feat(ivy): register references from NgModule annotations (#26906)

The `NgModuleDecoratorHandler` can now register all the references that
it finds in the `NgModule` metadata, such as `declarations`, `imports`,
`exports` etc.

This information can then be used by ngcc to work out if any of these
references are internal only and need to be manually exported from a
library's entry-point.

PR Close #26906

packages/compiler-cli/src/ngtsc/annotations/index.ts

@@ -15,4 +15,5 @@ export {DirectiveDecoratorHandler} from './src/directive';
 export {InjectableDecoratorHandler} from './src/injectable';
 export {NgModuleDecoratorHandler} from './src/ng_module';
 export {PipeDecoratorHandler} from './src/pipe';
+export {NoopReferencesRegistry, ReferencesRegistry} from './src/references_registry';
 export {CompilationScope, SelectorScopeRegistry} from './src/selector_scope';

packages/compiler-cli/src/ngtsc/annotations/src/ng_module.ts

@@ -15,6 +15,7 @@ import {Reference, ResolvedReference, ResolvedValue, reflectObjectLiteral, stati
 import {AnalysisOutput, CompileResult, DecoratorHandler} from '../../transform';
 
 import {generateSetClassMetadataCall} from './metadata';
+import {ReferencesRegistry} from './references_registry';
 import {SelectorScopeRegistry} from './selector_scope';
 import {getConstructorDependencies, isAngularCore, toR3Reference, unwrapExpression} from './util';
 
@@ -32,7 +33,8 @@ export interface NgModuleAnalysis {
 export class NgModuleDecoratorHandler implements DecoratorHandler<NgModuleAnalysis, Decorator> {
   constructor(
       private checker: ts.TypeChecker, private reflector: ReflectionHost,
-      private scopeRegistry: SelectorScopeRegistry, private isCore: boolean) {}
+      private scopeRegistry: SelectorScopeRegistry, private referencesRegistry: ReferencesRegistry,
+      private isCore: boolean) {}
 
   detect(node: ts.Declaration, decorators: Decorator[]|null): Decorator|undefined {
     if (!decorators) {
@@ -72,6 +74,7 @@ export class NgModuleDecoratorHandler implements DecoratorHandler<NgModuleAnalys
       const expr = ngModule.get('declarations') !;
       const declarationMeta = staticallyResolve(expr, this.reflector, this.checker);
       declarations = this.resolveTypeList(expr, declarationMeta, 'declarations');
+      this.referencesRegistry.add(...declarations);
     }
     let imports: Reference<ts.Declaration>[] = [];
     if (ngModule.has('imports')) {
@@ -80,6 +83,7 @@ export class NgModuleDecoratorHandler implements DecoratorHandler<NgModuleAnalys
           expr, this.reflector, this.checker,
           ref => this._extractModuleFromModuleWithProvidersFn(ref.node));
       imports = this.resolveTypeList(expr, importsMeta, 'imports');
+      this.referencesRegistry.add(...imports);
     }
     let exports: Reference<ts.Declaration>[] = [];
     if (ngModule.has('exports')) {
@@ -88,12 +92,14 @@ export class NgModuleDecoratorHandler implements DecoratorHandler<NgModuleAnalys
           expr, this.reflector, this.checker,
           ref => this._extractModuleFromModuleWithProvidersFn(ref.node));
       exports = this.resolveTypeList(expr, exportsMeta, 'exports');
+      this.referencesRegistry.add(...exports);
     }
     let bootstrap: Reference<ts.Declaration>[] = [];
     if (ngModule.has('bootstrap')) {
       const expr = ngModule.get('bootstrap') !;
       const bootstrapMeta = staticallyResolve(expr, this.reflector, this.checker);
       bootstrap = this.resolveTypeList(expr, bootstrapMeta, 'bootstrap');
+      this.referencesRegistry.add(...bootstrap);
     }
 
     // Register this module's information with the SelectorScopeRegistry. This ensures that during

packages/compiler-cli/src/ngtsc/annotations/src/references_registry.ts

@@ -0,0 +1,39 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import * as ts from 'typescript';
+import {Declaration} from '../../host';
+import {Reference} from '../../metadata';
+
+/**
+ * Implement this interface if you want DecoratorHandlers to register
+ * references that they find in their analysis of the code.
+ */
+export interface ReferencesRegistry {
+  /**
+   * Register one or more references in the registry.
+   * Only `ResolveReference` references are stored. Other types are ignored.
+   * @param references A collection of references to register.
+   */
+  add(...references: Reference<ts.Declaration>[]): void;
+  /**
+   * Create and return a mapping for the registered resolved references.
+   * @returns A map of reference identifiers to reference declarations.
+   */
+  getDeclarationMap(): Map<ts.Identifier, Declaration>;
+}
+
+/**
+ * This registry does nothing, since ngtsc does not currently need
+ * this functionality.
+ * The ngcc tool implements a working version for its purposes.
+ */
+export class NoopReferencesRegistry implements ReferencesRegistry {
+  add(...references: Reference<ts.Declaration>[]): void {}
+  getDeclarationMap(): Map<ts.Identifier, Declaration> { return new Map(); }
+}

packages/compiler-cli/src/ngtsc/program.ts

@@ -13,7 +13,7 @@ import * as ts from 'typescript';
 import * as api from '../transformers/api';
 import {nocollapseHack} from '../transformers/nocollapse_hack';
 
-import {ComponentDecoratorHandler, DirectiveDecoratorHandler, InjectableDecoratorHandler, NgModuleDecoratorHandler, PipeDecoratorHandler, ResourceLoader, SelectorScopeRegistry} from './annotations';
+import {ComponentDecoratorHandler, DirectiveDecoratorHandler, InjectableDecoratorHandler, NgModuleDecoratorHandler, NoopReferencesRegistry, PipeDecoratorHandler, ResourceLoader, SelectorScopeRegistry} from './annotations';
 import {BaseDefDecoratorHandler} from './annotations/src/base_def';
 import {TypeScriptReflectionHost} from './metadata';
 import {FileResourceLoader, HostResourceLoader} from './resource_loader';
@@ -214,6 +214,7 @@ export class NgtscProgram implements api.Program {
   private makeCompilation(): IvyCompilation {
     const checker = this.tsProgram.getTypeChecker();
     const scopeRegistry = new SelectorScopeRegistry(checker, this.reflector);
+    const referencesRegistry = new NoopReferencesRegistry();
 
     // Set up the IvyCompilation, which manages state for the Ivy transformer.
     const handlers = [
@@ -223,7 +224,8 @@ export class NgtscProgram implements api.Program {
           this.options.preserveWhitespaces || false, this.options.i18nUseExternalIds !== false),
       new DirectiveDecoratorHandler(checker, this.reflector, scopeRegistry, this.isCore),
       new InjectableDecoratorHandler(this.reflector, this.isCore),
-      new NgModuleDecoratorHandler(checker, this.reflector, scopeRegistry, this.isCore),
+      new NgModuleDecoratorHandler(
+          checker, this.reflector, scopeRegistry, referencesRegistry, this.isCore),
       new PipeDecoratorHandler(checker, this.reflector, scopeRegistry, this.isCore),
     ];