Files
wazero/internal/wasm/func_validation.go
Takeshi Yoneda be727a1440 Adds simd opcodes and feature flag (#555)
Signed-off-by: Takeshi Yoneda <takeshi@tetrate.io>
2022-05-13 12:29:59 +09:00

1518 lines
55 KiB
Go

package wasm
import (
"bytes"
"errors"
"fmt"
"strconv"
"strings"
"github.com/tetratelabs/wazero/api"
"github.com/tetratelabs/wazero/internal/leb128"
)
// The wazero specific limitation described at RATIONALE.md.
const maximumValuesOnStack = 1 << 27
// validateFunction validates the instruction sequence of a function.
// following the specification https://www.w3.org/TR/2019/REC-wasm-core-1-20191205/#instructions%E2%91%A2.
//
// * idx is the index in the FunctionSection
// * functions are the function index namespace, which is prefixed by imports. The value is the TypeSection index.
// * globals are the global index namespace, which is prefixed by imports.
// * memory is the potentially imported memory and can be nil.
// * table is the potentially imported table and can be nil.
// * declaredFunctionIndexes is the set of function indexes declared by declarative element segments which can be acceed by OpcodeRefFunc instruction.
//
// Returns an error if the instruction sequence is not valid,
// or potentially it can exceed the maximum number of values on the stack.
func (m *Module) validateFunction(enabledFeatures Features, idx Index, functions []Index,
globals []*GlobalType, memory *Memory, tables []*Table, declaredFunctionIndexes map[Index]struct{}) error {
return m.validateFunctionWithMaxStackValues(enabledFeatures, idx, functions, globals, memory, tables, maximumValuesOnStack, declaredFunctionIndexes)
}
// validateFunctionWithMaxStackValues is like validateFunction, but allows overriding maxStackValues for testing.
//
// * maxStackValues is the maximum height of values stack which the target is allowed to reach.
func (m *Module) validateFunctionWithMaxStackValues(
enabledFeatures Features,
idx Index,
functions []Index,
globals []*GlobalType,
memory *Memory,
tables []*Table,
maxStackValues int,
declaredFunctionIndexes map[Index]struct{},
) error {
functionType := m.TypeSection[m.FunctionSection[idx]]
body := m.CodeSection[idx].Body
localTypes := m.CodeSection[idx].LocalTypes
types := m.TypeSection
// We start with the outermost control block which is for function return if the code branches into it.
controlBlockStack := []*controlBlock{{blockType: functionType}}
// Create the valueTypeStack to track the state of Wasm value stacks at anypoint of execution.
valueTypeStack := &valueTypeStack{}
// Now start walking through all the instructions in the body while tracking
// control blocks and value types to check the validity of all instructions.
for pc := uint64(0); pc < uint64(len(body)); pc++ {
op := body[pc]
if OpcodeI32Load <= op && op <= OpcodeI64Store32 {
if memory == nil {
return fmt.Errorf("unknown memory access")
}
pc++
align, num, err := leb128.DecodeUint32(bytes.NewReader(body[pc:]))
if err != nil {
return fmt.Errorf("read memory align: %v", err)
}
switch op {
case OpcodeI32Load:
if 1<<align > 32/8 {
return fmt.Errorf("invalid memory alignment")
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return err
}
valueTypeStack.push(ValueTypeI32)
case OpcodeF32Load:
if 1<<align > 32/8 {
return fmt.Errorf("invalid memory alignment")
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return err
}
valueTypeStack.push(ValueTypeF32)
case OpcodeI32Store:
if 1<<align > 32/8 {
return fmt.Errorf("invalid memory alignment")
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return err
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return err
}
case OpcodeF32Store:
if 1<<align > 32/8 {
return fmt.Errorf("invalid memory alignment")
}
if err := valueTypeStack.popAndVerifyType(ValueTypeF32); err != nil {
return err
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return err
}
case OpcodeI64Load:
if 1<<align > 64/8 {
return fmt.Errorf("invalid memory alignment")
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return err
}
valueTypeStack.push(ValueTypeI64)
case OpcodeF64Load:
if 1<<align > 64/8 {
return fmt.Errorf("invalid memory alignment")
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return err
}
valueTypeStack.push(ValueTypeF64)
case OpcodeI64Store:
if 1<<align > 64/8 {
return fmt.Errorf("invalid memory alignment")
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI64); err != nil {
return err
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return err
}
case OpcodeF64Store:
if 1<<align > 64/8 {
return fmt.Errorf("invalid memory alignment")
}
if err := valueTypeStack.popAndVerifyType(ValueTypeF64); err != nil {
return err
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return err
}
case OpcodeI32Load8S:
if 1<<align > 1 {
return fmt.Errorf("invalid memory alignment")
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return err
}
valueTypeStack.push(ValueTypeI32)
case OpcodeI32Load8U:
if 1<<align > 1 {
return fmt.Errorf("invalid memory alignment")
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return err
}
valueTypeStack.push(ValueTypeI32)
case OpcodeI64Load8S, OpcodeI64Load8U:
if 1<<align > 1 {
return fmt.Errorf("invalid memory alignment")
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return err
}
valueTypeStack.push(ValueTypeI64)
case OpcodeI32Store8:
if 1<<align > 1 {
return fmt.Errorf("invalid memory alignment")
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return err
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return err
}
case OpcodeI64Store8:
if 1<<align > 1 {
return fmt.Errorf("invalid memory alignment")
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI64); err != nil {
return err
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return err
}
case OpcodeI32Load16S, OpcodeI32Load16U:
if 1<<align > 16/8 {
return fmt.Errorf("invalid memory alignment")
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return err
}
valueTypeStack.push(ValueTypeI32)
case OpcodeI64Load16S, OpcodeI64Load16U:
if 1<<align > 16/8 {
return fmt.Errorf("invalid memory alignment")
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return err
}
valueTypeStack.push(ValueTypeI64)
case OpcodeI32Store16:
if 1<<align > 16/8 {
return fmt.Errorf("invalid memory alignment")
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return err
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return err
}
case OpcodeI64Store16:
if 1<<align > 16/8 {
return fmt.Errorf("invalid memory alignment")
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI64); err != nil {
return err
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return err
}
case OpcodeI64Load32S, OpcodeI64Load32U:
if 1<<align > 32/8 {
return fmt.Errorf("invalid memory alignment")
