diff options
Diffstat (limited to 'js/src/wasm/WasmOpIter.h')
| -rw-r--r-- | js/src/wasm/WasmOpIter.h | 4239 |
1 files changed, 4239 insertions, 0 deletions
diff --git a/js/src/wasm/WasmOpIter.h b/js/src/wasm/WasmOpIter.h new file mode 100644 index 0000000000..c175921dc9 --- /dev/null +++ b/js/src/wasm/WasmOpIter.h @@ -0,0 +1,4239 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- + * vim: set ts=8 sts=2 et sw=2 tw=80: + * + * Copyright 2016 Mozilla Foundation + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#ifndef wasm_op_iter_h +#define wasm_op_iter_h + +#include "mozilla/CompactPair.h" +#include "mozilla/Poison.h" + +#include <type_traits> + +#include "js/Printf.h" +#include "wasm/WasmIntrinsic.h" +#include "wasm/WasmUtility.h" +#include "wasm/WasmValidate.h" + +namespace js { +namespace wasm { + +// The kind of a control-flow stack item. +enum class LabelKind : uint8_t { + Body, + Block, + Loop, + Then, + Else, + Try, + Catch, + CatchAll, +}; + +// The type of values on the operand stack during validation. This is either a +// ValType or the special type "Bottom". + +class StackType { + PackedTypeCode tc_; + + explicit StackType(PackedTypeCode tc) : tc_(tc) {} + + public: + StackType() : tc_(PackedTypeCode::invalid()) {} + + explicit StackType(const ValType& t) : tc_(t.packed()) { + MOZ_ASSERT(tc_.isValid()); + MOZ_ASSERT(!isStackBottom()); + } + + static StackType bottom() { + return StackType(PackedTypeCode::pack(TypeCode::Limit)); + } + + bool isStackBottom() const { + MOZ_ASSERT(tc_.isValid()); + return tc_.typeCode() == TypeCode::Limit; + } + + // Returns whether this input is nullable when interpreted as an operand. + // When the type is bottom for unreachable code, this returns false as that + // is the most permissive option. + bool isNullableAsOperand() const { + MOZ_ASSERT(tc_.isValid()); + return isStackBottom() ? false : tc_.isNullable(); + } + + ValType valType() const { + MOZ_ASSERT(tc_.isValid()); + MOZ_ASSERT(!isStackBottom()); + return ValType(tc_); + } + + ValType valTypeOr(ValType ifBottom) const { + MOZ_ASSERT(tc_.isValid()); + if (isStackBottom()) { + return ifBottom; + } + return valType(); + } + + ValType asNonNullable() const { + MOZ_ASSERT(tc_.isValid()); + MOZ_ASSERT(!isStackBottom()); + return ValType(tc_.withIsNullable(false)); + } + + bool isValidForUntypedSelect() const { + MOZ_ASSERT(tc_.isValid()); + if (isStackBottom()) { + return true; + } + switch (valType().kind()) { + case ValType::I32: + case ValType::F32: + case ValType::I64: + case ValType::F64: +#ifdef ENABLE_WASM_SIMD + case ValType::V128: +#endif + return true; + default: + return false; + } + } + + bool operator==(const StackType& that) const { + MOZ_ASSERT(tc_.isValid() && that.tc_.isValid()); + return tc_ == that.tc_; + } + + bool operator!=(const StackType& that) const { + MOZ_ASSERT(tc_.isValid() && that.tc_.isValid()); + return tc_ != that.tc_; + } +}; + +#ifdef DEBUG +// Families of opcodes that share a signature and validation logic. +enum class OpKind { + Block, + Loop, + Unreachable, + Drop, + I32, + I64, + F32, + F64, + V128, + Br, + BrIf, + BrTable, + Nop, + Unary, + Binary, + Ternary, + Comparison, + Conversion, + Load, + Store, + TeeStore, + MemorySize, + MemoryGrow, + Select, + GetLocal, + SetLocal, + TeeLocal, + GetGlobal, + SetGlobal, + TeeGlobal, + Call, + CallIndirect, +# ifdef ENABLE_WASM_FUNCTION_REFERENCES + CallRef, +# endif + OldCallDirect, + OldCallIndirect, + Return, + If, + Else, + End, + Wait, + Wake, + Fence, + AtomicLoad, + AtomicStore, + AtomicBinOp, + AtomicCompareExchange, + MemOrTableCopy, + DataOrElemDrop, + MemFill, + MemOrTableInit, + TableFill, + MemDiscard, + TableGet, + TableGrow, + TableSet, + TableSize, + RefNull, + RefFunc, + RefAsNonNull, + BrOnNull, + BrOnNonNull, + StructNew, + StructNewDefault, + StructGet, + StructSet, + ArrayNew, + ArrayNewFixed, + ArrayNewDefault, + ArrayNewData, + ArrayNewElem, + ArrayGet, + ArraySet, + ArrayLen, + ArrayCopy, + RefTestV5, + RefCastV5, + BrOnCastV5, + BrOnCastFailV5, + BrOnNonStructV5, + RefTest, + RefCast, + BrOnCast, + RefConversion, +# ifdef ENABLE_WASM_SIMD + ExtractLane, + ReplaceLane, + LoadLane, + StoreLane, + VectorShift, + VectorShuffle, +# endif + Catch, + CatchAll, + Delegate, + Throw, + Rethrow, + Try, + Intrinsic, +}; + +// Return the OpKind for a given Op. This is used for sanity-checking that +// API users use the correct read function for a given Op. +OpKind Classify(OpBytes op); +#endif + +// Common fields for linear memory access. +template <typename Value> +struct LinearMemoryAddress { + Value base; + uint64_t offset; + uint32_t align; + + LinearMemoryAddress() : offset(0), align(0) {} + LinearMemoryAddress(Value base, uint64_t offset, uint32_t align) + : base(base), offset(offset), align(align) {} +}; + +template <typename ControlItem> +class ControlStackEntry { + // Use a pair to optimize away empty ControlItem. + mozilla::CompactPair<BlockType, ControlItem> typeAndItem_; + + // The "base" of a control stack entry is valueStack_.length() minus + // type().params().length(), i.e., the size of the value stack "below" + // this block. + uint32_t valueStackBase_; + bool polymorphicBase_; + + LabelKind kind_; + + public: + ControlStackEntry(LabelKind kind, BlockType type, uint32_t valueStackBase) + : typeAndItem_(type, ControlItem()), + valueStackBase_(valueStackBase), + polymorphicBase_(false), + kind_(kind) { + MOZ_ASSERT(type != BlockType()); + } + + LabelKind kind() const { return kind_; } + BlockType type() const { return typeAndItem_.first(); } + ResultType resultType() const { return type().results(); } + ResultType branchTargetType() const { + return kind_ == LabelKind::Loop ? type().params() : type().results(); + } + uint32_t valueStackBase() const { return valueStackBase_; } + ControlItem& controlItem() { return typeAndItem_.second(); } + void setPolymorphicBase() { polymorphicBase_ = true; } + bool polymorphicBase() const { return polymorphicBase_; } + + void switchToElse() { + MOZ_ASSERT(kind() == LabelKind::Then); + kind_ = LabelKind::Else; + polymorphicBase_ = false; + } + + void switchToCatch() { + MOZ_ASSERT(kind() == LabelKind::Try || kind() == LabelKind::Catch); + kind_ = LabelKind::Catch; + polymorphicBase_ = false; + } + + void switchToCatchAll() { + MOZ_ASSERT(kind() == LabelKind::Try || kind() == LabelKind::Catch); + kind_ = LabelKind::CatchAll; + polymorphicBase_ = false; + } +}; + +// Track state of the non-defaultable locals. Every time such local is +// initialized, the stack will record at what depth and which local was set. +// On a block end, the "unset" state will be rolled back to how it was before +// the block started. +// +// It is very likely only a few functions will have non-defaultable locals and +// very few locals will be non-defaultable. This class is optimized to be fast +// for this common case. +class UnsetLocalsState { + struct SetLocalEntry { + uint32_t depth; + uint32_t localUnsetIndex; + SetLocalEntry(uint32_t depth_, uint32_t localUnsetIndex_) + : depth(depth_), localUnsetIndex(localUnsetIndex_) {} + }; + using SetLocalsStack = Vector<SetLocalEntry, 16, SystemAllocPolicy>; + using UnsetLocals = Vector<uint32_t, 16, SystemAllocPolicy>; + + static constexpr size_t WordSize = 4; + static constexpr size_t WordBits = WordSize * 8; + + // Bit array of "unset" function locals. Stores only unset states of the + // locals that are declared after the first non-defaultable local. + UnsetLocals unsetLocals_; + // Stack of "set" operations. Contains pair where the first field is a depth, + // and the second field is local id (offset by firstNonDefaultLocal_). + SetLocalsStack setLocalsStack_; + uint32_t firstNonDefaultLocal_; + + public: + UnsetLocalsState() : firstNonDefaultLocal_(UINT32_MAX) {} + + [[nodiscard]] bool init(const ValTypeVector& locals, size_t numParams); + + inline bool isUnset(uint32_t id) const { + if (MOZ_LIKELY(id < firstNonDefaultLocal_)) { + return false; + } + uint32_t localUnsetIndex = id - firstNonDefaultLocal_; + return unsetLocals_[localUnsetIndex / WordBits] & + (1 << (localUnsetIndex % WordBits)); + } + + inline void set(uint32_t id, uint32_t depth) { + MOZ_ASSERT(isUnset(id)); + MOZ_ASSERT(id >= firstNonDefaultLocal_ && + (id - firstNonDefaultLocal_) / WordBits < unsetLocals_.length()); + uint32_t localUnsetIndex = id - firstNonDefaultLocal_; + unsetLocals_[localUnsetIndex / WordBits] ^= 1 + << (localUnsetIndex % WordBits); + // The setLocalsStack_ is reserved upfront in the UnsetLocalsState::init. + // A SetLocalEntry will be pushed only once per local. + setLocalsStack_.infallibleEmplaceBack(depth, localUnsetIndex); + } + + inline void resetToBlock(uint32_t controlDepth) { + while (MOZ_UNLIKELY(setLocalsStack_.length() > 0) && + setLocalsStack_.back().depth > controlDepth) { + uint32_t localUnsetIndex = setLocalsStack_.back().localUnsetIndex; + MOZ_ASSERT(!(unsetLocals_[localUnsetIndex / WordBits] & + (1 << (localUnsetIndex % WordBits)))); + unsetLocals_[localUnsetIndex / WordBits] |= + 1 << (localUnsetIndex % WordBits); + setLocalsStack_.popBack(); + } + } + + int empty() const { return setLocalsStack_.empty(); } +}; + +template <typename Value> +class TypeAndValueT { + // Use a Pair to optimize away empty Value. + mozilla::CompactPair<StackType, Value> tv_; + + public: + TypeAndValueT() : tv_(StackType::bottom(), Value()) {} + explicit TypeAndValueT(StackType type) : tv_(type, Value()) {} + explicit TypeAndValueT(ValType type) : tv_(StackType(type), Value()) {} + TypeAndValueT(StackType type, Value value) : tv_(type, value) {} + TypeAndValueT(ValType type, Value value) : tv_(StackType(type), value) {} + StackType type() const { return tv_.first(); } + void setType(StackType type) { tv_.first() = type; } + Value value() const { return tv_.second(); } + void setValue(Value value) { tv_.second() = value; } +}; + +// An iterator over the bytes of a function body. It performs validation +// and unpacks the data into a usable form. +// +// The MOZ_STACK_CLASS attribute here is because of the use of DebugOnly. +// There's otherwise nothing inherent in this class which would require +// it to be used on the stack. +template <typename Policy> +class MOZ_STACK_CLASS OpIter : private Policy { + public: + using Value = typename Policy::Value; + using ValueVector = typename Policy::ValueVector; + using TypeAndValue = TypeAndValueT<Value>; + using TypeAndValueStack = Vector<TypeAndValue, 32, SystemAllocPolicy>; + using ControlItem = typename Policy::ControlItem; + using Control = ControlStackEntry<ControlItem>; + using ControlStack = Vector<Control, 16, SystemAllocPolicy>; + + enum Kind { + Func, + InitExpr, + }; + + private: + Kind kind_; + Decoder& d_; + const ModuleEnvironment& env_; + + TypeAndValueStack valueStack_; + TypeAndValueStack elseParamStack_; + ControlStack controlStack_; + UnsetLocalsState unsetLocals_; + // The exclusive max index of a global that can be accessed by global.get in + // this expression. When GC is enabled, this is any previously defined + // global. Otherwise this is always set to zero, and only imported immutable + // globals are allowed. + uint32_t maxInitializedGlobalsIndexPlus1_; + +#ifdef DEBUG + OpBytes op_; +#endif + size_t offsetOfLastReadOp_; + + [[nodiscard]] bool readFixedU8(uint8_t* out) { return d_.readFixedU8(out); } + [[nodiscard]] bool readFixedU32(uint32_t* out) { + return d_.readFixedU32(out); + } + [[nodiscard]] bool readVarS32(int32_t* out) { return d_.readVarS32(out); } + [[nodiscard]] bool readVarU32(uint32_t* out) { return d_.readVarU32(out); } + [[nodiscard]] bool readVarS64(int64_t* out) { return d_.readVarS64(out); } + [[nodiscard]] bool readVarU64(uint64_t* out) { return d_.readVarU64(out); } + [[nodiscard]] bool readFixedF32(float* out) { return d_.readFixedF32(out); } + [[nodiscard]] bool readFixedF64(double* out) { return d_.readFixedF64(out); } + + [[nodiscard]] bool readMemOrTableIndex(bool isMem, uint32_t* index); + [[nodiscard]] bool readLinearMemoryAddress(uint32_t byteSize, + LinearMemoryAddress<Value>* addr); + [[nodiscard]] bool readLinearMemoryAddressAligned( + uint32_t byteSize, LinearMemoryAddress<Value>* addr); + [[nodiscard]] bool readBlockType(BlockType* type); + [[nodiscard]] bool readGcTypeIndex(uint32_t* typeIndex); + [[nodiscard]] bool readStructTypeIndex(uint32_t* typeIndex); + [[nodiscard]] bool readArrayTypeIndex(uint32_t* typeIndex); + [[nodiscard]] bool readFuncTypeIndex(uint32_t* typeIndex); + [[nodiscard]] bool readFieldIndex(uint32_t* fieldIndex, + const StructType& structType); + + [[nodiscard]] bool popCallArgs(const ValTypeVector& expectedTypes, + ValueVector* values); + + [[nodiscard]] bool failEmptyStack(); + [[nodiscard]] bool popStackType(StackType* type, Value* value); + [[nodiscard]] bool popWithType(ValType expected, Value* value, + StackType* stackType); + [[nodiscard]] bool popWithType(ValType expected, Value* value); + [[nodiscard]] bool popWithType(ResultType expected, ValueVector* values); + template <typename ValTypeSpanT> + [[nodiscard]] bool popWithTypes(ValTypeSpanT expected, ValueVector* values); + [[nodiscard]] bool popWithRefType(Value* value, StackType* type); + // Check that the top of the value stack has type `expected`, bearing in + // mind that it may be a block type, hence involving multiple values. + // + // If the block's stack contains polymorphic values at its base (because we + // are in unreachable code) then suitable extra values are inserted into the + // value stack, as controlled by `rewriteStackTypes`: if this is true, + // polymorphic values have their types created/updated from `expected`. If + // it is false, such values are left as `StackType::bottom()`. + // + // If `values` is non-null, it is filled in with Value components of the + // relevant stack entries, including those of any new entries created. + [[nodiscard]] bool checkTopTypeMatches(ResultType expected, + ValueVector* values, + bool rewriteStackTypes); + + [[nodiscard]] bool pushControl(LabelKind kind, BlockType type); + [[nodiscard]] bool checkStackAtEndOfBlock(ResultType* type, + ValueVector* values); + [[nodiscard]] bool getControl(uint32_t relativeDepth, Control** controlEntry); + [[nodiscard]] bool checkBranchValueAndPush(uint32_t relativeDepth, + ResultType* type, + ValueVector* values); + [[nodiscard]] bool checkBrTableEntryAndPush(uint32_t* relativeDepth, + ResultType prevBranchType, + ResultType* branchType, + ValueVector* branchValues); + + [[nodiscard]] bool push(StackType t) { return valueStack_.emplaceBack(t); } + [[nodiscard]] bool push(ValType t) { return valueStack_.emplaceBack(t); } + [[nodiscard]] bool push(TypeAndValue tv) { return valueStack_.append(tv); } + [[nodiscard]] bool push(ResultType t) { + for (size_t i = 0; i < t.length(); i++) { + if (!push(t[i])) { + return false; + } + } + return true; + } + void infalliblePush(StackType