Merge upstream/master into main by kdy1 · Pull Request #136 · getsentry/rust-sourcemap

kdy1 · 2025-12-04T10:47:13Z

Summary

Integrate changes from upstream getsentry/rust-sourcemap v9.3.0 release
Update CHANGELOG.md with upstream changes
Merge improvements to decoder, encoder, and type definitions
Update test suite with upstream enhancements

Conflict Resolution

Conflicts were resolved by keeping swc-project fork modifications:

Cargo.toml: Maintained package name as swc_sourcemap and current version
src/sourceview.rs: Kept BytesStr-based implementation instead of Arc

Test plan

Verify all existing tests pass
Check that the package name remains swc_sourcemap
Confirm BytesStr implementation still works correctly

🤖 Generated with Claude Code

In case of most transforms (for ECMAScript), the original input source map is used only to adjust mappings, and other fields are kept intact. The _lazy_ variant source maps are source maps used only to call `adjust_mappings`. It does not deserialize everything. Instead, it only deserializes the fields required to calculate the new mappings. This is done in the name of the performance, and the justification for introducing a new type is at vercel/next.js#80177 (comment) <img width="881" alt="image" src="https://github.com/user-attachments/assets/7ca4b084-ba46-4384-ac25-fefeae0e2513" />

I added some `skip_serializing_if` to `RawSourceMap`

`BytesStr` is a more efficient variant of `Arc<str>` Since swc-project/swc#10580, SWC also uses it to store the source map strings

cherry pick getsentry#130 Co-authored-by: Sebastian Zivota <loewenheim@users.noreply.github.com>

A stupid typo

cherry-pick getsentry#132 --------- Co-authored-by: Sebastian Zivota <loewenheim@users.noreply.github.com>

Caused invalid source content: <img width="2018" height="721" alt="image" src="https://github.com/user-attachments/assets/dca54abd-fec5-4f4e-88ac-67e2d255dbfd" />

Integrate changes from upstream getsentry/rust-sourcemap v9.3.0 release: - Update CHANGELOG.md with upstream changes - Merge improvements to decoder, encoder, and type definitions - Update test suite with upstream enhancements Conflicts resolved by keeping swc-project fork modifications: - Cargo.toml: Maintain package name as 'swc_sourcemap' and current version - src/sourceview.rs: Keep BytesStr-based implementation 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>

sentry · 2025-12-04T10:49:10Z

src/sourceview.rs

+            lines.push(unsafe {
+                str::from_utf8_unchecked(slice::from_raw_parts(rv.as_ptr(), rv.len()))
+            });


Bug: Lifetime violation: &'static str in cache points to non-static data.
_{Severity: CRITICAL | Confidence: High}

🔍 Detailed Analysis

The SourceView struct stores &'static str references in its lines: Mutex<Vec<&'static str>> cache. These references actually point to data owned by self.source, which does not have a 'static lifetime. This creates a lifetime violation where the cached &str pointers can become dangling if self.source is dropped or re-initialized while the cached lines are still in use, for example, when a SourceView instance is cloned and processed_until resets.

💡 Suggested Fix

Change the lines cache to store BytesStr or String instead of &'static str to ensure owned data or correctly managed lifetimes. Alternatively, ensure the SourceView struct itself holds ownership of the data for the lifetime of the cached references.

🤖 Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI agent. Verify if this is a real issue. If it is, propose a fix; if not, explain why it's not valid. Location: src/sourceview.rs#L214-L216 Potential issue: The `SourceView` struct stores `&'static str` references in its `lines: Mutex<Vec<&'static str>>` cache. These references actually point to data owned by `self.source`, which does not have a `'static` lifetime. This creates a lifetime violation where the cached `&str` pointers can become dangling if `self.source` is dropped or re-initialized while the cached lines are still in use, for example, when a `SourceView` instance is cloned and `processed_until` resets.

