Implement transient get/set bytes32 hostios

Makefile

@@ -122,30 +122,38 @@ get_stylus_test_rust = $(wildcard $(stylus_test_dir)/$(1)/*.toml $(stylus_test_d
 get_stylus_test_c    = $(wildcard $(c_sdk)/examples/$(1)/*.c $(c_sdk)/examples/$(1)/*.h) $(stylus_lang_c)
 stylus_test_bfs      = $(wildcard $(stylus_test_dir)/bf/*.b)
 
-stylus_test_keccak_wasm           = $(call get_stylus_test_wasm,keccak)
-stylus_test_keccak_src            = $(call get_stylus_test_rust,keccak)
-stylus_test_keccak-100_wasm       = $(call get_stylus_test_wasm,keccak-100)
-stylus_test_keccak-100_src        = $(call get_stylus_test_rust,keccak-100)
-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_multicall_wasm        = $(call get_stylus_test_wasm,multicall)
-stylus_test_multicall_src         = $(call get_stylus_test_rust,multicall)
-stylus_test_log_wasm              = $(call get_stylus_test_wasm,log)
-stylus_test_log_src               = $(call get_stylus_test_rust,log)
-stylus_test_create_wasm           = $(call get_stylus_test_wasm,create)
-stylus_test_create_src            = $(call get_stylus_test_rust,create)
-stylus_test_evm-data_wasm         = $(call get_stylus_test_wasm,evm-data)
-stylus_test_evm-data_src          = $(call get_stylus_test_rust,evm-data)
-stylus_test_sdk-storage_wasm      = $(call get_stylus_test_wasm,sdk-storage)
-stylus_test_sdk-storage_src       = $(call get_stylus_test_rust,sdk-storage)
-stylus_test_erc20_wasm            = $(call get_stylus_test_wasm,erc20)
-stylus_test_erc20_src             = $(call get_stylus_test_rust,erc20)
-stylus_test_read-return-data_wasm = $(call get_stylus_test_wasm,read-return-data)
-stylus_test_read-return-data_src  = $(call get_stylus_test_rust,read-return-data)
-
-stylus_test_wasms = $(stylus_test_keccak_wasm) $(stylus_test_keccak-100_wasm) $(stylus_test_fallible_wasm) $(stylus_test_storage_wasm) $(stylus_test_multicall_wasm) $(stylus_test_log_wasm) $(stylus_test_create_wasm) $(stylus_test_sdk-storage_wasm) $(stylus_test_erc20_wasm) $(stylus_test_read-return-data_wasm) $(stylus_test_evm-data_wasm) $(stylus_test_bfs:.b=.wasm)
+stylus_test_keccak_wasm                     = $(call get_stylus_test_wasm,keccak)
+stylus_test_keccak_src                      = $(call get_stylus_test_rust,keccak)
+stylus_test_keccak-100_wasm                 = $(call get_stylus_test_wasm,keccak-100)
+stylus_test_keccak-100_src                  = $(call get_stylus_test_rust,keccak-100)
+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_multicall_wasm                  = $(call get_stylus_test_wasm,multicall)
+stylus_test_multicall_src                   = $(call get_stylus_test_rust,multicall)
+stylus_test_log_wasm                        = $(call get_stylus_test_wasm,log)
+stylus_test_log_src                         = $(call get_stylus_test_rust,log)
+stylus_test_create_wasm                     = $(call get_stylus_test_wasm,create)
+stylus_test_create_src                      = $(call get_stylus_test_rust,create)
+stylus_test_evm-data_wasm                   = $(call get_stylus_test_wasm,evm-data)
+stylus_test_evm-data_src                    = $(call get_stylus_test_rust,evm-data)
+stylus_test_sdk-storage_wasm                = $(call get_stylus_test_wasm,sdk-storage)
+stylus_test_sdk-storage_src                 = $(call get_stylus_test_rust,sdk-storage)
+stylus_test_erc20_wasm                      = $(call get_stylus_test_wasm,erc20)
+stylus_test_erc20_src                       = $(call get_stylus_test_rust,erc20)
+stylus_test_read-return-data_wasm           = $(call get_stylus_test_wasm,read-return-data)
+stylus_test_read-return-data_src            = $(call get_stylus_test_rust,read-return-data)
+stylus_test_transient-enter_wasm            = $(call get_stylus_test_wasm,transient-enter)
+stylus_test_transient-enter_src             = $(call get_stylus_test_rust,transient-enter)
+stylus_test_transient-reenter_wasm          = $(call get_stylus_test_wasm,transient-reenter)
+stylus_test_transient-reenter_src           = $(call get_stylus_test_rust,transient-reenter)
+stylus_test_transient-delegate-enter_wasm   = $(call get_stylus_test_wasm,transient-delegate-enter)
+stylus_test_transient-delegate-enter_src    = $(call get_stylus_test_rust,transient-delegate-enter)
+stylus_test_transient-delegate-reenter_wasm = $(call get_stylus_test_wasm,transient-delegate-reenter)
+stylus_test_transient-delegate-reenter_src  = $(call get_stylus_test_rust,transient-delegate-reenter)
+
+stylus_test_wasms = $(stylus_test_keccak_wasm) $(stylus_test_keccak-100_wasm) $(stylus_test_fallible_wasm) $(stylus_test_storage_wasm) $(stylus_test_multicall_wasm) $(stylus_test_log_wasm) $(stylus_test_create_wasm) $(stylus_test_sdk-storage_wasm) $(stylus_test_erc20_wasm) $(stylus_test_read-return-data_wasm) $(stylus_test_evm-data_wasm) $(stylus_test_bfs:.b=.wasm) $(stylus_test_transient-enter_wasm) $(stylus_test_transient-reenter_wasm) $(stylus_test_transient-delegate-enter_wasm) $(stylus_test_transient-delegate-reenter_wasm)
 stylus_benchmarks = $(wildcard $(stylus_dir)/*.toml $(stylus_dir)/src/*.rs) $(stylus_test_wasms)
 
