Crashes on release mode on Lazarus only

[YiannisKam]

The program below compiles and runs fine on debug mode on lazarus but fails to run properly on release mode particularly when trying to get ReadLn(PauseInput'); Why? Is it a bug?
And the weird thing is that when I compile and run from command line it works fine.
The crt unit is there because I'll need it later on for the GotoXY function..
Lazarus and compiler, both trunk.

Code: Pascal  [Select][+][-]

1. program project1;
2.  
3. {$mode objfpc}{$H+}
4.  
5. uses
6.   SysUtils, crt;
7.  
8. var
9.   TotalReps, BeepInterval, PauseDuration: Integer;
10.   PauseInput: String;
11.  
12.  
13. // Main program starts here
14. begin
15.   // Get the user input
16.   Write('Enter Total Reps: ');
17.   ReadLn(TotalReps);
18.  
19.   Write('Enter Pause Duration(or ENTER for default = 6): ');
20.   ReadLn(PauseInput);
21.  
22.   if not TryStrToInt(PauseInput, PauseDuration) then
23.     PauseDuration := 6;
24.  
25.   if PauseDuration < 6 then
26.     PauseDuration := 6;
27.  
28.   Write('Enter Interval: ');
29.   ReadLn(BeepInterval);
30.  
31.   ReadLn;
32. end.
33.  

[Martin_fr]

"Release mode" probably also means that "F9" in the IDE uses "run without debugger".  (not sure depends on exact Lazarus version).


I assume this might be Linux?

Then, when you run in the debugger or from a terminal (outside the IDE) there are StdIn/Out/Err set up (the debugger sets them to the IDE "debug > console output" which also acts as input).

But if you run without debugger, then there is no StdIn (nor StdOut/Err). And then you get an error.

[YiannisKam]

Sorry for forgetting to mention, I'm on Windows 10 64 bit. I set my project compiler options on release mode and I press (Run)F9, (not Run without debugging Shift-Ctrl-F9).

[af0815]

I think you start without a console. And on windows there is no aotomatic created console, so as Martin_fr say - it crash. You can remove the check from win32GUI app in the Project options (Compiler Options -> Config and Target) so a console will automatic created (on windows).

[YiannisKam]

No, it's not a gui app, it's command line program. Another weird thing that I've noticed is if I remove completely the crt unit and try the release mode on lazarus it works fine. That's really weird and doesn't make any sense.

[Martin_fr]

Sorry for forgetting to mention, I'm on Windows 10 64 bit. I set my project compiler options on release mode and I press (Run)F9, (not Run without debugging Shift-Ctrl-F9).

Well, if you are on windows, did you compile as console app? Does a console window opens when your app is run?

On Windows indeed StdIn/StdOut do not depend on the run with/without debugger. They only depend on the presence of such a console window, that should open up when your app is started.

That said, if you have Lazarus 3.n and the project (or the build modes) are new, then when you have "release mode" F9 is re-mapped to "run without debugger". (But it does not matter for your issue)


--- EDIT: just seen, partly answered in later posts...

[YiannisKam]

Project-New Project-Program and yes when I pressed run, the console window appeared. That's all. I experimented and removed the crt unit and it runs without any problem. But I want the crt unit for the GotoXY function.

[Thaddy]

remove crt. Period.

[YiannisKam]

Any alternative to GotoXY?

[korba812]

Do you get an error message, an exception, or does the console just disappear with the process of your application?
I have a similar problem with the fpc compiler - while compiling my project under Win 10, the console from time to time simply disappears along with the fpc process without any message.

remove crt. Period.

Why?

[YiannisKam]

I don't get any error. The console just disappears when trying to get input for the PauseInput variable. It disappears as soon as I press the enter key. What is weird is, if you remove the crt unit the program works fine. So I thought it would be nice to post the behavior here incase this is a bug. That all.

[Martin_fr]

I just found

Windows 10 - 64bit
Lazarus version: 3.99
FPC       version: 3.3.1

Unfortunately the forum hides your sig, when the "post reply form" is open, so I failed to see it before.


Have you tried with fpc 3.2.3 ?

I tested with (Win 10)
- Lazarus 3.4 fpc 3.2.2 => not reproduced
- Lazarus 3.99 Fpc 3.2.3 (and the IDE itself having a console win) => not reproduced.

I don't want to rebuild my tools now... So I wont test other combinations.

There could be (unknown) an issue if:
- The IDE is build with fpc 3.3.1
- your app is build with fpc 3.3.1

Further more, it could depend on the very exact compiler settings during compilation -o2 or -o3 -C...  and what not.... And it could also depend on the day on which you last upgraded your 3.3.1

[YiannisKam]

The forum is fine. I've set my signature after creating this topic and my apologies I haven't done that earlier.
I don't have any other compiler version installed. I used fpcupdeluxe if makes an important role to this 'issue' (Build Date: 2024-08-04 11:19)

[cdbc]

Hi
Hmmm... Have you tried {$APPTYPE CONSOLE} just below {$mode objfpc}{$H+}
IIRC this is needed on winders, for console apps
Regards Benny

[Martin_fr]

The forum is fine. I've set my signature after creating this topic and my apologies I haven't done that earlier.
I don't have any other compiler version installed. I used fpcupdeluxe if makes an important role to this 'issue' (Build Date: 2024-08-04 11:19)

Press reply, and while you type the reply scroll down and read your own post. Do you see the signature? I don't.

I usually (re-)read the details of the post while replying. So I usually miss any info from the signature. (Besides, when you change it in the future, the people will be confused because they will think this thread belongs to a newer version.