diff options
Diffstat (limited to 'compiler/rustc_parse/src/parser/expr.rs')
| -rw-r--r-- | compiler/rustc_parse/src/parser/expr.rs | 89 |
1 files changed, 57 insertions, 32 deletions
diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs index e284c7a11bc..e0917ba43e4 100644 --- a/compiler/rustc_parse/src/parser/expr.rs +++ b/compiler/rustc_parse/src/parser/expr.rs @@ -36,7 +36,7 @@ use super::pat::{CommaRecoveryMode, Expected, RecoverColon, RecoverComma}; use super::ty::{AllowPlus, RecoverQPath, RecoverReturnSign}; use super::{ AttrWrapper, BlockMode, ClosureSpans, ForceCollect, Parser, PathStyle, Restrictions, - SemiColonMode, SeqSep, TokenType, Trailing, + SemiColonMode, SeqSep, TokenType, Trailing, UsePreAttrPos, }; use crate::{errors, maybe_recover_from_interpolated_ty_qpath}; @@ -59,15 +59,30 @@ impl<'a> Parser<'a> { self.current_closure.take(); let attrs = self.parse_outer_attributes()?; - self.parse_expr_res(Restrictions::empty(), attrs) + self.parse_expr_res(Restrictions::empty(), attrs).map(|res| res.0) } /// Parses an expression, forcing tokens to be collected. pub fn parse_expr_force_collect(&mut self) -> PResult<'a, P<Expr>> { self.current_closure.take(); + // If the expression is associative (e.g. `1 + 2`), then any preceding + // outer attribute actually belongs to the first inner sub-expression. + // In which case we must use the pre-attr pos to include the attribute + // in the collected tokens for the outer expression. + let pre_attr_pos = self.collect_pos(); let attrs = self.parse_outer_attributes()?; - self.collect_tokens_no_attrs(|this| this.parse_expr_res(Restrictions::empty(), attrs)) + self.collect_tokens( + Some(pre_attr_pos), + AttrWrapper::empty(), + ForceCollect::Yes, + |this, _empty_attrs| { + let (expr, is_assoc) = this.parse_expr_res(Restrictions::empty(), attrs)?; + let use_pre_attr_pos = + if is_assoc { UsePreAttrPos::Yes } else { UsePreAttrPos::No }; + Ok((expr, Trailing::No, use_pre_attr_pos)) + }, + ) } pub fn parse_expr_anon_const(&mut self) -> PResult<'a, AnonConst> { @@ -77,7 +92,7 @@ impl<'a> Parser<'a> { fn parse_expr_catch_underscore(&mut self, restrictions: Restrictions) -> PResult<'a, P<Expr>> { let attrs = self.parse_outer_attributes()?; match self.parse_expr_res(restrictions, attrs) { - Ok(expr) => Ok(expr), + Ok((expr, _)) => Ok(expr), Err(err) => match self.token.ident() { Some((Ident { name: kw::Underscore, .. }, IdentIsRaw::No)) if self.may_recover() && self.look_ahead(1, |t| t == &token::Comma) => @@ -104,18 +119,20 @@ impl<'a> Parser<'a> { &mut self, r: Restrictions, attrs: AttrWrapper, - ) -> PResult<'a, P<Expr>> { + ) -> PResult<'a, (P<Expr>, bool)> { self.with_res(r, |this| this.parse_expr_assoc_with(0, attrs)) } /// Parses an associative expression with operators of at least `min_prec` precedence. + /// The `bool` in the return value indicates if it was an assoc expr, i.e. with an operator + /// followed by a subexpression (e.g. `1 + 2`). pub(super) fn parse_expr_assoc_with( &mut self, min_prec: usize, attrs: AttrWrapper, - ) -> PResult<'a, P<Expr>> { + ) -> PResult<'a, (P<Expr>, bool)> { let lhs = if self.token.is_range_separator() { - return self.parse_expr_prefix_range(attrs); + return self.parse_expr_prefix_range(attrs).map(|res| (res, false)); } else { self.parse_expr_prefix(attrs)? }; @@ -123,15 +140,17 @@ impl<'a> Parser<'a> { } /// Parses the rest of an associative expression (i.e. the part after the lhs) with operators - /// of at least `min_prec` precedence. + /// of at least `min_prec` precedence. The `bool` in the return value indicates if something + /// was actually parsed. pub(super) fn parse_expr_assoc_rest_with( &mut self, min_prec: usize, starts_stmt: bool, mut