rust-lang · tmiasko · May 9, 2025
diff --git a/compiler/rustc_interface/src/tests.rs b/compiler/rustc_interface/src/tests.rs
@@ -720,7 +720,7 @@ fn test_unstable_options_tracking_hash() {
     untracked!(pre_link_args, vec![String::from("abc"), String::from("def")]);
     untracked!(print_codegen_stats, true);
     untracked!(print_llvm_passes, true);
-    untracked!(print_mono_items, Some(String::from("abc")));
+    untracked!(print_mono_items, true);
     untracked!(print_type_sizes, true);
     untracked!(proc_macro_backtrace, true);
     untracked!(proc_macro_execution_strategy, ProcMacroExecutionStrategy::CrossThread);

diff --git a/compiler/rustc_monomorphize/messages.ftl b/compiler/rustc_monomorphize/messages.ftl
@@ -60,9 +60,6 @@ monomorphize_start_not_found = using `fn main` requires the standard library
 
 monomorphize_symbol_already_defined = symbol `{$symbol}` is already defined
 
-monomorphize_unknown_cgu_collection_mode =
-    unknown codegen-item collection mode '{$mode}', falling back to 'lazy' mode
-
 monomorphize_wasm_c_abi_transition =
     this function {$is_call ->
       [true] call

diff --git a/compiler/rustc_monomorphize/src/errors.rs b/compiler/rustc_monomorphize/src/errors.rs
@@ -64,12 +64,6 @@ pub(crate) struct EncounteredErrorWhileInstantiating {
 #[help]
 pub(crate) struct StartNotFound;
 
-#[derive(Diagnostic)]
-#[diag(monomorphize_unknown_cgu_collection_mode)]
-pub(crate) struct UnknownCguCollectionMode<'a> {
-    pub mode: &'a str,
-}
-
 #[derive(Diagnostic)]
 #[diag(monomorphize_abi_error_disabled_vector_type)]
 #[help]

diff --git a/compiler/rustc_monomorphize/src/partitioning.rs b/compiler/rustc_monomorphize/src/partitioning.rs
@@ -124,7 +124,7 @@ use rustc_target::spec::SymbolVisibility;
 use tracing::debug;
 
 use crate::collector::{self, MonoItemCollectionStrategy, UsageMap};
-use crate::errors::{CouldntDumpMonoStats, SymbolAlreadyDefined, UnknownCguCollectionMode};
+use crate::errors::{CouldntDumpMonoStats, SymbolAlreadyDefined};
 
 struct PartitioningCx<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
@@ -1127,27 +1127,10 @@ where
 }
 
 fn collect_and_partition_mono_items(tcx: TyCtxt<'_>, (): ()) -> MonoItemPartitions<'_> {
-    let collection_strategy = match tcx.sess.opts.unstable_opts.print_mono_items {
-        Some(ref s) => {
-            let mode = s.to_lowercase();
-            let mode = mode.trim();
-            if mode == "eager" {
-                MonoItemCollectionStrategy::Eager
-            } else {
-                if mode != "lazy" {
-                    tcx.dcx().emit_warn(UnknownCguCollectionMode { mode });
-                }
-
-                MonoItemCollectionStrategy::Lazy
-            }
-        }
-        None => {
-            if tcx.sess.link_dead_code() {
-                MonoItemCollectionStrategy::Eager
-            } else {
-                MonoItemCollectionStrategy::Lazy
-            }
-        }
+    let collection_strategy = if tcx.sess.link_dead_code() {
+        MonoItemCollectionStrategy::Eager
+    } else {
+        MonoItemCollectionStrategy::Lazy
     };
 
     let (items, usage_map) = collector::collect_crate_mono_items(tcx, collection_strategy);
@@ -1209,7 +1192,7 @@ fn collect_and_partition_mono_items(tcx: TyCtxt<'_>, (): ()) -> MonoItemPartitio
         }
     }
 
