Initial patch for output synchronization. See Savannah bug #33138.

Based on work by David Boyce <David.S.Boyce@gmail.com>.

7 files changed, 486 insertions, 13 deletions

diff --git a/doc/make.texi b/doc/make.texi
index dffa14d..1a760e1 100644
--- a/doc/make.texi
+++ b/doc/make.texi
@@ -4057,9 +4057,12 @@ If there is nothing looking like an integer after the @samp{-j} option,
 there is no limit on the number of job slots.  The default number of job
 slots is one, which means serial execution (one thing at a time).
 
-One unpleasant consequence of running several recipes simultaneously is
-that output generated by the recipes appears whenever each recipe
-sends it, so messages from different recipes may be interspersed.
+One consequence of running several recipes simultaneously is that by
+default, output from each recipe appears as soon as it is generated,
+with the result that messages from different recipes may be interspersed.
+This may create problems in interpreting output. If the @samp{-P} option
+is used, however, recipes will save their output until completion and
+then take turns writing it, with a more coherent result.
 
 Another problem is that two processes cannot both take input from the
 same device; so to make sure that only one recipe tries to take input
@@ -8612,6 +8615,24 @@ The data base output contains file name and line number information for
 recipe and variable definitions, so it can be a useful debugging tool
 in complex environments.
 
+@item -P
+@cindex @code{-P}
+@itemx --parallel-sync
+@cindex @code{--parallel-sync}
+@cindex parallel recipe execution, output
+When jobs are running in parallel under @samp{--jobs}, the output of
+each job is held until the job is complete thus ensuring that the output
+of each recipe is grouped together.
+
+With no argument or the argument @samp{1}, messages from each job in
+recursive makes are grouped together. With the argument @samp{2}, the
+complete output from any recursive make is grouped together. The latter
+achieves better grouping of output from related jobs, but causes longer
+delay, since messages do not appear until the recursive make has
+completed. Therefore @samp{-P} is more useful when watching the output
+while make runs, and @samp{-P2} is better suited when running a complex
+parallel build in the background and checking its output afterwards.
+
 @item -q
 @cindex @code{-q}
 @itemx --question
diff --git a/job.c b/job.c
index 2e2d3ff..dedd526 100644
--- a/job.c
+++ b/job.c
@@ -242,6 +242,16 @@ unsigned long job_counter = 0;
 /* Number of jobserver tokens this instance is currently using.  */
 
 unsigned int jobserver_tokens = 0;
+
+#ifdef PARALLEL_SYNC
+/* Semaphore for use in -j mode with parallel_sync. */
+
+int sync_handle = -1;
+
+#define STREAM_OK(strm)		((fcntl (fileno ((strm)), F_GETFD) != -1) || (errno != EBADF))
+
+#define FD_NOT_EMPTY(FD) ((FD) >= 0 && lseek ((FD), 0, SEEK_CUR) > 0)
+#endif /* PARALLEL_SYNC */
 
 #ifdef WINDOWS32
 /*
@@ -539,6 +549,184 @@ child_handler (int sig UNUSED)
   */
 }
 
