Merge bitcoin#29690: clang-tidy: Enable misc-no-recursion

78407b9 [clang-tidy] Enable the misc-no-recursion check (dergoegge)

Pull request description:

  Recursion is a frequent source of stack overflow bugs. Secondly, introduction of recursion can be non-obvious.

  This PR proposes to use the clang-tidy `misc-no-recursion` check to make introduction of new recursion obvious. We don't make use of recursion a lot in our code base but there are a few places that need suppressions anyway (mostly the descriptor and univalue/rpc code).

ACKs for top commit:
  stickies-v:
    ACK 78407b9
  TheCharlatan:
    Re-ACK 78407b9
  fanquake:
    ACK 78407b9

Tree-SHA512: 34126d704c46086fe7371906ca852c25ced1dbd5fcfd85bf623810cd171a797569a92a33c7e26b8dc01c30c7bbf81aa326718926e8354585091411989a4edb14

Author: fanquake

doc/developer-notes.md

@@ -115,6 +115,8 @@ code.
     Use `reinterpret_cast` and `const_cast` as appropriate.
   - Prefer [`list initialization ({})`](https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#Res-list) where possible.
     For example `int x{0};` instead of `int x = 0;` or `int x(0);`
+  - Recursion is checked by clang-tidy and thus must be made explicit. Use
+    `NOLINTNEXTLINE(misc-no-recursion)` to suppress the check.
 
 For function calls a namespace should be specified explicitly, unless such functions have been declared within it.
 Otherwise, [argument-dependent lookup](https://en.cppreference.com/w/cpp/language/adl), also known as ADL, could be

src/.clang-tidy

@@ -6,6 +6,7 @@ bugprone-string-constructor,
 bugprone-use-after-move,
 bugprone-lambda-function-name,
 misc-unused-using-decls,
+misc-no-recursion,
 modernize-use-default-member-init,
 modernize-use-emplace,
 modernize-use-noexcept,

src/merkleblock.cpp

@@ -54,6 +54,7 @@ CMerkleBlock::CMerkleBlock(const CBlock& block, CBloomFilter* filter, const std:
     txn = CPartialMerkleTree(vHashes, vMatch);
 }
 
+// NOLINTNEXTLINE(misc-no-recursion)
 uint256 CPartialMerkleTree::CalcHash(int height, unsigned int pos, const std::vector<uint256> &vTxid) {
     //we can never have zero txs in a merkle block, we always need the coinbase tx
     //if we do not have this assert, we can hit a memory access violation when indexing into vTxid
@@ -74,6 +75,7 @@ uint256 CPartialMerkleTree::CalcHash(int height, unsigned int pos, const std::ve
     }
 }
 
+// NOLINTNEXTLINE(misc-no-recursion)
 void CPartialMerkleTree::TraverseAndBuild(int height, unsigned int pos, const std::vector<uint256> &vTxid, const std::vector<bool> &vMatch) {
     // determine whether this node is the parent of at least one matched txid
     bool fParentOfMatch = false;
@@ -92,6 +94,7 @@ void CPartialMerkleTree::TraverseAndBuild(int height, unsigned int pos, const st
     }
 }
 
+// NOLINTNEXTLINE(misc-no-recursion)
 uint256 CPartialMerkleTree::TraverseAndExtract(int height, unsigned int pos, unsigned int &nBitsUsed, unsigned int &nHashUsed, std::vector<uint256> &vMatch, std::vector<unsigned int> &vnIndex) {
     if (nBitsUsed >= vBits.size()) {
         // overflowed the bits array - failure

src/node/interfaces.cpp

@@ -406,6 +406,7 @@ class NodeImpl : public Node
     NodeContext* m_context{nullptr};
 };
 
+// NOLINTNEXTLINE(misc-no-recursion)
 bool FillBlock(const CBlockIndex* index, const FoundBlock& block, UniqueLock<RecursiveMutex>& lock, const CChain& active, const BlockManager& blockman)
 {
     if (!index) return false;

src/qt/optionsmodel.cpp

@@ -396,6 +396,7 @@ bool OptionsModel::setData(const QModelIndex & index, const QVariant & value, in
     return successful;
 }
 