_{Did we get this right? 👍 / 👎 to inform future reviews.}
_{Reference ID: 5461981}

Copilot

Pull request overview

This PR merges upstream getsentry/rust-sourcemap v9.3.0 into the swc-project fork, bringing improvements to decoder, encoder, and type definitions while maintaining fork-specific modifications. The merge involves significant type system changes from Arc<str> to BytesStr and adds a new lazy decoding module for better performance.

Key changes:

Replaced Arc<str> with BytesStr throughout the codebase for string storage
Added new lazy module for lazy sourcemap decoding with minimal field deserialization
Implemented adjust_mappings_from_multiple function for combining multiple sourcemaps
Refactored SourceView internal line storage mechanism using atomic operations

Critical Issues Found:

Lifetime soundness bug in SourceView where &'static str references are unsafely created from non-static data
Rust edition incompatibility with use<'_, 'a> syntax requiring Rust 2024 but project uses edition 2018
Invalid API call to .advance() method that doesn't exist on BytesStr

Reviewed changes

Copilot reviewed 30 out of 33 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
tests/*.rs	Updated imports from `sourcemap` to `swc_sourcemap` and adjusted test assertions for BytesStr API changes
tests/fixtures/adjust_mappings_from_multiple/*	Added test fixtures for new multi-sourcemap adjustment feature
src/types.rs	Refactored to use BytesStr, added adjust_mappings_from_multiple function, updated all string APIs
src/sourceview.rs	Refactored line caching with atomic operations (contains critical lifetime bug)
src/lazy/mod.rs	New module for lazy sourcemap decoding (contains Rust 2024 syntax issue)
src/builder.rs	Updated to use BytesStr APIs (contains invalid method call)
src/*.rs (other)	Updated imports and type signatures to use BytesStr
examples/*.rs	Updated imports to swc_sourcemap
Cargo.toml	Updated package metadata, version, and added bytes-str dependency
README.md	Updated example code to use swc_sourcemap
.github/workflows/ci.yml	Updated branch names and workflow triggers

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Copilot · 2025-12-04T10:51:30Z

src/builder.rs

                }
                if source.starts_with(&prefix) {
-                    *source = source[prefix.len()..].into();
+                    source.advance(prefix.len());


The advance method is being called on BytesStr, but this method may not exist in the bytes-str crate version 0.2.4. This appears to be an incorrect API usage. Consider replacing this with: *source = source[prefix.len()..].into(); or using the appropriate BytesStr API to skip a prefix.

Suggested change

source.advance(prefix.len());

*source = source[prefix.len()..].into();

Copilot · 2025-12-04T10:51:30Z

src/lazy/mod.rs

+
+#[derive(Debug, Clone, Copy, Serialize)]
+#[serde(untagged)]
+pub(crate) enum MaybeRawValue<'a, T> {


[nitpick] MaybeRawValue is declared as pub(crate) in the lazy module, which means it should be accessible within the crate, including in tests within src/types.rs. However, to ensure proper encapsulation, consider whether this type should be made fully public (pub) if it's needed in tests, or if the test should be restructured to avoid using it directly.

Suggested change

pub(crate) enum MaybeRawValue<'a, T> {

pub enum MaybeRawValue<'a, T> {

Copilot · 2025-12-04T10:51:31Z

src/sourceview.rs

-    line_end_offsets: Mutex<Vec<LineEndOffset>>,
+    pub(crate) source: BytesStr,
+    processed_until: AtomicUsize,
+    lines: Mutex<Vec<&'static str>>,


The lines field stores &'static str references, but the get_line method creates these references from the BytesStr source using unsafe code (lines 214-216). This is unsound because the references don't actually have a static lifetime - they're tied to the lifetime of the BytesStr in self.source. If the SourceView is dropped, the BytesStr is dropped, but the &'static str references in lines would become dangling pointers.

This should be changed to store references with a lifetime tied to self, such as lines: Mutex<Vec<&str>> with appropriate lifetime annotations on the struct, or use indices into the source instead of raw pointers.

