From ca8184c15152e567cd572dd08729e06702ba9483 Mon Sep 17 00:00:00 2001
From: artheraone <126314488+artheraone@users.noreply.github.com>
Date: Fri, 10 Mar 2023 12:47:35 +0200
Subject: [PATCH] Run EWASM contracts

---
 core/vm/evm.go | 29 ++++++++++++++++++++++++-----
 1 file changed, 24 insertions(+), 5 deletions(-)

diff --git a/core/vm/evm.go b/core/vm/evm.go
index 148f5fc2c..6e2042bd4 100644
--- a/core/vm/evm.go
+++ b/core/vm/evm.go
@@ -17,6 +17,7 @@
 package vm
 
 import (
+	"errors"
 	"github.com/ethereum/evmc/v10/bindings/go/evmc"
 	"math/big"
 	"sync/atomic"
@@ -67,6 +68,24 @@ func (evm *EVM) statePrecompile(addr common.Address) (PrecompiledStateContract,
 	return p, ok
 }
 
+// run runs the given contract and takes care of running precompiles with a fallback to the byte code interpreter.
+func run(evm *EVM, contract *Contract, input []byte, readOnly bool) ([]byte, error) {
+	for _, interpreter := range evm.interpreters {
+		if interpreter.CanRun(contract.Code) {
+			if evm.interpreter != interpreter {
+				// Ensure that the interpreter pointer is set back
+				// to its current value upon return.
+				defer func(i Interpreter) {
+					evm.interpreter = i
+				}(evm.interpreter)
+				evm.interpreter = interpreter
+			}
+			return interpreter.Run(contract, input, readOnly)
+		}
+	}
+	return nil, errors.New("no compatible interpreter")
+}
+
 // BlockContext provides the EVM with auxiliary information. Once provided
 // it shouldn't be modified.
 type BlockContext struct {
@@ -251,7 +270,7 @@ func (evm *EVM) Call(caller ContractRef, addr common.Address, input []byte, gas
 			// The depth-check is already done, and precompiles handled above
 			contract := NewContract(caller, AccountRef(addrCopy), value, gas)
 			contract.SetCallCode(&addrCopy, evm.StateDB.GetCodeHash(addrCopy), code)
-			ret, err = evm.interpreter.Run(contract, input, false)
+			ret, err = run(evm, contract, input, false)
 			gas = contract.Gas
 		}
 	}
@@ -311,7 +330,7 @@ func (evm *EVM) CallCode(caller ContractRef, addr common.Address, input []byte,
 		// The contract is a scoped environment for this execution context only.
 		contract := NewContract(caller, AccountRef(caller.Address()), value, gas)
 		contract.SetCallCode(&addrCopy, evm.StateDB.GetCodeHash(addrCopy), evm.StateDB.GetCode(addrCopy))
-		ret, err = evm.interpreter.Run(contract, input, false)
+		ret, err = run(evm, contract, input, false)
 		gas = contract.Gas
 	}
 	if err != nil {
@@ -354,7 +373,7 @@ func (evm *EVM) DelegateCall(caller ContractRef, addr common.Address, input []by
 		// Initialise a new contract and make initialise the delegate values
 		contract := NewContract(caller, AccountRef(caller.Address()), nil, gas).AsDelegate()
 		contract.SetCallCode(&addrCopy, evm.StateDB.GetCodeHash(addrCopy), evm.StateDB.GetCode(addrCopy))
-		ret, err = evm.interpreter.Run(contract, input, false)
+		ret, err = run(evm, contract, input, false)
 		gas = contract.Gas
 	}
 	if err != nil {
@@ -413,7 +432,7 @@ func (evm *EVM) StaticCall(caller ContractRef, addr common.Address, input []byte
 		// When an error was returned by the EVM or when setting the creation code
 		// above we revert to the snapshot and consume any gas remaining. Additionally
 		// when we're in Homestead this also counts for code storage gas errors.
-		ret, err = evm.interpreter.Run(contract, input, true)
+		ret, err = run(evm, contract, input, true)
 		gas = contract.Gas
 	}
 	if err != nil {
@@ -486,7 +505,7 @@ func (evm *EVM) create(caller ContractRef, codeAndHash *codeAndHash, gas uint64,
 
 	start := time.Now()
 
-	ret, err := evm.interpreter.Run(contract, nil, false)
+	ret, err := run(evm, contract, nil, false)
 
 	// Check whether the max code size has been exceeded, assign err if the case.
 	if err == nil && evm.chainRules.IsEIP158 && len(ret) > params.MaxCodeSize {