Merge pull request rust-lang#18977 from ChayimFriedman2/fix-upmapping

fix: Fix missing upmapping in trait impls completion

Author: Veykril

src/tools/rust-analyzer/crates/ide-completion/src/completions/item_list/trait_impl.rs

@@ -85,7 +85,7 @@ fn complete_trait_impl_name(
     name: &Option<ast::Name>,
     kind: ImplCompletionKind,
 ) -> Option<()> {
-    let item = match name {
+    let macro_file_item = match name {
         Some(name) => name.syntax().parent(),
         None => {
             let token = &ctx.token;
@@ -96,20 +96,20 @@ fn complete_trait_impl_name(
             .parent()
         }
     }?;
-    let item = ctx.sema.original_syntax_node_rooted(&item)?;
+    let real_file_item = ctx.sema.original_syntax_node_rooted(&macro_file_item)?;
     // item -> ASSOC_ITEM_LIST -> IMPL
-    let impl_def = ast::Impl::cast(item.parent()?.parent()?)?;
+    let impl_def = ast::Impl::cast(macro_file_item.parent()?.parent()?)?;
     let replacement_range = {
         // ctx.sema.original_ast_node(item)?;
-        let first_child = item
+        let first_child = real_file_item
             .children_with_tokens()
             .find(|child| {
                 !matches!(
                     child.kind(),
                     SyntaxKind::COMMENT | SyntaxKind::WHITESPACE | SyntaxKind::ATTR
                 )
             })
-            .unwrap_or_else(|| SyntaxElement::Node(item.clone()));
+            .unwrap_or_else(|| SyntaxElement::Node(real_file_item.clone()));
 
         TextRange::new(first_child.text_range().start(), ctx.source_range().end())
     };
@@ -133,8 +133,11 @@ pub(crate) fn complete_trait_impl_item_by_name(
             acc,
             ctx,
             ImplCompletionKind::All,
-            match name_ref {
-                Some(name) => name.syntax().text_range(),
+            match name_ref
+                .as_ref()
+                .and_then(|name| ctx.sema.original_syntax_node_rooted(name.syntax()))
+            {
+                Some(name) => name.text_range(),
                 None => ctx.source_range(),
             },
             impl_,
@@ -516,7 +519,7 @@ fn function_declaration(
 mod tests {
     use expect_test::expect;
 
-    use crate::tests::{check_edit, check_no_kw};
+    use crate::tests::{check, check_edit, check_no_kw};
 
     #[test]
     fn no_completion_inside_fn() {
@@ -1639,4 +1642,51 @@ impl DesugaredAsyncTrait for () {
 "#,
         );
     }
+
+    #[test]
+    fn within_attr_macro() {
+        check(
+            r#"
+//- proc_macros: identity
+trait Trait {
+    fn foo(&self) {}
+    fn bar(&self) {}
+    fn baz(&self) {}
+}
+
+#[proc_macros::identity]
+impl Trait for () {
+    f$0
+}
+                "#,
+            expect![[r#"
+                me fn bar(..)
+                me fn baz(..)
+                me fn foo(..)
+                md proc_macros
+                kw crate::
+                kw self::
+            "#]],
+        );
+        check(
+            r#"
+//- proc_macros: identity
+trait Trait {
+    fn foo(&self) {}
+    fn bar(&self) {}
+    fn baz(&self) {}
+}
+
+#[proc_macros::identity]
+impl Trait for () {
+    fn $0
+}
+        "#,
+            expect![[r#"
+                me fn bar(..)
+                me fn baz(..)
+                me fn foo(..)
+            "#]],
+        );
+    }
 }

src/tools/rust-analyzer/crates/ide-completion/src/context/analysis.rs

@@ -5,7 +5,7 @@ use hir::{ExpandResult, Semantics, Type, TypeInfo, Variant};
 use ide_db::{active_parameter::ActiveParameter, RootDatabase};
 use itertools::Either;
 use syntax::{
-    algo::{ancestors_at_offset, find_node_at_offset, non_trivia_sibling},
+    algo::{self, ancestors_at_offset, find_node_at_offset, non_trivia_sibling},
     ast::{
         self, AttrKind, HasArgList, HasGenericArgs, HasGenericParams, HasLoopBody, HasName,
         NameOrNameRef,
@@ -85,6 +85,11 @@ pub(super) fn expand_and_analyze(
     })
 }
 
+fn token_at_offset_ignore_whitespace(file: &SyntaxNode, offset: TextSize) -> Option<SyntaxToken> {
+    let token = file.token_at_offset(offset).left_biased()?;
+    algo::skip_whitespace_token(token, Direction::Prev)
+}
+
 /// Expand attributes and macro calls at the current cursor position for both the original file
 /// and fake file repeatedly. As soon as one of the two expansions fail we stop so the original
 /// and speculative states stay in sync.
@@ -125,9 +130,7 @@ fn expand(
 
     // Left biased since there may already be an identifier token there, and we appended to it.
     if !sema.might_be_inside_macro_call(&fake_ident_token)
-        && original_file
-            .token_at_offset(original_offset + relative_offset)
-            .left_biased()
+        && token_at_offset_ignore_whitespace(&original_file, original_offset + relative_offset)
             .is_some_and(|original_token| !sema.might_be_inside_macro_call(&original_token))
     {
         // Recursion base case.
@@ -143,9 +146,11 @@ fn expand(
 
     let parent_item =
         |item: &ast::Item| item.syntax().ancestors().skip(1).find_map(ast::Item::cast);
+    let original_node = token_at_offset_ignore_whitespace(&original_file, original_offset)
+        .and_then(|token| token.parent_ancestors().find_map(ast::Item::cast));
     let ancestor_items = iter::successors(
         Option::zip(
-            find_node_at_offset::<ast::Item>(&original_file, original_offset),
+            original_node,
             find_node_at_offset::<ast::Item>(
                 &speculative_file,
                 fake_ident_token.text_range().start(),