[RFH] zsh shell function portability issue

[Paolo Bonzini]

You will remember the shell function portability issue in zsh...

Do you think that these functions:

ac_func_c_try_compile() {
  rm -f conftest.$ac_objext
  if { (ac_try="$ac_compile"
case "(($ac_try" in
  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
  *) ac_try_echo=$ac_try;;
esac
eval ac_try_echo="\"\$as_me:$LINENO: $ac_try_echo\""
$as_echo "$ac_try_echo") >&5
  (eval "$ac_compile") 2>conftest.er1
  ac_status=$?
  grep -v '^ *+' conftest.er1 >conftest.err
  rm -f conftest.er1
  cat conftest.err >&5
  $as_echo "$as_me:$LINENO: \$? = $ac_status" >&5
  (exit $ac_status); } && {
         test -z "$ac_c_werror_flag" ||
         test ! -s conftest.err
       } && test -s conftest.$ac_objext; then
  ac_retval=0
else
  $as_echo "$as_me: failed program was:" >&5
sed 's/^/| /' conftest.$ac_ext >&5

        ac_retval=1
fi

  rm -f core conftest.err conftest.$ac_objext
  return $ac_retval
}



and


ac_func_c_try_run() {
  if { (ac_try="$ac_link"
case "(($ac_try" in
  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
  *) ac_try_echo=$ac_try;;
esac
eval ac_try_echo="\"\$as_me:$LINENO: $ac_try_echo\""
$as_echo "$ac_try_echo") >&5
  (eval "$ac_link") 2>&5
  ac_status=$?
  $as_echo "$as_me:$LINENO: \$? = $ac_status" >&5
  (exit $ac_status); } && { ac_try='./conftest$ac_exeext'
  { (case "(($ac_try" in
  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
  *) ac_try_echo=$ac_try;;
esac
eval ac_try_echo="\"\$as_me:$LINENO: $ac_try_echo\""
$as_echo "$ac_try_echo") >&5
  (eval "$ac_try") 2>&5
  ac_status=$?
  $as_echo "$as_me:$LINENO: \$? = $ac_status" >&5
  (exit $ac_status); }; }; then
  ac_retval=0
else
  $as_echo "$as_me: program exited with status $ac_status" >&5
       $as_echo "$as_me: failed program was:" >&5
sed 's/^/| /' conftest.$ac_ext >&5

       ac_retval=$ac_status
fi

  rm -rf conftest.dSYM
  rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext
conftest.$ac_objext conftest$ac_exeext
  return $ac_retval
}

are portable?  (Yeah, the code is totally unreadable).

IMO the first should be okay because it only uses (exit ...) to drive an
&& construct.  In the second instead, I am worried about this:

  (eval "$ac_try") 2>&5
  ac_status=$?

but do we need that eval at all?  Maybe it can be replaced with a {...}
instead?

Thanks,

Paolo