+// NOLINTNEXTLINE(misc-no-recursion)
 QVariant OptionsModel::getOption(OptionID option, const std::string& suffix) const
 {
     auto setting = [&]{ return node().getPersistentSetting(SettingName(option) + suffix); };
@@ -508,6 +509,7 @@ QFont OptionsModel::getFontForMoney() const
     return getFontForChoice(m_font_money);
 }
 
+// NOLINTNEXTLINE(misc-no-recursion)
 bool OptionsModel::setOption(OptionID option, const QVariant& value, const std::string& suffix)
 {
     auto changed = [&] { return value.isValid() && value != getOption(option, suffix); };

src/rpc/util.cpp

@@ -414,6 +414,7 @@ struct Sections {
     /**
      * Recursive helper to translate an RPCArg into sections
      */
+    // NOLINTNEXTLINE(misc-no-recursion)
     void Push(const RPCArg& arg, const size_t current_indent = 5, const OuterType outer_type = OuterType::NONE)
     {
         const auto indent = std::string(current_indent, ' ');
@@ -953,6 +954,7 @@ std::string RPCArg::ToDescriptionString(bool is_named_arg) const
     return ret;
 }
 
+// NOLINTNEXTLINE(misc-no-recursion)
 void RPCResult::ToSections(Sections& sections, const OuterType outer_type, const int current_indent) const
 {
     // Indentation
@@ -1086,6 +1088,7 @@ static std::optional<UniValue::VType> ExpectedType(RPCResult::Type type)
     NONFATAL_UNREACHABLE();
 }
 
+// NOLINTNEXTLINE(misc-no-recursion)
 UniValue RPCResult::MatchesType(const UniValue& result) const
 {
     if (m_skip_type_check) {
@@ -1164,6 +1167,7 @@ void RPCResult::CheckInnerDoc() const
     CHECK_NONFATAL(inner_needed != m_inner.empty());
 }
 
+// NOLINTNEXTLINE(misc-no-recursion)
 std::string RPCArg::ToStringObj(const bool oneline) const
 {
     std::string res;
@@ -1202,6 +1206,7 @@ std::string RPCArg::ToStringObj(const bool oneline) const
     NONFATAL_UNREACHABLE();
 }
 
+// NOLINTNEXTLINE(misc-no-recursion)
 std::string RPCArg::ToString(const bool oneline) const
 {
     if (oneline && !m_opts.oneline_description.empty()) {
@@ -1228,6 +1233,7 @@ std::string RPCArg::ToString(const bool oneline) const
     case Type::OBJ:
     case Type::OBJ_NAMED_PARAMS:
     case Type::OBJ_USER_KEYS: {
+        // NOLINTNEXTLINE(misc-no-recursion)
         const std::string res = Join(m_inner, ",", [&](const RPCArg& i) { return i.ToStringObj(oneline); });
         if (m_type == Type::OBJ) {
             return "{" + res + "}";

src/rpc/util.h

@@ -162,6 +162,7 @@ struct RPCArgOptions {
                                          //!< methods set the also_positional flag and read values from both positions.
 };
 
+// NOLINTNEXTLINE(misc-no-recursion)
 struct RPCArg {
     enum class Type {
         OBJ,
@@ -271,6 +272,7 @@ struct RPCArg {
     std::string ToDescriptionString(bool is_named_arg) const;
 };
 
+// NOLINTNEXTLINE(misc-no-recursion)
 struct RPCResult {
     enum class Type {
         OBJ,

src/script/descriptor.cpp

@@ -599,6 +599,7 @@ class DescriptorImpl : public Descriptor
         COMPAT, // string calculation that mustn't change over time to stay compatible with previous software versions
     };
 
+    // NOLINTNEXTLINE(misc-no-recursion)
     bool IsSolvable() const override
     {
         for (const auto& arg : m_subdescriptor_args) {
@@ -607,6 +608,7 @@ class DescriptorImpl : public Descriptor
         return true;
     }
 
+    // NOLINTNEXTLINE(misc-no-recursion)
     bool IsRange() const final
     {
         for (const auto& pubkey : m_pubkey_args) {
@@ -618,6 +620,7 @@ class DescriptorImpl : public Descriptor
         return false;
     }
 
