/// A lifetime definition, e.g. `'a: 'b+'c+'d`
#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
pub struct LifetimeDef {
+ pub attrs: ThinVec<Attribute>,
pub lifetime: Lifetime,
pub bounds: Vec<Lifetime>
}
#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
pub struct TyParam {
+ pub attrs: ThinVec<Attribute>,
pub ident: Ident,
pub id: NodeId,
pub bounds: TyParamBounds,
fn typaram(&self,
span: Span,
id: ast::Ident,
+ attrs: Vec<ast::Attribute>,
bounds: ast::TyParamBounds,
default: Option<P<ast::Ty>>) -> ast::TyParam;
fn lifetime_def(&self,
span: Span,
name: ast::Name,
+ attrs: Vec<ast::Attribute>,
bounds: Vec<ast::Lifetime>)
-> ast::LifetimeDef;
fn typaram(&self,
span: Span,
id: ast::Ident,
+ attrs: Vec<ast::Attribute>,
bounds: ast::TyParamBounds,
default: Option<P<ast::Ty>>) -> ast::TyParam {
ast::TyParam {
ident: id,
id: ast::DUMMY_NODE_ID,
+ attrs: attrs.into(),
bounds: bounds,
default: default,
span: span
fn lifetime_def(&self,
span: Span,
name: ast::Name,
+ attrs: Vec<ast::Attribute>,
bounds: Vec<ast::Lifetime>)
-> ast::LifetimeDef {
ast::LifetimeDef {
+ attrs: attrs.into(),
lifetime: self.lifetime(span, name),
bounds: bounds
}
// Used to identify the `compiler_builtins` crate
// rustc internal
(active, compiler_builtins, "1.13.0", None),
+
+ // Allows attributes on lifetime/type formal parameters in generics (RFC 1327)
+ (active, generic_param_attrs, "1.11.0", Some(34761)),
);
declare_features! (
visit::walk_vis(self, vis)
}
+
+ fn visit_generics(&mut self, g: &ast::Generics) {
+ for t in &g.ty_params {
+ if !t.attrs.is_empty() {
+ gate_feature_post!(&self, generic_param_attrs, t.attrs[0].span,
+ "attributes on type parameter bindings are experimental");
+ }
+ }
+ visit::walk_generics(self, g)
+ }
+
+ fn visit_lifetime_def(&mut self, lifetime_def: &ast::LifetimeDef) {
+ if !lifetime_def.attrs.is_empty() {
+ gate_feature_post!(&self, generic_param_attrs, lifetime_def.attrs[0].span,
+ "attributes on lifetime bindings are experimental");
+ }
+ visit::walk_lifetime_def(self, lifetime_def)
+ }
}
pub fn get_features(span_handler: &Handler, krate_attrs: &[ast::Attribute]) -> Features {
}
pub fn noop_fold_ty_param<T: Folder>(tp: TyParam, fld: &mut T) -> TyParam {
- let TyParam {id, ident, bounds, default, span} = tp;
+ let TyParam {attrs, id, ident, bounds, default, span} = tp;
+ let attrs: Vec<_> = attrs.into();
TyParam {
+ attrs: attrs.into_iter()
+ .flat_map(|x| fld.fold_attribute(x).into_iter())
+ .collect::<Vec<_>>()
+ .into(),
id: fld.new_id(id),
ident: ident,
bounds: fld.fold_bounds(bounds),
pub fn noop_fold_lifetime_def<T: Folder>(l: LifetimeDef, fld: &mut T)
-> LifetimeDef {
+ let attrs: Vec<_> = l.attrs.into();
LifetimeDef {
+ attrs: attrs.into_iter()
+ .flat_map(|x| fld.fold_attribute(x).into_iter())
+ .collect::<Vec<_>>()
+ .into(),
lifetime: fld.fold_lifetime(l.lifetime),
bounds: fld.fold_lifetimes(l.bounds),
}
let lo = self.span.lo;
let (name, node) = if self.eat_keyword(keywords::Type) {
- let TyParam {ident, bounds, default, ..} = self.parse_ty_param()?;
+ let TyParam {ident, bounds, default, ..} = self.parse_ty_param(vec![])?;
self.expect(&token::Semi)?;
(ident, TraitItemKind::Type(bounds, default))
} else if self.is_const_item() {
/// Parses `lifetime_defs = [ lifetime_defs { ',' lifetime_defs } ]` where `lifetime_def =
/// lifetime [':' lifetimes]`
- pub fn parse_lifetime_defs(&mut self) -> PResult<'a, Vec<ast::LifetimeDef>> {
-
+ ///
+ /// If `followed_by_ty_params` is None, then we are in a context
+ /// where only lifetime parameters are allowed, and thus we should
+ /// error if we encounter attributes after the bound lifetimes.
+ ///
+ /// If `followed_by_ty_params` is Some(r), then there may be type
+ /// parameter bindings after the lifetimes, so we should pass
+ /// along the parsed attributes to be attached to the first such
+ /// type parmeter.
