1use crate::wasm_host::parse_wasm_extension_version;
2use crate::ExtensionManifest;
3use crate::{extension_manifest::ExtensionLibraryKind, GrammarManifestEntry};
4use anyhow::{anyhow, bail, Context as _, Result};
5use async_compression::futures::bufread::GzipDecoder;
6use async_tar::Archive;
7use futures::io::BufReader;
8use futures::AsyncReadExt;
9use http_client::{self, AsyncBody, HttpClient};
10use serde::Deserialize;
11use std::{
12 env, fs, mem,
13 path::{Path, PathBuf},
14 process::{Command, Stdio},
15 sync::Arc,
16};
17use wasm_encoder::{ComponentSectionId, Encode as _, RawSection, Section as _};
18use wasmparser::Parser;
19use wit_component::ComponentEncoder;
20
21/// Currently, we compile with Rust's `wasm32-wasi` target, which works with WASI `preview1`.
22/// But the WASM component model is based on WASI `preview2`. So we need an 'adapter' WASM
23/// module, which implements the `preview1` interface in terms of `preview2`.
24///
25/// Once Rust 1.78 is released, there will be a `wasm32-wasip2` target available, so we will
26/// not need the adapter anymore.
27const RUST_TARGET: &str = "wasm32-wasip1";
28const WASI_ADAPTER_URL: &str =
29 "https://github.com/bytecodealliance/wasmtime/releases/download/v18.0.2/wasi_snapshot_preview1.reactor.wasm";
30
31/// Compiling Tree-sitter parsers from C to WASM requires Clang 17, and a WASM build of libc
32/// and clang's runtime library. The `wasi-sdk` provides these binaries.
33///
34/// Once Clang 17 and its wasm target are available via system package managers, we won't need
35/// to download this.
36const WASI_SDK_URL: &str = "https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-21/";
37const WASI_SDK_ASSET_NAME: Option<&str> = if cfg!(target_os = "macos") {
38 Some("wasi-sdk-21.0-macos.tar.gz")
39} else if cfg!(target_os = "linux") {
40 Some("wasi-sdk-21.0-linux.tar.gz")
41} else if cfg!(target_os = "windows") {
42 Some("wasi-sdk-21.0.m-mingw.tar.gz")
43} else {
44 None
45};
46
47pub struct ExtensionBuilder {
48 cache_dir: PathBuf,
49 pub http: Arc<dyn HttpClient>,
50}
51
52pub struct CompileExtensionOptions {
53 pub release: bool,
54}
55
56#[derive(Deserialize)]
57struct CargoToml {
58 package: CargoTomlPackage,
59}
60
61#[derive(Deserialize)]
62struct CargoTomlPackage {
63 name: String,
64}
65
66impl ExtensionBuilder {
67 pub fn new(http_client: Arc<dyn HttpClient>, cache_dir: PathBuf) -> Self {
68 Self {
69 cache_dir,
70 http: http_client,
71 }
72 }
73
74 pub async fn compile_extension(
75 &self,
76 extension_dir: &Path,
77 extension_manifest: &mut ExtensionManifest,
78 options: CompileExtensionOptions,
79 ) -> Result<()> {
80 populate_defaults(extension_manifest, extension_dir)?;
81
82 if extension_dir.is_relative() {
83 bail!(
84 "extension dir {} is not an absolute path",
85 extension_dir.display()
86 );
87 }
88
89 fs::create_dir_all(&self.cache_dir).context("failed to create cache dir")?;
90
91 if extension_manifest.lib.kind == Some(ExtensionLibraryKind::Rust) {
92 log::info!("compiling Rust extension {}", extension_dir.display());
93 self.compile_rust_extension(extension_dir, extension_manifest, options)
94 .await
95 .context("failed to compile Rust extension")?;
96 log::info!("compiled Rust extension {}", extension_dir.display());
97 }
98
99 for (grammar_name, grammar_metadata) in &extension_manifest.grammars {
100 log::info!(
101 "compiling grammar {grammar_name} for extension {}",
102 extension_dir.display()
103 );
104 self.compile_grammar(extension_dir, grammar_name.as_ref(), grammar_metadata)
105 .await
106 .with_context(|| format!("failed to compile grammar '{grammar_name}'"))?;
107 log::info!(
108 "compiled grammar {grammar_name} for extension {}",
109 extension_dir.display()
110 );
111 }
112
113 log::info!("finished compiling extension {}", extension_dir.display());
114 Ok(())
115 }
116
117 async fn compile_rust_extension(
118 &self,
119 extension_dir: &Path,
