Fix workspace-cache segfault; harden, measure and speed up the language server

.github/workflows/build.yml

@@ -84,6 +84,15 @@ jobs:
           name: vscode-escript-native.win32-x64
           path: native/build/Release/vscode-escript-native.win32-x64.node
 
+      # Kept out of the .vsix (see .vscodeignore) but retained here so a crash
+      # dump from a released build can be resolved to a function and line.
+      - name: Upload Debug Symbols
+        uses: actions/upload-artifact@v4
+        with:
+          name: vscode-escript-native.win32-x64.symbols
+          path: native/build/Release/vscode-escript-native.win32-x64.pdb
+          if-no-files-found: warn
+
   mac:
     name: Build and Test [Mac]
     runs-on: macos-latest

.vscode/launch.json

@@ -8,11 +8,8 @@
 			"name": "Launch Client",
 			"runtimeExecutable": "${execPath}",
 			"args": ["--extensionDevelopmentPath=${workspaceRoot}"],
-			"outFiles": ["${workspaceRoot}/client/out/**/*.js"],
-			"preLaunchTask": {
-				"type": "npm",
-				"script": "watch"
-			}
+			"outFiles": ["${workspaceRoot}/dist/**/*.js"],
+			"preLaunchTask": "watch-all"
 		},
 		{
 			"name": "Attach to Language Server",

.vscode/tasks.json

@@ -17,17 +17,47 @@
 			"type": "npm",
 			"script": "watch",
 			"isBackground": true,
-			"group": {
-				"kind": "build",
-				"isDefault": true
+			"presentation": {
+				"panel": "dedicated",
+				"reveal": "never"
 			},
+			"problemMatcher": {
+				"owner": "esbuild",
+				"fileLocation": "relative",
+				"pattern": {
+					"regexp": "^✘ \\[ERROR\\] (.*)$",
+					"message": 1
+				},
+				"background": {
+					"activeBegins": true,
+					"beginsPattern": "\\[watch\\] build started",
+					"endsPattern": "\\[watch\\] build finished"
+				}
+			}
+		},
+		{
+			"type": "npm",
+			"script": "watch:tsc",
+			"isBackground": true,
 			"presentation": {
 				"panel": "dedicated",
 				"reveal": "never"
 			},
 			"problemMatcher": [
 				"$tsc-watch"
 			]
+		},
+		{
+			"label": "watch-all",
+			"dependsOn": [
+				"npm: watch",
+				"npm: watch:tsc"
+			],
+			"group": {
+				"kind": "build",
+				"isDefault": true
+			},
+			"problemMatcher": []
 		}
 	]
 }

.vscodeignore

@@ -1,30 +1,47 @@
+# Sources, build inputs and test material.
 .vscode/**
+.github/**
+.gitignore
 doc-assets/**/*
+docs/**
 **/*.ts
 **/*.map
-**/coverage
 **/*.d.ts
-.gitignore
+**/coverage
 **/tsconfig.json
 **/tsconfig.base.json
-.github/**
+**/package-lock.json
+**/*.tsbuildinfo
+.gitmodules
+native/jest.config.js
 client/test/**
-client/node_modules/**
-!client/node_modules/vscode-jsonrpc/**
-!client/node_modules/vscode-languageclient/**
-!client/node_modules/vscode-languageserver-protocol/**
-!client/node_modules/vscode-languageserver-types/**
-!client/node_modules/{minimatch,brace-expansion,concat-map,balanced-match}/**
-!client/node_modules/{semver,lru-cache,yallist}/**
 server/test/**
 native/test/**
 client/jest.e2e.config.js
 server/jest.config.js
+jest.config.js
+eslint.config.js
+esbuild.mjs
+grammars/*.yml
+
+# The client and server ship as the two bundles in dist/. Everything the old
+# unbundled layout needed -- tsc output next to three near-duplicate copies of
+# the vscode-languageserver trees -- is dead weight now, so no negation rules
+# are needed to carve exceptions out of node_modules.
+client/out/**
+server/out/**
+native/out/**
+node_modules/**
+client/node_modules/**
+server/node_modules/**
+native/node_modules/**
+
+# Native addon: ship the built binary, not the sources, the CMake tree or the
+# ~40 MB PDB that Release builds now emit.
 native/.clang-format
 native/CMakeLists.txt
 native/cpp/**
 native/prebuilds/**
-native/build/**
-!native/build/Release/**
 native/polserver/**
-native/node_modules/**
+native/build/**
+!native/build/Release/*.node

README.md

@@ -209,7 +209,7 @@ https://github.com/polserver/vscode-escript/issues.
 - Run the launch config.
 - In the new Visual Studio Code [Extension Development Host], open a POL distro
   folder that contains `pol.cfg` and `scripts/ecompile.cfg`.
-- Check the "ECompile Language Server" channel in the Output pane.
+- Check the "EScript Language Server" channel in the Output pane.
 