+#ifdef PARALLEL_SYNC
+/* Adds file descriptors to the child structure to support parallel_sync;
+   one for stdout and one for stderr as long as they are (a) open and
+   (b) separate. If stdout and stderr share a device they can share a
+   temp file too.  */
+static int
+assign_child_tempfiles (struct child *c, int combined)
+{
+  FILE *outstrm = NULL, *errstrm = NULL;
+  int o_ok, e_ok;
+  const char *suppressed = "parallel-sync suppressed: ";
+  char *failmode = NULL;
+
+  /* Check status of stdout and stderr before hooking up temp files. */
+  o_ok = STREAM_OK (stdout);
+  e_ok = STREAM_OK (stderr);
+
+  /* The tmpfile() function returns a FILE pointer but those can be in 
+     limited supply, so we immediately dup its file descriptor and keep
+     only that, closing the FILE pointer.  */
+
+  if (combined)
+    {
+      if (!(outstrm = tmpfile ()))
+	failmode = "tmpfile()";
+      else
+	errstrm = outstrm;
+    }
+  else if (o_ok && e_ok)
+    {
+      if (!(outstrm = tmpfile ()) || !(errstrm = tmpfile ()))
+	failmode = "tmpfile()";
+    }
+  else if (o_ok)
+    {
+      if (!(outstrm = tmpfile ()))
+	failmode = "tmpfile()";
+    }
+  else if (e_ok)
+    {
+      if (!(errstrm = tmpfile ()))
+	failmode = "tmpfile()";
+    }
+  else
+    failmode = "stdout";
+
+  if (!failmode && outstrm)
+    {
+      if ((c->outfd = dup (fileno (outstrm))) == -1)
+	failmode = "dup2()";
+      else
+	CLOSE_ON_EXEC (c->outfd);
+    }
+
+  if (!failmode && errstrm)
+    {
+      if (combined)
+	c->errfd = c->outfd;
+      else
+	{
+	  if ((c->errfd = dup (fileno (errstrm))) == -1)
+	    failmode = "dup2()";
+	  else
+	    CLOSE_ON_EXEC (c->errfd);
+	}
+    }
+
+  if (failmode)
+    perror_with_name (suppressed, failmode);
+
+  if (outstrm)
+    (void) fclose (outstrm);
+
+  if (errstrm && errstrm != outstrm)
+    (void) fclose (errstrm);
+
+  return failmode == NULL;
+}
+
+/* Support routine for sync_output() */
+static void
+pump_from_tmp_fd (int from_fd, int to_fd)
+{
+  ssize_t nleft, nwrite;
+  char buffer[8192];
+
+  if (lseek (from_fd, 0, SEEK_SET) == -1)
+    perror ("lseek()");
+
+  while (1)
+    {
+      char *write_buf = buffer;
+      EINTRLOOP (nleft, read (from_fd, buffer, sizeof (buffer)));
+      if (nleft < 0)
+	perror ("read()");
+      if (nleft <= 0)
+	break;
+      while (nleft > 0)
+      {
+        EINTRLOOP (nwrite, write (to_fd, write_buf, nleft));
+        if (nwrite < 0)
+          {
+            perror ("write()");
+            return;
+          }
+
+        write_buf += nwrite;
+        nleft -= nwrite;
+      }
+    }
+}
+
+/* Support routine for sync_output() */
+static void *
+acquire_semaphore (void)
+{
+  static struct flock fl;
+
+  fl.l_type = F_WRLCK;
+  fl.l_whence = SEEK_SET;
+  fl.l_start = 0; /* lock just one byte according to pid */
+  fl.l_len = 1;
+  if (fcntl (sync_handle, F_SETLKW, &fl) != -1)
+    return &fl;
+  perror ("fcntl()");
+  return NULL;
+}
+
+/* Support routine for sync_output() */
+static void
+release_semaphore (void *sem)
+{
+  struct flock *flp = (struct flock *)sem;
+  flp->l_type = F_UNLCK;
+  if (fcntl (sync_handle, F_SETLKW, flp) == -1)
+    perror ("fcntl()");
+}
+
+/* Synchronize the output of jobs in -j mode to keep the results of
+   each job together. This is done by holding the results in temp files,
+   one for stdout and potentially another for stderr, and only releasing
+   them to "real" stdout/stderr when a semaphore can be obtained. */
+
+static void
+sync_output (struct child *c)
+{
+  void *sem;
+
+  int outfd_not_empty = FD_NOT_EMPTY (c->outfd);
+  int errfd_not_empty = FD_NOT_EMPTY (c->errfd);
+
+  if ((outfd_not_empty || errfd_not_empty) && (sem = acquire_semaphore ()))
+    {
+      /*
+       * We've entered the "critical section" during which a lock is held.
+       * We want to keep it as short as possible.
+       */
+      if (outfd_not_empty)
+        {
+          log_working_directory (1, 1);
+          pump_from_tmp_fd (c->outfd, fileno (stdout));
+          log_working_directory (0, 1);
+        }
+      if (errfd_not_empty && c->errfd != c->outfd)
+        pump_from_tmp_fd (c->errfd, fileno (stderr));
+
+      /* Exit the critical section */
+      release_semaphore (sem);
+    }
+
+  if (c->outfd >= 0)
+    close (c->outfd);
+  if (c->errfd >= 0)
+    close (c->errfd);
+  c->outfd = c->errfd = -1;
+}
+#endif /* PARALLEL_SYNC */
+
 extern int shell_function_pid, shell_function_completed;
 