120 manifest: &mut ExtensionManifest,
121 options: CompileExtensionOptions,
122 ) -> Result<(), anyhow::Error> {
123 self.install_rust_wasm_target_if_needed()?;
124 let adapter_bytes = self.install_wasi_preview1_adapter_if_needed().await?;
125
126 let cargo_toml_content = fs::read_to_string(extension_dir.join("Cargo.toml"))?;
127 let cargo_toml: CargoToml = toml::from_str(&cargo_toml_content)?;
128
129 log::info!(
130 "compiling Rust crate for extension {}",
131 extension_dir.display()
132 );
133 let output = Command::new("cargo")
134 .args(["build", "--target", RUST_TARGET])
135 .args(options.release.then_some("--release"))
136 .arg("--target-dir")
137 .arg(extension_dir.join("target"))
138 .current_dir(extension_dir)
139 .output()
140 .context("failed to run `cargo`")?;
141 if !output.status.success() {
142 bail!(
143 "failed to build extension {}",
144 String::from_utf8_lossy(&output.stderr)
145 );
146 }
147
148 log::info!(
149 "compiled Rust crate for extension {}",
150 extension_dir.display()
151 );
152
153 let mut wasm_path = PathBuf::from(extension_dir);
154 wasm_path.extend([
155 "target",
156 RUST_TARGET,
157 if options.release { "release" } else { "debug" },
158 &cargo_toml
159 .package
160 .name
161 // The wasm32-wasip1 target normalizes `-` in package names to `_` in the resulting `.wasm` file.
162 .replace('-', "_"),
163 ]);
164 wasm_path.set_extension("wasm");
165
166 let wasm_bytes = fs::read(&wasm_path)
167 .with_context(|| format!("failed to read output module `{}`", wasm_path.display()))?;
168
169 let encoder = ComponentEncoder::default()
170 .module(&wasm_bytes)?
171 .adapter("wasi_snapshot_preview1", &adapter_bytes)
172 .context("failed to load adapter module")?
173 .validate(true);
174
175 log::info!(
176 "encoding wasm component for extension {}",
177 extension_dir.display()
178 );
179
180 let component_bytes = encoder
181 .encode()
182 .context("failed to encode wasm component")?;
183
184 let component_bytes = self
185 .strip_custom_sections(&component_bytes)
186 .context("failed to strip debug sections from wasm component")?;
187
188 let wasm_extension_api_version =
189 parse_wasm_extension_version(&manifest.id, &component_bytes)
190 .context("compiled wasm did not contain a valid zed extension api version")?;
191 manifest.lib.version = Some(wasm_extension_api_version);
192
193 let extension_file = extension_dir.join("extension.wasm");
194 fs::write(extension_file.clone(), &component_bytes)
195 .context("failed to write extension.wasm")?;
196
197 log::info!(
198 "extension {} written to {}",
199 extension_dir.display(),
200 extension_file.display()
201 );
202
203 Ok(())
204 }
205
206 async fn compile_grammar(
207 &self,
208 extension_dir: &Path,
209 grammar_name: &str,
210 grammar_metadata: &GrammarManifestEntry,
211 ) -> Result<()> {
212 let clang_path = self.install_wasi_sdk_if_needed().await?;
213
214 let mut grammar_repo_dir = extension_dir.to_path_buf();
215 grammar_repo_dir.extend(["grammars", grammar_name]);
216
217 let mut grammar_wasm_path = grammar_repo_dir.clone();
218 grammar_wasm_path.set_extension("wasm");
219
220 log::info!("checking out {grammar_name} parser");
221 self.checkout_repo(
222 &grammar_repo_dir,
223 &grammar_metadata.repository,
224 &grammar_metadata.rev,
225 )?;
226
227 let base_grammar_path = grammar_metadata
228 .path
229 .as_ref()
230 .map(|path| grammar_repo_dir.join(path))
231 .unwrap_or(grammar_repo_dir);
232
233 let src_path = base_grammar_path.join("src");
234 let parser_path = src_path.join("parser.c");
235 let scanner_path = src_path.join("scanner.c");
236
237 log::info!("compiling {grammar_name} parser");
238 let clang_output = Command::new(&clang_path)
239 .args(["-fPIC", "-shared", "-Os"])
240 .arg(format!("-Wl,--export=tree_sitter_{grammar_name}"))
241 .arg("-o")
242 .arg(&grammar_wasm_path)
243 .arg("-I")
244 .arg(&src_path)
245 .arg(&parser_path)
