hygiene: Reuse `MacroKind` in `ExpnKind`

Orthogonality and reuse are good.

2 files changed, 6 insertions, 15 deletions

diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
index 2f8d6f00ba7..04f124685cb 100644
--- a/src/libsyntax/ext/base.rs
+++ b/src/libsyntax/ext/base.rs
@@ -640,18 +640,10 @@ impl SyntaxExtension {
         }
     }
 
-    fn expn_kind(&self, descr: Symbol) -> ExpnKind {
-        match self.kind {
-            SyntaxExtensionKind::Bang(..) |
-            SyntaxExtensionKind::LegacyBang(..) => ExpnKind::MacroBang(descr),
-            _ => ExpnKind::MacroAttribute(descr),
-        }
-    }
-
-    pub fn expn_info(&self, call_site: Span, descr: &str) -> ExpnInfo {
+    pub fn expn_info(&self, call_site: Span, descr: Symbol) -> ExpnInfo {
         ExpnInfo {
             call_site,
-            kind: self.expn_kind(Symbol::intern(descr)),
+            kind: ExpnKind::Macro(self.macro_kind(), descr),
             def_site: self.span,
             default_transparency: self.default_transparency,
             allow_internal_unstable: self.allow_internal_unstable.clone(),
diff --git a/src/libsyntax/ext/derive.rs b/src/libsyntax/ext/derive.rs
index 24050be792b..68e7225c3cf 100644
--- a/src/libsyntax/ext/derive.rs
+++ b/src/libsyntax/ext/derive.rs
@@ -1,7 +1,7 @@
 use crate::attr::HasAttrs;
 use crate::ast;
 use crate::source_map::{ExpnInfo, ExpnKind};
-use crate::ext::base::ExtCtxt;
+use crate::ext::base::{ExtCtxt, MacroKind};
 use crate::ext::build::AstBuilder;
 use crate::parse::parser::PathStyle;
 use crate::symbol::{Symbol, sym};
@@ -46,7 +46,7 @@ pub fn collect_derives(cx: &mut ExtCtxt<'_>, attrs: &mut Vec<ast::Attribute>) ->
 pub fn add_derived_markers<T>(cx: &mut ExtCtxt<'_>, span: Span, traits: &[ast::Path], item: &mut T)
     where T: HasAttrs,
 {
-    let (mut names, mut pretty_name) = (FxHashSet::default(), "derive(".to_owned());
+    let (mut names, mut pretty_name) = (FxHashSet::default(), String::new());
     for (i, path) in traits.iter().enumerate() {
         if i > 0 {
             pretty_name.push_str(", ");
@@ -54,11 +54,10 @@ pub fn add_derived_markers<T>(cx: &mut ExtCtxt<'_>, span: Span, traits: &[ast::P
         pretty_name.push_str(&path.to_string());
         names.insert(unwrap_or!(path.segments.get(0), continue).ident.name);
     }
-    pretty_name.push(')');
 
     cx.current_expansion.mark.set_expn_info(ExpnInfo::with_unstable(
-        ExpnKind::MacroAttribute(Symbol::intern(&pretty_name)), span, cx.parse_sess.edition,
-        &[sym::rustc_attrs, sym::structural_match],
+        ExpnKind::Macro(MacroKind::Derive, Symbol::intern(&pretty_name)), span,
+        cx.parse_sess.edition, &[sym::rustc_attrs, sym::structural_match],
     ));
 
     let span = span.with_ctxt(cx.backtrace());