diff --git a/src/libsyntax/feature_gate/accepted.rs b/src/libsyntax/feature_gate/accepted.rs index 28e4d2c073c..6c0b271c6c5 100644 --- a/src/libsyntax/feature_gate/accepted.rs +++ b/src/libsyntax/feature_gate/accepted.rs @@ -1,14 +1,24 @@ //! List of the accepted feature gates. -use crate::symbol::{Symbol, sym}; +use crate::symbol::sym; +use super::{State, Feature}; macro_rules! declare_features { ($( $(#[doc = $doc:tt])* (accepted, $feature:ident, $ver:expr, $issue:expr, None), )+) => { /// Those language feature has since been Accepted (it was once Active) - pub const ACCEPTED_FEATURES: &[(Symbol, &str, Option, Option<&str>)] = &[ - $((sym::$feature, $ver, $issue, None)),+ + pub const ACCEPTED_FEATURES: &[Feature] = &[ + $( + Feature { + state: State::Accepted, + name: sym::$feature, + since: $ver, + issue: $issue, + edition: None, + description: concat!($($doc,)*), + } + ),+ ]; } } diff --git a/src/libsyntax/feature_gate/active.rs b/src/libsyntax/feature_gate/active.rs index 4008b79b141..c947b09fdcb 100644 --- a/src/libsyntax/feature_gate/active.rs +++ b/src/libsyntax/feature_gate/active.rs @@ -65,6 +65,16 @@ macro_rules! declare_features { }; } +impl Feature { + /// Set this feature in `Features`. Panics if called on a non-active feature. + pub fn set(&self, features: &mut Features, span: Span) { + match self.state { + State::Active { set } => set(features, span), + _ => panic!("Called `set` on feature `{}` which is not `active`", self.name) + } + } +} + // If you change this, please modify `src/doc/unstable-book` as well. // // Don't ever remove anything from this list; move them to `removed.rs`. diff --git a/src/libsyntax/feature_gate/check.rs b/src/libsyntax/feature_gate/check.rs index d82b287b6fb..344e5fd6e46 100644 --- a/src/libsyntax/feature_gate/check.rs +++ b/src/libsyntax/feature_gate/check.rs @@ -1,4 +1,4 @@ -use super::active::{ACTIVE_FEATURES, Features}; +use super::{active::{ACTIVE_FEATURES, Features}, Feature, State as FeatureState}; use super::accepted::ACCEPTED_FEATURES; use super::removed::{REMOVED_FEATURES, STABLE_REMOVED_FEATURES}; use super::builtin_attrs::{AttributeGate, AttributeType, BuiltinAttribute, BUILTIN_ATTRIBUTE_MAP}; @@ -127,17 +127,16 @@ pub fn check_attribute(attr: &ast::Attribute, parse_sess: &ParseSess, features: } fn find_lang_feature_issue(feature: Symbol) -> Option { - if let Some(info) = ACTIVE_FEATURES.iter().find(|t| t.0 == feature) { - let issue = info.2; + if let Some(info) = ACTIVE_FEATURES.iter().find(|t| t.name == feature) { // FIXME (#28244): enforce that active features have issue numbers - // assert!(issue.is_some()) - issue + // assert!(info.issue.is_some()) + info.issue } else { // search in Accepted, Removed, or Stable Removed features let found = ACCEPTED_FEATURES.iter().chain(REMOVED_FEATURES).chain(STABLE_REMOVED_FEATURES) - .find(|t| t.0 == feature); + .find(|t| t.name == feature); match found { - Some(&(_, _, issue, _)) => issue, + Some(&Feature { issue, .. }) => issue, None => panic!("Feature `{}` is not declared anywhere", feature), } } @@ -829,14 +828,18 @@ pub fn get_features(span_handler: &Handler, krate_attrs: &[ast::Attribute], continue; } - let removed = REMOVED_FEATURES.iter().find(|f| name == f.0); - let stable_removed = STABLE_REMOVED_FEATURES.iter().find(|f| name == f.0); - if let Some((.., reason)) = removed.or(stable_removed) { - feature_removed(span_handler, mi.span(), *reason); - continue; + let removed = REMOVED_FEATURES.iter().find(|f| name == f.name); + let stable_removed = STABLE_REMOVED_FEATURES.iter().find(|f| name == f.name); + if