Merge bitcoin/bitcoin#31896: refactor: Remove redundant and confusing calls to IsArgSet

0000fb3 doc: Remove outdated and stale todo comment (MarcoFalke)
fa2b529 refactor: Remove redundant call to IsArgSet (MarcoFalke)
fa29842 refactor: Remove IsArgSet guard when fallback value is provided (MarcoFalke)

Pull request description:

  `IsArgSet` is problematic:

  * It returns whether an arg has been set, even if it has been negated. `IsArgSet` is sometimes used to check for a truthy value, which is wrong, but usually harmless. Cleanup of those cases may or may not be done in a follow-up.
  * In most other cases, calling it is redundant, because the immediately following `Get*Arg` calls can already return an `std::optional` nullopt value to indicate an unset arg.

  So relieve both issues by removing all `IsArgSet` that are redundant.

ACKs for top commit:
  pablomartin4btc:
    re-ACK 0000fb3
  ryanofsky:
    Code review ACK 0000fb3. No changes since last review other than rebase.

Tree-SHA512: d142d71d136b2dbd5fd005667875099777704176f5e08fdeb38f05d6afce40b435a257c5bb6a1f545459fe4f81f967cee3083ab666cb0befdef3f6234f1e3d32

Author: fanquake

src/bitcoin-cli.cpp

@@ -1059,7 +1059,7 @@ static void ParseGetInfoResult(UniValue& result)
     }
 #endif
 
-    if (gArgs.IsArgSet("-color")) {
+    {
         const std::string color{gArgs.GetArg("-color", DEFAULT_COLOR_SETTING)};
         if (color == "always") {
             should_colorize = true;

src/init.cpp

@@ -1036,22 +1036,20 @@ bool AppInitParameterInteraction(const ArgsManager& args)
         return InitError(Untranslated("peertimeout must be a positive integer."));
     }
 
-    // Sanity check argument for min fee for including tx in block
-    // TODO: Harmonize which arguments need sanity checking and where that happens
-    if (args.IsArgSet("-blockmintxfee")) {
-        if (!ParseMoney(args.GetArg("-blockmintxfee", ""))) {
-            return InitError(AmountErrMsg("blockmintxfee", args.GetArg("-blockmintxfee", "")));
+    if (const auto arg{args.GetArg("-blockmintxfee")}) {
+        if (!ParseMoney(*arg)) {
+            return InitError(AmountErrMsg("blockmintxfee", *arg));
         }
     }
 
-    if (args.IsArgSet("-blockmaxweight")) {
+    {
         const auto max_block_weight = args.GetIntArg("-blockmaxweight", DEFAULT_BLOCK_MAX_WEIGHT);
         if (max_block_weight > MAX_BLOCK_WEIGHT) {
             return InitError(strprintf(_("Specified -blockmaxweight (%d) exceeds consensus maximum block weight (%d)"), max_block_weight, MAX_BLOCK_WEIGHT));
         }
     }
 
-    if (args.IsArgSet("-blockreservedweight")) {
+    {
         const auto block_reserved_weight = args.GetIntArg("-blockreservedweight", DEFAULT_BLOCK_RESERVED_WEIGHT);
         if (block_reserved_weight > MAX_BLOCK_WEIGHT) {
             return InitError(strprintf(_("Specified -blockreservedweight (%d) exceeds consensus maximum block weight (%d)"), block_reserved_weight, MAX_BLOCK_WEIGHT));
@@ -1183,11 +1181,10 @@ bool CheckHostPortOptions(const ArgsManager& args) {
         "-port",
         "-rpcport",
     }) {
-        if (args.IsArgSet(port_option)) {
-            const std::string port = args.GetArg(port_option, "");
+        if (const auto port{args.GetArg(port_option)}) {
             uint16_t n;
-            if (!ParseUInt16(port, &n) || n == 0) {
-                return InitError(InvalidPortErrMsg(port_option, port));
+            if (!ParseUInt16(*port, &n) || n == 0) {
+                return InitError(InvalidPortErrMsg(port_option, *port));
             }
         }
     }

src/node/mempool_args.cpp

@@ -48,20 +48,20 @@ util::Result<void> ApplyArgsManOptions(const ArgsManager& argsman, const CChainP
 
     // incremental relay fee sets the minimum feerate increase necessary for replacement in the mempool
     // and the amount the mempool min fee increases above the feerate of txs evicted due to mempool limiting.
-    if (argsman.IsArgSet("-incrementalrelayfee")) {
-        if (std::optional<CAmount> inc_relay_fee = ParseMoney(argsman.GetArg("-incrementalrelayfee", ""))) {
+    if (const auto arg{argsman.GetArg("-incrementalrelayfee")}) {
+        if (std::optional<CAmount> inc_relay_fee = ParseMoney(*arg)) {
             mempool_opts.incremental_relay_feerate = CFeeRate{inc_relay_fee.value()};
         } else {
-            return util::Error{AmountErrMsg("incrementalrelayfee", argsman.GetArg("-incrementalrelayfee", ""))};
+            return util::Error{AmountErrMsg("incrementalrelayfee", *arg)};
         }
     }
 
