mirror of
https://github.com/rust-lang/rust.git
synced 2024-11-22 06:44:35 +00:00
ce407429dd
Add new simpler and more explicit syntax for check-cfg <details> <summary> Old proposition (before the MCP) </summary> This PR adds a new simpler and more explicit syntax for check-cfg. It consist of two new form: - `exhaustive(names, values)` - `configure(name, "value1", "value2", ... "valueN")` The preview forms `names(...)` and `values(...)` have implicit meaning that are not strait-forward. In particular `values(foo)`&`values(bar)` and `names(foo, bar)` are not equivalent which has created [some confusions](https://github.com/rust-lang/rust/pull/98080). Also the `names()` and `values()` form are not clear either and again created some confusions where peoples believed that `values()`&`values(foo)` could be reduced to just `values(foo)`. To fix that the two new forms are made to be explicit and simpler. See the table of correspondence: - `names()` -> `exhaustive(names)` - `values()` -> `exhaustive(values)` - `names(foo)` -> `exhaustive(names)`&`configure(foo)` - `values(foo)` -> `configure(foo)` - `values(feat, "foo", "bar")` -> `configure(feat, "foo", "bar")` - `values(foo)`&`values(bar)` -> `configure(foo, bar)` - `names()`&`values()`&`values(my_cfg)` -> `exhaustive(names, values)`&`configure(my_cfg)` Another benefits of the new syntax is that it allow for further options (like conditional checking for --cfg, currently always on) without syntax change. The two previous forms are deprecated and will be removed once cargo and beta rustc have the necessary support. </details> This PR is the first part of the implementation of [MCP636 - Simplify and improve explicitness of the check-cfg syntax](https://github.com/rust-lang/compiler-team/issues/636). ## New `cfg` form It introduces the new [`cfg` form](https://github.com/rust-lang/compiler-team/issues/636) and deprecate the other two: ``` rustc --check-cfg 'cfg(name1, ..., nameN, values("value1", "value2", ... "valueN"))' ``` ## Default built-in names and values It also changes the default for the built-in names and values checking. - Built-in values checking would always be activated as long as a `--check-cfg` argument is present - Built-in names checking would always be activated as long as a `--check-cfg` argument is present **unless** if any `cfg(any())` arg is passed ~~**Note: depends on https://github.com/rust-lang/rust/pull/111068 but is reviewable (last two commits)!**~~ Resolve https://github.com/rust-lang/compiler-team/issues/636 r? `@petrochenkov` |
||
|---|---|---|
| .. | ||
| src | ||
| Cargo.toml | ||
| messages.ftl | ||