let Some(Feature { state, .. }) = removed.or(stable_removed) { + if let FeatureState::Removed { reason } + | FeatureState::Stabilized { reason } = state + { + feature_removed(span_handler, mi.span(), *reason); + continue; + } } - if let Some((_, since, ..)) = ACCEPTED_FEATURES.iter().find(|f| name == f.0) { + if let Some(Feature { since, .. }) = ACCEPTED_FEATURES.iter().find(|f| name == f.name) { let since = Some(Symbol::intern(since)); features.declared_lang_features.push((name, mi.span(), since)); continue; @@ -851,8 +854,8 @@ pub fn get_features(span_handler: &Handler, krate_attrs: &[ast::Attribute], } } - if let Some((.., set)) = ACTIVE_FEATURES.iter().find(|f| name == f.0) { - set(&mut features, mi.span()); + if let Some(f) = ACTIVE_FEATURES.iter().find(|f| name == f.name) { + f.set(&mut features, mi.span()); features.declared_lang_features.push((name, mi.span(), None)); continue; } diff --git a/src/libsyntax/feature_gate/mod.rs b/src/libsyntax/feature_gate/mod.rs index 97793bca1f5..1e41667ea41 100644 --- a/src/libsyntax/feature_gate/mod.rs +++ b/src/libsyntax/feature_gate/mod.rs @@ -18,6 +18,39 @@ mod active; mod builtin_attrs; mod check; +use std::fmt; +use crate::{edition::Edition, symbol::Symbol}; +use syntax_pos::Span; + +#[derive(Clone, Copy)] +pub enum State { + Accepted, + Active { set: fn(&mut Features, Span) }, + Removed { reason: Option<&'static str> }, + Stabilized { reason: Option<&'static str> }, +} + +impl fmt::Debug for State { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + match self { + State::Accepted { .. } => write!(f, "accepted"), + State::Active { .. } => write!(f, "active"), + State::Removed { .. } => write!(f, "removed"), + State::Stabilized { .. } => write!(f, "stabilized"), + } + } +} + +#[derive(Debug, Clone)] +pub struct Feature { + state: State, + name: Symbol, + since: &'static str, + issue: Option, + edition: Option, + description: &'static str, +} + pub use active::{Features, INCOMPLETE_FEATURES}; pub use builtin_attrs::{ AttributeGate, AttributeType, GatedCfg, diff --git a/src/libsyntax/feature_gate/removed.rs b/src/libsyntax/feature_gate/removed.rs index 6494c82e122..ad7d69b3e73 100644 --- a/src/libsyntax/feature_gate/removed.rs +++ b/src/libsyntax/feature_gate/removed.rs @@ -1,14 +1,24 @@ //! List of the removed feature gates. -use crate::symbol::{Symbol, sym}; +use crate::symbol::sym; +use super::{State, Feature}; macro_rules! declare_features { ($( $(#[doc = $doc:tt])* (removed, $feature:ident, $ver:expr, $issue:expr, None, $reason:expr), )+) => { /// Represents unstable features which have since been removed (it was once Active) - pub const REMOVED_FEATURES: &[(Symbol, &str, Option, Option<&str>)] = &[ - $((sym::$feature, $ver, $issue, $reason)),+ + pub const REMOVED_FEATURES: &[Feature] = &[ + $( + Feature { + state: State::Removed { reason: $reason }, + name: sym::$feature, + since: $ver, + issue: $issue, + edition: None, + description: concat!($($doc,)*), + } + ),+ ]; }; @@ -16,8 +26,17 @@ macro_rules! declare_features { $(#[doc = $doc:tt])* (stable_removed, $feature:ident, $ver:expr, $issue:expr, None), )+) => { /// Represents stable features which have since been removed (it was once Accepted) - pub const STABLE_REMOVED_FEATURES: &[(Symbol, &str, Option, Option<&str>)] = &[ - $((sym::$feature, $ver, $issue, None)),+ + pub const STABLE_REMOVED_FEATURES: &[Feature] = &[ + $( + Feature { + state: State::Stabilized { reason: None }, + name: sym::$feature, + since: $ver, + issue: $issue, + edition: None, + description: concat!($($doc,)*), + } + ),+ ]; }; }