perf: reduce dynamic dispatch for inspectors (#9011)

crates/evm/core/src/backend/cow.rs

@@ -62,10 +62,10 @@ impl<'a> CowBackend<'a> {
     /// Note: in case there are any cheatcodes executed that modify the environment, this will
     /// update the given `env` with the new values.
     #[instrument(name = "inspect", level = "debug", skip_all)]
-    pub fn inspect(
+    pub fn inspect<I: InspectorExt>(
         &mut self,
         env: &mut EnvWithHandlerCfg,
-        inspector: &mut dyn InspectorExt,
+        inspector: &mut I,
     ) -> eyre::Result<ResultAndState> {
         // this is a new call to inspect with a new env, so even if we've cloned the backend
         // already, we reset the initialized state

crates/evm/core/src/backend/mod.rs

@@ -751,10 +751,10 @@ impl Backend {
     /// Note: in case there are any cheatcodes executed that modify the environment, this will
     /// update the given `env` with the new values.
     #[instrument(name = "inspect", level = "debug", skip_all)]
-    pub fn inspect(
+    pub fn inspect<I: InspectorExt>(
         &mut self,
         env: &mut EnvWithHandlerCfg,
-        inspector: &mut dyn InspectorExt,
+        inspector: &mut I,
     ) -> eyre::Result<ResultAndState> {
         self.initialize(env);
         let mut evm = crate::utils::new_evm_with_inspector(self, env.clone(), inspector);

crates/evm/core/src/utils.rs

@@ -234,11 +234,11 @@ pub fn alphanet_handler_register<EXT, DB: revm::Database>(handler: &mut EvmHandl
 }
 
 /// Creates a new EVM with the given inspector.
-pub fn new_evm_with_inspector<'evm, 'i, 'db>(
+pub fn new_evm_with_inspector<'evm, 'i, 'db, I: InspectorExt + ?Sized>(
     db: &'db mut dyn DatabaseExt,
     env: revm::primitives::EnvWithHandlerCfg,
-    inspector: &'i mut dyn InspectorExt,
-) -> revm::Evm<'evm, &'i mut dyn InspectorExt, &'db mut dyn DatabaseExt> {
+    inspector: &'i mut I,
+) -> revm::Evm<'evm, &'i mut I, &'db mut dyn DatabaseExt> {
     let revm::primitives::EnvWithHandlerCfg { env, handler_cfg } = env;
 
     // NOTE: We could use `revm::Evm::builder()` here, but on the current patch it has some

crates/evm/evm/src/inspectors/stack.rs

@@ -543,14 +543,14 @@ impl<'a> InspectorStackRefMut<'a> {
         self.in_inner_context = true;
 
         let env = EnvWithHandlerCfg::new_with_spec_id(ecx.env.clone(), ecx.spec_id());
-        let res = {
-            let mut evm = crate::utils::new_evm_with_inspector(&mut ecx.db, env, self);
+        let res = self.with_stack(|inspector| {
+            let mut evm = crate::utils::new_evm_with_inspector(&mut ecx.db, env, inspector);
             let res = evm.transact();
 
             // need to reset the env in case it was modified via cheatcodes during execution
             ecx.env = evm.context.evm.inner.env;
             res
-        };
+        });
 
         self.in_inner_context = false;
         self.inner_context_data = None;
@@ -621,6 +621,25 @@ impl<'a> InspectorStackRefMut<'a> {
         };
         (InterpreterResult { result, output, gas }, address)
     }
+
+    /// Moves out of references, constructs an [`InspectorStack`] and runs the given closure with
+    /// it.
+    fn with_stack<O>(&mut self, f: impl FnOnce(&mut InspectorStack) -> O) -> O {
+        let mut stack = InspectorStack {
+            cheatcodes: self.cheatcodes.as_deref_mut().map(std::mem::take),
+            inner: std::mem::take(self.inner),
+        };
+
+        let out = f(&mut stack);
+
+        if let Some(cheats) = self.cheatcodes.as_deref_mut() {
+            *cheats = stack.cheatcodes.take().unwrap();
+        }
+
+        *self.inner = stack.inner;
+
+        out
+    }
 }
 
 impl<'a> Inspector<&mut dyn DatabaseExt> for InspectorStackRefMut<'a> {