Remove obsolete NODISCARD ifdef forest. Use [[nodiscard]] C++17 (bitc…

…oin#20499)

src/attributes.h

@@ -6,17 +6,4 @@
 #ifndef BITCOIN_ATTRIBUTES_H
 #define BITCOIN_ATTRIBUTES_H
 
-#if defined(__has_cpp_attribute)
-#  if __has_cpp_attribute(nodiscard)
-#    define NODISCARD [[nodiscard]]
-#  endif
-#endif
-#ifndef NODISCARD
-#  if defined(_MSC_VER) && _MSC_VER >= 1700
-#    define NODISCARD _Check_return_
-#  else
-#    define NODISCARD __attribute__((warn_unused_result))
-#  endif
-#endif
-
 #endif // BITCOIN_ATTRIBUTES_H

src/base58.h

@@ -35,13 +35,13 @@ std::string EncodeBase58(const std::vector<unsigned char>& vch);
  * return true if decoding is successful.
  * psz cannot be nullptr.
  */
-NODISCARD bool DecodeBase58(const char* psz, std::vector<unsigned char>& vchRet);
+[[nodiscard]] bool DecodeBase58(const char* psz, std::vector<unsigned char>& vchRet);
 
 /**
  * Decode a base58-encoded string (str) into a byte vector (vchRet).
  * return true if decoding is successful.
  */
-NODISCARD bool DecodeBase58(const std::string& str, std::vector<unsigned char>& vchRet);
+[[nodiscard]] bool DecodeBase58(const std::string& str, std::vector<unsigned char>& vchRet);
 
 /**
  * Encode a byte vector into a base58-encoded string, including checksum
@@ -52,12 +52,12 @@ std::string EncodeBase58Check(const std::vector<unsigned char>& vchIn);
  * Decode a base58-encoded string (psz) that includes a checksum into a byte
  * vector (vchRet), return true if decoding is successful
  */
-NODISCARD bool DecodeBase58Check(const char* psz, std::vector<unsigned char>& vchRet);
+[[nodiscard]] bool DecodeBase58Check(const char* psz, std::vector<unsigned char>& vchRet);
 
 /**
  * Decode a base58-encoded string (str) that includes a checksum into a byte
  * vector (vchRet), return true if decoding is successful
  */
-NODISCARD bool DecodeBase58Check(const std::string& str, std::vector<unsigned char>& vchRet);
+[[nodiscard]] bool DecodeBase58Check(const std::string& str, std::vector<unsigned char>& vchRet);
 
 #endif // BITCOIN_BASE58_H

src/core_io.h

@@ -23,8 +23,8 @@ class UniValue;
 // core_read.cpp
 CScript ParseScript(const std::string& s);
 std::string ScriptToAsmStr(const CScript& script, const bool fAttemptSighashDecode = false);
-NODISCARD bool DecodeHexTx(CMutableTransaction& tx, const std::string& hex_tx, bool try_no_witness = false, bool try_witness = true);
-NODISCARD bool DecodeHexBlk(CBlock&, const std::string& strHexBlk);
+[[nodiscard]] bool DecodeHexTx(CMutableTransaction& tx, const std::string& hex_tx, bool try_no_witness = false, bool try_witness = true);
+[[nodiscard]] bool DecodeHexBlk(CBlock&, const std::string& strHexBlk);
 bool DecodeHexBlockHeader(CBlockHeader&, const std::string& hex_header);
 
 /**

src/init.cpp

@@ -115,7 +115,7 @@ static fs::path GetPidFile()
     return AbsPathForConfigVal(fs::path(gArgs.GetArg("-pid", BITCOIN_PID_FILENAME)));
 }
 
-NODISCARD static bool CreatePidFile()
+[[nodiscard]] static bool CreatePidFile()
 {
     fsbridge::ofstream file{GetPidFile()};
     if (file) {

src/node/transaction.h

@@ -26,6 +26,6 @@
  * @param[in]  wait_callback wait until callbacks have been processed to avoid stale result due to a sequentially RPC.
  * return error
  */
-NODISCARD TransactionError BroadcastTransaction(CTransactionRef tx, std::string& err_string, const CAmount& max_tx_fee, bool relay, bool wait_callback);
+[[nodiscard]] TransactionError BroadcastTransaction(CTransactionRef tx, std::string& err_string, const CAmount& max_tx_fee, bool relay, bool wait_callback);
 
 #endif // BITCOIN_NODE_TRANSACTION_H

src/outputtype.h

@@ -27,7 +27,7 @@ enum class OutputType {
     CHANGE_AUTO,
 };
 
-NODISCARD bool ParseOutputType(const std::string& str, OutputType& output_type);
+[[nodiscard]] bool ParseOutputType(const std::string& str, OutputType& output_type);
 const std::string& FormatOutputType(OutputType type);
 
