Refactor Executive: revert "keep ExtVM by unique_ptr".

(reverted from commit cf56b9e963)

libethereum/Executive.cpp

@@ -249,7 +249,7 @@ bool Executive::call(CallParameters const& _p, u256 const& _gasPrice, Address co
 		{
 			m_outRef = _p.out; // Save ref to expected output buffer to be used in go()
 			bytes const& c = m_s.code(_p.codeAddress);
-			m_ext.reset(new ExtVM{m_s, m_lastHashes, _p.receiveAddress, _p.senderAddress, _origin, _p.value, _gasPrice, _p.data, &c, m_depth});
+			m_ext = make_shared<ExtVM>(m_s, m_lastHashes, _p.receiveAddress, _p.senderAddress, _origin, _p.value, _gasPrice, _p.data, &c, m_depth);
 		}
 	}
 
@@ -269,7 +269,7 @@ bool Executive::create(Address _sender, u256 _endowment, u256 _gasPrice, u256 _g
 
 	// Execute _init.
 	if (!_init.empty())
-		m_ext.reset(new ExtVM{m_s, m_lastHashes, m_newAddress, _sender, _origin, _endowment, _gasPrice, bytesConstRef(), _init, m_depth});
+		m_ext = make_shared<ExtVM>(m_s, m_lastHashes, m_newAddress, _sender, _origin, _endowment, _gasPrice, bytesConstRef(), _init, m_depth);
 
 	m_s.m_cache[m_newAddress] = Account(m_s.balance(m_newAddress), Account::ContractConception);
 	m_s.transferBalance(_sender, m_newAddress, _endowment);

libethereum/Executive.h

@@ -23,7 +23,6 @@
 #include <libevmcore/Instruction.h>
 #include <libethcore/Common.h>
 #include <libevm/VMFace.h>
-#include "ExtVM.h"
 #include "Transaction.h"
 
 namespace Json
@@ -38,6 +37,7 @@ namespace eth
 
 class State;
 class BlockChain;
+class ExtVM;
 struct Manifest;
 
 struct VMTraceChannel: public LogChannel { static const char* name(); static const int verbosity = 11; };
@@ -140,7 +140,7 @@ public:
 private:
 	State& m_s;							///< The state to which this operation/transaction is applied.
 	LastHashes m_lastHashes;
-	std::unique_ptr<ExtVM> m_ext;		///< The VM externality object for the VM execution or null if no VM is required.
+	std::shared_ptr<ExtVM> m_ext;		///< The VM externality object for the VM execution or null if no VM is required. shared_ptr used only to allow ExtVM forward reference.
 	bytesRef m_outRef;					///< Reference to "expected output" buffer.
 	ExecutionResult* m_res = nullptr;	///< Optional storage for execution results.
 	Address m_newAddress;				///< The address of the created contract in the case of create() being called.