1pub mod wit;
2
3use crate::ExtensionManifest;
4use anyhow::{anyhow, bail, Context as _, Result};
5use async_trait::async_trait;
6use extension::{
7 CodeLabel, Command, Completion, ExtensionHostProxy, KeyValueStoreDelegate, ProjectDelegate,
8 SlashCommand, SlashCommandArgumentCompletion, SlashCommandOutput, Symbol, WorktreeDelegate,
9};
10use fs::{normalize_path, Fs};
11use futures::future::LocalBoxFuture;
12use futures::{
13 channel::{
14 mpsc::{self, UnboundedSender},
15 oneshot,
16 },
17 future::BoxFuture,
18 Future, FutureExt, StreamExt as _,
19};
20use gpui::{App, AsyncApp, BackgroundExecutor, Task};
21use http_client::HttpClient;
22use language::LanguageName;
23use lsp::LanguageServerName;
24use node_runtime::NodeRuntime;
25use release_channel::ReleaseChannel;
26use semantic_version::SemanticVersion;
27use std::{
28 path::{Path, PathBuf},
29 sync::{Arc, OnceLock},
30};
31use wasmtime::{
32 component::{Component, ResourceTable},
33 Engine, Store,
34};
35use wasmtime_wasi::{self as wasi, WasiView};
36use wit::Extension;
37
38pub struct WasmHost {
39 engine: Engine,
40 release_channel: ReleaseChannel,
41 http_client: Arc<dyn HttpClient>,
42 node_runtime: NodeRuntime,
43 pub(crate) proxy: Arc<ExtensionHostProxy>,
44 fs: Arc<dyn Fs>,
45 pub work_dir: PathBuf,
46 _main_thread_message_task: Task<()>,
47 main_thread_message_tx: mpsc::UnboundedSender<MainThreadCall>,
48}
49
50#[derive(Clone)]
51pub struct WasmExtension {
52 tx: UnboundedSender<ExtensionCall>,
53 pub manifest: Arc<ExtensionManifest>,
54 pub work_dir: Arc<Path>,
55 #[allow(unused)]
56 pub zed_api_version: SemanticVersion,
57}
58
59#[async_trait]
60impl extension::Extension for WasmExtension {
61 fn manifest(&self) -> Arc<ExtensionManifest> {
62 self.manifest.clone()
63 }
64
65 fn work_dir(&self) -> Arc<Path> {
66 self.work_dir.clone()
67 }
68
69 async fn language_server_command(
70 &self,
71 language_server_id: LanguageServerName,
72 language_name: LanguageName,
73 worktree: Arc<dyn WorktreeDelegate>,
74 ) -> Result<Command> {
75 self.call(|extension, store| {
76 async move {
77 let resource = store.data_mut().table().push(worktree)?;
78 let command = extension
79 .call_language_server_command(
80 store,
81 &language_server_id,
82 &language_name,
83 resource,
84 )
85 .await?
86 .map_err(|err| anyhow!("{err}"))?;
87
88 Ok(command.into())
89 }
90 .boxed()
91 })
92 .await
93 }
94
95 async fn language_server_initialization_options(
96 &self,
97 language_server_id: LanguageServerName,
98 language_name: LanguageName,
99 worktree: Arc<dyn WorktreeDelegate>,
100 ) -> Result<Option<String>> {
101 self.call(|extension, store| {
102 async move {
103 let resource = store.data_mut().table().push(worktree)?;
104 let options = extension
105 .call_language_server_initialization_options(
106 store,
107 &language_server_id,
108 &language_name,
109 resource,
110 )
111 .await?
112 .map_err(|err| anyhow!("{err}"))?;
113 anyhow::Ok(options)
114 }
115 .boxed()
116 })
117 .await
118 }
119
120 async fn language_server_workspace_configuration(
121 &self,
122 language_server_id: LanguageServerName,
123 worktree: Arc<dyn WorktreeDelegate>,
124 ) -> Result<Option<String>> {
125 self.call(|extension, store| {
126 async move {
127 let resource = store.data_mut().table().push(worktree)?;
128 let options = extension
129 .call_language_server_workspace_configuration(
130 store,
131 &language_server_id,
132 resource,
133 )
134 .await?
