This is the mail archive of the cygwin@cygwin.com mailing list for the Cygwin project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]

Re: compiling QT on cygwin(latest stable version) please help




chavez wrote:
> g++ -L/usr/local/qt/lib -Wl,-rpath,/usr/local/qt/lib   -o
> /usr/local/qt/bin/uic
> uic.o ../shared/widgetdatabase.o ../shared/domtool.o
> ../integration/kdevelop/kde
> widgets.o   -lqutil -L../lib -lqt  -L/usr/X11R6/lib -I/usr/X11R6/include  -l
> SM -
> lICE -lXft -L/usr/X11R6/lib -lGLU -lGL -lXmu  -lXext -lX11 -lm

This command doesn't include "-lpng" so of course the link fails -- it's
looking for symbols from libpng but you didn't link with libpng.

> 
> >From what I can figure out the functions that it is trying to call are
> located in 'src/3rdparty/libpng/png.c'.  Has anyone come across this
> problem, or know how to fix it?  The header files include <png.h> in
> qpngio.cpp, png.h has a bunch of stuff like this( which i have no idea what
> it does, and therefore can't fix ):
> /* Return the user pointer associated with the I/O functions */
> extern PNG_EXPORT(png_voidp,png_get_io_ptr) PNGARG((png_structp png_ptr));
> /* Fatal error in PNG image of libpng - can't continue */
> extern PNG_EXPORT(void,png_error) PNGARG((png_structp png_ptr,
>    png_const_charp error));

Just a guess, but I don't think you're using any of the code in
src/3rdparty/libpng/.  The cygwin platform comes with the png libraries
already compiled and installed.  The qt configure is *most likely*
finding them (in /usr/include, /usr/lib) and building against the
headers in /usr/include.  The only problem I see is that the Makefile,
for whatever reason, forgets to add -lpng to the link command.

And no, I don't know why and I don't know how to fix it -- other than to
manually edit the Makefiles and add '-lpng' to LDFLAGS.

--Chuck

--
Want to unsubscribe from this list?
Check out: http://cygwin.com/ml/#unsubscribe-simple


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]