// 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 "src/wasm/wasm-interpreter.h" #include "src/utils.h" #include "src/wasm/decoder.h" #include "src/wasm/function-body-decoder.h" #include "src/wasm/wasm-external-refs.h" #include "src/wasm/wasm-limits.h" #include "src/wasm/wasm-module.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 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, >=) #define FOREACH_SIMPLE_BINOP_NAN(V) \ 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(F32CopySign, float) \ V(F64Min, double) \ V(F64Max, double) \ V(F64CopySign, double) \ V(I32AsmjsDivS, int32_t) \ V(I32AsmjsDivU, uint32_t) \ V(I32AsmjsRemS, int32_t) \ V(I32AsmjsRemU, uint32_t) #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, float) \ V(F32Neg, float) \ V(F32Ceil, float) \ V(F32Floor, float) \ V(F32Trunc, float) \ V(F32NearestInt, float) \ V(F64Abs, double) \ V(F64Neg, double) \ 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(I32ReinterpretF32, float) \ V(I64ReinterpretF64, double) \ V(I32AsmjsSConvertF32, float) \ V(I32AsmjsUConvertF32, float) \ V(I32AsmjsSConvertF64, double) \ V(I32AsmjsUConvertF64, double) #define FOREACH_OTHER_UNOP_NAN(V) \ V(F32Sqrt, float) \ V(F64Sqrt, double) static 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; } static inline uint32_t ExecuteI32DivU(uint32_t a, uint32_t b, TrapReason* trap) { if (b == 0) { *trap = kTrapDivByZero; return 0; } return a / b; } static 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; } static inline uint32_t ExecuteI32RemU(uint32_t a, uint32_t b, TrapReason* trap) { if (b == 0) { *trap = kTrapRemByZero; return 0; } return a % b; } static inline uint32_t ExecuteI32Shl(uint32_t a, uint32_t b, TrapReason* trap) { return a << (b & 0x1f); } static inline uint32_t ExecuteI32ShrU(uint32_t a, uint32_t b, TrapReason* trap) { return a >> (b & 0x1f); } static inline int32_t ExecuteI32ShrS(int32_t a, int32_t b, TrapReason* trap) { return a >> (b & 0x1f); } static 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; } static inline uint64_t ExecuteI64DivU(uint64_t a, uint64_t b, TrapReason* trap) { if (b == 0) { *trap = kTrapDivByZero; return 0; } return a / b; } static 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; } static inline uint64_t ExecuteI64RemU(uint64_t a, uint64_t b, TrapReason* trap) { if (b == 0) { *trap = kTrapRemByZero; return 0; } return a % b; } static inline uint64_t ExecuteI64Shl(uint64_t a, uint64_t b, TrapReason* trap) { return a << (b & 0x3f); } static inline uint64_t ExecuteI64ShrU(uint64_t a, uint64_t b, TrapReason* trap) { return a >> (b & 0x3f); } static inline int64_t ExecuteI64ShrS(int64_t a, int64_t b, TrapReason* trap) { return a >> (b & 0x3f); } static inline uint32_t ExecuteI32Ror(uint32_t a, uint32_t b, TrapReason* trap) { uint32_t shift = (b & 0x1f); return (a >> shift) | (a << (32 - shift)); } static inline uint32_t ExecuteI32Rol(uint32_t a, uint32_t b, TrapReason* trap) { uint32_t shift = (b & 0x1f); return (a << shift) | (a >> (32 - shift)); } static inline uint64_t ExecuteI64Ror(uint64_t a, uint64_t b, TrapReason* trap) { uint32_t shift = (b & 0x3f); return (a >> shift) | (a << (64 - shift)); } static inline uint64_t ExecuteI64Rol(uint64_t a, uint64_t b, TrapReason* trap) { uint32_t shift = (b & 0x3f); return (a << shift) | (a >> (64 - shift)); } static inline float ExecuteF32Min(float a, float b, TrapReason* trap) { return JSMin(a, b); } static inline float ExecuteF32Max(float a, float b, TrapReason* trap) { return JSMax(a, b); } static inline float ExecuteF32CopySign(float a, float b, TrapReason* trap) { return copysignf(a, b); } static inline double ExecuteF64Min(double a, double b, TrapReason* trap) { return JSMin(a, b); } static inline double ExecuteF64Max(double a, double b, TrapReason* trap) { return JSMax(a, b); } static inline double ExecuteF64CopySign(double a, double b, TrapReason* trap) { return copysign(a, b); } static 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; } static inline uint32_t ExecuteI32AsmjsDivU(uint32_t a, uint32_t b, TrapReason* trap) { if (b == 0) return 0; return a / b; } static 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; } static inline uint32_t ExecuteI32AsmjsRemU(uint32_t a, uint32_t b, TrapReason* trap) { if (b == 0) return 0; return a % b; } static inline int32_t ExecuteI32AsmjsSConvertF32(float a, TrapReason* trap) { return DoubleToInt32(a); } static inline uint32_t ExecuteI32AsmjsUConvertF32(float a, TrapReason* trap) { return DoubleToUint32(a); } static inline int32_t ExecuteI32AsmjsSConvertF64(double a, TrapReason* trap) { return DoubleToInt32(a); } static inline uint32_t ExecuteI32AsmjsUConvertF64(double a, TrapReason* trap) { return DoubleToUint32(a); } static int32_t ExecuteI32Clz(uint32_t val, TrapReason* trap) { return base::bits::CountLeadingZeros32(val); } static uint32_t ExecuteI32Ctz(uint32_t val, TrapReason* trap) { return base::bits::CountTrailingZeros32(val); } static uint32_t ExecuteI32Popcnt(uint32_t val, TrapReason* trap) { return word32_popcnt_wrapper(&val); } static inline uint32_t ExecuteI32Eqz(uint32_t val, TrapReason* trap) { return val == 0 ? 