From 31d289c9bc0bea53942cea6ccca760db53e6e3bd Mon Sep 17 00:00:00 2001
From: Jonathan Brouwer <jonathantbrouwer@gmail.com>
Date: Tue, 2 Dec 2025 19:42:41 +0100
Subject: [PATCH] Lower spans in `AttrPath` correctly

---
 compiler/rustc_attr_parsing/src/attributes/cfg.rs |  4 +++-
 compiler/rustc_attr_parsing/src/interface.rs      |  8 ++++----
 compiler/rustc_attr_parsing/src/validate_attr.rs  |  3 ++-
 compiler/rustc_hir/src/hir.rs                     | 11 ++++++++---
 4 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/compiler/rustc_attr_parsing/src/attributes/cfg.rs b/compiler/rustc_attr_parsing/src/attributes/cfg.rs
index e47fa075fbf7..bd228315b2c9 100644
--- a/compiler/rustc_attr_parsing/src/attributes/cfg.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/cfg.rs
@@ -1,3 +1,5 @@
+use std::convert::identity;
+
 use rustc_ast::token::Delimiter;
 use rustc_ast::tokenstream::DelimSpan;
 use rustc_ast::{AttrItem, Attribute, CRATE_NODE_ID, LitKind, NodeId, ast, token};
@@ -353,7 +355,7 @@ pub fn parse_cfg_attr(
                 span,
                 attr_span: cfg_attr.span,
                 template: CFG_ATTR_TEMPLATE,
-                path: AttrPath::from_ast(&cfg_attr.get_normal_item().path),
+                path: AttrPath::from_ast(&cfg_attr.get_normal_item().path, identity),
                 description: ParsedDescription::Attribute,
                 reason,
                 suggestions: CFG_ATTR_TEMPLATE
diff --git a/compiler/rustc_attr_parsing/src/interface.rs b/compiler/rustc_attr_parsing/src/interface.rs
index c6d8411e8356..87e29b7b0de6 100644
--- a/compiler/rustc_attr_parsing/src/interface.rs
+++ b/compiler/rustc_attr_parsing/src/interface.rs
@@ -300,9 +300,10 @@ impl<'sess, S: Stage> AttributeParser<'sess, S> {
                 // }
                 ast::AttrKind::Normal(n) => {
                     attr_paths.push(PathParser(Cow::Borrowed(&n.item.path)));
+                    let attr_path = AttrPath::from_ast(&n.item.path, lower_span);
 
                     self.check_attribute_safety(
-                        &AttrPath::from_ast(&n.item.path),
+                        &attr_path,
                         lower_span(n.item.span()),
                         n.item.unsafety,
                         &mut emit_lint,
@@ -321,7 +322,6 @@ impl<'sess, S: Stage> AttributeParser<'sess, S> {
                         ) else {
                             continue;
                         };
-                        let path = parser.path();
                         let args = parser.args();
                         for accept in accepts {
                             let mut cx: AcceptContext<'_, 'sess, S> = AcceptContext {
@@ -336,7 +336,7 @@ impl<'sess, S: Stage> AttributeParser<'sess, S> {
                                 attr_style: attr.style,
                                 parsed_description: ParsedDescription::Attribute,
                                 template: &accept.template,
-                                attr_path: path.get_attribute_path(),
+                                attr_path: attr_path.clone(),
                             };
 
                             (accept.accept_fn)(&mut cx, args);
@@ -361,7 +361,7 @@ impl<'sess, S: Stage> AttributeParser<'sess, S> {
                         // );
 
                         attributes.push(Attribute::Unparsed(Box::new(AttrItem {
-                            path: AttrPath::from_ast(&n.item.path),
+                            path: attr_path.clone(),
                             args: self.lower_attr_args(&n.item.args, lower_span),
                             id: HashIgnoredAttrId { attr_id: attr.id },
                             style: attr.style,
diff --git a/compiler/rustc_attr_parsing/src/validate_attr.rs b/compiler/rustc_attr_parsing/src/validate_attr.rs
index 9034fe45427f..c57e0baea05f 100644
--- a/compiler/rustc_attr_parsing/src/validate_attr.rs
+++ b/compiler/rustc_attr_parsing/src/validate_attr.rs
@@ -1,5 +1,6 @@
 //! Meta-syntax validation logic of attributes for post-expansion.
 
+use std::convert::identity;
 use std::slice;
 
 use rustc_ast::token::Delimiter;
@@ -163,7 +164,7 @@ pub fn check_builtin_meta_item(
     if deny_unsafety && let Safety::Unsafe(unsafe_span) = meta.unsafety {
         psess.dcx().emit_err(errors::InvalidAttrUnsafe {
             span: unsafe_span,
-            name: AttrPath::from_ast(&meta.path),
+            name: AttrPath::from_ast(&meta.path, identity),
         });
     }
 }
diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs
index 8f297677ff85..94c47b06e635 100644
--- a/compiler/rustc_hir/src/hir.rs
+++ b/compiler/rustc_hir/src/hir.rs
@@ -1193,10 +1193,15 @@ impl IntoDiagArg for AttrPath {
 }
 
 impl AttrPath {
-    pub fn from_ast(path: &ast::Path) -> Self {
+    pub fn from_ast(path: &ast::Path, lower_span: impl Copy + Fn(Span) -> Span) -> Self {
         AttrPath {
-            segments: path.segments.iter().map(|i| i.ident).collect::<Vec<_>>().into_boxed_slice(),
-            span: path.span,
+            segments: path
+                .segments
+                .iter()
+                .map(|i| Ident { name: i.ident.name, span: lower_span(i.ident.span) })
+                .collect::<Vec<_>>()
+                .into_boxed_slice(),
+            span: lower_span(path.span),
         }
     }
 }