Show hint example

ceno_emul/tests/test_elf.rs → ceno_host/tests/test_elf.rs

@@ -3,6 +3,8 @@ use ceno_emul::{
     CENO_PLATFORM, EmuContext, InsnKind, Platform, StepRecord, VMState,
     host_utils::read_all_messages,
 };
+use ceno_host::CenoStdin;
+use itertools::enumerate;
 
 #[test]
 fn test_ceno_rt_mini() -> Result<()> {
@@ -75,6 +77,20 @@ fn test_ceno_rt_io() -> Result<()> {
     Ok(())
 }
 
+#[test]
+fn test_hints() {
+    let mut hints = CenoStdin::default();
+    hints.write(&"This is my hint string.".to_string()).unwrap();
+    hints.write(&1997_u32).unwrap();
+    hints.write(&1999_u32).unwrap();
+
+    let all_messages = ceno_host::run(CENO_PLATFORM, ceno_examples::hints, &hints);
+    for (i, msg) in enumerate(&all_messages) {
+        println!("{i}: {msg}");
+    }
+    assert_eq!(all_messages[0], "3992003");
+}
+
 fn run(state: &mut VMState) -> Result<Vec<StepRecord>> {
     let steps = state.iter_until_halt().collect::<Result<Vec<_>>>()?;
     eprintln!("Emulator ran for {} steps.", steps.len());

guest/examples/examples/hints.rs

@@ -0,0 +1,20 @@
+#![no_main]
+#![no_std]
+
+extern crate ceno_rt;
+use ceno_rt::println;
+use core::fmt::Write;
+use rkyv::{Archived, string::ArchivedString};
+
+ceno_rt::entry!(main);
+fn main() {
+    let msg: &ArchivedString = ceno_rt::read();
+
+    let a: &Archived<u32> = ceno_rt::read();
+    let b: &Archived<u32> = ceno_rt::read();
+    let product: u32 = a * b;
+
+    assert_eq!(product, 3992003);
+    println!("{product}");
+    println!("This message is a hint: {msg}");
+}