Merge #20530: lint, refactor: Update cppcheck linter to c++17 and improve explicit usage

1e62350ca2 refactor: Improve use of explicit keyword (Fabian Jahr)
c502a6dbfb lint: Use c++17 std in cppcheck linter (Fabian Jahr)

Pull request description:

  I found the `extended-lint-cppcheck` linter still uses `std=c++11` when reviewing #20471. The only difference in the output after this change is one line is missing:

  ```
  src/script/descriptor.cpp:159:5: warning: Struct 'PubkeyProvider' has a constructor with 1 argument that is not explicit. [noExplicitConstructor]
  ```

  After some digging, I am still not sure why this one is ignored with c++17 when 40 other`noExplicitConstructor` warnings were still appearing.

  In the second commit, I fix these warnings, adding `explicit` where appropriate and adding fixes to ignore otherwise.

ACKs for top commit:
  practicalswift:
    cr ACK 1e62350ca2: patch looks correct!
  MarcoFalke:
    review ACK 1e62350ca2

Tree-SHA512: dff7b324429a57160e217cf38d9ddbb6e70c6cb3d3e3e0bd4013d88e07afc2292c3df94d0acf7122e9d486322821682ecf15c8f2724a78667764c05d47f89a12

src/net_processing.cpp

@@ -451,7 +451,7 @@ struct Peer {
     /** Work queue of items requested by this peer **/
     std::deque<CInv> m_getdata_requests GUARDED_BY(m_getdata_requests_mutex);
 
-    Peer(NodeId id) : m_id(id) {}
+    explicit Peer(NodeId id) : m_id(id) {}
 };
 
 using PeerRef = std::shared_ptr<Peer>;

src/node/interfaces.cpp

@@ -64,7 +64,7 @@ namespace {
 class NodeImpl : public Node
 {
 public:
-    NodeImpl(NodeContext* context) { setContext(context); }
+    explicit NodeImpl(NodeContext* context) { setContext(context); }
     void initLogging() override { InitLogging(*Assert(m_context->args)); }
     void initParameterInteraction() override { InitParameterInteraction(*Assert(m_context->args)); }
     bilingual_str getWarnings() override { return GetWarnings(true); }

src/pubkey.h

@@ -223,7 +223,7 @@ private:
 
 public:
     /** Construct an x-only pubkey from exactly 32 bytes. */
-    XOnlyPubKey(Span<const unsigned char> bytes);
+    explicit XOnlyPubKey(Span<const unsigned char> bytes);
 
     /** Verify a Schnorr signature against this public key.
      *

src/qt/test/addressbooktests.h

@@ -15,7 +15,7 @@ class Node;
 class AddressBookTests : public QObject
 {
 public:
-    AddressBookTests(interfaces::Node& node) : m_node(node) {}
+    explicit AddressBookTests(interfaces::Node& node) : m_node(node) {}
     interfaces::Node& m_node;
 
     Q_OBJECT

src/qt/test/rpcnestedtests.h

@@ -15,7 +15,7 @@ class Node;
 class RPCNestedTests : public QObject
 {
 public:
-    RPCNestedTests(interfaces::Node& node) : m_node(node) {}
+    explicit RPCNestedTests(interfaces::Node& node) : m_node(node) {}
     interfaces::Node& m_node;
 
     Q_OBJECT

src/qt/test/wallettests.h

@@ -15,7 +15,7 @@ class Node;
 class WalletTests : public QObject
 {
  public:
-    WalletTests(interfaces::Node& node) : m_node(node) {}
+    explicit WalletTests(interfaces::Node& node) : m_node(node) {}
     interfaces::Node& m_node;
 
     Q_OBJECT

src/rpc/request.h

@@ -40,7 +40,7 @@ public:
     std::string peerAddr;
     const util::Ref& context;
 
-    JSONRPCRequest(const util::Ref& context) : id(NullUniValue), params(NullUniValue), fHelp(false), context(context) {}
+    explicit JSONRPCRequest(const util::Ref& context) : id(NullUniValue), params(NullUniValue), fHelp(false), context(context) {}
 