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return err
}
valueTypeStack.push(ValueTypeI64)
case OpcodeI64Store32:
if 1<<align > 32/8 {
return fmt.Errorf("invalid memory alignment")
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI64); err != nil {
return err
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return err
}
}
pc += num
// offset
_, num, err = leb128.DecodeUint32(bytes.NewReader(body[pc:]))
if err != nil {
return fmt.Errorf("read memory offset: %v", err)
}
pc += num - 1
} else if OpcodeMemorySize <= op && op <= OpcodeMemoryGrow {
if memory == nil {
return fmt.Errorf("unknown memory access")
}
pc++
val, num, err := leb128.DecodeUint32(bytes.NewReader(body[pc:]))
if err != nil {
return fmt.Errorf("read immediate: %v", err)
}
if val != 0 || num != 1 {
return fmt.Errorf("memory instruction reserved bytes not zero with 1 byte")
}
switch Opcode(op) {
case OpcodeMemoryGrow:
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return err
}
valueTypeStack.push(ValueTypeI32)
case OpcodeMemorySize:
valueTypeStack.push(ValueTypeI32)
}
pc += num - 1
} else if OpcodeI32Const <= op && op <= OpcodeF64Const {
pc++
switch Opcode(op) {
case OpcodeI32Const:
_, num, err := leb128.DecodeInt32(bytes.NewReader(body[pc:]))
if err != nil {
return fmt.Errorf("read i32 immediate: %s", err)
}
pc += num - 1
valueTypeStack.push(ValueTypeI32)
case OpcodeI64Const:
_, num, err := leb128.DecodeInt64(bytes.NewReader(body[pc:]))
if err != nil {
return fmt.Errorf("read i64 immediate: %v", err)
}
valueTypeStack.push(ValueTypeI64)
pc += num - 1
case OpcodeF32Const:
valueTypeStack.push(ValueTypeF32)
pc += 3
case OpcodeF64Const:
valueTypeStack.push(ValueTypeF64)
pc += 7
}
} else if OpcodeLocalGet <= op && op <= OpcodeGlobalSet {
pc++
index, num, err := leb128.DecodeUint32(bytes.NewReader(body[pc:]))
if err != nil {
return fmt.Errorf("read immediate: %v", err)
}
pc += num - 1
switch op {
case OpcodeLocalGet:
inputLen := uint32(len(functionType.Params))
if l := uint32(len(localTypes)) + inputLen; index >= l {
return fmt.Errorf("invalid local index for %s %d >= %d(=len(locals)+len(parameters))",
OpcodeLocalGetName, index, l)
}
if index < inputLen {
valueTypeStack.push(functionType.Params[index])
} else {
valueTypeStack.push(localTypes[index-inputLen])
}
case OpcodeLocalSet:
inputLen := uint32(len(functionType.Params))
if l := uint32(len(localTypes)) + inputLen; index >= l {
return fmt.Errorf("invalid local index for %s %d >= %d(=len(locals)+len(parameters))",
OpcodeLocalSetName, index, l)
}
var expType ValueType
if index < inputLen {
expType = functionType.Params[index]
} else {
expType = localTypes[index-inputLen]
}
if err := valueTypeStack.popAndVerifyType(expType); err != nil {
return err
}
case OpcodeLocalTee:
inputLen := uint32(len(functionType.Params))
if l := uint32(len(localTypes)) + inputLen; index >= l {
return fmt.Errorf("invalid local index for %s %d >= %d(=len(locals)+len(parameters))",
OpcodeLocalTeeName, index, l)
}
var expType ValueType
if index < inputLen {
expType = functionType.Params[index]
} else {
expType = localTypes[index-inputLen]
}
if err := valueTypeStack.popAndVerifyType(expType); err != nil {
return err
}
valueTypeStack.push(expType)
case OpcodeGlobalGet:
if index >= uint32(len(globals)) {
return fmt.Errorf("invalid index for %s", OpcodeGlobalGetName)
}
valueTypeStack.push(globals[index].ValType)
case OpcodeGlobalSet:
if index >= uint32(len(globals)) {
return fmt.Errorf("invalid global index")
} else if !globals[index].Mutable {
return fmt.Errorf("%s when not mutable", OpcodeGlobalSetName)
} else if err := valueTypeStack.popAndVerifyType(
globals[index].ValType); err != nil {
return err
}
}
} else if op == OpcodeBr {
pc++
index, num, err := leb128.DecodeUint32(bytes.NewReader(body[pc:]))
if err != nil {
return fmt.Errorf("read immediate: %v", err)
} else if int(index) >= len(controlBlockStack) {
return fmt.Errorf("invalid %s operation: index out of range", OpcodeBrName)
}
pc += num - 1
// Check type soundness.
target := controlBlockStack[len(controlBlockStack)-int(index)-1]
targetResultType := target.blockType.Results
if target.op == OpcodeLoop {
// Loop operation doesn't require results since the continuation is
// the beginning of the loop.
targetResultType = []ValueType{}
}
if err = valueTypeStack.popResults(op, targetResultType, false); err != nil {
return err
}
// br instruction is stack-polymorphic.
valueTypeStack.unreachable()
} else if op == OpcodeBrIf {
pc++
index, num, err := leb128.DecodeUint32(bytes.NewReader(body[pc:]))
if err != nil {
return fmt.Errorf("read immediate: %v", err)
} else if int(index) >= len(controlBlockStack) {
return fmt.Errorf(
"invalid ln param given for %s: index=%d with %d for the current lable stack length",
OpcodeBrIfName, index, len(controlBlockStack))
}
pc += num - 1
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return fmt.Errorf("cannot pop the required operand for %s", OpcodeBrIfName)
}
// Check type soundness.
target := controlBlockStack[len(controlBlockStack)-int(index)-1]
targetResultType := target.blockType.Results
if target.op == OpcodeLoop {
// Loop operation doesn't require results since the continuation is
// the beginning of the loop.
targetResultType = []ValueType{}
}
if err := valueTypeStack.popResults(op, targetResultType, false); err != nil {
return err
}
// Push back the result
for _, t := range targetResultType {
valueTypeStack.push(t)
}
} else if op == OpcodeBrTable {
pc++
r := bytes.NewReader(body[pc:])
nl, num, err := leb128.DecodeUint32(r)
if err != nil {
return fmt.Errorf("read immediate: %w", err)
}
list := make([]uint32, nl)
for i := uint32(0); i < nl; i++ {
l, n, err := leb128.DecodeUint32(r)
if err != nil {
return fmt.Errorf("read immediate: %w", err)
}
num += n
list[i] = l
}
ln, n, err := leb128.DecodeUint32(r)
if err != nil {
return fmt.Errorf("read immediate: %w", err)
} else if int(ln) >= len(controlBlockStack) {
return fmt.Errorf(
"invalid ln param given for %s: ln=%d with %d for the current lable stack length",
OpcodeBrTableName, ln, len(controlBlockStack))
}
pc += n + num - 1
// Check type soundness.
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return fmt.Errorf("cannot pop the required operand for %s", OpcodeBrTableName)
}
lnLabel := controlBlockStack[len(controlBlockStack)-1-int(ln)]
expTypes := lnLabel.blockType.Results
if lnLabel.op == OpcodeLoop {
// Loop operation doesn't require results since the continuation is
// the beginning of the loop.
expTypes = []ValueType{}
}
if enabledFeatures.Get(FeatureReferenceTypes) {
// As of reference-types proposal, br_table on unreachable state
// can choose unknown types for expected parameter types for each label.