 /**

src/psbt.h

@@ -397,7 +397,7 @@ struct PartiallySignedTransaction
 
     /** Merge psbt into this. The two psbts must have the same underlying CTransaction (i.e. the
       * same actual Bitcoin transaction.) Returns true if the merge succeeded, false otherwise. */
-    NODISCARD bool Merge(const PartiallySignedTransaction& psbt);
+    [[nodiscard]] bool Merge(const PartiallySignedTransaction& psbt);
     bool IsSane() const;
     bool AddInput(const CTxIn& txin, PSBTInput& psbtin);
     bool AddOutput(const CTxOut& txout, const PSBTOutput& psbtout);
@@ -606,11 +606,11 @@ bool FinalizeAndExtractPSBT(PartiallySignedTransaction& psbtx, CMutableTransacti
  * @param[in]  psbtxs the PSBTs to combine
  * @return error (OK if we successfully combined the transactions, other error if they were not compatible)
  */
-NODISCARD TransactionError CombinePSBTs(PartiallySignedTransaction& out, const std::vector<PartiallySignedTransaction>& psbtxs);
+[[nodiscard]] TransactionError CombinePSBTs(PartiallySignedTransaction& out, const std::vector<PartiallySignedTransaction>& psbtxs);
 
 //! Decode a base64ed PSBT into a PartiallySignedTransaction
-NODISCARD bool DecodeBase64PSBT(PartiallySignedTransaction& decoded_psbt, const std::string& base64_psbt, std::string& error);
+[[nodiscard]] bool DecodeBase64PSBT(PartiallySignedTransaction& decoded_psbt, const std::string& base64_psbt, std::string& error);
 //! Decode a raw (binary blob) PSBT into a PartiallySignedTransaction
-NODISCARD bool DecodeRawPSBT(PartiallySignedTransaction& decoded_psbt, const std::string& raw_psbt, std::string& error);
+[[nodiscard]] bool DecodeRawPSBT(PartiallySignedTransaction& decoded_psbt, const std::string& raw_psbt, std::string& error);
 
 #endif // BITCOIN_PSBT_H

src/script/descriptor.cpp

@@ -690,7 +690,7 @@ std::vector<Span<const char>> Split(const Span<const char>& sp, char sep)
 }
 
 /** Parse a key path, being passed a split list of elements (the first element is ignored). */
-NODISCARD bool ParseKeyPath(const std::vector<Span<const char>>& split, KeyPath& out, std::string& error)
+[[nodiscard]] bool ParseKeyPath(const std::vector<Span<const char>>& split, KeyPath& out, std::string& error)
 {
     for (size_t i = 1; i < split.size(); ++i) {
         Span<const char> elem = split[i];

src/test/coins_tests.cpp

@@ -38,7 +38,7 @@ class CCoinsViewTest : public CCoinsView
     std::map<COutPoint, Coin> map_;
 
 public:
-    NODISCARD bool GetCoin(const COutPoint& outpoint, Coin& coin) const override
+    [[nodiscard]] bool GetCoin(const COutPoint& outpoint, Coin& coin) const override
     {
         std::map<COutPoint, Coin>::const_iterator it = map_.find(outpoint);
         if (it == map_.end()) {

src/util/bip32.h

@@ -10,7 +10,7 @@
 #include <vector>
 
 /** Parse an HD keypaths like "m/7/0'/2000". */
-NODISCARD bool ParseHDKeypath(const std::string& keypath_str, std::vector<uint32_t>& keypath);
+[[nodiscard]] bool ParseHDKeypath(const std::string& keypath_str, std::vector<uint32_t>& keypath);
 
 /** Write HD keypaths as strings */
 std::string WriteHDKeypath(const std::vector<uint32_t>& keypath);

src/util/moneystr.h

@@ -20,6 +20,6 @@
  */
 std::string FormatMoney(const CAmount& n);
 /** Parse an amount denoted in full coins. E.g. "0.0034" supplied on the command line. **/
-NODISCARD bool ParseMoney(const std::string& str, CAmount& nRet);
+[[nodiscard]] bool ParseMoney(const std::string& str, CAmount& nRet);
 
 #endif // BITCOIN_UTIL_MONEYSTR_H

src/util/strencodings.cpp

@@ -292,7 +292,7 @@ std::string DecodeBase32(const std::string& str, bool* pf_invalid)
     return std::string((const char*)vchRet.data(), vchRet.size());
 }
 
-NODISCARD static bool ParsePrechecks(const std::string& str)
+[[nodiscard]] static bool ParsePrechecks(const std::string& str)
 {
     if (str.empty()) // No empty string allowed
         return false;

src/util/strencodings.h

@@ -94,35 +94,35 @@ constexpr inline bool IsSpace(char c) noexcept {
  * @returns true if the entire string could be parsed as valid integer,
  *   false if not the entire string could be parsed or when overflow or underflow occurred.
  */
-NODISCARD bool ParseInt32(const std::string& str, int32_t *out);
+[[nodiscard]] bool ParseInt32(const std::string& str, int32_t *out);
 