-    if tcx.sess.opts.unstable_opts.print_mono_items.is_some() {
+    if tcx.sess.opts.unstable_opts.print_mono_items {
         let mut item_to_cgus: UnordMap<_, Vec<_>> = Default::default();
 
         for cgu in codegen_units {

diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
@@ -2408,10 +2408,8 @@ options! {
         "print codegen statistics (default: no)"),
     print_llvm_passes: bool = (false, parse_bool, [UNTRACKED],
         "print the LLVM optimization passes being run (default: no)"),
-    print_mono_items: Option<String> = (None, parse_opt_string, [UNTRACKED],
-        "print the result of the monomorphization collection pass. \
-         Value `lazy` means to use normal collection; `eager` means to collect all items.
-         Note that this overwrites the effect `-Clink-dead-code` has on collection!"),
+    print_mono_items: bool = (false, parse_bool, [UNTRACKED],
+        "print the result of the monomorphization collection pass (default: no)"),
     print_type_sizes: bool = (false, parse_bool, [UNTRACKED],
         "print layout information for each type encountered (default: no)"),
     proc_macro_backtrace: bool = (false, parse_bool, [UNTRACKED],

diff --git a/src/doc/rustc-dev-guide/src/tests/compiletest.md b/src/doc/rustc-dev-guide/src/tests/compiletest.md
@@ -325,12 +325,8 @@ The tests in [`tests/codegen-units`] test the
 [monomorphization](../backend/monomorph.md) collector and CGU partitioning.
 
 These tests work by running `rustc` with a flag to print the result of the
-monomorphization collection pass, and then special annotations in the file are
-used to compare against that.
-
-Each test should be annotated with the `//@
-compile-flags:-Zprint-mono-items=VAL` directive with the appropriate `VAL` to
-instruct `rustc` to print the monomorphization information.
+monomorphization collection pass, i.e., `-Zprint-mono-items`, and then special
+annotations in the file are used to compare against that.
 
 Then, the test should be annotated with comments of the form `//~ MONO_ITEM
 name` where `name` is the monomorphized string printed by rustc like `fn <u32 as

diff --git a/src/tools/compiletest/src/runtest.rs b/src/tools/compiletest/src/runtest.rs
@@ -1583,7 +1583,10 @@ impl<'test> TestCx<'test> {
             Crashes => {
                 set_mir_dump_dir(&mut rustc);
             }
-            Pretty | DebugInfo | Rustdoc | RustdocJson | RunMake | CodegenUnits | RustdocJs => {
+            CodegenUnits => {
+                rustc.arg("-Zprint-mono-items");
+            }
+            Pretty | DebugInfo | Rustdoc | RustdocJson | RunMake | RustdocJs => {
                 // do not use JSON output
             }
         }

diff --git a/tests/codegen-units/item-collection/asm-sym.rs b/tests/codegen-units/item-collection/asm-sym.rs
@@ -1,5 +1,5 @@
 //@ needs-asm-support
-//@ compile-flags: -Ccodegen-units=1 -Zprint-mono-items=lazy --crate-type=lib
+//@ compile-flags: -Ccodegen-units=1 --crate-type=lib
 
 #[inline(always)]
 pub unsafe fn f() {

diff --git a/tests/codegen-units/item-collection/closures.rs b/tests/codegen-units/item-collection/closures.rs
@@ -1,5 +1,5 @@
 //@ edition: 2021
-//@ compile-flags: -Zprint-mono-items=eager --crate-type=lib
+//@ compile-flags: -Clink-dead-code --crate-type=lib
 
 //~ MONO_ITEM fn async_fn @@
 //~ MONO_ITEM fn async_fn::{closure#0} @@

diff --git a/tests/codegen-units/item-collection/cross-crate-closures.rs b/tests/codegen-units/item-collection/cross-crate-closures.rs
@@ -1,6 +1,6 @@
 // We need to disable MIR inlining in both this and its aux-build crate. The MIR inliner
 // will just inline everything into our start function if we let it. As it should.
-//@ compile-flags:-Zprint-mono-items=eager -Zinline-mir=no
+//@ compile-flags:-Clink-dead-code -Zinline-mir=no
 
 #![deny(dead_code)]
 #![no_main]
@@ -11,12 +11,12 @@ extern crate cgu_extern_closures;
 //~ MONO_ITEM fn main @@ cross_crate_closures-cgu.0[External]
 #[no_mangle]
 extern "C" fn main(_: core::ffi::c_int, _: *const *const u8) -> core::ffi::c_int {
-    //~ MONO_ITEM fn cgu_extern_closures::inlined_fn @@ cross_crate_closures-cgu.0[Internal]
-    //~ MONO_ITEM fn cgu_extern_closures::inlined_fn::{closure#0} @@ cross_crate_closures-cgu.0[Internal]
+    //~ MONO_ITEM fn cgu_extern_closures::inlined_fn @@ cross_crate_closures-cgu.0[External]
+    //~ MONO_ITEM fn cgu_extern_closures::inlined_fn::{closure#0} @@ cross_crate_closures-cgu.0[External]
     let _ = cgu_extern_closures::inlined_fn(1, 2);
 
