Wasm (#691)

.cargo/config

@@ -7,3 +7,9 @@ rustflags = [
 rustdocflags = [
     "--cfg", "procmacro2_semver_exempt",
 ]
+
+[target.wasm32-unknown-unknown]
+rustflags = [
+    "--cfg", "procmacro2_semver_exempt",
+    "-C", "link-args=-z stack-size=16777216",
+]

Cargo.toml

@@ -1,5 +1,5 @@
 [workspace]
-members = ["ecmascript/visit"]
+members = ["ecmascript/visit", "wasm"]
 
 [package]
 name = "swc"

macros/common/src/lib.rs

@@ -1,6 +1,8 @@
 extern crate proc_macro;
 
-use pmutil::{synom_ext::FromSpan, SpanExt};
+use pmutil::synom_ext::FromSpan;
+#[cfg(procmacro2_semver_exempt)]
+use pmutil::SpanExt;
 use proc_macro2::Span;
 use syn::*;
 

package.json

@@ -1,6 +1,7 @@
 {
   "devDependencies": {
     "browserslist": "^4.8.7",
+    "jest": "^25.1.0",
     "sourcemap-validator": "^2.1.0"
   }
 }

src/config.rs

@@ -52,6 +52,7 @@ pub struct Options {
     #[serde(flatten, default)]
     pub config: Option<Config>,
 
+    #[cfg(not(target_arch = "wasm32"))]
     #[serde(default = "default_cwd")]
     pub cwd: PathBuf,
 
@@ -73,6 +74,7 @@ pub struct Options {
     #[serde(default = "default_swcrc")]
     pub swcrc: bool,
 
+    #[cfg(not(target_arch = "wasm32"))]
     #[serde(default)]
     pub swcrc_roots: Option<PathBuf>,
 
@@ -284,6 +286,7 @@ pub struct CallerOptions {
     pub name: String,
 }
 
+#[cfg(not(target_arch = "wasm32"))]
 fn default_cwd() -> PathBuf {
     ::std::env::current_dir().unwrap()
 }
@@ -645,12 +648,17 @@ impl GlobalPassOption {
         let envs = self.envs;
         InlineGlobals {
             globals: mk_map(cm, handler, self.vars.into_iter(), false),
-            envs: mk_map(
+
+            envs: if cfg!(target_arch = "wasm32") {
+                mk_map(cm, handler, vec![].into_iter(), true)
+            } else {
+                mk_map(
                     cm,
                     handler,
                     env::vars().filter(|(k, _)| envs.contains(&*k)),
                     true,
-            ),
+                )
+            },
         }
     }
 }

src/lib.rs

@@ -35,7 +35,11 @@ pub use ecmascript::{
     transforms::{chain_at, pass::Pass},
 };
 use serde::Serialize;
-use std::{fs::File, path::Path, sync::Arc};
+use std::{
+    fs::File,
+    path::{Path, PathBuf},
+    sync::Arc,
+};
 
 pub struct Compiler {
     /// swc uses rustc's span interning.
@@ -285,9 +289,13 @@ impl Compiler {
                 is_module,
                 ..
             } = opts;
-            let root = root
-                .clone()
-                .unwrap_or_else(|| ::std::env::current_dir().unwrap());
+            let root = root.clone().unwrap_or_else(|| {
+                if cfg!(target_arch = "wasm32") {
+                    PathBuf::new()
+                } else {
+                    ::std::env::current_dir().unwrap()
+                }
+            });
 
             let config_file = match config_file {
                 Some(ConfigFile::Str(ref s)) => {

wasm/Cargo.toml

@@ -0,0 +1,24 @@
+[package]
+name = "wasm"
+version = "0.1.0"
+authors = ["강동윤 <kdy1997.dev@gmail.com>"]
+license = "Apache-2.0/MIT"
+repository = "https://github.com/swc-project/swc.git"
+description = "wasm module for swc"
+edition = "2018"
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+swc = { path = "../" }
+serde_json = "1"
+once_cell = "1.3.1"
+path-clean = "0.1"
+serde = { version = "1", features = ["derive"] }
+wasm-bindgen-futures = "0.4.8"
+console_error_panic_hook = "0.1.6"
+
+[dependencies.wasm-bindgen]
+version = "0.2"
+features = ["serde-serialize"]

wasm/__tests__/error.js

@@ -0,0 +1,11 @@
+const swc = require("../pkg");
+
+it("properly reports error", function () {
+  expect(() => {
+    swc.transformSync("Foo {}", {});
+  }).toThrow("failed to process code: failed to parse module");
+
+  expect(() => {
+    swc.transformSync("Foo {}", {});
+  }).toThrow("error: Expected ';', '}' or <eof>");
+});

wasm/__tests__/simple.js

@@ -0,0 +1,5 @@
+const swc = require("../pkg");
+
+it("should be loadable", function () {
+  const output = swc.transformSync("class Foo {}", {});
+});

