chrishowells.co.uk

I examined the most recent source code package released by WD (Western Digital) for their WDTV product, and unfortunately WDTV is still a GPL violation.

I’m trying to statically compile a Qt application. There are lots of google hits for instructions on doing this, but none of the instructions actually appear to be complete, or indeed work.

Configuring Qt with -static is the easy bit, I built Qt with the following options:


chris@thinky:~/qt-embedded-linux-opensource-src-4.4.3$ ./configure -embedded x86 -static -fast -no-exceptions -no-stl -no-accessibility -no-qt3support -no-xmlpatterns -no-phonon -no-phonon-backend -no-svg -no-webkit -no-sse -no-3dnow -no-sse2 -qt-zlib -qt-gif -qt-libtiff -qt-libpng -no-libmng -qt-libjpeg -no-openssl -no-nis -no-cups -no-iconv -no-dbus -no-freetype -qt-gfx-linuxfb -no-glib


Then as I already have Qt 4 installed on my system due to KDE, need to set $PATH to run the correct tools:


export PATH=/home/chris/qt-embedded-linux-opensource-src-4.4.3/bin:$PATH


I decided to modify the t1 example as a test, so I modified the t1.pro file, by adding ’static’ to the CONFIG line


chris@thinky:~/qt-embedded-linux-opensource-src-4.4.3/examples/tutorials/tutorial/t1$ cat t1.pro
TEMPLATE = app
CONFIG += qt warn_on static
HEADERS =
SOURCES = main.cpp
TARGET = t1

chris@thinky:~/qt-embedded-linux-opensource-src-4.4.3/examples/tutorials/tutorial/t1$ qmake -config release
chris@thinky:~/qt-embedded-linux-opensource-src-4.4.3/examples/tutorials/tutorial/t1$ make clean && make
rm -f .obj/release-static-emb-x86/main.o
rm -f *~ core *.core
g++ -c -pipe -fno-exceptions -O2 -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -D_LARGEFILE64_SOURCE -D_LARGEFILE_SOURCE -I../../../../mkspecs/qws/linux-x86-g++ -I. -I../../../../include/QtCore -I../../../../include/QtCore -I../../../../include/QtNetwork -I../../../../include/QtNetwork -I../../../../include/QtGui -I../../../../include/QtGui -I../../../../include -I.moc/release-static-emb-x86 -I.uic/release-static-emb-x86 -o .obj/release-static-emb-x86/main.o main.cpp
g++ -fno-exceptions -Wl,-rpath,/usr/local/Trolltech/QtEmbedded-4.4.3/lib -Wl,-rpath,/usr/local/Trolltech/QtEmbedded-4.4.3/lib -o t1 .obj/release-static-emb-x86/main.o -L/home/chris/qt-embedded-linux-opensource-src-4.4.3/lib -lQtGui -L/home/chris/qt-embedded-linux-opensource-src-4.4.3/lib -lQtNetwork -lQtCore -lm -lrt -lpthread -ldl


However, the binary is still dynamically linked:


chris@thinky:~/qt-embedded-linux-opensource-src-4.4.3/examples/tutorials/tutorial/t1$ file t1
t1: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), for GNU/Linux 2.6.8, dynamically linked (uses shared libs), not stripped
chris@thinky:~/qt-embedded-linux-opensource-src-4.4.3/examples/tutorials/tutorial/t1$ ldd t1
linux-gate.so.1 => (0xffffe000)
librt.so.1 => /lib/tls/i686/cmov/librt.so.1 (0xb7fb5000)
libpthread.so.0 => /lib/tls/i686/cmov/libpthread.so.0 (0xb7f9d000)
libdl.so.2 => /lib/tls/i686/cmov/libdl.so.2 (0xb7f98000)
libstdc++.so.6 => /usr/lib/libstdc++.so.6 (0xb7ea5000)
libm.so.6 => /lib/tls/i686/cmov/libm.so.6 (0xb7e80000)
libgcc_s.so.1 => /lib/libgcc_s.so.1 (0xb7e75000)
libc.so.6 => /lib/tls/i686/cmov/libc.so.6 (0xb7d2b000)
/lib/ld-linux.so.2 (0xb7fdc000)


Google seems to be out of results, and I appear to be out of ideas, as does the official Qt documentation.

Speaking to a Qt developer (who shall rename nameless to preserve his sanity, although I appreciate his help :), you can configure qmake to make a fully static app by adding the following line to the qmake config:


QMAKE_LFLAGS += -static


After running qmake again, this leads to the following:


chris@thinky:~/qt-embedded-linux-opensource-src-4.4.3/examples/tutorials/tutorial/t1$ make
g++ -c -pipe -fno-exceptions -O2 -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -D_LARGEFILE64_SOURCE -D_LARGEFILE_SOURCE -I../../../../mkspecs/qws/linux-x86-g++ -I. -I../../../../include/QtCore -I../../../../include/QtCore -I../../../../include/QtNetwork -I../../../../include/QtNetwork -I../../../../include/QtGui -I../../../../include/QtGui -I../../../../include -I.moc/release-static-emb-x86 -I.uic/release-static-emb-x86 -o .obj/release-static-emb-x86/main.o main.cpp
g++ -fno-exceptions -static -Wl,-rpath,/usr/local/Trolltech/QtEmbedded-4.4.3/lib -Wl,-rpath,/usr/local/Trolltech/QtEmbedded-4.4.3/lib -o t1 .obj/release-static-emb-x86/main.o -L/home/chris/qt-embedded-linux-opensource-src-4.4.3/lib -lQtGui -L/home/chris/qt-embedded-linux-opensource-src-4.4.3/lib -lQtNetwork -lQtCore -lm -lrt -lpthread -ldl
/home/chris/qt-embedded-linux-opensource-src-4.4.3/lib/libQtCore.a(qlibrary_unix.o): In function `QLibraryPrivate::load_sys()':
qlibrary_unix.cpp:(.text+0x307): warning: Using 'dlopen' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/home/chris/qt-embedded-linux-opensource-src-4.4.3/lib/libQtCore.a(qfsfileengine_unix.o): In function `QFSFileEngine::owner(QAbstractFileEngine::FileOwner) const':
qfsfileengine_unix.cpp:(.text+0x838): warning: Using 'getgrgid_r' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
qfsfileengine_unix.cpp:(.text+0x736): warning: Using 'getpwuid_r' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/home/chris/qt-embedded-linux-opensource-src-4.4.3/lib/libQtNetwork.a(qhostinfo_unix.o): In function `QHostInfoAgent::fromName(QString const&)':
qhostinfo_unix.cpp:(.text+0x30e): warning: Using 'getaddrinfo' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking


Not good. It turns out that linking statically to glibc is hard, because getXXbyYY such as getpwuid_r require NSS, which is a loadable module….

Next step is to try compiling Qt against uClibc.

I took a series of images at the recent LivLug meeting and stitched them into this panorama, I’m quite pleased how it turned out. It’s not as good as it could be as I was trying to work quickly, on account of it being very cold indeed that evening. Will have to revisit during the summer and re-take it.

Canon EOS 20D, 100-400mm L, 10 second exposure, f/10.

(click for larger version)