[derive] Introduce Ctx type

[joshlf]

Use the Ctx type to carry the DeriveInput and zerocopy_crate: Path
values which are used by most functions.

---

• 　 [WIP][derive] Factor out unsafe impl block building #2893
• 👉 [derive] Introduce Ctx type #2890

Latest Update: v6 — Compare vs v5

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[gemini-code-assist]

Summary of Changes

Hello @joshlf, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request introduces a significant refactoring to the zerocopy-derive crate by implementing a new Ctx struct. This struct serves as a central container for the DeriveInput and the zerocopy_crate path, which are commonly used throughout the derive macro implementation. By consolidating these frequently accessed values into a single context object, the change aims to simplify function signatures, enhance code readability, and improve the overall maintainability of the macro's internal logic.

Highlights

• Introduced Ctx Struct: A new Ctx struct is added to centralize DeriveInput and the zerocopy_crate path, which were previously passed as separate arguments to many functions.
• Simplified Function Signatures: Many internal helper functions now accept a single &Ctx parameter, reducing argument clutter and improving readability.
• Improved Code Organization: The logic for extracting the zerocopy_crate path from attributes is now encapsulated within the Ctx::try_from_derive_input method, leading to better modularity.

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[gemini-code-assist]

Code Review

This pull request introduces a Ctx type to bundle DeriveInput and zerocopy_crate path, which are frequently passed together. This is a great refactoring that simplifies many function signatures and improves code maintainability. The changes are applied consistently across the derive macro codebase. I have one minor suggestion to improve performance slightly by moving a variable assignment out of a loop. Overall, this is a solid improvement.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.90%. Comparing base (dae16a5) to head (6ebdd8e).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2890   +/-   ##
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  Coverage   91.90%   91.90%           
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  Files          20       20           
  Lines        5877     5877           
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  Hits         5401     5401           
  Misses        476      476           

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