From 090be5eeaae8a3089bf92d6b4d9652ee9363af60 Mon Sep 17 00:00:00 2001
From: mu001999 <mu001999@outlook.com>
Date: Wed, 11 Mar 2026 23:40:02 +0800
Subject: [PATCH] Replacing `self` overwriting with proper resolution

---
 .../rustc_resolve/src/build_reduced_graph.rs  | 58 ++++++++++---------
 compiler/rustc_resolve/src/ident.rs           | 18 +++---
 2 files changed, 42 insertions(+), 34 deletions(-)

diff --git a/compiler/rustc_resolve/src/build_reduced_graph.rs b/compiler/rustc_resolve/src/build_reduced_graph.rs
index d00c306329b7..910d9c909f96 100644
--- a/compiler/rustc_resolve/src/build_reduced_graph.rs
+++ b/compiler/rustc_resolve/src/build_reduced_graph.rs
@@ -626,42 +626,42 @@ fn build_reduced_graph_for_use_tree(
 
         match use_tree.kind {
             ast::UseTreeKind::Simple(rename) => {
-                let mut ident = use_tree.ident();
                 let mut module_path = prefix;
-                let mut source = module_path.pop().unwrap();
+                let source = module_path.pop().unwrap();
 
                 // `true` for `...::{self [as target]}` imports, `false` otherwise.
                 let type_ns_only = nested && source.ident.name == kw::SelfLower;
 
+                // Suggest `use prefix::{self};` for `use prefix::self;`
                 if source.ident.name == kw::SelfLower
-                    && let Some(parent) = module_path.pop()
+                    && let Some(parent) = module_path.last()
+                    && !type_ns_only
+                    && (parent.ident.name != kw::PathRoot
+                        || self.r.path_root_is_crate_root(parent.ident))
                 {
-                    // Suggest `use prefix::{self};` for `use prefix::self;`
-                    if !type_ns_only
-                        && (parent.ident.name != kw::PathRoot
-                            || self.r.path_root_is_crate_root(parent.ident))
-                    {
-                        let span_with_rename = match rename {
-                            Some(rename) => source.ident.span.to(rename.span),
-                            None => source.ident.span,
-                        };
+                    let span_with_rename = match rename {
+                        Some(rename) => source.ident.span.to(rename.span),
+                        None => source.ident.span,
+                    };
 
-                        self.r.report_error(
-                            parent.ident.span.shrink_to_hi().to(source.ident.span),
-                            ResolutionError::SelfImportsOnlyAllowedWithin {
-                                root: parent.ident.name == kw::PathRoot,
-                                span_with_rename,
-                            },
-                        );
-                    }
-
-                    let self_span = source.ident.span;
-                    source = parent;
-                    if rename.is_none() {
-                        ident = Ident::new(source.ident.name, self_span);
-                    }
+                    self.r.report_error(
+                        parent.ident.span.shrink_to_hi().to(source.ident.span),
+                        ResolutionError::SelfImportsOnlyAllowedWithin {
+                            root: parent.ident.name == kw::PathRoot,
+                            span_with_rename,
+                        },
+                    );
                 }
 
+                let ident = if source.ident.name == kw::SelfLower
+                    && rename.is_none()
+                    && let Some(parent) = module_path.last()
+                {
+                    Ident::new(parent.ident.name, source.ident.span)
+                } else {
+                    use_tree.ident()
+                };
+
                 match source.ident.name {
                     kw::DollarCrate => {
                         if !module_path.is_empty() {
@@ -698,7 +698,11 @@ fn build_reduced_graph_for_use_tree(
                         }
                     }
                     // Deny `use ::{self};` after edition 2015
-                    kw::PathRoot if !self.r.path_root_is_crate_root(source.ident) => {
+                    kw::SelfLower
+                        if let Some(parent) = module_path.last()
+                            && parent.ident.name == kw::PathRoot
+                            && !self.r.path_root_is_crate_root(parent.ident) =>
+                    {
                         self.r.dcx().span_err(use_tree.span(), "extern prelude cannot be imported");
                         return;
                     }
diff --git a/compiler/rustc_resolve/src/ident.rs b/compiler/rustc_resolve/src/ident.rs
index 95d68e2f8b39..46b4a3aa2586 100644
--- a/compiler/rustc_resolve/src/ident.rs
+++ b/compiler/rustc_resolve/src/ident.rs
@@ -959,12 +959,16 @@ pub(crate) fn resolve_ident_in_module<'r>(
     ) -> Result<Decl<'ra>, Determinacy> {
         match module {
             ModuleOrUniformRoot::Module(module) => {
-                if ns == TypeNS
-                    && ident.name == kw::Super
-                    && let Some(module) =
-                        self.resolve_super_in_module(ident, Some(module), parent_scope)
-                {
-                    return Ok(module.self_decl.unwrap());
+                if ns == TypeNS {
+                    if ident.name == kw::SelfLower {
+                        return Ok(module.self_decl.unwrap());
+                    }
+                    if ident.name == kw::Super
+                        && let Some(module) =
+                            self.resolve_super_in_module(ident, Some(module), parent_scope)
+                    {
+                        return Ok(module.self_decl.unwrap());
+                    }
                 }
 
                 let (ident_key, def) = IdentKey::new_adjusted(ident, module.expansion);
@@ -1032,7 +1036,7 @@ pub(crate) fn resolve_ident_in_module<'r>(
                     {
                         let module = self.resolve_crate_root(ident);
                         return Ok(module.self_decl.unwrap());
-                    } else if ident.name == kw::Super || ident.name == kw::SelfLower {
+                    } else if ident.name == kw::Super {
                         // FIXME: Implement these with renaming requirements so that e.g.
                         // `use super;` doesn't work, but `use super as name;` does.
                         // Fall through here to get an error from `early_resolve_...`.