Shared library on windows fails when using moc

JoeCFD

@Mesrine Q_DECL_IMPORT and Q_DECL_EXPORT are hidden for example on Linux. No worries.

Christian Ehrlicher

@Mesrine said in Shared library on windows fails when using moc:

But still i have to define MYSHAREDLIB_EXPORT to nothing if compiling in other system apart from windows?

Why? Simply use it as explained in the Qt documentation...

SGaist

Hi,

You are over complicating things.

As already suggested by @Christian-Ehrlicher, just follow the doc:

create one header with the macro definition as shown in the documentation
in your code include that header in all the classes you want to export and use the macro there
update your CMakeLists.txt as shown
rebuild

And you should be good to go. There's really nothing more to it than that.

Mesrine

@SGaist

I tried on the shared library

#include <QtCore/QtGlobal>

#if defined(MYSHAREDLIB_LIBRARY)
# define MYSHAREDLIB_EXPORT Q_DECL_EXPORT
#else
#define MYSHAREDLIB_EXPORT Q_DECL_IMPORT
#endif
namespace qiota{

	namespace qpow {


		class MYSHAREDLIB_EXPORT nonceFinder : public QObject
		{
			Q_OBJECT
			public:

in the cmakelist.txt of the shared library

add_library(qpow include/pow/qpow.hpp qpow.cpp)
target_compile_definitions(qpow PRIVATE MYSHAREDLIB_LIBRARY)

As you can see on this commit
This compiles the library in windows, linux, macos shared and static as before.

I did the same for the client library as you can see for the
comparison of the branch

but this again fails for windows shared library as you can see form the workflow run with error