// https://github.com/WebAssembly/reference-types/pull/116
for i := range expTypes {
index := len(expTypes) - 1 - i
exp := expTypes[index]
actual, err := valueTypeStack.pop()
if err != nil {
return err
}
if actual == valueTypeUnknown {
// Re-assign the expected type to unknown.
expTypes[index] = valueTypeUnknown
} else if actual != exp {
return typeMismatchError(true, OpcodeBrTableName, actual, exp, i)
}
}
} else {
if err = valueTypeStack.popResults(op, expTypes, false); err != nil {
return err
}
}
for _, l := range list {
if int(l) >= len(controlBlockStack) {
return fmt.Errorf("invalid l param given for %s", OpcodeBrTableName)
}
label := controlBlockStack[len(controlBlockStack)-1-int(l)]
expType2 := label.blockType.Results
if label.op == OpcodeLoop {
// Loop operation doesn't require results since the continuation is
// the beginning of the loop.
expType2 = []ValueType{}
}
if len(expTypes) != len(expType2) {
return fmt.Errorf("incosistent block type length for %s at %d; %v (ln=%d) != %v (l=%d)", OpcodeBrTableName, l, expTypes, ln, expType2, l)
}
for i := range expTypes {
if expTypes[i] != valueTypeUnknown && expTypes[i] != expType2[i] {
return fmt.Errorf("incosistent block type for %s at %d", OpcodeBrTableName, l)
}
}
}
// br_table instruction is stack-polymorphic.
valueTypeStack.unreachable()
} else if op == OpcodeCall {
pc++
index, num, err := leb128.DecodeUint32(bytes.NewReader(body[pc:]))
if err != nil {
return fmt.Errorf("read immediate: %v", err)
}
pc += num - 1
if int(index) >= len(functions) {
return fmt.Errorf("invalid function index")
}
funcType := types[functions[index]]
for i := 0; i < len(funcType.Params); i++ {
if err := valueTypeStack.popAndVerifyType(funcType.Params[len(funcType.Params)-1-i]); err != nil {
return fmt.Errorf("type mismatch on %s operation param type: %v", OpcodeCallName, err)
}
}
for _, exp := range funcType.Results {
valueTypeStack.push(exp)
}
} else if op == OpcodeCallIndirect {
pc++
typeIndex, num, err := leb128.DecodeUint32(bytes.NewReader(body[pc:]))
if err != nil {
return fmt.Errorf("read immediate: %v", err)
}
pc += num
if int(typeIndex) >= len(types) {
return fmt.Errorf("invalid type index at %s: %d", OpcodeCallIndirectName, typeIndex)
}
tableIndex, num, err := leb128.DecodeUint32(bytes.NewReader(body[pc:]))
if err != nil {
return fmt.Errorf("read table index: %v", err)
}
pc += num - 1
if tableIndex != 0 {
if err := enabledFeatures.Require(FeatureReferenceTypes); err != nil {
return fmt.Errorf("table index must be zero but was %d: %w", tableIndex, err)
}
}
if tableIndex >= uint32(len(tables)) {
return fmt.Errorf("unknown table index: %d", tableIndex)
}
table := tables[tableIndex]
if table == nil {
return fmt.Errorf("table not given while having %s", OpcodeCallIndirectName)
} else if table.Type != RefTypeFuncref {
return fmt.Errorf("table is not funcref type but was %s for %s", RefTypeName(table.Type), OpcodeCallIndirectName)
}
if err = valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return fmt.Errorf("cannot pop the offset in table for %s", OpcodeCallIndirectName)
}
funcType := types[typeIndex]
for i := 0; i < len(funcType.Params); i++ {
if err = valueTypeStack.popAndVerifyType(funcType.Params[len(funcType.Params)-1-i]); err != nil {
return fmt.Errorf("type mismatch on %s operation input type", OpcodeCallIndirectName)
}
}
for _, exp := range funcType.Results {
valueTypeStack.push(exp)
}
} else if OpcodeI32Eqz <= op && op <= OpcodeI64Extend32S {
switch op {
case OpcodeI32Eqz:
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return fmt.Errorf("cannot pop the operand for %s: %v", OpcodeI32EqzName, err)
}
valueTypeStack.push(ValueTypeI32)
case OpcodeI32Eq, OpcodeI32Ne, OpcodeI32LtS,
OpcodeI32LtU, OpcodeI32GtS, OpcodeI32GtU, OpcodeI32LeS,
OpcodeI32LeU, OpcodeI32GeS, OpcodeI32GeU:
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return fmt.Errorf("cannot pop the 1st i32 operand for %s: %v", InstructionName(op), err)
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return fmt.Errorf("cannot pop the 2nd i32 operand for %s: %v", InstructionName(op), err)
}
valueTypeStack.push(ValueTypeI32)
case OpcodeI64Eqz:
if err := valueTypeStack.popAndVerifyType(ValueTypeI64); err != nil {
return fmt.Errorf("cannot pop the operand for %s: %v", OpcodeI64EqzName, err)
}
valueTypeStack.push(ValueTypeI32)
case OpcodeI64Eq, OpcodeI64Ne, OpcodeI64LtS,
OpcodeI64LtU, OpcodeI64GtS, OpcodeI64GtU,
OpcodeI64LeS, OpcodeI64LeU, OpcodeI64GeS, OpcodeI64GeU:
if err := valueTypeStack.popAndVerifyType(ValueTypeI64); err != nil {
return fmt.Errorf("cannot pop the 1st i64 operand for %s: %v", InstructionName(op), err)
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI64); err != nil {
return fmt.Errorf("cannot pop the 2nd i64 operand for %s: %v", InstructionName(op), err)
}
valueTypeStack.push(ValueTypeI32)
case OpcodeF32Eq, OpcodeF32Ne, OpcodeF32Lt, OpcodeF32Gt, OpcodeF32Le, OpcodeF32Ge:
if err := valueTypeStack.popAndVerifyType(ValueTypeF32); err != nil {
return fmt.Errorf("cannot pop the 1st f32 operand for %s: %v", InstructionName(op), err)
}
if err := valueTypeStack.popAndVerifyType(ValueTypeF32); err != nil {
return fmt.Errorf("cannot pop the 2nd f32 operand for %s: %v", InstructionName(op), err)
}
valueTypeStack.push(ValueTypeI32)
case OpcodeF64Eq, OpcodeF64Ne, OpcodeF64Lt, OpcodeF64Gt, OpcodeF64Le, OpcodeF64Ge:
if err := valueTypeStack.popAndVerifyType(ValueTypeF64); err != nil {
return fmt.Errorf("cannot pop the 1st f64 operand for %s: %v", InstructionName(op), err)
}
if err := valueTypeStack.popAndVerifyType(ValueTypeF64); err != nil {
return fmt.Errorf("cannot pop the 2nd f64 operand for %s: %v", InstructionName(op), err)
}
valueTypeStack.push(ValueTypeI32)
case OpcodeI32Clz, OpcodeI32Ctz, OpcodeI32Popcnt:
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return fmt.Errorf("cannot pop the i32 operand for %s: %v", InstructionName(op), err)
}
valueTypeStack.push(ValueTypeI32)
case OpcodeI32Add, OpcodeI32Sub, OpcodeI32Mul, OpcodeI32DivS,
OpcodeI32DivU, OpcodeI32RemS, OpcodeI32RemU, OpcodeI32And,
OpcodeI32Or, OpcodeI32Xor, OpcodeI32Shl, OpcodeI32ShrS,
OpcodeI32ShrU, OpcodeI32Rotl, OpcodeI32Rotr:
