desktop: show startup errors in a copyable window instead of bare "Failed to launch JVM" (#7261)

* desktop: show startup errors in a copyable window instead of bare "Failed to launch JVM" When any exception escapes main() before the app window appears - a missing DLL, a failed migration, broken AWT init - the jpackage launcher shows only "Failed to launch JVM" and the cause is recorded nowhere: the launcher runs without a console, so stderr is lost. Every report in #4146 stalled on this. Catch the error and show it in a native Win32 window laid out like a message box: an error icon and message, two clickable report links (the GitHub issue tracker and the support email) above a read-only selectable box with the stack trace, and an OK button. The links are SS_NOTIFY statics opened with ShellExecute (browser for the URL, mail client for the email). Native, not Swing, because broken AWT initialization is one of the failure causes. On Windows the process then exits cleanly so the launcher does not also show its own box; on other systems the error is rethrown to stderr. * docs: plan justifying desktop startup error window (#4146)
2026-09-01 22:18:43 +00:00 · 2026-07-17 15:41:54 +01:00
parent d60da754dc
commit 11f0b6bd51
3 changed files with 284 additions and 10 deletions
@@ -0,0 +1,164 @@
+package chat.simplex.common.platform
+
+import com.sun.jna.*
+import com.sun.jna.platform.win32.*
+import com.sun.jna.platform.win32.WinDef.*
+import com.sun.jna.platform.win32.WinUser.*
+import kotlin.system.exitProcess
+
+// Windows-only: shows a startup error the jpackage launcher otherwise hides behind "Failed to launch
+// JVM" (#4146); on Linux/Mac the error rethrown by the caller reaches stderr. Uses a native window,
+// not Swing, because broken AWT initialization can be the cause. Laid out like a message box: an error
+// icon and a message at the top, two clickable report links (the GitHub issue tracker and the support
+// email) above a read-only, selectable, scrolling box with the stack trace, and an OK button.
+fun showStartupError(e: Throwable) {
+  if (!desktopPlatform.isWindows()) return
+  try {
+    // Win32 edit controls only break lines on CRLF; normalize every line ending to one CRLF so the
+    // trace does not render as merged lines (the JVM's own separator is CRLF on Windows, LF elsewhere)
+    showWindowsErrorWindow("SimpleX failed to start", e.stackTraceToString().lines().joinToString("\r\n"))
+  } catch (_: Throwable) {
+    return // dialog failed to show; let the caller rethrow so the launcher's own box is the fallback
+  }
+  // The dialog was shown and dismissed. Exit cleanly so the jpackage launcher does not also show its
+  // own generic "Failed to launch JVM" box on top of ours (it shows that box on any nonzero exit).
+  exitProcess(0)
+}
+
+private const val ISSUES_URL = "https://github.com/simplex-chat/simplex-chat/issues"
+private const val SUPPORT_EMAIL = "chat@simplex.chat"
+
+// Win32 constants not defined in jna-platform
+private const val ES_MULTILINE = 0x0004
+private const val ES_READONLY = 0x0800
+private const val ES_AUTOVSCROLL = 0x0040
+private const val WS_EX_CLIENTEDGE = 0x0200
+private const val CW_USEDEFAULT = 0x80000000.toInt()
+private const val WM_SETTEXT = 0x000C
+private const val WM_SETFONT = 0x0030
+private const val WM_COMMAND = 0x0111
+private const val WM_CTLCOLORSTATIC = 0x0138
+private const val EM_SETLIMITTEXT = 0x00C5
+private const val SS_ICON = 0x0003
+private const val SS_NOTIFY = 0x0100
+private const val STM_SETICON = 0x0170
+private const val COLOR_WINDOW = 5
+private const val WHITE_BRUSH = 0
+private const val LINK_COLOR = 0x00EE0000 // COLORREF 0x00BBGGRR = link blue RGB(0,0,238)
+private const val IDI_ERROR = 32513
+private const val APP_ICON_ID = 1 // the app icon jpackage embeds in the launcher exe
+private const val DEFAULT_GUI_FONT = 17
+private const val OK_BUTTON_ID = 1
+private const val URL_LINK_ID = 2
+private const val EMAIL_LINK_ID = 3
+
+// Shows a modal-style native error dialog: error icon and message, two clickable report-link statics,
+// a read-only selectable edit control with the stack trace, and an OK button. Blocks on its own
+// message loop until the window is closed.
