how to fix " Missing argument to '-L' " error ?

Ahti · wrote on 15 Jun 2017, 09:30

Hi

I was working on a project in qt but suddenly it generated a strange error saying :

error: missing argument to '-L'

what is that ? and how should i fix it ?

please help.
thanks

JohanSolo · 15 Jun 2017, 10:12

Could you show your .pro file?
What exactly do you mean by "suddenly"? Did a restart, update occur between the working and non-working state?

Ahti · 15 Jun 2017, 12:03

@JohanSolo

#-------------------------------------------------
#
# Project created by Ahtisham 2016-08-16T13:18:59
#
#-------------------------------------------------

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = testMyProject
TEMPLATE = app


SOURCES += main.cpp\
       eyecare.cpp \
   others.cpp

HEADERS  += eyecare.h \
   others.h

FORMS    += eyecare.ui

RESOURCES += \
   images.qrc


win32:CONFIG(release,debug|release): LIBS += -L&&PWD/Dll/ -ldxva2
win32:CONFIG(release,debug|release): LIBS += -L$$PWD/Library/ -ldxva2
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/Library/ -ldxva2
else:unix: LIBS += -L$$PWD/Library/ -ldxva2

INCLUDEPATH += $$PWD/Library
DEPENDPATH += $$PWD/Library

win32:CONFIG(release, debug|release): LIBS += -L$$PWD/Library/ -luser32
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/Library/ -luser32
else:unix: LIBS += -L$$PWD/Library/ -luser32

INCLUDEPATH += $$PWD/Library
DEPENDPATH += $$PWD/Library

DISTFILES +=

no neither restart nor update occurred but i don't know what caused this problem it was working fine.

Eddy · wrote on 15 Jun 2017, 11:55

If you lucky you can clean (or even delete) the target folder)
Then run qmake + build.

Did you change any folders or library names?

Do you use a version system? Then you can compare the differences?

koahnig · 15 Jun 2017, 12:34

@Ahti said in how to fix " Missing argument to '-L' " error ?:

@JohanSolo

#-------------------------------------------------
#
# Project created by Ahtisham 2016-08-16T13:18:59
#
#-------------------------------------------------

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = testMyProject
TEMPLATE = app


SOURCES += main.cpp\
       eyecare.cpp \
   others.cpp

HEADERS  += eyecare.h \
   others.h

FORMS    += eyecare.ui

RESOURCES += \
   images.qrc


win32:CONFIG(release,debug|release): LIBS += -L&&PWD/Dll/ -ldxva2
win32:CONFIG(release,debug|release): LIBS += -L$$PWD/Library/ -ldxva2
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/Library/ -ldxva2
else:unix: LIBS += -L$$PWD/Library/ -ldxva2

INCLUDEPATH += $$PWD/Library
DEPENDPATH += $$PWD/Library

win32:CONFIG(release, debug|release): LIBS += -L$$PWD/Library/ -luser32
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/Library/ -luser32
else:unix: LIBS += -L$$PWD/Library/ -luser32

INCLUDEPATH += $$PWD/Library
DEPENDPATH += $$PWD/Library

DISTFILES +=

no neither restart nor update occurred but i don't know what caused this problem it was working fine.

In here shall be probably a '$' sign

win32:CONFIG(release,debug|release): LIBS += -L&&PWD/Dll/ -ldxva2

change to

win32:CONFIG(release,debug|release): LIBS += -L$$PWD/Dll/ -ldxva2

Ahti · wrote on 15 Jun 2017, 12:34

@koahnig

Now i get these errors:

https://ibb.co/eE4GiQ

:(

Ahti · 15 Jun 2017, 12:51

After doing what @Eddy said the app started to work :)

Eddy · 15 Jun 2017, 12:53

@Ahti

Good deal!

Ahti · E Eddy 15 Jun 2017, 12:51

@Eddy lol it still gives those 3 errors :(

Eddy · 15 Jun 2017, 13:07

Good to see it's funny to you ;-)

Can you edit the link to you image or just copy the text here? We cannot see the image in your previous post.
You can use an image provider to show it to us by following this topic
There is still a problem with the uploading of image in the Qt forum. The admins are working on it though.

