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// Copyright 2017 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_WASM_FUNCTION_BODY_DECODER_IMPL_H_
#define V8_WASM_FUNCTION_BODY_DECODER_IMPL_H_
// Do only include this header for implementing new Interface of the
// WasmFullDecoder.
#include <inttypes.h>
#include "src/base/platform/elapsed-timer.h"
#include "src/base/small-vector.h"
#include "src/utils/bit-vector.h"
#include "src/wasm/decoder.h"
#include "src/wasm/function-body-decoder.h"
#include "src/wasm/value-type.h"
#include "src/wasm/wasm-features.h"
#include "src/wasm/wasm-limits.h"
#include "src/wasm/wasm-module.h"
#include "src/wasm/wasm-opcodes.h"
#include "src/wasm/wasm-subtyping.h"
namespace v8 {
namespace internal {
namespace wasm {
struct WasmGlobal;
struct WasmException;
#define TRACE(...) \
do { \
if (FLAG_trace_wasm_decoder) PrintF(__VA_ARGS__); \
} while (false)
#define TRACE_INST_FORMAT " @%-8d #%-20s|"
// Return the evaluation of `condition` if validate==true, DCHECK that it's
// true and always return true otherwise.
#define VALIDATE(condition) \
(validate ? V8_LIKELY(condition) : [&] { \
DCHECK(condition); \
return true; \
}())
#define CHECK_PROTOTYPE_OPCODE(feat) \
DCHECK(this->module_->origin == kWasmOrigin); \
if (!VALIDATE(this->enabled_.has_##feat())) { \
this->DecodeError( \
"Invalid opcode 0x%x (enable with --experimental-wasm-" #feat ")", \
opcode); \
return 0; \
} \
this->detected_->Add(kFeature_##feat);
#define ATOMIC_OP_LIST(V) \
V(AtomicNotify, Uint32) \
V(I32AtomicWait, Uint32) \
V(I64AtomicWait, Uint64) \
V(I32AtomicLoad, Uint32) \
V(I64AtomicLoad, Uint64) \
V(I32AtomicLoad8U, Uint8) \
V(I32AtomicLoad16U, Uint16) \
V(I64AtomicLoad8U, Uint8) \
V(I64AtomicLoad16U, Uint16) \
V(I64AtomicLoad32U, Uint32) \
V(I32AtomicAdd, Uint32) \
V(I32AtomicAdd8U, Uint8) \
V(I32AtomicAdd16U, Uint16) \
V(I64AtomicAdd, Uint64) \
V(I64AtomicAdd8U, Uint8) \
V(I64AtomicAdd16U, Uint16) \
V(I64AtomicAdd32U, Uint32) \
V(I32AtomicSub, Uint32) \
V(I64AtomicSub, Uint64) \
V(I32AtomicSub8U, Uint8) \
V(I32AtomicSub16U, Uint16) \
V(I64AtomicSub8U, Uint8) \
V(I64AtomicSub16U, Uint16) \
V(I64AtomicSub32U, Uint32) \
V(I32AtomicAnd, Uint32) \
V(I64AtomicAnd, Uint64) \
V(I32AtomicAnd8U, Uint8) \
V(I32AtomicAnd16U, Uint16) \
V(I64AtomicAnd8U, Uint8) \
V(I64AtomicAnd16U, Uint16) \
V(I64AtomicAnd32U, Uint32) \
V(I32AtomicOr, Uint32) \
V(I64AtomicOr, Uint64) \
V(I32AtomicOr8U, Uint8) \
V(I32AtomicOr16U, Uint16) \
V(I64AtomicOr8U, Uint8) \
V(I64AtomicOr16U, Uint16) \
V(I64AtomicOr32U, Uint32) \
V(I32AtomicXor, Uint32) \
V(I64AtomicXor, Uint64) \
V(I32AtomicXor8U, Uint8) \
V(I32AtomicXor16U, Uint16) \
V(I64AtomicXor8U, Uint8) \
V(I64AtomicXor16U, Uint16) \
V(I64AtomicXor32U, Uint32) \
V(I32AtomicExchange, Uint32) \
V(I64AtomicExchange, Uint64) \
V(I32AtomicExchange8U, Uint8) \
V(I32AtomicExchange16U, Uint16) \
V(I64AtomicExchange8U, Uint8) \
V(I64AtomicExchange16U, Uint16) \
V(I64AtomicExchange32U, Uint32) \
V(I32AtomicCompareExchange, Uint32) \
V(I64AtomicCompareExchange, Uint64) \
V(I32AtomicCompareExchange8U, Uint8) \
V(I32AtomicCompareExchange16U, Uint16) \
V(I64AtomicCompareExchange8U, Uint8) \
V(I64AtomicCompareExchange16U, Uint16) \
V(I64AtomicCompareExchange32U, Uint32)
#define ATOMIC_STORE_OP_LIST(V) \
V(I32AtomicStore, Uint32) \
V(I64AtomicStore, Uint64) \
V(I32AtomicStore8U, Uint8) \
V(I32AtomicStore16U, Uint16) \
V(I64AtomicStore8U, Uint8) \
V(I64AtomicStore16U, Uint16) \
V(I64AtomicStore32U, Uint32)
// Decoder error with explicit PC and format arguments.
template <Decoder::ValidateFlag validate, typename... Args>
void DecodeError(Decoder* decoder, const byte* pc, const char* str,
Args&&... args) {
CHECK(validate == Decoder::kFullValidation ||
validate == Decoder::kBooleanValidation);
STATIC_ASSERT(sizeof...(Args) > 0);
if (validate == Decoder::kBooleanValidation) {
decoder->MarkError();
} else {
decoder->errorf(pc, str, std::forward<Args>(args)...);
}
}
// Decoder error with explicit PC and no format arguments.
template <Decoder::ValidateFlag validate>
void DecodeError(Decoder* decoder, const byte* pc, const char* str) {
CHECK(validate == Decoder::kFullValidation ||
validate == Decoder::kBooleanValidation);
if (validate == Decoder::kBooleanValidation) {
decoder->MarkError();
} else {
decoder->error(pc, str);
}
}
// Decoder error without explicit PC, but with format arguments.
template <Decoder::ValidateFlag validate, typename... Args>
void DecodeError(Decoder* decoder, const char* str, Args&&... args) {
CHECK(validate == Decoder::kFullValidation ||
validate == Decoder::kBooleanValidation);
STATIC_ASSERT(sizeof...(Args) > 0);
if (validate == Decoder::kBooleanValidation) {
decoder->MarkError();
} else {
decoder->errorf(str, std::forward<Args>(args)...);
}
}
// Decoder error without explicit PC and without format arguments.
template <Decoder::ValidateFlag validate>
void DecodeError(Decoder* decoder, const char* str) {
CHECK(validate == Decoder::kFullValidation ||
validate == Decoder::kBooleanValidation);
if (validate == Decoder::kBooleanValidation) {
decoder->MarkError();
} else {
decoder->error(str);
}
}
namespace value_type_reader {
V8_INLINE WasmFeature feature_for_heap_type(HeapType heap_type) {
switch (heap_type.representation()) {
case HeapType::kFunc:
case HeapType::kExtern:
return WasmFeature::kFeature_reftypes;
case HeapType::kExn:
return WasmFeature::kFeature_eh;
case HeapType::kEq:
case HeapType::kI31:
return WasmFeature::kFeature_gc;
default:
UNREACHABLE();
}
}
template <Decoder::ValidateFlag validate>
HeapType read_heap_type(Decoder* decoder, const byte* pc,
uint32_t* const length, const WasmFeatures& enabled) {
int64_t heap_index = decoder->read_i33v<validate>(pc, length, "heap type");
if (heap_index < 0) {
int64_t min_1_byte_leb128 = -64;
if (heap_index < min_1_byte_leb128) {
DecodeError<validate>(decoder, pc, "Unknown heap type %" PRId64,
heap_index);
return HeapType(HeapType::kBottom);
}
uint8_t uint_7_mask = 0x7F;
uint8_t code = static_cast<ValueTypeCode>(heap_index) & uint_7_mask;
switch (code) {
case kFuncRefCode:
case kExnRefCode:
case kEqRefCode:
case kExternRefCode:
case kI31RefCode: {
HeapType result = HeapType::from_code(code);
if (!VALIDATE(enabled.contains(feature_for_heap_type(result)))) {
DecodeError<validate>(
decoder, pc,
"invalid heap type '%s', enable with --experimental-wasm-%s",
result.name().c_str(),
WasmFeatures::name_for_feature(feature_for_heap_type(result)));
return HeapType(HeapType::kBottom);
}
return result;
}
default:
DecodeError<validate>(decoder, pc, "Unknown heap type %" PRId64,
heap_index);
return HeapType(HeapType::kBottom);
}
UNREACHABLE();
} else {
if (!VALIDATE(enabled.has_typed_funcref())) {
DecodeError<validate>(decoder, pc,
"Invalid indexed heap type, enable with "
"--experimental-wasm-typed-funcref");
return HeapType(HeapType::kBottom);
}
uint32_t type_index = static_cast<uint32_t>(heap_index);
if (!VALIDATE(type_index < kV8MaxWasmTypes)) {
DecodeError<validate>(
decoder, pc,
"Type index %u is greater than the maximum number %zu "
"of type definitions supported by V8",
type_index, kV8MaxWasmTypes);
return HeapType(HeapType::kBottom);
}
return HeapType(type_index);
}
}
// Read a value type starting at address 'pc' in 'decoder'.
// No bytes are consumed. The result is written into the 'result' parameter.
// Returns the amount of bytes read, or 0 if decoding failed.
// Registers an error if the type opcode is invalid iff validate is set.
template <Decoder::ValidateFlag validate>
ValueType read_value_type(Decoder* decoder, const byte* pc,
uint32_t* const length, const WasmFeatures& enabled) {
*length = 1;
byte val = decoder->read_u8<validate>(pc, "value type opcode");
if (decoder->failed()) {
return kWasmBottom;
}
ValueTypeCode code = static_cast<ValueTypeCode>(val);
switch (code) {
case kFuncRefCode:
case kExnRefCode:
case kEqRefCode:
case kExternRefCode:
case kI31RefCode: {
HeapType heap_type = HeapType::from_code(code);
ValueType result = ValueType::Ref(
heap_type, code == kI31RefCode ? kNonNullable : kNullable);
if (!VALIDATE(enabled.contains(feature_for_heap_type(heap_type)))) {
DecodeError<validate>(
decoder, pc,
"invalid value type '%s', enable with --experimental-wasm-%s",
result.name().c_str(),
WasmFeatures::name_for_feature(feature_for_heap_type(heap_type)));
return kWasmBottom;
}
return result;
}
case kI32Code:
return kWasmI32;
case kI64Code:
return kWasmI64;
case kF32Code:
return kWasmF32;
case kF64Code:
return kWasmF64;
case kRefCode:
case kOptRefCode: {
Nullability nullability = code == kOptRefCode ? kNullable : kNonNullable;
if (!VALIDATE(enabled.has_typed_funcref())) {
DecodeError<validate>(decoder, pc,
"Invalid type '(ref%s <heaptype>)', enable with "
"--experimental-wasm-typed-funcref",
nullability == kNullable ? " null" : "");
return kWasmBottom;
}
HeapType heap_type =
read_heap_type<validate>(decoder, pc + 1, length, enabled);
*length += 1;
return heap_type.is_bottom() ? kWasmBottom
: ValueType::Ref(heap_type, nullability);
}
case kRttCode: {
if (!VALIDATE(enabled.has_gc())) {
DecodeError<validate>(
decoder, pc,
"invalid value type 'rtt', enable with --experimental-wasm-gc");
return kWasmBottom;
}
uint32_t depth_length;
uint32_t depth =
decoder->read_u32v<validate>(pc + 1, &depth_length, "depth");
if (!VALIDATE(depth <= kV8MaxRttSubtypingDepth)) {
DecodeError<validate>(
decoder, pc,
"subtyping depth %u is greater than the maximum depth "
"%u supported by V8",
depth, kV8MaxRttSubtypingDepth);
return kWasmBottom;
}
HeapType heap_type = read_heap_type<validate>(
decoder, pc + depth_length + 1, length, enabled);
*length += depth_length + 1;
return heap_type.is_bottom() ? kWasmBottom
: ValueType::Rtt(heap_type, depth);
}
case kS128Code: {
if (!VALIDATE(enabled.has_simd())) {
DecodeError<validate>(
decoder, pc,
"invalid value type 's128', enable with --experimental-wasm-simd");
return kWasmBottom;
}
return kWasmS128;
}
// Although these codes are included in ValueTypeCode, they technically
// do not correspond to value types and are only used in specific
// contexts. The caller of this function is responsible for handling them.
case kVoidCode:
case kI8Code:
case kI16Code:
return kWasmBottom;
}
// Anything that doesn't match an enumeration value is an invalid type code.
return kWasmBottom;
}
} // namespace value_type_reader
// Helpers for decoding different kinds of immediates which follow bytecodes.
template <Decoder::ValidateFlag validate>
struct LocalIndexImmediate {
uint32_t index;
uint32_t length;
inline LocalIndexImmediate(Decoder* decoder, const byte* pc) {
index = decoder->read_u32v<validate>(pc, &length, "local index");
}
};
template <Decoder::ValidateFlag validate>
struct ExceptionIndexImmediate {
uint32_t index;
const WasmException* exception = nullptr;
uint32_t length;
inline ExceptionIndexImmediate(Decoder* decoder, const byte* pc) {
index = decoder->read_u32v<validate>(pc, &length, "exception index");
}
};
template <Decoder::ValidateFlag validate>
struct ImmI32Immediate {
int32_t value;
uint32_t length;
inline ImmI32Immediate(Decoder* decoder, const byte* pc) {
value = decoder->read_i32v<validate>(pc, &length, "immi32");
}
};
template <Decoder::ValidateFlag validate>
struct ImmI64Immediate {
int64_t value;
uint32_t length;
inline ImmI64Immediate(Decoder* decoder, const byte* pc) {
value = decoder->read_i64v<validate>(pc, &length, "immi64");
}
};
template <Decoder::ValidateFlag validate>
struct ImmF32Immediate {
float value;
uint32_t length = 4;
inline ImmF32Immediate(Decoder* decoder, const byte* pc) {
// We can't use bit_cast here because calling any helper function that
// returns a float would potentially flip NaN bits per C++ semantics, so we
// have to inline the memcpy call directly.
uint32_t tmp = decoder->read_u32<validate>(pc, "immf32");
memcpy(&value, &tmp, sizeof(value));
}
};
template <Decoder::ValidateFlag validate>
struct ImmF64Immediate {
double value;
uint32_t length = 8;
inline ImmF64Immediate(Decoder* decoder, const byte* pc) {
// Avoid bit_cast because it might not preserve the signalling bit of a NaN.
uint64_t tmp = decoder->read_u64<validate>(pc, "immf64");
memcpy(&value, &tmp, sizeof(value));
}
};
template <Decoder::ValidateFlag validate>
struct GlobalIndexImmediate {
uint32_t index;
ValueType type = kWasmStmt;
const WasmGlobal* global = nullptr;
uint32_t length;
inline GlobalIndexImmediate(Decoder* decoder, const byte* pc) {
index = decoder->read_u32v<validate>(pc, &length, "global index");
}
};
template <Decoder::ValidateFlag validate>
struct SelectTypeImmediate {
uint32_t length;
ValueType type;
inline SelectTypeImmediate(const WasmFeatures& enabled, Decoder* decoder,
const byte* pc) {
uint8_t num_types =
decoder->read_u32v<validate>(pc, &length, "number of select types");
if (!VALIDATE(num_types == 1)) {
DecodeError<validate>(
decoder, pc + 1,
"Invalid number of types. Select accepts exactly one type");
return;
}
uint32_t type_length;
type = value_type_reader::read_value_type<validate>(decoder, pc + length,
&type_length, enabled);
length += type_length;
if (!VALIDATE(type != kWasmBottom)) {
DecodeError<validate>(decoder, pc + 1, "invalid select type");
}
}
};
template <Decoder::ValidateFlag validate>
struct BlockTypeImmediate {
uint32_t length = 1;
ValueType type = kWasmStmt;
uint32_t sig_index = 0;
const FunctionSig* sig = nullptr;
inline BlockTypeImmediate(const WasmFeatures& enabled, Decoder* decoder,
const byte* pc) {
int64_t block_type =
decoder->read_i33v<validate>(pc, &length, "block type");
if (block_type < 0) {
constexpr int64_t kVoidCode_i64_extended = (~int64_t{0x7F}) | kVoidCode;
if (block_type == kVoidCode_i64_extended) return;
type = value_type_reader::read_value_type<validate>(decoder, pc, &length,
enabled);
if (!VALIDATE(type != kWasmBottom)) {
DecodeError<validate>(decoder, pc, "Invalid block type %" PRId64,
block_type);
}
} else {
if (!VALIDATE(enabled.has_mv())) {
DecodeError<validate>(decoder, pc,
"invalid block type %" PRId64
", enable with --experimental-wasm-mv",
block_type);
return;
}
type = kWasmBottom;
sig_index = static_cast<uint32_t>(block_type);
}
}
uint32_t in_arity() const {
if (type != kWasmBottom) return 0;
return static_cast<uint32_t>(sig->parameter_count());
}
uint32_t out_arity() const {
if (type == kWasmStmt) return 0;
if (type != kWasmBottom) return 1;
return static_cast<uint32_t>(sig->return_count());
}
ValueType in_type(uint32_t index) {
DCHECK_EQ(kWasmBottom, type);
return sig->GetParam(index);
}
ValueType out_type(uint32_t index) {
if (type == kWasmBottom) return sig->GetReturn(index);
DCHECK_NE(kWasmStmt, type);
DCHECK_EQ(0, index);
return type;
}
};
template <Decoder::ValidateFlag validate>
struct BranchDepthImmediate {
uint32_t depth;
uint32_t length;
inline BranchDepthImmediate(Decoder* decoder, const byte* pc) {
depth = decoder->read_u32v<validate>(pc, &length, "branch depth");
}
};
template <Decoder::ValidateFlag validate>
struct BranchOnExceptionImmediate {
BranchDepthImmediate<validate> depth;
ExceptionIndexImmediate<validate> index;
uint32_t length = 0;
inline BranchOnExceptionImmediate(Decoder* decoder, const byte* pc)
: depth(BranchDepthImmediate<validate>(decoder, pc)),
index(ExceptionIndexImmediate<validate>(decoder, pc + depth.length)) {
length = depth.length + index.length;
}
};
template <Decoder::ValidateFlag validate>
struct FunctionIndexImmediate {
uint32_t index = 0;
uint32_t length = 1;
inline FunctionIndexImmediate(Decoder* decoder, const byte* pc) {
index = decoder->read_u32v<validate>(pc, &length, "function index");
}
};
template <Decoder::ValidateFlag validate>
struct MemoryIndexImmediate {
uint32_t index = 0;
uint32_t length = 1;
inline MemoryIndexImmediate() = default;
inline MemoryIndexImmediate(Decoder* decoder, const byte* pc) {
index = decoder->read_u8<validate>(pc, "memory index");
if (!VALIDATE(index == 0)) {
DecodeError<validate>(decoder, pc, "expected memory index 0, found %u",
index);
}
}
};
template <Decoder::ValidateFlag validate>
struct TableIndexImmediate {
uint32_t index = 0;
uint32_t length = 1;
inline TableIndexImmediate() = default;
inline TableIndexImmediate(Decoder* decoder, const byte* pc) {
index = decoder->read_u32v<validate>(pc, &length, "table index");
}
};
// TODO(jkummerow): Introduce a common superclass for StructIndexImmediate and
// ArrayIndexImmediate? Maybe even FunctionIndexImmediate too?
template <Decoder::ValidateFlag validate>
struct StructIndexImmediate {
uint32_t index = 0;
uint32_t length = 0;
const StructType* struct_type = nullptr;
inline StructIndexImmediate(Decoder* decoder, const byte* pc) {
index = decoder->read_u32v<validate>(pc, &length, "struct index");
}
};
template <Decoder::ValidateFlag validate>
struct FieldIndexImmediate {
StructIndexImmediate<validate> struct_index;
uint32_t index = 0;
uint32_t length = 0;
inline FieldIndexImmediate(Decoder* decoder, const byte* pc)
: struct_index(decoder, pc) {
index = decoder->read_u32v<validate>(pc + struct_index.length, &length,
"field index");
length += struct_index.length;
}
};
template <Decoder::ValidateFlag validate>
struct ArrayIndexImmediate {
uint32_t index = 0;
uint32_t length = 0;
const ArrayType* array_type = nullptr;
inline ArrayIndexImmediate(Decoder* decoder, const byte* pc) {
index = decoder->read_u32v<validate>(pc, &length, "array index");
}
};
template <Decoder::ValidateFlag validate>
struct CallIndirectImmediate {
uint32_t table_index;
uint32_t sig_index;
const FunctionSig* sig = nullptr;
uint32_t length = 0;
inline CallIndirectImmediate(const WasmFeatures enabled, Decoder* decoder,
const byte* pc) {
uint32_t len = 0;
sig_index = decoder->read_u32v<validate>(pc, &len, "signature index");
TableIndexImmediate<validate> table(decoder, pc + len);
if (!VALIDATE((table.index == 0 && table.length == 1) ||
enabled.has_reftypes())) {
DecodeError<validate>(decoder, pc + len,
"expected table index 0, found %u", table.index);
}
table_index = table.index;
length = len + table.length;
}
};
template <Decoder::ValidateFlag validate>
struct CallFunctionImmediate {
uint32_t index;
const FunctionSig* sig = nullptr;
uint32_t length;
inline CallFunctionImmediate(Decoder* decoder, const byte* pc) {
index = decoder->read_u32v<validate>(pc, &length, "function index");
}
};
template <Decoder::ValidateFlag validate>
struct BranchTableImmediate {
uint32_t table_count;
const byte* start;
const byte* table;
inline BranchTableImmediate(Decoder* decoder, const byte* pc) {
start = pc;
uint32_t len = 0;
table_count = decoder->read_u32v<validate>(pc, &len, "table count");
table = pc + len;
}
};
// A helper to iterate over a branch table.
template <Decoder::ValidateFlag validate>
class BranchTableIterator {
public:
uint32_t cur_index() { return index_; }
bool has_next() { return VALIDATE(decoder_->ok()) && index_ <= table_count_; }
uint32_t next() {
DCHECK(has_next());
index_++;
uint32_t length;
uint32_t result =
decoder_->read_u32v<validate>(pc_, &length, "branch table entry");
pc_ += length;
return result;
}
// length, including the length of the {BranchTableImmediate}, but not the
// opcode.
uint32_t length() {
while (has_next()) next();
return static_cast<uint32_t>(pc_ - start_);
}
const byte* pc() { return pc_; }
BranchTableIterator(Decoder* decoder,
const BranchTableImmediate<validate>& imm)
: decoder_(decoder),
start_(imm.start),
pc_(imm.table),
table_count_(imm.table_count) {}
private:
Decoder* const decoder_;
const byte* start_;
const byte* pc_;
uint32_t index_ = 0; // the current index.
const uint32_t table_count_; // the count of entries, not including default.
