[SV 62654] Support GNU Make on z/OS

Original patches provided by Igor Todorovski <itodorov@ca.ibm.com>
Reworked by Paul Smith <psmith@gnu.org>.
Thanks to IBM for providing a test system.

* NEWS: Announce support.
* AUTHORS: Ditto.
* README.zOS: Provide details on building GNU Make on z/OS.
* build.sh (get_mk_var): z/OS sh has a strange bug which causes it to
generate extra lines of output: rework the function to print output
as we compute it instead of collecting it into a variable, which
works around this bug.
* src/makeint.h: Declare MK_OS_ZOS if we're building for z/OS.
* src/arscan.c: Don't include <ar.h> on z/OS.
* src/job.c: We can't change environ in ASCII mode on z/OS.
* src/main.c: Ditto.  Also we can't use pselect() on z/OS.
* src/posixos.c: pselect() seems to hang on z/OS: don't use it.
* tests/run_make_tests.pl: Handle different exit codes on z/OS.
* tests/test_driver.pl: Preserve some special z/OS env.vars.
Add special checks to output comparisons when on z/OS.
* tests/scripts/features/archives: Don't validate names.  Don't
try to compile empty files as IBM compilers complain.
* tests/scripts/features/shell_assignment: Fix octal value of #.
* tests/scripts/features/temp_stdin: Don't print "term".
* tests/scripts/functions/shell: Handle shell exit codes.
* tests/scripts/targets/ONESHELL: Ditto.
* tests/scripts/targets/POSIX: sh -x prints differently.
* tests/scripts/variables/SHELL: Ditto.

21 files changed, 201 insertions, 43 deletions

diff --git a/AUTHORS b/AUTHORS
index cb5a90d7..9be61730 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -48,6 +48,9 @@ GNU Make porting efforts:
       Troy Runkel <Troy.Runkel@mathworks.com>
       Juan M. Guerrero <juan.guerrero@gmx.de>
 
+  Port to z/OS by:
+      Igor Todorovski <itodorov@ca.ibm.com>
+
 -----------------------------------
 Other contributors:
 
diff --git a/Makefile.am b/Makefile.am
index 49190d64..686851ff 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -112,7 +112,7 @@ test_FILES =	tests/run_make_tests tests/run_make_tests.bat \
 # test/scripts are added via dist-hook below.
 
 EXTRA_DIST =	ChangeLog INSTALL README build.sh build.cfg.in $(man_MANS) \
-		src/mkconfig.h README.customs README.OS2 \
+		src/mkconfig.h README.customs README.OS2 README.zOS \
 		README.Amiga SCOPTIONS src/config.ami \
 		README.DOS builddos.bat src/configh.dos \
 		README.W32 build_w32.bat src/config.h.W32 \
diff --git a/NEWS b/NEWS
index e8fce031..20bb26ea 100644
--- a/NEWS
+++ b/NEWS
@@ -31,6 +31,10 @@ https://sv.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=110&se
   builds with archive creation.  See the "Dangers When Using Archives" section
   of the GNU Make manual, and https://savannah.gnu.org/bugs/index.php?14927
 
