Paper/patches/api/0021-Add-exception-reporting-event.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Zach Brown <zach.brown@destroystokyo.com>
Date: Mon, 29 Feb 2016 20:24:35 -0600
Subject: [PATCH] Add exception reporting event


diff --git a/src/main/java/com/destroystokyo/paper/event/server/ServerExceptionEvent.java b/src/main/java/com/destroystokyo/paper/event/server/ServerExceptionEvent.java
new file mode 100644
index 0000000000000000000000000000000000000000..9377ee1c2368ce058397037952d17bc010f66957
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/event/server/ServerExceptionEvent.java
@@ -0,0 +1,45 @@
+package com.destroystokyo.paper.event.server;
+
+import org.bukkit.Bukkit;
+import org.bukkit.event.Event;
+import org.bukkit.event.HandlerList;
+import com.destroystokyo.paper.exception.ServerException;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Called whenever an exception is thrown in a recoverable section of the server.
+ */
+public class ServerExceptionEvent extends Event {
+
+    private static final HandlerList HANDLER_LIST = new HandlerList();
+
+    @NotNull private final ServerException exception;
+
+    @ApiStatus.Internal
+    public ServerExceptionEvent(@NotNull ServerException exception) {
+        super(!Bukkit.isPrimaryThread());
+        this.exception = exception;
+    }
+
+    /**
+     * Gets the wrapped exception that was thrown.
+     *
+     * @return Exception thrown
+     */
+    @NotNull
+    public ServerException getException() {
+        return this.exception;
+    }
+
+    @NotNull
+    @Override
+    public HandlerList getHandlers() {
+        return HANDLER_LIST;
+    }
+
+    @NotNull
+    public static HandlerList getHandlerList() {
+        return HANDLER_LIST;
+    }
+}
diff --git a/src/main/java/com/destroystokyo/paper/exception/ServerCommandException.java b/src/main/java/com/destroystokyo/paper/exception/ServerCommandException.java
new file mode 100644
index 0000000000000000000000000000000000000000..6fb39af0479a818f7f1465bcdfe505ab4ff7da1a
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/exception/ServerCommandException.java
@@ -0,0 +1,64 @@
+package com.destroystokyo.paper.exception;
+
+import org.bukkit.command.Command;
+import org.bukkit.command.CommandSender;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Thrown when a command throws an exception
+ */
+public class ServerCommandException extends ServerException {
+
+    private final Command command;
+    private final CommandSender commandSender;
+    private final String[] arguments;
+
+    public ServerCommandException(String message, Throwable cause, Command command, CommandSender commandSender, String[] arguments) {
+        super(message, cause);
+        this.commandSender = checkNotNull(commandSender, "commandSender");
+        this.arguments = checkNotNull(arguments, "arguments");
+        this.command = checkNotNull(command, "command");
+    }
+
+    public ServerCommandException(Throwable cause, Command command, CommandSender commandSender, String[] arguments) {
+        super(cause);
+        this.commandSender = checkNotNull(commandSender, "commandSender");
+        this.arguments = checkNotNull(arguments, "arguments");
+        this.command = checkNotNull(command, "command");
+    }
+
+    protected ServerCommandException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace, Command command, CommandSender commandSender, String[] arguments) {
+        super(message, cause, enableSuppression, writableStackTrace);
+        this.commandSender = checkNotNull(commandSender, "commandSender");
+        this.arguments = checkNotNull(arguments, "arguments");
+        this.command = checkNotNull(command, "command");
+    }
+
+    /**
+     * Gets the command which threw the exception
+     *
+     * @return exception throwing command
+     */
+    public Command getCommand() {
+        return command;
+    }
+
+    /**
+     * Gets the command sender which executed the command request
+     *
+     * @return command sender of exception thrown command request
+     */
+    public CommandSender getCommandSender() {
+        return commandSender;
+    }
+
+    /**
+     * Gets the arguments which threw the exception for the command
+     *
+     * @return arguments of exception thrown command request
+     */
+    public String[] getArguments() {
+        return arguments;
+    }
+}
