Handling the compiler and loader flags using qmake [SOLVED]

[issam]

Hi,

I have to compile and link a Qt application which uses the GraphViz library. So I have to pass some flags to the compiler (g++) and the loader like this:

@
CFLAGS=pkg-config libgvc --cflags -Wall -g -O2
LDFLAGS=pkg-config libgvc --libs
@

How can I pass those flags through the qmake file ?

thnks in advance.

[SGaist]

Hi,

Have a look at the qmake Project file manual page, it shows how to use pkg-config with Qt's pro files

[issam]

Hi,

I have solved it like this :

@QMAKE_CXXFLAGS =pkg-config libgvc --cflags -Wall -g -O2
QMAKE_LFLAGS =pkg-config libgvc --libs@

thnks :)

[SGaist]

You should really use the PKGCONFIG variable, it will avoid you to modify these flags by hands

[issam]

Hi :)

I used PKGCONFIG like this:

@
CONFIG +=link_pkgconfig
PKGCONFIG = libgvc
PKGCONFIG += libgvc

QMAKE_CXXFLAGS = -Wall -g -O2
@

But i didn't understand correctly the advantage of PKGCONFIG!

[SGaist]

You avoid to have to set both QMAKE_CXXFLAGS and QMAKE_LFLAGS for each library you add through it

[issam]

Yes, you have right :)

@
CONFIG +=link_pkgconfig
PKGCONFIG = libgvc
PKGCONFIG += libgvc
@

Can you write two sentences about the advantages and basic role of the PKGCONFIG. I will be grateful :)

Thanks in advantage.

[SGaist]

What do you mean ?

[issam]

I mean some info about PKGCONFIG.

[SGaist]

PKGCONFIG contains the list of the library that you want to build against/link to and this content will be fed to the pkg-config command to retrieve the include paths and link flags.

Note that the libraries you list there must provide a pc file (most do)