};
template <Decoder::ValidateFlag validate>
struct MemoryAccessImmediate {
uint32_t alignment;
uint32_t offset;
uint32_t length = 0;
inline MemoryAccessImmediate(Decoder* decoder, const byte* pc,
uint32_t max_alignment) {
uint32_t alignment_length;
alignment =
decoder->read_u32v<validate>(pc, &alignment_length, "alignment");
if (!VALIDATE(alignment <= max_alignment)) {
DecodeError<validate>(
decoder, pc,
"invalid alignment; expected maximum alignment is %u, "
"actual alignment is %u",
max_alignment, alignment);
}
uint32_t offset_length;
offset = decoder->read_u32v<validate>(pc + alignment_length, &offset_length,
"offset");
length = alignment_length + offset_length;
}
};
// Immediate for SIMD lane operations.
template <Decoder::ValidateFlag validate>
struct SimdLaneImmediate {
uint8_t lane;
uint32_t length = 1;
inline SimdLaneImmediate(Decoder* decoder, const byte* pc) {
lane = decoder->read_u8<validate>(pc, "lane");
}
};
// Immediate for SIMD S8x16 shuffle operations.
template <Decoder::ValidateFlag validate>
struct Simd128Immediate {
uint8_t value[kSimd128Size] = {0};
inline Simd128Immediate(Decoder* decoder, const byte* pc) {
for (uint32_t i = 0; i < kSimd128Size; ++i) {
value[i] = decoder->read_u8<validate>(pc + i, "value");
}
}
};
template <Decoder::ValidateFlag validate>
struct MemoryInitImmediate {
uint32_t data_segment_index = 0;
MemoryIndexImmediate<validate> memory;
unsigned length = 0;
inline MemoryInitImmediate(Decoder* decoder, const byte* pc) {
uint32_t len = 0;
data_segment_index =
decoder->read_u32v<validate>(pc, &len, "data segment index");
memory = MemoryIndexImmediate<validate>(decoder, pc + len);
length = len + memory.length;
}
};
template <Decoder::ValidateFlag validate>
struct DataDropImmediate {
uint32_t index;
unsigned length;
inline DataDropImmediate(Decoder* decoder, const byte* pc) {
index = decoder->read_u32v<validate>(pc, &length, "data segment index");
}
};
template <Decoder::ValidateFlag validate>
struct MemoryCopyImmediate {
MemoryIndexImmediate<validate> memory_src;
MemoryIndexImmediate<validate> memory_dst;
unsigned length = 0;
inline MemoryCopyImmediate(Decoder* decoder, const byte* pc) {
memory_src = MemoryIndexImmediate<validate>(decoder, pc);
memory_dst =
MemoryIndexImmediate<validate>(decoder, pc + memory_src.length);
length = memory_src.length + memory_dst.length;
}
};
template <Decoder::ValidateFlag validate>
struct TableInitImmediate {
uint32_t elem_segment_index = 0;
TableIndexImmediate<validate> table;
unsigned length = 0;
inline TableInitImmediate(Decoder* decoder, const byte* pc) {
uint32_t len = 0;
elem_segment_index =
decoder->read_u32v<validate>(pc, &len, "elem segment index");
table = TableIndexImmediate<validate>(decoder, pc + len);
length = len + table.length;
}
};
template <Decoder::ValidateFlag validate>
struct ElemDropImmediate {
uint32_t index;
unsigned length;
inline ElemDropImmediate(Decoder* decoder, const byte* pc) {
index = decoder->read_u32v<validate>(pc, &length, "elem segment index");
}
};
template <Decoder::ValidateFlag validate>
struct TableCopyImmediate {
TableIndexImmediate<validate> table_dst;
TableIndexImmediate<validate> table_src;
unsigned length = 0;
inline TableCopyImmediate(Decoder* decoder, const byte* pc) {
table_dst = TableIndexImmediate<validate>(decoder, pc);
table_src = TableIndexImmediate<validate>(decoder, pc + table_dst.length);
length = table_src.length + table_dst.length;
}
};
template <Decoder::ValidateFlag validate>
struct HeapTypeImmediate {
uint32_t length = 1;
HeapType type = HeapType(HeapType::kBottom);
inline HeapTypeImmediate(const WasmFeatures& enabled, Decoder* decoder,
const byte* pc) {
type = value_type_reader::read_heap_type<validate>(decoder, pc, &length,
enabled);
}
};
template <Decoder::ValidateFlag validate>
struct PcForErrors {
PcForErrors(const byte* /* pc */) {}
const byte* pc() const { return nullptr; }
};
template <>
struct PcForErrors<Decoder::kFullValidation> {
const byte* pc_for_errors = nullptr;
PcForErrors(const byte* pc) : pc_for_errors(pc) {}
const byte* pc() const { return pc_for_errors; }
};
// An entry on the value stack.
template <Decoder::ValidateFlag validate>
struct ValueBase : public PcForErrors<validate> {
ValueType type = kWasmStmt;
ValueBase(const byte* pc, ValueType type)
: PcForErrors<validate>(pc), type(type) {}
};
template <typename Value>
struct Merge {
uint32_t arity = 0;
union { // Either multiple values or a single value.
Value* array;
Value first;
} vals = {nullptr}; // Initialize {array} with {nullptr}.
// Tracks whether this merge was ever reached. Uses precise reachability, like
// Reachability::kReachable.
bool reached;
explicit Merge(bool reached = false) : reached(reached) {}
Value& operator[](uint32_t i) {
DCHECK_GT(arity, i);
return arity == 1 ? vals.first : vals.array[i];
}
};
enum ControlKind : uint8_t {
kControlIf,
kControlIfElse,
kControlBlock,
kControlLoop,
kControlLet,
kControlTry,
kControlTryCatch
};
enum Reachability : uint8_t {
// reachable code.
kReachable,
// reachable code in unreachable block (implies normal validation).
kSpecOnlyReachable,
// code unreachable in its own block (implies polymorphic validation).
kUnreachable
};
// An entry on the control stack (i.e. if, block, loop, or try).
template <typename Value, Decoder::ValidateFlag validate>
struct ControlBase : public PcForErrors<validate> {
ControlKind kind = kControlBlock;
uint32_t locals_count = 0;
uint32_t stack_depth = 0; // stack height at the beginning of the construct.
Reachability reachability = kReachable;
// Values merged into the start or end of this control construct.
Merge<Value> start_merge;
Merge<Value> end_merge;
MOVE_ONLY_NO_DEFAULT_CONSTRUCTOR(ControlBase);
ControlBase(ControlKind kind, uint32_t locals_count, uint32_t stack_depth,
const uint8_t* pc, Reachability reachability)
: PcForErrors<validate>(pc),
kind(kind),
locals_count(locals_count),
stack_depth(stack_depth),
reachability(reachability),
start_merge(reachability == kReachable) {
DCHECK(kind == kControlLet || locals_count == 0);
}
// Check whether the current block is reachable.
bool reachable() const { return reachability == kReachable; }
// Check whether the rest of the block is unreachable.
// Note that this is different from {!reachable()}, as there is also the
// "indirect unreachable state", for which both {reachable()} and
// {unreachable()} return false.
bool unreachable() const { return reachability == kUnreachable; }
// Return the reachability of new control structs started in this block.
Reachability innerReachability() const {
return reachability == kReachable ? kReachable : kSpecOnlyReachable;
}
bool is_if() const { return is_onearmed_if() || is_if_else(); }
bool is_onearmed_if() const { return kind == kControlIf; }
bool is_if_else() const { return kind == kControlIfElse; }
bool is_block() const { return kind == kControlBlock; }
bool is_let() const { return kind == kControlLet; }
bool is_loop() const { return kind == kControlLoop; }
bool is_incomplete_try() const { return kind == kControlTry; }
bool is_try_catch() const { return kind == kControlTryCatch; }
bool is_try() const { return is_incomplete_try() || is_try_catch(); }
inline Merge<Value>* br_merge() {
return is_loop() ? &this->start_merge : &this->end_merge;
}
};
// This is the list of callback functions that an interface for the
// WasmFullDecoder should implement.
// F(Name, args...)
#define INTERFACE_FUNCTIONS(F) \
/* General: */ \
F(StartFunction) \
F(StartFunctionBody, Control* block) \
F(FinishFunction) \
F(OnFirstError) \
F(NextInstruction, WasmOpcode) \
/* Control: */ \
F(Block, Control* block) \
F(Loop, Control* block) \
F(Try, Control* block) \
F(Catch, Control* block, Value* exception) \
F(If, const Value& cond, Control* if_block) \
F(FallThruTo, Control* c) \
F(PopControl, Control* block) \
F(EndControl, Control* block) \
/* Instructions: */ \
F(UnOp, WasmOpcode opcode, const Value& value, Value* result) \
F(BinOp, WasmOpcode opcode, const Value& lhs, const Value& rhs, \
Value* result) \
F(I32Const, Value* result, int32_t value) \
F(I64Const, Value* result, int64_t value) \
F(F32Const, Value* result, float value) \
F(F64Const, Value* result, double value) \
F(RefNull, ValueType type, Value* result) \
F(RefFunc, uint32_t function_index, Value* result) \
F(RefAsNonNull, const Value& arg, Value* result) \
F(Drop, const Value& value) \
F(DoReturn, Vector<Value> values) \
F(LocalGet, Value* result, const LocalIndexImmediate<validate>& imm) \
F(LocalSet, const Value& value, const LocalIndexImmediate<validate>& imm) \
F(LocalTee, const Value& value, Value* result, \
const LocalIndexImmediate<validate>& imm) \
F(AllocateLocals, Vector<Value> local_values) \
F(DeallocateLocals, uint32_t count) \
F(GlobalGet, Value* result, const GlobalIndexImmediate<validate>& imm) \
F(GlobalSet, const Value& value, const GlobalIndexImmediate<validate>& imm) \
F(TableGet, const Value& index, Value* result, \
const TableIndexImmediate<validate>& imm) \
F(TableSet, const Value& index, const Value& value, \
const TableIndexImmediate<validate>& imm) \
F(Unreachable) \
F(Select, const Value& cond, const Value& fval, const Value& tval, \
Value* result) \
F(Br, Control* target) \
F(BrIf, const Value& cond, uint32_t depth) \
F(BrTable, const BranchTableImmediate<validate>& imm, const Value& key) \
F(Else, Control* if_block) \
F(LoadMem, LoadType type, const MemoryAccessImmediate<validate>& imm, \
const Value& index, Value* result) \
F(LoadTransform, LoadType type, LoadTransformationKind transform, \
const MemoryAccessImmediate<validate>& imm, const Value& index, \
Value* result) \
F(LoadLane, LoadType type, const Value& value, const Value& index, \
const MemoryAccessImmediate<validate>& imm, const uint8_t laneidx, \
Value* result) \
F(StoreMem, StoreType type, const MemoryAccessImmediate<validate>& imm, \
const Value& index, const Value& value) \
F(StoreLane, StoreType type, const MemoryAccessImmediate<validate>& imm, \
const Value& index, const Value& value, const uint8_t laneidx) \
F(CurrentMemoryPages, Value* result) \
F(MemoryGrow, const Value& value, Value* result) \
F(CallDirect, const CallFunctionImmediate<validate>& imm, \
const Value args[], Value returns[]) \
F(CallIndirect, const Value& index, \
const CallIndirectImmediate<validate>& imm, const Value args[], \
Value returns[]) \
F(CallRef, const Value& func_ref, const FunctionSig* sig, \
uint32_t sig_index, const Value args[], const Value returns[]) \
F(ReturnCallRef, const Value& func_ref, const FunctionSig* sig, \
uint32_t sig_index, const Value args[]) \
F(ReturnCall, const CallFunctionImmediate<validate>& imm, \
const Value args[]) \
F(ReturnCallIndirect, const Value& index, \
const CallIndirectImmediate<validate>& imm, const Value args[]) \
F(BrOnNull, const Value& ref_object, uint32_t depth) \
F(SimdOp, WasmOpcode opcode, Vector<Value> args, Value* result) \
F(SimdLaneOp, WasmOpcode opcode, const SimdLaneImmediate<validate>& imm, \
const Vector<Value> inputs, Value* result) \
F(S128Const, const Simd128Immediate<validate>& imm, Value* result) \
F(Simd8x16ShuffleOp, const Simd128Immediate<validate>& imm, \
const Value& input0, const Value& input1, Value* result) \
F(Throw, const ExceptionIndexImmediate<validate>& imm, \
const Vector<Value>& args) \
F(Rethrow, const Value& exception) \
F(BrOnException, const Value& exception, \
const ExceptionIndexImmediate<validate>& imm, uint32_t depth, \
Vector<Value> values) \
F(AtomicOp, WasmOpcode opcode, Vector<Value> args, \
const MemoryAccessImmediate<validate>& imm, Value* result) \
F(AtomicFence) \
F(MemoryInit, const MemoryInitImmediate<validate>& imm, const Value& dst, \
const Value& src, const Value& size) \
F(DataDrop, const DataDropImmediate<validate>& imm) \
F(MemoryCopy, const MemoryCopyImmediate<validate>& imm, const Value& dst, \
const Value& src, const Value& size) \
F(MemoryFill, const MemoryIndexImmediate<validate>& imm, const Value& dst, \
const Value& value, const Value& size) \
F(TableInit, const TableInitImmediate<validate>& imm, Vector<Value> args) \
F(ElemDrop, const ElemDropImmediate<validate>& imm) \
F(TableCopy, const TableCopyImmediate<validate>& imm, Vector<Value> args) \
F(TableGrow, const TableIndexImmediate<validate>& imm, const Value& value, \
const Value& delta, Value* result) \
F(TableSize, const TableIndexImmediate<validate>& imm, Value* result) \
F(TableFill, const TableIndexImmediate<validate>& imm, const Value& start, \
const Value& value, const Value& count) \
F(StructNewWithRtt, const StructIndexImmediate<validate>& imm, \
const Value& rtt, const Value args[], Value* result) \
F(StructNewDefault, const StructIndexImmediate<validate>& imm, \
const Value& rtt, Value* result) \
F(StructGet, const Value& struct_object, \
const FieldIndexImmediate<validate>& field, bool is_signed, Value* result) \
F(StructSet, const Value& struct_object, \
const FieldIndexImmediate<validate>& field, const Value& field_value) \
F(ArrayNewWithRtt, const ArrayIndexImmediate<validate>& imm, \
const Value& length, const Value& initial_value, const Value& rtt, \
Value* result) \
F(ArrayNewDefault, const ArrayIndexImmediate<validate>& imm, \
const Value& length, const Value& rtt, Value* result) \
F(ArrayGet, const Value& array_obj, \
const ArrayIndexImmediate<validate>& imm, const Value& index, \
bool is_signed, Value* result) \
F(ArraySet, const Value& array_obj, \
const ArrayIndexImmediate<validate>& imm, const Value& index, \
const Value& value) \
F(ArrayLen, const Value& array_obj, Value* result) \
F(I31New, const Value& input, Value* result) \
F(I31GetS, const Value& input, Value* result) \
F(I31GetU, const Value& input, Value* result) \
F(RttCanon, const HeapTypeImmediate<validate>& imm, Value* result) \
F(RttSub, const HeapTypeImmediate<validate>& imm, const Value& parent, \
Value* result) \
F(RefTest, const Value& obj, const Value& rtt, Value* result) \
F(RefCast, const Value& obj, const Value& rtt, Value* result) \
F(BrOnCast, const Value& obj, const Value& rtt, Value* result_on_branch, \
uint32_t depth) \
F(PassThrough, const Value& from, Value* to)
// Generic Wasm bytecode decoder with utilities for decoding immediates,
// lengths, etc.
template <Decoder::ValidateFlag validate>
class WasmDecoder : public Decoder {
public:
WasmDecoder(Zone* zone, const WasmModule* module, const WasmFeatures& enabled,
WasmFeatures* detected, const FunctionSig* sig, const byte* start,
const byte* end, uint32_t buffer_offset = 0)
: Decoder(start, end, buffer_offset),
local_types_(zone),
module_(module),
enabled_(enabled),
detected_(detected),
sig_(sig) {}
Zone* zone() const { return local_types_.get_allocator().zone(); }
uint32_t num_locals() const {
DCHECK_EQ(num_locals_, local_types_.size());
return num_locals_;
}
ValueType local_type(uint32_t index) const { return local_types_[index]; }
void InitializeLocalsFromSig() {
DCHECK_NOT_NULL(sig_);
DCHECK_EQ(0, this->local_types_.size());
local_types_.assign(sig_->parameters().begin(), sig_->parameters().end());
num_locals_ = static_cast<uint32_t>(sig_->parameters().size());
}
// Decodes local definitions in the current decoder.
// Returns true iff locals are found.
// Writes the total length of decoded locals in 'total_length'.
// If insert_position is present, the decoded locals will be inserted into the
// 'local_types_' of this decoder. Otherwise, this function is used just to
// check validity and determine the encoding length of the locals in bytes.
// The decoder's pc is not advanced. If no locals are found (i.e., no
// compressed uint32 is found at pc), this will exit as 'false' and without an
// error.
bool DecodeLocals(const byte* pc, uint32_t* total_length,
const base::Optional<uint32_t> insert_position) {
uint32_t length;
*total_length = 0;
// The 'else' value is useless, we pass it for convenience.
auto insert_iterator = insert_position.has_value()
? local_types_.begin() + insert_position.value()
: local_types_.begin();
// Decode local declarations, if any.
uint32_t entries =
read_u32v<kFullValidation>(pc, &length, "local decls count");
if (!VALIDATE(ok())) {
DecodeError(pc + *total_length, "invalid local decls count");
return false;
}
*total_length += length;
TRACE("local decls count: %u\n", entries);
while (entries-- > 0) {
if (!VALIDATE(more())) {
DecodeError(end(),
"expected more local decls but reached end of input");
return false;
}
uint32_t count = read_u32v<kFullValidation>(pc + *total_length, &length,
"local count");
if (!VALIDATE(ok())) {
DecodeError(pc + *total_length, "invalid local count");
return false;
}
DCHECK_LE(local_types_.size(), kV8MaxWasmFunctionLocals);
if (!VALIDATE(count <= kV8MaxWasmFunctionLocals - local_types_.size())) {
DecodeError(pc + *total_length, "local count too large");
return false;
}
*total_length += length;
ValueType type = value_type_reader::read_value_type<kFullValidation>(
this, pc + *total_length, &length, enabled_);
if (!VALIDATE(type != kWasmBottom)) {
DecodeError(pc + *total_length, "invalid local type");
return false;
}
*total_length += length;
if (insert_position.has_value()) {
// Move the insertion iterator to the end of the newly inserted locals.
insert_iterator =
local_types_.insert(insert_iterator, count, type) + count;
num_locals_ += count;
}
}
DCHECK(ok());
return true;
}
// Shorthand that forwards to the {DecodeError} functions above, passing our
// {validate} flag.
template <typename... Args>
void DecodeError(Args... args) {
wasm::DecodeError<validate>(this, std::forward<Args>(args)...);
}
static BitVector* AnalyzeLoopAssignment(WasmDecoder* decoder, const byte* pc,
uint32_t locals_count, Zone* zone) {
if (pc >= decoder->end()) return nullptr;
if (*pc != kExprLoop) return nullptr;
// The number of locals_count is augmented by 2 so that 'locals_count - 2'
// can be used to track mem_size, and 'locals_count - 1' to track mem_start.
