Qt5.15.2 amd64 Build from src - Missing symbol export "_cdecl QUnhandledException"

NiVa99

Hi,

After build in amd64 with MSVC2019 Qt5.15.2 from source, I made the observation that public _cdecl QUnhandledException symbol was not exported.

The source are from https://download.qt.io/archive/qt/5.15/5.15.2/single/

And the configuration cmd windows script is as this :

CALL "C:/Program Files (x86)/Microsoft Visual Studio/2019/Professional/VC/Auxiliary/Build/vcvarsall.bat" amd64
  
set "CMAKE_ROOT=C:\CMake\bin"
set "NINJA_ROOT=C:\ninja-win"
set "PERL_ROOT=C:\Strawberry\perl\bin"
   
set PATH=%CMAKE_ROOT%;%PATH%
set PATH=%NINJA_ROOT%;%PATH%
set PATH=%PERL_ROOT%;%PATH%
set PATH=C:\Python311-amd64;%PATH%
     
rem Check if the tools are in PATH
where perl.exe
where python.exe
where cmake.exe
where ninja.exe
 
set "MY_INSTALL_PATH=qt-5.15.2-build-vs2019"
set CL=/MP
 
cmake -G "Visual Studio 16 2019"

configure.bat -prefix %MY_INSTALL_PATH% -release -force-debug-info -platform win32-msvc -opensource -confirm-license -nomake tests -nomake examples

The differences is in Qt5Core.dll as shown on attached picture

And it results in error LNK 2001 unresolved external Symbol.

Erreur	LNK2001	symbole externe non résolu "__declspec(dllimport) public: virtual __cdecl QUnhandledException::~QUnhandledException(void)" (__imp_??1QUnhandledException@@UEAA@XZ)

Erreur	LNK2001	symbole externe non résolu "__declspec(dllimport) public: __cdecl QUnhandledException::QUnhandledException(void)" (__imp_??0QUnhandledException@@QEAA@XZ)

Erreur	LNK2001	symbole externe non résolu "__declspec(dllimport) public: void __cdecl QFutureInterfaceBase::reportException(class QException const &)" (__imp_?reportException@QFutureInterfaceBase@@QEAAXAEBVQException@@@Z)

Sample code was taken here qtconcurrentrun.html#using-member-functions

#include <iostream>

#include <QtCore/QObject>
#include <QtCore/QtCore>
#include <QtCore/QFuture> 
#include <QtCore/QUnhandledException>

#include <QtConcurrent/QtConcurrentVersion> 
#include <QtConcurrent/QtConcurrent> 
#include <QtConcurrent/QtConcurrentRun> 
#include <QtConcurrent/QtConcurrentMap>


int main()
{
    // from https://doc.qt.io/qt-5/qtconcurrentrun.html#using-member-functions
    QByteArray bytearray = "Hello World!";
    // QFuture<QList<QByteArray> > future = 
    QtConcurrent::run(bytearray, &QByteArray::split, ',');
    //QList<QByteArray> result = future.result();
}

NiVa99

By changing configure option like this

CALL "C:/Program Files (x86)/Microsoft Visual Studio/2019/Professional/VC/Auxiliary/Build/vcvarsall.bat" amd64
  
set "CMAKE_ROOT=C:\CMake\bin"
set "NINJA_ROOT=C:\ninja-win"
set "PERL_ROOT=C:\Strawberry\perl\bin"
   
set PATH=%CMAKE_ROOT%;%PATH%
set PATH=%NINJA_ROOT%;%PATH%
set PATH=%PERL_ROOT%;%PATH%
set PATH=C:\Python311-amd64;%PATH%
     
rem Check if the tools are in PATH
where perl.exe
where python.exe
where cmake.exe
where ninja.exe
 
set "MY_INSTALL_PATH=qt-5.15.2-build-vs2019"
set CL=/MP
 
cmake -G "Visual Studio 16 2019"

:: configure.bat -prefix %MY_INSTALL_PATH% -release -force-debug-info -platform win32-msvc -opensource -confirm-license -nomake tests -nomake examples
configure.bat -prefix %MY_INSTALL_PATH% **-developer-build** -release -force-debug-info -platform win32-msvc -opensource -confirm-license -nomake tests -nomake examples

It fixed the issue.

Christian Ehrlicher

You compile Qt without exceptions support and then wonder why an exception is not in your dll? Wow.

NiVa99

think -developer-build option is the main diff. I had tested with exceptions option and Qt5Core did not embbed QUnhandled::exception. Tested today.

Christian Ehrlicher

@NiVa99 said in Qt5.15.2 amd64 Build from src - Missing symbol export "_cdecl QUnhandledException":

think -developer-build option is the main diff. I

No, see the header of qexception.h - you disable a feature and Qt just does what you asked for.