Auto merge of #60317 - flip1995:internal_lints, r=oli-obk

Internal lints: usage_of_qualified_ty & ty_pass_by_reference

Closes #59952

Implements internal lints:

- `USAGE_OF_QUALIFIED_TY`
- `TY_PASS_BY_REFERENCE`

r? @oli-obk

5 files changed, 200 insertions, 1 deletions

diff --git a/src/test/ui-fulldeps/internal-lints/pass_ty_by_ref.rs b/src/test/ui-fulldeps/internal-lints/pass_ty_by_ref.rs
new file mode 100644
index 00000000000..075ce8b1a1c
--- /dev/null
+++ b/src/test/ui-fulldeps/internal-lints/pass_ty_by_ref.rs
@@ -0,0 +1,64 @@
+// compile-flags: -Z unstable-options
+
+#![feature(rustc_private)]
+#![deny(ty_pass_by_reference)]
+#![allow(unused)]
+
+extern crate rustc;
+
+use rustc::ty::{Ty, TyCtxt};
+
+fn ty_by_ref(
+    ty_val: Ty<'_>,
+    ty_ref: &Ty<'_>, //~ ERROR passing `Ty<'_>` by reference
+    ty_ctxt_val: TyCtxt<'_, '_, '_>,
+    ty_ctxt_ref: &TyCtxt<'_, '_, '_>, //~ ERROR passing `TyCtxt<'_, '_, '_>` by reference
+) {
+}
+
+fn ty_multi_ref(ty_multi: &&Ty<'_>, ty_ctxt_multi: &&&&TyCtxt<'_, '_, '_>) {}
+//~^ ERROR passing `Ty<'_>` by reference
+//~^^ ERROR passing `TyCtxt<'_, '_, '_>` by reference
+
+trait T {
+    fn ty_by_ref_in_trait(
+        ty_val: Ty<'_>,
+        ty_ref: &Ty<'_>, //~ ERROR passing `Ty<'_>` by reference
+        ty_ctxt_val: TyCtxt<'_, '_, '_>,
+        ty_ctxt_ref: &TyCtxt<'_, '_, '_>, //~ ERROR passing `TyCtxt<'_, '_, '_>` by reference
+    );
+
+    fn ty_multi_ref_in_trait(ty_multi: &&Ty<'_>, ty_ctxt_multi: &&&&TyCtxt<'_, '_, '_>);
+    //~^ ERROR passing `Ty<'_>` by reference
+    //~^^ ERROR passing `TyCtxt<'_, '_, '_>` by reference
+}
+
+struct Foo;
+
+impl T for Foo {
+    fn ty_by_ref_in_trait(
+        ty_val: Ty<'_>,
+        ty_ref: &Ty<'_>,
+        ty_ctxt_val: TyCtxt<'_, '_, '_>,
+        ty_ctxt_ref: &TyCtxt<'_, '_, '_>,
+    ) {
+    }
+
+    fn ty_multi_ref_in_trait(ty_multi: &&Ty<'_>, ty_ctxt_multi: &&&&TyCtxt<'_, '_, '_>) {}
+}
+
+impl Foo {
+    fn ty_by_ref_assoc(
+        ty_val: Ty<'_>,
+        ty_ref: &Ty<'_>, //~ ERROR passing `Ty<'_>` by reference
+        ty_ctxt_val: TyCtxt<'_, '_, '_>,
+        ty_ctxt_ref: &TyCtxt<'_, '_, '_>, //~ ERROR passing `TyCtxt<'_, '_, '_>` by reference
+    ) {
+    }
+
+    fn ty_multi_ref_assoc(ty_multi: &&Ty<'_>, ty_ctxt_multi: &&&&TyCtxt<'_, '_, '_>) {}
+    //~^ ERROR passing `Ty<'_>` by reference
+    //~^^ ERROR passing `TyCtxt<'_, '_, '_>` by reference
+}
+
+fn main() {}
diff --git a/src/test/ui-fulldeps/internal-lints/pass_ty_by_ref.stderr b/src/test/ui-fulldeps/internal-lints/pass_ty_by_ref.stderr
new file mode 100644
index 00000000000..f3e630f3be2
--- /dev/null
+++ b/src/test/ui-fulldeps/internal-lints/pass_ty_by_ref.stderr
@@ -0,0 +1,80 @@
+error: passing `Ty<'_>` by reference
+  --> $DIR/pass_ty_by_ref.rs:13:13
+   |
+LL |     ty_ref: &Ty<'_>,
