feat: add vm error tracer (#594)

* add vm error tracer

crates/zksync/core/src/vm/inspect.rs

@@ -1,6 +1,5 @@
 use alloy_primitives::{hex, Log};
 use era_test_node::{
-    bootloader_debug::{BootloaderDebug, BootloaderDebugTracer},
     config::node::ShowCalls,
     formatter,
     system_contracts::{Options, SystemContracts},
@@ -43,7 +42,11 @@ use crate::{
         db::{ZKVMData, DEFAULT_CHAIN_ID},
         env::{create_l1_batch_env, create_system_env},
         storage_view::StorageView,
-        tracer::{CallContext, CheatcodeTracer, CheatcodeTracerContext},
+        tracers::{
+            bootloader::{BootloaderDebug, BootloaderDebugTracer},
+            cheatcode::{CallContext, CheatcodeTracer, CheatcodeTracerContext},
+            error::ErrorTracer,
+        },
     },
 };
 use foundry_evm_abi::{
@@ -437,6 +440,7 @@ fn inspect_inner<S: ReadStorage>(
     let is_create = call_ctx.is_create;
     let bootloader_debug_tracer_result = Arc::new(OnceCell::default());
     let tracers = vec![
+        ErrorTracer.into_tracer_pointer(),
         CallTracer::new(call_tracer_result.clone()).into_tracer_pointer(),
         BootloaderDebugTracer { result: bootloader_debug_tracer_result.clone() }
             .into_tracer_pointer(),

crates/zksync/core/src/vm/mod.rs

@@ -4,10 +4,10 @@ mod farcall;
 mod inspect;
 mod runner;
 mod storage_view;
-mod tracer;
+mod tracers;
 
 pub use inspect::{
     batch_factory_dependencies, inspect, inspect_as_batch, ZKVMExecutionResult, ZKVMResult,
 };
 pub use runner::{balance, call, code_hash, create, encode_create_params, nonce, transact};
-pub use tracer::CheatcodeTracerContext;
+pub use tracers::cheatcode::CheatcodeTracerContext;

crates/zksync/core/src/vm/runner.rs

@@ -21,7 +21,7 @@ use crate::{
     vm::{
         db::ZKVMData,
         inspect::{inspect, inspect_as_batch, ZKVMExecutionResult, ZKVMResult},
-        tracer::{CallContext, CheatcodeTracerContext},
+        tracers::cheatcode::{CallContext, CheatcodeTracerContext},
     },
 };
 

crates/zksync/core/src/vm/tracer.rs → crates/zksync/core/src/vm/tracers/cheatcode.rs

@@ -27,12 +27,10 @@ use zksync_utils::bytecode::hash_bytecode;
 
 use crate::{
     convert::{ConvertAddress, ConvertH160, ConvertH256, ConvertU256},
-    vm::farcall::{CallAction, CallDepth},
+    vm::farcall::{CallAction, CallDepth, FarCallHandler},
     ZkPaymasterData, EMPTY_CODE,
 };
 
-use super::farcall::FarCallHandler;
-
 /// Selector for retrieving account version.
 /// This is used to override the caller's account version when deploying a contract
 /// So non-EOA addresses can also deploy within the VM.

crates/zksync/core/src/vm/tracers/error.rs

@@ -0,0 +1,51 @@
+use multivm::{
+    interface::dyn_tracers::vm_1_5_0::DynTracer,
+    vm_latest::{HistoryMode, SimpleMemory, VmTracer},
+    zk_evm_latest::{
+        tracing::{AfterDecodingData, VmLocalStateData},
+        vm_state::ErrorFlags,
+    },
+};
+use zksync_state::{ReadStorage, WriteStorage};
+
+/// A tracer to allow logging low-level vm errors.
+#[derive(Debug, Default)]
+pub struct ErrorTracer;
+
+impl<S: ReadStorage, H: HistoryMode> DynTracer<S, SimpleMemory<H>> for ErrorTracer {
+    fn after_decoding(
+        &mut self,
+        _state: VmLocalStateData<'_>,
+        data: AfterDecodingData,
+        _memory: &SimpleMemory<H>,
+    ) {
+        if data.error_flags_accumulated.is_empty() {
+            return;
+        }
+
+        let errors = parse_error_flags(&data.error_flags_accumulated);
+        tracing::error!("vm error: {}", errors.join(", "));
+    }
+}
+
+impl<S: WriteStorage, H: HistoryMode> VmTracer<S, H> for ErrorTracer {}
+
+fn parse_error_flags(error_flags: &ErrorFlags) -> Vec<String> {
+    let mut errors = vec![];
+    if error_flags.contains(ErrorFlags::INVALID_OPCODE) {
+        errors.push(String::from("Invalid opcode"));
+    }
+    if error_flags.contains(ErrorFlags::NOT_ENOUGH_ERGS) {
+        errors.push(String::from("Not enough gas"));
+    }
+    if error_flags.contains(ErrorFlags::PRIVILAGED_ACCESS_NOT_FROM_KERNEL) {
+        errors.push(String::from("Unauthorized privileged access"));
+    }
+    if error_flags.contains(ErrorFlags::WRITE_IN_STATIC_CONTEXT) {
+        errors.push(String::from("Write applied in static context"));
+    }
+    if error_flags.contains(ErrorFlags::CALLSTACK_IS_FULL) {
+        errors.push(String::from("Call stack full"));
+    }
+    errors
+}

crates/zksync/core/src/vm/tracers/mod.rs

@@ -0,0 +1,7 @@
+/// Contains tracer implementations for the zkEVM
+
+pub mod bootloader {
+    pub use era_test_node::bootloader_debug::{BootloaderDebug, BootloaderDebugTracer};
+}
+pub mod cheatcode;
+pub mod error;