signature_ids[code->function->sig_index]; int expected_canonical_id = module()->signature_ids[sig_index]; DCHECK_EQ(function_canonical_id, module()->signature_map.Find(code->function->sig)); if (function_canonical_id != expected_canonical_id) { return {ExternalCallResult::SIGNATURE_MISMATCH}; } } return {ExternalCallResult::INTERNAL, code}; } WasmCompiledModule* compiled_module = codemap()->instance()->compiled_module(); Isolate* isolate = compiled_module->GetIsolate(); Code* target; { DisallowHeapAllocation no_gc; // Get function to be called directly from the live instance to see latest // changes to the tables. // Canonicalize signature index. uint32_t canonical_sig_index = module()->signature_ids[sig_index]; DCHECK_EQ(canonical_sig_index, module()->signature_map.Find(module()->signatures[sig_index])); // Check signature. FixedArray* sig_tables = compiled_module->ptr_to_signature_tables(); if (table_index >= static_cast(sig_tables->length())) { return {ExternalCallResult::INVALID_FUNC}; } // Reconstitute the global handle to sig_table, and, further below, // to the function table, from the address stored in the // respective table of tables. int table_index_as_int = static_cast(table_index); Handle sig_table(reinterpret_cast( WasmCompiledModule::GetTableValue(sig_tables, table_index_as_int))); if (entry_index >= static_cast(sig_table->length())) { return {ExternalCallResult::INVALID_FUNC}; } int found_sig = Smi::ToInt(sig_table->get(static_cast(entry_index))); if (static_cast(found_sig) != canonical_sig_index) { return {ExternalCallResult::SIGNATURE_MISMATCH}; } // Get code object. FixedArray* fun_tables = compiled_module->ptr_to_function_tables(); DCHECK_EQ(sig_tables->length(), fun_tables->length()); Handle fun_table(reinterpret_cast( WasmCompiledModule::GetTableValue(fun_tables, table_index_as_int))); DCHECK_EQ(sig_table->length(), fun_table->length()); target = Code::cast(fun_table->get(static_cast(entry_index))); } // Call the code object. Use a new HandleScope to avoid leaking / // accumulating handles in the outer scope. HandleScope handle_scope(isolate); FunctionSig* signature = &codemap()->module()->signatures[table_index][sig_index]; return CallCodeObject(isolate, handle(target, isolate), signature); } inline Activation current_activation() { return activations_.empty() ? Activation(0, 0) : activations_.back(); } }; class InterpretedFrameImpl { public: InterpretedFrameImpl(ThreadImpl* thread, int index) : thread_(thread), index_(index) { DCHECK_LE(0, index); } const WasmFunction* function() const { return frame()->code->function; } int pc() const { DCHECK_LE(0, frame()->pc); DCHECK_GE(kMaxInt, frame()->pc); return static_cast(frame()->pc); } int GetParameterCount() const { DCHECK_GE(kMaxInt, function()->sig->parameter_count()); return static_cast(function()->sig->parameter_count()); } int GetLocalCount() const { size_t num_locals = function()->sig->parameter_count() + frame()->code->locals.type_list.size(); DCHECK_GE(kMaxInt, num_locals); return static_cast(num_locals); } int GetStackHeight() const { bool is_top_frame = static_cast(index_) + 1 == thread_->frames_.size(); size_t stack_limit = is_top_frame ? thread_->StackHeight() : thread_->frames_[index_ + 1].sp; DCHECK_LE(frame()->sp, stack_limit); size_t frame_size = stack_limit - frame()->sp; DCHECK_LE(GetLocalCount(), frame_size); return static_cast(frame_size) - GetLocalCount(); } WasmValue GetLocalValue(int index) const { DCHECK_LE(0, index); DCHECK_GT(GetLocalCount(), index); return thread_->GetStackValue(static_cast(frame()->sp) + index); } WasmValue GetStackValue(int index) const { DCHECK_LE(0, index); // Index must be within the number of stack values of this frame. DCHECK_GT(GetStackHeight(), index); return thread_->GetStackValue(static_cast(frame()->sp) + GetLocalCount() + index); } private: ThreadImpl* thread_; int index_; ThreadImpl::Frame* frame() const { DCHECK_GT(thread_->frames_.size(), index_); return &thread_->frames_[index_]; } }; // Converters between WasmInterpreter::Thread and WasmInterpreter::ThreadImpl. // Thread* is the public interface, without knowledge of the object layout. // This cast is potentially risky, but as long as we always cast it back before // accessing any data, it should be fine. UBSan is not complaining. WasmInterpreter::Thread* ToThread(ThreadImpl* impl) { return reinterpret_cast(impl); } ThreadImpl* ToImpl(WasmInterpreter::Thread* thread) { return reinterpret_cast(thread); } // Same conversion for