1pub mod wit;
2
3use crate::ExtensionManifest;
4use anyhow::{Context as _, Result, anyhow, bail};
5use async_trait::async_trait;
6use dap::{DebugRequest, StartDebuggingRequestArgumentsRequest};
7use extension::{
8 CodeLabel, Command, Completion, ContextServerConfiguration, DebugAdapterBinary,
9 DebugTaskDefinition, ExtensionHostProxy, KeyValueStoreDelegate, ProjectDelegate, SlashCommand,
10 SlashCommandArgumentCompletion, SlashCommandOutput, Symbol, WorktreeDelegate,
11};
12use fs::{Fs, normalize_path};
13use futures::future::LocalBoxFuture;
14use futures::{
15 Future, FutureExt, StreamExt as _,
16 channel::{
17 mpsc::{self, UnboundedSender},
18 oneshot,
19 },
20 future::BoxFuture,
21};
22use gpui::{App, AsyncApp, BackgroundExecutor, Task};
23use http_client::HttpClient;
24use language::LanguageName;
25use lsp::LanguageServerName;
26use moka::sync::Cache;
27use node_runtime::NodeRuntime;
28use release_channel::ReleaseChannel;
29use semantic_version::SemanticVersion;
30use std::borrow::Cow;
31use std::sync::LazyLock;
32use std::{
33 path::{Path, PathBuf},
34 sync::Arc,
35};
36use task::{DebugScenario, SpawnInTerminal, TaskTemplate, ZedDebugConfig};
37use wasmtime::{
38 CacheStore, Engine, Store,
39 component::{Component, ResourceTable},
40};
41use wasmtime_wasi::{self as wasi, WasiView};
42use wit::Extension;
43
44pub struct WasmHost {
45 engine: Engine,
46 release_channel: ReleaseChannel,
47 http_client: Arc<dyn HttpClient>,
48 node_runtime: NodeRuntime,
49 pub(crate) proxy: Arc<ExtensionHostProxy>,
50 fs: Arc<dyn Fs>,
51 pub work_dir: PathBuf,
52 _main_thread_message_task: Task<()>,
53 main_thread_message_tx: mpsc::UnboundedSender<MainThreadCall>,
54}
55
56#[derive(Clone)]
57pub struct WasmExtension {
58 tx: UnboundedSender<ExtensionCall>,
59 pub manifest: Arc<ExtensionManifest>,
60 pub work_dir: Arc<Path>,
61 #[allow(unused)]
62 pub zed_api_version: SemanticVersion,
63}
64
65#[async_trait]
66impl extension::Extension for WasmExtension {
67 fn manifest(&self) -> Arc<ExtensionManifest> {
68 self.manifest.clone()
69 }
70
71 fn work_dir(&self) -> Arc<Path> {
72 self.work_dir.clone()
73 }
74
75 async fn language_server_command(
76 &self,
77 language_server_id: LanguageServerName,
78 language_name: LanguageName,
79 worktree: Arc<dyn WorktreeDelegate>,
80 ) -> Result<Command> {
81 self.call(|extension, store| {
82 async move {
83 let resource = store.data_mut().table().push(worktree)?;
84 let command = extension
85 .call_language_server_command(
86 store,
87 &language_server_id,
88 &language_name,
89 resource,
90 )
91 .await?
92 .map_err(|err| store.data().extension_error(err))?;
93
94 Ok(command.into())
95 }
96 .boxed()
97 })
98 .await
99 }
100
101 async fn language_server_initialization_options(
102 &self,
103 language_server_id: LanguageServerName,
104 language_name: LanguageName,
105 worktree: Arc<dyn WorktreeDelegate>,
106 ) -> Result<Option<String>> {
107 self.call(|extension, store| {
108 async move {
109 let resource = store.data_mut().table().push(worktree)?;
110 let options = extension
111 .call_language_server_initialization_options(
112 store,
113 &language_server_id,
114 &language_name,
115 resource,
116 )
117 .await?
