diff options
Diffstat (limited to 'src/libsyntax')
| -rw-r--r-- | src/libsyntax/parse/parser.rs | 27 | ||||
| -rw-r--r-- | src/libsyntax/source_map.rs | 21 |
2 files changed, 38 insertions, 10 deletions
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs index 7b19bb760e0..d97d1e2f0f4 100644 --- a/src/libsyntax/parse/parser.rs +++ b/src/libsyntax/parse/parser.rs @@ -50,7 +50,10 @@ use crate::symbol::{Symbol, keywords}; use errors::{Applicability, DiagnosticBuilder, DiagnosticId, FatalError}; use rustc_target::spec::abi::{self, Abi}; -use syntax_pos::{Span, MultiSpan, BytePos, FileName}; +use syntax_pos::{ + Span, MultiSpan, BytePos, FileName, + hygiene::CompilerDesugaringKind, +}; use log::{debug, trace}; use std::borrow::Cow; @@ -8772,6 +8775,10 @@ impl<'a> Parser<'a> { /// The arguments of the function are replaced in HIR lowering with the arguments created by /// this function and the statements created here are inserted at the top of the closure body. fn construct_async_arguments(&mut self, asyncness: &mut Spanned<IsAsync>, decl: &mut FnDecl) { + // FIXME(davidtwco): This function should really live in the HIR lowering but because + // the types constructed here need to be used in parts of resolve so that the correct + // locals are considered upvars, it is currently easier for it to live here in the parser, + // where it can be constructed once. if let IsAsync::Async { ref mut arguments, .. } = asyncness.node { for (index, input) in decl.inputs.iter_mut().enumerate() { let id = ast::DUMMY_NODE_ID; @@ -8786,6 +8793,15 @@ impl<'a> Parser<'a> { // statement. let (binding_mode, ident, is_simple_pattern) = match input.pat.node { PatKind::Ident(binding_mode @ BindingMode::ByValue(_), ident, _) => { + // Simple patterns like this don't have a generated argument, but they are + // moved into the closure with a statement, so any `mut` bindings on the + // argument will be unused. This binding mode can't be removed, because + // this would affect the input to procedural macros, but they can have + // their span marked as being the result of a compiler desugaring so + // that they aren't linted against. + input.pat.span = self.sess.source_map().mark_span_with_reason( + CompilerDesugaringKind::Async, span, None); + (binding_mode, ident, true) } _ => (BindingMode::ByValue(Mutability::Mutable), ident, false), @@ -8855,15 +8871,6 @@ impl<'a> Parser<'a> { }) }; - // Remove mutability from arguments. If this is not a simple pattern, - // those arguments are replaced by `__argN`, so there is no need to do this. - if let PatKind::Ident(BindingMode::ByValue(mutability @ Mutability::Mutable), ..) = - &mut input.pat.node - { - assert!(is_simple_pattern); - *mutability = Mutability::Immutable; - } - let move_stmt = Stmt { id, node: StmtKind::Local(P(move_local)), span }; arguments.push(AsyncArgument { ident, arg, pat_stmt, move_stmt }); } diff --git a/src/libsyntax/source_map.rs b/src/libsyntax/source_map.rs index 08abbf5e8a4..215618bd09c 100644 --- a/src/libsyntax/source_map.rs +++ b/src/libsyntax/source_map.rs @@ -930,6 +930,27 @@ impl SourceMap { None } + + /// Reuses the span but adds information like the kind of the desugaring and features that are + /// allowed inside this span. + pub fn mark_span_with_reason( + &self, + reason: hygiene::CompilerDesugaringKind, + span: Span, + allow_internal_unstable: Option<Lrc<[symbol::Symbol]>>, + ) -> Span { + let mark = Mark::fresh(Mark::root()); + mark.set_expn_info(ExpnInfo { + call_site: span, + def_site: Some(span), + format: CompilerDesugaring(reason), + allow_internal_unstable, + allow_internal_unsafe: false, + local_inner_macros: false, + edition: hygiene::default_edition(), + }); + span.with_ctxt(SyntaxContext::empty().apply_mark(mark)) + } } impl SourceMapper for SourceMap { |