Merge pull request #47 from OffchainLabs/stylus-contract-calls

Contract Calls

Makefile

@@ -105,10 +105,12 @@ stylus_test_fallible_wasm   = $(call get_stylus_test_wasm,fallible)
 stylus_test_fallible_src    = $(call get_stylus_test_rust,fallible)
 stylus_test_storage_wasm    = $(call get_stylus_test_wasm,storage)
 stylus_test_storage_src     = $(call get_stylus_test_rust,storage)
+stylus_test_calls_wasm      = $(call get_stylus_test_wasm,calls)
+stylus_test_calls_src       = $(call get_stylus_test_rust,calls)
 stylus_test_siphash_wasm    = $(stylus_test_dir)/siphash/siphash.wasm
 stylus_test_siphash_src     = $(call get_stylus_test_c,siphash)
 
-stylus_test_wasms = $(stylus_test_keccak_wasm) $(stylus_test_keccak-100_wasm) $(stylus_test_fallible_wasm) $(stylus_test_storage_wasm) $(stylus_test_siphash_wasm)
+stylus_test_wasms = $(stylus_test_keccak_wasm) $(stylus_test_keccak-100_wasm) $(stylus_test_fallible_wasm) $(stylus_test_storage_wasm) $(stylus_test_siphash_wasm) $(stylus_test_calls_wasm)
 stylus_benchmarks = $(wildcard $(stylus_dir)/*.toml $(stylus_dir)/src/*.rs) $(stylus_test_wasms)
 stylus_files = $(wildcard $(stylus_dir)/*.toml $(stylus_dir)/src/*.rs) $(rust_prover_files)
 
@@ -342,6 +344,10 @@ $(stylus_test_storage_wasm): $(stylus_test_storage_src)
 	cargo build --manifest-path $< --release --target wasm32-unknown-unknown
 	@touch -c $@ # cargo might decide to not rebuild the binary
 
+$(stylus_test_calls_wasm): $(stylus_test_calls_src)
+	cargo build --manifest-path $< --release --target wasm32-unknown-unknown
+	@touch -c $@ # cargo might decide to not rebuild the binary
+
 $(stylus_test_siphash_wasm): $(stylus_test_siphash_src)
 	clang $(filter %.c, $^) -o $@ --target=wasm32 --no-standard-libraries -Wl,--no-entry -Oz
 

arbitrator/jit/src/user.rs

@@ -50,31 +50,28 @@ pub fn call_user_wasm(env: WasmEnvMut, sp: u32) {
     // skip the root since we don't use these
     sp.skip_u64();
 
-    macro_rules! error {
-        ($msg:expr, $report:expr) => {{
-            let outs = format!("{:?}", $report.wrap_err(eyre!($msg))).into_bytes();
-            sp.write_u8(UserOutcomeKind::Failure as u8).skip_space();
-            sp.write_ptr(heapify(outs));
-            if pricing.wasm_gas_price != 0 {
-                sp.write_u64_raw(evm_gas, pricing.wasm_to_evm(wasm_gas));
-            }
-            return;
-        }};
-    }
-
     // Safety: module came from compile_user_wasm
     let instance = unsafe { NativeInstance::deserialize(&module, config.clone()) };
-
     let mut instance = match instance {
         Ok(instance) => instance,
-        Err(error) => error!("failed to instantiate program", error),
+        Err(error) => panic!("failed to instantiate program {error:?}"),
     };
     instance.set_gas(wasm_gas);
     instance.set_stack(config.depth.max_depth);
 
-    let (status, outs) = match instance.run_main(&calldata, &config) {
-        Err(err) | Ok(UserOutcome::Failure(err)) => error!("failed to execute program", err),
-        Ok(outcome) => outcome.into_data(),
+    let status = match instance.run_main(&calldata, &config) {
+        Err(err) | Ok(UserOutcome::Failure(err)) => {
+            let outs = format!("{:?}", err.wrap_err(eyre!("failed to execute program")));
+            sp.write_u8(UserOutcomeKind::Failure as u8).skip_space();
+            sp.write_ptr(heapify(outs.into_bytes()));
+            UserOutcomeKind::Failure
+        }
+        Ok(outcome) => {
+            let (status, outs) = outcome.into_data();
+            sp.write_u8(status as u8).skip_space();
+            sp.write_ptr(heapify(outs));
+            status
+        }
     };
     if pricing.wasm_gas_price != 0 {
         let wasm_gas = match status {
@@ -83,8 +80,6 @@ pub fn call_user_wasm(env: WasmEnvMut, sp: u32) {
         };
         sp.write_u64_raw(evm_gas, pricing.wasm_to_evm(wasm_gas));
     }
-    sp.write_u8(status as u8).skip_space();
-    sp.write_ptr(heapify(outs));
 }
 
