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Diffstat (limited to 'src/doc/rustc-dev-guide/src/feature-gates.md')
| -rw-r--r-- | src/doc/rustc-dev-guide/src/feature-gates.md | 41 |
1 files changed, 6 insertions, 35 deletions
diff --git a/src/doc/rustc-dev-guide/src/feature-gates.md b/src/doc/rustc-dev-guide/src/feature-gates.md index 9e9a83ea6..8ad4fea1f 100644 --- a/src/doc/rustc-dev-guide/src/feature-gates.md +++ b/src/doc/rustc-dev-guide/src/feature-gates.md @@ -3,44 +3,16 @@ This chapter is intended to provide basic help for adding, removing, and modifying feature gates. +Note that this is specific to *language* feature gates; *library* feature gates use [a different +mechanism][libs-gate]. -## Adding a feature gate - -See ["Stability in code"] for help with adding a new feature; this section just -covers how to add the feature gate *declaration*. - -First, add the feature name to `rustc_span/src/symbol.rs` in the `Symbols {...}` block. - -Then, add a feature gate declaration to `rustc_feature/src/active.rs` in the active -`declare_features` block: - -```rust,ignore -/// description of feature -(active, $feature_name, "$current_nightly_version", Some($tracking_issue_number), $edition) -``` +[libs-gate]: ./stability.md -where `$edition` has the type `Option<Edition>`, and is typically -just `None`. - -For example: - -```rust,ignore -/// Allows defining identifiers beyond ASCII. -(active, non_ascii_idents, "1.0.0", Some(55467), None), -``` - -Features can be marked as incomplete, and trigger the warn-by-default [`incomplete_features` lint] -by setting their type to `incomplete`: - -```rust,ignore -/// Allows unsized rvalues at arguments and parameters. -(incomplete, unsized_locals, "1.30.0", Some(48055), None), -``` +## Adding a feature gate -When added, the current version should be the one for the current nightly. -Once the feature is moved to `accepted.rs`, the version is changed to that -nightly version. +See ["Stability in code"][adding] in the "Implementing new features" section for instructions. +[adding]: ./implementing_new_features.md#stability-in-code ## Removing a feature gate @@ -109,5 +81,4 @@ updating the declaration! ["Stability in code"]: ./implementing_new_features.md#stability-in-code -[`incomplete_features` lint]: https://doc.rust-lang.org/rustc/lints/listing/warn-by-default.html#incomplete-features ["Updating the feature-gate listing"]: ./stabilization_guide.md#updating-the-feature-gate-listing |