bf8ce32558
By replacing them with `{Open,Close}{Param,Brace,Bracket,Invisible}`.
PR #137902 made `ast::TokenKind` more like `lexer::TokenKind` by
replacing the compound `BinOp{,Eq}(BinOpToken)` variants with fieldless
variants `Plus`, `Minus`, `Star`, etc. This commit does a similar thing
with delimiters. It also makes `ast::TokenKind` more similar to
`parser::TokenType`.
This requires a few new methods:
- `TokenKind::is_{,open_,close_}delim()` replace various kinds of
pattern matches.
- `Delimiter::as_{open,close}_token_kind` are used to convert
`Delimiter` values to `TokenKind`.
Despite these additions, it's a net reduction in lines of code. This is
because e.g. `token::OpenParen` is so much shorter than
`token::OpenDelim(Delimiter::Parenthesis)` that many multi-line forms
reduce to single line forms. And many places where the number of lines
doesn't change are still easier to read, just because the names are
shorter, e.g.:
```
- } else if self.token != token::CloseDelim(Delimiter::Brace) {
+ } else if self.token != token::CloseBrace {
```
3086 lines
125 KiB
Rust
3086 lines
125 KiB
Rust
use std::mem::take;
|
|
use std::ops::{Deref, DerefMut};
|
|
|
|
use ast::token::IdentIsRaw;
|
|
use rustc_ast as ast;
|
|
use rustc_ast::ptr::P;
|
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use rustc_ast::token::{self, Lit, LitKind, Token, TokenKind};
|
|
use rustc_ast::util::parser::AssocOp;
|
|
use rustc_ast::{
|
|
AngleBracketedArg, AngleBracketedArgs, AnonConst, AttrVec, BinOpKind, BindingMode, Block,
|
|
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;
|
|
use rustc_errors::{
|
|
Applicability, Diag, DiagCtxtHandle, ErrorGuaranteed, PResult, Subdiagnostic, Suggestions,
|
|
pluralize,
|
|
};
|
|
use rustc_session::errors::ExprParenthesesNeeded;
|
|
use rustc_span::edit_distance::find_best_match_for_name;
|
|
use rustc_span::source_map::Spanned;
|
|
use rustc_span::symbol::used_keywords;
|
|
use rustc_span::{BytePos, DUMMY_SP, Ident, Span, SpanSnippetError, Symbol, kw, sym};
|
|
use thin_vec::{ThinVec, thin_vec};
|
|
use tracing::{debug, trace};
|
|
|
|
use super::pat::Expected;
|
|
use super::{
|
|
BlockMode, CommaRecoveryMode, ExpTokenPair, Parser, PathStyle, Restrictions, SemiColonMode,
|
|
SeqSep, TokenType,
|
|
};
|
|
use crate::errors::{
|
|
AddParen, AmbiguousPlus, AsyncMoveBlockIn2015, AsyncUseBlockIn2015, AttributeOnParamType,
|
|
AwaitSuggestion, BadQPathStage2, BadTypePlus, BadTypePlusSub, ColonAsSemi,
|
|
ComparisonOperatorsCannotBeChained, ComparisonOperatorsCannotBeChainedSugg,
|
|
ConstGenericWithoutBraces, ConstGenericWithoutBracesSugg, DocCommentDoesNotDocumentAnything,
|
|
DocCommentOnParamType, DoubleColonInBound, ExpectedIdentifier, ExpectedSemi, ExpectedSemiSugg,
|
|
GenericParamsWithoutAngleBrackets, GenericParamsWithoutAngleBracketsSugg,
|
|
HelpIdentifierStartsWithNumber, HelpUseLatestEdition, InInTypo, IncorrectAwait,
|
|
IncorrectSemicolon, IncorrectUseOfAwait, IncorrectUseOfUse, PatternMethodParamWithoutBody,
|
|
QuestionMarkInType, QuestionMarkInTypeSugg, SelfParamNotFirst, StructLiteralBodyWithoutPath,
|
|
StructLiteralBodyWithoutPathSugg, SuggAddMissingLetStmt, SuggEscapeIdentifier, SuggRemoveComma,
|
|
TernaryOperator, UnexpectedConstInGenericParam, UnexpectedConstParamDeclaration,
|
|
UnexpectedConstParamDeclarationSugg, UnmatchedAngleBrackets, UseEqInstead, WrapType,
|
|
};
|
|
use crate::parser::attr::InnerAttrPolicy;
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|
use crate::{exp, fluent_generated as fluent};
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|
|
|
/// Creates a placeholder argument.
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|
pub(super) fn dummy_arg(ident: Ident, guar: ErrorGuaranteed) -> Param {
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let pat = P(Pat {
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id: ast::DUMMY_NODE_ID,
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kind: PatKind::Ident(BindingMode::NONE, ident, None),
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span: ident.span,
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tokens: None,
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|
});
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let ty = Ty { kind: TyKind::Err(guar), span: ident.span, id: ast::DUMMY_NODE_ID, tokens: None };
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|
Param {
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|
attrs: AttrVec::default(),
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|
id: ast::DUMMY_NODE_ID,
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|
pat,
|
|
span: ident.span,
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ty: P(ty),
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|
is_placeholder: false,
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|
}
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|
}
|
|
|
|
pub(super) trait RecoverQPath: Sized + 'static {
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|
const PATH_STYLE: PathStyle = PathStyle::Expr;
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|
fn to_ty(&self) -> Option<P<Ty>>;
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|
fn recovered(qself: Option<P<QSelf>>, path: ast::Path) -> Self;
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|
}
|
|
|
|
impl RecoverQPath for Ty {
|
|
const PATH_STYLE: PathStyle = PathStyle::Type;
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|
fn to_ty(&self) -> Option<P<Ty>> {
|
|
Some(P(self.clone()))
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|
}
|
|
fn recovered(qself: Option<P<QSelf>>, path: ast::Path) -> Self {
|
|
Self {
|
|
span: path.span,
|
|
kind: TyKind::Path(qself, path),
|
|
id: ast::DUMMY_NODE_ID,
|
|
tokens: None,
|
|
}
|
|
}
|
|
}
|
|
|
|
impl RecoverQPath for Pat {
|
|
const PATH_STYLE: PathStyle = PathStyle::Pat;
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|
fn to_ty(&self) -> Option<P<Ty>> {
|
|
self.to_ty()
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|
}
|
|
fn recovered(qself: Option<P<QSelf>>, path: ast::Path) -> Self {
|
|
Self {
|
|
span: path.span,
|
|
kind: PatKind::Path(qself, path),
|
|
id: ast::DUMMY_NODE_ID,
|
|
tokens: None,
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|
}
|
|
}
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|
}
|
|
|
|
impl RecoverQPath for Expr {
|
|
fn to_ty(&self) -> Option<P<Ty>> {
|
|
self.to_ty()
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|
}
|
|
fn recovered(qself: Option<P<QSelf>>, path: ast::Path) -> Self {
|
|
Self {
|
|
span: path.span,
|
|
kind: ExprKind::Path(qself, path),
|
|
attrs: AttrVec::new(),
|
|
id: ast::DUMMY_NODE_ID,
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|
tokens: None,
|
|
}
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|
}
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|
}
|
|
|
|
/// Control whether the closing delimiter should be consumed when calling `Parser::consume_block`.
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|
pub(crate) enum ConsumeClosingDelim {
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|
Yes,
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|
No,
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|
}
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|
|
|
#[derive(Clone, Copy)]
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|
pub enum AttemptLocalParseRecovery {
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|
Yes,
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|
No,
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|
}
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|
|
|
impl AttemptLocalParseRecovery {
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|
pub(super) fn yes(&self) -> bool {
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|
match self {
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|
AttemptLocalParseRecovery::Yes => true,
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|
AttemptLocalParseRecovery::No => false,
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|
}
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|
}
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|
|
|
pub(super) fn no(&self) -> bool {
|
|
match self {
|
|
AttemptLocalParseRecovery::Yes => false,
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|
AttemptLocalParseRecovery::No => true,
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|
}
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|
}
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|
}
|
|
|
|
/// Information for emitting suggestions and recovering from
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|
/// C-style `i++`, `--i`, etc.
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|
#[derive(Debug, Copy, Clone)]
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|
struct IncDecRecovery {
|
|
/// Is this increment/decrement its own statement?
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|
standalone: IsStandalone,
|
|
/// Is this an increment or decrement?
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|
op: IncOrDec,
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|
/// Is this pre- or postfix?
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|
fixity: UnaryFixity,
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|
}
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|
|
|
/// Is an increment or decrement expression its own statement?
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|
#[derive(Debug, Copy, Clone)]
|
|
enum IsStandalone {
|
|
/// It's standalone, i.e., its own statement.
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|
Standalone,
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|
/// It's a subexpression, i.e., *not* standalone.
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|
Subexpr,
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|
}
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|
|
|
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
|
|
enum IncOrDec {
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|
Inc,
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Dec,
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|
}
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|
|
|
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
|
|
enum UnaryFixity {
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|
Pre,
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|
Post,
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|
}
|
|
|
|
impl IncOrDec {
|
|
fn chr(&self) -> char {
|
|
match self {
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|
Self::Inc => '+',
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|
Self::Dec => '-',
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|
}
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|
}
|
|
|
|
fn name(&self) -> &'static str {
|
|
match self {
|
|
Self::Inc => "increment",
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|
Self::Dec => "decrement",
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|
}
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|
}
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|
}
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|
|
|
impl std::fmt::Display for UnaryFixity {
|
|
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
|
|
match self {
|
|
Self::Pre => write!(f, "prefix"),
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|
Self::Post => write!(f, "postfix"),
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|
}
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|
}
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|
}
|
|
|
|
#[derive(Debug, rustc_macros::Subdiagnostic)]
|
|
#[suggestion(
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|
parse_misspelled_kw,
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|
applicability = "machine-applicable",
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|
code = "{similar_kw}",
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|
style = "verbose"
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|
)]
|
|
struct MisspelledKw {
|
|
similar_kw: String,
|
|
#[primary_span]
|
|
span: Span,
|
|
is_incorrect_case: bool,
|
|
}
|
|
|
|
/// Checks if the given `lookup` identifier is similar to any keyword symbol in `candidates`.
|
|
fn find_similar_kw(lookup: Ident, candidates: &[Symbol]) -> Option<MisspelledKw> {
|
|
let lowercase = lookup.name.as_str().to_lowercase();
|
|
let lowercase_sym = Symbol::intern(&lowercase);
|
|
if candidates.contains(&lowercase_sym) {
|
|
Some(MisspelledKw { similar_kw: lowercase, span: lookup.span, is_incorrect_case: true })
|
|
} else if let Some(similar_sym) = find_best_match_for_name(candidates, lookup.name, None) {
|
|
Some(MisspelledKw {
|
|
similar_kw: similar_sym.to_string(),
|
|
span: lookup.span,
|
|
is_incorrect_case: false,
|
|
})
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
|
|
struct MultiSugg {
|
|
msg: String,
|
|
patches: Vec<(Span, String)>,
|
|
applicability: Applicability,
|
|
}
|
|
|
|
impl MultiSugg {
|
|
fn emit(self, err: &mut Diag<'_>) {
|
|
err.multipart_suggestion(self.msg, self.patches, self.applicability);
|
|
}
|
|
|
|
fn emit_verbose(self, err: &mut Diag<'_>) {
|
|
err.multipart_suggestion_verbose(self.msg, self.patches, self.applicability);
|
|
}
|
|
}
|
|
|
|
/// SnapshotParser is used to create a snapshot of the parser
|
|
/// without causing duplicate errors being emitted when the `Parser`
|
|
/// is dropped.
|
|
pub struct SnapshotParser<'a> {
|
|
parser: Parser<'a>,
|
|
}
|
|
|
|
impl<'a> Deref for SnapshotParser<'a> {
|
|
type Target = Parser<'a>;
|
|
|
|
fn deref(&self) -> &Self::Target {
|
|
&self.parser
|
|
}
|
|
}
|
|
|
|
impl<'a> DerefMut for SnapshotParser<'a> {
|
|
fn deref_mut(&mut self) -> &mut Self::Target {
|
|
&mut self.parser
|
|
}
|
|
}
|
|
|
|
impl<'a> Parser<'a> {
|
|
pub fn dcx(&self) -> DiagCtxtHandle<'a> {
|
|
self.psess.dcx()
|
|
}
|
|
|
|
/// Replace `self` with `snapshot.parser`.
|
|
pub(super) fn restore_snapshot(&mut self, snapshot: SnapshotParser<'a>) {
|
|
*self = snapshot.parser;
|
|
}
|
|
|
|
/// Create a snapshot of the `Parser`.
|
|
pub fn create_snapshot_for_diagnostic(&self) -> SnapshotParser<'a> {
|
|
let snapshot = self.clone();
|
|
SnapshotParser { parser: snapshot }
|
|
}
|
|
|
|
pub(super) fn span_to_snippet(&self, span: Span) -> Result<String, SpanSnippetError> {
|
|
self.psess.source_map().span_to_snippet(span)
|
|
}
|
|
|
|
/// Emits an error with suggestions if an identifier was expected but not found.
|
|
///
|
|
/// Returns a possibly recovered identifier.
|
|
pub(super) fn expected_ident_found(
|
|
&mut self,
|
|
recover: bool,
|
|
) -> PResult<'a, (Ident, IdentIsRaw)> {
|
|
let valid_follow = &[
|
|
TokenKind::Eq,
|
|
TokenKind::Colon,
|
|
TokenKind::Comma,
|
|
TokenKind::Semi,
|
|
TokenKind::PathSep,
|
|
TokenKind::OpenBrace,
|
|
TokenKind::OpenParen,
|
|
TokenKind::CloseBrace,
|
|
TokenKind::CloseParen,
|
|
];
|
|
if let TokenKind::DocComment(..) = self.prev_token.kind
|
|
&& valid_follow.contains(&self.token.kind)
|
|
{
|
|
let err = self.dcx().create_err(DocCommentDoesNotDocumentAnything {
|
|
span: self.prev_token.span,
|
|
missing_comma: None,
|
|
});
|
|
return Err(err);
|
|
}
|
|
|
|
let mut recovered_ident = None;
|
|
// we take this here so that the correct original token is retained in
|
|
// the diagnostic, regardless of eager recovery.
|
|
let bad_token = self.token;
|
|
|
|
// suggest prepending a keyword in identifier position with `r#`
|
|
let suggest_raw = if let Some((ident, IdentIsRaw::No)) = self.token.ident()
|
|
&& ident.is_raw_guess()
|
|
&& self.look_ahead(1, |t| valid_follow.contains(&t.kind))
|
|
{
|
|
recovered_ident = Some((ident, IdentIsRaw::Yes));
|
|
|
|
// `Symbol::to_string()` is different from `Symbol::into_diag_arg()`,
|
|
// which uses `Symbol::to_ident_string()` and "helpfully" adds an implicit `r#`
|
|
let ident_name = ident.name.to_string();
|
|
|
|
Some(SuggEscapeIdentifier { span: ident.span.shrink_to_lo(), ident_name })
|
|
} else {
|
|
None
|
|
};
|
|
|
|
let suggest_remove_comma =
|
|
if self.token == token::Comma && self.look_ahead(1, |t| t.is_ident()) {
|
|
if recover {
|
|
self.bump();
|
|
recovered_ident = self.ident_or_err(false).ok();
|
|
};
|
|
|
|
Some(SuggRemoveComma { span: bad_token.span })
|
|
} else {
|
|
None
|
|
};
|
|
|
|
let help_cannot_start_number = self.is_lit_bad_ident().map(|(len, valid_portion)| {
|
|
let (invalid, valid) = self.token.span.split_at(len as u32);
|
|
|
|
recovered_ident = Some((Ident::new(valid_portion, valid), IdentIsRaw::No));
|
|
|
|
HelpIdentifierStartsWithNumber { num_span: invalid }
|
|
});
|
|
|
|
let err = ExpectedIdentifier {
|
|
span: bad_token.span,
|
|
token: bad_token,
|
|
suggest_raw,
|
|
suggest_remove_comma,
|
|
help_cannot_start_number,
|
|
};
|
|
let mut err = self.dcx().create_err(err);
|
|
|
|
// if the token we have is a `<`
|
|
// it *might* be a misplaced generic
|
|
// FIXME: could we recover with this?
