Semgrep + README

op-chain-ops/eof-crawler/README.md

@@ -4,6 +4,8 @@ Simple CLI tool to scan all accounts in a geth LevelDB for contracts that begin
 
 ## Usage
 
+1. Pass the directory of the Geth DB into the tool
 ```sh
 go run eof_crawler.go <db_path>
 ```
+2. Once the indexing has completed, an array of all EOF-prefixed contracts will be written to `eof_contracts.json`.

op-chain-ops/eof-crawler/eof_crawler.go

@@ -3,7 +3,6 @@ package main
 import (
 	"bytes"
 	"encoding/json"
-	"io/ioutil"
 	"log"
 	"os"
 	"time"
@@ -69,7 +68,10 @@ func main() {
 	for it.Next() {
 		// Decode the state account
 		var data types.StateAccount
-		rlp.DecodeBytes(it.Value, &data)
+		err := rlp.DecodeBytes(it.Value, &data)
+		if err != nil {
+			log.Fatalf("Failed to decode state account: %v", err)
+		}
 
 		// Check to see if the account has any code associated with it before performing
 		// more reads from the trie & db.
@@ -100,7 +102,6 @@ func main() {
 		code, err := stateDB.ContractCode(crypto.Keccak256Hash(addrBytes), common.BytesToHash(data.CodeHash))
 		if err != nil {
 			log.Fatalf("Could not load code for account %x: %v", addr, err)
-			continue
 		}
 
 		// Check if the contract's runtime bytecode starts with the EOF prefix.
@@ -125,7 +126,10 @@ func main() {
 	if err != nil {
 		log.Fatalf("Cannot marshal EOF contracts: %v", err)
 	}
-	err = ioutil.WriteFile("eof_contracts.json", file, 0644)
+	err = os.WriteFile("eof_contracts.json", file, 0644)
+	if err != nil {
+		log.Fatalf("Failed to write EOF contracts array to file: %v", err)
+	}
 
 	log.Printf("Wrote list of EOF contracts to `eof_contracts.json`")
 }