Merge bitcoin/bitcoin#30058: Encapsulate warnings in generalized node::Warnings and remove globals

260f8da refactor: remove warnings globals (stickies-v)
9c4b0b7 node: update uiInterface whenever warnings updated (stickies-v)
b071ad9 introduce and use the generalized `node::Warnings` interface (stickies-v)
20e616f move-only: move warnings from common to node (stickies-v)
bed29c4 refactor: remove unnecessary AppendWarning helper function (stickies-v)

Pull request description:

  This PR:
  - moves warnings from common to the node library and into the node namespace (as suggested in bitcoin/bitcoin#29845 (comment))
  - generalizes the warnings interface to `Warnings::Set()` and `Warnings::Unset()` methods, instead of having a separate function and globals for each warning. As a result, this simplifies the `kernel::Notifications` interface.
  - removes warnings.cpp from the kernel library
  - removes warning globals
  - adds testing for the warning logic

  Behaviour change introduced:
  - the `-alertnotify` command is executed for all `KernelNotifications::warningSet` calls, which now also covers the `LARGE_WORK_INVALID_CHAIN` warning
  - the GUI is updated automatically whenever a warning is (un)set, covering some code paths where it previously wouldn't be, e.g. when `node::AbortNode()` is called, or for the `LARGE_WORK_INVALID_CHAIN` warning

  Some discussion points:
  - ~is `const std::string& id` the best way to refer to warnings? Enums are an obvious alternative, but since we need to define warnings across libraries, strings seem like a straightforward solution.~ _edit: updated approach to use `node::Warning` and `kernel::Warning` enums._

ACKs for top commit:
  achow101:
    ACK 260f8da
  ryanofsky:
    Code review ACK 260f8da. Only change since last review was rebasing
  TheCharlatan:
    Re-ACK 260f8da

Tree-SHA512: a3fcedaee0d3ad64e9c111aeb30665162f98e0e72acd6a70b76ff2ddf4f0a34da4f97ce353c322a1668ca6ee4d8a81cc6e6d170c5bbeb7a43cffdaf66646b588

Author: achow101

doc/release-notes-30058.md

@@ -0,0 +1,7 @@
+- When running with -alertnotify, an alert can now be raised multiple
+times instead of just once. Previously, it was only raised when unknown
+new consensus rules were activated, whereas the scope has now been
+increased to include all kernel warnings. Specifically, alerts will now
+also be raised when an invalid chain with a large amount of work has
+been detected. Additional warnings may be added in the future.
+(#30058)

src/Makefile.am

@@ -196,6 +196,7 @@ BITCOIN_CORE_H = \
   kernel/messagestartchars.h \
   kernel/notifications_interface.h \
   kernel/validation_cache_sizes.h \
+  kernel/warning.h \
   key.h \
   key_io.h \
   logging.h \
@@ -239,6 +240,7 @@ BITCOIN_CORE_H = \
   node/types.h \
   node/utxo_snapshot.h \
   node/validation_cache_args.h \
+  node/warnings.h \
   noui.h \
   outputtype.h \
   policy/v3_policy.h \
@@ -367,7 +369,6 @@ BITCOIN_CORE_H = \
   wallet/wallettool.h \
   wallet/walletutil.h \
   walletinitinterface.h \
-  warnings.h \
   zmq/zmqabstractnotifier.h \
   zmq/zmqnotificationinterface.h \
   zmq/zmqpublishnotifier.h \
@@ -444,6 +445,7 @@ libbitcoin_node_a_SOURCES = \
   node/txreconciliation.cpp \
   node/utxo_snapshot.cpp \
   node/validation_cache_args.cpp \
+  node/warnings.cpp \
   noui.cpp \
   policy/v3_policy.cpp \
   policy/fees.cpp \
@@ -721,7 +723,6 @@ libbitcoin_common_a_SOURCES = \
   script/sign.cpp \
   script/signingprovider.cpp \
   script/solver.cpp \
-  warnings.cpp \
   $(BITCOIN_CORE_H)
 #
 
@@ -996,8 +997,7 @@ libbitcoinkernel_la_SOURCES = \
   util/tokenpipe.cpp \
   validation.cpp \
   validationinterface.cpp \
-  versionbits.cpp \
-  warnings.cpp
+  versionbits.cpp
 