     //! Initializes request information from another request object and the
     //! given context. The implementation should be updated if any members are

src/script/descriptor.cpp

@@ -156,7 +156,7 @@ protected:
     uint32_t m_expr_index;
 
 public:
-    PubkeyProvider(uint32_t exp_index) : m_expr_index(exp_index) {}
+    explicit PubkeyProvider(uint32_t exp_index) : m_expr_index(exp_index) {}
 
     virtual ~PubkeyProvider() = default;
 

src/script/standard.h

@@ -28,7 +28,7 @@ protected:
 
 public:
     BaseHash() : m_hash() {}
-    BaseHash(const HashType& in) : m_hash(in) {}
+    explicit BaseHash(const HashType& in) : m_hash(in) {}
 
     unsigned char* begin()
     {

src/test/fuzz/signature_checker.cpp

@@ -24,7 +24,7 @@ class FuzzedSignatureChecker : public BaseSignatureChecker
     FuzzedDataProvider& m_fuzzed_data_provider;
 
 public:
-    FuzzedSignatureChecker(FuzzedDataProvider& fuzzed_data_provider) : m_fuzzed_data_provider(fuzzed_data_provider)
+    explicit FuzzedSignatureChecker(FuzzedDataProvider& fuzzed_data_provider) : m_fuzzed_data_provider(fuzzed_data_provider)
     {
     }
 

src/test/util/logging.h

@@ -32,7 +32,7 @@ class DebugLogHelper
     void check_found();
 
 public:
-    DebugLogHelper(std::string message, MatchFn match = [](const std::string*){ return true; });
+    explicit DebugLogHelper(std::string message, MatchFn match = [](const std::string*){ return true; });
     ~DebugLogHelper() { check_found(); }
 };
 

src/test/util_tests.cpp

@@ -231,7 +231,7 @@ public:
         Optional<std::vector<std::string>> list_value;
         const char* error = nullptr;
 
-        Expect(util::SettingsValue s) : setting(std::move(s)) {}
+        explicit Expect(util::SettingsValue s) : setting(std::move(s)) {}
         Expect& DefaultString() { default_string = true; return *this; }
         Expect& DefaultInt() { default_int = true; return *this; }
         Expect& DefaultBool() { default_bool = true; return *this; }

src/tinyformat.h

@@ -514,7 +514,7 @@ class FormatArg
         { }
 
         template<typename T>
-        FormatArg(const T& value)
+        explicit FormatArg(const T& value)
             : m_value(static_cast<const void*>(&value)),
             m_formatImpl(&formatImpl<T>),
             m_toIntImpl(&toIntImpl<T>)
@@ -970,7 +970,7 @@ class FormatListN : public FormatList
     public:
 #ifdef TINYFORMAT_USE_VARIADIC_TEMPLATES
         template<typename... Args>
-        FormatListN(const Args&... args)
+        explicit FormatListN(const Args&... args)
             : FormatList(&m_formatterStore[0], N),
             m_formatterStore { FormatArg(args)... }
         { static_assert(sizeof...(args) == N, "Number of args must be N"); }

src/txmempool.h

@@ -855,7 +855,7 @@ public:
     class EpochGuard {
         const CTxMemPool& pool;
         public:
-        EpochGuard(const CTxMemPool& in);
+        explicit EpochGuard(const CTxMemPool& in);
         ~EpochGuard();
     };
     // N.B. GetFreshEpoch modifies mutable state via the EpochGuard construction

src/txrequest.cpp

@@ -170,7 +170,7 @@ using ByTxHashView = std::tuple<const uint256&, State, Priority>;
 class ByTxHashViewExtractor {
     const PriorityComputer& m_computer;
 public:
-    ByTxHashViewExtractor(const PriorityComputer& computer) : m_computer(computer) {}
+    explicit ByTxHashViewExtractor(const PriorityComputer& computer) : m_computer(computer) {}
     using result_type = ByTxHashView;
     result_type operator()(const Announcement& ann) const
     {
@@ -522,7 +522,7 @@ private:
     }
 
 public:
-    Impl(bool deterministic) :
+    explicit Impl(bool deterministic) :
         m_computer(deterministic),
         // Explicitly initialize m_index as we need to pass a reference to m_computer to ByTxHashViewExtractor.
         m_index(boost::make_tuple(