+ pub fn parse_lifetime_defs(&mut self,
+ followed_by_ty_params: Option<&mut Vec<ast::Attribute>>)
+ -> PResult<'a, Vec<ast::LifetimeDef>>
+ {
let mut res = Vec::new();
loop {
+ let attrs = self.parse_outer_attributes()?;
match self.token {
token::Lifetime(_) => {
let lifetime = self.parse_lifetime()?;
} else {
Vec::new()
};
- res.push(ast::LifetimeDef { lifetime: lifetime,
+ res.push(ast::LifetimeDef { attrs: attrs.into(),
+ lifetime: lifetime,
bounds: bounds });
}
_ => {
+ if let Some(recv) = followed_by_ty_params {
+ assert!(recv.is_empty());
+ *recv = attrs;
+ } else {
+ let msg = "encountered trailing attributes after lifetime parameters";
+ return Err(self.fatal(msg));
+ }
+ debug!("parse_lifetime_defs ret {:?}", res);
return Ok(res);
}
}
}
/// Matches typaram = IDENT (`?` unbound)? optbounds ( EQ ty )?
- fn parse_ty_param(&mut self) -> PResult<'a, TyParam> {
+ fn parse_ty_param(&mut self, preceding_attrs: Vec<ast::Attribute>) -> PResult<'a, TyParam> {
let span = self.span;
let ident = self.parse_ident()?;
};
Ok(TyParam {
+ attrs: preceding_attrs.into(),
ident: ident,
id: ast::DUMMY_NODE_ID,
bounds: bounds,
let span_lo = self.span.lo;
if self.eat(&token::Lt) {
- let lifetime_defs = self.parse_lifetime_defs()?;
+ let mut attrs = vec![];
+ let lifetime_defs = self.parse_lifetime_defs(Some(&mut attrs))?;
let mut seen_default = false;
+ let mut post_lifetime_attrs = Some(attrs);
let ty_params = self.parse_seq_to_gt(Some(token::Comma), |p| {
p.forbid_lifetime()?;
- let ty_param = p.parse_ty_param()?;
+ let attrs = match post_lifetime_attrs.as_mut() {
+ None => p.parse_outer_attributes()?,
+ Some(attrs) => mem::replace(attrs, vec![]),
+ };
+ post_lifetime_attrs = None;
+ let ty_param = p.parse_ty_param(attrs)?;
if ty_param.default.is_some() {
seen_default = true;
} else if seen_default {
let bound_lifetimes = if self.eat_keyword(keywords::For) {
// Higher ranked constraint.
self.expect(&token::Lt)?;
- let lifetime_defs = self.parse_lifetime_defs()?;
+ let lifetime_defs = self.parse_lifetime_defs(None)?;
self.expect_gt()?;
lifetime_defs
} else {
fn parse_late_bound_lifetime_defs(&mut self) -> PResult<'a, Vec<ast::LifetimeDef>> {
if self.eat_keyword(keywords::For) {
self.expect(&token::Lt)?;
- let lifetime_defs = self.parse_lifetime_defs()?;
+ let lifetime_defs = self.parse_lifetime_defs(None)?;
self.expect_gt()?;
Ok(lifetime_defs)
} else {
pub fn walk_lifetime_def<V: Visitor>(visitor: &mut V, lifetime_def: &LifetimeDef) {
visitor.visit_lifetime(&lifetime_def.lifetime);
walk_list!(visitor, visit_lifetime, &lifetime_def.bounds);
+ walk_list!(visitor, visit_attribute, &*lifetime_def.attrs);
}
pub fn walk_poly_trait_ref<V>(visitor: &mut V, trait_ref: &PolyTraitRef, _: &TraitBoundModifier)
visitor.visit_ident(param.span, param.ident);
walk_list!(visitor, visit_ty_param_bound, ¶m.bounds);
walk_list!(visitor, visit_ty, ¶m.default);
+ walk_list!(visitor, visit_attribute, &*param.attrs);
}
walk_list!(visitor, visit_lifetime_def, &generics.lifetimes);
for predicate in &generics.where_clause.predicates {
bounds.push((*declared_bound).clone());
}
- cx.typaram(self.span, ty_param.ident, P::from_vec(bounds), None)
+ cx.typaram(self.span, ty_param.ident, vec![], P::from_vec(bounds), None)
}));
// and similarly for where clauses
fn mk_ty_param(cx: &ExtCtxt,
span: Span,
name: &str,
+ attrs: &[ast::Attribute],
bounds: &[Path],
self_ident: Ident,
self_generics: &Generics)
cx.typarambound(path)
})
.collect();
- cx.typaram(span, cx.ident_of(name), bounds, None)
+ cx.typaram(span, cx.ident_of(name), attrs.to_owned(), bounds, None)
}
fn mk_generics(lifetimes: Vec<ast::LifetimeDef>, ty_params: Vec<ast::TyParam>, span: Span)
let bounds = bounds.iter()
.map(|b| cx.lifetime(span, cx.ident_of(*b).name))
.collect();
- cx.lifetime_def(span, cx.ident_of(*lt).name, bounds)
+ cx.lifetime_def(span, cx.ident_of(*lt).name, vec![], bounds)
})
.collect();
let ty_params = self.bounds
.map(|t| {
match *t {
(ref name, ref bounds) => {
- mk_ty_param(cx, span, *name, bounds, self_ty, self_generics)
+ mk_ty_param(cx, span, *name, &[], bounds, self_ty, self_generics)
}
}
})