diff --git a/src/bench/crypto_hash.cpp b/src/bench/crypto_hash.cpp
--- a/src/bench/crypto_hash.cpp
+++ b/src/bench/crypto_hash.cpp
@@ -71,17 +71,15 @@
 
 static void FastRandom_32bit(benchmark::State &state) {
     FastRandomContext rng(true);
-    uint32_t x = 0;
     while (state.KeepRunning()) {
-        x += rng.rand32();
+        rng.rand32();
     }
 }
 
 static void FastRandom_1bit(benchmark::State &state) {
     FastRandomContext rng(true);
-    uint32_t x = 0;
     while (state.KeepRunning()) {
-        x += rng.randbool();
+        rng.randbool();
     }
 }
 
diff --git a/src/bench/rollingbloom.cpp b/src/bench/rollingbloom.cpp
--- a/src/bench/rollingbloom.cpp
+++ b/src/bench/rollingbloom.cpp
@@ -11,7 +11,6 @@
     CRollingBloomFilter filter(120000, 0.000001);
     std::vector<uint8_t> data(32);
     uint32_t count = 0;
-    uint64_t match = 0;
     while (state.KeepRunning()) {
         count++;
         data[0] = count;
@@ -24,7 +23,7 @@
         data[1] = count >> 16;
         data[2] = count >> 8;
         data[3] = count;
-        match += filter.contains(data);
+        filter.contains(data);
     }
 }
 
diff --git a/src/test/script_tests.cpp b/src/test/script_tests.cpp
--- a/src/test/script_tests.cpp
+++ b/src/test/script_tests.cpp
@@ -2247,18 +2247,21 @@
         }
     }
 
+#ifdef UPDATE_JSON_TESTS
     std::string strGen;
+#endif
 
     for (TestBuilder &test : tests) {
         test.Test();
         std::string str = JSONPrettyPrint(test.GetJSON());
-#ifndef UPDATE_JSON_TESTS
+#ifdef UPDATE_JSON_TESTS
+        strGen += str + ",\n";
+#else
         if (tests_set.count(str) == 0) {
             BOOST_CHECK_MESSAGE(false, "Missing auto script_valid test: " +
                                            test.GetComment());
         }
 #endif
-        strGen += str + ",\n";
     }
 
 #ifdef UPDATE_JSON_TESTS
diff --git a/src/txmempool.cpp b/src/txmempool.cpp
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -723,8 +723,6 @@
                       memusage::DynamicUsage(links.children);
         bool fDependsWait = false;
         setEntries setParentCheck;
-        int64_t parentSizes = 0;
-        int64_t parentSigOpCount = 0;
         for (const CTxIn &txin : tx.vin) {
             // Check that every mempool transaction's inputs refer to available
             // coins, or other mempool tx's.
@@ -735,10 +733,7 @@
                 assert(tx2.vout.size() > txin.prevout.GetN() &&
                        !tx2.vout[txin.prevout.GetN()].IsNull());
                 fDependsWait = true;
-                if (setParentCheck.insert(it2).second) {
-                    parentSizes += it2->GetTxSize();
-                    parentSigOpCount += it2->GetSigOpCount();
-                }
+                setParentCheck.insert(it2);
             } else {
                 assert(pcoins->HaveCoin(txin.prevout));
             }