From ef1114a964bcb15ba5c60551f925d287eb153bb9 Mon Sep 17 00:00:00 2001 From: Nicholas Nethercote Date: Thu, 18 Apr 2024 12:44:11 +1000 Subject: [PATCH] Remove `NtPat`. The one notable test change is `tests/ui/macros/trace_faulty_macros.rs`. This commit removes the complicated `Interpolated` handling in `expected_expression_found` that results in a longer error message. But I think the new, shorter message is actually an improvement. The original complaint was in #71039, when the error message started with "error: expected expression, found `1 + 1`". That was confusing because `1 + 1` is an expression. Other than that, the reporter said "the whole error message is not too bad if you ignore the first line". Subsequently, extra complexity and wording was added to the error message. But I don't think the extra wording actually helps all that much. In particular, it still says of the `1+1` that "this is expected to be expression". This repeats the problem from the original complaint! This commit removes the extra complexity, reverting to a simpler error message. This is primarily because the traversal is a pain without `Interpolated` tokens. Nonetheless, I think the error message is *improved*. It now starts with "expected expression, found `pat` metavariable", which is much clearer and the real problem. It also doesn't say anything specific about `1+1`, which is good, because the `1+1` isn't really relevant to the error -- it's the `$e:pat` that's important. --- compiler/rustc_ast/src/ast_traits.rs | 2 - compiler/rustc_ast/src/mut_visit.rs | 1 - compiler/rustc_ast/src/token.rs | 5 -- compiler/rustc_ast/src/tokenstream.rs | 1 - compiler/rustc_expand/src/mbe/transcribe.rs | 18 +++++-- .../rustc_parse/src/parser/diagnostics.rs | 52 +------------------ compiler/rustc_parse/src/parser/item.rs | 8 +-- compiler/rustc_parse/src/parser/mod.rs | 4 +- .../rustc_parse/src/parser/nonterminal.rs | 24 +++++---- compiler/rustc_parse/src/parser/pat.rs | 37 ++++++++++--- tests/ui/macros/trace_faulty_macros.rs | 2 +- tests/ui/macros/trace_faulty_macros.stderr | 13 ++--- .../issue-65122-mac-invoc-in-mut-patterns.rs | 2 +- ...sue-65122-mac-invoc-in-mut-patterns.stderr | 4 +- tests/ui/parser/mut-patterns.rs | 2 +- tests/ui/parser/mut-patterns.stderr | 4 +- 16 files changed, 77 insertions(+), 102 deletions(-) diff --git a/compiler/rustc_ast/src/ast_traits.rs b/compiler/rustc_ast/src/ast_traits.rs index 346edc87c86b..8b94d65c44ec 100644 --- a/compiler/rustc_ast/src/ast_traits.rs +++ b/compiler/rustc_ast/src/ast_traits.rs @@ -202,7 +202,6 @@ impl HasTokens for Nonterminal { Nonterminal::NtItem(item) => item.tokens(), Nonterminal::NtStmt(stmt) => stmt.tokens(), Nonterminal::NtExpr(expr) | Nonterminal::NtLiteral(expr) => expr.tokens(), - Nonterminal::NtPat(pat) => pat.tokens(), Nonterminal::NtMeta(attr_item) => attr_item.tokens(), Nonterminal::NtPath(path) => path.tokens(), Nonterminal::NtBlock(block) => block.tokens(), @@ -213,7 +212,6 @@ impl HasTokens for Nonterminal { Nonterminal::NtItem(item) => item.tokens_mut(), Nonterminal::NtStmt(stmt) => stmt.tokens_mut(), Nonterminal::NtExpr(expr) | Nonterminal::NtLiteral(expr) => expr.tokens_mut(), - Nonterminal::NtPat(pat) => pat.tokens_mut(), Nonterminal::NtMeta(attr_item) => attr_item.tokens_mut(), Nonterminal::NtPath(path) => path.tokens_mut(), Nonterminal::NtBlock(block) => block.tokens_mut(), diff --git a/compiler/rustc_ast/src/mut_visit.rs b/compiler/rustc_ast/src/mut_visit.rs index 40b29fdba250..6ebe52738b9c 100644 --- a/compiler/rustc_ast/src/mut_visit.rs +++ b/compiler/rustc_ast/src/mut_visit.rs @@ -905,7 +905,6 @@ fn visit_nonterminal(vis: &mut T, nt: &mut token::Nonterminal) { vis.flat_map_stmt(stmt).expect_one("expected visitor to produce exactly one item") }) }), - token::NtPat(pat) => vis.visit_pat(pat), token::NtExpr(expr) => vis.visit_expr(expr), token::NtLiteral(expr) => vis.visit_expr(expr), token::NtMeta(item) => { diff --git a/compiler/rustc_ast/src/token.rs b/compiler/rustc_ast/src/token.rs index 97d121909f8d..ff8a68ff711e 100644 --- a/compiler/rustc_ast/src/token.rs +++ b/compiler/rustc_ast/src/token.rs @@ -659,7 +659,6 @@ impl Token { | NtExpr(..) | NtLiteral(..) | NtMeta(..) - | NtPat(..) | NtPath(..) ), OpenDelim(Delimiter::Invisible(InvisibleOrigin::MetaVar( @@ -1075,7 +1074,6 @@ pub enum Nonterminal { NtItem(P), NtBlock(P), NtStmt(P), - NtPat(P), NtExpr(P), NtLiteral(P), /// Stuff inside brackets for attributes @@ -1172,7 +1170,6 @@ impl Nonterminal { NtItem(item) => item.span, NtBlock(block) => block.span, NtStmt(stmt) => stmt.span, - NtPat(pat) => pat.span, NtExpr(expr) | NtLiteral(expr) => expr.span, NtMeta(attr_item) => attr_item.span(), NtPath(path) => path.span, @@ -1184,7 +1181,6 @@ impl Nonterminal { NtItem(..) => "item", NtBlock(..) => "block", NtStmt(..) => "statement", - NtPat(..) => "pattern", NtExpr(..) => "expression", NtLiteral(..) => "literal", NtMeta(..) => "attribute", @@ -1209,7 +1205,6 @@ impl fmt::Debug for Nonterminal { NtItem(..) => f.pad("NtItem(..)"), NtBlock(..) => f.pad("NtBlock(..)"), NtStmt(..) => f.pad("NtStmt(..)"), - NtPat(..) => f.pad("NtPat(..)"), NtExpr(..) => f.pad("NtExpr(..)"), NtLiteral(..) => f.pad("NtLiteral(..)"), NtMeta(..) => f.pad("NtMeta(..)"), diff --git a/compiler/rustc_ast/src/tokenstream.rs b/compiler/rustc_ast/src/tokenstream.rs index 1123ea3a449b..2b4c818fc322 100644 --- a/compiler/rustc_ast/src/tokenstream.rs +++ b/compiler/rustc_ast/src/tokenstream.rs @@ -468,7 +468,6 @@ impl TokenStream { TokenStream::token_alone(token::Semi, stmt.span) } Nonterminal::NtStmt(stmt) => TokenStream::from_ast(stmt), - Nonterminal::NtPat(pat) => TokenStream::from_ast(pat), Nonterminal::NtMeta(attr) => TokenStream::from_ast(attr), Nonterminal::NtPath(path) => TokenStream::from_ast(path), Nonterminal::NtExpr(expr) | Nonterminal::NtLiteral(expr) => TokenStream::from_ast(expr), diff --git a/compiler/rustc_expand/src/mbe/transcribe.rs b/compiler/rustc_expand/src/mbe/transcribe.rs index 7fe9fa7937d9..79f65a8c8b56 100644 --- a/compiler/rustc_expand/src/mbe/transcribe.rs +++ b/compiler/rustc_expand/src/mbe/transcribe.rs @@ -279,9 +279,9 @@ pub(super) fn transcribe<'a>( if let Some(cur_matched) = lookup_cur_matched(ident, interp, &repeats) { // We wrap the tokens in invisible delimiters, unless they are already wrapped // in invisible delimiters with the same `MetaVarKind`. Because some proc - // macros can't multiple layers of invisible delimiters of the same + // macros can't handle multiple layers of invisible delimiters of the same // `MetaVarKind`. This loses some span info, though it hopefully won't matter. - let mut mk_delimited = |mv_kind, mut stream: TokenStream| { + let mut mk_delimited = |mk_span, mv_kind, mut stream: TokenStream| { if stream.len() == 1 { let tree = stream.iter().next().unwrap(); if let TokenTree::Delimited(_, _, delim, inner) = tree @@ -295,6 +295,7 @@ pub(super) fn transcribe<'a>( // Emit as a token stream within `Delimiter::Invisible` to maintain // parsing priorities. marker.visit_span(&mut