1 : 0; } static int64_t ExecuteI64Clz(uint64_t val, TrapReason* trap) { return base::bits::CountLeadingZeros64(val); } static inline uint64_t ExecuteI64Ctz(uint64_t val, TrapReason* trap) { return base::bits::CountTrailingZeros64(val); } static inline int64_t ExecuteI64Popcnt(uint64_t val, TrapReason* trap) { return word64_popcnt_wrapper(&val); } static inline int32_t ExecuteI64Eqz(uint64_t val, TrapReason* trap) { return val == 0 ? 1 : 0; } static inline float ExecuteF32Abs(float a, TrapReason* trap) { return bit_cast(bit_cast(a) & 0x7fffffff); } static inline float ExecuteF32Neg(float a, TrapReason* trap) { return bit_cast(bit_cast(a) ^ 0x80000000); } static inline float ExecuteF32Ceil(float a, TrapReason* trap) { return ceilf(a); } static inline float ExecuteF32Floor(float a, TrapReason* trap) { return floorf(a); } static inline float ExecuteF32Trunc(float a, TrapReason* trap) { return truncf(a); } static inline float ExecuteF32NearestInt(float a, TrapReason* trap) { return nearbyintf(a); } static inline float ExecuteF32Sqrt(float a, TrapReason* trap) { float result = sqrtf(a); return result; } static inline double ExecuteF64Abs(double a, TrapReason* trap) { return bit_cast(bit_cast(a) & 0x7fffffffffffffff); } static inline double ExecuteF64Neg(double a, TrapReason* trap) { return bit_cast(bit_cast(a) ^ 0x8000000000000000); } static inline double ExecuteF64Ceil(double a, TrapReason* trap) { return ceil(a); } static inline double ExecuteF64Floor(double a, TrapReason* trap) { return floor(a); } static inline double ExecuteF64Trunc(double a, TrapReason* trap) { return trunc(a); } static inline double ExecuteF64NearestInt(double a, TrapReason* trap) { return nearbyint(a); } static inline double ExecuteF64Sqrt(double a, TrapReason* trap) { return sqrt(a); } static 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; } static 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; } static 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; } static 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; } static inline uint32_t ExecuteI32ConvertI64(int64_t a, TrapReason* trap) { return static_cast(a & 0xFFFFFFFF); } static int64_t ExecuteI64SConvertF32(float a, TrapReason* trap) { int64_t output; if (!float32_to_int64_wrapper(&a, &output)) { *trap = kTrapFloatUnrepresentable; } return output; } static int64_t ExecuteI64SConvertF64(double a, TrapReason* trap) { int64_t output; if (!float64_to_int64_wrapper(&a, &output)) { *trap = kTrapFloatUnrepresentable; } return output; } static uint64_t ExecuteI64UConvertF32(float a, TrapReason* trap) { uint64_t output; if (!float32_to_uint64_wrapper(&a, &output)) { *trap = kTrapFloatUnrepresentable; } return output; } static uint64_t ExecuteI64UConvertF64(double a, TrapReason* trap) { uint64_t output; if (!float64_to_uint64_wrapper(&a, &output)) { *trap = kTrapFloatUnrepresentable; } return output; } static inline int64_t ExecuteI64SConvertI32(int32_t a, TrapReason* trap) { return static_cast(a); } static inline int64_t ExecuteI64UConvertI32(uint32_t a, TrapReason* trap) { return static_cast(a); } static inline float ExecuteF32SConvertI32(int32_t a, TrapReason* trap) { return static_cast(a); } static inline float ExecuteF32UConvertI32(uint32_t a, TrapReason* trap) { return static_cast(a); } static inline float ExecuteF32SConvertI64(int64_t a, TrapReason* trap) { float output; int64_to_float32_wrapper(&a, &output); return output; } static inline float ExecuteF32UConvertI64(uint64_t a, TrapReason* trap) { float output; uint64_to_float32_wrapper(&a, &output); return output; } static inline float ExecuteF32ConvertF64(double a, TrapReason* trap) { return static_cast(a); } static inline float ExecuteF32ReinterpretI32(int32_t a, TrapReason* trap) { return bit_cast(a); } static inline double ExecuteF64SConvertI32(int32_t a, TrapReason* trap) { return static_cast(a); } static inline double ExecuteF64UConvertI32(uint32_t a, TrapReason* trap) { return static_cast(a); } static inline double ExecuteF64SConvertI64(int64_t a, TrapReason* trap) { double output; int64_to_float64_wrapper(&a, &output); return output; } static inline double ExecuteF64UConvertI64(uint64_t a, TrapReason* trap) { double output; uint64_to_float64_wrapper(&a, &output); return output; } static inline double ExecuteF64ConvertF32(float a, TrapReason* trap) { return static_cast(a); } static inline double ExecuteF64ReinterpretI64(int64_t a, TrapReason* trap) { return bit_cast(a); } static inline int32_t ExecuteI32ReinterpretF32(float