Merge #13815: util: Add [[nodiscard]] to all {Decode,Parse}[...](...) functions returning bool

9cc0230cfc Add NODISCARD to all {Decode,Parse}[...](...) functions returning bool. Sort includes. (practicalswift)
579497e77a tests: Explicitly ignore the return value of DecodeBase58(...) (practicalswift)
145fe95ec7 tests: Check return value of ParseParameters(...) (practicalswift)
7c5bc2a523 miner: Default to DEFAULT_BLOCK_MIN_TX_FEE if unable to parse -blockmintxfee (practicalswift)

Pull request description:

  Changes in this PR:
  * ~~Add linter to make sure the return value of `Parse[...](...)` is checked~~
  * Add `__attribute__((warn_unused_result))` to all `{Decode,Parse}[...](...)` functions returning `bool`
  * Fix violations

  Context:
  * #13712: `wallet: Fix non-determinism in ParseHDKeypath(...). Avoid using an uninitialized variable in path calculation.` would have been prevented by this

Tree-SHA512: 41a97899f2d5a26584235fa02b1ebfb4faacd81ea97e927022955a658fa7e15d07a1443b4b7635151a43259a1adf8f2f4de3c1c75d7b5f09f0d5496463a1dae6

15 files changed, 84 insertions, 53 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index 8dd0d31839..09daaebd23 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -95,6 +95,7 @@ endif
 BITCOIN_CORE_H = \
   addrdb.h \
   addrman.h \
+  attributes.h \
   base58.h \
   bech32.h \
   bloom.h \
diff --git a/src/attributes.h b/src/attributes.h
new file mode 100644
index 0000000000..45099bd8b8
--- /dev/null
+++ b/src/attributes.h
@@ -0,0 +1,22 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#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
diff --git a/src/base58.h b/src/base58.h
index 9d3f90652e..d6e0299a1e 100644
--- a/src/base58.h
+++ b/src/base58.h
@@ -14,6 +14,8 @@
 #ifndef BITCOIN_BASE58_H
 #define BITCOIN_BASE58_H
 
+#include <attributes.h>
+
 #include <string>
 #include <vector>
 
@@ -33,13 +35,13 @@ std::string EncodeBase58(const std::vector<unsigned char>& vch);
  * return true if decoding is successful.
  * psz cannot be nullptr.
  */
-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.
  */
-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
@@ -50,12 +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
  */
-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
  */
-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
diff --git a/src/bench/base58.cpp b/src/bench/base58.cpp
index a555376e40..e7702ec461 100644
--- a/src/bench/base58.cpp
+++ b/src/bench/base58.cpp
@@ -49,7 +49,7 @@ static void Base58Decode(benchmark::State& state)
     const char* addr = "17VZNX1SN5NtKa8UQFxwQbFeFc3iqRYhem";
     std::vector<unsigned char> vch;
     while (state.KeepRunning()) {
-        DecodeBase58(addr, vch);
+        (void) DecodeBase58(addr, vch);
     }
 }
 
diff --git a/src/core_io.h b/src/core_io.h
index 2c3b64d81e..6f87161f46 100644
--- a/src/core_io.h
+++ b/src/core_io.h
@@ -6,6 +6,7 @@
 #define BITCOIN_CORE_IO_H
 
 #include <amount.h>
+#include <attributes.h>
 
 #include <string>
 #include <vector>
@@ -22,8 +23,8 @@ class UniValue;
 // core_read.cpp
 CScript ParseScript(const std::string& s);
 std::string ScriptToAsmStr(const CScript& script, const bool fAttemptSighashDecode = false);
-bool DecodeHexTx(CMutableTransaction& tx, const std::string& hex_tx, bool try_no_witness = false, bool try_witness = true);
-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);
 