 # Required for obj/build.h to be generated first.
 # More details: https://www.gnu.org/software/automake/manual/html_node/Built-Sources-Example.html

src/Makefile.test.include

@@ -118,6 +118,7 @@ BITCOIN_TESTS =\
   test/net_peer_eviction_tests.cpp \
   test/net_tests.cpp \
   test/netbase_tests.cpp \
+  test/node_warnings_tests.cpp \
   test/orphanage_tests.cpp \
   test/peerman_tests.cpp \
   test/pmt_tests.cpp \

src/bitcoin-chainstate.cpp

@@ -16,6 +16,7 @@
 #include <kernel/checks.h>
 #include <kernel/context.h>
 #include <kernel/validation_cache_sizes.h>
+#include <kernel/warning.h>
 
 #include <consensus/validation.h>
 #include <core_io.h>
@@ -28,6 +29,7 @@
 #include <util/fs.h>
 #include <util/signalinterrupt.h>
 #include <util/task_runner.h>
+#include <util/translation.h>
 #include <validation.h>
 #include <validationinterface.h>
 
@@ -86,9 +88,13 @@ int main(int argc, char* argv[])
         {
             std::cout << "Progress: " << title.original << ", " << progress_percent << ", " << resume_possible << std::endl;
         }
-        void warning(const bilingual_str& warning) override
+        void warningSet(kernel::Warning id, const bilingual_str& message) override
         {
-            std::cout << "Warning: " << warning.original << std::endl;
+            std::cout << "Warning " << static_cast<int>(id) << " set: " << message.original << std::endl;
+        }
+        void warningUnset(kernel::Warning id) override
+        {
+            std::cout << "Warning " << static_cast<int>(id) << " unset" << std::endl;
         }
         void flushError(const bilingual_str& message) override
         {

src/bitcoind.cpp

@@ -17,6 +17,7 @@
 #include <kernel/context.h>
 #include <node/context.h>
 #include <node/interface_ui.h>
+#include <node/warnings.h>
 #include <noui.h>
 #include <util/check.h>
 #include <util/exception.h>
@@ -181,6 +182,8 @@ static bool AppInit(NodeContext& node)
             return false;
         }
 
+        node.warnings = std::make_unique<node::Warnings>();
+
         node.kernel = std::make_unique<kernel::Context>();
         node.ecc_context = std::make_unique<ECC_Context>();
         if (!AppInitSanityChecks(*node.kernel))

src/index/base.cpp

@@ -17,7 +17,6 @@
 #include <util/thread.h>
 #include <util/translation.h>
 #include <validation.h> // For g_chainman
-#include <warnings.h>
 
 #include <string>
 #include <utility>
@@ -31,7 +30,7 @@ template <typename... Args>
 void BaseIndex::FatalErrorf(const char* fmt, const Args&... args)
 {
     auto message = tfm::format(fmt, args...);
-    node::AbortNode(m_chain->context()->shutdown, m_chain->context()->exit_status, Untranslated(message));
+    node::AbortNode(m_chain->context()->shutdown, m_chain->context()->exit_status, Untranslated(message), m_chain->context()->warnings.get());
 }
 
 CBlockLocator GetLocator(interfaces::Chain& chain, const uint256& block_hash)

src/init.cpp

@@ -1486,7 +1486,7 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
 
     // ********************************************************* Step 7: load block chain
 
-    node.notifications = std::make_unique<KernelNotifications>(*Assert(node.shutdown), node.exit_status);
+    node.notifications = std::make_unique<KernelNotifications>(*Assert(node.shutdown), node.exit_status, *Assert(node.warnings));
     ReadNotificationArgs(args, *node.notifications);
     ChainstateManager::Options chainman_opts{
         .chainparams = chainparams,
@@ -1639,7 +1639,8 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
     assert(!node.peerman);
     node.peerman = PeerManager::make(*node.connman, *node.addrman,
                                      node.banman.get(), chainman,
-                                     *node.mempool, peerman_opts);
+                                     *node.mempool, *node.warnings,
+                                     peerman_opts);
     validation_signals.RegisterValidationInterface(node.peerman.get());
 