t) { valueStack_.infallibleEmplaceBack(t); } + void infalliblePush(ValType t) { + valueStack_.infallibleEmplaceBack(StackType(t)); + } + void infalliblePush(TypeAndValue tv) { valueStack_.infallibleAppend(tv); } + + void afterUnconditionalBranch() { + valueStack_.shrinkTo(controlStack_.back().valueStackBase()); + controlStack_.back().setPolymorphicBase(); + } + + inline bool checkIsSubtypeOf(FieldType actual, FieldType expected); + + inline bool checkIsSubtypeOf(RefType actual, RefType expected) { + return checkIsSubtypeOf(ValType(actual).fieldType(), + ValType(expected).fieldType()); + } + inline bool checkIsSubtypeOf(ValType actual, ValType expected) { + return checkIsSubtypeOf(actual.fieldType(), expected.fieldType()); + } + + inline bool checkIsSubtypeOf(ResultType params, ResultType results); + +#ifdef ENABLE_WASM_FUNCTION_REFERENCES + inline bool checkIsSubtypeOf(uint32_t actualTypeIndex, + uint32_t expectedTypeIndex); +#endif + + public: +#ifdef DEBUG + explicit OpIter(const ModuleEnvironment& env, Decoder& decoder, + Kind kind = OpIter::Func) + : kind_(kind), + d_(decoder), + env_(env), + maxInitializedGlobalsIndexPlus1_(0), + op_(OpBytes(Op::Limit)), + offsetOfLastReadOp_(0) {} +#else + explicit OpIter(const ModuleEnvironment& env, Decoder& decoder, + Kind kind = OpIter::Func) + : kind_(kind), + d_(decoder), + env_(env), + maxInitializedGlobalsIndexPlus1_(0), + offsetOfLastReadOp_(0) {} +#endif + + // Return the decoding byte offset. + uint32_t currentOffset() const { return d_.currentOffset(); } + + // Return the offset within the entire module of the last-read op. + size_t lastOpcodeOffset() const { + return offsetOfLastReadOp_ ? offsetOfLastReadOp_ : d_.currentOffset(); + } + + // Return a BytecodeOffset describing where the current op should be reported + // to trap/call. + BytecodeOffset bytecodeOffset() const { + return BytecodeOffset(lastOpcodeOffset()); + } + + // Test whether the iterator has reached the end of the buffer. + bool done() const { return d_.done(); } + + // Return a pointer to the end of the buffer being decoded by this iterator. + const uint8_t* end() const { return d_.end(); } + + // Report a general failure. + [[nodiscard]] bool fail(const char* msg) MOZ_COLD; + + // Report a general failure with a context + [[nodiscard]] bool fail_ctx(const char* fmt, const char* context) MOZ_COLD; + + // Report an unrecognized opcode. + [[nodiscard]] bool unrecognizedOpcode(const OpBytes* expr) MOZ_COLD; + + // Return whether the innermost block has a polymorphic base of its stack. + // Ideally this accessor would be removed; consider using something else. + bool currentBlockHasPolymorphicBase() const { + return !controlStack_.empty() && controlStack_.back().polymorphicBase(); + } + + // ------------------------------------------------------------------------ + // Decoding and validation interface. + + // Initialization and termination + + [[nodiscard]] bool startFunction(uint32_t funcIndex, + const ValTypeVector& locals); + [[nodiscard]] bool endFunction(const uint8_t* bodyEnd); + + [[nodiscard]] bool startInitExpr(ValType expected, + uint32_t maxInitializedGlobalsIndexPlus1); + [[nodiscard]] bool endInitExpr(); + + // Value and reference types + + [[nodiscard]] bool readValType(ValType* type); + [[nodiscard]] bool readHeapType(bool nullable, RefType* type); + + // Instructions + + [[nodiscard]] bool readOp(OpBytes* op); + [[nodiscard]] bool readReturn(ValueVector* values); + [[nodiscard]] bool readBlock(ResultType* paramType); + [[nodiscard]] bool readLoop(ResultType* paramType); + [[nodiscard]] bool readIf(ResultType* paramType, Value* condition); + [[nodiscard]] bool readElse(ResultType* paramType, ResultType* resultType, + ValueVector* thenResults); + [[nodiscard]] bool readEnd(LabelKind* kind, ResultType* type, + ValueVector* results, + ValueVector* resultsForEmptyElse); + void popEnd(); + [[nodiscard]] bool readBr(uint32_t* relativeDepth, ResultType* type, + ValueVector* values); + [[nodiscard]] bool readBrIf(uint32_t* relativeDepth, ResultType* type, + ValueVector* values, Value* condition); + [[nodiscard]] bool readBrTable(Uint32Vector* depths, uint32_t* defaultDepth, + ResultType* defaultBranchType, + ValueVector* branchValues, Value* index); + [[nodiscard]] bool readTry(ResultType* type); + [[nodiscard]] bool readCatch(LabelKind* kind, uint32_t* tagIndex, + ResultType* paramType, ResultType* resultType, + ValueVector* tryResults); + [[nodiscard]] bool readCatchAll(LabelKind* kind, ResultType* paramType, + ResultType* resultType, + ValueVector* tryResults); + [[nodiscard]] bool readDelegate(uint32_t* relativeDepth, + ResultType* resultType, + ValueVector* tryResults); + void popDelegate(); + [[nodiscard]] bool readThrow(uint32_t* tagIndex, ValueVector* argValues); + [[nodiscard]] bool readRethrow(uint32_t* relativeDepth); + [[nodiscard]] bool readUnreachable(); + [[nodiscard]] bool readDrop(); + [[nodiscard]] bool readUnary(ValType operandType, Value* input); + [[nodiscard]] bool readConversion(ValType operandType, ValType resultType, + Value* input); + [[nodiscard]] bool readBinary(ValType operandType, Value* lhs, Value* rhs); + [[nodiscard]] bool readComparison(ValType operandType, Value* lhs, + Value* rhs); + [[nodiscard]] bool readTernary(ValType operandType, Value* v0, Value* v1, + Value* v2); + [[nodiscard]] bool readLoad(ValType resultType, uint32_t byteSize, + LinearMemoryAddress<Value>* addr); + [[nodiscard]] bool readStore(ValType resultType, uint32_t byteSize, + LinearMemoryAddress<Value>* addr, Value* value); + [[nodiscard]] bool readTeeStore(ValType resultType, uint32_t byteSize, + LinearMemoryAddress<Value>* addr, + Value* value); + [[nodiscard]] bool readNop(); + [[nodiscard]] bool readMemorySize(); + [[nodiscard]] bool readMemoryGrow(Value* input); + [[nodiscard]] bool readSelect(bool typed, StackType* type, Value* trueValue, + Value* falseValue, Value* condition); + [[nodiscard]] bool readGetLocal(const ValTypeVector& locals, uint32_t* id); + [[nodiscard]] bool readSetLocal(const ValTypeVector& locals, uint32_t* id, + Value* value); + [[nodiscard]] bool readTeeLocal(const ValTypeVector& locals, uint32_t* id, + Value* value); + [[nodiscard]] bool readGetGlobal(uint32_t* id); + [[nodiscard]] bool readSetGlobal(uint32_t* id, Value* value); + [[nodiscard]] bool readTeeGlobal(uint32_t* id, Value* value); + [[nodiscard]] bool readI32Const(int32_t* i32); + [[nodiscard]] bool readI64Const(int64_t* i64); + [[nodiscard]] bool readF32Const(float* f32); + [[nodiscard]] bool readF64Const(double* f64); + [[nodiscard]] bool readRefFunc(uint32_t* funcIndex); + [[nodiscard]] bool readRefNull(RefType* type); + [[nodiscard]] bool readRefIsNull(Value* input); + [[nodiscard]] bool readRefAsNonNull(Value* input); + [[nodiscard]] bool readBrOnNull(uint32_t* relativeDepth, ResultType* type, + ValueVector* values, Value* condition); + [[nodiscard]] bool readBrOnNonNull(uint32_t* relativeDepth, ResultType* type, + ValueVector* values, Value* condition); + [[nodiscard]] bool readCall(uint32_t* funcTypeIndex, ValueVector* argValues); + [[nodiscard]] bool readCallIndirect(uint32_t* funcTypeIndex, + uint32_t* tableIndex, Value* callee, + ValueVector* argValues); +#ifdef ENABLE_WASM_FUNCTION_REFERENCES + [[nodiscard]] bool readCallRef(const FuncType** funcType, Value* callee, + ValueVector* argValues); +#endif + [[nodiscard]] bool readOldCallDirect(uint32_t numFuncImports, + uint32_t* funcTypeIndex, + ValueVector* argValues); + [[nodiscard]] bool readOldCallIndirect(uint32_t* funcTypeIndex, Value* callee, + ValueVector* argValues); + [[nodiscard]] bool readWake(LinearMemoryAddress<Value>* addr, Value* count); + [[nodiscard]] bool readWait(LinearMemoryAddress<Value>* addr, + ValType valueType, uint32_t byteSize, + Value* value, Value* timeout); + [[nodiscard]] bool readFence(); + [[nodiscard]] bool readAtomicLoad(LinearMemoryAddress<Value>* addr, + ValType resultType, uint32_t byteSize); + [[nodiscard]] bool readAtomicStore(LinearMemoryAddress<Value>* addr, + ValType resultType, uint32_t byteSize, + Value* value); + [[nodiscard]] bool readAtomicRMW(LinearMemoryAddress<Value>* addr, + ValType resultType, uint32_t byteSize, + Value* value); + [[nodiscard]] bool readAtomicCmpXchg(LinearMemoryAddress<Value>* addr, + ValType resultType, uint32_t byteSize, + Value* oldValue, Value* newValue); + [[nodiscard]] bool readMemOrTableCopy(bool isMem, + uint32_t* dstMemOrTableIndex, + Value* dst, + uint32_t* srcMemOrTableIndex, + Value* src, Value* len); + [[nodiscard]] bool readDataOrElemDrop(bool isData, uint32_t* segIndex); + [[nodiscard]] bool readMemFill(Value* start, Value* val, Value* len); + [[nodiscard]] bool readMemOrTableInit(bool isMem, uint32_t* segIndex, + uint32_t* dstTableIndex, Value* dst, + Value* src, Value* len); + [[nodiscard]] bool readTableFill(uint32_t* tableIndex, Value* start, + Value* val, Value* len); + [[nodiscard]] bool readMemDiscard(Value* start, Value* len); + [[nodiscard]] bool readTableGet(uint32_t* tableIndex, Value* index); + [[nodiscard]] bool readTableGrow(uint32_t* tableIndex, Value* initValue, + Value* delta); + [[nodiscard]] bool readTableSet(uint32_t* tableIndex, Value* index, + Value* value); + + [[nodiscard]] bool readTableSize(uint32_t* tableIndex); + +#ifdef ENABLE_WASM_GC + [[nodiscard]] bool readStructNew(uint32_t* typeIndex, ValueVector* argValues); + [[nodiscard]] bool readStructNewDefault(uint32_t* typeIndex); + [[nodiscard]] bool readStructGet(uint32_t* typeIndex, uint32_t* fieldIndex, + FieldWideningOp wideningOp, Value* ptr); + [[nodiscard]] bool readStructSet(uint32_t* typeIndex, uint32_t* fieldIndex, + Value* ptr, Value* val); + [[nodiscard]] bool readArrayNew(uint32_t* typeIndex, Value* numElements, + Value* argValue); + [[nodiscard]] bool readArrayNewFixed(uint32_t* typeIndex, + uint32_t* numElements, + ValueVector* values); + [[nodiscard]] bool readArrayNewDefault(uint32_t* typeIndex, + Value* numElements); + [[nodiscard]] bool readArrayNewData(uint32_t* typeIndex, uint32_t* segIndex, + Value* offset, Value* numElements); + [[nodiscard]] bool readArrayNewElem(uint32_t* typeIndex, uint32_t* segIndex, + Value* offset, Value* numElements); + [[nodiscard]] bool readArrayGet(uint32_t* typeIndex, + FieldWideningOp wideningOp, Value* index, + Value* ptr); + [[nodiscard]] bool readArraySet(uint32_t* typeIndex, Value* val, Value* index, + Value* ptr); + [[nodiscard]] bool readArrayLen(bool decodeIgnoredTypeIndex, Value* ptr); + [[nodiscard]] bool readArrayCopy(int32_t* elemSize, bool* elemsAreRefTyped, + Value* dstArray, Value* dstIndex, + Value* srcArray, Value* srcIndex, + Value* numElements); + [[nodiscard]] bool readRefTestV5(RefType* sourceType, uint32_t* typeIndex, + Value* ref); + [[nodiscard]] bool readRefCastV5(RefType* sourceType, uint32_t* typeIndex, + Value* ref); + [[nodiscard]] bool readBrOnCastV5(uint32_t* labelRelativeDepth, + RefType* sourceType, + uint32_t* castTypeIndex, + ResultType* labelType, ValueVector* values); + [[nodiscard]] bool readBrOnCastHeapV5(bool nullable, + uint32_t* labelRelativeDepth, + RefType* sourceType, RefType* destType, + ResultType* labelType, + ValueVector* values); + [[nodiscard]] bool readBrOnCastFailV5(uint32_t* labelRelativeDepth, + RefType* sourceType, + uint32_t* castTypeIndex, + ResultType* labelType, + ValueVector* values); + [[nodiscard]] bool readBrOnCastFailHeapV5( + bool nullable, uint32_t* labelRelativeDepth, RefType* sourceType, + RefType* destType, ResultType* labelType, ValueVector* values); + [[nodiscard]] bool readRefTest(bool nullable, RefType* sourceType, + RefType* destType, Value* ref); + [[nodiscard]] bool readRefCast(bool nullable, RefType* sourceType, + RefType* destType, Value* ref); + [[nodiscard]] bool readBrOnCast(bool* onSuccess, uint32_t* labelRelativeDepth, + RefType* sourceType, RefType* destType, + ResultType* labelType, ValueVector* values); + [[nodiscard]] bool checkBrOnCastCommonV5(uint32_t labelRelativeDepth, + RefType* sourceType, + ValType castToType, + ResultType* labelType, + ValueVector* values); + [[nodiscard]] bool checkBrOnCastFailCommonV5(uint32_t labelRelativeDepth, + RefType* sourceType, + ValType castToType, + ResultType* labelType, + ValueVector* values); + [[nodiscard]] bool readBrOnNonStructV5(uint32_t* labelRelativeDepth, + ResultType* labelType, + ValueVector* values); + [[nodiscard]] bool readRefConversion(RefType operandType, RefType resultType, + Value* operandValue); +#endif + +#ifdef ENABLE_WASM_SIMD + [[nodiscard]] bool readLaneIndex(uint32_t inputLanes, uint32_t* laneIndex); + [[nodiscard]] bool readExtractLane(ValType resultType, uint32_t inputLanes, + uint32_t* laneIndex, Value* input); + [[nodiscard]] bool readReplaceLane(ValType operandType, uint32_t inputLanes, + uint32_t* laneIndex, Value* baseValue, + Value* operand); + [[nodiscard]] bool readVectorShift(Value* baseValue, Value* shift); + [[nodiscard]] bool readVectorShuffle(Value* v1, Value* v2, V128* selectMask); + [[nodiscard]] bool readV128Const(V128* value); + [[nodiscard]] bool readLoadSplat(uint32_t byteSize, + LinearMemoryAddress<Value>* addr); + [[nodiscard]] bool readLoadExtend(LinearMemoryAddress<Value>* addr); + [[nodiscard]] bool readLoadLane(uint32_t byteSize, + LinearMemoryAddress<Value>* addr, + uint32_t* laneIndex, Value* input); + [[nodiscard]] bool readStoreLane(uint32_t byteSize, + LinearMemoryAddress<Value>* addr, + uint32_t* laneIndex, Value* input); +#endif + + [[nodiscard]] bool readIntrinsic(const Intrinsic** intrinsic, + ValueVector* params); + + // At a location where readOp is allowed, peek at the next opcode + // without consuming it or updating any internal state. + // Never fails: returns uint16_t(Op::Limit) in op->b0 if it can't read. + void peekOp(OpBytes* op); + + // ------------------------------------------------------------------------ + // Stack management. + + // Set the top N result values. + void setResults(size_t count, const ValueVector& values) { + MOZ_ASSERT(valueStack_.length() >= count); + size_t base = valueStack_.length() - count; + for (size_t i = 0; i < count; i++) { + valueStack_[base + i].setValue(values[i]); + } + } + + bool getResults(size_t count, ValueVector* values) { + MOZ_ASSERT(valueStack_.length() >= count); + if (!values->resize(count)) { + return false; + } + size_t base = valueStack_.length() - count; + for (size_t i = 0; i < count; i++) { + (*values)[i] = valueStack_[base + i].value(); + } + return true; + } + + // Set the result value of the current top-of-value-stack expression. + void setResult(Value value) { valueStack_.back().setValue(value); } + + // Return the result value of the current top-of-value-stack expression. + Value getResult() { return valueStack_.back().value(); } + + // Return a reference to the top of the control stack. + ControlItem& controlItem() { return controlStack_.back().controlItem(); } + + // Return a