a, TrapReason* trap) { return bit_cast(a); } static inline int64_t ExecuteI64ReinterpretF64(double a, TrapReason* trap) { return bit_cast(a); } static inline int32_t ExecuteGrowMemory(uint32_t delta_pages, WasmInstance* instance) { // TODO(ahaas): Move memory allocation to wasm-module.cc for better // encapsulation. if (delta_pages > wasm::kV8MaxWasmMemoryPages || delta_pages > instance->module->max_mem_pages) { return -1; } uint32_t old_size = instance->mem_size; uint32_t new_size; byte* new_mem_start; if (instance->mem_size == 0) { // TODO(gdeepti): Fix bounds check to take into account size of memtype. new_size = delta_pages * wasm::WasmModule::kPageSize; new_mem_start = static_cast(calloc(new_size, sizeof(byte))); if (!new_mem_start) { return -1; } } else { DCHECK_NOT_NULL(instance->mem_start); new_size = old_size + delta_pages * wasm::WasmModule::kPageSize; if (new_size / wasm::WasmModule::kPageSize > wasm::kV8MaxWasmMemoryPages || new_size / wasm::WasmModule::kPageSize > instance->module->max_mem_pages) { return -1; } new_mem_start = static_cast(realloc(instance->mem_start, new_size)); if (!new_mem_start) { return -1; } // Zero initializing uninitialized memory from realloc memset(new_mem_start + old_size, 0, new_size - old_size); } instance->mem_start = new_mem_start; instance->mem_size = new_size; return static_cast(old_size / WasmModule::kPageSize); } enum InternalOpcode { #define DECL_INTERNAL_ENUM(name, value) kInternal##name = value, FOREACH_INTERNAL_OPCODE(DECL_INTERNAL_ENUM) #undef DECL_INTERNAL_ENUM }; static 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)); } static const int kRunSteps = 1000; // 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 ControlTransfers : public ZoneObject { public: ControlTransferMap map_; ControlTransfers(Zone* zone, BodyLocalDecls* locals, const byte* start, const byte* end) : map_(zone) { // Represents a control flow label. struct CLabel : public ZoneObject { const byte* target; ZoneVector refs; explicit CLabel(Zone* zone) : target(nullptr), refs(zone) {} // Bind this label to the given PC. void Bind(ControlTransferMap* map, const byte* start, const byte* pc) { DCHECK_NULL(target); target = pc; for (auto from_pc : refs) { auto pcdiff = static_cast(target - from_pc); size_t offset = static_cast(from_pc - start); (*map)[offset] = pcdiff; } } // Reference this label from the given location. void Ref(ControlTransferMap* map, const byte* start, const byte* from_pc) { if (target) { // Target being bound before a reference means this is a loop. DCHECK_EQ(kExprLoop, *target); auto pcdiff = static_cast(target - from_pc); size_t offset = static_cast(from_pc - start); (*map)[offset] = pcdiff; } else { refs.push_back(from_pc); } } }; // An entry in the control stack. struct Control { const byte* pc; CLabel* end_label; CLabel* else_label; void Ref(ControlTransferMap* map, const byte* start, const byte* from_pc) { end_label->Ref(map, start, from_pc); } }; // 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. std::vector control_stack; CLabel* func_label = new (zone) CLabel(zone); control_stack.push_back({start, func_label, nullptr}); for (BytecodeIterator i(start, end, locals); i.has_next(); i.next()) { WasmOpcode opcode = i.current(); TRACE("@%u: control %s\n", i.pc_offset(), WasmOpcodes::OpcodeName(opcode)); switch (opcode) { case kExprBlock: { TRACE("control @%u: Block\n", i.pc_offset()); CLabel* label = new (zone) CLabel(zone); control_stack.push_back({i.pc(), label, nullptr}); break; } case kExprLoop: { TRACE("control @%u: Loop\n", i.pc_offset()); CLabel* label = new (zone) CLabel(zone); control_stack.push_back({i.pc(), label, nullptr}); label->Bind(&map_, start, i.pc()); break; } case kExprIf: { TRACE("control @%u: If\n", i.pc_offset()); CLabel* end_label = new (zone) CLabel(zone); CLabel* else_label = new (zone) CLabel(zone); control_stack.push_back({i.pc(), end_label, else_label}); else_label->Ref(&map_, start, i.pc()); break; } case kExprElse: { Control* c = &control_stack.back(); TRACE("control @%u: Else\n", i.pc_offset()); c->end_label->Ref(&map_, start, i.pc()); DCHECK_NOT_NULL(c->else_label); c->else_label->Bind(&map_, start, i.pc() + 1); c->else_label = nullptr; break; } case kExprEnd: { Control* c = &control_stack.back(); TRACE("control @%u: End\n", i.pc_offset()); if (c->end_label->target) { // only loops have bound labels. DCHECK_EQ(kExprLoop, *c->pc); } else { if (c->else_label) c->else_label->Bind(&map_, start, i.pc()); c->end_label->Bind(&map_, start, i.pc() + 1); } 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]; c->Ref(&map_, start, i.pc()); 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]; c->Ref(&map_, start, i.pc()); 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); 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->Ref(&map_, start, i.pc() + j); } break; } default: { break; } } } if (!func_label->target) func_label->Bind(&map_, start, end); } pcdiff_t Lookup(pc_t from) { auto result = map_.find(from); if (result == map_.end()) { V8_Fatal(__FILE__, __LINE__, "no control target for pc %zu", from); } return result->second; } }; // 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 ControlTransfers* targets; // helper for control flow. const byte* at(pc_t pc) { return start + pc; } }; // The main storage for interpreter code. It maps {WasmFunction} to the // metadata needed to execute each function. class CodeMap { public: Zone* zone_; const WasmModule* module_; ZoneVector interpreter_code_; CodeMap(const WasmModule* module, const uint8_t* module_start, Zone* zone) : zone_(zone), module_(module), interpreter_code_(zone) { if (module == nullptr) return; for (size_t i = 0; i < module->functions.size(); ++i) { const WasmFunction* function = &module->functions[i]; const byte* code_start = module_start + function->code_start_offset; const byte* code_end = module_start + function->code_end_offset; AddFunction(function, code_start, code_end); } } InterpreterCode* FindCode(const WasmFunction* function) { if (function->func_index < interpreter_code_.size()) { InterpreterCode* code = &interpreter_code_[function->func_index]; DCHECK_EQ(function, code->function); return Preprocess(code); } return nullptr; } InterpreterCode* GetCode(uint32_t function_index) { CHECK_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) { if (code->targets == nullptr && code->start) { // Compute the control targets map and the local declarations. CHECK(DecodeLocalDecls(&code->locals, code->start, code->end)); code->targets = new (zone_) ControlTransfers( zone_, &code->locals, code->orig_start, code->orig_end); } return code; } int 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); return static_cast(interpreter_code_.size()) - 1; } bool SetFunctionCode(const WasmFunction* function, const byte* start, const byte* end) { InterpreterCode* code = FindCode(function); if (code == nullptr) return false; code->targets = nullptr; code->orig_start = start; code->orig_end = end; code->start = const_cast(start); code->end = const_cast(end); Preprocess(code); return true; } }; namespace { // Responsible for executing code directly. class ThreadImpl { public: ThreadImpl(Zone* zone, CodeMap* codemap, WasmInstance* instance) : codemap_(codemap), instance_(instance), stack_(zone), frames_(zone), blocks_(zone), state_(WasmInterpreter::STOPPED), break_pc_(kInvalidPc), trap_reason_(kTrapCount), possible_nondeterminism_(false) {} //========================================================================== // Implementation of public interface for WasmInterpreter::Thread. //========================================================================== WasmInterpreter::State state() { return state_; } void PushFrame(const WasmFunction* function, WasmVal* args) { InterpreterCode* code = codemap()->FindCode(function); CHECK_NOT_NULL(code); frames_.push_back({code, 0, 0, stack_.size()}); for (size_t i = 0; i < function->sig->parameter_count(); ++i) { stack_.push_back(args[i]); } frames_.back().ret_pc = InitLocals(code); blocks_.push_back( {0, stack_.size(), frames_.size(), static_cast(code->function->sig->return_count())}); TRACE(" => PushFrame(#%u @%zu)\n", code->function->func_index, frames_.back().ret_pc); } WasmInterpreter::State Run() { do { TRACE(" => Run()\n"); if (state_ == WasmInterpreter::STOPPED || state_ == WasmInterpreter::PAUSED) { state_ = WasmInterpreter::RUNNING; Execute(frames_.back().code, frames_.back().ret_pc, kRunSteps); } } while (state_ == WasmInterpreter::STOPPED); return state_; } WasmInterpreter::State Step() { TRACE(" => Step()\n"); if (state_ == WasmInterpreter::STOPPED || state_ == WasmInterpreter::PAUSED) { state_ = WasmInterpreter::RUNNING; Execute(frames_.back().code, frames_.back().ret_pc, 1); } return state_; } void Pause() { UNIMPLEMENTED(); } void Reset() { TRACE("----- RESET -----\n"); stack_.clear(); frames_.clear(); state_ = WasmInterpreter::STOPPED; trap_reason_ = kTrapCount; possible_nondeterminism_ = false; } int GetFrameCount() { return static_cast(frames_.size()); } const WasmFrame* GetFrame(int index) { UNIMPLEMENTED(); return nullptr; } WasmFrame* GetMutableFrame(int index) { UNIMPLEMENTED(); return nullptr; } WasmVal GetReturnValue(int index) { if (state_ == WasmInterpreter::TRAPPED) return WasmVal(0xdeadbeef); CHECK_EQ(WasmInterpreter::FINISHED, state_); CHECK_LT(static_cast(index), stack_.size()); return stack_[index]; } pc_t GetBreakpointPc() { return break_pc_; } bool PossibleNondeterminism() { return possible_nondeterminism_; } private: // Entries on the stack of functions being evaluated. struct Frame { InterpreterCode* code; pc_t call_pc; pc_t