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Kryvich

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Posts posted by Kryvich

  1. Posted

    There are several free and opensource REST libraries available so you don't have to start from scratch. I would recommend

    • DMVCFramework --  a popular and powerful framework for web solution in Delphi. Supports RESTful and JSON-RPC APIs development.
    • WiRL -- RESTful Library for Delphi.
    • mORMot -- Synopse mORMot ORM/SOA/MVC framework

    See example applications to a specific framework.

  3. Posted

    6 minutes ago, Fr0sT.Brutal said:

    Bad practice that Delphi RTL started itself. If usual clause is not applicable for some reason, why not write "raise CreateInternalError(...)"? Mystery for me

    Definitely it would look better and not generate tons of compiler warnings in Delphi. They grab this practice from FPC. See pasresolver.pp, there are procedures like RaiseMsg, RaiseNotYetImplemented, RaiseInternalError, RaiseInvalidScopeForElement. All of them can be replaced with custom exceptions.

  4. Posted · Edited by Kryvich

    44 minutes ago, Uwe Raabe said:

    Agree. I prefer Pascal Analyzer to get notified about problems like the one this thread is all about. In contrast to the compiler, eliminating all warnings from Pascal Analyzer is not the goal. If I don't want to get notified the next time I can suppress it with a simple comment.

    I tried the TestInitialization project with Pascal Analyzer Lite, but it doesn't see a problem with using an uninitialized var parameter either. Perhaps the full paid version will determine this issue.

     

    pal-for-testinitialization.jpg

  5. Posted

    2 minutes ago, Attila Kovacs said:

    as I mentioned before, to avoid the hints you have to act so you could make it an error instead of a hint

    or are you the guy who having 2 kilometer of hints after a build?

    I try to never allow hints or warnings in the release code.

     

    Right now I am adapting the latest version of the PAS2JS transpiler for Delphi. I see dozens of warnings that Delphi shows. Most of them are false positive, such as an undefined function return value (W1035) after an exception is generated (RaiseInternalError(...);). But some potentially problematic places went unnoticed by the PAS2JS developers. Also, a lot of warnings are generated due to the different internal representation of strings in Free Pascal (UTF8) and Delphi (Unicodestring). I carefully study all warnings and correct the code.

  6. Posted · Edited by Kryvich

    26 minutes ago, Attila Kovacs said:

    that won't help much as out parameter also taking inputs without any warnings, which is more screwed as the original problem

    The compiler should generate absolutely the same code for var and out parameters, both for the calling and for the called subroutines. The only difference will be in the warnings it issues: 

    Warning                                            var parameter    out parameter   Where to show
1. W1036 Variable might not have been initialized  yes              no              Calling routine
2. The parameter must be initialized before use    no               yes             Called routine
3. Return value of parameter might be undefined    no               yes             Called routine

    Warnings 2. and 3. should work in the same way as for the Return value of a function (W1035 Return value of function might be undefined). That is, all the necessary checks (W1035, W1036) are already in the compiler, Embarcadero only has to apply them to the parameters where necessary.

  7. Posted · Edited by Kryvich

    18 hours ago, Attila Kovacs said:

    It's not the compilers job to do code analysis for you?

    Checking the initialization of var parameters before use is a basic thing that does not require deep analysis. In fact, it has already implemented for parameters passed by value. 

    procedure Test;

 procedure DoStuff({var} a: Integer);
 begin
  if a = 0 then
    a := 1;
 end;

var
 a: Integer;
begin
  DoStuff(a); // W1036 Variable 'a' might not have been initialized
  Writeln(a);
end;

     

  8. Posted · Edited by Kryvich

    13 hours ago, Dalija Prasnikar said:

    But, Delphi out parameters have some unpleasantries and many developers choose to use var instead. 

     

    https://delphisorcery.blogspot.com/2021/04/out-parameters-are-just-bad-var.html

    Good article. The main point against using the out parameter in Delphi is sub-optimal generated code, due to the need to maintain compatibility with C++ Builder.

     

    But how often is Delphi code used in C++? Maybe a better solution would be to add additional checks and parameter initializations to the calling C++ code?

  10. Posted

    I created a minimal reproducible example for this case. 

    program TestInitialization;
{$APPTYPE CONSOLE}

procedure Test;

 procedure DoStuff(var a: Integer);
 begin
  if a = 0 then
    a := 1;
 end;

var
 a: Integer;
begin
  DoStuff(a);
  Writeln(a);
end;

begin
  Test;
  Readln;
end.

    It's strange that the compiler doesn't show a warning W1036 Variable 'a' might not have been initialized. This is definitely an oversight.

    • Like 1

  15. Posted

    High DPI is a big step forward in Windows development. Like the transition to Unicode, it may require a careful study of the codebase, fixing custom rendering of forms, updating third party components. This will not be automatically fixed with a new patch of IDE.

  20. Posted

    54 minutes ago, John Kouraklis said:

    Unless you have only Win apps and things like Win utils, FMX or more correctly cross-platform is the only way to go.

    Not only. How about CrossVCL? They support Linux and OSX, and plan to support Android and iOS in 2021.

  24. Posted · Edited by Kryvich

    According to the probability theory, there is a 1/19 770 609 664 chance that on the next try you will get the desired 6-letter word. So the fact that after 400 billion attempts it has not been received looks suspicious, but not impossible. (19 770 609 664 = 52*52*52*52*52*52).

