diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs index 4a0c957333bca..ab61f77f5cb36 100644 --- a/src/libsyntax/feature_gate.rs +++ b/src/libsyntax/feature_gate.rs @@ -31,6 +31,7 @@ use crate::tokenstream::TokenTree; use errors::{Applicability, DiagnosticBuilder, Handler}; use rustc_data_structures::fx::FxHashMap; +use rustc_data_structures::sync::Lock; use rustc_target::spec::abi::Abi; use syntax_pos::{Span, DUMMY_SP, MultiSpan}; use log::debug; @@ -573,6 +574,9 @@ declare_features! ( // Allows `impl Trait` with multiple unrelated lifetimes. (active, member_constraints, "1.37.0", Some(61977), None), + // Allows `async || body` closures. + (active, async_closure, "1.37.0", Some(62290), None), + // ------------------------------------------------------------------------- // feature-group-end: actual feature gates // ------------------------------------------------------------------------- @@ -2191,9 +2195,6 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> { "labels on blocks are unstable"); } } - ast::ExprKind::Closure(_, ast::IsAsync::Async { .. }, ..) => { - gate_feature_post!(&self, async_await, e.span, "async closures are unstable"); - } ast::ExprKind::Async(..) => { gate_feature_post!(&self, async_await, e.span, "async blocks are unstable"); } @@ -2527,6 +2528,10 @@ pub fn get_features(span_handler: &Handler, krate_attrs: &[ast::Attribute], features } +fn for_each_in_lock(vec: &Lock>, f: impl Fn(&T)) { + vec.borrow().iter().for_each(f); +} + pub fn check_crate(krate: &ast::Crate, sess: &ParseSess, features: &Features, @@ -2539,27 +2544,26 @@ pub fn check_crate(krate: &ast::Crate, plugin_attributes, }; - sess - .param_attr_spans - .borrow() - .iter() - .for_each(|span| gate_feature!( - &ctx, - param_attrs, - *span, - "attributes on function parameters are unstable" - )); - - sess - .let_chains_spans - .borrow() - .iter() - .for_each(|span| gate_feature!( - &ctx, - let_chains, - *span, - "`let` expressions in this position are experimental" - )); + for_each_in_lock(&sess.param_attr_spans, |span| gate_feature!( + &ctx, + param_attrs, + *span, + "attributes on function parameters are unstable" + )); + + for_each_in_lock(&sess.let_chains_spans, |span| gate_feature!( + &ctx, + let_chains, + *span, + "`let` expressions in this position are experimental" + )); + + for_each_in_lock(&sess.async_closure_spans, |span| gate_feature!( + &ctx, + async_closure, + *span, + "async closures are unstable" + )); let visitor = &mut PostExpansionVisitor { context: &ctx, diff --git a/src/libsyntax/parse/lexer/mod.rs b/src/libsyntax/parse/lexer/mod.rs index 49f714e4e4654..3717bb435f69d 100644 --- a/src/libsyntax/parse/lexer/mod.rs +++ b/src/libsyntax/parse/lexer/mod.rs @@ -1452,6 +1452,7 @@ mod tests { ambiguous_block_expr_parse: Lock::new(FxHashMap::default()), param_attr_spans: Lock::new(Vec::new()), let_chains_spans: Lock::new(Vec::new()), + async_closure_spans: Lock::new(Vec::new()), } } diff --git a/src/libsyntax/parse/mod.rs b/src/libsyntax/parse/mod.rs index e19eab371f44e..4056905d5dd01 100644 --- a/src/libsyntax/parse/mod.rs +++ b/src/libsyntax/parse/mod.rs @@ -57,6 +57,8 @@ pub struct ParseSess { pub param_attr_spans: Lock>, // Places where `let` exprs were used and should be feature gated according to `let_chains`. pub let_chains_spans: Lock>, + // Places where `async || ..` exprs were used and should be feature gated. + pub async_closure_spans: Lock>, } impl ParseSess { @@ -84,6 +86,7 @@ impl ParseSess { ambiguous_block_expr_parse: Lock::new(FxHashMap::default()), param_attr_spans: Lock::new(Vec::new()), let_chains_spans: Lock::new(Vec::new()), + async_closure_spans: Lock::new(Vec::new()), } } diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs index cef14632e641f..a95b6891fb9d5 100644 --- a/src/libsyntax/parse/parser.rs +++ b/src/libsyntax/parse/parser.rs @@ -3221,21 +3221,24 @@ impl<'a> Parser<'a> { -> PResult<'a, P> { let lo = self.token.span; + let movability = if self.eat_keyword(kw::Static) { Movability::Static } else { Movability::Movable }; + let asyncness = if self.token.span.rust_2018() { self.parse_asyncness() } else { IsAsync::NotAsync }; - let capture_clause = if self.eat_keyword(kw::Move) { - CaptureBy::Value - } else { - CaptureBy::Ref - }; + if asyncness.is_async() { + // Feature gate `async ||` closures. + self.sess.async_closure_spans.borrow_mut().push(self.prev_span); + } + + let capture_clause = self.parse_capture_clause(); let decl = self.parse_fn_block_decl()?; let decl_hi = self.prev_span; let body = match decl.output { @@ -3257,7 +3260,7 @@ impl<'a> Parser<'a> { attrs)) } - // `else` token already eaten + /// `else` token already eaten fn parse_else_expr(&mut self) -> PResult<'a, P> { if self.eat_keyword(kw::If) { return self.parse_if_expr(ThinVec::new()); @@ -3306,7 +3309,7 @@ impl<'a> Parser<'a> { Ok(self.mk_expr(span, ExprKind::While(cond, body, opt_label), attrs)) } - // parse `loop {...}`, `loop` token already eaten + /// Parse `loop {...}`, `loop` token already eaten. fn parse_loop_expr(&mut self, opt_label: Option