     // ********************************************************* Step 8: start indexers

src/kernel/notifications_interface.h

@@ -16,6 +16,8 @@ namespace kernel {
 
 //! Result type for use with std::variant to indicate that an operation should be interrupted.
 struct Interrupted{};
+enum class Warning;
+
 
 //! Simple result type for functions that need to propagate an interrupt status and don't have other return values.
 using InterruptResult = std::variant<std::monostate, Interrupted>;
@@ -38,7 +40,8 @@ class Notifications
     [[nodiscard]] virtual InterruptResult blockTip(SynchronizationState state, CBlockIndex& index) { return {}; }
     virtual void headerTip(SynchronizationState state, int64_t height, int64_t timestamp, bool presync) {}
     virtual void progress(const bilingual_str& title, int progress_percent, bool resume_possible) {}
-    virtual void warning(const bilingual_str& warning) {}
+    virtual void warningSet(Warning id, const bilingual_str& message) {}
+    virtual void warningUnset(Warning id) {}
 
     //! The flush error notification is sent to notify the user that an error
     //! occurred while flushing block data to disk. Kernel code may ignore flush

src/kernel/warning.h

@@ -0,0 +1,14 @@
+// Copyright (c) 2024-present 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_KERNEL_WARNING_H
+#define BITCOIN_KERNEL_WARNING_H
+
+namespace kernel {
+enum class Warning {
+    UNKNOWN_NEW_RULES_ACTIVATED,
+    LARGE_WORK_INVALID_CHAIN,
+};
+} // namespace kernel
+#endif // BITCOIN_KERNEL_WARNING_H

src/net_processing.cpp

@@ -25,6 +25,7 @@
 #include <node/blockstorage.h>
 #include <node/timeoffsets.h>
 #include <node/txreconciliation.h>
+#include <node/warnings.h>
 #include <policy/fees.h>
 #include <policy/policy.h>
 #include <policy/settings.h>
@@ -489,7 +490,7 @@ class PeerManagerImpl final : public PeerManager
 public:
     PeerManagerImpl(CConnman& connman, AddrMan& addrman,
                     BanMan* banman, ChainstateManager& chainman,
-                    CTxMemPool& pool, Options opts);
+                    CTxMemPool& pool, node::Warnings& warnings, Options opts);
 
     /** Overridden from CValidationInterface. */
     void BlockConnected(ChainstateRole role, const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindexConnected) override
@@ -790,7 +791,8 @@ class PeerManagerImpl final : public PeerManager
     /** Next time to check for stale tip */
     std::chrono::seconds m_stale_tip_check_time GUARDED_BY(cs_main){0s};
 
-    TimeOffsets m_outbound_time_offsets;
+    node::Warnings& m_warnings;
+    TimeOffsets m_outbound_time_offsets{m_warnings};
 
     const Options m_opts;
 
@@ -2042,14 +2044,14 @@ std::optional<std::string> PeerManagerImpl::FetchBlock(NodeId peer_id, const CBl
 
 std::unique_ptr<PeerManager> PeerManager::make(CConnman& connman, AddrMan& addrman,
                                                BanMan* banman, ChainstateManager& chainman,
-                                               CTxMemPool& pool, Options opts)
+                                               CTxMemPool& pool, node::Warnings& warnings, Options opts)
 {
-    return std::make_unique<PeerManagerImpl>(connman, addrman, banman, chainman, pool, opts);
+    return std::make_unique<PeerManagerImpl>(connman, addrman, banman, chainman, pool, warnings, opts);
 }
 
 PeerManagerImpl::PeerManagerImpl(CConnman& connman, AddrMan& addrman,
                                  BanMan* banman, ChainstateManager& chainman,
-                                 CTxMemPool& pool, Options opts)
+                                 CTxMemPool& pool, node::Warnings& warnings, Options opts)
     : m_rng{opts.deterministic_rng},
       m_fee_filter_rounder{CFeeRate{DEFAULT_MIN_RELAY_TX_FEE}, m_rng},
       m_chainparams(chainman.GetParams()),
@@ -2058,6 +2060,7 @@ PeerManagerImpl::PeerManagerImpl(CConnman& connman, AddrMan& addrman,
       m_banman(banman),
       m_chainman(chainman),
       m_mempool(pool),
+      m_warnings{warnings},
       m_opts{opts}
 {
     // While Erlay support is incomplete, it must be enabled explicitly via -txreconciliation.