-    //~ MONO_ITEM fn cgu_extern_closures::inlined_fn_generic::<i32> @@ cross_crate_closures-cgu.0[Internal]
-    //~ MONO_ITEM fn cgu_extern_closures::inlined_fn_generic::<i32>::{closure#0} @@ cross_crate_closures-cgu.0[Internal]
+    //~ MONO_ITEM fn cgu_extern_closures::inlined_fn_generic::<i32> @@ cross_crate_closures-cgu.0[External]
+    //~ MONO_ITEM fn cgu_extern_closures::inlined_fn_generic::<i32>::{closure#0} @@ cross_crate_closures-cgu.0[External]
     let _ = cgu_extern_closures::inlined_fn_generic(3, 4, 5i32);
 
     // Nothing should be generated for this call, we just link to the instance

diff --git a/tests/codegen-units/item-collection/cross-crate-generic-functions.rs b/tests/codegen-units/item-collection/cross-crate-generic-functions.rs
@@ -1,4 +1,4 @@
-//@ compile-flags:-Zprint-mono-items=eager
+//@ compile-flags:-Clink-dead-code
 
 #![deny(dead_code)]
 #![crate_type = "lib"]

diff --git a/tests/codegen-units/item-collection/cross-crate-trait-method.rs b/tests/codegen-units/item-collection/cross-crate-trait-method.rs
@@ -1,4 +1,4 @@
-//@ compile-flags:-Zprint-mono-items=eager -Zinline-mir=no -Copt-level=0
+//@ compile-flags:-Clink-dead-code -Zinline-mir=no -Copt-level=0
 
 #![deny(dead_code)]
 #![crate_type = "lib"]

diff --git a/tests/codegen-units/item-collection/drop-glue-eager.rs b/tests/codegen-units/item-collection/drop-glue-eager.rs
@@ -1,6 +1,6 @@
 // Ensure that we *eagerly* monomorphize drop instances for structs with lifetimes.
 
-//@ compile-flags:-Zprint-mono-items=eager
+//@ compile-flags:-Clink-dead-code
 //@ compile-flags:--crate-type=lib
 
 //~ MONO_ITEM fn std::ptr::drop_in_place::<StructWithDrop> - shim(Some(StructWithDrop))

diff --git a/tests/codegen-units/item-collection/drop_in_place_intrinsic.rs b/tests/codegen-units/item-collection/drop_in_place_intrinsic.rs
@@ -1,4 +1,4 @@
-//@ compile-flags:-Zprint-mono-items=eager
+//@ compile-flags:-Clink-dead-code
 //@ compile-flags:-Zinline-mir=no
 //@ compile-flags: -O
 

diff --git a/tests/codegen-units/item-collection/function-as-argument.rs b/tests/codegen-units/item-collection/function-as-argument.rs
@@ -1,4 +1,4 @@
-//@ compile-flags:-Zprint-mono-items=eager -Zinline-mir=no
+//@ compile-flags:-Clink-dead-code -Zinline-mir=no
 
 #![deny(dead_code)]
 #![crate_type = "lib"]

diff --git a/tests/codegen-units/item-collection/generic-drop-glue.rs b/tests/codegen-units/item-collection/generic-drop-glue.rs
@@ -1,4 +1,4 @@
-//@ compile-flags:-Zprint-mono-items=eager
+//@ compile-flags:-Clink-dead-code
 //@ compile-flags: -O
 
 #![deny(dead_code)]

diff --git a/tests/codegen-units/item-collection/generic-functions.rs b/tests/codegen-units/item-collection/generic-functions.rs
@@ -1,4 +1,4 @@
-//@ compile-flags:-Zprint-mono-items=eager -Zinline-mir=no
+//@ compile-flags:-Clink-dead-code -Zinline-mir=no
 
