feat(swc/cli): add trace configuration for compile

crates/swc/src/lib.rs

@@ -684,6 +684,7 @@ impl Compiler {
         }
     }
 
+    #[tracing::instrument(level = "trace", skip_all)]
     pub fn read_config(&self, opts: &Options, name: &FileName) -> Result<Option<Config>, Error> {
         static CUR_DIR: Lazy<PathBuf> = Lazy::new(|| {
             if cfg!(target_arch = "wasm32") {
@@ -789,6 +790,7 @@ impl Compiler {
     /// This method handles merging of config.
     ///
     /// This method does **not** parse module.
+    #[tracing::instrument(level = "trace", skip_all)]
     pub fn parse_js_as_input<'a, P>(
         &'a self,
         fm: Lrc<SourceFile>,
@@ -836,6 +838,7 @@ impl Compiler {
         })
     }
 
+    #[tracing::instrument(level = "trace", skip_all)]
     pub fn transform(
         &self,
         handler: &Handler,
@@ -863,6 +866,7 @@ impl Compiler {
     ///
     /// This means, you can use `noop_visit_type`, `noop_fold_type` and
     /// `noop_visit_mut_type` in your visitor to reduce the binary size.
+    #[tracing::instrument(level = "trace", skip_all)]
     pub fn process_js_with_custom_pass<P1, P2>(
         &self,
         fm: Arc<SourceFile>,
@@ -923,6 +927,7 @@ impl Compiler {
         .context("failed to process js file")
     }
 
+    #[tracing::instrument(level = "trace", skip_all)]
     pub fn process_js_file(
         &self,
         fm: Arc<SourceFile>,
@@ -932,6 +937,7 @@ impl Compiler {
         self.process_js_with_custom_pass(fm, None, handler, opts, |_| noop(), |_| noop())
     }
 
+    #[tracing::instrument(level = "trace", skip_all)]
     pub fn minify(
         &self,
         fm: Arc<SourceFile>,
@@ -1053,6 +1059,7 @@ impl Compiler {
     /// You can use custom pass with this method.
     ///
     /// There exists a [PassBuilder] to help building custom passes.
+    #[tracing::instrument(level = "trace", skip_all)]
     pub fn process_js(
         &self,
         handler: &Handler,
@@ -1065,6 +1072,7 @@ impl Compiler {
         self.process_js_with_custom_pass(fm, Some(program), handler, opts, |_| noop(), |_| noop())
     }
 
+    #[tracing::instrument(level = "trace", skip_all)]
     fn process_js_inner(
         &self,
         handler: &Handler,
@@ -1107,6 +1115,7 @@ impl Compiler {
     }
 }
 
+#[tracing::instrument(level = "trace", skip_all)]
 fn load_swcrc(path: &Path) -> Result<Rc, Error> {
     fn convert_json_err(e: serde_json::Error) -> Error {
         let line = e.line();

crates/swc_cli/Cargo.toml

@@ -23,6 +23,10 @@ relative-path = "1.6.1"
 serde = { version = "1", features = ["derive"] }
 serde_json = { version = "1", features = ["unbounded_depth"] }
 atty = "0.2.14"
+tracing-chrome = "0.4.0"
+tracing-futures = "0.2.5"
+tracing-subscriber = { version = "0.3.9", features = ["env-filter"] }
+tracing = "0.1.31"
 
 [dependencies.path-absolutize]
 version = "3.0.11"

crates/swc_cli/src/commands/compile.rs

@@ -15,6 +15,8 @@ use swc::{
     try_with_handler, Compiler, TransformOutput,
 };
 use swc_common::{sync::Lazy, FileName, FilePathMapping, SourceMap};
+use tracing_chrome::{ChromeLayerBuilder, FlushGuard};
+use tracing_subscriber::{prelude::__tracing_subscriber_SubscriberExt, util::SubscriberInitExt};
 use walkdir::WalkDir;
 
