rust/compiler/rustc_parse/src/errors.rs

use rustc_ast::token::Token;
use rustc_ast::Path;
use rustc_errors::{fluent, AddToDiagnostic, Applicability, EmissionGuarantee, IntoDiagnostic};
use rustc_macros::{Diagnostic, Subdiagnostic};
use rustc_session::errors::ExprParenthesesNeeded;
use rustc_span::symbol::Ident;
use rustc_span::{Span, Symbol};

use crate::parser::TokenDescription;

#[derive(Diagnostic)]
#[diag(parse_maybe_report_ambiguous_plus)]
pub(crate) struct AmbiguousPlus {
    pub sum_ty: String,
    #[primary_span]
    #[suggestion(code = "({sum_ty})")]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_maybe_recover_from_bad_type_plus, code = "E0178")]
pub(crate) struct BadTypePlus {
    pub ty: String,
    #[primary_span]
    pub span: Span,
    #[subdiagnostic]
    pub sub: BadTypePlusSub,
}

#[derive(Subdiagnostic)]
pub(crate) enum BadTypePlusSub {
    #[suggestion(
        parse_add_paren,
        code = "{sum_with_parens}",
        applicability = "machine-applicable"
    )]
    AddParen {
        sum_with_parens: String,
        #[primary_span]
        span: Span,
    },
    #[label(parse_forgot_paren)]
    ForgotParen {
        #[primary_span]
        span: Span,
    },
    #[label(parse_expect_path)]
    ExpectPath {
        #[primary_span]
        span: Span,
    },
}

#[derive(Diagnostic)]
#[diag(parse_maybe_recover_from_bad_qpath_stage_2)]
pub(crate) struct BadQPathStage2 {
    #[primary_span]
    #[suggestion(code = "", applicability = "maybe-incorrect")]
    pub span: Span,
    pub ty: String,
}

#[derive(Diagnostic)]
#[diag(parse_incorrect_semicolon)]
pub(crate) struct IncorrectSemicolon<'a> {
    #[primary_span]
    #[suggestion(style = "short", code = "", applicability = "machine-applicable")]
    pub span: Span,
    #[help]
    pub opt_help: Option<()>,
    pub name: &'a str,
}

#[derive(Diagnostic)]
#[diag(parse_incorrect_use_of_await)]
pub(crate) struct IncorrectUseOfAwait {
    #[primary_span]
    #[suggestion(parentheses_suggestion, code = "", applicability = "machine-applicable")]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_incorrect_use_of_await)]
pub(crate) struct IncorrectAwait {
    #[primary_span]
    pub span: Span,
    #[suggestion(postfix_suggestion, code = "{expr}.await{question_mark}")]
    pub sugg_span: (Span, Applicability),
    pub expr: String,
    pub question_mark: &'static str,
}

#[derive(Diagnostic)]
#[diag(parse_in_in_typo)]
pub(crate) struct InInTypo {
    #[primary_span]
    pub span: Span,
    #[suggestion(code = "", applicability = "machine-applicable")]
    pub sugg_span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_invalid_variable_declaration)]
pub(crate) struct InvalidVariableDeclaration {
    #[primary_span]
    pub span: Span,
    #[subdiagnostic]
    pub sub: InvalidVariableDeclarationSub,
}

#[derive(Subdiagnostic)]
pub(crate) enum InvalidVariableDeclarationSub {
    #[suggestion(parse_switch_mut_let_order, applicability = "maybe-incorrect", code = "let mut")]
    SwitchMutLetOrder(#[primary_span] Span),
    #[suggestion(
        parse_missing_let_before_mut,
        applicability = "machine-applicable",
        code = "let mut"
    )]
    MissingLet(#[primary_span] Span),
    #[suggestion(parse_use_let_not_auto, applicability = "machine-applicable", code = "let")]
    UseLetNotAuto(#[primary_span] Span),
    #[suggestion(parse_use_let_not_var, applicability = "machine-applicable", code = "let")]
    UseLetNotVar(#[primary_span] Span),
}

#[derive(Diagnostic)]
#[diag(parse_invalid_comparison_operator)]
pub(crate) struct InvalidComparisonOperator {
    #[primary_span]
    pub span: Span,
    pub invalid: String,
    #[subdiagnostic]
    pub sub: InvalidComparisonOperatorSub,
}

#[derive(Subdiagnostic)]
pub(crate) enum InvalidComparisonOperatorSub {
    #[suggestion(
        use_instead,
        style = "short",
        applicability = "machine-applicable",
        code = "{correct}"
    )]
    Correctable {
        #[primary_span]
        span: Span,
        invalid: String,
        correct: String,
    },
    #[label(spaceship_operator_invalid)]
    Spaceship(#[primary_span] Span),
}

#[derive(Diagnostic)]
#[diag(parse_invalid_logical_operator)]
#[note]
pub(crate) struct InvalidLogicalOperator {
    #[primary_span]
    pub span: Span,
    pub incorrect: String,
    #[subdiagnostic]
    pub sub: InvalidLogicalOperatorSub,
}

