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iainsmithiainsmith
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Function Reference: Add explicit nonNull references & call_ref
instruction
1 parent 7ff06cc commit d502b70

19 files changed

+165
-83
lines changed

‎README.md

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@@ -70,6 +70,8 @@ and should work on the following platforms:
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| | [Memory64](https://github.com/WebAssembly/memory64/blob/main/proposals/memory64/Overview.md) | ✅ Implemented |
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| | [Tail call](https://github.com/WebAssembly/tail-call/blob/master/proposals/tail-call/Overview.md) | ✅ Implemented |
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| | [Threads and atomics](https://github.com/WebAssembly/threads/blob/master/proposals/threads/Overview.md) | 🚧 Parser implemented |
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| | [Typed Function References](https://github.com/WebAssembly/function-references/blob/main/proposals/function-references/Overview.md) | 📋 Todo |
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| | [Garbage Collection](https://github.com/WebAssembly/gc/blob/main/proposals/gc/Overview.md) | 📋 Todo |
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| WASI | WASI Preview 1 | ✅ Implemented |
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‎Sources/WAT/BinaryInstructionEncoder.swift

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@@ -392,4 +392,8 @@ extension BinaryInstructionEncoder {
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try encodeInstruction([0xFC, 0x10])
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try encodeImmediates(table: table)
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}
395+
mutating func visitCallRef(functionIndex: UInt32) throws {
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try encodeInstruction([0x14])
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try encodeImmediates(functionIndex: functionIndex)
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}
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}

‎Sources/WAT/Encoder.swift

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@@ -129,7 +129,9 @@ extension ReferenceType: WasmEncodable {
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func encode(to encoder: inout Encoder) {
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switch self {
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case .funcRef: encoder.output.append(0x70)
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case .funcRefNonNull: encoder.output.append(0x71)
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case .externRef: encoder.output.append(0x6F)
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case .externRefNonNull: encoder.output.append(0x6E) // Is this correct
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}
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}
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}

‎Sources/WAT/ParseTextInstruction.swift

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@@ -332,6 +332,9 @@ func parseTextInstruction<V: InstructionVisitor>(keyword: String, expressionPars
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case "i64.trunc_sat_f32_u": return { return try $0.visitConversion(.i64TruncSatF32U) }
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case "i64.trunc_sat_f64_s": return { return try $0.visitConversion(.i64TruncSatF64S) }
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case "i64.trunc_sat_f64_u": return { return try $0.visitConversion(.i64TruncSatF64U) }
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case "call_ref":
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let (functionIndex) = try expressionParser.visitCallRef(wat: &wat)
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return { return try $0.visitCallRef(functionIndex: functionIndex) }
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default: return nil
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}
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}

‎Sources/WAT/Parser/ExpressionParser.swift

Lines changed: 7 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -362,7 +362,9 @@ struct ExpressionParser<Visitor: InstructionVisitor> {
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}
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private mutating func refKind() throws -> ReferenceType {
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if try parser.takeKeyword("func") {
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if try parser.take(.id) {
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return .funcRef // not sure about this.
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} else if try parser.takeKeyword("func") {
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return .funcRef
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} else if try parser.takeKeyword("extern") {
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return .externRef
@@ -439,6 +441,10 @@ extension ExpressionParser {
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let use = try parser.expectIndexOrId()
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return UInt32(try wat.functionsMap.resolve(use: use).index)
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}
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mutating func visitCallRef(wat: inout Wat) throws -> UInt32 {
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let use = try parser.expectIndexOrId()
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return UInt32(try wat.types.resolve(use: use).index)
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}
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mutating func visitCallIndirect(wat: inout Wat) throws -> (typeIndex: UInt32, tableIndex: UInt32) {
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let tableIndex: UInt32
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if let tableId = try parser.takeIndexOrId() {

‎Sources/WAT/Parser/WastParser.swift

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@@ -67,7 +67,9 @@ struct WastParser {
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let value: Reference
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switch type {
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case .externRef: value = .extern(nil)
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case .externRefNonNull: value = .function(nil) // non null
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case .funcRef: value = .function(nil)
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case .funcRefNonNull: value = .function(nil) // non null
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}
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addValue(.ref(value))
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}

