From 7b1b17574bf1466ddd7e6657b6122244dc5a73ce Mon Sep 17 00:00:00 2001
From: Deadbeef <ent3rm4n@gmail.com>
Date: Tue, 12 Sep 2023 01:07:04 +0000
Subject: [PATCH] fix bugs with effects fallback

---
 compiler/rustc_monomorphize/src/collector.rs |  6 ------
 compiler/rustc_passes/src/lang_items.rs      | 12 ++++++++++--
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/compiler/rustc_monomorphize/src/collector.rs b/compiler/rustc_monomorphize/src/collector.rs
index 118b3862887..67e821dcf5a 100644
--- a/compiler/rustc_monomorphize/src/collector.rs
+++ b/compiler/rustc_monomorphize/src/collector.rs
@@ -815,12 +815,6 @@ fn visit_terminator(&mut self, terminator: &mir::Terminator<'tcx>, location: Loc
                     mir::AssertKind::BoundsCheck { .. } => LangItem::PanicBoundsCheck,
                     _ => LangItem::Panic,
                 };
-                let def_id = tcx.require_lang_item(lang_item, Some(source));
-                let instance = if has_host_effect {
-                    Instance::new(def_id, tcx.mk_args(&[tcx.consts.true_.into()]))
-                } else {
-                    Instance::mono(tcx, def_id)
-                };
                 push_mono_lang_item(self, lang_item);
             }
             mir::TerminatorKind::UnwindTerminate(reason) => {
diff --git a/compiler/rustc_passes/src/lang_items.rs b/compiler/rustc_passes/src/lang_items.rs
index 476394f30cc..7e837243918 100644
--- a/compiler/rustc_passes/src/lang_items.rs
+++ b/compiler/rustc_passes/src/lang_items.rs
@@ -20,7 +20,8 @@
 use rustc_hir::{LangItem, LanguageItems, Target};
 use rustc_middle::ty::TyCtxt;
 use rustc_session::cstore::ExternCrate;
-use rustc_span::{symbol::kw::Empty, Span};
+use rustc_span::symbol::kw::Empty;
+use rustc_span::{sym, Span};
 
 use rustc_middle::query::Providers;
 
@@ -157,7 +158,14 @@ fn collect_item_extended(&mut self, lang_item: LangItem, item_def_id: LocalDefId
             self.tcx.hir().get_by_def_id(item_def_id)
         {
             let (actual_num, generics_span) = match kind.generics() {
-                Some(generics) => (generics.params.len(), generics.span),
+                Some(generics) => (
+                    generics
+                        .params
+                        .iter()
+                        .filter(|p| !self.tcx.has_attr(p.def_id, sym::rustc_host))
+                        .count(),
+                    generics.span,
+                ),
                 None => (0, *item_span),
             };