support: Introduce new subdirectory for test infrastructure

The new test driver in <support/test-driver.c> has feature parity with
the old one.  The main difference is that its hooking mechanism is
based on functions and function pointers instead of macros.  This
commit also implements a new environment variable, TEST_COREDUMPS,
which disables the code which disables coredumps (that is, it enables
them if the invocation environment has not disabled them).

<test-skeleton.c> defines wrapper functions so that it is possible to
use existing macros with the new-style hook functionality.

This commit changes only a few test cases to the new test driver, to
make sure that it works as expected.

37 files changed, 1898 insertions, 0 deletions

diff --git a/support/Makefile b/support/Makefile
new file mode 100644
index 0000000..bd425af
--- /dev/null
+++ b/support/Makefile
@@ -0,0 +1,64 @@
+# Makefile for support library, used only at build and test time
+# Copyright (C) 2016 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+
+# The GNU C Library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <http://www.gnu.org/licenses/>.
+
+subdir := support
+
+include ../Makeconfig
+
+extra-libs := libsupport
+extra-libs-others = $(extra-libs)
+extra-libs-noinstall := $(extra-libs)
+
+libsupport-routines = \
+  check \
+  delayed_exit \
+  ignore_stderr \
+  oom_error \
+  set_fortify_handler \
+  support_test_main \
+  temp_file \
+  write_message \
+  xasprintf \
+  xcalloc \
+  xmalloc \
+  xpthread_barrier_destroy \
+  xpthread_barrier_init \
+  xpthread_barrier_wait \
+  xpthread_cancel \
+  xpthread_check_return \
+  xpthread_cond_wait \
+  xpthread_create \
+  xpthread_detach \
+  xpthread_join \
+  xpthread_mutex_lock \
+  xpthread_mutex_unlock \
+  xpthread_sigmask \
+  xpthread_spin_lock \
+  xpthread_spin_unlock \
+  xrealloc \
+
+libsupport-static-only-routines := $(libsupport-routines)
+# Only build one variant of the library.
+libsupport-inhibit-o := .os
+ifeq ($(build-shared),yes)
+libsupport-inhibit-o += .o
+endif
+
+tests = README-testing
+
+include ../Rules
diff --git a/support/README b/support/README
new file mode 100644
index 0000000..476cfcd
--- /dev/null
+++ b/support/README
@@ -0,0 +1,29 @@
+This subdirectory contains infrastructure which is not put into
+installed libraries, but may be linked into programs (installed or
+not) and tests.
+
+# Error-checking wrappers
+
+These wrappers test for error return codes an terminate the process on
+error.  They are declared in these header files:
+
+* support.h
+* xsignal.h
+* xthread.h
+
+In general, new wrappers should be added to support.h if possible.
+However, support.h must remain fully compatible with C90 and therefore
+cannot include headers which use identifers not reserved in C90.  If
+the wrappers need additional types, additional headers such as
+signal.h need to be introduced.
+
+# Test framework
+
+The test framework provides a main program for tests, including a
+timeout for hanging tests.  See README-testing.c for a minimal
+example, and test-driver.c for details how to use it.  The following
+header files provide related declarations:
+
+* check.h
+* temp_file.h
+* test-driver.h
diff --git a/support/README-testing.c b/support/README-testing.c
new file mode 100644
index 0000000..9d289c3
--- /dev/null
+++ b/support/README-testing.c
@@ -0,0 +1,19 @@
+/* This file contains an example test case which shows minimal use of
+   the test framework.  Additional testing hooks are described in
+   <support/test-driver.c>.  */
+
+/* This function will be called from the test driver.  */
+static int
+do_test (void)
+{
+  if (3 == 5)
+    /* Indicate failure.  */
+    return 1;
+  else
+    /* Indicate success.  */
+    return 0;
+}
+
+/* This file references do_test above and contains the definition of
+   the main function.  */
+#include <support/test-driver.c>
diff --git a/support/check.c b/support/check.c
new file mode 100644
index 0000000..75fdf52
--- /dev/null
+++ b/support/check.c
@@ -0,0 +1,53 @@
+/* Support code for reporting test results.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/check.h>
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+static void
+print_failure (const char *file, int line, const char *format, va_list ap)
+{
+  printf ("error: %s:%d: ", file, line);
+  vprintf (format, ap);
+  puts ("");
+}
+
+int
+support_print_failure_impl (const char *file, int line,
+                            const char *format, ...)
+{
+  va_list ap;
+  va_start (ap, format);
+  print_failure (file, line, format, ap);
+  va_end (ap);
+  return 1;
+}
+
+void
+support_exit_failure_impl (int status, const char *file, int line,
+                           const char *format, ...)
+{
+  va_list ap;
+  va_start (ap, format);
+  print_failure (file, line, format, ap);
+  va_end (ap);
+  exit (status);
+}
diff --git a/support/check.h b/support/check.h
new file mode 100644
index 0000000..ff2652c
--- /dev/null
+++ b/support/check.h
@@ -0,0 +1,49 @@
+/* Macros for reporting test results.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef SUPPORT_CHECK_H
+#define SUPPORT_CHECK_H
+
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+/* Print failure message to standard output and return 1.  */
+#define FAIL_RET(...) \
+  return support_print_failure_impl (__FILE__, __LINE__, __VA_ARGS__)
+
+/* Print failure message and terminate the process with STATUS.  */
+#define FAIL_EXIT(status, ...) \
+  support_exit_failure_impl (status, __FILE__, __LINE__, __VA_ARGS__)
+
+/* Print failure message and terminate with exit status 1.  */
+#define FAIL_EXIT1(...) \
+  support_exit_failure_impl (1, __FILE__, __LINE__, __VA_ARGS__)
+
+int support_print_failure_impl (const char *file, int line,
+                                const char *format, ...)
+  __attribute__ ((nonnull (1), format (printf, 3, 4)));
+void support_exit_failure_impl (int exit_status,
+                                const char *file, int line,
+                                const char *format, ...)
