//! * Functions called by the compiler itself.
use crate::check_attr::target_from_impl_item;
+use crate::errors::{
+ DuplicateLangItem, IncorrectTarget, LangItemOnIncorrectTarget, UnknownLangItem,
+};
use crate::weak_lang_items;
-use rustc_middle::middle::cstore::ExternCrate;
+use rustc_hir as hir;
+use rustc_hir::def::DefKind;
+use rustc_hir::def_id::{DefId, LocalDefId};
+use rustc_hir::lang_items::{extract, GenericRequirement};
+use rustc_hir::{LangItem, LanguageItems, Target};
use rustc_middle::ty::TyCtxt;
+use rustc_session::cstore::ExternCrate;
+use rustc_span::symbol::kw::Empty;
+use rustc_span::{sym, Span};
-use rustc_ast::Attribute;
-use rustc_errors::struct_span_err;
-use rustc_hir as hir;
-use rustc_hir::def_id::{DefId, LOCAL_CRATE};
-use rustc_hir::itemlikevisit::ItemLikeVisitor;
-use rustc_hir::lang_items::{extract, ITEM_REFS};
-use rustc_hir::{HirId, LangItem, LanguageItems, Target};
+use rustc_middle::query::Providers;
-use rustc_middle::ty::query::Providers;
+pub(crate) enum Duplicate {
+ Plain,
+ Crate,
+ CrateDepends,
+}
struct LanguageItemCollector<'tcx> {
items: LanguageItems,
tcx: TyCtxt<'tcx>,
}
-impl ItemLikeVisitor<'v> for LanguageItemCollector<'tcx> {
- fn visit_item(&mut self, item: &hir::Item<'_>) {
- self.check_for_lang(Target::from_item(item), item.hir_id, item.attrs);
-
- if let hir::ItemKind::Enum(def, ..) = &item.kind {
- for variant in def.variants {
- self.check_for_lang(Target::Variant, variant.id, variant.attrs);
- }
- }
- }
-
- fn visit_trait_item(&mut self, trait_item: &hir::TraitItem<'_>) {
- self.check_for_lang(
- Target::from_trait_item(trait_item),
- trait_item.hir_id,
- trait_item.attrs,
- )
- }
-
- fn visit_impl_item(&mut self, impl_item: &hir::ImplItem<'_>) {
- self.check_for_lang(
- target_from_impl_item(self.tcx, impl_item),
- impl_item.hir_id,
- impl_item.attrs,
- )
- }
-}
-
-impl LanguageItemCollector<'tcx> {
+impl<'tcx> LanguageItemCollector<'tcx> {
fn new(tcx: TyCtxt<'tcx>) -> LanguageItemCollector<'tcx> {
LanguageItemCollector { tcx, items: LanguageItems::new() }
}
- fn check_for_lang(&mut self, actual_target: Target, hir_id: HirId, attrs: &[Attribute]) {
- let check_name = |attr, sym| self.tcx.sess.check_name(attr, sym);
- if let Some((value, span)) = extract(check_name, &attrs) {
- match ITEM_REFS.get(&value).cloned() {
+ fn check_for_lang(&mut self, actual_target: Target, def_id: LocalDefId) {
+ let attrs = self.tcx.hir().attrs(self.tcx.hir().local_def_id_to_hir_id(def_id));
+ if let Some((name, span)) = extract(&attrs) {
+ match LangItem::from_name(name) {
// Known lang item with attribute on correct target.
- Some((item_index, expected_target)) if actual_target == expected_target => {
- let def_id = self.tcx.hir().local_def_id(hir_id);
- self.collect_item(item_index, def_id.to_def_id());
+ Some(lang_item) if actual_target == lang_item.target() => {
+ self.collect_item_extended(lang_item, def_id, span);
}
// Known lang item with attribute on incorrect target.
- Some((_, expected_target)) => {
- struct_span_err!(
- self.tcx.sess,
- span,
- E0718,
- "`{}` language item must be applied to a {}",
- value,
- expected_target,
- )
- .span_label(
+ Some(lang_item) => {
+ self.tcx.sess.emit_err(LangItemOnIncorrectTarget {
span,
- format!(
- "attribute should be applied to a {}, not a {}",
- expected_target, actual_target,
- ),
- )
- .emit();
+ name,
+ expected_target: lang_item.target(),
+ actual_target,
+ });
}
// Unknown lang item.
_ => {
- struct_span_err!(
- self.tcx.sess,
- span,
- E0522,
- "definition of an unknown language item: `{}`",
- value
- )
- .span_label(span, format!("definition of unknown language item `{}`", value))
- .emit();
+ self.tcx.sess.emit_err(UnknownLangItem { span, name });
}
}
}
}
- fn collect_item(&mut self, item_index: usize, item_def_id: DefId) {
+ fn collect_item(&mut self, lang_item: LangItem, item_def_id: DefId) {
// Check for duplicates.