 # user targets
@@ -233,6 +241,8 @@ clean:
 	rm -rf $(output_root)
 	rm -f contracts/test/prover/proofs/*.json contracts/test/prover/spec-proofs/*.json
 	rm -rf arbitrator/target
+	rm -f $(forward_dir)/forward.wat
+	rm -f $(forward_dir)/forward_stub.wat
 	rm -rf arbitrator/wasm-libraries/target
 	rm -f arbitrator/wasm-libraries/soft-float/soft-float.wasm
 	rm -f arbitrator/wasm-libraries/soft-float/*.o
@@ -418,6 +428,22 @@ $(stylus_test_read-return-data_wasm): $(stylus_test_read-return-data_src)
 	$(cargo_nightly) --manifest-path $< --release --config $(stylus_cargo)
 	@touch -c $@ # cargo might decide to not rebuild the binary
 
+$(stylus_test_transient-enter_wasm): $(stylus_test_transient-enter_src)
+	$(cargo_nightly) --manifest-path $< --release --config $(stylus_cargo)
+	@touch -c $@ # cargo might decide to not rebuild the binary
+
+$(stylus_test_transient-reenter_wasm): $(stylus_test_transient-reenter_src)
+	$(cargo_nightly) --manifest-path $< --release --config $(stylus_cargo)
+	@touch -c $@ # cargo might decide to not rebuild the binary
+
+$(stylus_test_transient-delegate-enter_wasm): $(stylus_test_transient-delegate-enter_src)
+	$(cargo_nightly) --manifest-path $< --release --config $(stylus_cargo)
+	@touch -c $@ # cargo might decide to not rebuild the binary
+
+$(stylus_test_transient-delegate-reenter_wasm): $(stylus_test_transient-delegate-reenter_src)
+	$(cargo_nightly) --manifest-path $< --release --config $(stylus_cargo)
+	@touch -c $@ # cargo might decide to not rebuild the binary
+
 $(stylus_test_sdk-storage_wasm): $(stylus_test_sdk-storage_src)
 	$(cargo_nightly) --manifest-path $< --release --config $(stylus_cargo)
 	@touch -c $@ # cargo might decide to not rebuild the binary

arbitrator/arbutil/src/evm/api.rs

@@ -34,6 +34,8 @@ impl From<u8> for EvmApiStatus {
 pub enum EvmApiMethod {
     GetBytes32,
     SetBytes32,
+    TransientGetBytes32,
+    TransientSetBytes32,
     ContractCall,
     DelegateCall,
     StaticCall,
@@ -57,6 +59,17 @@ pub trait EvmApi: Send + 'static {
     /// Analogous to `vm.SSTORE`.
     fn set_bytes32(&mut self, key: Bytes32, value: Bytes32) -> Result<u64>;
 
