impr: Better recovery from exceptions thrown in main thread (#1577)

This PR improves many things which can be seen by the commit name, but
the most important thing is the addition of a popup telling the user
when an exception is thrown


![image](https://github.com/WerWolv/ImHex/assets/42669835/db796416-9cce-4aa5-ad60-c22f05b5fc73)

lib/libimhex/include/hex/api/event_manager.hpp

@@ -23,7 +23,7 @@
         static void subscribe(void *token, Event::Callback function) { EventManager::subscribe<event_name>(token, function); }                  \
         static void unsubscribe(const EventManager::EventList::iterator &token) noexcept { EventManager::unsubscribe(token); }                  \
         static void unsubscribe(void *token) noexcept { EventManager::unsubscribe<event_name>(token); }                                         \
-        static void post(auto &&...args) noexcept { EventManager::post<event_name>(std::forward<decltype(args)>(args)...); }                    \
+        static void post(auto &&...args) { EventManager::post<event_name>(std::forward<decltype(args)>(args)...); }                    \
     };
 
 #define EVENT_DEF(event_name, ...)          EVENT_DEF_IMPL(event_name, #event_name, true, __VA_ARGS__)
@@ -72,11 +72,12 @@ namespace hex {
 
             explicit Event(Callback func) noexcept : m_func(std::move(func)) { }
 
-            void operator()(Params... params) const noexcept {
+            void operator()(std::string_view eventName, Params... params) const {
                 try {
                     m_func(params...);
                 } catch (const std::exception &e) {
-                    log::error("An exception occurred while handling event: {}", e.what());
+                    log::error("An exception occurred while handling event {}: {}", eventName, e.what());
+                    throw;
                 }
             }
 
@@ -173,12 +174,12 @@ namespace hex {
          * @param args Arguments to pass to the event
          */
         template<impl::EventType E>
-        static void post(auto &&...args) noexcept {
+        static void post(auto && ...args) {
             std::scoped_lock lock(getEventMutex());
 
             for (const auto &[id, event] : getEvents()) {
                 if (id == E::Id) {
-                    (*static_cast<E *const>(event.get()))(std::forward<decltype(args)>(args)...);
+                    (*static_cast<E *const>(event.get()))(wolv::type::getTypeName<E>(), std::forward<decltype(args)>(args)...);
                 }
             }
 
@@ -310,4 +311,8 @@ namespace hex {
     */
     EVENT_DEF(MovePerProviderData, prv::Provider *, prv::Provider *);
 
+    /**
+     * Called when ImHex managed to catch an error in a general try/catch to prevent/recover from a crash
+    */
+    EVENT_DEF(EventCrashRecovered, const std::exception &);
 }

main/gui/source/window/window.cpp

@@ -126,6 +126,7 @@ namespace hex {
             throw;
         } catch (const std::exception &e) {
             log::fatal("Unhandled exception: {}", e.what());
+            EventCrashRecovered::post(e);
         } catch (...) {
             log::fatal("Unhandled exception: Unknown exception");
         }
@@ -133,15 +134,19 @@ namespace hex {
 
     void errorRecoverLogCallback(void*, const char* fmt, ...) {
         va_list args;
-        va_start(args, fmt);
 
         std::string message;
-        message.resize(std::vsnprintf(nullptr, 0, fmt, args));
-        std::vsnprintf(message.data(), message.size(), fmt, args);
-        message.resize(message.size() - 1);
 
+        va_start(args, fmt);
+        message.resize(std::vsnprintf(nullptr, 0, fmt, args));
         va_end(args);
 
+        va_start(args, fmt);
+        std::vsnprintf(message.data(), message.size(), fmt, args);
+        va_end(args);
+
+        message.resize(message.size() - 1);
+
         log::error("{}", message);
     }
 

plugins/builtin/include/content/popups/popup_crash_recovered.hpp

@@ -0,0 +1,46 @@
+#pragma once
+
+#include <hex/ui/popup.hpp>
+
+#include <hex/api/localization_manager.hpp>
+
+#include <llvm/Demangle/Demangle.h>
+
+#include <string>
+
+namespace hex::plugin::builtin {
+
+    class PopupCrashRecovered : public Popup<PopupCrashRecovered> {
+    public:
+        PopupCrashRecovered(const std::exception &e)
+            : hex::Popup<PopupCrashRecovered>("hex.builtin.popup.crash_recover.title", false),
+              m_errorType(typeid(e).name()),
+              m_errorMessage(e.what) { }
+
+        void drawContent() override {
+            ImGuiExt::TextFormattedWrapped("hex.builtin.popup.crash_recover.message"_lang);
+
+            ImGuiExt::TextFormattedWrapped(hex::format("Error: {}: {}", llvm::itaniumDemangle(this->m_errorType), this->m_errorMessage));
+
+            if (ImGui::Button("hex.ui.common.okay"_lang)) {
+                this->close();
+            }
+        }
+
+        [[nodiscard]] ImGuiWindowFlags getFlags() const override {
+            return ImGuiWindowFlags_AlwaysAutoResize;
+        }
+
+        [[nodiscard]] ImVec2 getMinSize() const override {
+            return scaled({ 400, 100 });
+        }
+
+        [[nodiscard]] ImVec2 getMaxSize() const override {
+            return scaled({ 600, 300 });
+        }
+
+    private:
+        std::string m_errorType, m_errorMessage;
+    };
+
+}

plugins/builtin/romfs/lang/en_US.json

@@ -374,6 +374,8 @@
         "hex.builtin.popup.exit_application.desc": "You have unsaved changes made to your Project.\nAre you sure you want to exit?",
         "hex.builtin.popup.exit_application.title": "Exit Application?",
         "hex.builtin.popup.waiting_for_tasks.title": "Waiting for Tasks",
+        "hex.builtin.popup.crash_recover.title": "Crash recovery",
+        "hex.builtin.popup.crash_recover.message": "An exception was thrown, but ImHex was able to catch it and advert a crash",
         "hex.builtin.popup.blocking_task.title": "Running Task",
         "hex.builtin.popup.blocking_task.desc": "A task is currently executing.",
         "hex.builtin.popup.save_layout.title": "Save Layout",
@@ -498,7 +500,7 @@
         "hex.builtin.setting.toolbar.icons": "Toolbar Icons",
         "hex.builtin.shortcut.next_provider": "Select next provider",
         "hex.builtin.shortcut.prev_provider": "Select previous provider",
-        "hex.builtin.title_bar_button.debug_build": "Debug build",
+        "hex.builtin.title_bar_button.debug_build": "Debug build\nShift+Click to crash using exception\nCtrl+Click to crash using signal",
         "hex.builtin.title_bar_button.feedback": "Leave Feedback",
         "hex.builtin.tools.ascii_table": "ASCII table",
         "hex.builtin.tools.ascii_table.octal": "Show octal",

plugins/builtin/source/content/events.cpp

@@ -21,6 +21,7 @@
 #include <popups/popup_question.hpp>
 #include <content/popups/popup_tasks_waiting.hpp>
 #include <content/popups/popup_unsaved_changes.hpp>
+#include <content/popups/popup_crash_recovered.hpp>
 
 namespace hex::plugin::builtin {
 
@@ -48,6 +49,10 @@ namespace hex::plugin::builtin {
     void registerEventHandlers() {
 
         static bool imhexClosing = false;
+        EventCrashRecovered::subscribe([](const std::exception &e) {
+            PopupCrashRecovered::open(e);
+        });
+
         EventWindowClosing::subscribe([](GLFWwindow *window) {
             imhexClosing = false;
             if (ImHexApi::Provider::isDirty() && !imhexClosing) {