perf(codegen)!: borrow sourcemaps from codegen (#23422)

Summary:
- Upgrade oxc_sourcemap to 8.0.1.
- Return borrowed SourceMap from CodegenReturn.
- Support no-sourcemap feature builds used by benchmarks.

AI-assisted: yes

Cargo.lock

@@ -2628,9 +2628,9 @@ dependencies = [
 
 [[package]]
 name = "oxc_sourcemap"
-version = "7.0.0"
+version = "8.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "db3866f9075027840e0711b52e15d2e1ba076fc5f5f01c96eeedd26375410641"
+checksum = "174d2498c2390ccfab0a9caaf47ef5accda1d509aaa34a5be8f45e00e5299f04"
 dependencies = [
  "base64-simd",
  "json-escape-simd",

Cargo.toml

@@ -175,7 +175,7 @@ json-strip-comments = "3.1.0" # Strip JSON comments
 oxc-browserslist = "3.0.0" # Browser compatibility queries
 oxc_index = { version = "5.0.0", features = ["nonmax", "serde"] } # Type-safe indices
 oxc_resolver = "11.16.3" # Module resolution
-oxc_sourcemap = "7.0.0" # Source map generation
+oxc_sourcemap = "8.0.1" # Source map generation
 
 #
 allocator-api2 = "=0.2.21" # Allocator trait

crates/oxc/src/compiler.rs

@@ -27,7 +27,7 @@ impl CompilerInterface for Compiler {
         self.errors.extend(errors);
     }
 
-    fn after_codegen(&mut self, ret: CodegenReturn) {
+    fn after_codegen(&mut self, ret: CodegenReturn<'_>) {
         self.printed = ret.code;
     }
 }
@@ -112,7 +112,7 @@ pub trait CompilerInterface {
         ControlFlow::Continue(())
     }
 
-    fn after_isolated_declarations(&mut self, _ret: CodegenReturn) {}
+    fn after_isolated_declarations(&mut self, _ret: CodegenReturn<'_>) {}
 
     fn after_transform(
         &mut self,
@@ -122,7 +122,7 @@ pub trait CompilerInterface {
         ControlFlow::Continue(())
     }
 
-    fn after_codegen(&mut self, _ret: CodegenReturn) {}
+    fn after_codegen(&mut self, _ret: CodegenReturn<'_>) {}
 
     fn compile(&mut self, source_text: &str, source_type: SourceType, source_path: &Path) {
         let allocator = Allocator::default();
@@ -308,13 +308,13 @@ pub trait CompilerInterface {
         Mangler::new().with_options(options).build(program)
     }
 
-    fn codegen(
+    fn codegen<'a>(
         &self,
-        program: &Program<'_>,
+        program: &Program<'a>,
         source_path: &Path,
         mangler_return: Option<ManglerReturn>,
         options: CodegenOptions,
-    ) -> CodegenReturn {
+    ) -> CodegenReturn<'a> {
         let mut options = options;
         if self.enable_sourcemap() {
             options.source_map_path = Some(source_path.to_path_buf());

crates/oxc_codegen/src/lib.rs

@@ -3,6 +3,8 @@
 //! Code adapted from
 //! * [esbuild](https://github.com/evanw/esbuild/blob/v0.24.0/internal/js_printer/js_printer.go)
 
+#[cfg(not(feature = "sourcemap"))]
+use std::marker::PhantomData;
 use std::{borrow::Cow, cmp, slice};
 
 use cow_utils::CowUtils;
@@ -48,7 +50,7 @@ pub use oxc_data_structures::code_buffer::IndentChar;
 
 /// Output from [`Codegen::build`]
 #[non_exhaustive]
-pub struct CodegenReturn {
+pub struct CodegenReturn<'a> {
     /// The generated source code.
     pub code: String,
 
@@ -56,7 +58,10 @@ pub struct CodegenReturn {
     ///
     /// You must set [`CodegenOptions::source_map_path`] for this to be [`Some`].
     #[cfg(feature = "sourcemap")]
-    pub map: Option<oxc_sourcemap::OwnedSourceMap>,
+    pub map: Option<oxc_sourcemap::SourceMap<'a>>,
+
+    #[cfg(not(feature = "sourcemap"))]
+    _source_map_lifetime: PhantomData<&'a ()>,
 