#[derive(Subdiagnostic)]
pub(crate) enum InvalidLogicalOperatorSub {
    #[suggestion(
        use_amp_amp_for_conjunction,
        style = "short",
        applicability = "machine-applicable",
        code = "&&"
    )]
    Conjunction(#[primary_span] Span),
    #[suggestion(
        use_pipe_pipe_for_disjunction,
        style = "short",
        applicability = "machine-applicable",
        code = "||"
    )]
    Disjunction(#[primary_span] Span),
}

#[derive(Diagnostic)]
#[diag(parse_tilde_is_not_unary_operator)]
pub(crate) struct TildeAsUnaryOperator(
    #[primary_span]
    #[suggestion(style = "short", applicability = "machine-applicable", code = "!")]
    pub Span,
);

#[derive(Diagnostic)]
#[diag(parse_unexpected_token_after_not)]
pub(crate) struct NotAsNegationOperator {
    #[primary_span]
    pub negated: Span,
    pub negated_desc: String,
    #[subdiagnostic]
    pub sub: NotAsNegationOperatorSub,
}

#[derive(Subdiagnostic)]
pub enum NotAsNegationOperatorSub {
    #[suggestion(
        parse_unexpected_token_after_not_default,
        style = "short",
        applicability = "machine-applicable",
        code = "!"
    )]
    SuggestNotDefault(#[primary_span] Span),

    #[suggestion(
        parse_unexpected_token_after_not_bitwise,
        style = "short",
        applicability = "machine-applicable",
        code = "!"
    )]
    SuggestNotBitwise(#[primary_span] Span),

    #[suggestion(
        parse_unexpected_token_after_not_logical,
        style = "short",
        applicability = "machine-applicable",
        code = "!"
    )]
    SuggestNotLogical(#[primary_span] Span),
}

#[derive(Diagnostic)]
#[diag(parse_malformed_loop_label)]
pub(crate) struct MalformedLoopLabel {
    #[primary_span]
    #[suggestion(applicability = "machine-applicable", code = "{correct_label}")]
    pub span: Span,
    pub correct_label: Ident,
}

#[derive(Diagnostic)]
#[diag(parse_lifetime_in_borrow_expression)]
pub(crate) struct LifetimeInBorrowExpression {
    #[primary_span]
    pub span: Span,
    #[suggestion(applicability = "machine-applicable", code = "")]
    #[label]
    pub lifetime_span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_field_expression_with_generic)]
pub(crate) struct FieldExpressionWithGeneric(#[primary_span] pub Span);

#[derive(Diagnostic)]
#[diag(parse_macro_invocation_with_qualified_path)]
pub(crate) struct MacroInvocationWithQualifiedPath(#[primary_span] pub Span);

#[derive(Diagnostic)]
#[diag(parse_unexpected_token_after_label)]
pub(crate) struct UnexpectedTokenAfterLabel {
    #[primary_span]
    #[label(parse_unexpected_token_after_label)]
    pub span: Span,
    #[suggestion(suggestion_remove_label, style = "verbose", code = "")]
    pub remove_label: Option<Span>,
    #[subdiagnostic]
    pub enclose_in_block: Option<UnexpectedTokenAfterLabelSugg>,
}

#[derive(Subdiagnostic)]
#[multipart_suggestion(suggestion_enclose_in_block, applicability = "machine-applicable")]
pub(crate) struct UnexpectedTokenAfterLabelSugg {
    #[suggestion_part(code = "{{ ")]
    pub left: Span,
    #[suggestion_part(code = " }}")]
    pub right: Span,
}

#[derive(Diagnostic)]
#[diag(parse_require_colon_after_labeled_expression)]
#[note]
pub(crate) struct RequireColonAfterLabeledExpression {
    #[primary_span]
    pub span: Span,
    #[label]
    pub label: Span,
    #[suggestion(style = "short", applicability = "machine-applicable", code = ": ")]
    pub label_end: Span,
}

#[derive(Diagnostic)]
#[diag(parse_do_catch_syntax_removed)]
#[note]
pub(crate) struct DoCatchSyntaxRemoved {
    #[primary_span]
    #[suggestion(applicability = "machine-applicable", code = "try")]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_float_literal_requires_integer_part)]
pub(crate) struct FloatLiteralRequiresIntegerPart {
    #[primary_span]
    #[suggestion(applicability = "machine-applicable", code = "{correct}")]
    pub span: Span,
    pub correct: String,
}

#[derive(Diagnostic)]
#[diag(parse_missing_semicolon_before_array)]
pub(crate) struct MissingSemicolonBeforeArray {
    #[primary_span]
    pub open_delim: Span,
    #[suggestion(style = "verbose", applicability = "maybe-incorrect", code = ";")]
    pub semicolon: Span,
}

#[derive(Diagnostic)]
#[diag(parse_expect_dotdot_not_dotdotdot)]
pub(crate) struct MissingDotDot {
    #[primary_span]
    pub token_span: Span,
    #[suggestion(applicability = "maybe-incorrect", code = "..", style = "verbose")]
    pub sugg_span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_invalid_block_macro_segment)]
pub(crate) struct InvalidBlockMacroSegment {
    #[primary_span]
    pub span: Span,
    #[label]
    pub context: Span,
}

