Porting from Qt 5.15.2 to Qt 6.3.1

[SPlatten]

I'm trying to build an existing project previous using Qt 5.15.2, I've added the kit for 5.6.3.1, some differences in the folder structure, also a lot of things now won't compile, errors like:

/Users/sy/XMLMPAM/clsJSON.cpp:14: error: 'QTextCodec' file not found
../clsJSON.cpp:14:10: fatal error: 'QTextCodec' file not found
#include <QTextCodec>
         ^~~~~~~~~~~~
/Users/sy/XMLMPAM/clsMainWnd.h:379: error: 'QDesktopWidget' file not found
In file included from ../clsMainWnd.cpp:7:
In file included from ../../XMLMPAM/clsCNT.h:50:
../../XMLMPAM/clsMainWnd.h:379:14: fatal error: 'QDesktopWidget' file not found
    #include <QDesktopWidget>
             ^~~~~~~~~~~~~~~~
:-1: error: [clsJSON.o] Error 1
/Users/sy/XMLMPAM/clsDebugService.cpp:59: error: no member named 'midRef' in 'QString'
../clsDebugService.cpp:59:43: error: no member named 'midRef' in 'QString'
                uint16DebugLevel = strMsg.midRef(0, intLevelLength).toUInt();
                                   ~~~~~~ ^

Is this possible to port ? Is there a guide ?

[JKSH]

@SPlatten said in Porting from Qt 5.15.2 to Qt 5.6.3.1:

Is this possible to port ? Is there a guide ?

Porting guides normally describe how to port to a newer version, not to an older version.

Having said that, Qt 5.6 definitely has QTextCodec, QDesktopWidget, and QString::midRef().

some differences in the folder structure

This is probably the cause of your errors. Don't change the folder structure.

[J.Hilk]

@JKSH I'm almost 100% sure the OP meant Qt 6.3.1 instead of Qt 5.6.3.1

@SPlatten take a look here for at least a general guideline :
https://doc.qt.io/qt-6/portingguide.html

[SPlatten]

@JKSH, Sorry that was a typo/mistake on my part it should have read 6.3.1.

[JKSH]

@J-Hilk said in Porting from Qt 5.15.2 to Qt 5.6.3.1:

@JKSH I'm almost 100% sure the OP meant Qt 6.3.1 instead of Qt 5.6.3.1

D'oh, of course 😂

6.3.1 doesn't have QTextCodec, QDesktopWidget, and QString::midRef() indeed!

[SPlatten]

@JKSH , thank you, is there a way forward ?

[JKSH]

@SPlatten said in Porting from Qt 5.15.2 to Qt 6.3.1:

@JKSH , thank you, is there a way forward ?

You're welcome. Yes, the link that @J-Hilk posted shows you how to move forward. The first part of the process is to eliminate all deprecation warnings when you build with Qt 5.15.

[SPlatten]

@JKSH , @J-Hilk , thank you, will take a look now.