Merge bitcoin/bitcoin#26074: refactor: Set RPCArg options with designated initializers

fa2c72dda09f9b51332f6c7953ae81e573cc834f rpc: Set RPCArg options with designated initializers (MacroFake)

Pull request description:

  For optional constructor arguments, use a new struct. This comes with two benefits:
  * Earlier unused optional arguments can be omitted
  * Designated initializers can be used

ACKs for top commit:
  stickies-v:
    re-ACK fa2c72dda09f9b51332f6c7953ae81e573cc834f

Tree-SHA512: 2a0619548187cc7437fee2466ac4780746490622f202659f53641be01bc2a1fea4416d1a77f3e963bf7c4cce62899b61fab0b9683440cf82f68be44f63826658

8 files changed, 47 insertions, 49 deletions

diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index d1daf06732..93d11c8276 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -856,7 +856,7 @@ static RPCHelpMan gettxoutsetinfo()
                 "Note this call may take some time if you are not using coinstatsindex.\n",
                 {
                     {"hash_type", RPCArg::Type::STR, RPCArg::Default{"hash_serialized_2"}, "Which UTXO set hash should be calculated. Options: 'hash_serialized_2' (the legacy algorithm), 'muhash', 'none'."},
-                    {"hash_or_height", RPCArg::Type::NUM, RPCArg::DefaultHint{"the current best block"}, "The block hash or height of the target height (only available with coinstatsindex).", "", {"", "string or numeric"}},
+                    {"hash_or_height", RPCArg::Type::NUM, RPCArg::DefaultHint{"the current best block"}, "The block hash or height of the target height (only available with coinstatsindex).", RPCArgOptions{.type_str={"", "string or numeric"}}},
                     {"use_index", RPCArg::Type::BOOL, RPCArg::Default{true}, "Use coinstatsindex, if available."},
                 },
                 RPCResult{
@@ -1726,13 +1726,13 @@ static RPCHelpMan getblockstats()
                 "\nCompute per block statistics for a given window. All amounts are in satoshis.\n"
                 "It won't work for some heights with pruning.\n",
                 {
-                    {"hash_or_height", RPCArg::Type::NUM, RPCArg::Optional::NO, "The block hash or height of the target block", "", {"", "string or numeric"}},
+                    {"hash_or_height", RPCArg::Type::NUM, RPCArg::Optional::NO, "The block hash or height of the target block", RPCArgOptions{.type_str={"", "string or numeric"}}},
                     {"stats", RPCArg::Type::ARR, RPCArg::DefaultHint{"all values"}, "Values to plot (see result below)",
                         {
                             {"height", RPCArg::Type::STR, RPCArg::Optional::OMITTED, "Selected statistic"},
                             {"time", RPCArg::Type::STR, RPCArg::Optional::OMITTED, "Selected statistic"},
                         },
-                        "stats"},
+                        RPCArgOptions{.oneline_description="stats"}},
                 },
                 RPCResult{
             RPCResult::Type::OBJ, "", "",
@@ -2052,7 +2052,7 @@ static RPCHelpMan scantxoutset()
                     {"range", RPCArg::Type::RANGE, RPCArg::Default{1000}, "The range of HD chain indexes to explore (either end or [begin,end])"},
