Rollup merge of rust-lang#75084 - Aaron1011:stabilize/ident-new-raw, r=petrochenkov

Stabilize Ident::new_raw

Tracking issue: rust-lang#54723

This is a continuation of PR rust-lang#59002

Author: JohnTitor

library/proc_macro/src/lib.rs

@@ -848,7 +848,7 @@ impl Ident {
     /// Creates a new `Ident` with the given `string` as well as the specified
     /// `span`.
     /// The `string` argument must be a valid identifier permitted by the
-    /// language, otherwise the function will panic.
+    /// language (including keywords, e.g. `self` or `fn`). Otherwise, the function will panic.
     ///
     /// Note that `span`, currently in rustc, configures the hygiene information
     /// for this identifier.
@@ -870,7 +870,10 @@ impl Ident {
     }
 
     /// Same as `Ident::new`, but creates a raw identifier (`r#ident`).
-    #[unstable(feature = "proc_macro_raw_ident", issue = "54723")]
+    /// The `string` argument be a valid identifier permitted by the language
+    /// (including keywords, e.g. `fn`). Keywords which are usable in path segments
+    /// (e.g. `self`, `super`) are not supported, and will cause a panic.
+    #[stable(feature = "proc_macro_raw_ident", since = "1.47.0")]
     pub fn new_raw(string: &str, span: Span) -> Ident {
         Ident(bridge::client::Ident::new(string, span.0, true))
     }

src/test/ui/proc-macro/auxiliary/raw-ident.rs

@@ -0,0 +1,35 @@
+// force-host
+// no-prefer-dynamic
+
+#![crate_type = "proc-macro"]
+
+extern crate proc_macro;
+use proc_macro::{TokenStream, TokenTree, Ident, Punct, Spacing, Span};
+
+#[proc_macro]
+pub fn make_struct(input: TokenStream) -> TokenStream {
+    match input.into_iter().next().unwrap() {
+        TokenTree::Ident(ident) => {
+            vec![
+                TokenTree::Ident(Ident::new("struct", Span::call_site())),
+                TokenTree::Ident(Ident::new_raw(&ident.to_string(), Span::call_site())),
+                TokenTree::Punct(Punct::new(';', Spacing::Alone))
+            ].into_iter().collect()
+        }
+        _ => panic!()
+    }
+}
+
+#[proc_macro]
+pub fn make_bad_struct(input: TokenStream) -> TokenStream {
+    match input.into_iter().next().unwrap() {
+        TokenTree::Ident(ident) => {
+            vec![
+                TokenTree::Ident(Ident::new_raw("struct", Span::call_site())),
+                TokenTree::Ident(Ident::new(&ident.to_string(), Span::call_site())),
+                TokenTree::Punct(Punct::new(';', Spacing::Alone))
+            ].into_iter().collect()
+        }
+        _ => panic!()
+    }
+}

src/test/ui/proc-macro/raw-ident.rs

@@ -0,0 +1,16 @@
+// aux-build:raw-ident.rs
+
+#[macro_use] extern crate raw_ident;
+
+fn main() {
+    make_struct!(fn);
+    make_struct!(Foo);
+    make_struct!(await);
+
+    r#fn;
+    r#Foo;
+    Foo;
+    r#await;
+
+    make_bad_struct!(S); //~ ERROR expected one of
+}

src/test/ui/proc-macro/raw-ident.stderr

@@ -0,0 +1,10 @@
+error: expected one of `!`, `.`, `::`, `;`, `?`, `{`, `}`, or an operator, found `S`
+  --> $DIR/raw-ident.rs:15:5
+   |
+LL |     make_bad_struct!(S);
+   |     ^^^^^^^^^^^^^^^^^^^^ expected one of 8 possible tokens
+   |
+   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to previous error
+