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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->error("Invalid opcode (enable with --experimental-wasm-" #feat ")"); \
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)
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) {
uint8_t uint_7_mask = 0x7F;
uint8_t code = static_cast<ValueTypeCode>(heap_index) & uint_7_mask;
switch (code) {
case kLocalFuncRef:
case kLocalExnRef:
case kLocalEqRef:
case kLocalExternRef:
case kLocalI31Ref: {
HeapType result = HeapType::from_code(code);
if (!VALIDATE(enabled.contains(feature_for_heap_type(result)))) {
decoder->errorf(
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:
if (validate) {
decoder->errorf(pc, "Unknown heap type %" PRId64, heap_index);
}
return HeapType(HeapType::kBottom);
}
UNREACHABLE();
} else {
if (!VALIDATE(enabled.has_typed_funcref())) {
decoder->error(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)) {
decoder->errorf(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 kLocalFuncRef:
case kLocalExnRef:
case kLocalEqRef:
case kLocalExternRef:
case kLocalI31Ref: {
HeapType heap_type = HeapType::from_code(code);
ValueType result = ValueType::Ref(heap_type, kNullable);
if (!VALIDATE(enabled.contains(feature_for_heap_type(heap_type)))) {
decoder->errorf(
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 kLocalI32:
return kWasmI32;
case kLocalI64:
return kWasmI64;
case kLocalF32:
return kWasmF32;
case kLocalF64:
return kWasmF64;
case kLocalRef:
case kLocalOptRef: {
Nullability nullability = code == kLocalOptRef ? kNullable : kNonNullable;
if (!VALIDATE(enabled.has_typed_funcref())) {
decoder->errorf(pc,
"Invalid type 'ref%s', 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 kLocalRtt: {
if (!VALIDATE(enabled.has_gc())) {
decoder->error(
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");
// TODO(7748): Introduce a proper limit.
const uint32_t kMaxRttSubtypingDepth = 7;
if (!VALIDATE(depth <= kMaxRttSubtypingDepth)) {
decoder->errorf(pc,
"subtyping depth %u is greater than the maximum depth "
"%u supported by V8",
depth, kMaxRttSubtypingDepth);
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 kLocalS128:
if (!VALIDATE(enabled.has_simd())) {
decoder->error(pc,
"invalid value type 'Simd128', enable with "
"--experimental-wasm-simd");
return kWasmBottom;
}
return kWasmS128;
case kLocalVoid:
case kLocalI8:
case kLocalI16:
// Although these types are included in ValueType, they are technically
// not value types and are only used in specific contexts. The caller of
// this function is responsible to check for them separately.
break;
}
// Malformed modules specifying invalid types can get here.
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)) {
decoder->error(
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)) {
decoder->error(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) {
if ((static_cast<uint8_t>(block_type) & byte{0x7f}) == kLocalVoid) return;
type = value_type_reader::read_value_type<validate>(decoder, pc, &length,
enabled);
if (!VALIDATE(type != kWasmBottom)) {
decoder->errorf(pc, "Invalid block type %" PRId64, block_type);
}
} else {
if (!VALIDATE(enabled.has_mv())) {
decoder->errorf(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)) {
decoder->errorf(pc, "expected memory index 0, found %u", index);
}
}
};
template <Decoder::ValidateFlag validate>
struct TableIndexImmediate {
uint32_t index = 0;
unsigned 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())) {
decoder->errorf(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)) {
decoder->errorf(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);
}
};
// An entry on the value stack.
struct ValueBase {
const byte* pc = nullptr;
ValueType type = kWasmStmt;
ValueBase(const byte* pc, ValueType type) : pc(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>
struct ControlBase {
ControlKind kind = kControlBlock;
uint32_t locals_count = 0;
uint32_t stack_depth = 0; // stack height at the beginning of the construct.
