Backout Generate Custom Native State from Codegen

Summary:
This is the second diffs that backs out the Custom Native State from the Codegen. The reason why we are backing it out are:

1. It forces users to create new types in JS that are not ctually used there. For example, the NativeState you define, and eventually exports, in JS is not used anywhere in your JS code.
2. You need to put in the JS native state some types that does not exists in JS, only to have them generated by the Codegen. ImageRequest, for example, does not exists in JS, but you need it in your (iOS) state to load images
3. There are a lot of edge cases due to how C++ handles variables. Some variables needs to be created as pointers. Some others as `const &`. It does not scale to hard code all of them and there is the risk to have the same type that needs to be a pointer in some case and something else in others.
4. It is better to instruct the users on how to properly create a component with Custom State, Shadow Node and Descriptor.

## Changelog:
[General][Removed] - Back out parsing and generation of Custom Native State from Codegen

Reviewed By: cortinico

Differential Revision: D40426134

fbshipit-source-id: c368e122cc31ee8df056fe1bf6cecaab482140a4

packages/react-native-codegen/src/CodegenSchema.js

@@ -80,7 +80,6 @@ export type ComponentShape = $ReadOnly<{
   events: $ReadOnlyArray<EventTypeShape>,
   props: $ReadOnlyArray<NamedShape<PropTypeAnnotation>>,
   commands: $ReadOnlyArray<NamedShape<CommandTypeAnnotation>>,
-  state?: $ReadOnlyArray<NamedShape<StateTypeAnnotation>>,
 }>;
 
 export type OptionsShape = $ReadOnly<{
@@ -187,8 +186,6 @@ export type ReservedPropTypeAnnotation = $ReadOnly<{
     | 'ImageRequestPrimitive',
 }>;
 
-export type StateTypeAnnotation = PropTypeAnnotation;
-
 export type CommandTypeAnnotation = FunctionTypeAnnotation<
   CommandParamTypeAnnotation,
   VoidTypeAnnotation,

packages/react-native-codegen/src/generators/components/ComponentsGeneratorUtils.js

@@ -10,11 +10,7 @@
 
 'use strict';
 
-import type {
-  NamedShape,
-  PropTypeAnnotation,
-  StateTypeAnnotation,
-} from '../../CodegenSchema';
+import type {NamedShape, PropTypeAnnotation} from '../../CodegenSchema';
 
 import type {
   StringTypeAnnotation,
@@ -27,7 +23,6 @@ import type {
 } from '../../CodegenSchema';
 
 const {
-  convertDefaultTypeToString,
   getCppTypeForAnnotation,
   getEnumMaskName,
   getEnumName,
@@ -39,7 +34,6 @@ function getNativeTypeFromAnnotation(
   componentName: string,
   prop:
     | NamedShape<PropTypeAnnotation>
-    | NamedShape<StateTypeAnnotation>
     | {
         name: string,
         typeAnnotation:
@@ -133,28 +127,6 @@ function getNativeTypeFromAnnotation(
   }
 }
 
-function getStateConstituents(
-  componentName: string,
-  stateShape: NamedShape<StateTypeAnnotation>,
-): {
-  name: string,
-  varName: string,
-  type: string,
-  defaultValue: $FlowFixMe,
-} {
-  const name = stateShape.name;
-  const varName = `${name}_`;
-  const type = getNativeTypeFromAnnotation(componentName, stateShape, []);
-  const defaultValue = convertDefaultTypeToString(componentName, stateShape);
-
-  return {
-    name,
-    varName,
-    type,
-    defaultValue,
-  };
-}
-
 /// This function process some types if we need to customize them
 /// For example, the ImageSource and the reserved types could be trasformed into
 /// const address instead of using them as plain types.
@@ -239,9 +211,7 @@ const convertVarValueToPointer = (type: string, value: string): string => {
 };
 
 function getLocalImports(
-  properties:
-    | $ReadOnlyArray<NamedShape<PropTypeAnnotation>>
-    | $ReadOnlyArray<NamedShape<StateTypeAnnotation>>,
+  properties: $ReadOnlyArray<NamedShape<PropTypeAnnotation>>,
 ): Set<string> {
   const imports: Set<string> = new Set();
 
@@ -325,7 +295,6 @@ function getLocalImports(
 
 module.exports = {
   getNativeTypeFromAnnotation,
-  getStateConstituents,
   convertCtorParamToAddressType,
   convertGettersReturnTypeToAddressType,
   convertCtorInitToSharedPointers,

packages/react-native-codegen/src/generators/components/GenerateStateCpp.js

@@ -10,27 +10,17 @@
 
 'use strict';
 
-import type {
-  NamedShape,
-  SchemaType,
-  StateTypeAnnotation,
-} from '../../CodegenSchema';
-const {capitalize} = require('../Utils.js');
-const {
-  getStateConstituents,
-  convertGettersReturnTypeToAddressType,
-  convertVarValueToPointer,
-} = require('./ComponentsGeneratorUtils.js');
+import type {NamedShape, SchemaType} from '../../CodegenSchema';
 
 // File path -> contents
 type FilesOutput = Map<string, string>;
 
 const FileTemplate = ({
   libraryName,
-  stateGetters,
+  stateClasses,
 }: {
   libraryName: string,
-  stateGetters: string,
+  stateClasses: string,
 }) => `
 /**
  * This code was generated by [react-native-codegen](https://www.npmjs.com/package/react-native-codegen).
@@ -45,34 +35,13 @@ const FileTemplate = ({
 namespace facebook {
 namespace react {
 
-${stateGetters}
+${stateClasses}
 
 } // namespace react
 } // namespace facebook
 `;
 
-function generateStrings(
-  componentName: string,
-  state: $ReadOnlyArray<NamedShape<StateTypeAnnotation>>,
-) {
-  let getters = '';
-  state.forEach(stateShape => {
-    const {name, varName, type} = getStateConstituents(
-      componentName,
-      stateShape,
-    );
-
-    getters += `
-${convertGettersReturnTypeToAddressType(
-  type,
-)} ${componentName}State::get${capitalize(name)}() const {
-  return ${convertVarValueToPointer(type, varName)};
-}
-`;
-  });
-
-  return getters.trim();
-}
+const StateTemplate = ({stateName}: {stateName: string}) => '';
 
 module.exports = {
   generate(
@@ -83,7 +52,7 @@ module.exports = {
   ): FilesOutput {
     const fileName = 'States.cpp';
 
-    const stateGetters = Object.keys(schema.modules)
+    const stateClasses = Object.keys(schema.modules)
       .map(moduleName => {
         const module = schema.modules[moduleName];
         if (module.type !== 'Component') {
@@ -103,11 +72,9 @@ module.exports = {
               return null;
             }
 
-            const state = component.state;
-            if (!state) {
-              return '';
-            }
-            return generateStrings(componentName, state);
+            return StateTemplate({
+              stateName: `${componentName}State`,
+            });
           })
           .filter(Boolean)
           .join('\n');
@@ -117,7 +84,7 @@ module.exports = {
 
     const replacedTemplate = FileTemplate({
       libraryName,
-      stateGetters,
+      stateClasses,
     });
 
     return new Map([[fileName, replacedTemplate]]);