Merge pull request #112 from sjrd/constant-strings-for-typedata-name

Store the name data of classes along with constant strings.

Author: tanishiking

wasm/src/main/scala/ir2wasm/HelperFunctions.scala

@@ -264,13 +264,17 @@ object HelperFunctions {
         instrs += CALL(WasmFunctionName.stringConcat)
       } {
         // it is not an array; its name is stored in nameData
-        instrs += LOCAL_GET(typeDataParam)
-        instrs += STRUCT_GET(
-          WasmStructTypeName.typeData,
-          WasmFieldIdx.typeData.nameDataIdx
-        )
-        instrs += REF_AS_NOT_NULL
-        instrs += CALL(WasmFunctionName.createStringFromData)
+        for (
+          idx <- List(
+            WasmFieldIdx.typeData.nameOffsetIdx,
+            WasmFieldIdx.typeData.nameSizeIdx,
+            WasmFieldIdx.typeData.nameStringIndexIdx
+          )
+        ) {
+          instrs += LOCAL_GET(typeDataParam)
+          instrs += STRUCT_GET(WasmStructTypeName.typeData, idx)
+        }
+        instrs += CALL(WasmFunctionName.stringLiteral)
       }
 
       // typeData.name := <top of stack> ; leave it on the stack
@@ -483,7 +487,9 @@ object HelperFunctions {
         instrs += LOCAL_GET(typeDataParam)
 
         // typeData := new typeData(...)
-        instrs += REF_NULL(WasmHeapType.None) // nameData
+        instrs += I32_CONST(0) // nameOffset
+        instrs += I32_CONST(0) // nameSize
+        instrs += I32_CONST(0) // nameStringIndex
         instrs += I32_CONST(KindArray) // kind = KindArray
         instrs += I32_CONST(0) // specialInstanceTypes = 0
 

wasm/src/main/scala/ir2wasm/WasmBuilder.scala

@@ -281,13 +281,7 @@ class WasmBuilder(coreSpec: CoreSpec) {
         )
     }
 
-    val nameDataValueItems = nameStr.toList.map(c => I32_CONST(c.toInt))
-    val nameDataValueArrayNew =
-      ARRAY_NEW_FIXED(
-        WasmTypeName.WasmArrayTypeName.i16Array,
-        nameDataValueItems.size
-      )
-    val nameDataValue: List[WasmInstr] = nameDataValueItems :+ nameDataValueArrayNew
+    val nameDataValue: List[WasmInstr] = ctx.getConstantStringDataInstr(nameStr)
 
     val strictAncestorsValue: List[WasmInstr] = {
       typeRef match {

wasm/src/main/scala/wasm4s/Names.scala

@@ -313,12 +313,18 @@ object Names {
     // Fields of the typeData structs
     object typeData {
 
-      /** The name data as `(ref null (array u16))` so that it can be initialized as a constant.
+      /** The name data as the 3 arguments to `stringLiteral`.
         *
-        * It is non-null for primitives and for classes. It is null for array types, as array types
-        * compute their `name` from the `name` of their component type.
+        * It is only meaningful for primitives and for classes. For array types, they are all 0, as
+        * array types compute their `name` from the `name` of their component type.
         */
-      val nameData = new WasmFieldName("nameData")
+      val nameOffset = new WasmFieldName("nameOffset")
+
+      /** See `nameOffset`. */
+      val nameSize = new WasmFieldName("nameSize")
+
+      /** See `nameOffset`. */
+      val nameStringIndex = new WasmFieldName("nameStringIndex")
 
       /** The kind of type data, an `i32`.
         *
@@ -410,17 +416,19 @@ object Names {
     val uniqueRegularField = WasmFieldIdx(2)
 
     object typeData {
-      val nameDataIdx = WasmFieldIdx(0)
-      val kindIdx = WasmFieldIdx(1)
-      val specialInstanceTypesIdx = WasmFieldIdx(2)
-      val strictAncestorsIdx = WasmFieldIdx(3)
-      val componentTypeIdx = WasmFieldIdx(4)
-      val nameIdx = WasmFieldIdx(5)
-      val classOfIdx = WasmFieldIdx(6)
-      val arrayOfIdx = WasmFieldIdx(7)
-      val cloneFunctionIdx = WasmFieldIdx(8)
-      val isJSClassInstanceIdx = WasmFieldIdx(9)
-      val reflectiveProxiesIdx = WasmFieldIdx(10)
+      val nameOffsetIdx = WasmFieldIdx(0)
+      val nameSizeIdx = WasmFieldIdx(1)
+      val nameStringIndexIdx = WasmFieldIdx(2)
+      val kindIdx = WasmFieldIdx(3)
+      val specialInstanceTypesIdx = WasmFieldIdx(4)
+      val strictAncestorsIdx = WasmFieldIdx(5)
+      val componentTypeIdx = WasmFieldIdx(6)
+      val nameIdx = WasmFieldIdx(7)
+      val classOfIdx = WasmFieldIdx(8)
+      val arrayOfIdx = WasmFieldIdx(9)
+      val cloneFunctionIdx = WasmFieldIdx(10)
+      val isJSClassInstanceIdx = WasmFieldIdx(11)
+      val reflectiveProxiesIdx = WasmFieldIdx(12)
     }
 
     object reflectiveProxy {

wasm/src/main/scala/wasm4s/Wasm.scala

@@ -135,8 +135,18 @@ object WasmStructType {
   def typeData(implicit ctx: ReadOnlyWasmContext): WasmStructType = WasmStructType(
     List(
       WasmStructField(
-        WasmFieldName.typeData.nameData,
-        WasmRefType.nullable(WasmArrayTypeName.i16Array),
+        WasmFieldName.typeData.nameOffset,
+        WasmInt32,
+        isMutable = false
+      ),
+      WasmStructField(
+        WasmFieldName.typeData.nameSize,
+        WasmInt32,
+        isMutable = false
+      ),
+      WasmStructField(
+        WasmFieldName.typeData.nameStringIndex,
+        WasmInt32,
         isMutable = false
       ),
       WasmStructField(

wasm/src/main/scala/wasm4s/WasmContext.scala

@@ -200,16 +200,18 @@ abstract class TypeDefinableWasmContext extends ReadOnlyWasmContext { this: Wasm
     }
   }
 
-  def getConstantStringInstr(str: String): List[WasmInstr] = {
+  def getConstantStringInstr(str: String): List[WasmInstr] =
+    getConstantStringDataInstr(str) :+ WasmInstr.CALL(WasmFunctionName.stringLiteral)
+
+  def getConstantStringDataInstr(str: String): List[WasmInstr.I32_CONST] = {
     val data = addConstantStringGlobal(str)
     List(
       WasmInstr.I32_CONST(data.offset),
       // Assuming that the stringLiteral method will instantiate the
       // constant string from the data section using "array.newData $i16Array ..."
       // The length of the array should be equal to the length of the WTF-16 encoded string
       WasmInstr.I32_CONST(str.length()),
-      WasmInstr.I32_CONST(data.constantStringIndex),
-      WasmInstr.CALL(WasmFunctionName.stringLiteral)
+      WasmInstr.I32_CONST(data.constantStringIndex)
     )
   }