135 .map_err(|err| anyhow!("{err}"))?;
136 anyhow::Ok(options)
137 }
138 .boxed()
139 })
140 .await
141 }
142
143 async fn labels_for_completions(
144 &self,
145 language_server_id: LanguageServerName,
146 completions: Vec<Completion>,
147 ) -> Result<Vec<Option<CodeLabel>>> {
148 self.call(|extension, store| {
149 async move {
150 let labels = extension
151 .call_labels_for_completions(
152 store,
153 &language_server_id,
154 completions.into_iter().map(Into::into).collect(),
155 )
156 .await?
157 .map_err(|err| anyhow!("{err}"))?;
158
159 Ok(labels
160 .into_iter()
161 .map(|label| label.map(Into::into))
162 .collect())
163 }
164 .boxed()
165 })
166 .await
167 }
168
169 async fn labels_for_symbols(
170 &self,
171 language_server_id: LanguageServerName,
172 symbols: Vec<Symbol>,
173 ) -> Result<Vec<Option<CodeLabel>>> {
174 self.call(|extension, store| {
175 async move {
176 let labels = extension
177 .call_labels_for_symbols(
178 store,
179 &language_server_id,
180 symbols.into_iter().map(Into::into).collect(),
181 )
182 .await?
183 .map_err(|err| anyhow!("{err}"))?;
184
185 Ok(labels
186 .into_iter()
187 .map(|label| label.map(Into::into))
188 .collect())
189 }
190 .boxed()
191 })
192 .await
193 }
194
195 async fn complete_slash_command_argument(
196 &self,
197 command: SlashCommand,
198 arguments: Vec<String>,
199 ) -> Result<Vec<SlashCommandArgumentCompletion>> {
200 self.call(|extension, store| {
201 async move {
202 let completions = extension
203 .call_complete_slash_command_argument(store, &command.into(), &arguments)
204 .await?
205 .map_err(|err| anyhow!("{err}"))?;
206
207 Ok(completions.into_iter().map(Into::into).collect())
208 }
209 .boxed()
210 })
211 .await
212 }
213
214 async fn run_slash_command(
215 &self,
216 command: SlashCommand,
217 arguments: Vec<String>,
218 delegate: Option<Arc<dyn WorktreeDelegate>>,
219 ) -> Result<SlashCommandOutput> {
220 self.call(|extension, store| {
221 async move {
222 let resource = if let Some(delegate) = delegate {
223 Some(store.data_mut().table().push(delegate)?)
224 } else {
225 None
226 };
227
228 let output = extension
229 .call_run_slash_command(store, &command.into(), &arguments, resource)
230 .await?
231 .map_err(|err| anyhow!("{err}"))?;
232
233 Ok(output.into())
234 }
235 .boxed()
236 })
237 .await
238 }
239
240 async fn context_server_command(
241 &self,
242 context_server_id: Arc<str>,
243 project: Arc<dyn ProjectDelegate>,
244 ) -> Result<Command> {
245 self.call(|extension, store| {
246 async move {
247 let project_resource = store.data_mut().table().push(project)?;
248 let command = extension
249 .call_context_server_command(store, context_server_id.clone(), project_resource)
250 .await?
251 .map_err(|err| anyhow!("{err}"))?;
252 anyhow::Ok(command.into())
253 }
254 .boxed()
255 })
256 .await
257 }
258
259 async fn suggest_docs_packages(&self, provider: Arc<str>) -> Result<Vec<String>> {
260 self.call(|extension, store| {
261 async move {
262 let packages = extension
263 .call_suggest_docs_packages(store, provider.as_ref())
264 .await?
265 .map_err(|err| anyhow!("{err:?}"))?;
266
267 Ok(packages)
268 }
269 .boxed()
270 })
271 .await
272 }
273
274 async fn index_docs(
275 &self,
276 provider: Arc<str>,
277 package_name: Arc<str>,
278 kv_store: Arc<dyn KeyValueStoreDelegate>,
279 ) -> Result<()> {
280 self.call(|extension, store| {
281 async move {
282 let kv_store_resource = store.data_mut().table().push(kv_store)?;
283 extension
284 .call_index_docs(
285 store,
286 provider.as_ref(),
287 package_name.as_ref(),
288 kv_store_resource,
289 )
290 .await?
