From 5af861cf7b4a87857ca6aa9dab2ad277ea8c059b Mon Sep 17 00:00:00 2001
From: Dominik Stolz <d.stolz@tum.de>
Date: Wed, 17 Apr 2024 23:40:03 +0200
Subject: Disallow ambiguous attributes on expressions

---
 compiler/rustc_parse/src/parser/expr.rs | 32 +++++++++++++++++++-------------
 1 file changed, 19 insertions(+), 13 deletions(-)

(limited to 'compiler/rustc_parse/src/parser')

diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs
index 00947a4c585..1625173970a 100644
--- a/compiler/rustc_parse/src/parser/expr.rs
+++ b/compiler/rustc_parse/src/parser/expr.rs
@@ -327,7 +327,9 @@ impl<'a> Parser<'a> {
                 this.parse_expr_assoc_with(prec + prec_adjustment, LhsExpr::NotYetParsed)
             })?;
 
-            let span = self.mk_expr_sp(&lhs, lhs_span, rhs.span);
+            self.error_ambiguous_outer_attrs(&lhs, lhs_span, rhs.span);
+            let span = lhs_span.to(rhs.span);
+
             lhs = match op {
                 AssocOp::Add
                 | AssocOp::Subtract
@@ -426,6 +428,18 @@ impl<'a> Parser<'a> {
         });
     }
 
+    fn error_ambiguous_outer_attrs(&self, lhs: &P<Expr>, lhs_span: Span, rhs_span: Span) {
+        if let Some(attr) = lhs.attrs.iter().find(|a| a.style == AttrStyle::Outer) {
+            self.dcx().emit_err(errors::AmbiguousOuterAttributes {
+                span: attr.span.to(rhs_span),
+                sugg: errors::WrapInParentheses::Expression {
+                    left: attr.span.shrink_to_lo(),
+                    right: lhs_span.shrink_to_hi(),
+                },
+            });
+        }
+    }
+
     /// Possibly translate the current token to an associative operator.
     /// The method does not advance the current token.
     ///
@@ -506,7 +520,8 @@ impl<'a> Parser<'a> {
             None
         };
         let rhs_span = rhs.as_ref().map_or(cur_op_span, |x| x.span);
-        let span = self.mk_expr_sp(&lhs, lhs.span, rhs_span);
+        self.error_ambiguous_outer_attrs(&lhs, lhs.span, rhs_span);
+        let span = lhs.span.to(rhs_span);
         let limits =
             if op == AssocOp::DotDot { RangeLimits::HalfOpen } else { RangeLimits::Closed };
         let range = self.mk_range(Some(lhs), rhs, limits);
@@ -722,7 +737,8 @@ impl<'a> Parser<'a> {
         expr_kind: fn(P<Expr>, P<Ty>) -> ExprKind,
     ) -> PResult<'a, P<Expr>> {
         let mk_expr = |this: &mut Self, lhs: P<Expr>, rhs: P<Ty>| {
-            this.mk_expr(this.mk_expr_sp(&lhs, lhs_span, rhs.span), expr_kind(lhs, rhs))
+            this.error_ambiguous_outer_attrs(&lhs, lhs_span, rhs.span);
+            this.mk_expr(lhs_span.to(rhs.span), expr_kind(lhs, rhs))
         };
 
         // Save the state of the parser before parsing type normally, in case there is a
@@ -3807,16 +3823,6 @@ impl<'a> Parser<'a> {
         self.mk_expr(span, ExprKind::Err(guar))
     }
 
-    /// Create expression span ensuring the span of the parent node
-    /// is larger than the span of lhs and rhs, including the attributes.
-    fn mk_expr_sp(&self, lhs: &P<Expr>, lhs_span: Span, rhs_span: Span) -> Span {
-        lhs.attrs
-            .iter()
-            .find(|a| a.style == AttrStyle::Outer)
-            .map_or(lhs_span, |a| a.span)
-            .to(rhs_span)
-    }
-
     fn collect_tokens_for_expr(
         &mut self,
         attrs: AttrWrapper,
-- 
cgit 1.4.1-3-g733a5


From 9bd175c8a206cabbca2818d9cf509939b95301a8 Mon Sep 17 00:00:00 2001
From: klensy <klensy@users.noreply.github.com>
Date: Tue, 23 Apr 2024 11:23:20 +0300
Subject: parser: remove ununsed(no reads) max_angle_bracket_count field

---
 compiler/rustc_parse/src/parser/mod.rs  | 3 ---
 compiler/rustc_parse/src/parser/path.rs | 1 -
 2 files changed, 4 deletions(-)

(limited to 'compiler/rustc_parse/src/parser')

diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs
index 4a996f89a9a..cd8a5600c73 100644
--- a/compiler/rustc_parse/src/parser/mod.rs
+++ b/compiler/rustc_parse/src/parser/mod.rs
@@ -162,7 +162,6 @@ pub struct Parser<'a> {
     ///
     /// See the comments in the `parse_path_segment` function for more details.
     unmatched_angle_bracket_count: u16,
-    max_angle_bracket_count: u16,
     angle_bracket_nesting: u16,
 
     last_unexpected_token_span: Option<Span>,
@@ -430,7 +429,6 @@ impl<'a> Parser<'a> {
             num_bump_calls: 0,
             break_last_token: false,
             unmatched_angle_bracket_count: 0,
-            max_angle_bracket_count: 0,
             angle_bracket_nesting: 0,
             last_unexpected_token_span: None,
             subparser_name,
@@ -778,7 +776,6 @@ impl<'a> Parser<'a> {
         if ate {
             // See doc comment for `unmatched_angle_bracket_count`.
             self.unmatched_angle_bracket_count += 1;
-            self.max_angle_bracket_count += 1;
             debug!("eat_lt: (increment) count={:?}", self.unmatched_angle_bracket_count);
         }
         ate
diff --git a/compiler/rustc_parse/src/parser/path.rs b/compiler/rustc_parse/src/parser/path.rs
index 0f410772dd9..b97ec8c613d 100644
--- a/compiler/rustc_parse/src/parser/path.rs
+++ b/compiler/rustc_parse/src/parser/path.rs
@@ -299,7 +299,6 @@ impl<'a> Parser<'a> {
                 // parsing a new path.
                 if style == PathStyle::Expr {
                     self.unmatched_angle_bracket_count = 0;
-                    self.max_angle_bracket_count = 0;
                 }
 
                 // Generic arguments are found - `<`, `(`, `::<` or `::(`.
-- 
cgit 1.4.1-3-g733a5