InterpretedFrame and InterpretedFrameImpl. InterpretedFrame* ToFrame(InterpretedFrameImpl* impl) { return reinterpret_cast(impl); } const InterpretedFrameImpl* ToImpl(const InterpretedFrame* frame) { return reinterpret_cast(frame); } //============================================================================ // Implementation details of the heap objects scope. //============================================================================ class HeapObjectsScopeImpl { public: HeapObjectsScopeImpl(CodeMap* codemap, Handle instance) : codemap_(codemap), needs_reset(!codemap_->has_instance()) { if (needs_reset) { instance_ = handle(*instance); codemap_->SetInstanceObject(instance_); } else { DCHECK_EQ(*instance, codemap_->instance()); return; } } ~HeapObjectsScopeImpl() { if (!needs_reset) return; DCHECK_EQ(*instance_, codemap_->instance()); codemap_->ClearInstanceObject(); // Clear the handle, such that anyone who accidentally copied them will // notice. *instance_.location() = nullptr; } private: CodeMap* codemap_; Handle instance_; bool needs_reset; }; } // namespace //============================================================================ // Implementation of the pimpl idiom for WasmInterpreter::Thread. // Instead of placing a pointer to the ThreadImpl inside of the Thread object, // we just reinterpret_cast them. ThreadImpls are only allocated inside this // translation unit anyway. //============================================================================ WasmInterpreter::State WasmInterpreter::Thread::state() { return ToImpl(this)->state(); } void WasmInterpreter::Thread::InitFrame(const WasmFunction* function, WasmValue* args) { ToImpl(this)->InitFrame(function, args); } WasmInterpreter::State WasmInterpreter::Thread::Run(int num_steps) { return ToImpl(this)->Run(num_steps); } void WasmInterpreter::Thread::Pause() { return ToImpl(this)->Pause(); } void WasmInterpreter::Thread::Reset() { return ToImpl(this)->Reset(); } WasmInterpreter::Thread::ExceptionHandlingResult WasmInterpreter::Thread::HandleException(Isolate* isolate) { return ToImpl(this)->HandleException(isolate); } pc_t WasmInterpreter::Thread::GetBreakpointPc() { return ToImpl(this)->GetBreakpointPc(); } int WasmInterpreter::Thread::GetFrameCount() { return ToImpl(this)->GetFrameCount(); } std::unique_ptr WasmInterpreter::Thread::GetFrame(int index) { DCHECK_LE(0, index); DCHECK_GT(GetFrameCount(), index); return std::unique_ptr( ToFrame(new InterpretedFrameImpl(ToImpl(this), index))); } WasmValue WasmInterpreter::Thread::GetReturnValue(int index) { return ToImpl(this)->GetReturnValue(index); } TrapReason WasmInterpreter::Thread::GetTrapReason() { return ToImpl(this)->GetTrapReason(); } bool WasmInterpreter::Thread::PossibleNondeterminism() { return ToImpl(this)->PossibleNondeterminism(); } uint64_t WasmInterpreter::Thread::NumInterpretedCalls() { return ToImpl(this)->NumInterpretedCalls(); } void WasmInterpreter::Thread::AddBreakFlags(uint8_t flags) { ToImpl(this)->AddBreakFlags(flags); } void WasmInterpreter::Thread::ClearBreakFlags() { ToImpl(this)->ClearBreakFlags(); } uint32_t WasmInterpreter::Thread::NumActivations() { return ToImpl(this)->NumActivations(); } uint32_t WasmInterpreter::Thread::StartActivation() { return ToImpl(this)->StartActivation(); } void WasmInterpreter::Thread::FinishActivation(uint32_t id) { ToImpl(this)->FinishActivation(id); } uint32_t WasmInterpreter::Thread::ActivationFrameBase(uint32_t id) { return ToImpl(this)->ActivationFrameBase(id); } //============================================================================ // The implementation details of the interpreter. //============================================================================ class WasmInterpreterInternals : public ZoneObject { public: // Create a copy of the module bytes for the interpreter, since the passed // pointer might be invalidated after constructing the interpreter. const ZoneVector module_bytes_; CodeMap codemap_; ZoneVector threads_; WasmInterpreterInternals(Isolate* isolate, Zone* zone, const WasmModule* module, const ModuleWireBytes& wire_bytes, WasmContext* wasm_context) : module_bytes_(wire_bytes.start(), wire_bytes.end(), zone), codemap_(isolate, module, module_bytes_.data(), zone), threads_(zone) { threads_.emplace_back(zone, &codemap_, wasm_context); } }; //============================================================================ // Implementation of the public interface of the