#[derive(Diagnostic)]
#[diag(parse_if_expression_missing_then_block)]
pub(crate) struct IfExpressionMissingThenBlock {
    #[primary_span]
    pub if_span: Span,
    #[subdiagnostic]
    pub missing_then_block_sub: IfExpressionMissingThenBlockSub,
    #[subdiagnostic]
    pub let_else_sub: Option<IfExpressionLetSomeSub>,
}

#[derive(Subdiagnostic)]
pub(crate) enum IfExpressionMissingThenBlockSub {
    #[help(condition_possibly_unfinished)]
    UnfinishedCondition(#[primary_span] Span),
    #[help(add_then_block)]
    AddThenBlock(#[primary_span] Span),
}

#[derive(Subdiagnostic)]
#[help(parse_extra_if_in_let_else)]
pub(crate) struct IfExpressionLetSomeSub {
    #[primary_span]
    pub if_span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_if_expression_missing_condition)]
pub(crate) struct IfExpressionMissingCondition {
    #[primary_span]
    #[label(condition_label)]
    pub if_span: Span,
    #[label(block_label)]
    pub block_span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_expected_expression_found_let)]
pub(crate) struct ExpectedExpressionFoundLet {
    #[primary_span]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_expect_eq_instead_of_eqeq)]
pub(crate) struct ExpectedEqForLetExpr {
    #[primary_span]
    pub span: Span,
    #[suggestion(applicability = "maybe-incorrect", code = "=", style = "verbose")]
    pub sugg_span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_expected_else_block)]
pub(crate) struct ExpectedElseBlock {
    #[primary_span]
    pub first_tok_span: Span,
    pub first_tok: String,
    #[label]
    pub else_span: Span,
    #[suggestion(applicability = "maybe-incorrect", code = "if ")]
    pub condition_start: Span,
}

#[derive(Diagnostic)]
#[diag(parse_outer_attribute_not_allowed_on_if_else)]
pub(crate) struct OuterAttributeNotAllowedOnIfElse {
    #[primary_span]
    pub last: Span,

    #[label(branch_label)]
    pub branch_span: Span,

    #[label(ctx_label)]
    pub ctx_span: Span,
    pub ctx: String,

    #[suggestion(applicability = "machine-applicable", code = "")]
    pub attributes: Span,
}

#[derive(Diagnostic)]
#[diag(parse_missing_in_in_for_loop)]
pub(crate) struct MissingInInForLoop {
    #[primary_span]
    pub span: Span,
    #[subdiagnostic]
    pub sub: MissingInInForLoopSub,
}

#[derive(Subdiagnostic)]
pub(crate) enum MissingInInForLoopSub {
    // Has been misleading, at least in the past (closed Issue #48492), thus maybe-incorrect
    #[suggestion(use_in_not_of, style = "short", applicability = "maybe-incorrect", code = "in")]
    InNotOf(#[primary_span] Span),
    #[suggestion(add_in, style = "short", applicability = "maybe-incorrect", code = " in ")]
    AddIn(#[primary_span] Span),
}

#[derive(Diagnostic)]
#[diag(parse_missing_comma_after_match_arm)]
pub(crate) struct MissingCommaAfterMatchArm {
    #[primary_span]
    #[suggestion(applicability = "machine-applicable", code = ",")]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_catch_after_try)]
#[help]
pub(crate) struct CatchAfterTry {
    #[primary_span]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_comma_after_base_struct)]
#[note]
pub(crate) struct CommaAfterBaseStruct {
    #[primary_span]
    pub span: Span,
    #[suggestion(style = "short", applicability = "machine-applicable", code = "")]
    pub comma: Span,
}

#[derive(Diagnostic)]
#[diag(parse_eq_field_init)]
pub(crate) struct EqFieldInit {
    #[primary_span]
    pub span: Span,
    #[suggestion(applicability = "machine-applicable", code = ":")]
    pub eq: Span,
}

#[derive(Diagnostic)]
#[diag(parse_dotdotdot)]
pub(crate) struct DotDotDot {
    #[primary_span]
    #[suggestion(suggest_exclusive_range, applicability = "maybe-incorrect", code = "..")]
    #[suggestion(suggest_inclusive_range, applicability = "maybe-incorrect", code = "..=")]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_left_arrow_operator)]
pub(crate) struct LeftArrowOperator {
    #[primary_span]
    #[suggestion(applicability = "maybe-incorrect", code = "< -")]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_remove_let)]
pub(crate) struct RemoveLet {
    #[primary_span]
    #[suggestion(applicability = "machine-applicable", code = "")]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_use_eq_instead)]
pub(crate) struct UseEqInstead {
    #[primary_span]
    #[suggestion(style = "short", applicability = "machine-applicable", code = "=")]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_use_empty_block_not_semi)]
pub(crate) struct UseEmptyBlockNotSemi {
    #[primary_span]
    #[suggestion(style = "hidden", applicability = "machine-applicable", code = "{{}}")]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_comparison_interpreted_as_generic)]
pub(crate) struct ComparisonInterpretedAsGeneric {
    #[primary_span]
    #[label(label_comparison)]
    pub comparison: Span,
    pub r#type: Path,
    #[label(label_args)]
    pub args: Span,
    #[subdiagnostic]
    pub suggestion: ComparisonOrShiftInterpretedAsGenericSugg,
}

