rust/compiler/rustc_expand
Matthias Krüger af3c51d849
Rollup merge of #136107 - dingxiangfei2009:coerce-pointee-wellformed, r=compiler-errors
Introduce CoercePointeeWellformed for coherence checks at typeck stage

Fix #135206

This is the first PR to introduce the "wellformedness" check for `derive(CoercePointee)`.

This patch introduces a new error code to cover all the prerequisites of the said macro. The checks that is enforced with this patch is whether the data is indeed `struct` and whether the layout is set to `repr(transparent)`.

A following series of patch will arrive later to address the following concern.
1. #135217 so that we would only admit one single coercion on one type parameter, and leave the rest for future consideration in tandem of development of other coercion rules.
1. Enforcement of data field requirements.

**An open question** is whether there is a good schema to encode the `#[pointee]` as well, so that we could also check if the `#[pointee]` type parameter is indeed `?Sized`.

``@rustbot`` label F-derive_coerce_pointee
2025-02-11 02:53:42 +01:00
..
src Rollup merge of #136107 - dingxiangfei2009:coerce-pointee-wellformed, r=compiler-errors 2025-02-11 02:53:42 +01:00
Cargo.toml rename rustc_attr to rustc_attr_parsing and create rustc_attr_data_structures 2024-12-16 19:08:19 +01:00
messages.ftl Tweak expand_incomplete_parse warning. 2024-10-28 14:12:45 +11:00