bjoernager/rust
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Avoid too many expected symbols and reduce Nones

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This commit is contained in:
r0cky 2023-08-03 08:56:31 +00:00
parent 41e85c3d23
commit 8c8af6cf99
12 changed files with 58 additions and 64 deletions
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43
compiler/rustc_parse/src/parser/pat.rs
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@ -2,10 +2,11 @@ use super::{ForceCollect, Parser, PathStyle, TrailingToken};
use crate::errors::{
self, AmbiguousRangePattern, DotDotDotForRemainingFields, DotDotDotRangeToPatternNotAllowed,
DotDotDotRestPattern, EnumPatternInsteadOfIdentifier, ExpectedBindingLeftOfAt,
ExpectedCommaAfterPatternField, InclusiveRangeExtraEquals, InclusiveRangeMatchArrow,
InclusiveRangeNoEnd, InvalidMutInPattern, PatternOnWrongSideOfAt, RefMutOrderIncorrect,
RemoveLet, RepeatedMutInPattern, TopLevelOrPatternNotAllowed, TopLevelOrPatternNotAllowedSugg,
TrailingVertNotAllowed, UnexpectedLifetimeInPattern, UnexpectedVertVertBeforeFunctionParam,
ExpectedCommaAfterPatternField, GenericArgsInPatRequireTurbofishSyntax,
InclusiveRangeExtraEquals, InclusiveRangeMatchArrow, InclusiveRangeNoEnd, InvalidMutInPattern,
PatternOnWrongSideOfAt, RefMutOrderIncorrect, RemoveLet, RepeatedMutInPattern,
TopLevelOrPatternNotAllowed, TopLevelOrPatternNotAllowedSugg, TrailingVertNotAllowed,
UnexpectedLifetimeInPattern, UnexpectedVertVertBeforeFunctionParam,
UnexpectedVertVertInPattern,
};
use crate::{maybe_recover_from_interpolated_ty_qpath, maybe_whole};
@ -366,11 +367,11 @@ impl<'a> Parser<'a> {
// Parse _
PatKind::Wild
} else if self.eat_keyword(kw::Mut) {
self.parse_pat_ident_mut()?
self.parse_pat_ident_mut(syntax_loc)?
} else if self.eat_keyword(kw::Ref) {
// Parse ref ident @ pat / ref mut ident @ pat
let mutbl = self.parse_mutability();
self.parse_pat_ident(BindingAnnotation(ByRef::Yes, mutbl))?
self.parse_pat_ident(BindingAnnotation(ByRef::Yes, mutbl), syntax_loc)?
} else if self.eat_keyword(kw::Box) {
self.parse_pat_box()?
} else if self.check_inline_const(0) {
@ -392,7 +393,7 @@ impl<'a> Parser<'a> {
// Parse `ident @ pat`
// This can give false positives and parse nullary enums,
// they are dealt with later in resolve.
self.parse_pat_ident(BindingAnnotation::NONE)?
self.parse_pat_ident(BindingAnnotation::NONE, syntax_loc)?
} else if self.is_start_of_pat_with_path() {
// Parse pattern starting with a path
let (qself, path) = if self.eat_lt() {
@ -401,7 +402,7 @@ impl<'a> Parser<'a> {
(Some(qself), path)
} else {
// Parse an unqualified path
(None, self.parse_path(PathStyle::Pat, syntax_loc)?)
(None, self.parse_path(PathStyle::Pat)?)
};
let span = lo.to(self.prev_token.span);
@ -574,12 +575,12 @@ impl<'a> Parser<'a> {
}
/// Parse a mutable binding with the `mut` token already eaten.
fn parse_pat_ident_mut(&mut self) -> PResult<'a, PatKind> {
fn parse_pat_ident_mut(&mut self, syntax_loc: Option<PatternLocation>) -> PResult<'a, PatKind> {
let mut_span = self.prev_token.span;
if self.eat_keyword(kw::Ref) {
self.sess.emit_err(RefMutOrderIncorrect { span: mut_span.to(self.prev_token.span) });
return self.parse_pat_ident(BindingAnnotation::REF_MUT);
return self.parse_pat_ident(BindingAnnotation::REF_MUT, syntax_loc);
}
self.recover_additional_muts();
@ -784,7 +785,7 @@ impl<'a> Parser<'a> {
(Some(qself), path)
} else {
// Parse an unqualified path
(None, self.parse_path(PathStyle::Pat, None)?)
(None, self.parse_path(PathStyle::Pat)?)
};
let hi = self.prev_token.span;
Ok(self.mk_expr(lo.to(hi), ExprKind::Path(qself, path)))
@ -813,16 +814,28 @@ impl<'a> Parser<'a> {
| token::DotDotDot | token::DotDotEq | token::DotDot // A range pattern.
| token::ModSep // A tuple / struct variant pattern.
| token::Not)) // A macro expanding to a pattern.
// May suggest the turbofish syntax for generics, only valid for recoveries.
&& !(self.look_ahead(1, |t| t.kind == token::Lt)
&& self.look_ahead(2, |t| t.can_begin_type()))
}
/// Parses `ident` or `ident @ pat`.
/// Used by the copy foo and ref foo patterns to give a good
/// error message when parsing mistakes like `ref foo(a, b)`.
fn parse_pat_ident(&mut self, binding_annotation: BindingAnnotation) -> PResult<'a, PatKind> {
fn parse_pat_ident(
&mut self,
binding_annotation: BindingAnnotation,
syntax_loc: Option<PatternLocation>,
) -> PResult<'a, PatKind> {
let ident = self.parse_ident()?;
if !matches!(syntax_loc, Some(PatternLocation::FunctionParameter))
&& self.check_noexpect(&token::Lt)
&& self.look_ahead(1, |t| t.can_begin_type())
{
return Err(self.sess.create_err(GenericArgsInPatRequireTurbofishSyntax {
span: self.token.span,
suggest_turbofish: self.token.span.shrink_to_lo(),
}));
}
let sub = if self.eat(&token::At) {
Some(self.parse_pat_no_top_alt(Some(Expected::BindingPattern), None)?)
} else {