+* New platform: GNU Make is supported on z/OS
+  Thanks to Igor Todorovski <itodorov@ca.ibm.com> for the patches and testing
+  assistance.
+
 * Previously target-specific variables would inherit their "export" capability
   from parent target-specific variables even if they were marked private.  Now
   private parent target-specific variables have no affect.  For more details
diff --git a/README.zOS b/README.zOS
new file mode 100644
index 00000000..7ff50659
--- /dev/null
+++ b/README.zOS
@@ -0,0 +1,83 @@
+                                                                     -*-text-*-
+GNU Make has been ported to z/OS, tested on z/OS V2R4.
+
+
+PREREQUISITES
+-------------
+Building GNU Make requires certain tools be installed on your z/OS system.
+These tools can be downloaded from: https://github.com/ZOSOpenTools
+For detailed instructions on how to set up these tools, visit
+https://zosopentools.github.io/meta/#/Guides/Pre-req
+
+You will need curl, tar, and gzip to download and unpack the GNU Make release
+package, but presumably you've already worked this out if you're reading this
+document!
+
+You will need the IBM C/C++ compiler.  You can download a web deliverable
+add-on feature to your XL C/C++ compiler here:
+https://www-40.ibm.com/servers/resourcelink/svc00100.nsf/pages/xlCC++V241ForZOsV24
+
+Alternatively, you can install and manage C/C++ for Open Enterprise Languages
+on z/OS using RedHat OpenShift Container Platform and IBM Z and Cloud
+Modernization Stack.
+
+GNU Make has a dependency on the ZOSLIB library, which is documented here:
+https://zosopentools.github.io/meta/#/Guides/Zoslib.
+
+To obtain the latest release of zoslib, you can download it from here:
+https://github.com/ZOSOpenTools/zoslibport/releases.
+
+
+BUILDING
+--------
+If you are trying to build from a checked-out Git workspace, see README.git.
+
+Before building GNU Make, you will need to ensure that the following
+environment variables are set, to turn on z/OS enhanced ASCII support:
+
+  export _BPXK_AUTOCVT=ON
+  export _CEE_RUNOPTS="$_CEE_RUNOPTS FILETAG(AUTOCVT,AUTOTAG) POSIX(ON)"
+  export _TAG_REDIR_ERR=txt
+  export _TAG_REDIR_IN=txt
+  export _TAG_REDIR_OUT=txt
+
+To ensure proper functioning of xlclang, set the following environment
+variables before building:
+
+  export _CC_CCMODE=1
+  export _C89_CCMODE=1
+  export _CXX_CCMODE=1
+
+Set PATH_TO_ZOSLIB to the location of your zoslib installation; e.g.:
+
+  PATH_TO_ZOSLIB=$HOME/zopen/prod/zoslib
+
+Invoke ./configure as follows:
+
+  ./configure \
+      CC=xlclang \
+      CPPFLAGS="-DNSIG=42 -D_XOPEN_SOURCE=600 -D_ALL_SOURCE -D_OPEN_SYS_FILE_EXT=1 -D_AE_BIMODAL=1 -D_ENHANCED_ASCII_EXT=0xFFFFFFF -DZOSLIB_OVERRIDE_CLIB=1" \
+      CFLAGS="-qascii -std=gnu11 -qnocsect -qenum=int -I$PATH_TO_ZOSLIB/include" \
+      LDFLAGS="-L$PATH_TO_ZOSLIB/lib" \
+      LIBS="-lzoslib $PATH_TO_ZOSLIB/lib/CXXRT64.x"
+
+If you have an instance of make already available you can build with:
+
+  make
+
+If not, you can build with:
+
+  ./build.sh
+
+
+TESTING
+-------
+To run the regression tests you'll need to install Perl and enable it.
+Then you can run:
+
+  ./make check
+
+
+INSTALLING
+----------
+Copy the "make" program to wherever you want it to be installed, on your PATH.
diff --git a/build.sh b/build.sh
index 0813fcf4..96e8f91c 100755
--- a/build.sh
+++ b/build.sh
@@ -42,19 +42,13 @@ defines="-DLOCALEDIR=\"$localedir\" -DLIBDIR=\"$libdir\" -DINCLUDEDIR=\"$include
 # Print the value to stdout.
 get_mk_var ()
 {
-  file=$1
-  var=$2
-
-  val=
-  v=$(sed -e :a -e '/\\$/N; s/\\\n//; ta' "$file" | sed -n "s=^ *$var *\= *==p")
+  v=$(sed -e :a -e '/\\$/N; s/\\\n//; ta' "$1" | sed -n "s=^ *$2 *\= *==p")
   for w in $v; do
     case $w in
-      (\$[\(\{]*[\)\}]) w=${w#\$[\(\{]}; w=$(get_mk_var "$file" "${w%[\)\}]}") ;;
+      (\$[\(\{]*[\)\}]) w=${w#\$[\(\{]}; (get_mk_var "$1" "${w%[\)\}]}") ;;
+      (*) echo "$w" ;;
     esac
-    val="${val:+$val }$w"
   done
-
-  printf '%s\n' "$val"
 }
 