diff --git a/src/main/java/com/destroystokyo/paper/exception/ServerEventException.java b/src/main/java/com/destroystokyo/paper/exception/ServerEventException.java
new file mode 100644
index 0000000000000000000000000000000000000000..410b24139535cd5d8439ad581c43c61b5757fbf6
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/exception/ServerEventException.java
@@ -0,0 +1,52 @@
+package com.destroystokyo.paper.exception;
+
+import org.bukkit.event.Event;
+import org.bukkit.event.Listener;
+import org.bukkit.plugin.Plugin;
+
+import static com.google.common.base.Preconditions.*;
+
+/**
+ * Exception thrown when a server event listener throws an exception
+ */
+public class ServerEventException extends ServerPluginException {
+
+    private final Listener listener;
+    private final Event event;
+
+    public ServerEventException(String message, Throwable cause, Plugin responsiblePlugin, Listener listener, Event event) {
+        super(message, cause, responsiblePlugin);
+        this.listener = checkNotNull(listener, "listener");
+        this.event = checkNotNull(event, "event");
+    }
+
+    public ServerEventException(Throwable cause, Plugin responsiblePlugin, Listener listener, Event event) {
+        super(cause, responsiblePlugin);
+        this.listener = checkNotNull(listener, "listener");
+        this.event = checkNotNull(event, "event");
+    }
+
+    protected ServerEventException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace, Plugin responsiblePlugin, Listener listener, Event event) {
+        super(message, cause, enableSuppression, writableStackTrace, responsiblePlugin);
+        this.listener = checkNotNull(listener, "listener");
+        this.event = checkNotNull(event, "event");
+    }
+
+    /**
+     * Gets the listener which threw the exception
+     *
+     * @return event listener
+     */
+    public Listener getListener() {
+        return listener;
+    }
+
+    /**
+     * Gets the event which caused the exception
+     *
+     * @return event
+     */
+    public Event getEvent() {
+        return event;
+    }
+}
diff --git a/src/main/java/com/destroystokyo/paper/exception/ServerException.java b/src/main/java/com/destroystokyo/paper/exception/ServerException.java
new file mode 100644
index 0000000000000000000000000000000000000000..c06ea3942447d4824b83ff839cb449fb818dede1
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/exception/ServerException.java
@@ -0,0 +1,23 @@
+package com.destroystokyo.paper.exception;
+
+/**
+ * Wrapper exception for all exceptions that are thrown by the server.
+ */
+public class ServerException extends Exception {
+
+    public ServerException(String message) {
+        super(message);
+    }
+
+    public ServerException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public ServerException(Throwable cause) {
+        super(cause);
+    }
+
+    protected ServerException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
+        super(message, cause, enableSuppression, writableStackTrace);
+    }
+}
diff --git a/src/main/java/com/destroystokyo/paper/exception/ServerInternalException.java b/src/main/java/com/destroystokyo/paper/exception/ServerInternalException.java
new file mode 100644
index 0000000000000000000000000000000000000000..2c3effca7c9d6c904cbe248d312b74e2cd360acf
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/exception/ServerInternalException.java
@@ -0,0 +1,36 @@
+package com.destroystokyo.paper.exception;
+
+import java.util.logging.Level;
+import org.bukkit.Bukkit;
+import com.destroystokyo.paper.event.server.ServerExceptionEvent;
+
+/**
+ * Thrown when the internal server throws a recoverable exception.
+ */
+public class ServerInternalException extends ServerException {
+
+    public ServerInternalException(String message) {
+        super(message);
+    }
+
+    public ServerInternalException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public ServerInternalException(Throwable cause) {
+        super(cause);
+    }
+
+    protected ServerInternalException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
+        super(message, cause, enableSuppression, writableStackTrace);
+    }
+
+    public static void reportInternalException(Throwable cause) {
+        try {
+            Bukkit.getPluginManager().callEvent(new ServerExceptionEvent(new ServerInternalException(cause)));
+            ;
+        } catch (Throwable t) {
+            Bukkit.getLogger().log(Level.WARNING, "Exception posting ServerExceptionEvent", t); // Don't want to rethrow!