 /* Reap all dead children, storing the returned status and the new command
@@ -833,6 +1021,12 @@ reap_children (int block, int err)
         c->sh_batch_file = NULL;
       }
 
+#ifdef PARALLEL_SYNC
+      /* Synchronize parallel output if requested */
+      if (parallel_sync)
+	sync_output (c);
+#endif /* PARALLEL_SYNC */
+
       /* If this child had the good stdin, say it is now free.  */
       if (c->good_stdin)
         good_stdin_used = 0;
@@ -1413,6 +1607,45 @@ start_job_command (struct child *child)
 
 #else  /* !__EMX__ */
 
+#ifdef PARALLEL_SYNC
+      if (parallel_sync)
+	{
+	  static int combined_output;
+	  /* If parallel_sync is turned on, find a resource to
+	      synchronize on. This block is traversed only once. */
+	  if (sync_handle == -1)
+	    {
+	      struct stat stbuf_o, stbuf_e;
+
+	      if (STREAM_OK (stdout))
+		{
+		  sync_handle = fileno (stdout);
+		  combined_output =
+		    fstat (fileno (stdout), &stbuf_o) == 0 &&
+		    fstat (fileno (stderr), &stbuf_e) == 0 &&
+		    stbuf_o.st_dev == stbuf_e.st_dev &&
+		    stbuf_o.st_ino == stbuf_e.st_ino;
+		}
+	      else if (STREAM_OK (stderr))
+		sync_handle = fileno (stderr);
+	      else
+		{
+		  perror_with_name ("parallel-sync suppressed: ", "stderr");
+		  parallel_sync = 0;
+		}
+	    }
+
+	  /* If it still looks like we can synchronize, create a temp
+	      file to hold stdout (and one for stderr if separate). */
+	  if (parallel_sync >= PARALLEL_SYNC_COARSE
+	      || (parallel_sync == PARALLEL_SYNC_FINE && !(flags & COMMANDS_RECURSE)))
+	    {
+	      if (!assign_child_tempfiles (child, combined_output))
+	        parallel_sync = 0;
+	    }
+	}
+#endif /* PARALLEL_SYNC */
+
       child->pid = vfork ();
       environ = parent_environ;	/* Restore value child may have clobbered.  */
       if (child->pid == 0)
@@ -1436,6 +1669,23 @@ start_job_command (struct child *child)
             setrlimit (RLIMIT_STACK, &stack_limit);
 #endif
 
+#ifdef PARALLEL_SYNC
+	  /* Divert child output into tempfile(s) if parallel_sync in use. */
+	  if (parallel_sync)
+	    {
+	      int outfd = fileno (stdout);
+	      int errfd = fileno (stderr);
+
+	      if ((child->outfd >= 0 &&
+		  (close (outfd) == -1 || dup2 (child->outfd, outfd) == -1))
+		|| (child->errfd >= 0 &&
+		  (close (errfd) == -1 || dup2 (child->errfd, errfd) == -1)))
+		{
+		  perror_with_name ("parallel-sync: ", "dup2()");
+		}
+	    }
+#endif /* PARALLEL_SYNC */
+
 	  child_execute_job (child->good_stdin ? 0 : bad_stdin, 1,
                              argv, child->environment);
 	}
@@ -1769,6 +2019,9 @@ new_job (struct file *file)
   c->file = file;
   c->command_lines = lines;
   c->sh_batch_file = NULL;
+#ifdef PARALLEL_SYNC
+  c->outfd = c->errfd = -1;
+#endif
 
   /* Cache dontcare flag because file->dontcare can be changed once we
      return. Check dontcare inheritance mechanism for details.  */
diff --git a/job.h b/job.h
index 0b594a1..8d32bd7 100644
--- a/job.h
+++ b/job.h
@@ -34,6 +34,10 @@ this program.  If not, see <http://www.gnu.org/licenses/>.  */
 # define CLOSE_ON_EXEC(_d) (void) fcntl ((_d), F_SETFD, FD_CLOEXEC)
 #endif
 