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return fmt.Errorf("cannot pop the 1st operand for %s: %v", InstructionName(op), err)
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return fmt.Errorf("cannot pop the 2nd operand for %s: %v", InstructionName(op), err)
}
valueTypeStack.push(ValueTypeI32)
case OpcodeI64Clz, OpcodeI64Ctz, OpcodeI64Popcnt:
if err := valueTypeStack.popAndVerifyType(ValueTypeI64); err != nil {
return fmt.Errorf("cannot pop the i64 operand for %s: %v", InstructionName(op), err)
}
valueTypeStack.push(ValueTypeI64)
case OpcodeI64Add, OpcodeI64Sub, OpcodeI64Mul, OpcodeI64DivS,
OpcodeI64DivU, OpcodeI64RemS, OpcodeI64RemU, OpcodeI64And,
OpcodeI64Or, OpcodeI64Xor, OpcodeI64Shl, OpcodeI64ShrS,
OpcodeI64ShrU, OpcodeI64Rotl, OpcodeI64Rotr:
if err := valueTypeStack.popAndVerifyType(ValueTypeI64); err != nil {
return fmt.Errorf("cannot pop the 1st i64 operand for %s: %v", InstructionName(op), err)
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI64); err != nil {
return fmt.Errorf("cannot pop the 2nd i64 operand for %s: %v", InstructionName(op), err)
}
valueTypeStack.push(ValueTypeI64)
case OpcodeF32Abs, OpcodeF32Neg, OpcodeF32Ceil,
OpcodeF32Floor, OpcodeF32Trunc, OpcodeF32Nearest,
OpcodeF32Sqrt:
if err := valueTypeStack.popAndVerifyType(ValueTypeF32); err != nil {
return fmt.Errorf("cannot pop the 1st f32 operand for %s: %v", InstructionName(op), err)
}
valueTypeStack.push(ValueTypeF32)
case OpcodeF32Add, OpcodeF32Sub, OpcodeF32Mul,
OpcodeF32Div, OpcodeF32Min, OpcodeF32Max,
OpcodeF32Copysign:
if err := valueTypeStack.popAndVerifyType(ValueTypeF32); err != nil {
return fmt.Errorf("cannot pop the 1st f32 operand for %s: %v", InstructionName(op), err)
}
if err := valueTypeStack.popAndVerifyType(ValueTypeF32); err != nil {
return fmt.Errorf("cannot pop the 2nd f32 operand for %s: %v", InstructionName(op), err)
}
valueTypeStack.push(ValueTypeF32)
case OpcodeF64Abs, OpcodeF64Neg, OpcodeF64Ceil,
OpcodeF64Floor, OpcodeF64Trunc, OpcodeF64Nearest,
OpcodeF64Sqrt:
if err := valueTypeStack.popAndVerifyType(ValueTypeF64); err != nil {
return fmt.Errorf("cannot pop the 1st f64 operand for %s: %v", InstructionName(op), err)
}
valueTypeStack.push(ValueTypeF64)
case OpcodeF64Add, OpcodeF64Sub, OpcodeF64Mul,
OpcodeF64Div, OpcodeF64Min, OpcodeF64Max,
OpcodeF64Copysign:
if err := valueTypeStack.popAndVerifyType(ValueTypeF64); err != nil {
return fmt.Errorf("cannot pop the 1st f64 operand for %s: %v", InstructionName(op), err)
}
if err := valueTypeStack.popAndVerifyType(ValueTypeF64); err != nil {
return fmt.Errorf("cannot pop the 2nd f64 operand for %s: %v", InstructionName(op), err)
}
valueTypeStack.push(ValueTypeF64)
case OpcodeI32WrapI64:
if err := valueTypeStack.popAndVerifyType(ValueTypeI64); err != nil {
return fmt.Errorf("cannot pop the operand for %s: %v", OpcodeI32WrapI64Name, err)
}
valueTypeStack.push(ValueTypeI32)
case OpcodeI32TruncF32S, OpcodeI32TruncF32U:
if err := valueTypeStack.popAndVerifyType(ValueTypeF32); err != nil {
return fmt.Errorf("cannot pop the f32 operand for %s: %v", InstructionName(op), err)
}
valueTypeStack.push(ValueTypeI32)
case OpcodeI32TruncF64S, OpcodeI32TruncF64U:
if err := valueTypeStack.popAndVerifyType(ValueTypeF64); err != nil {
return fmt.Errorf("cannot pop the f64 operand for %s: %v", InstructionName(op), err)
}
valueTypeStack.push(ValueTypeI32)
case OpcodeI64ExtendI32S, OpcodeI64ExtendI32U:
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return fmt.Errorf("cannot pop the i32 operand for %s: %v", InstructionName(op), err)
}
valueTypeStack.push(ValueTypeI64)
case OpcodeI64TruncF32S, OpcodeI64TruncF32U:
if err := valueTypeStack.popAndVerifyType(ValueTypeF32); err != nil {
return fmt.Errorf("cannot pop the f32 operand for %s: %v", InstructionName(op), err)
}
valueTypeStack.push(ValueTypeI64)
case OpcodeI64TruncF64S, OpcodeI64TruncF64U:
if err := valueTypeStack.popAndVerifyType(ValueTypeF64); err != nil {
return fmt.Errorf("cannot pop the f64 operand for %s: %v", InstructionName(op), err)
}
valueTypeStack.push(ValueTypeI64)
case OpcodeF32ConvertI32s, OpcodeF32ConvertI32U:
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return fmt.Errorf("cannot pop the i32 operand for %s: %v", InstructionName(op), err)
}
valueTypeStack.push(ValueTypeF32)
case OpcodeF32ConvertI64S, OpcodeF32ConvertI64U:
if err := valueTypeStack.popAndVerifyType(ValueTypeI64); err != nil {
return fmt.Errorf("cannot pop the i64 operand for %s: %v", InstructionName(op), err)
}
valueTypeStack.push(ValueTypeF32)
case OpcodeF32DemoteF64:
if err := valueTypeStack.popAndVerifyType(ValueTypeF64); err != nil {
return fmt.Errorf("cannot pop the operand for %s: %v", OpcodeF32DemoteF64Name, err)
}
valueTypeStack.push(ValueTypeF32)
case OpcodeF64ConvertI32S, OpcodeF64ConvertI32U:
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return fmt.Errorf("cannot pop the i32 operand for %s: %v", InstructionName(op), err)
}
valueTypeStack.push(ValueTypeF64)
case OpcodeF64ConvertI64S, OpcodeF64ConvertI64U:
if err := valueTypeStack.popAndVerifyType(ValueTypeI64); err != nil {
return fmt.Errorf("cannot pop the i64 operand for %s: %v", InstructionName(op), err)
}
valueTypeStack.push(ValueTypeF64)
case OpcodeF64PromoteF32:
if err := valueTypeStack.popAndVerifyType(ValueTypeF32); err != nil {
return fmt.Errorf("cannot pop the operand for %s: %v", OpcodeF64PromoteF32Name, err)
}
valueTypeStack.push(ValueTypeF64)
case OpcodeI32ReinterpretF32:
if err := valueTypeStack.popAndVerifyType(ValueTypeF32); err != nil {
return fmt.Errorf("cannot pop the operand for %s: %v", OpcodeI32ReinterpretF32Name, err)
}
valueTypeStack.push(ValueTypeI32)
case OpcodeI64ReinterpretF64:
if err := valueTypeStack.popAndVerifyType(ValueTypeF64); err != nil {
return fmt.Errorf("cannot pop the operand for %s: %v", OpcodeI64ReinterpretF64Name, err)
}
valueTypeStack.push(ValueTypeI64)
case OpcodeF32ReinterpretI32:
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return fmt.Errorf("cannot pop the operand for %s: %v", OpcodeF32ReinterpretI32Name, err)
}
valueTypeStack.push(ValueTypeF32)
case OpcodeF64ReinterpretI64:
if err := valueTypeStack.popAndVerifyType(ValueTypeI64); err != nil {
return fmt.Errorf("cannot pop the operand for %s: %v", OpcodeF64ReinterpretI64Name, err)
