Merging upstream version 1.68.2+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

7 files changed, 229 insertions, 0 deletions

diff --git a/tests/ui/transmutability/visibility/assume/should_accept_if_dst_has_private_field.rs b/tests/ui/transmutability/visibility/assume/should_accept_if_dst_has_private_field.rs
new file mode 100644
index 000000000..8a41669c6
--- /dev/null
+++ b/tests/ui/transmutability/visibility/assume/should_accept_if_dst_has_private_field.rs
@@ -0,0 +1,38 @@
+// check-pass
+//! If visibility is assumed, a transmutation should be accepted even if the
+//! destination type contains a private field.
+
+#![crate_type = "lib"]
+#![feature(transmutability)]
+#![allow(dead_code)]
+
+mod assert {
+    use std::mem::{Assume, BikeshedIntrinsicFrom};
+
+    pub fn is_transmutable<Src, Dst, Context>()
+    where
+        Dst: BikeshedIntrinsicFrom<Src, Context, { Assume::SAFETY }>
+        // safety IS assumed --------------------^^^^^^^^^^^^^^^^^^
+    {}
+}
+
+mod src {
+    #[repr(C)] pub(self) struct Zst;
+
+    #[repr(C)] pub(in super) struct Src {
+        pub(self) field: Zst,
+    }
+}
+
+mod dst {
+    #[repr(C)] pub(in super) struct Zst;
+
+    #[repr(C)] pub(in super) struct Dst {
+        pub(self) field: Zst, // <- private field
+    }
+}
+
+fn test() {
+    struct Context;
+    assert::is_transmutable::<src::Src, dst::Dst, Context>();
+}
diff --git a/tests/ui/transmutability/visibility/assume/should_accept_if_dst_has_private_variant.rs b/tests/ui/transmutability/visibility/assume/should_accept_if_dst_has_private_variant.rs
new file mode 100644
index 000000000..dd57b877d
--- /dev/null
+++ b/tests/ui/transmutability/visibility/assume/should_accept_if_dst_has_private_variant.rs
@@ -0,0 +1,39 @@
+// check-pass
+//! If visibility is assumed, a transmutation should be accepted even if the
+//! destination type contains a private variant.
+
+#![crate_type = "lib"]
+#![feature(transmutability)]
+#![allow(dead_code)]
+
+mod assert {
+    use std::mem::{Assume, BikeshedIntrinsicFrom};
+
+    pub fn is_transmutable<Src, Dst, Context>()
+    where
+        Dst: BikeshedIntrinsicFrom<Src, Context, { Assume::SAFETY }>
+        // safety IS assumed --------------------^^^^^^^^^^^^^^^^^^
+    {}
+}
+
+mod src {
+    #[repr(C)] pub(self) struct Zst;
+
+    #[repr(C)] pub(in super) struct Src {
+        pub(self) field: Zst,
+    }
+}
+
+mod dst {
+    #[derive(Copy, Clone)]
+    #[repr(C)] pub(in super) struct Zst;
+
+    #[repr(C)] pub(in super) union Dst {
+        pub(self) field: Zst, // <- private variant
+    }
+}
+
+fn test() {
+    struct Context;
+    assert::is_transmutable::<src::Src, dst::Dst, Context>();
+}
diff --git a/tests/ui/transmutability/visibility/assume/should_accept_if_dst_has_tricky_unreachable_field.rs b/tests/ui/transmutability/visibility/assume/should_accept_if_dst_has_tricky_unreachable_field.rs
new file mode 100644
index 000000000..ebce8ce87
--- /dev/null
+++ b/tests/ui/transmutability/visibility/assume/should_accept_if_dst_has_tricky_unreachable_field.rs
@@ -0,0 +1,46 @@
+// check-pass
+//! Unless visibility is assumed, a transmutation should be rejected if the
+//! destination type contains an unreachable field (e.g., a public field with a
+//! private type). (This rule is distinct from type privacy, which still may
+//! forbid naming such types.)
+//!
+//! This test exercises a tricky-to-implement instance of this principle: the
+//! "pub-in-priv trick". In the below example, the type `dst::private::Zst` is
+//! unreachable from `Context`.
+
+#![crate_type = "lib"]
+#![feature(transmutability)]
+#![allow(dead_code)]
+
+mod assert {
+    use std::mem::{Assume, BikeshedIntrinsicFrom};
+
+    pub fn is_transmutable<Src, Dst, Context>()
+    where
+        Dst: BikeshedIntrinsicFrom<Src, Context, { Assume::SAFETY }>
+        // safety IS assumed --------------------^^^^^^^^^^^^^^^^^^
+    {}
+}
+
+mod src {
+    #[repr(C)] pub(in super) struct Zst;
+
+    #[repr(C)] pub(in super) struct Src {
+        pub(in super) field: Zst,
+    }
+}
+
+mod dst {
+    mod private {
+        #[repr(C)] pub struct Zst; // <- unreachable type
+    }
+
+    #[repr(C)] pub(in super) struct Dst {
+        pub(in super) field: private::Zst,
+    }
+}
+
+fn test() {
+    struct Context;
+    assert::is_transmutable::<src::Src, dst::Dst, Context>();
+}
diff --git a/tests/ui/transmutability/visibility/assume/should_accept_if_dst_has_unreachable_field.rs b/tests/ui/transmutability/visibility/assume/should_accept_if_dst_has_unreachable_field.rs
new file mode 100644
index 000000000..546fcbaa3
--- /dev/null
+++ b/tests/ui/transmutability/visibility/assume/should_accept_if_dst_has_unreachable_field.rs
@@ -0,0 +1,39 @@
+//! If visibility is assumed, a transmutation should be accepted even if the
+//! destination type contains an unreachable field (e.g., a public field with a
+//! private type). (This rule is distinct from type privacy, which still may
+//! forbid naming such types.)