+#ifdef POSIX /* PARALLEL_SYNC */
+#define PARALLEL_SYNC
+#endif /* POSIX */
+
 /* Structure describing a running or dead child process.  */
 
 struct child
@@ -60,6 +64,10 @@ struct child
     unsigned int good_stdin:1;	/* Nonzero if this child has a good stdin.  */
     unsigned int deleted:1;	/* Nonzero if targets have been deleted.  */
     unsigned int dontcare:1;    /* Saved dontcare flag.  */
+#ifdef PARALLEL_SYNC
+    int outfd;			/* Optional file descriptor for saving stdout */
+    int errfd;			/* Optional file descriptor for saving stderr */
+#endif /* PARALLEL_SYNC */
   };
 
 extern struct child *children;
diff --git a/main.c b/main.c
index 0a2774c..0447888 100644
--- a/main.c
+++ b/main.c
@@ -228,6 +228,15 @@ static unsigned int master_job_slots = 0;
 
 static unsigned int inf_jobs = 0;
 
+#ifdef PARALLEL_SYNC
+
+/* Default value for parallel sync without an argument.  */
+
+static unsigned int no_parallel_sync = 0;
+static unsigned int default_parallel_sync = PARALLEL_SYNC_FINE;
+
+#endif
+
 /* File descriptors for the jobs pipe.  */
 
 static struct stringlist *jobserver_fds = 0;
@@ -344,6 +353,10 @@ static const char *const usage[] =
                               Consider FILE to be very old and don't remake it.\n"),
     N_("\
   -p, --print-data-base       Print make's internal database.\n"),
+#ifdef PARALLEL_SYNC
+    N_("\
+  -P [2], --parallel-sync[=2] Synchronize output of parallel jobs [coarse].\n"),
+#endif
     N_("\
   -q, --question              Run no recipe; exit status says if up to date.\n"),
     N_("\
@@ -408,6 +421,11 @@ static const struct command_switch switches[] =
     { 'n', flag, &just_print_flag, 1, 1, 1, 0, 0, "just-print" },
     { 'o', filename, &old_files, 0, 0, 0, 0, 0, "old-file" },
     { 'p', flag, &print_data_base_flag, 1, 1, 0, 0, 0, "print-data-base" },
+#ifdef PARALLEL_SYNC
+    // { 'P', flag, &parallel_sync, 1, 1, 0, 0, 0, "parallel-sync" },  // two-state
+    { 'P', positive_int, &parallel_sync, 1, 1, 0, &default_parallel_sync,
+      &no_parallel_sync, "parallel-sync" },
+#endif
     { 'q', flag, &question_flag, 1, 1, 1, 0, 0, "question" },
     { 'r', flag, &no_builtin_rules_flag, 1, 1, 0, 0, 0, "no-builtin-rules" },
     { 'R', flag, &no_builtin_variables_flag, 1, 1, 0, 0, 0,
@@ -503,6 +521,14 @@ int second_expansion;
 
 int one_shell;
 
+/* Either PARALLEL_SYNC_FINE or PARALLEL_SYNC_COARSE
+   if the "--parallel-sync" option was given.
+   This attempts to synchronize the output of parallel
+   jobs such that the results of each job stay together.
+   It works best in combination with .ONESHELL.  */
+
+int parallel_sync;
+
 /* Nonzero if we have seen the '.NOTPARALLEL' target.
    This turns off parallel builds for this invocation of make.  */
 
@@ -2095,7 +2121,7 @@ main (int argc, char **argv, char **envp)
           if (print_data_base_flag)
             print_data_base ();
 
-          log_working_directory (0);
+          log_working_directory (0, 0);
 
           clean_jobserver (0);
 
@@ -3280,7 +3306,7 @@ die (int status)
           _x = chdir (directory_before_chdir);
         }
 
-      log_working_directory (0);
+      log_working_directory (0, 0);
     }
 
   exit (status);
@@ -3290,17 +3316,18 @@ die (int status)
    left (according to ENTERING) the current directory.  */
 
 void
-log_working_directory (int entering)
+log_working_directory (int entering, int force)
 {
   static int entered = 0;
 
   /* Print nothing without the flag.  Don't print the entering message
      again if we already have.  Don't print the leaving message if we
      haven't printed the entering message.  */
-  if (! print_directory_flag || entering == entered)
+  if (! print_directory_flag || (!force && entering == entered))
     return;
 
