perf(compiler-cli): optimize computation of type-check scope information (#38539)

When type-checking a component, the declaring NgModule scope is used
to create a directive matcher that contains flattened directive metadata,
i.e. the metadata of a directive and its base classes. This computation
is done for all components, whereas the type-check scope is constant per
NgModule. Additionally, the flattening of metadata is constant per
directive instance so doesn't necessarily have to be recomputed for
each component.

This commit introduces a `TypeCheckScopes` class that is responsible
for flattening directives and computing the scope per NgModule. It
caches the computed results as appropriate to avoid repeated computation.

PR Close #38539

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

@@ -16,7 +16,6 @@ import {DefaultImportRecorder, ModuleResolver, Reference, ReferenceEmitter} from
 import {DependencyTracker} from '../../incremental/api';
 import {IndexingContext} from '../../indexer';
 import {ClassPropertyMapping, DirectiveMeta, DirectiveTypeCheckMeta, extractDirectiveTypeCheckMeta, InjectableClassRegistry, MetadataReader, MetadataRegistry} from '../../metadata';
-import {flattenInheritedDirectiveMetadata} from '../../metadata/src/inheritance';
 import {EnumValue, PartialEvaluator} from '../../partial_evaluator';
 import {ClassDeclaration, Decorator, ReflectionHost, reflectObjectLiteral} from '../../reflection';
 import {ComponentScopeReader, LocalModuleScopeRegistry} from '../../scope';
@@ -31,6 +30,7 @@ import {createValueHasWrongTypeError, getDirectiveDiagnostics, getProviderDiagno
 import {extractDirectiveMetadata, parseFieldArrayValue} from './directive';
 import {compileNgFactoryDefField} from './factory';
 import {generateSetClassMetadataCall} from './metadata';
+import {TypeCheckScopes} from './typecheck_scopes';
 import {findAngularDecorator, isAngularCoreReference, isExpressionForwardReference, readBaseClass, resolveProvidersRequiringFactory, unwrapExpression, wrapFunctionExpressionsInParens} from './util';
 
 const EMPTY_MAP = new Map<string, Expression>();
@@ -95,6 +95,7 @@ export class ComponentDecoratorHandler implements
 
   private literalCache = new Map<Decorator, ts.ObjectLiteralExpression>();
   private elementSchemaRegistry = new DomElementSchemaRegistry();
+  private typeCheckScopes = new TypeCheckScopes(this.scopeReader, this.metaReader);
 
   /**
    * During the asynchronous preanalyze phase, it's necessary to parse the template to extract
@@ -423,36 +424,15 @@ export class ComponentDecoratorHandler implements
       return;
     }
 
-    const matcher = new SelectorMatcher<DirectiveMeta>();
-    const pipes = new Map<string, Reference<ClassDeclaration<ts.ClassDeclaration>>>();
-    let schemas: SchemaMetadata[] = [];
-
-    const scope = this.scopeReader.getScopeForComponent(node);
+    const scope = this.typeCheckScopes.getTypeCheckScope(node);
     if (scope === 'error') {
       // Don't type-check components that had errors in their scopes.
       return;
     }
 
-    if (scope !== null) {
-      for (const meta of scope.compilation.directives) {
-        if (meta.selector !== null) {
-          const extMeta = flattenInheritedDirectiveMetadata(this.metaReader, meta.ref);
-          matcher.addSelectables(CssSelector.parse(meta.selector), extMeta);
-        }
-      }
-      for (const {name, ref} of scope.compilation.pipes) {
-        if (!ts.isClassDeclaration(ref.node)) {
-          throw new Error(`Unexpected non-class declaration ${
-              ts.SyntaxKind[ref.node.kind]} for pipe ${ref.debugName}`);
-        }
-        pipes.set(name, ref as Reference<ClassDeclaration<ts.ClassDeclaration>>);
-      }
-      schemas = scope.schemas;
-    }
-
-    const binder = new R3TargetBinder(matcher);
+    const binder = new R3TargetBinder(scope.matcher);
     ctx.addTemplate(
-        new Reference(node), binder, meta.template.diagNodes, pipes, schemas,
+        new Reference(node), binder, meta.template.diagNodes, scope.pipes, scope.schemas,
         meta.template.sourceMapping, meta.template.file);
   }
 

