Properly implement `might_be_inside_macro_call()` using semantic information instead of syntactical hacks

And rename it to `is_inside_macro_call()` accordingly.

3 files changed, 69 insertions, 20 deletions

diff --git a/src/tools/rust-analyzer/crates/ide-completion/src/context.rs b/src/tools/rust-analyzer/crates/ide-completion/src/context.rs
index 3baf1f3de61..5287627790a 100644
--- a/src/tools/rust-analyzer/crates/ide-completion/src/context.rs
+++ b/src/tools/rust-analyzer/crates/ide-completion/src/context.rs
@@ -8,8 +8,8 @@ use std::{iter, ops::ControlFlow};
 
 use base_db::RootQueryDb as _;
 use hir::{
-    DisplayTarget, HasAttrs, Local, ModuleDef, ModuleSource, Name, PathResolution, ScopeDef,
-    Semantics, SemanticsScope, Symbol, Type, TypeInfo,
+    DisplayTarget, HasAttrs, InFile, Local, ModuleDef, ModuleSource, Name, PathResolution,
+    ScopeDef, Semantics, SemanticsScope, Symbol, Type, TypeInfo,
 };
 use ide_db::{
     FilePosition, FxHashMap, FxHashSet, RootDatabase, famous_defs::FamousDefs,
@@ -751,7 +751,7 @@ impl<'a> CompletionContext<'a> {
             original_offset,
         } = expand_and_analyze(
             &sema,
-            original_file.syntax().clone(),
+            InFile::new(editioned_file_id.into(), original_file.syntax().clone()),
             file_with_fake_ident.syntax().clone(),
             offset,
             &original_token,
diff --git a/src/tools/rust-analyzer/crates/ide-completion/src/context/analysis.rs b/src/tools/rust-analyzer/crates/ide-completion/src/context/analysis.rs
index 284876ffc88..7a2230b3e36 100644
--- a/src/tools/rust-analyzer/crates/ide-completion/src/context/analysis.rs
+++ b/src/tools/rust-analyzer/crates/ide-completion/src/context/analysis.rs
@@ -1,7 +1,7 @@
 //! Module responsible for analyzing the code surrounding the cursor for completion.
 use std::iter;
 
-use hir::{ExpandResult, Semantics, Type, TypeInfo, Variant};
+use hir::{ExpandResult, InFile, Semantics, Type, TypeInfo, Variant};
 use ide_db::{RootDatabase, active_parameter::ActiveParameter};
 use itertools::Either;
 use syntax::{
@@ -50,7 +50,7 @@ pub(super) struct AnalysisResult {
 
 pub(super) fn expand_and_analyze(
     sema: &Semantics<'_, RootDatabase>,
-    original_file: SyntaxNode,
+    original_file: InFile<SyntaxNode>,
     speculative_file: SyntaxNode,
     offset: TextSize,
     original_token: &SyntaxToken,
@@ -72,7 +72,7 @@ pub(super) fn expand_and_analyze(
         relative_offset,
     )
     .unwrap_or(ExpansionResult {
-        original_file,
+        original_file: original_file.value,
         speculative_file,
         original_offset: offset,
         speculative_offset: fake_ident_token.text_range().start(),
@@ -125,7 +125,7 @@ fn token_at_offset_ignore_whitespace(file: &SyntaxNode, offset: TextSize) -> Opt
 /// the best we can do.
 fn expand_maybe_stop(
     sema: &Semantics<'_, RootDatabase>,
-    original_file: SyntaxNode,
+    original_file: InFile<SyntaxNode>,
     speculative_file: SyntaxNode,
     original_offset: TextSize,
     fake_ident_token: SyntaxToken,
@@ -142,17 +142,16 @@ fn expand_maybe_stop(
         return result;
     }
 