ret_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; }; CodeMap* codemap_; WasmInstance* instance_; ZoneVector stack_; ZoneVector frames_; ZoneVector blocks_; WasmInterpreter::State state_; pc_t break_pc_; TrapReason trap_reason_; bool possible_nondeterminism_; CodeMap* codemap() { return codemap_; } WasmInstance* instance() { return instance_; } const WasmModule* module() { return instance_->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, pc_t call_pc, pc_t ret_pc) { CHECK_NOT_NULL(code); DCHECK(!frames_.empty()); frames_.back().call_pc = call_pc; frames_.back().ret_pc = ret_pc; size_t arity = code->function->sig->parameter_count(); DCHECK_GE(stack_.size(), arity); // The parameters will overlap the arguments already on the stack. frames_.push_back({code, 0, 0, stack_.size() - arity}); blocks_.push_back( {0, stack_.size(), frames_.size(), static_cast(code->function->sig->return_count())}); frames_.back().ret_pc = InitLocals(code); TRACE(" => push func#%u @%zu\n", code->function->func_index, frames_.back().ret_pc); } pc_t InitLocals(InterpreterCode* code) { for (auto p : code->locals.type_list) { WasmVal val; switch (p) { case kWasmI32: val = WasmVal(static_cast(0)); break; case kWasmI64: val = WasmVal(static_cast(0)); break; case kWasmF32: val = WasmVal(static_cast(0)); break; case kWasmF64: val = WasmVal(static_cast(0)); break; default: UNREACHABLE(); break; } stack_.push_back(val); } return code->locals.encoded_size; } void CommitPc(pc_t pc) { if (!frames_.empty()) { frames_.back().ret_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 LookupTarget(InterpreterCode* code, pc_t pc) { return static_cast(code->targets->Lookup(pc)); } int DoBreak(InterpreterCode* code, pc_t pc, size_t depth) { size_t bp = blocks_.size() - depth - 1; Block* target = &blocks_[bp]; DoStackTransfer(target->sp, target->arity); blocks_.resize(bp); return LookupTarget(code, pc); } bool DoReturn(InterpreterCode** code, pc_t* pc, pc_t* limit, size_t arity) { DCHECK_GT(frames_.size(), 0); // Pop all blocks for this frame. while (!blocks_.empty() && blocks_.back().fp == frames_.size()) { blocks_.pop_back(); } sp_t dest = frames_.back().sp; frames_.pop_back(); if (frames_.size() == 0) { // A return from the last frame terminates the execution. state_ = WasmInterpreter::FINISHED; DoStackTransfer(0, arity); TRACE(" => finish\n"); return false; } else { // Return to caller frame. Frame* top = &frames_.back(); *code = top->code; *pc = top->ret_pc; *limit = top->code->end - top->code->start; TRACE(" => pop func#%u @%zu\n", (*code)->function->func_index, *pc); DoStackTransfer(dest, arity); return true; } } void DoCall(InterpreterCode* target, pc_t* pc, pc_t ret_pc, pc_t* limit) { PushFrame(target, *pc, ret_pc); *pc = frames_.back().ret_pc; *limit = target->end - target->start; } // Copies {arity} values on the top of the stack down the stack to {dest}, // dropping the values in-between. void DoStackTransfer(sp_t dest, size_t arity) { // before: |---------------| pop_count | arity | // ^ 0 ^ dest ^ stack_.size() // // after: |---------------| arity | // ^ 0 ^ stack_.size() DCHECK_LE(dest, stack_.size()); DCHECK_LE(dest + arity, stack_.size()); size_t pop_count = stack_.size() - dest - arity; for (size_t i = 0; i < arity; i++) { stack_[dest + i] = stack_[dest + pop_count + i]; } stack_.resize(stack_.size() - pop_count); } void Execute(InterpreterCode* code, pc_t pc, int max) { Decoder decoder(code->start, code->end); pc_t limit = code->end - code->start; while (true) { if (max-- <= 0) { // Maximum number of instructions reached. state_ = WasmInterpreter::PAUSED; return CommitPc(pc); } if (pc >= limit) { // Fell off end of code; do an implicit return. TRACE("@%-3zu: ImplicitReturn\n", pc); if (!DoReturn(&code, &pc, &limit, code->function->sig->return_count())) return; decoder.Reset(code->start, code->end); continue; } const char* skip = " "; int len = 1; byte opcode = code->start[pc]; byte orig = opcode; if (opcode == kInternalBreakpoint) { orig = code->orig_start[pc]; if (SkipBreakpoint(code, pc)) { // skip breakpoint by switching on original code. skip = "[skip] "; } else { state_ = WasmInterpreter::PAUSED; TRACE("@%-3zu: [break] %-24s:", pc, WasmOpcodes::OpcodeName(static_cast(orig))); TraceValueStack(); TRACE("\n"); break_pc_ = pc; return CommitPc(pc); } } USE(skip); TRACE("@%-3zu: %s%-24s:", pc, skip, WasmOpcodes::OpcodeName(static_cast(orig))); TraceValueStack(); TRACE("\n"); switch (orig) { case kExprNop: break; case kExprBlock: { BlockTypeOperand operand(&decoder, code->at(pc)); blocks_.push_back({pc, stack_.size(), frames_.size(), operand.arity}); len = 1 + operand.length; break; } case kExprLoop: { BlockTypeOperand operand(&decoder, code->at(pc)); blocks_.push_back({pc, stack_.size(), frames_.size(), 0}); len = 1 + operand.length; break; } case kExprIf: { BlockTypeOperand