Adds a flag for Array.prototype method nested optimized functions (#2404)

Summary:
Release notes: adds a `arrayNestedOptimizedFunctionsEnabled` flag to enable nested optimized functions derived from Array.prototype methods (like `map`) and Array.from

This PR puts the existing (unstable) work for Array prototype methods behind a flag. The flag is enabled by default in React and serializer tests.
Pull Request resolved: https://github.com/facebook/prepack/pull/2404

Differential Revision: D9272747

Pulled By: trueadm

fbshipit-source-id: d7e53656a12cd6cff680a9ef0e2580a93d56e34e

scripts/debug-fb-www.js

@@ -74,6 +74,7 @@ let prepackOptions = {
   reactOutput: "jsx",
   reactVerbose: true,
   reactOptimizeNestedFunctions: false,
+  arrayNestedOptimizedFunctionsEnabled: false,
   inlineExpressions: true,
   invariantLevel: 0,
   abstractValueImpliesMax: 1000,

scripts/test-runner.js

@@ -363,7 +363,11 @@ function runTest(name, code, options: PrepackOptions, args) {
     internalDebug: true,
     serialize: true,
     uniqueSuffix: "",
+    arrayNestedOptimizedFunctionsEnabled: false,
   }): any): PrepackOptions); // Since PrepackOptions is an exact type I have to cast
+  if (code.includes("// arrayNestedOptimizedFunctionsEnabled")) {
+    options.arrayNestedOptimizedFunctionsEnabled = true;
+  }
   if (code.includes("// throws introspection error")) {
     try {
       let realmOptions = {

src/options.js

@@ -59,6 +59,7 @@ export type RealmOptions = {
   reactOptimizeNestedFunctions?: boolean,
   stripFlow?: boolean,
   abstractValueImpliesMax?: number,
+  arrayNestedOptimizedFunctionsEnabled?: boolean,
 };
 
 export type SerializerOptions = {

src/prepack-options.js

@@ -61,6 +61,7 @@ export type PrepackOptions = {|
   debuggerConfigArgs?: DebuggerConfigArguments,
   debugReproArgs?: DebugReproArguments,
   onParse?: BabelNodeFile => void,
+  arrayNestedOptimizedFunctionsEnabled?: boolean,
 |};
 
 export function getRealmOptions({
@@ -87,6 +88,7 @@ export function getRealmOptions({
   abstractValueImpliesMax,
   debuggerConfigArgs,
   debugReproArgs,
+  arrayNestedOptimizedFunctionsEnabled,
 }: PrepackOptions): RealmOptions {
   return {
     compatibility,
@@ -112,6 +114,7 @@ export function getRealmOptions({
     abstractValueImpliesMax,
     debuggerConfigArgs,
     debugReproArgs,
+    arrayNestedOptimizedFunctionsEnabled,
   };
 }
 

src/realm.js

@@ -337,6 +337,7 @@ export class Realm {
     this.debugNames = opts.debugNames;
     this._checkedObjectIds = new Map();
     this.optimizedFunctions = new Map();
+    this.arrayNestedOptimizedFunctionsEnabled = opts.arrayNestedOptimizedFunctionsEnabled || false;
   }
 
   statistics: RealmStatistics;
@@ -482,6 +483,7 @@ export class Realm {
   _checkedObjectIds: Map<ObjectValue | AbstractObjectValue, number>;
 
   optimizedFunctions: Map<FunctionValue | AbstractValue, ArgModel | void>;
+  arrayNestedOptimizedFunctionsEnabled: boolean;
 