118 .map_err(|err| store.data().extension_error(err))?;
119 anyhow::Ok(options)
120 }
121 .boxed()
122 })
123 .await
124 }
125
126 async fn language_server_workspace_configuration(
127 &self,
128 language_server_id: LanguageServerName,
129 worktree: Arc<dyn WorktreeDelegate>,
130 ) -> Result<Option<String>> {
131 self.call(|extension, store| {
132 async move {
133 let resource = store.data_mut().table().push(worktree)?;
134 let options = extension
135 .call_language_server_workspace_configuration(
136 store,
137 &language_server_id,
138 resource,
139 )
140 .await?
141 .map_err(|err| store.data().extension_error(err))?;
142 anyhow::Ok(options)
143 }
144 .boxed()
145 })
146 .await
147 }
148
149 async fn language_server_additional_initialization_options(
150 &self,
151 language_server_id: LanguageServerName,
152 target_language_server_id: LanguageServerName,
153 worktree: Arc<dyn WorktreeDelegate>,
154 ) -> Result<Option<String>> {
155 self.call(|extension, store| {
156 async move {
157 let resource = store.data_mut().table().push(worktree)?;
158 let options = extension
159 .call_language_server_additional_initialization_options(
160 store,
161 &language_server_id,
162 &target_language_server_id,
163 resource,
164 )
165 .await?
166 .map_err(|err| store.data().extension_error(err))?;
167 anyhow::Ok(options)
168 }
169 .boxed()
170 })
171 .await
172 }
173
174 async fn language_server_additional_workspace_configuration(
175 &self,
176 language_server_id: LanguageServerName,
177 target_language_server_id: LanguageServerName,
178 worktree: Arc<dyn WorktreeDelegate>,
179 ) -> Result<Option<String>> {
180 self.call(|extension, store| {
181 async move {
182 let resource = store.data_mut().table().push(worktree)?;
183 let options = extension
184 .call_language_server_additional_workspace_configuration(
185 store,
186 &language_server_id,
187 &target_language_server_id,
188 resource,
189 )
190 .await?
191 .map_err(|err| store.data().extension_error(err))?;
192 anyhow::Ok(options)
193 }
194 .boxed()
195 })
196 .await
197 }
198
199 async fn labels_for_completions(
200 &self,
201 language_server_id: LanguageServerName,
202 completions: Vec<Completion>,
203 ) -> Result<Vec<Option<CodeLabel>>> {
204 self.call(|extension, store| {
205 async move {
206 let labels = extension
207 .call_labels_for_completions(
208 store,
209 &language_server_id,
210 completions.into_iter().map(Into::into).collect(),
211 )
212 .await?
213 .map_err(|err| store.data().extension_error(err))?;
214
215 Ok(labels
216 .into_iter()
217 .map(|label| label.map(Into::into))
218 .collect())
219 }
220 .boxed()
221 })
222 .await
223 }
224
225 async fn labels_for_symbols(
226 &self,
227 language_server_id: LanguageServerName,
228 symbols: Vec<Symbol>,
229 ) -> Result<Vec<Option<CodeLabel>>> {
230 self.call(|extension, store| {
231 async move {
232 let labels = extension
233 .call_labels_for_symbols(
234 store,
235 &language_server_id,
236 symbols.into_iter().map(Into::into).collect(),
237 )
238 .await?
239 .map_err(|err| store.data().extension_error(err))?;
240
241 Ok(labels
242 .into_iter()
243 .map(|label| label.map(Into::into))
244 .collect())
245 }
246 .boxed()
247 })
248 .await
249 }
250
251 async fn complete_slash_command_argument(
252 &self,
253 command: SlashCommand,
254 arguments: Vec<String>,
255 ) -> Result<Vec<SlashCommandArgumentCompletion>> {
256 self.call(|extension, store| {
257 async move {
258 let completions = extension
259 .call_complete_slash_command_argument(store, &command.into(), &arguments)
260 .await?
261 .map_err(|err| store.data().extension_error(err))?;
262
263 Ok(completions.into_iter().map(Into::into).collect())
264 }
265 .boxed()
266 })
267 .await
268 }
269
270 async fn run_slash_command(
271 &self,
272 command: SlashCommand,
273 arguments: Vec<String>,
274 delegate: Option<Arc<dyn WorktreeDelegate>>,
275 ) -> Result<SlashCommandOutput> {
276 self.call(|extension, store| {
277 async move {
278 let resource = if let Some(delegate) = delegate {
279 Some(store.data_mut().table().push(delegate)?)
280 } else {
281 None
282 };
283
284 let output = extension
285 .call_run_slash_command(store, &command.into(), &arguments, resource)
286 .await?