+  __attribute__ ((noreturn, nonnull (2), format (printf, 4, 5)));
+
+
+__END_DECLS
+
+#endif /* SUPPORT_CHECK_H */
diff --git a/support/delayed_exit.c b/support/delayed_exit.c
new file mode 100644
index 0000000..d5b2e10
--- /dev/null
+++ b/support/delayed_exit.c
@@ -0,0 +1,57 @@
+/* Time-triggered process termination.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/xthread.h>
+#include <support/xsignal.h>
+
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+
+static void *
+delayed_exit_thread (void *seconds_as_ptr)
+{
+  int seconds = (uintptr_t) seconds_as_ptr;
+  struct timespec delay = { seconds, 0 };
+  struct timespec remaining = { 0 };
+  if (nanosleep (&delay, &remaining) != 0)
+    {
+      printf ("error: nanosleep: %m\n");
+      exit (1);
+    }
+  /* Exit the process sucessfully.  */
+  exit (0);
+  return NULL;
+}
+
+void
+delayed_exit (int seconds)
+{
+  /* Create the new thread with all signals blocked.  */
+  sigset_t all_blocked;
+  sigfillset (&all_blocked);
+  sigset_t old_set;
+  xpthread_sigmask (SIG_SETMASK, &all_blocked, &old_set);
+  /* Create a detached thread. */
+  pthread_t thr = xpthread_create
+    (NULL, delayed_exit_thread, (void *) (uintptr_t) seconds);
+  xpthread_detach (thr);
+  /* Restore the original signal mask.  */
+  xpthread_sigmask (SIG_SETMASK, &old_set, NULL);
+}
diff --git a/support/ignore_stderr.c b/support/ignore_stderr.c
new file mode 100644
index 0000000..1b35d06
--- /dev/null
+++ b/support/ignore_stderr.c
@@ -0,0 +1,38 @@
+/* Avoid all the buffer overflow messages on stderr.
+   Copyright (C) 2015-2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/support.h>
+
+#include <fcntl.h>
+#include <paths.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+void
+ignore_stderr (void)
+{
+  int fd = open (_PATH_DEVNULL, O_WRONLY);
+  if (fd == -1)
+    close (STDERR_FILENO);
+  else
+    {
+      dup2 (fd, STDERR_FILENO);
+      close (fd);
+    }
+  setenv ("LIBC_FATAL_STDERR_", "1", 1);
+}
diff --git a/support/oom_error.c b/support/oom_error.c
new file mode 100644
index 0000000..b28c5b4
--- /dev/null
+++ b/support/oom_error.c
@@ -0,0 +1,29 @@
+/* Reporting out-of-memory errors.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/support.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+
+void
+oom_error (const char *function, size_t size)
+{
+  printf ("%s: unable to allocate %zu bytes: %m\n", function, size);
+  exit (1);
+}
diff --git a/support/set_fortify_handler.c b/support/set_fortify_handler.c
new file mode 100644
index 0000000..a976f44
--- /dev/null
+++ b/support/set_fortify_handler.c
@@ -0,0 +1,34 @@
+/* Set signal handler for use in fortify tests.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/support.h>
+
+#include <signal.h>
+
+void
+set_fortify_handler (void (*handler) (int sig))
+{
+  struct sigaction sa;
+
+  sa.sa_handler = handler;
+  sa.sa_flags = 0;
+  sigemptyset (&sa.sa_mask);
+
+  sigaction (SIGABRT, &sa, NULL);
+  ignore_stderr ();
+}
diff --git a/support/support.h b/support/support.h
new file mode 100644
index 0000000..fc7fba9
--- /dev/null
+++ b/support/support.h
@@ -0,0 +1,58 @@
+/* Common extra functions.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* This header file should only contain definitions compatible with
+   C90.  (Using __attribute__ is fine because <features.h> provides a
+   fallback.)  */
+
+#ifndef SUPPORT_H
+#define SUPPORT_H
+
+#include <stddef.h>
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+/* Write a message to standard output.  Can be used in signal
+   handlers.  */
+void write_message (const char *message) __attribute__ ((nonnull (1)));
+
+/* Avoid all the buffer overflow messages on stderr.  */
+void ignore_stderr (void);
+
+/* Set fortification error handler.  Used when tests want to verify that bad
+   code is caught by the library.  */
+void set_fortify_handler (void (*handler) (int sig));
+
+/* Report an out-of-memory error for the allocation of SIZE bytes in
+   FUNCTION, terminating the process.  */
+void oom_error (const char *function, size_t size)
+  __attribute__ ((nonnull (1)));
+
+/* Error-checking wrapper functions which terminate the process on
+   error.  */
+
+void *xmalloc (size_t) __attribute__ ((malloc));
+void *xcalloc (size_t n, size_t s) __attribute__ ((malloc));
+void *xrealloc (void *p, size_t n);
+char *xasprintf (const char *format, ...)
+  __attribute__ ((format (printf, 1, 2), malloc));
+
+__END_DECLS
+
+#endif /* SUPPORT_H */
diff --git a/support/support_test_main.c b/support/support_test_main.c
new file mode 100644
index 0000000..72771bf
--- /dev/null
+++ b/support/support_test_main.c
@@ -0,0 +1,406 @@
+/* Main worker function for the test driver.