reference to an element in the control stack. + ControlItem& controlItem(uint32_t relativeDepth) { + return controlStack_[controlStack_.length() - 1 - relativeDepth] + .controlItem(); + } + + // Return the LabelKind of an element in the control stack. + LabelKind controlKind(uint32_t relativeDepth) { + return controlStack_[controlStack_.length() - 1 - relativeDepth].kind(); + } + + // Return a reference to the outermost element on the control stack. + ControlItem& controlOutermost() { return controlStack_[0].controlItem(); } + + // Test whether the control-stack is empty, meaning we've consumed the final + // end of the function body. + bool controlStackEmpty() const { return controlStack_.empty(); } + + // Return the depth of the control stack. + size_t controlStackDepth() const { return controlStack_.length(); } + + // Find the innermost control item of a specific kind, starting to search from + // a certain relative depth, and returning true if such innermost control item + // is found. The relative depth of the found item is returned via a parameter. + bool controlFindInnermostFrom(LabelKind kind, uint32_t fromRelativeDepth, + uint32_t* foundRelativeDepth) { + int32_t fromAbsoluteDepth = controlStack_.length() - fromRelativeDepth - 1; + for (int32_t i = fromAbsoluteDepth; i >= 0; i--) { + if (controlStack_[i].kind() == kind) { + *foundRelativeDepth = controlStack_.length() - 1 - i; + return true; + } + } + return false; + } + + bool controlFindInnermost(LabelKind kind, uint32_t* foundRelativeDepth) { + return controlFindInnermostFrom(kind, 0, foundRelativeDepth); + } +}; + +template <typename Policy> +inline bool OpIter<Policy>::checkIsSubtypeOf(FieldType subType, + FieldType superType) { + return CheckIsSubtypeOf(d_, env_, lastOpcodeOffset(), subType, superType); +} + +template <typename Policy> +inline bool OpIter<Policy>::checkIsSubtypeOf(ResultType params, + ResultType results) { + if (params.length() != results.length()) { + UniqueChars error( + JS_smprintf("type mismatch: expected %zu values, got %zu values", + results.length(), params.length())); + if (!error) { + return false; + } + return fail(error.get()); + } + for (uint32_t i = 0; i < params.length(); i++) { + ValType param = params[i]; + ValType result = results[i]; + if (!checkIsSubtypeOf(param, result)) { + return false; + } + } + return true; +} + +#ifdef ENABLE_WASM_FUNCTION_REFERENCES +template <typename Policy> +inline bool OpIter<Policy>::checkIsSubtypeOf(uint32_t actualTypeIndex, + uint32_t expectedTypeIndex) { + const TypeDef& actualTypeDef = env_.types->type(actualTypeIndex); + const TypeDef& expectedTypeDef = env_.types->type(expectedTypeIndex); + return CheckIsSubtypeOf( + d_, env_, lastOpcodeOffset(), + ValType(RefType::fromTypeDef(&actualTypeDef, true)), + ValType(RefType::fromTypeDef(&expectedTypeDef, true))); +} +#endif + +template <typename Policy> +inline bool OpIter<Policy>::unrecognizedOpcode(const OpBytes* expr) { + UniqueChars error(JS_smprintf("unrecognized opcode: %x %x", expr->b0, + IsPrefixByte(expr->b0) ? expr->b1 : 0)); + if (!error) { + return false; + } + + return fail(error.get()); +} + +template <typename Policy> +inline bool OpIter<Policy>::fail(const char* msg) { + return d_.fail(lastOpcodeOffset(), msg); +} + +template <typename Policy> +inline bool OpIter<Policy>::fail_ctx(const char* fmt, const char* context) { + UniqueChars error(JS_smprintf(fmt, context)); + if (!error) { + return false; + } + return fail(error.get()); +} + +template <typename Policy> +inline bool OpIter<Policy>::failEmptyStack() { + return valueStack_.empty() ? fail("popping value from empty stack") + : fail("popping value from outside block"); +} + +// This function pops exactly one value from the stack, yielding Bottom types in +// various cases and therefore making it the caller's responsibility to do the +// right thing for StackType::Bottom. Prefer (pop|top)WithType. This is an +// optimization for the super-common case where the caller is statically +// expecting the resulttype `[valtype]`. +template <typename Policy> +inline bool OpIter<Policy>::popStackType(StackType* type, Value* value) { + Control& block = controlStack_.back(); + + MOZ_ASSERT(valueStack_.length() >= block.valueStackBase()); + if (MOZ_UNLIKELY(valueStack_.length() == block.valueStackBase())) { + // If the base of this block's stack is polymorphic, then we can pop a + // dummy value of the bottom type; it won't be used since we're in + // unreachable code. + if (block.polymorphicBase()) { + *type = StackType::bottom(); + *value = Value(); + + // Maintain the invariant that, after a pop, there is always memory + // reserved to push a value infallibly. + return valueStack_.reserve(valueStack_.length() + 1); + } + + return failEmptyStack(); + } + + TypeAndValue& tv = valueStack_.back(); + *type = tv.type(); + *value = tv.value(); + valueStack_.popBack(); + return true; +} + +// This function pops exactly one value from the stack, checking that it has the +// expected type which can either be a specific value type or the bottom type. +template <typename Policy> +inline bool OpIter<Policy>::popWithType(ValType expectedType, Value* value, + StackType* stackType) { + if (!popStackType(stackType, value)) { + return false; + } + + return stackType->isStackBottom() || + checkIsSubtypeOf(stackType->valType(), expectedType); +} + +// This function pops exactly one value from the stack, checking that it has the +// expected type which can either be a specific value type or the bottom type. +template <typename Policy> +inline bool OpIter<Policy>::popWithType(ValType expectedType, Value* value) { + StackType stackType; + return popWithType(expectedType, value, &stackType); +} + +template <typename Policy> +inline bool OpIter<Policy>::popWithType(ResultType expected, + ValueVector* values) { + return popWithTypes(expected, values); +} + +// Pops each of the given expected types (in reverse, because it's a stack). +template <typename Policy> +template <typename ValTypeSpanT> +inline bool OpIter<Policy>::popWithTypes(ValTypeSpanT expected, + ValueVector* values) { + size_t expectedLength = expected.size(); + if (!values->resize(expectedLength)) { + return false; + } + for (size_t i = 0; i < expectedLength; i++) { + size_t reverseIndex = expectedLength - i - 1; + ValType expectedType = expected[reverseIndex]; + Value* value = &(*values)[reverseIndex]; + if (!popWithType(expectedType, value)) { + return false; + } + } + return true; +} + +// This function pops exactly one value from the stack, checking that it is a +// reference type. +template <typename Policy> +inline bool OpIter<Policy>::popWithRefType(Value* value, StackType* type) { + if (!popStackType(type, value)) { + return false; + } + + if (type->isStackBottom() || type->valType().isRefType()) { + return true; + } + + UniqueChars actualText = ToString(type->valType(), env_.types); + if (!actualText) { + return false; + } + + UniqueChars error(JS_smprintf( + "type mismatch: expression has type %s but expected a reference type", + actualText.get())); + if (!error) { + return false; + } + + return fail(error.get()); +} + +template <typename Policy> +inline bool OpIter<Policy>::checkTopTypeMatches(ResultType expected, + ValueVector* values, + bool rewriteStackTypes) { + if (expected.empty()) { + return true; + } + + Control& block = controlStack_.back(); + + size_t expectedLength = expected.length(); + if (values && !values->resize(expectedLength)) { + return false; + } + + for (size_t i = 0; i != expectedLength; i++) { + // We're iterating as-if we were popping each expected/actual type one by + // one, which means iterating the array of expected results backwards. + // The "current" value stack length refers to what the value stack length + // would have been if we were popping it. + size_t reverseIndex = expectedLength - i - 1; + ValType expectedType = expected[reverseIndex]; + auto collectValue = [&](const Value& v) { + if (values) { + (*values)[reverseIndex] = v; + } + }; + + size_t currentValueStackLength = valueStack_.length() - i; + + MOZ_ASSERT(currentValueStackLength >= block.valueStackBase()); + if (currentValueStackLength == block.valueStackBase()) { + if (!block.polymorphicBase()) { + return failEmptyStack(); + } + + // If the base of this block's stack is polymorphic, then we can just + // pull out as many fake values as we need to validate, and create dummy + // stack entries accordingly; they won't be used since we're in + // unreachable code. However, if `rewriteStackTypes` is true, we must + // set the types on these new entries to whatever `expected` requires + // them to be. + TypeAndValue newTandV = + rewriteStackTypes ? TypeAndValue(expectedType) : TypeAndValue(); + if (!valueStack_.insert(valueStack_.begin() + currentValueStackLength, + newTandV)) { + return false; + } + + collectValue(Value()); + } else { + TypeAndValue& observed = valueStack_[currentValueStackLength - 1]; + + if (observed.type().isStackBottom()) { + collectValue(Value()); + } else { + if (!checkIsSubtypeOf(observed.type().valType(), expectedType)) { + return false; + } + + collectValue(observed.value()); + } + + if (rewriteStackTypes) { + observed.setType(StackType(expectedType)); + } + } + } + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::pushControl(LabelKind kind, BlockType type) { + ResultType paramType = type.params(); + + ValueVector values; + if (!checkTopTypeMatches(paramType, &values, /*rewriteStackTypes=*/true)) { + return false; + } + MOZ_ASSERT(valueStack_.length() >= paramType.length()); + uint32_t valueStackBase = valueStack_.length() - paramType.length(); + return controlStack_.emplaceBack(kind, type, valueStackBase); +} + +template <typename Policy> +inline bool OpIter<Policy>::checkStackAtEndOfBlock(ResultType* expectedType, + ValueVector* values) { + Control& block = controlStack_.back(); + *expectedType = block.type().results(); + + MOZ_ASSERT(valueStack_.length() >= block.valueStackBase()); + if (expectedType->length() < valueStack_.length() - block.valueStackBase()) { + return fail("unused values not explicitly dropped by end of block"); + } + + return checkTopTypeMatches(*expectedType, values, + /*rewriteStackTypes=*/true); +} + +template <typename Policy> +inline bool OpIter<Policy>::getControl(uint32_t relativeDepth, + Control** controlEntry) { + if (relativeDepth >= controlStack_.length()) { + return fail("branch depth exceeds current nesting level"); + } + + *controlEntry = &controlStack_[controlStack_.length() - 1 - relativeDepth]; + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readBlockType(BlockType* type) { + uint8_t nextByte; + if (!d_.peekByte(&nextByte)) { + return fail("unable to read block type"); + } + + if (nextByte == uint8_t(TypeCode::BlockVoid)) { + d_.uncheckedReadFixedU8(); + *type = BlockType::VoidToVoid(); + return true; + } + + if ((nextByte & SLEB128SignMask) == SLEB128SignBit) { + ValType v; + if (!readValType(&v)) { + return false; + } + *type = BlockType::VoidToSingle(v); + return true; + } + + int32_t x; + if (!d_.readVarS32(&x) || x < 0 || uint32_t(x) >= env_.types->length()) { + return fail("invalid block type type index"); + } + + const TypeDef* typeDef = &env_.types->type(x); + if (!typeDef->isFuncType()) { + return fail("block type type index must be func type"); + } + + *type = BlockType::Func(typeDef->funcType()); + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readOp(OpBytes* op) { + MOZ_ASSERT(!controlStack_.empty()); + + offsetOfLastReadOp_ = d_.currentOffset(); + + if (MOZ_UNLIKELY(!d_.readOp(op))) { + return fail("unable to read opcode"); + } + +#ifdef DEBUG + op_ = *op; +#endif + + return true; +} + +template <typename Policy> +inline void OpIter<Policy>::peekOp(OpBytes* op) { + const uint8_t* pos = d_.currentPosition(); + + if (MOZ_UNLIKELY(!d_.readOp(op))) { + op->b0 = uint16_t(Op::Limit); + } + + d_.rollbackPosition(pos); +} + +template <typename Policy> +inline bool OpIter<Policy>::startFunction(uint32_t funcIndex, + const ValTypeVector& locals) { + MOZ_ASSERT(kind_ == OpIter::Func); + MOZ_ASSERT(elseParamStack_.empty()); + MOZ_ASSERT(valueStack_.empty()); + MOZ_ASSERT(controlStack_.empty()); + MOZ_ASSERT(op_.b0 == uint16_t(Op::Limit)); + MOZ_ASSERT(maxInitializedGlobalsIndexPlus1_ == 0); + BlockType type = BlockType::FuncResults(*env_.funcs[funcIndex].type); + + size_t numArgs = env_.funcs[funcIndex].type->args().length(); + if (!unsetLocals_.init(locals, numArgs)) { + return false; + } + + return pushControl(LabelKind::Body, type); +} + +template <typename Policy> +inline bool OpIter<Policy>::endFunction(const uint8_t* bodyEnd) { + if (d_.currentPosition() != bodyEnd) { + return fail("function body length mismatch"); + } + + if (!controlStack_.empty()) { + return fail("unbalanced function body control flow"); + } + MOZ_ASSERT(elseParamStack_.empty()); + MOZ_ASSERT(unsetLocals_.empty()); + +#ifdef DEBUG + op_ = OpBytes(Op::Limit); +#endif + valueStack_.clear(); + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::startInitExpr( + ValType expected, uint32_t maxInitializedGlobalsIndexPlus1) { + MOZ_ASSERT(kind_ == OpIter::InitExpr); + MOZ_ASSERT(elseParamStack_.empty()); + MOZ_ASSERT(valueStack_.empty()); + MOZ_ASSERT(controlStack_.empty()); + MOZ_ASSERT(maxInitializedGlobalsIndexPlus1_ == 0); + MOZ_ASSERT(op_.b0 == uint16_t(Op::Limit)); + + // GC allows accessing any previously defined global, not just those that are + // imported and immutable. + if (env_.features.gc) { + maxInitializedGlobalsIndexPlus1_ = maxInitializedGlobalsIndexPlus1; + } + + BlockType type = BlockType::VoidToSingle(expected); + return pushControl(LabelKind::Body, type); +} + +template <typename Policy> +inline bool OpIter<Policy>::endInitExpr() { + MOZ_ASSERT(controlStack_.empty()); + MOZ_ASSERT(elseParamStack_.empty()); + +#ifdef DEBUG + op_ = OpBytes(Op::Limit); +#endif + valueStack_.clear(); + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readValType(ValType* type) { + return d_.readValType(*env_.types, env_.features, type); +} + +template <typename Policy> +inline bool OpIter<Policy>::readHeapType(bool nullable, RefType* type) { + return d_.readHeapType(*env_.types, env_.features, nullable, type); +} + +template <typename Policy> +inline bool OpIter<Policy>::readReturn(ValueVector* values) { + MOZ_ASSERT(Classify(op_) == OpKind::Return); + + Control& body = controlStack_[0]; + MOZ_ASSERT(body.kind() == LabelKind::Body); + + if (!popWithType(body.resultType(), values)) { + return false; + } + + afterUnconditionalBranch(); + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readBlock(ResultType* paramType) { + MOZ_ASSERT(Classify(op_) == OpKind::Block); + + BlockType type; + if (!readBlockType(&type)) { + return false; + } + + *paramType = type.params(); + return pushControl(LabelKind::Block, type); +} + +template <typename Policy> +inline bool