[embind] Minor refactor to use more modern JS features (#21331)

Author: sbc100

src/embind/embind.js

@@ -101,7 +101,7 @@ var LibraryEmbind = {
       proto[methodName] = function(...args) {
         // TODO This check can be removed in -O3 level "unsafe" optimizations.
         if (!proto[methodName].overloadTable.hasOwnProperty(args.length)) {
-            throwBindingError(`Function '${humanName}' called with an invalid number of arguments (${args.length}) - expects one of (${proto[methodName].overloadTable})!`);
+          throwBindingError(`Function '${humanName}' called with an invalid number of arguments (${args.length}) - expects one of (${proto[methodName].overloadTable})!`);
         }
         return proto[methodName].overloadTable[args.length].apply(this, args);
       };
@@ -953,7 +953,7 @@ var LibraryEmbind = {
       throwUnboundTypeError(`Cannot call ${name} due to unbound types`, argTypes);
     }, argCount - 1);
 
-    whenDependentTypesAreResolved([], argTypes, function(argTypes) {
+    whenDependentTypesAreResolved([], argTypes, (argTypes) => {
       var invokerArgsArray = [argTypes[0] /* return value */, null /* no class 'this'*/].concat(argTypes.slice(1) /* actual params */);
       replacePublicSymbol(name, craftInvokerFunction(name, invokerArgsArray, null /* no class 'this'*/, rawInvoker, fn, isAsync), argCount - 1);
       return [];
@@ -1015,7 +1015,7 @@ var LibraryEmbind = {
     var rawConstructor = reg.rawConstructor;
     var rawDestructor = reg.rawDestructor;
 
-    whenDependentTypesAreResolved([rawTupleType], elementTypes, function(elementTypes) {
+    whenDependentTypesAreResolved([rawTupleType], elementTypes, (elementTypes) => {
       elements.forEach((elt, i) => {
         var getterReturnType = elementTypes[i];
         var getter = elt.getter;
@@ -1753,7 +1753,7 @@ var LibraryEmbind = {
     whenDependentTypesAreResolved(
       [rawType, rawPointerType, rawConstPointerType],
       baseClassRawType ? [baseClassRawType] : [],
-      function(base) {
+      (base) => {
         base = base[0];
 
         var baseClass;
@@ -1851,7 +1851,7 @@ var LibraryEmbind = {
     var args = [rawConstructor];
     var destructors = [];
 
-    whenDependentTypesAreResolved([], [rawClassType], function(classType) {
+    whenDependentTypesAreResolved([], [rawClassType], (classType) => {
       classType = classType[0];
       var humanName = `constructor ${classType.name}`;
 
@@ -1938,7 +1938,7 @@ var LibraryEmbind = {
     methodName = getFunctionName(methodName);
     rawInvoker = embind__requireFunction(invokerSignature, rawInvoker);
 
-    whenDependentTypesAreResolved([], [rawClassType], function(classType) {
+    whenDependentTypesAreResolved([], [rawClassType], (classType) => {
       classType = classType[0];
       var humanName = `${classType.name}.${methodName}`;
 
@@ -1969,11 +1969,13 @@ var LibraryEmbind = {
         proto[methodName].overloadTable[argCount - 2] = unboundTypesHandler;
       }
 
-      whenDependentTypesAreResolved([], rawArgTypes, function(argTypes) {
+      whenDependentTypesAreResolved([], rawArgTypes, (argTypes) => {
         var memberFunction = craftInvokerFunction(humanName, argTypes, classType, rawInvoker, context, isAsync);
 
-        // Replace the initial unbound-handler-stub function with the appropriate member function, now that all types
-        // are resolved. If multiple overloads are registered for this function, the function goes into an overload table.
+        // Replace the initial unbound-handler-stub function with the
+        // appropriate member function, now that all types are resolved. If
+        // multiple overloads are registered for this function, the function
+        // goes into an overload table.
         if (undefined === proto[methodName].overloadTable) {
           // Set argCount in case an overload is registered later
           memberFunction.argCount = argCount - 2;
@@ -2005,7 +2007,7 @@ var LibraryEmbind = {
     fieldName = readLatin1String(fieldName);
     getter = embind__requireFunction(getterSignature, getter);
 