-  entered = entering;
+  if (!force)
+    entered = entering;
 
   if (print_data_base_flag)
     fputs ("# ", stdout);
diff --git a/makeint.h b/makeint.h
index 6f2ee67..2273fad 100644
--- a/makeint.h
+++ b/makeint.h
@@ -396,7 +396,7 @@ void fatal ();
 #endif
 
 void die (int) __attribute__ ((noreturn));
-void log_working_directory (int);
+void log_working_directory (int, int);
 void pfatal_with_name (const char *) __attribute__ ((noreturn));
 void perror_with_name (const char *, const char *);
 void *xmalloc (unsigned int);
@@ -525,6 +525,9 @@ int strncasecmp (const char *s1, const char *s2, int n);
 # endif
 #endif
 
+#define PARALLEL_SYNC_FINE 1
+#define PARALLEL_SYNC_COARSE 2
+
 extern const gmk_floc *reading_file;
 extern const gmk_floc **expanding_var;
 
@@ -536,7 +539,7 @@ extern int env_overrides, no_builtin_rules_flag, no_builtin_variables_flag;
 extern int print_version_flag, print_directory_flag, check_symlink_flag;
 extern int warn_undefined_variables_flag, trace_flag, posix_pedantic;
 extern int not_parallel, second_expansion, clock_skew_detected;
-extern int rebuilding_makefiles, one_shell;
+extern int rebuilding_makefiles, one_shell, parallel_sync;
 
 /* can we run commands via 'sh -c xxx' or must we use batch files? */
 extern int batch_mode_shell;
diff --git a/misc.c b/misc.c
index 37fa1e1..ba8cc2e 100644
--- a/misc.c
+++ b/misc.c
@@ -231,10 +231,13 @@ message (prefix, fmt, va_alist)
   va_list args;
 #endif
 
-  log_working_directory (1);
+  log_working_directory (1, 0);
 
   if (fmt != 0)
     {
+      if (parallel_sync)
+        log_working_directory (1, 1);
+
       if (prefix)
 	{
 	  if (makelevel == 0)
@@ -246,6 +249,9 @@ message (prefix, fmt, va_alist)
       VA_PRINTF (stdout, fmt, args);
       VA_END (args);
       putchar ('\n');
+
+      if (parallel_sync)
+        log_working_directory (0, 1);
     }
 
   fflush (stdout);
@@ -267,7 +273,10 @@ error (flocp, fmt, va_alist)
   va_list args;
 #endif
 
-  log_working_directory (1);
+  if (parallel_sync)
+    log_working_directory (1, 1);
+  else
+    log_working_directory (1, 0);
 
   if (flocp && flocp->filenm)
     fprintf (stderr, "%s:%lu: ", flocp->filenm, flocp->lineno);
@@ -282,6 +291,9 @@ error (flocp, fmt, va_alist)
 
   putc ('\n', stderr);
   fflush (stderr);
+
+  if (parallel_sync)
+    log_working_directory (0, 1);
 }
 
 /* Print an error message and exit.  */
@@ -300,7 +312,10 @@ fatal (flocp, fmt, va_alist)
   va_list args;
 #endif
 
-  log_working_directory (1);
+  if (parallel_sync)
+    log_working_directory (1, 1);
+  else
+    log_working_directory (1, 0);
 
   if (flocp && flocp->filenm)
     fprintf (stderr, "%s:%lu: *** ", flocp->filenm, flocp->lineno);
@@ -315,6 +330,9 @@ fatal (flocp, fmt, va_alist)
 
   fputs (_(".  Stop.\n"), stderr);
 
