Merge #8776

8776: fix: fix unnecessary recomputations due to macros r=jonas-schievink a=jonas-schievink

This computes a macro's fragment kind eagerly (when the calling file is still available in parsed form) and stores it in the `MacroCallLoc`. This means that during expansion we no longer have to reparse the file containing the macro call, avoiding the unnecessary salsa dependencies (https://github.com/rust-analyzer/rust-analyzer/pull/8746#issuecomment-834776349).

Marking as draft until I manage to find a test for this problem, since for some reason `typing_inside_a_function_should_not_invalidate_expansions` does not catch this (which might indicate that I misunderstand the problem).

I've manually confirmed that this fixes the issue described in https://github.com/rust-analyzer/rust-analyzer/pull/8746#issuecomment-834776349:

```
    7ms - parse_query @ FileId(179)
   12ms - SourceBinder::to_module_def
       12ms - crate_def_map:wait
            5ms - item_tree_query (1 calls)
            7ms - ???
```

Co-authored-by: Jonas Schievink <[email protected]>

1 files changed, 10 insertions, 2 deletions

diff --git a/crates/hir_def/src/lib.rs b/crates/hir_def/src/lib.rs
index da46f16f7..e96ca953f 100644
--- a/crates/hir_def/src/lib.rs
+++ b/crates/hir_def/src/lib.rs
@@ -62,7 +62,8 @@ use hir_expand::{
     ast_id_map::FileAstId,
     eager::{expand_eager_macro, ErrorEmitted, ErrorSink},
     hygiene::Hygiene,
-    AstId, AttrId, HirFileId, InFile, MacroCallId, MacroCallKind, MacroDefId, MacroDefKind,
+    AstId, AttrId, FragmentKind, HirFileId, InFile, MacroCallId, MacroCallKind, MacroDefId,
+    MacroDefKind,
 };
 use la_arena::Idx;
 use nameres::DefMap;
@@ -652,6 +653,7 @@ impl AsMacroCall for InFile<&ast::MacroCall> {
         resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
         mut error_sink: &mut dyn FnMut(mbe::ExpandError),
     ) -> Result<Result<MacroCallId, ErrorEmitted>, UnresolvedMacro> {
+        let fragment = hir_expand::to_fragment_kind(self.value);
         let ast_id = AstId::new(self.file_id, db.ast_id_map(self.file_id).ast_id(self.value));
         let h = Hygiene::new(db.upcast(), self.file_id);
         let path = self.value.path().and_then(|path| path::ModPath::from_src(db, path, &h));
@@ -667,6 +669,7 @@ impl AsMacroCall for InFile<&ast::MacroCall> {
 
         macro_call_as_call_id(
             &AstIdWithPath::new(ast_id.file_id, ast_id.value, path),
+            fragment,
             db,
             krate,
             resolver,
@@ -695,6 +698,7 @@ pub struct UnresolvedMacro {
 
 fn macro_call_as_call_id(
     call: &AstIdWithPath<ast::MacroCall>,
+    fragment: FragmentKind,
     db: &dyn db::DefDatabase,
     krate: CrateId,
     resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
@@ -718,7 +722,11 @@ fn macro_call_as_call_id(
         .map(MacroCallId::from)
     } else {
         Ok(def
-            .as_lazy_macro(db.upcast(), krate, MacroCallKind::FnLike { ast_id: call.ast_id })
+            .as_lazy_macro(
+                db.upcast(),
+                krate,
+                MacroCallKind::FnLike { ast_id: call.ast_id, fragment },
+            )
             .into())
     };
     Ok(res)