const uint8_t* pc = nullptr;
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)
: kind(kind),
locals_count(locals_count),
stack_depth(stack_depth),
pc(pc),
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, 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(StoreMem, StoreType type, const MemoryAccessImmediate<validate>& imm, \
const Value& index, const Value& value) \
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(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(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(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 {
return static_cast<uint32_t>(local_types_.size());
}
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());
}
// 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_postion 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<kValidate>(pc, &length, "local decls count");
if (!VALIDATE(ok())) {
error(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())) {
error(end(), "expected more local decls but reached end of input");
return false;
}
uint32_t count =
read_u32v<kValidate>(pc + *total_length, &length, "local count");
if (!VALIDATE(ok())) {
error(pc + *total_length, "invalid local count");
return false;
}
DCHECK_LE(local_types_.size(), kV8MaxWasmFunctionLocals);
if (!VALIDATE(count <= kV8MaxWasmFunctionLocals - local_types_.size())) {
error(pc + *total_length, "local count too large");
return false;
}
*total_length += length;
ValueType type = value_type_reader::read_value_type<kValidate>(
this, pc + *total_length, &length, enabled_);
if (!VALIDATE(type != kWasmBottom)) {
error(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;
}
}
DCHECK(ok());
return true;
}
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())) {
errorf(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)) {
errorf(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())) {
errorf(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;
errorf(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())) {
errorf(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)) {
errorf(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)) {
errorf(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())) {
error("function table has to exist to execute call_indirect");
return false;
}
if (!VALIDATE(module_->tables[imm.table_index].type == kWasmFuncRef)) {
error("table of call_indirect must be of type funcref");
return false;
}
if (!Complete(imm)) {
errorf(pc, "invalid signature index: #%u", imm.sig_index);
return false;
}
return true;
}
inline bool Validate(const byte* pc, BranchDepthImmediate<validate>& imm,
size_t control_depth) {
if (!VALIDATE(imm.depth < control_depth)) {
errorf(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)) {
errorf(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)) {
error(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)) {
error(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)) {
errorf(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())) {
errorf(pc, "invalid function index: %u", imm.index);
return false;
}
if (!VALIDATE(module_->functions[imm.index].declared)) {
this->errorf(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)) {
errorf(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)) {
errorf(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)) {
errorf(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())) {
errorf(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())) {
errorf(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_))) {
errorf(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())) {
errorf(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_))) {
errorf(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())) {
error(pc, "invalid heap type");
return false;
}
if (!VALIDATE(imm.type.is_generic() ||
module_->has_array(imm.type.ref_index()) ||
module_->has_struct(imm.type.ref_index()))) {
errorf(
pc,
"Type index %u does not refer to a struct or array type definition",
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: {
byte numeric_index =
decoder->read_u8<validate>(pc + 1, "numeric_index");
WasmOpcode opcode =
static_cast<WasmOpcode>(kNumericPrefix << 8 | numeric_index);
switch (opcode) {
case kExprI32SConvertSatF32:
case kExprI32UConvertSatF32:
case kExprI32SConvertSatF64:
case kExprI32UConvertSatF64:
case kExprI64SConvertSatF32:
case kExprI64UConvertSatF32:
case kExprI64SConvertSatF64:
case kExprI64UConvertSatF64:
return 2;
case kExprMemoryInit: {
MemoryInitImmediate<validate> imm(decoder, pc + 2);
return 2 + imm.length;
}
case kExprDataDrop: {
DataDropImmediate<validate> imm(decoder, pc + 2);
return 2 + imm.length;
}
case kExprMemoryCopy: {
MemoryCopyImmediate<validate> imm(decoder, pc + 2);
return 2 + imm.length;
}
case kExprMemoryFill: {
MemoryIndexImmediate<validate> imm(decoder, pc + 2);
return 2 + imm.length;
}
case kExprTableInit: {
TableInitImmediate<validate> imm(decoder, pc + 2);
return 2 + imm.length;
}
case kExprElemDrop: {
ElemDropImmediate<validate> imm(decoder, pc + 2);
return 2 + imm.length;
}
case kExprTableCopy: {
TableCopyImmediate<validate> imm(decoder, pc + 2);
return 2 + imm.length;
}
case kExprTableGrow:
case kExprTableSize:
case kExprTableFill: {
TableIndexImmediate<validate> imm(decoder, pc + 2);
return 2 + imm.length;
}
default:
decoder->error(pc, "invalid numeric opcode");
return 2;
}
}
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 1 + length;
#define DECLARE_OPCODE_CASE(name, opcode, sig) case kExpr##name:
FOREACH_SIMD_1_OPERAND_OPCODE(DECLARE_OPCODE_CASE)
#undef DECLARE_OPCODE_CASE
return 2 + length;
#define DECLARE_OPCODE_CASE(name, opcode, sig) case kExpr##name:
FOREACH_SIMD_MEM_OPCODE(DECLARE_OPCODE_CASE)
FOREACH_SIMD_POST_MVP_MEM_OPCODE(DECLARE_OPCODE_CASE)
#undef DECLARE_OPCODE_CASE
{
MemoryAccessImmediate<validate> imm(decoder, pc + length + 1,
UINT32_MAX);
return 1 + length + imm.length;
}
// Shuffles require a byte per lane, or 16 immediate bytes.