- if let Some(original_def_id) = self.items.items[item_index] {
+ if let Some(original_def_id) = self.items.get(lang_item) {
if original_def_id != item_def_id {
- let lang_item = LangItem::from_u32(item_index as u32).unwrap();
- let name = lang_item.name();
- let mut err = match self.tcx.hir().span_if_local(item_def_id) {
- Some(span) => struct_span_err!(
- self.tcx.sess,
- span,
- E0152,
- "found duplicate lang item `{}`",
- name
- ),
- None => match self.tcx.extern_crate(item_def_id) {
- Some(ExternCrate { dependency_of, .. }) => {
- self.tcx.sess.struct_err(&format!(
- "duplicate lang item in crate `{}` (which `{}` depends on): `{}`.",
- self.tcx.crate_name(item_def_id.krate),
- self.tcx.crate_name(*dependency_of),
- name
- ))
- }
- _ => self.tcx.sess.struct_err(&format!(
- "duplicate lang item in crate `{}`: `{}`.",
- self.tcx.crate_name(item_def_id.krate),
- name
- )),
- },
+ let local_span = self.tcx.hir().span_if_local(item_def_id);
+ let lang_item_name = lang_item.name();
+ let crate_name = self.tcx.crate_name(item_def_id.krate);
+ let mut dependency_of = Empty;
+ let is_local = item_def_id.is_local();
+ let path = if is_local {
+ String::new()
+ } else {
+ self.tcx
+ .crate_extern_paths(item_def_id.krate)
+ .iter()
+ .map(|p| p.display().to_string())
+ .collect::<Vec<_>>()
+ .join(", ")
};
- if let Some(span) = self.tcx.hir().span_if_local(original_def_id) {
- err.span_note(span, "the lang item is first defined here");
+ let first_defined_span = self.tcx.hir().span_if_local(original_def_id);
+ let mut orig_crate_name = Empty;
+ let mut orig_dependency_of = Empty;
+ let orig_is_local = original_def_id.is_local();
+ let orig_path = if orig_is_local {
+ String::new()
} else {
- match self.tcx.extern_crate(original_def_id) {
- Some(ExternCrate { dependency_of, .. }) => {
- err.note(&format!(
- "the lang item is first defined in crate `{}` (which `{}` depends on)",
- self.tcx.crate_name(original_def_id.krate),
- self.tcx.crate_name(*dependency_of)
- ));
- }
- _ => {
- err.note(&format!(
- "the lang item is first defined in crate `{}`.",
- self.tcx.crate_name(original_def_id.krate)
- ));
- }
+ self.tcx
+ .crate_extern_paths(original_def_id.krate)
+ .iter()
+ .map(|p| p.display().to_string())
+ .collect::<Vec<_>>()
+ .join(", ")
+ };
+ if first_defined_span.is_none() {
+ orig_crate_name = self.tcx.crate_name(original_def_id.krate);
+ if let Some(ExternCrate { dependency_of: inner_dependency_of, .. }) =
+ self.tcx.extern_crate(original_def_id)
+ {
+ orig_dependency_of = self.tcx.crate_name(*inner_dependency_of);
}
- let mut note_def = |which, def_id: DefId| {
- let crate_name = self.tcx.crate_name(def_id.krate);
- let note = if def_id.is_local() {
- format!("{} definition in the local crate (`{}`)", which, crate_name)
- } else {
- let paths: Vec<_> = self
- .tcx
- .crate_extern_paths(def_id.krate)
- .iter()
- .map(|p| p.display().to_string())
- .collect();
- format!(
- "{} definition in `{}` loaded from {}",
- which,
- crate_name,
- paths.join(", ")
- )
- };
- err.note(¬e);
- };
- note_def("first", original_def_id);
- note_def("second", item_def_id);
}
- err.emit();
+
+ let duplicate = if local_span.is_some() {
+ Duplicate::Plain
+ } else {
+ match self.tcx.extern_crate(item_def_id) {
+ Some(ExternCrate { dependency_of: inner_dependency_of, .. }) => {
+ dependency_of = self.tcx.crate_name(*inner_dependency_of);
+ Duplicate::CrateDepends
+ }
+ _ => Duplicate::Crate,
+ }
+ };
+
+ self.tcx.sess.emit_err(DuplicateLangItem {
+ local_span,
+ lang_item_name,
+ crate_name,
+ dependency_of,
+ is_local,
+ path,
+ first_defined_span,
+ orig_crate_name,
+ orig_dependency_of,
+ orig_is_local,
+ orig_path,
+ duplicate,
+ });
}
}
// Matched.