+    /// Reads the 32-byte value in the EVM state trie at offset `key`.
+    /// Storage is discarded after every transaction
+    /// Returns the value.
+    /// Analogous to `vm.TLOAD`.
+    fn transient_get_bytes32(&mut self, key: Bytes32) -> Bytes32;
+
+    /// Stores the given value at the given key in the EVM state trie.
+    /// Storage is discarded after every transaction
+    /// Analogous to `vm.TSTORE`.
+    fn transient_set_bytes32(&mut self, key: Bytes32, value: Bytes32) -> Result<()>;
+
     /// Calls the contract at the given address.
     /// Returns the EVM return data's length, the gas cost, and whether the call succeeded.
     /// Analogous to `vm.CALL`.

arbitrator/arbutil/src/evm/js.rs

@@ -215,6 +215,20 @@ impl<T: JsCallIntoGo> EvmApi for JsEvmApi<T> {
         }
     }
 
+    fn transient_get_bytes32(&mut self, key: Bytes32) -> Bytes32 {
+        let [value] = call!(self, 1, TransientGetBytes32, key);
+        value.assert_bytes32()
+    }
+
+    fn transient_set_bytes32(&mut self, key: Bytes32, value: Bytes32) -> Result<()> {
+        let [out] = call!(self, 1, TransientSetBytes32, key, value);
+        match out {
+            ApiValueKind::Nil => Ok(()),
+            ApiValueKind::String(err) => bail!(err),
+            _ => unreachable!(),
+        }
+    }
+
     fn contract_call(
         &mut self,
         contract: Bytes20,

arbitrator/arbutil/src/evm/mod.rs

@@ -10,6 +10,9 @@ pub mod user;
 // params.SstoreSentryGasEIP2200
 pub const SSTORE_SENTRY_GAS: u64 = 2300;
 
+// params.WarmStorageReadCostEIP2929
+pub const TRANSIENT_BYTES32_GAS: u64 = 100;
+
 // params.LogGas and params.LogDataGas
 pub const LOG_TOPIC_GAS: u64 = 375;
 pub const LOG_DATA_GAS: u64 = 8;

arbitrator/stylus/src/evm_api.rs

@@ -21,6 +21,13 @@ pub struct GoEvmApi {
         gas_cost: *mut u64,
         error: *mut RustBytes,
     ) -> EvmApiStatus,
+    pub transient_get_bytes32: unsafe extern "C" fn(id: usize, key: Bytes32) -> Bytes32, // value
+    pub transient_set_bytes32: unsafe extern "C" fn(
+        id: usize,
+        key: Bytes32,
+        value: Bytes32,
+        error: *mut RustBytes,
+    ) -> EvmApiStatus,
     pub contract_call: unsafe extern "C" fn(
         id: usize,
         contract: Bytes20,
@@ -117,6 +124,21 @@ impl EvmApi for GoEvmApi {
         }
     }
 
+    fn transient_get_bytes32(&mut self, key: Bytes32) -> Bytes32 {
+        let value = call!(self, transient_get_bytes32, key);
+        value
+    }
+
+    fn transient_set_bytes32(&mut self, key: Bytes32, value: Bytes32) -> Result<()> {
+        let mut error = RustBytes::new(vec![]);
+        let api_status = call!(self, transient_set_bytes32, key, value, ptr!(error));
+        let error = into_vec!(error); // done here to always drop
+        match api_status {
+            EvmApiStatus::Success => Ok(()),
+            EvmApiStatus::Failure => Err(error!(error)),
+        }
+    }
+
     fn contract_call(
         &mut self,
         contract: Bytes20,

arbitrator/stylus/src/host.rs

@@ -117,6 +117,22 @@ pub(crate) fn storage_store_bytes32<E: EvmApi>(
     hostio!(env, storage_store_bytes32(key, value))
 }
 