#[derive(Diagnostic)]
#[diag(parse_shift_interpreted_as_generic)]
pub(crate) struct ShiftInterpretedAsGeneric {
    #[primary_span]
    #[label(label_comparison)]
    pub shift: Span,
    pub r#type: Path,
    #[label(label_args)]
    pub args: Span,
    #[subdiagnostic]
    pub suggestion: ComparisonOrShiftInterpretedAsGenericSugg,
}

#[derive(Subdiagnostic)]
#[multipart_suggestion(suggestion, applicability = "machine-applicable")]
pub(crate) struct ComparisonOrShiftInterpretedAsGenericSugg {
    #[suggestion_part(code = "(")]
    pub left: Span,
    #[suggestion_part(code = ")")]
    pub right: Span,
}

#[derive(Diagnostic)]
#[diag(parse_found_expr_would_be_stmt)]
pub(crate) struct FoundExprWouldBeStmt {
    #[primary_span]
    #[label]
    pub span: Span,
    pub token: Token,
    #[subdiagnostic]
    pub suggestion: ExprParenthesesNeeded,
}

#[derive(Diagnostic)]
#[diag(parse_leading_plus_not_supported)]
pub(crate) struct LeadingPlusNotSupported {
    #[primary_span]
    #[label]
    pub span: Span,
    #[suggestion(
        suggestion_remove_plus,
        style = "verbose",
        code = "",
        applicability = "machine-applicable"
    )]
    pub remove_plus: Option<Span>,
    #[subdiagnostic]
    pub add_parentheses: Option<ExprParenthesesNeeded>,
}

#[derive(Diagnostic)]
#[diag(parse_parentheses_with_struct_fields)]
pub(crate) struct ParenthesesWithStructFields {
    #[primary_span]
    pub span: Span,
    pub r#type: Path,
    #[subdiagnostic]
    pub braces_for_struct: BracesForStructLiteral,
    #[subdiagnostic]
    pub no_fields_for_fn: NoFieldsForFnCall,
}

#[derive(Subdiagnostic)]
#[multipart_suggestion(suggestion_braces_for_struct, applicability = "maybe-incorrect")]
pub(crate) struct BracesForStructLiteral {
    #[suggestion_part(code = " {{ ")]
    pub first: Span,
    #[suggestion_part(code = " }}")]
    pub second: Span,
}

#[derive(Subdiagnostic)]
#[multipart_suggestion(suggestion_no_fields_for_fn, applicability = "maybe-incorrect")]
pub(crate) struct NoFieldsForFnCall {
    #[suggestion_part(code = "")]
    pub fields: Vec<Span>,
}

#[derive(Diagnostic)]
#[diag(parse_labeled_loop_in_break)]
pub(crate) struct LabeledLoopInBreak {
    #[primary_span]
    pub span: Span,
    #[subdiagnostic]
    pub sub: WrapExpressionInParentheses,
}

#[derive(Subdiagnostic)]
#[multipart_suggestion(
    parse_sugg_wrap_expression_in_parentheses,
    applicability = "machine-applicable"
)]
pub(crate) struct WrapExpressionInParentheses {
    #[suggestion_part(code = "(")]
    pub left: Span,
    #[suggestion_part(code = ")")]
    pub right: Span,
}

#[derive(Diagnostic)]
#[diag(parse_array_brackets_instead_of_braces)]
pub(crate) struct ArrayBracketsInsteadOfSpaces {
    #[primary_span]
    pub span: Span,
    #[subdiagnostic]
    pub sub: ArrayBracketsInsteadOfSpacesSugg,
}

#[derive(Subdiagnostic)]
#[multipart_suggestion(suggestion, applicability = "maybe-incorrect")]
pub(crate) struct ArrayBracketsInsteadOfSpacesSugg {
    #[suggestion_part(code = "[")]
    pub left: Span,
    #[suggestion_part(code = "]")]
    pub right: Span,
}

#[derive(Diagnostic)]
#[diag(parse_match_arm_body_without_braces)]
pub(crate) struct MatchArmBodyWithoutBraces {
    #[primary_span]
    #[label(label_statements)]
    pub statements: Span,
    #[label(label_arrow)]
    pub arrow: Span,
    pub num_statements: usize,
    #[subdiagnostic]
    pub sub: MatchArmBodyWithoutBracesSugg,
}

