refactor: Pass script verify flags as uint32_t

They are cast to unsigned anyway when calling VerifyScript,
bitcoinconsensus_verify_script*, or CountWitnessSigOps.

src/bench/verify_script.cpp

@@ -21,7 +21,7 @@ static void VerifyScriptBench(benchmark::Bench& bench)
     const ECCVerifyHandle verify_handle;
     ECC_Start();
 
-    const int flags = SCRIPT_VERIFY_WITNESS | SCRIPT_VERIFY_P2SH;
+    const uint32_t flags{SCRIPT_VERIFY_WITNESS | SCRIPT_VERIFY_P2SH};
     const int witnessversion = 0;
 
     // Key pair.

src/consensus/tx_verify.cpp

@@ -135,7 +135,7 @@ unsigned int GetP2SHSigOpCount(const CTransaction& tx, const CCoinsViewCache& in
     return nSigOps;
 }
 
-int64_t GetTransactionSigOpCost(const CTransaction& tx, const CCoinsViewCache& inputs, int flags)
+int64_t GetTransactionSigOpCost(const CTransaction& tx, const CCoinsViewCache& inputs, uint32_t flags)
 {
     int64_t nSigOps = GetLegacySigOpCount(tx) * WITNESS_SCALE_FACTOR;
 

src/consensus/tx_verify.h

@@ -49,10 +49,10 @@ unsigned int GetP2SHSigOpCount(const CTransaction& tx, const CCoinsViewCache& ma
  * Compute total signature operation cost of a transaction.
  * @param[in] tx     Transaction for which we are computing the cost
  * @param[in] inputs Map of previous transactions that have outputs we're spending
- * @param[out] flags Script verification flags
+ * @param[in] flags Script verification flags
  * @return Total signature operation cost of tx
  */
-int64_t GetTransactionSigOpCost(const CTransaction& tx, const CCoinsViewCache& inputs, int flags);
+int64_t GetTransactionSigOpCost(const CTransaction& tx, const CCoinsViewCache& inputs, uint32_t flags);
 
 /**
  * Check if transaction is final and can be included in a block with the

src/script/interpreter.h

@@ -39,8 +39,7 @@ enum
  *  All flags are intended to be soft forks: the set of acceptable scripts under
  *  flags (A | B) is a subset of the acceptable scripts under flag (A).
  */
-enum
+enum : uint32_t {
-{
     SCRIPT_VERIFY_NONE      = 0,
 
     // Evaluate P2SH subscripts (BIP16).

src/test/fuzz/coins_view.cpp

@@ -258,7 +258,7 @@ FUZZ_TARGET_INIT(coins_view, initialize_coins_view)
                     // consensus/tx_verify.cpp:130: unsigned int GetP2SHSigOpCount(const CTransaction &, const CCoinsViewCache &): Assertion `!coin.IsSpent()' failed.
                     return;
                 }
-                const int flags = fuzzed_data_provider.ConsumeIntegral<int>();
+                const auto flags{fuzzed_data_provider.ConsumeIntegral<uint32_t>()};
                 if (!transaction.vin.empty() && (flags & SCRIPT_VERIFY_WITNESS) != 0 && (flags & SCRIPT_VERIFY_P2SH) == 0) {
                     // Avoid:
                     // script/interpreter.cpp:1705: size_t CountWitnessSigOps(const CScript &, const CScript &, const CScriptWitness *, unsigned int): Assertion `(flags & SCRIPT_VERIFY_P2SH) != 0' failed.

src/test/script_tests.cpp

@@ -123,7 +123,7 @@ static ScriptError_t ParseScriptError(const std::string& name)
 
 BOOST_FIXTURE_TEST_SUITE(script_tests, BasicTestingSetup)
 
-void DoTest(const CScript& scriptPubKey, const CScript& scriptSig, const CScriptWitness& scriptWitness, int flags, const std::string& message, int scriptError, CAmount nValue = 0)
+void DoTest(const CScript& scriptPubKey, const CScript& scriptSig, const CScriptWitness& scriptWitness, uint32_t flags, const std::string& message, int scriptError, CAmount nValue = 0)
 {
     bool expect = (scriptError == SCRIPT_ERR_OK);
     if (flags & SCRIPT_VERIFY_CLEANSTACK) {
@@ -139,8 +139,8 @@ void DoTest(const CScript& scriptPubKey, const CScript& scriptSig, const CScript
 
