[build] Move policy settings to new src/policy/settings unit

This moves the following policy settings functions and globals to a new
src/policy/settings unit in lib_server:

- `incrementalRelayFee`
- `dustRelayFee`
- `nBytesPerSigOp`
- `fIsBareMultisigStd`

These settings are only required by the node and should not be accessed
by other libraries.

src/policy/policy.cpp

@@ -10,6 +10,7 @@
 #include <consensus/validation.h>
 #include <validation.h>
 #include <coins.h>
+#include <policy/settings.h>
 #include <tinyformat.h>
 #include <util/system.h>
 #include <util/strencodings.h>
@@ -239,10 +240,6 @@ bool IsWitnessStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs)
     return true;
 }
 
-CFeeRate incrementalRelayFee = CFeeRate(DEFAULT_INCREMENTAL_RELAY_FEE);
-CFeeRate dustRelayFee = CFeeRate(DUST_RELAY_TX_FEE);
-unsigned int nBytesPerSigOp = DEFAULT_BYTES_PER_SIGOP;
-
 int64_t GetVirtualTransactionSize(int64_t nWeight, int64_t nSigOpCost)
 {
     return (std::max(nWeight, nSigOpCost * nBytesPerSigOp) + WITNESS_SCALE_FACTOR - 1) / WITNESS_SCALE_FACTOR;

src/policy/policy.h

@@ -34,6 +34,8 @@ static const unsigned int DEFAULT_MAX_MEMPOOL_SIZE = 300;
 static const unsigned int DEFAULT_INCREMENTAL_RELAY_FEE = 1000;
 /** Default for -bytespersigop */
 static const unsigned int DEFAULT_BYTES_PER_SIGOP = 20;
+/** Default for -permitbaremultisig */
+static const bool DEFAULT_PERMIT_BAREMULTISIG = true;
 /** The maximum number of witness stack items in a standard P2WSH script */
 static const unsigned int MAX_STANDARD_P2WSH_STACK_ITEMS = 100;
 /** The maximum size of each witness stack item in a standard P2WSH script */
@@ -98,10 +100,6 @@ bool AreInputsStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs)
      */
 bool IsWitnessStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs);
 
-extern CFeeRate incrementalRelayFee;
-extern CFeeRate dustRelayFee;
-extern unsigned int nBytesPerSigOp;
-
 /** Compute the virtual transaction size (weight reinterpreted as bytes). */
 int64_t GetVirtualTransactionSize(int64_t nWeight, int64_t nSigOpCost);
 int64_t GetVirtualTransactionSize(const CTransaction& tx, int64_t nSigOpCost = 0);

src/policy/settings.cpp

@@ -0,0 +1,14 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <policy/settings.h>
+
+#include <policy/feerate.h>
+#include <policy/policy.h>
+
+bool fIsBareMultisigStd = DEFAULT_PERMIT_BAREMULTISIG;
+CFeeRate incrementalRelayFee = CFeeRate(DEFAULT_INCREMENTAL_RELAY_FEE);
+CFeeRate dustRelayFee = CFeeRate(DUST_RELAY_TX_FEE);
+unsigned int nBytesPerSigOp = DEFAULT_BYTES_PER_SIGOP;

src/policy/settings.h

@@ -0,0 +1,17 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_POLICY_SETTINGS_H
+#define BITCOIN_POLICY_SETTINGS_H
+
+class CFeeRate;
+
+// Policy settings which are configurable at runtime.
+extern CFeeRate incrementalRelayFee;
+extern CFeeRate dustRelayFee;
+extern unsigned int nBytesPerSigOp;
+extern bool fIsBareMultisigStd;
+
+#endif // BITCOIN_POLICY_SETTINGS_H