sp); + with_metavar_spans(|mspans| mspans.insert(mk_span, sp)); // Both the open delim and close delim get the same span, which covers the // `$foo` in the decl macro RHS. TokenTree::Delimited( @@ -322,12 +323,21 @@ pub(super) fn transcribe<'a>( let kind = token::NtLifetime(*ident, *is_raw); TokenTree::token_alone(kind, sp) } + MatchedSingle(ParseNtResult::Pat(pat, pat_kind)) => mk_delimited( + pat.span, + MetaVarKind::Pat(*pat_kind), + TokenStream::from_ast(pat), + ), MatchedSingle(ParseNtResult::Ty(ty)) => { let is_path = matches!(&ty.kind, TyKind::Path(None, _path)); - mk_delimited(MetaVarKind::Ty { is_path }, TokenStream::from_ast(ty)) + mk_delimited( + ty.span, + MetaVarKind::Ty { is_path }, + TokenStream::from_ast(ty), + ) } MatchedSingle(ParseNtResult::Vis(vis)) => { - mk_delimited(MetaVarKind::Vis, TokenStream::from_ast(vis)) + mk_delimited(vis.span, MetaVarKind::Vis, TokenStream::from_ast(vis)) } MatchedSingle(ParseNtResult::Nt(nt)) => { // Other variables are emitted into the output stream as groups with diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs index 67abc2d53940..5291345a29dc 100644 --- a/compiler/rustc_parse/src/parser/diagnostics.rs +++ b/compiler/rustc_parse/src/parser/diagnostics.rs @@ -1,17 +1,15 @@ use std::mem::take; use std::ops::{Deref, DerefMut}; -use std::sync::Arc; use ast::token::IdentIsRaw; use rustc_ast as ast; use rustc_ast::ptr::P; use rustc_ast::token::{self, Delimiter, Lit, LitKind, Token, TokenKind}; -use rustc_ast::tokenstream::AttrTokenTree; use rustc_ast::util::parser::AssocOp; use rustc_ast::{ AngleBracketedArg, AngleBracketedArgs, AnonConst, AttrVec, BinOpKind, BindingMode, Block, - BlockCheckMode, Expr, ExprKind, GenericArg, Generics, HasTokens, Item, ItemKind, Param, Pat, - PatKind, Path, PathSegment, QSelf, Recovered, Ty, TyKind, + BlockCheckMode, Expr, ExprKind, GenericArg, Generics, Item, ItemKind, Param, Pat, PatKind, + Path, PathSegment, QSelf, Recovered, Ty, TyKind, }; use rustc_ast_pretty::pprust; use rustc_data_structures::fx::FxHashSet; @@ -2400,52 +2398,6 @@ impl<'a> Parser<'a> { err.subdiagnostic(ExprParenthesesNeeded::surrounding(*sp)); } err.span_label(span, "expected expression"); - - // Walk the chain of macro expansions for the current token to point at how the original - // code was interpreted. This helps the user realize when a macro argument of one type is - // later reinterpreted as a different type, like `$x:expr` being reinterpreted as `$x:pat` - // in a subsequent macro invocation (#71039). - let mut tok = self.token.clone(); - let mut labels = vec![]; - while let TokenKind::Interpolated(nt) = &tok.kind { - let tokens = nt.tokens(); - labels.push(Arc::clone(nt)); - if let Some(tokens) = tokens - && let tokens = tokens.to_attr_token_stream() - && let tokens = tokens.0.deref() - && let [AttrTokenTree::Token(token, _)] = &tokens[..] - { - tok = token.clone(); - } else { - break; - } - } - let mut iter = labels.into_iter().peekable(); - let mut show_link = false; - while let Some(nt) = iter.next() { - let descr = nt.descr(); - if let Some(next) = iter.peek() { - let next_descr = next.descr(); - if next_descr != descr { - err.span_label(next.use_span(), format!("this is expected to be {next_descr}")); - err.span_label( - nt.use_span(), - format!