}
valueTypeStack.push(ValueTypeF64)
case OpcodeI32Extend8S, OpcodeI32Extend16S:
if err := enabledFeatures.Require(FeatureSignExtensionOps); err != nil {
return fmt.Errorf("%s invalid as %v", instructionNames[op], err)
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return fmt.Errorf("cannot pop the operand for %s: %v", instructionNames[op], err)
}
valueTypeStack.push(ValueTypeI32)
case OpcodeI64Extend8S, OpcodeI64Extend16S, OpcodeI64Extend32S:
if err := enabledFeatures.Require(FeatureSignExtensionOps); err != nil {
return fmt.Errorf("%s invalid as %v", instructionNames[op], err)
}
if err := valueTypeStack.popAndVerifyType(ValueTypeI64); err != nil {
return fmt.Errorf("cannot pop the operand for %s: %v", instructionNames[op], err)
}
valueTypeStack.push(ValueTypeI64)
default:
return fmt.Errorf("invalid numeric instruction 0x%x", op)
}
} else if op >= OpcodeRefNull && op <= OpcodeRefFunc {
if err := enabledFeatures.Require(FeatureReferenceTypes); err != nil {
return fmt.Errorf("%s invalid as %v", instructionNames[op], err)
}
switch op {
case OpcodeRefNull:
pc++
switch reftype := body[pc]; reftype {
case ValueTypeExternref:
valueTypeStack.push(ValueTypeExternref)
case ValueTypeFuncref:
valueTypeStack.push(ValueTypeFuncref)
default:
return fmt.Errorf("unknown type for ref.null: 0x%x", reftype)
}
case OpcodeRefIsNull:
tp, err := valueTypeStack.pop()
if err != nil {
return fmt.Errorf("cannot pop the operand for ref.is_null: %v", err)
} else if !isReferenceValueType(tp) && tp != valueTypeUnknown {
return fmt.Errorf("type mismatch: expected reference type but was %s", ValueTypeName(tp))
}
valueTypeStack.push(ValueTypeI32)
case OpcodeRefFunc:
pc++
index, num, err := leb128.DecodeUint32(bytes.NewReader(body[pc:]))
if err != nil {
return fmt.Errorf("failed to read function index for ref.func: %v", err)
}
if _, ok := declaredFunctionIndexes[index]; !ok {
return fmt.Errorf("undeclared function index %d for ref.func", index)
}
pc += num - 1
valueTypeStack.push(ValueTypeFuncref)
}
} else if op == OpcodeTableGet || op == OpcodeTableSet {
if err := enabledFeatures.Require(FeatureReferenceTypes); err != nil {
return fmt.Errorf("%s is invalid as %v", InstructionName(op), err)
}
pc++
tableIndex, num, err := leb128.DecodeUint32(bytes.NewReader(body[pc:]))
if err != nil {
return fmt.Errorf("read immediate: %v", err)
}
if tableIndex >= uint32(len(tables)) {
return fmt.Errorf("table of index %d not found", tableIndex)
}
refType := tables[tableIndex].Type
if op == OpcodeTableGet {
if err := valueTypeStack.popAndVerifyType(api.ValueTypeI32); err != nil {
return fmt.Errorf("cannot pop the operand for table.get: %v", err)
}
valueTypeStack.push(refType)
} else {
if err := valueTypeStack.popAndVerifyType(refType); err != nil {
return fmt.Errorf("cannot pop the operand for table.set: %v", err)
}
if err := valueTypeStack.popAndVerifyType(api.ValueTypeI32); err != nil {
return fmt.Errorf("cannot pop the operand for table.set: %v", err)
}
}
pc += num - 1
} else if op == OpcodeMiscPrefix {
pc++
// Miscellaneous instructions come with two bytes which starts with OpcodeMiscPrefix,
// and the second byte determines the actual instruction.
miscOpcode := body[pc]
if miscOpcode >= OpcodeMiscI32TruncSatF32S && miscOpcode <= OpcodeMiscI64TruncSatF64U {
if err := enabledFeatures.Require(FeatureNonTrappingFloatToIntConversion); err != nil {
return fmt.Errorf("%s invalid as %v", miscInstructionNames[miscOpcode], err)
}
var inType, outType ValueType
switch miscOpcode {
case OpcodeMiscI32TruncSatF32S, OpcodeMiscI32TruncSatF32U:
inType, outType = ValueTypeF32, ValueTypeI32
case OpcodeMiscI32TruncSatF64S, OpcodeMiscI32TruncSatF64U:
inType, outType = ValueTypeF64, ValueTypeI32
case OpcodeMiscI64TruncSatF32S, OpcodeMiscI64TruncSatF32U:
inType, outType = ValueTypeF32, ValueTypeI64
case OpcodeMiscI64TruncSatF64S, OpcodeMiscI64TruncSatF64U:
inType, outType = ValueTypeF64, ValueTypeI64
}
if err := valueTypeStack.popAndVerifyType(inType); err != nil {
return fmt.Errorf("cannot pop the operand for %s: %v", miscInstructionNames[miscOpcode], err)
}
valueTypeStack.push(outType)
} else if miscOpcode >= OpcodeMiscMemoryInit && miscOpcode <= OpcodeMiscTableCopy {
if err := enabledFeatures.Require(FeatureBulkMemoryOperations); err != nil {
return fmt.Errorf("%s invalid as %v", miscInstructionNames[miscOpcode], err)
}
var params []ValueType
// Handle opcodes added in bulk-memory-operations/WebAssembly 2.0.
switch miscOpcode {
case OpcodeMiscDataDrop:
if m.DataCountSection == nil {
return fmt.Errorf("%s requires data count section", MiscInstructionName(miscOpcode))
}
// We need to read the index to the data section.
pc++
index, num, err := leb128.DecodeUint32(bytes.NewReader(body[pc:]))
if err != nil {
return fmt.Errorf("failed to read data segment index for %s: %v", MiscInstructionName(miscOpcode), err)
}
if int(index) >= len(m.DataSection) {
return fmt.Errorf("index %d out of range of data section(len=%d)", index, len(m.DataSection))
}
pc += num - 1
case OpcodeMiscMemoryInit, OpcodeMiscMemoryCopy, OpcodeMiscMemoryFill:
if memory == nil {
return fmt.Errorf("memory must exist for %s", MiscInstructionName(miscOpcode))
}
params = []ValueType{ValueTypeI32, ValueTypeI32, ValueTypeI32}
if miscOpcode == OpcodeMiscMemoryInit {
if m.DataCountSection == nil {
return fmt.Errorf("%s requires data count section", MiscInstructionName(miscOpcode))
}
// We need to read the index to the data section.
pc++
index, num, err := leb128.DecodeUint32(bytes.NewReader(body[pc:]))
if err != nil {
return fmt.Errorf("failed to read data segment index for %s: %v", MiscInstructionName(miscOpcode), err)
}
if int(index) >= len(m.DataSection) {
return fmt.Errorf("index %d out of range of data section(len=%d)", index, len(m.DataSection))
}
pc += num - 1
}
pc++
val, num, err := leb128.DecodeUint32(bytes.NewReader(body[pc:]))
if err != nil {
return fmt.Errorf("failed to read memory index for %s: %v", MiscInstructionName(miscOpcode), err)
}
if val != 0 || num != 1 {
return fmt.Errorf("%s reserved byte must be zero encoded with 1 byte", MiscInstructionName(miscOpcode))
}
if miscOpcode == OpcodeMiscMemoryCopy {
pc++
// memory.copy needs two memory index which are reserved as zero.