 # Compile source files.  Object files are put into $objs.
diff --git a/src/arscan.c b/src/arscan.c
index 75d678bf..edd4070c 100644
--- a/src/arscan.c
+++ b/src/arscan.c
@@ -331,7 +331,7 @@ ar_scan (const char *archive, ar_member_func_t function, const void *varg)
 #endif
 
 #ifndef WINDOWS32
-# if !defined (__ANDROID__) && !defined (__BEOS__)
+# if !defined (__ANDROID__) && !defined (__BEOS__) && !defined(MK_OS_ZOS)
 #  include <ar.h>
 # else
    /* These platforms don't have <ar.h> but have archives in the same format
diff --git a/src/job.c b/src/job.c
index a42c426c..3fab8012 100644
--- a/src/job.c
+++ b/src/job.c
@@ -2586,6 +2586,11 @@ exec_command (char **argv, char **envp)
   if (errno == ENOENT)
     errno = ENOEXEC;
 
+# elif MK_OS_ZOS
+  /* In z/OS we can't set environ in ASCII mode. */
+  environ = envp;
+  execvpe(argv[0], argv, envp);
+
 # else
 
   /* Run the program.  Don't use execvpe() as we want the search for argv[0]
@@ -2653,6 +2658,9 @@ exec_command (char **argv, char **envp)
         pid = spawnvpe (P_NOWAIT, shell, new_argv, envp);
         if (pid >= 0)
           break;
+# elif MK_OS_ZOS
+        /* In z/OS we can't set environ in ASCII mode. */
+        execvpe(shell, new_argv, envp);
 # else
         execvp (shell, new_argv);
 # endif
diff --git a/src/main.c b/src/main.c
index 4d4b88fe..433f5826 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1159,7 +1159,11 @@ temp_stdin_unlink ()
     }
 }
 
-#ifdef _AMIGA
+#ifdef MK_OS_ZOS
+extern char **environ;
+#endif
+
+#if defined(_AMIGA) || defined(MK_OS_ZOS)
 int
 main (int argc, char **argv)
 #else
@@ -1477,6 +1481,10 @@ main (int argc, char **argv, char **envp)
      done before $(MAKE) is figured out so its definitions will not be
      from the environment.  */
 
+#ifdef MK_OS_ZOS
+  char **envp = environ;
+#endif
+
 #ifndef _AMIGA
   {
     unsigned int i;
@@ -1997,7 +2005,7 @@ main (int argc, char **argv, char **envp)
 # endif
   }
 
-#ifdef HAVE_PSELECT
+#if defined(HAVE_PSELECT) && !defined(MK_OS_ZOS)
   /* If we have pselect() then we need to block SIGCHLD so it's deferred.  */
   {
     sigset_t block;
diff --git a/src/makeint.h b/src/makeint.h
index fe49cffd..187974e4 100644
--- a/src/makeint.h
+++ b/src/makeint.h
@@ -82,6 +82,11 @@ this program.  If not, see <https://www.gnu.org/licenses/>.  */
 extern int errno;
 #endif
 
+/* Define macros specifying which OS we are building for.  */
+#if defined(__MVS__)
+# define MK_OS_ZOS 1
+#endif
+
 #ifdef __VMS
 /* In strict ANSI mode, VMS compilers should not be defining the
    VMS macro.  Define it here instead of a bulk edit for the correct code.
diff --git a/src/posixos.c b/src/posixos.c
index 3e865cfd..164e0fba 100644
--- a/src/posixos.c
+++ b/src/posixos.c
@@ -24,6 +24,10 @@ this program.  If not, see <https://www.gnu.org/licenses/>.  */
 #elif defined(HAVE_SYS_FILE_H)
 # include <sys/file.h>
 #endif
+#if MK_OS_ZOS
+/* FIXME: HAVE_PSELECT path hangs on z/OS */
+#undef HAVE_PSELECT
+#endif
 
