Avoid unnecessary buildInfo read if host supports caching it (avoids in --build scenario) and some reporting cleanup

src/compiler/emitter.ts

@@ -705,17 +705,7 @@ namespace ts {
     /** File that isnt present resulting in error or output files */
     export type EmitUsingBuildInfoResult = string | readonly OutputFile[];
 
-    /*@internal*/
-    export interface EmitUsingBuildInfoHost extends ModuleResolutionHost {
-        getCurrentDirectory(): string;
-        getCanonicalFileName(fileName: string): string;
-        useCaseSensitiveFileNames(): boolean;
-        getNewLine(): string;
-        createHash?(data: string): string;
-        getBuildInfo?(fileName: string, configFilePath: string | undefined): BuildInfo | undefined;
-    }
-
-    function createSourceFilesFromBundleBuildInfo(bundle: BundleBuildInfo, buildInfoDirectory: string, host: EmitUsingBuildInfoHost): readonly SourceFile[] {
+    function createSourceFilesFromBundleBuildInfo(bundle: BundleBuildInfo, buildInfoDirectory: string, host: CompilerHost): readonly SourceFile[] {
         const jsBundle = Debug.checkDefined(bundle.js);
         const prologueMap = jsBundle.sources?.prologues && arrayToMap(jsBundle.sources.prologues, prologueInfo => prologueInfo.file);
         return bundle.sourceFiles.map((fileName, index) => {
@@ -745,22 +735,29 @@ namespace ts {
     /*@internal*/
     export function emitUsingBuildInfo(
         config: ParsedCommandLine,
-        host: EmitUsingBuildInfoHost,
+        host: CompilerHost,
+        getCommandLine: (ref: ProjectReference) => ParsedCommandLine | undefined,
+        customTransformers?: CustomTransformers
+    ): EmitUsingBuildInfoResult {
+        tracing?.push(tracing.Phase.Emit, "emitUsingBuildInfo", {}, /*separateBeginAndEnd*/ true);
+        performance.mark("beforeEmit");
+        const result = emitUsingBuildInfoWorker(config, host, getCommandLine, customTransformers);
+        performance.mark("afterEmit");
+        performance.measure("Emit", "beforeEmit", "afterEmit");
+        tracing?.pop();
+        return result;
+    }
+
+    function emitUsingBuildInfoWorker(
+        config: ParsedCommandLine,
+        host: CompilerHost,
         getCommandLine: (ref: ProjectReference) => ParsedCommandLine | undefined,
         customTransformers?: CustomTransformers
     ): EmitUsingBuildInfoResult {
         const createHash = maybeBind(host, host.createHash);
         const { buildInfoPath, jsFilePath, sourceMapFilePath, declarationFilePath, declarationMapPath } = getOutputPathsForBundle(config.options, /*forceDtsPaths*/ false);
-        let buildInfo: BuildInfo | undefined;
-        if (host.getBuildInfo) {
-            // If host directly provides buildinfo we can get it directly. This allows host to cache the buildinfo
-            buildInfo = host.getBuildInfo(buildInfoPath!, config.options.configFilePath);
-        }
-        else {
-            const buildInfoText = host.readFile(buildInfoPath!);
-            if (!buildInfoText) return buildInfoPath!;
-            buildInfo = getBuildInfo(buildInfoPath!, buildInfoText);
-        }
+        // If host directly provides buildinfo we can get it directly. This allows host to cache the buildinfo
+        const buildInfo = host.getBuildInfo!(buildInfoPath!, config.options.configFilePath);
         if (!buildInfo) return buildInfoPath!;
         if (!buildInfo.bundle || !buildInfo.bundle.js || (declarationFilePath && !buildInfo.bundle.dts)) return buildInfoPath!;
 