 /**
@@ -36,7 +37,7 @@ bool DecodeHexBlockHeader(CBlockHeader&, const std::string& hex_header);
  */
 bool ParseHashStr(const std::string& strHex, uint256& result);
 std::vector<unsigned char> ParseHexUV(const UniValue& v, const std::string& strName);
-bool DecodePSBT(PartiallySignedTransaction& psbt, const std::string& base64_tx, std::string& error);
+NODISCARD bool DecodePSBT(PartiallySignedTransaction& psbt, const std::string& base64_tx, std::string& error);
 int ParseSighashString(const UniValue& sighash);
 
 // core_write.cpp
diff --git a/src/miner.cpp b/src/miner.cpp
index feb86cab66..96c9cd6d2a 100644
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -70,9 +70,8 @@ static BlockAssembler::Options DefaultOptions()
     // If -blockmaxweight is not given, limit to DEFAULT_BLOCK_MAX_WEIGHT
     BlockAssembler::Options options;
     options.nBlockMaxWeight = gArgs.GetArg("-blockmaxweight", DEFAULT_BLOCK_MAX_WEIGHT);
-    if (gArgs.IsArgSet("-blockmintxfee")) {
-        CAmount n = 0;
-        ParseMoney(gArgs.GetArg("-blockmintxfee", ""), n);
+    CAmount n = 0;
+    if (gArgs.IsArgSet("-blockmintxfee") && ParseMoney(gArgs.GetArg("-blockmintxfee", ""), n)) {
         options.blockMinFeeRate = CFeeRate(n);
     } else {
         options.blockMinFeeRate = CFeeRate(DEFAULT_BLOCK_MIN_TX_FEE);
diff --git a/src/outputtype.h b/src/outputtype.h
index 4c4d93bc8b..6c30fd1950 100644
--- a/src/outputtype.h
+++ b/src/outputtype.h
@@ -6,6 +6,7 @@
 #ifndef BITCOIN_OUTPUTTYPE_H
 #define BITCOIN_OUTPUTTYPE_H
 
+#include <attributes.h>
 #include <keystore.h>
 #include <script/standard.h>
 
@@ -26,7 +27,7 @@ enum class OutputType {
     CHANGE_AUTO,
 };
 
-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);
 
 /**
diff --git a/src/rest.cpp b/src/rest.cpp
index 6c7e0384cb..4988e6ed26 100644
--- a/src/rest.cpp
+++ b/src/rest.cpp
@@ -3,20 +3,21 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#include <attributes.h>
 #include <chain.h>
 #include <chainparams.h>
 #include <core_io.h>
+#include <httpserver.h>
 #include <index/txindex.h>
 #include <primitives/block.h>
 #include <primitives/transaction.h>
-#include <validation.h>
-#include <httpserver.h>
 #include <rpc/blockchain.h>
 #include <rpc/server.h>
 #include <streams.h>
 #include <sync.h>
 #include <txmempool.h>
 #include <util/strencodings.h>
+#include <validation.h>
 #include <version.h>
 
 #include <boost/algorithm/string.hpp>
diff --git a/src/script/descriptor.cpp b/src/script/descriptor.cpp
index 90c4ddcc11..d343972c40 100644
--- a/src/script/descriptor.cpp
+++ b/src/script/descriptor.cpp
@@ -478,7 +478,7 @@ 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). */
-bool ParseKeyPath(const std::vector<Span<const char>>& split, KeyPath& out)
+NODISCARD bool ParseKeyPath(const std::vector<Span<const char>>& split, KeyPath& out)
 {
     for (size_t i = 1; i < split.size(); ++i) {
         Span<const char> elem = split[i];
diff --git a/src/test/getarg_tests.cpp b/src/test/getarg_tests.cpp
index 0432ede3e0..14ddf4d10e 100644
--- a/src/test/getarg_tests.cpp
+++ b/src/test/getarg_tests.cpp
@@ -28,7 +28,7 @@ static void ResetArgs(const std::string& strArg)
         vecChar.push_back(s.c_str());
 
     std::string error;
-    gArgs.ParseParameters(vecChar.size(), vecChar.data(), error);
+    BOOST_CHECK(gArgs.ParseParameters(vecChar.size(), vecChar.data(), error));
 }
 
