diff options
Diffstat (limited to 'src/libsyntax')
| -rw-r--r-- | src/libsyntax/attr/builtin.rs | 125 |
1 files changed, 63 insertions, 62 deletions
diff --git a/src/libsyntax/attr/builtin.rs b/src/libsyntax/attr/builtin.rs index 3c10f27b60a..a37b27f67bc 100644 --- a/src/libsyntax/attr/builtin.rs +++ b/src/libsyntax/attr/builtin.rs @@ -120,17 +120,21 @@ pub fn find_unwind_attr(diagnostic: Option<&Handler>, attrs: &[Attribute]) -> Op }) } -/// Represents the #[stable], #[unstable], #[rustc_{deprecated,const_unstable}] attributes. +/// Represents the #[stable], #[unstable], #[rustc_deprecated] attributes. #[derive(RustcEncodable, RustcDecodable, Copy, Clone, Debug, PartialEq, Eq, Hash, HashStable_Generic)] pub struct Stability { pub level: StabilityLevel, pub feature: Symbol, pub rustc_depr: Option<RustcDeprecation>, - /// `None` means the function is stable but needs to be a stable const fn, too - /// `Some` contains the feature gate required to be able to use the function - /// as const fn - pub const_stability: Option<Symbol>, +} + +/// Represents the #[rustc_const_unstable] and #[rustc_const_stable] attributes. +#[derive(RustcEncodable, RustcDecodable, Copy, Clone, Debug, + PartialEq, Eq, Hash, HashStable_Generic)] +pub struct ConstStability { + pub level: StabilityLevel, + pub feature: Symbol, /// whether the function has a `#[rustc_promotable]` attribute pub promotable: bool, /// whether the function has a `#[rustc_allow_const_fn_ptr]` attribute @@ -186,21 +190,21 @@ pub fn contains_feature_attr(attrs: &[Attribute], feature_name: Symbol) -> bool /// Collects stability info from all stability attributes in `attrs`. /// Returns `None` if no stability attributes are found. pub fn find_stability(sess: &ParseSess, attrs: &[Attribute], - item_sp: Span) -> Option<Stability> { + item_sp: Span) -> (Option<Stability>, Option<ConstStability>) { find_stability_generic(sess, attrs.iter(), item_sp) } fn find_stability_generic<'a, I>(sess: &ParseSess, attrs_iter: I, item_sp: Span) - -> Option<Stability> + -> (Option<Stability>, Option<ConstStability>) where I: Iterator<Item = &'a Attribute> { use StabilityLevel::*; let mut stab: Option<Stability> = None; let mut rustc_depr: Option<RustcDeprecation> = None; - let mut rustc_const_unstable: Option<Symbol> = None; + let mut const_stab: Option<ConstStability> = None; let mut promotable = false; let mut allow_const_fn_ptr = false; let diagnostic = &sess.span_diagnostic; @@ -209,6 +213,7 @@ fn find_stability_generic<'a, I>(sess: &ParseSess, if ![ sym::rustc_deprecated, sym::rustc_const_unstable, + sym::rustc_const_stable, sym::unstable, sym::stable, sym::rustc_promotable, @@ -287,7 +292,8 @@ fn find_stability_generic<'a, I>(sess: &ParseSess, } } - match meta.name_or_empty() { + let meta_name = meta.name_or_empty(); + match meta_name { sym::rustc_deprecated => { if rustc_depr.is_some() { span_err!(diagnostic, item_sp, E0540, @@ -315,23 +321,12 @@ fn find_stability_generic<'a, I>(sess: &ParseSess, } } } - sym::rustc_const_unstable => { - if rustc_const_unstable.is_some() { - span_err!(diagnostic, item_sp, E0553, - "multiple rustc_const_unstable attributes"); - continue 'outer - } - - get_meta!(feature); - if let Some(feature) = feature { - rustc_const_unstable = Some(feature); - } else { - span_err!(diagnostic, attr.span, E0629, "missing 'feature'"); - continue - } - } + sym::rustc_const_unstable | sym::unstable => { - if stab.is_some() { + if meta_name == sym::unstable && stab.is_some() { + handle_errors(sess, attr.span, AttrError::MultipleStabilityLevels); + break + } else if meta_name == sym::rustc_const_unstable && const_stab.is_some() { handle_errors(sess, attr.span, AttrError::MultipleStabilityLevels); break } @@ -398,18 +393,25 @@ fn find_stability_generic<'a, I>(sess: &ParseSess, } } }; - stab = Some(Stability { - level: Unstable { - reason, - issue, - is_soft, - }, - feature, - rustc_depr: None, - const_stability: None, - promotable: false, - allow_const_fn_ptr: false, - }) + let level = Unstable { + reason, + issue, + is_soft, + }; + if sym::unstable == meta_name { + stab = Some(Stability { + level, + feature, + rustc_depr: None, + }); + } else { + const_stab = Some(ConstStability { + level, + feature, + promotable: false, + allow_const_fn_ptr: false, + }); + } } (None, _, _) => { handle_errors(sess, attr.span, AttrError::MissingFeature); @@ -421,8 +423,12 @@ fn find_stability_generic<'a, I>(sess: &ParseSess, } } } + sym::rustc_const_stable | sym::stable => { - if stab.is_some() { + if meta_name == sym::stable && stab.is_some() { + handle_errors(sess, attr.span, AttrError::MultipleStabilityLevels); + break + } else if meta_name == sym::rustc_const_stable &&const_stab.is_some() { handle_errors(sess, attr.span, AttrError::MultipleStabilityLevels); break } @@ -464,16 +470,21 @@ fn find_stability_generic<'a, I>(sess: &ParseSess, match (feature, since) { (Some(feature), Some(since)) => { - stab = Some(Stability { - level: Stable { - since, - }, - feature, - rustc_depr: None, - const_stability: None, - promotable: false, - allow_const_fn_ptr: false, - }) + let level = Stable { since }; + if sym::stable == meta_name { + stab = Some(Stability { + level, + feature, + rustc_depr: None, + }); + } else { + const_stab = Some(ConstStability { + level, + feature, + promotable: false, + allow_const_fn_ptr: false, + }); + } } (None, _) => { handle_errors(sess, attr.span, AttrError::MissingFeature); @@ -502,29 +513,19 @@ fn find_stability_generic<'a, I>(sess: &ParseSess, } // Merge the const-unstable info into the stability info - if let Some(feature) = rustc_const_unstable { - if let Some(ref mut stab) = stab { - stab.const_stability = Some(feature); - } else { - span_err!(diagnostic, item_sp, E0630, - "rustc_const_unstable attribute must be paired with \ - either stable or unstable attribute"); - } - } - - // Merge the const-unstable info into the stability info if promotable || allow_const_fn_ptr { - if let Some(ref mut stab) = stab { + if let Some(ref mut stab) = const_stab { stab.promotable = promotable; stab.allow_const_fn_ptr = allow_const_fn_ptr; } else { span_err!(diagnostic, item_sp, E0717, "rustc_promotable and rustc_allow_const_fn_ptr attributes \ - must be paired with either stable or unstable attribute"); + must be paired with either a rustc_const_unstable or a rustc_const_stable \ + attribute"); } } - stab + (stab, const_stab) } pub fn find_crate_name(attrs: &[Attribute]) -> Option<Symbol> { |