resolve: Change &mut Resolver to &Resolver when possible

Author: petrochenkov

compiler/rustc_expand/src/base.rs

@@ -1042,7 +1042,7 @@ pub trait ResolverExpand {
     fn next_node_id(&mut self) -> NodeId;
     fn invocation_parent(&self, id: LocalExpnId) -> LocalDefId;
 
-    fn resolve_dollar_crates(&mut self);
+    fn resolve_dollar_crates(&self);
     fn visit_ast_fragment_with_placeholders(
         &mut self,
         expn_id: LocalExpnId,

compiler/rustc_resolve/src/build_reduced_graph.rs

@@ -84,7 +84,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
     /// Reachable macros with block module parents exist due to `#[macro_export] macro_rules!`,
     /// but they cannot use def-site hygiene, so the assumption holds
     /// (<https://github.com/rust-lang/rust/pull/77984#issuecomment-712445508>).
-    pub(crate) fn get_nearest_non_block_module(&mut self, mut def_id: DefId) -> Module<'ra> {
+    pub(crate) fn get_nearest_non_block_module(&self, mut def_id: DefId) -> Module<'ra> {
         loop {
             match self.get_module(def_id) {
                 Some(module) => return module,
@@ -93,14 +93,14 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
         }
     }
 
-    pub(crate) fn expect_module(&mut self, def_id: DefId) -> Module<'ra> {
+    pub(crate) fn expect_module(&self, def_id: DefId) -> Module<'ra> {
         self.get_module(def_id).expect("argument `DefId` is not a module")
     }
 
     /// If `def_id` refers to a module (in resolver's sense, i.e. a module item, crate root, enum,
     /// or trait), then this function returns that module's resolver representation, otherwise it
     /// returns `None`.
-    pub(crate) fn get_module(&mut self, def_id: DefId) -> Option<Module<'ra>> {
+    pub(crate) fn get_module(&self, def_id: DefId) -> Option<Module<'ra>> {
         match def_id.as_local() {
             Some(local_def_id) => self.local_module_map.get(&local_def_id).copied(),
             None => {
@@ -133,7 +133,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
         }
     }
 
-    pub(crate) fn expn_def_scope(&mut self, expn_id: ExpnId) -> Module<'ra> {
+    pub(crate) fn expn_def_scope(&self, expn_id: ExpnId) -> Module<'ra> {
         match expn_id.expn_data().macro_def_id {
             Some(def_id) => self.macro_def_scope(def_id),
             None => expn_id
@@ -143,7 +143,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
         }
     }
 
-    pub(crate) fn macro_def_scope(&mut self, def_id: DefId) -> Module<'ra> {
+    pub(crate) fn macro_def_scope(&self, def_id: DefId) -> Module<'ra> {
         if let Some(id) = def_id.as_local() {
             self.local_macro_def_scopes[&id]
         } else {

compiler/rustc_resolve/src/diagnostics.rs

@@ -2776,12 +2776,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
     }
 
     /// Finds a cfg-ed out item inside `module` with the matching name.
-    pub(crate) fn find_cfg_stripped(
-        &mut self,
-        err: &mut Diag<'_>,
-        segment: &Symbol,
-        module: DefId,
-    ) {
+    pub(crate) fn find_cfg_stripped(&self, err: &mut Diag<'_>, segment: &Symbol, module: DefId) {
         let local_items;
         let symbols = if module.is_local() {
             local_items = self
@@ -2807,7 +2802,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             }
 
             fn comes_from_same_module_for_glob(
-                r: &mut Resolver<'_, '_>,
+                r: &Resolver<'_, '_>,
                 parent_module: DefId,
                 module: DefId,
                 visited: &mut FxHashMap<DefId, bool>,

compiler/rustc_resolve/src/effective_visibilities.rs

@@ -38,11 +38,11 @@ pub(crate) struct EffectiveVisibilitiesVisitor<'a, 'ra, 'tcx> {
 }
 
 impl Resolver<'_, '_> {
-    fn nearest_normal_mod(&mut self, def_id: LocalDefId) -> LocalDefId {
+    fn nearest_normal_mod(&self, def_id: LocalDefId) -> LocalDefId {
         self.get_nearest_non_block_module(def_id.to_def_id()).nearest_parent_mod().expect_local()
     }
 
-    fn private_vis_import(&mut self, binding: NameBinding<'_>) -> Visibility {
+    fn private_vis_import(&self, binding: NameBinding<'_>) -> Visibility {
         let NameBindingKind::Import { import, .. } = binding.kind else { unreachable!() };
         Visibility::Restricted(
             import
@@ -52,7 +52,7 @@ impl Resolver<'_, '_> {
         )
     }
 
-    fn private_vis_def(&mut self, def_id: LocalDefId) -> Visibility {
+    fn private_vis_def(&self, def_id: LocalDefId) -> Visibility {
         // For mod items `nearest_normal_mod` returns its argument, but we actually need its parent.
         let normal_mod_id = self.nearest_normal_mod(def_id);
         if normal_mod_id == def_id {

compiler/rustc_resolve/src/lib.rs

@@ -1605,7 +1605,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
     }
 
     fn new_extern_module(
-        &mut self,
+        &self,
         parent: Option<Module<'ra>>,
         kind: ModuleKind,
         expn_id: ExpnId,
@@ -1996,7 +1996,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
         }
     }
 
-    fn resolve_crate_root(&mut self, ident: Ident) -> Module<'ra> {
+    fn resolve_crate_root(&self, ident: Ident) -> Module<'ra> {
         debug!("resolve_crate_root({:?})", ident);
         let mut ctxt = ident.span.ctxt();
         let mark = if ident.name == kw::DollarCrate {
@@ -2069,7 +2069,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
         module
     }
 
-    fn resolve_self(&mut self, ctxt: &mut SyntaxContext, module: Module<'ra>) -> Module<'ra> {
+    fn resolve_self(&self, ctxt: &mut SyntaxContext, module: Module<'ra>) -> Module<'ra> {
         let mut module = self.expect_module(module.nearest_parent_mod());
         while module.span.ctxt().normalize_to_macros_2_0() != *ctxt {
             let parent = module.parent.unwrap_or_else(|| self.expn_def_scope(ctxt.remove_mark()));

compiler/rustc_resolve/src/macros.rs

@@ -172,7 +172,7 @@ impl<'ra, 'tcx> ResolverExpand for Resolver<'ra, 'tcx> {
         self.invocation_parents[&id].parent_def
     }
 
-    fn resolve_dollar_crates(&mut self) {
+    fn resolve_dollar_crates(&self) {
         hygiene::update_dollar_crate_names(|ctxt| {
             let ident = Ident::new(kw::DollarCrate, DUMMY_SP.with_ctxt(ctxt));
             match self.resolve_crate_root(ident).kind {
@@ -1147,7 +1147,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
     ///
     /// Possibly replace its expander to a pre-defined one for built-in macros.
     pub(crate) fn compile_macro(
-        &mut self,
+        &self,
         macro_def: &ast::MacroDef,
         ident: Ident,
         attrs: &[rustc_hir::Attribute],