 #if !defined(FD_OK)
 # define FD_OK(_f) 1
@@ -617,7 +621,7 @@ jobserver_acquire (int timeout)
      go back and reap_children(), and try again.  */
   errno = saved_errno;
 
-  if (errno != EINTR && errno != EBADF)
+  if (errno != EINTR && errno != EBADF && errno != EAGAIN)
     pfatal_with_name (_("read jobs pipe"));
 
   if (errno == EBADF)
diff --git a/tests/run_make_tests.pl b/tests/run_make_tests.pl
index 1017cb44..a5d9b807 100644
--- a/tests/run_make_tests.pl
+++ b/tests/run_make_tests.pl
@@ -104,6 +104,7 @@ if ($^O eq 'VMS')
 # We want them from the C locale regardless of our current locale.
 
 $ERR_no_such_file = undef;
+$ERR_no_such_file_code = "2";
 $ERR_read_only_file = undef;
 $ERR_unreadable_file = undef;
 $ERR_nonexe_file = undef;
@@ -423,6 +424,9 @@ sub set_defaults
       print "Opened non-existent file! Skipping related tests.\n";
   } else {
       $ERR_no_such_file = "$!";
+      if ($osname eq 'os390') {
+          $ERR_no_such_file_code = "129";
+      }
   }
 
   unlink('file.out');
diff --git a/tests/scripts/features/archives b/tests/scripts/features/archives
index 2ad34d92..4e3434b5 100644
--- a/tests/scripts/features/archives
+++ b/tests/scripts/features/archives
@@ -212,7 +212,7 @@ if ($osname eq 'VMS') {
 # Check long names for archive members.
 # See Savannah bug #54395
 
-if ($osname ne 'VMS') {
+if ($osname ne 'VMS' && $osname ne 'os390') {
     my $pre = '1234567890123456';
     my $lib = 'libxx.a';
     my $cr = $created;
@@ -238,6 +238,9 @@ $pre%: ; touch \$\@
 
 # SV 61436 : Allow redefining archive rules to propagate timestamps
 
+# These don't work right on z/OS for some reason: archives not fully supported?
+
+if ($osname ne 'os390') {
 # Find the output when creating an archive from multiple files
 
 utouch(-10, 'a.o', 'b.o');
@@ -246,6 +249,9 @@ touch('b.o');
 my $add2 = `$ar $arflags mylib.a b.o $redir`;
 unlink('a.o', 'b.o', 'mylib.a');
 
+# Some systems complain when compiling empty files
+create_file('a.c', 'int i;');
+create_file('b.c', 'int j;');
 utouch(-20, 'a.c', 'b.c');
 
 run_make_test(q!
@@ -267,6 +273,7 @@ run_make_test(undef, $arvar, "Compile b.c\n$ar $arflags mylib.a b.o\n${add2}rm b
 run_make_test(undef, $arvar, "#MAKE#: 'mylib.a' is up to date.");
 
 unlink('a.c', 'b.c', 'a.o', 'b.o', 'mylib.a');
+}
 
 # This tells the test driver that the perl test script executed properly.
 1;
diff --git a/tests/scripts/features/output-sync b/tests/scripts/features/output-sync
index c6790d3b..20004e78 100644
--- a/tests/scripts/features/output-sync
+++ b/tests/scripts/features/output-sync
@@ -360,8 +360,8 @@ use POSIX ();
 # file.
 run_make_test(q!
 pid:=$(shell echo $$PPID)
-all:; @#HELPER# term $(pid) sleep 10
-!, '-O -j2', '/#MAKE#: \*\*\* \[#MAKEFILE#:3: all] Terminated/', POSIX::SIGTERM);
+all:; @#HELPER# -q term $(pid) sleep 10
+!, '-O -j2', '#MAKE#: *** [#MAKEFILE#:3: all] Terminated', POSIX::SIGTERM);
 }
 unlink($fout);
 
diff --git a/tests/scripts/features/shell_assignment b/tests/scripts/features/shell_assignment
index 686e4bd2..e3c369f7 100644
--- a/tests/scripts/features/shell_assignment
+++ b/tests/scripts/features/shell_assignment
@@ -19,10 +19,14 @@ all: ; @echo "<$(demo1)> <$(demo2)> <$(demo3)> <$(demo4)> <${demo5}>"
               '', "<  1   2 3 4  5     6   > <7 8  > <7 8  > < 2 3 > < 2 3  >\n");
 
