Skip parsing JSDoc when not needed (#52921)

Co-authored-by: Nathan Shively-Sanders <[email protected]>
Co-authored-by: Sheetal Nandi <[email protected]>

Author: 3 people

src/compiler/parser.ts

@@ -1324,7 +1324,10 @@ function setExternalModuleIndicator(sourceFile: SourceFile) {
     sourceFile.externalModuleIndicator = isFileProbablyExternalModule(sourceFile);
 }
 
-export function createSourceFile(fileName: string, sourceText: string, languageVersionOrOptions: ScriptTarget | CreateSourceFileOptions, setParentNodes = false, scriptKind?: ScriptKind): SourceFile {
+export function createSourceFile(fileName: string, sourceText: string, languageVersionOrOptions: ScriptTarget | CreateSourceFileOptions, setParentNodes?: boolean, scriptKind?: ScriptKind): SourceFile;
+/** @internal */
+export function createSourceFile(fileName: string, sourceText: string, languageVersionOrOptions: ScriptTarget | CreateSourceFileOptions, setParentNodes?: boolean, scriptKind?: ScriptKind, skipNonSemanticJSDoc?: boolean): SourceFile;
+export function createSourceFile(fileName: string, sourceText: string, languageVersionOrOptions: ScriptTarget | CreateSourceFileOptions, setParentNodes = false, scriptKind?: ScriptKind, skipNonSemanticJSDoc?: boolean): SourceFile {
     tracing?.push(tracing.Phase.Parse, "createSourceFile", { path: fileName }, /*separateBeginAndEnd*/ true);
     performance.mark("beforeParse");
     let result: SourceFile;
@@ -1336,14 +1339,14 @@ export function createSourceFile(fileName: string, sourceText: string, languageV
         impliedNodeFormat: format,
     } = typeof languageVersionOrOptions === "object" ? languageVersionOrOptions : ({ languageVersion: languageVersionOrOptions } as CreateSourceFileOptions);
     if (languageVersion === ScriptTarget.JSON) {
-        result = Parser.parseSourceFile(fileName, sourceText, languageVersion, /*syntaxCursor*/ undefined, setParentNodes, ScriptKind.JSON, noop);
+        result = Parser.parseSourceFile(fileName, sourceText, languageVersion, /*syntaxCursor*/ undefined, setParentNodes, ScriptKind.JSON, noop, skipNonSemanticJSDoc);
     }
     else {
         const setIndicator = format === undefined ? overrideSetExternalModuleIndicator : (file: SourceFile) => {
             file.impliedNodeFormat = format;
             return (overrideSetExternalModuleIndicator || setExternalModuleIndicator)(file);
         };
-        result = Parser.parseSourceFile(fileName, sourceText, languageVersion, /*syntaxCursor*/ undefined, setParentNodes, scriptKind, setIndicator);
+        result = Parser.parseSourceFile(fileName, sourceText, languageVersion, /*syntaxCursor*/ undefined, setParentNodes, scriptKind, setIndicator, skipNonSemanticJSDoc);
     }
     perfLogger?.logStopParseSourceFile();
 
@@ -1575,7 +1578,16 @@ namespace Parser {
     var parseErrorBeforeNextFinishedNode = false;
     /* eslint-enable no-var */
 
-    export function parseSourceFile(fileName: string, sourceText: string, languageVersion: ScriptTarget, syntaxCursor: IncrementalParser.SyntaxCursor | undefined, setParentNodes = false, scriptKind?: ScriptKind, setExternalModuleIndicatorOverride?: (file: SourceFile) => void): SourceFile {
+    export function parseSourceFile(
+        fileName: string,
+        sourceText: string,
+        languageVersion: ScriptTarget,
+        syntaxCursor: IncrementalParser.SyntaxCursor | undefined,
+        setParentNodes = false,
+        scriptKind?: ScriptKind,
+        setExternalModuleIndicatorOverride?: (file: SourceFile) => void,
+        skipNonSemanticJSDoc?: boolean,
+    ): SourceFile {
         scriptKind = ensureScriptKind(fileName, scriptKind);
         if (scriptKind === ScriptKind.JSON) {
             const result = parseJsonText(fileName, sourceText, languageVersion, syntaxCursor, setParentNodes);
@@ -1589,9 +1601,10 @@ namespace Parser {
             return result;
         }
 