 #![deny(dead_code)]
 #![crate_type = "lib"]

diff --git a/tests/codegen-units/item-collection/generic-impl.rs b/tests/codegen-units/item-collection/generic-impl.rs
@@ -1,4 +1,4 @@
-//@ compile-flags:-Zprint-mono-items=eager -Zinline-mir=no
+//@ compile-flags:-Clink-dead-code -Zinline-mir=no
 
 #![deny(dead_code)]
 #![crate_type = "lib"]

diff --git a/tests/codegen-units/item-collection/impl-in-non-instantiated-generic.rs b/tests/codegen-units/item-collection/impl-in-non-instantiated-generic.rs
@@ -1,4 +1,4 @@
-//@ compile-flags:-Zprint-mono-items=eager
+//@ compile-flags:-Clink-dead-code
 
 #![deny(dead_code)]
 #![crate_type = "lib"]

diff --git a/tests/codegen-units/item-collection/implicit-panic-call.rs b/tests/codegen-units/item-collection/implicit-panic-call.rs
@@ -1,5 +1,3 @@
-//@ compile-flags:-Zprint-mono-items=lazy
-
 // rust-lang/rust#90405
 // Ensure implicit panic calls are collected
 

diff --git a/tests/codegen-units/item-collection/instantiation-through-vtable.rs b/tests/codegen-units/item-collection/instantiation-through-vtable.rs
@@ -1,4 +1,4 @@
-//@ compile-flags:-Zprint-mono-items=eager -Zmir-opt-level=0
+//@ compile-flags:-Clink-dead-code -Zmir-opt-level=0
 
 #![deny(dead_code)]
 #![crate_type = "lib"]
@@ -24,15 +24,15 @@ impl<T> Trait for Struct<T> {
 pub fn start(_: isize, _: *const *const u8) -> isize {
     let s1 = Struct { _a: 0u32 };
 
-    //~ MONO_ITEM fn std::ptr::drop_in_place::<Struct<u32>> - shim(None) @@ instantiation_through_vtable-cgu.0[Internal]
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<Struct<u32>> - shim(None) @@ instantiation_through_vtable-cgu.0[External]
     //~ MONO_ITEM fn <Struct<u32> as Trait>::foo
     //~ MONO_ITEM fn <Struct<u32> as Trait>::bar
     let r1 = &s1 as &Trait;
     r1.foo();
     r1.bar();
 
     let s1 = Struct { _a: 0u64 };
-    //~ MONO_ITEM fn std::ptr::drop_in_place::<Struct<u64>> - shim(None) @@ instantiation_through_vtable-cgu.0[Internal]
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<Struct<u64>> - shim(None) @@ instantiation_through_vtable-cgu.0[External]
     //~ MONO_ITEM fn <Struct<u64> as Trait>::foo
     //~ MONO_ITEM fn <Struct<u64> as Trait>::bar
     let _ = &s1 as &Trait;

diff --git a/tests/codegen-units/item-collection/items-within-generic-items.rs b/tests/codegen-units/item-collection/items-within-generic-items.rs
@@ -1,4 +1,4 @@
-//@ compile-flags:-Zprint-mono-items=eager -Copt-level=0
+//@ compile-flags:-Clink-dead-code -Copt-level=0
 
 #![deny(dead_code)]
 #![crate_type = "lib"]

diff --git a/tests/codegen-units/item-collection/non-generic-closures.rs b/tests/codegen-units/item-collection/non-generic-closures.rs
@@ -1,39 +1,39 @@
-//@ compile-flags:-Zprint-mono-items=eager -Zinline-mir=no
+//@ compile-flags:-Clink-dead-code -Zinline-mir=no
 
 #![deny(dead_code)]
 #![crate_type = "lib"]
 
-//~ MONO_ITEM fn temporary @@ non_generic_closures-cgu.0[Internal]
+//~ MONO_ITEM fn temporary @@ non_generic_closures-cgu.0[External]
 fn temporary() {
-    //~ MONO_ITEM fn temporary::{closure#0} @@ non_generic_closures-cgu.0[Internal]
+    //~ MONO_ITEM fn temporary::{closure#0} @@ non_generic_closures-cgu.0[External]
     (|a: u32| {
         let _ = a;
     })(4);
 }
 
