Import https://github.com/tock/libtock-rs/core at commit 828c19d into third_party/lang-items/.

third_party/lang-items/src/alloc.rs

@@ -0,0 +1,45 @@
+use core::alloc::GlobalAlloc;
+use core::alloc::Layout;
+use core::ptr;
+use core::ptr::NonNull;
+use linked_list_allocator::Heap;
+
+static mut HEAP: Heap = Heap::empty();
+
+#[no_mangle]
+unsafe fn libtock_alloc_init(app_heap_start: usize, app_heap_size: usize) {
+    HEAP.init(app_heap_start, app_heap_size);
+}
+
+struct TockAllocator;
+
+unsafe impl GlobalAlloc for TockAllocator {
+    unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
+        HEAP.allocate_first_fit(layout)
+            .ok()
+            .map_or(ptr::null_mut(), NonNull::as_ptr)
+    }
+
+    unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
+        HEAP.deallocate(NonNull::new_unchecked(ptr), layout)
+    }
+}
+
+#[global_allocator]
+static ALLOCATOR: TockAllocator = TockAllocator;
+
+#[cfg(not(feature = "custom_alloc_error_handler"))]
+#[alloc_error_handler]
+unsafe fn alloc_error_handler(_: Layout) -> ! {
+    use crate::syscalls;
+
+    // Print 0x01 using the LowLevelDebug capsule (if available).
+    let _ = syscalls::command1_insecure(8, 2, 0x01);
+
+    // Signal a panic using the LowLevelDebug capsule (if available).
+    let _ = syscalls::command1_insecure(8, 1, 0x01);
+
+    loop {
+        syscalls::raw::yieldk();
+    }
+}