-        initializeState(fileName, sourceText, languageVersion, syntaxCursor, scriptKind);
+        skipNonSemanticJSDoc = !!skipNonSemanticJSDoc && scriptKind !== ScriptKind.JS && scriptKind !== ScriptKind.JSX;
+        initializeState(fileName, sourceText, languageVersion, syntaxCursor, scriptKind, skipNonSemanticJSDoc);
 
-        const result = parseSourceFileWorker(languageVersion, setParentNodes, scriptKind, setExternalModuleIndicatorOverride || setExternalModuleIndicator);
+        const result = parseSourceFileWorker(languageVersion, setParentNodes, scriptKind, setExternalModuleIndicatorOverride || setExternalModuleIndicator, skipNonSemanticJSDoc);
 
         clearState();
 
@@ -1600,7 +1613,7 @@ namespace Parser {
 
     export function parseIsolatedEntityName(content: string, languageVersion: ScriptTarget): EntityName | undefined {
         // Choice of `isDeclarationFile` should be arbitrary
-        initializeState("", content, languageVersion, /*syntaxCursor*/ undefined, ScriptKind.JS);
+        initializeState("", content, languageVersion, /*syntaxCursor*/ undefined, ScriptKind.JS, /*skipNonSemanticJSDoc*/ false);
         // Prime the scanner.
         nextToken();
         const entityName = parseEntityName(/*allowReservedWords*/ true);
@@ -1610,7 +1623,7 @@ namespace Parser {
     }
 
     export function parseJsonText(fileName: string, sourceText: string, languageVersion: ScriptTarget = ScriptTarget.ES2015, syntaxCursor?: IncrementalParser.SyntaxCursor, setParentNodes = false): JsonSourceFile {
-        initializeState(fileName, sourceText, languageVersion, syntaxCursor, ScriptKind.JSON);
+        initializeState(fileName, sourceText, languageVersion, syntaxCursor, ScriptKind.JSON, /*skipNonSemanticJSDoc*/ false);
         sourceFlags = contextFlags;
 
         // Prime the scanner.
@@ -1698,7 +1711,7 @@ namespace Parser {
         return result;
     }
 
-    function initializeState(_fileName: string, _sourceText: string, _languageVersion: ScriptTarget, _syntaxCursor: IncrementalParser.SyntaxCursor | undefined, _scriptKind: ScriptKind) {
+    function initializeState(_fileName: string, _sourceText: string, _languageVersion: ScriptTarget, _syntaxCursor: IncrementalParser.SyntaxCursor | undefined, _scriptKind: ScriptKind, _skipNonSemanticJSDoc: boolean) {
         NodeConstructor = objectAllocator.getNodeConstructor();
         TokenConstructor = objectAllocator.getTokenConstructor();
         IdentifierConstructor = objectAllocator.getIdentifierConstructor();
@@ -1739,13 +1752,15 @@ namespace Parser {
         scanner.setOnError(scanError);
         scanner.setScriptTarget(languageVersion);
         scanner.setLanguageVariant(languageVariant);
+        scanner.setSkipNonSemanticJSDoc(_skipNonSemanticJSDoc);
     }
 
     function clearState() {
         // Clear out the text the scanner is pointing at, so it doesn't keep anything alive unnecessarily.
         scanner.clearCommentDirectives();
         scanner.setText("");
         scanner.setOnError(undefined);
+        scanner.setSkipNonSemanticJSDoc(false);
 
         // Clear any data.  We don't want to accidentally hold onto it for too long.
         sourceText = undefined!;
@@ -1762,7 +1777,7 @@ namespace Parser {
         topLevel = true;
     }
 