+        }
+    }
+}
diff --git a/src/main/java/com/destroystokyo/paper/exception/ServerPluginEnableDisableException.java b/src/main/java/com/destroystokyo/paper/exception/ServerPluginEnableDisableException.java
new file mode 100644
index 0000000000000000000000000000000000000000..f016ba3b1b62e554a9bacbb9635f2dbe441b3c4e
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/exception/ServerPluginEnableDisableException.java
@@ -0,0 +1,20 @@
+package com.destroystokyo.paper.exception;
+
+import org.bukkit.plugin.Plugin;
+
+/**
+ * Thrown whenever there is an exception with any enabling or disabling of plugins.
+ */
+public class ServerPluginEnableDisableException extends ServerPluginException {
+    public ServerPluginEnableDisableException(String message, Throwable cause, Plugin responsiblePlugin) {
+        super(message, cause, responsiblePlugin);
+    }
+
+    public ServerPluginEnableDisableException(Throwable cause, Plugin responsiblePlugin) {
+        super(cause, responsiblePlugin);
+    }
+
+    protected ServerPluginEnableDisableException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace, Plugin responsiblePlugin) {
+        super(message, cause, enableSuppression, writableStackTrace, responsiblePlugin);
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/com/destroystokyo/paper/exception/ServerPluginException.java b/src/main/java/com/destroystokyo/paper/exception/ServerPluginException.java
new file mode 100644
index 0000000000000000000000000000000000000000..be3f92e3c6bcefe8b78da701b75121275001882e
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/exception/ServerPluginException.java
@@ -0,0 +1,36 @@
+package com.destroystokyo.paper.exception;
+
+import org.bukkit.plugin.Plugin;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Wrapper exception for all cases to which a plugin can be immediately blamed for
+ */
+public class ServerPluginException extends ServerException {
+    public ServerPluginException(String message, Throwable cause, Plugin responsiblePlugin) {
+        super(message, cause);
+        this.responsiblePlugin = checkNotNull(responsiblePlugin, "responsiblePlugin");
+    }
+
+    public ServerPluginException(Throwable cause, Plugin responsiblePlugin) {
+        super(cause);
+        this.responsiblePlugin = checkNotNull(responsiblePlugin, "responsiblePlugin");
+    }
+
+    protected ServerPluginException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace, Plugin responsiblePlugin) {
+        super(message, cause, enableSuppression, writableStackTrace);
+        this.responsiblePlugin = checkNotNull(responsiblePlugin, "responsiblePlugin");
+    }
+
+    private final Plugin responsiblePlugin;
+
+    /**
+     * Gets the plugin which is directly responsible for the exception being thrown
+     *
+     * @return plugin which is responsible for the exception throw
+     */
+    public Plugin getResponsiblePlugin() {
+        return responsiblePlugin;
+    }
+}
diff --git a/src/main/java/com/destroystokyo/paper/exception/ServerPluginMessageException.java b/src/main/java/com/destroystokyo/paper/exception/ServerPluginMessageException.java
new file mode 100644
index 0000000000000000000000000000000000000000..2faef4cb358ec65e32a6aba6426f0dd7ddf90d2a
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/exception/ServerPluginMessageException.java
@@ -0,0 +1,64 @@
+package com.destroystokyo.paper.exception;
+
+import org.bukkit.entity.Player;
+import org.bukkit.plugin.Plugin;
+
+import static com.google.common.base.Preconditions.*;
+
+/**
+ * Thrown when an incoming plugin message channel throws an exception
+ */
+public class ServerPluginMessageException extends ServerPluginException {
+
+    private final Player player;
+    private final String channel;
+    private final byte[] data;
+
+    public ServerPluginMessageException(String message, Throwable cause, Plugin responsiblePlugin, Player player, String channel, byte[] data) {
+        super(message, cause, responsiblePlugin);
+        this.player = checkNotNull(player, "player");
