1 files changed, 42 insertions, 0 deletions
diff --git a/tests/codegen-units/partitioning/incremental-merging.rs b/tests/codegen-units/partitioning/incremental-merging.rs
new file mode 100644
index 000000000..118b7bdf4
--- /dev/null
+++ b/tests/codegen-units/partitioning/incremental-merging.rs
@@ -0,0 +1,42 @@
+// We specify incremental here because we want to test the partitioning for
+// incremental compilation
+// incremental
+// compile-flags:-Zprint-mono-items=lazy
+// compile-flags:-Ccodegen-units=3
+
+#![crate_type = "rlib"]
+
+// This test makes sure that merging of CGUs works together with incremental
+// compilation but at the same time does not modify names of CGUs that were not
+// affected by merging.
+//
+// We expect CGUs `aaa` and `bbb` to be merged (because they are the smallest),
+// while `ccc` and `ddd` are supposed to stay untouched.
+
+pub mod aaa {
+    //~ MONO_ITEM fn aaa::foo @@ incremental_merging-aaa--incremental_merging-bbb[External]
+    pub fn foo(a: u64) -> u64 {
+        a + 1
+    }
+}
+
+pub mod bbb {
+    //~ MONO_ITEM fn bbb::foo @@ incremental_merging-aaa--incremental_merging-bbb[External]
+    pub fn foo(a: u64, b: u64) -> u64 {
+        a + b + 1
+    }
+}
+
+pub mod ccc {
+    //~ MONO_ITEM fn ccc::foo @@ incremental_merging-ccc[External]
+    pub fn foo(a: u64, b: u64, c: u64) -> u64 {
+        a + b + c + 1
+    }
+}
+
+pub mod ddd {
+    //~ MONO_ITEM fn ddd::foo @@ incremental_merging-ddd[External]
+    pub fn foo(a: u64, b: u64, c: u64, d: u64) -> u64 {
+        a + b + c + d + 1
+    }
+}