Rollup merge of rust-lang#40311 - nrc:save-proc-macro-attr, r=jseyfried

Expect macro defs in save-analysis and add expn info to spans for att…

…r proc macros

r? @jseyfried

Author: Ariel Ben-Yehuda

src/librustc_save_analysis/dump_visitor.rs

@@ -327,6 +327,9 @@ impl<'l, 'tcx: 'l, 'll, D: Dump + 'll> DumpVisitor<'l, 'tcx, 'll, D> {
                     scope: scope
                 }.lower(self.tcx));
             }
+            // With macros 2.0, we can legitimately get a ref to a macro, but
+            // we don't handle it properly for now (FIXME).
+            Def::Macro(..) => {}
             Def::Local(..) |
             Def::Upvar(..) |
             Def::SelfTy(..) |
@@ -336,7 +339,6 @@ impl<'l, 'tcx: 'l, 'll, D: Dump + 'll> DumpVisitor<'l, 'tcx, 'll, D> {
             Def::AssociatedTy(..) |
             Def::AssociatedConst(..) |
             Def::PrimTy(_) |
-            Def::Macro(..) |
             Def::Err => {
                span_bug!(span,
                          "process_def_kind for unexpected item: {:?}",

src/libsyntax/ext/expand.rs

@@ -464,8 +464,20 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                 let attr_toks = stream_for_attr_args(&attr, &self.cx.parse_sess);
                 let item_toks = stream_for_item(&item, &self.cx.parse_sess);
 
+                let span = Span {
+                    expn_id: self.cx.codemap().record_expansion(ExpnInfo {
+                        call_site: attr.span,
+                        callee: NameAndSpan {
+                            format: MacroAttribute(name),
+                            span: None,
+                            allow_internal_unstable: false,
+                        },
+                    }),
+                    ..attr.span
+                };
+
                 let tok_result = mac.expand(self.cx, attr.span, attr_toks, item_toks);
-                self.parse_expansion(tok_result, kind, name, attr.span)
+                self.parse_expansion(tok_result, kind, name, span)
             }
             SyntaxExtension::ProcMacroDerive(..) | SyntaxExtension::BuiltinDerive(..) => {
                 self.cx.span_err(attr.span, &format!("`{}` is a derive mode", name));