figuring out linker error on the dashboard

[Robby Stephenson]

On Wednesday 14 October 2009, Alexander Neundorf wrote:
> Can you please post the part which you snipped ?

Right, I guess I removed the important part, eh?
http://developer.kde.org/~dirk/dashboard/

cd tellico/src/tests && /usr/bin/cmake -E cmake_link_script 
CMakeFiles/gcstartest.dir/link.txt --verbose=1
/usr/local/bin/c++ -O2 -march=i586 -mtune=i686 -fmessage-length=0 -Wall -
D_FORTIFY_SOURCE=2 -fstack-protector -funwind-tables -fasynchronous-unwind-
tables -Werror=format-security -Wmissing-format-attribute -Wnon-virtual-dtor 
-Wno-long-long -ansi -Wundef -Wcast-align -Wchar-subscripts -Wall -W -
Wpointer-arith -Wformat-security -fno-exceptions -DQT_NO_EXCEPTIONS -fno-
check-new -fno-common -Woverloaded-virtual -fno-threadsafe-statics -
fvisibility=hidden -fvisibility-inlines-hidden -Wnon-virtual-dtor -Wno-long-
long -pedantic -Wextra -fno-check-new -O2 -DNDEBUG -DQT_NO_DEBUG -fPIC -
Wl,--enable-new-dtags CMakeFiles/gcstartest.dir/gcstartest_automoc.o 
CMakeFiles/gcstartest.dir/gcstartest.o -o gcstartest -rdynamic -Llib -Llib 
../../../lib/libtranslators.a ../../../lib/libmodels.a -lQtTest 
lib/libkdeui.so.5.4.0 lib/libkio.so.5.4.0 -lqimageblitz -lxml2 -lxslt -
lexslt ../../../lib/libtellicotest.a ../../../lib/libcollections.a 
../../../lib/libtranslators.a ../../../lib/libutils.a ../../../lib/libcore.a 
../../../lib/libimages.a ../../../lib/libcore.a ../../../lib/libgui.a 
lib/libkdeui.so.5.4.0 -lQtSvg lib/libkdecore.so.5.4.0 -lQtDBus -lQtCore -
lpthread -lQtNetwork -lQtXml -lQtGui -Wl,-rpath,lib -Wl,-rpath-link,lib
../../../lib/libimages.a(imagefactory.o): In function 
`Tellico::ImageFactory::createStyleImages(int, Tellico::StyleOptions 
const&)':
imagefactory.cpp:(.text+0x49a4): undefined reference to 
`Blitz::gradient(QSize const&, QColor const&, QColor const&, 
Blitz::GradientType)'
imagefactory.cpp:(.text+0x4a7c): undefined reference to 
`Blitz::unbalancedGradient(QSize const&, QColor const&, QColor const&, 
Blitz::GradientType, int, int)'
collect2: ld returned 1 exit status

>

-lqimageblitz  does come before ../../../lib/libimages.a there, it appears.

> Yes. Even if it's static, if it uses symbols from QImageBlitz, you
> should "link" it against QImageBlitz when using cmake. This will not
> really change anything in the binary static library file created, but
> then cmake will know that libimage needs QImageBlitz and will link
> everything you link against libimage also against QIMageBlitz.

OK, that makes sense. It still puzzles me as to  why that problem has only 
shown up on the dashboard build so far. No one else has experienced it...

> > At one point, I did notice weird things happened if I changed the order
> > of the libraries listed in the TARGET_LINK_LIBRARIES macro. I suppose
> > that
>
> For static libraries the order matters.
> If you have only static libs, if libA uses something from libB, then libB
> has to come after libA in the link command (it doesn't matter if it
> already appeared before). The linker loads the object files from libA
> which contain symbols used by "somebody". If these object files reference
> symbols which haven't been referenced before, it searches the libraries
> following libA for these symbols.

Thanks. All of my subdirectories are static libs that I link back to the 
main executable or test executable. I assume that's a typical way of setting 
things up? I'll need to add Qt and kdecore, at the least, to every lib, I 
think...

I appreciate the help.
Robby