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

260f8da71a refactor: remove warnings globals (stickies-v)
9c4b0b7ce4 node: update uiInterface whenever warnings updated (stickies-v)
b071ad9770 introduce and use the generalized `node::Warnings` interface (stickies-v)
20e616f864 move-only: move warnings from common to node (stickies-v)
bed29c481a 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 https://github.com/bitcoin/bitcoin/pull/29845#discussion_r1570069541)
  - 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 260f8da71a
  ryanofsky:
    Code review ACK 260f8da71a. Only change since last review was rebasing
  TheCharlatan:
    Re-ACK 260f8da71a

Tree-SHA512: a3fcedaee0d3ad64e9c111aeb30665162f98e0e72acd6a70b76ff2ddf4f0a34da4f97ce353c322a1668ca6ee4d8a81cc6e6d170c5bbeb7a43cffdaf66646b588

src/node/kernel_notifications.cpp

@@ -10,15 +10,16 @@
 #include <common/args.h>
 #include <common/system.h>
 #include <kernel/context.h>
+#include <kernel/warning.h>
 #include <logging.h>
 #include <node/abort.h>
 #include <node/interface_ui.h>
+#include <node/warnings.h>
 #include <util/check.h>
 #include <util/signalinterrupt.h>
 #include <util/strencodings.h>
 #include <util/string.h>
 #include <util/translation.h>
-#include <warnings.h>
 
 #include <cstdint>
 #include <string>
@@ -28,7 +29,6 @@ using util::ReplaceAll;
 
 static void AlertNotify(const std::string& strMessage)
 {
-    uiInterface.NotifyAlertChanged();
 #if HAVE_SYSTEM
     std::string strCmd = gArgs.GetArg("-alertnotify", "");
     if (strCmd.empty()) return;
@@ -46,16 +46,6 @@ static void AlertNotify(const std::string& strMessage)
 #endif
 }
 
-static void DoWarning(const bilingual_str& warning)
-{
-    static bool fWarned = false;
-    SetMiscWarning(warning);
-    if (!fWarned) {
-        AlertNotify(warning.original);
-        fWarned = true;
-    }
-}
-
 namespace node {
 
 kernel::InterruptResult KernelNotifications::blockTip(SynchronizationState state, CBlockIndex& index)
@@ -80,20 +70,27 @@ void KernelNotifications::progress(const bilingual_str& title, int progress_perc
     uiInterface.ShowProgress(title.translated, progress_percent, resume_possible);
 }
 
-void KernelNotifications::warning(const bilingual_str& warning)
+void KernelNotifications::warningSet(kernel::Warning id, const bilingual_str& message)
 {
-    DoWarning(warning);
+    if (m_warnings.Set(id, message)) {
+        AlertNotify(message.original);
+    }
+}
+
+void KernelNotifications::warningUnset(kernel::Warning id)
+{
+    m_warnings.Unset(id);
 }
 
 void KernelNotifications::flushError(const bilingual_str& message)
 {
-    AbortNode(&m_shutdown, m_exit_status, message);
+    AbortNode(&m_shutdown, m_exit_status, message, &m_warnings);
 }
 
 void KernelNotifications::fatalError(const bilingual_str& message)
 {
     node::AbortNode(m_shutdown_on_fatal_error ? &m_shutdown : nullptr,
-                    m_exit_status, message);
+                    m_exit_status, message, &m_warnings);
 }
 
 void ReadNotificationArgs(const ArgsManager& args, KernelNotifications& notifications)