New upstream version 1.67.1+dfsg1

[rustc.git] / compiler / rustc_middle / src / values.rs

diff --git a/compiler/rustc_middle/src/values.rs b/compiler/rustc_middle/src/values.rs
index f4b4c3fb05a7cb9e666741851661948f101a5215..70b98e59a8beab34f6e801b412526d6d5ac15aed 100644 (file)
--- a/compiler/rustc_middle/src/values.rs
+++ b/compiler/rustc_middle/src/values.rs
@@ -32,13 +32,23 @@ impl<'tcx> Value<TyCtxt<'tcx>> for ty::SymbolName<'_> {
 }
 
 impl<'tcx> Value<TyCtxt<'tcx>> for ty::Binder<'_, ty::FnSig<'_>> {
-    fn from_cycle_error(tcx: TyCtxt<'tcx>, _: &[QueryInfo]) -> Self {
+    fn from_cycle_error(tcx: TyCtxt<'tcx>, stack: &[QueryInfo]) -> Self {
         let err = tcx.ty_error();
-        // FIXME(compiler-errors): It would be nice if we could get the
-        // query key, so we could at least generate a fn signature that
-        // has the right arity.
+
+        let arity = if let Some(frame) = stack.get(0)
+            && frame.query.name == "fn_sig"
+            && let Some(def_id) = frame.query.def_id
+            && let Some(node) = tcx.hir().get_if_local(def_id)
+            && let Some(sig) = node.fn_sig()
+        {
+            sig.decl.inputs.len() + sig.decl.implicit_self.has_implicit_self() as usize
+        } else {
+            tcx.sess.abort_if_errors();
+            unreachable!()
+        };
+
         let fn_sig = ty::Binder::dummy(tcx.mk_fn_sig(
-            [].into_iter(),
+            std::iter::repeat(err).take(arity),
             err,
             false,
             rustc_hir::Unsafety::Normal,
@@ -185,7 +195,8 @@ fn find_item_ty_spans(
                 });
                 if check_params && let Some(args) = path.segments.last().unwrap().args {
                     let params_in_repr = tcx.params_in_repr(def_id);
-                    for (i, arg) in args.args.iter().enumerate() {
+                    // the domain size check is needed because the HIR may not be well-formed at this point
+                    for (i, arg) in args.args.iter().enumerate().take(params_in_repr.domain_size()) {
                         if let hir::GenericArg::Type(ty) = arg && params_in_repr.contains(i as u32) {
                             find_item_ty_spans(tcx, ty, needle, spans, seen_representable);
                         }