diff --git a/compiler/rustc_macros/src/diagnostics/mod.rs b/compiler/rustc_macros/src/diagnostics/mod.rs index bd84681cbb44b..a536eb3b04e69 100644 --- a/compiler/rustc_macros/src/diagnostics/mod.rs +++ b/compiler/rustc_macros/src/diagnostics/mod.rs @@ -140,7 +140,7 @@ pub fn lint_diagnostic_derive(s: Structure<'_>) -> TokenStream { /// ```fluent /// parser_expected_identifier = expected identifier /// -/// parser_expected_identifier-found = expected identifier, found {$found} +/// parser_expected_identifier_found = expected identifier, found {$found} /// /// parser_raw_identifier = escape `{$ident}` to use it as an identifier /// ``` diff --git a/compiler/rustc_parse/messages.ftl b/compiler/rustc_parse/messages.ftl index cd296dca133f5..a01e6f5ba113c 100644 --- a/compiler/rustc_parse/messages.ftl +++ b/compiler/rustc_parse/messages.ftl @@ -339,6 +339,7 @@ parse_expected_identifier = expected identifier parse_sugg_escape_identifier = escape `{$ident_name}` to use it as an identifier parse_sugg_remove_comma = remove this comma +parse_sugg_add_let_for_stmt = you might have meant to introduce a new binding parse_expected_semi_found_reserved_identifier_str = expected `;`, found reserved identifier `{$token}` parse_expected_semi_found_keyword_str = expected `;`, found keyword `{$token}` diff --git a/compiler/rustc_parse/src/errors.rs b/compiler/rustc_parse/src/errors.rs index 010a13aefa420..4dffdae1dc9bf 100644 --- a/compiler/rustc_parse/src/errors.rs +++ b/compiler/rustc_parse/src/errors.rs @@ -906,6 +906,18 @@ pub(crate) struct SuggRemoveComma { pub span: Span, } +#[derive(Subdiagnostic)] +#[suggestion( + parse_sugg_add_let_for_stmt, + style = "verbose", + applicability = "maybe-incorrect", + code = "let " +)] +pub(crate) struct SuggAddMissingLetStmt { + #[primary_span] + pub span: Span, +} + #[derive(Subdiagnostic)] pub(crate) enum ExpectedIdentifierFound { #[label(parse_expected_identifier_found_reserved_identifier)] diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs index 36883bd217211..3002f23da75cc 100644 --- a/compiler/rustc_parse/src/parser/diagnostics.rs +++ b/compiler/rustc_parse/src/parser/diagnostics.rs @@ -13,7 +13,7 @@ use crate::errors::{ IncorrectUseOfAwait, ParenthesesInForHead, ParenthesesInForHeadSugg, PatternMethodParamWithoutBody, QuestionMarkInType, QuestionMarkInTypeSugg, SelfParamNotFirst, StructLiteralBodyWithoutPath, StructLiteralBodyWithoutPathSugg, StructLiteralNeedingParens, - StructLiteralNeedingParensSugg, SuggEscapeIdentifier, SuggRemoveComma, + StructLiteralNeedingParensSugg, SuggAddMissingLetStmt, SuggEscapeIdentifier, SuggRemoveComma, UnexpectedConstInGenericParam, UnexpectedConstParamDeclaration, UnexpectedConstParamDeclarationSugg, UnmatchedAngleBrackets, UseEqInstead, }; @@ -32,8 +32,8 @@ use rustc_ast::{ use rustc_ast_pretty::pprust; use rustc_data_structures::fx::FxHashSet; use rustc_errors::{ - pluralize, Applicability, Diagnostic, DiagnosticBuilder, DiagnosticMessage, ErrorGuaranteed, - FatalError, Handler, IntoDiagnostic, MultiSpan, PResult, + pluralize, AddToDiagnostic, Applicability, Diagnostic, DiagnosticBuilder, DiagnosticMessage, + ErrorGuaranteed, FatalError, Handler, IntoDiagnostic, MultiSpan, PResult, }; use rustc_session::errors::ExprParenthesesNeeded; use rustc_span::source_map::Spanned; @@ -1006,6 +1006,31 @@ impl<'a> Parser<'a> { Err(e) } + /// Suggest add the missing `let` before the identifier in stmt + /// `a: Ty = 1` -> `let a: Ty = 1` + pub(super) fn suggest_add_missing_let_for_stmt( + &mut self, + err: &mut DiagnosticBuilder<'a, ErrorGuaranteed>, + ) { + if self.token == token::Colon { + let prev_span = self.prev_token.span.shrink_to_lo(); + let snapshot = self.create_snapshot_for_diagnostic(); + self.bump(); + match self.parse_ty() { + Ok(_) => { + if self.token == token::Eq { + let sugg = SuggAddMissingLetStmt { span: prev_span }; + sugg.add_to_diagnostic(err); + } + } + Err(e) => { + e.cancel(); + } + } + self.restore_snapshot(snapshot); + } + } + /// Check to see if a pair of chained operators looks like an attempt at chained comparison, /// e.g. `1 < x <= 3`. If so, suggest either splitting the comparison into two, or /// parenthesising the leftmost comparison. diff --git a/compiler/rustc_parse/src/parser/stmt.rs b/compiler/rustc_parse/src/parser/stmt.rs index 1c17de337e833..c35c32f272a93 100644 --- a/compiler/rustc_parse/src/parser/stmt.rs +++ b/compiler/rustc_parse/src/parser/stmt.rs @@ -99,7 +99,13 @@ impl<'a> Parser<'a> { ForceCollect::Yes => { self.collect_tokens_no_attrs(|this| this.parse_stmt_path_start(lo, attrs))? } - ForceCollect::No => self.parse_stmt_path_start(lo, attrs)?, + ForceCollect::No => match self.parse_stmt_path_start(lo, attrs) { + Ok(stmt) => stmt, + Err(mut err) => { + self.suggest_add_missing_let_for_stmt(&mut err); + return Err(err); + } + }, } } else if let Some(item) = self.parse_item_common( attrs.clone(), @@ -555,7 +561,6 @@ impl<'a> Parser<'a> { if self.token == token::Colon { // if next token is following a colon, it's likely a path // and we can suggest a path separator - let ident_span = self.prev_token.span; self.bump(); if self.token.span.lo() == self.prev_token.span.hi() { err.span_suggestion_verbose( @@ -565,14 +570,6 @@ impl<'a> Parser<'a> { Applicability::MaybeIncorrect, ); } - if self.look_ahead(1, |token| token == &token::Eq) { - err.span_suggestion_verbose( - ident_span.shrink_to_lo(), - "you might have meant to introduce a new binding", - "let ", - Applicability::MaybeIncorrect, - ); - } if self.sess.unstable_features.is_nightly_build() { // FIXME(Nilstrieb): Remove this again after a few months. err.note("type ascription syntax has been removed, see issue #101728 "); diff --git a/tests/ui/suggestions/type-ascription-instead-of-let.fixed b/tests/ui/suggestions/type-ascription-instead-of-let.fixed new file mode 100644 index 0000000000000..e3d03b6f22ad6 --- /dev/null +++ b/tests/ui/suggestions/type-ascription-instead-of-let.fixed @@ -0,0 +1,11 @@ +// run-rustfix + +fn fun(x: i32) -> i32 { x } + +fn main() { + let _closure_annotated = |value: i32| -> i32 { + let temp: i32 = fun(5i32); + //~^ ERROR expected identifier, found `:` + temp + value + 1 + }; +} diff --git a/tests/ui/suggestions/type-ascription-instead-of-let.rs b/tests/ui/suggestions/type-ascription-instead-of-let.rs index 5ad6024329861..6e1c86f967119 100644 --- a/tests/ui/suggestions/type-ascription-instead-of-let.rs +++ b/tests/ui/suggestions/type-ascription-instead-of-let.rs @@ -1,7 +1,9 @@ +// run-rustfix + fn fun(x: i32) -> i32 { x } fn main() { - let closure_annotated = |value: i32| -> i32 { + let _closure_annotated = |value: i32| -> i32 { temp: i32 = fun(5i32); //~^ ERROR expected identifier, found `:` temp + value + 1 diff --git a/tests/ui/suggestions/type-ascription-instead-of-let.stderr