operand(&decoder, code->at(pc)); WasmVal cond = Pop(); bool is_true = cond.to() != 0; blocks_.push_back({pc, stack_.size(), frames_.size(), operand.arity}); if (is_true) { // fall through to the true block. len = 1 + operand.length; TRACE(" true => fallthrough\n"); } else { len = LookupTarget(code, pc); TRACE(" false => @%zu\n", pc + len); } break; } case kExprElse: { blocks_.pop_back(); len = LookupTarget(code, pc); TRACE(" end => @%zu\n", pc + len); break; } case kExprSelect: { WasmVal cond = Pop(); WasmVal fval = Pop(); WasmVal tval = Pop(); Push(pc, 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)); WasmVal 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(&code, &pc, &limit, arity)) return; decoder.Reset(code->start, code->end); continue; } case kExprUnreachable: { DoTrap(kTrapUnreachable, pc); return CommitPc(pc); } case kExprEnd: { blocks_.pop_back(); break; } case kExprI32Const: { ImmI32Operand operand(&decoder, code->at(pc)); Push(pc, WasmVal(operand.value)); len = 1 + operand.length; break; } case kExprI64Const: { ImmI64Operand operand(&decoder, code->at(pc)); Push(pc, WasmVal(operand.value)); len = 1 + operand.length; break; } case kExprF32Const: { ImmF32Operand operand(&decoder, code->at(pc)); Push(pc, WasmVal(operand.value)); len = 1 + operand.length; break; } case kExprF64Const: { ImmF64Operand operand(&decoder, code->at(pc)); Push(pc, WasmVal(operand.value)); len = 1 + operand.length; break; } case kExprGetLocal: { LocalIndexOperand operand(&decoder, code->at(pc)); Push(pc, stack_[frames_.back().sp + operand.index]); len = 1 + operand.length; break; } case kExprSetLocal: { LocalIndexOperand operand(&decoder, code->at(pc)); WasmVal val = Pop(); stack_[frames_.back().sp + operand.index] = val; len = 1 + operand.length; break; } case kExprTeeLocal: { LocalIndexOperand operand(&decoder, code->at(pc)); WasmVal val = Pop(); stack_[frames_.back().sp + operand.index] = val; Push(pc, val); len = 1 + operand.length; break; } case kExprDrop: { Pop(); break; } case kExprCallFunction: { CallFunctionOperand operand(&decoder, code->at(pc)); InterpreterCode* target = codemap()->GetCode(operand.index); DoCall(target, &pc, pc + 1 + operand.length, &limit); code = target; decoder.Reset(code->start, code->end); continue; } 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); InterpreterCode* target = codemap()->GetIndirectCode(0, entry_index); if (target == nullptr) { return DoTrap(kTrapFuncInvalid, pc); } else if (target->function->sig_index != operand.index) { // If not an exact match, we have to do a canonical check. // TODO(titzer): make this faster with some kind of caching? const WasmIndirectFunctionTable* table = &module()->function_tables[0]; int function_key = table->map.Find(target->function->sig); if (function_key < 0 || (function_key != table->map.Find(module()->signatures[operand.index]))) { return DoTrap(kTrapFuncSigMismatch, pc); } } DoCall(target, &pc, pc + 1 + operand.length, &limit); code = target; decoder.Reset(code->start, code->end); continue; } case kExprGetGlobal: { GlobalIndexOperand operand(&decoder, code->at(pc)); const WasmGlobal* global = &module()->globals[operand.index]; byte* ptr = instance()->globals_start + global->offset; ValueType type = global->type; WasmVal val; if (type == kWasmI32) { val = WasmVal(*reinterpret_cast(ptr)); } else if (type == kWasmI64) { val = WasmVal(*reinterpret_cast(ptr)); } else if (type == kWasmF32) { val = WasmVal(*reinterpret_cast(ptr)); } else if (type == kWasmF64) { val = WasmVal(*reinterpret_cast(ptr)); } else { UNREACHABLE(); } Push(pc, val); len = 1 + operand.length; break; } case kExprSetGlobal: { GlobalIndexOperand operand(&decoder, code->at(pc)); const WasmGlobal* global = &module()->globals[operand.index]; byte* ptr = instance()->globals_start + global->offset; ValueType type = global->type; WasmVal val = Pop(); if (type == kWasmI32) { *reinterpret_cast(ptr) = val.to(); } else if (type == kWasmI64) { *reinterpret_cast(ptr) = val.to(); } else if (type == kWasmF32) { *reinterpret_cast(ptr) = val.to(); } else if (type == kWasmF64) { *reinterpret_cast(ptr) = val.to(); } else { UNREACHABLE(); } len = 1 + operand.length; break; } #define LOAD_CASE(name, ctype, mtype) \ case kExpr##name: { \ MemoryAccessOperand operand(&decoder, code->at(pc), sizeof(ctype)); \ uint32_t index = Pop().to(); \ size_t effective_mem_size = instance()->mem_size - sizeof(mtype); \ if (operand.offset > effective_mem_size || \ index > (effective_mem_size - operand.offset)) { \ return DoTrap(kTrapMemOutOfBounds, pc); \ } \ byte* addr = instance()->mem_start + operand.offset + index; \ WasmVal result(static_cast(ReadLittleEndianValue(addr))); \ Push(pc, result); \ len = 1 + operand.length; \ break; \ } LOAD_CASE(I32LoadMem8S, int32_t, int8_t); LOAD_CASE(I32LoadMem8U, int32_t, uint8_t); LOAD_CASE(I32LoadMem16S, int32_t, int16_t); LOAD_CASE(I32LoadMem16U, int32_t, uint16_t); LOAD_CASE(I64LoadMem8S, int64_t, int8_t); LOAD_CASE(I64LoadMem8U, int64_t, uint8_t); LOAD_CASE(I64LoadMem16S, int64_t, int16_t); LOAD_CASE(I64LoadMem16U, int64_t, uint16_t); LOAD_CASE(I64LoadMem32S, int64_t, int32_t); LOAD_CASE(I64LoadMem32U, int64_t, uint32_t); LOAD_CASE(I32LoadMem, int32_t, int32_t); LOAD_CASE(I64LoadMem, int64_t, int64_t); LOAD_CASE(F32LoadMem, float, float); LOAD_CASE(F64LoadMem, double, double); #undef LOAD_CASE #define STORE_CASE(name, ctype, mtype) \ case kExpr##name: { \ MemoryAccessOperand operand(&decoder, code->at(pc), sizeof(ctype)); \ WasmVal val = Pop(); \ uint32_t index = Pop().to(); \ size_t effective_mem_size = instance()->mem_size - sizeof(mtype); \ if (operand.offset > effective_mem_size || \ index > (effective_mem_size - operand.offset)) { \ return DoTrap(kTrapMemOutOfBounds, pc); \ } \ byte* addr = instance()->mem_start + operand.offset + index; \ WriteLittleEndianValue(addr, static_cast(val.to())); \ len = 1 + operand.length; \ break; \ } STORE_CASE(I32StoreMem8, int32_t, int8_t); STORE_CASE(I32StoreMem16, int32_t, int16_t); STORE_CASE(I64StoreMem8, int64_t, int8_t); STORE_CASE(I64StoreMem16, int64_t, int16_t); STORE_CASE(I64StoreMem32, int64_t, int32_t); STORE_CASE(I32StoreMem, int32_t, int32_t); STORE_CASE(I64StoreMem, int64_t, int64_t); STORE_CASE(F32StoreMem, float, float); STORE_CASE(F64StoreMem, double, double); #undef STORE_CASE #define ASMJS_LOAD_CASE(name, ctype, mtype, defval) \ case kExpr##name: { \ uint32_t index = Pop().to(); \ ctype result; \ if (index >= (instance()->mem_size - sizeof(mtype))) { \ result = defval; \ } else { \ byte* addr = instance()->mem_start + index; \ /* TODO(titzer): alignment for asmjs load mem? */ \ result = static_cast(*reinterpret_cast(addr)); \ } \ Push(pc, WasmVal(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: { \ WasmVal val = Pop(); \ uint32_t index = Pop().to(); \ if (index < (instance()->mem_size - sizeof(mtype))) { \ byte* addr = instance()->mem_start + index; \ /* TODO(titzer): alignment for asmjs store mem? */ \ *(reinterpret_cast(addr)) = static_cast(val.to()); \ } \ Push(pc, 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(); Push(pc, WasmVal(ExecuteGrowMemory(delta_pages, instance()))); len = 1 + operand.length; break; } case kExprMemorySize: { MemoryIndexOperand operand(&decoder, code->at(pc)); Push(pc, WasmVal(static_cast(instance()->mem_size / WasmModule::kPageSize))); len = 1 + operand.length; break; } #define EXECUTE_SIMPLE_BINOP(name, ctype, op) \ case kExpr##name: { \ WasmVal rval = Pop(); \ WasmVal lval = Pop(); \ WasmVal result(lval.to() op rval.to()); \ Push(pc, result); \ break; \ } FOREACH_SIMPLE_BINOP(EXECUTE_SIMPLE_BINOP) #undef EXECUTE_SIMPLE_BINOP #define EXECUTE_SIMPLE_BINOP_NAN(name, ctype, op) \ case kExpr##name: { \ WasmVal rval = Pop(); \ WasmVal lval = Pop(); \ ctype result = lval.to() op rval.to(); \ possible_nondeterminism_ |= std::isnan(result); \ WasmVal result_val(result); \ Push(pc, result_val); \ break; \ } FOREACH_SIMPLE_BINOP_NAN(EXECUTE_SIMPLE_BINOP_NAN) #undef EXECUTE_SIMPLE_BINOP_NAN #define EXECUTE_OTHER_BINOP(name, ctype) \ case kExpr##name: { \ TrapReason trap = kTrapCount; \ volatile ctype rval = Pop().to(); \ volatile ctype lval = Pop().to(); \ WasmVal result(Execute##name(lval, rval, &trap)); \ if (trap != kTrapCount) return DoTrap(trap, pc); \ Push(pc, result); \ break; \ } FOREACH_OTHER_BINOP(EXECUTE_OTHER_BINOP) #undef EXECUTE_OTHER_BINOP #define EXECUTE_OTHER_UNOP(name, ctype) \ case kExpr##name: { \ TrapReason trap = kTrapCount; \ volatile ctype val = Pop().to(); \ WasmVal result(Execute##name(val, &trap)); \ if (trap != kTrapCount) return DoTrap(trap, pc); \ Push(pc, result); \ break; \ } FOREACH_OTHER_UNOP(EXECUTE_OTHER_UNOP) #undef EXECUTE_OTHER_UNOP #define EXECUTE_OTHER_UNOP_NAN(name, ctype) \ case kExpr##name: { \ TrapReason trap = kTrapCount; \ volatile ctype val = Pop().to(); \ ctype result = Execute##name(val, &trap); \ possible_nondeterminism_ |= std::isnan(result); \ WasmVal result_val(result); \ if (trap != kTrapCount) return DoTrap(trap, pc); \ Push(pc, result_val); \ break; \ } FOREACH_OTHER_UNOP_NAN(EXECUTE_OTHER_UNOP_NAN) #undef EXECUTE_OTHER_UNOP_NAN default: V8_Fatal(__FILE__, __LINE__, "Unknown or unimplemented opcode #%d:%s", code->start[pc], OpcodeName(code->start[pc])); UNREACHABLE(); } pc += len; } UNREACHABLE(); // above decoding loop should run forever. } WasmVal Pop() { DCHECK_GT(stack_.size(), 0); DCHECK_GT(frames_.size(), 0); DCHECK_GT(stack_.size(), frames_.back().llimit()); // can't pop into locals WasmVal val = stack_.back(); stack_.pop_back(); return val; } void PopN(int n) { DCHECK_GE(stack_.size(), n); DCHECK_GT(frames_.size(), 0); size_t nsize = stack_.size() - n; DCHECK_GE(nsize, frames_.back().llimit()); // can't pop into locals stack_.resize(nsize); } WasmVal PopArity(size_t arity) { if (arity == 0) return WasmVal(); CHECK_EQ(1, arity); return Pop(); } void Push(pc_t pc, WasmVal val) { // TODO(titzer): store PC as well? if (val.type != kWasmStmt) stack_.push_back(val); } void TraceStack(const char* phase, pc_t pc) { if (FLAG_trace_wasm_interpreter) { PrintF("%s @%zu", phase, pc); UNIMPLEMENTED(); PrintF("\n"); } } void TraceValueStack() { 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; if (FLAG_trace_wasm_interpreter) { for (size_t i = sp; i < stack_.size(); ++i) { if (i < plimit) PrintF(" p%zu:", i); else if (i < llimit) PrintF(" l%zu:", i); else PrintF(" s%zu:", i); WasmVal val = stack_[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; } } } } }; // 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); } static ThreadImpl* ToImpl(WasmInterpreter::Thread* thread) { return reinterpret_cast(thread); } } // 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::PushFrame(const WasmFunction* function, WasmVal* args) { return ToImpl(this)->PushFrame(function, args); } WasmInterpreter::State WasmInterpreter::Thread::Run() { return ToImpl(this)->Run(); } WasmInterpreter::State WasmInterpreter::Thread::Step() { return ToImpl(this)->Step(); } void WasmInterpreter::Thread::Pause() { return ToImpl(this)->Pause(); } void WasmInterpreter::Thread::Reset() { return ToImpl(this)->Reset(); } pc_t WasmInterpreter::Thread::GetBreakpointPc() { return ToImpl(this)->GetBreakpointPc(); } int WasmInterpreter::Thread::GetFrameCount() { return ToImpl(this)->GetFrameCount(); } const WasmFrame* WasmInterpreter::Thread::GetFrame(int index) { return ToImpl(this)->GetFrame(index); } WasmFrame* WasmInterpreter::Thread::GetMutableFrame(int index) { return ToImpl(this)->GetMutableFrame(index); } WasmVal WasmInterpreter::Thread::GetReturnValue(int index) { return ToImpl(this)->GetReturnValue(index); } bool WasmInterpreter::Thread::PossibleNondeterminism() { return ToImpl(this)->PossibleNondeterminism(); } //============================================================================ // The implementation details of the interpreter. //============================================================================ class WasmInterpreterInternals : public ZoneObject { public: WasmInstance* instance_; // 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(Zone* zone, const ModuleBytesEnv& env) : instance_(env.instance), module_bytes_(env.module_bytes.start(), env.module_bytes.end(), zone), codemap_(env.instance ? env.instance->module : nullptr, module_bytes_.data(), zone), threads_(zone) { threads_.push_back(ThreadImpl(zone, &codemap_, env.instance)); } void Delete() { threads_.clear(); } }; //============================================================================ // Implementation of the public interface of the interpreter. //============================================================================ WasmInterpreter::WasmInterpreter(const ModuleBytesEnv& env, AccountingAllocator* allocator) : zone_(allocator, ZONE_NAME), internals_(new (&zone_) WasmInterpreterInternals(&zone_, env)) {} WasmInterpreter::~WasmInterpreter() { internals_->Delete(); } 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_.FindCode(function); if (!code) return false; 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_.FindCode(function); if (!code) return false; 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]); } WasmVal WasmInterpreter::GetLocalVal(const WasmFrame* frame, int index) { CHECK_GE(index, 0); UNIMPLEMENTED(); WasmVal none; none.type = kWasmStmt; return none; } WasmVal WasmInterpreter::GetExprVal(const WasmFrame* frame, int pc) { UNIMPLEMENTED(); WasmVal none; none.type = kWasmStmt; return none; } void WasmInterpreter::SetLocalVal(WasmFrame* frame, int index, WasmVal val) { UNIMPLEMENTED(); } void WasmInterpreter::SetExprVal(WasmFrame* frame, int pc, WasmVal val) { UNIMPLEMENTED(); } size_t WasmInterpreter::GetMemorySize() { return internals_->instance_->mem_size; } WasmVal WasmInterpreter::ReadMemory(size_t offset) { UNIMPLEMENTED(); return WasmVal(); } void WasmInterpreter::WriteMemory(size_t offset, WasmVal val) { UNIMPLEMENTED(); } int WasmInterpreter::AddFunctionForTesting(const WasmFunction* function) { return internals_->codemap_.AddFunction(function, nullptr, nullptr); } bool WasmInterpreter::SetFunctionCodeForTesting(const WasmFunction* function, const byte* start, const byte* end) { return internals_->codemap_.SetFunctionCode(function, start, end); } ControlTransferMap WasmInterpreter::ComputeControlTransfersForTesting( Zone* zone, const byte* start, const byte* end) { ControlTransfers targets(zone, nullptr, start, end); return targets.map_; } } // namespace wasm } // namespace internal } // namespace v8