 /// Reads the length of a rust `Vec`

arbitrator/langs/rust/src/contract.rs

@@ -0,0 +1,65 @@
+// Copyright 2023, Offchain Labs, Inc.
+// For license information, see https://github.com/OffchainLabs/nitro/blob/master/LICENSE
+
+use super::util::{Bytes20, Bytes32};
+
+#[derive(Copy, Clone)]
+#[repr(C)]
+struct RustVec {
+    ptr: *mut u8,
+    len: usize,
+    cap: usize,
+}
+
+impl Default for RustVec {
+    fn default() -> Self {
+        Self {
+            ptr: std::ptr::null_mut(),
+            len: 0,
+            cap: 0,
+        }
+    }
+}
+
+#[link(wasm_import_module = "forward")]
+extern "C" {
+    fn call_contract(
+        contract: *const u8,
+        calldata: *const u8,
+        calldata_len: usize,
+        value: *const u8,
+        gas: u64,
+        return_data_len: *mut usize,
+    ) -> u8;
+
+    /// A noop when there's never been a call
+    fn read_return_data(dest: *mut u8);
+}
+
+/// Calls the contract at the given address, with options for passing value or limiting the amount of gas provided.
+/// On failure, the output consists of the call's revert data.
+pub fn call(contract: Bytes20, calldata: &[u8], value: Option<Bytes32>, gas: Option<u64>) -> Result<Vec<u8>, Vec<u8>> {
+    let mut outs_len = 0;
+    let value = value.unwrap_or_default();
+    let gas = gas.unwrap_or(u64::MAX); // will be clamped by 63/64 rule
+    let status = unsafe {
+        call_contract(
+            contract.ptr(),
+            calldata.as_ptr(),
+            calldata.len(),
+            value.ptr(),
+            gas,
+            &mut outs_len as *mut _,
+        )
+    };
+    let outs = unsafe {
+        let mut outs = Vec::with_capacity(outs_len);
+        read_return_data(outs.as_mut_ptr());
+        outs.set_len(outs_len);
+        outs
+    };
+    match status {
+        0 => Ok(outs),
+        _ => Err(outs),
+    }
+}

arbitrator/langs/rust/src/lib.rs

@@ -3,6 +3,7 @@
 
 pub use util::{Bytes20, Bytes32};
 
+pub mod contract;
 pub mod debug;
 mod util;
 

arbitrator/langs/rust/src/util.rs

@@ -1,6 +1,14 @@
-use std::{array::TryFromSliceError, borrow::Borrow, fmt::{self, Debug, Display, Formatter}, ops::{Deref, DerefMut}};
+// Copyright 2023, Offchain Labs, Inc.
+// For license information, see https://github.com/OffchainLabs/nitro/blob/master/LICENSE
 
-#[derive(Default)]
+use std::{
+    array::TryFromSliceError,
+    borrow::Borrow,
+    fmt::{self, Debug, Display, Formatter},
+    ops::{Deref, DerefMut},
+};
+
+#[derive(Copy, Clone, Default)]
 #[repr(C)]
 pub struct Bytes20(pub [u8; 20]);
 
@@ -82,7 +90,7 @@ impl Debug for Bytes20 {
     }
 }
 
-#[derive(Default)]
+#[derive(Copy, Clone, Default)]
 #[repr(C)]
 pub struct Bytes32(pub [u8; 32]);
 
@@ -163,4 +171,3 @@ impl Debug for Bytes32 {
         write!(f, "{}", hex::encode(self))
     }
 }
-

arbitrator/prover/src/binary.rs

@@ -525,7 +525,7 @@ impl<'a> WasmBinary<'a> {
         bound.update_module(self)?;
         start.update_module(self)?;
 