|
|
if self.token == token::Lt {
|
|
// all keywords that could have generic applied
|
|
let valid_prev_keywords =
|
|
[kw::Fn, kw::Type, kw::Struct, kw::Enum, kw::Union, kw::Trait];
|
|
|
|
// If we've expected an identifier,
|
|
// and the current token is a '<'
|
|
// if the previous token is a valid keyword
|
|
// that might use a generic, then suggest a correct
|
|
// generic placement (later on)
|
|
let maybe_keyword = self.prev_token;
|
|
if valid_prev_keywords.into_iter().any(|x| maybe_keyword.is_keyword(x)) {
|
|
// if we have a valid keyword, attempt to parse generics
|
|
// also obtain the keywords symbol
|
|
match self.parse_generics() {
|
|
Ok(generic) => {
|
|
if let TokenKind::Ident(symbol, _) = maybe_keyword.kind {
|
|
let ident_name = symbol;
|
|
// at this point, we've found something like
|
|
// `fn <T>id`
|
|
// and current token should be Ident with the item name (i.e. the function name)
|
|
// if there is a `<` after the fn name, then don't show a suggestion, show help
|
|
|
|
if !self.look_ahead(1, |t| *t == token::Lt)
|
|
&& let Ok(snippet) =
|
|
self.psess.source_map().span_to_snippet(generic.span)
|
|
{
|
|
err.multipart_suggestion_verbose(
|
|
format!("place the generic parameter name after the {ident_name} name"),
|
|
vec![
|
|
(self.token.span.shrink_to_hi(), snippet),
|
|
(generic.span, String::new())
|
|
],
|
|
Applicability::MaybeIncorrect,
|
|
);
|
|
} else {
|
|
err.help(format!(
|
|
"place the generic parameter name after the {ident_name} name"
|
|
));
|
|
}
|
|
}
|
|
}
|
|
Err(err) => {
|
|
// if there's an error parsing the generics,
|
|
// then don't do a misplaced generics suggestion
|
|
// and emit the expected ident error instead;
|
|
err.cancel();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if let Some(recovered_ident) = recovered_ident
|
|
&& recover
|
|
{
|
|
err.emit();
|
|
Ok(recovered_ident)
|
|
} else {
|
|
Err(err)
|
|
}
|
|
}
|
|
|
|
pub(super) fn expected_ident_found_err(&mut self) -> Diag<'a> {
|
|
self.expected_ident_found(false).unwrap_err()
|
|
}
|
|
|
|
/// Checks if the current token is a integer or float literal and looks like
|
|
/// it could be a invalid identifier with digits at the start.
|
|
///
|
|
/// Returns the number of characters (bytes) composing the invalid portion
|
|
/// of the identifier and the valid portion of the identifier.
|
|
pub(super) fn is_lit_bad_ident(&mut self) -> Option<(usize, Symbol)> {
|
|
// ensure that the integer literal is followed by a *invalid*
|
|
// suffix: this is how we know that it is a identifier with an
|
|
// invalid beginning.
|
|
if let token::Literal(Lit {
|
|
kind: token::LitKind::Integer | token::LitKind::Float,
|
|
symbol,
|
|
suffix: Some(suffix), // no suffix makes it a valid literal
|
|
}) = self.token.kind
|
|
&& rustc_ast::MetaItemLit::from_token(&self.token).is_none()
|
|
{
|
|
Some((symbol.as_str().len(), suffix))
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
|
|
pub(super) fn expected_one_of_not_found(
|
|
&mut self,
|
|
edible: &[ExpTokenPair<'_>],
|
|
inedible: &[ExpTokenPair<'_>],
|
|
) -> PResult<'a, ErrorGuaranteed> {
|
|
debug!("expected_one_of_not_found(edible: {:?}, inedible: {:?})", edible, inedible);
|
|
fn tokens_to_string(tokens: &[TokenType]) -> String {
|
|
let mut i = tokens.iter();
|
|
// This might be a sign we need a connect method on `Iterator`.
|
|
let b = i.next().map_or_else(String::new, |t| t.to_string());
|
|
i.enumerate().fold(b, |mut b, (i, a)| {
|
|
if tokens.len() > 2 && i == tokens.len() - 2 {
|
|
b.push_str(", or ");
|
|
} else if tokens.len() == 2 && i == tokens.len() - 2 {
|
|
b.push_str(" or ");
|
|
} else {
|
|
b.push_str(", ");
|
|
}
|
|
b.push_str(&a.to_string());
|
|
b
|
|
})
|
|
}
|
|
|
|
for exp in edible.iter().chain(inedible.iter()) {
|
|
self.expected_token_types.insert(exp.token_type);
|
|
}
|
|
let mut expected: Vec<_> = self.expected_token_types.iter().collect();
|
|
expected.sort_by_cached_key(|x| x.to_string());
|
|
expected.dedup();
|
|
|
|
let sm = self.psess.source_map();
|
|
|
|
// Special-case "expected `;`" errors.
|
|
if expected.contains(&TokenType::Semi) {
|
|
// If the user is trying to write a ternary expression, recover it and
|
|
// return an Err to prevent a cascade of irrelevant diagnostics.
|
|
if self.prev_token == token::Question
|
|
&& let Err(e) = self.maybe_recover_from_ternary_operator()
|
|
{
|
|
return Err(e);
|
|
}
|
|
|
|
if self.token.span == DUMMY_SP || self.prev_token.span == DUMMY_SP {
|
|
// Likely inside a macro, can't provide meaningful suggestions.
|
|
} else if !sm.is_multiline(self.prev_token.span.until(self.token.span)) {
|
|
// The current token is in the same line as the prior token, not recoverable.
|
|
} else if [token::Comma, token::Colon].contains(&self.token.kind)
|
|
&& self.prev_token == token::CloseParen
|
|
{
|
|
// Likely typo: The current token is on a new line and is expected to be
|
|
// `.`, `;`, `?`, or an operator after a close delimiter token.
|
|
//
|
|
// let a = std::process::Command::new("echo")
|
|
// .arg("1")
|
|
// ,arg("2")
|
|
// ^
|
|
// https://github.com/rust-lang/rust/issues/72253
|
|
} else if self.look_ahead(1, |t| {
|
|
t == &token::CloseBrace || t.can_begin_expr() && *t != token::Colon
|
|
}) && [token::Comma, token::Colon].contains(&self.token.kind)
|
|
{
|
|
// Likely typo: `,` → `;` or `:` → `;`. This is triggered if the current token is
|
|
// either `,` or `:`, and the next token could either start a new statement or is a
|
|
// block close. For example:
|
|
//
|
|
// let x = 32:
|
|
// let y = 42;
|
|
let guar = self.dcx().emit_err(ExpectedSemi {
|
|
span: self.token.span,
|
|
token: self.token,
|
|
unexpected_token_label: None,
|
|
sugg: ExpectedSemiSugg::ChangeToSemi(self.token.span),
|
|
});
|
|
self.bump();
|
|
return Ok(guar);
|
|
} else if self.look_ahead(0, |t| {
|
|
t == &token::CloseBrace
|
|
|| ((t.can_begin_expr() || t.can_begin_item())
|
|
&& t != &token::Semi
|
|
&& t != &token::Pound)
|
|
// Avoid triggering with too many trailing `#` in raw string.
|
|
|| (sm.is_multiline(
|
|
self.prev_token.span.shrink_to_hi().until(self.token.span.shrink_to_lo()),
|
|
) && t == &token::Pound)
|
|
}) && !expected.contains(&TokenType::Comma)
|
|
{
|
|
// Missing semicolon typo. This is triggered if the next token could either start a
|
|
// new statement or is a block close. For example:
|
|
//
|
|
// let x = 32
|
|
// let y = 42;
|
|
let span = self.prev_token.span.shrink_to_hi();
|
|
let guar = self.dcx().emit_err(ExpectedSemi {
|
|
span,
|
|
token: self.token,
|
|
unexpected_token_label: Some(self.token.span),
|
|
sugg: ExpectedSemiSugg::AddSemi(span),
|
|
});
|
|
return Ok(guar);
|
|
}
|
|
}
|
|
|
|
if self.token == TokenKind::EqEq
|
|
&& self.prev_token.is_ident()
|
|
&& expected.contains(&TokenType::Eq)
|
|
{
|
|
// Likely typo: `=` → `==` in let expr or enum item
|
|
return Err(self.dcx().create_err(UseEqInstead { span: self.token.span }));
|
|
}
|
|
|
|
if (self.token.is_keyword(kw::Move) || self.token.is_keyword(kw::Use))
|
|
&& self.prev_token.is_keyword(kw::Async)
|
|
{
|
|
// The 2015 edition is in use because parsing of `async move` or `async use` has failed.
|
|
let span = self.prev_token.span.to(self.token.span);
|
|
if self.token.is_keyword(kw::Move) {
|
|
return Err(self.dcx().create_err(AsyncMoveBlockIn2015 { span }));
|
|
} else {
|
|
// kw::Use
|
|
return Err(self.dcx().create_err(AsyncUseBlockIn2015 { span }));
|
|
}
|
|
}
|
|
|
|
let expect = tokens_to_string(&expected);
|
|
let actual = super::token_descr(&self.token);
|
|
let (msg_exp, (label_sp, label_exp)) = if expected.len() > 1 {
|
|
let fmt = format!("expected one of {expect}, found {actual}");
|
|
let short_expect = if expected.len() > 6 {
|
|
format!("{} possible tokens", expected.len())
|
|
} else {
|
|
expect
|
|
};
|
|
(fmt, (self.prev_token.span.shrink_to_hi(), format!("expected one of {short_expect}")))
|
|
} else if expected.is_empty() {
|
|
(
|
|
format!("unexpected token: {actual}"),
|
|
(self.prev_token.span, "unexpected token after this".to_string()),
|
|
)
|
|
} else {
|
|
(
|
|
format!("expected {expect}, found {actual}"),
|
|
(self.prev_token.span.shrink_to_hi(), format!("expected {expect}")),
|
|
)
|
|
};
|
|
self.last_unexpected_token_span = Some(self.token.span);
|
|
// FIXME: translation requires list formatting (for `expect`)
|
|
let mut err = self.dcx().struct_span_err(self.token.span, msg_exp);
|
|
|
|
self.label_expected_raw_ref(&mut err);
|
|
|
|
// Look for usages of '=>' where '>=' was probably intended
|
|
if self.token == token::FatArrow
|
|
&& expected.iter().any(|tok| matches!(tok, TokenType::Operator | TokenType::Le))
|
|
&& !expected.iter().any(|tok| matches!(tok, TokenType::FatArrow | TokenType::Comma))
|
|
{
|
|
err.span_suggestion(
|
|
self.token.span,
|
|
"you might have meant to write a \"greater than or equal to\" comparison",
|
|
">=",
|
|
Applicability::MaybeIncorrect,
|
|
);
|
|
}
|
|
|
|
if let TokenKind::Ident(symbol, _) = &self.prev_token.kind {
|
|
if ["def", "fun", "func", "function"].contains(&symbol.as_str()) {
|
|
err.span_suggestion_short(
|
|
self.prev_token.span,
|
|
format!("write `fn` instead of `{symbol}` to declare a function"),
|
|
"fn",
|
|
Applicability::MachineApplicable,
|
|
);
|
|
}
|
|
}
|
|
|
|
if let TokenKind::Ident(prev, _) = &self.prev_token.kind
|
|
&& let TokenKind::Ident(cur, _) = &self.token.kind
|
|
{
|
|
let concat = Symbol::intern(&format!("{prev}{cur}"));
|
|
let ident = Ident::new(concat, DUMMY_SP);
|
|
if ident.is_used_keyword() || ident.is_reserved() || ident.is_raw_guess() {
|
|
let concat_span = self.prev_token.span.to(self.token.span);
|
|
err.span_suggestion_verbose(
|
|
concat_span,
|
|
format!("consider removing the space to spell keyword `{concat}`"),
|
|
concat,
|
|
Applicability::MachineApplicable,
|
|
);
|
|
}
|
|
}
|
|
|
|
// Try to detect an intended c-string literal while using a pre-2021 edition. The heuristic
|
|
// here is to identify a cooked, uninterpolated `c` id immediately followed by a string, or
|
|
// a cooked, uninterpolated `cr` id immediately followed by a string or a `#`, in an edition
|
|
// where c-string literals are not allowed. There is the very slight possibility of a false
|
|
// positive for a `cr#` that wasn't intended to start a c-string literal, but identifying
|
|
// that in the parser requires unbounded lookahead, so we only add a hint to the existing
|
|
// error rather than replacing it entirely.
|
|
if ((self.prev_token == TokenKind::Ident(sym::c, IdentIsRaw::No)
|
|
&& matches!(&self.token.kind, TokenKind::Literal(token::Lit { kind: token::Str, .. })))
|
|
|| (self.prev_token == TokenKind::Ident(sym::cr, IdentIsRaw::No)
|
|
&& matches!(
|
|
&self.token.kind,
|
|
TokenKind::Literal(token::Lit { kind: token::Str, .. }) | token::Pound
|
|
)))
|
|
&& self.prev_token.span.hi() == self.token.span.lo()
|
|
&& !self.token.span.at_least_rust_2021()
|
|
{
|
|
err.note("you may be trying to write a c-string literal");
|
|
err.note("c-string literals require Rust 2021 or later");
|
|
err.subdiagnostic(HelpUseLatestEdition::new());
|
|
}
|
|
|
|
// `pub` may be used for an item or `pub(crate)`
|
|
if self.prev_token.is_ident_named(sym::public)
|
|
&& (self.token.can_begin_item() || self.token == TokenKind::OpenParen)
|
|
{
|
|
err.span_suggestion_short(
|
|
self.prev_token.span,
|
|
"write `pub` instead of `public` to make the item public",
|
|
"pub",
|
|
Applicability::MachineApplicable,
|
|
);
|
|
}
|
|
|
|
if let token::DocComment(kind, style, _) = self.token.kind {
|
|
// We have something like `expr //!val` where the user likely meant `expr // !val`
|
|
let pos = self.token.span.lo() + BytePos(2);
|
|
let span = self.token.span.with_lo(pos).with_hi(pos);
|
|
err.span_suggestion_verbose(
|
|
span,
|
|
format!(
|
|
"add a space before {} to write a regular comment",
|
|
match (kind, style) {
|
|
(token::CommentKind::Line, ast::AttrStyle::Inner) => "`!`",
|
|
(token::CommentKind::Block, ast::AttrStyle::Inner) => "`!`",
|
|
(token::CommentKind::Line, ast::AttrStyle::Outer) => "the last `/`",
|
|
(token::CommentKind::Block, ast::AttrStyle::Outer) => "the last `*`",
|
|
},
|
|
),
|
|
" ".to_string(),
|
|
Applicability::MachineApplicable,
|
|
);
|
|
}
|
|
|
|
let sp = if self.token == token::Eof {
|
|
// This is EOF; don't want to point at the following char, but rather the last token.
|
|
self.prev_token.span
|
|
} else {
|
|
label_sp
|
|
};
|
|
|
|
if self.check_too_many_raw_str_terminators(&mut err) {
|
|
if expected.contains(&TokenType::Semi) && self.eat(exp!(Semi)) {
|
|
let guar = err.emit();
|
|
return Ok(guar);
|
|
} else {
|
|
return Err(err);
|
|
}
|
|
}
|
|
|
|
if self.prev_token.span == DUMMY_SP {
|
|
// Account for macro context where the previous span might not be
|
|
// available to avoid incorrect output (#54841).
|
|
err.span_label(self.token.span, label_exp);
|
|
} else if !sm.is_multiline(self.token.span.shrink_to_hi().until(sp.shrink_to_lo())) {
|
|
// When the spans are in the same line, it means that the only content between
|
|
// them is whitespace, point at the found token in that case:
|
|
//
|
|
// X | () => { syntax error };
|
|
// | ^^^^^ expected one of 8 possible tokens here
|
|
//
|
|
// instead of having:
|
|
//
|
|
// X | () => { syntax error };
|
|
// | -^^^^^ unexpected token
|
|
// | |
|
|
// | expected one of 8 possible tokens here
|
|
err.span_label(self.token.span, label_exp);
|
|
} else {
|
|
err.span_label(sp, label_exp);
|
|
err.span_label(self.token.span, "unexpected token");
|
|
}
|
|
|
|
// Check for misspelled keywords if there are no suggestions added to the diagnostic.
|
|
if matches!(&err.suggestions, Suggestions::Enabled(list) if list.is_empty()) {
|
|
self.check_for_misspelled_kw(&mut err, &expected);
|
|
}
|
|
Err(err)
|
|
}
|
|
|
|
/// Adds a label when `&raw EXPR` was written instead of `&raw const EXPR`/`&raw mut EXPR`.
