From 92f20ec18a767ff6d1868f3ca667999988552ef7 Mon Sep 17 00:00:00 2001
From: Guillaume Ballet <gballet@gmail.com>
Date: Thu, 11 Oct 2018 15:06:49 +0200
Subject: [PATCH] core/vm: tweak the `--vm.ewasm=` option format

---
 core/vm/interpreter.go |  2 +-
 eth/backend.go         | 15 ++++++++++++++-
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/core/vm/interpreter.go b/core/vm/interpreter.go
index 952d96dd4d..37b561f1de 100644
--- a/core/vm/interpreter.go
+++ b/core/vm/interpreter.go
@@ -43,7 +43,7 @@ type Config struct {
 	JumpTable [256]operation
 
 	// Type of the EWASM interpreter
-	EWASMInterpreter string
+	EWASMInterpreter map[string]string
 	// Type of the EVM interpreter
 	EVMInterpreter string
 }
diff --git a/eth/backend.go b/eth/backend.go
index b555b064ad..cfca5859bc 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -22,6 +22,7 @@ import (
 	"fmt"
 	"math/big"
 	"runtime"
+	"strings"
 	"sync"
 	"sync/atomic"
 
@@ -148,10 +149,22 @@ func New(ctx *node.ServiceContext, config *Config) (*Ethereum, error) {
 		}
 		rawdb.WriteDatabaseVersion(chainDb, core.BlockChainVersion)
 	}
+
+	ewasmOptions := make(map[string]string)
+	if len(config.EWASMInterpreter) > 0 {
+		for _, option := range strings.Split(config.EWASMInterpreter, ",") {
+			opt := strings.Split(option, ":")
+			if len(opt) != 2 || len(opt[0]) == 0 {
+				panic(fmt.Sprintf("Invalid ewasm option: expected a format of name:value, got: %s", option))
+			}
+			ewasmOptions[opt[0]] = opt[1]
+		}
+	}
+
 	var (
 		vmConfig = vm.Config{
 			EnablePreimageRecording: config.EnablePreimageRecording,
-			EWASMInterpreter:        config.EWASMInterpreter,
+			EWASMInterpreter:        ewasmOptions,
 			EVMInterpreter:          config.EVMInterpreter,
 		}
 		cacheConfig = &core.CacheConfig{Disabled: config.NoPruning, TrieNodeLimit: config.TrieCache, TrieTimeLimit: config.TrieTimeout}