Validation: Check the type of the initial value of a global variable

Author: kateinoigakukun

Sources/WasmKit/Execution/ConstEvaluation.swift

@@ -104,29 +104,3 @@ extension WasmParser.ElementSegment {
         }
     }
 }
-
-extension WasmTypes.Reference {
-    fileprivate func checkType(_ type: WasmTypes.ReferenceType) throws {
-        switch (self, type) {
-        case (.function, .funcRef): return
-        case (.extern, .externRef): return
-        default:
-            throw ValidationError("Expect \(type) but got \(self)")
-        }
-    }
-}
-
-extension Value {
-    fileprivate func checkType(_ type: WasmTypes.ValueType) throws {
-        switch (self, type) {
-        case (.i32, .i32): return
-        case (.i64, .i64): return
-        case (.f32, .f32): return
-        case (.f64, .f64): return
-        case (.ref(let ref), .ref(let refType)):
-            try ref.checkType(refType)
-        default:
-            throw ValidationError("Expect \(type) but got \(self)")
-        }
-    }
-}

Sources/WasmKit/Execution/Instances.swift

@@ -571,7 +571,8 @@ struct GlobalEntity /* : ~Copyable */ {
     }
     let globalType: GlobalType
 
-    init(globalType: GlobalType, initialValue: Value) {
+    init(globalType: GlobalType, initialValue: Value) throws {
+        try initialValue.checkType(globalType.valueType)
         rawValue = UntypedValue(initialValue)
         self.globalType = globalType
     }
@@ -620,14 +621,14 @@ public struct Global: Equatable {
     /// WebAssembly module.
     @available(*, deprecated, renamed: "init(store:type:value:)")
     public init(globalType: GlobalType, initialValue: Value, store: Store) {
-        self.init(store: store, type: globalType, value: initialValue)
+        try! self.init(store: store, type: globalType, value: initialValue)
     }
 
     /// Initializes a new global instance with the given type and initial value.
     /// The returned global instance may be used to instantiate a new
     /// WebAssembly module.
-    public init(store: Store, type: GlobalType, value: Value) {
-        let handle = store.allocator.allocate(globalType: type, initialValue: value)
+    public init(store: Store, type: GlobalType, value: Value) throws {
+        let handle = try store.allocator.allocate(globalType: type, initialValue: value)
         self.init(handle: handle, allocator: store.allocator)
     }
 }

Sources/WasmKit/Execution/StoreAllocator.swift

@@ -374,7 +374,7 @@ extension StoreAllocator {
                 let initialValue = try global.initializer.evaluate(
                     context: constEvalContext, expectedType: global.type.valueType
                 )
-                return allocate(globalType: global.type, initialValue: initialValue)
+                return try allocate(globalType: global.type, initialValue: initialValue)
             }
         )
 
@@ -507,8 +507,8 @@ extension StoreAllocator {
 
     /// > Note:
     /// <https://webassembly.github.io/spec/core/exec/modules.html#alloc-global>
-    func allocate(globalType: GlobalType, initialValue: Value) -> InternalGlobal {
-        let pointer = globals.allocate(initializing: GlobalEntity(globalType: globalType, initialValue: initialValue))
+    func allocate(globalType: GlobalType, initialValue: Value) throws -> InternalGlobal {
+        let pointer = try globals.allocate(initializing: GlobalEntity(globalType: globalType, initialValue: initialValue))
         return InternalGlobal(unsafe: pointer)
     }
 

Sources/WasmKit/Validator.swift

@@ -140,3 +140,29 @@ struct ModuleValidator {
         }
     }
 }
+
+extension WasmTypes.Reference {
+    func checkType(_ type: WasmTypes.ReferenceType) throws {
+        switch (self, type) {
+        case (.function, .funcRef): return
+        case (.extern, .externRef): return
+        default:
+            throw ValidationError("Expect \(type) but got \(self)")
+        }
+    }
+}
+
+extension Value {
+    func checkType(_ type: WasmTypes.ValueType) throws {
+        switch (self, type) {
+        case (.i32, .i32): return
+        case (.i64, .i64): return
+        case (.f32, .f32): return
+        case (.f64, .f64): return
+        case (.ref(let ref), .ref(let refType)):
+            try ref.checkType(refType)
+        default:
+            throw ValidationError("Expect \(type) but got \(self)")
+        }
+    }
+}