@@ -783,28 +780,28 @@ namespace ts {
         if (declarationMapPath && computeSignature(declarationMapText!, createHash) !== buildInfo.bundle.dts!.mapHash) return declarationMapPath;
 
         const buildInfoDirectory = getDirectoryPath(getNormalizedAbsolutePath(buildInfoPath!, host.getCurrentDirectory()));
-        const ownPrependInput = createInputFiles(
+        const ownPrependInput = createInputFilesWithFileTexts(
+            jsFilePath,
             jsFileText,
-            declarationText!,
             sourceMapFilePath,
             sourceMapText,
+            declarationFilePath,
+            declarationText!,
             declarationMapPath,
             declarationMapText,
-            jsFilePath,
-            declarationFilePath,
             buildInfoPath,
             buildInfo,
             /*onlyOwnText*/ true
         );
         const outputFiles: OutputFile[] = [];
-        const prependNodes = createPrependNodes(config.projectReferences, getCommandLine, f => host.readFile(f));
+        const prependNodes = createPrependNodes(config.projectReferences, getCommandLine, f => host.readFile(f), host);
         const sourceFilesForJsEmit = createSourceFilesFromBundleBuildInfo(buildInfo.bundle, buildInfoDirectory, host);
         let changedDtsText: string | undefined;
         let changedDtsData: WriteFileCallbackData | undefined;
         const emitHost: EmitHost = {
             getPrependNodes: memoize(() => [...prependNodes, ownPrependInput]),
             getCanonicalFileName: host.getCanonicalFileName,
-            getCommonSourceDirectory: () => getNormalizedAbsolutePath(buildInfo!.bundle!.commonSourceDirectory, buildInfoDirectory),
+            getCommonSourceDirectory: () => getNormalizedAbsolutePath(buildInfo.bundle!.commonSourceDirectory, buildInfoDirectory),
             getCompilerOptions: () => config.options,
             getCurrentDirectory: () => host.getCurrentDirectory(),
             getNewLine: () => host.getNewLine(),
@@ -826,13 +823,13 @@ namespace ts {
                         break;
                     case buildInfoPath:
                         const newBuildInfo = data!.buildInfo!;
-                        newBuildInfo.program = buildInfo!.program;
+                        newBuildInfo.program = buildInfo.program;
                         if (newBuildInfo.program && changedDtsText !== undefined && config.options.composite) {
                             // Update the output signature
                             (newBuildInfo.program as ProgramBundleEmitBuildInfo).outSignature = computeSignature(changedDtsText, createHash, changedDtsData);
                         }
                         // Update sourceFileInfo
-                        const { js, dts, sourceFiles } = buildInfo!.bundle!;
+                        const { js, dts, sourceFiles } = buildInfo.bundle!;
                         newBuildInfo.bundle!.js!.sources = js!.sources;
                         if (dts) {
                             newBuildInfo.bundle!.dts!.sources = dts.sources;

