Now that all literals are C-Strings, rename and update the documentation of this macro to clarify its intended purpose.
Link: https://github.com/Rust-for-Linux/linux/issues/1075 Acked-by: Greg Kroah-Hartman <[email protected]> Reviewed-by: Alice Ryhl <[email protected]> Signed-off-by: Tamir Duberstein <[email protected]> --- This patch completes the work of replacing our custom `CStr` with upstream's. --- rust/kernel/bug.rs | 2 +- rust/kernel/configfs.rs | 2 +- rust/kernel/drm/ioctl.rs | 2 +- rust/kernel/kunit.rs | 3 ++- rust/kernel/str.rs | 19 ++++++++++++++----- rust/kernel/sync.rs | 4 ++-- rust/kernel/sync/lock/global.rs | 3 ++- rust/kernel/workqueue.rs | 6 +++--- 8 files changed, 26 insertions(+), 15 deletions(-) diff --git a/rust/kernel/bug.rs b/rust/kernel/bug.rs index ed943960f851..f7cb673b1766 100644 --- a/rust/kernel/bug.rs +++ b/rust/kernel/bug.rs @@ -80,7 +80,7 @@ macro_rules! warn_flags { // with a valid null-terminated string. unsafe { $crate::bindings::warn_slowpath_fmt( - $crate::c_str!(::core::file!()).as_char_ptr(), + $crate::str_to_cstr!(::core::file!()).as_char_ptr(), line!() as $crate::ffi::c_int, $flags as $crate::ffi::c_uint, ::core::ptr::null(), diff --git a/rust/kernel/configfs.rs b/rust/kernel/configfs.rs index 2339c6467325..930f17bb2041 100644 --- a/rust/kernel/configfs.rs +++ b/rust/kernel/configfs.rs @@ -1000,7 +1000,7 @@ macro_rules! configfs_attrs { $crate::configfs::Attribute<$attr, $data, $data> = unsafe { $crate::configfs::Attribute::new( - $crate::c_str!(::core::stringify!($name)), + $crate::str_to_cstr!(::core::stringify!($name)), ) }; )* diff --git a/rust/kernel/drm/ioctl.rs b/rust/kernel/drm/ioctl.rs index cf328101dde4..6a87f489dc88 100644 --- a/rust/kernel/drm/ioctl.rs +++ b/rust/kernel/drm/ioctl.rs @@ -157,7 +157,7 @@ macro_rules! declare_drm_ioctls { }, flags: $flags, name: $crate::str::as_char_ptr_in_const_context( - $crate::c_str!(::core::stringify!($cmd)), + $crate::str_to_cstr!(::core::stringify!($cmd)), ), } ),*]; diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs index f93f24a60bdd..5802a3507ecc 100644 --- a/rust/kernel/kunit.rs +++ b/rust/kernel/kunit.rs @@ -59,7 +59,8 @@ macro_rules! kunit_assert { static FILE: &'static $crate::str::CStr = $file; static LINE: i32 = ::core::line!() as i32 - $diff; - static CONDITION: &'static $crate::str::CStr = $crate::c_str!(stringify!($condition)); + static CONDITION: &'static $crate::str::CStr = + $crate::str_to_cstr!(stringify!($condition)); // SAFETY: FFI call without safety requirements. let kunit_test = unsafe { $crate::bindings::kunit_get_current_test() }; diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs index fa87779d2253..8bb40de007d4 100644 --- a/rust/kernel/str.rs +++ b/rust/kernel/str.rs @@ -376,19 +376,28 @@ fn as_ref(&self) -> &BStr { } } -/// Creates a new [`CStr`] from a string literal. +/// Creates a new [`CStr`] at compile time. /// -/// The string literal should not contain any `NUL` bytes. +/// Rust supports C string literals since Rust 1.77, and they should be used instead of this macro +/// where possible. This macro exists to allow static *non-literal* C strings to be created at +/// compile time. This is most often used in other macros. +/// +/// # Panics +/// +/// This macro panics if the operand contains an interior `NUL` byte. /// /// # Examples /// /// ``` -/// # use kernel::c_str; +/// # use kernel::str_to_cstr; /// # use kernel::str::CStr; -/// const MY_CSTR: &CStr = c_str!("My awesome CStr!"); +/// const MY_CSTR: &CStr = str_to_cstr!(concat!(file!(), ":", line!(), ": My CStr!")); /// ``` #[macro_export] -macro_rules! c_str { +macro_rules! str_to_cstr { + // NB: we could write `($str:lit) => compile_error!("use a C string literal instead");` here but + // that would trigger when the literal is at the top of several macro expansions. That would be + // too limiting to macro authors, so we rely on the name as a hint instead. ($str:expr) => {{ const S: &str = concat!($str, "\0"); const C: &$crate::str::CStr = match $crate::str::CStr::from_bytes_with_nul(S.as_bytes()) { diff --git a/rust/kernel/sync.rs b/rust/kernel/sync.rs index 993dbf2caa0e..ecf02a67ec35 100644 --- a/rust/kernel/sync.rs +++ b/rust/kernel/sync.rs @@ -154,9 +154,9 @@ macro_rules! static_lock_class { #[macro_export] macro_rules! optional_name { () => { - $crate::c_str!(::core::concat!(::core::file!(), ":", ::core::line!())) + $crate::str_to_cstr!(::core::concat!(::core::file!(), ":", ::core::line!())) }; ($name:literal) => { - $crate::c_str!($name) + $crate::str_to_cstr!($name) }; } diff --git a/rust/kernel/sync/lock/global.rs b/rust/kernel/sync/lock/global.rs index aecbdc34738f..81f46229be7d 100644 --- a/rust/kernel/sync/lock/global.rs +++ b/rust/kernel/sync/lock/global.rs @@ -272,7 +272,8 @@ macro_rules! global_lock { $pub enum $name {} impl $crate::sync::lock::GlobalLockBackend for $name { - const NAME: &'static $crate::str::CStr = $crate::c_str!(::core::stringify!($name)); + const NAME: &'static $crate::str::CStr = + $crate::str_to_cstr!(::core::stringify!($name)); type Item = $valuety; type Backend = $crate::global_lock_inner!(backend $kind); diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs index 706e833e9702..7616d71df68e 100644 --- a/rust/kernel/workqueue.rs +++ b/rust/kernel/workqueue.rs @@ -212,7 +212,7 @@ macro_rules! new_delayed_work { $crate::workqueue::DelayedWork::new( $crate::optional_name!(), $crate::static_lock_class!(), - $crate::c_str!(::core::concat!( + $crate::str_to_cstr!(::core::concat!( ::core::file!(), ":", ::core::line!(), @@ -223,9 +223,9 @@ macro_rules! new_delayed_work { }; ($name:literal) => { $crate::workqueue::DelayedWork::new( - $crate::c_str!($name), + $crate::str_to_cstr!($name), $crate::static_lock_class!(), - $crate::c_str!(::core::concat!($name, "_timer")), + $crate::str_to_cstr!(::core::concat!($name, "_timer")), $crate::static_lock_class!(), ) }; --- base-commit: 11439c4635edd669ae435eec308f4ab8a0804808 change-id: 20260302-cstr-rename-macro-64201be6c969 Best regards, -- Tamir Duberstein <[email protected]>