src/validation.cpp

@@ -449,7 +449,7 @@ namespace {
 class MemPoolAccept
 {
 public:
-    MemPoolAccept(CTxMemPool& mempool) : m_pool(mempool), m_view(&m_dummy), m_viewmempool(&::ChainstateActive().CoinsTip(), m_pool),
+    explicit MemPoolAccept(CTxMemPool& mempool) : m_pool(mempool), m_view(&m_dummy), m_viewmempool(&::ChainstateActive().CoinsTip(), m_pool),
         m_limit_ancestors(gArgs.GetArg("-limitancestorcount", DEFAULT_ANCESTOR_LIMIT)),
         m_limit_ancestor_size(gArgs.GetArg("-limitancestorsize", DEFAULT_ANCESTOR_SIZE_LIMIT)*1000),
         m_limit_descendants(gArgs.GetArg("-limitdescendantcount", DEFAULT_DESCENDANT_LIMIT)),
@@ -482,7 +482,7 @@ private:
     // All the intermediate state that gets passed between the various levels
     // of checking a given transaction.
     struct Workspace {
-        Workspace(const CTransactionRef& ptx) : m_ptx(ptx), m_hash(ptx->GetHash()) {}
+        explicit Workspace(const CTransactionRef& ptx) : m_ptx(ptx), m_hash(ptx->GetHash()) {}
         std::set<uint256> m_conflicts;
         CTxMemPool::setEntries m_all_conflicting;
         CTxMemPool::setEntries m_ancestors;

src/wallet/bdb.h

@@ -56,7 +56,7 @@ public:
     std::unordered_map<std::string, WalletDatabaseFileId> m_fileids;
     std::condition_variable_any m_db_in_use;
 
-    BerkeleyEnvironment(const fs::path& env_directory);
+    explicit BerkeleyEnvironment(const fs::path& env_directory);
     BerkeleyEnvironment();
     ~BerkeleyEnvironment();
     void Reset();

src/wallet/scriptpubkeyman.h

@@ -172,7 +172,7 @@ protected:
     WalletStorage& m_storage;
 
 public:
-    ScriptPubKeyMan(WalletStorage& storage) : m_storage(storage) {}
+    explicit ScriptPubKeyMan(WalletStorage& storage) : m_storage(storage) {}
     virtual ~ScriptPubKeyMan() {};
     virtual bool GetNewDestination(const OutputType type, CTxDestination& dest, std::string& error) { return false; }
     virtual isminetype IsMine(const CScript& script) const { return ISMINE_NO; }
@@ -504,7 +504,7 @@ class LegacySigningProvider : public SigningProvider
 private:
     const LegacyScriptPubKeyMan& m_spk_man;
 public:
-    LegacySigningProvider(const LegacyScriptPubKeyMan& spk_man) : m_spk_man(spk_man) {}
+    explicit LegacySigningProvider(const LegacyScriptPubKeyMan& spk_man) : m_spk_man(spk_man) {}
 
     bool GetCScript(const CScriptID &scriptid, CScript& script) const override { return m_spk_man.GetCScript(scriptid, script); }
     bool HaveCScript(const CScriptID &scriptid) const override { return m_spk_man.HaveCScript(scriptid); }