case kExprS128Const:
case kExprS8x16Shuffle:
return 1 + length + kSimd128Size;
default:
decoder->error(pc, "invalid SIMD opcode");
return 1 + length;
}
}
case kAtomicPrefix: {
byte atomic_index = decoder->read_u8<validate>(pc + 1, "atomic_index");
WasmOpcode opcode =
static_cast<WasmOpcode>(kAtomicPrefix << 8 | 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 + 2, UINT32_MAX);
return 2 + 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 2 + 1;
}
default:
decoder->error(pc, "invalid Atomics opcode");
return 2;
}
}
case kGCPrefix: {
byte gc_index = decoder->read_u8<validate>(pc + 1, "gc_index");
WasmOpcode opcode = static_cast<WasmOpcode>(kGCPrefix << 8 | gc_index);
switch (opcode) {
case kExprStructNewWithRtt:
case kExprStructNewDefault: {
StructIndexImmediate<validate> imm(decoder, pc + 2);
return 2 + imm.length;
}
case kExprStructGet:
case kExprStructGetS:
case kExprStructGetU:
case kExprStructSet: {
FieldIndexImmediate<validate> imm(decoder, pc + 2);
return 2 + imm.length;
}
case kExprArrayNewWithRtt:
case kExprArrayNewDefault:
case kExprArrayGet:
case kExprArrayGetS:
case kExprArrayGetU:
case kExprArraySet:
case kExprArrayLen: {
ArrayIndexImmediate<validate> imm(decoder, pc + 2);
return 2 + imm.length;
}
case kExprBrOnCast: {
BranchDepthImmediate<validate> imm(decoder, pc + 2);
return 2 + 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 + 2);
return 2 + imm.length;
}
case kExprI31New:
case kExprI31GetS:
case kExprI31GetU:
return 2;
case kExprRefTest:
case kExprRefCast: {
HeapTypeImmediate<validate> ht1(WasmFeatures::All(), decoder,
pc + 2);
HeapTypeImmediate<validate> ht2(WasmFeatures::All(), decoder,
pc + 2 + ht1.length);
return 2 + ht1.length + ht2.length;
}
default:
// This is unreachable except for malformed modules.
decoder->error(pc, "invalid gc opcode");
return 2;
}
}
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 kExprStructGet:
case kExprStructGetS:
case kExprStructGetU:
case kExprI31New:
case kExprI31GetS:
case kExprI31GetU:
case kExprArrayLen:
case kExprRttSub:
return {1, 1};
case kExprStructSet:
return {2, 0};
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_;
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)...),
stack_(zone),
control_(zone) {}
Interface& interface() { return interface_; }
bool Decode() {
DCHECK(stack_.empty());
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);
for (uint32_t index = params_count; index < this->num_locals(); index++) {
if (!VALIDATE(this->local_type(index).is_defaultable())) {
this->errorf(
this->pc(),
"Cannot define function-level local of non-defaultable type %s",
this->local_type(index).name().c_str());
}
}
this->consume_bytes(locals_length);
CALL_INTERFACE(StartFunction);
DecodeFunctionBody();
if (!this->failed()) CALL_INTERFACE(FinishFunction);
// Generate a better error message whether the unterminated control
// structure is the function body block or an innner structure.