val, num, err := leb128.DecodeUint32(bytes.NewReader(body[pc:]))
if err != nil {
return fmt.Errorf("failed to read memory index for %s: %v", MiscInstructionName(miscOpcode), err)
}
if val != 0 || num != 1 {
return fmt.Errorf("%s reserved byte must be zero encoded with 1 byte", MiscInstructionName(miscOpcode))
}
}
case OpcodeMiscTableInit:
params = []ValueType{ValueTypeI32, ValueTypeI32, ValueTypeI32}
pc++
elementIndex, num, err := leb128.DecodeUint32(bytes.NewReader(body[pc:]))
if err != nil {
return fmt.Errorf("failed to read element segment index for %s: %v", MiscInstructionName(miscOpcode), err)
}
if int(elementIndex) >= len(m.ElementSection) {
return fmt.Errorf("index %d out of range of element section(len=%d)", elementIndex, len(m.ElementSection))
}
pc += num
tableIndex, num, err := leb128.DecodeUint32(bytes.NewReader(body[pc:]))
if err != nil {
return fmt.Errorf("failed to read source table index for %s: %v", MiscInstructionName(miscOpcode), err)
}
if tableIndex != 0 {
if err := enabledFeatures.Require(FeatureReferenceTypes); err != nil {
return fmt.Errorf("source table index must be zero for %s as %v", MiscInstructionName(miscOpcode), err)
}
}
if tableIndex >= uint32(len(tables)) {
return fmt.Errorf("table of index %d not found", tableIndex)
}
if m.ElementSection[elementIndex].Type != tables[tableIndex].Type {
return fmt.Errorf("type mismatch for table.init: element type %s does not match table type %s",
RefTypeName(m.ElementSection[elementIndex].Type),
RefTypeName(tables[tableIndex].Type),
)
}
pc += num - 1
case OpcodeMiscElemDrop:
pc++
elementIndex, num, err := leb128.DecodeUint32(bytes.NewReader(body[pc:]))
if err != nil {
return fmt.Errorf("failed to read element segment index for %s: %v", MiscInstructionName(miscOpcode), err)
} else if int(elementIndex) >= len(m.ElementSection) {
return fmt.Errorf("index %d out of range of element section(len=%d)", elementIndex, len(m.ElementSection))
}
pc += num - 1
case OpcodeMiscTableCopy:
params = []ValueType{ValueTypeI32, ValueTypeI32, ValueTypeI32}
pc++
dstTableIndex, num, err := leb128.DecodeUint32(bytes.NewReader(body[pc:]))
if err != nil {
return fmt.Errorf("failed to read destination table index for %s: %v", MiscInstructionName(miscOpcode), err)
}
if dstTableIndex != 0 {
if err := enabledFeatures.Require(FeatureReferenceTypes); err != nil {
return fmt.Errorf("destination table index must be zero for %s as %v", MiscInstructionName(miscOpcode), err)
}
}
if dstTableIndex >= uint32(len(tables)) {
return fmt.Errorf("table of index %d not found", dstTableIndex)
}
pc += num
srcTableIndex, num, err := leb128.DecodeUint32(bytes.NewReader(body[pc:]))
if err != nil {
return fmt.Errorf("failed to read source table index for %s: %v", MiscInstructionName(miscOpcode), err)
}
if srcTableIndex != 0 {
if err := enabledFeatures.Require(FeatureReferenceTypes); err != nil {
return fmt.Errorf("source table index must be zero for %s as %v", MiscInstructionName(miscOpcode), err)
}
}
if srcTableIndex >= uint32(len(tables)) {
return fmt.Errorf("table of index %d not found", srcTableIndex)
}
if tables[srcTableIndex].Type != tables[dstTableIndex].Type {
return fmt.Errorf("table type mismatch for table.copy: %s (src) != %s (dst)",
RefTypeName(tables[srcTableIndex].Type), RefTypeName(tables[dstTableIndex].Type))
}
pc += num - 1
}
for _, p := range params {
if err := valueTypeStack.popAndVerifyType(p); err != nil {
return fmt.Errorf("cannot pop the operand for %s: %v", miscInstructionNames[miscOpcode], err)
}
}
} else if miscOpcode >= OpcodeMiscTableGrow && miscOpcode <= OpcodeMiscTableFill {
if err := enabledFeatures.Require(FeatureReferenceTypes); err != nil {
return fmt.Errorf("%s invalid as %v", miscInstructionNames[miscOpcode], err)
}
pc++
tableIndex, num, err := leb128.DecodeUint32(bytes.NewReader(body[pc:]))
if err != nil {
return fmt.Errorf("failed to read table index for %s: %v", MiscInstructionName(miscOpcode), err)
}
if tableIndex >= uint32(len(tables)) {
return fmt.Errorf("table of index %d not found", tableIndex)
}
pc += num - 1
var params, results []ValueType
reftype := tables[tableIndex].Type
if miscOpcode == OpcodeMiscTableGrow {
params = []ValueType{ValueTypeI32, reftype}
results = []ValueType{ValueTypeI32}
} else if miscOpcode == OpcodeMiscTableSize {
results = []ValueType{ValueTypeI32}
} else if miscOpcode == OpcodeMiscTableFill {
params = []ValueType{ValueTypeI32, reftype, ValueTypeI32}
}
for _, p := range params {
if err := valueTypeStack.popAndVerifyType(p); err != nil {
return fmt.Errorf("cannot pop the operand for %s: %v", miscInstructionNames[miscOpcode], err)
}
}
for _, r := range results {
valueTypeStack.push(r)
}
}
} else if op == OpcodeVecPrefix {
pc++
// Vector instructions come with two bytes which starts with OpcodeVecPrefix,
// and the second byte determines the actual instruction.
vecOpcode := body[pc]
if err := enabledFeatures.Require(FeatureSIMD); err != nil {
return fmt.Errorf("%s invalid as %v", vectorInstructionName[vecOpcode], err)
}
switch vecOpcode {
default:
return fmt.Errorf("TODO: SIMD instruction %s will be implemented in #506", vectorInstructionName[vecOpcode])
}
} else if op == OpcodeBlock {
bt, num, err := DecodeBlockType(types, bytes.NewReader(body[pc+1:]), enabledFeatures)
if err != nil {
return fmt.Errorf("read block: %w", err)
}
controlBlockStack = append(controlBlockStack, &controlBlock{
startAt: pc,
blockType: bt,
blockTypeBytes: num,
})
if err = valueTypeStack.popParams(op, bt.Params, false); err != nil {
return err
}
// Plus we have to push any block params again.
for _, p := range bt.Params {
valueTypeStack.push(p)
}
valueTypeStack.pushStackLimit(len(bt.Params))
pc += num
} else if op == OpcodeLoop {
bt, num, err := DecodeBlockType(types, bytes.NewReader(body[pc+1:]), enabledFeatures)
if err != nil {
return fmt.Errorf("read block: %w", err)
}
controlBlockStack = append(controlBlockStack, &controlBlock{
startAt: pc,
blockType: bt,
blockTypeBytes: num,
op: op,
})
if err = valueTypeStack.popParams(op, bt.Params, false); err != nil {
return err
}
// Plus we have to push any block params again.