  cmake --build .
  shell: C:\Program Files\PowerShell\7\pwsh.EXE -command ". '{0}'"
  env:
    CommandPromptType: Native
    DevEnvDir: C:\Program Files\Microsoft Visual Studio\2022\Enterprise\Common7\IDE\
    ExtensionSdkDir: C:\Program Files (x86)\Microsoft SDKs\Windows Kits\10\ExtensionSDKs
    EXTERNAL_INCLUDE: C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.34.31933\include;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.34.31933\ATLMFC\include;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Auxiliary\VS\include;C:\Program Files (x86)\Windows Kits\10\include\10.0.22621.0\ucrt;C:\Program Files (x86)\Windows Kits\10\\include\10.0.22621.0\\um;C:\Program Files (x86)\Windows Kits\10\\include\10.0.22621.0\\shared;C:\Program Files (x86)\Windows Kits\10\\include\10.0.22621.0\\winrt;C:\Program Files (x86)\Windows Kits\10\\include\10.0.22621.0\\cppwinrt;C:\Program Files (x86)\Windows Kits\NETFXSDK\4.8\include\um
    Framework40Version: v4.0
    FrameworkDir: C:\Windows\Microsoft.NET\Framework64\
    FrameworkDir64: C:\Windows\Microsoft.NET\Framework64\
    FrameworkVersion: v4.0.30319
    FrameworkVersion64: v4.0.30319
    FSHARPINSTALLDIR: C:\Program Files\Microsoft Visual Studio\2022\Enterprise\Common7\IDE\CommonExtensions\Microsoft\FSharp\Tools
    HTMLHelpDir: C:\Program Files (x86)\HTML Help Workshop
    INCLUDE: C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.34.31933\include;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.34.31933\ATLMFC\include;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Auxiliary\VS\include;C:\Program Files (x86)\Windows Kits\10\include\10.0.22621.0\ucrt;C:\Program Files (x86)\Windows Kits\10\\include\10.0.22621.0\\um;C:\Program Files (x86)\Windows Kits\10\\include\10.0.22621.0\\shared;C:\Program Files (x86)\Windows Kits\10\\include\10.0.22621.0\\winrt;C:\Program Files (x86)\Windows Kits\10\\include\10.0.22621.0\\cppwinrt;C:\Program Files (x86)\Windows Kits\NETFXSDK\4.8\include\um
    is_x64_arch: true
    LIB: C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.34.31933\ATLMFC\lib\x64;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.34.31933\lib\x64;C:\Program Files (x86)\Windows Kits\NETFXSDK\4.8\lib\um\x64;C:\Program Files (x86)\Windows Kits\10\lib\10.0.22621.0\ucrt\x64;C:\Program Files (x86)\Windows Kits\10\\lib\10.0.22621.0\\um\x64
    LIBPATH: C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.34.31933\ATLMFC\lib\x64;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.34.31933\lib\x64;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.34.31933\lib\x86\store\references;C:\Program Files (x86)\Windows Kits\10\UnionMetadata\10.0.22621.0;C:\Program Files (x86)\Windows Kits\10\References\10.0.22621.0;C:\Windows\Microsoft.NET\Framework64\v4.0.30319
    NETFXSDKDir: C:\Program Files (x86)\Windows Kits\NETFXSDK\4.8\