#[derive(Subdiagnostic)]
pub(crate) enum MatchArmBodyWithoutBracesSugg {
    #[multipart_suggestion(suggestion_add_braces, applicability = "machine-applicable")]
    AddBraces {
        #[suggestion_part(code = "{{ ")]
        left: Span,
        #[suggestion_part(code = " }}")]
        right: Span,
    },
    #[suggestion(
        suggestion_use_comma_not_semicolon,
        code = ",",
        applicability = "machine-applicable"
    )]
    UseComma {
        #[primary_span]
        semicolon: Span,
    },
}

#[derive(Diagnostic)]
#[diag(parse_struct_literal_not_allowed_here)]
pub(crate) struct StructLiteralNotAllowedHere {
    #[primary_span]
    pub span: Span,
    #[subdiagnostic]
    pub sub: StructLiteralNotAllowedHereSugg,
}

#[derive(Subdiagnostic)]
#[multipart_suggestion(suggestion, applicability = "machine-applicable")]
pub(crate) struct StructLiteralNotAllowedHereSugg {
    #[suggestion_part(code = "(")]
    pub left: Span,
    #[suggestion_part(code = ")")]
    pub right: Span,
}

#[derive(Diagnostic)]
#[diag(parse_invalid_interpolated_expression)]
pub(crate) struct InvalidInterpolatedExpression {
    #[primary_span]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_invalid_literal_suffix_on_tuple_index)]
pub(crate) struct InvalidLiteralSuffixOnTupleIndex {
    #[primary_span]
    #[label]
    pub span: Span,
    pub suffix: Symbol,
    #[help(tuple_exception_line_1)]
    #[help(tuple_exception_line_2)]
    #[help(tuple_exception_line_3)]
    pub exception: Option<()>,
}

#[derive(Diagnostic)]
#[diag(parse_non_string_abi_literal)]
pub(crate) struct NonStringAbiLiteral {
    #[primary_span]
    #[suggestion(code = "\"C\"", applicability = "maybe-incorrect")]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_mismatched_closing_delimiter)]
pub(crate) struct MismatchedClosingDelimiter {
    #[primary_span]
    pub spans: Vec<Span>,
    pub delimiter: String,
    #[label(label_unmatched)]
    pub unmatched: Span,
    #[label(label_opening_candidate)]
    pub opening_candidate: Option<Span>,
    #[label(label_unclosed)]
    pub unclosed: Option<Span>,
}

#[derive(Diagnostic)]
#[diag(parse_incorrect_visibility_restriction, code = "E0704")]
#[help]
pub(crate) struct IncorrectVisibilityRestriction {
    #[primary_span]
    #[suggestion(code = "in {inner_str}", applicability = "machine-applicable")]
    pub span: Span,
    pub inner_str: String,
}

#[derive(Diagnostic)]
#[diag(parse_assignment_else_not_allowed)]
pub(crate) struct AssignmentElseNotAllowed {
    #[primary_span]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_expected_statement_after_outer_attr)]
pub(crate) struct ExpectedStatementAfterOuterAttr {
    #[primary_span]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_doc_comment_does_not_document_anything, code = "E0585")]
#[help]
pub(crate) struct DocCommentDoesNotDocumentAnything {
    #[primary_span]
    pub span: Span,
    #[suggestion(code = ",", applicability = "machine-applicable")]
    pub missing_comma: Option<Span>,
}

#[derive(Diagnostic)]
#[diag(parse_const_let_mutually_exclusive)]
pub(crate) struct ConstLetMutuallyExclusive {
    #[primary_span]
    #[suggestion(code = "const", applicability = "maybe-incorrect")]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_invalid_expression_in_let_else)]
pub(crate) struct InvalidExpressionInLetElse {
    #[primary_span]
    pub span: Span,
    pub operator: &'static str,
    #[subdiagnostic]
    pub sugg: WrapExpressionInParentheses,
}

#[derive(Diagnostic)]
#[diag(parse_invalid_curly_in_let_else)]
pub(crate) struct InvalidCurlyInLetElse {
    #[primary_span]
    pub span: Span,
    #[subdiagnostic]
    pub sugg: WrapExpressionInParentheses,
}

#[derive(Diagnostic)]
#[diag(parse_compound_assignment_expression_in_let)]
#[help]
pub(crate) struct CompoundAssignmentExpressionInLet {
    #[primary_span]
    #[suggestion(style = "short", code = "=", applicability = "maybe-incorrect")]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_suffixed_literal_in_attribute)]
#[help]
pub(crate) struct SuffixedLiteralInAttribute {
    #[primary_span]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_invalid_meta_item)]
pub(crate) struct InvalidMetaItem {
    #[primary_span]
    pub span: Span,
    pub token: Token,
}

#[derive(Subdiagnostic)]
#[suggestion(
    parse_sugg_escape_to_use_as_identifier,
    style = "verbose",
    applicability = "maybe-incorrect",
    code = "r#"
)]
pub(crate) struct SuggEscapeToUseAsIdentifier {
    #[primary_span]
    pub span: Span,
    pub ident_name: String,
}

#[derive(Subdiagnostic)]
#[suggestion(parse_sugg_remove_comma, applicability = "machine-applicable", code = "")]
pub(crate) struct SuggRemoveComma {
    #[primary_span]
    pub span: Span,
}