 ## NVIM LSP integration
 Run `npm install && npm build` in this folder. This installs all necessary

client/src/activatePolDebug.ts

@@ -116,7 +116,9 @@ class PolDebugConfigurationProvider implements vscode.DebugConfigurationProvider
                         config.pid = selectionPid;
                     }
                 } catch (e) {
-                    vscode.window.showErrorMessage(`Could not get process list from debug server: ${e.message}`).then(_ => { });
+                    const detail = e instanceof Error ? (e.stack ?? e.message) : String(e);
+                    console.error(`Could not get process list from debug server: ${detail}`);
+                    vscode.window.showErrorMessage(`Could not get process list from debug server: ${e instanceof Error ? e.message : String(e)}`).then(_ => { });
                     return undefined;
                 } finally {
                     try {

client/src/extension.ts

@@ -4,32 +4,57 @@
  * ------------------------------------------------------------------------------------------ */
 
 import * as path from 'path';
-import { workspace, ExtensionContext } from 'vscode';
+import { workspace, ExtensionContext, Uri, Disposable } from 'vscode';
 
 import { activatePolDebug } from './activatePolDebug';
 import {
     LanguageClient,
     LanguageClientOptions,
     ServerOptions,
-    State,
     TransportKind
 } from 'vscode-languageclient/node';
 
-let client: LanguageClient;
+let client: LanguageClient | undefined;
 
-export function activate(context: ExtensionContext) {
+/**
+ * Whether any workspace folder is a POL distribution.
+ *
+ * This is the same test the server applies in `onInitialize`: without both files
+ * it never calls `workspace.open()`, so `compilercfg` is never read and no
+ * analysis can work. Checking here as well means a workspace the server would
+ * have rejected does not get a forked Node process and a 2.6 MB native addon
+ * loaded into it first.
+ *
+ * It matters because the extension activates more widely than it can serve:
+ * `contributes.languages` binds `escriptcfg` to `.cfg`, so opening a `setup.cfg`
+ * in an unrelated project activates this extension.
+ */
+async function isPolWorkspace(): Promise<boolean> {
+    for (const folder of workspace.workspaceFolders ?? []) {
+        try {
+            await workspace.fs.stat(Uri.joinPath(folder.uri, 'pol.cfg'));
+            await workspace.fs.stat(Uri.joinPath(folder.uri, 'scripts', 'ecompile.cfg'));
+            return true;
+        } catch {
+            // Not a POL distribution; try the next folder.
+        }
+    }
+    return false;
+}
+
+function startClient(context: ExtensionContext): LanguageClient {
     // The server is implemented in node
-    let serverModule = context.asAbsolutePath(
-        path.join('server', 'out', 'index.js')
+    const serverModule = context.asAbsolutePath(
+        path.join('dist', 'server.js')
     );
     // The debug options for the server
     // --inspect=6009: runs the server in Node's Inspector mode so VS Code can attach to the server for debugging
-    let debugOptions = { execArgv: ['--nolazy', '--inspect=6009'] };
+    const debugOptions = { execArgv: ['--nolazy', '--inspect=6009'] };
     const args = [`--storageUri=${context.storageUri}`];
 
     // If the extension is launched in debug mode then the debug server options are used
     // Otherwise the run options are used
-    let serverOptions: ServerOptions = {
+    const serverOptions: ServerOptions = {
         run: { module: serverModule, transport: TransportKind.ipc, args },
         debug: {
             module: serverModule,
@@ -40,7 +65,7 @@ export function activate(context: ExtensionContext) {
     };
 
