feat(codegen): add sourcemap feature flag

[Boshen]

Oxlint uses oxc_codegen for fixes, but do not require sourcemap.

[Copilot]

Pull request overview

This PR adds a sourcemap feature flag to the oxc_codegen crate, allowing consumers like oxlint to use codegen for fixes without pulling in sourcemap dependencies. The feature is enabled by default to maintain backward compatibility.

Key changes:

• Made oxc_sourcemap an optional dependency with a sourcemap feature flag (enabled by default)
• Added conditional compilation attributes throughout the codebase for sourcemap-related code
• Updated all workspace consumers to explicitly enable or disable the sourcemap feature based on their needs

Reviewed changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
crates/oxc_codegen/Cargo.toml	Defines the sourcemap feature flag, makes oxc_sourcemap optional, and sets it as default
crates/oxc_codegen/src/lib.rs	Gates sourcemap module, types, fields, and methods behind #[cfg(feature = "sourcemap")] with no-op implementations when disabled
crates/oxc_codegen/tests/integration/main.rs	Gates sourcemap test module behind the feature flag
Cargo.toml	Sets default-features = false for the workspace-level oxc_codegen reference
crates/oxc/Cargo.toml	Enables sourcemap feature when the codegen feature is used
crates/oxc_linter/Cargo.toml	Disables default features to avoid pulling in sourcemap dependency (key optimization for oxlint)
crates/oxc_minifier/Cargo.toml	Explicitly enables sourcemap feature as minifier generates source maps
crates/oxc_isolated_declarations/Cargo.toml	Enables sourcemap in dev-dependencies for testing
crates/oxc_transformer/Cargo.toml	Enables sourcemap in dev-dependencies for testing
crates/oxc_transformer_plugins/Cargo.toml	Enables sourcemap in dev-dependencies for testing
napi/minify/Cargo.toml	Enables sourcemap feature as the minify API exposes source maps
tasks/ast_tools/Cargo.toml	Enables sourcemap feature for AST tools
tasks/benchmark/Cargo.toml	Enables sourcemap feature for benchmarking
tasks/minsize/Cargo.toml	Enables sourcemap feature for minsize testing

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[codspeed-hq]

CodSpeed Performance Report

Merging #17305 will not alter performance

_{Comparing feat/sourcemap-feature-flag (c1aa6cb) with main (8e4409a)}

Summary

✅ 42 untouched
⏩ 3 skipped¹

Footnotes

1. 3 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[Boshen]

Merge activity

• Dec 23, 10:22 AM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Dec 23, 10:28 AM UTC: Boshen added this pull request to the Graphite merge queue.
• Dec 23, 10:34 AM UTC: Merged by the Graphite merge queue.