287 .map_err(|err| store.data().extension_error(err))?;
288
289 Ok(output.into())
290 }
291 .boxed()
292 })
293 .await
294 }
295
296 async fn context_server_command(
297 &self,
298 context_server_id: Arc<str>,
299 project: Arc<dyn ProjectDelegate>,
300 ) -> Result<Command> {
301 self.call(|extension, store| {
302 async move {
303 let project_resource = store.data_mut().table().push(project)?;
304 let command = extension
305 .call_context_server_command(store, context_server_id.clone(), project_resource)
306 .await?
307 .map_err(|err| store.data().extension_error(err))?;
308 anyhow::Ok(command.into())
309 }
310 .boxed()
311 })
312 .await
313 }
314
315 async fn context_server_configuration(
316 &self,
317 context_server_id: Arc<str>,
318 project: Arc<dyn ProjectDelegate>,
319 ) -> Result<Option<ContextServerConfiguration>> {
320 self.call(|extension, store| {
321 async move {
322 let project_resource = store.data_mut().table().push(project)?;
323 let Some(configuration) = extension
324 .call_context_server_configuration(
325 store,
326 context_server_id.clone(),
327 project_resource,
328 )
329 .await?
330 .map_err(|err| store.data().extension_error(err))?
331 else {
332 return Ok(None);
333 };
334
335 Ok(Some(configuration.try_into()?))
336 }
337 .boxed()
338 })
339 .await
340 }
341
342 async fn suggest_docs_packages(&self, provider: Arc<str>) -> Result<Vec<String>> {
343 self.call(|extension, store| {
344 async move {
345 let packages = extension
346 .call_suggest_docs_packages(store, provider.as_ref())
347 .await?
348 .map_err(|err| store.data().extension_error(err))?;
349
350 Ok(packages)
351 }
352 .boxed()
353 })
354 .await
355 }
356
357 async fn index_docs(
358 &self,
359 provider: Arc<str>,
360 package_name: Arc<str>,
361 kv_store: Arc<dyn KeyValueStoreDelegate>,
362 ) -> Result<()> {
363 self.call(|extension, store| {
364 async move {
365 let kv_store_resource = store.data_mut().table().push(kv_store)?;
366 extension
367 .call_index_docs(
368 store,
369 provider.as_ref(),
370 package_name.as_ref(),
371 kv_store_resource,
372 )
373 .await?
374 .map_err(|err| store.data().extension_error(err))?;
375
376 anyhow::Ok(())
377 }
378 .boxed()
379 })
380 .await
381 }
382
383 async fn get_dap_binary(
384 &self,
385 dap_name: Arc<str>,
386 config: DebugTaskDefinition,
387 user_installed_path: Option<PathBuf>,
388 worktree: Arc<dyn WorktreeDelegate>,
389 ) -> Result<DebugAdapterBinary> {
390 self.call(|extension, store| {
391 async move {
392 let resource = store.data_mut().table().push(worktree)?;
393 let dap_binary = extension
394 .call_get_dap_binary(store, dap_name, config, user_installed_path, resource)
395 .await?
396 .map_err(|err| store.data().extension_error(err))?;
397 let dap_binary = dap_binary.try_into()?;
398 Ok(dap_binary)
399 }
400 .boxed()
401 })
402 .await
403 }
404 async fn dap_request_kind(
405 &self,
406 dap_name: Arc<str>,
407 config: serde_json::Value,
408 ) -> Result<StartDebuggingRequestArgumentsRequest> {
409 self.call(|extension, store| {
410 async move {
411 let kind = extension
412 .call_dap_request_kind(store, dap_name, config)
413 .await?
414 .map_err(|err| store.data().extension_error(err))?;
415 Ok(kind.into())
416 }
417 .boxed()
418 })
419 .await
420 }
421
422 async fn dap_config_to_scenario(&self, config: ZedDebugConfig) -> Result<DebugScenario> {
423 self.call(|extension, store| {
424 async move {
425 let kind = extension
426 .call_dap_config_to_scenario(store, config)
427 .await?