|
|
///
|
|
/// Given that not all parser diagnostics flow through `expected_one_of_not_found`, this
|
|
/// label may need added to other diagnostics emission paths as needed.
|
|
pub(super) fn label_expected_raw_ref(&mut self, err: &mut Diag<'_>) {
|
|
if self.prev_token.is_keyword(kw::Raw)
|
|
&& self.expected_token_types.contains(TokenType::KwMut)
|
|
&& self.expected_token_types.contains(TokenType::KwConst)
|
|
&& self.token.can_begin_expr()
|
|
{
|
|
err.span_suggestions(
|
|
self.prev_token.span.shrink_to_hi(),
|
|
"`&raw` must be followed by `const` or `mut` to be a raw reference expression",
|
|
[" const".to_string(), " mut".to_string()],
|
|
Applicability::MaybeIncorrect,
|
|
);
|
|
}
|
|
}
|
|
|
|
/// Checks if the current token or the previous token are misspelled keywords
|
|
/// and adds a helpful suggestion.
|
|
fn check_for_misspelled_kw(&self, err: &mut Diag<'_>, expected: &[TokenType]) {
|
|
let Some((curr_ident, _)) = self.token.ident() else {
|
|
return;
|
|
};
|
|
let expected_token_types: &[TokenType] =
|
|
expected.len().checked_sub(10).map_or(&expected, |index| &expected[index..]);
|
|
let expected_keywords: Vec<Symbol> =
|
|
expected_token_types.iter().filter_map(|token| token.is_keyword()).collect();
|
|
|
|
// When there are a few keywords in the last ten elements of `self.expected_token_types`
|
|
// and the current token is an identifier, it's probably a misspelled keyword. This handles
|
|
// code like `async Move {}`, misspelled `if` in match guard, misspelled `else` in
|
|
// `if`-`else` and misspelled `where` in a where clause.
|
|
if !expected_keywords.is_empty()
|
|
&& !curr_ident.is_used_keyword()
|
|
&& let Some(misspelled_kw) = find_similar_kw(curr_ident, &expected_keywords)
|
|
{
|
|
err.subdiagnostic(misspelled_kw);
|
|
// We don't want other suggestions to be added as they are most likely meaningless
|
|
// when there is a misspelled keyword.
|
|
err.seal_suggestions();
|
|
} else if let Some((prev_ident, _)) = self.prev_token.ident()
|
|
&& !prev_ident.is_used_keyword()
|
|
{
|
|
// We generate a list of all keywords at runtime rather than at compile time
|
|
// so that it gets generated only when the diagnostic needs it.
|
|
// Also, it is unlikely that this list is generated multiple times because the
|
|
// parser halts after execution hits this path.
|
|
let all_keywords = used_keywords(|| prev_ident.span.edition());
|
|
|
|
// Otherwise, check the previous token with all the keywords as possible candidates.
|
|
// This handles code like `Struct Human;` and `While a < b {}`.
|
|
// We check the previous token only when the current token is an identifier to avoid
|
|
// false positives like suggesting keyword `for` for `extern crate foo {}`.
|
|
if let Some(misspelled_kw) = find_similar_kw(prev_ident, &all_keywords) {
|
|
err.subdiagnostic(misspelled_kw);
|
|
// We don't want other suggestions to be added as they are most likely meaningless
|
|
// when there is a misspelled keyword.
|
|
err.seal_suggestions();
|
|
}
|
|
}
|
|
}
|
|
|
|
/// The user has written `#[attr] expr` which is unsupported. (#106020)
|
|
pub(super) fn attr_on_non_tail_expr(&self, expr: &Expr) -> ErrorGuaranteed {
|
|
// Missing semicolon typo error.
|
|
let span = self.prev_token.span.shrink_to_hi();
|
|
let mut err = self.dcx().create_err(ExpectedSemi {
|
|
span,
|
|
token: self.token,
|
|
unexpected_token_label: Some(self.token.span),
|
|
sugg: ExpectedSemiSugg::AddSemi(span),
|
|
});
|
|
let attr_span = match &expr.attrs[..] {
|
|
[] => unreachable!(),
|
|
[only] => only.span,
|
|
[first, rest @ ..] => {
|
|
for attr in rest {
|
|
err.span_label(attr.span, "");
|
|
}
|
|
first.span
|
|
}
|
|
};
|
|
err.span_label(
|
|
attr_span,
|
|
format!(
|
|
"only `;` terminated statements or tail expressions are allowed after {}",
|
|
if expr.attrs.len() == 1 { "this attribute" } else { "these attributes" },
|
|
),
|
|
);
|
|
if self.token == token::Pound && self.look_ahead(1, |t| *t == token::OpenBracket) {
|
|
// We have
|
|
// #[attr]
|
|
// expr
|
|
// #[not_attr]
|
|
// other_expr
|
|
err.span_label(span, "expected `;` here");
|
|
err.multipart_suggestion(
|
|
"alternatively, consider surrounding the expression with a block",
|
|
vec![
|
|
(expr.span.shrink_to_lo(), "{ ".to_string()),
|
|
(expr.span.shrink_to_hi(), " }".to_string()),
|
|
],
|
|
Applicability::MachineApplicable,
|
|
);
|
|
|
|
// Special handling for `#[cfg(...)]` chains
|
|
let mut snapshot = self.create_snapshot_for_diagnostic();
|
|
if let [attr] = &expr.attrs[..]
|
|
&& let ast::AttrKind::Normal(attr_kind) = &attr.kind
|
|
&& let [segment] = &attr_kind.item.path.segments[..]
|
|
&& segment.ident.name == sym::cfg
|
|
&& let Some(args_span) = attr_kind.item.args.span()
|
|
&& let next_attr = match snapshot.parse_attribute(InnerAttrPolicy::Forbidden(None))
|
|
{
|
|
Ok(next_attr) => next_attr,
|
|
Err(inner_err) => {
|
|
inner_err.cancel();
|
|
return err.emit();
|
|
}
|
|
}
|
|
&& let ast::AttrKind::Normal(next_attr_kind) = next_attr.kind
|
|
&& let Some(next_attr_args_span) = next_attr_kind.item.args.span()
|
|
&& let [next_segment] = &next_attr_kind.item.path.segments[..]
|
|
&& segment.ident.name == sym::cfg
|
|
{
|
|
let next_expr = match snapshot.parse_expr() {
|
|
Ok(next_expr) => next_expr,
|
|
Err(inner_err) => {
|
|
inner_err.cancel();
|
|
return err.emit();
|
|
}
|
|
};
|
|
// We have for sure
|
|
// #[cfg(..)]
|
|
// expr
|
|
// #[cfg(..)]
|
|
// other_expr
|
|
// So we suggest using `if cfg!(..) { expr } else if cfg!(..) { other_expr }`.
|
|
let margin = self.psess.source_map().span_to_margin(next_expr.span).unwrap_or(0);
|
|
let sugg = vec![
|
|
(attr.span.with_hi(segment.span().hi()), "if cfg!".to_string()),
|
|
(args_span.shrink_to_hi().with_hi(attr.span.hi()), " {".to_string()),
|
|
(expr.span.shrink_to_lo(), " ".to_string()),
|
|
(
|
|
next_attr.span.with_hi(next_segment.span().hi()),
|
|
"} else if cfg!".to_string(),
|
|
),
|
|
(
|
|
next_attr_args_span.shrink_to_hi().with_hi(next_attr.span.hi()),
|
|
" {".to_string(),
|
|
),
|
|
(next_expr.span.shrink_to_lo(), " ".to_string()),
|
|
(next_expr.span.shrink_to_hi(), format!("\n{}}}", " ".repeat(margin))),
|
|
];
|
|
err.multipart_suggestion(
|
|
"it seems like you are trying to provide different expressions depending on \
|
|
`cfg`, consider using `if cfg!(..)`",
|
|
sugg,
|
|
Applicability::MachineApplicable,
|
|
);
|
|
}
|
|
}
|
|
|
|
err.emit()
|
|
}
|
|
|
|
fn check_too_many_raw_str_terminators(&mut self, err: &mut Diag<'_>) -> bool {
|
|
let sm = self.psess.source_map();
|
|
match (&self.prev_token.kind, &self.token.kind) {
|
|
(
|
|
TokenKind::Literal(Lit {
|
|
kind: LitKind::StrRaw(n_hashes) | LitKind::ByteStrRaw(n_hashes),
|
|
..
|
|
}),
|
|
TokenKind::Pound,
|
|
) if !sm.is_multiline(
|
|
self.prev_token.span.shrink_to_hi().until(self.token.span.shrink_to_lo()),
|
|
) =>
|
|
{
|
|
let n_hashes: u8 = *n_hashes;
|
|
err.primary_message("too many `#` when terminating raw string");
|
|
let str_span = self.prev_token.span;
|
|
let mut span = self.token.span;
|
|
let mut count = 0;
|
|
while self.token == TokenKind::Pound
|
|
&& !sm.is_multiline(span.shrink_to_hi().until(self.token.span.shrink_to_lo()))
|
|
{
|
|
span = span.with_hi(self.token.span.hi());
|
|
self.bump();
|
|
count += 1;
|
|
}
|
|
err.span(span);
|
|
err.span_suggestion(
|
|
span,
|
|
format!("remove the extra `#`{}", pluralize!(count)),
|
|
"",
|
|
Applicability::MachineApplicable,
|
|
);
|
|
err.span_label(
|
|
str_span,
|
|
format!("this raw string started with {n_hashes} `#`{}", pluralize!(n_hashes)),
|
|
);
|
|
true
|
|
}
|
|
_ => false,
|
|
}
|
|
}
|
|
|
|
pub(super) fn maybe_suggest_struct_literal(
|
|
&mut self,
|
|
lo: Span,
|
|
s: BlockCheckMode,
|
|
maybe_struct_name: token::Token,
|
|
) -> Option<PResult<'a, P<Block>>> {
|
|
if self.token.is_ident() && self.look_ahead(1, |t| t == &token::Colon) {
|
|
// We might be having a struct literal where people forgot to include the path:
|
|
// fn foo() -> Foo {
|
|
// field: value,
|
|
// }
|
|
debug!(?maybe_struct_name, ?self.token);
|
|
let mut snapshot = self.create_snapshot_for_diagnostic();
|
|
let path = Path {
|
|
segments: ThinVec::new(),
|
|
span: self.prev_token.span.shrink_to_lo(),
|
|
tokens: None,
|
|
};
|
|
let struct_expr = snapshot.parse_expr_struct(None, path, false);
|
|
let block_tail = self.parse_block_tail(lo, s, AttemptLocalParseRecovery::No);
|
|
return Some(match (struct_expr, block_tail) {
|
|
(Ok(expr), Err(err)) => {
|
|
// We have encountered the following:
|
|
// fn foo() -> Foo {
|
|
// field: value,
|
|
// }
|
|
// Suggest:
|
|
// fn foo() -> Foo { Path {
|
|
// field: value,
|
|
// } }
|
|
err.cancel();
|
|
self.restore_snapshot(snapshot);
|
|
let guar = self.dcx().emit_err(StructLiteralBodyWithoutPath {
|
|
span: expr.span,
|
|
sugg: StructLiteralBodyWithoutPathSugg {
|
|
before: expr.span.shrink_to_lo(),
|
|
after: expr.span.shrink_to_hi(),
|
|
},
|
|
});
|
|
Ok(self.mk_block(
|
|
thin_vec![self.mk_stmt_err(expr.span, guar)],
|
|
s,
|
|
lo.to(self.prev_token.span),
|
|
))
|
|
}
|
|
(Err(err), Ok(tail)) => {
|
|
// We have a block tail that contains a somehow valid expr.
|
|
err.cancel();
|
|
Ok(tail)
|
|
}
|
|
(Err(snapshot_err), Err(err)) => {
|
|
// We don't know what went wrong, emit the normal error.
|
|
snapshot_err.cancel();
|
|
self.consume_block(exp!(OpenBrace), exp!(CloseBrace), ConsumeClosingDelim::Yes);
|
|
Err(err)
|
|
}
|
|
(Ok(_), Ok(tail)) => Ok(tail),
|
|
});
|
|
}
|
|
None
|
|
}
|
|
|
|
pub(super) fn recover_closure_body(
|
|
&mut self,
|
|
mut err: Diag<'a>,
|
|
before: token::Token,
|
|
prev: token::Token,
|
|
token: token::Token,
|
|
lo: Span,
|
|
decl_hi: Span,
|
|
) -> PResult<'a, P<Expr>> {
|
|
err.span_label(lo.to(decl_hi), "while parsing the body of this closure");
|
|
let guar = match before.kind {
|
|
token::OpenBrace if token.kind != token::OpenBrace => {
|
|
// `{ || () }` should have been `|| { () }`
|
|
err.multipart_suggestion(
|
|
"you might have meant to open the body of the closure, instead of enclosing \
|
|
the closure in a block",
|
|
vec![
|
|
(before.span, String::new()),
|
|
(prev.span.shrink_to_hi(), " {".to_string()),
|
|
],
|
|
Applicability::MaybeIncorrect,
|
|
);
|
|
let guar = err.emit();
|
|
self.eat_to_tokens(&[exp!(CloseBrace)]);
|
|
guar
|
|
}
|
|
token::OpenParen if token.kind != token::OpenBrace => {
|
|
// We are within a function call or tuple, we can emit the error
|
|
// and recover.
|
|
self.eat_to_tokens(&[exp!(CloseParen), exp!(Comma)]);
|
|
|
|
err.multipart_suggestion_verbose(
|
|
"you might have meant to open the body of the closure",
|
|
vec![
|
|
(prev.span.shrink_to_hi(), " {".to_string()),
|
|
(self.token.span.shrink_to_lo(), "}".to_string()),
|
|
],
|
|
Applicability::MaybeIncorrect,
|
|
);
|
|
err.emit()
|
|
}
|
|
_ if token.kind != token::OpenBrace => {
|
|
// We don't have a heuristic to correctly identify where the block
|
|
// should be closed.
|
|
err.multipart_suggestion_verbose(
|
|
"you might have meant to open the body of the closure",
|
|
vec![(prev.span.shrink_to_hi(), " {".to_string())],
|
|
Applicability::HasPlaceholders,
|
|
);
|
|
return Err(err);
|
|
}
|
|
_ => return Err(err),
|
|
};
|
|
Ok(self.mk_expr_err(lo.to(self.token.span), guar))
|
|
}
|
|
|
|
/// Eats and discards tokens until one of `closes` is encountered. Respects token trees,
|
|
/// passes through any errors encountered. Used for error recovery.
|
|
pub(super) fn eat_to_tokens(&mut self, closes: &[ExpTokenPair<'_>]) {
|
|
if let Err(err) = self
|
|
.parse_seq_to_before_tokens(closes, &[], SeqSep::none(), |p| Ok(p.parse_token_tree()))
|
|
{
|
|
err.cancel();
|
|
}
|
|
}
|
|
|
|
/// This function checks if there are trailing angle brackets and produces
|
|
/// a diagnostic to suggest removing them.
|
|
///
|
|
/// ```ignore (diagnostic)
|
|
/// let _ = [1, 2, 3].into_iter().collect::<Vec<usize>>>>();
|
|
/// ^^ help: remove extra angle brackets
|
|
/// ```
|
|
///
|
|
/// If `true` is returned, then trailing brackets were recovered, tokens were consumed
|
|
/// up until one of the tokens in 'end' was encountered, and an error was emitted.
|
|
pub(super) fn check_trailing_angle_brackets(
|
|
&mut self,
|
|
segment: &PathSegment,
|
|
end: &[ExpTokenPair<'_>],
|
|
) -> Option<ErrorGuaranteed> {
|
|
if !self.may_recover() {
|
|
return None;
|
|
}
|
|
|
|
// This function is intended to be invoked after parsing a path segment where there are two
|
|
// cases:
|
|
//
|
|
// 1. A specific token is expected after the path segment.
|
|
// eg. `x.foo(`, `x.foo::<u32>(` (parenthesis - method call),
|
|
// `Foo::`, or `Foo::<Bar>::` (mod sep - continued path).
|
|
// 2. No specific token is expected after the path segment.
|
|
// eg. `x.foo` (field access)
|
|
//
|
|
// This function is called after parsing `.foo` and before parsing the token `end` (if
|
|
// present). This includes any angle bracket arguments, such as `.foo::<u32>` or
|
|
// `Foo::<Bar>`.
