pthread_rwlock_t & __USE_UNIX98 problem

["Hu, Boris" <boris hu intel com>]

arm-linux-gcc -g -c tst-rwlock1.c  -I../sysdeps/pthread 
-I../sysdeps/unix/sysv/linux/arm
tst-rwlock1.c:27: `pthread_rwlock_t' undeclared (first use in this function)
tst-rwlock1.c:27: (Each undeclared identifier is reported only once
tst-rwlock1.c:27: for each function it appears in.)
tst-rwlock1.c:27: parse error before "r"
tst-rwlock1.c:30: `r' undeclared (first use in this function)

Check  /nptl/sysdeps/unix/sysv/linux/arm/bits/pthreadtypes.h.
We could find the pthread_rwlock_t is protected by 
__USE_UNIX98.  We could compile tst-rwlock1.c with 
-D_GNU_SOURCE or -D_XOPEN_SOURCE=500 but how about the 
nptl library's compilation? 

another strange problem is that I add the following line
to sysdeps/geneic/lib-start.c
printf("  %p \n" __pthread_initialize_minimal );

output is (nil) to run tst-rwlock1 while it has a specified value when 
run other test cases. 

any hints? thanks. 

  Boris
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To know what I don't know
To learn what I don't know
To contribute what I know
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