 /**
  * Convert string to signed 64-bit integer with strict parse error feedback.
  * @returns true if the entire string could be parsed as valid integer,
  *   false if not the entire string could be parsed or when overflow or underflow occurred.
  */
-NODISCARD bool ParseInt64(const std::string& str, int64_t *out);
+[[nodiscard]] bool ParseInt64(const std::string& str, int64_t *out);
 
 /**
  * Convert decimal string to unsigned 32-bit integer with strict parse error feedback.
  * @returns true if the entire string could be parsed as valid integer,
  *   false if not the entire string could be parsed or when overflow or underflow occurred.
  */
-NODISCARD bool ParseUInt32(const std::string& str, uint32_t *out);
+[[nodiscard]] bool ParseUInt32(const std::string& str, uint32_t *out);
 
 /**
  * Convert decimal string to unsigned 64-bit integer with strict parse error feedback.
  * @returns true if the entire string could be parsed as valid integer,
  *   false if not the entire string could be parsed or when overflow or underflow occurred.
  */
-NODISCARD bool ParseUInt64(const std::string& str, uint64_t *out);
+[[nodiscard]] bool ParseUInt64(const std::string& str, uint64_t *out);
 
 /**
  * Convert string to double with strict parse error feedback.
  * @returns true if the entire string could be parsed as valid double,
  *   false if not the entire string could be parsed or when overflow or underflow occurred.
  */
-NODISCARD bool ParseDouble(const std::string& str, double *out);
+[[nodiscard]] bool ParseDouble(const std::string& str, double *out);
 
 template<typename T>
 std::string HexStr(const T itbegin, const T itend)
@@ -172,7 +172,7 @@ bool TimingResistantEqual(const T& a, const T& b)
  * @returns true on success, false on error.
  * @note The result must be in the range (-10^18,10^18), otherwise an overflow error will trigger.
  */
-NODISCARD bool ParseFixedPoint(const std::string &val, int decimals, int64_t *amount_out);
+[[nodiscard]] bool ParseFixedPoint(const std::string &val, int decimals, int64_t *amount_out);
 
 /** Convert from one power-of-2 number base to another. */
 template<int frombits, int tobits, bool pad, typename O, typename I>

src/util/string.h

@@ -12,7 +12,7 @@
 #include <string>
 #include <vector>
 
-NODISCARD inline std::string TrimString(const std::string& str, const std::string& pattern = " \f\n\r\t\v")
+[[nodiscard]] inline std::string TrimString(const std::string& str, const std::string& pattern = " \f\n\r\t\v")
 {
     std::string::size_type front = str.find_first_not_of(pattern);
     if (front == std::string::npos) {
@@ -48,7 +48,7 @@ inline std::string Join(const std::vector<std::string>& list, const std::string&
 /**
  * Check if a string does not contain any embedded NUL (\0) characters
  */
-NODISCARD inline bool ValidAsCString(const std::string& str) noexcept
+[[nodiscard]] inline bool ValidAsCString(const std::string& str) noexcept
 {
     return str.size() == strlen(str.c_str());
 }

src/util/system.cpp

@@ -287,7 +287,7 @@ class ArgsManagerHelper {
  * that debug log output is not sent to any file at all).
  */
 
-NODISCARD static bool InterpretOption(std::string key, std::string val, unsigned int flags,
+[[nodiscard]] static bool InterpretOption(std::string key, std::string val, unsigned int flags,
                                       std::map<std::string, std::vector<std::string>>& args,
                                       std::string& error)
 {

src/util/system.h

@@ -166,7 +166,7 @@ class ArgsManager
     std::map<OptionsCategory, std::map<std::string, Arg>> m_available_args GUARDED_BY(cs_args);
     std::list<SectionInfo> m_config_sections GUARDED_BY(cs_args);
 
-    NODISCARD bool ReadConfigStream(std::istream& stream, const std::string& filepath, std::string& error, bool ignore_invalid_keys = false);
+    [[nodiscard]] bool ReadConfigStream(std::istream& stream, const std::string& filepath, std::string& error, bool ignore_invalid_keys = false);
 
 public:
     ArgsManager();
@@ -176,8 +176,8 @@ class ArgsManager
      */
     void SelectConfigNetwork(const std::string& network);
 
-    NODISCARD bool ParseParameters(int argc, const char* const argv[], std::string& error);
-    NODISCARD bool ReadConfigFiles(std::string& error, bool ignore_invalid_keys = false);
+    [[nodiscard]] bool ParseParameters(int argc, const char* const argv[], std::string& error);
+    [[nodiscard]] bool ReadConfigFiles(std::string& error, bool ignore_invalid_keys = false);
 
     /**
      * Log warnings for options in m_section_only_args when

src/wallet/psbtwallet.h

@@ -24,7 +24,7 @@
  * @param[in]  bip32derivs whether to fill in bip32 derivation information if available
  * return error
  */
-NODISCARD TransactionError FillPSBT(const CWallet* pwallet,
+[[nodiscard]] TransactionError FillPSBT(const CWallet* pwallet,
               PartiallySignedTransaction& psbtx,
               bool& complete,
               int sighash_type = 1 /* SIGHASH_ALL */,