BitVector* assigned = zone->New<BitVector>(locals_count, zone);
int depth = 0;
// Iteratively process all AST nodes nested inside the loop.
while (pc < decoder->end() && VALIDATE(decoder->ok())) {
WasmOpcode opcode = static_cast<WasmOpcode>(*pc);
uint32_t length = 1;
switch (opcode) {
case kExprLoop:
case kExprIf:
case kExprBlock:
case kExprTry:
length = OpcodeLength(decoder, pc);
depth++;
break;
case kExprLocalSet: // fallthru
case kExprLocalTee: {
LocalIndexImmediate<validate> imm(decoder, pc + 1);
if (assigned->length() > 0 &&
imm.index < static_cast<uint32_t>(assigned->length())) {
// Unverified code might have an out-of-bounds index.
assigned->Add(imm.index);
}
length = 1 + imm.length;
break;
}
case kExprMemoryGrow:
case kExprCallFunction:
case kExprCallIndirect:
case kExprReturnCall:
case kExprReturnCallIndirect:
// Add instance cache nodes to the assigned set.
// TODO(titzer): make this more clear.
assigned->Add(locals_count - 1);
length = OpcodeLength(decoder, pc);
break;
case kExprEnd:
depth--;
break;
default:
length = OpcodeLength(decoder, pc);
break;
}
if (depth <= 0) break;
pc += length;
}
return VALIDATE(decoder->ok()) ? assigned : nullptr;
}
inline bool Validate(const byte* pc, LocalIndexImmediate<validate>& imm) {
if (!VALIDATE(imm.index < num_locals())) {
DecodeError(pc, "invalid local index: %u", imm.index);
return false;
}
return true;
}
inline bool Complete(ExceptionIndexImmediate<validate>& imm) {
if (!VALIDATE(imm.index < module_->exceptions.size())) return false;
imm.exception = &module_->exceptions[imm.index];
return true;
}
inline bool Validate(const byte* pc, ExceptionIndexImmediate<validate>& imm) {
if (!Complete(imm)) {
DecodeError(pc, "Invalid exception index: %u", imm.index);
return false;
}
return true;
}
inline bool Validate(const byte* pc, GlobalIndexImmediate<validate>& imm) {
if (!VALIDATE(imm.index < module_->globals.size())) {
DecodeError(pc, "invalid global index: %u", imm.index);
return false;
}
imm.global = &module_->globals[imm.index];
imm.type = imm.global->type;
return true;
}
inline bool Complete(StructIndexImmediate<validate>& imm) {
if (!VALIDATE(module_->has_struct(imm.index))) return false;
imm.struct_type = module_->struct_type(imm.index);
return true;
}
inline bool Validate(const byte* pc, StructIndexImmediate<validate>& imm) {
if (Complete(imm)) return true;
DecodeError(pc, "invalid struct index: %u", imm.index);
return false;
}
inline bool Validate(const byte* pc, FieldIndexImmediate<validate>& imm) {
if (!Validate(pc, imm.struct_index)) return false;
if (!VALIDATE(imm.index < imm.struct_index.struct_type->field_count())) {
DecodeError(pc + imm.struct_index.length, "invalid field index: %u",
imm.index);
return false;
}
return true;
}
inline bool Complete(ArrayIndexImmediate<validate>& imm) {
if (!VALIDATE(module_->has_array(imm.index))) return false;
imm.array_type = module_->array_type(imm.index);
return true;
}
inline bool Validate(const byte* pc, ArrayIndexImmediate<validate>& imm) {
if (!Complete(imm)) {
DecodeError(pc, "invalid array index: %u", imm.index);
return false;
}
return true;
}
inline bool CanReturnCall(const FunctionSig* target_sig) {
if (target_sig == nullptr) return false;
size_t num_returns = sig_->return_count();
if (num_returns != target_sig->return_count()) return false;
for (size_t i = 0; i < num_returns; ++i) {
if (sig_->GetReturn(i) != target_sig->GetReturn(i)) return false;
}
return true;
}
inline bool Complete(CallFunctionImmediate<validate>& imm) {
if (!VALIDATE(imm.index < module_->functions.size())) return false;
imm.sig = module_->functions[imm.index].sig;
if (imm.sig->return_count() > 1) {
this->detected_->Add(kFeature_mv);
}
return true;
}
inline bool Validate(const byte* pc, CallFunctionImmediate<validate>& imm) {
if (!Complete(imm)) {
DecodeError(pc, "invalid function index: %u", imm.index);
return false;
}
return true;
}
inline bool Complete(CallIndirectImmediate<validate>& imm) {
if (!VALIDATE(module_->has_signature(imm.sig_index))) return false;
imm.sig = module_->signature(imm.sig_index);
if (imm.sig->return_count() > 1) {
this->detected_->Add(kFeature_mv);
}
return true;
}
inline bool Validate(const byte* pc, CallIndirectImmediate<validate>& imm) {
if (!VALIDATE(imm.table_index < module_->tables.size())) {
DecodeError(pc, "call_indirect: table index immediate out of bounds");
return false;
}
ValueType table_type = module_->tables[imm.table_index].type;
if (!VALIDATE(IsSubtypeOf(table_type, kWasmFuncRef, module_))) {
DecodeError(
pc, "call_indirect: immediate table #%u is not of a function type",
imm.table_index);
return false;
}
if (!Complete(imm)) {
DecodeError(pc, "invalid signature index: #%u", imm.sig_index);
return false;
}
// Check that the dynamic signature for this call is a subtype of the static
// type of the table the function is defined in.
ValueType immediate_type = ValueType::Ref(imm.sig_index, kNonNullable);
if (!VALIDATE(IsSubtypeOf(immediate_type, table_type, module_))) {
DecodeError(pc,
"call_indirect: Immediate signature #%u is not a subtype of "
"immediate table #%u",
imm.sig_index, imm.table_index);
}
return true;
}
inline bool Validate(const byte* pc, BranchDepthImmediate<validate>& imm,
size_t control_depth) {
if (!VALIDATE(imm.depth < control_depth)) {
DecodeError(pc, "invalid branch depth: %u", imm.depth);
return false;
}
return true;
}
inline bool Validate(const byte* pc, BranchTableImmediate<validate>& imm,
size_t block_depth) {
if (!VALIDATE(imm.table_count <= kV8MaxWasmFunctionBrTableSize)) {
DecodeError(pc, "invalid table count (> max br_table size): %u",
imm.table_count);
return false;
}
return checkAvailable(imm.table_count);
}
inline bool Validate(const byte* pc,
BranchOnExceptionImmediate<validate>& imm,
size_t control_size) {
return Validate(pc, imm.depth, control_size) &&
Validate(pc + imm.depth.length, imm.index);
}
inline bool Validate(const byte* pc, WasmOpcode opcode,
SimdLaneImmediate<validate>& imm) {
uint8_t num_lanes = 0;
switch (opcode) {
case kExprF64x2ExtractLane:
case kExprF64x2ReplaceLane:
case kExprI64x2ExtractLane:
case kExprI64x2ReplaceLane:
num_lanes = 2;
break;
case kExprF32x4ExtractLane:
case kExprF32x4ReplaceLane:
case kExprI32x4ExtractLane:
case kExprI32x4ReplaceLane:
num_lanes = 4;
break;
case kExprI16x8ExtractLaneS:
case kExprI16x8ExtractLaneU:
case kExprI16x8ReplaceLane:
num_lanes = 8;
break;
case kExprI8x16ExtractLaneS:
case kExprI8x16ExtractLaneU:
case kExprI8x16ReplaceLane:
num_lanes = 16;
break;
default:
UNREACHABLE();
break;
}
if (!VALIDATE(imm.lane >= 0 && imm.lane < num_lanes)) {
DecodeError(pc, "invalid lane index");
return false;
} else {
return true;
}
}
inline bool Validate(const byte* pc, Simd128Immediate<validate>& imm) {
uint8_t max_lane = 0;
for (uint32_t i = 0; i < kSimd128Size; ++i) {
max_lane = std::max(max_lane, imm.value[i]);
}
// Shuffle indices must be in [0..31] for a 16 lane shuffle.
if (!VALIDATE(max_lane < 2 * kSimd128Size)) {
DecodeError(pc, "invalid shuffle mask");
return false;
}
return true;
}
inline bool Complete(BlockTypeImmediate<validate>& imm) {
if (imm.type != kWasmBottom) return true;
if (!VALIDATE(module_->has_signature(imm.sig_index))) return false;
imm.sig = module_->signature(imm.sig_index);
if (imm.sig->return_count() > 1) {
this->detected_->Add(kFeature_mv);
}
return true;
}
inline bool Validate(const byte* pc, BlockTypeImmediate<validate>& imm) {
if (!Complete(imm)) {
DecodeError(pc, "block type index %u out of bounds (%zu types)",
imm.sig_index, module_->types.size());
return false;
}
return true;
}
inline bool Validate(const byte* pc, FunctionIndexImmediate<validate>& imm) {
if (!VALIDATE(imm.index < module_->functions.size())) {
DecodeError(pc, "invalid function index: %u", imm.index);
return false;
}
if (!VALIDATE(module_->functions[imm.index].declared)) {
DecodeError(pc, "undeclared reference to function #%u", imm.index);
return false;
}
return true;
}
inline bool Validate(const byte* pc, MemoryIndexImmediate<validate>& imm) {
if (!VALIDATE(module_->has_memory)) {
DecodeError(pc, "memory instruction with no memory");
return false;
}
return true;
}
inline bool Validate(const byte* pc, MemoryInitImmediate<validate>& imm) {
if (!VALIDATE(imm.data_segment_index <
module_->num_declared_data_segments)) {
DecodeError(pc, "invalid data segment index: %u", imm.data_segment_index);
return false;
}
if (!Validate(pc + imm.length - imm.memory.length, imm.memory))
return false;
return true;
}
inline bool Validate(const byte* pc, DataDropImmediate<validate>& imm) {
if (!VALIDATE(imm.index < module_->num_declared_data_segments)) {
DecodeError(pc, "invalid data segment index: %u", imm.index);
return false;
}
return true;
}
inline bool Validate(const byte* pc, MemoryCopyImmediate<validate>& imm) {
return Validate(pc, imm.memory_src) &&
Validate(pc + imm.memory_src.length, imm.memory_dst);
}
inline bool Validate(const byte* pc, TableIndexImmediate<validate>& imm) {
if (!VALIDATE(imm.index < module_->tables.size())) {
DecodeError(pc, "invalid table index: %u", imm.index);
return false;
}
return true;
}
inline bool Validate(const byte* pc, TableInitImmediate<validate>& imm) {
if (!VALIDATE(imm.elem_segment_index < module_->elem_segments.size())) {
DecodeError(pc, "invalid element segment index: %u",
imm.elem_segment_index);
return false;
}
if (!Validate(pc + imm.length - imm.table.length, imm.table)) {
return false;
}
ValueType elem_type = module_->elem_segments[imm.elem_segment_index].type;
if (!VALIDATE(IsSubtypeOf(elem_type, module_->tables[imm.table.index].type,
module_))) {
DecodeError(pc, "table %u is not a super-type of %s", imm.table.index,
elem_type.name().c_str());
return false;
}
return true;
}
inline bool Validate(const byte* pc, ElemDropImmediate<validate>& imm) {
if (!VALIDATE(imm.index < module_->elem_segments.size())) {
DecodeError(pc, "invalid element segment index: %u", imm.index);
return false;
}
return true;
}
inline bool Validate(const byte* pc, TableCopyImmediate<validate>& imm) {
if (!Validate(pc, imm.table_src)) return false;
if (!Validate(pc + imm.table_src.length, imm.table_dst)) return false;
ValueType src_type = module_->tables[imm.table_src.index].type;
if (!VALIDATE(IsSubtypeOf(
src_type, module_->tables[imm.table_dst.index].type, module_))) {
DecodeError(pc, "table %u is not a super-type of %s", imm.table_dst.index,
src_type.name().c_str());
return false;
}
return true;
}
inline bool Validate(const byte* pc, HeapTypeImmediate<validate>& imm) {
if (!VALIDATE(!imm.type.is_bottom())) {
DecodeError(pc, "invalid heap type");
return false;
}
if (!VALIDATE(imm.type.is_generic() ||
module_->has_type(imm.type.ref_index()))) {
DecodeError(pc, "Type index %u is out of bounds", imm.type.ref_index());
return false;
}
return true;
}
static uint32_t OpcodeLength(WasmDecoder* decoder, const byte* pc) {
WasmOpcode opcode = static_cast<WasmOpcode>(*pc);
switch (opcode) {
#define DECLARE_OPCODE_CASE(name, opcode, sig) case kExpr##name:
FOREACH_LOAD_MEM_OPCODE(DECLARE_OPCODE_CASE)
FOREACH_STORE_MEM_OPCODE(DECLARE_OPCODE_CASE)
#undef DECLARE_OPCODE_CASE
{
MemoryAccessImmediate<validate> imm(decoder, pc + 1, UINT32_MAX);
return 1 + imm.length;
}
case kExprBr:
case kExprBrIf: {
BranchDepthImmediate<validate> imm(decoder, pc + 1);
return 1 + imm.length;
}
case kExprGlobalGet:
case kExprGlobalSet: {
GlobalIndexImmediate<validate> imm(decoder, pc + 1);
return 1 + imm.length;
}
case kExprTableGet:
case kExprTableSet: {
TableIndexImmediate<validate> imm(decoder, pc + 1);
return 1 + imm.length;
}
case kExprCallFunction:
case kExprReturnCall: {
CallFunctionImmediate<validate> imm(decoder, pc + 1);
return 1 + imm.length;
}
case kExprCallIndirect:
case kExprReturnCallIndirect: {
CallIndirectImmediate<validate> imm(WasmFeatures::All(), decoder,
pc + 1);
return 1 + imm.length;
}
case kExprTry:
case kExprIf: // fall through
case kExprLoop:
case kExprBlock: {
BlockTypeImmediate<validate> imm(WasmFeatures::All(), decoder, pc + 1);
return 1 + imm.length;
}
case kExprLet: {
BlockTypeImmediate<validate> imm(WasmFeatures::All(), decoder, pc + 1);
uint32_t locals_length;
bool locals_result =
decoder->DecodeLocals(decoder->pc() + 1 + imm.length,
&locals_length, base::Optional<uint32_t>());
return 1 + imm.length + (locals_result ? locals_length : 0);
}
case kExprThrow: {
ExceptionIndexImmediate<validate> imm(decoder, pc + 1);
return 1 + imm.length;
}
case kExprBrOnExn: {
BranchOnExceptionImmediate<validate> imm(decoder, pc + 1);
return 1 + imm.length;
}
case kExprBrOnNull: {
BranchDepthImmediate<validate> imm(decoder, pc + 1);
return 1 + imm.length;
}
case kExprLocalGet:
case kExprLocalSet:
case kExprLocalTee: {
LocalIndexImmediate<validate> imm(decoder, pc + 1);
return 1 + imm.length;
}
case kExprSelectWithType: {
SelectTypeImmediate<validate> imm(WasmFeatures::All(), decoder, pc + 1);
return 1 + imm.length;
}
case kExprBrTable: {
BranchTableImmediate<validate> imm(decoder, pc + 1);
BranchTableIterator<validate> iterator(decoder, imm);
return 1 + iterator.length();
}
case kExprI32Const: {
ImmI32Immediate<validate> imm(decoder, pc + 1);
return 1 + imm.length;
}
case kExprI64Const: {
ImmI64Immediate<validate> imm(decoder, pc + 1);
return 1 + imm.length;
}
case kExprRefNull: {
HeapTypeImmediate<validate> imm(WasmFeatures::All(), decoder, pc + 1);
return 1 + imm.length;
}
case kExprRefIsNull: {
return 1;
}
case kExprRefFunc: {
FunctionIndexImmediate<validate> imm(decoder, pc + 1);
return 1 + imm.length;
}
case kExprMemoryGrow:
case kExprMemorySize: {
MemoryIndexImmediate<validate> imm(decoder, pc + 1);
return 1 + imm.length;
}
case kExprF32Const:
return 5;
case kExprF64Const:
return 9;
case kNumericPrefix: {
uint32_t length = 0;
opcode = decoder->read_prefixed_opcode<validate>(pc, &length);
switch (opcode) {
case kExprI32SConvertSatF32:
case kExprI32UConvertSatF32:
case kExprI32SConvertSatF64:
case kExprI32UConvertSatF64:
case kExprI64SConvertSatF32:
case kExprI64UConvertSatF32:
case kExprI64SConvertSatF64:
case kExprI64UConvertSatF64:
return length;
case kExprMemoryInit: {
MemoryInitImmediate<validate> imm(decoder, pc + length);
return length + imm.length;
}
case kExprDataDrop: {
DataDropImmediate<validate> imm(decoder, pc + length);
return length + imm.length;
}
case kExprMemoryCopy: {
MemoryCopyImmediate<validate> imm(decoder, pc + length);
return length + imm.length;
}
case kExprMemoryFill: {
MemoryIndexImmediate<validate> imm(decoder, pc + length);
return length + imm.length;
}
case kExprTableInit: {
TableInitImmediate<validate> imm(decoder, pc + length);
return length + imm.length;
}
case kExprElemDrop: {
ElemDropImmediate<validate> imm(decoder, pc + length);
return length + imm.length;
}
case kExprTableCopy: {
TableCopyImmediate<validate> imm(decoder, pc + length);
return length + imm.length;
}
case kExprTableGrow:
case kExprTableSize:
case kExprTableFill: {
TableIndexImmediate<validate> imm(decoder, pc + length);
return length + imm.length;
}
default:
decoder->DecodeError(pc, "invalid numeric opcode");
return length;
}
}
case kSimdPrefix: {
uint32_t length = 0;
opcode = decoder->read_prefixed_opcode<validate>(pc, &length);
switch (opcode) {
#define DECLARE_OPCODE_CASE(name, opcode, sig) case kExpr##name:
FOREACH_SIMD_0_OPERAND_OPCODE(DECLARE_OPCODE_CASE)
#undef DECLARE_OPCODE_CASE
return length;
#define DECLARE_OPCODE_CASE(name, opcode, sig) case kExpr##name:
FOREACH_SIMD_1_OPERAND_OPCODE(DECLARE_OPCODE_CASE)
#undef DECLARE_OPCODE_CASE
return length + 1;
#define DECLARE_OPCODE_CASE(name, opcode, sig) case kExpr##name:
FOREACH_SIMD_MEM_OPCODE(DECLARE_OPCODE_CASE)
#undef DECLARE_OPCODE_CASE
{
MemoryAccessImmediate<validate> imm(decoder, pc + length,
UINT32_MAX);
return length + imm.length;
}
case kExprS128Load8Lane:
case kExprS128Load16Lane:
case kExprS128Load32Lane:
case kExprS128Load64Lane:
case kExprS128Store8Lane:
case kExprS128Store16Lane:
case kExprS128Store32Lane:
case kExprS128Store64Lane: {
MemoryAccessImmediate<validate> imm(decoder, pc + length,
UINT32_MAX);
// 1 more byte for lane index immediate.
return length + imm.length + 1;
}
// Shuffles require a byte per lane, or 16 immediate bytes.
case kExprS128Const:
case kExprI8x16Shuffle:
return length + kSimd128Size;
default:
decoder->DecodeError(pc, "invalid SIMD opcode");
return length;
}
}
case kAtomicPrefix: {
uint32_t length = 0;
opcode = decoder->read_prefixed_opcode<validate>(pc, &length,
"atomic_index");
switch (opcode) {
#define DECLARE_OPCODE_CASE(name, opcode, sig) case kExpr##name:
FOREACH_ATOMIC_OPCODE(DECLARE_OPCODE_CASE)
#undef DECLARE_OPCODE_CASE
{
MemoryAccessImmediate<validate> imm(decoder, pc + length,
UINT32_MAX);
return length + imm.length;
}
#define DECLARE_OPCODE_CASE(name, opcode, sig) case kExpr##name:
FOREACH_ATOMIC_0_OPERAND_OPCODE(DECLARE_OPCODE_CASE)
#undef DECLARE_OPCODE_CASE
{
return length + 1;
}
default:
decoder->DecodeError(pc, "invalid Atomics opcode");
return length;
}
}
case kGCPrefix: {
uint32_t length = 0;
opcode =
decoder->read_prefixed_opcode<validate>(pc, &length, "gc_index");
switch (opcode) {
case kExprStructNewWithRtt:
case kExprStructNewDefault: {
StructIndexImmediate<validate> imm(decoder, pc + length);
return length + imm.length;
}
case kExprStructGet:
case kExprStructGetS:
case kExprStructGetU:
case kExprStructSet: {
FieldIndexImmediate<validate> imm(decoder, pc + length);
return length + imm.length;
}
case kExprArrayNewWithRtt:
case kExprArrayNewDefault:
case kExprArrayGet:
case kExprArrayGetS:
case kExprArrayGetU:
case kExprArraySet:
case kExprArrayLen: {
ArrayIndexImmediate<validate> imm(decoder, pc + length);
return length + imm.length;
}
case kExprBrOnCast: {
BranchDepthImmediate<validate> imm(decoder, pc + length);
return length + imm.length;
}
case kExprRttCanon:
case kExprRttSub: {
// TODO(7748): Account for rtt.sub's additional immediates if
// they stick.