|
|
|
|
// We only care about trailing angle brackets if we previously parsed angle bracket
|
|
// arguments. This helps stop us incorrectly suggesting that extra angle brackets be
|
|
// removed in this case:
|
|
//
|
|
// `x.foo >> (3)` (where `x.foo` is a `u32` for example)
|
|
//
|
|
// This case is particularly tricky as we won't notice it just looking at the tokens -
|
|
// it will appear the same (in terms of upcoming tokens) as below (since the `::<u32>` will
|
|
// have already been parsed):
|
|
//
|
|
// `x.foo::<u32>>>(3)`
|
|
let parsed_angle_bracket_args =
|
|
segment.args.as_ref().is_some_and(|args| args.is_angle_bracketed());
|
|
|
|
debug!(
|
|
"check_trailing_angle_brackets: parsed_angle_bracket_args={:?}",
|
|
parsed_angle_bracket_args,
|
|
);
|
|
if !parsed_angle_bracket_args {
|
|
return None;
|
|
}
|
|
|
|
// Keep the span at the start so we can highlight the sequence of `>` characters to be
|
|
// removed.
|
|
let lo = self.token.span;
|
|
|
|
// We need to look-ahead to see if we have `>` characters without moving the cursor forward
|
|
// (since we might have the field access case and the characters we're eating are
|
|
// actual operators and not trailing characters - ie `x.foo >> 3`).
|
|
let mut position = 0;
|
|
|
|
// We can encounter `>` or `>>` tokens in any order, so we need to keep track of how
|
|
// many of each (so we can correctly pluralize our error messages) and continue to
|
|
// advance.
|
|
let mut number_of_shr = 0;
|
|
let mut number_of_gt = 0;
|
|
while self.look_ahead(position, |t| {
|
|
trace!("check_trailing_angle_brackets: t={:?}", t);
|
|
if *t == token::Shr {
|
|
number_of_shr += 1;
|
|
true
|
|
} else if *t == token::Gt {
|
|
number_of_gt += 1;
|
|
true
|
|
} else {
|
|
false
|
|
}
|
|
}) {
|
|
position += 1;
|
|
}
|
|
|
|
// If we didn't find any trailing `>` characters, then we have nothing to error about.
|
|
debug!(
|
|
"check_trailing_angle_brackets: number_of_gt={:?} number_of_shr={:?}",
|
|
number_of_gt, number_of_shr,
|
|
);
|
|
if number_of_gt < 1 && number_of_shr < 1 {
|
|
return None;
|
|
}
|
|
|
|
// Finally, double check that we have our end token as otherwise this is the
|
|
// second case.
|
|
if self.look_ahead(position, |t| {
|
|
trace!("check_trailing_angle_brackets: t={:?}", t);
|
|
end.iter().any(|exp| exp.tok == &t.kind)
|
|
}) {
|
|
// Eat from where we started until the end token so that parsing can continue
|
|
// as if we didn't have those extra angle brackets.
|
|
self.eat_to_tokens(end);
|
|
let span = lo.to(self.prev_token.span);
|
|
|
|
let num_extra_brackets = number_of_gt + number_of_shr * 2;
|
|
return Some(self.dcx().emit_err(UnmatchedAngleBrackets { span, num_extra_brackets }));
|
|
}
|
|
None
|
|
}
|
|
|
|
/// Check if a method call with an intended turbofish has been written without surrounding
|
|
/// angle brackets.
|
|
pub(super) fn check_turbofish_missing_angle_brackets(&mut self, segment: &mut PathSegment) {
|
|
if !self.may_recover() {
|
|
return;
|
|
}
|
|
|
|
if self.token == token::PathSep && segment.args.is_none() {
|
|
let snapshot = self.create_snapshot_for_diagnostic();
|
|
self.bump();
|
|
let lo = self.token.span;
|
|
match self.parse_angle_args(None) {
|
|
Ok(args) => {
|
|
let span = lo.to(self.prev_token.span);
|
|
// Detect trailing `>` like in `x.collect::Vec<_>>()`.
|
|
let mut trailing_span = self.prev_token.span.shrink_to_hi();
|
|
while self.token == token::Shr || self.token == token::Gt {
|
|
trailing_span = trailing_span.to(self.token.span);
|
|
self.bump();
|
|
}
|
|
if self.token == token::OpenParen {
|
|
// Recover from bad turbofish: `foo.collect::Vec<_>()`.
|
|
segment.args = Some(AngleBracketedArgs { args, span }.into());
|
|
|
|
self.dcx().emit_err(GenericParamsWithoutAngleBrackets {
|
|
span,
|
|
sugg: GenericParamsWithoutAngleBracketsSugg {
|
|
left: span.shrink_to_lo(),
|
|
right: trailing_span,
|
|
},
|
|
});
|
|
} else {
|
|
// This doesn't look like an invalid turbofish, can't recover parse state.
|
|
self.restore_snapshot(snapshot);
|
|
}
|
|
}
|
|
Err(err) => {
|
|
// We couldn't parse generic parameters, unlikely to be a turbofish. Rely on
|
|
// generic parse error instead.
|
|
err.cancel();
|
|
self.restore_snapshot(snapshot);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/// When writing a turbofish with multiple type parameters missing the leading `::`, we will
|
|
/// encounter a parse error when encountering the first `,`.
|
|
pub(super) fn check_mistyped_turbofish_with_multiple_type_params(
|
|
&mut self,
|
|
mut e: Diag<'a>,
|
|
expr: &mut P<Expr>,
|
|
) -> PResult<'a, ErrorGuaranteed> {
|
|
if let ExprKind::Binary(binop, _, _) = &expr.kind
|
|
&& let ast::BinOpKind::Lt = binop.node
|
|
&& self.eat(exp!(Comma))
|
|
{
|
|
let x = self.parse_seq_to_before_end(
|
|
exp!(Gt),
|
|
SeqSep::trailing_allowed(exp!(Comma)),
|
|
|p| match p.parse_generic_arg(None)? {
|
|
Some(arg) => Ok(arg),
|
|
// If we didn't eat a generic arg, then we should error.
|
|
None => p.unexpected_any(),
|
|
},
|
|
);
|
|
match x {
|
|
Ok((_, _, Recovered::No)) => {
|
|
if self.eat(exp!(Gt)) {
|
|
// We made sense of it. Improve the error message.
|
|
e.span_suggestion_verbose(
|
|
binop.span.shrink_to_lo(),
|
|
fluent::parse_sugg_turbofish_syntax,
|
|
"::",
|
|
Applicability::MaybeIncorrect,
|
|
);
|
|
match self.parse_expr() {
|
|
Ok(_) => {
|
|
// The subsequent expression is valid. Mark
|
|
// `expr` as erroneous and emit `e` now, but
|
|
// return `Ok` so parsing can continue.
|
|
let guar = e.emit();
|
|
*expr = self.mk_expr_err(expr.span.to(self.prev_token.span), guar);
|
|
return Ok(guar);
|
|
}
|
|
Err(err) => {
|
|
err.cancel();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
Ok((_, _, Recovered::Yes(_))) => {}
|
|
Err(err) => {
|
|
err.cancel();
|
|
}
|
|
}
|
|
}
|
|
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 Diag<'a>) {
|
|
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_diag(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. The return value indicates if recovery happened.
|
|
fn attempt_chained_comparison_suggestion(
|
|
&mut self,
|
|
err: &mut ComparisonOperatorsCannotBeChained,
|
|
inner_op: &Expr,
|
|
outer_op: &Spanned<AssocOp>,
|
|
) -> bool {
|
|
if let ExprKind::Binary(op, l1, r1) = &inner_op.kind {
|
|
if let ExprKind::Field(_, ident) = l1.kind
|
|
&& !ident.is_numeric()
|
|
&& !matches!(r1.kind, ExprKind::Lit(_))
|
|
{
|
|
// The parser has encountered `foo.bar<baz`, the likelihood of the turbofish
|
|
// suggestion being the only one to apply is high.
|
|
return false;
|
|
}
|
|
return match (op.node, &outer_op.node) {
|
|
// `x == y == z`
|
|
(BinOpKind::Eq, AssocOp::Binary(BinOpKind::Eq)) |
|
|
// `x < y < z` and friends.
|
|
(BinOpKind::Lt, AssocOp::Binary(BinOpKind::Lt | BinOpKind::Le)) |
|
|
(BinOpKind::Le, AssocOp::Binary(BinOpKind::Lt | BinOpKind::Le)) |
|
|
// `x > y > z` and friends.
|
|
(BinOpKind::Gt, AssocOp::Binary(BinOpKind::Gt | BinOpKind::Ge)) |
|
|
(BinOpKind::Ge, AssocOp::Binary(BinOpKind::Gt | BinOpKind::Ge)) => {
|
|
let expr_to_str = |e: &Expr| {
|
|
self.span_to_snippet(e.span)
|
|
.unwrap_or_else(|_| pprust::expr_to_string(e))
|
|
};
|
|
err.chaining_sugg = Some(ComparisonOperatorsCannotBeChainedSugg::SplitComparison {
|
|
span: inner_op.span.shrink_to_hi(),
|
|
middle_term: expr_to_str(r1),
|
|
});
|
|
false // Keep the current parse behavior, where the AST is `(x < y) < z`.
|
|
}
|
|
// `x == y < z`
|
|
(
|
|
BinOpKind::Eq,
|
|
AssocOp::Binary(BinOpKind::Lt | BinOpKind::Le | BinOpKind::Gt | BinOpKind::Ge)
|
|
) => {
|
|
// Consume `z`/outer-op-rhs.
|
|
let snapshot = self.create_snapshot_for_diagnostic();
|
|
match self.parse_expr() {
|
|
Ok(r2) => {
|
|
// We are sure that outer-op-rhs could be consumed, the suggestion is
|
|
// likely correct.
|
|
err.chaining_sugg = Some(ComparisonOperatorsCannotBeChainedSugg::Parenthesize {
|
|
left: r1.span.shrink_to_lo(),
|
|
right: r2.span.shrink_to_hi(),
|
|
});
|
|
true
|
|
}
|
|
Err(expr_err) => {
|
|
expr_err.cancel();
|
|
self.restore_snapshot(snapshot);
|
|
true
|
|
}
|
|
}
|
|
}
|
|
// `x > y == z`
|
|
(
|
|
BinOpKind::Lt | BinOpKind::Le | BinOpKind::Gt | BinOpKind::Ge,
|
|
AssocOp::Binary(BinOpKind::Eq)
|
|
) => {
|
|
let snapshot = self.create_snapshot_for_diagnostic();
|
|
// At this point it is always valid to enclose the lhs in parentheses, no
|
|
// further checks are necessary.
|
|
match self.parse_expr() {
|
|
Ok(_) => {
|
|
err.chaining_sugg = Some(ComparisonOperatorsCannotBeChainedSugg::Parenthesize {
|
|
left: l1.span.shrink_to_lo(),
|
|
right: r1.span.shrink_to_hi(),
|
|
});
|
|
true
|
|
}
|
|
Err(expr_err) => {
|
|
expr_err.cancel();
|
|
self.restore_snapshot(snapshot);
|
|
false
|
|
}
|
|
}
|
|
}
|
|
_ => false
|
|
};
|
|
}
|
|
false
|
|
}
|
|
|
|
/// Produces an error if comparison operators are chained (RFC #558).
|
|
/// We only need to check the LHS, not the RHS, because all comparison ops have same
|
|
/// precedence (see `fn precedence`) and are left-associative (see `fn fixity`).
|
|
///
|
|
/// This can also be hit if someone incorrectly writes `foo<bar>()` when they should have used
|
|
/// the turbofish (`foo::<bar>()`) syntax. We attempt some heuristic recovery if that is the
|
|
/// case.
|
|
///
|
|
/// Keep in mind that given that `outer_op.is_comparison()` holds and comparison ops are left
|
|
/// associative we can infer that we have:
|
|
///
|
|
/// ```text
|
|
/// outer_op
|
|
/// / \
|
|
/// inner_op r2
|
|
/// / \
|
|
/// l1 r1
|
|
/// ```
|
|
pub(super) fn check_no_chained_comparison(
|
|
&mut self,
|
|
inner_op: &Expr,
|
|
outer_op: &Spanned<AssocOp>,
|
|
) -> PResult<'a, Option<P<Expr>>> {
|
|
debug_assert!(
|
|
outer_op.node.is_comparison(),
|
|
"check_no_chained_comparison: {:?} is not comparison",
|
|
outer_op.node,
|
|
);
|
|
|
|
let mk_err_expr =
|
|
|this: &Self, span, guar| Ok(Some(this.mk_expr(span, ExprKind::Err(guar))));
|
|
|
|
match &inner_op.kind {
|
|
ExprKind::Binary(op, l1, r1) if op.node.is_comparison() => {
|
|
let mut err = ComparisonOperatorsCannotBeChained {
|
|
span: vec![op.span, self.prev_token.span],
|
|
suggest_turbofish: None,
|
|
help_turbofish: false,
|
|
chaining_sugg: None,
|
|
};
|
|
|
|
// Include `<` to provide this recommendation even in a case like
|
|
// `Foo<Bar<Baz<Qux, ()>>>`
|
|
if op.node == BinOpKind::Lt && outer_op.node == AssocOp::Binary(BinOpKind::Lt)
|
|
|| outer_op.node == AssocOp::Binary(BinOpKind::Gt)
|
|
{
|
|
if outer_op.node == AssocOp::Binary(BinOpKind::Lt) {
|
|
let snapshot = self.create_snapshot_for_diagnostic();
|
|
self.bump();
|
|
// So far we have parsed `foo<bar<`, consume the rest of the type args.
|
|
let modifiers = [(token::Lt, 1), (token::Gt, -1), (token::Shr, -2)];
|
|
self.consume_tts(1, &modifiers);
|
|
|
|
if !matches!(self.token.kind, token::OpenParen | token::PathSep) {
|
|
// We don't have `foo< bar >(` or `foo< bar >::`, so we rewind the
|
|
// parser and bail out.
|
|
self.restore_snapshot(snapshot);
|
|
}
|
|
}
|
|
return if self.token == token::PathSep {
|
|
// We have some certainty that this was a bad turbofish at this point.
|
|
// `foo< bar >::`
|
|
if let ExprKind::Binary(o, ..) = inner_op.kind
|
|
&& o.node == BinOpKind::Lt
|
|
{
|
|
err.suggest_turbofish = Some(op.span.shrink_to_lo());
|
|
} else {
|
|
err.help_turbofish = true;
|
|
}
|
|
|
|
let snapshot = self.create_snapshot_for_diagnostic();
|
|
self.bump(); // `::`
|
|
|
|
// Consume the rest of the likely `foo<bar>::new()` or return at `foo<bar>`.
|
|
match self.parse_expr() {
|
|
Ok(_) => {
|
|
// 99% certain that the suggestion is correct, continue parsing.
|
|
let guar = self.dcx().emit_err(err);
|
|
// FIXME: actually check that the two expressions in the binop are
|
|
// paths and resynthesize new fn call expression instead of using
|
|
// `ExprKind::Err` placeholder.
|
|
mk_err_expr(self, inner_op.span.to(self.prev_token.span), guar)
|
|
}
|
|
Err(expr_err) => {
|
|
expr_err.cancel();
|
|
// Not entirely sure now, but we bubble the error up with the
|
|
// suggestion.
|
|
self.restore_snapshot(snapshot);
|
|
Err(self.dcx().create_err(err))
|
|
}
|
|
}
|
|
} else if self.token == token::OpenParen {
|
|
// We have high certainty that this was a bad turbofish at this point.
|
|
// `foo< bar >(`
|
|
if let ExprKind::Binary(o, ..) = inner_op.kind
|
|
&& o.node == BinOpKind::Lt
|
|
{
|
|
err.suggest_turbofish = Some(op.span.shrink_to_lo());
|
|
} else {
|
|
err.help_turbofish = true;
|
|
}
|
|
// Consume the fn call arguments.
|
|
match self.consume_fn_args() {
|
|
Err(()) => Err(self.dcx().create_err(err)),
|
|
Ok(()) => {
|
|
let guar = self.dcx().emit_err(err);
|
|
// FIXME: actually check that the two expressions in the binop are
|
|
// paths and resynthesize new fn call expression instead of using
|
|
// `ExprKind::Err` placeholder.
|
|
mk_err_expr(self, inner_op.span.to(self.prev_token.span), guar)
|
|
}
|
|
}
|
|
} else {
|
|
if !matches!(l1.kind, ExprKind::Lit(_))
|
|
&& !matches!(r1.kind, ExprKind::Lit(_))
|
|
{
|
|
// All we know is that this is `foo < bar >` and *nothing* else. Try to
|
|
// be helpful, but don't attempt to recover.