for _, p := range bt.Params {
valueTypeStack.push(p)
}
valueTypeStack.pushStackLimit(len(bt.Params))
pc += num
} else if op == OpcodeIf {
bt, num, err := DecodeBlockType(types, bytes.NewReader(body[pc+1:]), enabledFeatures)
if err != nil {
return fmt.Errorf("read block: %w", err)
}
controlBlockStack = append(controlBlockStack, &controlBlock{
startAt: pc,
blockType: bt,
blockTypeBytes: num,
op: op,
})
if err = valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return fmt.Errorf("cannot pop the operand for 'if': %v", err)
}
if err = valueTypeStack.popParams(op, bt.Params, false); err != nil {
return err
}
// Plus we have to push any block params again.
for _, p := range bt.Params {
valueTypeStack.push(p)
}
valueTypeStack.pushStackLimit(len(bt.Params))
pc += num
} else if op == OpcodeElse {
bl := controlBlockStack[len(controlBlockStack)-1]
bl.elseAt = pc
// Check the type soundness of the instructions *before* entering this else Op.
if err := valueTypeStack.popResults(OpcodeIf, bl.blockType.Results, true); err != nil {
return err
}
// Before entering instructions inside else, we pop all the values pushed by then block.
valueTypeStack.resetAtStackLimit()
// Plus we have to push any block params again.
for _, p := range bl.blockType.Params {
valueTypeStack.push(p)
}
} else if op == OpcodeEnd {
bl := controlBlockStack[len(controlBlockStack)-1]
bl.endAt = pc
controlBlockStack = controlBlockStack[:len(controlBlockStack)-1]
// OpcodeEnd can end a block or the function itself. Check to see what it is:
ifMissingElse := bl.op == OpcodeIf && bl.elseAt <= bl.startAt
if ifMissingElse {
// If this is the end of block without else, the number of block's results and params must be same.
// Otherwise, the value stack would result in the inconsistent state at runtime.
if !bytes.Equal(bl.blockType.Results, bl.blockType.Params) {
return typeCountError(false, OpcodeElseName, bl.blockType.Params, bl.blockType.Results)
}
// -1 skips else, to handle if block without else properly.
bl.elseAt = bl.endAt - 1
}
// Determine the block context
ctx := "" // the outer-most block: the function return
if bl.op == OpcodeIf && !ifMissingElse && bl.elseAt > 0 {
ctx = OpcodeElseName
} else if bl.op != 0 {
ctx = InstructionName(bl.op)
}
// Check return types match
if err := valueTypeStack.requireStackValues(false, ctx, bl.blockType.Results, true); err != nil {
return err
}
// Put the result types at the end after resetting at the stack limit
// since we might have Any type between the limit and the current top.
valueTypeStack.resetAtStackLimit()
for _, exp := range bl.blockType.Results {
valueTypeStack.push(exp)
}
// We exit if/loop/block, so reset the constraints on the stack manipulation
// on values previously pushed by outer blocks.
valueTypeStack.popStackLimit()
} else if op == OpcodeReturn {
// Same formatting as OpcodeEnd on the outer-most block
if err := valueTypeStack.requireStackValues(false, "", functionType.Results, false); err != nil {
return err
}
// return instruction is stack-polymorphic.
valueTypeStack.unreachable()
} else if op == OpcodeDrop {
_, err := valueTypeStack.pop()
if err != nil {
return fmt.Errorf("invalid drop: %v", err)
}
} else if op == OpcodeSelect || op == OpcodeTypedSelect {
if err := valueTypeStack.popAndVerifyType(ValueTypeI32); err != nil {
return fmt.Errorf("type mismatch on 3rd select operand: %v", err)
}
v1, err := valueTypeStack.pop()
if err != nil {
return fmt.Errorf("invalid select: %v", err)
}
v2, err := valueTypeStack.pop()
if err != nil {
return fmt.Errorf("invalid select: %v", err)
}
if op == OpcodeTypedSelect {
if err := enabledFeatures.Require(FeatureReferenceTypes); err != nil {
return fmt.Errorf("%s is invalid as %w", InstructionName(op), err)
}
pc++
if numTypeImmeidates := body[pc]; numTypeImmeidates != 1 {
return fmt.Errorf("too many type immediates for %s", InstructionName(op))
}
pc++
tp := body[pc]
if tp != ValueTypeI32 && tp != ValueTypeI64 && tp != ValueTypeF32 && tp != ValueTypeF64 &&
tp != api.ValueTypeExternref && tp != ValueTypeFuncref {
return fmt.Errorf("invalid type %s for %s", ValueTypeName(tp), OpcodeTypedSelectName)
}
} else if isReferenceValueType(v1) || isReferenceValueType(v2) {
return fmt.Errorf("reference types cannot be used for non typed select instruction")
}
if v1 != v2 && v1 != valueTypeUnknown && v2 != valueTypeUnknown {
return fmt.Errorf("type mismatch on 1st and 2nd select operands")
}
if v1 == valueTypeUnknown {
valueTypeStack.push(v2)
} else {
valueTypeStack.push(v1)
}
} else if op == OpcodeUnreachable {
// unreachable instruction is stack-polymorphic.
valueTypeStack.unreachable()
} else if op == OpcodeNop {
} else {
return fmt.Errorf("invalid instruction 0x%x", op)
}
}
if len(controlBlockStack) > 0 {
return fmt.Errorf("ill-nested block exists")
}
if valueTypeStack.maximumStackPointer > maxStackValues {
return fmt.Errorf("function may have %d stack values, which exceeds limit %d", valueTypeStack.maximumStackPointer, maxStackValues)
}
return nil
}
type valueTypeStack struct {
stack []ValueType
stackLimits []int
maximumStackPointer int
}
const (
// Only used in the analyzeFunction below.
valueTypeUnknown = ValueType(0xFF)
)
func (s *valueTypeStack) tryPop() (vt ValueType, limit int, ok bool) {
if len(s.stackLimits) > 0 {
limit = s.stackLimits[len(s.stackLimits)-1]
}
stackLen := len(s.stack)
if stackLen <= limit {
return
} else if stackLen == limit+1 && s.stack[limit] == valueTypeUnknown {
vt = valueTypeUnknown
ok = true
return
} else {
vt = s.stack[stackLen-1]
s.stack = s.stack[:stackLen-1]
ok = true
return
}
}
func (s *valueTypeStack) pop() (ValueType, error) {
if vt, limit, ok := s.tryPop(); ok {
return vt, nil
} else {
return 0, fmt.Errorf("invalid operation: trying to pop at %d with limit %d", len(s.stack), limit)
}
}
// popAndVerifyType returns an error if the stack value is unexpected.
func (s *valueTypeStack) popAndVerifyType(expected ValueType) error {
have, _, ok := s.tryPop()
if !ok {
return fmt.Errorf("%s missing", ValueTypeName(expected))
}
if have != expected && have != valueTypeUnknown && expected != valueTypeUnknown {
return fmt.Errorf("type mismatch: expected %s, but was %s", ValueTypeName(expected), ValueTypeName(have))
}
return nil
}
func (s *valueTypeStack) push(v ValueType) {
s.stack = append(s.stack, v)
if sp := len(s.stack); sp > s.maximumStackPointer {
s.maximumStackPointer = sp
}
}
func (s *valueTypeStack) unreachable() {
s.resetAtStackLimit()
s.stack = append(s.stack, valueTypeUnknown)
}
func (s *valueTypeStack) resetAtStackLimit() {
if len(s.stackLimits) != 0 {
s.stack = s.stack[:s.stackLimits[len(s.stackLimits)-1]]
} else {
s.stack = []ValueType{}
}
}
func (s *valueTypeStack) popStackLimit() {
if len(s.stackLimits) != 0 {
s.stackLimits = s.stackLimits[:len(s.stackLimits)-1]
}
}
// pushStackLimit pushes the control frame's bottom of the stack.