OpIter<Policy>::readLoop(ResultType* paramType) { + MOZ_ASSERT(Classify(op_) == OpKind::Loop); + + BlockType type; + if (!readBlockType(&type)) { + return false; + } + + *paramType = type.params(); + return pushControl(LabelKind::Loop, type); +} + +template <typename Policy> +inline bool OpIter<Policy>::readIf(ResultType* paramType, Value* condition) { + MOZ_ASSERT(Classify(op_) == OpKind::If); + + BlockType type; + if (!readBlockType(&type)) { + return false; + } + + if (!popWithType(ValType::I32, condition)) { + return false; + } + + if (!pushControl(LabelKind::Then, type)) { + return false; + } + + *paramType = type.params(); + size_t paramsLength = type.params().length(); + return elseParamStack_.append(valueStack_.end() - paramsLength, paramsLength); +} + +template <typename Policy> +inline bool OpIter<Policy>::readElse(ResultType* paramType, + ResultType* resultType, + ValueVector* thenResults) { + MOZ_ASSERT(Classify(op_) == OpKind::Else); + + Control& block = controlStack_.back(); + if (block.kind() != LabelKind::Then) { + return fail("else can only be used within an if"); + } + + *paramType = block.type().params(); + if (!checkStackAtEndOfBlock(resultType, thenResults)) { + return false; + } + + valueStack_.shrinkTo(block.valueStackBase()); + + size_t nparams = block.type().params().length(); + MOZ_ASSERT(elseParamStack_.length() >= nparams); + valueStack_.infallibleAppend(elseParamStack_.end() - nparams, nparams); + elseParamStack_.shrinkBy(nparams); + + // Reset local state to the beginning of the 'if' block for the new block + // started by 'else'. + unsetLocals_.resetToBlock(controlStack_.length() - 1); + + block.switchToElse(); + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readEnd(LabelKind* kind, ResultType* type, + ValueVector* results, + ValueVector* resultsForEmptyElse) { + MOZ_ASSERT(Classify(op_) == OpKind::End); + + Control& block = controlStack_.back(); + + if (!checkStackAtEndOfBlock(type, results)) { + return false; + } + + if (block.kind() == LabelKind::Then) { + ResultType params = block.type().params(); + // If an `if` block ends with `end` instead of `else`, then the `else` block + // implicitly passes the `if` parameters as the `else` results. In that + // case, assert that the `if`'s param type matches the result type. + if (params != block.type().results()) { + return fail("if without else with a result value"); + } + + size_t nparams = params.length(); + MOZ_ASSERT(elseParamStack_.length() >= nparams); + if (!resultsForEmptyElse->resize(nparams)) { + return false; + } + const TypeAndValue* elseParams = elseParamStack_.end() - nparams; + for (size_t i = 0; i < nparams; i++) { + (*resultsForEmptyElse)[i] = elseParams[i].value(); + } + elseParamStack_.shrinkBy(nparams); + } + + *kind = block.kind(); + return true; +} + +template <typename Policy> +inline void OpIter<Policy>::popEnd() { + MOZ_ASSERT(Classify(op_) == OpKind::End); + + controlStack_.popBack(); + unsetLocals_.resetToBlock(controlStack_.length()); +} + +template <typename Policy> +inline bool OpIter<Policy>::checkBranchValueAndPush(uint32_t relativeDepth, + ResultType* type, + ValueVector* values) { + Control* block = nullptr; + if (!getControl(relativeDepth, &block)) { + return false; + } + + *type = block->branchTargetType(); + return checkTopTypeMatches(*type, values, /*rewriteStackTypes=*/false); +} + +template <typename Policy> +inline bool OpIter<Policy>::readBr(uint32_t* relativeDepth, ResultType* type, + ValueVector* values) { + MOZ_ASSERT(Classify(op_) == OpKind::Br); + + if (!readVarU32(relativeDepth)) { + return fail("unable to read br depth"); + } + + if (!checkBranchValueAndPush(*relativeDepth, type, values)) { + return false; + } + + afterUnconditionalBranch(); + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readBrIf(uint32_t* relativeDepth, ResultType* type, + ValueVector* values, Value* condition) { + MOZ_ASSERT(Classify(op_) == OpKind::BrIf); + + if (!readVarU32(relativeDepth)) { + return fail("unable to read br_if depth"); + } + + if (!popWithType(ValType::I32, condition)) { + return false; + } + + return checkBranchValueAndPush(*relativeDepth, type, values); +} + +#define UNKNOWN_ARITY UINT32_MAX + +template <typename Policy> +inline bool OpIter<Policy>::checkBrTableEntryAndPush( + uint32_t* relativeDepth, ResultType prevBranchType, ResultType* type, + ValueVector* branchValues) { + if (!readVarU32(relativeDepth)) { + return fail("unable to read br_table depth"); + } + + Control* block = nullptr; + if (!getControl(*relativeDepth, &block)) { + return false; + } + + *type = block->branchTargetType(); + + if (prevBranchType.valid()) { + if (prevBranchType.length() != type->length()) { + return fail("br_table targets must all have the same arity"); + } + + // Avoid re-collecting the same values for subsequent branch targets. + branchValues = nullptr; + } + + return checkTopTypeMatches(*type, branchValues, /*rewriteStackTypes=*/false); +} + +template <typename Policy> +inline bool OpIter<Policy>::readBrTable(Uint32Vector* depths, + uint32_t* defaultDepth, + ResultType* defaultBranchType, + ValueVector* branchValues, + Value* index) { + MOZ_ASSERT(Classify(op_) == OpKind::BrTable); + + uint32_t tableLength; + if (!readVarU32(&tableLength)) { + return fail("unable to read br_table table length"); + } + + if (tableLength > MaxBrTableElems) { + return fail("br_table too big"); + } + + if (!popWithType(ValType::I32, index)) { + return false; + } + + if (!depths->resize(tableLength)) { + return false; + } + + ResultType prevBranchType; + for (uint32_t i = 0; i < tableLength; i++) { + ResultType branchType; + if (!checkBrTableEntryAndPush(&(*depths)[i], prevBranchType, &branchType, + branchValues)) { + return false; + } + prevBranchType = branchType; + } + + if (!checkBrTableEntryAndPush(defaultDepth, prevBranchType, defaultBranchType, + branchValues)) { + return false; + } + + MOZ_ASSERT(defaultBranchType->valid()); + + afterUnconditionalBranch(); + return true; +} + +#undef UNKNOWN_ARITY + +template <typename Policy> +inline bool OpIter<Policy>::readTry(ResultType* paramType) { + MOZ_ASSERT(Classify(op_) == OpKind::Try); + + BlockType type; + if (!readBlockType(&type)) { + return false; + } + + *paramType = type.params(); + return pushControl(LabelKind::Try, type); +} + +template <typename Policy> +inline bool OpIter<Policy>::readCatch(LabelKind* kind, uint32_t* tagIndex, + ResultType* paramType, + ResultType* resultType, + ValueVector* tryResults) { + MOZ_ASSERT(Classify(op_) == OpKind::Catch); + + if (!readVarU32(tagIndex)) { + return fail("expected tag index"); + } + if (*tagIndex >= env_.tags.length()) { + return fail("tag index out of range"); + } + + Control& block = controlStack_.back(); + if (block.kind() == LabelKind::CatchAll) { + return fail("catch cannot follow a catch_all"); + } + if (block.kind() != LabelKind::Try && block.kind() != LabelKind::Catch) { + return fail("catch can only be used within a try-catch"); + } + *kind = block.kind(); + *paramType = block.type().params(); + + if (!checkStackAtEndOfBlock(resultType, tryResults)) { + return false; + } + + valueStack_.shrinkTo(block.valueStackBase()); + block.switchToCatch(); + // Reset local state to the beginning of the 'try' block. + unsetLocals_.resetToBlock(controlStack_.length() - 1); + + return push(env_.tags[*tagIndex].type->resultType()); +} + +template <typename Policy> +inline bool OpIter<Policy>::readCatchAll(LabelKind* kind, ResultType* paramType, + ResultType* resultType, + ValueVector* tryResults) { + MOZ_ASSERT(Classify(op_) == OpKind::CatchAll); + + Control& block = controlStack_.back(); + if (block.kind() != LabelKind::Try && block.kind() != LabelKind::Catch) { + return fail("catch_all can only be used within a try-catch"); + } + *kind = block.kind(); + *paramType = block.type().params(); + + if (!checkStackAtEndOfBlock(resultType, tryResults)) { + return false; + } + + valueStack_.shrinkTo(block.valueStackBase()); + block.switchToCatchAll(); + // Reset local state to the beginning of the 'try' block. + unsetLocals_.resetToBlock(controlStack_.length() - 1); + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readDelegate(uint32_t* relativeDepth, + ResultType* resultType, + ValueVector* tryResults) { + MOZ_ASSERT(Classify(op_) == OpKind::Delegate); + + Control& block = controlStack_.back(); + if (block.kind() != LabelKind::Try) { + return fail("delegate can only be used within a try"); + } + + uint32_t delegateDepth; + if (!readVarU32(&delegateDepth)) { + return fail("unable to read delegate depth"); + } + + // Depths for delegate start counting in the surrounding block. + if (delegateDepth >= controlStack_.length() - 1) { + return fail("delegate depth exceeds current nesting level"); + } + *relativeDepth = delegateDepth + 1; + + // Because `delegate` acts like `end` and ends the block, we will check + // the stack here. + return checkStackAtEndOfBlock(resultType, tryResults); +} + +// We need popDelegate because readDelegate cannot pop the control stack +// itself, as its caller may need to use the control item for delegate. +template <typename Policy> +inline void OpIter<Policy>::popDelegate() { + MOZ_ASSERT(Classify(op_) == OpKind::Delegate); + + controlStack_.popBack(); +} + +template <typename Policy> +inline bool OpIter<Policy>::readThrow(uint32_t* tagIndex, + ValueVector* argValues) { + MOZ_ASSERT(Classify(op_) == OpKind::Throw); + + if (!readVarU32(tagIndex)) { + return fail("expected tag index"); + } + if (*tagIndex >= env_.tags.length()) { + return fail("tag index out of range"); + } + + if (!popWithType(env_.tags[*tagIndex].type->resultType(), argValues)) { + return false; + } + + afterUnconditionalBranch(); + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readRethrow(uint32_t* relativeDepth) { + MOZ_ASSERT(Classify(op_) == OpKind::Rethrow); + + if (!readVarU32(relativeDepth)) { + return fail("unable to read rethrow depth"); + } + + if (*relativeDepth >= controlStack_.length()) { + return fail("rethrow depth exceeds current nesting level"); + } + LabelKind kind = controlKind(*relativeDepth); + if (kind != LabelKind::Catch && kind != LabelKind::CatchAll) { + return fail("rethrow target was not a catch block"); + } + + afterUnconditionalBranch(); + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readUnreachable() { + MOZ_ASSERT(Classify(op_) == OpKind::Unreachable); + + afterUnconditionalBranch(); + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readDrop() { + MOZ_ASSERT(Classify(op_) == OpKind::Drop); + StackType type; + Value value; + return popStackType(&type, &value); +} + +template <typename Policy> +inline bool OpIter<Policy>::readUnary(ValType operandType, Value* input) { + MOZ_ASSERT(Classify(op_) == OpKind::Unary); + + if (!popWithType(operandType, input)) { + return false; + } + + infalliblePush(operandType); + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readConversion(ValType operandType, + ValType resultType, Value* input) { + MOZ_ASSERT(Classify(op_) == OpKind::Conversion); + + if (!popWithType(operandType, input)) { + return false; + } + + infalliblePush(resultType); + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readBinary(ValType operandType, Value* lhs, + Value* rhs) { + MOZ_ASSERT(Classify(op_) == OpKind::Binary); + + if (!popWithType(operandType, rhs)) { + return false; + } + + if (!popWithType(operandType, lhs)) { + return false; + } + + infalliblePush(operandType); + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readComparison(ValType operandType, Value* lhs, + Value* rhs) { + MOZ_ASSERT(Classify(op_) == OpKind::Comparison); + + if (!popWithType(operandType, rhs)) { + return false; + } + + if (!popWithType(operandType, lhs)) { + return false; + } + + infalliblePush(ValType::I32); + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readTernary(ValType operandType, Value* v0, + Value* v1, Value* v2) { + MOZ_ASSERT(Classify(op_) == OpKind::Ternary); + + if (!popWithType(operandType, v2)) { + return false; + } + + if (!popWithType(operandType, v1)) { + return false; + } + + if (!popWithType(operandType, v0)) { + return false; + } + + infalliblePush(operandType); + + return true; +} + +// For memories, the index is currently always a placeholder zero byte. +// +// For tables, the index is a placeholder zero byte until we get multi-table +// with the reftypes proposal. +// +// The zero-ness of the value must be checked by the caller. +template <typename Policy> +inline bool OpIter<Policy>::readMemOrTableIndex(bool isMem, uint32_t* index) { + bool readByte = isMem; + if (readByte) { + uint8_t indexTmp; + if (!readFixedU8(&indexTmp)) { + return fail("unable to read memory or table index"); + } + *index = indexTmp; + } else { + if (!readVarU32(index)) { + return fail("unable to read memory or table index"); + } + } + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readLinearMemoryAddress( + uint32_t byteSize, LinearMemoryAddress<Value>* addr) { + if (!env_.usesMemory()) { + return fail("can't touch memory without memory"); + } + + IndexType it = env_.memory->indexType(); + + uint32_t alignLog2; + if (!readVarU32(&alignLog2)) { + return fail("unable to read load alignment"); + } + + if (!readVarU64(&addr->offset)) { + return fail("unable to read load offset"); + } + + if (it == IndexType::I32 && addr->offset > UINT32_MAX) { + return fail("offset too large for memory type"); + } + + if (alignLog2 >= 32 || (uint32_t(1) << alignLog2) > byteSize) { + return fail("greater than natural alignment"); + } + + if (!popWithType(ToValType(it), &addr->base)) { + return false; + } + + addr->align = uint32_t(1) << alignLog2; + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readLinearMemoryAddressAligned( + uint32_t byteSize, LinearMemoryAddress<Value>* addr) { + if (!readLinearMemoryAddress(byteSize, addr)) { + return false; + } + + if (addr->align != byteSize) { + return fail("not natural alignment"); + } + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readLoad(ValType resultType, uint32_t byteSize, + LinearMemoryAddress<Value>* addr) { + MOZ_ASSERT(Classify(op_) == OpKind::Load); + + if (!readLinearMemoryAddress(byteSize, addr)) { + return false; + } + + infalliblePush(resultType); + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readStore(ValType resultType, uint32_t byteSize, + LinearMemoryAddress<Value>* addr, + Value* value) { + MOZ_ASSERT(Classify(op_) == OpKind::Store); + + if (!popWithType(resultType, value)) { + return false; + } + + if (!readLinearMemoryAddress(byteSize, addr)) { + return false; + } + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readTeeStore(ValType resultType, uint32_t byteSize, + LinearMemoryAddress<Value>* addr, + Value* value) { + MOZ_ASSERT(Classify(op_) == OpKind::TeeStore); + + if (!popWithType(resultType, value)) { + return false; + } + + if (!readLinearMemoryAddress(byteSize, addr)) { + return