428 .map_err(|err| store.data().extension_error(err))?;
429 Ok(kind)
430 }
431 .boxed()
432 })
433 .await
434 }
435
436 async fn dap_locator_create_scenario(
437 &self,
438 locator_name: String,
439 build_config_template: TaskTemplate,
440 resolved_label: String,
441 debug_adapter_name: String,
442 ) -> Result<Option<DebugScenario>> {
443 self.call(|extension, store| {
444 async move {
445 extension
446 .call_dap_locator_create_scenario(
447 store,
448 locator_name,
449 build_config_template,
450 resolved_label,
451 debug_adapter_name,
452 )
453 .await
454 }
455 .boxed()
456 })
457 .await
458 }
459 async fn run_dap_locator(
460 &self,
461 locator_name: String,
462 config: SpawnInTerminal,
463 ) -> Result<DebugRequest> {
464 self.call(|extension, store| {
465 async move {
466 extension
467 .call_run_dap_locator(store, locator_name, config)
468 .await?
469 .map_err(|err| store.data().extension_error(err))
470 }
471 .boxed()
472 })
473 .await
474 }
475}
476
477pub struct WasmState {
478 manifest: Arc<ExtensionManifest>,
479 pub table: ResourceTable,
480 ctx: wasi::WasiCtx,
481 pub host: Arc<WasmHost>,
482}
483
484type MainThreadCall = Box<dyn Send + for<'a> FnOnce(&'a mut AsyncApp) -> LocalBoxFuture<'a, ()>>;
485
486type ExtensionCall = Box<
487 dyn Send + for<'a> FnOnce(&'a mut Extension, &'a mut Store<WasmState>) -> BoxFuture<'a, ()>,
488>;
489
490fn wasm_engine() -> wasmtime::Engine {
491 static WASM_ENGINE: LazyLock<wasmtime::Engine> = LazyLock::new(|| {
492 let mut config = wasmtime::Config::new();
493 config.wasm_component_model(true);
494 config.async_support(true);
495 config
496 .enable_incremental_compilation(cache_store())
497 .unwrap();
498 wasmtime::Engine::new(&config).unwrap()
499 });
500
501 WASM_ENGINE.clone()
502}
503
504fn cache_store() -> Arc<IncrementalCompilationCache> {
505 static CACHE_STORE: LazyLock<Arc<IncrementalCompilationCache>> =
506 LazyLock::new(|| Arc::new(IncrementalCompilationCache::new()));
507 CACHE_STORE.clone()
508}
509
510impl WasmHost {
511 pub fn new(
512 fs: Arc<dyn Fs>,
513 http_client: Arc<dyn HttpClient>,
514 node_runtime: NodeRuntime,
515 proxy: Arc<ExtensionHostProxy>,
516 work_dir: PathBuf,
517 cx: &mut App,
518 ) -> Arc<Self> {
519 let (tx, mut rx) = mpsc::unbounded::<MainThreadCall>();
520 let task = cx.spawn(async move |cx| {
521 while let Some(message) = rx.next().await {
522 message(cx).await;
523 }
524 });
525 Arc::new(Self {
526 engine: wasm_engine(),
527 fs,
528 work_dir,
529 http_client,
530 node_runtime,
531 proxy,
532 release_channel: ReleaseChannel::global(cx),
533 _main_thread_message_task: task,
534 main_thread_message_tx: tx,
535 })
536 }
537
538 pub fn load_extension(
539 self: &Arc<Self>,
540 wasm_bytes: Vec<u8>,
541 manifest: &Arc<ExtensionManifest>,
542 executor: BackgroundExecutor,
543 ) -> Task<Result<WasmExtension>> {
544 let this = self.clone();
545 let manifest = manifest.clone();
546 executor.clone().spawn(async move {
547 let zed_api_version = parse_wasm_extension_version(&manifest.id, &wasm_bytes)?;
548
