feat: showing low-level VM errors (#311)

* feat: showing low-level VM errors

* silenced clippy warning

* Update to latest version and check-in e2e test that displays console errors

* fix lint

---------

Co-authored-by: Nicolas Villanueva <[email protected]>
Co-authored-by: MexicanAce <[email protected]>

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "era_test_node"
-version = "0.1.0-alpha.27"
+version = "0.1.0-alpha.28"
 edition = "2018"
 authors = ["The Matter Labs Team <[email protected]>"]
 homepage = "https://zksync.io/"

e2e-tests/contracts/Fib.sol

@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: UNLICENSED
+
+pragma solidity ^0.8.0;
+
+contract Fib {
+    function fib(uint256 n) public pure returns (uint256) {
+        return n <= 1 ? 1 : fib(n - 1) + fib(n - 2);
+    }
+}

e2e-tests/test/fib.test.ts

@@ -0,0 +1,24 @@
+import { Wallet } from "zksync-web3";
+import * as hre from "hardhat";
+import { Deployer } from "@matterlabs/hardhat-zksync-deploy";
+import { RichAccounts } from "../helpers/constants";
+import { deployContract, expectThrowsAsync, getTestProvider } from "../helpers/utils";
+
+const provider = getTestProvider();
+
+describe("Test Fib error flags", function () {
+  it("Should print to the console NOT ENOUGH ERGS", async function () {
+    const action = async () => {
+      const wallet = new Wallet(RichAccounts[0].PrivateKey, provider);
+
+      const deployer = new Deployer(hre, wallet);
+      const fib = await deployContract(deployer, "Fib");
+      await fib.fib(100);
+    };
+
+    // This is expected to throw and the console is expected to show:
+    //   XX:YY:ZZ ERROR !! Got error flags:
+    //   XX:YY:ZZ ERROR NOT ENOUGH ERGS
+    await expectThrowsAsync(action, "call revert exception");
+  });
+});

src/node/call_error_tracer.rs

@@ -0,0 +1,62 @@
+use zksync_multivm::{
+    tracers::dynamic::vm_1_5_0::DynTracer,
+    vm_latest::{HistoryMode, SimpleMemory, VmTracer},
+    zk_evm_latest::{
+        tracing::{AfterDecodingData, VmLocalStateData},
+        vm_state::ErrorFlags,
+    },
+};
+use zksync_state::interface::WriteStorage;
+
+pub struct CallErrorTracer {}
+
+impl CallErrorTracer {
+    pub fn new() -> Self {
+        Self {}
+    }
+}
+
+impl<S, H: HistoryMode> DynTracer<S, SimpleMemory<H>> for CallErrorTracer {
+    fn after_decoding(
+        &mut self,
+        _state: VmLocalStateData<'_>,
+        data: AfterDecodingData,
+        _memory: &SimpleMemory<H>,
+    ) {
+        if !data.error_flags_accumulated.is_empty() {
+            tracing::error!("!! Got error flags: ");
+            if data
+                .error_flags_accumulated
+                .contains(ErrorFlags::INVALID_OPCODE)
+            {
+                tracing::error!("INVALID OPCODE");
+            }
+            if data
+                .error_flags_accumulated
+                .contains(ErrorFlags::NOT_ENOUGH_ERGS)
+            {
+                tracing::error!("NOT ENOUGH ERGS");
+            }
+            if data
+                .error_flags_accumulated
+                .contains(ErrorFlags::PRIVILAGED_ACCESS_NOT_FROM_KERNEL)
+            {
+                tracing::error!("PRIVILEGED ACCESS");
+            }
+            if data
+                .error_flags_accumulated
+                .contains(ErrorFlags::WRITE_IN_STATIC_CONTEXT)
+            {
+                tracing::error!("WRITE IN STATIC");
+            }
+            if data
+                .error_flags_accumulated
+                .contains(ErrorFlags::CALLSTACK_IS_FULL)
+            {
+                tracing::error!("CALLSTACK IS FULL");
+            }
+        }
+    }
+}
+
+impl<S: WriteStorage, H: HistoryMode> VmTracer<S, H> for CallErrorTracer {}

src/node/in_memory.rs

@@ -12,7 +12,10 @@ use crate::{
     filters::EthFilters,
     fork::{block_on, ForkDetails, ForkSource, ForkStorage},
     formatter,
-    node::{fee_model::TestNodeFeeInputProvider, storage_logs::print_storage_logs_details},
+    node::{
+        call_error_tracer::CallErrorTracer, fee_model::TestNodeFeeInputProvider,
+        storage_logs::print_storage_logs_details,
+    },
     observability::Observability,
     system_contracts::{self, SystemContracts},
     utils::{bytecode_to_factory_dep, create_debug_output, into_jsrpc_error, to_human_size},
@@ -1036,9 +1039,11 @@ impl<S: ForkSource + std::fmt::Debug + Clone> InMemoryNode<S> {
 
         let call_tracer_result = Arc::new(OnceCell::default());
 
-        let custom_tracer = CallTracer::new(call_tracer_result.clone()).into_tracer_pointer();
-
-        let tx_result = vm.inspect(&mut custom_tracer.into(), VmExecutionMode::OneTx);
+        let tracers = vec![
+            CallErrorTracer::new().into_tracer_pointer(),
+            CallTracer::new(call_tracer_result.clone()).into_tracer_pointer(),
+        ];
+        let tx_result = vm.inspect(&mut tracers.into(), VmExecutionMode::OneTx);
 
         let call_traces = Arc::try_unwrap(call_tracer_result)
             .unwrap()
@@ -1345,6 +1350,7 @@ impl<S: ForkSource + std::fmt::Debug + Clone> InMemoryNode<S> {
         let call_tracer_result = Arc::new(OnceCell::default());
         let bootloader_debug_result = Arc::new(OnceCell::default());
 
+        tracers.push(CallErrorTracer::new().into_tracer_pointer());
         tracers.push(CallTracer::new(call_tracer_result.clone()).into_tracer_pointer());
         tracers.push(
             BootloaderDebugTracer {

src/node/mod.rs

@@ -1,6 +1,7 @@
 //! In-memory node, that supports forking other networks.
 
 mod anvil;
+mod call_error_tracer;
 mod config_api;
 mod debug;
 mod eth;