Add a test

2 files changed, 14 insertions, 4 deletions

diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs
index 09286a8ed24..8fd84d8c053 100644
--- a/compiler/rustc_codegen_ssa/src/mir/block.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/block.rs
@@ -1693,11 +1693,15 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
 
         self.set_debug_loc(&mut bx, mir::SourceInfo::outermost(self.mir.span));
 
-        let (fn_abi, fn_ptr, _instance) = common::build_langcall(&bx, None, reason.lang_item());
-        let fn_ty = bx.fn_decl_backend_type(fn_abi);
+        let (fn_abi, fn_ptr, instance) = common::build_langcall(&bx, None, reason.lang_item());
+        if is_call_from_compiler_builtins_to_upstream_monomorphization(bx.tcx(), instance) {
+            bx.abort();
+        } else {
+            let fn_ty = bx.fn_decl_backend_type(fn_abi);
 
-        let llret = bx.call(fn_ty, None, Some(fn_abi), fn_ptr, &[], funclet.as_ref());
-        bx.apply_attrs_to_cleanup_callsite(llret);
+            let llret = bx.call(fn_ty, None, Some(fn_abi), fn_ptr, &[], funclet.as_ref());
+            bx.apply_attrs_to_cleanup_callsite(llret);
+        }
 
         bx.unreachable();
 
diff --git a/compiler/rustc_middle/src/ty/instance.rs b/compiler/rustc_middle/src/ty/instance.rs
index 814c3629b08..b82e959844f 100644
--- a/compiler/rustc_middle/src/ty/instance.rs
+++ b/compiler/rustc_middle/src/ty/instance.rs
@@ -10,6 +10,7 @@ use rustc_hir::lang_items::LangItem;
 use rustc_index::bit_set::FiniteBitSet;
 use rustc_macros::HashStable;
 use rustc_middle::ty::normalize_erasing_regions::NormalizationError;
+use rustc_span::def_id::LOCAL_CRATE;
 use rustc_span::Symbol;
 
 use std::assert_matches::assert_matches;
@@ -168,6 +169,11 @@ impl<'tcx> Instance<'tcx> {
         // If this a non-generic instance, it cannot be a shared monomorphization.
         self.args.non_erasable_generics(tcx, self.def_id()).next()?;
 
+        // compiler_builtins cannot use upstream monomorphizations.
+        if tcx.is_compiler_builtins(LOCAL_CRATE) {
+            return None;
+        }
+
         match self.def {
             InstanceDef::Item(def) => tcx
                 .upstream_monomorphizations_for(def)