 # TEST 1: Handle '#' the same way as BSD make
+$hashOctal = "\\043";
+if ($osname eq 'os390') {
+  $hashOctal = "\\173";
+}
 
 run_make_test('
 foo1!=echo bar#baz
-hash != printf \'\043\'
+hash != printf \'' . $hashOctal . '\'
 foo2!= echo "bar$(hash)baz"
 
 all: ; @echo "<$(foo1)> <$(hash)> <$(foo2)>"
diff --git a/tests/scripts/features/temp_stdin b/tests/scripts/features/temp_stdin
index 92cb6980..5230f367 100644
--- a/tests/scripts/features/temp_stdin
+++ b/tests/scripts/features/temp_stdin
@@ -67,13 +67,15 @@ use POSIX ();
 &utouch(-600, 'bye.mk');
 close(STDIN);
 open(STDIN, "<", 'input.mk') || die "$0: cannot open input.mk for reading: $!";
+
 run_make_test(q!
 include bye.mk
-pid:=$(shell echo $$PPID)
+pid := $(shell echo $$PPID)
 all:;
-bye.mk: force; @#HELPER# term $(pid) sleep 10
+bye.mk: force; @#HELPER# -q term $(pid) sleep 10
 force:
-!, '-f-', '/#MAKE#: \*\*\* \[#MAKEFILE#:5: bye.mk] Terminated/', POSIX::SIGTERM);
+!,
+              '-f-', '#MAKE#: *** [#MAKEFILE#:5: bye.mk] Terminated', POSIX::SIGTERM);
 }
 unlink($fout);
 
diff --git a/tests/scripts/functions/shell b/tests/scripts/functions/shell
index d89a0c83..55fec05b 100644
--- a/tests/scripts/functions/shell
+++ b/tests/scripts/functions/shell
@@ -148,7 +148,9 @@ all: ; @echo $(.SHELLSTATUS)
        # Solaris 10 perl 5.8.4 puts signal number + 128 into the high 8 bits.
        $ret >>= 8;
     }
-    $ret |= 128;
+    if ($osname ne 'os390') {
+      $ret |= 128;
+    }
 
     run_make_test('.PHONY: all
 $(shell kill -2 $$$$)
diff --git a/tests/scripts/targets/ONESHELL b/tests/scripts/targets/ONESHELL
index f9da14b3..0ae9b5b7 100644
--- a/tests/scripts/targets/ONESHELL
+++ b/tests/scripts/targets/ONESHELL
@@ -115,7 +115,7 @@ all:; @print "it works\n"
 SHELL = #PERL#
 .SHELLFLAGS =
 all:; @print "it works"
-!, '', "Can't open perl script \"print \"it works\"\": $ERR_no_such_file\n#MAKE#: *** [#MAKEFILE#:5: all] Error 2", 512);
+!, '', "Can't open perl script \"print \"it works\"\": $ERR_no_such_file\n#MAKE#: *** [#MAKEFILE#:5: all] Error $ERR_no_such_file_code", 512);
 
     # No .SHELLFLAGS.
     # sv 61805.
@@ -123,7 +123,7 @@ all:; @print "it works"
 .ONESHELL:
 SHELL = #PERL#
 all:; @print "it works"
-!, '', "Can't open perl script \"print \"it works\"\": $ERR_no_such_file\n#MAKE#: *** [#MAKEFILE#:4: all] Error 2", 512);
+!, '', "Can't open perl script \"print \"it works\"\": $ERR_no_such_file\n#MAKE#: *** [#MAKEFILE#:4: all] Error $ERR_no_such_file_code", 512);
 