+        this.channel = checkNotNull(channel, "channel");
+        this.data = checkNotNull(data, "data");
+    }
+
+    public ServerPluginMessageException(Throwable cause, Plugin responsiblePlugin, Player player, String channel, byte[] data) {
+        super(cause, responsiblePlugin);
+        this.player = checkNotNull(player, "player");
+        this.channel = checkNotNull(channel, "channel");
+        this.data = checkNotNull(data, "data");
+    }
+
+    protected ServerPluginMessageException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace, Plugin responsiblePlugin, Player player, String channel, byte[] data) {
+        super(message, cause, enableSuppression, writableStackTrace, responsiblePlugin);
+        this.player = checkNotNull(player, "player");
+        this.channel = checkNotNull(channel, "channel");
+        this.data = checkNotNull(data, "data");
+    }
+
+    /**
+     * Gets the channel to which the error occurred from receiving data from
+     *
+     * @return exception channel
+     */
+    public String getChannel() {
+        return channel;
+    }
+
+    /**
+     * Gets the data to which the error occurred from
+     *
+     * @return exception data
+     */
+    public byte[] getData() {
+        return data;
+    }
+
+    /**
+     * Gets the player which the plugin message causing the exception originated from
+     *
+     * @return exception player
+     */
+    public Player getPlayer() {
+        return player;
+    }
+}
diff --git a/src/main/java/com/destroystokyo/paper/exception/ServerSchedulerException.java b/src/main/java/com/destroystokyo/paper/exception/ServerSchedulerException.java
new file mode 100644
index 0000000000000000000000000000000000000000..2d0b2d4a9b3e5bdeec0e4ea7ab69858d86aa3715
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/exception/ServerSchedulerException.java
@@ -0,0 +1,37 @@
+package com.destroystokyo.paper.exception;
+
+import org.bukkit.scheduler.BukkitTask;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Thrown when a plugin's scheduler fails with an exception
+ */
+public class ServerSchedulerException extends ServerPluginException {
+
+    private final BukkitTask task;
+
+    public ServerSchedulerException(String message, Throwable cause, BukkitTask task) {
+        super(message, cause, task.getOwner());
+        this.task = checkNotNull(task, "task");
+    }
+
+    public ServerSchedulerException(Throwable cause, BukkitTask task) {
+        super(cause, task.getOwner());
+        this.task = checkNotNull(task, "task");
+    }
+
+    protected ServerSchedulerException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace, BukkitTask task) {
+        super(message, cause, enableSuppression, writableStackTrace, task.getOwner());
+        this.task = checkNotNull(task, "task");
+    }
+
+    /**
+     * Gets the task which threw the exception
+     *
+     * @return exception throwing task
+     */
+    public BukkitTask getTask() {
+        return task;
+    }
+}
diff --git a/src/main/java/com/destroystokyo/paper/exception/ServerTabCompleteException.java b/src/main/java/com/destroystokyo/paper/exception/ServerTabCompleteException.java
new file mode 100644
index 0000000000000000000000000000000000000000..5582999fe94c7a3dac655044ccc6d078cd9521a1
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/exception/ServerTabCompleteException.java
@@ -0,0 +1,22 @@
+package com.destroystokyo.paper.exception;
+
+import org.bukkit.command.Command;
+import org.bukkit.command.CommandSender;
+
+/**
+ * Called when a tab-complete request throws an exception
+ */
+public class ServerTabCompleteException extends ServerCommandException {
+
+    public ServerTabCompleteException(String message, Throwable cause, Command command, CommandSender commandSender, String[] arguments) {
+        super(message, cause, command, commandSender, arguments);
+    }
+
+    public ServerTabCompleteException(Throwable cause, Command command, CommandSender commandSender, String[] arguments) {
+        super(cause, command, commandSender, arguments);
+    }
+