    Path: C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.34.31933\bin\HostX64\x64;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\Common7\IDE\VC\VCPackages;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\Common7\IDE\CommonExtensions\Microsoft\TestWindow;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\Common7\IDE\CommonExtensions\Microsoft\TeamFoundation\Team Explorer;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\MSBuild\Current\bin\Roslyn;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\Team Tools\Performance Tools\x64;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\Team Tools\Performance Tools;C:\Program Files (x86)\Microsoft SDKs\Windows\v10.0A\bin\NETFX 4.8 Tools\x64\;C:\Program Files (x86)\HTML Help Workshop;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\Common7\IDE\CommonExtensions\Microsoft\FSharp\Tools;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\Common7\IDE\Extensions\Microsoft\CodeCoverage.Console;C:\Program Files (x86)\Windows Kits\10\bin\10.0.22621.0\\x64;C:\Program Files (x86)\Windows Kits\10\bin\\x64;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\\MSBuild\Current\Bin\amd64;C:\Windows\Microsoft.NET\Framework64\v4.0.30319;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\Common7\IDE\;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\Common7\Tools\;C:\Program Files\MongoDB\Server\5.0\bin;C:\aliyun-cli;C:\vcpkg;C:\Program Files (x86)\NSIS\;C:\tools\zstd;C:\Program Files\Mercurial\;C:\hostedtoolcache\windows\stack\2.9.3\x64;C:\cabal\bin;C:\\ghcup\bin;C:\Program Files\dotnet;C:\mysql\bin;C:\Program Files\R\R-4.3.0\bin\x64;C:\SeleniumWebDrivers\GeckoDriver;C:\Program Files (x86)\sbt\bin;C:\Program Files (x86)\GitHub CLI;C:\Program Files\Git\bin;C:\Program Files (x86)\pipx_bin;C:\npm\prefix;C:\hostedtoolcache\windows\go\1.20.4\x64\bin;C:\hostedtoolcache\windows\Python\3.9.13\x64\Scripts;C:\hostedtoolcache\windows\Python\3.9.13\x64;C:\hostedtoolcache\windows\Ruby\3.0.6\x64\bin;C:\Program Files\OpenSSL\bin;C:\tools\kotlinc\bin;C:\hostedtoolcache\windows\Java_Temurin-Hotspot_jdk\8.0.372-7\x64\bin;C:\Program Files\ImageMagick-7.1.1-Q16-HDRI;C:\Program Files (x86)\Microsoft SDKs\Azure\CLI2\wbin;C:\ProgramData\kind;C:\Program Files\Microsoft\jdk-11.0.16.101-hotspot\bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Windows\System32\OpenSSH\;C:\Program Files\dotnet\;C:\ProgramData\Chocolatey\bin;C:\Program Files\PowerShell\7\;C:\Program Files\Microsoft\Web Platform Installer\;C:\Program Files\Microsoft SQL Server\Client SDK\ODBC\170\Tools\Binn\;C:\Program Files\Microsoft SQL Server\150\Tools\Binn\;C:\Strawberry\c\bin;C:\Strawberry\perl\site\bin;C:\Strawberry\perl\bin;C:\ProgramData\chocolatey\lib\pulumi\tools\Pulumi\bin;C:\Program Files\TortoiseSVN\bin;C:\Program Files\CMake\bin;C:\ProgramData\chocolatey\lib\maven\apache-maven-3.8.7\bin;C:\Program Files\Microsoft Service Fabric\bin\Fabric\Fabric.Code;C:\Program Files\Microsoft SDKs\Service Fabric\Tools\ServiceFabricLocalClusterManager;C:\Program Files\nodejs\;C:\Program Files\Git\cmd;C:\Program Files\Git\mingw64\bin;C:\Program Files\Git\usr\bin;C:\Program Files\GitHub CLI\;c:\tools\php;C:\SeleniumWebDrivers\ChromeDriver\;C:\SeleniumWebDrivers\EdgeDriver\;C:\Program Files\Amazon\AWSCLIV2\;C:\Program Files\Amazon\SessionManagerPlugin\bin\;C:\Program Files\Amazon\AWSSAMCLI\bin\;C:\Program Files\Microsoft SQL Server\130\Tools\Binn\;C:\Program Files\LLVM\bin;C:\Users\runneradmin\.dotnet\tools;C:\Users\runneradmin\.cargo\bin;C:\Users\runneradmin\AppData\Local\Microsoft\WindowsApps;C:\Program Files (x86)\Microsoft Visual Studio\Installer;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\Llvm\x64\bin;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\Common7\IDE\CommonExtensions\Microsoft\CMake\Ninja;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\Common7\IDE\VC\Linux\bin\ConnectionManagerExe