interpreter. //============================================================================ WasmInterpreter::WasmInterpreter(Isolate* isolate, const WasmModule* module, const ModuleWireBytes& wire_bytes, WasmContext* wasm_context) : zone_(isolate->allocator(), ZONE_NAME), internals_(new (&zone_) WasmInterpreterInternals( isolate, &zone_, module, wire_bytes, wasm_context)) {} WasmInterpreter::~WasmInterpreter() { internals_->~WasmInterpreterInternals(); } void WasmInterpreter::Run() { internals_->threads_[0].Run(); } void WasmInterpreter::Pause() { internals_->threads_[0].Pause(); } bool WasmInterpreter::SetBreakpoint(const WasmFunction* function, pc_t pc, bool enabled) { InterpreterCode* code = internals_->codemap_.GetCode(function); size_t size = static_cast(code->end - code->start); // Check bounds for {pc}. if (pc < code->locals.encoded_size || pc >= size) return false; // Make a copy of the code before enabling a breakpoint. if (enabled && code->orig_start == code->start) { code->start = reinterpret_cast(zone_.New(size)); memcpy(code->start, code->orig_start, size); code->end = code->start + size; } bool prev = code->start[pc] == kInternalBreakpoint; if (enabled) { code->start[pc] = kInternalBreakpoint; } else { code->start[pc] = code->orig_start[pc]; } return prev; } bool WasmInterpreter::GetBreakpoint(const WasmFunction* function, pc_t pc) { InterpreterCode* code = internals_->codemap_.GetCode(function); size_t size = static_cast(code->end - code->start); // Check bounds for {pc}. if (pc < code->locals.encoded_size || pc >= size) return false; // Check if a breakpoint is present at that place in the code. return code->start[pc] == kInternalBreakpoint; } bool WasmInterpreter::SetTracing(const WasmFunction* function, bool enabled) { UNIMPLEMENTED(); return false; } int WasmInterpreter::GetThreadCount() { return 1; // only one thread for now. } WasmInterpreter::Thread* WasmInterpreter::GetThread(int id) { CHECK_EQ(0, id); // only one thread for now. return ToThread(&internals_->threads_[id]); } void WasmInterpreter::AddFunctionForTesting(const WasmFunction* function) { internals_->codemap_.AddFunction(function, nullptr, nullptr); } void WasmInterpreter::SetFunctionCodeForTesting(const WasmFunction* function, const byte* start, const byte* end) { internals_->codemap_.SetFunctionCode(function, start, end); } ControlTransferMap WasmInterpreter::ComputeControlTransfersForTesting( Zone* zone, const WasmModule* module, const byte* start, const byte* end) { // Create some dummy structures, to avoid special-casing the implementation // just for testing. FunctionSig sig(0, 0, nullptr); WasmFunction function{&sig, 0, 0, {0, 0}, {0, 0}, false, false}; InterpreterCode code{ &function, BodyLocalDecls(zone), start, end, nullptr, nullptr, nullptr}; // Now compute and return the control transfers. SideTable side_table(zone, module, &code); return side_table.map_; } //============================================================================ // Implementation of the frame inspection interface. //============================================================================ const WasmFunction* InterpretedFrame::function() const { return ToImpl(this)->function(); } int InterpretedFrame::pc() const { return ToImpl(this)->pc(); } int InterpretedFrame::GetParameterCount() const { return ToImpl(this)->GetParameterCount(); } int InterpretedFrame::GetLocalCount() const { return ToImpl(this)->GetLocalCount(); } int InterpretedFrame::GetStackHeight() const { return ToImpl(this)->GetStackHeight(); } WasmValue InterpretedFrame::GetLocalValue(int index) const { return ToImpl(this)->GetLocalValue(index); } WasmValue InterpretedFrame::GetStackValue(int index) const { return ToImpl(this)->GetStackValue(index); } //============================================================================ // Public API of the heap objects scope. //============================================================================ WasmInterpreter::HeapObjectsScope::HeapObjectsScope( WasmInterpreter* interpreter, Handle instance) { static_assert(sizeof(data) == sizeof(HeapObjectsScopeImpl), "Size mismatch"); new (data) HeapObjectsScopeImpl(&interpreter->internals_->codemap_, instance); } WasmInterpreter::HeapObjectsScope::~HeapObjectsScope() { reinterpret_cast(data)->~HeapObjectsScopeImpl(); } #undef TRACE #undef FOREACH_INTERNAL_OPCODE #undef WASM_CTYPES #undef FOREACH_SIMPLE_BINOP #undef FOREACH_OTHER_BINOP #undef FOREACH_OTHER_UNOP } // namespace wasm } // namespace internal } // namespace v8