diff options
Diffstat (limited to 'src/libsyntax/ext/expand.rs')
| -rw-r--r-- | src/libsyntax/ext/expand.rs | 144 |
1 files changed, 76 insertions, 68 deletions
diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs index c1d52c97455..7b4a5167446 100644 --- a/src/libsyntax/ext/expand.rs +++ b/src/libsyntax/ext/expand.rs @@ -4,7 +4,7 @@ use crate::attr::{self, HasAttrs}; use crate::source_map::respan; use crate::config::StripUnconfigured; use crate::ext::base::*; -use crate::ext::proc_macro::collect_derives; +use crate::ext::proc_macro::{collect_derives, MarkAttrs}; use crate::ext::hygiene::{ExpnId, SyntaxContext, ExpnData, ExpnKind}; use crate::ext::tt::macro_rules::annotate_err_with_kind; use crate::ext::placeholders::{placeholder, PlaceholderExpander}; @@ -305,10 +305,12 @@ impl<'a, 'b> MacroExpander<'a, 'b> { continue }; - let scope = + let eager_expansion_root = if self.monotonic { invoc.expansion_data.id } else { orig_expansion_data.id }; - let ext = match self.cx.resolver.resolve_macro_invocation(&invoc, scope, force) { - Ok(ext) => ext, + let res = match self.cx.resolver.resolve_macro_invocation( + &invoc, eager_expansion_root, force + ) { + Ok(res) => res, Err(Indeterminate) => { undetermined_invocations.push(invoc); continue @@ -318,57 +320,74 @@ impl<'a, 'b> MacroExpander<'a, 'b> { progress = true; let ExpansionData { depth, id: expn_id, .. } = invoc.expansion_data; self.cx.current_expansion = invoc.expansion_data.clone(); - self.cx.current_expansion.id = scope; // FIXME(jseyfried): Refactor out the following logic - let (expanded_fragment, new_invocations) = if let Some(ext) = ext { - let fragment = self.expand_invoc(invoc, &ext.kind); - self.collect_invocations(fragment, &[]) - } else if let InvocationKind::DeriveContainer { derives: traits, item } = invoc.kind { - 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.mut_span_err(span, - "`derive` may only be applied to \ - structs, enums and unions"); - if let ast::AttrStyle::Inner = attr.style { - let trait_list = traits.iter() - .map(|t| t.to_string()).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(); + let (expanded_fragment, new_invocations) = match res { + InvocationRes::Single(ext) => { + let fragment = self.expand_invoc(invoc, &ext.kind); + self.collect_invocations(fragment, &[]) } + InvocationRes::DeriveContainer(exts) => { + let (derives, item) = match invoc.kind { + InvocationKind::DeriveContainer { derives, item } => (derives, item), + _ => 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.mut_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| t.to_string()).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(); + } - let mut item = self.fully_configure(item); - item.visit_attrs(|attrs| attrs.retain(|a| a.path != sym::derive)); - let derive_placeholders = - all_derive_placeholders.entry(invoc.expansion_data.id).or_default(); - - derive_placeholders.reserve(traits.len()); - invocations.reserve(traits.len()); - for path in traits { - let expn_id = ExpnId::fresh(None); - derive_placeholders.push(NodeId::placeholder_from_expn_id(expn_id)); - invocations.push(Invocation { - kind: InvocationKind::Derive { path, item: item.clone() }, - fragment_kind: invoc.fragment_kind, - expansion_data: ExpansionData { - id: expn_id, - ..invoc.expansion_data.clone() - }, - }); + let mut item = self.fully_configure(item); + item.visit_attrs(|attrs| attrs.retain(|a| a.path != sym::derive)); + let mut helper_attrs = Vec::new(); + let mut has_copy = false; + for ext in exts { + helper_attrs.extend(&ext.helper_attrs); + has_copy |= ext.is_derive_copy; + } + // Mark derive helpers inside this item as known and used. + // FIXME: This is a hack, derive helpers should be integrated with regular name + // resolution instead. For example, helpers introduced by a derive container + // can be in scope for all code produced by that container's expansion. + item.visit_with(&mut MarkAttrs(&helper_attrs)); + if has_copy { + self.cx.resolver.add_derives(invoc.expansion_data.id, SpecialDerives::COPY); + } + + let derive_placeholders = + all_derive_placeholders.entry(invoc.expansion_data.id).or_default(); + derive_placeholders.reserve(derives.len()); + invocations.reserve(derives.len()); + for path in derives { + let expn_id = ExpnId::fresh(None); + derive_placeholders.push(NodeId::placeholder_from_expn_id(expn_id)); + invocations.push(Invocation { + kind: InvocationKind::Derive { path, item: item.clone() }, + fragment_kind: invoc.fragment_kind, + expansion_data: ExpansionData { + id: expn_id, + ..invoc.expansion_data.clone() + }, + }); + } + let fragment = invoc.fragment_kind + .expect_from_annotatables(::std::iter::once(item)); + self.collect_invocations(fragment, derive_placeholders) } - let fragment = invoc.fragment_kind - .expect_from_annotatables(::std::iter::once(item)); - self.collect_invocations(fragment, derive_placeholders) - } else { - unreachable!() }; if expanded_fragments.len() < depth { @@ -564,7 +583,6 @@ impl<'a, 'b> MacroExpander<'a, 'b> { return fragment_kind.dummy(span); } let meta = ast::MetaItem { node: ast::MetaItemKind::Word, span, path }; - let span = span.with_ctxt(self.cx.backtrace()); let items = expander.expand(self.cx, span, &meta, item); fragment_kind.expect_from_annotatables(items) } @@ -1209,9 +1227,13 @@ impl<'a, 'b> MutVisitor for InvocationCollector<'a, 'b> { } } - fn visit_generic_params(&mut self, params: &mut Vec<ast::GenericParam>) { - self.cfg.configure_generic_params(params); - noop_visit_generic_params(params, self); + fn flat_map_generic_param( + &mut self, + param: ast::GenericParam + ) -> SmallVec<[ast::GenericParam; 1]> + { + let param = configure!(self, param); + noop_flat_map_generic_param(param, self) } fn visit_attribute(&mut self, at: &mut ast::Attribute) { @@ -1388,17 +1410,3 @@ impl<'feat> ExpansionConfig<'feat> { self.features.map_or(false, |features| features.custom_inner_attributes) } } - -// A Marker adds the given mark to the syntax context. -#[derive(Debug)] -pub struct Marker(pub ExpnId); - -impl MutVisitor for Marker { - fn visit_span(&mut self, span: &mut Span) { - *span = span.apply_mark(self.0) - } - - fn visit_mac(&mut self, mac: &mut ast::Mac) { - noop_visit_mac(mac, self) - } -} |