test/lint/extended-lint-cppcheck.sh

@@ -30,6 +30,7 @@ IGNORED_WARNINGS=(
     "src/protocol.h:.* Class 'CMessageHeader' has a constructor with 1 argument that is not explicit."
     "src/qt/guiutil.h:.* Class 'ItemDelegate' has a constructor with 1 argument that is not explicit."
     "src/rpc/util.h:.* Struct 'RPCResults' has a constructor with 1 argument that is not explicit."
+    "src/rpc/util.h:.* Struct 'UniValueType' has a constructor with 1 argument that is not explicit."
     "src/rpc/util.h:.* style: Struct 'UniValueType' has a constructor with 1 argument that is not explicit."
     "src/script/descriptor.cpp:.* Class 'AddressDescriptor' has a constructor with 1 argument that is not explicit."
     "src/script/descriptor.cpp:.* Class 'ComboDescriptor' has a constructor with 1 argument that is not explicit."
@@ -42,6 +43,11 @@ IGNORED_WARNINGS=(
     "src/script/descriptor.cpp:.* Class 'WSHDescriptor' has a constructor with 1 argument that is not explicit."
     "src/script/script.h:.* Class 'CScript' has a constructor with 1 argument that is not explicit."
     "src/script/standard.h:.* Class 'CScriptID' has a constructor with 1 argument that is not explicit."
+    "src/span.h:.* Class 'Span < const CRPCCommand >' has a constructor with 1 argument that is not explicit."
+    "src/span.h:.* Class 'Span < const char >' has a constructor with 1 argument that is not explicit."
+    "src/span.h:.* Class 'Span < const std :: vector <unsigned char > >' has a constructor with 1 argument that is not explicit."
+    "src/span.h:.* Class 'Span < const uint8_t >' has a constructor with 1 argument that is not explicit."
+    "src/span.h:.* Class 'Span' has a constructor with 1 argument that is not explicit."
     "src/support/allocators/secure.h:.* Struct 'secure_allocator < char >' has a constructor with 1 argument that is not explicit."
     "src/support/allocators/secure.h:.* Struct 'secure_allocator < RNGState >' has a constructor with 1 argument that is not explicit."
     "src/support/allocators/secure.h:.* Struct 'secure_allocator < unsigned char >' has a constructor with 1 argument that is not explicit."
@@ -49,6 +55,9 @@ IGNORED_WARNINGS=(
     "src/test/checkqueue_tests.cpp:.* Struct 'FailingCheck' has a constructor with 1 argument that is not explicit."
     "src/test/checkqueue_tests.cpp:.* Struct 'MemoryCheck' has a constructor with 1 argument that is not explicit."
     "src/test/checkqueue_tests.cpp:.* Struct 'UniqueCheck' has a constructor with 1 argument that is not explicit."
+    "src/test/fuzz/util.h:.* Class 'FuzzedFileProvider' has a constructor with 1 argument that is not explicit."
+    "src/test/fuzz/util.h:.* Class 'FuzzedAutoFileProvider' has a constructor with 1 argument that is not explicit."
+    "src/util/ref.h:.* Class 'Ref' has a constructor with 1 argument that is not explicit."
     "src/wallet/db.h:.* Class 'BerkeleyEnvironment' has a constructor with 1 argument that is not explicit."
 )
 
@@ -66,7 +75,7 @@ function join_array {
 ENABLED_CHECKS_REGEXP=$(join_array "|" "${ENABLED_CHECKS[@]}")
 IGNORED_WARNINGS_REGEXP=$(join_array "|" "${IGNORED_WARNINGS[@]}")
 WARNINGS=$(git ls-files -- "*.cpp" "*.h" ":(exclude)src/leveldb/" ":(exclude)src/crc32c/" ":(exclude)src/secp256k1/" ":(exclude)src/univalue/" | \
-    xargs cppcheck --enable=all -j "$(getconf _NPROCESSORS_ONLN)" --language=c++ --std=c++11 --template=gcc -D__cplusplus -DCLIENT_VERSION_BUILD -DCLIENT_VERSION_IS_RELEASE -DCLIENT_VERSION_MAJOR -DCLIENT_VERSION_MINOR -DCOPYRIGHT_YEAR -DDEBUG -I src/ -q 2>&1 | sort -u | \
+    xargs cppcheck --enable=all -j "$(getconf _NPROCESSORS_ONLN)" --language=c++ --std=c++17 --template=gcc -D__cplusplus -DCLIENT_VERSION_BUILD -DCLIENT_VERSION_IS_RELEASE -DCLIENT_VERSION_MAJOR -DCLIENT_VERSION_MINOR -DCOPYRIGHT_YEAR -DDEBUG -I src/ -q 2>&1 | sort -u | \
     grep -E "${ENABLED_CHECKS_REGEXP}" | \
     grep -vE "${IGNORED_WARNINGS_REGEXP}")
 if [[ ${WARNINGS} != "" ]]; then