wasm/package.json

@@ -0,0 +1,5 @@
+{
+  "devDependencies": {
+    "jest": "^25.1.0"
+  }
+}

wasm/scripts/build.sh

@@ -0,0 +1 @@
+wasm-pack build --debug --scope swc -t nodejs

wasm/scripts/test.sh

@@ -0,0 +1,6 @@
+#!/usr/bin/env bash
+
+set -eu
+
+./scripts/build.sh
+npx jest

wasm/src/lib.rs

@@ -0,0 +1,162 @@
+#![feature(box_syntax)]
+
+use once_cell::sync::Lazy;
+use std::{
+    fmt::{self, Display, Formatter},
+    io::{self, Write},
+    sync::{Arc, RwLock},
+};
+use swc::{
+    common::{
+        errors::{EmitterWriter, Handler, HandlerFlags, SourceMapperDyn},
+        FileName, FilePathMapping, SourceMap,
+    },
+    config::{InputSourceMap, Options, ParseOptions, SourceMapsConfig},
+    ecmascript::ast::Program,
+    Compiler,
+};
+use wasm_bindgen::prelude::*;
+
+#[wasm_bindgen(js_name = "parseSync")]
+pub fn parse_sync(s: &str, opts: JsValue) -> Result<JsValue, JsValue> {
+    console_error_panic_hook::set_once();
+
+    let opts: ParseOptions = opts
+        .into_serde()
+        .map_err(|err| format!("failed to parse options: {}", err))?;
+
+    let (c, errors) = compiler();
+
+    let fm = c.cm.new_source_file(FileName::Anon, s.into());
+    let (prog, src_map) = c
+        .parse_js(
+            fm,
+            opts.target,
+            opts.syntax,
+            opts.is_module,
+            opts.comments,
+            &InputSourceMap::Bool(false),
+        )
+        .map_err(|err| format!("failed to parse: {}\n{}", err, errors))?;
+
+    let mut source_map = vec![];
+    if let Some(src_map) = src_map {
+        src_map
+            .to_writer(&mut source_map)
+            .map_err(|err| format!("failed to print source map file: {}", err))?;
+    }
+
+    Ok(
+        JsValue::from_serde(&(prog, &*String::from_utf8_lossy(&source_map)))
+            .map_err(|err| format!("failed to return value: {}", err))?,
+    )
+}
+
+#[wasm_bindgen(js_name = "printSync")]
+pub fn print_sync(s: JsValue, opts: JsValue) -> Result<JsValue, JsValue> {
+    console_error_panic_hook::set_once();
+
+    let program: Program = s
+        .into_serde()
+        .map_err(|err| format!("not a program: {}", err))?;
+
+    let opts: Options = opts
+        .into_serde()
+        .map_err(|err| format!("failed to parse options: {}", err))?;
+
+    let (c, errors) = compiler();
+
+    let s = c
+        .print(
+            &program,
+            c.comments(),
+            opts.source_maps
+                .clone()
+                .unwrap_or(SourceMapsConfig::Bool(false)),
+            None,
+            opts.config.unwrap_or_default().minify.unwrap_or_default(),
+        )
+        .map_err(|err| format!("failed to print: {}\n{}", err, errors))?;
+
+    Ok(JsValue::from_serde(&s).map_err(|err| format!("failed to print: {}\n{}", err, errors))?)
+}
+
+#[wasm_bindgen(js_name = "transformSync")]
+pub fn transform_sync(s: &str, opts: JsValue) -> Result<JsValue, JsValue> {
+    console_error_panic_hook::set_once();
+
+    let opts: Options = opts
+        .into_serde()
+        .map_err(|err| format!("failed to parse options: {}", err))?;
+
+    let (c, errors) = compiler();
+
+    let fm = c.cm.new_source_file(FileName::Anon, s.into());
+    let out = c
+        .process_js_file(fm, &opts)
+        .map_err(|err| format!("failed to process code: {}\n{}", err, errors))?;
+
+    Ok(JsValue::from_serde(&out).unwrap())
+}
+
+fn compiler() -> (Compiler, BufferedError) {
+    let cm = codemap();
+
+    let (handler, errors) = new_handler(cm.clone());
+
+    let c = Compiler::new(cm.clone(), handler);
+
+    (c, errors)
+}
+
+/// Get global sourcemap
+fn codemap() -> Arc<SourceMap> {
+    static CM: Lazy<Arc<SourceMap>> =
+        Lazy::new(|| Arc::new(SourceMap::new(FilePathMapping::empty())));
+
+    CM.clone()
+}
+
+/// Creates a new handler which emits to returned buffer.
+fn new_handler(cm: Arc<SourceMapperDyn>) -> (Handler, BufferedError) {
+    let e = BufferedError::default();
+
+    let handler = Handler::with_emitter_and_flags(
+        Box::new(EmitterWriter::new(
+            Box::new(e.clone()),
+            Some(cm.clone()),
+            false,
+            false,
+        )),
+        HandlerFlags {
+            treat_err_as_bug: false,
+            can_emit_warnings: true,
+            ..Default::default()
+        },
+    );
+
+    (handler, e)
+}
+
+#[derive(Clone, Default)]
+pub(crate) struct BufferedError(Arc<RwLock<String>>);
+
+impl Write for BufferedError {
+    fn write(&mut self, d: &[u8]) -> io::Result<usize> {
+        self.0
+            .write()
+            .unwrap()
+            .push_str(&String::from_utf8_lossy(d));
+
+        Ok(d.len())
+    }
+    fn flush(&mut self) -> io::Result<()> {
+        Ok(())
+    }
+}
+
+impl Display for BufferedError {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        Display::fmt(&self.0.read().unwrap(), f)
+    }
+}