Compiling ServFox or other Threaded Applications tip

If you take a look at the ServFox source, you'll notice that it uses pthreads.
This is a threading library that is provided in the BSP distribution (in uClinux-dist/lib/lib/libpthread.a)

Unfortunately, it doesn't compile well at all with the default gcc 3.0, and gcc complains about missing pthread header function bits.

Code: [Select]

make
arm-elf-gcc -O2 -DLINUX  -c -o server.o server.c
arm-elf-gcc -O2 -DLINUX  -c -o spcav4l.o spcav4l.c
arm-elf-gcc -O2 -DLINUX  -c -o utils.o utils.c
arm-elf-gcc -O2 -DLINUX  -c -o tcputils.o tcputils.c
arm-elf-gcc -O2 -DLINUX  -o servfox server.o spcav4l.o utils.o tcputils.o  -lpthread
/usr/local/arm_tools/bin/../lib/gcc-lib/arm-elf/3.0/../../../../arm-elf/lib/libpthread.a(join.o): In function `pthread_exit':
join.o(.text+0x190): undefined reference to `thcfg'
/usr/local/arm_tools/bin/../lib/gcc-lib/arm-elf/3.0/../../../../arm-elf/lib/libpthread.a(join.o): In function `$a':
join.o(.text+0x25c): undefined reference to `thcfg'
/usr/local/arm_tools/bin/../lib/gcc-lib/arm-elf/3.0/../../../../arm-elf/lib/libpthread.a(join.o): In function `pthread_join':
join.o(.text+0x48c): undefined reference to `thcfg'
/usr/local/arm_tools/bin/../lib/gcc-lib/arm-elf/3.0/../../../../arm-elf/lib/libpthread.a(join.o): In function `pthread_detach':
join.o(.text+0x600): undefined reference to `thcfg'
/usr/local/arm_tools/bin/../lib/gcc-lib/arm-elf/3.0/../../../../arm-elf/lib/libpthread.a(manager.o): In function `pthread_allocate_stack':
manager.o(.text+0x4d4): undefined reference to `thcfg'
/usr/local/arm_tools/bin/../lib/gcc-lib/arm-elf/3.0/../../../../arm-elf/lib/libpthread.a(manager.o)(.text+0x854): more undefined references to `thcfg' follow
collect2: ld returned 1 exit status
make: *** [servfox] Error 1

Hmm, lets have a quick look at our compiler.

Code: [Select]

arm-elf-gcc -v
Reading specs from /usr/local/arm_tools/bin/../lib/gcc-lib/arm-elf/3.0/specs
Configured with: ../gcc-3.0/configure --target=arm-elf --host=i686-pc-linux --build=i686-pc-linux --prefix=/home/clyu2/gcc3.0/arm_com --with-gnu-ld --with-gnu-as : (reconfigured) ../gcc-3.0/configure --target=arm-elf --host=i686-pc-linux --build=i686-pc-linux --prefix=/home/clyu2/gcc3.0/arm_com --with-gnu-ld --with-gnu-as --with-newlib : (reconfigured) ../gcc-3.0/configure --target=arm-elf --host=i686-pc-linux --build=i686-pc-linux --prefix=/home/clyu2/gcc3.0/arm_com --with-gnu-ld --with-gnu-as --with-newlib : (reconfigured) ../gcc-3.0/configure --target=arm-elf --host=i686-pc-linux --build=i686-pc-linux --prefix=/home/clyu2/gcc3.0/arm_com --with-gnu-ld --with-gnu-as --with-newlib : (reconfigured) ../gcc-3.0/configure --target=arm-elf --host=i686-pc-linux --build=i686-pc-linux --prefix=/home/clyu2/gcc3.0/arm_com --with-gnu-ld --with-gnu-as --with-newlib : (reconfigured) ../gcc-3.0/configure --target=arm-elf --host=i686-pc-linux --build=i686-pc-linux --prefix=/home/clyu2/gcc3.0/arm_com --with-gnu-ld --with-gnu-as --with-newlib : (reconfigured) ../gcc-3.0/configure --target=arm-elf --host=i686-pc-linux --build=i686-pc-linux --prefix=/home/clyu2/gcc3.0/arm_com --with-gnu-ld --with-gnu-as --with-newlib : (reconfigured) ../gcc-3.0/configure --target=arm-elf --host=i686-pc-linux --build=i686-pc-linux --prefix=/home/clyu2/gcc3.0/arm_com --with-gnu-ld --with-gnu-as --with-newlib : (reconfigured) ../gcc-3.0/configure --target=arm-elf --host=i686-pc-linux --build=i686-pc-linux --prefix=/home/clyu2/gcc3.0/arm_com --with-gnu-ld --with-gnu-as --with-newlib
Thread model: single
gcc version 3.0

Any bonus points for working out what the issue is?  Hint, our Thread model could be an issue
Thats what you get when you use the default toolchains from a BSP, sigh..


What to do?

Use our gcc 3.3.4 compiler!


Remember to make clean first, so that the borked .o files are gone, and run gcc (3.3.4)

Code: [Select]

make clean
Cleaning up directory.
rm -f *.a *.o servfox   core *~ log errlog
minty servfox # make
arm-elf-gcc -O2 -DLINUX  -c -o server.o server.c
arm-elf-gcc -O2 -DLINUX  -c -o spcav4l.o spcav4l.c
arm-elf-gcc -O2 -DLINUX  -c -o utils.o utils.c
arm-elf-gcc -O2 -DLINUX  -c -o tcputils.o tcputils.c
arm-elf-gcc -O2 -DLINUX  -o servfox server.o spcav4l.o utils.o tcputils.o  -lpthread

Nice and clean with 3.3.4!

Code: [Select]

arm-elf-gcc -v
Reading specs from /usr/local/arm_tools_3.3.4/bin/../lib/gcc-lib/arm-elf/3.3.4/specs
Configured with: /Temp/make-compile/arm-tool/gcc-3.3.4/configure --target=arm-elf --prefix=/Temp/make-compile/arm_tools_3.3.4 --enable-languages=c,c++ --enable-target-optspace --with-gnu-ld --with-local-prefix=/Temp/make-compile/arm_tools_3.3.4/arm-elf --disable-nls --disable-__cxa_atexit --enable-c99 --enable-long-long --disable-clocale --disable-c-mbchar --enable-static --disable-shared --enable-threads=posix --enable-cxx-flags="-D_ISOC99_SOURCE -D_BSD_SOURCE"
Thread model: posix
gcc version 3.3.4

No thread problems now!