+   Copyright (C) 1998-2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/test-driver.h>
+#include <support/temp_file-internal.h>
+
+#include <assert.h>
+#include <errno.h>
+#include <getopt.h>
+#include <malloc.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/param.h>
+#include <sys/resource.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <time.h>
+#include <unistd.h>
+
+static const struct option default_options[] =
+{
+  { "direct", no_argument, NULL, OPT_DIRECT },
+  { "test-dir", required_argument, NULL, OPT_TESTDIR },
+  { NULL, 0, NULL, 0 }
+};
+
+/* Show people how to run the program.  */
+static void
+usage (const struct option *options)
+{
+  size_t i;
+
+  printf ("Usage: %s [options]\n"
+          "\n"
+          "Environment Variables:\n"
+          "  TIMEOUTFACTOR          An integer used to scale the timeout\n"
+          "  TMPDIR                 Where to place temporary files\n"
+          "  TEST_COREDUMPS         Do not disable coredumps if set\n"
+          "\n",
+          program_invocation_short_name);
+  printf ("Options:\n");
+  for (i = 0; options[i].name; ++i)
+    {
+      int indent;
+
+      indent = printf ("  --%s", options[i].name);
+      if (options[i].has_arg == required_argument)
+        indent += printf (" <arg>");
+      printf ("%*s", 25 - indent, "");
+      switch (options[i].val)
+        {
+        case OPT_DIRECT:
+          printf ("Run the test directly (instead of forking & monitoring)");
+          break;
+        case OPT_TESTDIR:
+          printf ("Override the TMPDIR env var");
+          break;
+        }
+      printf ("\n");
+    }
+}
+
+/* The PID of the test process.  */
+static pid_t test_pid;
+
+/* The cleanup handler passed to test_main.  */
+static void (*cleanup_function) (void);
+
+/* Timeout handler.  We kill the child and exit with an error.  */
+static void
+__attribute__ ((noreturn))
+signal_handler (int sig)
+{
+  int killed;
+  int status;
+
+  assert (test_pid > 1);
+  /* Kill the whole process group.  */
+  kill (-test_pid, SIGKILL);
+  /* In case setpgid failed in the child, kill it individually too.  */
+  kill (test_pid, SIGKILL);
+
+  /* Wait for it to terminate.  */
+  int i;
+  for (i = 0; i < 5; ++i)
+    {
+      killed = waitpid (test_pid, &status, WNOHANG|WUNTRACED);
+      if (killed != 0)
+        break;
+
+      /* Delay, give the system time to process the kill.  If the
+         nanosleep() call return prematurely, all the better.  We
+         won't restart it since this probably means the child process
+         finally died.  */
+      struct timespec ts;
+      ts.tv_sec = 0;
+      ts.tv_nsec = 100000000;
+      nanosleep (&ts, NULL);
+    }
+  if (killed != 0 && killed != test_pid)
+    {
+      printf ("Failed to kill test process: %m\n");
+      exit (1);
+    }
+
+  if (cleanup_function != NULL)
+    cleanup_function ();
+
+  if (sig == SIGINT)
+    {
+      signal (sig, SIG_DFL);
+      raise (sig);
+    }
+
+  if (killed == 0 || (WIFSIGNALED (status) && WTERMSIG (status) == SIGKILL))
+    puts ("Timed out: killed the child process");
+  else if (WIFSTOPPED (status))
+    printf ("Timed out: the child process was %s\n",
+            strsignal (WSTOPSIG (status)));
+  else if (WIFSIGNALED (status))
+    printf ("Timed out: the child process got signal %s\n",
+            strsignal (WTERMSIG (status)));
+  else
+    printf ("Timed out: killed the child process but it exited %d\n",
+            WEXITSTATUS (status));
+
+  /* Exit with an error.  */
+  exit (1);
+}
+
+/* Run test_function or test_function_argv.  */
+static int
+run_test_function (int argc, char **argv, const struct test_config *config)
+{
+  if (config->test_function != NULL)
+    return config->test_function ();
+  else if (config->test_function_argv != NULL)
+    return config->test_function_argv (argc, argv);
+  else
+    {
+      printf ("error: no test function defined\n");
+      exit (1);
+    }
+}
+
+static bool test_main_called;
+
+const char *test_dir = NULL;
+
+int
+support_test_main (int argc, char **argv, const struct test_config *config)
+{
+  if (test_main_called)
+    {
+      printf ("error: test_main called for a second time\n");
+      exit (1);
+    }
+  test_main_called = true;
+  const struct option *options;
+  if (config->options != NULL)
+    options = config->options;
+  else
+    options = default_options;
+
+  cleanup_function = config->cleanup_function;
+
+  int direct = 0;       /* Directly call the test function?  */
+  int status;
+  int opt;
+  unsigned int timeoutfactor = 1;
+  pid_t termpid;
+
+  if (!config->no_mallopt)
+    {
+      /* Make uses of freed and uninitialized memory known.  Do not
+         pull in a definition for mallopt if it has not been defined
+         already.  */
+      extern __typeof__ (mallopt) mallopt __attribute__ ((weak));
+      if (mallopt != NULL)
+        mallopt (M_PERTURB, 42);
+    }
+
+  while ((opt = getopt_long (argc, argv, "+", options, NULL)) != -1)
+    switch (opt)
+      {
+      case '?':
+        usage (options);
+        exit (1);
+      case OPT_DIRECT:
+        direct = 1;
+        break;
+      case OPT_TESTDIR:
+        test_dir = optarg;
+        break;
+      default:
+        if (config->cmdline_function != NULL)
+          config->cmdline_function (opt);
+      }
+
+  /* If set, read the test TIMEOUTFACTOR value from the environment.