b/tests/ui/suggestions/type-ascription-instead-of-let.stderr index fb697b0ccfd5e..065b1f4d3538e 100644 --- a/tests/ui/suggestions/type-ascription-instead-of-let.stderr +++ b/tests/ui/suggestions/type-ascription-instead-of-let.stderr @@ -1,8 +1,13 @@ error: expected identifier, found `:` - --> $DIR/type-ascription-instead-of-let.rs:5:13 + --> $DIR/type-ascription-instead-of-let.rs:7:13 | LL | temp: i32 = fun(5i32); | ^ expected identifier + | +help: you might have meant to introduce a new binding + | +LL | let temp: i32 = fun(5i32); + | +++ error: aborting due to previous error diff --git a/tests/ui/type/missing-let-in-binding-2.fixed b/tests/ui/type/missing-let-in-binding-2.fixed new file mode 100644 index 0000000000000..d64013c8c8385 --- /dev/null +++ b/tests/ui/type/missing-let-in-binding-2.fixed @@ -0,0 +1,5 @@ +// run-rustfix + +fn main() { + let _v: Vec = vec![1, 2, 3]; //~ ERROR expected identifier, found `:` +} diff --git a/tests/ui/type/missing-let-in-binding-2.rs b/tests/ui/type/missing-let-in-binding-2.rs new file mode 100644 index 0000000000000..f95f7bef21585 --- /dev/null +++ b/tests/ui/type/missing-let-in-binding-2.rs @@ -0,0 +1,5 @@ +// run-rustfix + +fn main() { + _v: Vec = vec![1, 2, 3]; //~ ERROR expected identifier, found `:` +} diff --git a/tests/ui/type/missing-let-in-binding-2.stderr b/tests/ui/type/missing-let-in-binding-2.stderr new file mode 100644 index 0000000000000..2e10125943e75 --- /dev/null +++ b/tests/ui/type/missing-let-in-binding-2.stderr @@ -0,0 +1,13 @@ +error: expected identifier, found `:` + --> $DIR/missing-let-in-binding-2.rs:4:7 + | +LL | _v: Vec = vec![1, 2, 3]; + | ^ expected identifier + | +help: you might have meant to introduce a new binding + | +LL | let _v: Vec = vec![1, 2, 3]; + | +++ + +error: aborting due to previous error + diff --git a/tests/ui/type/missing-let-in-binding-3.rs b/tests/ui/type/missing-let-in-binding-3.rs new file mode 100644 index 0000000000000..d56b1393336b1 --- /dev/null +++ b/tests/ui/type/missing-let-in-binding-3.rs @@ -0,0 +1,5 @@ +struct A { + : :u8, //~ ERROR expected identifier, found `:` +} + +fn main() {} diff --git a/tests/ui/type/missing-let-in-binding-3.stderr b/tests/ui/type/missing-let-in-binding-3.stderr new file mode 100644 index 0000000000000..ca828ce37eb7a --- /dev/null +++ b/tests/ui/type/missing-let-in-binding-3.stderr @@ -0,0 +1,10 @@ +error: expected identifier, found `:` + --> $DIR/missing-let-in-binding-3.rs:2:5 + | +LL | struct A { + | - while parsing this struct +LL | : :u8, + | ^ expected identifier + +error: aborting due to previous error + diff --git a/tests/ui/type/missing-let-in-binding-4.rs b/tests/ui/type/missing-let-in-binding-4.rs new file mode 100644 index 0000000000000..879a6fedcd677 --- /dev/null +++ b/tests/ui/type/missing-let-in-binding-4.rs @@ -0,0 +1,5 @@ +struct A { + : u8 =, //~ ERROR expected identifier, found `:` +} + +fn main() {} diff --git a/tests/ui/type/missing-let-in-binding-4.stderr b/tests/ui/type/missing-let-in-binding-4.stderr new file mode 100644 index 0000000000000..e6f173a665870 --- /dev/null +++ b/tests/ui/type/missing-let-in-binding-4.stderr @@ -0,0 +1,10 @@ +error: expected identifier, found `:` + --> $DIR/missing-let-in-binding-4.rs:2:5 + | +LL | struct A { + | - while parsing this struct +LL | : u8 =, + | ^ expected identifier + +error: aborting due to previous error +