HeapTypeImmediate<validate> imm(WasmFeatures::All(), decoder,
pc + length);
return length + imm.length;
}
case kExprI31New:
case kExprI31GetS:
case kExprI31GetU:
return length;
case kExprRefTest:
case kExprRefCast: {
HeapTypeImmediate<validate> ht1(WasmFeatures::All(), decoder,
pc + length);
HeapTypeImmediate<validate> ht2(WasmFeatures::All(), decoder,
pc + length + ht1.length);
return length + ht1.length + ht2.length;
}
default:
// This is unreachable except for malformed modules.
decoder->DecodeError(pc, "invalid gc opcode");
return length;
}
}
default:
return 1;
}
}
// TODO(clemensb): This is only used by the interpreter; move there.
V8_EXPORT_PRIVATE std::pair<uint32_t, uint32_t> StackEffect(const byte* pc) {
WasmOpcode opcode = static_cast<WasmOpcode>(*pc);
// Handle "simple" opcodes with a fixed signature first.
const FunctionSig* sig = WasmOpcodes::Signature(opcode);
if (!sig) sig = WasmOpcodes::AsmjsSignature(opcode);
if (sig) return {sig->parameter_count(), sig->return_count()};
#define DECLARE_OPCODE_CASE(name, opcode, sig) case kExpr##name:
// clang-format off
switch (opcode) {
case kExprSelect:
case kExprSelectWithType:
return {3, 1};
case kExprTableSet:
FOREACH_STORE_MEM_OPCODE(DECLARE_OPCODE_CASE)
return {2, 0};
FOREACH_LOAD_MEM_OPCODE(DECLARE_OPCODE_CASE)
case kExprTableGet:
case kExprLocalTee:
case kExprMemoryGrow:
case kExprRefAsNonNull:
case kExprBrOnNull:
case kExprRefIsNull:
return {1, 1};
case kExprLocalSet:
case kExprGlobalSet:
case kExprDrop:
case kExprBrIf:
case kExprBrTable:
case kExprIf:
case kExprRethrow:
return {1, 0};
case kExprLocalGet:
case kExprGlobalGet:
case kExprI32Const:
case kExprI64Const:
case kExprF32Const:
case kExprF64Const:
case kExprRefNull:
case kExprRefFunc:
case kExprMemorySize:
return {0, 1};
case kExprCallFunction: {
CallFunctionImmediate<validate> imm(this, pc + 1);
CHECK(Complete(imm));
return {imm.sig->parameter_count(), imm.sig->return_count()};
}
case kExprCallIndirect: {
CallIndirectImmediate<validate> imm(this->enabled_, this, pc + 1);
CHECK(Complete(imm));
// Indirect calls pop an additional argument for the table index.
return {imm.sig->parameter_count() + 1,
imm.sig->return_count()};
}
case kExprThrow: {
ExceptionIndexImmediate<validate> imm(this, pc + 1);
CHECK(Complete(imm));
DCHECK_EQ(0, imm.exception->sig->return_count());
return {imm.exception->sig->parameter_count(), 0};
}
case kExprBr:
case kExprBlock:
case kExprLoop:
case kExprEnd:
case kExprElse:
case kExprTry:
case kExprCatch:
case kExprBrOnExn:
case kExprNop:
case kExprReturn:
case kExprReturnCall:
case kExprReturnCallIndirect:
case kExprUnreachable:
return {0, 0};
case kExprLet:
// TODO(7748): Implement
return {0, 0};
case kNumericPrefix:
case kAtomicPrefix:
case kSimdPrefix: {
opcode = this->read_prefixed_opcode<validate>(pc);
switch (opcode) {
FOREACH_SIMD_1_OPERAND_1_PARAM_OPCODE(DECLARE_OPCODE_CASE)
return {1, 1};
FOREACH_SIMD_1_OPERAND_2_PARAM_OPCODE(DECLARE_OPCODE_CASE)
FOREACH_SIMD_MASK_OPERAND_OPCODE(DECLARE_OPCODE_CASE)
return {2, 1};
FOREACH_SIMD_CONST_OPCODE(DECLARE_OPCODE_CASE)
return {0, 1};
default: {
sig = WasmOpcodes::Signature(opcode);
if (sig) {
return {sig->parameter_count(), sig->return_count()};
} else {
UNREACHABLE();
}
}
}
}
case kGCPrefix: {
opcode = this->read_prefixed_opcode<validate>(pc);
switch (opcode) {
case kExprStructNewDefault:
case kExprStructGet:
case kExprStructGetS:
case kExprStructGetU:
case kExprI31New:
case kExprI31GetS:
case kExprI31GetU:
case kExprArrayLen:
case kExprRttSub:
return {1, 1};
case kExprStructSet:
return {2, 0};
case kExprArrayNewDefault:
case kExprArrayGet:
case kExprArrayGetS:
case kExprArrayGetU:
case kExprRefTest:
case kExprRefCast:
case kExprBrOnCast:
return {2, 1};
case kExprArraySet:
return {3, 0};
case kExprRttCanon:
return {0, 1};
case kExprArrayNewWithRtt:
return {3, 1};
case kExprStructNewWithRtt: {
StructIndexImmediate<validate> imm(this, this->pc_ + 2);
this->Complete(imm);
return {imm.struct_type->field_count() + 1, 1};
}
default:
UNREACHABLE();
}
}
default:
FATAL("unimplemented opcode: %x (%s)", opcode,
WasmOpcodes::OpcodeName(opcode));
return {0, 0};
}
#undef DECLARE_OPCODE_CASE
// clang-format on
}
// The {Zone} is implicitly stored in the {ZoneAllocator} which is part of
// this {ZoneVector}. Hence save one field and just get it from there if
// needed (see {zone()} accessor below).
ZoneVector<ValueType> local_types_;
// Cached value, for speed (yes, it's measurably faster to load this value
// than to load the start and end pointer from a vector, subtract and shift).
uint32_t num_locals_ = 0;
const WasmModule* module_;
const WasmFeatures enabled_;
WasmFeatures* detected_;
const FunctionSig* sig_;
};
#define CALL_INTERFACE(name, ...) interface_.name(this, ##__VA_ARGS__)
#define CALL_INTERFACE_IF_REACHABLE(name, ...) \
do { \
DCHECK(!control_.empty()); \
DCHECK_EQ(current_code_reachable_, \
this->ok() && control_.back().reachable()); \
if (current_code_reachable_) { \
interface_.name(this, ##__VA_ARGS__); \
} \
} while (false)
#define CALL_INTERFACE_IF_PARENT_REACHABLE(name, ...) \
do { \
DCHECK(!control_.empty()); \
if (VALIDATE(this->ok()) && \
(control_.size() == 1 || control_at(1)->reachable())) { \
interface_.name(this, ##__VA_ARGS__); \
} \
} while (false)
template <Decoder::ValidateFlag validate, typename Interface>
class WasmFullDecoder : public WasmDecoder<validate> {
using Value = typename Interface::Value;
using Control = typename Interface::Control;
using ArgVector = base::SmallVector<Value, 8>;
// All Value types should be trivially copyable for performance. We push, pop,
// and store them in local variables.
ASSERT_TRIVIALLY_COPYABLE(Value);
public:
template <typename... InterfaceArgs>
WasmFullDecoder(Zone* zone, const WasmModule* module,
const WasmFeatures& enabled, WasmFeatures* detected,
const FunctionBody& body, InterfaceArgs&&... interface_args)
: WasmDecoder<validate>(zone, module, enabled, detected, body.sig,
body.start, body.end, body.offset),
interface_(std::forward<InterfaceArgs>(interface_args)...),
control_(zone) {}
Interface& interface() { return interface_; }
bool Decode() {
DCHECK_EQ(stack_end_, stack_);
DCHECK(control_.empty());
DCHECK_LE(this->pc_, this->end_);
DCHECK_EQ(this->num_locals(), 0);
this->InitializeLocalsFromSig();
uint32_t params_count = static_cast<uint32_t>(this->num_locals());
uint32_t locals_length;
this->DecodeLocals(this->pc(), &locals_length, params_count);
this->consume_bytes(locals_length);
for (uint32_t index = params_count; index < this->num_locals(); index++) {
if (!VALIDATE(this->local_type(index).is_defaultable())) {
this->DecodeError(
"Cannot define function-level local of non-defaultable type %s",
this->local_type(index).name().c_str());
return this->TraceFailed();
}
}
CALL_INTERFACE(StartFunction);
DecodeFunctionBody();
if (this->failed()) return TraceFailed();
if (!VALIDATE(control_.empty())) {
if (control_.size() > 1) {
this->DecodeError(control_.back().pc(),
"unterminated control structure");
} else {
this->DecodeError("function body must end with \"end\" opcode");
}
return TraceFailed();
}
CALL_INTERFACE(FinishFunction);
if (this->failed()) return TraceFailed();
TRACE("wasm-decode ok\n\n");
return true;
}
bool TraceFailed() {
if (this->error_.offset()) {
TRACE("wasm-error module+%-6d func+%d: %s\n\n", this->error_.offset(),
this->GetBufferRelativeOffset(this->error_.offset()),
this->error_.message().c_str());
} else {
TRACE("wasm-error: %s\n\n", this->error_.message().c_str());
}
return false;
}
const char* SafeOpcodeNameAt(const byte* pc) {
if (!pc) return "<null>";
if (pc >= this->end_) return "<end>";
WasmOpcode opcode = static_cast<WasmOpcode>(*pc);
if (!WasmOpcodes::IsPrefixOpcode(opcode)) {
return WasmOpcodes::OpcodeName(static_cast<WasmOpcode>(opcode));
}
opcode = this->template read_prefixed_opcode<Decoder::kFullValidation>(pc);
return WasmOpcodes::OpcodeName(opcode);
}
inline WasmCodePosition position() {
int offset = static_cast<int>(this->pc_ - this->start_);
DCHECK_EQ(this->pc_ - this->start_, offset); // overflows cannot happen
return offset;
}
inline uint32_t control_depth() const {
return static_cast<uint32_t>(control_.size());
}
inline Control* control_at(uint32_t depth) {
DCHECK_GT(control_.size(), depth);
return &control_.back() - depth;
}
inline uint32_t stack_size() const {
DCHECK_GE(stack_end_, stack_);
DCHECK_GE(kMaxUInt32, stack_end_ - stack_);
return static_cast<uint32_t>(stack_end_ - stack_);
}
inline Value* stack_value(uint32_t depth) {
DCHECK_LT(0, depth);
DCHECK_GE(stack_size(), depth);
return stack_end_ - depth;
}
void SetSucceedingCodeDynamicallyUnreachable() {
Control* current = &control_.back();
if (current->reachable()) {
current->reachability = kSpecOnlyReachable;
current_code_reachable_ = false;
}
}
private:
Interface interface_;
// The value stack, stored as individual pointers for maximum performance.
Value* stack_ = nullptr;
Value* stack_end_ = nullptr;
Value* stack_capacity_end_ = nullptr;
ASSERT_TRIVIALLY_COPYABLE(Value);
// stack of blocks, loops, and ifs.
ZoneVector<Control> control_;
// Controls whether code should be generated for the current block (basically
// a cache for {ok() && control_.back().reachable()}).
bool current_code_reachable_ = true;
static Value UnreachableValue(const uint8_t* pc) {
return Value{pc, kWasmBottom};
}
bool CheckHasMemory() {
if (!VALIDATE(this->module_->has_memory)) {
this->DecodeError(this->pc_ - 1, "memory instruction with no memory");
return false;
}
return true;
}
bool CheckSimdPostMvp(WasmOpcode opcode) {
if (!FLAG_wasm_simd_post_mvp && WasmOpcodes::IsSimdPostMvpOpcode(opcode)) {
this->DecodeError(
"simd opcode not available, enable with --wasm-simd-post-mvp");
return false;
}
return true;
}
#ifdef DEBUG
class TraceLine {
public:
explicit TraceLine(WasmFullDecoder* decoder) : decoder_(decoder) {
WasmOpcode opcode = static_cast<WasmOpcode>(*decoder->pc());
if (!WasmOpcodes::IsPrefixOpcode(opcode)) AppendOpcode(opcode);
}
void AppendOpcode(WasmOpcode opcode) {
DCHECK(!WasmOpcodes::IsPrefixOpcode(opcode));
Append(TRACE_INST_FORMAT, decoder_->startrel(decoder_->pc_),
WasmOpcodes::OpcodeName(opcode));
}
~TraceLine() {
if (!FLAG_trace_wasm_decoder) return;
AppendStackState();
PrintF("%.*s\n", len_, buffer_);
}
// Appends a formatted string.
PRINTF_FORMAT(2, 3)
void Append(const char* format, ...) {
if (!FLAG_trace_wasm_decoder) return;
va_list va_args;
va_start(va_args, format);
size_t remaining_len = kMaxLen - len_;
Vector<char> remaining_msg_space(buffer_ + len_, remaining_len);
int len = VSNPrintF(remaining_msg_space, format, va_args);
va_end(va_args);
len_ += len < 0 ? remaining_len : len;
}
private:
void AppendStackState() {
DCHECK(FLAG_trace_wasm_decoder);
Append(" ");
for (Control& c : decoder_->control_) {
switch (c.kind) {
case kControlIf:
Append("I");
break;
case kControlBlock:
Append("B");
break;
case kControlLoop:
Append("L");
break;
case kControlTry:
Append("T");
break;
case kControlIfElse:
case kControlTryCatch:
case kControlLet: // TODO(7748): Implement
break;
}
if (c.start_merge.arity) Append("%u-", c.start_merge.arity);
Append("%u", c.end_merge.arity);
if (!c.reachable()) Append("%c", c.unreachable() ? '*' : '#');
}
Append(" | ");
for (size_t i = 0; i < decoder_->stack_size(); ++i) {
Value& val = decoder_->stack_[i];
Append(" %c", val.type.short_name());
}
}
static constexpr int kMaxLen = 512;
char buffer_[kMaxLen];
int len_ = 0;
WasmFullDecoder* const decoder_;
};
#else
class TraceLine {
public:
explicit TraceLine(WasmFullDecoder*) {}
void AppendOpcode(WasmOpcode) {}
PRINTF_FORMAT(2, 3)
void Append(const char* format, ...) {}
};
#endif
#define DECODE(name) \
static int Decode##name(WasmFullDecoder* decoder, WasmOpcode opcode) { \
TraceLine trace_msg(decoder); \
return decoder->Decode##name##Impl(&trace_msg, opcode); \
} \
V8_INLINE int Decode##name##Impl(TraceLine* trace_msg, WasmOpcode opcode)
DECODE(Nop) { return 1; }
#define BUILD_SIMPLE_OPCODE(op, _, sig) \
DECODE(op) { return BuildSimpleOperator_##sig(kExpr##op); }
FOREACH_SIMPLE_OPCODE(BUILD_SIMPLE_OPCODE)
#undef BUILD_SIMPLE_OPCODE
DECODE(Block) {
BlockTypeImmediate<validate> imm(this->enabled_, this, this->pc_ + 1);
if (!this->Validate(this->pc_ + 1, imm)) return 0;
ArgVector args = PopArgs(imm.sig);
Control* block = PushControl(kControlBlock);
SetBlockType(block, imm, args.begin());
CALL_INTERFACE_IF_REACHABLE(Block, block);
PushMergeValues(block, &block->start_merge);
return 1 + imm.length;
}
DECODE(Rethrow) {
CHECK_PROTOTYPE_OPCODE(eh);
Value exception = Pop(0, kWasmExnRef);
CALL_INTERFACE_IF_REACHABLE(Rethrow, exception);
EndControl();
return 1;
}
DECODE(Throw) {
CHECK_PROTOTYPE_OPCODE(eh);
ExceptionIndexImmediate<validate> imm(this, this->pc_ + 1);
if (!this->Validate(this->pc_ + 1, imm)) return 0;
ArgVector args = PopArgs(imm.exception->ToFunctionSig());
CALL_INTERFACE_IF_REACHABLE(Throw, imm, VectorOf(args));
EndControl();
return 1 + imm.length;
}
DECODE(Try) {
CHECK_PROTOTYPE_OPCODE(eh);
BlockTypeImmediate<validate> imm(this->enabled_, this, this->pc_ + 1);
if (!this->Validate(this->pc_ + 1, imm)) return 0;
ArgVector args = PopArgs(imm.sig);
Control* try_block = PushControl(kControlTry);
SetBlockType(try_block, imm, args.begin());
CALL_INTERFACE_IF_REACHABLE(Try, try_block);
PushMergeValues(try_block, &try_block->start_merge);
return 1 + imm.length;
}
DECODE(Catch) {
CHECK_PROTOTYPE_OPCODE(eh);
if (!VALIDATE(!control_.empty())) {
this->DecodeError("catch does not match any try");
return 0;
}
Control* c = &control_.back();
if (!VALIDATE(c->is_try())) {
this->DecodeError("catch does not match any try");
return 0;
}
if (!VALIDATE(c->is_incomplete_try())) {
this->DecodeError("catch already present for try");
return 0;
}
c->kind = kControlTryCatch;
FallThruTo(c);
DCHECK_LE(stack_ + c->stack_depth, stack_end_);
stack_end_ = stack_ + c->stack_depth;
c->reachability = control_at(1)->innerReachability();
current_code_reachable_ = this->ok() && c->reachable();
Value* exception = Push(kWasmExnRef);
CALL_INTERFACE_IF_PARENT_REACHABLE(Catch, c, exception);
return 1;
}
DECODE(BrOnExn) {
CHECK_PROTOTYPE_OPCODE(eh);
BranchOnExceptionImmediate<validate> imm(this, this->pc_ + 1);
if (!this->Validate(this->pc() + 1, imm, control_.size())) return 0;
Control* c = control_at(imm.depth.depth);
Value exception = Pop(0, kWasmExnRef);
const WasmExceptionSig* sig = imm.index.exception->sig;
int value_count = static_cast<int>(sig->parameter_count());
// TODO(wasm): This operand stack mutation is an ugly hack to make
// both type checking here as well as environment merging in the
// graph builder interface work out of the box. We should introduce
// special handling for both and do minimal/no stack mutation here.
EnsureStackSpace(value_count);
for (int i = 0; i < value_count; ++i) Push(sig->GetParam(i));
Vector<Value> values(stack_ + c->stack_depth, value_count);
TypeCheckBranchResult check_result = TypeCheckBranch(c, true);
if (this->failed()) return 0;
if (V8_LIKELY(check_result == kReachableBranch)) {
CALL_INTERFACE(BrOnException, exception, imm.index, imm.depth.depth,
values);
c->br_merge()->reached = true;
} else if (check_result == kInvalidStack) {
return 0;
}
for (int i = value_count - 1; i >= 0; i--) Pop(i);
Value* pexception = Push(kWasmExnRef);
*pexception = exception;
return 1 + imm.length;
}
DECODE(BrOnNull) {
CHECK_PROTOTYPE_OPCODE(typed_funcref);
BranchDepthImmediate<validate> imm(this, this->pc_ + 1);
if (!this->Validate(this->pc_ + 1, imm, control_.size())) return 0;
Value ref_object = Pop(0);
if (this->failed()) return 0;
Control* c = control_at(imm.depth);
TypeCheckBranchResult check_result = TypeCheckBranch(c, true);
if (V8_LIKELY(check_result == kReachableBranch)) {
switch (ref_object.type.kind()) {
case ValueType::kBottom:
// We are in unreachable code, just forward the bottom value.
case ValueType::kRef: {
Value* result = Push(ref_object.type);
CALL_INTERFACE(PassThrough, ref_object, result);
break;
}
case ValueType::kOptRef: {
// We need to Push the result value after calling BrOnNull on
// the interface. Therefore we must sync the ref_object and
// result nodes afterwards (in PassThrough).