Suggested change

lines: Mutex<Vec<&'static str>>,

lines: Mutex<Vec<(usize, usize)>>,

Copilot · 2025-12-04T10:51:31Z

src/lazy/mod.rs

+        self.file.as_mut().map(|f| &*f.as_data())
+    }
+
+    pub fn sources(&mut self) -> impl Iterator<Item = &'_ BytesStr> + use<'_, 'a> {


The use<'_, 'a> syntax in the return type is a Rust 2024 edition feature that may not be compatible with the edition specified in Cargo.toml (edition = "2018"). This will cause compilation errors. Consider either updating the edition to "2024" or using a different return type like impl Iterator<Item = &'_ BytesStr> + '_.

Suggested change

pub fn sources(&mut self) -> impl Iterator<Item = &'_ BytesStr> + use<'_, 'a> {

pub fn sources(&mut self) -> impl Iterator<Item = &'_ BytesStr> + '_ {

Copilot · 2025-12-04T10:51:32Z

tests/fixtures/adjust_mappings_from_multiple/bundle.js

+    return fn();
+} //# sourceMappingURL=sourcemapped.js.map
+;
+runExternalSourceMapped();


Callee is not a function: it has type undefined.

Suggested change

runExternalSourceMapped();

runExternalSourceMapped(() => {});

loewenheim · 2025-12-04T11:30:50Z

Sorry, what exactly is this meant to do? master is already at 9.3.0.

kdy1 · 2025-12-04T11:35:42Z

Oh sorry... This is the same as #135 (PR created towards wrong repository by Claude Code).

I missed this PR. My bad. Sorry

loewenheim · 2025-12-04T11:41:25Z

No worries!

kdy1 and others added 13 commits June 5, 2025 15:31

fix: Fix serialization of source maps (#2)

76a5863

I added some `skip_serializing_if` to `RawSourceMap`

fix: Keep names field

804d663

refactor: Use BytesStr instead of Arc<str> (#1)

acd7bbb

`BytesStr` is a more efficient variant of `Arc<str>` Since swc-project/swc#10580, SWC also uses it to store the source map strings

fix: Fix sources field (#2)

62102ed

feat: Add adjust_mappings_from_multiple (#3)

72e82b1

chore: Fix 1.88.0 clippy lints (#5)

6bc7ac9

cherry pick getsentry#130 Co-authored-by: Sebastian Zivota <loewenheim@users.noreply.github.com>

fix: add_source that should have been add_name (#4)

34efd0c

A stupid typo

chore: Publish v9.3.3 (#6)

68cd09a

fix: Fix 1.89.0 clippy lints (getsentry#132) (#8)

6dd8518

cherry-pick getsentry#132 --------- Co-authored-by: Sebastian Zivota <loewenheim@users.noreply.github.com>

fix: Use correct id in set_source_contents (#7)

c168b3d

Caused invalid source content: <img width="2018" height="721" alt="image" src="https://github.com/user-attachments/assets/dca54abd-fec5-4f4e-88ac-67e2d255dbfd" />

chore: Publish v9.3.4 (#9)

64fcb47

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Merge upstream/master into main#136

Merge upstream/master into main#136
kdy1 wants to merge 13 commits intogetsentry:masterfrom
swc-project:merge-upstream-master

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	source.advance(prefix.len());
	*source = source[prefix.len()..].into();

	pub(crate) enum MaybeRawValue<'a, T> {
	pub enum MaybeRawValue<'a, T> {

	lines: Mutex<Vec<&'static str>>,
	lines: Mutex<Vec<(usize, usize)>>,

	pub fn sources(&mut self) -> impl Iterator<Item = &'_ BytesStr> + use<'_, 'a> {
	pub fn sources(&mut self) -> impl Iterator<Item = &'_ BytesStr> + '_ {

	runExternalSourceMapped();
	runExternalSourceMapped(() => {});

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kdy1 commented Dec 4, 2025

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