How to add qsvg

[Aceman2000]

Hi,

I have an app, which has some .svg files as resources. These get passed to QIcon constructors. When my app is built dynamically, everything works, but I want to build my app statically. When I do that, the icons disappear. Sometimes I get errors from QObject::moveToThread saying that some object not being in the corrent thread (I'm not calling moveToThread), and that my ':/something.svg' files cannot be loaded because Unknown error. I also can't add qsvg to my application, because I get wierd "undefined reference to `qt_plugin_instance_qsvg()'" errors.

Thanks for any help.

[wysota]

You need an SVG icon engine to be present in your application. If you compiled the application statically, you have to import the appropriate static plugin into your application. See the docs about static plugins for more details.

[Aceman2000]

Thanks for your reply,

I've read the doc like a thousand times (so if the solution really is there, I have selective vision ;) ). I did add a QT_PLUGIN += qsvg line to my .pro file, and also a Q_IMPORT_PLUGIN(qsvg) above my main(). This is producing the linker error (undefined reference to qt_plugin_instance_qsvg() ). It looks I'm missing something, but I can't figure out what... :o

[wysota]

Do you have the static plugin compiled?

[Aceman2000]

Afaik, yes. I have libqsvg4.a, libqsvg.a, libqsvgd.a, and qsvg4.dll in qt/4.3.3/plugins/iconengines

[Aceman2000]

up .

[jacek]

Do you use QMake binary from static Qt build? That linker error about plugin instance usually appears when you link a normal non-static plugin with your application.

[Aceman2000]

I have configured Qt with -static -release -no-exceptions.

[jacek]

Do you have more than one Qt version installed?

[Aceman2000]

No, only 4.3.3, and it's in the default directory, too.

[jacek]

Do you compile your application in the release mode?

[Aceman2000]

Yes. The linker error is in main.o (main.cpp contains the Q_IMPORT_PLUGIN(qsvg) line). Also, my project file now contains every combination of QT, _, PLUGIN, PLUGINS, +=, and qsvg that seems logical :)

[wysota]

Could you show us the sizes of files in iconengines? ls -l will do the trick on U*ix systems.

[jacek]

Could you post the command that make uses to link your application?

Run make > somefile.txt and find the line with -lqsvg in somefile.txt.

[Aceman2000]

Make stdout:

mingw32-make -f Makefile.Release
mingw32-make[1]: Entering directory `D:/prog/qt/sendfile'
g++ -static -enable-stdcall-fixup -Wl,-enable-auto-import -Wl,-enable-runtime-pseudo-reloc -Wl,-s -Wl,-subsystem,windows -o release\sendfile.exe object_script.sendfile.Release -L"c:\Qt\4.3.3\lib" -lmingw32 -lqtmain -LC:/Qt/4.3.3/plugins/iconengines -lqsvg4 -lQtXml -lQtGui -lQtNetwork -lgdi32 -lcomdlg32 -loleaut32 -limm32 -lwinmm -lwinspool -lmsimg32 -lQtCore -lkernel32 -luser32 -lshell32 -luuid -lole32 -ladvapi32 -lws2_32
mingw32-make[1]: Leaving directory `D:/prog/qt/sendfile'

-lqsvg doesn't appear, not even with

LIBS += -L$$[QT_INSTALL_PLUGINS]/iconengines -lqsvg

Dir in iconengines:

29 508 libqsvg.a
2 146 libqsvg4.a
1 255 072 libqsvgd.a
45 568 qsvg4.dll

[wysota]

You have two installations mixed up. libqsvg4.a and qsvg4.dll are an import and dynamic libraries from a shared installation and libqsvg.a and libqsvgd.a are static plugins (release and debug version respectively). I suggest moving libqsvg4.a and the dll out of the directory as the first thing to do as your application tries to link against the dynamic version of the plugin instead of the static one - hence the error.

And by the way, what is the contents of your lib subdirectory of the Qt installation? Do those libraries have .a or .dll extensions? If .a files have small sizes, they are import modules for dynamic libraries and not static versions of them.

[Aceman2000]

I used the Qt installer, and then ran a configure command. Will reinstall, maybe it cleans things up...

[wysota]

Why did you run configure? If you ran configure, then you should run make afterwards. Do you want a static compilation or is it just a way to solve your svg problems?

[Aceman2000]

I'm following these instructions: http://wiki.qtcentre.org/index.php?title=Building_static_Qt_on_Windows

I was misunderstandable, I did run configure AND make. Sorry about that. I want one exe file that needs no DLL's.

[wysota]

So I suggest you download the source code only and then configure and make. Don't install binaries or you'll be mixing two installations.

[Aceman2000]

Problem solved!

I'm not sure what solved it, so here's a list of what I did:

-uninstall Qt, remove any remaining files by hand
-reinstall Qt
-edit the g++ mkspecs (add -static to lflags)
-configure -static -release -no-qt3support -no-exceptions -no-qmake -fast
-make sub-corelib,sub-gui,sub-network,sub-svg, and sub-plugins (maybe I forgot one)

My .pro file's relevant lines are now

QT += svg
QTPLUGIN += qsvg
LIBS += -L$$[QT_INSTALL_PLUGINS]/iconengines
LIBS += $$[QT_INSTALL_PLUGINS]/iconengines/libqsvg.a

With this, my program compiles and shows the icons when run.

Thanks!

[wysota]

-edit the g++ mkspecs (add -static to lflags)
Huh? What for? Running configure -static should have taken care of that.

[Aceman2000]

Because this (http://wiki.qtcentre.org/index.php?title=Building_static_Qt_on_Windows) says so :)

[jpn]

Huh? What for? Running configure -static should have taken care of that.
As far as I remember it was required to kill dependency to mingwm10.dll. Notice that -static is added to QMAKE_LFLAGS. All what "configure -static" does is that it adds "CONFIG += static" which is not enough to kill the aforementioned dependency.

[wysota]

It's just for convenience, so that you don't have to add it to your projects. But ok, if J-P says it's "required" then let's agree it is :)

[jpn]

It's just for convenience, so that you don't have to add it to your projects. But ok, if J-P says it's "required" then let's agree it is :)
Heh, but you would have to add it to Qt project as well, wouldn't you?

[wysota]

Only if you didn't want MinGW dependencies. And let's face it, most Windows machines do have that library installed.

[jpn]

Only if you didn't want MinGW dependencies. And let's face it, most Windows machines do have that library installed.
I'm afraid I have to disagree with that. Usually you have mingwm10.dll available if and only if you have MinGW installed AND its bin folder added to PATH.

[Aceman2000]

I agree, at first (long time ago) my program didn't even execute (complaining about mingwm10.dll), only when I ran it from a Qt command prompt (which 'fixed' PATH).