+   |             ^^^^^^^ help: try passing by value: `Ty<'_>`
+   |
+note: lint level defined here
+  --> $DIR/pass_ty_by_ref.rs:4:9
+   |
+LL | #![deny(ty_pass_by_reference)]
+   |         ^^^^^^^^^^^^^^^^^^^^
+
+error: passing `TyCtxt<'_, '_, '_>` by reference
+  --> $DIR/pass_ty_by_ref.rs:15:18
+   |
+LL |     ty_ctxt_ref: &TyCtxt<'_, '_, '_>,
+   |                  ^^^^^^^^^^^^^^^^^^^ help: try passing by value: `TyCtxt<'_, '_, '_>`
+
+error: passing `Ty<'_>` by reference
+  --> $DIR/pass_ty_by_ref.rs:19:28
+   |
+LL | fn ty_multi_ref(ty_multi: &&Ty<'_>, ty_ctxt_multi: &&&&TyCtxt<'_, '_, '_>) {}
+   |                            ^^^^^^^ help: try passing by value: `Ty<'_>`
+
+error: passing `TyCtxt<'_, '_, '_>` by reference
+  --> $DIR/pass_ty_by_ref.rs:19:55
+   |
+LL | fn ty_multi_ref(ty_multi: &&Ty<'_>, ty_ctxt_multi: &&&&TyCtxt<'_, '_, '_>) {}
+   |                                                       ^^^^^^^^^^^^^^^^^^^ help: try passing by value: `TyCtxt<'_, '_, '_>`
+
+error: passing `Ty<'_>` by reference
+  --> $DIR/pass_ty_by_ref.rs:26:17
+   |
+LL |         ty_ref: &Ty<'_>,
+   |                 ^^^^^^^ help: try passing by value: `Ty<'_>`
+
+error: passing `TyCtxt<'_, '_, '_>` by reference
+  --> $DIR/pass_ty_by_ref.rs:28:22
+   |
+LL |         ty_ctxt_ref: &TyCtxt<'_, '_, '_>,
+   |                      ^^^^^^^^^^^^^^^^^^^ help: try passing by value: `TyCtxt<'_, '_, '_>`
+
+error: passing `Ty<'_>` by reference
+  --> $DIR/pass_ty_by_ref.rs:31:41
+   |
+LL |     fn ty_multi_ref_in_trait(ty_multi: &&Ty<'_>, ty_ctxt_multi: &&&&TyCtxt<'_, '_, '_>);
+   |                                         ^^^^^^^ help: try passing by value: `Ty<'_>`
+
+error: passing `TyCtxt<'_, '_, '_>` by reference
+  --> $DIR/pass_ty_by_ref.rs:31:68
+   |
+LL |     fn ty_multi_ref_in_trait(ty_multi: &&Ty<'_>, ty_ctxt_multi: &&&&TyCtxt<'_, '_, '_>);
+   |                                                                    ^^^^^^^^^^^^^^^^^^^ help: try passing by value: `TyCtxt<'_, '_, '_>`
+
+error: passing `Ty<'_>` by reference
+  --> $DIR/pass_ty_by_ref.rs:53:17
+   |
+LL |         ty_ref: &Ty<'_>,
+   |                 ^^^^^^^ help: try passing by value: `Ty<'_>`
+
+error: passing `TyCtxt<'_, '_, '_>` by reference
+  --> $DIR/pass_ty_by_ref.rs:55:22
+   |
+LL |         ty_ctxt_ref: &TyCtxt<'_, '_, '_>,
+   |                      ^^^^^^^^^^^^^^^^^^^ help: try passing by value: `TyCtxt<'_, '_, '_>`
+
+error: passing `Ty<'_>` by reference
+  --> $DIR/pass_ty_by_ref.rs:59:38
+   |
+LL |     fn ty_multi_ref_assoc(ty_multi: &&Ty<'_>, ty_ctxt_multi: &&&&TyCtxt<'_, '_, '_>) {}
+   |                                      ^^^^^^^ help: try passing by value: `Ty<'_>`
+
+error: passing `TyCtxt<'_, '_, '_>` by reference
+  --> $DIR/pass_ty_by_ref.rs:59:65
+   |
