4 files changed, 56 insertions, 0 deletions
diff --git a/src/test/ui/modules/auxiliary/dummy_lib.rs b/src/test/ui/modules/auxiliary/dummy_lib.rs
new file mode 100644
index 000000000..ef805c1f0
--- /dev/null
+++ b/src/test/ui/modules/auxiliary/dummy_lib.rs
@@ -0,0 +1,2 @@
+#[allow(dead_code)]
+pub struct Dummy;
diff --git a/src/test/ui/modules/special_module_name.rs b/src/test/ui/modules/special_module_name.rs
new file mode 100644
index 000000000..15c59b2da
--- /dev/null
+++ b/src/test/ui/modules/special_module_name.rs
@@ -0,0 +1,8 @@
+mod lib;
+//~^ WARN found module declaration for lib.rs
+//~| ERROR file not found for module `lib`
+mod main;
+//~^ WARN found module declaration for main.rs
+//~| ERROR file not found for module `main`
+
+fn main() {}
diff --git a/src/test/ui/modules/special_module_name.stderr b/src/test/ui/modules/special_module_name.stderr
new file mode 100644
index 000000000..8b3da2938
--- /dev/null
+++ b/src/test/ui/modules/special_module_name.stderr
@@ -0,0 +1,37 @@
+error[E0583]: file not found for module `lib`
+  --> $DIR/special_module_name.rs:1:1
+   |
+LL | mod lib;
+   | ^^^^^^^^
+   |
+   = help: to create the module `lib`, create file "$DIR/lib.rs" or "$DIR/lib/mod.rs"
+
+error[E0583]: file not found for module `main`
+  --> $DIR/special_module_name.rs:4:1
+   |
+LL | mod main;
+   | ^^^^^^^^^
+   |
+   = help: to create the module `main`, create file "$DIR/main.rs" or "$DIR/main/mod.rs"
+
+warning: found module declaration for lib.rs
+  --> $DIR/special_module_name.rs:1:1
+   |
+LL | mod lib;
+   | ^^^^^^^^
+   |
+   = note: `#[warn(special_module_name)]` on by default
+   = note: lib.rs is the root of this crate's library target
+   = help: to refer to it from other targets, use the library's name as the path
+
+warning: found module declaration for main.rs
+  --> $DIR/special_module_name.rs:4:1
+   |
+LL | mod main;
+   | ^^^^^^^^^
+   |
+   = note: a binary crate cannot be used as library
+
+error: aborting due to 2 previous errors; 2 warnings emitted
+
+For more information about this error, try `rustc --explain E0583`.
diff --git a/src/test/ui/modules/special_module_name_ignore.rs b/src/test/ui/modules/special_module_name_ignore.rs
new file mode 100644
index 000000000..07cea9b2b
--- /dev/null
+++ b/src/test/ui/modules/special_module_name_ignore.rs
@@ -0,0 +1,9 @@
+// run-pass
+
+#[path = "auxiliary/dummy_lib.rs"]
+mod lib;
+
+#[path = "auxiliary/dummy_lib.rs"]
+mod main;
+
+fn main() {}