                 }},
             },
-                        "[scanobjects,...]"},
+            RPCArgOptions{.oneline_description="[scanobjects,...]"}},
         },
         {
             RPCResult{"when action=='start'; only returns after scan completes", RPCResult::Type::OBJ, "", "", {
diff --git a/src/rpc/mining.cpp b/src/rpc/mining.cpp
index 354af22ef4..c4bd03fa9f 100644
--- a/src/rpc/mining.cpp
+++ b/src/rpc/mining.cpp
@@ -524,7 +524,7 @@ static RPCHelpMan getblocktemplate()
                     {"str", RPCArg::Type::STR, RPCArg::Optional::OMITTED, "other client side supported softfork deployment"},
                 }},
             },
-                        "\"template_request\""},
+            RPCArgOptions{.oneline_description="\"template_request\""}},
         },
         {
             RPCResult{"If the proposal was accepted with mode=='proposal'", RPCResult::Type::NONE, "", ""},
diff --git a/src/rpc/server.cpp b/src/rpc/server.cpp
index e7bef79554..1d7bd2eb94 100644
--- a/src/rpc/server.cpp
+++ b/src/rpc/server.cpp
@@ -168,7 +168,7 @@ static RPCHelpMan stop()
     // to the client (intended for testing)
                 "\nRequest a graceful shutdown of " PACKAGE_NAME ".",
                 {
-                    {"wait", RPCArg::Type::NUM, RPCArg::Optional::OMITTED_NAMED_ARG, "how long to wait in ms", "", {}, /*hidden=*/true},
+                    {"wait", RPCArg::Type::NUM, RPCArg::Optional::OMITTED_NAMED_ARG, "how long to wait in ms", RPCArgOptions{.hidden=true}},
                 },
                 RPCResult{RPCResult::Type::STR, "", "A string with the content '" + RESULT + "'"},
                 RPCExamples{""},
diff --git a/src/rpc/util.cpp b/src/rpc/util.cpp
index 43935650fa..3e98e89791 100644
--- a/src/rpc/util.cpp
+++ b/src/rpc/util.cpp
@@ -418,8 +418,8 @@ struct Sections {
         case RPCArg::Type::BOOL: {
             if (outer_type == OuterType::NONE) return; // Nothing more to do for non-recursive types on first recursion
             auto left = indent;
-            if (arg.m_type_str.size() != 0 && push_name) {
-                left += "\"" + arg.GetName() + "\": " + arg.m_type_str.at(0);
+            if (arg.m_opts.type_str.size() != 0 && push_name) {
+                left += "\"" + arg.GetName() + "\": " + arg.m_opts.type_str.at(0);
             } else {
                 left += push_name ? arg.ToStringObj(/*oneline=*/false) : arg.ToString(/*oneline=*/false);
             }
@@ -618,7 +618,7 @@ std::string RPCHelpMan::ToString() const
     ret += m_name;
     bool was_optional{false};
     for (const auto& arg : m_args) {
-        if (arg.m_hidden) break; // Any arg that follows is also hidden
+        if (arg.m_opts.hidden) break; // Any arg that follows is also hidden
         const bool optional = arg.IsOptional();
         ret += " ";
         if (optional) {
@@ -639,7 +639,7 @@ std::string RPCHelpMan::ToString() const
     Sections sections;
     for (size_t i{0}; i < m_args.size(); ++i) {
         const auto& arg = m_args.at(i);
-        if (arg.m_hidden) break; // Any arg that follows is also hidden
+        if (arg.m_opts.hidden) break; // Any arg that follows is also hidden
 