-//~ MONO_ITEM fn assigned_to_variable_but_not_executed @@ non_generic_closures-cgu.0[Internal]
+//~ MONO_ITEM fn assigned_to_variable_but_not_executed @@ non_generic_closures-cgu.0[External]
 fn assigned_to_variable_but_not_executed() {
     //~ MONO_ITEM fn assigned_to_variable_but_not_executed::{closure#0}
     let _x = |a: i16| {
         let _ = a + 1;
     };
 }
 
-//~ MONO_ITEM fn assigned_to_variable_executed_indirectly @@ non_generic_closures-cgu.0[Internal]
+//~ MONO_ITEM fn assigned_to_variable_executed_indirectly @@ non_generic_closures-cgu.0[External]
 fn assigned_to_variable_executed_indirectly() {
-    //~ MONO_ITEM fn assigned_to_variable_executed_indirectly::{closure#0} @@ non_generic_closures-cgu.0[Internal]
-    //~ MONO_ITEM fn <{closure@TEST_PATH:28:13: 28:21} as std::ops::FnOnce<(i32,)>>::call_once - shim @@ non_generic_closures-cgu.0[Internal]
-    //~ MONO_ITEM fn <{closure@TEST_PATH:28:13: 28:21} as std::ops::FnOnce<(i32,)>>::call_once - shim(vtable) @@ non_generic_closures-cgu.0[Internal]
-    //~ MONO_ITEM fn std::ptr::drop_in_place::<{closure@TEST_PATH:28:13: 28:21}> - shim(None) @@ non_generic_closures-cgu.0[Internal]
+    //~ MONO_ITEM fn assigned_to_variable_executed_indirectly::{closure#0} @@ non_generic_closures-cgu.0[External]
+    //~ MONO_ITEM fn <{closure@TEST_PATH:28:13: 28:21} as std::ops::FnOnce<(i32,)>>::call_once - shim @@ non_generic_closures-cgu.0[External]
+    //~ MONO_ITEM fn <{closure@TEST_PATH:28:13: 28:21} as std::ops::FnOnce<(i32,)>>::call_once - shim(vtable) @@ non_generic_closures-cgu.0[External]
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<{closure@TEST_PATH:28:13: 28:21}> - shim(None) @@ non_generic_closures-cgu.0[External]
     let f = |a: i32| {
         let _ = a + 2;
     };
     run_closure(&f);
 }
 
-//~ MONO_ITEM fn assigned_to_variable_executed_directly @@ non_generic_closures-cgu.0[Internal]
+//~ MONO_ITEM fn assigned_to_variable_executed_directly @@ non_generic_closures-cgu.0[External]
 fn assigned_to_variable_executed_directly() {
-    //~ MONO_ITEM fn assigned_to_variable_executed_directly::{closure#0} @@ non_generic_closures-cgu.0[Internal]
+    //~ MONO_ITEM fn assigned_to_variable_executed_directly::{closure#0} @@ non_generic_closures-cgu.0[External]
     let f = |a: i64| {
         let _ = a + 3;
     };
@@ -51,7 +51,7 @@ pub fn start(_: isize, _: *const *const u8) -> isize {
     0
 }
 
-//~ MONO_ITEM fn run_closure @@ non_generic_closures-cgu.0[Internal]
+//~ MONO_ITEM fn run_closure @@ non_generic_closures-cgu.0[External]
 fn run_closure(f: &Fn(i32)) {
     f(3);
 }
diff --git a/tests/codegen-units/item-collection/non-generic-drop-glue.rs b/tests/codegen-units/item-collection/non-generic-drop-glue.rs
@@ -1,4 +1,4 @@
-//@ compile-flags:-Zprint-mono-items=eager
+//@ compile-flags:-Clink-dead-code
 //@ compile-flags: -O
 
 #![deny(dead_code)]

diff --git a/tests/codegen-units/item-collection/non-generic-functions.rs b/tests/codegen-units/item-collection/non-generic-functions.rs
@@ -1,4 +1,4 @@
-//@ compile-flags:-Zprint-mono-items=eager
+//@ compile-flags:-Clink-dead-code
 
 #![deny(dead_code)]
 #![crate_type = "lib"]

diff --git a/tests/codegen-units/item-collection/overloaded-operators.rs b/tests/codegen-units/item-collection/overloaded-operators.rs
@@ -1,4 +1,4 @@
-//@ compile-flags:-Zprint-mono-items=eager
+//@ compile-flags:-Clink-dead-code
 