    Platform: x64
    UCRTVersion: 10.0.22621.0
    UniversalCRTSdkDir: C:\Program Files (x86)\Windows Kits\10\
    VCIDEInstallDir: C:\Program Files\Microsoft Visual Studio\2022\Enterprise\Common7\IDE\VC\
    VCINSTALLDIR: C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\
    VCToolsInstallDir: C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.34.31933\
    VCToolsRedistDir: C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Redist\MSVC\14.34.31931\
    VCToolsVersion: 14.34.31933
    VisualStudioVersion: 17.0
    VS170COMNTOOLS: C:\Program Files\Microsoft Visual Studio\2022\Enterprise\Common7\Tools\
    VSCMD_ARG_app_plat: Desktop
    VSCMD_ARG_HOST_ARCH: x64
    VSCMD_ARG_TGT_ARCH: x64
    VSCMD_VER: 17.5.5
    VSINSTALLDIR: C:\Program Files\Microsoft Visual Studio\2022\Enterprise\
    VSSDK150INSTALL: C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VSSDK
    VSSDKINSTALL: C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VSSDK
    WindowsLibPath: C:\Program Files (x86)\Windows Kits\10\UnionMetadata\10.0.22621.0;C:\Program Files (x86)\Windows Kits\10\References\10.0.22621.0
    WindowsSdkBinPath: C:\Program Files (x86)\Windows Kits\10\bin\
    WindowsSdkDir: C:\Program Files (x86)\Windows Kits\10\
    WindowsSDKLibVersion: 10.0.22621.0\
    WindowsSdkVerBinPath: C:\Program Files (x86)\Windows Kits\10\bin\10.0.22621.0\
    WindowsSDKVersion: 10.0.22621.0\
    WindowsSDK_ExecutablePath_x64: C:\Program Files (x86)\Microsoft SDKs\Windows\v10.0A\bin\NETFX 4.8 Tools\x64\
    WindowsSDK_ExecutablePath_x86: C:\Program Files (x86)\Microsoft SDKs\Windows\v10.0A\bin\NETFX 4.8 Tools\
    __DOTNET_ADD_64BIT: 1
    __DOTNET_PREFERRED_BITNESS: 64
    __VSCMD_PREINIT_PATH: C:\Program Files\MongoDB\Server\5.0\bin;C:\aliyun-cli;C:\vcpkg;C:\Program Files (x86)\NSIS\;C:\tools\zstd;C:\Program Files\Mercurial\;C:\hostedtoolcache\windows\stack\2.9.3\x64;C:\cabal\bin;C:\\ghcup\bin;C:\Program Files\dotnet;C:\mysql\bin;C:\Program Files\R\R-4.3.0\bin\x64;C:\SeleniumWebDrivers\GeckoDriver;C:\Program Files (x86)\sbt\bin;C:\Program Files (x86)\GitHub CLI;C:\Program Files\Git\bin;C:\Program Files (x86)\pipx_bin;C:\npm\prefix;C:\hostedtoolcache\windows\go\1.20.4\x64\bin;C:\hostedtoolcache\windows\Python\3.9.13\x64\Scripts;C:\hostedtoolcache\windows\Python\3.9.13\x64;C:\hostedtoolcache\windows\Ruby\3.0.6\x64\bin;C:\Program Files\OpenSSL\bin;C:\tools\kotlinc\bin;C:\hostedtoolcache\windows\Java_Temurin-Hotspot_jdk\8.0.372-7\x64\bin;C:\Program Files\ImageMagick-7.1.1-Q16-HDRI;C:\Program Files (x86)\Microsoft SDKs\Azure\CLI2\wbin;C:\ProgramData\kind;C:\Program Files\Microsoft\jdk-11.0.16.101-hotspot\bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Windows\System32\OpenSSH\;C:\Program Files\dotnet\;C:\ProgramData\Chocolatey\bin;C:\Program Files\PowerShell\7\;C:\Program Files\Microsoft\Web Platform Installer\;C:\Program Files\Microsoft SQL Server\Client SDK\ODBC\170\Tools\Binn\;C:\Program Files\Microsoft SQL Server\150\Tools\Binn\;C:\Strawberry\c\bin;C:\Strawberry\perl\site\bin;C:\Strawberry\perl\bin;C:\ProgramData\chocolatey\lib\pulumi\tools\Pulumi\bin;C:\Program Files\TortoiseSVN\bin;C:\Program Files\CMake\bin;C:\ProgramData\chocolatey\lib\maven\apache-maven-3.8.7\bin;C:\Program