246 .args(scanner_path.exists().then_some(scanner_path))
247 .output()
248 .context("failed to run clang")?;
249 if !clang_output.status.success() {
250 bail!(
251 "failed to compile {} parser with clang: {}",
252 grammar_name,
253 String::from_utf8_lossy(&clang_output.stderr),
254 );
255 }
256
257 Ok(())
258 }
259
260 fn checkout_repo(&self, directory: &Path, url: &str, rev: &str) -> Result<()> {
261 let git_dir = directory.join(".git");
262
263 if directory.exists() {
264 let remotes_output = Command::new("git")
265 .arg("--git-dir")
266 .arg(&git_dir)
267 .args(["remote", "-v"])
268 .output()?;
269 let has_remote = remotes_output.status.success()
270 && String::from_utf8_lossy(&remotes_output.stdout)
271 .lines()
272 .any(|line| {
273 let mut parts = line.split(|c: char| c.is_whitespace());
274 parts.next() == Some("origin") && parts.any(|part| part == url)
275 });
276 if !has_remote {
277 bail!(
278 "grammar directory '{}' already exists, but is not a git clone of '{}'",
279 directory.display(),
280 url
281 );
282 }
283 } else {
284 fs::create_dir_all(directory).with_context(|| {
285 format!("failed to create grammar directory {}", directory.display(),)
286 })?;
287 let init_output = Command::new("git")
288 .arg("init")
289 .current_dir(directory)
290 .output()?;
291 if !init_output.status.success() {
292 bail!(
293 "failed to run `git init` in directory '{}'",
294 directory.display()
295 );
296 }
297
298 let remote_add_output = Command::new("git")
299 .arg("--git-dir")
300 .arg(&git_dir)
301 .args(["remote", "add", "origin", url])
302 .output()
303 .context("failed to execute `git remote add`")?;
304 if !remote_add_output.status.success() {
305 bail!(
306 "failed to add remote {url} for git repository {}",
307 git_dir.display()
308 );
309 }
310 }
311
312 let fetch_output = Command::new("git")
313 .arg("--git-dir")
314 .arg(&git_dir)
315 .args(["fetch", "--depth", "1", "origin", rev])
316 .output()
317 .context("failed to execute `git fetch`")?;
318
319 let checkout_output = Command::new("git")
320 .arg("--git-dir")
321 .arg(&git_dir)
322 .args(["checkout", rev])
323 .current_dir(directory)
324 .output()
325 .context("failed to execute `git checkout`")?;
326 if !checkout_output.status.success() {
327 if !fetch_output.status.success() {
328 bail!(
329 "failed to fetch revision {} in directory '{}'",
330 rev,
331 directory.display()
332 );
333 }
334 bail!(
335 "failed to checkout revision {} in directory '{}': {}",
336 rev,
337 directory.display(),
338 String::from_utf8_lossy(&checkout_output.stderr)
339 );
340 }
341
342 Ok(())
343 }
344
345 fn install_rust_wasm_target_if_needed(&self) -> Result<()> {
346 let rustc_output = Command::new("rustc")
347 .arg("--print")
348 .arg("sysroot")
349 .output()
350 .context("failed to run rustc")?;
351 if !rustc_output.status.success() {
352 bail!(
353 "failed to retrieve rust sysroot: {}",
354 String::from_utf8_lossy(&rustc_output.stderr)
355 );
356 }
357
358 let sysroot = PathBuf::from(String::from_utf8(rustc_output.stdout)?.trim());
359 if sysroot.join("lib/rustlib").join(RUST_TARGET).exists() {
360 return Ok(());
361 }
362
363 let output = Command::new("rustup")
364 .args(["target", "add", RUST_TARGET])
365 .stderr(Stdio::inherit())
366 .stdout(Stdio::inherit())
367 .output()
368 .context("failed to run `rustup target add`")?;
369 if !output.status.success() {
370 bail!("failed to install the `{RUST_TARGET}` target");
371 }
372
373 Ok(())
374 }
375
376 async fn install_wasi_preview1_adapter_if_needed(&self) -> Result<Vec<u8>> {
377 let cache_path = self.cache_dir.join("wasi_snapshot_preview1.reactor.wasm");
378 if let Ok(content) = fs::read(&cache_path) {
379 if Parser::is_core_wasm(&content) {
380 return Ok(content);
381 }
382 }
383
384 fs::remove_file(&cache_path).ok();
385
386 log::info!(
387 "downloading wasi adapter module to {}",
388 cache_path.display()
389 );
