DynArrayLoadJson does not work like Delphi in FPC

[idigger]

System Information

• Operating system: Windows
• Processor architecture: x86-64
• Device: Computer
• FPC version: 3.3.1 [2024/06/26] for i386, Trunk 0c745fb257
• Mormot2 version: master 70e2e9c

note: The latest FPC already supports RTTI for records (https://gitlab.com/freepascal.org/fpc/source/-/issues/40798)

Example Project

program project1;

{$ifdef FPC}
{$mode delphi}
{$else}
{$APPTYPE CONSOLE}
{$endif}

{$I mormot.defines.inc}

uses
  {$I mormot.uses.inc}
  {$IFDEF DCC}System.{$ENDIF}Classes, {$IFDEF DCC}System.{$ENDIF}SysUtils,
  mormot.core.base,
  mormot.core.rtti,
  mormot.core.variants,
  mormot.core.json;

type

  {$RTTI EXPLICIT
     PROPERTIES([vcPublished])
     FIELDS([vcPublic])
     METHODS([])}

  TEFloor = packed record
    el: WORD;
    fl: array of Byte;
  end;

  TECtrl = packed record
    ecid: WORD;
    expd: array of Byte;
    efl: array of TEFloor;
    icod: UTF8String;
    pt: array of Integer;
    adv: BYTE;
  end;
  TECtrls = Array of TECtrl;

var
  tmp1, tmp2: UTf8String;
  ec: TECtrls;
begin
  tmp1 := '[{"ecid":12,"expd":[80,17,18],"efl":[{"el":0,"fl":[1,2]},{"el":1,"fl":[4,5]}],"icod":"123456","pt":[1,2,3],"adv":5}]';
  DynArrayLoadJson(ec, tmp1, TypeInfo(TECtrls));
  WriteLn(tmp1);

  tmp2 := DynArraySaveJson(ec, TypeInfo(TECtrls));
  WriteLn(tmp2);

  if tmp1 = tmp2 then WriteLn('ok')
  else                WriteLn('failed');

end.

The above programs are compiled with fpc and run as follows.

# fpc project1.pas -Fic:\mORMot2\src -Fuc:\mORMot2\src\core;c:\mORMot2\src\lib -Flc:\mORMot2\static\i386-win32
Free Pascal Compiler version 3.3.1 [2024/06/26] for i386
Copyright (c) 1993-2024 by Florian Klaempfl and others
Target OS: Win32 for i386
Compiling project1.pas
Linking project1.exe
895 lines compiled, 0.3 sec, 563504 bytes code, 20004 bytes data

# project1
[{"ecid":12,"expd":[80,17,18],"efl":[{"el":0,"fl":[1,2]},{"el":1,"fl":[4,5]}],"icod":"123456","pt":[1,2,3],"adv":5}]
[]
failed

Relevant 3rd party information

The above program is compiled by delphi and the results are as follows

# dcc32 project1.pas -Ic:\mORMot2\src;c:\mORMot2\static\i386-win32 -Uc:\mORMot2\src\core;c:\mORMot2\src\lib -NSSystem;Winapi
Embarcadero Delphi for Win32 compiler version 36.0
Copyright (c) 1983,2024 Embarcadero Technologies, Inc.
c:\mORMot2\src\mormot.defines.inc(792)
c:\mORMot2\src\mormot.uses.inc(50)
project1.pas(56)
897 lines, 0.11 seconds, 1439256 bytes code, 103032 bytes data.

# project1.exe
[{"ecid":12,"expd":[80,17,18],"efl":[{"el":0,"fl":[1,2]},{"el":1,"fl":[4,5]}],"icod":"123456","pt":[1,2,3],"adv":5}]
[{"ecid":12,"expd":[80,17,18],"efl":[{"el":0,"fl":[1,2]},{"el":1,"fl":[4,5]}],"icod":"123456","pt":[1,2,3],"adv":5}]
ok

[synopse]

Please try above commit.

I don't have FPC trunk installed yet, but I will try to.

[idigger]

project1.pas adds the following statement before TEFloor = packed record.

{$RTTI EXPLICIT
PROPERTIES([vcPublished])
FIELDS([vcPublic])
METHODS([])}

Recompile and run, everything is fine.

You were amazing.

Thank you for your quick response and quick repair.