Files\Microsoft Service Fabric\bin\Fabric\Fabric.Code;C:\Program Files\Microsoft SDKs\Service Fabric\Tools\ServiceFabricLocalClusterManager;C:\Program Files\nodejs\;C:\Program Files\Git\cmd;C:\Program Files\Git\mingw64\bin;C:\Program Files\Git\usr\bin;C:\Program Files\GitHub CLI\;c:\tools\php;C:\Program Files (x86)\sbt\bin;C:\SeleniumWebDrivers\ChromeDriver\;C:\SeleniumWebDrivers\EdgeDriver\;C:\Program Files\Amazon\AWSCLIV2\;C:\Program Files\Amazon\SessionManagerPlugin\bin\;C:\Program Files\Amazon\AWSSAMCLI\bin\;C:\Program Files\Microsoft SQL Server\130\Tools\Binn\;C:\Program Files\LLVM\bin;C:\Users\runneradmin\.dotnet\tools;C:\Users\runneradmin\.cargo\bin;C:\Users\runneradmin\AppData\Local\Microsoft\WindowsApps;C:\Program Files (x86)\Microsoft Visual Studio\Installer
    pythonLocation: C:\hostedtoolcache\windows\Python\3.11.3\x64
[42/101] Building CXX object _deps\qed25519-build\CMakeFiles\qed25519.dir\qed25519.cpp.obj
[43/101] Linking CXX shared library qbech32.dll
[44/101] Building C object _deps\qed25519-build\CMakeFiles\qed25519.dir\src\add_scalar.c.obj
[45/101] Linking CXX shared library qpow.dll
[46/101] Building C object _deps\qed25519-build\CMakeFiles\qed25519.dir\src\fe.c.obj
[47/101] Building C object _deps\qed25519-build\CMakeFiles\qed25519.dir\src\ge.c.obj
[48/101] Building C object _deps\qed25519-build\CMakeFiles\qed25519.dir\src\key_exchange.c.obj
[49/101] Building C object _deps\qed25519-build\CMakeFiles\qed25519.dir\src\keypair.c.obj
[50/101] Automatic MOC and UIC for target qclient
[51/101] Building C object _deps\qed25519-build\CMakeFiles\qed25519.dir\src\sc.c.obj
[52/101] Building CXX object CMakeFiles\qclient.dir\qclient_autogen\mocs_compilation.cpp.obj
[53/101] Building CXX object CMakeFiles\qclient.dir\qclient.cpp.obj
[54/101] Building CXX object CMakeFiles\qclient.dir\src\qnode_response.cpp.obj
[55/101] Building CXX object CMakeFiles\qclient.dir\src\qnode_info.cpp.obj
[56/101] Building CXX object CMakeFiles\qclient.dir\src\qnode_tips.cpp.obj
[57/101] Building CXX object CMakeFiles\qclient.dir\src\qnode_blockId.cpp.obj
[58/101] Building CXX object CMakeFiles\qclient.dir\src\qnode_block.cpp.obj
[59/101] Building CXX object CMakeFiles\qclient.dir\src\qnode_outputs.cpp.obj
[60/101] Building C object _deps\qed25519-build\CMakeFiles\qed25519.dir\src\sha512.c.obj
[61/101] Building C object _deps\qed25519-build\CMakeFiles\qed25519.dir\src\sign.c.obj
[62/101] Building C object _deps\qed25519-build\CMakeFiles\qed25519.dir\src\verify.c.obj
[63/101] Automatic MOC and UIC for target qslip10
[64/101] Building CXX object _deps\qslip10-build\CMakeFiles\qslip10.dir\qslip10_autogen\mocs_compilation.cpp.obj
[65/101] Linking CXX shared library qclient.dll
FAILED: qclient.dll qclient.lib 
cmd.exe /C "cmd.exe /C ""C:\Program Files\CMake\bin\cmake.exe" -E __create_def D:\a\_temp\build\CMakeFiles\qclient.dir\.\exports.def D:\a\_temp\build\CMakeFiles\qclient.dir\.