#[derive(Subdiagnostic)]
pub(crate) enum ExpectedIdentifierFound {
    #[label(parse_expected_identifier_found_reserved_identifier)]
    ReservedIdentifier(#[primary_span] Span),
    #[label(parse_expected_identifier_found_keyword)]
    Keyword(#[primary_span] Span),
    #[label(parse_expected_identifier_found_reserved_keyword)]
    ReservedKeyword(#[primary_span] Span),
    #[label(parse_expected_identifier_found_doc_comment)]
    DocComment(#[primary_span] Span),
    #[label(parse_expected_identifier)]
    Other(#[primary_span] Span),
}

impl ExpectedIdentifierFound {
    pub fn new(token_descr: Option<TokenDescription>, span: Span) -> Self {
        (match token_descr {
            Some(TokenDescription::ReservedIdentifier) => {
                ExpectedIdentifierFound::ReservedIdentifier
            }
            Some(TokenDescription::Keyword) => ExpectedIdentifierFound::Keyword,
            Some(TokenDescription::ReservedKeyword) => ExpectedIdentifierFound::ReservedKeyword,
            Some(TokenDescription::DocComment) => ExpectedIdentifierFound::DocComment,
            None => ExpectedIdentifierFound::Other,
        })(span)
    }
}

pub(crate) struct ExpectedIdentifier {
    pub span: Span,
    pub token: Token,
    pub suggest_raw: Option<SuggEscapeToUseAsIdentifier>,
    pub suggest_remove_comma: Option<SuggRemoveComma>,
}

impl<'a, G: EmissionGuarantee> IntoDiagnostic<'a, G> for ExpectedIdentifier {
    #[track_caller]
    fn into_diagnostic(
        self,
        handler: &'a rustc_errors::Handler,
    ) -> rustc_errors::DiagnosticBuilder<'a, G> {
        let token_descr = super::parser::TokenDescription::from_token(&self.token);

        let mut diag = handler.struct_diagnostic(match token_descr {
            Some(TokenDescription::ReservedIdentifier) => {
                fluent::parse_expected_identifier_found_reserved_identifier_str
            }
            Some(TokenDescription::Keyword) => fluent::parse_expected_identifier_found_keyword_str,
            Some(TokenDescription::ReservedKeyword) => {
                fluent::parse_expected_identifier_found_reserved_keyword_str
            }
            Some(TokenDescription::DocComment) => {
                fluent::parse_expected_identifier_found_doc_comment_str
            }
            None => fluent::parse_expected_identifier_found_str,
        });
        diag.set_span(self.span);
        diag.set_arg("token", self.token);

        if let Some(sugg) = self.suggest_raw {
            sugg.add_to_diagnostic(&mut diag);
        }

        ExpectedIdentifierFound::new(token_descr, self.span).add_to_diagnostic(&mut diag);

        if let Some(sugg) = self.suggest_remove_comma {
            sugg.add_to_diagnostic(&mut diag);
        }

        diag
    }
}

pub(crate) struct ExpectedSemi {
    pub span: Span,
    pub token: Token,

    pub unexpected_token_label: Option<Span>,
    pub sugg: ExpectedSemiSugg,
}

impl<'a, G: EmissionGuarantee> IntoDiagnostic<'a, G> for ExpectedSemi {
    #[track_caller]
    fn into_diagnostic(
        self,
        handler: &'a rustc_errors::Handler,
    ) -> rustc_errors::DiagnosticBuilder<'a, G> {
        let token_descr = super::parser::TokenDescription::from_token(&self.token);

        let mut diag = handler.struct_diagnostic(match token_descr {
            Some(TokenDescription::ReservedIdentifier) => {
                fluent::parse_expected_semi_found_reserved_identifier_str
            }
            Some(TokenDescription::Keyword) => fluent::parse_expected_semi_found_keyword_str,
            Some(TokenDescription::ReservedKeyword) => {
                fluent::parse_expected_semi_found_reserved_keyword_str
            }
            Some(TokenDescription::DocComment) => fluent::parse_expected_semi_found_doc_comment_str,
            None => fluent::parse_expected_semi_found_str,
        });
        diag.set_span(self.span);
        diag.set_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);
        }

        self.sugg.add_to_diagnostic(&mut diag);

        diag
    }
}

#[derive(Subdiagnostic)]
pub(crate) enum ExpectedSemiSugg {
    #[suggestion(parse_sugg_change_this_to_semi, code = ";", applicability = "machine-applicable")]
    ChangeToSemi(#[primary_span] Span),
    #[suggestion(
        parse_sugg_add_semi,
        style = "short",
        code = ";",
        applicability = "machine-applicable"
    )]
    AddSemi(#[primary_span] Span),
}

#[derive(Diagnostic)]
#[diag(parse_struct_literal_body_without_path)]
pub(crate) struct StructLiteralBodyWithoutPath {
    #[primary_span]
    pub span: Span,
    #[subdiagnostic]
    pub sugg: StructLiteralBodyWithoutPathSugg,
}