549 let component = Component::from_binary(&this.engine, &wasm_bytes)
550 .context("failed to compile wasm component")?;
551
552 let mut store = wasmtime::Store::new(
553 &this.engine,
554 WasmState {
555 ctx: this.build_wasi_ctx(&manifest).await?,
556 manifest: manifest.clone(),
557 table: ResourceTable::new(),
558 host: this.clone(),
559 },
560 );
561
562 let mut extension = Extension::instantiate_async(
563 &mut store,
564 this.release_channel,
565 zed_api_version,
566 &component,
567 )
568 .await?;
569
570 extension
571 .call_init_extension(&mut store)
572 .await
573 .context("failed to initialize wasm extension")?;
574
575 let (tx, mut rx) = mpsc::unbounded::<ExtensionCall>();
576 executor
577 .spawn(async move {
578 while let Some(call) = rx.next().await {
579 (call)(&mut extension, &mut store).await;
580 }
581 })
582 .detach();
583
584 Ok(WasmExtension {
585 manifest: manifest.clone(),
586 work_dir: this.work_dir.join(manifest.id.as_ref()).into(),
587 tx,
588 zed_api_version,
589 })
590 })
591 }
592
593 async fn build_wasi_ctx(&self, manifest: &Arc<ExtensionManifest>) -> Result<wasi::WasiCtx> {
594 let extension_work_dir = self.work_dir.join(manifest.id.as_ref());
595 self.fs
596 .create_dir(&extension_work_dir)
597 .await
598 .context("failed to create extension work dir")?;
599
600 let file_perms = wasi::FilePerms::all();
601 let dir_perms = wasi::DirPerms::all();
602
603 Ok(wasi::WasiCtxBuilder::new()
604 .inherit_stdio()
605 .preopened_dir(&extension_work_dir, ".", dir_perms, file_perms)?
606 .preopened_dir(
607 &extension_work_dir,
608 extension_work_dir.to_string_lossy(),
609 dir_perms,
610 file_perms,
611 )?
612 .env("PWD", extension_work_dir.to_string_lossy())
613 .env("RUST_BACKTRACE", "full")
614 .build())
615 }
616
617 pub fn writeable_path_from_extension(&self, id: &Arc<str>, path: &Path) -> Result<PathBuf> {
618 let extension_work_dir = self.work_dir.join(id.as_ref());
619 let path = normalize_path(&extension_work_dir.join(path));
620 anyhow::ensure!(
621 path.starts_with(&extension_work_dir),
622 "cannot write to path {path:?}",
623 );
624 Ok(path)
625 }
626}
627
628pub fn parse_wasm_extension_version(
629 extension_id: &str,
630 wasm_bytes: &[u8],
631) -> Result<SemanticVersion> {
632 let mut version = None;
633
634 for part in wasmparser::Parser::new(0).parse_all(wasm_bytes) {
635 if let wasmparser::Payload::CustomSection(s) =
636 part.context("error parsing wasm extension")?
637 {
638 if s.name() == "zed:api-version" {
639 version = parse_wasm_extension_version_custom_section(s.data());
640 if version.is_none() {
641 bail!(
642 "extension {} has invalid zed:api-version section: {:?}",
643 extension_id,
644 s.data()
645 );
646 }
647 }
648 }
649 }
650
651 // The reason we wait until we're done parsing all of the Wasm bytes to return the version
652 // is to work around a panic that can happen inside of Wasmtime when the bytes are invalid.
653 //
654 // By parsing the entirety of the Wasm bytes before we return, we're able to detect this problem
655 // earlier as an `Err` rather than as a panic.