     /// All the legal comments returned from [LegalComment::Linked] or [LegalComment::External].
     pub legal_comments: Vec<Comment>,
@@ -246,7 +251,7 @@ impl<'a> Codegen<'a> {
     ///
     /// A source map will be generated if [`CodegenOptions::source_map_path`] is set.
     #[must_use]
-    pub fn build(mut self, program: &Program<'a>) -> CodegenReturn {
+    pub fn build(mut self, program: &Program<'a>) -> CodegenReturn<'a> {
         self.quote = if self.options.single_quote { Quote::Single } else { Quote::Double };
         self.source_text = Some(program.source_text);
         self.indent = self.options.initial_indent;
@@ -265,6 +270,8 @@ impl<'a> Codegen<'a> {
             code,
             #[cfg(feature = "sourcemap")]
             map,
+            #[cfg(not(feature = "sourcemap"))]
+            _source_map_lifetime: PhantomData,
             legal_comments,
         }
     }

crates/oxc_codegen/src/sourcemap_builder.rs

@@ -1,8 +1,9 @@
-use std::path::Path;
+use std::{borrow::Cow, path::Path};
 
 use oxc_index::{IndexVec, define_nonmax_u32_index_type};
 use oxc_span::Span;
 use oxc_syntax::line_terminator::{LS, LS_LAST_2_BYTES, LS_OR_PS_FIRST_BYTE, PS, PS_LAST_2_BYTES};
+use rustc_hash::FxHashMap;
 
 /// Number of lines to check with linear search when translating byte position to line index
 const LINE_SEARCH_LINEAR_ITERATIONS: usize = 16;
@@ -45,14 +46,15 @@ pub struct ColumnOffsets {
     columns: Box<[u32]>,
 }
 
-#[expect(clippy::struct_field_names)]
 pub struct SourcemapBuilder<'a> {
-    source_id: u32,
+    source_name: String,
     original_source: &'a str,
+    names: Vec<&'a str>,
+    names_map: FxHashMap<&'a str, u32>,
+    tokens: Vec<oxc_sourcemap::Token>,
     last_generated_update: usize,
     last_position: Option<u32>,
     line_offset_tables: LineOffsetTables,
-    sourcemap_builder: oxc_sourcemap::SourceMapBuilder,
     generated_line: u32,
     generated_column: u32,
     /// Tracks the last accessed line index to optimize sequential lookups in `search_original_line_and_column`.
@@ -63,25 +65,37 @@ pub struct SourcemapBuilder<'a> {
 
 impl<'a> SourcemapBuilder<'a> {
     pub fn new(path: &Path, source_text: &'a str) -> Self {
-        let mut sourcemap_builder = oxc_sourcemap::SourceMapBuilder::default();
         let line_offset_tables = Self::generate_line_offset_tables(source_text);
-        let source_id =
-            sourcemap_builder.set_source_and_content(path.to_string_lossy().as_ref(), source_text);
         Self {
-            source_id,
+            source_name: path.to_string_lossy().into_owned(),
             original_source: source_text,
+            names: Vec::new(),
+            names_map: FxHashMap::default(),
+            tokens: Vec::new(),
             last_generated_update: 0,
             last_position: None,
             line_offset_tables,
-            sourcemap_builder,
             generated_line: 0,
             generated_column: 0,
             last_line_lookup: 0,
         }
     }
 
-    pub fn into_sourcemap(self) -> oxc_sourcemap::OwnedSourceMap {
-        self.sourcemap_builder.into_owned_sourcemap()
+    pub fn into_sourcemap(mut self) -> oxc_sourcemap::SourceMap<'a> {
+        self.names.shrink_to_fit();
+        self.tokens.shrink_to_fit();
+
+        oxc_sourcemap::SourceMap::from_parts(oxc_sourcemap::SourceMapParts {
+            file: None,
+            names: self.names.into_iter().map(Cow::Borrowed).collect(),
+            source_root: None,
+            sources: vec![Cow::Owned(self.source_name)],
+            source_contents: vec![Some(Cow::Borrowed(self.original_source))],
+            tokens: self.tokens.into_boxed_slice(),
+            token_chunks: None,
+            x_google_ignore_list: None,
+            debug_id: None,
+        })
     }
 
     pub fn add_source_mapping_for_name(&mut self, output: &[u8], span: Span, name: &str) {
@@ -99,24 +113,34 @@ impl<'a> SourcemapBuilder<'a> {
         self.add_source_mapping(output, span.start, token_name);
     }
 