( - "this is interpreted as {}, but it is expected to be {}", - next_descr, descr, - ), - ); - show_link = true; - } - } - } - if show_link { - err.note( - "when forwarding a matched fragment to another macro-by-example, matchers in the \ - second macro will see an opaque AST of the fragment type, not the underlying \ - tokens", - ); - } err } diff --git a/compiler/rustc_parse/src/parser/item.rs b/compiler/rustc_parse/src/parser/item.rs index c923717ecaf2..5765a5b5315b 100644 --- a/compiler/rustc_parse/src/parser/item.rs +++ b/compiler/rustc_parse/src/parser/item.rs @@ -4,7 +4,7 @@ use std::mem; use ast::token::IdentIsRaw; use rustc_ast::ast::*; use rustc_ast::ptr::P; -use rustc_ast::token::{self, Delimiter, TokenKind}; +use rustc_ast::token::{self, Delimiter, InvisibleOrigin, MetaVarKind, TokenKind}; use rustc_ast::tokenstream::{DelimSpan, TokenStream, TokenTree}; use rustc_ast::util::case::Case; use rustc_ast::{self as ast}; @@ -3071,8 +3071,10 @@ impl<'a> Parser<'a> { fn is_named_param(&self) -> bool { let offset = match &self.token.kind { - token::Interpolated(nt) => match &**nt { - token::NtPat(..) => return self.look_ahead(1, |t| t == &token::Colon), + token::OpenDelim(Delimiter::Invisible(origin)) => match origin { + InvisibleOrigin::MetaVar(MetaVarKind::Pat(_)) => { + return self.check_noexpect_past_close_delim(&token::Colon); + } _ => 0, }, token::BinOp(token::And) | token::AndAnd => 1, diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs index 80a33a760059..ca9671f90fee 100644 --- a/compiler/rustc_parse/src/parser/mod.rs +++ b/compiler/rustc_parse/src/parser/mod.rs @@ -24,7 +24,8 @@ pub use pat::{CommaRecoveryMode, RecoverColon, RecoverComma}; use path::PathStyle; use rustc_ast::ptr::P; use rustc_ast::token::{ - self, Delimiter, IdentIsRaw, InvisibleOrigin, MetaVarKind, Nonterminal, Token, TokenKind, + self, Delimiter, IdentIsRaw, InvisibleOrigin, MetaVarKind, Nonterminal, NtPatKind, Token, + TokenKind, }; use rustc_ast::tokenstream::{AttrsTarget, Spacing, TokenStream, TokenTree}; use rustc_ast::util::case::Case; @@ -1745,6 +1746,7 @@ pub enum ParseNtResult { Tt(TokenTree), Ident(Ident, IdentIsRaw), Lifetime(Ident, IdentIsRaw), + Pat(P, NtPatKind), Ty(P), Vis(P), diff --git a/compiler/rustc_parse/src/parser/nonterminal.rs b/compiler/rustc_parse/src/parser/nonterminal.rs index f202f85752e1..39a0d4151ec6 100644 --- a/compiler/rustc_parse/src/parser/nonterminal.rs +++ b/compiler/rustc_parse/src/parser/nonterminal.rs @@ -49,7 +49,6 @@ impl<'a> Parser<'a> { fn nt_may_be_ident(nt: &Nonterminal) -> bool { match nt { NtStmt(_) - | NtPat(_) | NtExpr(_) | NtLiteral(_) // `true`, `false` | NtMeta(_) @@ -99,7 +98,7 @@ impl<'a> Parser<'a> { token::NtLifetime(..) => true, token::Interpolated(nt) => match &**nt { NtBlock(_) | NtStmt(_) | NtExpr(_) | NtLiteral(_) => true, - NtItem(_) | NtPat(_) | NtMeta(_) | NtPath(_) => false, + NtItem(_) | NtMeta(_) | NtPath(_) => false, }, token::OpenDelim(Delimiter::Invisible(InvisibleOrigin::MetaVar(k))) => match k { MetaVarKind::Block @@ -170,15 +169,18 @@ impl<'a> Parser<'a> { } }, NonterminalKind::Pat(pat_kind) => { - NtPat(self.collect_tokens_no_attrs(|this| match pat_kind { - PatParam { .. } => this.parse_pat_no_top_alt(None, None), - PatWithOr => this.parse_pat_no_top_guard( - None, - RecoverComma::No, - RecoverColon::No, - CommaRecoveryMode::EitherTupleOrPipe, - ), - })?) + return Ok(ParseNtResult::Pat( + self.collect_tokens_no_attrs(|this| match pat_kind { + PatParam { .. } => this.parse_pat_no_top_alt(None, None), + PatWithOr => this.parse_pat_no_top_guard( + None, + RecoverComma::No, + RecoverColon::No, + CommaRecoveryMode::EitherTupleOrPipe, + ), + })?, + pat_kind, + )); } NonterminalKind::Expr(_) => NtExpr(self.parse_expr_force_collect()?), NonterminalKind::Literal => { diff --git a/compiler/rustc_parse/src/parser/pat.rs b/compiler/rustc_parse/src/parser/pat.rs index 8ce749ec8141..40f2e228b24e 100644 --- a/compiler/rustc_parse/src/parser/pat.rs +++ b/compiler/rustc_parse/src/parser/pat.rs @@ -2,7 +2,8 @@ use std::ops::Bound; use rustc_ast::mut_visit::{self, MutVisitor}; use rustc_ast::ptr::P; -use rustc_ast::token::{self, BinOpToken, Delimiter, IdentIsRaw, Token}; +use rustc_ast::token::NtPatKind::*; +use rustc_ast::token::{self, BinOpToken, Delimiter, IdentIsRaw, MetaVarKind, Token}; use rustc_ast::util::parser::ExprPrecedence; use rustc_ast::visit::{self, Visitor}; use rustc_ast::{ @@ -30,7 +31,7 @@ use crate::errors::{ UnexpectedVertVertInPattern, WrapInParens, }; use crate::parser::expr::{DestructuredFloat, could_be_unclosed_char_literal}; -use crate::{exp, maybe_recover_from_interpolated_ty_qpath, maybe_whole}; +use crate::{exp, maybe_recover_from_interpolated_ty_qpath}; #[derive(PartialEq, Copy, Clone)] pub enum Expected { @@ -689,6 +690,27 @@ impl<'a> Parser<'a> { PatVisitor { parser: self, stmt, arm: None, field: None }.visit_stmt(stmt); } + fn eat_metavar_pat(&mut self) -> Option> { + // Must try both kinds of pattern nonterminals. + if let Some(pat) = self.eat_metavar_seq_with_matcher( + |mv_kind| matches!(mv_kind, MetaVarKind::Pat(PatParam { .. })), + |this| this.parse_pat_no_top_alt(None, None), + ) { + Some(pat) + } else if let Some(pat) = self.eat_metavar_seq(MetaVarKind::Pat(PatWithOr), |this| { + this.parse_pat_no_top_guard( + None, + RecoverComma::No, + RecoverColon::No, + CommaRecoveryMode::EitherTupleOrPipe, + ) + }) { + Some(pat) + } else { + None + } + } + /// Parses a pattern, with a setting whether modern range patterns (e.g., `a..=b`, `a..b` are /// allowed). fn parse_pat_with_range_pat( @@ -698,7 +720,10 @@ impl<'a> Parser<'a> { syntax_loc: Option, ) -> PResult<'a, P> { maybe_recover_from_interpolated_ty_qpath!(self, true); - maybe_whole!(self, NtPat, |pat| pat); + + if let Some(pat) = self.eat_metavar_pat() { + return Ok(pat); + } let mut lo = self.token.span; @@ -1043,10 +1068,8 @@ impl<'a> Parser<'a> { self.recover_additional_muts(); // Make sure we don't allow e.g. `let mut $p;` where `$p:pat`. - if let token::Interpolated(nt) = &self.token.kind { - if let token::NtPat(..) = &**nt { - self.expected_ident_found_err().emit(); - } + if let Some(MetaVarKind::Pat(_)) = self.token.is_metavar_seq() { + self.expected_ident_found_err().emit(); } // Parse the pattern we hope to be an identifier. diff --git a/tests/ui/macros/trace_faulty_macros.rs b/tests/ui/macros/trace_faulty_macros.rs index 87036bb9c6f7..e0cbbd8f5c9e 100644 --- a/tests/ui/macros/trace_faulty_macros.rs +++ b/tests/ui/macros/trace_faulty_macros.rs @@ -46,7 +46,7 @@ macro_rules! test { (let $p:pat = $e:expr) => {test!(($p,$e))}; // this should be expr // vvv - (($p:pat, $e:pat)) => {let $p = $e;}; //~ ERROR expected expression, found pattern `1+1` + (($p:pat, $e:pat)) => {let $p = $e;}; //~ ERROR expected expression, found `pat` metavariable } fn foo() { diff --git a/tests/ui/macros/trace_faulty_macros.stderr b/tests/ui/macros/trace_faulty_macros.stderr index 10ad3faab161..73fed66e6190 100644 --- a/tests/ui/macros/trace_faulty_macros.stderr +++ b/tests/ui/macros/trace_faulty_macros.stderr @@ -50,7 +50,7 @@ LL | my_recursive_macro!