-    whenDependentTypesAreResolved([], [classType], function(classType) {
+    whenDependentTypesAreResolved([], [classType], (classType) => {
       classType = classType[0];
       var humanName = `${classType.name}.${fieldName}`;
       var desc = {
@@ -2026,7 +2028,7 @@ var LibraryEmbind = {
       whenDependentTypesAreResolved(
         [],
         (setter ? [getterReturnType, setterArgumentType] : [getterReturnType]),
-    function(types) {
+      (types) => {
         var getterReturnType = types[0];
         var desc = {
           get() {
@@ -2071,7 +2073,7 @@ var LibraryEmbind = {
     methodName = readLatin1String(methodName);
     methodName = getFunctionName(methodName);
     rawInvoker = embind__requireFunction(invokerSignature, rawInvoker);
-    whenDependentTypesAreResolved([], [rawClassType], function(classType) {
+    whenDependentTypesAreResolved([], [rawClassType], (classType) => {
       classType = classType[0];
       var humanName = `${classType.name}.${methodName}`;
 
@@ -2095,7 +2097,7 @@ var LibraryEmbind = {
         proto[methodName].overloadTable[argCount-1] = unboundTypesHandler;
       }
 
-      whenDependentTypesAreResolved([], rawArgTypes, function(argTypes) {
+      whenDependentTypesAreResolved([], rawArgTypes, (argTypes) => {
         // Replace the initial unbound-types-handler stub with the proper
         // function. If multiple overloads are registered, the function handlers
         // go into an overload table.
@@ -2138,7 +2140,7 @@ var LibraryEmbind = {
     fieldName = readLatin1String(fieldName);
     getter = embind__requireFunction(getterSignature, getter);
 
-    whenDependentTypesAreResolved([], [rawClassType], function(classType) {
+    whenDependentTypesAreResolved([], [rawClassType], (classType) => {
       classType = classType[0];
       var humanName = `${classType.name}.${fieldName}`;
       var desc = {
@@ -2160,7 +2162,7 @@ var LibraryEmbind = {
 
       Object.defineProperty(classType.registeredClass.constructor, fieldName, desc);
 
-      whenDependentTypesAreResolved([], [rawFieldType], function(fieldType) {
+      whenDependentTypesAreResolved([], [rawFieldType], (fieldType) => {
         fieldType = fieldType[0];
         var desc = {
           get() {
@@ -2282,7 +2284,7 @@ var LibraryEmbind = {
     rawShare = embind__requireFunction(shareSignature, rawShare);
     rawDestructor = embind__requireFunction(destructorSignature, rawDestructor);
 
-    whenDependentTypesAreResolved([rawType], [rawPointeeType], function(pointeeType) {
+    whenDependentTypesAreResolved([rawType], [rawPointeeType], (pointeeType) => {
       pointeeType = pointeeType[0];
 
       var registeredPointer = new RegisteredPointer(name,
@@ -2342,7 +2344,7 @@ var LibraryEmbind = {
   _embind_register_constant__deps: ['$readLatin1String', '$whenDependentTypesAreResolved'],
   _embind_register_constant: (name, type, value) => {
     name = readLatin1String(name);
-    whenDependentTypesAreResolved([], [type], function(type) {
+    whenDependentTypesAreResolved([], [type], (type) => {
       type = type[0];
       Module[name] = type['fromWireType'](value);
       return [];