-    pub fn add_source_mapping(&mut self, output: &[u8], position: u32, name: Option<&str>) {
+    pub fn add_source_mapping(&mut self, output: &[u8], position: u32, name: Option<&'a str>) {
         if self.last_position == Some(position) {
             return;
         }
         let (original_line, original_column) = self.search_original_line_and_column(position);
         self.update_generated_line_and_column(output);
-        let name_id = name.map(|s| self.sourcemap_builder.add_name(s));
-        self.sourcemap_builder.add_token(
+        let name_id = name.map(|s| self.add_name(s));
+        self.tokens.push(oxc_sourcemap::Token::new(
             self.generated_line,
             self.generated_column,
             original_line,
             original_column,
-            Some(self.source_id),
+            Some(0),
             name_id,
-        );
+        ));
         self.last_position = Some(position);
     }
 
+    fn add_name(&mut self, name: &'a str) -> u32 {
+        if let Some(&id) = self.names_map.get(name) {
+            return id;
+        }
+        let id = u32::try_from(self.names.len()).expect("sourcemap names length should fit in u32");
+        self.names_map.insert(name, id);
+        self.names.push(name);
+        id
+    }
+
     #[expect(clippy::cast_possible_truncation)]
     fn search_original_line_and_column(&mut self, position: u32) -> (u32, u32) {
         let original_line = self.search_original_line(position);

crates/oxc_codegen/tests/integration/tester.rs

@@ -1,5 +1,6 @@
 use oxc_allocator::Allocator;
-use oxc_codegen::{Codegen, CodegenOptions, CodegenReturn};
+use oxc_ast::ast::Comment;
+use oxc_codegen::{Codegen, CodegenOptions};
 use oxc_parser::{ParseOptions, Parser};
 use oxc_span::SourceType;
 
@@ -95,14 +96,20 @@ pub fn codegen(source_text: &str) -> String {
 }
 
 #[track_caller]
-pub fn codegen_options(source_text: &str, options: &CodegenOptions) -> CodegenReturn {
+pub fn codegen_options(source_text: &str, options: &CodegenOptions) -> CodegenTestReturn {
     let allocator = Allocator::default();
     let source_type = SourceType::ts();
     let ret = Parser::new(&allocator, source_text, source_type).parse();
     assert!(ret.diagnostics.is_empty(), "Parse errors: {:?}", ret.diagnostics);
     let mut options = options.clone();
     options.single_quote = true;
-    Codegen::new().with_options(options).build(&ret.program)
+    let ret = Codegen::new().with_options(options).build(&ret.program);
+    CodegenTestReturn { code: ret.code, legal_comments: ret.legal_comments }
+}
+
+pub struct CodegenTestReturn {
+    pub code: String,
+    pub legal_comments: Vec<Comment>,
 }
 
 #[track_caller]

crates/oxc_minifier/examples/minifier.rs

@@ -81,15 +81,15 @@ fn main() -> std::io::Result<()> {
     Ok(())
 }
 
-fn minify(
-    allocator: &Allocator,
-    source_text: &str,
+fn minify<'a>(
+    allocator: &'a Allocator,
+    source_text: &'a str,
     source_type: SourceType,
     source_map_path: Option<PathBuf>,
     mangle: bool,
     nospace: bool,
     max_iterations: Option<u8>,
-) -> CodegenReturn {
+) -> CodegenReturn<'a> {
     let ret = Parser::new(allocator, source_text, source_type).parse();
     assert!(ret.diagnostics.is_empty());
     let mut program = ret.program;

napi/transform/src/transformer.rs

@@ -871,12 +871,12 @@ impl CompilerInterface for Compiler {
         self.inject.clone()
     }
 
-    fn after_codegen(&mut self, ret: CodegenReturn) {
+    fn after_codegen(&mut self, ret: CodegenReturn<'_>) {
         self.printed = ret.code;
         self.printed_sourcemap = ret.map.map(SourceMap::from);
     }
 
-    fn after_isolated_declarations(&mut self, ret: CodegenReturn) {
+    fn after_isolated_declarations(&mut self, ret: CodegenReturn<'_>) {
         self.declaration.replace(ret.code);
         self.declaration_map = ret.map.map(SourceMap::from);
     }

tasks/coverage/src/driver.rs

@@ -119,7 +119,7 @@ impl CompilerInterface for Driver {
         ControlFlow::Continue(())
     }
 
-    fn after_codegen(&mut self, ret: CodegenReturn) {
+    fn after_codegen(&mut self, ret: CodegenReturn<'_>) {
         self.printed = ret.code;
     }
 }

tasks/transform_conformance/src/driver.rs

@@ -52,7 +52,7 @@ impl CompilerInterface for Driver {
         self.errors.extend(errors);
     }
 
-    fn after_codegen(&mut self, ret: CodegenReturn) {
+    fn after_codegen(&mut self, ret: CodegenReturn<'_>) {
         self.printed = ret.code;
     }