5 files changed, 33 insertions, 1 deletions
diff --git a/src/consensus/amount.h b/src/consensus/amount.h
new file mode 100644
index 0000000000..59b8e3417a
--- /dev/null
+++ b/src/consensus/amount.h
@@ -0,0 +1,29 @@
+// 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_CONSENSUS_AMOUNT_H
+#define BITCOIN_CONSENSUS_AMOUNT_H
+
+#include <cstdint>
+
+/** Amount in satoshis (Can be negative) */
+typedef int64_t CAmount;
+
+/** The amount of satoshis in one BTC. */
+static constexpr CAmount COIN = 100000000;
+
+/** No amount larger than this (in satoshi) is valid.
+ *
+ * Note that this constant is *not* the total money supply, which in Bitcoin
+ * currently happens to be less than 21,000,000 BTC for various reasons, but
+ * rather a sanity check. As this sanity check is used by consensus-critical
+ * validation code, the exact value of the MAX_MONEY constant is consensus
+ * critical; in unusual circumstances like a(nother) overflow bug that allowed
+ * for the creation of coins out of thin air modification could lead to a fork.
+ * */
+static constexpr CAmount MAX_MONEY = 21000000 * COIN;
+inline bool MoneyRange(const CAmount& nValue) { return (nValue >= 0 && nValue <= MAX_MONEY); }
+
+#endif // BITCOIN_CONSENSUS_AMOUNT_H
diff --git a/src/consensus/tx_check.cpp b/src/consensus/tx_check.cpp
index bb8cd10c63..de4824fadc 100644
--- a/src/consensus/tx_check.cpp
+++ b/src/consensus/tx_check.cpp
@@ -4,6 +4,7 @@
 
 #include <consensus/tx_check.h>
 
+#include <consensus/amount.h>
 #include <primitives/transaction.h>
 #include <consensus/validation.h>
 
diff --git a/src/consensus/tx_verify.cpp b/src/consensus/tx_verify.cpp
index 0ab790ccdc..a07adae536 100644
--- a/src/consensus/tx_verify.cpp
+++ b/src/consensus/tx_verify.cpp
@@ -4,6 +4,7 @@
 
 #include <consensus/tx_verify.h>
 
+#include <consensus/amount.h>
 #include <consensus/consensus.h>
 #include <primitives/transaction.h>
 #include <script/interpreter.h>
diff --git a/src/consensus/tx_verify.h b/src/consensus/tx_verify.h
index 264433c33d..777556808a 100644
--- a/src/consensus/tx_verify.h
+++ b/src/consensus/tx_verify.h
@@ -5,7 +5,7 @@
 #ifndef BITCOIN_CONSENSUS_TX_VERIFY_H
 #define BITCOIN_CONSENSUS_TX_VERIFY_H
 
-#include <amount.h>
+#include <consensus/amount.h>
 
 #include <stdint.h>
 #include <vector>
diff --git a/src/consensus/validation.h b/src/consensus/validation.h
index c4d305434a..05416d0aca 100644
--- a/src/consensus/validation.h
+++ b/src/consensus/validation.h
@@ -53,6 +53,7 @@ enum class TxValidationResult {
      */
     TX_CONFLICT,
     TX_MEMPOOL_POLICY,        //!< violated mempool's fee/size/descendant/RBF/etc limits
+    TX_NO_MEMPOOL,            //!< this node does not have a mempool so can't validate the transaction
 };
 
 /** A "reason" why a block was invalid, suitable for determining whether the