expand: Feature gate out-of-line modules in proc macro input

6 files changed, 132 insertions, 0 deletions

diff --git a/src/test/ui/proc-macro/attributes-on-modules-fail.rs b/src/test/ui/proc-macro/attributes-on-modules-fail.rs
new file mode 100644
index 00000000000..c8bc0b34374
--- /dev/null
+++ b/src/test/ui/proc-macro/attributes-on-modules-fail.rs
@@ -0,0 +1,29 @@
+// aux-build:test-macros.rs
+
+#[macro_use]
+extern crate test_macros;
+
+#[identity_attr] //~ ERROR custom attributes cannot be applied to modules
+mod m {
+    pub struct X;
+
+    type A = Y; //~ ERROR cannot find type `Y` in this scope
+}
+
+struct Y;
+type A = X; //~ ERROR cannot find type `X` in this scope
+
+#[derive(Copy)] //~ ERROR `derive` may only be applied to structs, enums and unions
+mod n {}
+
+#[empty_attr]
+mod module; //~ ERROR non-inline modules in proc macro input are unstable
+
+#[empty_attr] //~ ERROR custom attributes cannot be applied to modules
+mod outer {
+    mod inner; //~ ERROR non-inline modules in proc macro input are unstable
+
+    mod inner_inline {} // OK
+}
+
+fn main() {}
diff --git a/src/test/ui/proc-macro/attributes-on-modules-fail.stderr b/src/test/ui/proc-macro/attributes-on-modules-fail.stderr
new file mode 100644
index 00000000000..34a5a5aaa54
--- /dev/null
+++ b/src/test/ui/proc-macro/attributes-on-modules-fail.stderr
@@ -0,0 +1,76 @@
+error[E0658]: custom attributes cannot be applied to modules
+  --> $DIR/attributes-on-modules-fail.rs:6:1
+   |
+LL | #[identity_attr]
+   | ^^^^^^^^^^^^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/54727
+   = help: add `#![feature(proc_macro_hygiene)]` to the crate attributes to enable
+
+error: `derive` may only be applied to structs, enums and unions
+  --> $DIR/attributes-on-modules-fail.rs:16:1
+   |
+LL | #[derive(Copy)]
+   | ^^^^^^^^^^^^^^^
+
+error[E0658]: non-inline modules in proc macro input are unstable
+  --> $DIR/attributes-on-modules-fail.rs:20:1
+   |
+LL | mod module;
+   | ^^^^^^^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/54727
+   = help: add `#![feature(proc_macro_hygiene)]` to the crate attributes to enable
+
+error[E0658]: non-inline modules in proc macro input are unstable
+  --> $DIR/attributes-on-modules-fail.rs:24:5
+   |
+LL |     mod inner;
+   |     ^^^^^^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/54727
+   = help: add `#![feature(proc_macro_hygiene)]` to the crate attributes to enable
+
+error[E0658]: custom attributes cannot be applied to modules
+  --> $DIR/attributes-on-modules-fail.rs:22:1
+   |
+LL | #[empty_attr]
+   | ^^^^^^^^^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/54727
+   = help: add `#![feature(proc_macro_hygiene)]` to the crate attributes to enable
+
+error[E0412]: cannot find type `Y` in this scope
+  --> $DIR/attributes-on-modules-fail.rs:10:14
+   |
+LL |     type A = Y;
+   |     ---------^- similarly named type alias `A` defined here
+   |
+help: a type alias with a similar name exists
+   |
+LL |     type A = A;
+   |              ^
+help: possible candidate is found in another module, you can import it into scope
+   |
+LL |     use Y;
+   |
+
+error[E0412]: cannot find type `X` in this scope
+  --> $DIR/attributes-on-modules-fail.rs:14:10
+   |
+LL | type A = X;
+   | ---------^- similarly named type alias `A` defined here
+   |
+help: a type alias with a similar name exists
+   |
+LL | type A = A;
+   |          ^
+help: possible candidate is found in another module, you can import it into scope
+   |
+LL | use m::X;
+   |
+
+error: aborting due to 7 previous errors
+
+Some errors have detailed explanations: E0412, E0658.
+For more information about an error, try `rustc --explain E0412`.
diff --git a/src/test/ui/proc-macro/attributes-on-modules.rs b/src/test/ui/proc-macro/attributes-on-modules.rs
new file mode 100644
index 00000000000..12c3ac6d947
--- /dev/null
+++ b/src/test/ui/proc-macro/attributes-on-modules.rs
@@ -0,0 +1,13 @@
+// aux-build:test-macros.rs
+
+#[macro_use]
+extern crate test_macros;
+
+#[identity_attr] //~ ERROR custom attributes cannot be applied to modules
+mod m {
+    pub struct S;
+}
+
+fn main() {
+    let s = m::S;
+}
diff --git a/src/test/ui/proc-macro/attributes-on-modules.stderr b/src/test/ui/proc-macro/attributes-on-modules.stderr
new file mode 100644
index 00000000000..df75f0bf4b1
--- /dev/null
+++ b/src/test/ui/proc-macro/attributes-on-modules.stderr
@@ -0,0 +1,12 @@
+error[E0658]: custom attributes cannot be applied to modules
+  --> $DIR/attributes-on-modules.rs:6:1
+   |
+LL | #[identity_attr]
+   | ^^^^^^^^^^^^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/54727
+   = help: add `#![feature(proc_macro_hygiene)]` to the crate attributes to enable
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0658`.
diff --git a/src/test/ui/proc-macro/module.rs b/src/test/ui/proc-macro/module.rs
new file mode 100644
index 00000000000..5777ed89983
--- /dev/null
+++ b/src/test/ui/proc-macro/module.rs
@@ -0,0 +1 @@
+// ignore-test
diff --git a/src/test/ui/proc-macro/outer/inner.rs b/src/test/ui/proc-macro/outer/inner.rs
new file mode 100644
index 00000000000..5777ed89983
--- /dev/null
+++ b/src/test/ui/proc-macro/outer/inner.rs
@@ -0,0 +1 @@
+// ignore-test