diff --git a/src/librustc/hir/lowering.rs b/src/librustc/hir/lowering.rs index 848e9ca58e595..4d5707560b048 100644 --- a/src/librustc/hir/lowering.rs +++ b/src/librustc/hir/lowering.rs @@ -50,7 +50,6 @@ use errors::Applicability; use rustc_data_structures::fx::FxHashSet; use rustc_data_structures::indexed_vec::IndexVec; use rustc_data_structures::thin_vec::ThinVec; -use rustc_data_structures::sync::Lrc; use std::collections::{BTreeSet, BTreeMap}; use std::mem; @@ -59,10 +58,10 @@ use syntax::attr; use syntax::ast; use syntax::ast::*; use syntax::errors; -use syntax::ext::hygiene::{Mark, SyntaxContext}; +use syntax::ext::hygiene::Mark; use syntax::print::pprust; use syntax::ptr::P; -use syntax::source_map::{self, respan, CompilerDesugaringKind, Spanned}; +use syntax::source_map::{respan, CompilerDesugaringKind, Spanned}; use syntax::std_inject; use syntax::symbol::{keywords, Symbol}; use syntax::tokenstream::{TokenStream, TokenTree}; @@ -854,27 +853,6 @@ impl<'a> LoweringContext<'a> { Ident::with_empty_ctxt(Symbol::gensym(s)) } - /// Reuses the span but adds information like the kind of the desugaring and features that are - /// allowed inside this span. - fn mark_span_with_reason( - &self, - reason: CompilerDesugaringKind, - span: Span, - allow_internal_unstable: Option>, - ) -> Span { - let mark = Mark::fresh(Mark::root()); - mark.set_expn_info(source_map::ExpnInfo { - call_site: span, - def_site: Some(span), - format: source_map::CompilerDesugaring(reason), - allow_internal_unstable, - allow_internal_unsafe: false, - local_inner_macros: false, - edition: source_map::hygiene::default_edition(), - }); - span.with_ctxt(SyntaxContext::empty().apply_mark(mark)) - } - fn with_anonymous_lifetime_mode( &mut self, anonymous_lifetime_mode: AnonymousLifetimeMode, @@ -1162,7 +1140,7 @@ impl<'a> LoweringContext<'a> { attrs: ThinVec::new(), }; - let unstable_span = self.mark_span_with_reason( + let unstable_span = self.sess.source_map().mark_span_with_reason( CompilerDesugaringKind::Async, span, Some(vec![ @@ -1569,7 +1547,7 @@ impl<'a> LoweringContext<'a> { // desugaring that explicitly states that we don't want to track that. // Not tracking it makes lints in rustc and clippy very fragile as // frequently opened issues show. - let exist_ty_span = self.mark_span_with_reason( + let exist_ty_span = self.sess.source_map().mark_span_with_reason( CompilerDesugaringKind::ExistentialReturnType, span, None, @@ -2443,7 +2421,7 @@ impl<'a> LoweringContext<'a> { ) -> hir::FunctionRetTy { let span = output.span(); - let exist_ty_span = self.mark_span_with_reason( + let exist_ty_span = self.sess.source_map().mark_span_with_reason( CompilerDesugaringKind::Async, span, None, @@ -4179,7 +4157,7 @@ impl<'a> LoweringContext<'a> { }), ExprKind::TryBlock(ref body) => { self.with_catch_scope(body.id, |this| { - let unstable_span = this.mark_span_with_reason( + let unstable_span = this.sess.source_map().mark_span_with_reason( CompilerDesugaringKind::TryBlock, body.span, Some(vec![ @@ -4612,7 +4590,7 @@ impl<'a> LoweringContext<'a> { // expand let mut head = self.lower_expr(head); let head_sp = head.span; - let desugared_span = self.mark_span_with_reason( + let desugared_span = self.sess.source_map().mark_span_with_reason( CompilerDesugaringKind::ForLoop, head_sp, None, @@ -4773,7 +4751,7 @@ impl<'a> LoweringContext<'a> { // return Try::from_error(From::from(err)), // } - let unstable_span = self.mark_span_with_reason( + let unstable_span = self.sess.source_map().mark_span_with_reason( CompilerDesugaringKind::QuestionMark, e.span, Some(vec![ @@ -4781,7 +4759,7 @@ impl<'a> LoweringContext<'a> { ].into()), ); let try_span = self.sess.source_map().end_point(e.span); - let try_span = self.mark_span_with_reason( + let try_span = self.sess.source_map().mark_span_with_reason( CompilerDesugaringKind::QuestionMark, try_span, Some(vec![ @@ -5566,12 +5544,12 @@ impl<'a> LoweringContext<'a> { ); self.sess.abort_if_errors(); } - let span = self.mark_span_with_reason( + let span = self.sess.source_map().mark_span_with_reason( CompilerDesugaringKind::Await, await_span, None, ); - let gen_future_span = self.mark_span_with_reason( + let gen_future_span = self.sess.source_map().mark_span_with_reason( CompilerDesugaringKind::Await, await_span, Some(vec![Symbol::intern("gen_future")].into()), diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs index 7b19bb760e07a..d97d1e2f0f4ee 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, 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 08abbf5e8a4dc..215618bd09ca3 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>, + ) -> 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 { diff --git a/src/test/ui/async-await/auxiliary/issue-60674.rs b/src/test/ui/async-await/auxiliary/issue-60674.rs new file mode 100644 index 0000000000000..680c6e55e5668 --- /dev/null +++ b/src/test/ui/async-await/auxiliary/issue-60674.rs @@ -0,0 +1,12 @@ +// force-host +// no-prefer-dynamic +#![crate_type = "proc-macro"] + +extern crate proc_macro; +use proc_macro::TokenStream; + +#[proc_macro_attribute] +pub fn attr(_args: TokenStream, input: TokenStream) -> TokenStream { + println!("{}", input); + TokenStream::new() +} diff --git a/src/test/ui/async-await/issue-60674.rs b/src/test/ui/async-await/issue-60674.rs new file mode 100644 index 0000000000000..37e356e5baf48 --- /dev/null +++ b/src/test/ui/async-await/issue-60674.rs @@ -0,0 +1,14 @@ +// aux-build:issue-60674.rs +// compile-pass +// edition:2018 +#![feature(async_await)] + +// This is a regression test that ensures that `mut` patterns are not lost when provided as input +// to a proc macro. + +extern crate issue_60674; + +#[issue_60674::attr] +async fn f(mut x: u8) {} + +fn main() {} diff --git a/src/test/ui/async-await/issue-60674.stdout b/src/test/ui/async-await/issue-60674.stdout new file mode 100644 index 0000000000000..a93944db1c591 --- /dev/null +++ b/src/test/ui/async-await/issue-60674.stdout @@ -0,0 +1 @@ +async fn f(mut x: u8) { }