|
|
err.help_turbofish = true;
|
|
}
|
|
|
|
// If it looks like a genuine attempt to chain operators (as opposed to a
|
|
// misformatted turbofish, for instance), suggest a correct form.
|
|
let recovered = self
|
|
.attempt_chained_comparison_suggestion(&mut err, inner_op, outer_op);
|
|
if recovered {
|
|
let guar = self.dcx().emit_err(err);
|
|
mk_err_expr(self, inner_op.span.to(self.prev_token.span), guar)
|
|
} else {
|
|
// These cases cause too many knock-down errors, bail out (#61329).
|
|
Err(self.dcx().create_err(err))
|
|
}
|
|
};
|
|
}
|
|
let recovered =
|
|
self.attempt_chained_comparison_suggestion(&mut err, inner_op, outer_op);
|
|
let guar = self.dcx().emit_err(err);
|
|
if recovered {
|
|
return mk_err_expr(self, inner_op.span.to(self.prev_token.span), guar);
|
|
}
|
|
}
|
|
_ => {}
|
|
}
|
|
Ok(None)
|
|
}
|
|
|
|
fn consume_fn_args(&mut self) -> Result<(), ()> {
|
|
let snapshot = self.create_snapshot_for_diagnostic();
|
|
self.bump(); // `(`
|
|
|
|
// Consume the fn call arguments.
|
|
let modifiers = [(token::OpenParen, 1), (token::CloseParen, -1)];
|
|
self.consume_tts(1, &modifiers);
|
|
|
|
if self.token == token::Eof {
|
|
// Not entirely sure that what we consumed were fn arguments, rollback.
|
|
self.restore_snapshot(snapshot);
|
|
Err(())
|
|
} else {
|
|
// 99% certain that the suggestion is correct, continue parsing.
|
|
Ok(())
|
|
}
|
|
}
|
|
|
|
pub(super) fn maybe_report_ambiguous_plus(&mut self, impl_dyn_multi: bool, ty: &Ty) {
|
|
if impl_dyn_multi {
|
|
self.dcx().emit_err(AmbiguousPlus {
|
|
span: ty.span,
|
|
suggestion: AddParen { lo: ty.span.shrink_to_lo(), hi: ty.span.shrink_to_hi() },
|
|
});
|
|
}
|
|
}
|
|
|
|
/// Swift lets users write `Ty?` to mean `Option<Ty>`. Parse the construct and recover from it.
|
|
pub(super) fn maybe_recover_from_question_mark(&mut self, ty: P<Ty>) -> P<Ty> {
|
|
if self.token == token::Question {
|
|
self.bump();
|
|
let guar = self.dcx().emit_err(QuestionMarkInType {
|
|
span: self.prev_token.span,
|
|
sugg: QuestionMarkInTypeSugg {
|
|
left: ty.span.shrink_to_lo(),
|
|
right: self.prev_token.span,
|
|
},
|
|
});
|
|
self.mk_ty(ty.span.to(self.prev_token.span), TyKind::Err(guar))
|
|
} else {
|
|
ty
|
|
}
|
|
}
|
|
|
|
/// Rust has no ternary operator (`cond ? then : else`). Parse it and try
|
|
/// to recover from it if `then` and `else` are valid expressions. Returns
|
|
/// an err if this appears to be a ternary expression.
|
|
pub(super) fn maybe_recover_from_ternary_operator(&mut self) -> PResult<'a, ()> {
|
|
if self.prev_token != token::Question {
|
|
return PResult::Ok(());
|
|
}
|
|
|
|
let lo = self.prev_token.span.lo();
|
|
let snapshot = self.create_snapshot_for_diagnostic();
|
|
|
|
if match self.parse_expr() {
|
|
Ok(_) => true,
|
|
Err(err) => {
|
|
err.cancel();
|
|
// The colon can sometimes be mistaken for type
|
|
// ascription. Catch when this happens and continue.
|
|
self.token == token::Colon
|
|
}
|
|
} {
|
|
if self.eat_noexpect(&token::Colon) {
|
|
match self.parse_expr() {
|
|
Ok(_) => {
|
|
return Err(self
|
|
.dcx()
|
|
.create_err(TernaryOperator { span: self.token.span.with_lo(lo) }));
|
|
}
|
|
Err(err) => {
|
|
err.cancel();
|
|
}
|
|
};
|
|
}
|
|
}
|
|
self.restore_snapshot(snapshot);
|
|
Ok(())
|
|
}
|
|
|
|
pub(super) fn maybe_recover_from_bad_type_plus(&mut self, ty: &Ty) -> PResult<'a, ()> {
|
|
// Do not add `+` to expected tokens.
|
|
if !self.token.is_like_plus() {
|
|
return Ok(());
|
|
}
|
|
|
|
self.bump(); // `+`
|
|
let _bounds = self.parse_generic_bounds()?;
|
|
let sub = match &ty.kind {
|
|
TyKind::Ref(_lifetime, mut_ty) => {
|
|
let lo = mut_ty.ty.span.shrink_to_lo();
|
|
let hi = self.prev_token.span.shrink_to_hi();
|
|
BadTypePlusSub::AddParen { suggestion: AddParen { lo, hi } }
|
|
}
|
|
TyKind::Ptr(..) | TyKind::BareFn(..) => {
|
|
BadTypePlusSub::ForgotParen { span: ty.span.to(self.prev_token.span) }
|
|
}
|
|
_ => BadTypePlusSub::ExpectPath { span: ty.span },
|
|
};
|
|
|
|
self.dcx().emit_err(BadTypePlus { span: ty.span, sub });
|
|
|
|
Ok(())
|
|
}
|
|
|
|
pub(super) fn recover_from_prefix_increment(
|
|
&mut self,
|
|
operand_expr: P<Expr>,
|
|
op_span: Span,
|
|
start_stmt: bool,
|
|
) -> PResult<'a, P<Expr>> {
|
|
let standalone = if start_stmt { IsStandalone::Standalone } else { IsStandalone::Subexpr };
|
|
let kind = IncDecRecovery { standalone, op: IncOrDec::Inc, fixity: UnaryFixity::Pre };
|
|
self.recover_from_inc_dec(operand_expr, kind, op_span)
|
|
}
|
|
|
|
pub(super) fn recover_from_postfix_increment(
|
|
&mut self,
|
|
operand_expr: P<Expr>,
|
|
op_span: Span,
|
|
start_stmt: bool,
|
|
) -> PResult<'a, P<Expr>> {
|
|
let kind = IncDecRecovery {
|
|
standalone: if start_stmt { IsStandalone::Standalone } else { IsStandalone::Subexpr },
|
|
op: IncOrDec::Inc,
|
|
fixity: UnaryFixity::Post,
|
|
};
|
|
self.recover_from_inc_dec(operand_expr, kind, op_span)
|
|
}
|
|
|
|
pub(super) fn recover_from_postfix_decrement(
|
|
&mut self,
|
|
operand_expr: P<Expr>,
|
|
op_span: Span,
|
|
start_stmt: bool,
|
|
) -> PResult<'a, P<Expr>> {
|
|
let kind = IncDecRecovery {
|
|
standalone: if start_stmt { IsStandalone::Standalone } else { IsStandalone::Subexpr },
|
|
op: IncOrDec::Dec,
|
|
fixity: UnaryFixity::Post,
|
|
};
|
|
self.recover_from_inc_dec(operand_expr, kind, op_span)
|
|
}
|
|
|
|
fn recover_from_inc_dec(
|
|
&mut self,
|
|
base: P<Expr>,
|
|
kind: IncDecRecovery,
|
|
op_span: Span,
|
|
) -> PResult<'a, P<Expr>> {
|
|
let mut err = self.dcx().struct_span_err(
|
|
op_span,
|
|
format!("Rust has no {} {} operator", kind.fixity, kind.op.name()),
|
|
);
|
|
err.span_label(op_span, format!("not a valid {} operator", kind.fixity));
|
|
|
|
let help_base_case = |mut err: Diag<'_, _>, base| {
|
|
err.help(format!("use `{}= 1` instead", kind.op.chr()));
|
|
err.emit();
|
|
Ok(base)
|
|
};
|
|
|
|
// (pre, post)
|
|
let spans = match kind.fixity {
|
|
UnaryFixity::Pre => (op_span, base.span.shrink_to_hi()),
|
|
UnaryFixity::Post => (base.span.shrink_to_lo(), op_span),
|
|
};
|
|
|
|
match kind.standalone {
|
|
IsStandalone::Standalone => {
|
|
self.inc_dec_standalone_suggest(kind, spans).emit_verbose(&mut err)
|
|
}
|
|
IsStandalone::Subexpr => {
|
|
let Ok(base_src) = self.span_to_snippet(base.span) else {
|
|
return help_base_case(err, base);
|
|
};
|
|
match kind.fixity {
|
|
UnaryFixity::Pre => {
|
|
self.prefix_inc_dec_suggest(base_src, kind, spans).emit(&mut err)
|
|
}
|
|
UnaryFixity::Post => {
|
|
// won't suggest since we can not handle the precedences
|
|
// for example: `a + b++` has been parsed (a + b)++ and we can not suggest here
|
|
if !matches!(base.kind, ExprKind::Binary(_, _, _)) {
|
|
self.postfix_inc_dec_suggest(base_src, kind, spans).emit(&mut err)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
Err(err)
|
|
}
|
|
|
|
fn prefix_inc_dec_suggest(
|
|
&mut self,
|
|
base_src: String,
|
|
kind: IncDecRecovery,
|
|
(pre_span, post_span): (Span, Span),
|
|
) -> MultiSugg {
|
|
MultiSugg {
|
|
msg: format!("use `{}= 1` instead", kind.op.chr()),
|
|
patches: vec![
|
|
(pre_span, "{ ".to_string()),
|
|
(post_span, format!(" {}= 1; {} }}", kind.op.chr(), base_src)),
|
|
],
|
|
applicability: Applicability::MachineApplicable,
|
|
}
|
|
}
|
|
|
|
fn postfix_inc_dec_suggest(
|
|
&mut self,
|
|
base_src: String,
|
|
kind: IncDecRecovery,
|
|
(pre_span, post_span): (Span, Span),
|
|
) -> MultiSugg {
|
|
let tmp_var = if base_src.trim() == "tmp" { "tmp_" } else { "tmp" };
|
|
MultiSugg {
|
|
msg: format!("use `{}= 1` instead", kind.op.chr()),
|
|
patches: vec![
|
|
(pre_span, format!("{{ let {tmp_var} = ")),
|
|
(post_span, format!("; {} {}= 1; {} }}", base_src, kind.op.chr(), tmp_var)),
|
|
],
|
|
applicability: Applicability::HasPlaceholders,
|
|
}
|
|
}
|
|
|
|
fn inc_dec_standalone_suggest(
|
|
&mut self,
|
|
kind: IncDecRecovery,
|
|
(pre_span, post_span): (Span, Span),
|
|
) -> MultiSugg {
|
|
let mut patches = Vec::new();
|
|
|
|
if !pre_span.is_empty() {
|
|
patches.push((pre_span, String::new()));
|
|
}
|
|
|
|
patches.push((post_span, format!(" {}= 1", kind.op.chr())));
|
|
MultiSugg {
|
|
msg: format!("use `{}= 1` instead", kind.op.chr()),
|
|
patches,
|
|
applicability: Applicability::MachineApplicable,
|
|
}
|
|
}
|
|
|
|
/// Tries to recover from associated item paths like `[T]::AssocItem` / `(T, U)::AssocItem`.
|
|
/// Attempts to convert the base expression/pattern/type into a type, parses the `::AssocItem`
|
|
/// tail, and combines them into a `<Ty>::AssocItem` expression/pattern/type.
|
|
pub(super) fn maybe_recover_from_bad_qpath<T: RecoverQPath>(
|
|
&mut self,
|
|
base: P<T>,
|
|
) -> PResult<'a, P<T>> {
|
|
if !self.may_recover() {
|
|
return Ok(base);
|
|
}
|
|
|
|
// Do not add `::` to expected tokens.
|
|
if self.token == token::PathSep {
|
|
if let Some(ty) = base.to_ty() {
|
|
return self.maybe_recover_from_bad_qpath_stage_2(ty.span, ty);
|
|
}
|
|
}
|
|
Ok(base)
|
|
}
|
|
|
|
/// Given an already parsed `Ty`, parses the `::AssocItem` tail and
|
|
/// combines them into a `<Ty>::AssocItem` expression/pattern/type.
|
|
pub(super) fn maybe_recover_from_bad_qpath_stage_2<T: RecoverQPath>(
|
|
&mut self,
|
|
ty_span: Span,
|
|
ty: P<Ty>,
|
|
) -> PResult<'a, P<T>> {
|
|
self.expect(exp!(PathSep))?;
|
|
|
|
let mut path = ast::Path { segments: ThinVec::new(), span: DUMMY_SP, tokens: None };
|
|
self.parse_path_segments(&mut path.segments, T::PATH_STYLE, None)?;
|
|
path.span = ty_span.to(self.prev_token.span);
|
|
|
|
self.dcx().emit_err(BadQPathStage2 {
|
|
span: ty_span,
|
|
wrap: WrapType { lo: ty_span.shrink_to_lo(), hi: ty_span.shrink_to_hi() },
|
|
});
|
|
|
|
let path_span = ty_span.shrink_to_hi(); // Use an empty path since `position == 0`.
|
|
Ok(P(T::recovered(Some(P(QSelf { ty, path_span, position: 0 })), path)))
|
|
}
|
|
|
|
/// This function gets called in places where a semicolon is NOT expected and if there's a
|
|
/// semicolon it emits the appropriate error and returns true.
|
|
pub fn maybe_consume_incorrect_semicolon(&mut self, previous_item: Option<&Item>) -> bool {
|
|
if self.token != TokenKind::Semi {
|
|
return false;
|
|
}
|
|
|
|
// Check previous item to add it to the diagnostic, for example to say
|
|
// `enum declarations are not followed by a semicolon`
|
|
let err = match previous_item {
|
|
Some(previous_item) => {
|
|
let name = match previous_item.kind {
|
|
// Say "braced struct" because tuple-structs and
|
|
// braceless-empty-struct declarations do take a semicolon.
|
|
ItemKind::Struct(..) => "braced struct",
|
|
_ => previous_item.kind.descr(),
|
|
};
|
|
IncorrectSemicolon { span: self.token.span, name, show_help: true }
|
|
}
|
|
None => IncorrectSemicolon { span: self.token.span, name: "", show_help: false },
|
|
};
|
|
self.dcx().emit_err(err);
|
|
|
|
self.bump();
|
|
true
|
|
}
|
|
|
|
/// Creates a `Diag` for an unexpected token `t` and tries to recover if it is a
|
|
/// closing delimiter.
|
|
pub(super) fn unexpected_try_recover(&mut self, t: &TokenKind) -> PResult<'a, Recovered> {
|
|
let token_str = pprust::token_kind_to_string(t);
|
|
let this_token_str = super::token_descr(&self.token);
|
|
let (prev_sp, sp) = match (&self.token.kind, self.subparser_name) {
|
|
// Point at the end of the macro call when reaching end of macro arguments.
|
|
(token::Eof, Some(_)) => {
|
|
let sp = self.prev_token.span.shrink_to_hi();
|
|
(sp, sp)
|
|
}
|
|
// We don't want to point at the following span after DUMMY_SP.
|
|
// This happens when the parser finds an empty TokenStream.
|
|
_ if self.prev_token.span == DUMMY_SP => (self.token.span, self.token.span),
|
|
// EOF, don't want to point at the following char, but rather the last token.
|
|
(token::Eof, None) => (self.prev_token.span, self.token.span),
|
|
_ => (self.prev_token.span.shrink_to_hi(), self.token.span),
|
|
};
|
|
let msg = format!(
|
|
"expected `{}`, found {}",
|
|
token_str,
|
|
match (&self.token.kind, self.subparser_name) {
|
|
(token::Eof, Some(origin)) => format!("end of {origin}"),
|
|
_ => this_token_str,
|
|
},
|
|
);
|
|
let mut err = self.dcx().struct_span_err(sp, msg);
|
|
let label_exp = format!("expected `{token_str}`");
|
|
let sm = self.psess.source_map();
|
|
if !sm.is_multiline(prev_sp.until(sp)) {
|
|
// When the spans are in the same line, it means that the only content
|
|
// between them is whitespace, point only at the found token.