     // Verify that removing flags from a passing test or adding flags to a failing test does not change the result.
     for (int i = 0; i < 16; ++i) {
-        int extra_flags = InsecureRandBits(16);
+        uint32_t extra_flags(InsecureRandBits(16));
-        int combined_flags = expect ? (flags & ~extra_flags) : (flags | extra_flags);
+        uint32_t combined_flags{expect ? (flags & ~extra_flags) : (flags | extra_flags)};
         // Weed out some invalid flag combinations.
         if (combined_flags & SCRIPT_VERIFY_CLEANSTACK && ~combined_flags & (SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS)) continue;
         if (combined_flags & SCRIPT_VERIFY_WITNESS && ~combined_flags & SCRIPT_VERIFY_P2SH) continue;
@@ -150,7 +150,7 @@ void DoTest(const CScript& scriptPubKey, const CScript& scriptSig, const CScript
 #if defined(HAVE_CONSENSUS_LIB)
     CDataStream stream(SER_NETWORK, PROTOCOL_VERSION);
     stream << tx2;
-    int libconsensus_flags = flags & bitcoinconsensus_SCRIPT_FLAGS_VERIFY_ALL;
+    uint32_t libconsensus_flags{flags & bitcoinconsensus_SCRIPT_FLAGS_VERIFY_ALL};
     if (libconsensus_flags == flags) {
         int expectedSuccessCode = expect ? 1 : 0;
         if (flags & bitcoinconsensus_SCRIPT_FLAGS_VERIFY_WITNESS) {
@@ -258,7 +258,7 @@ private:
     bool havePush;
     std::vector<unsigned char> push;
     std::string comment;
-    int flags;
+    uint32_t flags;
     int scriptError;
     CAmount nValue;
 
@@ -278,7 +278,7 @@ private:
     }
 
 public:
-    TestBuilder(const CScript& script_, const std::string& comment_, int flags_, bool P2SH = false, WitnessMode wm = WitnessMode::NONE, int witnessversion = 0, CAmount nValue_ = 0) : script(script_), havePush(false), comment(comment_), flags(flags_), scriptError(SCRIPT_ERR_OK), nValue(nValue_)
+    TestBuilder(const CScript& script_, const std::string& comment_, uint32_t flags_, bool P2SH = false, WitnessMode wm = WitnessMode::NONE, int witnessversion = 0, CAmount nValue_ = 0) : script(script_), havePush(false), comment(comment_), flags(flags_), scriptError(SCRIPT_ERR_OK), nValue(nValue_)
     {
         CScript scriptPubKey = script;
         if (wm == WitnessMode::PKH) {
@@ -1677,7 +1677,7 @@ static void AssetTest(const UniValue& test)
     const std::vector<CTxOut> prevouts = TxOutsFromJSON(test["prevouts"]);
     BOOST_CHECK(prevouts.size() == mtx.vin.size());
     size_t idx = test["index"].get_int64();
-    unsigned int test_flags = ParseScriptFlags(test["flags"].get_str());
+    uint32_t test_flags{ParseScriptFlags(test["flags"].get_str())};
     bool fin = test.exists("final") && test["final"].get_bool();
 
     if (test.exists("success")) {

src/test/sigopcount_tests.cpp

@@ -67,7 +67,7 @@ BOOST_AUTO_TEST_CASE(GetSigOpCount)
  * Verifies script execution of the zeroth scriptPubKey of tx output and
  * zeroth scriptSig and witness of tx input.
  */
-static ScriptError VerifyWithFlag(const CTransaction& output, const CMutableTransaction& input, int flags)
+static ScriptError VerifyWithFlag(const CTransaction& output, const CMutableTransaction& input, uint32_t flags)
 {
     ScriptError error;
     CTransaction inputi(input);
@@ -121,7 +121,7 @@ BOOST_AUTO_TEST_CASE(GetTxSigOpCost)
     key.MakeNewKey(true);
     CPubKey pubkey = key.GetPubKey();
     // Default flags
-    int flags = SCRIPT_VERIFY_WITNESS | SCRIPT_VERIFY_P2SH;
+    const uint32_t flags{SCRIPT_VERIFY_WITNESS | SCRIPT_VERIFY_P2SH};
 
     // Multisig script (legacy counting)
     {

src/test/transaction_tests.cpp

@@ -446,7 +446,7 @@ static void CreateCreditAndSpend(const FillableSigningProvider& keystore, const
     assert(input.vin[0].scriptWitness.stack == inputm.vin[0].scriptWitness.stack);
 }
 
-static void CheckWithFlag(const CTransactionRef& output, const CMutableTransaction& input, int flags, bool success)
+static void CheckWithFlag(const CTransactionRef& output, const CMutableTransaction& input, uint32_t flags, bool success)
 {
     ScriptError error;
     CTransaction inputi(input);