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authorRichard Henderson <richard.henderson@linaro.org>2025-09-18 07:05:58 -0700
committerRichard Henderson <richard.henderson@linaro.org>2025-09-18 07:05:59 -0700
commitccafa85a97e38698b798115bba6c18c849846e25 (patch)
treea7d4941f050d4b621cffe2a71657a1bd39c35d4b /rust/common/src/assertions.rs
parentf0007b7f03e2d7fc33e71c3a582f2364c51a226b (diff)
parent00c0911c68e5bd664de1a261b74c390f4c0be83d (diff)
downloadfocaccia-qemu-ccafa85a97e38698b798115bba6c18c849846e25.tar.gz
focaccia-qemu-ccafa85a97e38698b798115bba6c18c849846e25.zip
Merge tag 'for-upstream' of https://gitlab.com/bonzini/qemu into staging
* cpu-exec: more cleanups to CPU loop exits
* python: bump bundled Meson to 1.9.0
* rust: require Rust 1.83.0
* rust: temporarily remove from Ubuntu CI
* rust: vmstate: convert to use builder pattern
* rust: split "qemu-api" crate
* rust: rename qemu_api_macros -> qemu_macros
* rust: re-export qemu macros from other crates
* x86: fix functional test failure for Xen emulation
* x86: cleanups

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# gpg: Signature made Wed 17 Sep 2025 10:02:19 AM PDT
# gpg:                using RSA key F13338574B662389866C7682BFFBD25F78C7AE83
# gpg:                issuer "pbonzini@redhat.com"
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [unknown]
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>" [unknown]
# gpg: WARNING: The key's User ID is not certified with a trusted signature!
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* tag 'for-upstream' of https://gitlab.com/bonzini/qemu: (60 commits)
  accel/kvm: Set guest_memfd_offset to non-zero value only when guest_memfd is valid
  accel/kvm: Zero out mem explicitly in kvm_set_user_memory_region()
  accel/kvm: Switch to check KVM_CAP_GUEST_MEMFD and KVM_CAP_USER_MEMORY2 on VM
  i386/kvm: Drop KVM_CAP_X86_SMM check in kvm_arch_init()
  multiboot: Fix the split lock
  target/i386: Define enum X86ASIdx for x86's address spaces
  i386/cpu: Enable SMM cpu address space under KVM
  hpet: guard IRQ handling with BQL
  rust: do not inline do_init_io
  rust: meson: remove unnecessary complication in device crates
  docs: update rust.rst
  rust: re-export qemu macros from common/qom/hwcore
  rust: re-export qemu_macros internal helper in "bits"
  rust: repurpose qemu_api -> tests
  rust/pl011: drop dependency on qemu_api
  rust/hpet: drop now unneeded qemu_api dep
  rust: rename qemu_api_macros -> qemu_macros
  rust: split "hwcore" crate
  rust: split "system" crate
  rust: split "chardev" crate
  ...

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'rust/common/src/assertions.rs')
-rw-r--r--rust/common/src/assertions.rs148
1 files changed, 148 insertions, 0 deletions
diff --git a/rust/common/src/assertions.rs b/rust/common/src/assertions.rs
new file mode 100644
index 0000000000..91f83a5d3d
--- /dev/null
+++ b/rust/common/src/assertions.rs
@@ -0,0 +1,148 @@
+// Copyright 2024, Red Hat Inc.
+// Author(s): Paolo Bonzini <pbonzini@redhat.com>
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#![doc(hidden)]
+//! This module provides macros to check the equality of types and
+//! the type of `struct` fields.  This can be useful to ensure that
+//! types match the expectations of C code.
+//!
+//! Documentation is hidden because it only exposes macros, which
+//! are exported directly from `common`.
+
+// Based on https://stackoverflow.com/questions/64251852/x/70978292#70978292
+// (stackoverflow answers are released under MIT license).
+
+#[doc(hidden)]
+pub trait EqType {
+    type Itself;
+}
+
+impl<T> EqType for T {
+    type Itself = T;
+}
+
+/// Assert that two types are the same.
+///
+/// # Examples
+///
+/// ```
+/// # use common::assert_same_type;
+/// # use std::ops::Deref;
+/// assert_same_type!(u32, u32);
+/// assert_same_type!(<Box<u32> as Deref>::Target, u32);
+/// ```
+///
+/// Different types will cause a compile failure
+///
+/// ```compile_fail
+/// # use common::assert_same_type;
+/// assert_same_type!(&Box<u32>, &u32);
+/// ```
+#[macro_export]
+macro_rules! assert_same_type {
+    ($t1:ty, $t2:ty) => {
+        const _: () = {
+            #[allow(unused)]
+            fn assert_same_type(v: $t1) {
+                fn types_must_be_equal<T, U>(_: T)
+                where
+                    T: $crate::assertions::EqType<Itself = U>,
+                {
+                }
+                types_must_be_equal::<_, $t2>(v);
+            }
+        };
+    };
+}
+
+/// Assert that a field of a struct has the given type.
+///
+/// # Examples
+///
+/// ```
+/// # use common::assert_field_type;
+/// pub struct A {
+///     field1: u32,
+/// }
+///
+/// assert_field_type!(A, field1, u32);
+/// ```
+///
+/// Different types will cause a compile failure
+///
+/// ```compile_fail
+/// # use common::assert_field_type;
+/// # pub struct A { field1: u32 }
+/// assert_field_type!(A, field1, i32);
+/// ```
+#[macro_export]
+macro_rules! assert_field_type {
+    (@internal $param_name:ident, $ti:ty, $t:ty, $($field:tt)*) => {
+        const _: () = {
+            #[allow(unused)]
+            const fn assert_field_type($param_name: &$t) {
+                const fn types_must_be_equal<T, U>(_: &T)
+                where
+                    T: $crate::assertions::EqType<Itself = U>,
+                {
+                }
+                types_must_be_equal::<_, $ti>(&$($field)*);
+            }
+        };
+    };
+
+    ($t:ty, $i:tt, $ti:ty) => {
+        $crate::assert_field_type!(@internal v, $ti, $t, v.$i);
+    };
+}
+
+/// Assert that an expression matches a pattern.  This can also be
+/// useful to compare enums that do not implement `Eq`.
+///
+/// # Examples
+///
+/// ```
+/// # use common::assert_match;
+/// // JoinHandle does not implement `Eq`, therefore the result
+/// // does not either.
+/// let result: Result<std::thread::JoinHandle<()>, u32> = Err(42);
+/// assert_match!(result, Err(42));
+/// ```
+#[macro_export]
+macro_rules! assert_match {
+    ($a:expr, $b:pat) => {
+        assert!(
+            match $a {
+                $b => true,
+                _ => false,
+            },
+            "{} = {:?} does not match {}",
+            stringify!($a),
+            $a,
+            stringify!($b)
+        );
+    };
+}
+
+/// Assert at compile time that an expression is true.  This is similar
+/// to `const { assert!(...); }` but it works outside functions, as well as
+/// on versions of Rust before 1.79.
+///
+/// # Examples
+///
+/// ```
+/// # use common::static_assert;
+/// static_assert!("abc".len() == 3);
+/// ```
+///
+/// ```compile_fail
+/// # use common::static_assert;
+/// static_assert!("abc".len() == 2); // does not compile
+/// ```
+#[macro_export]
+macro_rules! static_assert {
+    ($x:expr) => {
+        const _: () = assert!($x);
+    };
+}