+    protected ServerTabCompleteException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace, Command command, CommandSender commandSender, String[] arguments) {
+        super(message, cause, enableSuppression, writableStackTrace, command, commandSender, arguments);
+    }
+}
diff --git a/src/main/java/org/bukkit/command/SimpleCommandMap.java b/src/main/java/org/bukkit/command/SimpleCommandMap.java
index 36fc2c35395c72f8b81a2a2f3265fd205384ce26..c7fa1d235cea78bda4656ed66b8d42b119cc50fb 100644
--- a/src/main/java/org/bukkit/command/SimpleCommandMap.java
+++ b/src/main/java/org/bukkit/command/SimpleCommandMap.java
@@ -156,11 +156,14 @@ public class SimpleCommandMap implements CommandMap {
             target.execute(sender, sentCommandLabel, Arrays.copyOfRange(args, 1, args.length));
             } // target.timings.stopTiming(); // Spigot // Paper
         } catch (CommandException ex) {
+            server.getPluginManager().callEvent(new com.destroystokyo.paper.event.server.ServerExceptionEvent(new com.destroystokyo.paper.exception.ServerCommandException(ex, target, sender, args))); // Paper
             //target.timings.stopTiming(); // Spigot // Paper
             throw ex;
         } catch (Throwable ex) {
             //target.timings.stopTiming(); // Spigot // Paper
-            throw new CommandException("Unhandled exception executing '" + commandLine + "' in " + target, ex);
+            String msg = "Unhandled exception executing '" + commandLine + "' in " + target;
+            server.getPluginManager().callEvent(new com.destroystokyo.paper.event.server.ServerExceptionEvent(new com.destroystokyo.paper.exception.ServerCommandException(ex, target, sender, args))); // Paper
+            throw new CommandException(msg, ex);
         }
 
         // return true as command was handled
@@ -239,7 +242,9 @@ public class SimpleCommandMap implements CommandMap {
         } catch (CommandException ex) {
             throw ex;
         } catch (Throwable ex) {
-            throw new CommandException("Unhandled exception executing tab-completer for '" + cmdLine + "' in " + target, ex);
+            String msg = "Unhandled exception executing tab-completer for '" + cmdLine + "' in " + target;
+            server.getPluginManager().callEvent(new com.destroystokyo.paper.event.server.ServerExceptionEvent(new com.destroystokyo.paper.exception.ServerTabCompleteException(msg, ex, target, sender, args))); // Paper
+            throw new CommandException(msg, ex);
         }
     }
 
diff --git a/src/main/java/org/bukkit/plugin/SimplePluginManager.java b/src/main/java/org/bukkit/plugin/SimplePluginManager.java
index e7b1895d3918487d711afcbe41d76863d85c0a62..003bece642b682985625db93cad93026352bfc66 100644
--- a/src/main/java/org/bukkit/plugin/SimplePluginManager.java
+++ b/src/main/java/org/bukkit/plugin/SimplePluginManager.java
@@ -528,7 +528,8 @@ public final class SimplePluginManager implements PluginManager {
             try {
                 plugin.getPluginLoader().enablePlugin(plugin);
             } catch (Throwable ex) {
-                server.getLogger().log(Level.SEVERE, "Error occurred (in the plugin loader) while enabling " + plugin.getDescription().getFullName() + " (Is it up to date?)", ex);
+                handlePluginException("Error occurred (in the plugin loader) while enabling "
+                        + plugin.getDescription().getFullName() + " (Is it up to date?)", ex, plugin);
             }
 
             HandlerList.bakeAll();
@@ -551,32 +552,37 @@ public final class SimplePluginManager implements PluginManager {
             try {
                 plugin.getPluginLoader().disablePlugin(plugin);
             } catch (Throwable ex) {
-                server.getLogger().log(Level.SEVERE, "Error occurred (in the plugin loader) while disabling " + plugin.getDescription().getFullName() + " (Is it up to date?)", ex);
+                handlePluginException("Error occurred (in the plugin loader) while disabling "
+                        + plugin.getDescription().getFullName() + " (Is it up to date?)", ex, plugin); // Paper
