diff options
| -rw-r--r-- | src/librustc/hir/map/def_collector.rs | 15 | ||||
| -rw-r--r-- | src/librustc/hir/map/definitions.rs | 2 | ||||
| -rw-r--r-- | src/test/ui/attributes/unnamed-field-attributes.rs | 9 |
3 files changed, 24 insertions, 2 deletions
diff --git a/src/librustc/hir/map/def_collector.rs b/src/librustc/hir/map/def_collector.rs index bffb4df836e..b42fbd5c0a1 100644 --- a/src/librustc/hir/map/def_collector.rs +++ b/src/librustc/hir/map/def_collector.rs @@ -170,9 +170,13 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> { } fn visit_variant_data(&mut self, data: &'a VariantData) { + // The assumption here is that non-`cfg` macro expansion cannot change field indices. + // It currently holds because only inert attributes are accepted on fields, + // and every such attribute expands into a single field after it's resolved. for (index, field) in data.fields().iter().enumerate() { if field.is_placeholder { self.visit_macro_invoc(field.id); + self.definitions.placeholder_field_indices.insert(field.id, index); continue; } let name = field.ident.map(|ident| ident.name) @@ -338,12 +342,19 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> { } } + // This method is called only when we are visiting an individual field + // after expanding an attribute on it. fn visit_struct_field(&mut self, sf: &'a StructField) { if sf.is_placeholder { self.visit_macro_invoc(sf.id) } else { - let name = sf.ident.map(|ident| ident.name) - .unwrap_or_else(|| panic!("don't know the field number in this context")); + let name = sf.ident.map_or_else( + || { + let expn_id = NodeId::placeholder_from_expn_id(self.expansion); + sym::integer(self.definitions.placeholder_field_indices[&expn_id]) + }, + |ident| ident.name, + ); let def = self.create_def(sf.id, DefPathData::ValueNs(name.as_interned_str()), sf.span); diff --git a/src/librustc/hir/map/definitions.rs b/src/librustc/hir/map/definitions.rs index 651fe8449ac..187bc593324 100644 --- a/src/librustc/hir/map/definitions.rs +++ b/src/librustc/hir/map/definitions.rs @@ -104,6 +104,8 @@ pub struct Definitions { /// When collecting definitions from an AST fragment produced by a macro invocation `ExpnId` /// we know what parent node that fragment should be attached to thanks to this table. invocation_parents: FxHashMap<ExpnId, DefIndex>, + /// Indices of unnamed struct or variant fields with unresolved attributes. + pub(super) placeholder_field_indices: NodeMap<usize>, } /// A unique identifier that we can use to lookup a definition diff --git a/src/test/ui/attributes/unnamed-field-attributes.rs b/src/test/ui/attributes/unnamed-field-attributes.rs new file mode 100644 index 00000000000..93f364047e9 --- /dev/null +++ b/src/test/ui/attributes/unnamed-field-attributes.rs @@ -0,0 +1,9 @@ +// check-pass + +struct S( + #[rustfmt::skip] u8, + u16, + #[rustfmt::skip] u32, +); + +fn main() {} |