 #![deny(dead_code)]
 #![crate_type = "lib"]

diff --git a/tests/codegen-units/item-collection/static-init.rs b/tests/codegen-units/item-collection/static-init.rs
@@ -1,4 +1,4 @@
-//@ compile-flags:-Zprint-mono-items=eager
+//@ compile-flags:-Clink-dead-code
 
 #![crate_type = "lib"]
 

diff --git a/tests/codegen-units/item-collection/statics-and-consts.rs b/tests/codegen-units/item-collection/statics-and-consts.rs
@@ -1,4 +1,4 @@
-//@ compile-flags:-Zprint-mono-items=eager
+//@ compile-flags:-Clink-dead-code
 
 #![deny(dead_code)]
 #![crate_type = "lib"]

diff --git a/tests/codegen-units/item-collection/trait-implementations.rs b/tests/codegen-units/item-collection/trait-implementations.rs
@@ -1,4 +1,4 @@
-//@ compile-flags:-Zprint-mono-items=eager -Zinline-mir=no
+//@ compile-flags:-Clink-dead-code -Zinline-mir=no
 
 #![deny(dead_code)]
 #![crate_type = "lib"]

diff --git a/tests/codegen-units/item-collection/trait-method-as-argument.rs b/tests/codegen-units/item-collection/trait-method-as-argument.rs
@@ -1,4 +1,4 @@
-//@ compile-flags:-Zprint-mono-items=eager -Zinline-mir=no
+//@ compile-flags:-Clink-dead-code -Zinline-mir=no
 
 #![deny(dead_code)]
 #![crate_type = "lib"]

diff --git a/tests/codegen-units/item-collection/trait-method-default-impl.rs b/tests/codegen-units/item-collection/trait-method-default-impl.rs
@@ -1,4 +1,4 @@
-//@ compile-flags:-Zprint-mono-items=eager -Zinline-mir=no
+//@ compile-flags:-Clink-dead-code -Zinline-mir=no
 
 #![deny(dead_code)]
 #![crate_type = "lib"]

diff --git a/tests/codegen-units/item-collection/transitive-drop-glue.rs b/tests/codegen-units/item-collection/transitive-drop-glue.rs
@@ -1,4 +1,4 @@
-//@ compile-flags:-Zprint-mono-items=eager
+//@ compile-flags:-Clink-dead-code
 //@ compile-flags: -O
 
 #![deny(dead_code)]

diff --git a/tests/codegen-units/item-collection/tuple-drop-glue.rs b/tests/codegen-units/item-collection/tuple-drop-glue.rs
@@ -1,4 +1,4 @@
-//@ compile-flags:-Zprint-mono-items=eager
+//@ compile-flags:-Clink-dead-code
 //@ compile-flags: -O
 
 #![deny(dead_code)]

diff --git a/tests/codegen-units/item-collection/unreferenced-const-fn.rs b/tests/codegen-units/item-collection/unreferenced-const-fn.rs
@@ -1,5 +1,3 @@
-//@ compile-flags:-Zprint-mono-items=lazy
-
 #![deny(dead_code)]
 #![crate_type = "rlib"]
 

diff --git a/tests/codegen-units/item-collection/unreferenced-inline-function.rs b/tests/codegen-units/item-collection/unreferenced-inline-function.rs
@@ -1,5 +1,3 @@
-//@ compile-flags:-Zprint-mono-items=lazy
-
 // N.B., we do not expect *any* monomorphization to be generated here.
 
 #![deny(dead_code)]

diff --git a/tests/codegen-units/item-collection/unsizing.rs b/tests/codegen-units/item-collection/unsizing.rs
@@ -1,4 +1,3 @@
-//@ compile-flags:-Zprint-mono-items=eager
 //@ compile-flags:-Zmir-opt-level=0
 
 #![deny(dead_code)]

diff --git a/tests/codegen-units/item-collection/unused-traits-and-generics.rs b/tests/codegen-units/item-collection/unused-traits-and-generics.rs
@@ -1,4 +1,4 @@
-//@ compile-flags:-Zprint-mono-items=eager
+//@ compile-flags:-Clink-dead-code
 
 #![crate_type = "lib"]
 #![deny(dead_code)]