if (!VALIDATE(control_.empty())) {
if (control_.size() > 1) {
this->error(control_.back().pc, "unterminated control structure");
} else if (control_.size() == 1) {
this->error("function body must end with \"end\" opcode");
}
}
if (!VALIDATE(this->ok())) return this->TraceFailed();
TRACE("wasm-decode %s\n\n", VALIDATE(this->ok()) ? "ok" : "failed");
return true;
}
bool TraceFailed() {
TRACE("wasm-error module+%-6d func+%d: %s\n\n", this->error_.offset(),
this->GetBufferRelativeOffset(this->error_.offset()),
this->error_.message().c_str());
return false;
}
const char* SafeOpcodeNameAt(const byte* pc) {
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::kValidate>(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(kMaxUInt32, stack_.size());
return static_cast<uint32_t>(stack_.size());
}
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_;
ZoneVector<Value> stack_; // stack of values.
ZoneVector<Control> control_; // stack of blocks, loops, and ifs.
// 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->error(this->pc_ - 1, "memory instruction with no memory");
return false;
}
return true;
}
bool CheckHasMemoryForAtomics() {
if (FLAG_wasm_atomics_on_non_shared_memory && CheckHasMemory()) return true;
if (!VALIDATE(this->module_->has_shared_memory)) {
this->error(this->pc_ - 1, "Atomic opcodes used without shared memory");
return false;
}
return true;
}
bool CheckSimdPostMvp(WasmOpcode opcode) {
if (!FLAG_wasm_simd_post_mvp && WasmOpcodes::IsSimdPostMvpOpcode(opcode)) {
this->error(
"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];
WasmOpcode val_opcode = static_cast<WasmOpcode>(*val.pc);
if (WasmOpcodes::IsPrefixOpcode(val_opcode)) {
val_opcode =
decoder_->template read_prefixed_opcode<Decoder::kNoValidate>(
val.pc);
}
Append(" %c@%d:%s", val.type.short_name(),
static_cast<int>(val.pc - decoder_->start_),
WasmOpcodes::OpcodeName(val_opcode));
// If the decoder failed, don't try to decode the immediates, as this
// can trigger a DCHECK failure.
if (decoder_->failed()) continue;
switch (val_opcode) {
case kExprI32Const: {
ImmI32Immediate<Decoder::kNoValidate> imm(decoder_, val.pc + 1);
Append("[%d]", imm.value);
break;
}
case kExprLocalGet:
case kExprLocalSet:
case kExprLocalTee: {
LocalIndexImmediate<Decoder::kNoValidate> imm(decoder_, val.pc + 1);
Append("[%u]", imm.index);
break;
}
case kExprGlobalGet:
case kExprGlobalSet: {
GlobalIndexImmediate<Decoder::kNoValidate> imm(decoder_,
val.pc + 1);
Append("[%u]", imm.index);
break;
}
default:
break;
}
}
}
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->error("catch does not match any try");
return 0;
}
Control* c = &control_.back();
if (!VALIDATE(c->is_try())) {
this->error("catch does not match any try");
return 0;
}
if (!VALIDATE(c->is_incomplete_try())) {
this->error("catch already present for try");
return 0;
}
c->kind = kControlTryCatch;
FallThruTo(c);
stack_.erase(stack_.begin() + c->stack_depth, stack_.end());
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;
size_t value_count = 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.
for (size_t i = 0; i < value_count; ++i) Push(sig->GetParam(i));
Vector<Value> values(stack_.data() + 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 = static_cast<int>(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::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->error(this->pc_, "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())) {