-    if (argsman.IsArgSet("-minrelaytxfee")) {
-        if (std::optional<CAmount> min_relay_feerate = ParseMoney(argsman.GetArg("-minrelaytxfee", ""))) {
+    if (const auto arg{argsman.GetArg("-minrelaytxfee")}) {
+        if (std::optional<CAmount> min_relay_feerate = ParseMoney(*arg)) {
             // High fee check is done afterward in CWallet::Create()
             mempool_opts.min_relay_feerate = CFeeRate{min_relay_feerate.value()};
         } else {
-            return util::Error{AmountErrMsg("minrelaytxfee", argsman.GetArg("-minrelaytxfee", ""))};
+            return util::Error{AmountErrMsg("minrelaytxfee", *arg)};
         }
     } else if (mempool_opts.incremental_relay_feerate > mempool_opts.min_relay_feerate) {
         // Allow only setting incremental fee to control both
@@ -71,11 +71,11 @@ util::Result<void> ApplyArgsManOptions(const ArgsManager& argsman, const CChainP
 
     // Feerate used to define dust.  Shouldn't be changed lightly as old
     // implementations may inadvertently create non-standard transactions
-    if (argsman.IsArgSet("-dustrelayfee")) {
-        if (std::optional<CAmount> parsed = ParseMoney(argsman.GetArg("-dustrelayfee", ""))) {
+    if (const auto arg{argsman.GetArg("-dustrelayfee")}) {
+        if (std::optional<CAmount> parsed = ParseMoney(*arg)) {
             mempool_opts.dust_relay_feerate = CFeeRate{parsed.value()};
         } else {
-            return util::Error{AmountErrMsg("dustrelayfee", argsman.GetArg("-dustrelayfee", ""))};
+            return util::Error{AmountErrMsg("dustrelayfee", *arg)};
         }
     }
 

src/qt/intro.cpp

@@ -140,9 +140,9 @@ Intro::Intro(QWidget *parent, int64_t blockchain_size_gb, int64_t chain_state_si
 
     const int min_prune_target_GB = std::ceil(MIN_DISK_SPACE_FOR_BLOCK_FILES / 1e9);
     ui->pruneGB->setRange(min_prune_target_GB, std::numeric_limits<int>::max());
-    if (gArgs.IsArgSet("-prune")) {
+    if (const auto arg{gArgs.GetIntArg("-prune")}) {
         m_prune_checkbox_is_default = false;
-        ui->prune->setChecked(gArgs.GetIntArg("-prune", 0) >= 1);
+        ui->prune->setChecked(*arg >= 1);
         ui->prune->setEnabled(false);
     }
     ui->pruneGB->setValue(m_prune_target_gb);

src/wallet/wallet.cpp

@@ -3124,10 +3124,10 @@ std::shared_ptr<CWallet> CWallet::Create(WalletContext& context, const std::stri
         walletInstance->m_default_change_type = parsed.value();
     }
 
-    if (args.IsArgSet("-mintxfee")) {
-        std::optional<CAmount> min_tx_fee = ParseMoney(args.GetArg("-mintxfee", ""));
+    if (const auto arg{args.GetArg("-mintxfee")}) {
+        std::optional<CAmount> min_tx_fee = ParseMoney(*arg);
         if (!min_tx_fee) {
-            error = AmountErrMsg("mintxfee", args.GetArg("-mintxfee", ""));
+            error = AmountErrMsg("mintxfee", *arg);
             return nullptr;
         } else if (min_tx_fee.value() > HIGH_TX_FEE_PER_KB) {
             warnings.push_back(AmountHighWarn("-mintxfee") + Untranslated(" ") +
@@ -3137,8 +3137,8 @@ std::shared_ptr<CWallet> CWallet::Create(WalletContext& context, const std::stri
         walletInstance->m_min_fee = CFeeRate{min_tx_fee.value()};
     }
 
-    if (args.IsArgSet("-maxapsfee")) {
-        const std::string max_aps_fee{args.GetArg("-maxapsfee", "")};
+    if (const auto arg{args.GetArg("-maxapsfee")}) {
+        const std::string& max_aps_fee{*arg};
         if (max_aps_fee == "-1") {
             walletInstance->m_max_aps_fee = -1;
         } else if (std::optional<CAmount> max_fee = ParseMoney(max_aps_fee)) {
@@ -3153,10 +3153,10 @@ std::shared_ptr<CWallet> CWallet::Create(WalletContext& context, const std::stri
         }
     }
 
