Fix implicit declaration warnings

[IgorTodorovskiIBM]

Various projects emit implicit declaration warnings. Although these are considered warnings, they can have an impact on functionality. For example, if execvp is implicitly declared, we'll pick up the EBCDIC definition. This is because the execvp symbol represents the EBCDIC definition, whereas ASCII definition is in symbol @@A00085.

Here's a list based on a grep of all of the Jenkins logs:

arc4random.c getentropy
basenc.c __disableautocvt
bufwrite.c __chgfdccsid
builtin.c fwrite_unlocked
builtin.c lgamma_r
builtin.c setenv
check_aliases.c getpwnam
combine-diff.c __disableautocvt
copy.c __copyfdccsid
copy.c __setfdccsid
debug.c fwrite_unlocked
defaults.c getpwnam
diff.c __disableautocvt
diff.c validate_codeset
digest.c __disableautocvt
entry.c __chgfdcodeset
entry.c __disableautocvt
entry.c __setfdbinary
entry.c __setfdtext
entry.c truncate
exp_chan.c exp_background_channelhandler
exp_clib.c alarm
exp_clib.c close
exp_clib.c execvp
exp_clib.c exp_init_tty
exp_clib.c fork
exp_clib.c pipe
exp_clib.c read
exp_clib.c setpgrp
exp_clib.c setsid
exp_clib.c waitpid
exp_clib.c write
exp_main_sub.c exp_tty_cooked_echo
expr.c mpz_out_str
exp_trap.c exp_dsleep
extract.c lseek
extract.c read
extract.c symlink
extract.c unlink
factor.c mpz_out_str
fileio.c __file_needs_conversion
fileio.c isatty
fileio.c lseek
fileio.c read
fileio.c unlink
fileio.c write
findkey.c bcmp
findme.c free
findme.c getenv
gdbmfetch.c bcopy
gdbmopen.c bcopy
gdbmseq.c bcopy
gdbmstore.c bcopy
getprogname.c getpid
getrandom.c getrandom
ialloc.h reallocarray
iconv.c iconv
iconv_open.c iconv_open
io.c fwrite_unlocked
libm.h significand
main.c fn
mischelp.c gnupg_unsetenv
mmap_alloc.c malloc
object-file.c __disableautocvt
od.c __disableautocvt
os390.c __setfdccsid
perl.c init_os_extras
pipeline.c clearenv
popt.c execvp
poptconfig.c close
poptconfig.c getenv
poptconfig.c lseek
poptconfig.c read
poptint.h free
process.c close
process.c lseek
process.c read
pty_termios.c expErrnoMsg
random.c getentropy
read-cache.c __disableautocvt
rndgetentropy.c getentropy
routines.c mkstemp
screen.c tgetent
screen.c tgetflag
screen.c tgetnum
screen.c tgetstr
screen.c tgoto
screen.c tputs
sort.c setenv
strlist.c fnmatch
strndup.c strnlen
subst.c __chgfdccsid
syscall.c lutimes
tempfile.c mkdtemp
ttyio.c close
ttyio.c read
ttyname_dev.c minor
unix.c chown
unix.c fchown
unix.c lchown
unix.c utime
unzip.c isatty
util2.c nanosleep
xmbsrtowcs.c mbsnrtowcs
xvasprintf.c vasprintf
zipinfo.c isatty

I don't have the project information because this is a grep of the generic Port-Build job logs, but we should be able to easily figure out the project based on the source file name.

[IgorTodorovskiIBM]

• The exp_* issues are from expect and is covered under https://github.com/ZOSOpenTools/expectport/issues/1

[MikeFultonDev]

Do you have ideas on how this might be fixed @IgorTodorovskiIBM ?