feat: support override methods in services

[m62624]

Resolves #1179

[gemini-code-assist]

Summary of Changes

Hello @m62624, 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 enhancement by enabling method overriding in services, providing a powerful mechanism for customizing inherited behavior. It integrates a new #[override_entry] macro into the macro system, allowing developers to define custom implementations for methods from extended services. The changes are thoroughly demonstrated with new examples and validated with dedicated test cases, ensuring robust and flexible service development.

Highlights

• New #[override_entry] Macro: Introduced a new procedural macro #[override_entry] that allows methods within a service to override methods inherited from its base services. This macro supports both short-typed style (e.g., #[override_entry(walker_service_methods::Walk)]) and manual style (e.g., #[override_entry(MammalService, 1)]) for specifying the overridden method.
• Service Method Overriding Support: The core macro system has been updated to correctly handle method overriding. This includes modifications to how service methods are dispatched, ensuring that overridden methods are called instead of their base implementations when specified.
• Demonstration and Testing: A new example module inheritance has been added to showcase the functionality of service method overriding, including composite and chained service inheritance. Corresponding test cases (inheritance_redefine_works) have been added to validate the correct behavior of overridden methods.
• Client-Side Updates: The client IDL (demo_client.idl) and generated Rust client code (demo_client.rs) have been updated to include the new Inheritance and Chain services, ensuring that client applications can interact with these new service structures.
• Macro Snapshot Updates: Numerous snapshot tests across ethexe/macros-tests and macros/core/tests have been updated to reflect the changes in macro expansion logic, confirming that the new #[override_entry] attribute and related features are correctly processed during compilation.

Using Gemini Code Assist

The full guide for Gemini Code Assist can be found on our documentation page, here are some quick tips.

Invoking Gemini

You can request assistance from Gemini at any point by creating a comment using either /gemini <command> or @gemini-code-assist <command>. Below is a summary of the supported commands on the current page.

Feature	Command	Description
Code Review	/gemini review	Performs a code review for the current pull request in its current state.
Pull Request Summary	/gemini summary	Provides a summary of the current pull request in its current state.
Comment	@gemini-code-assist	Responds in comments when explicitly tagged, both in pull request comments and review comments.
Help	/gemini help	Displays a list of available commands.

Customization

To customize Gemini Code Assist for GitHub experience, repository maintainers can create a configuration file and/or provide a custom code review style guide (such as PEP-8 for Python) by creating and adding files to a .gemini/ folder in the base of the repository. Detailed instructions can be found here.

Limitations & Feedback

Gemini Code Assist may make mistakes. Please leave feedback on any instances where its feedback is incorrect or counter productive. You can react with 👍 and 👎 on @gemini-code-assist comments. If you're interested in giving your feedback about your experience with Gemini Code Assist for Github and other Google products, sign up here.

You can also get AI-powered code generation, chat, as well as code reviews directly in the IDE at no cost with the Gemini Code Assist IDE Extension.

Footnotes

1. Review the Privacy Notices, Generative AI Prohibited Use Policy, Terms of Service, and learn how to configure Gemini Code Assist in GitHub here. Gemini can make mistakes, so double check it and use code with caution. ↩

[gemini-code-assist]

Code Review

This pull request introduces a significant new feature: the ability to override methods in services. The changes span across the macro implementations, client code generation, and example applications to demonstrate the functionality. The core logic for handling overrides in the gservice macro seems well-thought-out. I've identified a few areas for improvement, including an inefficiency in the new example code, a potential bug in the client code generation, a logic issue in the new override_entry attribute macro, and a small redundancy in the macro implementation. Addressing these points will help ensure the robustness and maintainability of this new feature.

[github-actions]

🔬 Benchmark Comparison

Benchmark	Current	Baseline	Change	Change %	Status
compute	465_520_439_916	465_485_012_100	+35_427_816	+0.01%	✅
alloc-0	595_257_257	561_979_259	+33_277_998	+5.92%	❌
alloc-12	598_814_243	565_520_788	+33_293_455	+5.89%	❌
alloc-143	758_644_535	725_298_850	+33_345_685	+4.60%	⚠️
alloc-986	861_644_733	828_290_220	+33_354_513	+4.03%	⚠️
alloc-10945	2_215_897_006	2_042_673_536	+173_223_470	+8.48%	❌
alloc-46367	6_541_274_107	6_507_908_597	+33_365_510	+0.51%	✅
alloc-121392	17_167_907_284	17_134_416_241	+33_491_043	+0.20%	✅
alloc-317810	43_905_221_311	43_871_725_854	+33_495_457	+0.08%	✅
counter_sync	691_375_058	665_515_676	+25_859_382	+3.89%	⚠️
counter_async	861_425_456	837_190_903	+24_234_553	+2.89%	⚠️
cross_program	2_390_677_183	2_393_184_894	-2_507_711	-0.10%	✅
redirect	3_462_462_934	3_425_067_798	+37_395_136	+1.09%	⚠️
stack_0	794_273_112	778_805_232	+15_467_880	+1.99%	⚠️
stack_1	3_758_139_476	3_693_170_602	+64_968_874	+1.76%	⚠️
stack_5	15_654_437_392	15_391_130_019	+263_307_373	+1.71%	⚠️
stack_10	29_379_956_259	28_866_676_553	+513_279_706	+1.78%	⚠️
stack_20	65_711_991_205	64_389_067_225	+1_322_923_980	+2.05%	⚠️

Legend

• 🚀 Significant improvement (>5% reduction)
• 👍 Minor improvement (<5% reduction)
• ✅ No significant change
• ⚠️ Minor regression (<5% increase)
• ❌ Significant regression (>5% increase)

---

_{🤖 This comment was automatically generated by the benchmark comparison workflow at 116aece.}