src/compiler/factory/nodeFactory.ts

@@ -6742,14 +6742,6 @@ namespace ts {
         javascriptText: string,
         declarationText: string
     ): InputFiles;
-    export function createInputFiles(
-        readFileText: (path: string) => string | undefined,
-        javascriptPath: string,
-        javascriptMapPath: string | undefined,
-        declarationPath: string,
-        declarationMapPath: string | undefined,
-        buildInfoPath: string | undefined
-    ): InputFiles;
     export function createInputFiles(
         javascriptText: string,
         declarationText: string,
@@ -6758,19 +6750,13 @@ namespace ts {
         declarationMapPath: string | undefined,
         declarationMapText: string | undefined
     ): InputFiles;
-    /*@internal*/
     export function createInputFiles(
-        javascriptText: string,
-        declarationText: string,
+        readFileText: (path: string) => string | undefined,
+        javascriptPath: string,
         javascriptMapPath: string | undefined,
-        javascriptMapText: string | undefined,
+        declarationPath: string,
         declarationMapPath: string | undefined,
-        declarationMapText: string | undefined,
-        javascriptPath: string | undefined,
-        declarationPath: string | undefined,
-        buildInfoPath?: string | undefined,
-        buildInfo?: BuildInfo,
-        oldFileOfCurrentEmit?: boolean
+        buildInfoPath: string | undefined
     ): InputFiles;
     export function createInputFiles(
         javascriptTextOrReadFileText: string | ((path: string) => string | undefined),
@@ -6779,62 +6765,106 @@ namespace ts {
         javascriptMapTextOrDeclarationPath?: string,
         declarationMapPath?: string,
         declarationMapTextOrBuildInfoPath?: string,
-        javascriptPath?: string | undefined,
-        declarationPath?: string | undefined,
-        buildInfoPath?: string | undefined,
-        buildInfo?: BuildInfo,
-        oldFileOfCurrentEmit?: boolean
+    ): InputFiles {
+        return !isString(javascriptTextOrReadFileText) ?
+            createInputFilesWithFilePaths(
+                javascriptTextOrReadFileText,
+                declarationTextOrJavascriptPath,
+                javascriptMapPath,
+                javascriptMapTextOrDeclarationPath!,
+                declarationMapPath,
+                declarationMapTextOrBuildInfoPath,
+            ) :
+            createInputFilesWithFileTexts(
+                /*javascriptPath*/ undefined,
+                javascriptTextOrReadFileText,
+                javascriptMapPath,
+                javascriptMapTextOrDeclarationPath,
+                /*declarationPath*/ undefined,
+                declarationTextOrJavascriptPath,
+                declarationMapPath,
+                declarationMapTextOrBuildInfoPath,
+            );
+    }
+    /*@internal*/
+    export function createInputFilesWithFilePaths(
+        readFileText: (path: string) => string | undefined,
+        javascriptPath: string,
+        javascriptMapPath: string | undefined,
+        declarationPath: string,
+        declarationMapPath: string | undefined,
+        buildInfoPath: string | undefined,
+        host?: CompilerHost,
+        options?: CompilerOptions,
     ): InputFiles {
         const node = parseNodeFactory.createInputFiles();
-        if (!isString(javascriptTextOrReadFileText)) {
-            const cache = new Map<string, string | false>();
-            const textGetter = (path: string | undefined) => {
-                if (path === undefined) return undefined;
-                let value = cache.get(path);
-                if (value === undefined) {
-                    value = javascriptTextOrReadFileText(path);
-                    cache.set(path, value !== undefined ? value : false);
+        node.javascriptPath = javascriptPath;
+        node.javascriptMapPath = javascriptMapPath;
+        node.declarationPath = declarationPath;
+        node.declarationMapPath = declarationMapPath;
+        node.buildInfoPath = buildInfoPath;
+        const cache = new Map<string, string | false>();
+        const textGetter = (path: string | undefined) => {
+            if (path === undefined) return undefined;
+            let value = cache.get(path);
+            if (value === undefined) {
+                value = readFileText(path);
+                cache.set(path, value !== undefined ? value : false);
+            }
+            return value !== false ? value as string : undefined;
+        };
+        const definedTextGetter = (path: string) => {
+            const result = textGetter(path);
+            return result !== undefined ? result : `/* Input file ${path} was missing */\r\n`;
+        };
+        let buildInfo: BuildInfo | false;
+        const getAndCacheBuildInfo = () => {