-        let count = config.debug.count_ops.then(|| Counter::new());
+        let count = config.debug.count_ops.then(Counter::new);
         if let Some(count) = &count {
             count.update_module(self)?;
         }

arbitrator/prover/src/host.rs

@@ -3,7 +3,7 @@
 
 use crate::{
     machine::{Function, InboxIdentifier},
-    programs::StylusGlobals,
+    programs::{run::UserOutcomeKind, StylusGlobals},
     value::{ArbValueType, FunctionType, IntegerValType},
     wavm::{IBinOpType, Instruction, Opcode},
 };
@@ -202,7 +202,7 @@ pub fn get_host_impl(module: &str, name: &str) -> eyre::Result<Function> {
                 // λ(module, main, args_len) -> status
                 opcode!(PushErrorGuard);
                 opcode!(ArbitraryJumpIf, code.len() + 3);
-                opcode!(I32Const, 1);
+                opcode!(I32Const, UserOutcomeKind::Failure as u32);
                 opcode!(Return);
 
                 // jumps here in the happy case

arbitrator/prover/src/programs/config.rs

@@ -1,6 +1,8 @@
 // Copyright 2022-2023, Offchain Labs, Inc.
 // For license information, see https://github.com/nitro/blob/master/LICENSE
 
+#![allow(clippy::field_reassign_with_default)]
+
 use eyre::{bail, Result};
 use std::fmt::Debug;
 use wasmer_types::Bytes;

arbitrator/prover/src/programs/counter.rs

@@ -36,6 +36,12 @@ impl Counter {
     }
 }
 
+impl Default for Counter {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl<M> Middleware<M> for Counter
 where
     M: ModuleMod,
@@ -115,7 +121,7 @@ impl<'a> FuncMiddleware<'a> for FuncCounter<'a> {
             for (op, count) in increments {
                 let opslen = operators.len();
                 let offset = *operators.entry(op).or_insert(opslen);
-                let global = *counters.get(offset).ok_or(eyre!("no global"))?;
+                let global = *counters.get(offset).ok_or_else(|| eyre!("no global"))?;
                 out.extend(update(global.as_u32(), count));
             }
 

arbitrator/prover/src/programs/meter.rs

@@ -6,7 +6,7 @@ use crate::Machine;
 use arbutil::operator::OperatorInfo;
 use eyre::Result;
 use parking_lot::Mutex;
-use std::fmt::Debug;
+use std::fmt::{Debug, Display};
 use wasmer_types::{GlobalIndex, GlobalInit, LocalFunctionIndex, Type};
 use wasmparser::{Operator, Type as WpType, TypeOrFuncType};
 
@@ -191,6 +191,15 @@ impl Into<u64> for MachineMeter {
     }
 }
 
+impl Display for MachineMeter {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Ready(gas) => write!(f, "{gas} gas"),
+            Self::Exhausted => write!(f, "exhausted"),
+        }
+    }
+}
+
 /// Note: implementers may panic if uninstrumented
 pub trait MeteredMachine {
     fn gas_left(&mut self) -> MachineMeter;

arbitrator/prover/src/programs/run.rs

@@ -68,9 +68,23 @@ impl Display for UserOutcome {
             OutOfGas => write!(f, "out of gas"),
             OutOfStack => write!(f, "out of stack"),
             Revert(data) => {
-                let text = String::from_utf8(data.clone()).unwrap_or(hex::encode(data));
+                let text = String::from_utf8(data.clone()).unwrap_or_else(|_| hex::encode(data));
                 write!(f, "revert {text}")
             }
         }
     }
 }
+
+impl Display for UserOutcomeKind {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let as_u8 = *self as u8;
+        use UserOutcomeKind::*;
+        match self {
+            Success => write!(f, "success ({as_u8})"),
+            Revert => write!(f, "revert ({as_u8})"),
+            Failure => write!(f, "failure ({as_u8})"),
+            OutOfGas => write!(f, "out of gas ({as_u8})"),
+            OutOfStack => write!(f, "out of stack ({as_u8})"),
+        }
+    }
+}

arbitrator/stylus/Cargo.toml

@@ -15,6 +15,7 @@ parking_lot = "0.12.1"
 thiserror = "1.0.33"
 libc = "0.2.108"
 eyre = "0.6.5"
+rand = "0.8.5"
 fnv = "1.0.7"
 sha3 = "0.10.5"
 hex = "0.4.3"

arbitrator/stylus/cbindgen.toml

@@ -5,3 +5,6 @@ include_guard = "arbitrator_bindings"
 parse_deps = true
 include = ["prover"]
 extra_bindings = ["prover"]
+
+[enum]
+prefix_with_name = true