Rollup merge of #148808 - nnethercote:resolve-cleanups, r=chenyukang,petrochenkov

Some resolve cleanups

Minor improvements I found while looking over this code.

r? ```````@petrochenkov```````

compiler/rustc_expand/src/base.rs

@@ -1099,6 +1099,9 @@ pub fn expn_data(
 pub struct DeriveResolution {
     pub path: ast::Path,
     pub item: Annotatable,
+    // FIXME: currently this field is only used in `is_none`/`is_some` conditions. However, the
+    // `Arc<SyntaxExtension>` will be used if the FIXME in `MacroExpander::fully_expand_fragment`
+    // is completed.
     pub exts: Option<Arc<SyntaxExtension>>,
     pub is_const: bool,
 }

compiler/rustc_resolve/src/ident.rs

@@ -458,14 +458,11 @@ struct Flags: u8 {
                         let mut result = Err(Determinacy::Determined);
                         for derive in parent_scope.derives {
                             let parent_scope = &ParentScope { derives: &[], ..*parent_scope };
-                            match this.reborrow().resolve_macro_path(
+                            match this.reborrow().resolve_derive_macro_path(
                                 derive,
-                                MacroKind::Derive,
                                 parent_scope,
-                                true,
                                 force,
                                 ignore_import,
-                                None,
                             ) {
                                 Ok((Some(ext), _)) => {
                                     if ext.helper_attrs.contains(&ident.name) {

compiler/rustc_resolve/src/macros.rs

@@ -396,14 +396,11 @@ fn resolve_derives(
         for (i, resolution) in entry.resolutions.iter_mut().enumerate() {
             if resolution.exts.is_none() {
                 resolution.exts = Some(
-                    match self.cm().resolve_macro_path(
+                    match self.cm().resolve_derive_macro_path(
                         &resolution.path,
-                        MacroKind::Derive,
                         &parent_scope,
-                        true,
                         force,
                         None,
-                        None,
                     ) {
                         Ok((Some(ext), _)) => {
                             if !ext.helper_attrs.is_empty() {
@@ -571,7 +568,6 @@ fn smart_resolve_macro_path(
             path,
             kind,
             parent_scope,
-            true,
             force,
             deleg_impl,
             invoc_in_mod_inert_attr.map(|def_id| (def_id, node_id)),
@@ -713,26 +709,22 @@ fn smart_resolve_macro_path(
         Ok((ext, res))
     }
 
-    pub(crate) fn resolve_macro_path<'r>(
+    pub(crate) fn resolve_derive_macro_path<'r>(
         self: CmResolver<'r, 'ra, 'tcx>,
         path: &ast::Path,
-        kind: MacroKind,
         parent_scope: &ParentScope<'ra>,
-        trace: bool,
         force: bool,
         ignore_import: Option<Import<'ra>>,
-        suggestion_span: Option<Span>,
     ) -> Result<(Option<Arc<SyntaxExtension>>, Res), Determinacy> {
         self.resolve_macro_or_delegation_path(
             path,
-            kind,
+            MacroKind::Derive,
             parent_scope,
-            trace,
             force,
             None,
             None,
             ignore_import,
-            suggestion_span,
+            None,
         )
     }
 
@@ -741,7 +733,6 @@ fn resolve_macro_or_delegation_path<'r>(
         ast_path: &ast::Path,
         kind: MacroKind,
         parent_scope: &ParentScope<'ra>,
-        trace: bool,
         force: bool,
         deleg_impl: Option<LocalDefId>,
         invoc_in_mod_inert_attr: Option<(LocalDefId, NodeId)>,
@@ -780,16 +771,14 @@ fn resolve_macro_or_delegation_path<'r>(
                 PathResult::Module(..) => unreachable!(),
             };
 
-            if trace {
-                self.multi_segment_macro_resolutions.borrow_mut(&self).push((
-                    path,
-                    path_span,
-                    kind,
-                    *parent_scope,
-                    res.ok(),
-                    ns,
-                ));
-            }
+            self.multi_segment_macro_resolutions.borrow_mut(&self).push((
+                path,
+                path_span,
+                kind,
+                *parent_scope,
+                res.ok(),
+                ns,
+            ));
 
             self.prohibit_imported_non_macro_attrs(None, res.ok(), path_span);
             res
@@ -807,15 +796,13 @@ fn resolve_macro_or_delegation_path<'r>(
                 return Err(Determinacy::Undetermined);
             }
 
-            if trace {
-                self.single_segment_macro_resolutions.borrow_mut(&self).push((
-                    path[0].ident,
-                    kind,
-                    *parent_scope,
-                    binding.ok(),
-                    suggestion_span,
-                ));
-            }
+            self.single_segment_macro_resolutions.borrow_mut(&self).push((
+                path[0].ident,
+                kind,
+                *parent_scope,
+                binding.ok(),
+                suggestion_span,
+            ));
 
             let res = binding.map(|binding| binding.res());
             self.prohibit_imported_non_macro_attrs(binding.ok(), res.ok(), path_span);