lhs: P<Expr>, - ) -> PResult<'a, P<Expr>> { + ) -> PResult<'a, (P<Expr>, bool)> { + let mut parsed_something = false; if !self.should_continue_as_assoc_expr(&lhs) { - return Ok(lhs); + return Ok((lhs, parsed_something)); } self.expected_tokens.push(TokenType::Operator); @@ -156,10 +175,11 @@ impl<'a> Parser<'a> { self.err_larrow_operator(self.token.span); } + parsed_something = true; self.bump(); if op.node.is_comparison() { if let Some(expr) = self.check_no_chained_comparison(&lhs, &op)? { - return Ok(expr); + return Ok((expr, parsed_something)); } } @@ -263,7 +283,7 @@ impl<'a> Parser<'a> { // the special cases. The code is here only for future convenience. Fixity::None => 1, }; - let rhs = self.with_res(restrictions - Restrictions::STMT_EXPR, |this| { + let (rhs, _) = self.with_res(restrictions - Restrictions::STMT_EXPR, |this| { let attrs = this.parse_outer_attributes()?; this.parse_expr_assoc_with(prec + prec_adjustment, attrs) })?; @@ -319,7 +339,7 @@ impl<'a> Parser<'a> { } } - Ok(lhs) + Ok((lhs, parsed_something)) } fn should_continue_as_assoc_expr(&mut self, lhs: &Expr) -> bool { @@ -441,7 +461,8 @@ impl<'a> Parser<'a> { let attrs = self.parse_outer_attributes()?; Some( self.parse_expr_assoc_with(prec + 1, attrs) - .map_err(|err| self.maybe_err_dotdotlt_syntax(maybe_lt, err))?, + .map_err(|err| self.maybe_err_dotdotlt_syntax(maybe_lt, err))? + .0, ) } else { None @@ -498,7 +519,7 @@ impl<'a> Parser<'a> { // RHS must be parsed with more associativity than the dots. let attrs = this.parse_outer_attributes()?; this.parse_expr_assoc_with(op.unwrap().precedence() + 1, attrs) - .map(|x| (lo.to(x.span), Some(x))) + .map(|(x, _)| (lo.to(x.span), Some(x))) .map_err(|err| this.maybe_err_dotdotlt_syntax(maybe_lt, err))? } else { (lo, None) @@ -2335,7 +2356,7 @@ impl<'a> Parser<'a> { let token = self.token.clone(); let attrs = self.parse_outer_attributes()?; match self.parse_expr_res(restrictions, attrs) { - Ok(expr) => expr, + Ok((expr, _)) => expr, Err(err) => self.recover_closure_body(err, before, prev, token, lo, decl_hi)?, } } @@ -2445,7 +2466,7 @@ impl<'a> Parser<'a> { fn parse_fn_block_param(&mut self) -> PResult<'a, Param> { let lo = self.token.span; let attrs = self.parse_outer_attributes()?; - self.collect_tokens_trailing_token(attrs, ForceCollect::No, |this, attrs| { + self.collect_tokens(None, attrs, ForceCollect::No, |this, attrs| { let pat = this.parse_pat_no_top_alt(Some(Expected::ParameterName), None)?; let ty = if this.eat(&token::Colon) { this.parse_ty()? @@ -2463,6 +2484,7 @@ impl<'a> Parser<'a> { is_placeholder: false, }, Trailing::from(this.token == token::Comma), + UsePreAttrPos::No, )) }) } @@ -2583,7 +2605,7 @@ impl<'a> Parser<'a> { /// Parses the condition of a `if` or `while` expression. fn parse_expr_cond(&mut self) -> PResult<'a, P<Expr>> { let attrs = self.parse_outer_attributes()?; - let mut cond = + let (mut cond, _) = self.parse_expr_res(Restrictions::NO_STRUCT_LITERAL | Restrictions::ALLOW_LET, attrs)?; CondChecker::new(self).visit_expr(&mut cond); @@ -2632,7 +2654,7 @@ impl<'a> Parser<'a> { self.expect(&token::Eq)?; } let attrs = self.parse_outer_attributes()?; - let expr = self.parse_expr_assoc_with(1 + prec_let_scrutinee_needs_par(), attrs)?; + let (expr, _) = self.parse_expr_assoc_with(1 + prec_let_scrutinee_needs_par(), attrs)?; let span = lo.to(expr.span); Ok(self.mk_expr(span, ExprKind::Let(pat, expr, span, recovered))) } @@ -2766,7 +2788,7 @@ impl<'a> Parser<'a> { // We know for sure we have seen `for ($SOMETHING in`. In the happy path this would // happen right before the return of this method. let attrs = self.parse_outer_attributes()?; - let expr = match self.parse_expr_res(Restrictions::NO_STRUCT_LITERAL, attrs) { + let (expr, _) = match self.parse_expr_res(Restrictions::NO_STRUCT_LITERAL, attrs) { Ok(expr) => expr, Err(expr_err) => { // We don't know what followed the `in`, so cancel and bubble up the @@ -2801,7 +2823,7 @@ impl<'a> Parser<'a> { } self.check_for_for_in_in_typo(self.prev_token.span); let attrs = self.parse_outer_attributes()?; - let expr = self.parse_expr_res(Restrictions::NO_STRUCT_LITERAL, attrs)?; + let (expr, _) = self.parse_expr_res(Restrictions::NO_STRUCT_LITERAL, attrs)?; Ok((pat, expr)) } @@ -2921,7 +2943,7 @@ impl<'a> Parser<'a> { fn parse_expr_match(&mut self) -> PResult<'a, P<Expr>> { let match_span = self.prev_token.span; let attrs = self.parse_outer_attributes()?; - let scrutinee = self.parse_expr_res(Restrictions::NO_STRUCT_LITERAL, attrs)?; + let (scrutinee, _) = self.parse_expr_res(Restrictions::NO_STRUCT_LITERAL, attrs)?; self.parse_match_block(match_span, match_span, scrutinee, MatchKind::Prefix) } @@ -3069,7 +3091,7 @@ impl<'a> Parser<'a> { pub(super) fn parse_arm(&mut self) -> PResult<'a, Arm> { let attrs = self.parse_outer_attributes()?; - self.collect_tokens_trailing_token(attrs, ForceCollect::No, |this, attrs| { + self.collect_tokens(None, attrs, ForceCollect::No, |this, attrs| { let lo = this.token.span; let (pat, guard) = this.parse_match_arm_pat_and_guard()?; @@ -3126,7 +3148,7 @@ impl<'a> Parser<'a> { let arm_start_span = this.token.span; let attrs = this.parse_outer_attributes()?; - let expr = + let (expr, _) = this.parse_expr_res(Restrictions::STMT_EXPR, attrs).map_err(|mut err| { err.span_label(arrow_span, "while parsing the `match` arm starting here"); err @@ -3244,6 +3266,7 @@ impl<'a> Parser<'a> { is_placeholder: false, }, Trailing::No, + UsePreAttrPos::No, )) }) } @@ -3334,8 +3357,9 @@ impl<'a> Parser<'a> { fn parse_match_guard_condition(&mut self) -> PResult<'a, P<Expr>> { let attrs = self.parse_outer_attributes()?; - self.parse_expr_res(Restrictions::ALLOW_LET | Restrictions::IN_IF_GUARD, attrs).map_err( - |mut err| { + match self.parse_expr_res(Restrictions::ALLOW_LET | Restrictions::IN_IF_GUARD, attrs) { + Ok((expr, _)) => Ok(expr), + Err(mut err) => { if self.prev_token == token::OpenDelim(Delimiter::Brace) { let sugg_sp = self.prev_token.span.shrink_to_lo(); // Consume everything within the braces, let's avoid further parse @@ -3355,9 +3379,9 @@ impl<'a> Parser<'a> { err.span_suggestion_verbose(sugg_sp, msg, "=> ", applicability); } } - err - }, - ) + Err(err) + } + } } pub(crate) fn is_builtin(&self) -> bool { @@ -3708,7 +3732,7 @@ impl<'a> Parser<'a> { fn parse_expr_field(&mut self) -> PResult<'a, ExprField> { let attrs = self.parse_outer_attributes()?; self.recover_vcs_conflict_marker(); - self.collect_tokens_trailing_token(attrs, ForceCollect::No, |this, attrs| { + self.collect_tokens(None, attrs, ForceCollect::No, |this, attrs| { let lo = this.token.span; // Check if a colon exists one ahead. This means we're parsing a fieldname. @@ -3753,6 +3777,7 @@ impl<'a> Parser<'a> { is_placeholder: false, }, Trailing::from(this.token == token::Comma), + UsePreAttrPos::No, )) }) } @@ -3846,7 +3871,7 @@ impl<'a> Parser<'a> { attrs: AttrWrapper, f: impl FnOnce(&mut Self, ast::AttrVec) -> PResult<'a, P<Expr>>, ) -> PResult<'a, P<Expr>> { - self.collect_tokens_trailing_token(attrs, ForceCollect::No, |this, attrs| { + self.collect_tokens(None, attrs, ForceCollect::No, |this, attrs| { let res = f(this, attrs)?; let trailing = Trailing::from( this.restrictions.contains(Restrictions::STMT_EXPR) @@ -3856,7 +3881,7 @@ impl<'a> Parser<'a> { // `#[attr] expr,` always captures a trailing comma. || this.token == token::Comma, ); - Ok((res, trailing)) + Ok((res, trailing, UsePreAttrPos::No)) }) } } |