setjmp
======

POSIX specification: http://www.opengroup.org/susv3xsh/setjmp.html

Gnulib module: ---

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  * POSIX does not specify whether setjmp saves the signal mask in the jmp_buf.  It does on BSD platforms, and on glibc platforms when _BSD_SOURCE is defined; in this case setjmp behaves like sigsetjmp(.,1), and functions _setjmp and _longjmp are available that don't save or restore the signal mask.  On System V platforms (excluding HP-UX), and on glibc platforms by default, setjmp doesn't save the signal mask.