@node setjmp
@subsection @code{setjmp}
@findex setjmp

POSIX specification:@* @url{https://pubs.opengroup.org/onlinepubs/9799919799/functions/setjmp.html}

Gnulib module: ---

Portability problems fixed by Gnulib:
@itemize
@end itemize

Portability problems not fixed by Gnulib:
@itemize
@item
POSIX does not specify whether @code{setjmp} saves the signal mask in the
@code{jmp_buf}.  It does on BSD platforms, and on glibc platforms when
@code{_BSD_SOURCE} (and/or @code{_DEFAULT_SOURCE} on glibc >= 2.19) is defined;
in this case @code{setjmp} behaves like @code{sigsetjmp(.,1)}, and functions
@code{_setjmp} and @code{_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, @code{setjmp} doesn't save the signal mask.
@end itemize