+    // NOLINTNEXTLINE(misc-no-recursion)
     virtual bool ToStringSubScriptHelper(const SigningProvider* arg, std::string& ret, const StringType type, const DescriptorCache* cache = nullptr) const
     {
         size_t pos = 0;
@@ -630,6 +633,7 @@ class DescriptorImpl : public Descriptor
         return true;
     }
 
+    // NOLINTNEXTLINE(misc-no-recursion)
     virtual bool ToStringHelper(const SigningProvider* arg, std::string& out, const StringType type, const DescriptorCache* cache = nullptr) const
     {
         std::string extra = ToStringExtra();
@@ -682,6 +686,7 @@ class DescriptorImpl : public Descriptor
         return ret;
     }
 
+    // NOLINTNEXTLINE(misc-no-recursion)
     bool ExpandHelper(int pos, const SigningProvider& arg, const DescriptorCache* read_cache, std::vector<CScript>& output_scripts, FlatSigningProvider& out, DescriptorCache* write_cache) const
     {
         std::vector<std::pair<CPubKey, KeyOriginInfo>> entries;
@@ -723,6 +728,7 @@ class DescriptorImpl : public Descriptor
         return ExpandHelper(pos, DUMMY_SIGNING_PROVIDER, &read_cache, output_scripts, out, nullptr);
     }
 
+    // NOLINTNEXTLINE(misc-no-recursion)
     void ExpandPrivate(int pos, const SigningProvider& provider, FlatSigningProvider& out) const final
     {
         for (const auto& p : m_pubkey_args) {
@@ -750,6 +756,7 @@ class DescriptorImpl : public Descriptor
 
     std::optional<int64_t> MaxSatisfactionElems() const override { return {}; }
 
+    // NOLINTNEXTLINE(misc-no-recursion)
     void GetPubKeys(std::set<CPubKey>& pubkeys, std::set<CExtPubKey>& ext_pubs) const override
     {
         for (const auto& p : m_pubkey_args) {
@@ -1579,6 +1586,7 @@ struct KeyParser {
 };
 
 /** Parse a script in a particular context. */
+// NOLINTNEXTLINE(misc-no-recursion)
 std::unique_ptr<DescriptorImpl> ParseScript(uint32_t& key_exp_index, Span<const char>& sp, ParseScriptContext ctx, FlatSigningProvider& out, std::string& error)
 {
     using namespace spanparsing;
@@ -1886,6 +1894,7 @@ std::unique_ptr<DescriptorImpl> InferMultiA(const CScript& script, ParseScriptCo
     return std::make_unique<MultiADescriptor>(match->first, std::move(keys));
 }
 
+// NOLINTNEXTLINE(misc-no-recursion)
 std::unique_ptr<DescriptorImpl> InferScript(const CScript& script, ParseScriptContext ctx, const SigningProvider& provider)
 {
     if (ctx == ParseScriptContext::P2TR && script.size() == 34 && script[0] == 32 && script[33] == OP_CHECKSIG) {

src/test/miniscript_tests.cpp

@@ -297,6 +297,7 @@ using miniscript::operator"" _mst;
 using Node = miniscript::Node<CPubKey>;
 
 /** Compute all challenges (pubkeys, hashes, timelocks) that occur in a given Miniscript. */
+// NOLINTNEXTLINE(misc-no-recursion)
 std::set<Challenge> FindChallenges(const NodeRef& ref) {
     std::set<Challenge> chal;
     for (const auto& key : ref->keys) {

src/test/validation_block_tests.cpp

@@ -127,6 +127,7 @@ std::shared_ptr<const CBlock> MinerTestingSetup::BadBlock(const uint256& prev_ha
     return ret;
 }
 
+// NOLINTNEXTLINE(misc-no-recursion)
 void MinerTestingSetup::BuildChain(const uint256& root, int height, const unsigned int invalid_rate, const unsigned int branch_rate, const unsigned int max_size, std::vector<std::shared_ptr<const CBlock>>& blocks)
 {
     if (height <= 0 || blocks.size() >= max_size) return;