+     This value is used to scale the default test timeout values. */
+  char *envstr_timeoutfactor = getenv ("TIMEOUTFACTOR");
+  if (envstr_timeoutfactor != NULL)
+    {
+      char *envstr_conv = envstr_timeoutfactor;
+      unsigned long int env_fact;
+
+      env_fact = strtoul (envstr_timeoutfactor, &envstr_conv, 0);
+      if (*envstr_conv == '\0' && envstr_conv != envstr_timeoutfactor)
+        timeoutfactor = MAX (env_fact, 1);
+    }
+
+  /* Set TMPDIR to specified test directory.  */
+  if (test_dir != NULL)
+    {
+      setenv ("TMPDIR", test_dir, 1);
+
+      if (chdir (test_dir) < 0)
+        {
+          printf ("chdir: %m\n");
+          exit (1);
+        }
+    }
+  else
+    {
+      test_dir = getenv ("TMPDIR");
+      if (test_dir == NULL || test_dir[0] == '\0')
+        test_dir = "/tmp";
+    }
+  if (support_set_test_dir != NULL)
+    support_set_test_dir (test_dir);
+
+  int timeout = config->timeout;
+  if (timeout == 0)
+    timeout =  DEFAULT_TIMEOUT;
+
+  /* Make sure we see all message, even those on stdout.  */
+  setvbuf (stdout, NULL, _IONBF, 0);
+
+  /* Make sure temporary files are deleted.  */
+  if (support_delete_temp_files != NULL)
+      atexit (support_delete_temp_files);
+
+  /* Correct for the possible parameters.  */
+  argv[optind - 1] = argv[0];
+  argv += optind - 1;
+  argc -= optind - 1;
+
+  /* Call the initializing function, if one is available.  */
+  if (config->prepare_function != NULL)
+    config->prepare_function (argc, argv);
+
+  const char *envstr_direct = getenv ("TEST_DIRECT");
+  if (envstr_direct != NULL)
+    {
+      FILE *f = fopen (envstr_direct, "w");
+      if (f == NULL)
+        {
+          printf ("cannot open TEST_DIRECT output file '%s': %m\n",
+                  envstr_direct);
+          exit (1);
+        }
+
+      fprintf (f, "timeout=%u\ntimeoutfactor=%u\n",
+               config->timeout, timeoutfactor);
+      if (config->expected_status != 0)
+        fprintf (f, "exit=%u\n", config->expected_status);
+      if (config->expected_signal != 0)
+        fprintf (f, "signal=%s\n", strsignal (config->expected_signal));
+
+      if (support_print_temp_files != NULL)
+        support_print_temp_files (f);
+
+      fclose (f);
+      direct = 1;
+    }
+
+  bool disable_coredumps;
+  {
+    const char *coredumps = getenv ("TEST_COREDUMPS");
+    disable_coredumps = coredumps == NULL || coredumps[0] == '\0';
+  }
+
+  /* If we are not expected to fork run the function immediately.  */
+  if (direct)
+    return run_test_function (argc, argv, config);
+
+  /* Set up the test environment:
+     - prevent core dumps
+     - set up the timer
+     - fork and execute the function.  */
+
+  pid_t test_pid = fork ();
+  if (test_pid == 0)
+    {
+      /* This is the child.  */
+      if (disable_coredumps)
+        {
+          /* Try to avoid dumping core.  This is necessary because we
+             run the test from the source tree, and the coredumps
+             would end up there (and not in the build tree).  */
+          struct rlimit core_limit;
+          core_limit.rlim_cur = 0;
+          core_limit.rlim_max = 0;
+          setrlimit (RLIMIT_CORE, &core_limit);
+        }
+
+      /* We put the test process in its own pgrp so that if it bogusly
+         generates any job control signals, they won't hit the whole build.  */
+      if (setpgid (0, 0) != 0)
+        printf ("Failed to set the process group ID: %m\n");
+
+      /* Execute the test function and exit with the return value.   */
+      exit (run_test_function (argc, argv, config));
+    }
+  else if (test_pid < 0)
+    {
+      printf ("Cannot fork test program: %m\n");
+      exit (1);
+    }
+
+  /* Set timeout.  */
+  signal (SIGALRM, signal_handler);
+  alarm (config->timeout * timeoutfactor);
+
+  /* Make sure we clean up if the wrapper gets interrupted.  */
+  signal (SIGINT, signal_handler);
+
+  /* Wait for the regular termination.  */
+  termpid = TEMP_FAILURE_RETRY (waitpid (test_pid, &status, 0));
+  if (termpid == -1)
+    {
+      printf ("Waiting for test program failed: %m\n");
+      exit (1);
+    }
+  if (termpid != test_pid)
+    {
+      printf ("Oops, wrong test program terminated: expected %ld, got %ld\n",
+              (long int) test_pid, (long int) termpid);
+      exit (1);
+    }
+
+  /* Process terminated normaly without timeout etc.  */
+  if (WIFEXITED (status))
+    {
+      if (config->expected_status == 0)
+        {
+          if (config->expected_signal == 0)
+            /* Simply exit with the return value of the test.  */
+            return WEXITSTATUS (status);
+          else
+            {
+              printf ("Expected signal '%s' from child, got none\n",
+                      strsignal (config->expected_signal));
+              exit (1);
+            }
+        }
+      else
+        {
+          /* Non-zero exit status is expected */
+          if (WEXITSTATUS (status) != config->expected_status)
+            {
+              printf ("Expected status %d, got %d\n",
+                      config->expected_status, WEXITSTATUS (status));
+              exit (1);
+            }
+        }
+      return 0;
+    }
+  /* Process was killed by timer or other signal.  */
+  else
+    {
+      if (config->expected_signal == 0)
+        {
+          printf ("Didn't expect signal from child: got `%s'\n",
+                  strsignal (WTERMSIG (status)));
+          exit (1);
+        }
+      else if (WTERMSIG (status) != config->expected_signal)
+        {
+          printf ("Incorrect signal from child: got `%s', need `%s'\n",
+                  strsignal (WTERMSIG (status)),
+                  strsignal (config->expected_signal));
+          exit (1);
+        }
+
+      return 0;
+    }
+}
diff --git a/support/temp_file-internal.h b/support/temp_file-internal.h
new file mode 100644
index 0000000..1da9c4f
--- /dev/null
+++ b/support/temp_file-internal.h
@@ -0,0 +1,31 @@
+/* Internal weak declarations for temporary file handling.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef SUPPORT_TEMP_FILE_INTERNAL_H
+#define SUPPORT_TEMP_FILE_INTERNAL_H
+
+/* These functions are called by the test driver if they are
+   defined.  Tests should not call them directly.  */
+
+#include <stdio.h>
+
+void support_set_test_dir (const char *name) __attribute__ ((weak));
+void support_delete_temp_files (void) __attribute__ ((weak));
+void support_print_temp_files (FILE *) __attribute__ ((weak));
+
+#endif /* SUPPORT_TEMP_FILE_INTERNAL_H */
diff --git a/support/temp_file.c b/support/temp_file.c
new file mode 100644
index 0000000..a67ab0b
--- /dev/null
+++ b/support/temp_file.c
@@ -0,0 +1,125 @@
+/* Temporary file handling for tests.