CALL_INTERFACE(BrOnNull, ref_object, imm.depth);
Value* result =
Push(ValueType::Ref(ref_object.type.heap_type(), kNonNullable));
CALL_INTERFACE(PassThrough, ref_object, result);
c->br_merge()->reached = true;
break;
}
default:
this->DecodeError("invalid argument type to br_on_null");
return 0;
}
} else if (check_result == kInvalidStack) {
return 0;
}
return 1 + imm.length;
}
DECODE(Let) {
CHECK_PROTOTYPE_OPCODE(typed_funcref);
BlockTypeImmediate<validate> imm(this->enabled_, this, this->pc_ + 1);
if (!this->Validate(this->pc_ + 1, imm)) return 0;
uint32_t old_local_count = this->num_locals();
// Temporarily add the let-defined values to the beginning of the function
// locals.
uint32_t locals_length;
if (!this->DecodeLocals(this->pc() + 1 + imm.length, &locals_length, 0)) {
return 0;
}
uint32_t num_added_locals = this->num_locals() - old_local_count;
ArgVector let_local_values =
PopArgs(static_cast<uint32_t>(imm.in_arity()),
VectorOf(this->local_types_.data(), num_added_locals));
ArgVector args = PopArgs(imm.sig);
Control* let_block = PushControl(kControlLet, num_added_locals);
SetBlockType(let_block, imm, args.begin());
CALL_INTERFACE_IF_REACHABLE(Block, let_block);
PushMergeValues(let_block, &let_block->start_merge);
CALL_INTERFACE_IF_REACHABLE(AllocateLocals, VectorOf(let_local_values));
return 1 + imm.length + locals_length;
}
DECODE(Loop) {
BlockTypeImmediate<validate> imm(this->enabled_, this, this->pc_ + 1);
if (!this->Validate(this->pc_ + 1, imm)) return 0;
ArgVector args = PopArgs(imm.sig);
Control* block = PushControl(kControlLoop);
SetBlockType(&control_.back(), imm, args.begin());
CALL_INTERFACE_IF_REACHABLE(Loop, block);
PushMergeValues(block, &block->start_merge);
return 1 + imm.length;
}
DECODE(If) {
BlockTypeImmediate<validate> imm(this->enabled_, this, this->pc_ + 1);
if (!this->Validate(this->pc_ + 1, imm)) return 0;
Value cond = Pop(0, kWasmI32);
ArgVector args = PopArgs(imm.sig);
if (!VALIDATE(this->ok())) return 0;
Control* if_block = PushControl(kControlIf);
SetBlockType(if_block, imm, args.begin());
CALL_INTERFACE_IF_REACHABLE(If, cond, if_block);
PushMergeValues(if_block, &if_block->start_merge);
return 1 + imm.length;
}
DECODE(Else) {
if (!VALIDATE(!control_.empty())) {
this->DecodeError("else does not match any if");
return 0;
}
Control* c = &control_.back();
if (!VALIDATE(c->is_if())) {
this->DecodeError("else does not match an if");
return 0;
}
if (!VALIDATE(c->is_onearmed_if())) {
this->DecodeError("else already present for if");
return 0;
}
if (!TypeCheckFallThru()) return 0;
c->kind = kControlIfElse;
CALL_INTERFACE_IF_PARENT_REACHABLE(Else, c);
if (c->reachable()) c->end_merge.reached = true;
PushMergeValues(c, &c->start_merge);
c->reachability = control_at(1)->innerReachability();
current_code_reachable_ = this->ok() && c->reachable();
return 1;
}
DECODE(End) {
if (!VALIDATE(!control_.empty())) {
this->DecodeError("end does not match any if, try, or block");
return 0;
}
Control* c = &control_.back();
if (!VALIDATE(!c->is_incomplete_try())) {
this->DecodeError("missing catch or catch-all in try");
return 0;
}
if (c->is_onearmed_if()) {
if (!VALIDATE(c->end_merge.arity == c->start_merge.arity)) {
this->DecodeError(
c->pc(), "start-arity and end-arity of one-armed if must match");
return 0;
}
if (!TypeCheckOneArmedIf(c)) return 0;
}
if (c->is_let()) {
this->local_types_.erase(this->local_types_.begin(),
this->local_types_.begin() + c->locals_count);
this->num_locals_ -= c->locals_count;
CALL_INTERFACE_IF_REACHABLE(DeallocateLocals, c->locals_count);
}
if (!TypeCheckFallThru()) return 0;
if (control_.size() == 1) {
// If at the last (implicit) control, check we are at end.
if (!VALIDATE(this->pc_ + 1 == this->end_)) {
this->DecodeError(this->pc_ + 1, "trailing code after function end");
return 0;
}
// The result of the block is the return value.
trace_msg->Append("\n" TRACE_INST_FORMAT, startrel(this->pc_),
"(implicit) return");
DoReturn();
control_.clear();
return 1;
}
PopControl(c);
return 1;
}
DECODE(Select) {
Value cond = Pop(2, kWasmI32);
Value fval = Pop(1);
Value tval = Pop(0, fval.type);
ValueType type = tval.type == kWasmBottom ? fval.type : tval.type;
if (!VALIDATE(!type.is_reference_type())) {
this->DecodeError(
"select without type is only valid for value type inputs");
return 0;
}
Value* result = Push(type);
CALL_INTERFACE_IF_REACHABLE(Select, cond, fval, tval, result);
return 1;
}
DECODE(SelectWithType) {
CHECK_PROTOTYPE_OPCODE(reftypes);
SelectTypeImmediate<validate> imm(this->enabled_, this, this->pc_ + 1);
if (this->failed()) return 0;
Value cond = Pop(2, kWasmI32);
Value fval = Pop(1, imm.type);
Value tval = Pop(0, imm.type);
Value* result = Push(imm.type);
CALL_INTERFACE_IF_REACHABLE(Select, cond, fval, tval, result);
return 1 + imm.length;
}
DECODE(Br) {
BranchDepthImmediate<validate> imm(this, this->pc_ + 1);
if (!this->Validate(this->pc_ + 1, imm, control_.size())) return 0;
Control* c = control_at(imm.depth);
TypeCheckBranchResult check_result = TypeCheckBranch(c, false);
if (V8_LIKELY(check_result == kReachableBranch)) {
if (imm.depth == control_.size() - 1) {
DoReturn();
} else {
CALL_INTERFACE(Br, c);
c->br_merge()->reached = true;
}
} else if (check_result == kInvalidStack) {
return 0;
}
EndControl();
return 1 + imm.length;
}
DECODE(BrIf) {
BranchDepthImmediate<validate> imm(this, this->pc_ + 1);
if (!this->Validate(this->pc_ + 1, imm, control_.size())) return 0;
Value cond = Pop(0, kWasmI32);
if (this->failed()) return 0;
Control* c = control_at(imm.depth);
TypeCheckBranchResult check_result = TypeCheckBranch(c, true);
if (V8_LIKELY(check_result == kReachableBranch)) {
CALL_INTERFACE(BrIf, cond, imm.depth);
c->br_merge()->reached = true;
} else if (check_result == kInvalidStack) {
return 0;
}
return 1 + imm.length;
}
DECODE(BrTable) {
BranchTableImmediate<validate> imm(this, this->pc_ + 1);
BranchTableIterator<validate> iterator(this, imm);
Value key = Pop(0, kWasmI32);
if (this->failed()) return 0;
if (!this->Validate(this->pc_ + 1, imm, control_.size())) return 0;
// Cache the branch targets during the iteration, so that we can set
// all branch targets as reachable after the {CALL_INTERFACE} call.
std::vector<bool> br_targets(control_.size());
// The result types of the br_table instruction. We have to check the
// stack against these types. Only needed during validation.
std::vector<ValueType> result_types;
while (iterator.has_next()) {
const uint32_t index = iterator.cur_index();
const byte* pos = iterator.pc();
uint32_t target = iterator.next();
if (!VALIDATE(ValidateBrTableTarget(target, pos, index))) return 0;
// Avoid redundant branch target checks.
if (br_targets[target]) continue;
br_targets[target] = true;
if (validate) {
if (index == 0) {
// With the first branch target, initialize the result types.
result_types = InitializeBrTableResultTypes(target);
} else if (!UpdateBrTableResultTypes(&result_types, target, pos,
index)) {
return 0;
}
}
}
if (!VALIDATE(TypeCheckBrTable(result_types))) return 0;
DCHECK(this->ok());
if (current_code_reachable_) {
CALL_INTERFACE(BrTable, imm, key);
for (int i = 0, e = control_depth(); i < e; ++i) {
if (!br_targets[i]) continue;
control_at(i)->br_merge()->reached = true;
}
}
EndControl();
return 1 + iterator.length();
}
DECODE(Return) {
if (V8_LIKELY(current_code_reachable_)) {
if (!VALIDATE(TypeCheckReturn())) return 0;
DoReturn();
} else {
// We pop all return values from the stack to check their type.
// Since we deal with unreachable code, we do not have to keep the
// values.
int num_returns = static_cast<int>(this->sig_->return_count());
for (int i = num_returns - 1; i >= 0; --i) {
Pop(i, this->sig_->GetReturn(i));
}
}
EndControl();
return 1;
}
DECODE(Unreachable) {
CALL_INTERFACE_IF_REACHABLE(Unreachable);
EndControl();
return 1;
}
DECODE(I32Const) {
ImmI32Immediate<validate> imm(this, this->pc_ + 1);
Value* value = Push(kWasmI32);
CALL_INTERFACE_IF_REACHABLE(I32Const, value, imm.value);
return 1 + imm.length;
}
DECODE(I64Const) {
ImmI64Immediate<validate> imm(this, this->pc_ + 1);
Value* value = Push(kWasmI64);
CALL_INTERFACE_IF_REACHABLE(I64Const, value, imm.value);
return 1 + imm.length;
}
DECODE(F32Const) {
ImmF32Immediate<validate> imm(this, this->pc_ + 1);
Value* value = Push(kWasmF32);
CALL_INTERFACE_IF_REACHABLE(F32Const, value, imm.value);
return 1 + imm.length;
}
DECODE(F64Const) {
ImmF64Immediate<validate> imm(this, this->pc_ + 1);
Value* value = Push(kWasmF64);
CALL_INTERFACE_IF_REACHABLE(F64Const, value, imm.value);
return 1 + imm.length;
}
DECODE(RefNull) {
CHECK_PROTOTYPE_OPCODE(reftypes);
HeapTypeImmediate<validate> imm(this->enabled_, this, this->pc_ + 1);
if (!this->Validate(this->pc_ + 1, imm)) return 0;
ValueType type = ValueType::Ref(imm.type, kNullable);
Value* value = Push(type);
CALL_INTERFACE_IF_REACHABLE(RefNull, type, value);
return 1 + imm.length;
}
DECODE(RefIsNull) {
CHECK_PROTOTYPE_OPCODE(reftypes);
Value value = Pop(0);
Value* result = Push(kWasmI32);
switch (value.type.kind()) {
case ValueType::kOptRef:
CALL_INTERFACE_IF_REACHABLE(UnOp, kExprRefIsNull, value, result);
return 1;
case ValueType::kBottom:
// We are in unreachable code, the return value does not matter.
case ValueType::kRef:
// For non-nullable references, the result is always false.
CALL_INTERFACE_IF_REACHABLE(I32Const, result, 0);
return 1;
default:
if (validate) {
this->DecodeError(
"invalid argument type to ref.is_null. Expected reference type, "
"got %s",
value.type.name().c_str());
return 0;
}
UNREACHABLE();
}
}
DECODE(RefFunc) {
CHECK_PROTOTYPE_OPCODE(reftypes);
FunctionIndexImmediate<validate> imm(this, this->pc_ + 1);
if (!this->Validate(this->pc_ + 1, imm)) return 0;
HeapType heap_type(this->enabled_.has_typed_funcref()
? this->module_->functions[imm.index].sig_index
: HeapType::kFunc);
Value* value = Push(ValueType::Ref(heap_type, kNonNullable));
CALL_INTERFACE_IF_REACHABLE(RefFunc, imm.index, value);
return 1 + imm.length;
}
DECODE(RefAsNonNull) {
CHECK_PROTOTYPE_OPCODE(typed_funcref);
Value value = Pop(0);
switch (value.type.kind()) {
case ValueType::kBottom:
// We are in unreachable code. Forward the bottom value.
case ValueType::kRef: {
Value* result = Push(value.type);
CALL_INTERFACE_IF_REACHABLE(PassThrough, value, result);
return 1;
}
case ValueType::kOptRef: {
Value* result =
Push(ValueType::Ref(value.type.heap_type(), kNonNullable));
CALL_INTERFACE_IF_REACHABLE(RefAsNonNull, value, result);
return 1;
}
default:
if (validate) {
this->DecodeError(
"invalid agrument type to ref.as_non_null: Expected reference "
"type, got %s",
value.type.name().c_str());
}
return 0;
}
}
DECODE(LocalGet) {
LocalIndexImmediate<validate> imm(this, this->pc_ + 1);
if (!this->Validate(this->pc_ + 1, imm)) return 0;
Value* value = Push(this->local_type(imm.index));
CALL_INTERFACE_IF_REACHABLE(LocalGet, value, imm);
return 1 + imm.length;
}
DECODE(LocalSet) {
LocalIndexImmediate<validate> imm(this, this->pc_ + 1);
if (!this->Validate(this->pc_ + 1, imm)) return 0;
Value value = Pop(0, this->local_type(imm.index));
CALL_INTERFACE_IF_REACHABLE(LocalSet, value, imm);
return 1 + imm.length;
}
DECODE(LocalTee) {
LocalIndexImmediate<validate> imm(this, this->pc_ + 1);
if (!this->Validate(this->pc_ + 1, imm)) return 0;
Value value = Pop(0, this->local_type(imm.index));
Value* result = Push(value.type);
CALL_INTERFACE_IF_REACHABLE(LocalTee, value, result, imm);
return 1 + imm.length;
}
DECODE(Drop) {
Value value = Pop(0);
CALL_INTERFACE_IF_REACHABLE(Drop, value);
return 1;
}
DECODE(GlobalGet) {
GlobalIndexImmediate<validate> imm(this, this->pc_ + 1);
if (!this->Validate(this->pc_ + 1, imm)) return 0;
Value* result = Push(imm.type);
CALL_INTERFACE_IF_REACHABLE(GlobalGet, result, imm);
return 1 + imm.length;
}
DECODE(GlobalSet) {
GlobalIndexImmediate<validate> imm(this, this->pc_ + 1);
if (!this->Validate(this->pc_ + 1, imm)) return 0;
if (!VALIDATE(imm.global->mutability)) {
this->DecodeError("immutable global #%u cannot be assigned", imm.index);
return 0;
}
Value value = Pop(0, imm.type);
CALL_INTERFACE_IF_REACHABLE(GlobalSet, value, imm);
return 1 + imm.length;
}
DECODE(TableGet) {
CHECK_PROTOTYPE_OPCODE(reftypes);
TableIndexImmediate<validate> imm(this, this->pc_ + 1);
if (!this->Validate(this->pc_ + 1, imm)) return 0;
Value index = Pop(0, kWasmI32);
Value* result = Push(this->module_->tables[imm.index].type);
CALL_INTERFACE_IF_REACHABLE(TableGet, index, result, imm);
return 1 + imm.length;
}
DECODE(TableSet) {
CHECK_PROTOTYPE_OPCODE(reftypes);
TableIndexImmediate<validate> imm(this, this->pc_ + 1);
if (!this->Validate(this->pc_ + 1, imm)) return 0;
Value value = Pop(1, this->module_->tables[imm.index].type);
Value index = Pop(0, kWasmI32);
CALL_INTERFACE_IF_REACHABLE(TableSet, index, value, imm);
return 1 + imm.length;
}
DECODE(LoadMem) {
// Hard-code the list of load types. The opcodes are highly unlikely to
// ever change, and we have some checks here to guard against that.
static_assert(sizeof(LoadType) == sizeof(uint8_t), "LoadType is compact");
static constexpr uint8_t kMinOpcode = kExprI32LoadMem;
static constexpr uint8_t kMaxOpcode = kExprI64LoadMem32U;
static constexpr LoadType kLoadTypes[] = {
LoadType::kI32Load, LoadType::kI64Load, LoadType::kF32Load,
LoadType::kF64Load, LoadType::kI32Load8S, LoadType::kI32Load8U,
LoadType::kI32Load16S, LoadType::kI32Load16U, LoadType::kI64Load8S,
LoadType::kI64Load8U, LoadType::kI64Load16S, LoadType::kI64Load16U,
LoadType::kI64Load32S, LoadType::kI64Load32U};
STATIC_ASSERT(arraysize(kLoadTypes) == kMaxOpcode - kMinOpcode + 1);
DCHECK_LE(kMinOpcode, opcode);
DCHECK_GE(kMaxOpcode, opcode);
return DecodeLoadMem(kLoadTypes[opcode - kMinOpcode]);
}
DECODE(StoreMem) {
// Hard-code the list of store types. The opcodes are highly unlikely to
// ever change, and we have some checks here to guard against that.
static_assert(sizeof(StoreType) == sizeof(uint8_t), "StoreType is compact");
static constexpr uint8_t kMinOpcode = kExprI32StoreMem;
static constexpr uint8_t kMaxOpcode = kExprI64StoreMem32;
static constexpr StoreType kStoreTypes[] = {
StoreType::kI32Store, StoreType::kI64Store, StoreType::kF32Store,
StoreType::kF64Store, StoreType::kI32Store8, StoreType::kI32Store16,
StoreType::kI64Store8, StoreType::kI64Store16, StoreType::kI64Store32};
STATIC_ASSERT(arraysize(kStoreTypes) == kMaxOpcode - kMinOpcode + 1);
DCHECK_LE(kMinOpcode, opcode);
DCHECK_GE(kMaxOpcode, opcode);
return DecodeStoreMem(kStoreTypes[opcode - kMinOpcode]);
}
DECODE(MemoryGrow) {
if (!CheckHasMemory()) return 0;
MemoryIndexImmediate<validate> imm(this, this->pc_ + 1);
if (!VALIDATE(this->module_->origin == kWasmOrigin)) {
this->DecodeError("grow_memory is not supported for asmjs modules");
return 0;
}
Value value = Pop(0, kWasmI32);
Value* result = Push(kWasmI32);
CALL_INTERFACE_IF_REACHABLE(MemoryGrow, value, result);
return 1 + imm.length;
}
DECODE(MemorySize) {
if (!CheckHasMemory()) return 0;
MemoryIndexImmediate<validate> imm(this, this->pc_ + 1);
Value* result = Push(kWasmI32);
CALL_INTERFACE_IF_REACHABLE(CurrentMemoryPages, result);
return 1 + imm.length;
}
DECODE(CallFunction) {
CallFunctionImmediate<validate> imm(this, this->pc_ + 1);
if (!this->Validate(this->pc_ + 1, imm)) return 0;
ArgVector args = PopArgs(imm.sig);
Value* returns = PushReturns(imm.sig);
CALL_INTERFACE_IF_REACHABLE(CallDirect, imm, args.begin(), returns);
return 1 + imm.length;
}
DECODE(CallIndirect) {
CallIndirectImmediate<validate> imm(this->enabled_, this, this->pc_ + 1);
if (!this->Validate(this->pc_ + 1, imm)) return 0;
Value index = Pop(0, kWasmI32);
ArgVector args = PopArgs(imm.sig);
Value* returns = PushReturns(imm.sig);
CALL_INTERFACE_IF_REACHABLE(CallIndirect, index, imm, args.begin(),
returns);
return 1 + imm.length;
}
DECODE(ReturnCall) {
CHECK_PROTOTYPE_OPCODE(return_call);
CallFunctionImmediate<validate> imm(this, this->pc_ + 1);
if (!this->Validate(this->pc_ + 1, imm)) return 0;
if (!VALIDATE(this->CanReturnCall(imm.sig))) {
this->DecodeError("%s: %s", WasmOpcodes::OpcodeName(kExprReturnCall),
"tail call return types mismatch");
return 0;
}
ArgVector args = PopArgs(imm.sig);
CALL_INTERFACE_IF_REACHABLE(ReturnCall, imm, args.begin());
EndControl();
return 1 + imm.length;
}
DECODE(ReturnCallIndirect) {
CHECK_PROTOTYPE_OPCODE(return_call);
CallIndirectImmediate<validate> imm(this->enabled_, this, this->pc_ + 1);
if (!this->Validate(this->pc_ + 1, imm)) return 0;
if (!VALIDATE(this->CanReturnCall(imm.sig))) {
this->DecodeError("%s: %s",
WasmOpcodes::OpcodeName(kExprReturnCallIndirect),
"tail call return types mismatch");
return 0;
}
Value index = Pop(0, kWasmI32);
ArgVector args = PopArgs(imm.sig);
CALL_INTERFACE_IF_REACHABLE(ReturnCallIndirect, index, imm, args.begin());
EndControl();
return 1 + imm.length;
}
DECODE(CallRef) {
CHECK_PROTOTYPE_OPCODE(typed_funcref);
Value func_ref = Pop(0);
ValueType func_type = func_ref.type;
if (func_type == kWasmBottom) {
// We are in unreachable code, maintain the polymorphic stack.