 static void SetupArgs(const std::vector<std::string>& args)
diff --git a/src/test/util_tests.cpp b/src/test/util_tests.cpp
index ff19b12a9c..f461c7496f 100644
--- a/src/test/util_tests.cpp
+++ b/src/test/util_tests.cpp
@@ -210,13 +210,13 @@ BOOST_AUTO_TEST_CASE(util_ParseParameters)
 
     std::string error;
     testArgs.SetupArgs(4, avail_args);
-    testArgs.ParseParameters(0, (char**)argv_test, error);
+    BOOST_CHECK(testArgs.ParseParameters(0, (char**)argv_test, error));
     BOOST_CHECK(testArgs.GetOverrideArgs().empty() && testArgs.GetConfigArgs().empty());
 
-    testArgs.ParseParameters(1, (char**)argv_test, error);
+    BOOST_CHECK(testArgs.ParseParameters(1, (char**)argv_test, error));
     BOOST_CHECK(testArgs.GetOverrideArgs().empty() && testArgs.GetConfigArgs().empty());
 
-    testArgs.ParseParameters(7, (char**)argv_test, error);
+    BOOST_CHECK(testArgs.ParseParameters(7, (char**)argv_test, error));
     // expectation: -ignored is ignored (program name argument),
     // -a, -b and -ccc end up in map, -d ignored because it is after
     // a non-option argument (non-GNU option parsing)
@@ -242,7 +242,7 @@ BOOST_AUTO_TEST_CASE(util_GetBoolArg)
         "ignored", "-a", "-nob", "-c=0", "-d=1", "-e=false", "-f=true"};
     std::string error;
     testArgs.SetupArgs(6, avail_args);
-    testArgs.ParseParameters(7, (char**)argv_test, error);
+    BOOST_CHECK(testArgs.ParseParameters(7, (char**)argv_test, error));
 
     // Each letter should be set.
     for (const char opt : "abcdef")
@@ -278,7 +278,7 @@ BOOST_AUTO_TEST_CASE(util_GetBoolArgEdgeCases)
     const char *argv_test[] = {"ignored", "-nofoo", "-foo", "-nobar=0"};
     testArgs.SetupArgs(2, avail_args);
     std::string error;
-    testArgs.ParseParameters(4, (char**)argv_test, error);
+    BOOST_CHECK(testArgs.ParseParameters(4, (char**)argv_test, error));
 
     // This was passed twice, second one overrides the negative setting.
     BOOST_CHECK(!testArgs.IsArgNegated("-foo"));
@@ -290,7 +290,7 @@ BOOST_AUTO_TEST_CASE(util_GetBoolArgEdgeCases)
 
     // Config test
     const char *conf_test = "nofoo=1\nfoo=1\nnobar=0\n";
-    testArgs.ParseParameters(1, (char**)argv_test, error);
+    BOOST_CHECK(testArgs.ParseParameters(1, (char**)argv_test, error));
     testArgs.ReadConfigString(conf_test);
 
     // This was passed twice, second one overrides the negative setting,
@@ -305,7 +305,7 @@ BOOST_AUTO_TEST_CASE(util_GetBoolArgEdgeCases)
     // Combined test
     const char *combo_test_args[] = {"ignored", "-nofoo", "-bar"};
     const char *combo_test_conf = "foo=1\nnobar=1\n";
-    testArgs.ParseParameters(3, (char**)combo_test_args, error);
+    BOOST_CHECK(testArgs.ParseParameters(3, (char**)combo_test_args, error));
     testArgs.ReadConfigString(combo_test_conf);
 
     // Command line overrides, but doesn't erase old setting
@@ -557,38 +557,38 @@ BOOST_AUTO_TEST_CASE(util_GetChainName)
     const char* testnetconf = "testnet=1\nregtest=0\n[test]\nregtest=1";
     std::string error;
 