false; + } + + infalliblePush(TypeAndValue(resultType, *value)); + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readNop() { + MOZ_ASSERT(Classify(op_) == OpKind::Nop); + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readMemorySize() { + MOZ_ASSERT(Classify(op_) == OpKind::MemorySize); + + if (!env_.usesMemory()) { + return fail("can't touch memory without memory"); + } + + uint8_t flags; + if (!readFixedU8(&flags)) { + return fail("failed to read memory flags"); + } + + if (flags != uint8_t(0)) { + return fail("unexpected flags"); + } + + ValType ptrType = ToValType(env_.memory->indexType()); + return push(ptrType); +} + +template <typename Policy> +inline bool OpIter<Policy>::readMemoryGrow(Value* input) { + MOZ_ASSERT(Classify(op_) == OpKind::MemoryGrow); + + if (!env_.usesMemory()) { + return fail("can't touch memory without memory"); + } + + uint8_t flags; + if (!readFixedU8(&flags)) { + return fail("failed to read memory flags"); + } + + if (flags != uint8_t(0)) { + return fail("unexpected flags"); + } + + ValType ptrType = ToValType(env_.memory->indexType()); + if (!popWithType(ptrType, input)) { + return false; + } + + infalliblePush(ptrType); + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readSelect(bool typed, StackType* type, + Value* trueValue, Value* falseValue, + Value* condition) { + MOZ_ASSERT(Classify(op_) == OpKind::Select); + + if (typed) { + uint32_t length; + if (!readVarU32(&length)) { + return fail("unable to read select result length"); + } + if (length != 1) { + return fail("bad number of results"); + } + ValType result; + if (!readValType(&result)) { + return fail("invalid result type for select"); + } + + if (!popWithType(ValType::I32, condition)) { + return false; + } + if (!popWithType(result, falseValue)) { + return false; + } + if (!popWithType(result, trueValue)) { + return false; + } + + *type = StackType(result); + infalliblePush(*type); + return true; + } + + if (!popWithType(ValType::I32, condition)) { + return false; + } + + StackType falseType; + if (!popStackType(&falseType, falseValue)) { + return false; + } + + StackType trueType; + if (!popStackType(&trueType, trueValue)) { + return false; + } + + if (!falseType.isValidForUntypedSelect() || + !trueType.isValidForUntypedSelect()) { + return fail("invalid types for untyped select"); + } + + if (falseType.isStackBottom()) { + *type = trueType; + } else if (trueType.isStackBottom() || falseType == trueType) { + *type = falseType; + } else { + return fail("select operand types must match"); + } + + infalliblePush(*type); + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readGetLocal(const ValTypeVector& locals, + uint32_t* id) { + MOZ_ASSERT(Classify(op_) == OpKind::GetLocal); + + if (!readVarU32(id)) { + return fail("unable to read local index"); + } + + if (*id >= locals.length()) { + return fail("local.get index out of range"); + } + + if (unsetLocals_.isUnset(*id)) { + return fail("local.get read from unset local"); + } + + return push(locals[*id]); +} + +template <typename Policy> +inline bool OpIter<Policy>::readSetLocal(const ValTypeVector& locals, + uint32_t* id, Value* value) { + MOZ_ASSERT(Classify(op_) == OpKind::SetLocal); + + if (!readVarU32(id)) { + return fail("unable to read local index"); + } + + if (*id >= locals.length()) { + return fail("local.set index out of range"); + } + + if (unsetLocals_.isUnset(*id)) { + unsetLocals_.set(*id, controlStackDepth()); + } + + return popWithType(locals[*id], value); +} + +template <typename Policy> +inline bool OpIter<Policy>::readTeeLocal(const ValTypeVector& locals, + uint32_t* id, Value* value) { + MOZ_ASSERT(Classify(op_) == OpKind::TeeLocal); + + if (!readVarU32(id)) { + return fail("unable to read local index"); + } + + if (*id >= locals.length()) { + return fail("local.set index out of range"); + } + + if (unsetLocals_.isUnset(*id)) { + unsetLocals_.set(*id, controlStackDepth()); + } + + ValueVector single; + if (!checkTopTypeMatches(ResultType::Single(locals[*id]), &single, + /*rewriteStackTypes=*/true)) { + return false; + } + + *value = single[0]; + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readGetGlobal(uint32_t* id) { + MOZ_ASSERT(Classify(op_) == OpKind::GetGlobal); + + if (!d_.readGlobalIndex(id)) { + return false; + } + + if (*id >= env_.globals.length()) { + return fail("global.get index out of range"); + } + + // Initializer expressions can access immutable imported globals, or any + // previously defined global with GC enabled. + if (kind_ == OpIter::InitExpr && *id >= maxInitializedGlobalsIndexPlus1_ && + (!env_.globals[*id].isImport() || env_.globals[*id].isMutable())) { + return fail( + "global.get in initializer expression must reference a global " + "immutable import"); + } + + return push(env_.globals[*id].type()); +} + +template <typename Policy> +inline bool OpIter<Policy>::readSetGlobal(uint32_t* id, Value* value) { + MOZ_ASSERT(Classify(op_) == OpKind::SetGlobal); + + if (!d_.readGlobalIndex(id)) { + return false; + } + + if (*id >= env_.globals.length()) { + return fail("global.set index out of range"); + } + + if (!env_.globals[*id].isMutable()) { + return fail("can't write an immutable global"); + } + + return popWithType(env_.globals[*id].type(), value); +} + +template <typename Policy> +inline bool OpIter<Policy>::readTeeGlobal(uint32_t* id, Value* value) { + MOZ_ASSERT(Classify(op_) == OpKind::TeeGlobal); + + if (!d_.readGlobalIndex(id)) { + return false; + } + + if (*id >= env_.globals.length()) { + return fail("global.set index out of range"); + } + + if (!env_.globals[*id].isMutable()) { + return fail("can't write an immutable global"); + } + + ValueVector single; + if (!checkTopTypeMatches(ResultType::Single(env_.globals[*id].type()), + &single, + /*rewriteStackTypes=*/true)) { + return false; + } + + MOZ_ASSERT(single.length() == 1); + *value = single[0]; + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readI32Const(int32_t* i32) { + MOZ_ASSERT(Classify(op_) == OpKind::I32); + + if (!d_.readI32Const(i32)) { + return false; + } + + return push(ValType::I32); +} + +template <typename Policy> +inline bool OpIter<Policy>::readI64Const(int64_t* i64) { + MOZ_ASSERT(Classify(op_) == OpKind::I64); + + if (!d_.readI64Const(i64)) { + return false; + } + + return push(ValType::I64); +} + +template <typename Policy> +inline bool OpIter<Policy>::readF32Const(float* f32) { + MOZ_ASSERT(Classify(op_) == OpKind::F32); + + if (!d_.readF32Const(f32)) { + return false; + } + + return push(ValType::F32); +} + +template <typename Policy> +inline bool OpIter<Policy>::readF64Const(double* f64) { + MOZ_ASSERT(Classify(op_) == OpKind::F64); + + if (!d_.readF64Const(f64)) { + return false; + } + + return push(ValType::F64); +} + +template <typename Policy> +inline bool OpIter<Policy>::readRefFunc(uint32_t* funcIndex) { + MOZ_ASSERT(Classify(op_) == OpKind::RefFunc); + + if (!d_.readFuncIndex(funcIndex)) { + return false; + } + if (*funcIndex >= env_.funcs.length()) { + return fail("function index out of range"); + } + if (kind_ == OpIter::Func && !env_.funcs[*funcIndex].canRefFunc()) { + return fail( + "function index is not declared in a section before the code section"); + } + +#ifdef ENABLE_WASM_FUNCTION_REFERENCES + // When function references enabled, push type index on the stack, e.g. for + // validation of the call_ref instruction. + if (env_.functionReferencesEnabled()) { + const uint32_t typeIndex = env_.funcs[*funcIndex].typeIndex; + const TypeDef& typeDef = env_.types->type(typeIndex); + return push(RefType::fromTypeDef(&typeDef, false)); + } +#endif + return push(RefType::func()); +} + +template <typename Policy> +inline bool OpIter<Policy>::readRefNull(RefType* type) { + MOZ_ASSERT(Classify(op_) == OpKind::RefNull); + + if (!d_.readRefNull(*env_.types, env_.features, type)) { + return false; + } + return push(*type); +} + +template <typename Policy> +inline bool OpIter<Policy>::readRefIsNull(Value* input) { + MOZ_ASSERT(Classify(op_) == OpKind::Conversion); + + StackType type; + if (!popWithRefType(input, &type)) { + return false; + } + return push(ValType::I32); +} + +template <typename Policy> +inline bool OpIter<Policy>::readRefAsNonNull(Value* input) { + MOZ_ASSERT(Classify(op_) == OpKind::RefAsNonNull); + + StackType type; + if (!popWithRefType(input, &type)) { + return false; + } + + if (type.isStackBottom()) { + infalliblePush(type); + } else { + infalliblePush(TypeAndValue(type.asNonNullable(), *input)); + } + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readBrOnNull(uint32_t* relativeDepth, + ResultType* type, ValueVector* values, + Value* condition) { + MOZ_ASSERT(Classify(op_) == OpKind::BrOnNull); + + if (!readVarU32(relativeDepth)) { + return fail("unable to read br_on_null depth"); + } + + StackType refType; + if (!popWithRefType(condition, &refType)) { + return false; + } + + if (!checkBranchValueAndPush(*relativeDepth, type, values)) { + return false; + } + + if (refType.isStackBottom()) { + return push(refType); + } + return push(TypeAndValue(refType.asNonNullable(), *condition)); +} + +template <typename Policy> +inline bool OpIter<Policy>::readBrOnNonNull(uint32_t* relativeDepth, + ResultType* type, + ValueVector* values, + Value* condition) { + MOZ_ASSERT(Classify(op_) == OpKind::BrOnNonNull); + + if (!readVarU32(relativeDepth)) { + return fail("unable to read br_on_non_null depth"); + } + + Control* block = nullptr; + if (!getControl(*relativeDepth, &block)) { + return false; + } + + *type = block->branchTargetType(); + + // Check we at least have one type in the branch target type. + if (type->length() < 1) { + return fail("type mismatch: target block type expected to be [_, ref]"); + } + + // Pop the condition reference. + StackType refType; + if (!popWithRefType(condition, &refType)) { + return false; + } + + // Push non-nullable version of condition reference on the stack, prior + // checking the target type below. + if (!(refType.isStackBottom() + ? push(refType) + : push(TypeAndValue(refType.asNonNullable(), *condition)))) { + return false; + } + + // Check if the type stack matches the branch target type. + if (!checkTopTypeMatches(*type, values, /*rewriteStackTypes=*/false)) { + return false; + } + + // Pop the condition reference -- the null-branch does not receive the value. + StackType unusedType; + Value unusedValue; + return popStackType(&unusedType, &unusedValue); +} + +template <typename Policy> +inline bool OpIter<Policy>::popCallArgs(const ValTypeVector& expectedTypes, + ValueVector* values) { + // Iterate through the argument types backward so that pops occur in the + // right order. + + if (!values->resize(expectedTypes.length())) { + return false; + } + + for (int32_t i = int32_t(expectedTypes.length()) - 1; i >= 0; i--) { + if (!popWithType(expectedTypes[i], &(*values)[i])) { + return false; + } + } + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readCall(uint32_t* funcTypeIndex, + ValueVector* argValues) { + MOZ_ASSERT(Classify(op_) == OpKind::Call); + + if (!readVarU32(funcTypeIndex)) { + return fail("unable to read call function index"); + } + + if (*funcTypeIndex >= env_.funcs.length()) { + return fail("callee index out of range"); + } + + const FuncType& funcType = *env_.funcs[*funcTypeIndex].type; + + if (!popCallArgs(funcType.args(), argValues)) { + return false; + } + + return push(ResultType::Vector(funcType.results())); +} + +template <typename Policy> +inline bool OpIter<Policy>::readCallIndirect(uint32_t* funcTypeIndex, + uint32_t* tableIndex, + Value* callee, + ValueVector* argValues) { + MOZ_ASSERT(Classify(op_) == OpKind::CallIndirect); + MOZ_ASSERT(funcTypeIndex != tableIndex); + + if (!readVarU32(funcTypeIndex)) { + return fail("unable to read call_indirect signature index"); + } + + if (*funcTypeIndex >= env_.numTypes()) { + return fail("signature index out of range"); + } + + if (!readVarU32(tableIndex)) { + return fail("unable to read call_indirect table index"); + } + if (*tableIndex >= env_.tables.length()) { + // Special case this for improved user experience. + if (!env_.tables.length()) { + return fail("can't call_indirect without a table"); + } + return fail("table index out of range for call_indirect"); + } + if (!env_.tables[*tableIndex].elemType.isFuncHierarchy()) { + return fail("indirect calls must go through a table of 'funcref'"); + } + + if (!popWithType(ValType::I32, callee)) { + return false; + } + + const TypeDef& typeDef = env_.types->type(*funcTypeIndex); + if (!typeDef.isFuncType()) { + return fail("expected signature type"); + } + const FuncType& funcType = typeDef.funcType(); + + if (!popCallArgs(funcType.args(), argValues)) { + return false; + } + + return push(ResultType::Vector(funcType.results())); +} + +#ifdef ENABLE_WASM_FUNCTION_REFERENCES +template <typename Policy> +inline bool OpIter<Policy>::readCallRef(const FuncType** funcType, + Value* callee, ValueVector* argValues) { + MOZ_ASSERT(Classify(op_) == OpKind::CallRef); + + uint32_t funcTypeIndex; + if (!readFuncTypeIndex(&funcTypeIndex)) { + return false; + } + + const TypeDef& typeDef = env_.types->type(funcTypeIndex); + *funcType = &typeDef.funcType(); + + if (!popWithType(ValType(RefType::fromTypeDef(&typeDef, true)), callee)) { + return false; + } + + if (!popCallArgs((*funcType)->args(), argValues)) { + return false; + } + + return push(ResultType::Vector((*funcType)->results())); +} +#endif + +template <typename Policy> +inline bool OpIter<Policy>::readOldCallDirect(uint32_t numFuncImports, + uint32_t* funcTypeIndex, + ValueVector* argValues) { + MOZ_ASSERT(Classify(op_) == OpKind::OldCallDirect); + + uint32_t funcDefIndex; + if (!readVarU32(&funcDefIndex)) { + return fail("unable to read call function index"); + } + + if (UINT32_MAX - funcDefIndex < numFuncImports) { + return fail("callee index out of range"); + } + + *funcTypeIndex = numFuncImports + funcDefIndex; + + if (*funcTypeIndex >= env_.funcs.length()) { + return fail("callee index out of range"); + } + + const FuncType& funcType = *env_.funcs[*funcTypeIndex].type; + + if (!popCallArgs(funcType.args(), argValues)) { + return false; + } + + return push(ResultType::Vector(funcType.results())); +} + +template <typename Policy> +inline bool OpIter<Policy>::readOldCallIndirect(uint32_t* funcTypeIndex, + Value* callee, + ValueVector* argValues) { + MOZ_ASSERT(Classify(op_) == OpKind::OldCallIndirect); + + if (!readVarU32(funcTypeIndex)) { + return fail("unable to read call_indirect signature index"); + } + + if (*funcTypeIndex >= env_.numTypes()) { + return fail("signature index out of range"); + } + + const TypeDef& typeDef = env_.types->type(*funcTypeIndex); + if (!typeDef.isFuncType()) { + return fail("expected signature type"); + } + const FuncType& funcType = typeDef.funcType(); + + if (!popCallArgs(funcType.args(), argValues)) { + return false; + } + + if (!popWithType(ValType::I32, callee)) { + return