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

9cc0230 Add NODISCARD to all {Decode,Parse}[...](...) functions returning bool. Sort includes. (practicalswift)
579497e tests: Explicitly ignore the return value of DecodeBase58(...) (practicalswift)
145fe95 tests: Check return value of ParseParameters(...) (practicalswift)
7c5bc2a 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

Author: MarcoFalke

src/Makefile.am

@@ -95,6 +95,7 @@ endif
 BITCOIN_CORE_H = \
   addrdb.h \
   addrman.h \
+  attributes.h \
   base58.h \
   bech32.h \
   bloom.h \

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

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

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);
     }
 }
 

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

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);

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);
 
 /**

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>

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];

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)