-    function parseSourceFileWorker(languageVersion: ScriptTarget, setParentNodes: boolean, scriptKind: ScriptKind, setExternalModuleIndicator: (file: SourceFile) => void): SourceFile {
+    function parseSourceFileWorker(languageVersion: ScriptTarget, setParentNodes: boolean, scriptKind: ScriptKind, setExternalModuleIndicator: (file: SourceFile) => void, skipNonSemanticJSDoc: boolean): SourceFile {
         const isDeclarationFile = isDeclarationFileName(fileName);
         if (isDeclarationFile) {
             contextFlags |= NodeFlags.Ambient;
@@ -1789,6 +1804,7 @@ namespace Parser {
         sourceFile.identifierCount = identifierCount;
         sourceFile.identifiers = identifiers;
         sourceFile.parseDiagnostics = attachFileToDiagnostics(parseDiagnostics, sourceFile);
+        sourceFile.skipNonSemanticJSDoc = skipNonSemanticJSDoc;
         if (jsDocDiagnostics) {
             sourceFile.jsDocDiagnostics = attachFileToDiagnostics(jsDocDiagnostics, sourceFile);
         }
@@ -8670,7 +8686,7 @@ namespace Parser {
 
     export namespace JSDocParser {
         export function parseJSDocTypeExpressionForTests(content: string, start: number | undefined, length: number | undefined): { jsDocTypeExpression: JSDocTypeExpression; diagnostics: Diagnostic[]; } | undefined {
-            initializeState("file.js", content, ScriptTarget.Latest, /*syntaxCursor*/ undefined, ScriptKind.JS);
+            initializeState("file.js", content, ScriptTarget.Latest, /*syntaxCursor*/ undefined, ScriptKind.JS, /*skipNonSemanticJSDoc*/ false);
             scanner.setText(content, start, length);
             currentToken = scanner.scan();
             const jsDocTypeExpression = parseJSDocTypeExpression();
@@ -8720,7 +8736,7 @@ namespace Parser {
         }
 
         export function parseIsolatedJSDocComment(content: string, start: number | undefined, length: number | undefined): { jsDoc: JSDoc; diagnostics: Diagnostic[]; } | undefined {
-            initializeState("", content, ScriptTarget.Latest, /*syntaxCursor*/ undefined, ScriptKind.JS);
+            initializeState("", content, ScriptTarget.Latest, /*syntaxCursor*/ undefined, ScriptKind.JS, /*skipNonSemanticJSDoc*/ false);
             const jsDoc = doInsideOfContext(NodeFlags.JSDoc, () => parseJSDocCommentWorker(start, length));
 
             const sourceFile = { languageVariant: LanguageVariant.Standard, text: content } as SourceFile;
@@ -9788,7 +9804,7 @@ namespace IncrementalParser {
         if (sourceFile.statements.length === 0) {
             // If we don't have any statements in the current source file, then there's no real
             // way to incrementally parse.  So just do a full parse instead.
-            return Parser.parseSourceFile(sourceFile.fileName, newText, sourceFile.languageVersion, /*syntaxCursor*/ undefined, /*setParentNodes*/ true, sourceFile.scriptKind, sourceFile.setExternalModuleIndicator);
+            return Parser.parseSourceFile(sourceFile.fileName, newText, sourceFile.languageVersion, /*syntaxCursor*/ undefined, /*setParentNodes*/ true, sourceFile.scriptKind, sourceFile.setExternalModuleIndicator, sourceFile.skipNonSemanticJSDoc);
         }
 
         // Make sure we're not trying to incrementally update a source file more than once.  Once
@@ -9851,7 +9867,7 @@ namespace IncrementalParser {
         // inconsistent tree.  Setting the parents on the new tree should be very fast.  We
         // will immediately bail out of walking any subtrees when we can see that their parents
         // are already correct.
-        const result = Parser.parseSourceFile(sourceFile.fileName, newText, sourceFile.languageVersion, syntaxCursor, /*setParentNodes*/ true, sourceFile.scriptKind, sourceFile.setExternalModuleIndicator);
+        const result = Parser.parseSourceFile(sourceFile.fileName, newText, sourceFile.languageVersion, syntaxCursor, /*setParentNodes*/ true, sourceFile.scriptKind, sourceFile.setExternalModuleIndicator, sourceFile.skipNonSemanticJSDoc);
         result.commentDirectives = getNewCommentDirectives(
             sourceFile.commentDirectives,
             result.commentDirectives,