return 1;
}
if (!VALIDATE(func_type.is_object_reference_type() &&
func_type.has_index() &&
this->module_->has_signature(func_type.ref_index()))) {
this->DecodeError(
"call_ref: Expected function reference on top of stack, found %s of "
"type %s instead",
SafeOpcodeNameAt(func_ref.pc()), func_type.name().c_str());
return 0;
}
const FunctionSig* sig = this->module_->signature(func_type.ref_index());
ArgVector args = PopArgs(sig);
Value* returns = PushReturns(sig);
CALL_INTERFACE_IF_REACHABLE(CallRef, func_ref, sig, func_type.ref_index(),
args.begin(), returns);
return 1;
}
DECODE(ReturnCallRef) {
CHECK_PROTOTYPE_OPCODE(typed_funcref);
CHECK_PROTOTYPE_OPCODE(return_call);
Value func_ref = Pop(0);
ValueType func_type = func_ref.type;
if (func_type == kWasmBottom) {
// We are in unreachable code, maintain the polymorphic stack.
return 1;
}
if (!VALIDATE(func_type.is_object_reference_type() &&
func_type.has_index() &&
this->module_->has_signature(func_type.ref_index()))) {
this->DecodeError(
"return_call_ref: Expected function reference on top of stack, found "
"%s of type %s instead",
SafeOpcodeNameAt(func_ref.pc()), func_type.name().c_str());
return 0;
}
const FunctionSig* sig = this->module_->signature(func_type.ref_index());
ArgVector args = PopArgs(sig);
CALL_INTERFACE_IF_REACHABLE(ReturnCallRef, func_ref, sig,
func_type.ref_index(), args.begin());
EndControl();
return 1;
}
DECODE(Numeric) {
uint32_t opcode_length = 0;
WasmOpcode full_opcode = this->template read_prefixed_opcode<validate>(
this->pc_, &opcode_length, "numeric index");
if (full_opcode == kExprTableGrow || full_opcode == kExprTableSize ||
full_opcode == kExprTableFill) {
CHECK_PROTOTYPE_OPCODE(reftypes);
} else if (full_opcode >= kExprMemoryInit) {
CHECK_PROTOTYPE_OPCODE(bulk_memory);
}
trace_msg->AppendOpcode(full_opcode);
return DecodeNumericOpcode(full_opcode, opcode_length);
}
DECODE(Simd) {
CHECK_PROTOTYPE_OPCODE(simd);
uint32_t opcode_length = 0;
WasmOpcode full_opcode = this->template read_prefixed_opcode<validate>(
this->pc_, &opcode_length);
if (!VALIDATE(this->ok())) return 0;
trace_msg->AppendOpcode(full_opcode);
return DecodeSimdOpcode(full_opcode, opcode_length);
}
DECODE(Atomic) {
CHECK_PROTOTYPE_OPCODE(threads);
uint32_t opcode_length = 0;
WasmOpcode full_opcode = this->template read_prefixed_opcode<validate>(
this->pc_, &opcode_length, "atomic index");
trace_msg->AppendOpcode(full_opcode);
return DecodeAtomicOpcode(full_opcode, opcode_length);
}
DECODE(GC) {
CHECK_PROTOTYPE_OPCODE(gc);
uint32_t opcode_length = 0;
WasmOpcode full_opcode = this->template read_prefixed_opcode<validate>(
this->pc_, &opcode_length, "gc index");
trace_msg->AppendOpcode(full_opcode);
return DecodeGCOpcode(full_opcode, opcode_length);
}
#define SIMPLE_PROTOTYPE_CASE(name, opc, sig) \
DECODE(name) { return BuildSimplePrototypeOperator(opcode); }
FOREACH_SIMPLE_PROTOTYPE_OPCODE(SIMPLE_PROTOTYPE_CASE)
#undef SIMPLE_PROTOTYPE_CASE
DECODE(UnknownOrAsmJs) {
// Deal with special asmjs opcodes.
if (!VALIDATE(is_asmjs_module(this->module_))) {
this->DecodeError("Invalid opcode 0x%x", opcode);
return 0;
}
const FunctionSig* sig = WasmOpcodes::AsmjsSignature(opcode);
DCHECK_NOT_NULL(sig);
return BuildSimpleOperator(opcode, sig);
}
#undef DECODE
using OpcodeHandler = int (*)(WasmFullDecoder*, WasmOpcode);
// Ideally we would use template specialization for the different opcodes, but
// GCC does not allow to specialize templates in class scope
// (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85282), and specializing
// outside the class is not allowed for non-specialized classes.
// Hence just list all implementations explicitly here, which also gives more
// freedom to use the same implementation for different opcodes.
#define DECODE_IMPL(opcode) DECODE_IMPL2(kExpr##opcode, opcode)
#define DECODE_IMPL2(opcode, name) \
if (idx == opcode) return &WasmFullDecoder::Decode##name
static constexpr OpcodeHandler GetOpcodeHandlerTableEntry(size_t idx) {
DECODE_IMPL(Nop);
#define BUILD_SIMPLE_OPCODE(op, _, sig) DECODE_IMPL(op);
FOREACH_SIMPLE_OPCODE(BUILD_SIMPLE_OPCODE)
#undef BUILD_SIMPLE_OPCODE
DECODE_IMPL(Block);
DECODE_IMPL(Rethrow);
DECODE_IMPL(Throw);
DECODE_IMPL(Try);
DECODE_IMPL(Catch);
DECODE_IMPL(BrOnExn);
DECODE_IMPL(BrOnNull);
DECODE_IMPL(Let);
DECODE_IMPL(Loop);
DECODE_IMPL(If);
DECODE_IMPL(Else);
DECODE_IMPL(End);
DECODE_IMPL(Select);
DECODE_IMPL(SelectWithType);
DECODE_IMPL(Br);
DECODE_IMPL(BrIf);
DECODE_IMPL(BrTable);
DECODE_IMPL(Return);
DECODE_IMPL(Unreachable);
DECODE_IMPL(I32Const);
DECODE_IMPL(I64Const);
DECODE_IMPL(F32Const);
DECODE_IMPL(F64Const);
DECODE_IMPL(RefNull);
DECODE_IMPL(RefIsNull);
DECODE_IMPL(RefFunc);
DECODE_IMPL(RefAsNonNull);
DECODE_IMPL(LocalGet);
DECODE_IMPL(LocalSet);
DECODE_IMPL(LocalTee);
DECODE_IMPL(Drop);
DECODE_IMPL(GlobalGet);
DECODE_IMPL(GlobalSet);
DECODE_IMPL(TableGet);
DECODE_IMPL(TableSet);
#define DECODE_LOAD_MEM(op, ...) DECODE_IMPL2(kExpr##op, LoadMem);
FOREACH_LOAD_MEM_OPCODE(DECODE_LOAD_MEM)
#undef DECODE_LOAD_MEM
#define DECODE_STORE_MEM(op, ...) DECODE_IMPL2(kExpr##op, StoreMem);
FOREACH_STORE_MEM_OPCODE(DECODE_STORE_MEM)
#undef DECODE_LOAD_MEM
DECODE_IMPL(MemoryGrow);
DECODE_IMPL(MemorySize);
DECODE_IMPL(CallFunction);
DECODE_IMPL(CallIndirect);
DECODE_IMPL(ReturnCall);
DECODE_IMPL(ReturnCallIndirect);
DECODE_IMPL(CallRef);
DECODE_IMPL(ReturnCallRef);
DECODE_IMPL2(kNumericPrefix, Numeric);
DECODE_IMPL2(kSimdPrefix, Simd);
DECODE_IMPL2(kAtomicPrefix, Atomic);
DECODE_IMPL2(kGCPrefix, GC);
#define SIMPLE_PROTOTYPE_CASE(name, opc, sig) DECODE_IMPL(name);
FOREACH_SIMPLE_PROTOTYPE_OPCODE(SIMPLE_PROTOTYPE_CASE)
#undef SIMPLE_PROTOTYPE_CASE
return &WasmFullDecoder::DecodeUnknownOrAsmJs;
}
#undef DECODE_IMPL
#undef DECODE_IMPL2
OpcodeHandler GetOpcodeHandler(uint8_t opcode) {
#ifndef V8_OS_STARBOARD
static constexpr std::array<OpcodeHandler, 256> kOpcodeHandlers =
base::make_array<256>(GetOpcodeHandlerTableEntry);
#else
DCHECK(false);
static constexpr std::array<OpcodeHandler, 256> kOpcodeHandlers{};
#endif
return kOpcodeHandlers[opcode];
}
void DecodeFunctionBody() {
TRACE("wasm-decode %p...%p (module+%u, %d bytes)\n", this->start(),
this->end(), this->pc_offset(),
static_cast<int>(this->end() - this->start()));
// Set up initial function block.
{
Control* c = PushControl(kControlBlock);
InitMerge(&c->start_merge, 0, [](uint32_t) -> Value { UNREACHABLE(); });
InitMerge(&c->end_merge,
static_cast<uint32_t>(this->sig_->return_count()),
[&](uint32_t i) {
return Value{this->pc_, this->sig_->GetReturn(i)};
});
CALL_INTERFACE(StartFunctionBody, c);
}
// Decode the function body.
while (this->pc_ < this->end_) {
// Most operations only grow the stack by at least one element (unary and
// binary operations, local.get, constants, ...). Thus check that there is
// enough space for those operations centrally, and avoid any bounds
// checks in those operations.
EnsureStackSpace(1);
uint8_t first_byte = *this->pc_;
WasmOpcode opcode = static_cast<WasmOpcode>(first_byte);
CALL_INTERFACE_IF_REACHABLE(NextInstruction, opcode);
OpcodeHandler handler = GetOpcodeHandler(first_byte);
int len = (*handler)(this, opcode);
this->pc_ += len;
}
if (!VALIDATE(this->pc_ == this->end_)) {
this->DecodeError("Beyond end of code");
}
}
void EndControl() {
DCHECK(!control_.empty());
Control* current = &control_.back();
DCHECK_LE(stack_ + current->stack_depth, stack_end_);
stack_end_ = stack_ + current->stack_depth;
CALL_INTERFACE_IF_REACHABLE(EndControl, current);
current->reachability = kUnreachable;
current_code_reachable_ = false;
}
template <typename func>
void InitMerge(Merge<Value>* merge, uint32_t arity, func get_val) {
merge->arity = arity;
if (arity == 1) {
merge->vals.first = get_val(0);
} else if (arity > 1) {
merge->vals.array = this->zone()->template NewArray<Value>(arity);
for (uint32_t i = 0; i < arity; i++) {
merge->vals.array[i] = get_val(i);
}
}
}
void SetBlockType(Control* c, BlockTypeImmediate<validate>& imm,
Value* args) {
const byte* pc = this->pc_;
InitMerge(&c->end_merge, imm.out_arity(), [pc, &imm](uint32_t i) {
return Value{pc, imm.out_type(i)};
});
InitMerge(&c->start_merge, imm.in_arity(),
[args](uint32_t i) { return args[i]; });
}
// Pops arguments as required by signature.
V8_INLINE ArgVector PopArgs(const FunctionSig* sig) {
int count = sig ? static_cast<int>(sig->parameter_count()) : 0;
ArgVector args(count);
for (int i = count - 1; i >= 0; --i) {
args[i] = Pop(i, sig->GetParam(i));
}
return args;
}
V8_INLINE ArgVector PopArgs(const StructType* type) {
int count = static_cast<int>(type->field_count());
ArgVector args(count);
for (int i = count - 1; i >= 0; i--) {
args[i] = Pop(i, type->field(i).Unpacked());
}
return args;
}
V8_INLINE ArgVector PopArgs(uint32_t base_index,
Vector<ValueType> arg_types) {
ArgVector args(arg_types.size());
for (int i = static_cast<int>(arg_types.size()) - 1; i >= 0; i--) {
args[i] = Pop(base_index + i, arg_types[i]);
}
return args;
}
ValueType GetReturnType(const FunctionSig* sig) {
DCHECK_GE(1, sig->return_count());
return sig->return_count() == 0 ? kWasmStmt : sig->GetReturn();
}
Control* PushControl(ControlKind kind, uint32_t locals_count = 0) {
Reachability reachability =
control_.empty() ? kReachable : control_.back().innerReachability();
control_.emplace_back(kind, locals_count, stack_size(), this->pc_,
reachability);
current_code_reachable_ = this->ok() && reachability == kReachable;
return &control_.back();
}
void PopControl(Control* c) {
DCHECK_EQ(c, &control_.back());
CALL_INTERFACE_IF_PARENT_REACHABLE(PopControl, c);
// A loop just leaves the values on the stack.
if (!c->is_loop()) PushMergeValues(c, &c->end_merge);
bool parent_reached =
c->reachable() || c->end_merge.reached || c->is_onearmed_if();
control_.pop_back();
// If the parent block was reachable before, but the popped control does not
// return to here, this block becomes "spec only reachable".
if (!parent_reached) SetSucceedingCodeDynamicallyUnreachable();
current_code_reachable_ = control_.back().reachable();
}
int DecodeLoadMem(LoadType type, int prefix_len = 1) {
if (!CheckHasMemory()) return 0;
MemoryAccessImmediate<validate> imm(this, this->pc_ + prefix_len,
type.size_log_2());
ValueType index_type = this->module_->is_memory64 ? kWasmI64 : kWasmI32;
Value index = Pop(0, index_type);
Value* result = Push(type.value_type());
CALL_INTERFACE_IF_REACHABLE(LoadMem, type, imm, index, result);
return prefix_len + imm.length;
}
int DecodeLoadTransformMem(LoadType type, LoadTransformationKind transform,
uint32_t opcode_length) {
if (!CheckHasMemory()) return 0;
// Load extends always load 64-bits.
uint32_t max_alignment =
transform == LoadTransformationKind::kExtend ? 3 : type.size_log_2();
MemoryAccessImmediate<validate> imm(this, this->pc_ + opcode_length,
max_alignment);
ValueType index_type = this->module_->is_memory64 ? kWasmI64 : kWasmI32;
Value index = Pop(0, index_type);
Value* result = Push(kWasmS128);
CALL_INTERFACE_IF_REACHABLE(LoadTransform, type, transform, imm, index,
result);
return opcode_length + imm.length;
}
int DecodeLoadLane(LoadType type, uint32_t opcode_length) {
if (!CheckHasMemory()) return 0;
MemoryAccessImmediate<validate> mem_imm(this, this->pc_ + opcode_length,
type.size_log_2());
SimdLaneImmediate<validate> lane_imm(
this, this->pc_ + opcode_length + mem_imm.length);
Value v128 = Pop(1, kWasmS128);
Value index = Pop(0, kWasmI32);
Value* result = Push(kWasmS128);
CALL_INTERFACE_IF_REACHABLE(LoadLane, type, v128, index, mem_imm,
lane_imm.lane, result);
return opcode_length + mem_imm.length + lane_imm.length;
}
int DecodeStoreLane(StoreType type, uint32_t opcode_length) {
if (!CheckHasMemory()) return 0;
MemoryAccessImmediate<validate> mem_imm(this, this->pc_ + opcode_length,
type.size_log_2());
SimdLaneImmediate<validate> lane_imm(
this, this->pc_ + opcode_length + mem_imm.length);
Value v128 = Pop(1, kWasmS128);
Value index = Pop(0, kWasmI32);
CALL_INTERFACE_IF_REACHABLE(StoreLane, type, mem_imm, index, v128,
lane_imm.lane);
return opcode_length + mem_imm.length + lane_imm.length;
}
int DecodeStoreMem(StoreType store, int prefix_len = 1) {
if (!CheckHasMemory()) return 0;
MemoryAccessImmediate<validate> imm(this, this->pc_ + prefix_len,
store.size_log_2());
Value value = Pop(1, store.value_type());
ValueType index_type = this->module_->is_memory64 ? kWasmI64 : kWasmI32;
Value index = Pop(0, index_type);
CALL_INTERFACE_IF_REACHABLE(StoreMem, store, imm, index, value);
return prefix_len + imm.length;
}
bool ValidateBrTableTarget(uint32_t target, const byte* pos, int index) {
if (!VALIDATE(target < this->control_.size())) {
this->DecodeError(pos, "improper branch in br_table target %u (depth %u)",
index, target);
return false;
}
return true;
}
std::vector<ValueType> InitializeBrTableResultTypes(uint32_t target) {
Merge<Value>* merge = control_at(target)->br_merge();
int br_arity = merge->arity;
std::vector<ValueType> result(br_arity);
for (int i = 0; i < br_arity; ++i) {
result[i] = (*merge)[i].type;
}
return result;
}
bool UpdateBrTableResultTypes(std::vector<ValueType>* result_types,
uint32_t target, const byte* pos, int index) {
Merge<Value>* merge = control_at(target)->br_merge();
int br_arity = merge->arity;
// First we check if the arities match.
if (!VALIDATE(br_arity == static_cast<int>(result_types->size()))) {
this->DecodeError(pos,
"inconsistent arity in br_table target %u (previous "
"was %zu, this one is %u)",
index, result_types->size(), br_arity);
return false;
}
for (int i = 0; i < br_arity; ++i) {
if (this->enabled_.has_reftypes()) {
// The expected type is the biggest common sub type of all targets.
