Update rust example to use BPF enabled infrastructure (#2974)

programs/bpf/rust/noop/src/lib.rs

@@ -7,6 +7,17 @@ mod solana_sdk;
 
 use solana_sdk::*;
 
+struct SStruct {
+    x: u64,
+    y: u64,
+    z: u64,
+}
+
+#[inline(never)]
+fn return_sstruct() -> SStruct {
+    SStruct { x: 1, y: 2, z: 3 }
+}
+
 fn process(ka: &mut [SolKeyedAccount], data: &[u8], info: &SolClusterInfo) -> bool {
     sol_log("Tick height:");
     sol_log_64(info.tick_height, 0, 0, 0, 0);
@@ -18,5 +29,27 @@ fn process(ka: &mut [SolKeyedAccount], data: &[u8], info: &SolClusterInfo) -> bo
     // programs will have specific requirements so they can do their work.
     sol_log("Account keys and instruction input data:");
     sol_log_params(ka, data);
+
+    {
+        // Test - use core methods, unwrap
+
+        // valid bytes, in a stack-allocated array
+        let sparkle_heart = [240, 159, 146, 150];
+
+        let result_str = core::str::from_utf8(&sparkle_heart).unwrap();
+
+        sol_log_64(0, 0, 0, 0, result_str.len() as u64);
+        sol_log(result_str);
+        assert_eq!("💖", result_str);
+    }
+
+    {
+        // Test - struct return
+        let s = return_sstruct();
+        sol_log_64(0, 0, s.x, s.y, s.z);
+        assert_eq!(s.x + s.y + s.z, 6);
+    }
+
+    sol_log("Success");
     true
 }