src/embind/embind_shared.js

@@ -153,9 +153,9 @@ var LibraryEmbindShared = {
   $heap32VectorToArray: (count, firstElement) => {
     var array = [];
     for (var i = 0; i < count; i++) {
-        // TODO(https://github.com/emscripten-core/emscripten/issues/17310):
-        // Find a way to hoist the `>> 2` or `>> 3` out of this loop.
-        array.push({{{ makeGetValue('firstElement', `i * ${POINTER_SIZE}`, '*') }}});
+      // TODO(https://github.com/emscripten-core/emscripten/issues/17310):
+      // Find a way to hoist the `>> 2` or `>> 3` out of this loop.
+      array.push({{{ makeGetValue('firstElement', `i * ${POINTER_SIZE}`, '*') }}});
     }
     return array;
   },
@@ -165,14 +165,16 @@ var LibraryEmbindShared = {
   $requireRegisteredType: (rawType, humanName) => {
     var impl = registeredTypes[rawType];
     if (undefined === impl) {
-        throwBindingError(humanName + " has unknown type " + getTypeName(rawType));
+      throwBindingError(`${humanName} has unknown type ${getTypeName(rawType)}`);
     }
     return impl;
   },
 
   $usesDestructorStack(argTypes) {
-    for (var i = 1; i < argTypes.length; ++i) { // Skip return value at index 0 - it's not deleted here.
-      if (argTypes[i] !== null && argTypes[i].destructorFunction === undefined) { // The type does not define a destructor function - must use dynamic stack
+    // Skip return value at index 0 - it's not deleted here.
+    for (var i = 1; i < argTypes.length; ++i) {
+      // The type does not define a destructor function - must use dynamic stack
+      if (argTypes[i] !== null && argTypes[i].destructorFunction === undefined) {
         return true;
       }
     }
@@ -252,11 +254,12 @@ var LibraryEmbindShared = {
     invokerFnBody +=
         (returns || isAsync ? "var rv = ":"") + "invoker(fn"+(argsListWired.length>0?", ":"")+argsListWired+");\n";
 
+    var returnVal = returns ? "rv" : "";
 #if ASYNCIFY == 1
     args1.push("Asyncify");
 #endif
 #if ASYNCIFY
-    invokerFnBody += "function onDone(" + (returns ? "rv" : "") + ") {\n";
+    invokerFnBody += `function onDone(${returnVal}) {\n`;
 #endif
 
     if (needsDestructorStack) {
@@ -265,8 +268,8 @@ var LibraryEmbindShared = {
       for (var i = isClassMethodFunc?1:2; i < argTypes.length; ++i) { // Skip return value at index 0 - it's not deleted here. Also skip class type if not a method.
         var paramName = (i === 1 ? "thisWired" : ("arg"+(i - 2)+"Wired"));
         if (argTypes[i].destructorFunction !== null) {
-          invokerFnBody += paramName+"_dtor("+paramName+");\n";
-          args1.push(paramName+"_dtor");
+          invokerFnBody += `${paramName}_dtor(${paramName});\n`;
+          args1.push(`${paramName}_dtor`);
         }
       }
     }
@@ -285,10 +288,10 @@ var LibraryEmbindShared = {
 
 #if ASYNCIFY == 1
     invokerFnBody += "}\n";
-    invokerFnBody += "return Asyncify.currData ? Asyncify.whenDone().then(onDone) : onDone(" + (returns ? "rv" : "") +");\n"
+    invokerFnBody += `return Asyncify.currData ? Asyncify.whenDone().then(onDone) : onDone(${returnVal});\n`
 #elif ASYNCIFY == 2
     invokerFnBody += "}\n";
-    invokerFnBody += "return " + (isAsync ? "rv.then(onDone)" : "onDone(" + (returns ? "rv" : "") + ")") + ";";
+    invokerFnBody += "return " + (isAsync ? "rv.then(onDone)" : `onDone(${returnVal})`) + ";";
 #endif
 
     invokerFnBody += "}\n";

src/library_ccall.js

@@ -143,8 +143,6 @@ addToLibrary({
       return getCFunc(ident);
     }
 #endif
-    return function() {
-      return ccall(ident, returnType, argTypes, arguments, opts);
-    }
+    return (...args) => ccall(ident, returnType, argTypes, args, opts);
   },
 });