+private fun showWindowsErrorWindow(title: String, trace: String) {
+  val user32 = User32.INSTANCE
+  val user32native = NativeLibrary.getInstance("user32")
+  val gdi32 = NativeLibrary.getInstance("gdi32")
+  val shellExecute = NativeLibrary.getInstance("shell32").getFunction("ShellExecuteW")
+  val sendMessageW = user32native.getFunction("SendMessageW")
+  val hInstance = Kernel32.INSTANCE.GetModuleHandle(null)
+  val className = "SimpleXStartupError"
+
+  // Paint static backgrounds white to match the window, and draw the two link statics in blue
+  val whiteBrush = gdi32.getFunction("GetStockObject").invokePointer(arrayOf<Any?>(Integer.valueOf(WHITE_BRUSH)))
+  val setTextColor = gdi32.getFunction("SetTextColor")
+  // The link statics' HWNDs, set once created and read back in the paint callback
+  var urlLinkHwnd = 0L
+  var emailLinkHwnd = 0L
+
+  fun open(target: String) = shellExecute.invokePointer(arrayOf<Any?>(
+    Pointer.NULL, WString("open"), WString(target), Pointer.NULL, Pointer.NULL, Integer.valueOf(SW_SHOWNORMAL)))
+
+  val wndProc = WindowProc { hwnd, uMsg, wParam, lParam ->
+    when {
+      // A click on the OK button or a link static arrives as WM_COMMAND with the control id in LOWORD
+      uMsg == WM_COMMAND -> {
+        when (wParam.toInt() and 0xFFFF) {
+          OK_BUTTON_ID -> user32.DestroyWindow(hwnd)
+          URL_LINK_ID -> open(ISSUES_URL)                 // open the issue tracker in a browser
+          EMAIL_LINK_ID -> open("mailto:$SUPPORT_EMAIL")  // open the mail client
+        }
+        LRESULT(0)
+      }
+      uMsg == WM_CTLCOLORSTATIC -> {
+        if (lParam.toLong() == urlLinkHwnd || lParam.toLong() == emailLinkHwnd) {
+          setTextColor.invokeInt(arrayOf<Any?>(Pointer.createConstant(wParam.toLong()), Integer.valueOf(LINK_COLOR)))
+        }
+        LRESULT(Pointer.nativeValue(whiteBrush))
+      }
+      uMsg == WM_DESTROY -> { user32.PostQuitMessage(0); LRESULT(0) }
+      else -> user32.DefWindowProc(hwnd, uMsg, wParam, lParam)
+    }
+  }
+
+  // Prefer the app's own icon so the title bar/taskbar is not the default "unknown" icon; fall back
+  // to the system error icon (also shown in the window below).
+  val hErrorIcon = user32native.getFunction("LoadIconW").invokePointer(arrayOf<Any?>(Pointer.NULL, Pointer.createConstant(IDI_ERROR)))
+  val hAppIcon = user32native.getFunction("LoadIconW").invokePointer(arrayOf<Any?>(hInstance, Pointer.createConstant(APP_ICON_ID)))
+  val windowIcon = hAppIcon ?: hErrorIcon // invokePointer returns null when the exe has no such icon
+
+  val windowClass = WNDCLASSEX()
+  windowClass.cbSize = windowClass.size()
+  windowClass.lpfnWndProc = wndProc
+  windowClass.hInstance = hInstance
+  windowClass.lpszClassName = className
+  windowClass.hbrBackground = HBRUSH(Pointer.createConstant(COLOR_WINDOW + 1)) // system window (light) color
+  windowClass.hIcon = HICON(windowIcon)
+  windowClass.hIconSm = HICON(windowIcon)
+  user32.RegisterClassEx(windowClass)
+
+  // If the window cannot be created, throw rather than enter the message loop: with no window,
+  // GetMessage would block forever. The caller's catch then rethrows and the launcher box is shown.