ValueType type = (*result_types)[i];
(*result_types)[i] =
CommonSubtype((*result_types)[i], (*merge)[i].type, this->module_);
if (!VALIDATE((*result_types)[i] != kWasmBottom)) {
this->DecodeError(pos,
"inconsistent type in br_table target %u (previous "
"was %s, this one is %s)",
index, type.name().c_str(),
(*merge)[i].type.name().c_str());
return false;
}
} else {
// All target must have the same signature.
if (!VALIDATE((*result_types)[i] == (*merge)[i].type)) {
this->DecodeError(pos,
"inconsistent type in br_table target %u (previous "
"was %s, this one is %s)",
index, (*result_types)[i].name().c_str(),
(*merge)[i].type.name().c_str());
return false;
}
}
}
return true;
}
bool TypeCheckBrTable(const std::vector<ValueType>& result_types) {
int br_arity = static_cast<int>(result_types.size());
if (V8_LIKELY(!control_.back().unreachable())) {
int available =
static_cast<int>(stack_size()) - control_.back().stack_depth;
// There have to be enough values on the stack.
if (!VALIDATE(available >= br_arity)) {
this->DecodeError(
"expected %u elements on the stack for branch to @%d, found %u",
br_arity, startrel(control_.back().pc()), available);
return false;
}
Value* stack_values = stack_end_ - br_arity;
// Type-check the topmost br_arity values on the stack.
for (int i = 0; i < br_arity; ++i) {
Value& val = stack_values[i];
if (!VALIDATE(IsSubtypeOf(val.type, result_types[i], this->module_))) {
this->DecodeError("type error in merge[%u] (expected %s, got %s)", i,
result_types[i].name().c_str(),
val.type.name().c_str());
return false;
}
}
} else { // !control_.back().reachable()
// Pop values from the stack, accoring to the expected signature.
for (int i = 0; i < br_arity; ++i) Pop(i + 1, result_types[i]);
}
return this->ok();
}
uint32_t SimdConstOp(uint32_t opcode_length) {
Simd128Immediate<validate> imm(this, this->pc_ + opcode_length);
auto* result = Push(kWasmS128);
CALL_INTERFACE_IF_REACHABLE(S128Const, imm, result);
return opcode_length + kSimd128Size;
}
uint32_t SimdExtractLane(WasmOpcode opcode, ValueType type,
uint32_t opcode_length) {
SimdLaneImmediate<validate> imm(this, this->pc_ + opcode_length);
if (this->Validate(this->pc_ + opcode_length, opcode, imm)) {
Value inputs[] = {Pop(0, kWasmS128)};
Value* result = Push(type);
CALL_INTERFACE_IF_REACHABLE(SimdLaneOp, opcode, imm, ArrayVector(inputs),
result);
}
return opcode_length + imm.length;
}
uint32_t SimdReplaceLane(WasmOpcode opcode, ValueType type,
uint32_t opcode_length) {
SimdLaneImmediate<validate> imm(this, this->pc_ + opcode_length);
if (this->Validate(this->pc_ + opcode_length, opcode, imm)) {
Value inputs[2] = {UnreachableValue(this->pc_),
UnreachableValue(this->pc_)};
inputs[1] = Pop(1, type);
inputs[0] = Pop(0, kWasmS128);
Value* result = Push(kWasmS128);
CALL_INTERFACE_IF_REACHABLE(SimdLaneOp, opcode, imm, ArrayVector(inputs),
result);
}
return opcode_length + imm.length;
}
uint32_t Simd8x16ShuffleOp(uint32_t opcode_length) {
Simd128Immediate<validate> imm(this, this->pc_ + opcode_length);
if (this->Validate(this->pc_ + opcode_length, imm)) {
Value input1 = Pop(1, kWasmS128);
Value input0 = Pop(0, kWasmS128);
Value* result = Push(kWasmS128);
CALL_INTERFACE_IF_REACHABLE(Simd8x16ShuffleOp, imm, input0, input1,
result);
}
return opcode_length + 16;
}
uint32_t DecodeSimdOpcode(WasmOpcode opcode, uint32_t opcode_length) {
// opcode_length is the number of bytes that this SIMD-specific opcode takes
// up in the LEB128 encoded form.
switch (opcode) {
case kExprF64x2ExtractLane:
return SimdExtractLane(opcode, kWasmF64, opcode_length);
case kExprF32x4ExtractLane:
return SimdExtractLane(opcode, kWasmF32, opcode_length);
case kExprI64x2ExtractLane:
return SimdExtractLane(opcode, kWasmI64, opcode_length);
case kExprI32x4ExtractLane:
case kExprI16x8ExtractLaneS:
case kExprI16x8ExtractLaneU:
case kExprI8x16ExtractLaneS:
case kExprI8x16ExtractLaneU:
return SimdExtractLane(opcode, kWasmI32, opcode_length);
case kExprF64x2ReplaceLane:
return SimdReplaceLane(opcode, kWasmF64, opcode_length);
case kExprF32x4ReplaceLane:
return SimdReplaceLane(opcode, kWasmF32, opcode_length);
case kExprI64x2ReplaceLane:
return SimdReplaceLane(opcode, kWasmI64, opcode_length);
case kExprI32x4ReplaceLane:
case kExprI16x8ReplaceLane:
case kExprI8x16ReplaceLane:
return SimdReplaceLane(opcode, kWasmI32, opcode_length);
case kExprI8x16Shuffle:
return Simd8x16ShuffleOp(opcode_length);
case kExprS128LoadMem:
return DecodeLoadMem(LoadType::kS128Load, opcode_length);
case kExprS128StoreMem:
return DecodeStoreMem(StoreType::kS128Store, opcode_length);
case kExprS128Load32Zero:
return DecodeLoadTransformMem(LoadType::kI32Load,
LoadTransformationKind::kZeroExtend,
opcode_length);
case kExprS128Load64Zero:
return DecodeLoadTransformMem(LoadType::kI64Load,
LoadTransformationKind::kZeroExtend,
opcode_length);
case kExprS128Load8Splat:
return DecodeLoadTransformMem(LoadType::kI32Load8S,
LoadTransformationKind::kSplat,
opcode_length);
case kExprS128Load16Splat:
return DecodeLoadTransformMem(LoadType::kI32Load16S,
LoadTransformationKind::kSplat,
opcode_length);
case kExprS128Load32Splat:
return DecodeLoadTransformMem(
LoadType::kI32Load, LoadTransformationKind::kSplat, opcode_length);
case kExprS128Load64Splat:
return DecodeLoadTransformMem(
LoadType::kI64Load, LoadTransformationKind::kSplat, opcode_length);
case kExprS128Load8x8S:
return DecodeLoadTransformMem(LoadType::kI32Load8S,
LoadTransformationKind::kExtend,
opcode_length);
case kExprS128Load8x8U:
return DecodeLoadTransformMem(LoadType::kI32Load8U,
LoadTransformationKind::kExtend,
opcode_length);
case kExprS128Load16x4S:
return DecodeLoadTransformMem(LoadType::kI32Load16S,
LoadTransformationKind::kExtend,
opcode_length);
case kExprS128Load16x4U:
return DecodeLoadTransformMem(LoadType::kI32Load16U,
LoadTransformationKind::kExtend,
opcode_length);
case kExprS128Load32x2S:
return DecodeLoadTransformMem(LoadType::kI64Load32S,
LoadTransformationKind::kExtend,
opcode_length);
case kExprS128Load32x2U:
return DecodeLoadTransformMem(LoadType::kI64Load32U,
LoadTransformationKind::kExtend,
opcode_length);
case kExprS128Load8Lane: {
return DecodeLoadLane(LoadType::kI32Load8S, opcode_length);
}
case kExprS128Load16Lane: {
return DecodeLoadLane(LoadType::kI32Load16S, opcode_length);
}
case kExprS128Load32Lane: {
return DecodeLoadLane(LoadType::kI32Load, opcode_length);
}
case kExprS128Load64Lane: {
return DecodeLoadLane(LoadType::kI64Load, opcode_length);
}
case kExprS128Store8Lane: {
return DecodeStoreLane(StoreType::kI32Store8, opcode_length);
}
case kExprS128Store16Lane: {
return DecodeStoreLane(StoreType::kI32Store16, opcode_length);
}
case kExprS128Store32Lane: {
return DecodeStoreLane(StoreType::kI32Store, opcode_length);
}
case kExprS128Store64Lane: {
return DecodeStoreLane(StoreType::kI64Store, opcode_length);
}
case kExprS128Const:
return SimdConstOp(opcode_length);
default: {
if (!CheckSimdPostMvp(opcode)) {
return 0;
}
const FunctionSig* sig = WasmOpcodes::Signature(opcode);
if (!VALIDATE(sig != nullptr)) {
this->DecodeError("invalid simd opcode");
return 0;
}
ArgVector args = PopArgs(sig);
Value* results =
sig->return_count() == 0 ? nullptr : Push(GetReturnType(sig));
CALL_INTERFACE_IF_REACHABLE(SimdOp, opcode, VectorOf(args), results);
return opcode_length;
}
}
}
int DecodeGCOpcode(WasmOpcode opcode, uint32_t opcode_length) {
switch (opcode) {
case kExprStructNewWithRtt: {
StructIndexImmediate<validate> imm(this, this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, imm)) return 0;
Value rtt = Pop(imm.struct_type->field_count());
if (!VALIDATE(rtt.type.is_rtt() || rtt.type.is_bottom())) {
this->DecodeError(
"struct.new_with_rtt expected rtt, found %s of type %s",
SafeOpcodeNameAt(rtt.pc()), rtt.type.name().c_str());
return 0;
}
// TODO(7748): Drop this check if {imm} is dropped from the proposal
// à la https://github.com/WebAssembly/function-references/pull/31.
if (!VALIDATE(rtt.type.is_bottom() ||
rtt.type.heap_representation() == imm.index)) {
this->DecodeError(
"struct.new_with_rtt expected rtt for type %d, found rtt for "
"type %s",
imm.index, rtt.type.heap_type().name().c_str());
return 0;
}
ArgVector args = PopArgs(imm.struct_type);
Value* value = Push(ValueType::Ref(imm.index, kNonNullable));
CALL_INTERFACE_IF_REACHABLE(StructNewWithRtt, imm, rtt, args.begin(),
value);
return opcode_length + imm.length;
}
case kExprStructNewDefault: {
StructIndexImmediate<validate> imm(this, this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, imm)) return 0;
if (validate) {
for (uint32_t i = 0; i < imm.struct_type->field_count(); i++) {
ValueType ftype = imm.struct_type->field(i);
if (!VALIDATE(ftype.is_defaultable())) {
this->DecodeError(
"struct.new_default_with_rtt: struct type %d has "
"non-defaultable type %s for field %d",
imm.index, ftype.name().c_str(), i);
return 0;
}
}
}
Value rtt = Pop(0);
if (!VALIDATE(rtt.type.is_rtt() || rtt.type.is_bottom())) {
this->DecodeError(
"struct.new_default_with_rtt expected rtt, found %s of type %s",
SafeOpcodeNameAt(rtt.pc()), rtt.type.name().c_str());
return 0;
}
// TODO(7748): Drop this check if {imm} is dropped from the proposal
// à la https://github.com/WebAssembly/function-references/pull/31.
if (!VALIDATE(rtt.type.is_bottom() ||
rtt.type.heap_representation() == imm.index)) {
this->DecodeError(
"struct.new_default_with_rtt expected rtt for type %d, found rtt "
"for type %s",
imm.index, rtt.type.heap_type().name().c_str());
return 0;
}
Value* value = Push(ValueType::Ref(imm.index, kNonNullable));
CALL_INTERFACE_IF_REACHABLE(StructNewDefault, imm, rtt, value);
return opcode_length + imm.length;
}
case kExprStructGet: {
FieldIndexImmediate<validate> field(this, this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, field)) return 0;
ValueType field_type =
field.struct_index.struct_type->field(field.index);
if (!VALIDATE(!field_type.is_packed())) {
this->DecodeError(
"struct.get used with a field of packed type. Use struct.get_s "
"or struct.get_u instead.");
return 0;
}
Value struct_obj =
Pop(0, ValueType::Ref(field.struct_index.index, kNullable));
Value* value = Push(field_type);
CALL_INTERFACE_IF_REACHABLE(StructGet, struct_obj, field, true, value);
return opcode_length + field.length;
}
case kExprStructGetU:
case kExprStructGetS: {
FieldIndexImmediate<validate> field(this, this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, field)) return 0;
ValueType field_type =
field.struct_index.struct_type->field(field.index);
if (!VALIDATE(field_type.is_packed())) {
this->DecodeError(
"%s is only valid for packed struct fields. Use struct.get "
"instead.",
WasmOpcodes::OpcodeName(opcode));
return 0;
}
Value struct_obj =
Pop(0, ValueType::Ref(field.struct_index.index, kNullable));
Value* value = Push(field_type.Unpacked());
CALL_INTERFACE_IF_REACHABLE(StructGet, struct_obj, field,
opcode == kExprStructGetS, value);
return opcode_length + field.length;
}
case kExprStructSet: {
FieldIndexImmediate<validate> field(this, this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, field)) return 0;
const StructType* struct_type = field.struct_index.struct_type;
if (!VALIDATE(struct_type->mutability(field.index))) {
this->DecodeError("setting immutable struct field");
return 0;
}
Value field_value = Pop(1, struct_type->field(field.index).Unpacked());
Value struct_obj =
Pop(0, ValueType::Ref(field.struct_index.index, kNullable));
CALL_INTERFACE_IF_REACHABLE(StructSet, struct_obj, field, field_value);
return opcode_length + field.length;
}
case kExprArrayNewWithRtt: {
ArrayIndexImmediate<validate> imm(this, this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, imm)) return 0;
Value rtt = Pop(2);
if (!VALIDATE(rtt.type.is_rtt() || rtt.type.is_bottom())) {
this->DecodeError(
this->pc_ + opcode_length,
"array.new_with_rtt expected rtt, found %s of type %s",
SafeOpcodeNameAt(rtt.pc()), rtt.type.name().c_str());
return 0;
}
// TODO(7748): Drop this check if {imm} is dropped from the proposal
// à la https://github.com/WebAssembly/function-references/pull/31.
if (!VALIDATE(rtt.type.is_bottom() ||
rtt.type.heap_representation() == imm.index)) {
this->DecodeError(
this->pc_ + opcode_length,
"array.new_with_rtt expected rtt for type %d, found "
"rtt for type %s",
imm.index, rtt.type.heap_type().name().c_str());
return 0;
}
Value length = Pop(1, kWasmI32);
Value initial_value = Pop(0, imm.array_type->element_type().Unpacked());
Value* value = Push(ValueType::Ref(imm.index, kNonNullable));
CALL_INTERFACE_IF_REACHABLE(ArrayNewWithRtt, imm, length, initial_value,
rtt, value);
return opcode_length + imm.length;
}
case kExprArrayNewDefault: {
ArrayIndexImmediate<validate> imm(this, this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, imm)) return 0;
if (!VALIDATE(imm.array_type->element_type().is_defaultable())) {
this->DecodeError(
"array.new_default_with_rtt: array type %d has "
"non-defaultable element type %s",
imm.index, imm.array_type->element_type().name().c_str());
return 0;
}
Value rtt = Pop(1);
if (!VALIDATE(rtt.type.is_rtt() || rtt.type.is_bottom())) {
this->DecodeError(
this->pc_ + opcode_length,
"array.new_default_with_rtt expected rtt, found %s of type %s",
SafeOpcodeNameAt(rtt.pc()), rtt.type.name().c_str());
return 0;
}
// TODO(7748): Drop this check if {imm} is dropped from the proposal
// à la https://github.com/WebAssembly/function-references/pull/31.
if (!VALIDATE(rtt.type.is_bottom() ||
rtt.type.heap_representation() == imm.index)) {
this->DecodeError(this->pc_ + opcode_length,
"array.new_default_with_rtt expected rtt for type "
"%d, found rtt for type %s",
imm.index, rtt.type.heap_type().name().c_str());
return 0;
}
Value length = Pop(0, kWasmI32);
Value* value = Push(ValueType::Ref(imm.index, kNonNullable));
CALL_INTERFACE_IF_REACHABLE(ArrayNewDefault, imm, length, rtt, value);
return opcode_length + imm.length;
}
case kExprArrayGetS:
case kExprArrayGetU: {
ArrayIndexImmediate<validate> imm(this, this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, imm)) return 0;
if (!VALIDATE(imm.array_type->element_type().is_packed())) {
this->DecodeError(
"%s is only valid for packed arrays. Use array.get instead.",
WasmOpcodes::OpcodeName(opcode));
return 0;
}
Value index = Pop(1, kWasmI32);
Value array_obj = Pop(0, ValueType::Ref(imm.index, kNullable));
Value* value = Push(imm.array_type->element_type().Unpacked());
CALL_INTERFACE_IF_REACHABLE(ArrayGet, array_obj, imm, index,
opcode == kExprArrayGetS, value);
return opcode_length + imm.length;
}
case kExprArrayGet: {
ArrayIndexImmediate<validate> imm(this, this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, imm)) return 0;
if (!VALIDATE(!imm.array_type->element_type().is_packed())) {
this->DecodeError(
"array.get used with a field of packed type. Use array.get_s or "
"array.get_u instead.");
return 0;
}
Value index = Pop(1, kWasmI32);
Value array_obj = Pop(0, ValueType::Ref(imm.index, kNullable));
Value* value = Push(imm.array_type->element_type());
CALL_INTERFACE_IF_REACHABLE(ArrayGet, array_obj, imm, index, true,
value);
return opcode_length + imm.length;
}
case kExprArraySet: {
ArrayIndexImmediate<validate> imm(this, this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, imm)) return 0;
if (!VALIDATE(imm.array_type->mutability())) {
this->DecodeError("setting element of immutable array");
return 0;
}
Value value = Pop(2, imm.array_type->element_type().Unpacked());
Value index = Pop(1, kWasmI32);
Value array_obj = Pop(0, ValueType::Ref(imm.index, kNullable));
CALL_INTERFACE_IF_REACHABLE(ArraySet, array_obj, imm, index, value);
return opcode_length + imm.length;
}
case kExprArrayLen: {
ArrayIndexImmediate<validate> imm(this, this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, imm)) return 0;
Value array_obj = Pop(0, ValueType::Ref(imm.index, kNullable));
Value* value = Push(kWasmI32);
CALL_INTERFACE_IF_REACHABLE(ArrayLen, array_obj, value);
return opcode_length + imm.length;
}
case kExprI31New: {
Value input = Pop(0, kWasmI32);
Value* value = Push(kWasmI31Ref);
CALL_INTERFACE_IF_REACHABLE(I31New, input, value);
return opcode_length;
}
case kExprI31GetS: {
Value i31 = Pop(0, kWasmI31Ref);
Value* value = Push(kWasmI32);
CALL_INTERFACE_IF_REACHABLE(I31GetS, i31, value);
return opcode_length;
}
case kExprI31GetU: {
Value i31 = Pop(0, kWasmI31Ref);
Value* value = Push(kWasmI32);
CALL_INTERFACE_IF_REACHABLE(I31GetU, i31, value);
return opcode_length;
}
case kExprRttCanon: {
HeapTypeImmediate<validate> imm(this->enabled_, this,
this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, imm)) return 0;
Value* value = Push(ValueType::Rtt(imm.type, 1));
CALL_INTERFACE_IF_REACHABLE(RttCanon, imm, value);
return opcode_length + imm.length;
}
case kExprRttSub: {
// TODO(7748): The proposal currently includes additional immediates
// here: the subtyping depth <n> and the "parent type", see:
// https://github.com/WebAssembly/gc/commit/20a80e34 .
// If these immediates don't get dropped (in the spirit of
// https://github.com/WebAssembly/function-references/pull/31 ),
// implement them here.
HeapTypeImmediate<validate> imm(this->enabled_, this,
this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, imm)) return 0;
Value parent = Pop(0);
if (parent.type.is_bottom()) {
Push(kWasmBottom);
} else {
// TODO(7748): Consider exposing "IsSubtypeOfHeap(HeapType t1, t2)" so
// we can avoid creating (ref heaptype) wrappers here.
if (!VALIDATE(parent.type.is_rtt() &&
IsSubtypeOf(ValueType::Ref(imm.type, kNonNullable),
ValueType::Ref(parent.type.heap_type(),
kNonNullable),
this->module_))) {
this->DecodeError("rtt.sub requires a supertype rtt on stack");
return 0;
}
Value* value =
Push(ValueType::Rtt(imm.type, parent.type.depth() + 1));
CALL_INTERFACE_IF_REACHABLE(RttSub, imm, parent, value);
}
return opcode_length + imm.length;
}
case kExprRefTest: {
// "Tests whether {obj}'s runtime type is a runtime subtype of {rtt}."
HeapTypeImmediate<validate> obj_type(this->enabled_, this,
this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, obj_type)) return 0;
int len = opcode_length + obj_type.length;
HeapTypeImmediate<validate> rtt_type(this->enabled_, this,
this->pc_ + len);
if (!this->Validate(this->pc_ + len, rtt_type)) return 0;
len += rtt_type.length;
// The static type of {obj} must be a supertype of the {rtt}'s type.
if (!VALIDATE(IsSubtypeOf(ValueType::Ref(rtt_type.type, kNonNullable),
ValueType::Ref(obj_type.type, kNonNullable),
this->module_))) {
this->DecodeError(
"ref.test: rtt type must be subtype of object type");
return 0;
}
Value rtt = Pop(1);
if (!VALIDATE(
(rtt.type.is_rtt() && rtt.type.heap_type() == rtt_type.type) ||
rtt.type == kWasmBottom)) {
this->DecodeError("ref.test: expected rtt for type %s but got %s",
rtt_type.type.name().c_str(),
rtt.type.name().c_str());
return 0;
}
Value obj = Pop(0, ValueType::Ref(obj_type.type, kNullable));
Value* value = Push(kWasmI32);
CALL_INTERFACE_IF_REACHABLE(RefTest, obj, rtt, value);
return len;
}
case kExprRefCast: {
HeapTypeImmediate<validate> obj_type(this->enabled_, this,
this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, obj_type)) return 0;
int len = opcode_length + obj_type.length;
HeapTypeImmediate<validate> rtt_type(this->enabled_, this,
this->pc_ + len);
if (!this->Validate(this->pc_ + len, rtt_type)) return 0;
len += rtt_type.length;
if (!VALIDATE(IsSubtypeOf(ValueType::Ref(rtt_type.type, kNonNullable),
ValueType::Ref(obj_type.type, kNonNullable),
this->module_))) {
this->DecodeError(
"ref.cast: rtt type must be subtype of object type");
return 0;
}
Value rtt = Pop(1);
if (!VALIDATE(
(rtt.type.is_rtt() && rtt.type.heap_type() == rtt_type.type) ||
rtt.type == kWasmBottom)) {
this->DecodeError("ref.cast: expected rtt for type %s but got %s",
rtt_type.type.name().c_str(),
rtt.type.name().c_str());
return 0;
}
Value obj = Pop(0, ValueType::Ref(obj_type.type, kNullable));
Value* value = Push(ValueType::Ref(rtt_type.type, kNonNullable));
CALL_INTERFACE_IF_REACHABLE(RefCast, obj, rtt, value);
return len;
}
case kExprBrOnCast: {
BranchDepthImmediate<validate> branch_depth(this,
this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, branch_depth,
control_.size())) {
return 0;
}
// TODO(7748): If the heap type immediates remain in the spec, read
// them here.