+pub(crate) fn transient_load_bytes32<E: EvmApi>(
+    mut env: WasmEnvMut<E>,
+    key: u32,
+    dest: u32,
+) -> MaybeEscape {
+    hostio!(env, transient_load_bytes32(key, dest))
+}
+
+pub(crate) fn transient_store_bytes32<E: EvmApi>(
+    mut env: WasmEnvMut<E>,
+    key: u32,
+    value: u32,
+) -> MaybeEscape {
+    hostio!(env, transient_store_bytes32(key, value))
+}
+
 pub(crate) fn call_contract<E: EvmApi>(
     mut env: WasmEnvMut<E>,
     contract: u32,

arbitrator/stylus/src/native.rs

@@ -126,6 +126,8 @@ impl<E: EvmApi> NativeInstance<E> {
                 "write_result" => func!(host::write_result),
                 "storage_load_bytes32" => func!(host::storage_load_bytes32),
                 "storage_store_bytes32" => func!(host::storage_store_bytes32),
+                "transient_load_bytes32" => func!(host::transient_load_bytes32),
+                "transient_store_bytes32" => func!(host::transient_store_bytes32),
                 "call_contract" => func!(host::call_contract),
                 "delegate_call_contract" => func!(host::delegate_call_contract),
                 "static_call_contract" => func!(host::static_call_contract),
@@ -332,6 +334,8 @@ pub fn module(wasm: &[u8], compile: CompileConfig) -> Result<Vec<u8>> {
             "write_result" => stub!(|_: u32, _: u32|),
             "storage_load_bytes32" => stub!(|_: u32, _: u32|),
             "storage_store_bytes32" => stub!(|_: u32, _: u32|),
+            "transient_load_bytes32" => stub!(|_: u32, _: u32|),
+            "transient_store_bytes32" => stub!(|_: u32, _: u32|),
             "call_contract" => stub!(u8 <- |_: u32, _: u32, _: u32, _: u32, _: u64, _: u32|),
             "delegate_call_contract" => stub!(u8 <- |_: u32, _: u32, _: u32, _: u64, _: u32|),
             "static_call_contract" => stub!(u8 <- |_: u32, _: u32, _: u32, _: u64, _: u32|),

arbitrator/stylus/src/test/api.rs

@@ -17,6 +17,7 @@ use super::TestInstance;
 pub(crate) struct TestEvmApi {
     contracts: Arc<Mutex<HashMap<Bytes20, Vec<u8>>>>,
     storage: Arc<Mutex<HashMap<Bytes20, HashMap<Bytes32, Bytes32>>>>,
+    transient_storage: Arc<Mutex<HashMap<Bytes20, HashMap<Bytes32, Bytes32>>>>,
     program: Bytes20,
     write_result: Arc<Mutex<Vec<u8>>>,
     compile: CompileConfig,
@@ -33,9 +34,12 @@ impl TestEvmApi {
         let mut storage = HashMap::new();
         storage.insert(program, HashMap::new());
 
+        let mut transient_storage = HashMap::new();
+
         let api = TestEvmApi {
             contracts: Arc::new(Mutex::new(HashMap::new())),
             storage: Arc::new(Mutex::new(storage)),
+            transient_storage: Arc::new(Mutex::new(transient_storage)),
             program,
             write_result: Arc::new(Mutex::new(vec![])),
             compile,
@@ -77,6 +81,20 @@ impl EvmApi for TestEvmApi {
         Ok(22100) // pretend worst case
     }
 
+    fn transient_get_bytes32(&mut self, key: Bytes32) -> Bytes32 {
+        let transient_storage = &mut self.transient_storage.lock();
+        let transient_storage = transient_storage.get_mut(&self.program).unwrap();
+        let value = transient_storage.get(&key).cloned().unwrap_or_default();
+        value
+    }
+
+    fn transient_set_bytes32(&mut self, key: Bytes32, value: Bytes32) -> Result<()> {
+        let transient_storage = &mut self.transient_storage.lock();
+        let transient_storage = transient_storage.get_mut(&self.program).unwrap();
+        transient_storage.insert(key, value);
+        Ok(())
+    }
+
     /// Simulates a contract call.
     /// Note: this call function is for testing purposes only and deviates from onchain behavior.
     fn contract_call(

arbitrator/stylus/tests/transient-delegate-enter/.cargo/config

@@ -0,0 +1,2 @@
+[build]
+target = "wasm32-unknown-unknown"