+   Copyright (C) 1998-2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* This is required to get an mkstemp which can create large files on
+   some 32-bit platforms. */
+#define _FILE_OFFSET_BITS 64
+
+#include <support/temp_file.h>
+#include <support/temp_file-internal.h>
+#include <support/support.h>
+
+#include <paths.h>
+#include <search.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+/* List of temporary files.  */
+static struct temp_name_list
+{
+  struct qelem q;
+  char *name;
+} *temp_name_list;
+
+/* Location of the temporary files.  Set by the test skeleton via
+   support_set_test_dir.  The string is not be freed.  */
+static const char *test_dir = _PATH_TMP;
+
+void
+add_temp_file (const char *name)
+{
+  struct temp_name_list *newp
+    = (struct temp_name_list *) xcalloc (sizeof (*newp), 1);
+  char *newname = strdup (name);
+  if (newname != NULL)
+    {
+      newp->name = newname;
+      if (temp_name_list == NULL)
+	temp_name_list = (struct temp_name_list *) &newp->q;
+      else
+	insque (newp, temp_name_list);
+    }
+  else
+    free (newp);
+}
+
+int
+create_temp_file (const char *base, char **filename)
+{
+  char *fname;
+  int fd;
+
+  fname = (char *) xmalloc (strlen (test_dir) + 1 + strlen (base)
+			    + sizeof ("XXXXXX"));
+  strcpy (stpcpy (stpcpy (stpcpy (fname, test_dir), "/"), base), "XXXXXX");
+
+  fd = mkstemp (fname);
+  if (fd == -1)
+    {
+      printf ("cannot open temporary file '%s': %m\n", fname);
+      free (fname);
+      return -1;
+    }
+
+  add_temp_file (fname);
+  if (filename != NULL)
+    *filename = fname;
+  else
+    free (fname);
+
+  return fd;
+}
+
+/* Helper functions called by the test skeleton follow.  */
+
+void
+support_set_test_dir (const char *path)
+{
+  test_dir = path;
+}
+
+void
+support_delete_temp_files (void)
+{
+  while (temp_name_list != NULL)
+    {
+      remove (temp_name_list->name);
+      free (temp_name_list->name);
+
+      struct temp_name_list *next
+	= (struct temp_name_list *) temp_name_list->q.q_forw;
+      free (temp_name_list);
+      temp_name_list = next;
+    }
+}
+
+void
+support_print_temp_files (FILE *f)
+{
+  if (temp_name_list != NULL)
+    {
+      struct temp_name_list *n;
+      fprintf (f, "temp_files=(\n");
+      for (n = temp_name_list;
+           n != NULL;
+           n = (struct temp_name_list *) n->q.q_forw)
+        fprintf (f, "  '%s'\n", n->name);
+      fprintf (f, ")\n");
+    }
+}
diff --git a/support/temp_file.h b/support/temp_file.h
new file mode 100644
index 0000000..1955f7b
--- /dev/null
+++ b/support/temp_file.h
@@ -0,0 +1,37 @@
+/* Declarations for temporary file handling.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef SUPPORT_TEMP_FILE_H
+#define SUPPORT_TEMP_FILE_H
+
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+/* Schedule a temporary file for deletion on exit.  */
+void add_temp_file (const char *name);
+
+/* Create a temporary file.  Return the opened file descriptor on
+   success, or -1 on failure.  Write the file name to *FILENAME if
+   FILENAME is not NULL.  In this case, the caller is expected to free
+   *FILENAME.  */
+int create_temp_file (const char *base, char **filename);
+
+__END_DECLS
+
+#endif /* SUPPORT_TEMP_FILE_H */
diff --git a/support/test-driver.c b/support/test-driver.c
new file mode 100644
index 0000000..3a61b7b
--- /dev/null
+++ b/support/test-driver.c
@@ -0,0 +1,158 @@
+/* Main function for test programs.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* This file should be included from test cases.  It will define a
+   main function which provides the test wrapper.
+
+   It assumes that the test case defines a function
+
+     int do_test (void);
+
+   and arranges for that function being called under the test wrapper.
+   The do_test function should return 0 to indicate a passing test, 1
+   to indicate a failing test, or 77 to indicate an unsupported test.
+   Other result values could be used to indicate a failing test, but
+   the result of the expression is passed to exit and exit only
+   returns the lower 8 bits of its input.  A non-zero return with some
+   values could cause a test to incorrectly be considered passing when
+   it really failed.  For this reason, the function should always
+   return 0 (EXIT_SUCCESS), 1 (EXIT_FAILURE), or 77
+   (EXIT_UNSUPPORTED).
+
+   The test function may print out diagnostic or warning messages as well
+   as messages about failures.  These messages should be printed to stdout
+   and not stderr so that the output is properly ordered with respect to
+   the rest of the glibc testsuite run output.
+
+   Several preprocessors macros can be defined before including this
+   file.
+
+   The name of the do_test function can be changed with the
+   TEST_FUNCTION macro.  It must expand to the desired function name.
+
+   If the test case needs access to command line parameters, it must
+   define the TEST_FUNCTION_ARGV macro with the name of the test
+   function.  It must have the following type:
+
+     int TEST_FUNCTION_ARGV (int argc, char **argv);
+
+   This overrides the do_test default function and is incompatible
+   with the TEST_FUNCTION macro.
+
+   If PREPARE is defined, it must expand to the name of a function of
+   the type
+
+     void PREPARE (int argc, char **);
+
+   This function will be called early, after parsing the command line,
+   but before running the test, in the parent process which acts as
+   the test supervisor.