 /// Configuration option for transform files.
@@ -77,6 +79,16 @@ pub struct CompileOptions {
     /// Files to compile
     #[clap(group = "input")]
     files: Vec<PathBuf>,
+
+    /// Enable experimantal trace profiling
+    /// generates trace compatible with trace event format.
+    #[clap(group = "experimental_trace", long)]
+    experimental_trace: bool,
+
+    /// Set file name for the trace output. If not specified,
+    /// `trace-{unix epoch time}.json` will be used by default.
+    #[clap(group = "experimental_trace", long)]
+    trace_out_file: Option<String>,
     //Flags legacy @swc/cli supports, might need some thoughts if we need support same.
     //log_watch_compilation: bool,
     //copy_files: bool,
@@ -97,6 +109,7 @@ static DEFAULT_EXTENSIONS: &[&str] = &["js", "jsx", "es6", "es", "mjs", "ts", "t
 /// Infer list of files to be transformed from cli arguments.
 /// If given input is a directory, it'll traverse it and collect all supported
 /// files.
+#[tracing::instrument(level = "trace", skip_all)]
 fn get_files_list(
     raw_files_input: &[PathBuf],
     extensions: &[String],
@@ -246,8 +259,27 @@ fn collect_stdin_input() -> Option<String> {
     )
 }
 
+fn init_trace(out_file: &Option<String>) -> Option<FlushGuard> {
+    let layer = if let Some(trace_out_file) = out_file {
+        ChromeLayerBuilder::new()
+            .file(trace_out_file.clone())
+            .include_args(true)
+    } else {
+        ChromeLayerBuilder::new().include_args(true)
+    };
+
+    let (chrome_layer, guard) = layer.build();
+    tracing_subscriber::registry()
+        .with(chrome_layer)
+        .try_init()
+        .expect("Should able to register trace");
+
+    Some(guard)
+}
+
 impl super::CommandRunner for CompileOptions {
-    fn execute(&self) -> anyhow::Result<()> {
+    #[tracing::instrument(level = "trace", skip_all)]
+    fn execute_inner(&self) -> anyhow::Result<()> {
         let stdin_input = collect_stdin_input();
 
         if stdin_input.is_some() && !self.files.is_empty() {
@@ -259,6 +291,8 @@ impl super::CommandRunner for CompileOptions {
         }
 
         if let Some(stdin_input) = stdin_input {
+            let span = tracing::span!(tracing::Level::TRACE, "compile_stdin");
+            let _ = span.enter();
             let comp = COMPILER.clone();
 
             let result = try_with_handler(comp.cm.clone(), false, |handler| {
@@ -323,4 +357,20 @@ impl super::CommandRunner for CompileOptions {
 
         Ok(())
     }
+
+    fn execute(&self) -> anyhow::Result<()> {
+        let guard = if self.experimental_trace {
+            init_trace(&self.trace_out_file)
+        } else {
+            None
+        };
+
+        let ret = self.execute_inner();
+
+        if let Some(guard) = guard {
+            guard.flush();
+        }
+
+        ret
+    }
 }

crates/swc_cli/src/commands/mod.rs

@@ -13,7 +13,7 @@ pub enum Command {
     #[clap(subcommand)]
     Plugin(PluginSubcommand),
     /// Run SWC's transformer.
-    Compile(CompileOptions),
+    Compile(Box<CompileOptions>),
 }
 
 #[derive(Parser)]
@@ -25,4 +25,5 @@ pub struct SwcCliOptions {
 
 pub trait CommandRunner {
     fn execute(&self) -> anyhow::Result<()>;
+    fn execute_inner(&self) -> anyhow::Result<()>;
 }

crates/swc_cli/src/commands/plugin.rs

@@ -109,6 +109,10 @@ fn write_ignore_file(base_path: &Path) -> Result<()> {
 }
 
 impl super::CommandRunner for PluginScaffoldOptions {
+    fn execute_inner(&self) -> Result<()> {
+        Ok(())
+    }
+
     /// Create a rust project for the plugin from template.
     /// This largely mimic https://github.com/rust-lang/cargo/blob/master/src/cargo/ops/cargo_new.rs,
     /// but also thinner implementation based on some assumptions like skipping
@@ -217,7 +221,7 @@ pub struct TransformVisitor;
 
 impl VisitMut for TransformVisitor {
     // Implement necessary visit_mut_* methods for actual custom transform.
-    // A comprehensive list of possible visitor methods can be found here: 
+    // A comprehensive list of possible visitor methods can be found here:
     // https://rustdoc.swc.rs/swc_ecma_visit/trait.VisitMut.html
 }