Adding upstream version 110.0.1.upstream/110.0.1upstream

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

1 files changed, 84 insertions, 0 deletions

diff --git a/third_party/rust/memoffset-0.5.6/src/raw_field.rs b/third_party/rust/memoffset-0.5.6/src/raw_field.rs
new file mode 100644
index 0000000000..51a4c4190c
--- /dev/null
+++ b/third_party/rust/memoffset-0.5.6/src/raw_field.rs
@@ -0,0 +1,84 @@
+// Copyright (c) 2020 Gilad Naaman, Ralf Jung
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+/// `raw_const!`, or just ref-then-cast when that is not available.
+#[cfg(feature = "unstable_raw")]
+#[macro_export]
+#[doc(hidden)]
+macro_rules! _memoffset__raw_const {
+    ($path:expr) => {{
+        $crate::ptr::raw_const!($path)
+    }};
+}
+#[cfg(not(feature = "unstable_raw"))]
+#[macro_export]
+#[doc(hidden)]
+macro_rules! _memoffset__raw_const {
+    ($path:expr) => {{
+        // This is UB because we create an intermediate reference to uninitialized memory.
+        // Nothing we can do about that without `raw_const!` though.
+        &$path as *const _
+    }};
+}
+
+/// Deref-coercion protection macro.
+#[cfg(allow_clippy)]
+#[macro_export]
+#[doc(hidden)]
+macro_rules! _memoffset__field_check {
+    ($type:path, $field:tt) => {
+        // Make sure the field actually exists. This line ensures that a
+        // compile-time error is generated if $field is accessed through a
+        // Deref impl.
+        #[allow(clippy::unneeded_field_pattern)]
+        let $type { $field: _, .. };
+    };
+}
+#[cfg(not(allow_clippy))]
+#[macro_export]
+#[doc(hidden)]
+macro_rules! _memoffset__field_check {
+    ($type:path, $field:tt) => {
+        // Make sure the field actually exists. This line ensures that a
+        // compile-time error is generated if $field is accessed through a
+        // Deref impl.
+        let $type { $field: _, .. };
+    };
+}
+
+/// Computes a const raw pointer to the given field of the given base pointer
+/// to the given parent type.
+///
+/// The `base` pointer *must not* be dangling, but it *may* point to
+/// uninitialized memory.
+#[macro_export(local_inner_macros)]
+macro_rules! raw_field {
+    ($base:expr, $parent:path, $field:tt) => {{
+        _memoffset__field_check!($parent, $field);
+
+        // Get the field address.
+        // Crucially, we know that this will not trigger a deref coercion because
+        // of the field check we did above.
+        #[allow(unused_unsafe)] // for when the macro is used in an unsafe block
+        unsafe {
+            _memoffset__raw_const!((*($base as *const $parent)).$field)
+        }
+    }};
+}