-    test_args.ParseParameters(0, (char**)argv_testnet, error);
+    BOOST_CHECK(test_args.ParseParameters(0, (char**)argv_testnet, error));
     BOOST_CHECK_EQUAL(test_args.GetChainName(), "main");
 
-    test_args.ParseParameters(2, (char**)argv_testnet, error);
+    BOOST_CHECK(test_args.ParseParameters(2, (char**)argv_testnet, error));
     BOOST_CHECK_EQUAL(test_args.GetChainName(), "test");
 
-    test_args.ParseParameters(2, (char**)argv_regtest, error);
+    BOOST_CHECK(test_args.ParseParameters(2, (char**)argv_regtest, error));
     BOOST_CHECK_EQUAL(test_args.GetChainName(), "regtest");
 
-    test_args.ParseParameters(3, (char**)argv_test_no_reg, error);
+    BOOST_CHECK(test_args.ParseParameters(3, (char**)argv_test_no_reg, error));
     BOOST_CHECK_EQUAL(test_args.GetChainName(), "test");
 
-    test_args.ParseParameters(3, (char**)argv_both, error);
+    BOOST_CHECK(test_args.ParseParameters(3, (char**)argv_both, error));
     BOOST_CHECK_THROW(test_args.GetChainName(), std::runtime_error);
 
-    test_args.ParseParameters(0, (char**)argv_testnet, error);
+    BOOST_CHECK(test_args.ParseParameters(0, (char**)argv_testnet, error));
     test_args.ReadConfigString(testnetconf);
     BOOST_CHECK_EQUAL(test_args.GetChainName(), "test");
 
-    test_args.ParseParameters(2, (char**)argv_testnet, error);
+    BOOST_CHECK(test_args.ParseParameters(2, (char**)argv_testnet, error));
     test_args.ReadConfigString(testnetconf);
     BOOST_CHECK_EQUAL(test_args.GetChainName(), "test");
 
-    test_args.ParseParameters(2, (char**)argv_regtest, error);
+    BOOST_CHECK(test_args.ParseParameters(2, (char**)argv_regtest, error));
     test_args.ReadConfigString(testnetconf);
     BOOST_CHECK_THROW(test_args.GetChainName(), std::runtime_error);
 
-    test_args.ParseParameters(3, (char**)argv_test_no_reg, error);
+    BOOST_CHECK(test_args.ParseParameters(3, (char**)argv_test_no_reg, error));
     test_args.ReadConfigString(testnetconf);
     BOOST_CHECK_EQUAL(test_args.GetChainName(), "test");
 
-    test_args.ParseParameters(3, (char**)argv_both, error);
+    BOOST_CHECK(test_args.ParseParameters(3, (char**)argv_both, error));
     test_args.ReadConfigString(testnetconf);
     BOOST_CHECK_THROW(test_args.GetChainName(), std::runtime_error);
 
@@ -596,23 +596,23 @@ BOOST_AUTO_TEST_CASE(util_GetChainName)
     // [test] regtest=1 potentially relevant) doesn't break things
     test_args.SelectConfigNetwork("test");
 
-    test_args.ParseParameters(0, (char**)argv_testnet, error);
+    BOOST_CHECK(test_args.ParseParameters(0, (char**)argv_testnet, error));
     test_args.ReadConfigString(testnetconf);
     BOOST_CHECK_EQUAL(test_args.GetChainName(), "test");
 
-    test_args.ParseParameters(2, (char**)argv_testnet, error);
+    BOOST_CHECK(test_args.ParseParameters(2, (char**)argv_testnet, error));
     test_args.ReadConfigString(testnetconf);
     BOOST_CHECK_EQUAL(test_args.GetChainName(), "test");
 
-    test_args.ParseParameters(2, (char**)argv_regtest, error);
+    BOOST_CHECK(test_args.ParseParameters(2, (char**)argv_regtest, error));
     test_args.ReadConfigString(testnetconf);
     BOOST_CHECK_THROW(test_args.GetChainName(), std::runtime_error);
 
