[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.

5 files changed, 29 insertions, 4 deletions

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)