|
|
err.span_label(sp, label_exp);
|
|
} else {
|
|
err.span_label(prev_sp, label_exp);
|
|
err.span_label(sp, "unexpected token");
|
|
}
|
|
Err(err)
|
|
}
|
|
|
|
pub(super) fn expect_semi(&mut self) -> PResult<'a, ()> {
|
|
if self.eat(exp!(Semi)) || self.recover_colon_as_semi() {
|
|
return Ok(());
|
|
}
|
|
self.expect(exp!(Semi)).map(drop) // Error unconditionally
|
|
}
|
|
|
|
pub(super) fn recover_colon_as_semi(&mut self) -> bool {
|
|
let line_idx = |span: Span| {
|
|
self.psess
|
|
.source_map()
|
|
.span_to_lines(span)
|
|
.ok()
|
|
.and_then(|lines| Some(lines.lines.get(0)?.line_index))
|
|
};
|
|
|
|
if self.may_recover()
|
|
&& self.token == token::Colon
|
|
&& self.look_ahead(1, |next| line_idx(self.token.span) < line_idx(next.span))
|
|
{
|
|
self.dcx().emit_err(ColonAsSemi { span: self.token.span });
|
|
self.bump();
|
|
return true;
|
|
}
|
|
|
|
false
|
|
}
|
|
|
|
/// Consumes alternative await syntaxes like `await!(<expr>)`, `await <expr>`,
|
|
/// `await? <expr>`, `await(<expr>)`, and `await { <expr> }`.
|
|
pub(super) fn recover_incorrect_await_syntax(
|
|
&mut self,
|
|
await_sp: Span,
|
|
) -> PResult<'a, P<Expr>> {
|
|
let (hi, expr, is_question) = if self.token == token::Bang {
|
|
// Handle `await!(<expr>)`.
|
|
self.recover_await_macro()?
|
|
} else {
|
|
self.recover_await_prefix(await_sp)?
|
|
};
|
|
let (sp, guar) = self.error_on_incorrect_await(await_sp, hi, &expr, is_question);
|
|
let expr = self.mk_expr_err(await_sp.to(sp), guar);
|
|
self.maybe_recover_from_bad_qpath(expr)
|
|
}
|
|
|
|
fn recover_await_macro(&mut self) -> PResult<'a, (Span, P<Expr>, bool)> {
|
|
self.expect(exp!(Bang))?;
|
|
self.expect(exp!(OpenParen))?;
|
|
let expr = self.parse_expr()?;
|
|
self.expect(exp!(CloseParen))?;
|
|
Ok((self.prev_token.span, expr, false))
|
|
}
|
|
|
|
fn recover_await_prefix(&mut self, await_sp: Span) -> PResult<'a, (Span, P<Expr>, bool)> {
|
|
let is_question = self.eat(exp!(Question)); // Handle `await? <expr>`.
|
|
let expr = if self.token == token::OpenBrace {
|
|
// Handle `await { <expr> }`.
|
|
// This needs to be handled separately from the next arm to avoid
|
|
// interpreting `await { <expr> }?` as `<expr>?.await`.
|
|
self.parse_expr_block(None, self.token.span, BlockCheckMode::Default)
|
|
} else {
|
|
self.parse_expr()
|
|
}
|
|
.map_err(|mut err| {
|
|
err.span_label(await_sp, format!("while parsing this incorrect await expression"));
|
|
err
|
|
})?;
|
|
Ok((expr.span, expr, is_question))
|
|
}
|
|
|
|
fn error_on_incorrect_await(
|
|
&self,
|
|
lo: Span,
|
|
hi: Span,
|
|
expr: &Expr,
|
|
is_question: bool,
|
|
) -> (Span, ErrorGuaranteed) {
|
|
let span = lo.to(hi);
|
|
let guar = self.dcx().emit_err(IncorrectAwait {
|
|
span,
|
|
suggestion: AwaitSuggestion {
|
|
removal: lo.until(expr.span),
|
|
dot_await: expr.span.shrink_to_hi(),
|
|
question_mark: if is_question { "?" } else { "" },
|
|
},
|
|
});
|
|
(span, guar)
|
|
}
|
|
|
|
/// If encountering `future.await()`, consumes and emits an error.
|
|
pub(super) fn recover_from_await_method_call(&mut self) {
|
|
if self.token == token::OpenParen && self.look_ahead(1, |t| t == &token::CloseParen) {
|
|
// future.await()
|
|
let lo = self.token.span;
|
|
self.bump(); // (
|
|
let span = lo.to(self.token.span);
|
|
self.bump(); // )
|
|
|
|
self.dcx().emit_err(IncorrectUseOfAwait { span });
|
|
}
|
|
}
|
|
///
|
|
/// If encountering `x.use()`, consumes and emits an error.
|
|
pub(super) fn recover_from_use(&mut self) {
|
|
if self.token == token::OpenParen && self.look_ahead(1, |t| t == &token::CloseParen) {
|
|
// var.use()
|
|
let lo = self.token.span;
|
|
self.bump(); // (
|
|
let span = lo.to(self.token.span);
|
|
self.bump(); // )
|
|
|
|
self.dcx().emit_err(IncorrectUseOfUse { span });
|
|
}
|
|
}
|
|
|
|
pub(super) fn try_macro_suggestion(&mut self) -> PResult<'a, P<Expr>> {
|
|
let is_try = self.token.is_keyword(kw::Try);
|
|
let is_questionmark = self.look_ahead(1, |t| t == &token::Bang); //check for !
|
|
let is_open = self.look_ahead(2, |t| t == &token::OpenParen); //check for (
|
|
|
|
if is_try && is_questionmark && is_open {
|
|
let lo = self.token.span;
|
|
self.bump(); //remove try
|
|
self.bump(); //remove !
|
|
let try_span = lo.to(self.token.span); //we take the try!( span
|
|
self.bump(); //remove (
|
|
let is_empty = self.token == token::CloseParen; //check if the block is empty
|
|
self.consume_block(exp!(OpenParen), exp!(CloseParen), ConsumeClosingDelim::No); //eat the block
|
|
let hi = self.token.span;
|
|
self.bump(); //remove )
|
|
let mut err = self.dcx().struct_span_err(lo.to(hi), "use of deprecated `try` macro");
|
|
err.note("in the 2018 edition `try` is a reserved keyword, and the `try!()` macro is deprecated");
|
|
let prefix = if is_empty { "" } else { "alternatively, " };
|
|
if !is_empty {
|
|
err.multipart_suggestion(
|
|
"you can use the `?` operator instead",
|
|
vec![(try_span, "".to_owned()), (hi, "?".to_owned())],
|
|
Applicability::MachineApplicable,
|
|
);
|
|
}
|
|
err.span_suggestion(lo.shrink_to_lo(), format!("{prefix}you can still access the deprecated `try!()` macro using the \"raw identifier\" syntax"), "r#", Applicability::MachineApplicable);
|
|
let guar = err.emit();
|
|
Ok(self.mk_expr_err(lo.to(hi), guar))
|
|
} else {
|
|
Err(self.expected_expression_found()) // The user isn't trying to invoke the try! macro
|
|
}
|
|
}
|
|
|
|
/// When trying to close a generics list and encountering code like
|
|
/// ```text
|
|
/// impl<S: Into<std::borrow::Cow<'static, str>> From<S> for Canonical {}
|
|
/// // ^ missing > here
|
|
/// ```
|
|
/// we provide a structured suggestion on the error from `expect_gt`.
|
|
pub(super) fn expect_gt_or_maybe_suggest_closing_generics(
|
|
&mut self,
|
|
params: &[ast::GenericParam],
|
|
) -> PResult<'a, ()> {
|
|
let Err(mut err) = self.expect_gt() else {
|
|
return Ok(());
|
|
};
|
|
// Attempt to find places where a missing `>` might belong.
|
|
if let [.., ast::GenericParam { bounds, .. }] = params
|
|
&& let Some(poly) = bounds
|
|
.iter()
|
|
.filter_map(|bound| match bound {
|
|
ast::GenericBound::Trait(poly) => Some(poly),
|
|
_ => None,
|
|
})
|
|
.next_back()
|
|
{
|
|
err.span_suggestion_verbose(
|
|
poly.span.shrink_to_hi(),
|
|
"you might have meant to end the type parameters here",
|
|
">",
|
|
Applicability::MaybeIncorrect,
|
|
);
|
|
}
|
|
Err(err)
|
|
}
|
|
|
|
pub(super) fn recover_seq_parse_error(
|
|
&mut self,
|
|
open: ExpTokenPair<'_>,
|
|
close: ExpTokenPair<'_>,
|
|
lo: Span,
|
|
err: Diag<'a>,
|
|
) -> P<Expr> {
|
|
let guar = err.emit();
|
|
// Recover from parse error, callers expect the closing delim to be consumed.
|
|
self.consume_block(open, close, ConsumeClosingDelim::Yes);
|
|
self.mk_expr(lo.to(self.prev_token.span), ExprKind::Err(guar))
|
|
}
|
|
|
|
/// Eats tokens until we can be relatively sure we reached the end of the
|
|
/// statement. This is something of a best-effort heuristic.
|
|
///
|
|
/// We terminate when we find an unmatched `}` (without consuming it).
|
|
pub(super) fn recover_stmt(&mut self) {
|
|
self.recover_stmt_(SemiColonMode::Ignore, BlockMode::Ignore)
|
|
}
|
|
|
|
/// If `break_on_semi` is `Break`, then we will stop consuming tokens after
|
|
/// finding (and consuming) a `;` outside of `{}` or `[]` (note that this is
|
|
/// approximate -- it can mean we break too early due to macros, but that
|
|
/// should only lead to sub-optimal recovery, not inaccurate parsing).
|
|
///
|
|
/// If `break_on_block` is `Break`, then we will stop consuming tokens
|
|
/// after finding (and consuming) a brace-delimited block.
|
|
pub(super) fn recover_stmt_(
|
|
&mut self,
|
|
break_on_semi: SemiColonMode,
|
|
break_on_block: BlockMode,
|
|
) {
|
|
let mut brace_depth = 0;
|
|
let mut bracket_depth = 0;
|
|
let mut in_block = false;
|
|
debug!("recover_stmt_ enter loop (semi={:?}, block={:?})", break_on_semi, break_on_block);
|
|
loop {
|
|
debug!("recover_stmt_ loop {:?}", self.token);
|
|
match self.token.kind {
|
|
token::OpenBrace => {
|
|
brace_depth += 1;
|
|
self.bump();
|
|
if break_on_block == BlockMode::Break && brace_depth == 1 && bracket_depth == 0
|
|
{
|
|
in_block = true;
|
|
}
|
|
}
|
|
token::OpenBracket => {
|
|
bracket_depth += 1;
|
|
self.bump();
|
|
}
|
|
token::CloseBrace => {
|
|
if brace_depth == 0 {
|
|
debug!("recover_stmt_ return - close delim {:?}", self.token);
|
|
break;
|
|
}
|
|
brace_depth -= 1;
|
|
self.bump();
|
|
if in_block && bracket_depth == 0 && brace_depth == 0 {
|
|
debug!("recover_stmt_ return - block end {:?}", self.token);
|
|
break;
|
|
}
|
|
}
|
|
token::CloseBracket => {
|
|
bracket_depth -= 1;
|
|
if bracket_depth < 0 {
|
|
bracket_depth = 0;
|
|
}
|
|
self.bump();
|
|
}
|
|
token::Eof => {
|
|
debug!("recover_stmt_ return - Eof");
|
|
break;
|
|
}
|
|
token::Semi => {
|
|
self.bump();
|
|
if break_on_semi == SemiColonMode::Break
|
|
&& brace_depth == 0
|
|
&& bracket_depth == 0
|
|
{
|
|
debug!("recover_stmt_ return - Semi");
|
|
break;
|
|
}
|
|
}
|
|
token::Comma
|
|
if break_on_semi == SemiColonMode::Comma
|
|
&& brace_depth == 0
|
|
&& bracket_depth == 0 =>
|
|
{
|
|
break;
|
|
}
|
|
_ => self.bump(),
|
|
}
|
|
}
|
|
}
|
|
|
|
pub(super) fn check_for_for_in_in_typo(&mut self, in_span: Span) {
|
|
if self.eat_keyword(exp!(In)) {
|
|
// a common typo: `for _ in in bar {}`
|
|
self.dcx().emit_err(InInTypo {
|
|
span: self.prev_token.span,
|
|
sugg_span: in_span.until(self.prev_token.span),
|
|
});
|
|
}
|
|
}
|
|
|
|
pub(super) fn eat_incorrect_doc_comment_for_param_type(&mut self) {
|
|
if let token::DocComment(..) = self.token.kind {
|
|
self.dcx().emit_err(DocCommentOnParamType { span: self.token.span });
|
|
self.bump();
|
|
} else if self.token == token::Pound && self.look_ahead(1, |t| *t == token::OpenBracket) {
|
|
let lo = self.token.span;
|
|
// Skip every token until next possible arg.
|
|
while self.token != token::CloseBracket {
|
|
self.bump();
|
|
}
|
|
let sp = lo.to(self.token.span);
|
|
self.bump();
|
|
self.dcx().emit_err(AttributeOnParamType { span: sp });
|
|
}
|
|
}
|
|
|
|
pub(super) fn parameter_without_type(
|
|
&mut self,
|
|
err: &mut Diag<'_>,
|
|
pat: P<ast::Pat>,
|
|
require_name: bool,
|
|
first_param: bool,
|
|
) -> Option<Ident> {
|
|
// If we find a pattern followed by an identifier, it could be an (incorrect)
|
|
// C-style parameter declaration.
|
|
if self.check_ident()
|
|
&& self.look_ahead(1, |t| *t == token::Comma || *t == token::CloseParen)
|
|
{
|
|
// `fn foo(String s) {}`
|
|
let ident = self.parse_ident().unwrap();
|
|
let span = pat.span.with_hi(ident.span.hi());
|
|
|
|
err.span_suggestion(
|
|
span,
|
|
"declare the type after the parameter binding",
|
|
"<identifier>: <type>",
|
|
Applicability::HasPlaceholders,
|
|
);
|
|
return Some(ident);
|
|
} else if require_name
|
|
&& (self.token == token::Comma
|
|
|| self.token == token::Lt
|
|
|| self.token == token::CloseParen)
|
|
{
|
|
let rfc_note = "anonymous parameters are removed in the 2018 edition (see RFC 1685)";
|
|
|
|
let (ident, self_sugg, param_sugg, type_sugg, self_span, param_span, type_span) =
|
|
match pat.kind {
|
|
PatKind::Ident(_, ident, _) => (
|
|
ident,
|
|
"self: ",
|
|
": TypeName".to_string(),
|
|
"_: ",
|
|
pat.span.shrink_to_lo(),
|
|
pat.span.shrink_to_hi(),
|
|
pat.span.shrink_to_lo(),
|
|
),
|
|
// Also catches `fn foo(&a)`.
|
|
PatKind::Ref(ref inner_pat, mutab)
|
|
if matches!(inner_pat.clone().into_inner().kind, PatKind::Ident(..)) =>
|
|
{
|
|
match inner_pat.clone().into_inner().kind {
|
|
PatKind::Ident(_, ident, _) => {
|
|
let mutab = mutab.prefix_str();
|
|
(
|
|
ident,
|
|
"self: ",
|
|
format!("{ident}: &{mutab}TypeName"),
|
|
"_: ",
|
|
pat.span.shrink_to_lo(),
|
|
pat.span,
|
|
pat.span.shrink_to_lo(),
|
|
)
|
|
}
|
|
_ => unreachable!(),
|
|
}
|
|
}
|
|
_ => {
|
|
// Otherwise, try to get a type and emit a suggestion.
|
|
if let Some(_) = pat.to_ty() {
|
|
err.span_suggestion_verbose(
|
|
pat.span.shrink_to_lo(),
|
|
"explicitly ignore the parameter name",
|
|
"_: ".to_string(),
|
|
Applicability::MachineApplicable,
|
|
);
|
|
err.note(rfc_note);
|
|
}
|
|
|
|
return None;
|
|
}
|
|
};
|
|
|
|
// `fn foo(a, b) {}`, `fn foo(a<x>, b<y>) {}` or `fn foo(usize, usize) {}`
|
|
if first_param {
|
|
err.span_suggestion_verbose(
|
|
self_span,
|
|
"if this is a `self` type, give it a parameter name",
|
|
self_sugg,
|
|
Applicability::MaybeIncorrect,
|
|
);
|
|
}
|
|
// Avoid suggesting that `fn foo(HashMap<u32>)` is fixed with a change to
|
|
// `fn foo(HashMap: TypeName<u32>)`.
