Re: cyclictest hangs with posix interval timers !?

[Robert Schwebel <r.schwebel@pengutronix.de>]

On Mon, Jan 08, 2007 at 11:10:16AM +0100, Steven Scholz wrote:
> As I wrote I have problems linking it statically!
> 
>  gcc -Wall -O2  -lpthread -lrt cyclictest.c -o cyclictest -static
> 
> results in

...
 
> while
> 
>  gcc -Wall -O2 cyclictest.c -o cyclictest -lrt -lpthread -static
> 
> compiles and links fine!
> 
> Any idea why the order matters?

The order does always matter. From 'info gcc': 

     It makes a difference where in the command you write this option;
     the linker searches and processes libraries and object files in
     the order they are specified.  Thus, `foo.o -lz bar.o' searches
     library `z' after file `foo.o' but before `bar.o'.  If `bar.o'
     refers to functions in `z', those functions may not be loaded.

So in your first case, run with -v to see the linker options:

rsc@isonoe:~/tmp/cyclictest$ gcc -v -Wall -O2  -lpthread -lrt cyclictest.c -o cyclictest -static 2>&1 | grep collect2
 /usr/lib/gcc/i486-linux-gnu/4.1.2/collect2 -m elf_i386 -static -o
cyclictest /usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../lib/crt1.o
/usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../lib/crti.o
/usr/lib/gcc/i486-linux-gnu/4.1.2/crtbeginT.o
-L/usr/lib/gcc/i486-linux-gnu/4.1.2 -L/usr/lib/gcc/i486-linux-gnu/4.1.2
-L/usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../lib -L/lib/../lib
-L/usr/lib/../lib -lpthread -lrt /tmp/cc2ooNdo.o --start-group -lgcc
-lgcc_eh -lc --end-group /usr/lib/gcc/i486-linux-gnu/4.1.2/crtend.o
/usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../lib/crtn.o
collect2: ld returned 1 exit status

... crt1.o crti.o crtbeginT.o -lpthread -lrt cc2ooNdo.o crtend.o

Robert
-- 
 Dipl.-Ing. Robert Schwebel | http://www.pengutronix.de
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