     # Pass a quoted string with spaces to oneshell.
     # sv 61805.
diff --git a/tests/scripts/targets/POSIX b/tests/scripts/targets/POSIX
index bd716861..ade0b1ee 100644
--- a/tests/scripts/targets/POSIX
+++ b/tests/scripts/targets/POSIX
@@ -16,12 +16,18 @@ all: ; \@#HELPER# -q fail 1; true
 # User settings must override .POSIX
 # In the standard .POSIX must be the first thing in the makefile
 # but we relax that rule in GNU Make.
+
+# Different versions of sh generate different output for -x so check it
+my $script = subst_make_string('#HELPER# -q fail 1; true');
+my $flags = '-xc';
+my $out = `$sh_name $flags '$script' 2>&1`;
+
 run_make_test(qq!
-.SHELLFLAGS = -xc
+.SHELLFLAGS = $flags
 .POSIX:
-all: ; \@#HELPER# -q fail 1; true
+all: ; \@$script
 !,
-              '', "+ #HELPER# -q fail 1\n+ true\n");
+              '', $out);
 
 # Test the default value of various POSIX-specific variables
 my %POSIX = (AR => 'ar', ARFLAGS => '-rv',
diff --git a/tests/scripts/variables/SHELL b/tests/scripts/variables/SHELL
index fa3b5fc8..b18754fa 100644
--- a/tests/scripts/variables/SHELL
+++ b/tests/scripts/variables/SHELL
@@ -66,8 +66,8 @@ one two:;@echo "$@: $(SHELL) $$SHELL"
 
 # Test .SHELLFLAGS
 
-# We don't know the output here: on Solaris for example, every line printed
-# by the shell in -x mode has a trailing space (!!)
+# We don't know the output here: on some systems, for example, every line
+# printed by the shell in -x mode has a trailing space!
 my $script = 'true; true';
 my $flags = '-xc';
 my $out = `$sh_name $flags '$script' 2>&1`;
@@ -94,10 +94,14 @@ all: ; \@$script
               '', $out);
 }
 
+$script = subst_make_string('true; #HELPER# -q fail 1; true');
+$flags = '-xec';
+$out = `$sh_name $flags '$script' 2>&1`;
+
 run_make_test(qq!
-.SHELLFLAGS = -xec
-all: ; \@true; #HELPER# -q fail 1; true
+.SHELLFLAGS = $flags
+all: ; \@$script
 !,
-              '', "+ true\n+ #HELPER# -q fail 1\n#MAKE#: *** [#MAKEFILE#:3: all] Error 1\n", 512);
+              '', "${out}#MAKE#: *** [#MAKEFILE#:3: all] Error 1", 512);
 
 1;
diff --git a/tests/test_driver.pl b/tests/test_driver.pl
index 32f48777..e7e57763 100644
--- a/tests/test_driver.pl
+++ b/tests/test_driver.pl
@@ -148,7 +148,7 @@ sub resetENV
   # through Perl 5.004.  It was fixed in Perl 5.004_01, but we don't
   # want to require that here, so just delete each one individually.
 
-  if ($^O ne 'VMS') {
+  if ($osname ne 'VMS') {
     foreach $v (keys %ENV) {
       delete $ENV{$v};
     }
@@ -205,6 +205,9 @@ sub toplevel
            'PURIFYOPTIONS',
            # Windows-specific things
            'Path', 'SystemRoot', 'TEMP', 'TMP', 'USERPROFILE', 'PATHEXT',
+           # z/OS specific things
+           'LIBPATH', '_BPXK_AUTOCVT',
+           '_TAG_REDIR_IN',  '_TAG_REDIR_OUT',
            # DJGPP-specific things
            'DJDIR', 'DJGPP', 'SHELL', 'COMSPEC', 'HOSTNAME', 'LFN',
            'FNCASE', '387', 'EMU387', 'GROUP'
@@ -417,8 +420,7 @@ sub get_osname
     $port_type = 'VMS-DCL';
   }
   # Everything else, right now, is UNIX.  Note that we should integrate
-  # the VOS support into this as well and get rid of $vos; we'll do
-  # that next time.
+  # the VOS support into this as well and get rid of $vos
   else {
     $port_type = 'UNIX';
   }
@@ -615,7 +617,7 @@ sub run_all_tests
     $perl_testname = "$scriptpath$pathsep$testname";
     $testname =~ s/(\.pl|\.perl)$//;
     $testpath = "$workpath$pathsep$testname";
-    $extext = '_' if $^O eq 'VMS';
+    $extext = '_' if $osname eq 'VMS';
     $log_filename = "$testpath.$logext";
     $diff_filename = "$testpath.$diffext";
     $base_filename = "$testpath.$baseext";
@@ -906,6 +908,21 @@ sub compare_answer_vms
   return 0;
 }
 
