sysctrl: print example names

examples/sysctrl/hello-sysctrl/examples/uart0.rs

@@ -2,10 +2,12 @@
 #![no_main]
 
 use headsail_bsp::{rt::entry, uart::uart_write};
+use hello_sysctrl::print_example_name;
 use panic_halt as _;
 
 #[entry]
 fn main() -> ! {
+    print_example_name!();
     uart_write("Hello world!");
     loop {}
 }

examples/sysctrl/hello-sysctrl/src/lib.rs

@@ -1,2 +1,14 @@
 #![no_std]
 #![no_main]
+
+/// Print the name of the current file, i.e., test name.
+///
+/// This must be a macro to make sure core::file matches the file this is
+/// invoked in.
+#[macro_export]
+macro_rules! print_example_name {
+    () => {
+        use headsail_bsp::sprintln;
+        sprintln!("[{}]", core::file!());
+    };
+}