Add value test

Author: smoelius

integration/stylus/value.sol

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity >=0.8.0;
+
+contract C {
+    function test() public payable returns (uint256) {
+        return this.other{value: msg.value}();
+    }
+
+    function other() public payable returns (uint256) {
+        uint256 value = msg.value;
+        print("value = {}".format(value));
+        assert(value == 1000000000000000000);
+        return value;
+    }
+}

src/emit/stylus/target.rs

@@ -840,7 +840,17 @@ impl<'a> TargetRuntime<'a> for StylusTarget {
             bin.builder
                 .build_store(value, contract_args.value.unwrap())
                 .unwrap();
-            args.push(value.into());
+            // smoelius: Value is little-endian and must be byte-swapped.
+            let temp = bin.builder.build_alloca(bin.value_type(), "value").unwrap();
+            call!(
+                "__leNtobeN",
+                &[
+                    value.into(),
+                    temp.into(),
+                    i32_const!(bin.ns.value_length as u64).into()
+                ]
+            );
+            args.push(temp.into())
         }
 
         let gas = gas_calculation(bin, contract_args.gas.unwrap());
@@ -1221,6 +1231,10 @@ impl<'a> TargetRuntime<'a> for StylusTarget {
 
                 timestamp.into()
             }
+            Expression::Builtin {
+                kind: Builtin::Value,
+                ..
+            } => self.value_transferred(bin).into(),
             _ => unimplemented!("{expr:?}"),
         }
     }
@@ -1270,7 +1284,28 @@ impl<'a> TargetRuntime<'a> for StylusTarget {
 
     /// Return the value we received
     fn value_transferred<'b>(&self, bin: &Binary<'b>) -> IntValue<'b> {
-        unimplemented!()
+        emit_context!(bin);
+
+        let value = bin.builder.build_alloca(bin.value_type(), "value").unwrap();
+
+        call!("msg_value", &[value.into()], "value_transferred");
+
+        // smoelius: `value` is big-endian and must be byte-swapped.
+        let temp = bin.builder.build_alloca(bin.value_type(), "value").unwrap();
+
+        call!(
+            "__beNtoleN",
+            &[
+                value.into(),
+                temp.into(),
+                i32_const!(bin.ns.value_length as u64).into()
+            ]
+        );
+
+        bin.builder
+            .build_load(bin.value_type(), temp, "value")
+            .unwrap()
+            .into_int_value()
     }
 
     /// Terminate execution, destroy bin and send remaining funds to addr

tests/stylus_tests/mod.rs

@@ -3,3 +3,4 @@ mod counter;
 mod milestone_1;
 mod milestone_2;
 mod milestone_3;
+mod value;

tests/stylus_tests/value.rs

@@ -0,0 +1,24 @@
+//! This test expects you to have a devnode running:
+//! <https://docs.arbitrum.io/run-arbitrum-node/run-nitro-dev-node>
+//!
+//! It also expects `cargo-stylus` and `cast` to be installed:
+//! - <https://github.com/OffchainLabs/cargo-stylus>
+//! - <https://book.getfoundry.sh/cast/>
+#![warn(clippy::pedantic)]
+
+use crate::{deploy, send, MUTEX};
+use std::path::PathBuf;
+
+#[test]
+fn value() {
+    let _lock = MUTEX.lock();
+    let (tempdir, address) = deploy(
+        PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("integration/stylus/value.sol"),
+        "C",
+    )
+    .unwrap();
+    let dir = &tempdir;
+
+    let stdout = send(dir, &address, ["test()", "--value=1000000000000000000"]).unwrap();
+    println!("{}", &stdout);
+}