+  val window = user32.CreateWindowEx(
+    0, className, title, WS_CAPTION or WS_SYSMENU or WS_VISIBLE,
+    CW_USEDEFAULT, CW_USEDEFAULT, 760, 520,
+    null, null, hInstance, null
+  ) ?: throw IllegalStateException("failed to create startup error window")
+  val client = RECT()
+  user32.GetClientRect(window, client)
+  val cw = client.right
+  val ch = client.bottom
+
+  val iconView = user32.CreateWindowEx(0, "STATIC", null, WS_CHILD or WS_VISIBLE or SS_ICON,
+    18, 18, 32, 32, window, null, hInstance, null)
+  user32.SendMessage(iconView, STM_SETICON, WPARAM(Pointer.nativeValue(hErrorIcon)), LPARAM(0))
+
+  user32.CreateWindowEx(0, "STATIC", "SimpleX could not start. Copy the error below and report it via:",
+    WS_CHILD or WS_VISIBLE, 60, 20, cw - 80, 20, window, null, hInstance, null)
+  val urlLink = user32.CreateWindowEx(0, "STATIC", ISSUES_URL, WS_CHILD or WS_VISIBLE or SS_NOTIFY,
+    60, 46, cw - 80, 18, window, HMENU(Pointer.createConstant(URL_LINK_ID)), hInstance, null)
+  urlLinkHwnd = Pointer.nativeValue(urlLink.pointer)
+  val emailLink = user32.CreateWindowEx(0, "STATIC", SUPPORT_EMAIL, WS_CHILD or WS_VISIBLE or SS_NOTIFY,
+    60, 68, cw - 80, 18, window, HMENU(Pointer.createConstant(EMAIL_LINK_ID)), hInstance, null)
+  emailLinkHwnd = Pointer.nativeValue(emailLink.pointer)
+
+  val traceView = user32.CreateWindowEx(WS_EX_CLIENTEDGE, "EDIT", null,
+    WS_CHILD or WS_VISIBLE or WS_VSCROLL or ES_MULTILINE or ES_READONLY or ES_AUTOVSCROLL,
+    18, 96, cw - 36, ch - 96 - 54, window, null, hInstance, null)
+  user32.SendMessage(traceView, EM_SETLIMITTEXT, WPARAM(0), LPARAM(0)) // do not truncate long traces
+  sendMessageW.invokePointer(arrayOf<Any?>(traceView, Integer.valueOf(WM_SETTEXT), Pointer.NULL, WString(trace)))
+
+  val okButton = user32.CreateWindowEx(0, "BUTTON", "OK", WS_CHILD or WS_VISIBLE or BS_DEFPUSHBUTTON,
+    cw - 98, ch - 42, 80, 30, window, HMENU(Pointer.createConstant(OK_BUTTON_ID)), hInstance, null)
+
+  // The default control font is the dated bitmap "System" font; use the standard dialog font
+  val hFont = gdi32.getFunction("GetStockObject").invokePointer(arrayOf<Any?>(Integer.valueOf(DEFAULT_GUI_FONT)))
+  for (view in listOf(urlLink, emailLink, traceView, okButton)) {
+    user32.SendMessage(view, WM_SETFONT, WPARAM(Pointer.nativeValue(hFont)), LPARAM(1))
+  }
+
+  user32.ShowWindow(window, SW_SHOWNORMAL)
+  user32.SetForegroundWindow(window)
+  user32.SetFocus(traceView) // so Ctrl+A / Ctrl+C act on the trace immediately
+
+  val msg = MSG()
+  while (user32.GetMessage(msg, null, 0, 0) > 0) {
+    user32.TranslateMessage(msg)
+    user32.DispatchMessage(msg)
+  }
+}