refactor(otel-thread-ctx): add const offset assertions for ThreadContextRecord#2018
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## main #2018 +/- ##
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- Coverage 72.90% 72.88% -0.02%
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Files 457 457
Lines 75769 75769
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Base automatically changed from
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May 20, 2026 16:58
…extRecord
Add compile-time offset_of assertions for every field of the
ThreadContextRecord struct, guarding against silent ABI breakage if
someone reorders or resizes fields in the future.
Move the existing size assertion out of `new()` into a top-level
`const _: () = { ... }` block next to the struct definition, so it
runs unconditionally at compile time regardless of code path.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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#2019) # What does this PR do? Follow-up to #2018. Minor doc and style improvements in `libdd-otel-thread-ctx`. - Add a safety comment for the `unsafe` dereference in `ThreadContext::update()` - Fix `set_attrs` doc comment referencing `record.attrs_data` instead of `self.attrs_data` - Use `u8::try_from(val_len).unwrap_or_else(...)` for value length capping in `set_attrs`, making the `u8` invariant statically guaranteed instead of relying on a manual `if` + a comment # Motivation The `unsafe` block in `update()` lacked a safety justification. The `try_from` pattern eliminates the `as u8` cast and the stale comment that referenced a `min()` that didn't exist. # Additional Notes N/A # How to test the change? ``` cargo test -p libdd-otel-thread-ctx ``` All 8 existing tests pass unchanged. Co-authored-by: yann.hamdaoui <yann.hamdaoui@datadoghq.com>
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What does this PR do?
Follow-up to #2016.
Adds compile-time
mem::offset_of!assertions for every field ofThreadContextRecord, catching accidental ABI breakage (field reordering, padding changes) at compile time rather than at runtime in a profiler.The existing size-only assertion from inside
new()is moved to a top-levelconst _: () = { ... }block next to the struct definition so it fires unconditionally regardless of code path.Motivation
ThreadContextRecordhas a fixed ABI read by out-of-process eBPF readers. The previous singlesize_of == 640check would still pass if fields were reordered without changing the total size. Per-field offset assertions make this impossible.Additional Notes
N/A
How to test the change?
N/A