rust: replace c_str! with c"" literals

Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

4 files changed, 3 insertions, 65 deletions

diff --git a/rust/qemu-api/src/c_str.rs b/rust/qemu-api/src/c_str.rs
deleted file mode 100644
index 3fa61b59c7..0000000000
--- a/rust/qemu-api/src/c_str.rs
+++ /dev/null
@@ -1,61 +0,0 @@
-// 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 a macro to define a constant of type
-//! [`CStr`](std::ffi::CStr), for compatibility with versions of
-//! Rust that lack `c""` literals.
-//!
-//! Documentation is hidden because it only exposes macros, which
-//! are exported directly from `qemu_api`.
-
-#[macro_export]
-/// Given a string constant _without_ embedded or trailing NULs, return
-/// a `CStr`.
-///
-/// Needed for compatibility with Rust <1.77.
-macro_rules! c_str {
-    ($str:expr) => {{
-        const STRING: &str = concat!($str, "\0");
-        const BYTES: &[u8] = STRING.as_bytes();
-
-        // "for" is not allowed in const context... oh well,
-        // everybody loves some lisp.  This could be turned into
-        // a procedural macro if this is a problem; alternatively
-        // Rust 1.72 makes CStr::from_bytes_with_nul a const function.
-        const fn f(b: &[u8], i: usize) {
-            if i == b.len() - 1 {
-            } else if b[i] == 0 {
-                panic!("c_str argument contains NUL")
-            } else {
-                f(b, i + 1)
-            }
-        }
-        f(BYTES, 0);
-
-        // SAFETY: absence of NULs apart from the final byte was checked above
-        unsafe { std::ffi::CStr::from_bytes_with_nul_unchecked(BYTES) }
-    }};
-}
-
-#[cfg(test)]
-mod tests {
-    use std::ffi::CStr;
-
-    use crate::c_str;
-
-    #[test]
-    fn test_cstr_macro() {
-        let good = c_str!("🦀");
-        let good_bytes = b"\xf0\x9f\xa6\x80\0";
-        assert_eq!(good.to_bytes_with_nul(), good_bytes);
-    }
-
-    #[test]
-    fn test_cstr_macro_const() {
-        const GOOD: &CStr = c_str!("🦀");
-        const GOOD_BYTES: &[u8] = b"\xf0\x9f\xa6\x80\0";
-        assert_eq!(GOOD.to_bytes_with_nul(), GOOD_BYTES);
-    }
-}
diff --git a/rust/qemu-api/src/cell.rs b/rust/qemu-api/src/cell.rs
index 1cb9fdcd53..05ce09f6cb 100644
--- a/rust/qemu-api/src/cell.rs
+++ b/rust/qemu-api/src/cell.rs
@@ -77,13 +77,13 @@
 //!
 //! ```
 //! # use qemu_api::prelude::*;
-//! # use qemu_api::{c_str, cell::BqlRefCell, irq::InterruptSource, irq::IRQState};
+//! # use qemu_api::{cell::BqlRefCell, irq::InterruptSource, irq::IRQState};
 //! # use qemu_api::{sysbus::SysBusDevice, qom::Owned, qom::ParentField};
 //! # const N_GPIOS: usize = 8;
 //! # struct PL061Registers { /* ... */ }
 //! # unsafe impl ObjectType for PL061State {
 //! #     type Class = <SysBusDevice as ObjectType>::Class;
-//! #     const TYPE_NAME: &'static std::ffi::CStr = c_str!("pl061");
+//! #     const TYPE_NAME: &'static std::ffi::CStr = c"pl061";
 //! # }
 //! struct PL061State {
 //!     parent_obj: ParentField<SysBusDevice>,
diff --git a/rust/qemu-api/src/lib.rs b/rust/qemu-api/src/lib.rs
index 90c1963666..234a94e3c2 100644
--- a/rust/qemu-api/src/lib.rs
+++ b/rust/qemu-api/src/lib.rs
@@ -15,7 +15,6 @@ pub mod prelude;
 
 pub mod assertions;
 pub mod bitops;
-pub mod c_str;
 pub mod callbacks;
 pub mod cell;
 pub mod chardev;
diff --git a/rust/qemu-api/src/vmstate.rs b/rust/qemu-api/src/vmstate.rs
index 205f35a21f..9c8b2398e9 100644
--- a/rust/qemu-api/src/vmstate.rs
+++ b/rust/qemu-api/src/vmstate.rs
@@ -427,7 +427,7 @@ unsafe impl<T: VMState, const N: usize> VMState for [T; N] {
 macro_rules! vmstate_unused {
     ($size:expr) => {{
         $crate::bindings::VMStateField {
-            name: $crate::c_str!("unused").as_ptr(),
+            name: c"unused".as_ptr(),
             size: $size,
             info: unsafe { ::core::ptr::addr_of!($crate::bindings::vmstate_info_unused_buffer) },
             flags: $crate::bindings::VMStateFlags::VMS_BUFFER,