\exports.def.objs && cd D:\a\_temp\build" && "C:\Program Files\CMake\bin\cmake.exe" -E vs_link_dll --intdir=CMakeFiles\qclient.dir --rc=C:\PROGRA~2\WI3CF2~1\10\bin\100226~1.0\x64\rc.exe --mt=C:\PROGRA~2\WI3CF2~1\10\bin\100226~1.0\x64\mt.exe --manifests  -- C:\PROGRA~1\MICROS~2\2022\ENTERP~1\VC\Tools\MSVC\1434~1.319\bin\HostX64\x64\link.exe /nologo CMakeFiles\qclient.dir\qclient_autogen\mocs_compilation.cpp.obj CMakeFiles\qclient.dir\qclient.cpp.obj CMakeFiles\qclient.dir\src\qnode_response.cpp.obj CMakeFiles\qclient.dir\src\qnode_info.cpp.obj CMakeFiles\qclient.dir\src\qnode_tips.cpp.obj CMakeFiles\qclient.dir\src\qnode_blockId.cpp.obj CMakeFiles\qclient.dir\src\qnode_block.cpp.obj CMakeFiles\qclient.dir\src\qnode_outputs.cpp.obj  /out:qclient.dll /implib:qclient.lib /pdb:qclient.pdb /dll /version:0.0 /machine:x64 /INCREMENTAL:NO  /DEF:CMakeFiles\qclient.dir\.\exports.def  D:\a\Qclient-IOTA\Qt\6.5.0\msvc2019_64\lib\Qt6Network.lib  _deps\qblock-build\qblock.lib  _deps\qpow-build\qpow.lib  ws2_32.lib  _deps\qbigint-build\qbigint.lib  D:\a\Qclient-IOTA\Qt\6.5.0\msvc2019_64\lib\Qt6Core.lib  mpr.lib  userenv.lib  kernel32.lib user32.lib gdi32.lib winspool.lib shell32.lib ole32.lib oleaut32.lib uuid.lib comdlg32.lib advapi32.lib  && cd ."
LINK: command "C:\PROGRA~1\MICROS~2\2022\ENTERP~1\VC\Tools\MSVC\1434~1.319\bin\HostX64\x64\link.exe /nologo CMakeFiles\qclient.dir\qclient_autogen\mocs_compilation.cpp.obj CMakeFiles\qclient.dir\qclient.cpp.obj CMakeFiles\qclient.dir\src\qnode_response.cpp.obj CMakeFiles\qclient.dir\src\qnode_info.cpp.obj CMakeFiles\qclient.dir\src\qnode_tips.cpp.obj CMakeFiles\qclient.dir\src\qnode_blockId.cpp.obj CMakeFiles\qclient.dir\src\qnode_block.cpp.obj CMakeFiles\qclient.dir\src\qnode_outputs.cpp.obj /out:qclient.dll /implib:qclient.lib /pdb:qclient.pdb /dll /version:0.0 /machine:x64 /INCREMENTAL:NO /DEF:CMakeFiles\qclient.dir\.\exports.def D:\a\Qclient-IOTA\Qt\6.5.0\msvc2019_64\lib\Qt6Network.lib _deps\qblock-build\qblock.lib _deps\qpow-build\qpow.lib ws2_32.lib _deps\qbigint-build\qbigint.lib D:\a\Qclient-IOTA\Qt\6.5.0\msvc2019_64\lib\Qt6Core.lib mpr.lib userenv.lib kernel32.lib user32.lib gdi32.lib winspool.lib shell32.lib ole32.lib oleaut32.lib uuid.lib comdlg32.lib advapi32.lib /MANIFEST /MANIFESTFILE:qclient.dll.manifest" failed (exit code 1120) with the following output:
   Creating library qclient.lib and object qclient.exp
qclient.cpp.obj : error LNK2019: unresolved external symbol "public: static struct QMetaObject const qiota::qpow::nonceFinder::staticMetaObject" (?staticMetaObject@nonceFinder@qpow@qiota@@2UQMetaObject@@B) referenced in function "public: static class QMetaObject::Connection __cdecl QObject::connect<void (__cdecl qiota::qpow::nonceFinder::*)(void),class `public: __cdecl `public: __cdecl `public: void __cdecl qiota::Client::send_block(class qiota::qblocks::Block const &)'::`2'::<lambda_2>::operator()(void)const '::`2'::<lambda_1>::operator()(void)const '::`5'::<lambda_2> >(class qiota::qpow::nonceFinder const *,void (__cdecl qiota::qpow::nonceFinder::*)(void),class QObject const *,class `public: __cdecl `public: __cdecl `public: void __cdecl qiota::Client::send_block(class qiota::qblocks::Block const &)'::`2'::<lambda_2>::operator()(void)const '::`2'::<lambda_1>::operator()(void)const '::`5'::<lambda_2>,enum Qt::ConnectionType)" (??$connect@P8nonceFinder@qpow@qiota@@EAAXXZV<lambda_2>@?4???R<lambda_1>@?1???R4?1??send_block@Client@3@QEAAXAEBVBlock@qblocks@3@@Z@QEBA@XZ@QEBA@XZ@@QObject@@SA?AVConnection@QMetaObject@@PEBVnonceFinder@qpow@qiota@@P8345@EAAXXZPEBV0@V<lambda_2>@?4???R<lambda_1>@?1???R6?1??send_block@Client@5@QEAAXAEBVBlock@qblocks@5@@Z@QEBA@XZ@QEBA@XZ@W4ConnectionType@Qt@@@Z)