291 .map_err(|err| anyhow!("{err:?}"))?;
292
293 anyhow::Ok(())
294 }
295 .boxed()
296 })
297 .await
298 }
299}
300
301pub struct WasmState {
302 manifest: Arc<ExtensionManifest>,
303 pub table: ResourceTable,
304 ctx: wasi::WasiCtx,
305 pub host: Arc<WasmHost>,
306}
307
308type MainThreadCall = Box<dyn Send + for<'a> FnOnce(&'a mut AsyncApp) -> LocalBoxFuture<'a, ()>>;
309
310type ExtensionCall = Box<
311 dyn Send + for<'a> FnOnce(&'a mut Extension, &'a mut Store<WasmState>) -> BoxFuture<'a, ()>,
312>;
313
314fn wasm_engine() -> wasmtime::Engine {
315 static WASM_ENGINE: OnceLock<wasmtime::Engine> = OnceLock::new();
316
317 WASM_ENGINE
318 .get_or_init(|| {
319 let mut config = wasmtime::Config::new();
320 config.wasm_component_model(true);
321 config.async_support(true);
322 wasmtime::Engine::new(&config).unwrap()
323 })
324 .clone()
325}
326
327impl WasmHost {
328 pub fn new(
329 fs: Arc<dyn Fs>,
330 http_client: Arc<dyn HttpClient>,
331 node_runtime: NodeRuntime,
332 proxy: Arc<ExtensionHostProxy>,
333 work_dir: PathBuf,
334 cx: &mut App,
335 ) -> Arc<Self> {
336 let (tx, mut rx) = mpsc::unbounded::<MainThreadCall>();
337 let task = cx.spawn(async move |cx| {
338 while let Some(message) = rx.next().await {
339 message(cx).await;
340 }
341 });
342 Arc::new(Self {
343 engine: wasm_engine(),
344 fs,
345 work_dir,
346 http_client,
347 node_runtime,
348 proxy,
349 release_channel: ReleaseChannel::global(cx),
350 _main_thread_message_task: task,
351 main_thread_message_tx: tx,
352 })
353 }
354
355 pub fn load_extension(
356 self: &Arc<Self>,
357 wasm_bytes: Vec<u8>,
358 manifest: &Arc<ExtensionManifest>,
359 executor: BackgroundExecutor,
360 ) -> Task<Result<WasmExtension>> {
361 let this = self.clone();
362 let manifest = manifest.clone();
363 executor.clone().spawn(async move {
364 let zed_api_version = parse_wasm_extension_version(&manifest.id, &wasm_bytes)?;
365
366 let component = Component::from_binary(&this.engine, &wasm_bytes)
367 .context("failed to compile wasm component")?;
368
369 let mut store = wasmtime::Store::new(
370 &this.engine,
371 WasmState {
372 ctx: this.build_wasi_ctx(&manifest).await?,
373 manifest: manifest.clone(),
374 table: ResourceTable::new(),
375 host: this.clone(),
376 },
377 );
378
379 let mut extension = Extension::instantiate_async(
380 &mut store,
381 this.release_channel,
382 zed_api_version,
383 &component,
384 )
385 .await?;
386
387 extension
388 .call_init_extension(&mut store)
389 .await
390 .context("failed to initialize wasm extension")?;
391
392 let (tx, mut rx) = mpsc::unbounded::<ExtensionCall>();
393 executor
394 .spawn(async move {
395 while let Some(call) = rx.next().await {
396 (call)(&mut extension, &mut store).await;
397 }
398 })
399 .detach();
400
401 Ok(WasmExtension {
402 manifest: manifest.clone(),
403 work_dir: this.work_dir.join(manifest.id.as_ref()).into(),
404 tx,
405 zed_api_version,
406 })
407 })
408 }
409
410 async fn build_wasi_ctx(&self, manifest: &Arc<ExtensionManifest>) -> Result<wasi::WasiCtx> {
411 let extension_work_dir = self.work_dir.join(manifest.id.as_ref());
412 self.fs
413 .create_dir(&extension_work_dir)
414 .await
415 .context("failed to create extension work dir")?;
416
417 let file_perms = wasi::FilePerms::all();
418 let dir_perms = wasi::DirPerms::all();
419
420 Ok(wasi::WasiCtxBuilder::new()
421 .inherit_stdio()
422 .preopened_dir(&extension_work_dir, ".", dir_perms, file_perms)?
423 .preopened_dir(
424 &extension_work_dir,
425 extension_work_dir.to_string_lossy(),
426 dir_perms,
427 file_perms,
428 )?