false; + } + + return push(ResultType::Vector(funcType.results())); +} + +template <typename Policy> +inline bool OpIter<Policy>::readWake(LinearMemoryAddress<Value>* addr, + Value* count) { + MOZ_ASSERT(Classify(op_) == OpKind::Wake); + + if (!popWithType(ValType::I32, count)) { + return false; + } + + uint32_t byteSize = 4; // Per spec; smallest WAIT is i32. + + if (!readLinearMemoryAddressAligned(byteSize, addr)) { + return false; + } + + infalliblePush(ValType::I32); + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readWait(LinearMemoryAddress<Value>* addr, + ValType valueType, uint32_t byteSize, + Value* value, Value* timeout) { + MOZ_ASSERT(Classify(op_) == OpKind::Wait); + + if (!popWithType(ValType::I64, timeout)) { + return false; + } + + if (!popWithType(valueType, value)) { + return false; + } + + if (!readLinearMemoryAddressAligned(byteSize, addr)) { + return false; + } + + infalliblePush(ValType::I32); + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readFence() { + MOZ_ASSERT(Classify(op_) == OpKind::Fence); + uint8_t flags; + if (!readFixedU8(&flags)) { + return fail("expected memory order after fence"); + } + if (flags != 0) { + return fail("non-zero memory order not supported yet"); + } + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readAtomicLoad(LinearMemoryAddress<Value>* addr, + ValType resultType, + uint32_t byteSize) { + MOZ_ASSERT(Classify(op_) == OpKind::AtomicLoad); + + if (!readLinearMemoryAddressAligned(byteSize, addr)) { + return false; + } + + infalliblePush(resultType); + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readAtomicStore(LinearMemoryAddress<Value>* addr, + ValType resultType, + uint32_t byteSize, Value* value) { + MOZ_ASSERT(Classify(op_) == OpKind::AtomicStore); + + if (!popWithType(resultType, value)) { + return false; + } + + if (!readLinearMemoryAddressAligned(byteSize, addr)) { + return false; + } + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readAtomicRMW(LinearMemoryAddress<Value>* addr, + ValType resultType, uint32_t byteSize, + Value* value) { + MOZ_ASSERT(Classify(op_) == OpKind::AtomicBinOp); + + if (!popWithType(resultType, value)) { + return false; + } + + if (!readLinearMemoryAddressAligned(byteSize, addr)) { + return false; + } + + infalliblePush(resultType); + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readAtomicCmpXchg(LinearMemoryAddress<Value>* addr, + ValType resultType, + uint32_t byteSize, + Value* oldValue, + Value* newValue) { + MOZ_ASSERT(Classify(op_) == OpKind::AtomicCompareExchange); + + if (!popWithType(resultType, newValue)) { + return false; + } + + if (!popWithType(resultType, oldValue)) { + return false; + } + + if (!readLinearMemoryAddressAligned(byteSize, addr)) { + return false; + } + + infalliblePush(resultType); + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readMemOrTableCopy(bool isMem, + uint32_t* dstMemOrTableIndex, + Value* dst, + uint32_t* srcMemOrTableIndex, + Value* src, Value* len) { + MOZ_ASSERT(Classify(op_) == OpKind::MemOrTableCopy); + MOZ_ASSERT(dstMemOrTableIndex != srcMemOrTableIndex); + + // Spec requires (dest, src) as of 2019-10-04. + if (!readMemOrTableIndex(isMem, dstMemOrTableIndex)) { + return false; + } + if (!readMemOrTableIndex(isMem, srcMemOrTableIndex)) { + return false; + } + + if (isMem) { + if (!env_.usesMemory()) { + return fail("can't touch memory without memory"); + } + if (*srcMemOrTableIndex != 0 || *dstMemOrTableIndex != 0) { + return fail("memory index out of range for memory.copy"); + } + } else { + if (*dstMemOrTableIndex >= env_.tables.length() || + *srcMemOrTableIndex >= env_.tables.length()) { + return fail("table index out of range for table.copy"); + } + ValType dstElemType = env_.tables[*dstMemOrTableIndex].elemType; + ValType srcElemType = env_.tables[*srcMemOrTableIndex].elemType; + if (!checkIsSubtypeOf(srcElemType, dstElemType)) { + return false; + } + } + + ValType ptrType = isMem ? ToValType(env_.memory->indexType()) : ValType::I32; + + if (!popWithType(ptrType, len)) { + return false; + } + + if (!popWithType(ptrType, src)) { + return false; + } + + if (!popWithType(ptrType, dst)) { + return false; + } + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readDataOrElemDrop(bool isData, + uint32_t* segIndex) { + MOZ_ASSERT(Classify(op_) == OpKind::DataOrElemDrop); + + if (!readVarU32(segIndex)) { + return fail("unable to read segment index"); + } + + if (isData) { + if (env_.dataCount.isNothing()) { + return fail("data.drop requires a DataCount section"); + } + if (*segIndex >= *env_.dataCount) { + return fail("data.drop segment index out of range"); + } + } else { + if (*segIndex >= env_.elemSegments.length()) { + return fail("element segment index out of range for elem.drop"); + } + } + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readMemFill(Value* start, Value* val, Value* len) { + MOZ_ASSERT(Classify(op_) == OpKind::MemFill); + + if (!env_.usesMemory()) { + return fail("can't touch memory without memory"); + } + + uint8_t memoryIndex; + if (!readFixedU8(&memoryIndex)) { + return fail("failed to read memory index"); + } + if (!env_.usesMemory()) { + return fail("can't touch memory without memory"); + } + if (memoryIndex != 0) { + return fail("memory index must be zero"); + } + + ValType ptrType = ToValType(env_.memory->indexType()); + + if (!popWithType(ptrType, len)) { + return false; + } + + if (!popWithType(ValType::I32, val)) { + return false; + } + + if (!popWithType(ptrType, start)) { + return false; + } + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readMemOrTableInit(bool isMem, uint32_t* segIndex, + uint32_t* dstTableIndex, + Value* dst, Value* src, + Value* len) { + MOZ_ASSERT(Classify(op_) == OpKind::MemOrTableInit); + MOZ_ASSERT(segIndex != dstTableIndex); + + if (!readVarU32(segIndex)) { + return fail("unable to read segment index"); + } + + uint32_t memOrTableIndex = 0; + if (!readMemOrTableIndex(isMem, &memOrTableIndex)) { + return false; + } + + if (isMem) { + if (!env_.usesMemory()) { + return fail("can't touch memory without memory"); + } + if (memOrTableIndex != 0) { + return fail("memory index must be zero"); + } + if (env_.dataCount.isNothing()) { + return fail("memory.init requires a DataCount section"); + } + if (*segIndex >= *env_.dataCount) { + return fail("memory.init segment index out of range"); + } + } else { + if (memOrTableIndex >= env_.tables.length()) { + return fail("table index out of range for table.init"); + } + *dstTableIndex = memOrTableIndex; + + if (*segIndex >= env_.elemSegments.length()) { + return fail("table.init segment index out of range"); + } + if (!checkIsSubtypeOf(env_.elemSegments[*segIndex]->elemType, + env_.tables[*dstTableIndex].elemType)) { + return false; + } + } + + if (!popWithType(ValType::I32, len)) { + return false; + } + + if (!popWithType(ValType::I32, src)) { + return false; + } + + ValType ptrType = isMem ? ToValType(env_.memory->indexType()) : ValType::I32; + return popWithType(ptrType, dst); +} + +template <typename Policy> +inline bool OpIter<Policy>::readTableFill(uint32_t* tableIndex, Value* start, + Value* val, Value* len) { + MOZ_ASSERT(Classify(op_) == OpKind::TableFill); + + if (!readVarU32(tableIndex)) { + return fail("unable to read table index"); + } + if (*tableIndex >= env_.tables.length()) { + return fail("table index out of range for table.fill"); + } + + if (!popWithType(ValType::I32, len)) { + return false; + } + if (!popWithType(env_.tables[*tableIndex].elemType, val)) { + return false; + } + if (!popWithType(ValType::I32, start)) { + return false; + } + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readMemDiscard(Value* start, Value* len) { + MOZ_ASSERT(Classify(op_) == OpKind::MemDiscard); + + if (!env_.usesMemory()) { + return fail("can't touch memory without memory"); + } + + uint8_t memoryIndex; + if (!readFixedU8(&memoryIndex)) { + return fail("failed to read memory index"); + } + if (memoryIndex != 0) { + return fail("memory index must be zero"); + } + + ValType ptrType = ToValType(env_.memory->indexType()); + + if (!popWithType(ptrType, len)) { + return false; + } + + if (!popWithType(ptrType, start)) { + return false; + } + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readTableGet(uint32_t* tableIndex, Value* index) { + MOZ_ASSERT(Classify(op_) == OpKind::TableGet); + + if (!readVarU32(tableIndex)) { + return fail("unable to read table index"); + } + if (*tableIndex >= env_.tables.length()) { + return fail("table index out of range for table.get"); + } + + if (!popWithType(ValType::I32, index)) { + return false; + } + + infalliblePush(env_.tables[*tableIndex].elemType); + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readTableGrow(uint32_t* tableIndex, + Value* initValue, Value* delta) { + MOZ_ASSERT(Classify(op_) == OpKind::TableGrow); + + if (!readVarU32(tableIndex)) { + return fail("unable to read table index"); + } + if (*tableIndex >= env_.tables.length()) { + return fail("table index out of range for table.grow"); + } + + if (!popWithType(ValType::I32, delta)) { + return false; + } + if (!popWithType(env_.tables[*tableIndex].elemType, initValue)) { + return false; + } + + infalliblePush(ValType::I32); + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readTableSet(uint32_t* tableIndex, Value* index, + Value* value) { + MOZ_ASSERT(Classify(op_) == OpKind::TableSet); + + if (!readVarU32(tableIndex)) { + return fail("unable to read table index"); + } + if (*tableIndex >= env_.tables.length()) { + return fail("table index out of range for table.set"); + } + + if (!popWithType(env_.tables[*tableIndex].elemType, value)) { + return false; + } + if (!popWithType(ValType::I32, index)) { + return false; + } + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readTableSize(uint32_t* tableIndex) { + MOZ_ASSERT(Classify(op_) == OpKind::TableSize); + + *tableIndex = 0; + + if (!readVarU32(tableIndex)) { + return fail("unable to read table index"); + } + if (*tableIndex >= env_.tables.length()) { + return fail("table index out of range for table.size"); + } + + return push(ValType::I32); +} + +template <typename Policy> +inline bool OpIter<Policy>::readGcTypeIndex(uint32_t* typeIndex) { + if (!d_.readTypeIndex(typeIndex)) { + return false; + } + + if (*typeIndex >= env_.types->length()) { + return fail("type index out of range"); + } + + if (!env_.types->type(*typeIndex).isStructType() && + !env_.types->type(*typeIndex).isArrayType()) { + return fail("not a gc type"); + } + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readStructTypeIndex(uint32_t* typeIndex) { + if (!readVarU32(typeIndex)) { + return fail("unable to read type index"); + } + + if (*typeIndex >= env_.types->length()) { + return fail("type index out of range"); + } + + if (!env_.types->type(*typeIndex).isStructType()) { + return fail("not a struct type"); + } + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readArrayTypeIndex(uint32_t* typeIndex) { + if (!readVarU32(typeIndex)) { + return fail("unable to read type index"); + } + + if (*typeIndex >= env_.types->length()) { + return fail("type index out of range"); + } + + if (!env_.types->type(*typeIndex).isArrayType()) { + return fail("not an array type"); + } + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readFuncTypeIndex(uint32_t* typeIndex) { + if (!readVarU32(typeIndex)) { + return fail("unable to read type index"); + } + + if (*typeIndex >= env_.types->length()) { + return fail("type index out of range"); + } + + if (!env_.types->type(*typeIndex).isFuncType()) { + return fail("not an func type"); + } + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readFieldIndex(uint32_t* fieldIndex, + const StructType& structType) { + if (!readVarU32(fieldIndex)) { + return fail("unable to read field index"); + } + + if (structType.fields_.length() <= *fieldIndex) { + return fail("field index out of range"); + } + + return true; +} + +#ifdef ENABLE_WASM_GC + +template <typename Policy> +inline bool OpIter<Policy>::readStructNew(uint32_t* typeIndex, + ValueVector* argValues) { + MOZ_ASSERT(Classify(op_) == OpKind::StructNew); + + if (!readStructTypeIndex(typeIndex)) { + return false; + } + + const TypeDef& typeDef = env_.types->type(*typeIndex); + const StructType& structType = typeDef.structType(); + + if (!argValues->resize(structType.fields_.length())) { + return false; + } + + static_assert(MaxStructFields <= INT32_MAX, "Or we iloop below"); + + for (int32_t i = structType.fields_.length() - 1; i >= 0; i--) { + if (!popWithType(structType.fields_[i].type.widenToValType(), + &(*argValues)[i])) { + return false; + } + } + + return push(RefType::fromTypeDef(&typeDef, false)); +} + +template <typename Policy> +inline bool OpIter<Policy>::readStructNewDefault(uint32_t* typeIndex) { + MOZ_ASSERT(Classify(op_) == OpKind::StructNewDefault); + + if (!readStructTypeIndex(typeIndex)) { + return false; + } + + const TypeDef& typeDef = env_.types->type(*typeIndex); + const StructType& structType = typeDef.structType(); + + if (!structType.isDefaultable()) { + return fail("struct must be defaultable"); + } + + return push(RefType::fromTypeDef(&typeDef, false)); +} + +template <typename Policy> +inline bool OpIter<Policy>::readStructGet(uint32_t* typeIndex, + uint32_t* fieldIndex, + FieldWideningOp wideningOp, + Value* ptr) { + MOZ_ASSERT(typeIndex != fieldIndex); + MOZ_ASSERT(Classify(op_) == OpKind::StructGet); + + if (!readStructTypeIndex(typeIndex)) { + return false; + } + + const TypeDef& typeDef = env_.types->type(*typeIndex); + const StructType& structType = typeDef.structType(); + + if (!readFieldIndex(fieldIndex, structType)) { + return false; + } + + if (!popWithType(RefType::fromTypeDef(&typeDef, true), ptr)) { + return false; + } + + FieldType fieldType = structType.fields_[*fieldIndex].type; + + if (fieldType.isValType() && wideningOp != FieldWideningOp::None) { + return fail("must not specify signedness for unpacked field type"); + } + + if (!fieldType.isValType() && wideningOp == FieldWideningOp::None) { + return fail("must specify signedness for packed field type"); + } + + return push(fieldType.widenToValType()); +} + +template <typename Policy> +inline bool OpIter<Policy>::readStructSet(uint32_t* typeIndex, + uint32_t* fieldIndex, Value* ptr, + Value* val) { + MOZ_ASSERT(typeIndex != fieldIndex); + MOZ_ASSERT(Classify(op_) == OpKind::StructSet); + + if (!readStructTypeIndex(typeIndex)) { + return false; + } + + const TypeDef& typeDef = env_.types->type(*typeIndex); + const StructType& structType = typeDef.structType(); + + if (!readFieldIndex(fieldIndex, structType)) { + return false; + } + + if (!popWithType(structType.fields_[*fieldIndex].type.widenToValType(), + val)) { + return false; + } + + if (!structType.fields_[*fieldIndex].isMutable) { + return fail("field is not mutable"); + } + + if (!popWithType(RefType::fromTypeDef(&typeDef, true), ptr)) { + return false; + } + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readArrayNew(uint32_t* typeIndex, + Value* numElements, Value* argValue) { + MOZ_ASSERT(Classify(op_) == OpKind::ArrayNew); + + if (!readArrayTypeIndex(typeIndex)) { + return false; + } + + const TypeDef& typeDef = env_.types->type(*typeIndex); + const ArrayType& arrayType = typeDef.arrayType(); + + if (!popWithType(ValType::I32, numElements)) { + return false; + } + + if (!popWithType(arrayType.elementType_.widenToValType(), argValue)) { + return false; + } + + return push(RefType::fromTypeDef(&typeDef, false)); +} + +template <typename Policy> +inline bool OpIter<Policy>::readArrayNewFixed(uint32_t* typeIndex, + uint32_t* numElements, + ValueVector* values) { + MOZ_ASSERT(Classify(op_) == OpKind::ArrayNewFixed); + MOZ_ASSERT(values->length() == 0); + + if (!readArrayTypeIndex(typeIndex)) { + return false; + } + + const TypeDef& typeDef = env_.types->type(*typeIndex); + const ArrayType& arrayType = typeDef.arrayType(); + + if (!readVarU32(numElements)) { + return false; + } + // Don't resize `values` so as to hold `numElements`. If `numElements` is + // absurdly large, this will will take a large amount of time and memory, + // which will be wasted because `popWithType` in the loop below will soon + // start failing anyway. + + ValType widenedElementType = arrayType.elementType_.widenToValType(); + for (uint32_t i = 0; i < *numElements; i++) { + Value v; + if (!popWithType(widenedElementType, &v)) { + return false; + } + if (!values->append(v)) { + return false; + } + } + + return push(RefType::fromTypeDef(&typeDef, false)); +} + +template <typename Policy> +inline bool OpIter<Policy>::readArrayNewDefault(uint32_t* typeIndex, + Value* numElements) { + MOZ_ASSERT(Classify(op_) == OpKind::ArrayNewDefault); + + if (!readArrayTypeIndex(typeIndex)) { + return false; + } + + const TypeDef& typeDef = env_.types->type(*typeIndex); + const ArrayType& arrayType = typeDef.arrayType(); + + if (!popWithType(ValType::I32, numElements)) { + return false; + } + + if (!arrayType.elementType_.isDefaultable()) { + return fail("array must be defaultable"); + } + + return push(RefType::fromTypeDef(&typeDef, false)); +} + +template <typename Policy> +inline bool OpIter<Policy>::readArrayNewData(uint32_t* typeIndex, + uint32_t* segIndex, Value* offset, + Value* numElements) { + MOZ_ASSERT(Classify(op_) == OpKind::ArrayNewData); + + if (!readArrayTypeIndex(typeIndex)) { + return false; + } + + if (!readVarU32(segIndex)) { + return fail("unable to read segment index"); + } + + const TypeDef& typeDef = env_.types->type(*typeIndex); + const ArrayType& arrayType = typeDef.arrayType(); + FieldType elemType = arrayType.elementType_; + if (!elemType.isNumber() && !elemType.isPacked() && !elemType.isVector()) { + return fail("element type must be i8/i16/i32/i64/f32/f64/v128"); + } + if (env_.dataCount.isNothing()) { + return fail("datacount section missing"); + } + if (*segIndex >= *env_.dataCount) { + return fail("segment index is out of range"); + } + + if (!popWithType(ValType::I32, numElements)) { + return false; + } + if (!popWithType(ValType::I32, offset)) { + return false; + } + + return push(RefType::fromTypeDef(&typeDef, false)); +} + +template <typename Policy> +inline bool OpIter<Policy>::readArrayNewElem(uint32_t* typeIndex, + uint32_t* segIndex, Value* offset, + Value* numElements) { + MOZ_ASSERT(Classify(op_) == OpKind::ArrayNewData); + + if (!readArrayTypeIndex(typeIndex)) { + return false; + } + + if (!readVarU32(segIndex)) { + return fail("unable to read segment index"); + } + + const TypeDef& typeDef = env_.types->type(*typeIndex); + const ArrayType& arrayType = typeDef.arrayType(); + FieldType dstElemType = arrayType.elementType_; + if (!dstElemType.isRefType()) { + return fail("element type is not a reftype"); + } + if (*segIndex >= env_.elemSegments.length()) { + return fail("segment index is out of range"); + } + + const ElemSegment* elemSeg = env_.elemSegments[*segIndex]; + RefType srcElemType = elemSeg->elemType; + // srcElemType needs to be a subtype (child) of dstElemType + if (!checkIsSubtypeOf(srcElemType, dstElemType.refType())) { + return fail("incompatible element types"); + } + + if (!popWithType(ValType::I32, numElements)) { + return false; + } + if (!popWithType(ValType::I32, offset)) { + return false; + } + + return push(RefType::fromTypeDef(&typeDef, false)); +} + +template <typename Policy> +inline bool OpIter<Policy>::readArrayGet(uint32_t* typeIndex, + FieldWideningOp wideningOp, + Value* index, Value* ptr) { + MOZ_ASSERT(Classify(op_) == OpKind::ArrayGet); + + if (!readArrayTypeIndex(typeIndex)) { + return false; + } + + const TypeDef& typeDef = env_.types->type(*typeIndex); + const ArrayType& arrayType = typeDef.arrayType(); + + if (!popWithType(ValType::I32, index)) { + return false; + } + + if (!popWithType(RefType::fromTypeDef(&typeDef, true), ptr)) { + return false; + } + + FieldType fieldType = arrayType.elementType_; + + if (fieldType.isValType() && wideningOp != FieldWideningOp::None) { + return fail("must not specify signedness for unpacked element type"); + } + + if (!fieldType.isValType() && wideningOp == FieldWideningOp::None) { + return fail("must specify signedness for packed element type"); + } + + return push(fieldType.widenToValType()); +} + +template <typename Policy> +inline bool OpIter<Policy>::readArraySet(uint32_t* typeIndex, Value* val, + Value* index, Value* ptr) { + MOZ_ASSERT(Classify(op_) == OpKind::ArraySet); + + if (!readArrayTypeIndex(typeIndex)) { + return false; + } + + const TypeDef& typeDef = env_.types->type(*typeIndex); + const ArrayType& arrayType = typeDef.arrayType(); + + if (!arrayType.isMutable_) { + return fail("array is not mutable"); + } + + if (!popWithType(arrayType.elementType_.widenToValType(), val)) { + return false; + } + + if (!popWithType(ValType::I32, index)) { + return false; + } + + if (!popWithType(RefType::fromTypeDef(&typeDef, true), ptr)) { + return false; + } + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readArrayLen(bool decodeIgnoredTypeIndex, + Value* ptr) { + MOZ_ASSERT(Classify(op_) == OpKind::ArrayLen); + + // TODO: remove once V8 removes array.len with type index from their snapshot + uint32_t unused; + if (decodeIgnoredTypeIndex && !readVarU32(&unused)) { + return false; + } + + if (!popWithType(RefType::array(), ptr)) { + return false; + } + + return push(ValType::I32); +} + +template <typename Policy> +inline bool OpIter<Policy>::readArrayCopy(int32_t* elemSize, + bool* elemsAreRefTyped, + Value* dstArray, Value* dstIndex, + Value* srcArray, Value* srcIndex, + Value* numElements) { + // *elemSize is set to 1/2/4/8/16, and *elemsAreRefTyped is set to indicate + // *ref-typeness of elements. + MOZ_ASSERT(Classify(op_) == OpKind::ArrayCopy); + + uint32_t dstTypeIndex, srcTypeIndex; + if (!readArrayTypeIndex(&dstTypeIndex)) { + return false; + } + if (!readArrayTypeIndex(&srcTypeIndex)) { + return false; + } + + // `dstTypeIndex`/`srcTypeIndex` are ensured by the above to both be array + // types. Reject if: + // * the dst array is not of mutable type + // * the element types are incompatible + const TypeDef& dstTypeDef = env_.types->type(dstTypeIndex); + const ArrayType& dstArrayType = dstTypeDef.arrayType(); + const TypeDef& srcTypeDef = env_.types->type(srcTypeIndex); + const ArrayType& srcArrayType = srcTypeDef.arrayType(); + FieldType dstElemType = dstArrayType.elementType_; + FieldType srcElemType = srcArrayType.elementType_; + if (!dstArrayType.isMutable_) { + return fail("destination array is not mutable"); + } + + if (!checkIsSubtypeOf(srcElemType, dstElemType)) { + return fail("incompatible element types"); + } + bool dstIsRefType = dstElemType.isRefType(); + MOZ_ASSERT(dstIsRefType == srcElemType.isRefType()); + + *elemSize = int32_t(dstElemType.size()); + *elemsAreRefTyped = dstIsRefType; + MOZ_ASSERT(*elemSize >= 1 && *elemSize <= 16); + MOZ_ASSERT_IF(*elemsAreRefTyped, *elemSize == 4 || *elemSize == 8); + + if (!popWithType(ValType::I32, numElements)) { + return false; + } + if (!popWithType(ValType::I32, srcIndex)) { + return false; + } + if (!popWithType(RefType::fromTypeDef(&srcTypeDef, true), srcArray)) { + return false; + } + if (!popWithType(ValType::I32, dstIndex)) { + return false; + } + if (!popWithType(RefType::fromTypeDef(&dstTypeDef, true), dstArray)) { + return false; + } + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readRefTestV5(RefType* sourceType, + uint32_t* typeIndex, Value* ref) { + MOZ_ASSERT(Classify(op_) == OpKind::RefTestV5); + + if (!readGcTypeIndex(typeIndex)) { + return false; + } + + StackType inputType; + if (!popWithType(RefType::any(), ref)) { + return false; + } + *sourceType = inputType.valTypeOr(RefType::any()).refType(); + + return push(ValType(ValType::I32)); +} + +template <typename Policy> +inline bool OpIter<Policy>::readRefCastV5(RefType* sourceType, + uint32_t* typeIndex, Value* ref) { + MOZ_ASSERT(Classify(op_) == OpKind::RefCastV5); + + if (!readGcTypeIndex(typeIndex)) { + return false; + } + + StackType inputType; + if (!popWithType(RefType::any(), ref, &inputType)) { + return false; + } + *sourceType = inputType.valTypeOr(RefType::any()).refType(); + + const TypeDef& typeDef = env_.types->type(*typeIndex); + return push(RefType::fromTypeDef(&typeDef, inputType.isNullableAsOperand())); +} + +template <typename Policy> +inline bool OpIter<Policy>::readRefTest(bool nullable, RefType* sourceType, + RefType* destType, Value* ref) { + MOZ_ASSERT(Classify(op_) == OpKind::RefTest); + + if (!readHeapType(nullable, destType)) { + return false; + } + + StackType inputType; + if (!popWithType(destType->topType(), ref, &inputType)) { + return false; + } + *sourceType = inputType.valTypeOr(RefType::any()).refType(); + + if (!destType->isAnyHierarchy()) { + return fail("ref.test only supports the any hierarchy for now"); + } + + return push(ValType(ValType::I32)); +} + +template <typename Policy> +inline bool OpIter<Policy>::readRefCast(bool nullable, RefType* sourceType, + RefType* destType, Value* ref) { + MOZ_ASSERT(Classify(op_) == OpKind::RefCast); + + if (!readHeapType(nullable, destType)) { + return false; + } + + StackType inputType; + if (!popWithType(destType->topType(), ref, &inputType)) { + return false; + } + *sourceType = inputType.valTypeOr(RefType::any()).refType(); + + if (!destType->isAnyHierarchy()) { + return fail("ref.cast only supports the any hierarchy for now"); + } + + return push(*destType); +} + +// `br_on_cast <flags> <labelRelativeDepth> <rt1> <rt2>` +// branches if a reference has a given heap type. +// +// V6 spec text follows - note that br_on_cast and br_on_cast_fail are both +// handled by this function (disambiguated by a flag). +// +// * `br_on_cast <labelidx> <reftype> <reftype>` branches if a reference has a +// given type +// - `br_on_cast $l rt1 rt2 : [t0* rt1] -> [t0* rt1\rt2]` +// - iff `$l : [t0* rt2]` +// - and `rt2 <: rt1` +// - passes operand along with branch under target type, plus possible extra +// args +// - if `rt2` contains `null`, branches on null, otherwise does not +// * `br_on_cast_fail <labelidx> <reftype> <reftype>` branches if a reference +// does not have a given type +// - `br_on_cast_fail $l rt1 rt2 : [t0* rt1] -> [t0* rt2]` +// - iff `$l : [t0* rt1\rt2]` +// - and `rt2 <: rt1` +// - passes operand along with branch, plus possible extra args +// - if `rt2` contains `null`, does not branch on null, otherwise does +// where: +// - `(ref null1? ht1)\(ref null ht2) = (ref ht1)` +// - `(ref null1? ht1)\(ref ht2) = (ref null1? ht1)` +// +// The `rt1\rt2` syntax is a "diff" - it is basically rt1 minus rt2, because a +// successful cast to rt2 will branch away. So if rt2 allows null, the result +// after a non-branch will be non-null; on the other hand, if rt2 is +// non-nullable, the cast will have nothing to say about nullability and the +// nullability of rt1 will be preserved. +// +// `values` will be nonempty after the call, and its last entry will be the +// type that causes a branch (rt1\rt2 or rt2, depending). + +template <typename Policy> +inline bool OpIter<Policy>::readBrOnCast(bool* onSuccess, + uint32_t* labelRelativeDepth, + RefType* sourceType, RefType* destType, + ResultType* labelType, + ValueVector* values) { + MOZ_ASSERT(Classify(op_) == OpKind::BrOnCast); + + uint8_t flags; + if (!readFixedU8(&flags)) { + return fail("unable to read br_on_cast flags"); + } + bool sourceNullable = flags & (1 << 0); + bool destNullable = flags & (1 << 1); + *onSuccess = !(flags & (1 << 2)); + + if (!readVarU32(labelRelativeDepth)) { + return fail("unable to read br_on_cast depth"); + } + + // This is distinct from the actual source type we pop from the stack, which + // can be more specific and allow for better optimizations. + RefType immediateSourceType; + if (!readHeapType(sourceNullable, &immediateSourceType)) { + return fail("unable to read br_on_cast source type"); + } + + if (!readHeapType(destNullable, destType)) { + return fail("unable to read br_on_cast dest type"); + } + + // Check that source and destination types are compatible + if (!checkIsSubtypeOf(*destType, immediateSourceType)) { + return fail( + "type mismatch: source and destination types for cast are " + "incompatible"); + } + + RefType typeOnSuccess = *destType; + // This is rt1\rt2 + RefType typeOnFail = + destNullable ? immediateSourceType.asNonNullable() : immediateSourceType; + RefType typeOnBranch = *onSuccess ? typeOnSuccess : typeOnFail; + RefType typeOnFallthrough = *onSuccess ? typeOnFail : typeOnSuccess; + + if (!typeOnSuccess.isAnyHierarchy() || !typeOnFail.isAnyHierarchy()) { + return fail( + "br_on_cast and br_on_cast_fail only support the any hierarchy for " + "now"); + } + + // Get the branch target type, which will also determine the type of extra + // values that are passed along on branch. + Control* block = nullptr; + if (!getControl(*labelRelativeDepth, &block)) { + return false; + } + *labelType = block->branchTargetType(); + + // Check we have at least one value slot in the branch target type, so as to + // receive the casted or non-casted type when we branch. + const size_t labelTypeNumValues = labelType->length(); + if (labelTypeNumValues < 1) { + return fail("type mismatch: branch target type has no value types"); + } + + // The last value slot in the branch target type is what is being cast. + // This slot is guaranteed to exist by the above check. + + // Check that the branch target type can accept typeOnBranch. + if (!checkIsSubtypeOf(typeOnBranch, (*labelType)[labelTypeNumValues - 1])) { + return false; + } + + // Replace the top operand with the result of falling through. Even branching + // on success can change the type on top of the stack on fallthrough. + Value inputValue; + StackType inputType; + if (!popWithType(immediateSourceType, &inputValue, &inputType)) { + return false; + } + *sourceType = inputType.valTypeOr(RefType::any()).refType(); + infalliblePush(TypeAndValue(typeOnFallthrough, inputValue)); + + // Create a copy of the branch target type, with the relevant value slot + // replaced by typeOnFallthrough. + ValTypeVector fallthroughTypes; + if (!labelType->cloneToVector(&fallthroughTypes)) { + return false; + } + fallthroughTypes[labelTypeNumValues - 1] = typeOnFallthrough; + + return checkTopTypeMatches(ResultType::Vector(fallthroughTypes), values, + /*rewriteStackTypes=*/false); +} + +template <typename Policy> +inline bool OpIter<Policy>::checkBrOnCastCommonV5(uint32_t labelRelativeDepth, + RefType* sourceType, + ValType castToType, + ResultType* labelType, + ValueVector* values) { + if (!