Dead code in 'elf/rtld.c' with respect to USE___THREAD?

[Steven J. Hill]

Greetings.

I am curious about the code blocks in 'elf/rtld.c' that are surrounded
by '#if USE___THREAD'. How can this code ever be activated? Looking at
'include/tls.h' we have:

#if USE_TLS && HAVE___THREAD \
     && (!defined NOT_IN_libc || defined IS_IN_libpthread)

# define USE___THREAD 1

#else

# define USE___THREAD 0

#endif

Where are the cases that 'elf/rtld.c' are built as part of the pthreads
library or built into the C library? Thanks in advance for clarification.

-Steve