src/compiler/program.ts

@@ -402,6 +402,7 @@ export function createGetSourceFile(
     readFile: ProgramHost<any>["readFile"],
     getCompilerOptions: () => CompilerOptions,
     setParentNodes: boolean | undefined,
+    skipNonSemanticJSDocParsing: boolean | undefined,
 ): CompilerHost["getSourceFile"] {
     return (fileName, languageVersionOrOptions, onError) => {
         let text: string | undefined;
@@ -417,7 +418,7 @@ export function createGetSourceFile(
             }
             text = "";
         }
-        return text !== undefined ? createSourceFile(fileName, text, languageVersionOrOptions, setParentNodes) : undefined;
+        return text !== undefined ? createSourceFile(fileName, text, languageVersionOrOptions, setParentNodes, /*scriptKind*/ undefined, skipNonSemanticJSDocParsing) : undefined;
     };
 }
 
@@ -455,7 +456,12 @@ export function createWriteFileMeasuringIO(
 }
 
 /** @internal */
-export function createCompilerHostWorker(options: CompilerOptions, setParentNodes?: boolean, system: System = sys): CompilerHost {
+export function createCompilerHostWorker(
+    options: CompilerOptions,
+    setParentNodes?: boolean,
+    skipNonSemanticJSDocParsing?: boolean,
+    system: System = sys,
+): CompilerHost {
     const existingDirectories = new Map<string, boolean>();
     const getCanonicalFileName = createGetCanonicalFileName(system.useCaseSensitiveFileNames);
     function directoryExists(directoryPath: string): boolean {
@@ -476,7 +482,7 @@ export function createCompilerHostWorker(options: CompilerOptions, setParentNode
     const newLine = getNewLineCharacter(options);
     const realpath = system.realpath && ((path: string) => system.realpath!(path));
     const compilerHost: CompilerHost = {
-        getSourceFile: createGetSourceFile(fileName => compilerHost.readFile(fileName), () => options, setParentNodes),
+        getSourceFile: createGetSourceFile(fileName => compilerHost.readFile(fileName), () => options, setParentNodes, skipNonSemanticJSDocParsing),
         getDefaultLibLocation,
         getDefaultLibFileName: options => combinePaths(getDefaultLibLocation(), getDefaultLibFileName(options)),
         writeFile: createWriteFileMeasuringIO(

src/compiler/scanner.ts

@@ -114,6 +114,8 @@ export interface Scanner {
     // callback returns something truthy, then the scanner state is not rolled back.  The result
     // of invoking the callback is returned from this function.
     tryScan<T>(callback: () => T): T;
+    /** @internal */
+    setSkipNonSemanticJSDoc(skip: boolean): void;
 }
 
 /** @internal */
@@ -343,6 +345,11 @@ const commentDirectiveRegExSingleLine = /^\/\/\/?\s*@(ts-expect-error|ts-ignore)
  */
 const commentDirectiveRegExMultiLine = /^(?:\/|\*)*\s*@(ts-expect-error|ts-ignore)/;
 
+/**
+ * Test for whether a comment contains a JSDoc tag needed by the checker when run in tsc.
+ */
+const semanticJSDocTagRegEx = /@(?:see|link)/i;
+
 function lookupInUnicodeMap(code: number, map: readonly number[]): boolean {
     // Bail out quickly if it couldn't possibly be in the map.
     if (code < map[0]) {
@@ -1001,6 +1008,8 @@ export function createScanner(languageVersion: ScriptTarget, skipTrivia: boolean
     var commentDirectives: CommentDirective[] | undefined;
     var inJSDocType = 0;
 
+    var skipNonSemanticJSDoc = false;
+
     setText(text, start, length);
 
     var scanner: Scanner = {
@@ -1052,6 +1061,7 @@ export function createScanner(languageVersion: ScriptTarget, skipTrivia: boolean
         tryScan,
         lookAhead,
         scanRange,
+        setSkipNonSemanticJSDoc,
     };
     /* eslint-enable no-var */
 
@@ -1971,9 +1981,7 @@ export function createScanner(languageVersion: ScriptTarget, skipTrivia: boolean
                     // Multi-line comment
                     if (text.charCodeAt(pos + 1) === CharacterCodes.asterisk) {
                         pos += 2;
-                        if (text.charCodeAt(pos) === CharacterCodes.asterisk && text.charCodeAt(pos + 1) !== CharacterCodes.slash) {
-                            tokenFlags |= TokenFlags.PrecedingJSDocComment;
-                        }
+                        const isJSDoc = text.charCodeAt(pos) === CharacterCodes.asterisk && text.charCodeAt(pos + 1) !== CharacterCodes.slash;
 