+
+   If CLEANUP_HANDLER is defined, it must expand to the name of a
+   function of the type
+
+     void CLEANUP_HANDLER (void);
+
+   This function will be called from the timeout (SIGALRM) signal
+   handler.
+
+   If EXPECTED_SIGNAL is defined, it must expanded to a constant which
+   denotes the expected signal number.
+
+   If EXPECTED_STATUS is defined, it must expand to the expected exit
+   status.
+
+   If TIMEOUT is defined, it must be positive constant.  It overrides
+   the default test timeout and is measured in seconds.
+
+   If TEST_NO_MALLOPT is defined, the test wrapper will not call
+   mallopt.
+
+   Custom command line handling can be implemented by defining the
+   CMDLINE_OPTION macro (after including the <getopt.h> header; this
+   requires _GNU_SOURCE to be defined).  This macro must expand to a
+   to a comma-separated list of braced initializers for struct option
+   from <getopt.h>, with a trailing comma.  CMDLINE_PROCESS can be
+   defined as the name of a function which is called to process these
+   options.  The function is passed the option character/number and
+   has this type:
+
+     void CMDLINE_PROCESS (int);
+*/
+
+#include <support/test-driver.h>
+
+#include <string.h>
+
+int
+main (int argc, char **argv)
+{
+  struct test_config test_config;
+  memset (&test_config, 0, sizeof (test_config));
+
+#ifdef PREPARE
+  test_config.prepare_function = (PREPARE);
+#endif
+
+#if defined (TEST_FUNCTION) && defined (TEST_FUNCTON_ARGV)
+# error TEST_FUNCTION and TEST_FUNCTION_ARGV cannot be defined at the same time
+#endif
+#if defined (TEST_FUNCTION)
+  test_config.test_function = TEST_FUNCTION;
+#elif defined (TEST_FUNCTION_ARGV)
+  test_config.test_function_argv = TEST_FUNCTION_ARGV;
+#else
+  test_config.test_function = do_test;
+#endif
+
+#ifdef CLEANUP_HANDLER
+  test_config.cleanup_function = CLEANUP_HANDLER;
+#endif
+
+#ifdef EXPECTED_SIGNAL
+  test_config.expected_signal = (EXPECTED_SIGNAL);
+#endif
+
+#ifdef EXPECTED_STATUS
+  test_config.expected_status = (EXPECTED_STATUS);
+#endif
+
+#ifdef TEST_NO_MALLOPT
+  test_config.no_mallopt = 1;
+#endif
+
+#ifdef TIMEOUT
+  test_config.timeout = TIMEOUT;
+#endif
+
+#ifdef CMDLINE_OPTIONS
+  struct option options[] =
+    {
+      CMDLINE_OPTIONS
+      { "direct", no_argument, NULL, OPT_DIRECT },
+      { "test-dir", required_argument, NULL, OPT_TESTDIR },
+      { NULL, 0, NULL, 0 }
+    };
+  test_config.options = &options;
+#endif
+#ifdef CMDLINE_PROCESS
+  test_config.cmdline_function = CMDLINE_PROCESS;
+#endif
+
+  return support_test_main (argc, argv, &test_config);
+}
diff --git a/support/test-driver.h b/support/test-driver.h
new file mode 100644
index 0000000..7787e9c
--- /dev/null
+++ b/support/test-driver.h
@@ -0,0 +1,68 @@
+/* Interfaces for the test driver.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef SUPPORT_TEST_DRIVER_H
+#define SUPPORT_TEST_DRIVER_H
+
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+struct test_config
+{
+  void (*prepare_function) (int argc, char **argv);
+  int (*test_function) (void);
+  int (*test_function_argv) (int argc, char **argv);
+  void (*cleanup_function) (void);
+  void (*cmdline_function) (int);
+  const void *options;   /* Custom options if not NULL.  */
+  int timeout;           /* Test timeout in seconds.  */
+  int expected_status;   /* Expected exit status.  */
+  int expected_signal;   /* If non-zero, expect termination by signal.  */
+  char no_mallopt;       /* Boolean flag to disable mallopt.  */
+};
+
+enum
+  {
+    /* Test exit status which indicates that the feature is
+       unsupported. */
+    EXIT_UNSUPPORTED = 77,
+
+    /* Default timeout is twenty seconds.  Tests should normally
+       complete faster than this, but if they don't, that's abnormal
+       (a bug) anyways.  */
+    DEFAULT_TIMEOUT = 20,
+
+    /* Used for command line argument parsing.  */
+    OPT_DIRECT = 1000,
+    OPT_TESTDIR,
+  };
+
+/* Options provided by the test driver.  */
+#define TEST_DEFAULT_OPTIONS                            \
+  { "direct", no_argument, NULL, OPT_DIRECT },          \
+  { "test-dir", required_argument, NULL, OPT_TESTDIR }, \
+
+/* The directory the test should use for temporary files.  */
+extern const char *test_dir;
+
+int support_test_main (int argc, char **argv, const struct test_config *);
+
+__END_DECLS
+
+#endif /* SUPPORT_TEST_DRIVER_H */
diff --git a/support/write_message.c b/support/write_message.c
new file mode 100644
index 0000000..be145e7
--- /dev/null
+++ b/support/write_message.c
@@ -0,0 +1,29 @@
+/* Write a message to standard output.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/support.h>
+
+#include <string.h>
+#include <unistd.h>
+
+void
+write_message (const char *message)
+{
+  ssize_t unused __attribute__ ((unused));
+  unused = write (STDOUT_FILENO, message, strlen (message));
+}
diff --git a/support/xasprintf.c b/support/xasprintf.c
new file mode 100644
index 0000000..b9dc91b
--- /dev/null
+++ b/support/xasprintf.c
@@ -0,0 +1,38 @@
+/* Error-checking wrapper for asprintf.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/support.h>
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+char *
+xasprintf (const char *format, ...)
