Updates for Rust 1.82 (#2449)

Rust 1.82 adds `&raw` expressions, and marks some attributes as unsafe.

Author: qwandor

.github/workflows/build.yml

@@ -55,6 +55,9 @@ jobs:
       - name: Setup Rust cache
         uses: ./.github/workflows/setup-rust-cache
 
+      - name: Update Rust
+        run: rustup update
+
       - name: Build Rust code
         run: cargo build
 
@@ -89,7 +92,9 @@ jobs:
           sudo apt install gcc-aarch64-linux-gnu
 
       - name: Install toolchain
-        run: rustup target add ${{ matrix.target }}
+        run: |
+          rustup update
+          rustup target add ${{ matrix.target }}
 
       - name: Build Rust code
         working-directory: ${{ matrix.directory }}
@@ -140,6 +145,9 @@ jobs:
           sudo apt update
           sudo apt install gettext
 
+      - name: Update Rust
+        run: rustup update
+
       - name: Install mdbook
         uses: ./.github/workflows/install-mdbook
 

src/android/interoperability/java/src/lib.rs

@@ -20,7 +20,8 @@ use jni::sys::jstring;
 use jni::JNIEnv;
 
 /// HelloWorld::hello method implementation.
-#[no_mangle]
+// SAFETY: There is no other global function of this name.
+#[unsafe(no_mangle)]
 pub extern "system" fn Java_HelloWorld_hello(
     mut env: JNIEnv,
     _class: JClass,

src/android/interoperability/with-c.md

@@ -6,14 +6,13 @@ Similarly, you can export Rust functions and call them from C.
 You can do it by hand if you want:
 
 ```rust
-extern "C" {
-    fn abs(x: i32) -> i32;
+unsafe extern "C" {
+    safe fn abs(x: i32) -> i32;
 }
 
 fn main() {
     let x = -42;
-    // SAFETY: `abs` doesn't have any safety requirements.
-    let abs_x = unsafe { abs(x) };
+    let abs_x = abs(x);
     println!("{x}, {abs_x}");
 }
 ```

src/android/interoperability/with-c/hand-written.md

@@ -3,14 +3,13 @@
 We can declare external functions by hand:
 
 ```rust
-extern "C" {
-    fn abs(x: i32) -> i32;
+unsafe extern "C" {
+    safe fn abs(x: i32) -> i32;
 }
 
 fn main() {
     let x = -42;
-    // SAFETY: `abs` doesn't have any safety requirements.
-    let abs_x = unsafe { abs(x) };
+    let abs_x = abs(x);
     println!("{x}, {abs_x}");
 }
 ```

src/android/interoperability/with-c/rust.md

@@ -42,8 +42,8 @@ Build, push, and run the binary on your device:
 
 <details>
 
-`#[no_mangle]` disables Rust's usual name mangling, so the exported symbol will
-just be the name of the function. You can also use
-`#[export_name = "some_name"]` to specify whatever name you want.
+`#[unsafe(no_mangle)]` disables Rust's usual name mangling, so the exported
+symbol will just be the name of the function. You can also use
+`#[unsafe(export_name = "some_name")]` to specify whatever name you want.
 
 </details>

src/android/interoperability/with-c/rust/libanalyze/analyze.rs

@@ -19,7 +19,8 @@
 use std::os::raw::c_int;
 
 /// Analyze the numbers.
-#[no_mangle]
+// SAFETY: There is no other global function of this name.
+#[unsafe(no_mangle)]
 pub extern "C" fn analyze_numbers(x: c_int, y: c_int) {
     if x < y {
         println!("x ({x}) is smallest!");

src/bare-metal/aps/better-uart/driver.md

@@ -8,7 +8,7 @@ Now let's use the new `Registers` struct in our driver.
 
 <details>
 
-- Note the use of `addr_of!` / `addr_of_mut!` to get pointers to individual
-  fields without creating an intermediate reference, which would be unsound.
+- Note the use of `&raw const` / `&raw mut` to get pointers to individual fields
+  without creating an intermediate reference, which would be unsound.
 
 </details>

src/bare-metal/aps/examples/src/exceptions.rs

@@ -17,49 +17,57 @@ use log::error;
 use smccc::psci::system_off;
 use smccc::Hvc;
 
-#[no_mangle]
+// SAFETY: There is no other global function of this name.
+#[unsafe(no_mangle)]
 extern "C" fn sync_exception_current(_elr: u64, _spsr: u64) {
     error!("sync_exception_current");
     system_off::<Hvc>().unwrap();
 }
 
-#[no_mangle]
+// SAFETY: There is no other global function of this name.
+#[unsafe(no_mangle)]
 extern "C" fn irq_current(_elr: u64, _spsr: u64) {
     error!("irq_current");
     system_off::<Hvc>().unwrap();
 }
 
-#[no_mangle]
+// SAFETY: There is no other global function of this name.
+#[unsafe(no_mangle)]
 extern "C" fn fiq_current(_elr: u64, _spsr: u64) {
     error!("fiq_current");
     system_off::<Hvc>().unwrap();
 }
 
-#[no_mangle]
+// SAFETY: There is no other global function of this name.
+#[unsafe(no_mangle)]
 extern "C" fn serr_current(_elr: u64, _spsr: u64) {
     error!("serr_current");
     system_off::<Hvc>().unwrap();
 }
 
-#[no_mangle]
+// SAFETY: There is no other global function of this name.
+#[unsafe(no_mangle)]
 extern "C" fn sync_lower(_elr: u64, _spsr: u64) {
     error!("sync_lower");
     system_off::<Hvc>().unwrap();
 }
 
-#[no_mangle]
+// SAFETY: There is no other global function of this name.
+#[unsafe(no_mangle)]
 extern "C" fn irq_lower(_elr: u64, _spsr: u64) {
     error!("irq_lower");
     system_off::<Hvc>().unwrap();
 }
 
-#[no_mangle]
+// SAFETY: There is no other global function of this name.
+#[unsafe(no_mangle)]
 extern "C" fn fiq_lower(_elr: u64, _spsr: u64) {
     error!("fiq_lower");
     system_off::<Hvc>().unwrap();
 }
 
-#[no_mangle]
+// SAFETY: There is no other global function of this name.
+#[unsafe(no_mangle)]
 extern "C" fn serr_lower(_elr: u64, _spsr: u64) {
     error!("serr_lower");
     system_off::<Hvc>().unwrap();

src/bare-metal/aps/examples/src/main_improved.rs

@@ -29,7 +29,8 @@ use smccc::Hvc;
 /// Base address of the primary PL011 UART.
 const PL011_BASE_ADDRESS: *mut u32 = 0x900_0000 as _;
 
-#[no_mangle]
+// SAFETY: There is no other global function of this name.
+#[unsafe(no_mangle)]
 extern "C" fn main(x0: u64, x1: u64, x2: u64, x3: u64) {
     // SAFETY: `PL011_BASE_ADDRESS` is the base address of a PL011 device, and
     // nothing else accesses that address range.

src/bare-metal/aps/examples/src/main_logger.rs

@@ -29,7 +29,8 @@ use smccc::Hvc;
 /// Base address of the primary PL011 UART.
 const PL011_BASE_ADDRESS: *mut u32 = 0x900_0000 as _;
 
-#[no_mangle]
+// SAFETY: There is no other global function of this name.
+#[unsafe(no_mangle)]
 extern "C" fn main(x0: u64, x1: u64, x2: u64, x3: u64) {
     // SAFETY: `PL011_BASE_ADDRESS` is the base address of a PL011 device, and
     // nothing else accesses that address range.