Hint: Parameter "Sender" not used ?

[majid.ebru]

Hi

in my program , i have many this hint (and an other hints) :

unit_Main.pas(1594,30) Hint: Parameter "Sender" not used

what do i do?

i should clear? or ....??

thankyou

[Eugene Loza]

You may just not pay attention to it.
If you want a cleaner messages box, you may right-click this message and Hide this message by inserting {$warn ... off} to unit "...".

[Zath]

If it's a hint about standard component etc. I'd ignore it but if its something you've declared then it might be worthwhile to take notice.

[JuhaManninen]

You may just not pay attention to it.
If you want a cleaner messages box, you may right-click this message and Hide this message by inserting {$warn ... off} to unit "...".

It is safer to use the
 "Hide message by inserting IDE directive {%H-}".
It only hides the one message you wanted to hide.

See also under project options: Compiler Options -> Verbosity -> 'Show hints for parameter "Sender" not used'.

[zeljko]

See also under project options: Compiler Options -> Verbosity -> 'Show hints for parameter "Sender" not used'.

Definitelly better than polluting source with {%H-}

[majid.ebru]

project options: Compiler Options -> Verbosity -> 'Show hints for parameter "Sender" not used'.

thankyou

i unchecked it.

but i have many hint:

Code: Pascal  [Select][+][-]

1. unit_Main.pas(1712,54) Hint: Parameter "Shift" not used
2. .
3. unit_Main.pas(1710,7) Hint: Parameter "MousePos" not used
4. .
5. unit_Main.pas(1715,29) Hint: Parameter "Handled" not used
6. .
7. unit_Main.pas(1757,30) Hint: Parameter "X" not used
8. unit_Main.pas(1757,30) Hint: Parameter "Y" not used
9. //    procedure P_P1_9_ACMouseDown(Sender: TObject; Button: TMouseButton;
10. //      Shift: TShiftState; X, Y: Integer);
11. .
12. unit_Main.pas(1699,51) Hint: Parameter "Button" not used
13. .
14. .
15. .
16. .
17. .
18. .
19.  

for these hints , what do i do?

[PatBayford]

Depends what they are - if they are unused variables/parameters, just remove them - search/replace is great for this.
The most common reason for this is when you use the code generator to start your event handlers, but you don't need all the standard passed parameters.

[JuhaManninen]

Depends what they are - if they are unused variables/parameters, just remove them - search/replace is great for this.
The most common reason for this is when you use the code generator to start your event handlers, but you don't need all the standard passed parameters.

You cannot remove parameters from event handlers because their signature must match the events.
The compiler shows an error if you try to assign such wrong handler in code.
Unfortunately the form streaming system does not check the signature. It means you can change it in code and no error is shown when loading an LFM file, but later unpredictable errors may occur.

[engkin]

You cannot remove parameters from event handlers because their signature must match the events.
The compiler shows an error if you try to assign such wrong handler in code.

Too bad we can not remove the identifier and leave the type:

Code: Pascal  [Select][+][-]

1.     procedure Button1Click(: TObject);

[wp]

Hints and warnings are not bad: they give you an indication that something MAY be wrong. After long debugging sessions I found many a bug immediately once I decided to look at the hints and warnings in the message window!

The problem is that there are so many of them. You can modifiy the source code to get rid of them (e.g., add that {%H-} directive mentioned above, or call dummy procedures "Unused(Sender, x, y)" like TAChart does). But the problem is that modifications in the source code are difficult to revert.

At the application level the best thing is to go to the project options, "Compiler options" > "Messages": type in the "Filter" line part of the massage phrase "not used" and you will see only the related messages. Uncheck them and rebuild the project --> the hints and warnings will be gone. The point is that this did not change the source code, just the project file - if you later need the hints and warnings back you just do the same and check them again.

This was already written above, but maybe you did not catch the point.

[dbannon]

Said WP

"Compiler options" > "Messages": type in the "Filter" line part of the massage phrase "not used" and you will see only the related messages. Uncheck them ....

Good tip WP. Is there an equivalent when we use Lazbuild ? Its so much wordier and I live in terror of missing something important .....

(I do use --quiet --quiet but it does not offer fine grain control.)

Davo

[Ñuño_Martínez]

That hint is just to warn you that may be you are not using the procedure/function properly.  On events I recommend you to use the Sender parameter.

Anyway, you can avoid that hint by code, like re-assigning it.  For example:

Code: Pascal  [Select][+][-]

1.   PROCEDURE TMyClass.AnEvent (Sender: TObject);
2.   BEGIN
3.     Sender := Sender;
4.     ... Do things here ...
5.   END;
6.  

The compiler will optimize it and do nothing.  If parameter is CONST you can do:

Code: Pascal  [Select][+][-]

1.   PROCEDURE MyProcedure (CONST aParam: INTEGER);
2.   BEGIN
3.     IF aParam <> aParam THEN EXIT;
4.     ... Do things here ...
5.   END;
6.  

Again, the compiler will optimize it in most cases.

I prefer the "code" way instead of the "directive" way because it is more visible.

[ASerge]

Code: Pascal  [Select][+][-]

1.   PROCEDURE TMyClass.AnEvent (Sender: TObject);
2.   BEGIN
3.     Sender := Sender;
4.     ... Do things here ...
5.   END;
6.  

Code: Pascal  [Select][+][-]

1.   PROCEDURE MyProcedure (CONST aParam: INTEGER);
2.   BEGIN
3.     IF aParam <> aParam THEN EXIT;
4.     ... Do things here ...
5.   END;
6.  

In both cases, an extra code is generated.
If you are ready to make changes to the source code, then as indicated by @wp, you can use the procedure.
I propose a procedure that, unlike TAChart, does not generate code at all.

Code: Pascal  [Select][+][-]

1. {$PUSH}
2. {$WARN 5024 OFF : Parameter "$1" not used}
3. procedure Unused(const P: Pointer); inline; overload;
4. begin
5. end;
6.  
7. procedure Unused(const I: Integer); inline; overload;
8. begin
9. end;
10.  
11. procedure Unused(const S: string); inline; overload;
12. begin
13. end;
14. {$POP}
15.  
16. procedure Test(Param1: Integer; const Param2: string);
17. begin
18.   Unused(Param1);
19.   Unused(Param2);
20. end;
21.  
22. procedure TForm1.FormCreate(Sender: TObject);
23. begin
24.   Unused(Sender);
25.   Test(1, '2');
26. end;

The generated code is the same as if there were no calls to Unused at all.

[Ñuño_Martínez]

@ASerge: That solution looks nicer and better than mine. I should remember it.

[marcov]

In a past job, we had a solution like {%h-} that filters compiler output integrated into the build automation tool.

It would save both the filtered and unfiltered log, and some filters were more permanent (like all Kylix related warnings in D7, to avoid having to flag them all).

There was a plan to further extend the principle with types of warnings (something like {%H- 5045,5046} to suppress only warning 5045 and 5046 on that line, but I changed jobs, so never saw that.