+{
+  va_list ap;
+  va_start (ap, format);
+  char *result;
+  if (vasprintf (&result, format, ap) < 0)
+    {
+      printf ("error: asprintf: %m\n");
+      exit (1);
+    }
+  va_end (ap);
+  return result;
+}
diff --git a/support/xcalloc.c b/support/xcalloc.c
new file mode 100644
index 0000000..0ba5061
--- /dev/null
+++ b/support/xcalloc.c
@@ -0,0 +1,34 @@
+/* Error-checking wrapper for calloc.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/support.h>
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+void *
+xcalloc (size_t n, size_t s)
+{
+  void *p;
+
+  p = calloc (n, s);
+  if (p == NULL)
+    oom_error ("calloc", n * s);
+  return p;
+}
diff --git a/support/xmalloc.c b/support/xmalloc.c
new file mode 100644
index 0000000..8b0fc62
--- /dev/null
+++ b/support/xmalloc.c
@@ -0,0 +1,34 @@
+/* Error-checking wrapper for malloc.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/support.h>
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+void *
+xmalloc (size_t n)
+{
+  void *p;
+
+  p = malloc (n);
+  if (p == NULL)
+    oom_error ("malloc", n);
+  return p;
+}
diff --git a/support/xpthread_barrier_destroy.c b/support/xpthread_barrier_destroy.c
new file mode 100644
index 0000000..f9ce97c
--- /dev/null
+++ b/support/xpthread_barrier_destroy.c
@@ -0,0 +1,26 @@
+/* pthread_barrier_destroy with error checking.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/xthread.h>
+
+void
+xpthread_barrier_destroy (pthread_barrier_t *barrier)
+{
+  xpthread_check_return ("pthread_barrier_destroy",
+                         pthread_barrier_destroy (barrier));
+}
diff --git a/support/xpthread_barrier_init.c b/support/xpthread_barrier_init.c
new file mode 100644
index 0000000..1eba8c9
--- /dev/null
+++ b/support/xpthread_barrier_init.c
@@ -0,0 +1,27 @@
+/* pthread_barrier_init with error checking.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/xthread.h>
+
+void
+xpthread_barrier_init (pthread_barrier_t *barrier,
+                       pthread_barrierattr_t *attr, unsigned int count)
+{
+  xpthread_check_return ("pthread_barrier_init",
+                         pthread_barrier_init (barrier, attr, count));
+}
diff --git a/support/xpthread_barrier_wait.c b/support/xpthread_barrier_wait.c
new file mode 100644
index 0000000..45139f4
--- /dev/null
+++ b/support/xpthread_barrier_wait.c
@@ -0,0 +1,28 @@
+/* pthread_barrier_wait with error checking.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/xthread.h>
+
+int
+xpthread_barrier_wait (pthread_barrier_t *barrier)
+{
+  int ret = pthread_barrier_wait (barrier);
+  if (ret != 0 && ret != PTHREAD_BARRIER_SERIAL_THREAD)
+    xpthread_check_return ("pthread_barrier_wait", ret);
+  return ret == PTHREAD_BARRIER_SERIAL_THREAD;
+}
diff --git a/support/xpthread_cancel.c b/support/xpthread_cancel.c
new file mode 100644
index 0000000..dfbcf68
--- /dev/null
+++ b/support/xpthread_cancel.c
@@ -0,0 +1,25 @@
+/* pthread_cancel with error checking.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/xthread.h>
+
+void
+xpthread_cancel (pthread_t thr)
+{
+  xpthread_check_return ("pthread_cancel", pthread_cancel (thr));
+}
diff --git a/support/xpthread_check_return.c b/support/xpthread_check_return.c
new file mode 100644
index 0000000..8781ee1
--- /dev/null
+++ b/support/xpthread_check_return.c
@@ -0,0 +1,34 @@
+/* Return value checking for pthread functions, exit variant.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/xthread.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+void
+xpthread_check_return (const char *function, int value)
+{
+  if (value != 0)
+    {
+      errno = value;
+      printf ("error: %s: %m\n", function);
+      exit (1);
+    }
+}
diff --git a/support/xpthread_cond_wait.c b/support/xpthread_cond_wait.c
new file mode 100644
index 0000000..844ae58
--- /dev/null
+++ b/support/xpthread_cond_wait.c
@@ -0,0 +1,26 @@
+/* pthread_cond_wait with error checking.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/xthread.h>
+
+void
+xpthread_cond_wait (pthread_cond_t *cond, pthread_mutex_t *mutex)
+{
+  xpthread_check_return
+    ("pthread_cond_wait", pthread_cond_wait (cond, mutex));
+}
diff --git a/support/xpthread_create.c b/support/xpthread_create.c
new file mode 100644
index 0000000..96d2d09
--- /dev/null
+++ b/support/xpthread_create.c
@@ -0,0 +1,29 @@
+/* pthread_create with error checking.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/xthread.h>
+
+pthread_t
+xpthread_create (pthread_attr_t *attr,
+                 void *(*thread_func) (void *), void *closure)
+{
+  pthread_t thr;
+  xpthread_check_return
+    ("pthread_create", pthread_create (&thr, attr, thread_func, closure));
+  return thr;
+}
diff --git a/support/xpthread_detach.c b/support/xpthread_detach.c
new file mode 100644
index 0000000..971cb72
--- /dev/null
+++ b/support/xpthread_detach.c
@@ -0,0 +1,25 @@
+/* pthread_detach with error checking.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/xthread.h>
+
+void
+xpthread_detach (pthread_t thr)
+{
+  xpthread_check_return ("pthread_detach", pthread_detach (thr));
+}
diff --git a/support/xpthread_join.c b/support/xpthread_join.c
new file mode 100644
index 0000000..1ab8620
--- /dev/null
+++ b/support/xpthread_join.c
@@ -0,0 +1,27 @@
+/* pthread_join with error checking.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/xthread.h>
+
+void *
+xpthread_join (pthread_t thr)
+{
+  void *result;
+  xpthread_check_return ("pthread_join", pthread_join (thr, &result));