429 .env("PWD", extension_work_dir.to_string_lossy())
430 .env("RUST_BACKTRACE", "full")
431 .build())
432 }
433
434 pub fn writeable_path_from_extension(&self, id: &Arc<str>, path: &Path) -> Result<PathBuf> {
435 let extension_work_dir = self.work_dir.join(id.as_ref());
436 let path = normalize_path(&extension_work_dir.join(path));
437 if path.starts_with(&extension_work_dir) {
438 Ok(path)
439 } else {
440 Err(anyhow!("cannot write to path {}", path.display()))
441 }
442 }
443}
444
445pub fn parse_wasm_extension_version(
446 extension_id: &str,
447 wasm_bytes: &[u8],
448) -> Result<SemanticVersion> {
449 let mut version = None;
450
451 for part in wasmparser::Parser::new(0).parse_all(wasm_bytes) {
452 if let wasmparser::Payload::CustomSection(s) =
453 part.context("error parsing wasm extension")?
454 {
455 if s.name() == "zed:api-version" {
456 version = parse_wasm_extension_version_custom_section(s.data());
457 if version.is_none() {
458 bail!(
459 "extension {} has invalid zed:api-version section: {:?}",
460 extension_id,
461 s.data()
462 );
463 }
464 }
465 }
466 }
467
468 // The reason we wait until we're done parsing all of the Wasm bytes to return the version
469 // is to work around a panic that can happen inside of Wasmtime when the bytes are invalid.
470 //
471 // By parsing the entirety of the Wasm bytes before we return, we're able to detect this problem
472 // earlier as an `Err` rather than as a panic.
473 version.ok_or_else(|| anyhow!("extension {} has no zed:api-version section", extension_id))
474}
475
476fn parse_wasm_extension_version_custom_section(data: &[u8]) -> Option<SemanticVersion> {
477 if data.len() == 6 {
478 Some(SemanticVersion::new(
479 u16::from_be_bytes([data[0], data[1]]) as _,
480 u16::from_be_bytes([data[2], data[3]]) as _,
481 u16::from_be_bytes([data[4], data[5]]) as _,
482 ))
483 } else {
484 None
485 }
486}
487
488impl WasmExtension {
489 pub async fn load(
490 extension_dir: PathBuf,
491 manifest: &Arc<ExtensionManifest>,
492 wasm_host: Arc<WasmHost>,
493 cx: &AsyncApp,
494 ) -> Result<Self> {
495 let path = extension_dir.join("extension.wasm");
496
497 let mut wasm_file = wasm_host
498 .fs
499 .open_sync(&path)
500 .await
501 .context("failed to open wasm file")?;
502
503 let mut wasm_bytes = Vec::new();
504 wasm_file
505 .read_to_end(&mut wasm_bytes)
506 .context("failed to read wasm")?;
507
508 wasm_host
509 .load_extension(wasm_bytes, manifest, cx.background_executor().clone())
510 .await
511 .with_context(|| format!("failed to load wasm extension {}", manifest.id))
512 }
513
514 pub async fn call<T, Fn>(&self, f: Fn) -> T
515 where
516 T: 'static + Send,
517 Fn: 'static
518 + Send
519 + for<'a> FnOnce(&'a mut Extension, &'a mut Store<WasmState>) -> BoxFuture<'a, T>,
520 {
521 let (return_tx, return_rx) = oneshot::channel();
522 self.tx
523 .clone()
524 .unbounded_send(Box::new(move |extension, store| {
525 async {
526 let result = f(extension, store).await;
527 return_tx.send(result).ok();
528 }
529 .boxed()
530 }))
531 .expect("wasm extension channel should not be closed yet");
532 return_rx.await.expect("wasm extension channel")
533 }
534}
535
536impl WasmState {
537 fn on_main_thread<T, Fn>(&self, f: Fn) -> impl 'static + Future<Output = T>
538 where
539 T: 'static + Send,
540 Fn: 'static + Send + for<'a> FnOnce(&'a mut AsyncApp) -> LocalBoxFuture<'a, T>,
541 {
542 let (return_tx, return_rx) = oneshot::channel();
543 self.host
544 .main_thread_message_tx
545 .clone()
546 .unbounded_send(Box::new(move |cx| {
547 async {
548 let result = f(cx).await;
549 return_tx.send(result).ok();
550 }
551 .boxed_local()
552 }))
553 .expect("main thread message channel should not be closed yet");
554 async move { return_rx.await.expect("main thread message channel") }
555 }
556
557 fn work_dir(&self) -> PathBuf {
558 self.host.work_dir.join(self.manifest.id.as_ref())
559 }
560}
561
562impl wasi::WasiView for WasmState {
563 fn table(&mut self) -> &mut ResourceTable {
564 &mut self.table
565 }
566
567 fn ctx(&mut self) -> &mut wasi::WasiCtx {
568 &mut self.ctx
569 }
570}