(castToType.isRefType() && castToType.refType().isAnyHierarchy())) { + return fail("br_on_cast v5 only supports the any hierarchy"); + } + + // The casted from type is any subtype of anyref. + ValType anyrefType(RefType::any()); + *sourceType = RefType::any(); + + // Get the branch target type, which will also determine the type of extra + // values that are passed along with the casted type. This validates + // requirement (1). + Control* block = nullptr; + if (!getControl(labelRelativeDepth, &block)) { + return false; + } + *labelType = block->branchTargetType(); + + // Check we have at least one value slot in the branch target type, so as to + // receive the casted type in the case where the cast succeeds. + const size_t labelTypeNumValues = labelType->length(); + if (labelTypeNumValues < 1) { + return fail("type mismatch: branch target type has no value slots"); + } + + // The last value slot in the branch target type is what is being cast. + // This slot is guaranteed to exist by the above check. + + // Check that the branch target type can accept castType. The branch target + // may specify a supertype of castType, and this is okay. Validates (2). + if (!checkIsSubtypeOf(castToType, (*labelType)[labelTypeNumValues - 1])) { + return false; + } + + // Create a copy of the branch target type, with the relevant value slot + // replaced by anyrefType. Use this to check that the stack has the proper + // types to branch to the target type. + // + // TODO: We could avoid a potential allocation here by handwriting a custom + // checkTopTypeMatches that handles this case. + ValTypeVector fallthroughType; + if (!labelType->cloneToVector(&fallthroughType)) { + return false; + } + fallthroughType[labelTypeNumValues - 1] = anyrefType; + + // Validates the first half of (3), if we pretend that topType is eqref, + // which it isn't really. + return checkTopTypeMatches(ResultType::Vector(fallthroughType), values, + /*rewriteStackTypes=*/false); +} + +// `br_on_cast <labelRelativeDepth> null? <castTypeIndex>` +// branches if a reference has a given heap type +// +// br_on_cast $label null? castType : [t0* (ref null argType)] -> +// [t0* (ref null2? argType)] +// (1) iff $label : [t0* labelType] +// (2) and (ref null3? castType) <: labelType +// (3) and castType <: topType and argType <: topType +// where topType is a common super type +// (4) and null? = null3? =/= null2? +// +// - passes operand along with branch under target type, +// plus possible extra args +// - if null? is present, branches on null, otherwise does not +// +// Currently unhandled: +// (3) partial check, and not really right +// (4) neither checked nor implemented +// +// `values` will be nonempty after the call, and its last entry will be that +// of the argument. + +template <typename Policy> +inline bool OpIter<Policy>::readBrOnCastV5(uint32_t* labelRelativeDepth, + RefType* sourceType, + uint32_t* castTypeIndex, + ResultType* labelType, + ValueVector* values) { + MOZ_ASSERT(Classify(op_) == OpKind::BrOnCastV5); + + if (!readVarU32(labelRelativeDepth)) { + return fail("unable to read br_on_cast depth"); + } + + if (!readGcTypeIndex(castTypeIndex)) { + return false; + } + + // The casted to type is a non-nullable reference to the type index + // specified as an immediate. + const TypeDef& castTypeDef = env_.types->type(*castTypeIndex); + ValType castType(RefType::fromTypeDef(&castTypeDef, false)); + + return checkBrOnCastCommonV5(*labelRelativeDepth, sourceType, castType, + labelType, values); +} + +template <typename Policy> +inline bool OpIter<Policy>::readBrOnCastHeapV5( + bool nullable, uint32_t* labelRelativeDepth, RefType* sourceType, + RefType* destType, ResultType* labelType, ValueVector* values) { + MOZ_ASSERT(Classify(op_) == OpKind::BrOnCastV5); + + if (!readVarU32(labelRelativeDepth)) { + return fail("unable to read br_on_cast depth"); + } + + if (!readHeapType(nullable, destType)) { + return false; + } + + ValType castToType(*destType); + return checkBrOnCastCommonV5(*labelRelativeDepth, sourceType, castToType, + labelType, values); +} + +// `br_on_cast_fail <labelRelativeDepth> null? <castTypeIndex>` +// branches if a reference does not have a given heap type +// +// br_on_cast_fail $label null? castType : [t0* (ref null argType)] -> +// [t0* (ref null2? castType)] +// (1) iff $label : [t0* labelType] +// (2) and (ref null3? argType) <: labelType +// (3) and castType <: topType and argType <: topType +// where topType is a common super type +// (4) and null? = null2? =/= null3? +// +// - passes operand along with branch, plus possible extra args +// - if null? is present, does not branch on null, otherwise does +// +// Currently unhandled: +// (3) partial check, and not really right +// (4) neither checked nor implemented +// +// `values` will be nonempty after the call, and its last entry will be that +// of the argument. +template <typename Policy> +inline bool OpIter<Policy>::checkBrOnCastFailCommonV5( + uint32_t labelRelativeDepth, RefType* sourceType, ValType castToType, + ResultType* labelType, ValueVector* values) { + if (!(castToType.isRefType() && castToType.refType().isAnyHierarchy())) { + return fail("br_on_cast_fail v5 only supports the any hierarchy"); + } + + // Get the branch target type, which will also determine the type of extra + // values that are passed along with the casted type. This validates + // requirement (1). + Control* block = nullptr; + if (!getControl(labelRelativeDepth, &block)) { + return false; + } + *labelType = block->branchTargetType(); + + // Check we at least have one value slot in the branch target type, so as to + // receive the argument value in the case where the cast fails. + if (labelType->length() < 1) { + return fail("type mismatch: branch target type has no value slots"); + } + + // Check all operands match the failure label's target type. Validates (2). + if (!checkTopTypeMatches(*labelType, values, + /*rewriteStackTypes=*/false)) { + return false; + } + + // The top operand needs to be compatible with the casted from type. + // Validates the first half of (3), if we pretend that topType is eqref, + // which it isn't really. + Value ignored; + StackType inputValue; + if (!popWithType(ValType(RefType::any()), &ignored, &inputValue)) { + return false; + } + *sourceType = inputValue.valTypeOr(RefType::any()).refType(); + + // The top result in the fallthrough case is the casted to type. + infalliblePush(TypeAndValue(castToType, ignored)); + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readBrOnCastFailV5(uint32_t* labelRelativeDepth, + RefType* sourceType, + uint32_t* castTypeIndex, + ResultType* labelType, + ValueVector* values) { + MOZ_ASSERT(Classify(op_) == OpKind::BrOnCastFailV5); + + if (!readVarU32(labelRelativeDepth)) { + return fail("unable to read br_on_cast_fail depth"); + } + + if (!readGcTypeIndex(castTypeIndex)) { + return false; + } + + // The casted to type is a non-nullable reference to the type index + // specified as an immediate. + const TypeDef& castToTypeDef = env_.types->type(*castTypeIndex); + ValType castToType(RefType::fromTypeDef(&castToTypeDef, false)); + + return checkBrOnCastFailCommonV5(*labelRelativeDepth, sourceType, castToType, + labelType, values); +} + +template <typename Policy> +inline bool OpIter<Policy>::readBrOnCastFailHeapV5( + bool nullable, uint32_t* labelRelativeDepth, RefType* sourceType, + RefType* destType, ResultType* labelType, ValueVector* values) { + MOZ_ASSERT(Classify(op_) == OpKind::BrOnCastFailV5); + + if (!readVarU32(labelRelativeDepth)) { + return fail("unable to read br_on_cast_fail depth"); + } + + if (!readHeapType(nullable, destType)) { + return false; + } + + ValType castToType(*destType); + return checkBrOnCastFailCommonV5(*labelRelativeDepth, sourceType, castToType, + labelType, values); +} + +template <typename Policy> +inline bool OpIter<Policy>::readBrOnNonStructV5(uint32_t* labelRelativeDepth, + ResultType* labelType, + ValueVector* values) { + MOZ_ASSERT(Classify(op_) == OpKind::BrOnNonStructV5); + + if (!readVarU32(labelRelativeDepth)) { + return fail("unable to read br_on_non_struct depth"); + } + + RefType sourceTypeIgnored; + + // The casted to type is a non-nullable reference to a struct. + ValType castToType(RefType::struct_().asNonNullable()); + + return checkBrOnCastFailCommonV5(*labelRelativeDepth, &sourceTypeIgnored, + castToType, labelType, values); +} + +template <typename Policy> +inline bool OpIter<Policy>::readRefConversion(RefType operandType, + RefType resultType, + Value* operandValue) { + MOZ_ASSERT(Classify(op_) == OpKind::RefConversion); + + StackType actualOperandType; + if (!popWithType(ValType(operandType), operandValue, &actualOperandType)) { + return false; + } + + // The result nullability is the same as the operand nullability + bool outputNullable = actualOperandType.isNullableAsOperand(); + infalliblePush(ValType(resultType.withIsNullable(outputNullable))); + return true; +} + +#endif // ENABLE_WASM_GC + +#ifdef ENABLE_WASM_SIMD + +template <typename Policy> +inline bool OpIter<Policy>::readLaneIndex(uint32_t inputLanes, + uint32_t* laneIndex) { + uint8_t tmp; + if (!readFixedU8(&tmp)) { + return false; // Caller signals error + } + if (tmp >= inputLanes) { + return false; + } + *laneIndex = tmp; + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readExtractLane(ValType resultType, + uint32_t inputLanes, + uint32_t* laneIndex, Value* input) { + MOZ_ASSERT(Classify(op_) == OpKind::ExtractLane); + + if (!readLaneIndex(inputLanes, laneIndex)) { + return fail("missing or invalid extract_lane lane index"); + } + + if (!popWithType(ValType::V128, input)) { + return false; + } + + infalliblePush(resultType); + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readReplaceLane(ValType operandType, + uint32_t inputLanes, + uint32_t* laneIndex, + Value* baseValue, Value* operand) { + MOZ_ASSERT(Classify(op_) == OpKind::ReplaceLane); + + if (!readLaneIndex(inputLanes, laneIndex)) { + return fail("missing or invalid replace_lane lane index"); + } + + if (!popWithType(operandType, operand)) { + return false; + } + + if (!popWithType(ValType::V128, baseValue)) { + return false; + } + + infalliblePush(ValType::V128); + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readVectorShift(Value* baseValue, Value* shift) { + MOZ_ASSERT(Classify(op_) == OpKind::VectorShift); + + if (!popWithType(ValType::I32, shift)) { + return false; + } + + if (!popWithType(ValType::V128, baseValue)) { + return false; + } + + infalliblePush(ValType::V128); + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readVectorShuffle(Value* v1, Value* v2, + V128* selectMask) { + MOZ_ASSERT(Classify(op_) == OpKind::VectorShuffle); + + for (unsigned char& byte : selectMask->bytes) { + uint8_t tmp; + if (!readFixedU8(&tmp)) { + return fail("unable to read shuffle index"); + } + if (tmp > 31) { + return fail("shuffle index out of range"); + } + byte = tmp; + } + + if (!popWithType(ValType::V128, v2)) { + return false; + } + + if (!popWithType(ValType::V128, v1)) { + return false; + } + + infalliblePush(ValType::V128); + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readV128Const(V128* value) { + MOZ_ASSERT(Classify(op_) == OpKind::V128); + + if (!d_.readV128Const(value)) { + return false; + } + + return push(ValType::V128); +} + +template <typename Policy> +inline bool OpIter<Policy>::readLoadSplat(uint32_t byteSize, + LinearMemoryAddress<Value>* addr) { + MOZ_ASSERT(Classify(op_) == OpKind::Load); + + if (!readLinearMemoryAddress(byteSize, addr)) { + return false; + } + + infalliblePush(ValType::V128); + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readLoadExtend(LinearMemoryAddress<Value>* addr) { + MOZ_ASSERT(Classify(op_) == OpKind::Load); + + if (!readLinearMemoryAddress(/*byteSize=*/8, addr)) { + return false; + } + + infalliblePush(ValType::V128); + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readLoadLane(uint32_t byteSize, + LinearMemoryAddress<Value>* addr, + uint32_t* laneIndex, Value* input) { + MOZ_ASSERT(Classify(op_) == OpKind::LoadLane); + + if (!popWithType(ValType::V128, input)) { + return false; + } + + if (!readLinearMemoryAddress(byteSize, addr)) { + return false; + } + + uint32_t inputLanes = 16 / byteSize; + if (!readLaneIndex(inputLanes, laneIndex)) { + return fail("missing or invalid load_lane lane index"); + } + + infalliblePush(ValType::V128); + + return true; +} + +template <typename Policy> +inline bool OpIter<Policy>::readStoreLane(uint32_t byteSize, + LinearMemoryAddress<Value>* addr, + uint32_t* laneIndex, Value* input) { + MOZ_ASSERT(Classify(op_) == OpKind::StoreLane); + + if (!popWithType(ValType::V128, input)) { + return false; + } + + if (!readLinearMemoryAddress(byteSize, addr)) { + return false; + } + + uint32_t inputLanes = 16 / byteSize; + if (!readLaneIndex(inputLanes, laneIndex)) { + return fail("missing or invalid store_lane lane index"); + } + + return true; +} + +#endif // ENABLE_WASM_SIMD + +template <typename Policy> +inline bool OpIter<Policy>::readIntrinsic(const Intrinsic** intrinsic, + ValueVector* params) { + MOZ_ASSERT(Classify(op_) == OpKind::Intrinsic); + + uint32_t id; + if (!d_.readVarU32(&id)) { + return false; + } + + if (id >= uint32_t(IntrinsicId::Limit)) { + return fail("intrinsic index out of range"); + } + + *intrinsic = &Intrinsic::getFromId(IntrinsicId(id)); + + if (!env_.usesMemory()) { + return fail("can't touch memory without memory"); + } + return popWithTypes((*intrinsic)->params, params); +} + +} // namespace wasm +} // namespace js + +static_assert(std::is_trivially_copyable< + js::wasm::TypeAndValueT<mozilla::Nothing>>::value, + "Must be trivially copyable"); +static_assert(std::is_trivially_destructible< + js::wasm::TypeAndValueT<mozilla::Nothing>>::value, + "Must be trivially destructible"); + +static_assert(std::is_trivially_copyable< + js::wasm::ControlStackEntry<mozilla::Nothing>>::value, + "Must be trivially copyable"); +static_assert(std::is_trivially_destructible< + js::wasm::ControlStackEntry<mozilla::Nothing>>::value, + "Must be trivially destructible"); + +#endif // wasm_op_iter_h |