390 let mut response = self
391 .http
392 .get(WASI_ADAPTER_URL, AsyncBody::default(), true)
393 .await?;
394
395 let mut content = Vec::new();
396 let mut body = BufReader::new(response.body_mut());
397 body.read_to_end(&mut content).await?;
398
399 fs::write(&cache_path, &content)
400 .with_context(|| format!("failed to save file {}", cache_path.display()))?;
401
402 if !Parser::is_core_wasm(&content) {
403 bail!("downloaded wasi adapter is invalid");
404 }
405 Ok(content)
406 }
407
408 async fn install_wasi_sdk_if_needed(&self) -> Result<PathBuf> {
409 let url = if let Some(asset_name) = WASI_SDK_ASSET_NAME {
410 format!("{WASI_SDK_URL}/{asset_name}")
411 } else {
412 bail!("wasi-sdk is not available for platform {}", env::consts::OS);
413 };
414
415 let wasi_sdk_dir = self.cache_dir.join("wasi-sdk");
416 let mut clang_path = wasi_sdk_dir.clone();
417 clang_path.extend(["bin", &format!("clang{}", env::consts::EXE_SUFFIX)]);
418
419 if fs::metadata(&clang_path).map_or(false, |metadata| metadata.is_file()) {
420 return Ok(clang_path);
421 }
422
423 let mut tar_out_dir = wasi_sdk_dir.clone();
424 tar_out_dir.set_extension("archive");
425
426 fs::remove_dir_all(&wasi_sdk_dir).ok();
427 fs::remove_dir_all(&tar_out_dir).ok();
428
429 log::info!("downloading wasi-sdk to {}", wasi_sdk_dir.display());
430 let mut response = self.http.get(&url, AsyncBody::default(), true).await?;
431 let body = BufReader::new(response.body_mut());
432 let body = GzipDecoder::new(body);
433 let tar = Archive::new(body);
434 tar.unpack(&tar_out_dir)
435 .await
436 .context("failed to unpack wasi-sdk archive")?;
437
438 let inner_dir = fs::read_dir(&tar_out_dir)?
439 .next()
440 .ok_or_else(|| anyhow!("no content"))?
441 .context("failed to read contents of extracted wasi archive directory")?
442 .path();
443 fs::rename(&inner_dir, &wasi_sdk_dir).context("failed to move extracted wasi dir")?;
444 fs::remove_dir_all(&tar_out_dir).ok();
445
446 Ok(clang_path)
447 }
448
449 // This was adapted from:
450 // https://github.com/bytecodealliance/wasm-tools/1791a8f139722e9f8679a2bd3d8e423e55132b22/src/bin/wasm-tools/strip.rs
451 fn strip_custom_sections(&self, input: &Vec<u8>) -> Result<Vec<u8>> {
452 use wasmparser::Payload::*;
453
454 let strip_custom_section = |name: &str| name.starts_with(".debug");
455
456 let mut output = Vec::new();
457 let mut stack = Vec::new();
458
459 for payload in Parser::new(0).parse_all(input) {
460 let payload = payload?;
461
462 // Track nesting depth, so that we don't mess with inner producer sections:
463 match payload {
464 Version { encoding, .. } => {
465 output.extend_from_slice(match encoding {
466 wasmparser::Encoding::Component => &wasm_encoder::Component::HEADER,
467 wasmparser::Encoding::Module => &wasm_encoder::Module::HEADER,
468 });
469 }
470 ModuleSection { .. } | ComponentSection { .. } => {
471 stack.push(mem::take(&mut output));
472 continue;
473 }
474 End { .. } => {
475 let mut parent = match stack.pop() {
476 Some(c) => c,
477 None => break,
478 };
479 if output.starts_with(&wasm_encoder::Component::HEADER) {
480 parent.push(ComponentSectionId::Component as u8);
481 output.encode(&mut parent);
482 } else {
483 parent.push(ComponentSectionId::CoreModule as u8);
484 output.encode(&mut parent);
485 }
486 output = parent;
487 }
488 _ => {}
489 }
490
491 if let CustomSection(c) = &payload {
492 if strip_custom_section(c.name()) {
493 continue;
494 }
495 }
496
497 if let Some((id, range)) = payload.as_section() {
498 RawSection {
499 id,
500 data: &input[range],
501 }
502 .append_to(&mut output);
503 }
504 }
505
506 Ok(output)
507 }
508}
509
510fn populate_defaults(manifest: &mut ExtensionManifest, extension_path: &Path) -> Result<()> {
511 // For legacy extensions on the v0 schema (aka, using `extension.json`), clear out any existing
512 // contents of the computed fields, since we don't care what the existing values are.