Edit : did you check the hint from @koahnig ?

Ahti · E Eddy 15 Jun 2017, 12:59

@Eddy see i edited the post

changing from && to $$ ? yes i did that but now i am gettings those errors

note the problem is with those Dll files i know it because when i delete them and run my project it works.

Eddy · 15 Jun 2017, 13:48

why do you have those 2 lines?

win32:CONFIG(release,debug|release): LIBS += -L$$PWD/Dll/ -ldxva2
win32:CONFIG(release,debug|release): LIBS += -L$$PWD/Library/ -ldxva2

Is one of them not enough?
The Dll path seems redundant since you don't use it further on

Ahti · 15 Jun 2017, 14:13

@Eddy

Okay removed everything except :

win32:CONFIG(release,debug|release): LIBS += -L$$PWD/Dll/ -ldxva2

but still getting those 3 errors

I use that Dll file for getting some windows functions that i need in my project.
functions like :
GetDesktopWindow();
MonitorFromWIndow();
GetCurrentBrightness();
etc

Eddy · 15 Jun 2017, 15:46

what is in your $$PWD/Dll/ folder?

koahnig · A Ahti 15 Jun 2017, 13:48

@Ahti said in how to fix " Missing argument to '-L' " error ?:

@Eddy

Okay removed everything except :
win32:CONFIG(release,debug|release): LIBS += -L$$PWD/Dll/ -ldxva2
but still getting those 3 errors

I use that Dll file for getting some windows functions that i need in my project.
functions like :
GetDesktopWindow();
MonitorFromWIndow();
GetCurrentBrightness();
etc

The problem ist that this is only working for release. Therefore, you need to be sure that you are in release mode.
Also sometimes it is good to rerun qmake and possibly rebuild your libraries.

Ahti · 15 Jun 2017, 15:47

@Eddy

3 windows dll files

dxva2.dll, dxva264.dll and user32.dll

koahnig · 15 Jun 2017, 15:58

@Ahti said in how to fix " Missing argument to '-L' " error ?:

@Eddy

3 windows dll files

dxva2.dll, dxva264.dll and user32.dll

no libs with those file names?
The dlls are used during run time, but while linking you need to have the libs created together with the dlls there.

Ahti · 15 Jun 2017, 16:04

@koahnig

now i got the libs but still getting that error :(

koahnig · 16 Jun 2017, 12:59

@Ahti said in how to fix " Missing argument to '-L' " error ?:

@koahnig

now i got the libs but still getting that error :(

What is the actual error message with your current configuration?
Probably it would be good also to post the current .pro file.

Ahti · 16 Jun 2017, 13:06

@koahnig

those three errors that i already mentioned.

my new pro file:

#-------------------------------------------------
#
# Project created by Ahtisham 2016-08-16T13:18:59
#
#-------------------------------------------------

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = testMyProject
TEMPLATE = app


SOURCES += main.cpp\
        eyecare.cpp \
    others.cpp

HEADERS  += eyecare.h \
    others.h

FORMS    += eyecare.ui

RESOURCES += \
    images.qrc


win32:CONFIG(release,debug|release): LIBS += -L$$PWD/Dll/ -ldxva2
win32:CONFIG(release,debug|release): LIBS += -L$$PWD/Library/ -ldxva2
else:win32:CONFIG(debug,debug|release): LIBS += -L$$PWD/Library/ -ldxva2
else:unix: LIBS += -L$$PWD/Library/ -ldxva2

INCLUDEPATH += $$PWD/Library
DEPENDPATH += $$PWD/Library

win32:CONFIG(release, debug|release): LIBS += -L$$PWD/Library/ -luser32
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/Library/ -luser32
else:unix: LIBS += -L$$PWD/Library/ -luser32

INCLUDEPATH += $$PWD/Library
DEPENDPATH += $$PWD/Library

DISTFILES +=