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

@@ -0,0 +1,105 @@
+/**
+ * @license
+ * Copyright Google LLC 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 {CssSelector, SchemaMetadata, SelectorMatcher} from '@angular/compiler';
+import * as ts from 'typescript';
+
+import {Reference} from '../../imports';
+import {DirectiveMeta, flattenInheritedDirectiveMetadata, MetadataReader} from '../../metadata';
+import {ClassDeclaration} from '../../reflection';
+import {ComponentScopeReader} from '../../scope';
+
+/**
+ * The scope that is used for type-check code generation of a component template.
+ */
+export interface TypeCheckScope {
+  /**
+   * A `SelectorMatcher` instance that contains the flattened directive metadata of all directives
+   * that are in the compilation scope of the declaring NgModule.
+   */
+  matcher: SelectorMatcher<DirectiveMeta>;
+
+  /**
+   * The pipes that are available in the compilation scope.
+   */
+  pipes: Map<string, Reference<ClassDeclaration<ts.ClassDeclaration>>>;
+
+  /**
+   * The schemas that are used in this scope.
+   */
+  schemas: SchemaMetadata[];
+}
+
+/**
+ * Computes scope information to be used in template type checking.
+ */
+export class TypeCheckScopes {
+  /**
+   * Cache of flattened directive metadata. Because flattened metadata is scope-invariant it's
+   * cached individually, such that all scopes refer to the same flattened metadata.
+   */
+  private flattenedDirectiveMetaCache = new Map<ClassDeclaration, DirectiveMeta>();
+
+  /**
+   * Cache of the computed type check scope per NgModule declaration.
+   */
+  private scopeCache = new Map<ClassDeclaration, TypeCheckScope>();
+
+  constructor(private scopeReader: ComponentScopeReader, private metaReader: MetadataReader) {}
+
+  /**
+   * Computes the type-check scope information for the component declaration. If the NgModule
+   * contains an error, then 'error' is returned. If the component is not declared in any NgModule,
+   * an empty type-check scope is returned.
+   */
+  getTypeCheckScope(node: ClassDeclaration): TypeCheckScope|'error' {
+    const matcher = new SelectorMatcher<DirectiveMeta>();
+    const pipes = new Map<string, Reference<ClassDeclaration<ts.ClassDeclaration>>>();
+
+    const scope = this.scopeReader.getScopeForComponent(node);
+    if (scope === null) {
+      return {matcher, pipes, schemas: []};
+    } else if (scope === 'error') {
+      return scope;
+    }
+
+    if (this.scopeCache.has(scope.ngModule)) {
+      return this.scopeCache.get(scope.ngModule)!;
+    }
+
+    for (const meta of scope.compilation.directives) {
+      if (meta.selector !== null) {
+        const extMeta = this.getInheritedDirectiveMetadata(meta.ref);
+        matcher.addSelectables(CssSelector.parse(meta.selector), extMeta);
+      }
+    }
+
+    for (const {name, ref} of scope.compilation.pipes) {
+      if (!ts.isClassDeclaration(ref.node)) {
+        throw new Error(`Unexpected non-class declaration ${
+            ts.SyntaxKind[ref.node.kind]} for pipe ${ref.debugName}`);
+      }
+      pipes.set(name, ref as Reference<ClassDeclaration<ts.ClassDeclaration>>);
+    }
+
+    const typeCheckScope: TypeCheckScope = {matcher, pipes, schemas: scope.schemas};
+    this.scopeCache.set(scope.ngModule, typeCheckScope);
+    return typeCheckScope;
+  }
+
+  private getInheritedDirectiveMetadata(ref: Reference<ClassDeclaration>): DirectiveMeta {
+    const clazz = ref.node;
+    if (this.flattenedDirectiveMetaCache.has(clazz)) {
+      return this.flattenedDirectiveMetaCache.get(clazz)!;
+    }
+
+    const meta = flattenInheritedDirectiveMetadata(this.metaReader, ref);
+    this.flattenedDirectiveMetaCache.set(clazz, meta);
+    return meta;
+  }
+}

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

@@ -8,6 +8,7 @@
 
 export * from './src/api';
 export {DtsMetadataReader} from './src/dts';
+export {flattenInheritedDirectiveMetadata} from './src/inheritance';
 export {CompoundMetadataRegistry, LocalMetadataRegistry, InjectableClassRegistry} from './src/registry';
 export {extractDirectiveTypeCheckMeta, CompoundMetadataReader} from './src/util';
 export {BindingPropertyName, ClassPropertyMapping, ClassPropertyName, InputOrOutput} from './src/property_mapping';

packages/compiler-cli/src/ngtsc/metadata/src/inheritance.ts

@@ -26,6 +26,9 @@ export function flattenInheritedDirectiveMetadata(
   if (topMeta === null) {
     throw new Error(`Metadata not found for directive: ${dir.debugName}`);
   }
+  if (topMeta.baseClass === null) {
+    return topMeta;
+  }
 
   const coercedInputFields = new Set<ClassPropertyName>();
   const undeclaredInputFields = new Set<ClassPropertyName>();

packages/compiler-cli/src/ngtsc/scope/src/local.ts

@@ -26,6 +26,7 @@ export interface LocalNgModuleData {
 }
 
 export interface LocalModuleScope extends ExportScope {
+  ngModule: ClassDeclaration;
   compilation: ScopeData;
   reexports: Reexport[]|null;
   schemas: SchemaMetadata[];
@@ -433,7 +434,8 @@ export class LocalModuleScopeRegistry implements MetadataRegistry, ComponentScop
     }
 
     // Finally, produce the `LocalModuleScope` with both the compilation and export scopes.
-    const scope = {
+    const scope: LocalModuleScope = {
+      ngModule: ngModule.ref.node,
       compilation: {
         directives: Array.from(compilationDirectives.values()),
         pipes: Array.from(compilationPipes.values()),