‎Sources/WAT/Parser/WatParser.swift

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Original file line numberDiff line numberDiff line change
@@ -606,29 +606,59 @@ struct WatParser {
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}
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mutating func valueType() throws -> ValueType {
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if try parser.peek(.leftParen) != nil {
610+
return try _referenceValueType()
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} else {
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return try _valueType()
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}
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}
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// must consume right paren
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mutating func _referenceValueType() throws -> ValueType {
618+
var isNullable = false
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_ = try parser.takeParenBlockStart("ref")
620+
if try parser.peekKeyword() == "null" {
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_ = try parser.takeKeyword("null")
622+
isNullable = true
623+
}
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625+
if try parser.takeId() != nil {
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_ = try parser.take(.rightParen)
627+
return .ref(refType(keyword: "func", isNullable: isNullable)!)
628+
}
629+
630+
let keyword = try parser.expectKeyword()
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_ = try parser.take(.rightParen)
632+
if let refType = refType(keyword: keyword, isNullable: isNullable) { return .ref(refType) }
633+
throw WatParserError("unexpected value type \(keyword)", location: parser.lexer.location())
634+
}
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mutating func _valueType() throws -> ValueType {
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let keyword = try parser.expectKeyword()
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switch keyword {
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case "i32": return .i32
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case "i64": return .i64
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case "f32": return .f32
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case "f64": return .f64
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default:
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if let refType = refType(keyword: keyword) { return .ref(refType) }
644+
if let refType = refType(keyword: keyword, isNullable: true) { return .ref(refType) }
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throw WatParserError("unexpected value type \(keyword)", location: parser.lexer.location())
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}
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}
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621-
mutating func refType(keyword: String) -> ReferenceType? {
649+
mutating func refType(keyword: String, isNullable: Bool) -> ReferenceType? {
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switch keyword {
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case "funcref": return .funcRef
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case "externref": return .externRef
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case "func": return isNullable ? .funcRef : .funcRefNonNull
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case "extern": return isNullable ? .externRef : .externRefNonNull
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default: return nil
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}
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}
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mutating func refType() throws -> ReferenceType {
630660
let keyword = try parser.expectKeyword()
631-
guard let refType = refType(keyword: keyword) else {
661+
guard let refType = refType(keyword: keyword, isNullable: true) else {
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throw WatParserError("unexpected ref type \(keyword)", location: parser.lexer.location())
633663
}
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return refType

‎Sources/WasmKit/Execution/ConstEvaluation.swift

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@@ -62,8 +62,8 @@ extension ConstExpression {
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return try context.globalValue(globalIndex)
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case .refNull(let type):
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switch type {
65-
case .externRef: return .ref(.extern(nil))
66-
case .funcRef: return .ref(.function(nil))
65+
case .externRef, .externRefNonNull: return .ref(.extern(nil))
66+
case .funcRef, .funcRefNonNull: return .ref(.function(nil))
6767
}
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case .refFunc(let functionIndex):
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return try .ref(context.functionRef(functionIndex))

‎Sources/WasmKit/Execution/Instances.swift

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@@ -277,8 +277,12 @@ struct TableEntity /* : ~Copyable */ {
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switch tableType.elementType {
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case .funcRef:
279279
emptyElement = .function(nil)
280+
case .funcRefNonNull:
281+
emptyElement = .function(nil) // shouldn't be null
280282
case .externRef:
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emptyElement = .extern(nil)
284+
case .externRefNonNull:
285+
emptyElement = .extern(nil) // shouldn't be null
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}
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let numberOfElements = Int(tableType.limits.min)

‎Sources/WasmKit/Execution/Instructions/Misc.swift

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@@ -22,9 +22,9 @@ extension Execution {
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mutating func refNull(sp: Sp, immediate: Instruction.RefNullOperand) {
2323
let value: Value
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switch immediate.type {
25-
case .externRef:
25+
case .externRef, .externRefNonNull:
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value = .ref(.extern(nil))
27-
case .funcRef:
27+
case .funcRef, .funcRefNonNull:
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value = .ref(.function(nil))
2929
}
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sp[immediate.result] = UntypedValue(value)

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