Avoid going through the happy path in case of non-fn builtin calls

compiler/rustc_hir_typeck/src/callee.rs

@@ -4,7 +4,7 @@ use super::{Expectation, FnCtxt, TupleArgumentsFlag};
 
 use crate::type_error_struct;
 use rustc_ast::util::parser::PREC_POSTFIX;
-use rustc_errors::{struct_span_err, Applicability, Diagnostic, StashKey};
+use rustc_errors::{struct_span_err, Applicability, Diagnostic, ErrorGuaranteed, StashKey};
 use rustc_hir as hir;
 use rustc_hir::def::{self, CtorKind, Namespace, Res};
 use rustc_hir::def_id::DefId;
@@ -424,21 +424,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     }
                 }
 
-                self.report_invalid_callee(call_expr, callee_expr, callee_ty, arg_exprs);
-
-                // This is the "default" function signature, used in case of error.
-                // In that case, we check each argument against "error" in order to
-                // set up all the node type bindings.
-                (
-                    ty::Binder::dummy(self.tcx.mk_fn_sig(
-                        self.err_args(arg_exprs.len()).into_iter(),
-                        self.tcx.ty_error(),
-                        false,
-                        hir::Unsafety::Normal,
-                        abi::Abi::Rust,
-                    )),
-                    None,
-                )
+                let err = self.report_invalid_callee(call_expr, callee_expr, callee_ty, arg_exprs);
+
+                return self.tcx.ty_error_with_guaranteed(err);
             }
         };
 
@@ -591,7 +579,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         callee_expr: &'tcx hir::Expr<'tcx>,
         callee_ty: Ty<'tcx>,
         arg_exprs: &'tcx [hir::Expr<'tcx>],
-    ) {
+    ) -> ErrorGuaranteed {
         let mut unit_variant = None;
         if let hir::ExprKind::Path(qpath) = &callee_expr.kind
             && let Res::Def(def::DefKind::Ctor(kind, CtorKind::Const), _)
@@ -720,7 +708,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 err.span_label(span, label);
             }
         }
-        err.emit();
+        err.emit()
     }
 
     fn confirm_deferred_closure_call(

compiler/rustc_middle/src/ty/subst.rs

@@ -400,6 +400,7 @@ impl<'tcx> InternalSubsts<'tcx> {
     }
 
     #[inline]
+    #[track_caller]
     pub fn type_at(&self, i: usize) -> Ty<'tcx> {
         if let GenericArgKind::Type(ty) = self[i].unpack() {
             ty
@@ -409,6 +410,7 @@ impl<'tcx> InternalSubsts<'tcx> {
     }
 
     #[inline]
+    #[track_caller]
     pub fn region_at(&self, i: usize) -> ty::Region<'tcx> {
         if let GenericArgKind::Lifetime(lt) = self[i].unpack() {
             lt
@@ -418,6 +420,7 @@ impl<'tcx> InternalSubsts<'tcx> {
     }
 
     #[inline]
+    #[track_caller]
     pub fn const_at(&self, i: usize) -> ty::Const<'tcx> {
         if let GenericArgKind::Const(ct) = self[i].unpack() {
             ct
@@ -427,6 +430,7 @@ impl<'tcx> InternalSubsts<'tcx> {
     }
 
     #[inline]
+    #[track_caller]
     pub fn type_for_def(&self, def: &ty::GenericParamDef) -> GenericArg<'tcx> {
         self.type_at(def.index as usize).into()
     }