Add entrypoint tracing

packages/next/build/index.ts

@@ -660,6 +660,8 @@ export default async function build(
     const serverPropsPages = new Set<string>()
     const additionalSsgPaths = new Map<string, Array<string>>()
     const additionalSsgPathsEncoded = new Map<string, Array<string>>()
+    const pageTraceIncludes = new Map<string, Array<string>>()
+    const pageTraceExcludes = new Map<string, Array<string>>()
     const pageInfos = new Map<string, PageInfo>()
     const pagesManifest = JSON.parse(
       await promises.readFile(manifestPath, 'utf8')
@@ -841,6 +843,11 @@ export default async function build(
                   )
                 })
 
+                if (config.experimental.nftTracing) {
+                  pageTraceIncludes.set(page, workerResult.traceIncludes || [])
+                  pageTraceExcludes.set(page, workerResult.traceExcludes || [])
+                }
+
                 if (
                   workerResult.isStatic === false &&
                   (workerResult.isHybridAmp || workerResult.isAmpOnly)
@@ -979,6 +986,63 @@ export default async function build(
       )
     }
 
+    if (config.experimental.nftTracing) {
+      const globOrig = require('next/dist/compiled/glob') as typeof import('next/dist/compiled/glob')
+      const glob = (pattern: string): Promise<string[]> => {
+        return new Promise((resolve, reject) => {
+          globOrig(pattern, { cwd: dir }, (err, files) => {
+            if (err) {
+              return reject(err)
+            }
+            resolve(files)
+          })
+        })
+      }
+
+      for (const page of pageKeys) {
+        const includeGlobs = pageTraceIncludes.get(page)
+        const excludeGlobs = pageTraceExcludes.get(page)
+
+        if (!includeGlobs?.length && !excludeGlobs?.length) {
+          continue
+        }
+
+        const traceFile = path.join(
+          distDir,
+          'server/pages',
+          `${page}.js.nft.json`
+        )
+        const traceContent = JSON.parse(
+          await promises.readFile(traceFile, 'utf8')
+        )
+        let includes: string[] = []
+        let excludes: string[] = []
+
+        if (includeGlobs?.length) {
+          for (const includeGlob of includeGlobs) {
+            includes.push(...(await glob(includeGlob)))
+          }
+        }
+
+        if (excludeGlobs?.length) {
+          for (const excludeGlob of excludeGlobs) {
+            excludes.push(...(await glob(excludeGlob)))
+          }
+        }
+
+        const combined = new Set([...traceContent.files, ...includes])
+        excludes.forEach((file) => combined.delete(file))
+
+        await promises.writeFile(
+          traceFile,
+          JSON.stringify({
+            version: traceContent.version,
+            files: [...combined],
+          })
+        )
+      }
+    }
+
     if (serverPropsPages.size > 0 || ssgPages.size > 0) {
       // We update the routes manifest after the build with the
       // data routes since we can't determine these until after build

packages/next/build/utils.ts

@@ -23,7 +23,7 @@ import { getRouteMatcher, getRouteRegex } from '../shared/lib/router/utils'
 import { isDynamicRoute } from '../shared/lib/router/utils/is-dynamic'
 import escapePathDelimiters from '../shared/lib/router/utils/escape-path-delimiters'
 import { findPageFile } from '../server/lib/find-page-file'
-import { GetStaticPaths } from 'next/types'
+import { GetStaticPaths, PageConfig } from 'next/types'
 import { denormalizePagePath } from '../server/normalize-page-path'
 import { BuildManifest } from '../server/get-page-files'
 import { removePathTrailingSlash } from '../client/normalize-trailing-slash'
@@ -831,6 +831,8 @@ export async function isPageStatic(
   encodedPrerenderRoutes?: string[]
   prerenderFallback?: boolean | 'blocking'
   isNextImageImported?: boolean
+  traceIncludes?: string[]
+  traceExcludes?: string[]
 }> {
   const isPageStaticSpan = trace('is-page-static-utils', parentId)
   return isPageStaticSpan.traceAsyncFn(async () => {
@@ -925,7 +927,7 @@ export async function isPageStatic(
       }
 
       const isNextImageImported = (global as any).__NEXT_IMAGE_IMPORTED
-      const config = mod.config || {}
+      const config: PageConfig = mod.config || {}
       return {
         isStatic: !hasStaticProps && !hasGetInitialProps && !hasServerProps,
         isHybridAmp: config.amp === 'hybrid',
@@ -936,6 +938,8 @@ export async function isPageStatic(
         hasStaticProps,
         hasServerProps,
         isNextImageImported,
+        traceIncludes: config.unstable_includeFiles || [],
+        traceExcludes: config.unstable_excludeFiles || [],
       }
     } catch (err) {
       if (err.code === 'MODULE_NOT_FOUND') return {}

packages/next/build/webpack-config.ts

@@ -38,6 +38,7 @@ import BuildStatsPlugin from './webpack/plugins/build-stats-plugin'
 import ChunkNamesPlugin from './webpack/plugins/chunk-names-plugin'
 import { JsConfigPathsPlugin } from './webpack/plugins/jsconfig-paths-plugin'
 import { DropClientPage } from './webpack/plugins/next-drop-client-page-plugin'
+import { TraceEntryPointsPlugin } from './webpack/plugins/next-trace-entrypoints-plugin'
 import NextJsSsrImportPlugin from './webpack/plugins/nextjs-ssr-import'
 import NextJsSSRModuleCachePlugin from './webpack/plugins/nextjs-ssr-module-cache'
 import PagesManifestPlugin from './webpack/plugins/pages-manifest-plugin'
@@ -1245,6 +1246,12 @@ export default async function getBaseWebpackConfig(
           pagesDir,
         }),
       !isServer && new DropClientPage(),
+      config.experimental.nftTracing &&
+        !isLikeServerless &&
+        isServer &&
+        !dev &&
+        isWebpack5 &&
+        new TraceEntryPointsPlugin({ appDir: dir }),
       // Moment.js is an extremely popular library that bundles large locale files
       // by default due to how Webpack interprets its code. This is a practical
       // solution that requires the user to opt into importing specific locales.