+
+#![crate_type = "lib"]
+#![feature(transmutability)]
+#![allow(dead_code)]
+
+mod assert {
+    use std::mem::{Assume, BikeshedIntrinsicFrom};
+
+    pub fn is_transmutable<Src, Dst, Context>()
+    where
+        Dst: BikeshedIntrinsicFrom<Src, Context, { Assume::SAFETY }>
+        // safety IS assumed --------------------^^^^^^^^^^^^^^^^^^
+    {}
+}
+
+mod src {
+    #[repr(C)] pub(self) struct Zst;
+
+    #[repr(C)] pub(in super) struct Src {
+        pub(self) field: Zst,
+    }
+}
+
+mod dst {
+    #[repr(C)] pub(self) struct Zst; // <- unreachable type
+
+    #[repr(C)] pub(in super) struct Dst {
+        pub(in super) field: Zst, //~ ERROR private type
+    }
+}
+
+fn test() {
+    struct Context;
+    assert::is_transmutable::<src::Src, dst::Dst, Context>();
+}
diff --git a/tests/ui/transmutability/visibility/assume/should_accept_if_dst_has_unreachable_field.stderr b/tests/ui/transmutability/visibility/assume/should_accept_if_dst_has_unreachable_field.stderr
new file mode 100644
index 000000000..be83b7ce3
--- /dev/null
+++ b/tests/ui/transmutability/visibility/assume/should_accept_if_dst_has_unreachable_field.stderr
@@ -0,0 +1,12 @@
+error[E0446]: private type `dst::Zst` in public interface
+  --> $DIR/should_accept_if_dst_has_unreachable_field.rs:32:9
+   |
+LL |     #[repr(C)] pub(self) struct Zst; // <- unreachable type
+   |                -------------------- `dst::Zst` declared as private
+...
+LL |         pub(in super) field: Zst,
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^ can't leak private type
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0446`.
diff --git a/tests/ui/transmutability/visibility/assume/should_accept_if_dst_has_unreachable_ty.rs b/tests/ui/transmutability/visibility/assume/should_accept_if_dst_has_unreachable_ty.rs
new file mode 100644
index 000000000..b9b74d183
--- /dev/null
+++ b/tests/ui/transmutability/visibility/assume/should_accept_if_dst_has_unreachable_ty.rs
@@ -0,0 +1,40 @@
+//! If visibility is assumed, a transmutation should be accepted even if the
+//! destination type contains an unreachable field (e.g., a public field with a
+//! private type). (This rule is distinct from type privacy, which still may
+//! forbid naming such types.)
+
+#![crate_type = "lib"]
+#![feature(transmutability)]
+#![allow(dead_code)]
+
+mod assert {
+    use std::mem::{Assume, BikeshedIntrinsicFrom};
+
+    pub fn is_transmutable<Src, Dst, Context>()
+    where
+        Dst: BikeshedIntrinsicFrom<Src, Context, { Assume::SAFETY }>
+        // safety IS assumed --------------------^^^^^^^^^^^^^^^^^^
+    {}
+}
+
+mod src {
+    #[repr(C)] pub(self) struct Zst;
+
+    #[repr(C)] pub(in super) struct Src {
+        pub(self) field: Zst,
+    }
+}
+
+mod dst {
+    #[repr(C)] pub(in super) struct Zst;
+
+    // unreachable type
+    #[repr(C)] pub(self) struct Dst {
+        pub(in super) field: Zst,
+    }
+}
+
+fn test() {
+    struct Context;
+    assert::is_transmutable::<src::Src, dst::Dst, Context>(); //~ ERROR `Dst` is private
+}
diff --git a/tests/ui/transmutability/visibility/assume/should_accept_if_dst_has_unreachable_ty.stderr b/tests/ui/transmutability/visibility/assume/should_accept_if_dst_has_unreachable_ty.stderr
new file mode 100644
index 000000000..827df05de
--- /dev/null
+++ b/tests/ui/transmutability/visibility/assume/should_accept_if_dst_has_unreachable_ty.stderr
@@ -0,0 +1,15 @@
+error[E0603]: struct `Dst` is private
+  --> $DIR/should_accept_if_dst_has_unreachable_ty.rs:39:46
+   |
+LL |     assert::is_transmutable::<src::Src, dst::Dst, Context>();
+   |                                              ^^^ private struct
+   |
+note: the struct `Dst` is defined here
+  --> $DIR/should_accept_if_dst_has_unreachable_ty.rs:32:16
+   |
+LL |     #[repr(C)] pub(self) struct Dst {
+   |                ^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0603`.