Move `#[do_not_recommend]` to the `#[diagnostic]` namespace

This commit moves the `#[do_not_recommend]` attribute to the
`#[diagnostic]` namespace. It still requires
`#![feature(do_not_recommend)]` to work.

1 files changed, 11 insertions, 0 deletions

diff --git a/compiler/rustc_ast/src/attr/mod.rs b/compiler/rustc_ast/src/attr/mod.rs
index 0684163617f..d5c9fc960c8 100644
--- a/compiler/rustc_ast/src/attr/mod.rs
+++ b/compiler/rustc_ast/src/attr/mod.rs
@@ -13,6 +13,7 @@ use crate::util::literal::escape_string_symbol;
 use rustc_index::bit_set::GrowableBitSet;
 use rustc_span::symbol::{sym, Ident, Symbol};
 use rustc_span::Span;
+use smallvec::{smallvec, SmallVec};
 use std::iter;
 use std::sync::atomic::{AtomicU32, Ordering};
 use thin_vec::{thin_vec, ThinVec};
@@ -87,10 +88,20 @@ impl Attribute {
             AttrKind::DocComment(..) => None,
         }
     }
+
     pub fn name_or_empty(&self) -> Symbol {
         self.ident().unwrap_or_else(Ident::empty).name
     }
 
+    pub fn path(&self) -> SmallVec<[Symbol; 1]> {
+        match &self.kind {
+            AttrKind::Normal(normal) => {
+                normal.item.path.segments.iter().map(|s| s.ident.name).collect()
+            }
+            AttrKind::DocComment(..) => smallvec![sym::doc],
+        }
+    }
+
     #[inline]
     pub fn has_name(&self, name: Symbol) -> bool {
         match &self.kind {