+  return result;
+}
diff --git a/support/xpthread_mutex_lock.c b/support/xpthread_mutex_lock.c
new file mode 100644
index 0000000..3a72cab
--- /dev/null
+++ b/support/xpthread_mutex_lock.c
@@ -0,0 +1,25 @@
+/* pthread_mutex_lock with error checking.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/xthread.h>
+
+void
+xpthread_mutex_lock (pthread_mutex_t *mutex)
+{
+  xpthread_check_return ("pthread_mutex_lock", pthread_mutex_lock (mutex));
+}
diff --git a/support/xpthread_mutex_unlock.c b/support/xpthread_mutex_unlock.c
new file mode 100644
index 0000000..640bf31
--- /dev/null
+++ b/support/xpthread_mutex_unlock.c
@@ -0,0 +1,25 @@
+/* pthread_mutex_unlock with error checking.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/xthread.h>
+
+void
+xpthread_mutex_unlock (pthread_mutex_t *mutex)
+{
+  xpthread_check_return ("pthread_mutex_unlock", pthread_mutex_unlock (mutex));
+}
diff --git a/support/xpthread_sigmask.c b/support/xpthread_sigmask.c
new file mode 100644
index 0000000..6a938c8
--- /dev/null
+++ b/support/xpthread_sigmask.c
@@ -0,0 +1,34 @@
+/* pthread_sigmask with error checking.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/xsignal.h>
+#include <support/support.h>
+
+#include <unistd.h>
+
+void
+xpthread_sigmask (int how, const sigset_t *set, sigset_t *oldset)
+{
+  if (pthread_sigmask (how, set, oldset) != 0)
+    {
+      write_message ("error: pthread_setmask failed\n");
+      /* Do not use exit because pthread_sigmask can be called from a
+         signal handler.  */
+      _exit (1);
+    }
+}
diff --git a/support/xpthread_spin_lock.c b/support/xpthread_spin_lock.c
new file mode 100644
index 0000000..3e7b0b8
--- /dev/null
+++ b/support/xpthread_spin_lock.c
@@ -0,0 +1,25 @@
+/* pthread_spin_lock with error checking.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/xthread.h>
+
+void
+xpthread_spin_lock (pthread_spinlock_t *lock)
+{
+  xpthread_check_return ("pthread_spin_lock", pthread_spin_lock (lock));
+}
diff --git a/support/xpthread_spin_unlock.c b/support/xpthread_spin_unlock.c
new file mode 100644
index 0000000..7a5047b
--- /dev/null
+++ b/support/xpthread_spin_unlock.c
@@ -0,0 +1,25 @@
+/* pthread_spin_unlock with error checking.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/xthread.h>
+
+void
+xpthread_spin_unlock (pthread_spinlock_t *lock)
+{
+  xpthread_check_return ("pthread_spin_unlock", pthread_spin_unlock (lock));
+}
diff --git a/support/xrealloc.c b/support/xrealloc.c
new file mode 100644
index 0000000..6c5a5a3
--- /dev/null
+++ b/support/xrealloc.c
@@ -0,0 +1,32 @@
+/* Error-checking wrapper for realloc.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/support.h>
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+void *
+xrealloc (void *p, size_t n)
+{
+  void *result = realloc (p, n);
+  if (result == NULL && (n > 0 || p == NULL))
+    oom_error ("realloc", n);
+  return result;
+}
diff --git a/support/xsignal.h b/support/xsignal.h
new file mode 100644
index 0000000..b105214
--- /dev/null
+++ b/support/xsignal.h
@@ -0,0 +1,34 @@
+/* Support functionality for using signals.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef SUPPORT_SIGNAL_H
+#define SUPPORT_SIGNAL_H
+
+#include <signal.h>
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+/* The following functions call the corresponding libpthread functions
+   and terminate the process on error.  */
+
+void xpthread_sigmask (int how, const sigset_t *set, sigset_t *oldset);
+
+__END_DECLS
+
+#endif /* SUPPORT_SIGNAL_H */
diff --git a/support/xthread.h b/support/xthread.h
new file mode 100644
index 0000000..f0dc0fa
--- /dev/null
+++ b/support/xthread.h
@@ -0,0 +1,61 @@
+/* Support functionality for using threads.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef SUPPORT_THREAD_H
+#define SUPPORT_THREAD_H
+
+#include <pthread.h>
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+/* Terminate the process (with exit status 0) after SECONDS have
+   elapsed, from a helper thread.  The process is terminated with the
+   exit function, so atexit handlers are executed.  */
+void delayed_exit (int seconds);
+
+/* Terminate the process (with exit status 1) if VALUE is not zero.
+   In that case, print a failure message to standard output mentioning
+   FUNCTION.  The process is terminated with the exit function, so
+   atexit handlers are executed.  */
+void xpthread_check_return (const char *function, int value);
+
+/* The following functions call the corresponding libpthread functions
+   and terminate the process on error.  */
+
+void xpthread_barrier_init (pthread_barrier_t *barrier,
+                            pthread_barrierattr_t *attr, unsigned int count);
+void xpthread_barrier_destroy (pthread_barrier_t *barrier);
+void xpthread_mutex_lock (pthread_mutex_t *mutex);
+void xpthread_mutex_unlock (pthread_mutex_t *mutex);
+void xpthread_spin_lock (pthread_spinlock_t *lock);
+void xpthread_spin_unlock (pthread_spinlock_t *lock);
+void xpthread_cond_wait (pthread_cond_t * cond, pthread_mutex_t * mutex);
+pthread_t xpthread_create (pthread_attr_t *attr,
+                           void *(*thread_func) (void *), void *closure);
+void xpthread_detach (pthread_t thr);
+void xpthread_cancel (pthread_t thr);
+void *xpthread_join (pthread_t thr);
+
+/* This function returns non-zero if pthread_barrier_wait returned
+   PTHREAD_BARRIER_SERIAL_THREAD.  */
+int xpthread_barrier_wait (pthread_barrier_t *barrier);
+
+__END_DECLS
+
+#endif /* SUPPORT_THREAD_H */