-    if (args.IsArgSet("-fallbackfee")) {
-        std::optional<CAmount> fallback_fee = ParseMoney(args.GetArg("-fallbackfee", ""));
+    if (const auto arg{args.GetArg("-fallbackfee")}) {
+        std::optional<CAmount> fallback_fee = ParseMoney(*arg);
         if (!fallback_fee) {
-            error = strprintf(_("Invalid amount for %s=<amount>: '%s'"), "-fallbackfee", args.GetArg("-fallbackfee", ""));
+            error = strprintf(_("Invalid amount for %s=<amount>: '%s'"), "-fallbackfee", *arg);
             return nullptr;
         } else if (fallback_fee.value() > HIGH_TX_FEE_PER_KB) {
             warnings.push_back(AmountHighWarn("-fallbackfee") + Untranslated(" ") +
@@ -3168,10 +3168,10 @@ std::shared_ptr<CWallet> CWallet::Create(WalletContext& context, const std::stri
     // Disable fallback fee in case value was set to 0, enable if non-null value
     walletInstance->m_allow_fallback_fee = walletInstance->m_fallback_fee.GetFeePerK() != 0;
 
-    if (args.IsArgSet("-discardfee")) {
-        std::optional<CAmount> discard_fee = ParseMoney(args.GetArg("-discardfee", ""));
+    if (const auto arg{args.GetArg("-discardfee")}) {
+        std::optional<CAmount> discard_fee = ParseMoney(*arg);
         if (!discard_fee) {
-            error = strprintf(_("Invalid amount for %s=<amount>: '%s'"), "-discardfee", args.GetArg("-discardfee", ""));
+            error = strprintf(_("Invalid amount for %s=<amount>: '%s'"), "-discardfee", *arg);
             return nullptr;
         } else if (discard_fee.value() > HIGH_TX_FEE_PER_KB) {
             warnings.push_back(AmountHighWarn("-discardfee") + Untranslated(" ") +
@@ -3180,12 +3180,12 @@ std::shared_ptr<CWallet> CWallet::Create(WalletContext& context, const std::stri
         walletInstance->m_discard_rate = CFeeRate{discard_fee.value()};
     }
 
-    if (args.IsArgSet("-paytxfee")) {
+    if (const auto arg{args.GetArg("-paytxfee")}) {
         warnings.push_back(_("-paytxfee is deprecated and will be fully removed in v31.0."));
 
-        std::optional<CAmount> pay_tx_fee = ParseMoney(args.GetArg("-paytxfee", ""));
+        std::optional<CAmount> pay_tx_fee = ParseMoney(*arg);
         if (!pay_tx_fee) {
-            error = AmountErrMsg("paytxfee", args.GetArg("-paytxfee", ""));
+            error = AmountErrMsg("paytxfee", *arg);
             return nullptr;
         } else if (pay_tx_fee.value() > HIGH_TX_FEE_PER_KB) {
             warnings.push_back(AmountHighWarn("-paytxfee") + Untranslated(" ") +
@@ -3196,34 +3196,34 @@ std::shared_ptr<CWallet> CWallet::Create(WalletContext& context, const std::stri
 
         if (chain && walletInstance->m_pay_tx_fee < chain->relayMinFee()) {
             error = strprintf(_("Invalid amount for %s=<amount>: '%s' (must be at least %s)"),
-                "-paytxfee", args.GetArg("-paytxfee", ""), chain->relayMinFee().ToString());
+                "-paytxfee", *arg, chain->relayMinFee().ToString());
             return nullptr;
         }
     }
 
-    if (args.IsArgSet("-maxtxfee")) {
-        std::optional<CAmount> max_fee = ParseMoney(args.GetArg("-maxtxfee", ""));
+    if (const auto arg{args.GetArg("-maxtxfee")}) {
+        std::optional<CAmount> max_fee = ParseMoney(*arg);
         if (!max_fee) {
-            error = AmountErrMsg("maxtxfee", args.GetArg("-maxtxfee", ""));
+            error = AmountErrMsg("maxtxfee", *arg);
             return nullptr;
         } else if (max_fee.value() > HIGH_MAX_TX_FEE) {
             warnings.push_back(strprintf(_("%s is set very high! Fees this large could be paid on a single transaction."), "-maxtxfee"));
         }
 
         if (chain && CFeeRate{max_fee.value(), 1000} < chain->relayMinFee()) {
             error = strprintf(_("Invalid amount for %s=<amount>: '%s' (must be at least the minrelay fee of %s to prevent stuck transactions)"),
-                "-maxtxfee", args.GetArg("-maxtxfee", ""), chain->relayMinFee().ToString());
+                "-maxtxfee", *arg, chain->relayMinFee().ToString());
             return nullptr;
         }
 
         walletInstance->m_default_max_tx_fee = max_fee.value();
     }
 
-    if (args.IsArgSet("-consolidatefeerate")) {
-        if (std::optional<CAmount> consolidate_feerate = ParseMoney(args.GetArg("-consolidatefeerate", ""))) {
+    if (const auto arg{args.GetArg("-consolidatefeerate")}) {
+        if (std::optional<CAmount> consolidate_feerate = ParseMoney(*arg)) {
             walletInstance->m_consolidate_feerate = CFeeRate(*consolidate_feerate);
         } else {
-            error = AmountErrMsg("consolidatefeerate", args.GetArg("-consolidatefeerate", ""));
+            error = AmountErrMsg("consolidatefeerate", *arg);
             return nullptr;
         }
     }