         if (i == 0) ret += "\nArguments:\n";
 
@@ -704,8 +704,8 @@ std::string RPCArg::ToDescriptionString() const
 {
     std::string ret;
     ret += "(";
-    if (m_type_str.size() != 0) {
-        ret += m_type_str.at(1);
+    if (m_opts.type_str.size() != 0) {
+        ret += m_opts.type_str.at(1);
     } else {
         switch (m_type) {
         case Type::STR_HEX:
@@ -991,7 +991,7 @@ std::string RPCArg::ToStringObj(const bool oneline) const
 
 std::string RPCArg::ToString(const bool oneline) const
 {
-    if (oneline && !m_oneline_description.empty()) return m_oneline_description;
+    if (oneline && !m_opts.oneline_description.empty()) return m_opts.oneline_description;
 
     switch (m_type) {
     case Type::STR_HEX:
diff --git a/src/rpc/util.h b/src/rpc/util.h
index e883dc008e..9aa5df00b1 100644
--- a/src/rpc/util.h
+++ b/src/rpc/util.h
@@ -137,6 +137,12 @@ enum class OuterType {
     NONE, // Only set on first recursion
 };
 
+struct RPCArgOptions {
+    std::string oneline_description{};   //!< Should be empty unless it is supposed to override the auto-generated summary line
+    std::vector<std::string> type_str{}; //!< Should be empty unless it is supposed to override the auto-generated type strings. Vector length is either 0 or 2, m_opts.type_str.at(0) will override the type of the value in a key-value pair, m_opts.type_str.at(1) will override the type in the argument description.
+    bool hidden{false};                  //!< For testing only
+};
+
 struct RPCArg {
     enum class Type {
         OBJ,
@@ -169,30 +175,25 @@ struct RPCArg {
     using DefaultHint = std::string;
     using Default = UniValue;
     using Fallback = std::variant<Optional, /* hint for default value */ DefaultHint, /* default constant value */ Default>;
+
     const std::string m_names; //!< The name of the arg (can be empty for inner args, can contain multiple aliases separated by | for named request arguments)
     const Type m_type;
-    const bool m_hidden;
     const std::vector<RPCArg> m_inner; //!< Only used for arrays or dicts
     const Fallback m_fallback;
     const std::string m_description;
-    const std::string m_oneline_description; //!< Should be empty unless it is supposed to override the auto-generated summary line
-    const std::vector<std::string> m_type_str; //!< Should be empty unless it is supposed to override the auto-generated type strings. Vector length is either 0 or 2, m_type_str.at(0) will override the type of the value in a key-value pair, m_type_str.at(1) will override the type in the argument description.
+    const RPCArgOptions m_opts;
 
     RPCArg(
         const std::string name,
         const Type type,
         const Fallback fallback,
         const std::string description,
-        const std::string oneline_description = "",
-        const std::vector<std::string> type_str = {},
-        const bool hidden = false)
+        RPCArgOptions opts = {})
         : m_names{std::move(name)},
           m_type{std::move(type)},
-          m_hidden{hidden},
           m_fallback{std::move(fallback)},
           m_description{std::move(description)},
-          m_oneline_description{std::move(oneline_description)},
-          m_type_str{std::move(type_str)}
+          m_opts{std::move(opts)}
     {
         CHECK_NONFATAL(type != Type::ARR && type != Type::OBJ && type != Type::OBJ_USER_KEYS);
     }
@@ -203,16 +204,13 @@ struct RPCArg {
         const Fallback fallback,
         const std::string description,
         const std::vector<RPCArg> inner,
-        const std::string oneline_description = "",
-        const std::vector<std::string> type_str = {})
+        RPCArgOptions opts = {})
         : m_names{std::move(name)},
           m_type{std::move(type)},
-          m_hidden{false},
           m_inner{std::move(inner)},
           m_fallback{std::move(fallback)},
           m_description{std::move(description)},
-          m_oneline_description{std::move(oneline_description)},
-          m_type_str{std::move(type_str)}
+          m_opts{std::move(opts)}
     {
         CHECK_NONFATAL(type == Type::ARR || type == Type::OBJ || type == Type::OBJ_USER_KEYS);
     }
@@ -227,7 +225,7 @@ struct RPCArg {
 
