From cfafa9380b446b74708986a344172ec48e295740 Mon Sep 17 00:00:00 2001 From: Nicholas Nethercote Date: Thu, 18 Apr 2024 08:58:06 +1000 Subject: [PATCH] Add metavariables to `TokenDescription`. Pasted metavariables are wrapped in invisible delimiters, which pretty-print as empty strings, and changing that can break some proc macros. But error messages saying "expected identifer, found ``" are bad. So this commit adds support for metavariables in `TokenDescription` so they print as "metavariable" in error messages, instead of "``". It's not used meaningfully yet, but will be needed to get rid of interpolated tokens. --- compiler/rustc_parse/messages.ftl | 7 +++++ compiler/rustc_parse/src/errors.rs | 28 ++++++++++++++++-- compiler/rustc_parse/src/parser/mod.rs | 39 +++++++++++++++++--------- 3 files changed, 58 insertions(+), 16 deletions(-) diff --git a/compiler/rustc_parse/messages.ftl b/compiler/rustc_parse/messages.ftl index ef259703f0c..cafd4b6dca2 100644 --- a/compiler/rustc_parse/messages.ftl +++ b/compiler/rustc_parse/messages.ftl @@ -216,6 +216,9 @@ parse_expected_identifier_found_doc_comment = expected identifier, found doc com parse_expected_identifier_found_doc_comment_str = expected identifier, found doc comment `{$token}` parse_expected_identifier_found_keyword = expected identifier, found keyword parse_expected_identifier_found_keyword_str = expected identifier, found keyword `{$token}` +parse_expected_identifier_found_metavar = expected identifier, found metavariable +# This one deliberately doesn't print a token. +parse_expected_identifier_found_metavar_str = expected identifier, found metavariable parse_expected_identifier_found_reserved_identifier = expected identifier, found reserved identifier parse_expected_identifier_found_reserved_identifier_str = expected identifier, found reserved identifier `{$token}` parse_expected_identifier_found_reserved_keyword = expected identifier, found reserved keyword @@ -227,6 +230,8 @@ parse_expected_mut_or_const_in_raw_pointer_type = expected `mut` or `const` keyw parse_expected_semi_found_doc_comment_str = expected `;`, found doc comment `{$token}` parse_expected_semi_found_keyword_str = expected `;`, found keyword `{$token}` +# This one deliberately doesn't print a token. +parse_expected_semi_found_metavar_str = expected `;`, found metavariable parse_expected_semi_found_reserved_identifier_str = expected `;`, found reserved identifier `{$token}` parse_expected_semi_found_reserved_keyword_str = expected `;`, found reserved keyword `{$token}` parse_expected_semi_found_str = expected `;`, found `{$token}` @@ -864,6 +869,8 @@ parse_unexpected_token_after_not_logical = use `!` to perform logical negation parse_unexpected_token_after_struct_name = expected `where`, `{"{"}`, `(`, or `;` after struct name parse_unexpected_token_after_struct_name_found_doc_comment = expected `where`, `{"{"}`, `(`, or `;` after struct name, found doc comment `{$token}` parse_unexpected_token_after_struct_name_found_keyword = expected `where`, `{"{"}`, `(`, or `;` after struct name, found keyword `{$token}` +# This one deliberately doesn't print a token. +parse_unexpected_token_after_struct_name_found_metavar = expected `where`, `{"{"}`, `(`, or `;` after struct name, found metavar parse_unexpected_token_after_struct_name_found_other = expected `where`, `{"{"}`, `(`, or `;` after struct name, found `{$token}` parse_unexpected_token_after_struct_name_found_reserved_identifier = expected `where`, `{"{"}`, `(`, or `;` after struct name, found reserved identifier `{$token}` diff --git a/compiler/rustc_parse/src/errors.rs b/compiler/rustc_parse/src/errors.rs index 37eb463cba6..9bdb99dc000 100644 --- a/compiler/rustc_parse/src/errors.rs +++ b/compiler/rustc_parse/src/errors.rs @@ -1086,6 +1086,8 @@ pub(crate) enum ExpectedIdentifierFound { ReservedKeyword(#[primary_span] Span), #[label(parse_expected_identifier_found_doc_comment)] DocComment(#[primary_span] Span), + #[label(parse_expected_identifier_found_metavar)] + MetaVar(#[primary_span] Span), #[label(parse_expected_identifier)] Other(#[primary_span] Span), } @@ -1099,6 +1101,7 @@ impl ExpectedIdentifierFound { Some(TokenDescription::Keyword) => ExpectedIdentifierFound::Keyword, Some(TokenDescription::ReservedKeyword) => ExpectedIdentifierFound::ReservedKeyword, Some(TokenDescription::DocComment) => ExpectedIdentifierFound::DocComment, + Some(TokenDescription::MetaVar(_)) => ExpectedIdentifierFound::MetaVar, None => ExpectedIdentifierFound::Other, })(span) } @@ -1117,6 +1120,7 @@ impl<'a, G: EmissionGuarantee> Diagnostic<'a, G> for ExpectedIdentifier { fn into_diag(self, dcx: DiagCtxtHandle<'a>, level: Level) -> Diag<'a, G> { let token_descr = TokenDescription::from_token(&self.token); + let mut add_token = true; let mut diag = Diag::new(dcx, level, match token_descr { Some(TokenDescription::ReservedIdentifier) => { fluent::parse_expected_identifier_found_reserved_identifier_str @@ -1128,10 +1132,16 @@ impl<'a, G: EmissionGuarantee> Diagnostic<'a, G> for ExpectedIdentifier { Some(TokenDescription::DocComment) => { fluent::parse_expected_identifier_found_doc_comment_str } + Some(TokenDescription::MetaVar(_)) => { + add_token = false; + fluent::parse_expected_identifier_found_metavar_str + } None => fluent::parse_expected_identifier_found_str, }); diag.span(self.span); - diag.arg("token", self.token); + if add_token { + diag.arg("token", self.token); + } if let Some(sugg) = self.suggest_raw { sugg.add_to_diag(&mut diag); @@ -1171,6 +1181,7 @@ impl<'a, G: EmissionGuarantee> Diagnostic<'a, G> for ExpectedSemi { fn into_diag(self, dcx: DiagCtxtHandle<'a>, level: Level) -> Diag<'a, G> { let token_descr = TokenDescription::from_token(&self.token); + let mut add_token = true; let mut diag = Diag::new(dcx, level, match token_descr { Some(TokenDescription::ReservedIdentifier) => { fluent::parse_expected_semi_found_reserved_identifier_str @@ -1180,10 +1191,16 @@ impl<'a, G: EmissionGuarantee> Diagnostic<'a, G> for ExpectedSemi { fluent::parse_expected_semi_found_reserved_keyword_str } Some(TokenDescription::DocComment) => fluent::parse_expected_semi_found_doc_comment_str, + Some(TokenDescription::MetaVar(_)) => { + add_token = false; + fluent::parse_expected_semi_found_metavar_str + } None => fluent::parse_expected_semi_found_str, }); diag.span(self.span); - diag.arg("token", self.token); + if add_token { + diag.arg("token", self.token); + } if let Some(unexpected_token_label) = self.unexpected_token_label { diag.span_label(unexpected_token_label, fluent::parse_label_unexpected_token); @@ -1925,6 +1942,12 @@ pub(crate) enum UnexpectedTokenAfterStructName { span: Span, token: Token, }, + #[diag(parse_unexpected_token_after_struct_name_found_metavar)] + MetaVar { + #[primary_span] + #[label(parse_unexpected_token_after_struct_name)] + span: Span, + }, #[diag(parse_unexpected_token_after_struct_name_found_other)] Other { #[primary_span] @@ -1941,6 +1964,7 @@ impl UnexpectedTokenAfterStructName { Some(TokenDescription::Keyword) => Self::Keyword { span, token }, Some(TokenDescription::ReservedKeyword) => Self::ReservedKeyword { span, token }, Some(TokenDescription::DocComment) => Self::DocComment { span, token }, + Some(TokenDescription::MetaVar(_)) => Self::MetaVar { span }, None => Self::Other { span, token }, } } diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs index 226f29f9900..0ed8d152d2d 100644 --- a/compiler/rustc_parse/src/parser/mod.rs +++ b/compiler/rustc_parse/src/parser/mod.rs @@ -21,7 +21,9 @@ pub(crate) use item::FnParseMode; pub use pat::{CommaRecoveryMode, RecoverColon, RecoverComma}; use path::PathStyle; use rustc_ast::ptr::P; -use rustc_ast::token::{self, Delimiter, IdentIsRaw, Nonterminal, Token, TokenKind}; +use rustc_ast::token::{ + self, Delimiter, IdentIsRaw, InvisibleOrigin, MetaVarKind, Nonterminal, Token, TokenKind, +}; use rustc_ast::tokenstream::{ AttrsTarget, DelimSpacing, DelimSpan, Spacing, TokenStream, TokenTree, TokenTreeCursor, }; @@ -410,6 +412,12 @@ pub(super) enum TokenDescription { Keyword, ReservedKeyword, DocComment, + + // Expanded metavariables are wrapped in invisible delimiters which aren't + // pretty-printed. In error messages we must handle these specially + // otherwise we get confusing things in messages like "expected `(`, found + // ``". It's better to say e.g. "expected `(`, found type metavariable". + MetaVar(MetaVarKind), } impl TokenDescription { @@ -419,26 +427,29 @@ impl TokenDescription { _ if token.is_used_keyword() => Some(TokenDescription::Keyword), _ if token.is_unused_keyword() => Some(TokenDescription::ReservedKeyword), token::DocComment(..) => Some(TokenDescription::DocComment), + token::OpenDelim(Delimiter::Invisible(InvisibleOrigin::MetaVar(kind))) => { + Some(TokenDescription::MetaVar(kind)) + } _ => None, } } } pub fn token_descr(token: &Token) -> String { - let name = pprust::token_to_string(token).to_string(); + let s = pprust::token_to_string(token).to_string(); - let kind = match (TokenDescription::from_token(token), &token.kind) { - (Some(TokenDescription::ReservedIdentifier), _) => Some("reserved identifier"), - (Some(TokenDescription::Keyword), _) => Some("keyword"), - (Some(TokenDescription::ReservedKeyword), _) => Some("reserved keyword"), - (Some(TokenDescription::DocComment), _) => Some("doc comment"), - (None, TokenKind::NtIdent(..)) => Some("identifier"), - (None, TokenKind::NtLifetime(..)) => Some("lifetime"), - (None, TokenKind::Interpolated(node)) => Some(node.descr()), - (None, _) => None, - }; - - if let Some(kind) = kind { format!("{kind} `{name}`") } else { format!("`{name}`") } + match (TokenDescription::from_token(token), &token.kind) { + (Some(TokenDescription::ReservedIdentifier), _) => format!("reserved identifier `{s}`"), + (Some(TokenDescription::Keyword), _) => format!("keyword `{s}`"), + (Some(TokenDescription::ReservedKeyword), _) => format!("reserved keyword `{s}`"), + (Some(TokenDescription::DocComment), _) => format!("doc comment `{s}`"), + // Deliberately doesn't print `s`, which is empty. + (Some(TokenDescription::MetaVar(kind)), _) => format!("`{kind}` metavariable"), + (None, TokenKind::NtIdent(..)) => format!("identifier `{s}`"), + (None, TokenKind::NtLifetime(..)) => format!("lifetime `{s}`"), + (None, TokenKind::Interpolated(node)) => format!("{} `{s}`", node.descr()), + (None, _) => format!("`{s}`"), + } } impl<'a> Parser<'a> {