-    test_args.ParseParameters(2, (char**)argv_test_no_reg, error);
+    BOOST_CHECK(test_args.ParseParameters(2, (char**)argv_test_no_reg, error));
     test_args.ReadConfigString(testnetconf);
     BOOST_CHECK_EQUAL(test_args.GetChainName(), "test");
 
-    test_args.ParseParameters(3, (char**)argv_both, error);
+    BOOST_CHECK(test_args.ParseParameters(3, (char**)argv_both, error));
     test_args.ReadConfigString(testnetconf);
     BOOST_CHECK_THROW(test_args.GetChainName(), std::runtime_error);
 }
diff --git a/src/util/moneystr.h b/src/util/moneystr.h
index 9133f46d5d..b8e2812a96 100644
--- a/src/util/moneystr.h
+++ b/src/util/moneystr.h
@@ -9,16 +9,17 @@
 #ifndef BITCOIN_UTIL_MONEYSTR_H
 #define BITCOIN_UTIL_MONEYSTR_H
 
-#include <stdint.h>
-#include <string>
-
 #include <amount.h>
+#include <attributes.h>
+
+#include <cstdint>
+#include <string>
 
 /* Do not use these functions to represent or parse monetary amounts to or from
  * JSON but use AmountFromValue and ValueFromAmount for that.
  */
 std::string FormatMoney(const CAmount& n);
-bool ParseMoney(const std::string& str, CAmount& nRet);
-bool ParseMoney(const char* pszIn, CAmount& nRet);
+NODISCARD bool ParseMoney(const std::string& str, CAmount& nRet);
+NODISCARD bool ParseMoney(const char* pszIn, CAmount& nRet);
 
 #endif // BITCOIN_UTIL_MONEYSTR_H
diff --git a/src/util/strencodings.cpp b/src/util/strencodings.cpp
index 2a2df43337..46146be66f 100644
--- a/src/util/strencodings.cpp
+++ b/src/util/strencodings.cpp
@@ -263,7 +263,7 @@ std::string DecodeBase32(const std::string& str)
     return std::string((const char*)vchRet.data(), vchRet.size());
 }
 
-static bool ParsePrechecks(const std::string& str)
+NODISCARD static bool ParsePrechecks(const std::string& str)
 {
     if (str.empty()) // No empty string allowed
         return false;
diff --git a/src/util/strencodings.h b/src/util/strencodings.h
index 87ccf40a1b..7d16d7dcfd 100644
--- a/src/util/strencodings.h
+++ b/src/util/strencodings.h
@@ -9,7 +9,9 @@
 #ifndef BITCOIN_UTIL_STRENCODINGS_H
 #define BITCOIN_UTIL_STRENCODINGS_H
 
-#include <stdint.h>
+#include <attributes.h>
+
+#include <cstdint>
 #include <string>
 #include <vector>
 
@@ -92,35 +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.
  */
-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.
  */
-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.
  */
-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.
  */
-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.
  */
-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, bool fSpaces=false)
@@ -173,7 +175,7 @@ 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.
  */
-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>
@@ -200,7 +202,7 @@ bool ConvertBits(const O& outfn, I it, I end) {
 }
 
 /** Parse an HD keypaths like "m/7/0'/2000". */
-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);
 
 /**
  * Converts the given character to its lowercase equivalent.
diff --git a/src/util/system.h b/src/util/system.h
index 5634b8dd61..bebb089a2a 100644
--- a/src/util/system.h
+++ b/src/util/system.h
@@ -14,6 +14,7 @@
 #include <config/bitcoin-config.h>
 #endif
 
+#include <attributes.h>
 #include <compat.h>
 #include <fs.h>
 #include <logging.h>
@@ -159,7 +160,7 @@ public:
      */
     void SelectConfigNetwork(const std::string& network);
 
-    bool ParseParameters(int argc, const char* const argv[], std::string& error);
+    NODISCARD bool ParseParameters(int argc, const char* const argv[], std::string& error);
     bool ReadConfigFiles(std::string& error, bool ignore_invalid_keys = false);
 
     /**