   // to force flow to type the annotations
   isCompatibleWith(compatibility: Compatibility): boolean {

src/values/ArrayValue.js

@@ -80,7 +80,7 @@ function createArrayWithWidenedNumericProperty(
   let abstractArrayValue = new ArrayValue(realm, intrinsicName);
 
   if (possibleNestedOptimizedFunctions !== undefined) {
-    if (!realm.react.enabled || realm.react.optimizeNestedFunctions) {
+    if (realm.arrayNestedOptimizedFunctionsEnabled && (!realm.react.enabled || realm.react.optimizeNestedFunctions)) {
       evaluatePossibleNestedOptimizedFunctionsAndStoreEffects(
         realm,
         abstractArrayValue,

test/react/setupReactTests.js

@@ -133,6 +133,7 @@ ${source}
       reactEnabled: true,
       reactOutput: useJSXOutput ? "jsx" : "create-element",
       reactOptimizeNestedFunctions: true,
+      arrayNestedOptimizedFunctionsEnabled: true,
       inlineExpressions: true,
       invariantLevel: 0,
       stripFlow: true,

test/serializer/additional-functions/NestedOptimizedFunction17.js

@@ -1,3 +1,5 @@
+// arrayNestedOptimizedFunctionsEnabled
+
 function fn(props, cond, cond2, cond3) {
   var arr = Array.from(props.x);
   var newObj;

test/serializer/optimized-functions/ArrayFrom3.js

@@ -1,3 +1,5 @@
+// arrayNestedOptimizedFunctionsEnabled
+
 function fn(x, y) {
   var edges = Array.from(x);
   var items = edges

test/serializer/optimized-functions/ArrayFrom6.js

@@ -1,4 +1,5 @@
 // does not contain:// this function should be inlined
+// arrayNestedOptimizedFunctionsEnabled
 
 (function() {
   function add(a, b) {

test/serializer/optimized-functions/ArrayFrom7.js

@@ -1,4 +1,5 @@
 // does not contain:// this function should be inlined
+// arrayNestedOptimizedFunctionsEnabled
 
 (function() {
   var obj = {

test/serializer/optimized-functions/ArrayFrom8.js

@@ -1,4 +1,5 @@
 // does contain:// this function should not be inlined
+// arrayNestedOptimizedFunctionsEnabled
 
 (function() {
   var obj = {

test/serializer/optimized-functions/ArrayFrom9.js

@@ -1,4 +1,5 @@
 // does contain:// this function should not be inlined
+// arrayNestedOptimizedFunctionsEnabled
 
 (function() {
   function add(a, b) {

test/serializer/optimized-functions/DefineOptFuncInsideFuncInsideOptFunc.js

@@ -1,3 +1,4 @@
+// arrayNestedOptimizedFunctionsEnabled
 // skip lint
 // The original issue here was that nested is defined inside of fn2 which is a non-optimized function
 // called by fn (an optimized function). That caused Prepack to not detect that nested was nested

test/serializer/optimized-functions/Issue2358.js

@@ -1,3 +1,5 @@
+// arrayNestedOptimizedFunctionsEnabled
+
 function fn(x, y, obj, cond) {
   var arr = Array.from(x);
   var arr2 = Array.from(y);

test/serializer/optimized-functions/Issue2359-1.js

@@ -1,3 +1,5 @@
+// arrayNestedOptimizedFunctionsEnabled
+
 function fn(x, cond, abstractFunc) {
   var arr = Array.from(x);
 

test/serializer/optimized-functions/Issue2392-1.js

@@ -1,3 +1,5 @@
+// arrayNestedOptimizedFunctionsEnabled
+
 function fn(x, obj, cond, cond4) {
   var arr = Array.from(x);
 

test/serializer/optimized-functions/Issue2392-2.js

@@ -1,3 +1,5 @@
+// arrayNestedOptimizedFunctionsEnabled
+
 function fn(x, obj, cond, cond2, cond3, cond4) {
   var arr = Array.from(x);
   var a;

test/serializer/optimized-functions/Issue2398.js

@@ -1,3 +1,5 @@
+// arrayNestedOptimizedFunctionsEnabled
+
 function fn(props, cond) {
   var arr = Array.from(props.x);
   var newObj;