     /**
      * Return the type string of the argument.
-     * Set oneline to allow it to be overridden by a custom oneline type string (m_oneline_description).
+     * Set oneline to allow it to be overridden by a custom oneline type string (m_opts.oneline_description).
      */
     std::string ToString(bool oneline) const;
     /**
diff --git a/src/wallet/rpc/backup.cpp b/src/wallet/rpc/backup.cpp
index 6cc3a71e19..8babbb4298 100644
--- a/src/wallet/rpc/backup.cpp
+++ b/src/wallet/rpc/backup.cpp
@@ -1266,15 +1266,15 @@ RPCHelpMan importmulti()
                                 {
                                     {"desc", RPCArg::Type::STR, RPCArg::Optional::OMITTED, "Descriptor to import. If using descriptor, do not also provide address/scriptPubKey, scripts, or pubkeys"},
                                     {"scriptPubKey", RPCArg::Type::STR, RPCArg::Optional::NO, "Type of scriptPubKey (string for script, json for address). Should not be provided if using a descriptor",
-                                        /*oneline_description=*/"", {"\"<script>\" | { \"address\":\"<address>\" }", "string / json"}
+                                        RPCArgOptions{.type_str={"\"<script>\" | { \"address\":\"<address>\" }", "string / json"}}
                                     },
                                     {"timestamp", RPCArg::Type::NUM, RPCArg::Optional::NO, "Creation time of the key expressed in " + UNIX_EPOCH_TIME + ",\n"
-        "                                                              or the string \"now\" to substitute the current synced blockchain time. The timestamp of the oldest\n"
-        "                                                              key will determine how far back blockchain rescans need to begin for missing wallet transactions.\n"
-        "                                                              \"now\" can be specified to bypass scanning, for keys which are known to never have been used, and\n"
-        "                                                              0 can be specified to scan the entire blockchain. Blocks up to 2 hours before the earliest key\n"
-        "                                                              creation time of all keys being imported by the importmulti call will be scanned.",
-                                        /*oneline_description=*/"", {"timestamp | \"now\"", "integer / string"}
+                                        "or the string \"now\" to substitute the current synced blockchain time. The timestamp of the oldest\n"
+                                        "key will determine how far back blockchain rescans need to begin for missing wallet transactions.\n"
+                                        "\"now\" can be specified to bypass scanning, for keys which are known to never have been used, and\n"
+                                        "0 can be specified to scan the entire blockchain. Blocks up to 2 hours before the earliest key\n"
+                                        "creation time of all keys being imported by the importmulti call will be scanned.",
+                                        RPCArgOptions{.type_str={"timestamp | \"now\"", "integer / string"}}
                                     },
                                     {"redeemscript", RPCArg::Type::STR, RPCArg::Optional::OMITTED, "Allowed only if the scriptPubKey is a P2SH or P2SH-P2WSH address/scriptPubKey"},
                                     {"witnessscript", RPCArg::Type::STR, RPCArg::Optional::OMITTED, "Allowed only if the scriptPubKey is a P2SH-P2WSH or P2WSH address/scriptPubKey"},
@@ -1296,12 +1296,12 @@ RPCHelpMan importmulti()
                                 },
                             },
                         },
-                        "\"requests\""},
+                        RPCArgOptions{.oneline_description="\"requests\""}},
                     {"options", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED_NAMED_ARG, "",
                         {
                             {"rescan", RPCArg::Type::BOOL, RPCArg::Default{true}, "Scan the chain and mempool for wallet transactions after all imports."},
                         },
-                        "\"options\""},
+                        RPCArgOptions{.oneline_description="\"options\""}},
                 },
                 RPCResult{
                     RPCResult::Type::ARR, "", "Response is an array with the same size as the input that has the execution result",
@@ -1609,18 +1609,18 @@ RPCHelpMan importdescriptors()
                                     {"range", RPCArg::Type::RANGE, RPCArg::Optional::OMITTED, "If a ranged descriptor is used, this specifies the end or the range (in the form [begin,end]) to import"},
                                     {"next_index", RPCArg::Type::NUM, RPCArg::Optional::OMITTED, "If a ranged descriptor is set to active, this specifies the next index to generate addresses from"},
                                     {"timestamp", RPCArg::Type::NUM, RPCArg::Optional::NO, "Time from which to start rescanning the blockchain for this descriptor, in " + UNIX_EPOCH_TIME + "\n"
-        "                                                              Use the string \"now\" to substitute the current synced blockchain time.\n"
-        "                                                              \"now\" can be specified to bypass scanning, for outputs which are known to never have been used, and\n"
