Adopt Rust 2024 edition

I'm considering this a breaking change. I'll try to introduce new
sections that rely on the user's `unsafe` keyword for linker placement.

Rust 2024 has different opinions on format, and clippy has new thoughts.
Let's adopt them.

2 files changed, 15 insertions, 21 deletions

diff --git a/src/host.rs b/src/host.rs
index ba299dd..2598d50 100644
--- a/src/host.rs
+++ b/src/host.rs
@@ -639,12 +639,12 @@ impl RuntimeBuilder {
     fn check_configurations(&self) -> Result<(), String> {
         if self.family.flexram_bank_count() < self.flexram_banks.bank_count() {
             return Err(format!(
-            "Chip {:?} only has {} total FlexRAM banks. Cannot allocate {:?}, a total of {} banks",
-            self.family,
-            self.family.flexram_bank_count(),
-            self.flexram_banks,
-            self.flexram_banks.bank_count()
-        ));
+                "Chip {:?} only has {} total FlexRAM banks. Cannot allocate {:?}, a total of {} banks",
+                self.family,
+                self.family.flexram_bank_count(),
+                self.flexram_banks,
+                self.flexram_banks.bank_count()
+            ));
         }
         if self.flexram_banks.ocram < self.family.bootrom_ocram_banks() {
             return Err(format!(
@@ -653,13 +653,13 @@ impl RuntimeBuilder {
                 self.family.bootrom_ocram_banks()
             ));
         }
-        if let Some(flash_opts) = &self.flash_opts {
-            if !flash_opts.flexspi.supported_for_family(self.family) {
-                return Err(format!(
-                    "Chip {:?} does not support {:?}",
-                    self.family, flash_opts.flexspi
-                ));
-            }
+        if let Some(flash_opts) = &self.flash_opts
+            && !flash_opts.flexspi.supported_for_family(self.family)
+        {
+            return Err(format!(
+                "Chip {:?} does not support {:?}",
+                self.family, flash_opts.flexspi
+            ));
         }
 
         fn prevent_flash(name: &str, memory: Memory) -> Result<(), String> {
diff --git a/src/target.rs b/src/target.rs
index 98072e0..d0e2223 100644
--- a/src/target.rs
+++ b/src/target.rs
@@ -135,14 +135,8 @@ __pre_init:
 /// The returned pointer is guaranteed to be 4-byte aligned.
 #[inline]
 pub fn heap_end() -> *mut u32 {
-    extern "C" {
+    unsafe extern "C" {
         static mut __eheap: c_void;
     }
-
-    // It used to be unsafe. Keeping it unsafe is backwards
-    // compatible.
-    #[allow(unused_unsafe)]
-    unsafe {
-        core::ptr::addr_of_mut!(__eheap) as _
-    }
+    &raw mut __eheap as _
 }