From: Alice Ryhl <aliceryhl@google.com>
Date: Wed, 27 Aug 2025 13:12:16 +0000 (+0000)
Subject: rust: use the new name Location::file_as_c_str() in Rust >= 1.91.0
X-Git-Tag: v6.17-rc5~7^2~1
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c09461a0d24fba8a847a37a381626141da22d8ee;p=thirdparty%2Fkernel%2Fstable.git

rust: use the new name Location::file_as_c_str() in Rust >= 1.91.0

As part of the stabilization of Location::file_with_nul(), it was brought
up that the with_nul() suffix usually means something else in Rust APIs,
so the API is being renamed prior to stabilization [1].

Thus, use the new name on new rustc versions.

Link: https://www.github.com/rust-lang/rust/pull/145928 [1]
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20250827-file_as_c_str-v1-1-d3f5a3916a9c@google.com
[ Kept `cfg` separation. Reworded slightly. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---

diff --git a/init/Kconfig b/init/Kconfig
index 8363202512193..e7459cbea6ca8 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -145,6 +145,9 @@ config RUSTC_HAS_UNNECESSARY_TRANSMUTES
 config RUSTC_HAS_FILE_WITH_NUL
 	def_bool RUSTC_VERSION >= 108900
 
+config RUSTC_HAS_FILE_AS_C_STR
+	def_bool RUSTC_VERSION >= 109100
+
 config PAHOLE_VERSION
 	int
 	default $(shell,$(srctree)/scripts/pahole-version.sh $(PAHOLE))
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index ed53169e795c0..fef97f2a50984 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -296,7 +296,7 @@ macro_rules! asm {
 
 /// Gets the C string file name of a [`Location`].
 ///
-/// If `file_with_nul()` is not available, returns a string that warns about it.
+/// If `Location::file_as_c_str()` is not available, returns a string that warns about it.
 ///
 /// [`Location`]: core::panic::Location
 ///
@@ -310,8 +310,8 @@ macro_rules! asm {
 ///     let caller = core::panic::Location::caller();
 ///
 ///     // Output:
-///     // - A path like "rust/kernel/example.rs" if file_with_nul() is available.
-///     // - "<Location::file_with_nul() not supported>" otherwise.
+///     // - A path like "rust/kernel/example.rs" if `file_as_c_str()` is available.
+///     // - "<Location::file_as_c_str() not supported>" otherwise.
 ///     let caller_file = file_from_location(caller);
 ///
 ///     // Prints out the message with caller's file name.
@@ -326,7 +326,12 @@ macro_rules! asm {
 /// ```
 #[inline]
 pub fn file_from_location<'a>(loc: &'a core::panic::Location<'a>) -> &'a core::ffi::CStr {
-    #[cfg(CONFIG_RUSTC_HAS_FILE_WITH_NUL)]
+    #[cfg(CONFIG_RUSTC_HAS_FILE_AS_C_STR)]
+    {
+        loc.file_as_c_str()
+    }
+
+    #[cfg(all(CONFIG_RUSTC_HAS_FILE_WITH_NUL, not(CONFIG_RUSTC_HAS_FILE_AS_C_STR)))]
     {
         loc.file_with_nul()
     }
@@ -334,6 +339,6 @@ pub fn file_from_location<'a>(loc: &'a core::panic::Location<'a>) -> &'a core::f
     #[cfg(not(CONFIG_RUSTC_HAS_FILE_WITH_NUL))]
     {
         let _ = loc;
-        c"<Location::file_with_nul() not supported>"
+        c"<Location::file_as_c_str() not supported>"
     }
 }