-    // This needs to come after the recursive call, because our "inside macro" detection is subtly wrong
-    // with regard to attribute macros named `test` that are not std's test. So hopefully we will expand
-    // them successfully above and be able to analyze.
-    // 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)
-        && token_at_offset_ignore_whitespace(&original_file, original_offset + relative_offset)
-            .is_some_and(|original_token| !sema.might_be_inside_macro_call(&original_token))
+    // We can't check whether the fake expansion is inside macro call, because that requires semantic info.
+    // But hopefully checking just the real one should be enough.
+    if token_at_offset_ignore_whitespace(&original_file.value, original_offset + relative_offset)
+        .is_some_and(|original_token| {
+            !sema.is_inside_macro_call(original_file.with_value(&original_token))
+        })
     {
         // Recursion base case.
         Some(ExpansionResult {
-            original_file,
+            original_file: original_file.value,
             speculative_file,
             original_offset,
             speculative_offset: fake_ident_token.text_range().start(),
@@ -166,7 +165,7 @@ fn expand_maybe_stop(
 
 fn expand(
     sema: &Semantics<'_, RootDatabase>,
-    original_file: SyntaxNode,
+    original_file: InFile<SyntaxNode>,
     speculative_file: SyntaxNode,
     original_offset: TextSize,
     fake_ident_token: SyntaxToken,
@@ -176,7 +175,7 @@ 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)
+    let original_node = token_at_offset_ignore_whitespace(&original_file.value, original_offset)
         .and_then(|token| token.parent_ancestors().find_map(ast::Item::cast));
     let ancestor_items = iter::successors(
         Option::zip(
@@ -249,7 +248,7 @@ fn expand(
     }
 
     // No attributes have been expanded, so look for macro_call! token trees or derive token trees
-    let orig_tt = ancestors_at_offset(&original_file, original_offset)
+    let orig_tt = ancestors_at_offset(&original_file.value, original_offset)
         .map_while(Either::<ast::TokenTree, ast::Meta>::cast)
         .last()?;
     let spec_tt = ancestors_at_offset(&speculative_file, fake_ident_token.text_range().start())
@@ -292,7 +291,7 @@ fn expand(
                 fake_mapped_tokens.into_iter().min_by_key(|(_, rank)| *rank)
             {
                 return Some(ExpansionResult {
-                    original_file,
+                    original_file: original_file.value,
                     speculative_file,
                     original_offset,
                     speculative_offset: fake_ident_token.text_range().start(),
@@ -349,7 +348,7 @@ fn expand(
                                 }
                                 let result = expand_maybe_stop(
                                     sema,
-                                    actual_expansion.clone(),
+                                    InFile::new(file.into(), actual_expansion.clone()),
                                     fake_expansion.clone(),
                                     new_offset,
                                     fake_mapped_token,
diff --git a/src/tools/rust-analyzer/crates/ide-completion/src/tests/expression.rs b/src/tools/rust-analyzer/crates/ide-completion/src/tests/expression.rs
index e5467767d42..b46e4c32061 100644
--- a/src/tools/rust-analyzer/crates/ide-completion/src/tests/expression.rs
+++ b/src/tools/rust-analyzer/crates/ide-completion/src/tests/expression.rs
@@ -2112,6 +2112,56 @@ fn foo() {
 }
 
 #[test]
+fn cfg_attr_attr_macro() {
+    check(
+        r#"
+//- proc_macros: identity
+#[cfg_attr(test, proc_macros::identity)]
+fn foo() {
+    $0
+}
+    "#,
+        expect![[r#"
+            fn foo()  fn()
+            md proc_macros
+            bt u32     u32
+            kw async
+            kw const
+            kw crate::
+            kw enum
+            kw extern
+            kw false
+            kw fn
+            kw for
+            kw if
+            kw if let
+            kw impl
+            kw impl for
+            kw let
+            kw letm
+            kw loop
+            kw match
+            kw mod
+            kw return
+            kw self::
+            kw static
+            kw struct
+            kw trait
+            kw true
+            kw type
+            kw union
+            kw unsafe
+            kw use
+            kw while
+            kw while let
+            sn macro_rules
+            sn pd
+            sn ppd
+        "#]],
+    );
+}
+
+#[test]
 fn escaped_label() {
     check(
         r#"