[soareschen]

Overview

[deepseek-v4.1-flash] Every macro that declares a public item now emits a short doc for it, so a crate can enable #![warn(missing_docs)] without the lint reporting generated code. A user's own doc comment is preserved, and a #[cgp_fn] function's doc now stays on the method instead of moving to the trait.

Motivation

missing_docs runs after macro expansion, so it reports the items a macro generates, and a doc comment written on the invocation never reaches them: rustdoc does not document macro invocations, so the macro must emit the documentation itself. Before this change, a crate that used a component and enabled the lint failed the build on the component marker, the provider struct, the namespace items, and the data derives' companion types.

Impact

The generated lines name the item and link the trait it belongs to, such as Component marker for [CanGreet]. and Provider GreetHello for [Greeter].. A generated line is never appended after a user's doc: it fills a gap, so no item carries both.

A doc on a #[cgp_component] consumer trait is copied onto the five items the macro derives from it, which is harmless on docs.rs because impl docs are not rendered. A doc on a cgp_namespace! or delegate_components! invocation is dropped with an unused_doc_comments warning, so the generated line is all those items can carry.

The generated_docs module in the test library denies missing_docs while using every macro, so a generated item that loses its line fails the build. It lives in the library crate because missing_docs only fires on items exported from a library, and a test binary exports nothing. Three snapshots pin where a user's doc comment lands, in the concept targets that own their macros.