diff options
| -rw-r--r-- | src/librustc_expand/expand.rs | 44 |
1 files changed, 22 insertions, 22 deletions
diff --git a/src/librustc_expand/expand.rs b/src/librustc_expand/expand.rs index 90692fe1ec9..c7c7f62918d 100644 --- a/src/librustc_expand/expand.rs +++ b/src/librustc_expand/expand.rs @@ -451,28 +451,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> { _ => unreachable!(), }; if !item.derive_allowed() { - let attr = attr::find_by_name(item.attrs(), sym::derive) - .expect("`derive` attribute should exist"); - let span = attr.span; - let mut err = self.cx.struct_span_err( - span, - "`derive` may only be applied to structs, enums and unions", - ); - if let ast::AttrStyle::Inner = attr.style { - let trait_list = derives - .iter() - .map(|t| pprust::path_to_string(t)) - .collect::<Vec<_>>(); - let suggestion = format!("#[derive({})]", trait_list.join(", ")); - err.span_suggestion( - span, - "try an outer attribute", - suggestion, - // We don't 𝑘𝑛𝑜𝑤 that the following item is an ADT - Applicability::MaybeIncorrect, - ); - } - err.emit(); + self.error_derive_forbidden_on_non_adt(&derives, &item); } let mut item = self.fully_configure(item); @@ -521,6 +500,27 @@ impl<'a, 'b> MacroExpander<'a, 'b> { fragment_with_placeholders } + fn error_derive_forbidden_on_non_adt(&self, derives: &[Path], item: &Annotatable) { + let attr = + attr::find_by_name(item.attrs(), sym::derive).expect("`derive` attribute should exist"); + let span = attr.span; + let mut err = self + .cx + .struct_span_err(span, "`derive` may only be applied to structs, enums and unions"); + if let ast::AttrStyle::Inner = attr.style { + let trait_list = derives.iter().map(|t| pprust::path_to_string(t)).collect::<Vec<_>>(); + let suggestion = format!("#[derive({})]", trait_list.join(", ")); + err.span_suggestion( + span, + "try an outer attribute", + suggestion, + // We don't 𝑘𝑛𝑜𝑤 that the following item is an ADT + Applicability::MaybeIncorrect, + ); + } + err.emit(); + } + fn resolve_imports(&mut self) { if self.monotonic { self.cx.resolver.resolve_imports(); |