[pbs-devel] [PATCH proxmox] lang: Remove offsetof macro

[pbs-devel] [PATCH proxmox] lang: Remove offsetof macro

[Maximiliano Sandoval]

With rust 1.90 this will crash while running cargo test with

$ RUST_BACKTRACE=1 cargo test

null pointer dereference occurred
stack backtrace:
   0: __rustc::rust_begin_unwind
             at /usr/src/rustc-1.90.0/library/std/src/panicking.rs:697:5
   1: core::panicking::panic_nounwind_fmt::runtime
             at /usr/src/rustc-1.90.0/library/core/src/panicking.rs:117:22
   2: core::panicking::panic_nounwind_fmt
             at /usr/src/rustc-1.90.0/library/core/src/intrinsics/mod.rs:2367:9
   3: core::panicking::panic_null_pointer_dereference
             at /usr/src/rustc-1.90.0/library/core/src/panicking.rs:311:5
   4: rust_out::main::_doctest_main_proxmox_lang_src_lib_rs_71_0
   5: rust_out::main
   6: core::ops::function::FnOnce::call_once

Note that the deref_nullptr lint is going to be denied by default on 1.93.

Signed-off-by: Maximiliano Sandoval <m.sandoval@proxmox.com>
---

As far as my greeping was able to tell, there should be no other users than the
docstring.

 proxmox-lang/src/lib.rs | 22 ----------------------
 1 file changed, 22 deletions(-)

diff --git a/proxmox-lang/src/lib.rs b/proxmox-lang/src/lib.rs
index 0abfd507..0c33710b 100644
--- a/proxmox-lang/src/lib.rs
+++ b/proxmox-lang/src/lib.rs
@@ -66,28 +66,6 @@ macro_rules! static_assert_size {
     };
 }
 
-/// Evaluates to the offset (in bytes) of a given member within a struct
-///
-/// ```
-/// # use proxmox_lang::offsetof;
-///
-/// #[repr(C)]
-/// struct Stuff {
-///     first: u32,
-///     second: u32,
-/// }
-///
-/// assert_eq!(offsetof!(Stuff, second), 4);
-///
-/// ```
-#[deprecated = "use std::mem::offset_of! instead"]
-#[macro_export]
-macro_rules! offsetof {
-    ($ty:ty, $field:ident) => {
-        unsafe { &(*(std::ptr::null::<$ty>())).$field as *const _ as usize }
-    };
-}
-
 /// Shortcut for generating an `&'static CStr`.
 ///
 /// This takes a *string* (*not* a *byte-string*), appends a terminating zero, and calls
-- 
2.47.3



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Re: [pbs-devel] [PATCH proxmox] lang: Remove offsetof macro

[Christian Ebner]

On 1/26/26 3:11 PM, Maximiliano Sandoval wrote:
> With rust 1.90 this will crash while running cargo test with
> 
> $ RUST_BACKTRACE=1 cargo test
> 
> null pointer dereference occurred
> stack backtrace:
>     0: __rustc::rust_begin_unwind
>               at /usr/src/rustc-1.90.0/library/std/src/panicking.rs:697:5
>     1: core::panicking::panic_nounwind_fmt::runtime
>               at /usr/src/rustc-1.90.0/library/core/src/panicking.rs:117:22
>     2: core::panicking::panic_nounwind_fmt
>               at /usr/src/rustc-1.90.0/library/core/src/intrinsics/mod.rs:2367:9
>     3: core::panicking::panic_null_pointer_dereference
>               at /usr/src/rustc-1.90.0/library/core/src/panicking.rs:311:5
>     4: rust_out::main::_doctest_main_proxmox_lang_src_lib_rs_71_0
>     5: rust_out::main
>     6: core::ops::function::FnOnce::call_once
> 
> Note that the deref_nullptr lint is going to be denied by default on 1.93.
> 
> Signed-off-by: Maximiliano Sandoval <m.sandoval@proxmox.com>
> ---
> 
> As far as my greeping was able to tell, there should be no other users than the
> docstring.

Could not find any remaining users in our codebase as well, and since 
this macro has been deprecated since June 2024 according to the debian 
changelog, any remaining users should have already been moved to 
`std::mem::offset_of!` replacement anyways.

Therefore consider:

Acked-by: Christian Ebner <c.ebner@proxmox.com>