+  if (parallel_sync)
+    log_working_directory (0, 1);
+
   die (2);
 }
 
diff --git a/tests/scripts/features/parallel-sync b/tests/scripts/features/parallel-sync
new file mode 100644
index 0000000..29e5564
--- /dev/null
+++ b/tests/scripts/features/parallel-sync
@@ -0,0 +1,143 @@
+#                                                                    -*-perl-*-
+
+$description = "Test parallel-sync (-P) option.";
+
+$details = "Test the synchronization of output from parallel jobs.";
+
+if (!$parallel_jobs) {
+  return -1;
+}
+
+if ($vos) {
+  $sleep_command = "sleep -seconds";
+}
+else {
+  $sleep_command = "sleep";
+}
+
+# The following subdirectories with Makefiles are used in several
+# of the following tests.
+mkdir('foo', 0777);
+mkdir('bar', 0777);
+
+open(MAKEFILE,"> foo/Makefile");
+print MAKEFILE <<EOF;
+all: foo
+
+foo:
+	\@echo foo: start; $sleep_command 2; echo foo: end
+
+foo-fail:
+	\@$sleep_command 2; false
+EOF
+close(MAKEFILE);
+
+open(MAKEFILE,"> bar/Makefile");
+print MAKEFILE <<EOF;
+all: bar baz
+
+bar:
+	\@echo bar: start; $sleep_command 1; echo bar: end
+
+baz:
+	\@echo baz: start; $sleep_command 4; echo baz: end
+EOF
+close(MAKEFILE);
+
+# Test coarse synchronization.
+run_make_test('
+all: make-foo make-bar
+
+make-foo:
+	$(MAKE) -C foo
+
+make-bar:
+	$(MAKE) -C bar',
+'-j -P2',
+"#MAKEPATH# -C foo
+#MAKEPATH# -C bar
+#MAKE#[1]: Entering directory '#PWD#/foo'
+#MAKE#[1]: Entering directory '#PWD#/foo'
+foo: start
+foo: end
+#MAKE#[1]: Leaving directory '#PWD#/foo'
+#MAKE#[1]: Leaving directory '#PWD#/foo'
+#MAKE#[1]: Entering directory '#PWD#/bar'
+#MAKE#[1]: Entering directory '#PWD#/bar'
+bar: start
+bar: end
+#MAKE#[1]: Leaving directory '#PWD#/bar'
+#MAKE#[1]: Entering directory '#PWD#/bar'
+baz: start
+baz: end
+#MAKE#[1]: Leaving directory '#PWD#/bar'
+#MAKE#[1]: Leaving directory '#PWD#/bar'\n");
+
+# Test fine synchronization.
+run_make_test('
+all: make-foo make-bar
+
+make-foo:
+	$(MAKE) -C foo
+
+make-bar:
+	$(MAKE) -C bar',
+'-j -P',
+"#MAKEPATH# -C foo
+#MAKEPATH# -C bar
+#MAKE#[1]: Entering directory '#PWD#/foo'
+#MAKE#[1]: Entering directory '#PWD#/bar'
+#MAKE#[1]: Entering directory '#PWD#/bar'
+bar: start
+bar: end
+#MAKE#[1]: Leaving directory '#PWD#/bar'
+#MAKE#[1]: Entering directory '#PWD#/foo'
+foo: start
+foo: end
+#MAKE#[1]: Leaving directory '#PWD#/foo'
+#MAKE#[1]: Leaving directory '#PWD#/foo'
+#MAKE#[1]: Entering directory '#PWD#/bar'
+baz: start
+baz: end
+#MAKE#[1]: Leaving directory '#PWD#/bar'
+#MAKE#[1]: Leaving directory '#PWD#/bar'\n");
+
+# Test that messages from make itself are enclosed with
+# "Entering/Leaving directory" messages.
+run_make_test('
+all: make-foo-fail make-bar-bar
+
+make-foo-fail:
+	$(MAKE) -C foo foo-fail
+
+make-bar-bar:
+	$(MAKE) -C bar bar',
+'-j -P',
+"#MAKEPATH# -C foo foo-fail
+#MAKEPATH# -C bar bar
+#MAKE#[1]: Entering directory '#PWD#/foo'
+#MAKE#[1]: Entering directory '#PWD#/bar'
+#MAKE#[1]: Entering directory '#PWD#/bar'
+bar: start
+bar: end
+#MAKE#[1]: Leaving directory '#PWD#/bar'
+#MAKE#[1]: Leaving directory '#PWD#/bar'
+#MAKE#[1]: Entering directory '#PWD#/foo'
+Makefile:7: recipe for target 'foo-fail' failed
+#MAKE#[1]: Leaving directory '#PWD#/foo'
+#MAKE#[1]: Entering directory '#PWD#/foo'
+#MAKE#[1]: *** [foo-fail] Error 1
+#MAKE#[1]: Leaving directory '#PWD#/foo'
+#MAKE#[1]: Leaving directory '#PWD#/foo'
+#MAKEFILE#:5: recipe for target 'make-foo-fail' failed
+#MAKE#: *** [make-foo-fail] Error 2\n",
+512);
+
+# Remove temporary directories and contents.
+rmfiles('foo/Makefile');
+rmdir('foo');
+rmfiles('bar/Makefile');
+rmdir('bar');
+
+# This tells the test driver that the perl test script executed properly.
+1;