New upstream version 1.57.0+dfsg1

[rustc.git] / compiler / rustc_passes / src / check_attr.rs

diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs
index fd438bdc9005ac5557c389bfa58ec7c9a5c860fe..e5fbddda74427a8e0d60b8d0c4a5681854e01bb0 100644 (file)
--- a/compiler/rustc_passes/src/check_attr.rs
+++ b/compiler/rustc_passes/src/check_attr.rs
@@ -9,7 +9,7 @@ use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::TyCtxt;
 
 use rustc_ast::{ast, AttrStyle, Attribute, Lit, LitKind, NestedMetaItem};
-use rustc_data_structures::stable_set::FxHashSet;
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_errors::{pluralize, struct_span_err, Applicability};
 use rustc_feature::{AttributeType, BUILTIN_ATTRIBUTE_MAP};
 use rustc_hir as hir;
@@ -66,6 +66,7 @@ impl CheckAttrVisitor<'tcx> {
         target: Target,
         item: Option<ItemLike<'_>>,
     ) {
+        let mut doc_aliases = FxHashMap::default();
         let mut is_valid = true;
         let mut specified_inline = None;
         let mut seen = FxHashSet::default();
@@ -79,7 +80,13 @@ impl CheckAttrVisitor<'tcx> {
                 sym::track_caller => {
                     self.check_track_caller(hir_id, &attr.span, attrs, span, target)
                 }
-                sym::doc => self.check_doc_attrs(attr, hir_id, target, &mut specified_inline),
+                sym::doc => self.check_doc_attrs(
+                    attr,
+                    hir_id,
+                    target,
+                    &mut specified_inline,
+                    &mut doc_aliases,
+                ),
                 sym::no_link => self.check_no_link(hir_id, &attr, span, target),
                 sym::export_name => self.check_export_name(hir_id, &attr, span, target),
                 sym::rustc_layout_scalar_valid_range_start
@@ -104,6 +111,7 @@ impl CheckAttrVisitor<'tcx> {
                 sym::default_method_body_is_const => {
                     self.check_default_method_body_is_const(attr, span, target)
                 }
+                sym::must_not_suspend => self.check_must_not_suspend(&attr, span, target),
                 sym::rustc_const_unstable
                 | sym::rustc_const_stable
                 | sym::unstable
@@ -511,6 +519,7 @@ impl CheckAttrVisitor<'tcx> {
         hir_id: HirId,
         target: Target,
         is_list: bool,
+        aliases: &mut FxHashMap<String, Span>,
     ) -> bool {
         let tcx = self.tcx;
         let err_fn = move |span: Span, msg: &str| {
@@ -581,17 +590,38 @@ impl CheckAttrVisitor<'tcx> {
         if &*item_name.as_str() == doc_alias {
             return err_fn(meta.span(), "is the same as the item's name");
         }
+        let span = meta.span();
+        if let Err(entry) = aliases.try_insert(doc_alias.to_owned(), span) {
+            self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, span, |lint| {
+                lint.build("doc alias is duplicated")
+                    .span_label(*entry.entry.get(), "first defined here")
+                    .emit();
+            });
+        }
         true
     }
 
-    fn check_doc_alias(&self, meta: &NestedMetaItem, hir_id: HirId, target: Target) -> bool {
+    fn check_doc_alias(
+        &self,
+        meta: &NestedMetaItem,
+        hir_id: HirId,
+        target: Target,
+        aliases: &mut FxHashMap<String, Span>,
+    ) -> bool {
         if let Some(values) = meta.meta_item_list() {
             let mut errors = 0;
             for v in values {
                 match v.literal() {
                     Some(l) => match l.kind {
                         LitKind::Str(s, _) => {
-                            if !self.check_doc_alias_value(v, &s.as_str(), hir_id, target, true) {
+                            if !self.check_doc_alias_value(
+                                v,
+                                &s.as_str(),
+                                hir_id,
+                                target,
+                                true,
+                                aliases,
+                            ) {
                                 errors += 1;
                             }
                         }
@@ -620,7 +650,7 @@ impl CheckAttrVisitor<'tcx> {
             }
             errors == 0
         } else if let Some(doc_alias) = meta.value_str().map(|s| s.to_string()) {
-            self.check_doc_alias_value(meta, &doc_alias, hir_id, target, false)
+            self.check_doc_alias_value(meta, &doc_alias, hir_id, target, false, aliases)
         } else {
             self.tcx
                 .sess
@@ -857,6 +887,7 @@ impl CheckAttrVisitor<'tcx> {
         hir_id: HirId,
         target: Target,
         specified_inline: &mut Option<(bool, Span)>,
+        aliases: &mut FxHashMap<String, Span>,
     ) -> bool {
         let mut is_valid = true;
 
@@ -866,7 +897,7 @@ impl CheckAttrVisitor<'tcx> {
                     match i_meta.name_or_empty() {
                         sym::alias
                             if !self.check_attr_not_crate_level(&meta, hir_id, "alias")
-                                || !self.check_doc_alias(&meta, hir_id, target) =>
+                                || !self.check_doc_alias(&meta, hir_id, target, aliases) =>
                         {
                             is_valid = false
                         }
@@ -907,6 +938,7 @@ impl CheckAttrVisitor<'tcx> {
                         // plugins: removed, but rustdoc warns about it itself
                         sym::alias
                         | sym::cfg
+                        | sym::cfg_hide
                         | sym::hidden
                         | sym::html_favicon_url
                         | sym::html_logo_url
@@ -1014,6 +1046,21 @@ impl CheckAttrVisitor<'tcx> {
         is_valid
     }
 
+    /// Checks if `#[must_not_suspend]` is applied to a function. Returns `true` if valid.
+    fn check_must_not_suspend(&self, attr: &Attribute, span: &Span, target: Target) -> bool {
+        match target {
+            Target::Struct | Target::Enum | Target::Union | Target::Trait => true,
+            _ => {
+                self.tcx
+                    .sess
+                    .struct_span_err(attr.span, "`must_not_suspend` attribute should be applied to a struct, enum, or trait")
+                        .span_label(*span, "is not a struct, enum, or trait")
+                        .emit();
+                false
+            }
+        }
+    }
+
     /// Checks if `#[cold]` is applied to a non-function. Returns `true` if valid.
     fn check_cold(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) {
         match target {
@@ -1720,8 +1767,7 @@ impl CheckAttrVisitor<'tcx> {
     fn check_macro_export(&self, hir_id: HirId, attr: &Attribute, target: Target) {
         if target != Target::MacroDef {
             self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| {
-                lint.build(&format!("`#[macro_export]` only has an effect on macro definitions"))
-                    .emit();
+                lint.build("`#[macro_export]` only has an effect on macro definitions").emit();
             });
         }
     }