+            if (buildInfo === undefined && buildInfoPath) {
+                if (host?.getBuildInfo) {
+                    buildInfo = host.getBuildInfo(buildInfoPath, options!.configFilePath) ?? false;
                 }
-                return value !== false ? value as string : undefined;
-            };
-            const definedTextGetter = (path: string) => {
-                const result = textGetter(path);
-                return result !== undefined ? result : `/* Input file ${path} was missing */\r\n`;
-            };
-            let buildInfo: BuildInfo | false;
-            const getAndCacheBuildInfo = (getText: () => string | undefined) => {
-                if (buildInfo === undefined) {
-                    const result = getText();
-                    buildInfo = result !== undefined ? getBuildInfo(node.buildInfoPath!, result) ?? false : false;
+                else {
+                    const result = textGetter(buildInfoPath);
+                    buildInfo = result !== undefined ? getBuildInfo(buildInfoPath, result) ?? false : false;
                 }
-                return buildInfo || undefined;
-            };
-            node.javascriptPath = declarationTextOrJavascriptPath;
-            node.javascriptMapPath = javascriptMapPath;
-            node.declarationPath = Debug.checkDefined(javascriptMapTextOrDeclarationPath);
-            node.declarationMapPath = declarationMapPath;
-            node.buildInfoPath = declarationMapTextOrBuildInfoPath;
-            Object.defineProperties(node, {
-                javascriptText: { get() { return definedTextGetter(declarationTextOrJavascriptPath); } },
-                javascriptMapText: { get() { return textGetter(javascriptMapPath); } }, // TODO:: if there is inline sourceMap in jsFile, use that
-                declarationText: { get() { return definedTextGetter(Debug.checkDefined(javascriptMapTextOrDeclarationPath)); } },
-                declarationMapText: { get() { return textGetter(declarationMapPath); } }, // TODO:: if there is inline sourceMap in dtsFile, use that
-                buildInfo: { get() { return getAndCacheBuildInfo(() => textGetter(declarationMapTextOrBuildInfoPath)); } }
-            });
-        }
-        else {
-            node.javascriptText = javascriptTextOrReadFileText;
-            node.javascriptMapPath = javascriptMapPath;
-            node.javascriptMapText = javascriptMapTextOrDeclarationPath;
-            node.declarationText = declarationTextOrJavascriptPath;
-            node.declarationMapPath = declarationMapPath;
-            node.declarationMapText = declarationMapTextOrBuildInfoPath;
-            node.javascriptPath = javascriptPath;
-            node.declarationPath = declarationPath;
-            node.buildInfoPath = buildInfoPath;
-            node.buildInfo = buildInfo;
-            node.oldFileOfCurrentEmit = oldFileOfCurrentEmit;
-        }
+            }
+            return buildInfo || undefined;
+        };
+        Object.defineProperties(node, {
+            javascriptText: { get: () => definedTextGetter(javascriptPath) },
+            javascriptMapText: { get: () => textGetter(javascriptMapPath) }, // TODO:: if there is inline sourceMap in jsFile, use that
+            declarationText: { get: () => definedTextGetter(Debug.checkDefined(declarationPath)) },
+            declarationMapText: { get: () => textGetter(declarationMapPath) }, // TODO:: if there is inline sourceMap in dtsFile, use that
+            buildInfo: { get: getAndCacheBuildInfo },
+        });
+        return node;
+    }
+    /*@internal*/
+    export function createInputFilesWithFileTexts(
+        javascriptPath: string | undefined,
+        javascriptText: string,
+        javascriptMapPath: string | undefined,
+        javascriptMapText: string | undefined,
+        declarationPath: string | undefined,
+        declarationText: string,
+        declarationMapPath: string | undefined,
+        declarationMapText: string | undefined,
+        buildInfoPath?: string,
+        buildInfo?: BuildInfo,
+        oldFileOfCurrentEmit?: boolean,
+    ): InputFiles {
+        const node = parseNodeFactory.createInputFiles();
+        node.javascriptPath = javascriptPath;
+        node.javascriptText = javascriptText;
+        node.javascriptMapPath = javascriptMapPath;
+        node.javascriptMapText = javascriptMapText;
+        node.declarationPath = declarationPath;
+        node.declarationText = declarationText;
+        node.declarationMapPath = declarationMapPath;
+        node.declarationMapText = declarationMapText;
+        node.buildInfoPath = buildInfoPath;
+        node.buildInfo = buildInfo;
+        node.oldFileOfCurrentEmit = oldFileOfCurrentEmit;
         return node;
     }