|
|
if self.token != token::Lt {
|
|
err.span_suggestion_verbose(
|
|
param_span,
|
|
"if this is a parameter name, give it a type",
|
|
param_sugg,
|
|
Applicability::HasPlaceholders,
|
|
);
|
|
}
|
|
err.span_suggestion_verbose(
|
|
type_span,
|
|
"if this is a type, explicitly ignore the parameter name",
|
|
type_sugg,
|
|
Applicability::MachineApplicable,
|
|
);
|
|
err.note(rfc_note);
|
|
|
|
// Don't attempt to recover by using the `X` in `X<Y>` as the parameter name.
|
|
return if self.token == token::Lt { None } else { Some(ident) };
|
|
}
|
|
None
|
|
}
|
|
|
|
pub(super) fn recover_arg_parse(&mut self) -> PResult<'a, (P<ast::Pat>, P<ast::Ty>)> {
|
|
let pat = self.parse_pat_no_top_alt(Some(Expected::ArgumentName), None)?;
|
|
self.expect(exp!(Colon))?;
|
|
let ty = self.parse_ty()?;
|
|
|
|
self.dcx().emit_err(PatternMethodParamWithoutBody { span: pat.span });
|
|
|
|
// Pretend the pattern is `_`, to avoid duplicate errors from AST validation.
|
|
let pat =
|
|
P(Pat { kind: PatKind::Wild, span: pat.span, id: ast::DUMMY_NODE_ID, tokens: None });
|
|
Ok((pat, ty))
|
|
}
|
|
|
|
pub(super) fn recover_bad_self_param(&mut self, mut param: Param) -> PResult<'a, Param> {
|
|
let span = param.pat.span;
|
|
let guar = self.dcx().emit_err(SelfParamNotFirst { span });
|
|
param.ty.kind = TyKind::Err(guar);
|
|
Ok(param)
|
|
}
|
|
|
|
pub(super) fn consume_block(
|
|
&mut self,
|
|
open: ExpTokenPair<'_>,
|
|
close: ExpTokenPair<'_>,
|
|
consume_close: ConsumeClosingDelim,
|
|
) {
|
|
let mut brace_depth = 0;
|
|
loop {
|
|
if self.eat(open) {
|
|
brace_depth += 1;
|
|
} else if self.check(close) {
|
|
if brace_depth == 0 {
|
|
if let ConsumeClosingDelim::Yes = consume_close {
|
|
// Some of the callers of this method expect to be able to parse the
|
|
// closing delimiter themselves, so we leave it alone. Otherwise we advance
|
|
// the parser.
|
|
self.bump();
|
|
}
|
|
return;
|
|
} else {
|
|
self.bump();
|
|
brace_depth -= 1;
|
|
continue;
|
|
}
|
|
} else if self.token == token::Eof {
|
|
return;
|
|
} else {
|
|
self.bump();
|
|
}
|
|
}
|
|
}
|
|
|
|
pub(super) fn expected_expression_found(&self) -> Diag<'a> {
|
|
let (span, msg) = match (&self.token.kind, self.subparser_name) {
|
|
(&token::Eof, Some(origin)) => {
|
|
let sp = self.prev_token.span.shrink_to_hi();
|
|
(sp, format!("expected expression, found end of {origin}"))
|
|
}
|
|
_ => (
|
|
self.token.span,
|
|
format!("expected expression, found {}", super::token_descr(&self.token)),
|
|
),
|
|
};
|
|
let mut err = self.dcx().struct_span_err(span, msg);
|
|
let sp = self.psess.source_map().start_point(self.token.span);
|
|
if let Some(sp) = self.psess.ambiguous_block_expr_parse.borrow().get(&sp) {
|
|
err.subdiagnostic(ExprParenthesesNeeded::surrounding(*sp));
|
|
}
|
|
err.span_label(span, "expected expression");
|
|
err
|
|
}
|
|
|
|
fn consume_tts(
|
|
&mut self,
|
|
mut acc: i64, // `i64` because malformed code can have more closing delims than opening.
|
|
// Not using `FxHashMap` due to `token::TokenKind: !Eq + !Hash`.
|
|
modifier: &[(token::TokenKind, i64)],
|
|
) {
|
|
while acc > 0 {
|
|
if let Some((_, val)) = modifier.iter().find(|(t, _)| self.token == *t) {
|
|
acc += *val;
|
|
}
|
|
if self.token == token::Eof {
|
|
break;
|
|
}
|
|
self.bump();
|
|
}
|
|
}
|
|
|
|
/// Replace duplicated recovered parameters with `_` pattern to avoid unnecessary errors.
|
|
///
|
|
/// This is necessary because at this point we don't know whether we parsed a function with
|
|
/// anonymous parameters or a function with names but no types. In order to minimize
|
|
/// unnecessary errors, we assume the parameters are in the shape of `fn foo(a, b, c)` where
|
|
/// the parameters are *names* (so we don't emit errors about not being able to find `b` in
|
|
/// the local scope), but if we find the same name multiple times, like in `fn foo(i8, i8)`,
|
|
/// we deduplicate them to not complain about duplicated parameter names.
|
|
pub(super) fn deduplicate_recovered_params_names(&self, fn_inputs: &mut ThinVec<Param>) {
|
|
let mut seen_inputs = FxHashSet::default();
|
|
for input in fn_inputs.iter_mut() {
|
|
let opt_ident = if let (PatKind::Ident(_, ident, _), TyKind::Err(_)) =
|
|
(&input.pat.kind, &input.ty.kind)
|
|
{
|
|
Some(*ident)
|
|
} else {
|
|
None
|
|
};
|
|
if let Some(ident) = opt_ident {
|
|
if seen_inputs.contains(&ident) {
|
|
input.pat.kind = PatKind::Wild;
|
|
}
|
|
seen_inputs.insert(ident);
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Handle encountering a symbol in a generic argument list that is not a `,` or `>`. In this
|
|
/// case, we emit an error and try to suggest enclosing a const argument in braces if it looks
|
|
/// like the user has forgotten them.
|
|
pub(super) fn handle_ambiguous_unbraced_const_arg(
|
|
&mut self,
|
|
args: &mut ThinVec<AngleBracketedArg>,
|
|
) -> PResult<'a, bool> {
|
|
// If we haven't encountered a closing `>`, then the argument is malformed.
|
|
// It's likely that the user has written a const expression without enclosing it
|
|
// in braces, so we try to recover here.
|
|
let arg = args.pop().unwrap();
|
|
// FIXME: for some reason using `unexpected` or `expected_one_of_not_found` has
|
|
// adverse side-effects to subsequent errors and seems to advance the parser.
|
|
// We are causing this error here exclusively in case that a `const` expression
|
|
// could be recovered from the current parser state, even if followed by more
|
|
// arguments after a comma.
|
|
let mut err = self.dcx().struct_span_err(
|
|
self.token.span,
|
|
format!("expected one of `,` or `>`, found {}", super::token_descr(&self.token)),
|
|
);
|
|
err.span_label(self.token.span, "expected one of `,` or `>`");
|
|
match self.recover_const_arg(arg.span(), err) {
|
|
Ok(arg) => {
|
|
args.push(AngleBracketedArg::Arg(arg));
|
|
if self.eat(exp!(Comma)) {
|
|
return Ok(true); // Continue
|
|
}
|
|
}
|
|
Err(err) => {
|
|
args.push(arg);
|
|
// We will emit a more generic error later.
|
|
err.delay_as_bug();
|
|
}
|
|
}
|
|
Ok(false) // Don't continue.
|
|
}
|
|
|
|
/// Attempt to parse a generic const argument that has not been enclosed in braces.
|
|
/// There are a limited number of expressions that are permitted without being encoded
|
|
/// in braces:
|
|
/// - Literals.
|
|
/// - Single-segment paths (i.e. standalone generic const parameters).
|
|
/// All other expressions that can be parsed will emit an error suggesting the expression be
|
|
/// wrapped in braces.
|
|
pub(super) fn handle_unambiguous_unbraced_const_arg(&mut self) -> PResult<'a, P<Expr>> {
|
|
let start = self.token.span;
|
|
let attrs = self.parse_outer_attributes()?;
|
|
let (expr, _) =
|
|
self.parse_expr_res(Restrictions::CONST_EXPR, attrs).map_err(|mut err| {
|
|
err.span_label(
|
|
start.shrink_to_lo(),
|
|
"while parsing a const generic argument starting here",
|
|
);
|
|
err
|
|
})?;
|
|
if !self.expr_is_valid_const_arg(&expr) {
|
|
self.dcx().emit_err(ConstGenericWithoutBraces {
|
|
span: expr.span,
|
|
sugg: ConstGenericWithoutBracesSugg {
|
|
left: expr.span.shrink_to_lo(),
|
|
right: expr.span.shrink_to_hi(),
|
|
},
|
|
});
|
|
}
|
|
Ok(expr)
|
|
}
|
|
|
|
fn recover_const_param_decl(&mut self, ty_generics: Option<&Generics>) -> Option<GenericArg> {
|
|
let snapshot = self.create_snapshot_for_diagnostic();
|
|
let param = match self.parse_const_param(AttrVec::new()) {
|
|
Ok(param) => param,
|
|
Err(err) => {
|
|
err.cancel();
|
|
self.restore_snapshot(snapshot);
|
|
return None;
|
|
}
|
|
};
|
|
|
|
let ident = param.ident.to_string();
|
|
let sugg = match (ty_generics, self.psess.source_map().span_to_snippet(param.span())) {
|
|
(Some(Generics { params, span: impl_generics, .. }), Ok(snippet)) => {
|
|
Some(match ¶ms[..] {
|
|
[] => UnexpectedConstParamDeclarationSugg::AddParam {
|
|
impl_generics: *impl_generics,
|
|
incorrect_decl: param.span(),
|
|
snippet,
|
|
ident,
|
|
},
|
|
[.., generic] => UnexpectedConstParamDeclarationSugg::AppendParam {
|
|
impl_generics_end: generic.span().shrink_to_hi(),
|
|
incorrect_decl: param.span(),
|
|
snippet,
|
|
ident,
|
|
},
|
|
})
|
|
}
|
|
_ => None,
|
|
};
|
|
let guar =
|
|
self.dcx().emit_err(UnexpectedConstParamDeclaration { span: param.span(), sugg });
|
|
|
|
let value = self.mk_expr_err(param.span(), guar);
|
|
Some(GenericArg::Const(AnonConst { id: ast::DUMMY_NODE_ID, value }))
|
|
}
|
|
|
|
pub(super) fn recover_const_param_declaration(
|
|
&mut self,
|
|
ty_generics: Option<&Generics>,
|
|
) -> PResult<'a, Option<GenericArg>> {
|
|
// We have to check for a few different cases.
|
|
if let Some(arg) = self.recover_const_param_decl(ty_generics) {
|
|
return Ok(Some(arg));
|
|
}
|
|
|
|
// We haven't consumed `const` yet.
|
|
let start = self.token.span;
|
|
self.bump(); // `const`
|
|
|
|
// Detect and recover from the old, pre-RFC2000 syntax for const generics.
|
|
let mut err = UnexpectedConstInGenericParam { span: start, to_remove: None };
|
|
if self.check_const_arg() {
|
|
err.to_remove = Some(start.until(self.token.span));
|
|
self.dcx().emit_err(err);
|
|
Ok(Some(GenericArg::Const(self.parse_const_arg()?)))
|
|
} else {
|
|
let after_kw_const = self.token.span;
|
|
self.recover_const_arg(after_kw_const, self.dcx().create_err(err)).map(Some)
|
|
}
|
|
}
|
|
|
|
/// Try to recover from possible generic const argument without `{` and `}`.
|
|
///
|
|
/// When encountering code like `foo::< bar + 3 >` or `foo::< bar - baz >` we suggest
|
|
/// `foo::<{ bar + 3 }>` and `foo::<{ bar - baz }>`, respectively. We only provide a suggestion
|
|
/// if we think that the resulting expression would be well formed.
|
|
pub(super) fn recover_const_arg(
|
|
&mut self,
|
|
start: Span,
|
|
mut err: Diag<'a>,
|
|
) -> PResult<'a, GenericArg> {
|
|
let is_op_or_dot = AssocOp::from_token(&self.token)
|
|
.and_then(|op| {
|
|
if let AssocOp::Binary(
|
|
BinOpKind::Gt
|
|
| BinOpKind::Lt
|
|
| BinOpKind::Shr
|
|
| BinOpKind::Ge
|
|
)
|
|
// Don't recover from `foo::<bar = baz>`, because this could be an attempt to
|
|
// assign a value to a defaulted generic parameter.
|
|
| AssocOp::Assign
|
|
| AssocOp::AssignOp(_) = op
|
|
{
|
|
None
|
|
} else {
|
|
Some(op)
|
|
}
|
|
})
|
|
.is_some()
|
|
|| self.token == TokenKind::Dot;
|
|
// This will be true when a trait object type `Foo +` or a path which was a `const fn` with
|
|
// type params has been parsed.
|
|
let was_op = matches!(self.prev_token.kind, token::Plus | token::Shr | token::Gt);
|
|
if !is_op_or_dot && !was_op {
|
|
// We perform these checks and early return to avoid taking a snapshot unnecessarily.
|
|
return Err(err);
|
|
}
|
|
let snapshot = self.create_snapshot_for_diagnostic();
|
|
if is_op_or_dot {
|
|
self.bump();
|
|
}
|
|
match (|| {
|
|
let attrs = self.parse_outer_attributes()?;
|
|
self.parse_expr_res(Restrictions::CONST_EXPR, attrs)
|
|
})() {
|
|
Ok((expr, _)) => {
|
|
// Find a mistake like `MyTrait<Assoc == S::Assoc>`.
|
|
if snapshot.token == token::EqEq {
|
|
err.span_suggestion(
|
|
snapshot.token.span,
|
|
"if you meant to use an associated type binding, replace `==` with `=`",
|
|
"=",
|
|
Applicability::MaybeIncorrect,
|
|
);
|
|
let guar = err.emit();
|
|
let value = self.mk_expr_err(start.to(expr.span), guar);
|
|
return Ok(GenericArg::Const(AnonConst { id: ast::DUMMY_NODE_ID, value }));
|
|
} else if snapshot.token == token::Colon
|
|
&& expr.span.lo() == snapshot.token.span.hi()
|
|
&& matches!(expr.kind, ExprKind::Path(..))
|
|
{
|
|
// Find a mistake like "foo::var:A".
|
|
err.span_suggestion(
|
|
snapshot.token.span,
|
|
"write a path separator here",
|
|
"::",
|
|
Applicability::MaybeIncorrect,
|
|
);
|
|
let guar = err.emit();
|
|
return Ok(GenericArg::Type(
|
|
self.mk_ty(start.to(expr.span), TyKind::Err(guar)),
|
|
));
|
|
} else if self.token == token::Comma || self.token.kind.should_end_const_arg() {
|
|
// Avoid the following output by checking that we consumed a full const arg:
|
|
// help: expressions must be enclosed in braces to be used as const generic
|
|
// arguments
|
|
// |
|
|
// LL | let sr: Vec<{ (u32, _, _) = vec![] };
|
|
// | ^ ^
|
|
return Ok(self.dummy_const_arg_needs_braces(err, start.to(expr.span)));
|
|
}
|
|
}
|
|
Err(err) => {
|
|
err.cancel();
|
|
}
|
|
}
|
|
self.restore_snapshot(snapshot);
|
|
Err(err)
|
|
}
|
|
|
|
/// Try to recover from an unbraced const argument whose first token [could begin a type][ty].
|
|
///
|
|
/// [ty]: token::Token::can_begin_type
|
|
pub(crate) fn recover_unbraced_const_arg_that_can_begin_ty(
|
|
&mut self,
|
|
mut snapshot: SnapshotParser<'a>,
|
|
) -> Option<P<ast::Expr>> {
|
|
match (|| {
|
|
let attrs = self.parse_outer_attributes()?;
|
|
snapshot.parse_expr_res(Restrictions::CONST_EXPR, attrs)
|
|
})() {
|
|
// Since we don't know the exact reason why we failed to parse the type or the
|
|
// expression, employ a simple heuristic to weed out some pathological cases.