     // Options to control the language client
-    let clientOptions: LanguageClientOptions = {
+    const clientOptions: LanguageClientOptions = {
         // Register the server for plain text documents
         documentSelector: [{ scheme: 'file', language: 'escript' }],
         synchronize: {
@@ -52,24 +77,64 @@ export function activate(context: ExtensionContext) {
         }
     };
 
-    // Create the language client and start the client.
-    client = new LanguageClient(
+    const started = new LanguageClient(
         'escript',
         'EScript Language Server',
         serverOptions,
         clientOptions
     );
 
     // Start the client. This will also launch the server
-    client.start();
+    started.start();
 
+    return started;
+}
+
+export async function activate(context: ExtensionContext) {
+    // Cheap and unconditional: registering the debug providers costs nothing and
+    // must happen before a 'pol' session is resolved.
     activatePolDebug(context);
 
     workspace.onDidChangeConfiguration(e => {
-        client.sendNotification('didChangeConfiguration', {
+        // Without this check every settings change in the window -- including
+        // unrelated extensions' -- pushes a config notification, which can
+        // restart the workspace cache build.
+        if (!e.affectsConfiguration('escript')) {
+            return;
+        }
+        client?.sendNotification('didChangeConfiguration', {
             configuration: workspace.getConfiguration('escript')
         });
+    }, undefined, context.subscriptions);
+
+    const startIfPol = async () => {
+        if (client || !await isPolWorkspace()) {
+            return;
+        }
+        // Checked again: the activation-time call and a folder event can both
+        // pass the first check before either probe resolves.
+        if (client) {
+            return;
+        }
+        client = startClient(context);
+    };
+
+    // A POL distribution can be added to the window after activation, so the
+    // check has to be repeated rather than made once at startup.
+    let folderWatch: Disposable | undefined = workspace.onDidChangeWorkspaceFolders(async () => {
+        await startIfPol();
+        if (client) {
+            folderWatch?.dispose();
+            folderWatch = undefined;
+        }
     });
+    context.subscriptions.push({ dispose: () => folderWatch?.dispose() });
+
+    await startIfPol();
+    if (client) {
+        folderWatch.dispose();
+        folderWatch = undefined;
+    }
 }
 
 export function deactivate(): Thenable<void> | undefined {

esbuild.mjs

@@ -0,0 +1,53 @@
+/**
+ * Bundles the extension host client and the language server.
+ *
+ * Before this, both shipped as raw `tsc` output next to their own
+ * `node_modules`, so the `.vsix` carried three near-identical copies of the
+ * `vscode-jsonrpc` / `vscode-languageserver-*` trees -- ~750 files and ~4.3 MB
+ * to support ~67 KB of project code -- and the server paid for resolving and
+ * parsing all of it on every boot.
+ *
+ * Two things are deliberately left external:
+ *
+ *  - `vscode`, which is injected by the extension host and has no package.
+ *  - `*.node`, the compiled addon. `native/src/index.ts` locates it at runtime
+ *    through a computed `require()`, which esbuild leaves alone; the roots it
+ *    searches account for this file's bundled location.
+ */
+import { build, context } from 'esbuild';
+
+const watch = process.argv.includes('--watch');
+const production = !watch;
+
+/** @type {import('esbuild').BuildOptions} */
+const common = {
+    bundle: true,
+    format: 'cjs',
+    platform: 'node',
+    target: 'node18',
+    external: ['vscode', '*.node'],
+    minify: false,
+    sourcemap: production ? false : 'inline',
+    logLevel: 'info'
+};
+
+const entries = [
+    {
+        ...common,
+        entryPoints: ['client/src/extension.ts'],
+        outfile: 'dist/extension.js'
+    },
+    {
+        ...common,
+        entryPoints: ['server/src/index.ts'],
+        outfile: 'dist/server.js'
+    }
+];
+
+if (watch) {
+    // The Extension Development Host loads `dist/`, so the debug launch's watch
+    // task has to rebuild it; `tsc -b -w` alone only refreshes `*/out`.
+    await Promise.all(entries.map(async options => (await context(options)).watch()));
+} else {
+    await Promise.all(entries.map(options => build(options)));
+}

eslint.config.js

@@ -27,6 +27,8 @@ module.exports = [
             'native/node_modules/**',
             'native/polserver/**',
             'native/out/**',
+            // Generated bundles, not sources.
+            'dist/**',
             'coverage',
         ]
     }