513 if manifest.schema_version.is_v0() {
514 manifest.languages.clear();
515 manifest.grammars.clear();
516 manifest.themes.clear();
517 }
518
519 let cargo_toml_path = extension_path.join("Cargo.toml");
520 if cargo_toml_path.exists() {
521 manifest.lib.kind = Some(ExtensionLibraryKind::Rust);
522 }
523
524 let languages_dir = extension_path.join("languages");
525 if languages_dir.exists() {
526 for entry in fs::read_dir(&languages_dir).context("failed to list languages dir")? {
527 let entry = entry?;
528 let language_dir = entry.path();
529 let config_path = language_dir.join("config.toml");
530 if config_path.exists() {
531 let relative_language_dir =
532 language_dir.strip_prefix(extension_path)?.to_path_buf();
533 if !manifest.languages.contains(&relative_language_dir) {
534 manifest.languages.push(relative_language_dir);
535 }
536 }
537 }
538 }
539
540 let themes_dir = extension_path.join("themes");
541 if themes_dir.exists() {
542 for entry in fs::read_dir(&themes_dir).context("failed to list themes dir")? {
543 let entry = entry?;
544 let theme_path = entry.path();
545 if theme_path.extension() == Some("json".as_ref()) {
546 let relative_theme_path = theme_path.strip_prefix(extension_path)?.to_path_buf();
547 if !manifest.themes.contains(&relative_theme_path) {
548 manifest.themes.push(relative_theme_path);
549 }
550 }
551 }
552 }
553
554 let snippets_json_path = extension_path.join("snippets.json");
555 if snippets_json_path.exists() {
556 manifest.snippets = Some(snippets_json_path);
557 }
558
559 // For legacy extensions on the v0 schema (aka, using `extension.json`), we want to populate the grammars in
560 // the manifest using the contents of the `grammars` directory.
561 if manifest.schema_version.is_v0() {
562 let grammars_dir = extension_path.join("grammars");
563 if grammars_dir.exists() {
564 for entry in fs::read_dir(&grammars_dir).context("failed to list grammars dir")? {
565 let entry = entry?;
566 let grammar_path = entry.path();
567 if grammar_path.extension() == Some("toml".as_ref()) {
568 #[derive(Deserialize)]
569 struct GrammarConfigToml {
570 pub repository: String,
571 pub commit: String,
572 #[serde(default)]
573 pub path: Option<String>,
574 }
575
576 let grammar_config = fs::read_to_string(&grammar_path)?;
577 let grammar_config: GrammarConfigToml = toml::from_str(&grammar_config)?;
578
579 let grammar_name = grammar_path
580 .file_stem()
581 .and_then(|stem| stem.to_str())
582 .ok_or_else(|| anyhow!("no grammar name"))?;
583 if !manifest.grammars.contains_key(grammar_name) {
584 manifest.grammars.insert(
585 grammar_name.into(),
586 GrammarManifestEntry {
587 repository: grammar_config.repository,
588 rev: grammar_config.commit,
589 path: grammar_config.path,
590 },
591 );
592 }
593 }
594 }
595 }
596 }
597
598 Ok(())
599}