|
|
Ok((expr, _)) if let token::Comma | token::Gt = snapshot.token.kind => {
|
|
self.restore_snapshot(snapshot);
|
|
Some(expr)
|
|
}
|
|
Ok(_) => None,
|
|
Err(err) => {
|
|
err.cancel();
|
|
None
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Creates a dummy const argument, and reports that the expression must be enclosed in braces
|
|
pub(super) fn dummy_const_arg_needs_braces(&self, mut err: Diag<'a>, span: Span) -> GenericArg {
|
|
err.multipart_suggestion(
|
|
"expressions must be enclosed in braces to be used as const generic \
|
|
arguments",
|
|
vec![(span.shrink_to_lo(), "{ ".to_string()), (span.shrink_to_hi(), " }".to_string())],
|
|
Applicability::MaybeIncorrect,
|
|
);
|
|
let guar = err.emit();
|
|
let value = self.mk_expr_err(span, guar);
|
|
GenericArg::Const(AnonConst { id: ast::DUMMY_NODE_ID, value })
|
|
}
|
|
|
|
/// Some special error handling for the "top-level" patterns in a match arm,
|
|
/// `for` loop, `let`, &c. (in contrast to subpatterns within such).
|
|
pub(crate) fn maybe_recover_colon_colon_in_pat_typo(
|
|
&mut self,
|
|
mut first_pat: P<Pat>,
|
|
expected: Option<Expected>,
|
|
) -> P<Pat> {
|
|
if token::Colon != self.token.kind {
|
|
return first_pat;
|
|
}
|
|
if !matches!(first_pat.kind, PatKind::Ident(_, _, None) | PatKind::Path(..))
|
|
|| !self.look_ahead(1, |token| token.is_ident() && !token.is_reserved_ident())
|
|
{
|
|
let mut snapshot_type = self.create_snapshot_for_diagnostic();
|
|
snapshot_type.bump(); // `:`
|
|
match snapshot_type.parse_ty() {
|
|
Err(inner_err) => {
|
|
inner_err.cancel();
|
|
}
|
|
Ok(ty) => {
|
|
let Err(mut err) = self.expected_one_of_not_found(&[], &[]) else {
|
|
return first_pat;
|
|
};
|
|
err.span_label(ty.span, "specifying the type of a pattern isn't supported");
|
|
self.restore_snapshot(snapshot_type);
|
|
let span = first_pat.span.to(ty.span);
|
|
first_pat = self.mk_pat(span, PatKind::Wild);
|
|
err.emit();
|
|
}
|
|
}
|
|
return first_pat;
|
|
}
|
|
// The pattern looks like it might be a path with a `::` -> `:` typo:
|
|
// `match foo { bar:baz => {} }`
|
|
let colon_span = self.token.span;
|
|
// We only emit "unexpected `:`" error here if we can successfully parse the
|
|
// whole pattern correctly in that case.
|
|
let mut snapshot_pat = self.create_snapshot_for_diagnostic();
|
|
let mut snapshot_type = self.create_snapshot_for_diagnostic();
|
|
|
|
// Create error for "unexpected `:`".
|
|
match self.expected_one_of_not_found(&[], &[]) {
|
|
Err(mut err) => {
|
|
// Skip the `:`.
|
|
snapshot_pat.bump();
|
|
snapshot_type.bump();
|
|
match snapshot_pat.parse_pat_no_top_alt(expected, None) {
|
|
Err(inner_err) => {
|
|
inner_err.cancel();
|
|
}
|
|
Ok(mut pat) => {
|
|
// We've parsed the rest of the pattern.
|
|
let new_span = first_pat.span.to(pat.span);
|
|
let mut show_sugg = false;
|
|
// Try to construct a recovered pattern.
|
|
match &mut pat.kind {
|
|
PatKind::Struct(qself @ None, path, ..)
|
|
| PatKind::TupleStruct(qself @ None, path, _)
|
|
| PatKind::Path(qself @ None, path) => match &first_pat.kind {
|
|
PatKind::Ident(_, ident, _) => {
|
|
path.segments.insert(0, PathSegment::from_ident(*ident));
|
|
path.span = new_span;
|
|
show_sugg = true;
|
|
first_pat = pat;
|
|
}
|
|
PatKind::Path(old_qself, old_path) => {
|
|
path.segments = old_path
|
|
.segments
|
|
.iter()
|
|
.cloned()
|
|
.chain(take(&mut path.segments))
|
|
.collect();
|
|
path.span = new_span;
|
|
*qself = old_qself.clone();
|
|
first_pat = pat;
|
|
show_sugg = true;
|
|
}
|
|
_ => {}
|
|
},
|
|
PatKind::Ident(BindingMode::NONE, ident, None) => {
|
|
match &first_pat.kind {
|
|
PatKind::Ident(_, old_ident, _) => {
|
|
let path = PatKind::Path(
|
|
None,
|
|
Path {
|
|
span: new_span,
|
|
segments: thin_vec![
|
|
PathSegment::from_ident(*old_ident),
|
|
PathSegment::from_ident(*ident),
|
|
],
|
|
tokens: None,
|
|
},
|
|
);
|
|
first_pat = self.mk_pat(new_span, path);
|
|
show_sugg = true;
|
|
}
|
|
PatKind::Path(old_qself, old_path) => {
|
|
let mut segments = old_path.segments.clone();
|
|
segments.push(PathSegment::from_ident(*ident));
|
|
let path = PatKind::Path(
|
|
old_qself.clone(),
|
|
Path { span: new_span, segments, tokens: None },
|
|
);
|
|
first_pat = self.mk_pat(new_span, path);
|
|
show_sugg = true;
|
|
}
|
|
_ => {}
|
|
}
|
|
}
|
|
_ => {}
|
|
}
|
|
if show_sugg {
|
|
err.span_suggestion_verbose(
|
|
colon_span.until(self.look_ahead(1, |t| t.span)),
|
|
"maybe write a path separator here",
|
|
"::",
|
|
Applicability::MaybeIncorrect,
|
|
);
|
|
} else {
|
|
first_pat = self.mk_pat(new_span, PatKind::Wild);
|
|
}
|
|
self.restore_snapshot(snapshot_pat);
|
|
}
|
|
}
|
|
match snapshot_type.parse_ty() {
|
|
Err(inner_err) => {
|
|
inner_err.cancel();
|
|
}
|
|
Ok(ty) => {
|
|
err.span_label(ty.span, "specifying the type of a pattern isn't supported");
|
|
self.restore_snapshot(snapshot_type);
|
|
let new_span = first_pat.span.to(ty.span);
|
|
first_pat = self.mk_pat(new_span, PatKind::Wild);
|
|
}
|
|
}
|
|
err.emit();
|
|
}
|
|
_ => {
|
|
// Carry on as if we had not done anything. This should be unreachable.
|
|
}
|
|
};
|
|
first_pat
|
|
}
|
|
|
|
/// If `loop_header` is `Some` and an unexpected block label is encountered,
|
|
/// it is suggested to be moved just before `loop_header`, else it is suggested to be removed.
|
|
pub(crate) fn maybe_recover_unexpected_block_label(
|
|
&mut self,
|
|
loop_header: Option<Span>,
|
|
) -> bool {
|
|
// Check for `'a : {`
|
|
if !(self.check_lifetime()
|
|
&& self.look_ahead(1, |t| *t == token::Colon)
|
|
&& self.look_ahead(2, |t| *t == token::OpenBrace))
|
|
{
|
|
return false;
|
|
}
|
|
let label = self.eat_label().expect("just checked if a label exists");
|
|
self.bump(); // eat `:`
|
|
let span = label.ident.span.to(self.prev_token.span);
|
|
let mut diag = self
|
|
.dcx()
|
|
.struct_span_err(span, "block label not supported here")
|
|
.with_span_label(span, "not supported here");
|
|
if let Some(loop_header) = loop_header {
|
|
diag.multipart_suggestion(
|
|
"if you meant to label the loop, move this label before the loop",
|
|
vec![
|
|
(label.ident.span.until(self.token.span), String::from("")),
|
|
(loop_header.shrink_to_lo(), format!("{}: ", label.ident)),
|
|
],
|
|
Applicability::MachineApplicable,
|
|
);
|
|
} else {
|
|
diag.tool_only_span_suggestion(
|
|
label.ident.span.until(self.token.span),
|
|
"remove this block label",
|
|
"",
|
|
Applicability::MachineApplicable,
|
|
);
|
|
}
|
|
diag.emit();
|
|
true
|
|
}
|
|
|
|
/// Some special error handling for the "top-level" patterns in a match arm,
|
|
/// `for` loop, `let`, &c. (in contrast to subpatterns within such).
|
|
pub(crate) fn maybe_recover_unexpected_comma(
|
|
&mut self,
|
|
lo: Span,
|
|
rt: CommaRecoveryMode,
|
|
) -> PResult<'a, ()> {
|
|
if self.token != token::Comma {
|
|
return Ok(());
|
|
}
|
|
|
|
// An unexpected comma after a top-level pattern is a clue that the
|
|
// user (perhaps more accustomed to some other language) forgot the
|
|
// parentheses in what should have been a tuple pattern; return a
|
|
// suggestion-enhanced error here rather than choking on the comma later.
|
|
let comma_span = self.token.span;
|
|
self.bump();
|
|
if let Err(err) = self.skip_pat_list() {
|
|
// We didn't expect this to work anyway; we just wanted to advance to the
|
|
// end of the comma-sequence so we know the span to suggest parenthesizing.
|
|
err.cancel();
|
|
}
|
|
let seq_span = lo.to(self.prev_token.span);
|
|
let mut err = self.dcx().struct_span_err(comma_span, "unexpected `,` in pattern");
|
|
if let Ok(seq_snippet) = self.span_to_snippet(seq_span) {
|
|
err.multipart_suggestion(
|
|
format!(
|
|
"try adding parentheses to match on a tuple{}",
|
|
if let CommaRecoveryMode::LikelyTuple = rt { "" } else { "..." },
|
|
),
|
|
vec![
|
|
(seq_span.shrink_to_lo(), "(".to_string()),
|
|
(seq_span.shrink_to_hi(), ")".to_string()),
|
|
],
|
|
Applicability::MachineApplicable,
|
|
);
|
|
if let CommaRecoveryMode::EitherTupleOrPipe = rt {
|
|
err.span_suggestion(
|
|
seq_span,
|
|
"...or a vertical bar to match on multiple alternatives",
|
|
seq_snippet.replace(',', " |"),
|
|
Applicability::MachineApplicable,
|
|
);
|
|
}
|
|
}
|
|
Err(err)
|
|
}
|
|
|
|
pub(crate) fn maybe_recover_bounds_doubled_colon(&mut self, ty: &Ty) -> PResult<'a, ()> {
|
|
let TyKind::Path(qself, path) = &ty.kind else { return Ok(()) };
|
|
let qself_position = qself.as_ref().map(|qself| qself.position);
|
|
for (i, segments) in path.segments.windows(2).enumerate() {
|
|
if qself_position.is_some_and(|pos| i < pos) {
|
|
continue;
|
|
}
|
|
if let [a, b] = segments {
|
|
let (a_span, b_span) = (a.span(), b.span());
|
|
let between_span = a_span.shrink_to_hi().to(b_span.shrink_to_lo());
|
|
if self.span_to_snippet(between_span).as_deref() == Ok(":: ") {
|
|
return Err(self.dcx().create_err(DoubleColonInBound {
|
|
span: path.span.shrink_to_hi(),
|
|
between: between_span,
|
|
}));
|
|
}
|
|
}
|
|
}
|
|
Ok(())
|
|
}
|
|
|
|
/// Check for exclusive ranges written as `..<`
|
|
pub(crate) fn maybe_err_dotdotlt_syntax(&self, maybe_lt: Token, mut err: Diag<'a>) -> Diag<'a> {
|
|
if maybe_lt == token::Lt
|
|
&& (self.expected_token_types.contains(TokenType::Gt)
|
|
|| matches!(self.token.kind, token::Literal(..)))
|
|
{
|
|
err.span_suggestion(
|
|
maybe_lt.span,
|
|
"remove the `<` to write an exclusive range",
|
|
"",
|
|
Applicability::MachineApplicable,
|
|
);
|
|
}
|
|
err
|
|
}
|
|
|
|
/// This checks if this is a conflict marker, depending of the parameter passed.
|
|
///
|
|
/// * `<<<<<<<`
|
|
/// * `|||||||`
|
|
/// * `=======`
|
|
/// * `>>>>>>>`
|
|
///
|
|
pub(super) fn is_vcs_conflict_marker(
|
|
&mut self,
|
|
long_kind: &TokenKind,
|
|
short_kind: &TokenKind,
|
|
) -> bool {
|
|
(0..3).all(|i| self.look_ahead(i, |tok| tok == long_kind))
|
|
&& self.look_ahead(3, |tok| tok == short_kind)
|
|
}
|
|
|
|
fn conflict_marker(&mut self, long_kind: &TokenKind, short_kind: &TokenKind) -> Option<Span> {
|
|
if self.is_vcs_conflict_marker(long_kind, short_kind) {
|
|
let lo = self.token.span;
|
|
for _ in 0..4 {
|
|
self.bump();
|
|
}
|
|
return Some(lo.to(self.prev_token.span));
|
|
}
|
|
None
|
|
}
|
|
|
|
pub(super) fn recover_vcs_conflict_marker(&mut self) {
|
|
// <<<<<<<
|
|
let Some(start) = self.conflict_marker(&TokenKind::Shl, &TokenKind::Lt) else {
|
|
return;
|
|
};
|
|
let mut spans = Vec::with_capacity(3);
|
|
spans.push(start);
|
|
// |||||||
|
|
let mut middlediff3 = None;
|
|
// =======
|
|
let mut middle = None;
|
|
// >>>>>>>
|
|
let mut end = None;
|
|
loop {
|
|
if self.token == TokenKind::Eof {
|
|
break;
|
|
}
|
|
if let Some(span) = self.conflict_marker(&TokenKind::OrOr, &TokenKind::Or) {
|
|
middlediff3 = Some(span);
|
|
}
|
|
if let Some(span) = self.conflict_marker(&TokenKind::EqEq, &TokenKind::Eq) {
|
|
middle = Some(span);
|
|
}
|
|
if let Some(span) = self.conflict_marker(&TokenKind::Shr, &TokenKind::Gt) {
|
|
spans.push(span);
|
|
end = Some(span);
|
|
break;
|
|
}
|
|
self.bump();
|
|
}
|
|
|
|
let mut err = self.dcx().struct_span_fatal(spans, "encountered diff marker");
|
|
match middlediff3 {
|
|
// We're using diff3
|
|
Some(middlediff3) => {
|
|
err.span_label(
|
|
start,
|
|
"between this marker and `|||||||` is the code that we're merging into",
|
|
);
|
|
err.span_label(middlediff3, "between this marker and `=======` is the base code (what the two refs diverged from)");
|
|
}
|
|
None => {
|
|
err.span_label(
|
|
start,
|
|
"between this marker and `=======` is the code that we're merging into",
|
|
);
|
|
}
|
|
};
|
|
|
|
if let Some(middle) = middle {
|
|
err.span_label(middle, "between this marker and `>>>>>>>` is the incoming code");
|
|
}
|
|
if let Some(end) = end {
|
|
err.span_label(end, "this marker concludes the conflict region");
|
|
}
|
|
err.note(
|
|
"conflict markers indicate that a merge was started but could not be completed due \
|
|
to merge conflicts\n\
|
|
to resolve a conflict, keep only the code you want and then delete the lines \
|
|
containing conflict markers",
|
|
);
|
|
err.help(
|
|
"if you're having merge conflicts after pulling new code:\n\
|
|
the top section is the code you already had and the bottom section is the remote code\n\
|
|
if you're in the middle of a rebase:\n\
|
|
the top section is the code being rebased onto and the bottom section is the code \
|
|
coming from the current commit being rebased",
|
|
);
|
|
|
|
err.note(
|
|
"for an explanation on these markers from the `git` documentation:\n\
|
|
visit <https://git-scm.com/book/en/v2/Git-Tools-Advanced-Merging#_checking_out_conflicts>",
|
|
);
|
|
|
|
err.emit();
|
|
}
|
|
|
|
/// Parse and throw away a parenthesized comma separated
|
|
/// sequence of patterns until `)` is reached.
|
|
fn skip_pat_list(&mut self) -> PResult<'a, ()> {
|
|
while !self.check(exp!(CloseParen)) {
|
|
self.parse_pat_no_top_alt(None, None)?;
|
|
if !self.eat(exp!(Comma)) {
|
|
return Ok(());
|
|
}
|
|
}
|
|
Ok(())
|
|
}
|
|
}
|