Showcase custom opcode clz on revm evm framework

Cargo.toml

@@ -33,7 +33,7 @@ members = [
     "examples/uniswap_get_reserves",
     "examples/uniswap_v2_usdc_swap",
     "examples/erc20_gas",
-    #"examples/custom_opcodes",
+    "examples/instruction_table_override",
 ]
 resolver = "2"
 default-members = ["crates/revm"]

crates/database/src/in_memory_db.rs

@@ -389,7 +389,7 @@ impl AccountState {
     }
 }
 
-/// Custom benchmarking DB that only has account info for the zero address.
+/// Custom benchmarking DB that only has account info for the FFADDRESS address.
 ///
 /// Any other address will return an empty account.
 #[derive(Debug, Default, Clone)]

crates/interpreter/src/instructions/macros.rs

@@ -135,7 +135,7 @@ macro_rules! popn {
         };
     };
 }
-
+#[macro_export]
 macro_rules! popn_top {
     ([ $($x:ident),* ], $top:ident, $interpreterreter:expr $(,$ret:expr)? ) => {
         let Some(([$( $x ),*], $top)) = $interpreterreter.stack.popn_top() else {

examples/custom_opcodes/Cargo.toml → examples/instruction_table_override/Cargo.toml

@@ -1,5 +1,5 @@
 [package]
-name = "example-custom-opcodes"
+name = "example-instruction-table-override"
 version = "0.0.0"
 publish = false
 authors.workspace = true
@@ -9,6 +9,7 @@ license.workspace = true
 repository.workspace = true
 readme.workspace = true
 
+
 [package.metadata.docs.rs]
 all-features = true
 rustdoc-args = ["--cfg", "docsrs"]
@@ -22,5 +23,9 @@ rust_2018_idioms = "deny"
 all = "warn"
 
 [dependencies]
+# Core revm dependencies
 revm.workspace = true
-database.workspace = true
+database = { workspace = true }
+
+# Error handling
+anyhow = "1.0.89"

examples/instruction_table_override/src/exec.rs

@@ -0,0 +1,15 @@
+use crate::handler::CustomOpcodeHandler;
+use revm::{
+    context_interface::{
+        result::{EVMError, HaltReason, InvalidTransaction, ResultAndState},
+        DatabaseGetter,
+    },
+    database_interface::Database,
+    handler::handler::{EthContext, EthHandler},
+};
+
+pub fn transact_custom_opcode<DB: Database, CTX: EthContext + DatabaseGetter<Database = DB>>(
+    ctx: &mut CTX,
+) -> Result<ResultAndState<HaltReason>, EVMError<<DB as Database>::Error, InvalidTransaction>> {
+    CustomOpcodeHandler::<CTX, _>::new().run(ctx)
+}