qt does not try to find a 3rd party lib even though its location is specified

ohuohuo

@kenchan no, it's on Ubuntu12.04 32bit. The compile output is:

23:39:32: Running build steps for project RemoteClient...
23:39:32: Configuration unchanged, skipping qmake step.
23:39:32: Starting: "/usr/bin/make" -w
make: Entering directory /home/.../QtWorkspace/RemoteClient-build-desktop-Qt_4_8_1_in_PATH__System__Debug' make: Nothing to be done for first'.
make: Leaving directory `/home/.../QtWorkspace/RemoteClient-build-desktop-Qt_4_8_1_in_PATH__System__Debug'
23:39:32: The process "/usr/bin/make" exited normally.

kenchan

hmm not very useful since you are not rebuilding...
now what does it look like when you do this...
clean
run qmake
build or rebuild just to be sure :-)

ohuohuo

@kenchan yeah, I rebuilt that , but it's large file which part you think would be most interesting?
output of just ran qmake:
00:01:05: Running build steps for project RemoteClient...
00:01:05: Starting: "/usr/bin/qmake-qt4" /home/.../QtWorkspace/RemoteClient/RemoteClient.pro -r -spec linux-g++ CONFIG+=debug CONFIG+=declarative_debug
00:01:05: The process "/usr/bin/qmake-qt4" exited normally.

ohuohuo

@kenchan I looked at the output of ldd, it seems that this program does not depend on libMPCtrl.so and libPlayCtrl.so files. And after I changed to unix{
LIBS += -L./lib/ -Wl,-rpath=./lib/,-rpath=./ -lhcnetsdk -lPlayCtrl -lMPCtrl
}, I can neither find libMPCtrl.so nor libPlayCtrl.so.

kenchan

@ohuohuo good point, i guess you mean it is a large project with many source files?
OK how about cutting a bit that shows the last couple of compiled modules and then the linker stuff up to the end, or is that still too much?

kenchan

so if you don't link to them it will not run, is that the problem?

KeithS

@ohuohuo

"it seems that this program does not depend on libMPCtrl.so and libPlayCtrl.so files"

So maybe I'm missing something, but from what you have said it seems your app does not depend on the shared libraries hence that's why it doesn't try and load them? What exactly is the error message you are getting when you try and run the app?

btw I think your LIBS line in the .pro file is not quite right:

unix{
LIBS += -L./lib/ -Wl,-rpath=./lib/,-rpath=./ -lhcnetsdk -lPlayCtrl -lMPCtrl
}

The rpath stuff does not belong here, it should be in QMAKE_LFLAGS e.g I have:

QMAKE_LFLAGS += -rdynamic
QMAKE_LFLAGS += '-Wl,-rpath,'$$ORIGIN/../lib',-z,origin'
QMAKE_LFLAGS_RPATH=

which makes the executable look in <executable_dir>../lib for the shared libs to be loaded at runtime. Then for 3rd party libs I use:

LIBS += -L<path_to_lib> -l<lib_name>

You don't need a trailing '/' after the -L path.

asanka424

If you don't get any compile errors or runtime errors and your only concern is those .so files are not being read while your program is in run, my guess is that your program is not using those library functions at all

ohuohuo

@asanka424 exactly, so the question is how can I load these libs, I must use functions in them

asanka424

In your code do you call functions from that library?

ohuohuo

@asanka424 yeah, and when I call it, the SDK will show me an error "Fail to load Player SDK"

asanka424

so when you start your executable it runs but when it reaches that particular call it will show an error? If that is the case, my guess is that your library needs some pluggins and it doesn't find those (or that) pluggin(s).

I didn't look at the library. Is it related to playing video? If so it probably relying on some codecs. (Just a guess)

ohuohuo

@asanka424 you know what, I have an example program, which provided by vender, it works fine! no any plugins, no other things, same libs. And I checked out its pro. file, they have same functionalities. while mine just doesn't work...

asanka424

@ohuohuo Ok so this for me to understand your setup.

You have a code from a vendor you can build and run without any problem

When you code the same functionality in your code it compiles and runs but gives you errors while its running?

Am I correct?

ohuohuo

@kenchan no, it will run nevertheless, but just gives me this error from SDK itself (not leads to a crash) "Failed to load Player SDK" when I call one of its functions in the missing lib. I guess calling other functions in the same lib will be the same result. functions in other libs, which are loaded like libhcnetsdk.so is good to call.

ohuohuo

@asanka424 exactly! well, I mean of course source code is not the same, but same functionalities and the input parameters to the function are correct.

ohuohuo

@KeithS Thanks much for your reply. But after I used QMAKE_LFLAGS instand of LIBS, a lot of undefined reference errors come out.

asanka424

@ohuohuo in vendors .pro file does it set any rpaths? If your program directly uses any functions of those libraries, it won't compile. Is this a multimedia application?

KeithS

@ohuohuo
What errors do you get? It may be you have an error in your .pro file.

ohuohuo

@asanka424 yes. But why it won't compile? I have those dynamic libs, too. It is remote video application, it can connect to a remote device,which as server.

this is the whole .pro file:

TEMPLATE = app

UI_DIR = obj/Gui
MOC_DIR = obj/Moc
OBJECTS_DIR = obj/Obj

TARGET = ../lib/QtClientDemo
QT += core
gui
opengl

TRANSLATIONS = ../../translation/QtDemo_zh_CN.ts

RESOURCES = ../../src/Player.qrc

win32 {
}

unix {
LIBS += -L../lib/ -Wl,-rpath=../lib/,-rpath=./ -lhcnetsdk -lPlayCtrl -lMPCtrl
}

HEADERS += ../../src/MainWindow/DeviceTree/DeviceAttr/deviceattr.h
... // I replaced a bunch of paths here with ellipsis
../../src/Public/DemoPublic.h

SOURCES += ../../src/MainWindow/DeviceTree/DeviceAttr/deviceattr.cpp
... //I replaced a bunch of paths here with ellipsis
../../src/RealPlay/FramePlayWnd.cpp

FORMS += ../../src/MainWindow/DeviceTree/DeviceAttr/deviceattr.ui
...//I replaced a bunch of paths here with ellipsis
../../src/RealPlay/FramePlayWnd.ui

INCLUDEPATH += ../../src/MainWindow/DeviceTree/
...//I replaced a bunch of paths here with ellipsis
../../src/Public

include(../../src/ParaConfig/configure_params/RemoteParams/RemoteParams.pri)
...//I replaced a bunch of paths here with ellipsis
include(../../src/ParaConfig/configure_params/HardDiskParams/HardDiskParams.pri)