                         let commentClosed = false;
                         let lastLineStart = tokenStart;
@@ -1994,6 +2002,10 @@ export function createScanner(languageVersion: ScriptTarget, skipTrivia: boolean
                             }
                         }
 
+                        if (isJSDoc && (!skipNonSemanticJSDoc || semanticJSDocTagRegEx.test(text.slice(fullStartPos, pos)))) {
+                            tokenFlags |= TokenFlags.PrecedingJSDocComment;
+                        }
+
                         commentDirectives = appendIfCommentDirective(commentDirectives, text.slice(lastLineStart, pos), commentDirectiveRegExMultiLine, lastLineStart);
 
                         if (!commentClosed) {
@@ -2775,6 +2787,10 @@ export function createScanner(languageVersion: ScriptTarget, skipTrivia: boolean
         languageVariant = variant;
     }
 
+    function setSkipNonSemanticJSDoc(skip: boolean) {
+        skipNonSemanticJSDoc = skip;
+    }
+
     function resetTokenState(position: number) {
         Debug.assert(position >= 0);
         pos = position;

src/compiler/types.ts

@@ -4297,6 +4297,8 @@ export interface SourceFile extends Declaration, LocalsContainer {
 
     /** @internal */ exportedModulesFromDeclarationEmit?: ExportedModulesFromDeclarationEmit;
     /** @internal */ endFlowNode?: FlowNode;
+
+    /** @internal */ skipNonSemanticJSDoc?: boolean;
 }
 
 /** @internal */

src/compiler/watch.ts

@@ -746,6 +746,7 @@ export function createCompilerHostFromProgramHost(host: ProgramHost<any>, getCom
             (fileName, encoding) => !encoding ? compilerHost.readFile(fileName) : host.readFile(fileName, encoding),
             getCompilerOptions,
             /*setParentNodes*/ undefined,
+            host.skipNonSemanticJSDocParsing,
         ),
         getDefaultLibLocation: maybeBind(host, host.getDefaultLibLocation),
         getDefaultLibFileName: options => host.getDefaultLibFileName(options),

src/compiler/watchPublic.ts

@@ -118,8 +118,11 @@ export function readBuilderProgram(compilerOptions: CompilerOptions, host: ReadB
     return createBuilderProgramUsingProgramBuildInfo(buildInfo, buildInfoPath, host);
 }
 
-export function createIncrementalCompilerHost(options: CompilerOptions, system = sys): CompilerHost {
-    const host = createCompilerHostWorker(options, /*setParentNodes*/ undefined, system);
+export function createIncrementalCompilerHost(options: CompilerOptions, system?: System): CompilerHost;
+/** @internal */
+export function createIncrementalCompilerHost(options: CompilerOptions, system?: System, skipNonSemanticJSDocParsing?: boolean): CompilerHost;
+export function createIncrementalCompilerHost(options: CompilerOptions, system = sys, skipNonSemanticJSDocParsing?: boolean): CompilerHost {
+    const host = createCompilerHostWorker(options, /*setParentNodes*/ undefined, skipNonSemanticJSDocParsing, system);
     host.createHash = maybeBind(system, system.createHash);
     host.storeFilesChangingSignatureDuringEmit = system.storeFilesChangingSignatureDuringEmit;
     setGetSourceFileAsHashVersioned(host);
@@ -254,6 +257,13 @@ export interface ProgramHost<T extends BuilderProgram> {
      * Returns the module resolution cache used by a provided `resolveModuleNames` implementation so that any non-name module resolution operations (eg, package.json lookup) can reuse it
      */
     getModuleResolutionCache?(): ModuleResolutionCache | undefined;
+
+    /**
+     * True if it's safe for the parser to skip parsing non-semantic JSDoc tags.
+     *
+     * @internal
+     */
+    skipNonSemanticJSDocParsing?: boolean;
 }
 /**
  * Internal interface used to wire emit through same host