656 version.with_context(|| format!("extension {extension_id} has no zed:api-version section"))
657}
658
659fn parse_wasm_extension_version_custom_section(data: &[u8]) -> Option<SemanticVersion> {
660 if data.len() == 6 {
661 Some(SemanticVersion::new(
662 u16::from_be_bytes([data[0], data[1]]) as _,
663 u16::from_be_bytes([data[2], data[3]]) as _,
664 u16::from_be_bytes([data[4], data[5]]) as _,
665 ))
666 } else {
667 None
668 }
669}
670
671impl WasmExtension {
672 pub async fn load(
673 extension_dir: PathBuf,
674 manifest: &Arc<ExtensionManifest>,
675 wasm_host: Arc<WasmHost>,
676 cx: &AsyncApp,
677 ) -> Result<Self> {
678 let path = extension_dir.join("extension.wasm");
679
680 let mut wasm_file = wasm_host
681 .fs
682 .open_sync(&path)
683 .await
684 .context("failed to open wasm file")?;
685
686 let mut wasm_bytes = Vec::new();
687 wasm_file
688 .read_to_end(&mut wasm_bytes)
689 .context("failed to read wasm")?;
690
691 wasm_host
692 .load_extension(wasm_bytes, manifest, cx.background_executor().clone())
693 .await
694 .with_context(|| format!("failed to load wasm extension {}", manifest.id))
695 }
696
697 pub async fn call<T, Fn>(&self, f: Fn) -> T
698 where
699 T: 'static + Send,
700 Fn: 'static
701 + Send
702 + for<'a> FnOnce(&'a mut Extension, &'a mut Store<WasmState>) -> BoxFuture<'a, T>,
703 {
704 let (return_tx, return_rx) = oneshot::channel();
705 self.tx
706 .clone()
707 .unbounded_send(Box::new(move |extension, store| {
708 async {
709 let result = f(extension, store).await;
710 return_tx.send(result).ok();
711 }
712 .boxed()
713 }))
714 .expect("wasm extension channel should not be closed yet");
715 return_rx.await.expect("wasm extension channel")
716 }
717}
718
719impl WasmState {
720 fn on_main_thread<T, Fn>(&self, f: Fn) -> impl 'static + Future<Output = T>
721 where
722 T: 'static + Send,
723 Fn: 'static + Send + for<'a> FnOnce(&'a mut AsyncApp) -> LocalBoxFuture<'a, T>,
724 {
725 let (return_tx, return_rx) = oneshot::channel();
726 self.host
727 .main_thread_message_tx
728 .clone()
729 .unbounded_send(Box::new(move |cx| {
730 async {
731 let result = f(cx).await;
732 return_tx.send(result).ok();
733 }
734 .boxed_local()
735 }))
736 .expect("main thread message channel should not be closed yet");
737 async move { return_rx.await.expect("main thread message channel") }
738 }
739
740 fn work_dir(&self) -> PathBuf {
741 self.host.work_dir.join(self.manifest.id.as_ref())
742 }
743
744 fn extension_error(&self, message: String) -> anyhow::Error {
745 anyhow!(
746 "from extension \"{}\" version {}: {}",
747 self.manifest.name,
748 self.manifest.version,
749 message
750 )
751 }
752}
753
754impl wasi::WasiView for WasmState {
755 fn table(&mut self) -> &mut ResourceTable {
756 &mut self.table
757 }
758
759 fn ctx(&mut self) -> &mut wasi::WasiCtx {
760 &mut self.ctx
761 }
762}
763
764/// Wrapper around a mini-moka bounded cache for storing incremental compilation artifacts.
765/// Since wasm modules have many similar elements, this can save us a lot of work at the
766/// cost of a small memory footprint. However, we don't want this to be unbounded, so we use
767/// a LFU/LRU cache to evict less used cache entries.
768#[derive(Debug)]
769struct IncrementalCompilationCache {
770 cache: Cache<Vec<u8>, Vec<u8>>,
771}
772
773impl IncrementalCompilationCache {
774 fn new() -> Self {
775 let cache = Cache::builder()
776 // Cap this at 32 MB for now. Our extensions turn into roughly 512kb in the cache,
777 // which means we could store 64 completely novel extensions in the cache, but in
778 // practice we will more than that, which is more than enough for our use case.
779 .max_capacity(32 * 1024 * 1024)
780 .weigher(|k: &Vec<u8>, v: &Vec<u8>| (k.len() + v.len()).try_into().unwrap_or(u32::MAX))
781 .build();
782 Self { cache }
783 }
784}
785
786impl CacheStore for IncrementalCompilationCache {
787 fn get(&self, key: &[u8]) -> Option<Cow<'_, [u8]>> {
788 self.cache.get(key).map(|v| v.into())
789 }
790
791 fn insert(&self, key: &[u8], value: Vec<u8>) -> bool {
792 self.cache.insert(key.to_vec(), value);
793 true
794 }
795}