#[derive(Subdiagnostic)]
#[multipart_suggestion(suggestion, applicability = "has-placeholders")]
pub(crate) struct StructLiteralBodyWithoutPathSugg {
    #[suggestion_part(code = "{{ SomeStruct ")]
    pub before: Span,
    #[suggestion_part(code = " }}")]
    pub after: Span,
}

#[derive(Diagnostic)]
#[diag(parse_struct_literal_needing_parens)]
pub(crate) struct StructLiteralNeedingParens {
    #[primary_span]
    pub span: Span,
    #[subdiagnostic]
    pub sugg: StructLiteralNeedingParensSugg,
}

#[derive(Subdiagnostic)]
#[multipart_suggestion(suggestion, applicability = "machine-applicable")]
pub(crate) struct StructLiteralNeedingParensSugg {
    #[suggestion_part(code = "(")]
    pub before: Span,
    #[suggestion_part(code = ")")]
    pub after: Span,
}

#[derive(Diagnostic)]
#[diag(parse_unmatched_angle_brackets)]
pub(crate) struct UnmatchedAngleBrackets {
    #[primary_span]
    #[suggestion(code = "", applicability = "machine-applicable")]
    pub span: Span,
    pub num_extra_brackets: usize,
}

#[derive(Diagnostic)]
#[diag(parse_generic_parameters_without_angle_brackets)]
pub(crate) struct GenericParamsWithoutAngleBrackets {
    #[primary_span]
    pub span: Span,
    #[subdiagnostic]
    pub sugg: GenericParamsWithoutAngleBracketsSugg,
}

#[derive(Subdiagnostic)]
#[multipart_suggestion(suggestion, applicability = "machine-applicable")]
pub(crate) struct GenericParamsWithoutAngleBracketsSugg {
    #[suggestion_part(code = "<")]
    pub left: Span,
    #[suggestion_part(code = ">")]
    pub right: Span,
}

#[derive(Diagnostic)]
#[diag(parse_comparison_operators_cannot_be_chained)]
pub(crate) struct ComparisonOperatorsCannotBeChained {
    #[primary_span]
    pub span: Vec<Span>,
    #[suggestion(
        parse_sugg_turbofish_syntax,
        style = "verbose",
        code = "::",
        applicability = "maybe-incorrect"
    )]
    pub suggest_turbofish: Option<Span>,
    #[help(parse_sugg_turbofish_syntax)]
    #[help(sugg_parentheses_for_function_args)]
    pub help_turbofish: Option<()>,
    #[subdiagnostic]
    pub chaining_sugg: Option<ComparisonOperatorsCannotBeChainedSugg>,
}

#[derive(Subdiagnostic)]
pub(crate) enum ComparisonOperatorsCannotBeChainedSugg {
    #[suggestion(
        sugg_split_comparison,
        style = "verbose",
        code = " && {middle_term}",
        applicability = "maybe-incorrect"
    )]
    SplitComparison {
        #[primary_span]
        span: Span,
        middle_term: String,
    },
    #[multipart_suggestion(sugg_parenthesize, applicability = "maybe-incorrect")]
    Parenthesize {
        #[suggestion_part(code = "(")]
        left: Span,
        #[suggestion_part(code = ")")]
        right: Span,
    },
}

#[derive(Diagnostic)]
#[diag(parse_question_mark_in_type)]
pub(crate) struct QuestionMarkInType {
    #[primary_span]
    #[label]
    pub span: Span,
    #[subdiagnostic]
    pub sugg: QuestionMarkInTypeSugg,
}

#[derive(Subdiagnostic)]
#[multipart_suggestion(suggestion, applicability = "machine-applicable")]
pub(crate) struct QuestionMarkInTypeSugg {
    #[suggestion_part(code = "Option<")]
    pub left: Span,
    #[suggestion_part(code = ">")]
    pub right: Span,
}

#[derive(Diagnostic)]
#[diag(parse_unexpected_parentheses_in_for_head)]
pub(crate) struct ParenthesesInForHead {
    #[primary_span]
    pub span: Vec<Span>,
    #[subdiagnostic]
    pub sugg: ParenthesesInForHeadSugg,
}

#[derive(Subdiagnostic)]
#[multipart_suggestion(suggestion, applicability = "machine-applicable")]
pub(crate) struct ParenthesesInForHeadSugg {
    #[suggestion_part(code = "{left_snippet}")]
    pub left: Span,
    pub left_snippet: String,
    #[suggestion_part(code = "{right_snippet}")]
    pub right: Span,
    pub right_snippet: String,
}

#[derive(Diagnostic)]
#[diag(parse_doc_comment_on_param_type)]
pub(crate) struct DocCommentOnParamType {
    #[primary_span]
    #[label]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_attribute_on_param_type)]
pub(crate) struct AttributeOnParamType {
    #[primary_span]
    #[label]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_pattern_method_param_without_body, code = "E0642")]
pub(crate) struct PatternMethodParamWithoutBody {
    #[primary_span]
    #[suggestion(code = "_", applicability = "machine-applicable")]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_self_param_not_first)]
pub(crate) struct SelfParamNotFirst {
    #[primary_span]
    #[label]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_invalid_identifier_with_leading_number)]
pub(crate) struct InvalidIdentiferStartsWithNumber {
    #[primary_span]
    #[label]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_const_generic_without_braces)]
pub(crate) struct ConstGenericWithoutBraces {
    #[primary_span]
    pub span: Span,
    #[subdiagnostic]
    pub sugg: ConstGenericWithoutBracesSugg,
}