+LL |     fn ty_multi_ref_assoc(ty_multi: &&Ty<'_>, ty_ctxt_multi: &&&&TyCtxt<'_, '_, '_>) {}
+   |                                                                 ^^^^^^^^^^^^^^^^^^^ help: try passing by value: `TyCtxt<'_, '_, '_>`
+
+error: aborting due to 12 previous errors
+
diff --git a/src/test/ui-fulldeps/internal-lints/qualified_ty_ty_ctxt.rs b/src/test/ui-fulldeps/internal-lints/qualified_ty_ty_ctxt.rs
new file mode 100644
index 00000000000..5e10697ec66
--- /dev/null
+++ b/src/test/ui-fulldeps/internal-lints/qualified_ty_ty_ctxt.rs
@@ -0,0 +1,35 @@
+// compile-flags: -Z unstable-options
+
+#![feature(rustc_private)]
+#![deny(usage_of_qualified_ty)]
+#![allow(unused)]
+
+extern crate rustc;
+
+use rustc::ty::{self, Ty, TyCtxt};
+
+macro_rules! qualified_macro {
+    ($a:ident) => {
+        fn ty_in_macro(
+            ty_q: ty::Ty<'_>,
+            ty: Ty<'_>,
+            ty_ctxt_q: ty::TyCtxt<'_, '_, '_>,
+            ty_ctxt: TyCtxt<'_, '_, '_>,
+        ) {
+            println!("{}", stringify!($a));
+        }
+    };
+}
+
+fn ty_qualified(
+    ty_q: ty::Ty<'_>, //~ ERROR usage of qualified `ty::Ty<'_>`
+    ty: Ty<'_>,
+    ty_ctxt_q: ty::TyCtxt<'_, '_, '_>, //~ ERROR usage of qualified `ty::TyCtxt<'_, '_, '_>`
+    ty_ctxt: TyCtxt<'_, '_, '_>,
+) {
+}
+
+
+fn main() {
+    qualified_macro!(a);
+}
diff --git a/src/test/ui-fulldeps/internal-lints/qualified_ty_ty_ctxt.stderr b/src/test/ui-fulldeps/internal-lints/qualified_ty_ty_ctxt.stderr
new file mode 100644
index 00000000000..31d776cd9e0
--- /dev/null
+++ b/src/test/ui-fulldeps/internal-lints/qualified_ty_ty_ctxt.stderr
@@ -0,0 +1,20 @@
+error: usage of qualified `ty::Ty<'_>`
+  --> $DIR/qualified_ty_ty_ctxt.rs:25:11
+   |
+LL |     ty_q: ty::Ty<'_>,
+   |           ^^^^^^^^^^ help: try using it unqualified: `Ty<'_>`
+   |
+note: lint level defined here
+  --> $DIR/qualified_ty_ty_ctxt.rs:4:9
+   |
+LL | #![deny(usage_of_qualified_ty)]
+   |         ^^^^^^^^^^^^^^^^^^^^^
+
+error: usage of qualified `ty::TyCtxt<'_, '_, '_>`
+  --> $DIR/qualified_ty_ty_ctxt.rs:27:16
+   |
+LL |     ty_ctxt_q: ty::TyCtxt<'_, '_, '_>,
+   |                ^^^^^^^^^^^^^^^^^^^^^^ help: try using it unqualified: `TyCtxt<'_, '_, '_>`
+
+error: aborting due to 2 previous errors
+
diff --git a/src/test/ui-fulldeps/internal-lints/ty_tykind_usage.stderr b/src/test/ui-fulldeps/internal-lints/ty_tykind_usage.stderr
index 4e94af12453..10229a331c2 100644
--- a/src/test/ui-fulldeps/internal-lints/ty_tykind_usage.stderr
+++ b/src/test/ui-fulldeps/internal-lints/ty_tykind_usage.stderr
@@ -190,7 +190,7 @@ error: usage of `ty::TyKind`
 LL |     fn ty_kind(ty_bad: TyKind<'_>, ty_good: Ty<'_>) {}
    |                        ^^^^^^^^^^
    |
-   = help: try using `ty::Ty` instead
+   = help: try using `Ty` instead
 
 error: aborting due to 31 previous errors