Add a TyPat in the AST to reuse the generic arg lowering logic

1 files changed, 15 insertions, 3 deletions

diff --git a/compiler/rustc_builtin_macros/src/pattern_type.rs b/compiler/rustc_builtin_macros/src/pattern_type.rs
index a600a9f316a..a55c7e962d0 100644
--- a/compiler/rustc_builtin_macros/src/pattern_type.rs
+++ b/compiler/rustc_builtin_macros/src/pattern_type.rs
@@ -1,6 +1,6 @@
 use rustc_ast::ptr::P;
 use rustc_ast::tokenstream::TokenStream;
-use rustc_ast::{Pat, Ty, ast};
+use rustc_ast::{AnonConst, DUMMY_NODE_ID, Ty, TyPat, TyPatKind, ast};
 use rustc_errors::PResult;
 use rustc_expand::base::{self, DummyResult, ExpandResult, ExtCtxt, MacroExpanderResult};
 use rustc_parse::exp;
@@ -21,12 +21,24 @@ pub(crate) fn expand<'cx>(
     ExpandResult::Ready(base::MacEager::ty(cx.ty(sp, ast::TyKind::Pat(ty, pat))))
 }
 
-fn parse_pat_ty<'a>(cx: &mut ExtCtxt<'a>, stream: TokenStream) -> PResult<'a, (P<Ty>, P<Pat>)> {
+fn parse_pat_ty<'a>(cx: &mut ExtCtxt<'a>, stream: TokenStream) -> PResult<'a, (P<Ty>, P<TyPat>)> {
     let mut parser = cx.new_parser_from_tts(stream);
 
     let ty = parser.parse_ty()?;
     parser.expect_keyword(exp!(Is))?;
-    let pat = parser.parse_pat_no_top_alt(None, None)?;
+    let pat = parser.parse_pat_no_top_alt(None, None)?.into_inner();
+
+    let kind = match pat.kind {
+        ast::PatKind::Range(start, end, include_end) => TyPatKind::Range(
+            start.map(|value| P(AnonConst { id: DUMMY_NODE_ID, value })),
+            end.map(|value| P(AnonConst { id: DUMMY_NODE_ID, value })),
+            include_end,
+        ),
+        ast::PatKind::Err(guar) => TyPatKind::Err(guar),
+        _ => TyPatKind::Err(cx.dcx().span_err(pat.span, "pattern not supported in pattern types")),
+    };
+
+    let pat = P(TyPat { id: pat.id, kind, span: pat.span, tokens: pat.tokens });
 
     Ok((ty, pat))
 }