- self.items.items[item_index] = Some(item_def_id);
- if let Some(group) = LangItem::from_u32(item_index as u32).unwrap().group() {
- self.items.groups[group as usize].push(item_def_id);
+ self.items.set(lang_item, item_def_id);
+ }
+
+ // Like collect_item() above, but also checks whether the lang item is declared
+ // with the right number of generic arguments.
+ fn collect_item_extended(&mut self, lang_item: LangItem, item_def_id: LocalDefId, span: Span) {
+ let name = lang_item.name();
+
+ // Now check whether the lang_item has the expected number of generic
+ // arguments. Generally speaking, binary and indexing operations have
+ // one (for the RHS/index), unary operations have none, the closure
+ // traits have one for the argument list, generators have one for the
+ // resume argument, and ordering/equality relations have one for the RHS
+ // Some other types like Box and various functions like drop_in_place
+ // have minimum requirements.
+
+ if let hir::Node::Item(hir::Item { kind, span: item_span, .. }) =
+ self.tcx.hir().get_by_def_id(item_def_id)
+ {
+ let (actual_num, generics_span) = match kind.generics() {
+ Some(generics) => (
+ generics
+ .params
+ .iter()
+ .filter(|p| !self.tcx.has_attr(p.def_id, sym::rustc_host))
+ .count(),
+ generics.span,
+ ),
+ None => (0, *item_span),
+ };
+
+ let mut at_least = false;
+ let required = match lang_item.required_generics() {
+ GenericRequirement::Exact(num) if num != actual_num => Some(num),
+ GenericRequirement::Minimum(num) if actual_num < num => {
+ at_least = true;
+ Some(num)}
+ ,
+ // If the number matches, or there is no requirement, handle it normally
+ _ => None,
+ };
+
+ if let Some(num) = required {
+ // We are issuing E0718 "incorrect target" here, because while the
+ // item kind of the target is correct, the target is still wrong
+ // because of the wrong number of generic arguments.
+ self.tcx.sess.emit_err(IncorrectTarget {
+ span,
+ generics_span,
+ name: name.as_str(),
+ kind: kind.descr(),
+ num,
+ actual_num,
+ at_least,
+ });
+
+ // return early to not collect the lang item
+ return;
+ }
}
+
+ self.collect_item(lang_item, item_def_id.to_def_id());
}
}
/// Traverses and collects all the lang items in all crates.
-fn collect(tcx: TyCtxt<'_>) -> LanguageItems {
+fn get_lang_items(tcx: TyCtxt<'_>, (): ()) -> LanguageItems {
// Initialize the collector.
let mut collector = LanguageItemCollector::new(tcx);
// Collect lang items in other crates.
- for &cnum in tcx.crates().iter() {
- for &(def_id, item_index) in tcx.defined_lang_items(cnum).iter() {
- collector.collect_item(item_index, def_id);
+ for &cnum in tcx.crates(()).iter() {
+ for &(def_id, lang_item) in tcx.defined_lang_items(cnum).iter() {
+ collector.collect_item(lang_item, def_id);
}
}
// Collect lang items in this crate.
- tcx.hir().krate().visit_all_item_likes(&mut collector);
+ let crate_items = tcx.hir_crate_items(());
+
+ for id in crate_items.items() {
+ collector
+ .check_for_lang(Target::from_def_kind(tcx.def_kind(id.owner_id)), id.owner_id.def_id);
+
+ if matches!(tcx.def_kind(id.owner_id), DefKind::Enum) {
+ let item = tcx.hir().item(id);
+ if let hir::ItemKind::Enum(def, ..) = &item.kind {
+ for variant in def.variants {
+ collector.check_for_lang(Target::Variant, variant.def_id);
+ }
+ }
+ }
+ }
+
+ // FIXME: avoid calling trait_item() when possible
+ for id in crate_items.trait_items() {
+ let item = tcx.hir().trait_item(id);
+ collector.check_for_lang(Target::from_trait_item(item), item.owner_id.def_id)
+ }
+
+ // FIXME: avoid calling impl_item() when possible
+ for id in crate_items.impl_items() {
+ let item = tcx.hir().impl_item(id);
+ collector.check_for_lang(target_from_impl_item(tcx, item), item.owner_id.def_id)
+ }
// Extract out the found lang items.
let LanguageItemCollector { mut items, .. } = collector;
}
pub fn provide(providers: &mut Providers) {
- providers.get_lang_items = |tcx, id| {
- assert_eq!(id, LOCAL_CRATE);
- collect(tcx)
- };
+ providers.get_lang_items = get_lang_items;
}
projects / rustc.git / blobdiff