Re: Show dialog box for uncaught exception (Windows, lld-link)
On Sunday, 5 May 2024 at 18:28:29 UTC, SimonN wrote:
My implementation for the message box is now:
According to [UTF-8
Everywhere](https://utf8everywhere.org/#windows), I shouldn't use
`MessageBoxA` at all. The `A` means ANSI codepages, _not_ UTF-8.
My above code _will_ show garbage output when there is some
non-ASCII in the exception message.
Better: Convert to UTF-16 yourself and call `MessageBoxW`:
version (Windows) {
import core.sys.windows.windows;
import std.conv;
const wstring messageBody = wtext(/* ... */, "\0");
MessageBoxW(null, messageBody.ptr, null, MB_ICONERROR);
throw /* ... */;
}
-- Simon
Re: Show dialog box for uncaught exception (Windows, lld-link)
On Sunday, 5 May 2024 at 17:15:10 UTC, Steven Schveighoffer wrote:
} catch(Exception e) {
visualDisplayOfException(e);
throw e;
}
Thanks! That's practically the same pattern that I already use
for logging: Try-catch near the entry point, show the message,
re-throw. My implementation for the message box is now:
catch (Throwable t) {
import core.sys.windows.windows;
const string errText = /* ... parse t ... */
MessageBoxA(null, errText.ptr, null, MB_ICONERROR);
}
That solves my problem. Even though I don't pass my game's window
as the parent of the message box (first argument, where I pass
`null`), the graphical game halts before exiting, shows the
error, and users can screenshot both together. That's good.
From your answer, I'll assume: There is no standardized way in
the D ecosystem (e.g., by calling a DRuntime function from my
usercode) to opt into displaying such a message box for uncaught
exceptions. I have to call third-party APIs myself.
Or is there something after all? From reading the 2019 thread
[Deactivate windows MessageBox dialog on
exception](https://forum.dlang.org/post/tlhjypvsaxzymccfc...@forum.dlang.org), it sounds like we should get an error box when we link with `-subsystem:windows`, and no box otherwise.
-- Simon
Re: Show dialog box for uncaught exception (Windows, lld-link)
On Sunday, 5 May 2024 at 14:55:20 UTC, SimonN wrote:
My application is a graphical game. I close stdout and stderr
by passing `-subsystem:windows` to `lld-link` to suppress the
extra console window. For a few fatal errors (missing required
resources, can't open display, ...), I throw exceptions, log
them to logfile, then re-throw them to crash. I can tell
Windows users to look in the logfile, but it would be more
fitting on Windows to show an error dialog box in addition to
the logging.
```d
int realMain(string[] args)
{
// all your normal code goes here
}
int main(string[] args)
{
version(Windows) {
try {
realMain(args);
} catch(Exception e) {
visualDisplayOfException(e);
throw e;
}
} else {
// presumably, non-windows systems shouldn't show a
graphical Exception
// trace?
realMain(args);
}
}
```
-Steve
Show dialog box for uncaught exception (Windows, lld-link)
Hi, for Windows, I link my executables with `lld-link`, whether for 32-bit and 64-bit and whether I've built with LDC or DMD. How can I generate a dialog box for uncaught exceptions that fly out of my executable's `main()`? When I linked with Optlink years ago for Windows 32-bit, it generated an error dialog box for an uncaught exception. But with `lld-link`, the exception's message lands only on stderr. I didn't see anything related in `lld-link -help`. Can I configure DRuntime in a special way at runtime? My application is a graphical game. I close stdout and stderr by passing `-subsystem:windows` to `lld-link` to suppress the extra console window. For a few fatal errors (missing required resources, can't open display, ...), I throw exceptions, log them to logfile, then re-throw them to crash. I can tell Windows users to look in the logfile, but it would be more fitting on Windows to show an error dialog box in addition to the logging. -- Simon
