rust: replace c_str! with c"" literals

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

7 files changed, 14 insertions, 79 deletions

diff --git a/rust/qemu-api/meson.build b/rust/qemu-api/meson.build
index 95e65643ae..1696df705b 100644
--- a/rust/qemu-api/meson.build
+++ b/rust/qemu-api/meson.build
@@ -20,7 +20,6 @@ _qemu_api_rs = static_library(
       'src/callbacks.rs',
       'src/cell.rs',
       'src/chardev.rs',
-      'src/c_str.rs',
       'src/errno.rs',
       'src/irq.rs',
       'src/memory.rs',
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,
diff --git a/rust/qemu-api/tests/tests.rs b/rust/qemu-api/tests/tests.rs
index d045808c3a..a658a49fcf 100644
--- a/rust/qemu-api/tests/tests.rs
+++ b/rust/qemu-api/tests/tests.rs
@@ -6,7 +6,6 @@ use std::{ffi::CStr, ptr::addr_of};
 
 use qemu_api::{
     bindings::{module_call_init, module_init_type, qdev_prop_bool},
-    c_str,
     cell::{self, BqlCell},
     declare_properties, define_property,
     prelude::*,
@@ -21,7 +20,7 @@ mod vmstate_tests;
 
 // Test that macros can compile.
 pub static VMSTATE: VMStateDescription = VMStateDescription {
-    name: c_str!("name").as_ptr(),
+    name: c"name".as_ptr(),
     unmigratable: true,
     ..Zeroable::ZERO
 };
@@ -48,7 +47,7 @@ impl DummyClass {
 declare_properties! {
     DUMMY_PROPERTIES,
         define_property!(
-            c_str!("migrate-clk"),
+            c"migrate-clk",
             DummyState,
             migrate_clock,
             unsafe { &qdev_prop_bool },
@@ -58,7 +57,7 @@ declare_properties! {
 
 unsafe impl ObjectType for DummyState {
     type Class = DummyClass;
-    const TYPE_NAME: &'static CStr = c_str!("dummy");
+    const TYPE_NAME: &'static CStr = c"dummy";
 }
 
 impl ObjectImpl for DummyState {
@@ -92,7 +91,7 @@ pub struct DummyChildClass {
 
 unsafe impl ObjectType for DummyChildState {
     type Class = DummyChildClass;
-    const TYPE_NAME: &'static CStr = c_str!("dummy_child");
+    const TYPE_NAME: &'static CStr = c"dummy_child";
 }
 
 impl ObjectImpl for DummyChildState {
diff --git a/rust/qemu-api/tests/vmstate_tests.rs b/rust/qemu-api/tests/vmstate_tests.rs
index cc3527a9b6..ad0fc5cd5d 100644
--- a/rust/qemu-api/tests/vmstate_tests.rs
+++ b/rust/qemu-api/tests/vmstate_tests.rs
@@ -14,7 +14,6 @@ use qemu_api::{
         vmstate_info_bool, vmstate_info_int32, vmstate_info_int64, vmstate_info_int8,
         vmstate_info_uint64, vmstate_info_uint8, vmstate_info_unused_buffer, VMStateFlags,
     },
-    c_str,
     cell::{BqlCell, Opaque},
     impl_vmstate_forward,
     vmstate::{VMStateDescription, VMStateField},
@@ -43,7 +42,7 @@ struct FooA {
 }
 
 static VMSTATE_FOOA: VMStateDescription = VMStateDescription {
-    name: c_str!("foo_a").as_ptr(),
+    name: c"foo_a".as_ptr(),
     version_id: 1,
     minimum_version_id: 1,
     fields: vmstate_fields! {
@@ -173,7 +172,7 @@ fn validate_foob(_state: &FooB, _version_id: u8) -> bool {
 }
 
 static VMSTATE_FOOB: VMStateDescription = VMStateDescription {
-    name: c_str!("foo_b").as_ptr(),
+    name: c"foo_b".as_ptr(),
     version_id: 2,
     minimum_version_id: 1,
     fields: vmstate_fields! {
@@ -337,7 +336,7 @@ struct FooC {
 }
 
 static VMSTATE_FOOC: VMStateDescription = VMStateDescription {
-    name: c_str!("foo_c").as_ptr(),
+    name: c"foo_c".as_ptr(),
     version_id: 3,
     minimum_version_id: 1,
     fields: vmstate_fields! {
@@ -452,13 +451,13 @@ fn validate_food_2(_state: &FooD, _version_id: u8) -> bool {
 }
 
 static VMSTATE_FOOD: VMStateDescription = VMStateDescription {
-    name: c_str!("foo_d").as_ptr(),
+    name: c"foo_d".as_ptr(),
     version_id: 3,
     minimum_version_id: 1,
     fields: vmstate_fields! {
-        vmstate_validate!(FooD, c_str!("foo_d_0"), FooD::validate_food_0),
-        vmstate_validate!(FooD, c_str!("foo_d_1"), FooD::validate_food_1),
-        vmstate_validate!(FooD, c_str!("foo_d_2"), validate_food_2),
+        vmstate_validate!(FooD, c"foo_d_0", FooD::validate_food_0),
+        vmstate_validate!(FooD, c"foo_d_1", FooD::validate_food_1),
+        vmstate_validate!(FooD, c"foo_d_2", validate_food_2),
     },
     ..Zeroable::ZERO
 };