small refactor

test_program_methods/guest/src/bin/clock_chain_caller.rs

@@ -0,0 +1,35 @@
+use nssa_core::program::{
+    AccountPostState, ChainedCall, ProgramId, ProgramInput, ProgramOutput, read_nssa_inputs,
+};
+use risc0_zkvm::serde::to_vec;
+
+type Instruction = (ProgramId, u64); // (clock_program_id, timestamp)
+
+/// A program that chain-calls the clock program with the clock accounts it received as pre-states.
+/// Used in tests to verify that user transactions cannot modify clock accounts, even indirectly
+/// via chain calls.
+fn main() {
+    let (
+        ProgramInput {
+            pre_states,
+            instruction: (clock_program_id, timestamp),
+        },
+        instruction_words,
+    ) = read_nssa_inputs::<Instruction>();
+
+    let post_states: Vec<_> = pre_states
+        .iter()
+        .map(|pre| AccountPostState::new(pre.account.clone()))
+        .collect();
+
+    let chained_call = ChainedCall {
+        program_id: clock_program_id,
+        instruction_data: to_vec(&timestamp).unwrap(),
+        pre_states: pre_states.clone(),
+        pda_seeds: vec![],
+    };
+
+    ProgramOutput::new(instruction_words, pre_states, post_states)
+        .with_chained_calls(vec![chained_call])
+        .write();
+}