Value rtt = Pop(1);
if (!VALIDATE(rtt.type.is_rtt() || rtt.type.is_bottom())) {
this->DecodeError("br_on_cast[1]: expected rtt on stack");
return 0;
}
Value obj = Pop(0);
if (!VALIDATE(obj.type.is_object_reference_type() ||
rtt.type.is_bottom())) {
this->DecodeError("br_on_cast[0]: expected reference on stack");
return 0;
}
// The static type of {obj} must be a supertype of {rtt}'s type.
if (!VALIDATE(
rtt.type.is_bottom() || obj.type.is_bottom() ||
IsSubtypeOf(ValueType::Ref(rtt.type.heap_type(), kNonNullable),
ValueType::Ref(obj.type.heap_type(), kNonNullable),
this->module_))) {
this->DecodeError(
"br_on_cast: rtt type must be a subtype of object type");
return 0;
}
Control* c = control_at(branch_depth.depth);
Value* result_on_branch =
Push(rtt.type.is_bottom()
? kWasmBottom
: ValueType::Ref(rtt.type.heap_type(), kNonNullable));
TypeCheckBranchResult check_result = TypeCheckBranch(c, true);
if (V8_LIKELY(check_result == kReachableBranch)) {
CALL_INTERFACE(BrOnCast, obj, rtt, result_on_branch,
branch_depth.depth);
c->br_merge()->reached = true;
} else if (check_result == kInvalidStack) {
return 0;
}
Pop(0); // Drop {result_on_branch}, restore original value.
Value* result_on_fallthrough = Push(obj.type);
*result_on_fallthrough = obj;
return opcode_length + branch_depth.length;
}
default:
this->DecodeError("invalid gc opcode");
return 0;
}
}
uint32_t DecodeAtomicOpcode(WasmOpcode opcode, uint32_t opcode_length) {
ValueType ret_type;
const FunctionSig* sig = WasmOpcodes::Signature(opcode);
if (!VALIDATE(sig != nullptr)) {
this->DecodeError("invalid atomic opcode");
return 0;
}
MachineType memtype;
switch (opcode) {
#define CASE_ATOMIC_STORE_OP(Name, Type) \
case kExpr##Name: { \
memtype = MachineType::Type(); \
ret_type = kWasmStmt; \
break; /* to generic mem access code below */ \
}
ATOMIC_STORE_OP_LIST(CASE_ATOMIC_STORE_OP)
#undef CASE_ATOMIC_OP
#define CASE_ATOMIC_OP(Name, Type) \
case kExpr##Name: { \
memtype = MachineType::Type(); \
ret_type = GetReturnType(sig); \
break; /* to generic mem access code below */ \
}
ATOMIC_OP_LIST(CASE_ATOMIC_OP)
#undef CASE_ATOMIC_OP
case kExprAtomicFence: {
byte zero =
this->template read_u8<validate>(this->pc_ + opcode_length, "zero");
if (!VALIDATE(zero == 0)) {
this->DecodeError(this->pc_ + opcode_length,
"invalid atomic operand");
return 0;
}
CALL_INTERFACE_IF_REACHABLE(AtomicFence);
return 1 + opcode_length;
}
default:
this->DecodeError("invalid atomic opcode");
return 0;
}
if (!CheckHasMemory()) return 0;
MemoryAccessImmediate<validate> imm(
this, this->pc_ + opcode_length,
ElementSizeLog2Of(memtype.representation()));
// TODO(10949): Fix this for memory64 (index type should be kWasmI64
// then).
CHECK(!this->module_->is_memory64);
ArgVector args = PopArgs(sig);
Value* result = ret_type == kWasmStmt ? nullptr : Push(GetReturnType(sig));
CALL_INTERFACE_IF_REACHABLE(AtomicOp, opcode, VectorOf(args), imm, result);
return opcode_length + imm.length;
}
unsigned DecodeNumericOpcode(WasmOpcode opcode, uint32_t opcode_length) {
const FunctionSig* sig = WasmOpcodes::Signature(opcode);
if (!VALIDATE(sig != nullptr)) {
this->DecodeError("invalid numeric opcode");
return 0;
}
switch (opcode) {
case kExprI32SConvertSatF32:
case kExprI32UConvertSatF32:
case kExprI32SConvertSatF64:
case kExprI32UConvertSatF64:
case kExprI64SConvertSatF32:
case kExprI64UConvertSatF32:
case kExprI64SConvertSatF64:
case kExprI64UConvertSatF64: {
BuildSimpleOperator(opcode, sig);
return opcode_length;
}
case kExprMemoryInit: {
MemoryInitImmediate<validate> imm(this, this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, imm)) return 0;
Value size = Pop(2, sig->GetParam(2));
Value src = Pop(1, sig->GetParam(1));
Value dst = Pop(0, sig->GetParam(0));
CALL_INTERFACE_IF_REACHABLE(MemoryInit, imm, dst, src, size);
return opcode_length + imm.length;
}
case kExprDataDrop: {
DataDropImmediate<validate> imm(this, this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, imm)) return 0;
CALL_INTERFACE_IF_REACHABLE(DataDrop, imm);
return opcode_length + imm.length;
}
case kExprMemoryCopy: {
MemoryCopyImmediate<validate> imm(this, this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, imm)) return 0;
Value size = Pop(2, sig->GetParam(2));
Value src = Pop(1, sig->GetParam(1));
Value dst = Pop(0, sig->GetParam(0));
CALL_INTERFACE_IF_REACHABLE(MemoryCopy, imm, dst, src, size);
return opcode_length + imm.length;
}
case kExprMemoryFill: {
MemoryIndexImmediate<validate> imm(this, this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, imm)) return 0;
Value size = Pop(2, sig->GetParam(2));
Value value = Pop(1, sig->GetParam(1));
Value dst = Pop(0, sig->GetParam(0));
CALL_INTERFACE_IF_REACHABLE(MemoryFill, imm, dst, value, size);
return opcode_length + imm.length;
}
case kExprTableInit: {
TableInitImmediate<validate> imm(this, this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, imm)) return 0;
ArgVector args = PopArgs(sig);
CALL_INTERFACE_IF_REACHABLE(TableInit, imm, VectorOf(args));
return opcode_length + imm.length;
}
case kExprElemDrop: {
ElemDropImmediate<validate> imm(this, this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, imm)) return 0;
CALL_INTERFACE_IF_REACHABLE(ElemDrop, imm);
return opcode_length + imm.length;
}
case kExprTableCopy: {
TableCopyImmediate<validate> imm(this, this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, imm)) return 0;
ArgVector args = PopArgs(sig);
CALL_INTERFACE_IF_REACHABLE(TableCopy, imm, VectorOf(args));
return opcode_length + imm.length;
}
case kExprTableGrow: {
TableIndexImmediate<validate> imm(this, this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, imm)) return 0;
Value delta = Pop(1, sig->GetParam(1));
Value value = Pop(0, this->module_->tables[imm.index].type);
Value* result = Push(kWasmI32);
CALL_INTERFACE_IF_REACHABLE(TableGrow, imm, value, delta, result);
return opcode_length + imm.length;
}
case kExprTableSize: {
TableIndexImmediate<validate> imm(this, this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, imm)) return 0;
Value* result = Push(kWasmI32);
CALL_INTERFACE_IF_REACHABLE(TableSize, imm, result);
return opcode_length + imm.length;
}
case kExprTableFill: {
TableIndexImmediate<validate> imm(this, this->pc_ + opcode_length);
if (!this->Validate(this->pc_ + opcode_length, imm)) return 0;
Value count = Pop(2, sig->GetParam(2));
Value value = Pop(1, this->module_->tables[imm.index].type);
Value start = Pop(0, sig->GetParam(0));
CALL_INTERFACE_IF_REACHABLE(TableFill, imm, start, value, count);
return opcode_length + imm.length;
}
default:
this->DecodeError("invalid numeric opcode");
return 0;
}
}
void DoReturn() {
size_t return_count = this->sig_->return_count();
if (return_count > 1) {
this->detected_->Add(kFeature_mv);
}
DCHECK_GE(stack_size(), return_count);
Vector<Value> return_values =
Vector<Value>{stack_end_ - return_count, return_count};
CALL_INTERFACE_IF_REACHABLE(DoReturn, return_values);
}
V8_INLINE void EnsureStackSpace(int slots_needed) {
if (V8_LIKELY(stack_capacity_end_ - stack_end_ >= slots_needed)) return;
GrowStackSpace(slots_needed);
}
V8_NOINLINE void GrowStackSpace(int slots_needed) {
size_t new_stack_capacity =
std::max(size_t{8},
base::bits::RoundUpToPowerOfTwo(stack_size() + slots_needed));
Value* new_stack =
this->zone()->template NewArray<Value>(new_stack_capacity);
if (stack_) {
std::copy(stack_, stack_end_, new_stack);
this->zone()->DeleteArray(stack_, stack_capacity_end_ - stack_);
}
stack_end_ = new_stack + (stack_end_ - stack_);
stack_ = new_stack;
stack_capacity_end_ = new_stack + new_stack_capacity;
}
V8_INLINE Value* Push(ValueType type) {
DCHECK_NE(kWasmStmt, type);
// {EnsureStackSpace} should have been called before, either in the central
// decoding loop, or individually if more than one element is pushed.
DCHECK_GT(stack_capacity_end_, stack_end_);
*stack_end_ = Value{this->pc_, type};
++stack_end_;
return stack_end_ - 1;
}
void PushMergeValues(Control* c, Merge<Value>* merge) {
DCHECK_EQ(c, &control_.back());
DCHECK(merge == &c->start_merge || merge == &c->end_merge);
DCHECK_LE(stack_ + c->stack_depth, stack_end_);
stack_end_ = stack_ + c->stack_depth;
if (merge->arity == 1) {
// {EnsureStackSpace} should have been called before in the central
// decoding loop.
DCHECK_GT(stack_capacity_end_, stack_end_);
*stack_end_++ = merge->vals.first;
} else {
EnsureStackSpace(merge->arity);
for (uint32_t i = 0; i < merge->arity; i++) {
*stack_end_++ = merge->vals.array[i];
}
}
DCHECK_EQ(c->stack_depth + merge->arity, stack_size());
}
Value* PushReturns(const FunctionSig* sig) {
size_t return_count = sig->return_count();
EnsureStackSpace(static_cast<int>(return_count));
for (size_t i = 0; i < return_count; ++i) {
Push(sig->GetReturn(i));
}
return stack_end_ - return_count;
}
// We do not inline these functions because doing so causes a large binary
// size increase. Not inlining them should not create a performance
// degradation, because their invocations are guarded by V8_LIKELY.
V8_NOINLINE void PopTypeError(int index, Value val, ValueType expected) {
this->DecodeError(val.pc(), "%s[%d] expected type %s, found %s of type %s",
SafeOpcodeNameAt(this->pc_), index,
expected.name().c_str(), SafeOpcodeNameAt(val.pc()),
val.type.name().c_str());
}
V8_NOINLINE void NotEnoughArgumentsError(int index) {
this->DecodeError(
"not enough arguments on the stack for %s, expected %d more",
SafeOpcodeNameAt(this->pc_), index + 1);
}
V8_INLINE Value Pop(int index, ValueType expected) {
Value val = Pop(index);
if (!VALIDATE(IsSubtypeOf(val.type, expected, this->module_) ||
val.type == kWasmBottom || expected == kWasmBottom)) {
PopTypeError(index, val, expected);
}
return val;
}
V8_INLINE Value Pop(int index) {
DCHECK(!control_.empty());
uint32_t limit = control_.back().stack_depth;
if (stack_size() <= limit) {
// Popping past the current control start in reachable code.
if (!VALIDATE(control_.back().unreachable())) {
NotEnoughArgumentsError(index);
}
return UnreachableValue(this->pc_);
}
DCHECK_LT(stack_, stack_end_);
stack_end_--;
return *stack_end_;
}
// Pops values from the stack, as defined by {merge}. Thereby we type-check
// unreachable merges. Afterwards the values are pushed again on the stack
// according to the signature in {merge}. This is done so follow-up validation
// is possible.
bool TypeCheckUnreachableMerge(Merge<Value>& merge, bool conditional_branch) {
int arity = merge.arity;
// For conditional branches, stack value '0' is the condition of the branch,
// and the result values start at index '1'.
int index_offset = conditional_branch ? 1 : 0;
for (int i = arity - 1; i >= 0; --i) Pop(index_offset + i, merge[i].type);
// Push values of the correct type back on the stack.
EnsureStackSpace(arity);
for (int i = 0; i < arity; ++i) Push(merge[i].type);
return this->ok();
}
int startrel(const byte* ptr) { return static_cast<int>(ptr - this->start_); }
void FallThruTo(Control* c) {
DCHECK_EQ(c, &control_.back());
if (!TypeCheckFallThru()) return;
if (!c->reachable()) return;
if (!c->is_loop()) CALL_INTERFACE(FallThruTo, c);
c->end_merge.reached = true;
}
bool TypeCheckMergeValues(Control* c, Merge<Value>* merge) {
// This is a CHECK instead of a DCHECK because {validate} is a constexpr,
// and a CHECK makes the whole function unreachable.
static_assert(validate, "Call this function only within VALIDATE");
DCHECK(merge == &c->start_merge || merge == &c->end_merge);
DCHECK_GE(stack_size(), c->stack_depth + merge->arity);
// The computation of {stack_values} is only valid if {merge->arity} is >0.
DCHECK_LT(0, merge->arity);
Value* stack_values = stack_end_ - merge->arity;
// Typecheck the topmost {merge->arity} values on the stack.
for (uint32_t i = 0; i < merge->arity; ++i) {
Value& val = stack_values[i];
Value& old = (*merge)[i];
if (!VALIDATE(IsSubtypeOf(val.type, old.type, this->module_))) {
this->DecodeError("type error in merge[%u] (expected %s, got %s)", i,
old.type.name().c_str(), val.type.name().c_str());
return false;
}
}
return true;
}
bool TypeCheckOneArmedIf(Control* c) {
static_assert(validate, "Call this function only within VALIDATE");
DCHECK(c->is_onearmed_if());
DCHECK_EQ(c->start_merge.arity, c->end_merge.arity);
for (uint32_t i = 0; i < c->start_merge.arity; ++i) {
Value& start = c->start_merge[i];
Value& end = c->end_merge[i];
if (!VALIDATE(IsSubtypeOf(start.type, end.type, this->module_))) {
this->DecodeError("type error in merge[%u] (expected %s, got %s)", i,
end.type.name().c_str(), start.type.name().c_str());
return false;
}
}
return true;
}
bool TypeCheckFallThru() {
static_assert(validate, "Call this function only within VALIDATE");
Control& c = control_.back();
if (V8_LIKELY(c.reachable())) {
uint32_t expected = c.end_merge.arity;
DCHECK_GE(stack_size(), c.stack_depth);
uint32_t actual = stack_size() - c.stack_depth;
// Fallthrus must match the arity of the control exactly.
if (!VALIDATE(actual == expected)) {
this->DecodeError(
"expected %u elements on the stack for fallthru to @%d, found %u",
expected, startrel(c.pc()), actual);
return false;
}
if (expected == 0) return true; // Fast path.
return TypeCheckMergeValues(&c, &c.end_merge);
}
// Type-check an unreachable fallthru. First we do an arity check, then a
// type check. Note that type-checking may require an adjustment of the
// stack, if some stack values are missing to match the block signature.
Merge<Value>& merge = c.end_merge;
int arity = static_cast<int>(merge.arity);
int available = static_cast<int>(stack_size()) - c.stack_depth;
// For fallthrus, not more than the needed values should be available.
if (!VALIDATE(available <= arity)) {
this->DecodeError(
"expected %u elements on the stack for fallthru to @%d, found %u",
arity, startrel(c.pc()), available);
return false;
}
// Pop all values from the stack for type checking of existing stack
// values.
return TypeCheckUnreachableMerge(merge, false);
}
enum TypeCheckBranchResult {
kReachableBranch,
kUnreachableBranch,
kInvalidStack,
};
TypeCheckBranchResult TypeCheckBranch(Control* c, bool conditional_branch) {
if (V8_LIKELY(control_.back().reachable())) {
// We only do type-checking here. This is only needed during validation.
if (!validate) return kReachableBranch;
// Branches must have at least the number of values expected; can have
// more.
uint32_t expected = c->br_merge()->arity;
if (expected == 0) return kReachableBranch; // Fast path.
DCHECK_GE(stack_size(), control_.back().stack_depth);
uint32_t actual =
static_cast<uint32_t>(stack_size()) - control_.back().stack_depth;
if (!VALIDATE(actual >= expected)) {
this->DecodeError(
"expected %u elements on the stack for br to @%d, found %u",
expected, startrel(c->pc()), actual);
return kInvalidStack;
}
return TypeCheckMergeValues(c, c->br_merge()) ? kReachableBranch
: kInvalidStack;
}
return TypeCheckUnreachableMerge(*c->br_merge(), conditional_branch)
? kUnreachableBranch
: kInvalidStack;
}
bool TypeCheckReturn() {
int num_returns = static_cast<int>(this->sig_->return_count());
// No type checking is needed if there are no returns.
if (num_returns == 0) return true;
// Returns must have at least the number of values expected; can have more.
int num_available =
static_cast<int>(stack_size()) - control_.back().stack_depth;
if (!VALIDATE(num_available >= num_returns)) {
this->DecodeError(
"expected %u elements on the stack for return, found %u", num_returns,
num_available);
return false;
}
// Typecheck the topmost {num_returns} values on the stack.
// This line requires num_returns > 0.
Value* stack_values = stack_end_ - num_returns;
for (int i = 0; i < num_returns; ++i) {
Value& val = stack_values[i];
ValueType expected_type = this->sig_->GetReturn(i);
if (!VALIDATE(IsSubtypeOf(val.type, expected_type, this->module_))) {
this->DecodeError("type error in return[%u] (expected %s, got %s)", i,
expected_type.name().c_str(),
val.type.name().c_str());
return false;
}
}
return true;
}
void onFirstError() override {
this->end_ = this->pc_; // Terminate decoding loop.
this->current_code_reachable_ = false;
TRACE(" !%s\n", this->error_.message().c_str());
CALL_INTERFACE(OnFirstError);
}
int BuildSimplePrototypeOperator(WasmOpcode opcode) {
if (opcode == kExprRefEq) {
CHECK_PROTOTYPE_OPCODE(gc);
}
const FunctionSig* sig = WasmOpcodes::Signature(opcode);
return BuildSimpleOperator(opcode, sig);
}
int BuildSimpleOperator(WasmOpcode opcode, const FunctionSig* sig) {
DCHECK_GE(1, sig->return_count());
ValueType ret = sig->return_count() == 0 ? kWasmStmt : sig->GetReturn(0);
if (sig->parameter_count() == 1) {
return BuildSimpleOperator(opcode, ret, sig->GetParam(0));
} else {
DCHECK_EQ(2, sig->parameter_count());
return BuildSimpleOperator(opcode, ret, sig->GetParam(0),
sig->GetParam(1));
}
}
int BuildSimpleOperator(WasmOpcode opcode, ValueType return_type,
ValueType arg_type) {
Value val = Pop(0, arg_type);
Value* ret = return_type == kWasmStmt ? nullptr : Push(return_type);
CALL_INTERFACE_IF_REACHABLE(UnOp, opcode, val, ret);
return 1;
}
int BuildSimpleOperator(WasmOpcode opcode, ValueType return_type,
ValueType lhs_type, ValueType rhs_type) {
Value rval = Pop(1, rhs_type);
Value lval = Pop(0, lhs_type);
Value* ret = return_type == kWasmStmt ? nullptr : Push(return_type);
CALL_INTERFACE_IF_REACHABLE(BinOp, opcode, lval, rval, ret);
return 1;
}
#define DEFINE_SIMPLE_SIG_OPERATOR(sig, ...) \
int BuildSimpleOperator_##sig(WasmOpcode opcode) { \
return BuildSimpleOperator(opcode, __VA_ARGS__); \
}
FOREACH_SIGNATURE(DEFINE_SIMPLE_SIG_OPERATOR)
#undef DEFINE_SIMPLE_SIG_OPERATOR
};
#undef CALL_INTERFACE
#undef CALL_INTERFACE_IF_REACHABLE
#undef CALL_INTERFACE_IF_PARENT_REACHABLE
class EmptyInterface {
public:
static constexpr Decoder::ValidateFlag validate = Decoder::kFullValidation;
using Value = ValueBase<validate>;
using Control = ControlBase<Value, validate>;
using FullDecoder = WasmFullDecoder<validate, EmptyInterface>;
#define DEFINE_EMPTY_CALLBACK(name, ...) \
void name(FullDecoder* decoder, ##__VA_ARGS__) {}
INTERFACE_FUNCTIONS(DEFINE_EMPTY_CALLBACK)
#undef DEFINE_EMPTY_CALLBACK
};
#undef TRACE
#undef TRACE_INST_FORMAT
#undef VALIDATE
#undef CHECK_PROTOTYPE_OPCODE
} // namespace wasm
} // namespace internal
} // namespace v8
#endif // V8_WASM_FUNCTION_BODY_DECODER_IMPL_H_