     

    By the way, here are the probabilities of finding a word with fewer characters:

    1-letter word: 1/52,

    2-letter word: 1/2 704,

    3-letter word: 1/140 608,

    4-letter word: 1/7 311 616,

    5-letter word: 1/380 204 032,

    6-letter word: 1/19 770 609 664.

    • Like 1

  25. Posted

    @emailx45 Yes, I can reproduce in VirtualBox 6.1 with Windows 10 and Delphi 10.4.2 installed. 

     

    Error: Invalid Class Typecast. Details:

    Quote

    [21386672]{vclide270.bpl} GDIPlus.GradientTabs.TGradientButton.FormDPI (Line 358, "GDIPlus.GradientTabs.pas" + 1) + $F
    [5005A496]{rtl270.bpl  } System.ErrorAt (Line 5781, "System.pas" + 3) + $4
    [5005FFD3]{rtl270.bpl  } System.@AsClass (Line 18460, "System.pas" + 3) + $5
    [21386672]{vclide270.bpl} GDIPlus.GradientTabs.TGradientButton.FormDPI (Line 358, "GDIPlus.GradientTabs.pas" + 1) + $F
    [21386BC6]{vclide270.bpl} GDIPlus.GradientTabs.TScrollerButton.PaintLeftArrow (Line 520, "GDIPlus.GradientTabs.pas" + 3) + $2
    [21386B85]{vclide270.bpl} GDIPlus.GradientTabs.TScrollerButton.Paint (Line 508, "GDIPlus.GradientTabs.pas" + 3) + $2
    [50D01E19]{vcl270.bpl  } Vcl.Controls.TGraphicControl.WMPaint (Line 14009, "Vcl.Controls.pas" + 7) + $5
    [50CF7172]{vcl270.bpl  } Vcl.Controls.TControl.WndProc (Line 7480, "Vcl.Controls.pas" + 91) + $6
    [50CF6DAC]{vcl270.bpl  } Vcl.Controls.TControl.Perform (Line 7258, "Vcl.Controls.pas" + 10) + $8
    [50CFC56E]{vcl270.bpl  } Vcl.Controls.TWinControl.PaintControls (Line 10582, "Vcl.Controls.pas" + 27) + $D
    [50CFC36B]{vcl270.bpl  } Vcl.Controls.TWinControl.PaintHandler (Line 10528, "Vcl.Controls.pas" + 24) + $8
    [50CFCBF4]{vcl270.bpl  } Vcl.Controls.TWinControl.WMPaint (Line 10711, "Vcl.Controls.pas" + 6) + $5
    [50D02BC1]{vcl270.bpl  } Vcl.Controls.TCustomControl.WMPaint (Line 14385, "Vcl.Controls.pas" + 2) + $4
    [50CF7172]{vcl270.bpl  } Vcl.Controls.TControl.WndProc (Line 7480, "Vcl.Controls.pas" + 91) + $6
    [50CF8C36]{vcl270.bpl  } Vcl.Controls.TControl.GetStyleName (Line 8510, "Vcl.Controls.pas" + 1) + $8
    [50CF8C56]{vcl270.bpl  } Vcl.Controls.TControl.GetStyleName (Line 8512, "Vcl.Controls.pas" + 3) + $7
    [5005A240]{rtl270.bpl  } System.@GetMem (Line 4843, "System.pas" + 20) + $0
    [50061E56]{rtl270.bpl  } System.@NewUnicodeString (Line 25659, "System.pas" + 10) + $0
    [500622F1]{rtl270.bpl  } System.@UStrAsg (Line 26649, "System.pas" + 19) + $0
    [5005A25C]{rtl270.bpl  } System.@FreeMem (Line 4891, "System.pas" + 20) + $0
    [50061F75]{rtl270.bpl  } System.@UStrArrayClr (Line 26028, "System.pas" + 16) + $0
    [50CF8D13]{vcl270.bpl  } Vcl.Controls.TControl.IsCustomStyleActive (Line 8526, "Vcl.Controls.pas" + 😎 + $15
    [50CFC0C7]{vcl270.bpl  } Vcl.Controls.TWinControl.WndProc (Line 10424, "Vcl.Controls.pas" + 169) + $6
    [50CFB614]{vcl270.bpl  } Vcl.Controls.TWinControl.MainWndProc (Line 10113, "Vcl.Controls.pas" + 3) + $6
    [501826A4]{rtl270.bpl  } System.Classes.StdWndProc (Line 18175, "System.Classes.pas" + 😎 + $0
    [50E5C233]{vcl270.bpl  } Vcl.Forms.TApplication.ProcessMessage (Line 11028, "Vcl.Forms.pas" + 23) + $1
    [50E5C276]{vcl270.bpl  } Vcl.Forms.TApplication.HandleMessage (Line 11058, "Vcl.Forms.pas" + 1) + $4
    [50E5C5AD]{vcl270.bpl  } Vcl.Forms.TApplication.Run (Line 11196, "Vcl.Forms.pas" + 26) + $3
    [00524DB8]{bds.exe     } bds.bds (Line 222, "" + 13) + $2

    Though I never used this view in modern IDEs. Palette Tool window is more convenient on modern wide displays.

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