#[derive(Subdiagnostic)]
#[multipart_suggestion(suggestion, applicability = "machine-applicable")]
pub(crate) struct ConstGenericWithoutBracesSugg {
    #[suggestion_part(code = "{{ ")]
    pub left: Span,
    #[suggestion_part(code = " }}")]
    pub right: Span,
}

#[derive(Diagnostic)]
#[diag(parse_unexpected_const_param_declaration)]
pub(crate) struct UnexpectedConstParamDeclaration {
    #[primary_span]
    #[label]
    pub span: Span,
    #[subdiagnostic]
    pub sugg: Option<UnexpectedConstParamDeclarationSugg>,
}

#[derive(Subdiagnostic)]
pub(crate) enum UnexpectedConstParamDeclarationSugg {
    #[multipart_suggestion(suggestion, applicability = "machine-applicable")]
    AddParam {
        #[suggestion_part(code = "<{snippet}>")]
        impl_generics: Span,
        #[suggestion_part(code = "{ident}")]
        incorrect_decl: Span,
        snippet: String,
        ident: String,
    },
    #[multipart_suggestion(suggestion, applicability = "machine-applicable")]
    AppendParam {
        #[suggestion_part(code = ", {snippet}")]
        impl_generics_end: Span,
        #[suggestion_part(code = "{ident}")]
        incorrect_decl: Span,
        snippet: String,
        ident: String,
    },
}

#[derive(Diagnostic)]
#[diag(parse_unexpected_const_in_generic_param)]
pub(crate) struct UnexpectedConstInGenericParam {
    #[primary_span]
    pub span: Span,
    #[suggestion(style = "verbose", code = "", applicability = "maybe-incorrect")]
    pub to_remove: Option<Span>,
}

#[derive(Diagnostic)]
#[diag(parse_async_move_order_incorrect)]
pub(crate) struct AsyncMoveOrderIncorrect {
    #[primary_span]
    #[suggestion(style = "verbose", code = "async move", applicability = "maybe-incorrect")]
    pub span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_double_colon_in_bound)]
pub(crate) struct DoubleColonInBound {
    #[primary_span]
    pub span: Span,
    #[suggestion(code = ": ", applicability = "machine-applicable")]
    pub between: Span,
}

#[derive(Diagnostic)]
#[diag(parse_fn_ptr_with_generics)]
pub(crate) struct FnPtrWithGenerics {
    #[primary_span]
    pub span: Span,
    #[subdiagnostic]
    pub sugg: Option<FnPtrWithGenericsSugg>,
}

#[derive(Subdiagnostic)]
#[multipart_suggestion(suggestion, applicability = "maybe-incorrect")]
pub(crate) struct FnPtrWithGenericsSugg {
    #[suggestion_part(code = "{snippet}")]
    pub left: Span,
    pub snippet: String,
    #[suggestion_part(code = "")]
    pub right: Span,
    pub arity: usize,
    pub for_param_list_exists: bool,
}

#[derive(Diagnostic)]
#[diag(parse_unexpected_if_with_if)]
pub(crate) struct UnexpectedIfWithIf(
    #[primary_span]
    #[suggestion(applicability = "machine-applicable", code = " ", style = "verbose")]
    pub Span,
);

#[derive(Diagnostic)]
#[diag(parse_maybe_fn_typo_with_impl)]
pub(crate) struct FnTypoWithImpl {
    #[primary_span]
    #[suggestion(applicability = "maybe-incorrect", code = "impl", style = "verbose")]
    pub fn_span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_expected_fn_path_found_fn_keyword)]
pub(crate) struct ExpectedFnPathFoundFnKeyword {
    #[primary_span]
    #[suggestion(applicability = "machine-applicable", code = "Fn", style = "verbose")]
    pub fn_token_span: Span,
}

#[derive(Diagnostic)]
#[diag(parse_where_clause_before_tuple_struct_body)]
pub(crate) struct WhereClauseBeforeTupleStructBody {
    #[primary_span]
    #[label]
    pub span: Span,
    #[label(name_label)]
    pub name: Span,
    #[label(body_label)]
    pub body: Span,
    #[subdiagnostic]
    pub sugg: Option<WhereClauseBeforeTupleStructBodySugg>,
}

#[derive(Subdiagnostic)]
#[multipart_suggestion(suggestion, applicability = "machine-applicable")]
pub(crate) struct WhereClauseBeforeTupleStructBodySugg {
    #[suggestion_part(code = "{snippet}")]
    pub left: Span,
    pub snippet: String,
    #[suggestion_part(code = "")]
    pub right: Span,
}