func (s *valueTypeStack) pushStackLimit(params int) {
limit := len(s.stack) - params
s.stackLimits = append(s.stackLimits, limit)
}
func (s *valueTypeStack) popParams(oc Opcode, want []ValueType, checkAboveLimit bool) error {
return s.requireStackValues(true, InstructionName(oc), want, checkAboveLimit)
}
func (s *valueTypeStack) popResults(oc Opcode, want []ValueType, checkAboveLimit bool) error {
return s.requireStackValues(false, InstructionName(oc), want, checkAboveLimit)
}
func (s *valueTypeStack) requireStackValues(
isParam bool,
context string,
want []ValueType,
checkAboveLimit bool,
) error {
limit := 0
if len(s.stackLimits) > 0 {
limit = s.stackLimits[len(s.stackLimits)-1]
}
// Iterate backwards as we are comparing the desired slice against stack value types.
countWanted := len(want)
// First, check if there are enough values on the stack.
have := make([]ValueType, 0, countWanted)
for i := countWanted - 1; i >= 0; i-- {
popped, _, ok := s.tryPop()
if !ok {
if len(have) > len(want) {
return typeCountError(isParam, context, have, want)
}
return typeCountError(isParam, context, have, want)
}
have = append(have, popped)
}
// Now, check if there are too many values.
if checkAboveLimit {
if !(limit == len(s.stack) || (limit+1 == len(s.stack) && s.stack[limit] == valueTypeUnknown)) {
return typeCountError(isParam, context, append(s.stack, want...), want)
}
}
// Finally, check the types of the values:
for i, v := range have {
nextWant := want[countWanted-i-1] // have is in reverse order (stack)
if v != nextWant && v != valueTypeUnknown && nextWant != valueTypeUnknown {
return typeMismatchError(isParam, context, v, nextWant, i)
}
}
return nil
}
// typeMismatchError returns an error similar to go compiler's error on type mismatch.
func typeMismatchError(isParam bool, context string, have ValueType, want ValueType, i int) error {
var ret strings.Builder
ret.WriteString("cannot use ")
ret.WriteString(ValueTypeName(have))
if context != "" {
ret.WriteString(" in ")
ret.WriteString(context)
ret.WriteString(" block")
}
if isParam {
ret.WriteString(" as param")
} else {
ret.WriteString(" as result")
}
ret.WriteString("[")
ret.WriteString(strconv.Itoa(i))
ret.WriteString("] type ")
ret.WriteString(ValueTypeName(want))
return errors.New(ret.String())
}
// typeCountError returns an error similar to go compiler's error on type count mismatch.
func typeCountError(isParam bool, context string, have []ValueType, want []ValueType) error {
var ret strings.Builder
if len(have) > len(want) {
ret.WriteString("too many ")
} else {
ret.WriteString("not enough ")
}
if isParam {
ret.WriteString("params")
} else {
ret.WriteString("results")
}
if context != "" {
if isParam {
ret.WriteString(" for ")
} else {
ret.WriteString(" in ")
}
ret.WriteString(context)
ret.WriteString(" block")
}
ret.WriteString("\n\thave (")
writeValueTypes(have, &ret)
ret.WriteString(")\n\twant (")
writeValueTypes(want, &ret)
ret.WriteByte(')')
return errors.New(ret.String())
}
func writeValueTypes(vts []ValueType, ret *strings.Builder) {
switch len(vts) {
case 0:
case 1:
ret.WriteString(api.ValueTypeName(vts[0]))
default:
ret.WriteString(api.ValueTypeName(vts[0]))
for _, vt := range vts[1:] {
ret.WriteString(", ")
ret.WriteString(api.ValueTypeName(vt))
}
}
}
func (s *valueTypeStack) String() string {
var typeStrs, limits []string
for _, v := range s.stack {
var str string
if v == valueTypeUnknown {
str = "unknown"
} else if v == ValueTypeI32 {
str = "i32"
} else if v == ValueTypeI64 {
str = "i64"
} else if v == ValueTypeF32 {
str = "f32"
} else if v == ValueTypeF64 {
str = "f64"
}
typeStrs = append(typeStrs, str)
}
for _, d := range s.stackLimits {
limits = append(limits, fmt.Sprintf("%d", d))
}
return fmt.Sprintf("{stack: [%s], limits: [%s]}",
strings.Join(typeStrs, ", "), strings.Join(limits, ","))
}
type controlBlock struct {
startAt, elseAt, endAt uint64
blockType *FunctionType
blockTypeBytes uint64
// op is zero when the outermost block
op Opcode
}
func DecodeBlockType(types []*FunctionType, r *bytes.Reader, enabledFeatures Features) (*FunctionType, uint64, error) {
return decodeBlockTypeImpl(func(index int64) (*FunctionType, error) {
if index < 0 || (index >= int64(len(types))) {
return nil, fmt.Errorf("type index out of range: %d", index)
}
return types[index], nil
}, r, enabledFeatures)
}
// decodeBlockTypeImpl decodes the type index from a positive 33-bit signed integer. Negative numbers indicate up to one
// WebAssembly 1.0 (20191205) compatible result type. Positive numbers are decoded when `enabledFeatures` include
// FeatureMultiValue and include an index in the Module.TypeSection.
//
// See https://www.w3.org/TR/2019/REC-wasm-core-1-20191205/#binary-blocktype
// See https://github.com/WebAssembly/spec/blob/main/proposals/multi-value/Overview.md
func decodeBlockTypeImpl(functionTypeResolver func(index int64) (*FunctionType, error), r *bytes.Reader, enabledFeatures Features) (*FunctionType, uint64, error) {
raw, num, err := leb128.DecodeInt33AsInt64(r)
if err != nil {
return nil, 0, fmt.Errorf("decode int33: %w", err)
}
var ret *FunctionType
switch raw {
case -64: // 0x40 in original byte = nil
ret = &FunctionType{}
case -1: // 0x7f in original byte = i32
ret = &FunctionType{Results: []ValueType{ValueTypeI32}}
case -2: // 0x7e in original byte = i64
ret = &FunctionType{Results: []ValueType{ValueTypeI64}}
case -3: // 0x7d in original byte = f32
ret = &FunctionType{Results: []ValueType{ValueTypeF32}}
case -4: // 0x7c in original byte = f64
ret = &FunctionType{Results: []ValueType{ValueTypeF64}}
case -16: // 0x70 in original byte = funcref
ret = &FunctionType{Results: []ValueType{ValueTypeExternref}}
case -17: // 0x6f in original byte = externref
ret = &FunctionType{Results: []ValueType{ValueTypeExternref}}
default:
if err = enabledFeatures.Require(FeatureMultiValue); err != nil {
return nil, num, fmt.Errorf("block with function type return invalid as %v", err)
}
ret, err = functionTypeResolver(raw)
}
return ret, num, err
}