             }
 
             try {
                 server.getScheduler().cancelTasks(plugin);
             } catch (Throwable ex) {
-                server.getLogger().log(Level.SEVERE, "Error occurred (in the plugin loader) while cancelling tasks for " + plugin.getDescription().getFullName() + " (Is it up to date?)", ex);
+                handlePluginException("Error occurred (in the plugin loader) while cancelling tasks for "
+                        + plugin.getDescription().getFullName() + " (Is it up to date?)", ex, plugin); // Paper
             }
 
             try {
                 server.getServicesManager().unregisterAll(plugin);
             } catch (Throwable ex) {
-                server.getLogger().log(Level.SEVERE, "Error occurred (in the plugin loader) while unregistering services for " + plugin.getDescription().getFullName() + " (Is it up to date?)", ex);
+                handlePluginException("Error occurred (in the plugin loader) while unregistering services for "
+                        + plugin.getDescription().getFullName() + " (Is it up to date?)", ex, plugin); // Paper
             }
 
             try {
                 HandlerList.unregisterAll(plugin);
             } catch (Throwable ex) {
-                server.getLogger().log(Level.SEVERE, "Error occurred (in the plugin loader) while unregistering events for " + plugin.getDescription().getFullName() + " (Is it up to date?)", ex);
+                handlePluginException("Error occurred (in the plugin loader) while unregistering events for "
+                        + plugin.getDescription().getFullName() + " (Is it up to date?)", ex, plugin); // Paper
             }
 
             try {
                 server.getMessenger().unregisterIncomingPluginChannel(plugin);
                 server.getMessenger().unregisterOutgoingPluginChannel(plugin);
             } catch (Throwable ex) {
-                server.getLogger().log(Level.SEVERE, "Error occurred (in the plugin loader) while unregistering plugin channels for " + plugin.getDescription().getFullName() + " (Is it up to date?)", ex);
+                handlePluginException("Error occurred (in the plugin loader) while unregistering plugin channels for "
+                        + plugin.getDescription().getFullName() + " (Is it up to date?)", ex, plugin); // Paper
             }
 
             try {
@@ -589,6 +595,13 @@ public final class SimplePluginManager implements PluginManager {
         }
     }
 
+    // Paper start
+    private void handlePluginException(String msg, Throwable ex, Plugin plugin) {
+        server.getLogger().log(Level.SEVERE, msg, ex);
+        callEvent(new com.destroystokyo.paper.event.server.ServerExceptionEvent(new com.destroystokyo.paper.exception.ServerPluginEnableDisableException(msg, ex, plugin)));
+    }
+    // Paper end
+
     @Override
     public void clearPlugins() {
         if (true) {this.paperPluginManager.clearPlugins(); return;} // Paper
@@ -654,7 +667,13 @@ public final class SimplePluginManager implements PluginManager {
                             ));
                 }
             } catch (Throwable ex) {
-                server.getLogger().log(Level.SEVERE, "Could not pass event " + event.getEventName() + " to " + registration.getPlugin().getDescription().getFullName(), ex);
+                // Paper start - error reporting
+                String msg = "Could not pass event " + event.getEventName() + " to " + registration.getPlugin().getDescription().getFullName();
+                server.getLogger().log(Level.SEVERE, msg, ex);
+                if (!(event instanceof com.destroystokyo.paper.event.server.ServerExceptionEvent)) { // We don't want to cause an endless event loop
+                    callEvent(new com.destroystokyo.paper.event.server.ServerExceptionEvent(new com.destroystokyo.paper.exception.ServerEventException(msg, ex, registration.getPlugin(), registration.getListener(), event)));
+                }
+                // Paper end
             }
         }
     }