-        "                                                              0 can be specified to scan the entire blockchain. Blocks up to 2 hours before the earliest timestamp\n"
+                                        "Use the string \"now\" to substitute the current synced blockchain time.\n"
+                                        "\"now\" can be specified to bypass scanning, for outputs which are known to never have been used, and\n"
+                                        "0 can be specified to scan the entire blockchain. Blocks up to 2 hours before the earliest timestamp\n"
                                         "of all descriptors being imported will be scanned as well as the mempool.",
-                                        /*oneline_description=*/"", {"timestamp | \"now\"", "integer / string"}
+                                        RPCArgOptions{.type_str={"timestamp | \"now\"", "integer / string"}}
                                     },
                                     {"internal", RPCArg::Type::BOOL, RPCArg::Default{false}, "Whether matching outputs should be treated as not incoming payments (e.g. change)"},
                                     {"label", RPCArg::Type::STR, RPCArg::Default{""}, "Label to assign to the address, only allowed with internal=false. Disabled for ranged descriptors"},
                                 },
                             },
                         },
-                        "\"requests\""},
+                        RPCArgOptions{.oneline_description="\"requests\""}},
                 },
                 RPCResult{
                     RPCResult::Type::ARR, "", "Response is an array with the same size as the input that has the execution result",
diff --git a/src/wallet/rpc/coins.cpp b/src/wallet/rpc/coins.cpp
index 2a59a5d778..9c0c953a7a 100644
--- a/src/wallet/rpc/coins.cpp
+++ b/src/wallet/rpc/coins.cpp
@@ -516,7 +516,7 @@ RPCHelpMan listunspent()
                             {"maximumCount", RPCArg::Type::NUM, RPCArg::DefaultHint{"unlimited"}, "Maximum number of UTXOs"},
                             {"minimumSumAmount", RPCArg::Type::AMOUNT, RPCArg::DefaultHint{"unlimited"}, "Minimum sum value of all UTXOs in " + CURRENCY_UNIT + ""},
                         },
-                        "query_options"},
+                        RPCArgOptions{.oneline_description="query_options"}},
                 },
                 RPCResult{
                     RPCResult::Type::ARR, "", "",
diff --git a/src/wallet/rpc/spend.cpp b/src/wallet/rpc/spend.cpp
index 819d4ea5d4..ebf694157b 100644
--- a/src/wallet/rpc/spend.cpp
+++ b/src/wallet/rpc/spend.cpp
@@ -317,7 +317,7 @@ RPCHelpMan sendmany()
                 "\nSend multiple times. Amounts are double-precision floating point numbers." +
         HELP_REQUIRING_PASSPHRASE,
                 {
-                    {"dummy", RPCArg::Type::STR, RPCArg::Optional::NO, "Must be set to \"\" for backwards compatibility.", "\"\""},
+                    {"dummy", RPCArg::Type::STR, RPCArg::Optional::NO, "Must be set to \"\" for backwards compatibility.", RPCArgOptions{.oneline_description="\"\""}},
                     {"amounts", RPCArg::Type::OBJ_USER_KEYS, RPCArg::Optional::NO, "The addresses and amounts",
                         {
                             {"address", RPCArg::Type::AMOUNT, RPCArg::Optional::NO, "The bitcoin address is the key, the numeric amount (can be string) in " + CURRENCY_UNIT + " is the value"},
@@ -774,7 +774,7 @@ RPCHelpMan fundrawtransaction()
                              },
                         },
                         FundTxDoc()),
-                        "options"},
+                        RPCArgOptions{.oneline_description="options"}},
                     {"iswitness", RPCArg::Type::BOOL, RPCArg::DefaultHint{"depends on heuristic tests"}, "Whether the transaction hex is a serialized witness transaction.\n"
                         "If iswitness is not present, heuristic tests will be used in decoding.\n"
                         "If true, only witness deserialization will be tried.\n"
@@ -968,7 +968,7 @@ static RPCHelpMan bumpfee_helper(std::string method_name)
                     {"estimate_mode", RPCArg::Type::STR, RPCArg::Default{"unset"}, "The fee estimate mode, must be one of (case insensitive):\n"
                      "\"" + FeeModes("\"\n\"") + "\""},
                 },
-                "options"},
+                RPCArgOptions{.oneline_description="options"}},
         },
         RPCResult{
             RPCResult::Type::OBJ, "", "", Cat(
@@ -1173,7 +1173,7 @@ RPCHelpMan send()
                     },
                 },
                 FundTxDoc()),
-                "options"},
+                RPCArgOptions{.oneline_description="options"}},
         },
         RPCResult{
             RPCResult::Type::OBJ, "", "",
@@ -1281,7 +1281,7 @@ RPCHelpMan sendall()
                     },
                     FundTxDoc()
                 ),
-                "options"
+                RPCArgOptions{.oneline_description="options"}
             },
         },
         RPCResult{
@@ -1611,7 +1611,7 @@ RPCHelpMan walletcreatefundedpsbt()
                             },
                         },
                         FundTxDoc()),
-                        "options"},
+                        RPCArgOptions{.oneline_description="options"}},
                     {"bip32derivs", RPCArg::Type::BOOL, RPCArg::Default{true}, "Include BIP 32 derivation paths for public keys if we know them"},
                 },
                 RPCResult{