qclient.dll : fatal error LNK1120: 1 unresolved externals

[66/101] Building CXX object _deps\qslip10-build\CMakeFiles\qslip10.dir\qslip10.cpp.obj
[67/101] Building C object _deps\qed25519-build\CMakeFiles\qed25519.dir\src\seed.c.obj
ninja: build stopped: subcommand failed.
Error: Process completed with exit code 1.

I believe is the same error than before.

Christian Ehrlicher

I don't see the include of the generated moc file 'moc_qpow.h' in your code.

Mesrine

@Christian-Ehrlicher
Where should i put this on qpow.cpp?

Christian Ehrlicher

@Mesrine doesn't matter - includes should go to the top.

Mesrine

@Mesrine

I have checked the moc produced source in windows
The file is inside build/qpow_autogen/652RYH7CFW/moc_qpow.cpp and the symbol the linker is complaining is defined like this:

Q_CONSTINIT const QMetaObject qiota::qpow::nonceFinder::staticMetaObject = { {
    QMetaObject::SuperData::link<QObject::staticMetaObject>(),
    qt_meta_stringdata_CLASSqiotaSCOPEqpowSCOPEnonceFinderENDCLASS.offsetsAndSizes,
    qt_meta_data_CLASSqiotaSCOPEqpowSCOPEnonceFinderENDCLASS,
    qt_static_metacall,
    nullptr,
    qt_incomplete_metaTypeArray<qt_meta_stringdata_CLASSqiotaSCOPEqpowSCOPEnonceFinderENDCLASS_t,
        // Q_OBJECT / Q_GADGET
        QtPrivate::TypeAndForceComplete<nonceFinder, std::true_type>,
        // method 'nonce_found'
        QtPrivate::TypeAndForceComplete<void, std::false_type>,
        QtPrivate::TypeAndForceComplete<quint64, std::false_type>,
        // method 'nonce_not_found'
        QtPrivate::TypeAndForceComplete<void, std::false_type>
    >,
    nullptr
} };

Due to the fact that the linker only complains when building shared library on windows and i have also tried

#include "qpow.moc"

on the class source giving me the same error.
Could it be that moc is not exporting the symbol for windows(like using Q_DECL_EXPORT and Q_DECL_IMPORT in the definition) ?

Mesrine

@Mesrine
So the QObject macro will expand in my class and declare the missing symbol on my class header file like

public: static struct QMetaObject const qiota::qpow::WorkerThread::staticMetaObject.

This symbol is then defined in the moc generated sources that can be included on the class source file or the resulting .obj can be linked to the library.

But the thing is that the expansion of QObject in my class maybe do not put

public: 
Q_DECL_EXPORT(Q_DECL_IMPORT) static struct QMetaObject const qiota::qpow::WorkerThread::staticMetaObject.

So the symbol is not correctly (exported)imported for windows shared.
Is this reasoning correct?

Mesrine

@Mesrine
You can see a much simpler reproducible example of the issue here

Christian Ehrlicher

And even there I don't see where you include "moc_foo.cpp" for AUTOMOC or do the moc by yourself anywhere.

Mesrine

@Christian-Ehrlicher
According to qt I do not need to include the header moc files when using cmake.
I will try and let you know.

Mesrine

@Mesrine
As maybe you can see the build fail with the same error.
But you can check now that the files are included.

Mesrine

@Christian-Ehrlicher
The Automoc is done automatically
as i have added in CMakeLists.txt

qt_standard_project_setup()

that this set AUTOMOC variable ON.

Christian Ehrlicher

I did not see (and not use by myself) qt_standard_project_setup() so you're correct with the automoc.

You use the same define for the export definition for both libraries - how should this work?

JoeCFD

@Mesrine

your libA uses libB. libA imports libB. So do not define WINDOWS_SHAREDLIB in libA
target_compile_definitions(libA PRIVATE WINDOWS_SHAREDLIB) <= can not have this one?

#if defined(WINDOWS_SHAREDLIB)
# define SHAREDLIB_EXPORT Q_DECL_EXPORT
#else
#define SHAREDLIB_EXPORT Q_DECL_IMPORT  <===libA needs this one if WINDOWS_SHAREDLIB is not defined.
#endif

Mesrine

@Christian-Ehrlicher
Thats a good point. Thanks!
Using the same definition for both libraries if not included correctly the headers could define the export on the symbol that should have an import statement.

This is not completely clear to me so Let me try.
I let you know :).

Yes, that was the problem. Many thanks.