Switch to a bitflags `MacroKinds` to support macros with more than one kind

Review everything that uses `MacroKind`, and switch anything that could
refer to more than one kind to use `MacroKinds`.

Add a new `SyntaxExtensionKind::MacroRules` for `macro_rules!` macros,
using the concrete `MacroRulesMacroExpander` type, and have it track
which kinds it can handle. Eliminate the separate optional `attr_ext`,
now that a `SyntaxExtension` can handle multiple macro kinds.

This also avoids the need to downcast when calling methods on
`MacroRulesMacroExpander`, such as `get_unused_rule`.

Integrate macro kind checking into name resolution's
`sub_namespace_match`, so that we only find a macro if it's the right
type, and eliminate the special-case hack for attributes.

1 files changed, 5 insertions, 5 deletions

diff --git a/compiler/rustc_resolve/src/lib.rs b/compiler/rustc_resolve/src/lib.rs
index b43f71913d9..797f4f619e3 100644
--- a/compiler/rustc_resolve/src/lib.rs
+++ b/compiler/rustc_resolve/src/lib.rs
@@ -53,7 +53,8 @@ use rustc_feature::BUILTIN_ATTRIBUTES;
 use rustc_hir::attrs::StrippedCfgItem;
 use rustc_hir::def::Namespace::{self, *};
 use rustc_hir::def::{
-    self, CtorOf, DefKind, DocLinkResMap, LifetimeRes, NonMacroAttrKind, PartialRes, PerNS,
+    self, CtorOf, DefKind, DocLinkResMap, LifetimeRes, MacroKinds, NonMacroAttrKind, PartialRes,
+    PerNS,
 };
 use rustc_hir::def_id::{CRATE_DEF_ID, CrateNum, DefId, LOCAL_CRATE, LocalDefId, LocalDefIdMap};
 use rustc_hir::definitions::DisambiguatorState;
@@ -969,8 +970,8 @@ impl<'ra> NameBindingData<'ra> {
         matches!(self.res(), Res::Def(DefKind::AssocConst | DefKind::AssocFn | DefKind::AssocTy, _))
     }
 
-    fn macro_kind(&self) -> Option<MacroKind> {
-        self.res().macro_kind()
+    fn macro_kinds(&self) -> Option<MacroKinds> {
+        self.res().macro_kinds()
     }
 
     // Suppose that we resolved macro invocation with `invoc_parent_expansion` to binding `binding`
@@ -1030,14 +1031,13 @@ struct DeriveData {
 
 struct MacroData {
     ext: Arc<SyntaxExtension>,
-    attr_ext: Option<Arc<SyntaxExtension>>,
     nrules: usize,
     macro_rules: bool,
 }
 
 impl MacroData {
     fn new(ext: Arc<SyntaxExtension>) -> MacroData {
-        MacroData { ext, attr_ext: None, nrules: 0, macro_rules: false }
+        MacroData { ext, nrules: 0, macro_rules: false }
     }
 }