(); = note: expanding `my_recursive_macro! { }` = note: to `my_recursive_macro! ();` -error: expected expression, found pattern `A { a : a, b : 0, c : _, .. }` +error: expected expression, found `pat` metavariable --> $DIR/trace_faulty_macros.rs:16:9 | LL | $a @@ -69,22 +69,15 @@ LL | #[derive(Debug)] LL | fn use_derive_macro_as_attr() {} | -------------------------------- not a `struct`, `enum` or `union` -error: expected expression, found pattern `1+1` +error: expected expression, found `pat` metavariable --> $DIR/trace_faulty_macros.rs:49:37 | -LL | (let $p:pat = $e:expr) => {test!(($p,$e))}; - | -- this is interpreted as expression, but it is expected to be pattern -... LL | (($p:pat, $e:pat)) => {let $p = $e;}; | ^^ expected expression ... LL | test!(let x = 1+1); - | ------------------ - | | | - | | this is expected to be expression - | in this macro invocation + | ------------------ in this macro invocation | - = note: when forwarding a matched fragment to another macro-by-example, matchers in the second macro will see an opaque AST of the fragment type, not the underlying tokens = note: this error originates in the macro `test` (in Nightly builds, run with -Z macro-backtrace for more info) note: trace_macro diff --git a/tests/ui/parser/issues/issue-65122-mac-invoc-in-mut-patterns.rs b/tests/ui/parser/issues/issue-65122-mac-invoc-in-mut-patterns.rs index 30f3781bf774..1a0833ebb2f6 100644 --- a/tests/ui/parser/issues/issue-65122-mac-invoc-in-mut-patterns.rs +++ b/tests/ui/parser/issues/issue-65122-mac-invoc-in-mut-patterns.rs @@ -12,7 +12,7 @@ macro_rules! mac2 { ($eval:pat) => { let mut $eval = (); //~^ ERROR `mut` must be followed by a named binding - //~| ERROR expected identifier, found `does_not_exist!()` + //~| ERROR expected identifier, found metavariable }; } diff --git a/tests/ui/parser/issues/issue-65122-mac-invoc-in-mut-patterns.stderr b/tests/ui/parser/issues/issue-65122-mac-invoc-in-mut-patterns.stderr index dda37d83282c..59e1b64686b4 100644 --- a/tests/ui/parser/issues/issue-65122-mac-invoc-in-mut-patterns.stderr +++ b/tests/ui/parser/issues/issue-65122-mac-invoc-in-mut-patterns.stderr @@ -15,11 +15,11 @@ LL - let mut $eval = (); LL + let $eval = (); | -error: expected identifier, found `does_not_exist!()` +error: expected identifier, found metavariable --> $DIR/issue-65122-mac-invoc-in-mut-patterns.rs:13:17 | LL | let mut $eval = (); - | ^^^^^ expected identifier + | ^^^^^ expected identifier, found metavariable ... LL | mac2! { does_not_exist!() } | --------------------------- in this macro invocation diff --git a/tests/ui/parser/mut-patterns.rs b/tests/ui/parser/mut-patterns.rs index 45968a516e3d..ed33968c627e 100644 --- a/tests/ui/parser/mut-patterns.rs +++ b/tests/ui/parser/mut-patterns.rs @@ -45,7 +45,7 @@ pub fn main() { // Make sure we don't accidentally allow `mut $p` where `$p:pat`. macro_rules! foo { ($p:pat) => { - let mut $p = 0; //~ ERROR expected identifier, found `x` + let mut $p = 0; //~ ERROR expected identifier, found metavariable } } foo!(x); diff --git a/tests/ui/parser/mut-patterns.stderr b/tests/ui/parser/mut-patterns.stderr index 43f6a344bf39..9dda2499f03c 100644 --- a/tests/ui/parser/mut-patterns.stderr +++ b/tests/ui/parser/mut-patterns.stderr @@ -158,11 +158,11 @@ LL - let mut W(mut a, W(b, W(ref c, W(d, B { box f })))) LL + let W(mut a, W(mut b, W(ref c, W(mut d, B { box mut f })))) | -error: expected identifier, found `x` +error: expected identifier, found metavariable --> $DIR/mut-patterns.rs:48:21 | LL | let mut $p = 0; - | ^^ expected identifier + | ^^ expected identifier, found metavariable ... LL | foo!(x); | ------- in this macro invocation