X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=compiler%2Frustc_parse%2Fsrc%2Fparser%2Fnonterminal.rs;h=5635fbbb978ea00413b3ecc1e88ef73643956afe;hb=0566ccc72fc49e0a30fedebca754c8cc10bb1a73;hp=fc25e883666d1f85f2d9ea5059b6b5561e3c01fc;hpb=f5fe425c925ef36d5f4c18cfa44173fc42de31b8;p=rust.git

diff --git a/compiler/rustc_parse/src/parser/nonterminal.rs b/compiler/rustc_parse/src/parser/nonterminal.rs
index fc25e883666..5635fbbb978 100644
--- a/compiler/rustc_parse/src/parser/nonterminal.rs
+++ b/compiler/rustc_parse/src/parser/nonterminal.rs
@@ -61,7 +61,8 @@ fn may_be_ident(nt: &token::Nonterminal) -> bool {
                 },
                 _ => false,
             },
-            NonterminalKind::Pat2015 { .. } | NonterminalKind::Pat2021 { .. } => match token.kind {
+            NonterminalKind::PatParam { .. } | NonterminalKind::Pat2021 { .. } => {
+                match token.kind {
                 token::Ident(..) |                  // box, ref, mut, and other identifiers (can stricten)
                 token::OpenDelim(token::Paren) |    // tuple pattern
                 token::OpenDelim(token::Bracket) |  // slice pattern
@@ -78,7 +79,8 @@ fn may_be_ident(nt: &token::Nonterminal) -> bool {
                 token::BinOp(token::Or) =>  matches!(kind, NonterminalKind::Pat2021 {..}),
                 token::Interpolated(ref nt) => may_be_ident(nt),
                 _ => false,
-            },
+            }
+            }
             NonterminalKind::Lifetime => match token.kind {
                 token::Lifetime(_) => true,
                 token::Interpolated(ref nt) => {
@@ -118,9 +120,9 @@ pub fn parse_nonterminal(&mut self, kind: NonterminalKind) -> PResult<'a, Nonter
                     return Err(self.struct_span_err(self.token.span, "expected a statement"));
                 }
             },
-            NonterminalKind::Pat2015 { .. } | NonterminalKind::Pat2021 { .. } => {
+            NonterminalKind::PatParam { .. } | NonterminalKind::Pat2021 { .. } => {
                 token::NtPat(self.collect_tokens_no_attrs(|this| match kind {
-                    NonterminalKind::Pat2015 { .. } => this.parse_pat_no_top_alt(None),
+                    NonterminalKind::PatParam { .. } => this.parse_pat_no_top_alt(None),
                     NonterminalKind::Pat2021 { .. } => {
                         this.parse_pat_allow_top_alt(None, RecoverComma::No)
                     }
@@ -128,22 +130,7 @@ pub fn parse_nonterminal(&mut self, kind: NonterminalKind) -> PResult<'a, Nonter
                 })?)
             }
 
-            // If there are attributes present, then `parse_expr` will end up collecting tokens,
-            // turning the outer `collect_tokens_no_attrs` into a no-op due to the already present
-            // tokens. If there are *not* attributes present, then the outer
-            // `collect_tokens_no_attrs` will ensure that we will end up collecting tokens for the
-            // expressions.
-            //
-            // This is less efficient than it could be, since the outer `collect_tokens_no_attrs`
-            // still needs to snapshot the `TokenCursor` before calling `parse_expr`, even when
-            // `parse_expr` will end up collecting tokens. Ideally, this would work more like
-            // `parse_item`, and take in a `ForceCollect` parameter. However, this would require
-            // adding a `ForceCollect` parameter in a bunch of places in expression parsing
-            // for little gain. If the perf impact from this turns out to be noticeable, we should
-            // revisit this apporach.
-            NonterminalKind::Expr => {
-                token::NtExpr(self.collect_tokens_no_attrs(|this| this.parse_expr())?)
-            }
+            NonterminalKind::Expr => token::NtExpr(self.parse_expr_force_collect()?),
             NonterminalKind::Literal => {
                 // The `:literal` matcher does not support attributes
                 token::NtLiteral(
@@ -168,9 +155,7 @@ pub fn parse_nonterminal(&mut self, kind: NonterminalKind) -> PResult<'a, Nonter
             NonterminalKind::Path => token::NtPath(
                 self.collect_tokens_no_attrs(|this| this.parse_path(PathStyle::Type))?,
             ),
-            NonterminalKind::Meta => {
-                token::NtMeta(P(self.collect_tokens_no_attrs(|this| this.parse_attr_item(false))?))
-            }
+            NonterminalKind::Meta => token::NtMeta(P(self.parse_attr_item(true)?)),
             NonterminalKind::TT => token::NtTT(self.parse_token_tree()),
             NonterminalKind::Vis => token::NtVis(
                 self.collect_tokens_no_attrs(|this| this.parse_visibility(FollowedByType::Yes))?,