+sub compare_answer_zos
+{
+  my ($kgo, $log) = @_;
+
+  # z/OS emits "Error 143" or "SIGTERM" instead of terminated
+  $log =~ s/Error 143/Terminated/gm;
+  $log =~ s/SIGTERM/Terminated/gm;
+
+  # z/OS error messages have a prefix
+  $log =~ s/EDC5129I No such file or directory\./No such file or directory/gm;
+  $log =~ s/FSUM7351 not found/not found/gm;
+
+  return $log eq $kgo;
+}
+
 sub compare_answer
 {
   my ($kgo, $log) = @_;
@@ -937,7 +954,10 @@ sub compare_answer
   return 1 if ($mlog eq $mkgo);
 
   # VMS is a whole thing...
-  return 1 if ($^O eq 'VMS' && compare_answer_vms($kgo, $log));
+  return 1 if ($osname eq 'VMS' && compare_answer_vms($kgo, $log));
+
+  # z/OS has its own quirks
+  return 1 if ($osname eq 'os390' && compare_answer_zos($kgo, $log));
 
   # See if the answer might be a regex.
   if ($kgo =~ m,^/(.+)/$,) {
@@ -1067,7 +1087,7 @@ sub detach_default_output
   @OUTSTACK or error("default output stack has flown under!\n", 1);
 
   close(STDOUT);
-  close(STDERR) unless $^O eq 'VMS';
+  close(STDERR) unless $osname eq 'VMS';
 
 
   open (STDOUT, '>&', pop @OUTSTACK) or error("ddo: $! duping STDOUT\n", 1);
@@ -1077,7 +1097,7 @@ sub detach_default_output
 sub _run_with_timeout
 {
   my $code;
-  if ($^O eq 'VMS') {
+  if ($osname eq 'VMS') {
     #local $SIG{ALRM} = sub {
     #    my $e = $ERRSTACK[0];
     #    print $e "\nTest timed out after $test_timeout seconds\n";
@@ -1173,7 +1193,7 @@ sub run_command
   print "\nrun_command: @_\n" if $debug;
   my $code = _run_command(@_);
   print "run_command returned $code.\n" if $debug;
-  print "vms status = ${^CHILD_ERROR_NATIVE}\n" if $debug and $^O eq 'VMS';
+  print "vms status = ${^CHILD_ERROR_NATIVE}\n" if $debug and $osname eq 'VMS';
   return $code;
 }
 
@@ -1195,7 +1215,7 @@ sub run_command_with_output
   $err and die $err;
 
   print "run_command_with_output returned $code.\n" if $debug;
-  print "vms status = ${^CHILD_ERROR_NATIVE}\n" if $debug and $^O eq 'VMS';
+  print "vms status = ${^CHILD_ERROR_NATIVE}\n" if $debug and $osname eq 'VMS';
   return $code;
 }
 
@@ -1243,7 +1263,7 @@ sub remove_directory_tree_inner
         return 0;
       }
     } else {
-      if ($^O ne 'VMS') {
+      if ($osname ne 'VMS') {
         if (!unlink $object) {
           print "Cannot unlink $object: $!\n";
           return 0;
diff --git a/tests/thelp.pl b/tests/thelp.pl
index c95b54ae..55650521 100755
--- a/tests/thelp.pl
+++ b/tests/thelp.pl
@@ -108,7 +108,7 @@ sub op {
     }
 
     if ($op eq 'term') {
-        print "term $nm\n";
+        print "term $nm\n" unless $quiet;
         kill('TERM', $nm);
         return 1;
     }