Squashed 'third_party/elfutils/' content from commit 555e15e

Change-Id: I61cde98949e47e5c8c09c33260de17f30921be79
git-subtree-dir: third_party/elfutils
git-subtree-split: 555e15ebe8bf1eb33d00747173cfc80cc65648a4
diff --git a/tests/dwfl-proc-attach.c b/tests/dwfl-proc-attach.c
new file mode 100644
index 0000000..e7bb201
--- /dev/null
+++ b/tests/dwfl-proc-attach.c
@@ -0,0 +1,103 @@
+/* Test dwfl_linux_proc_attach works without any modules.
+   Copyright (C) 2015 Red Hat, Inc.
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   elfutils 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <error.h>
+#include <unistd.h>
+#ifdef __linux__
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/user.h>
+#include <fcntl.h>
+#include <string.h>
+#include ELFUTILS_HEADER(dwfl)
+#include <pthread.h>
+#endif
+
+#ifndef __linux__
+int
+main (int argc __attribute__ ((unused)), char **argv __attribute__ ((unused)))
+{
+  printf ("dwfl_linux_proc_attach unsupported.\n");
+  return 77;
+}
+#else /* __linux__ */
+
+static pthread_t thread1;
+static pthread_t thread2;
+
+static void *
+sleeper (void* d __attribute__ ((unused)))
+{
+  sleep (60);
+  return NULL;
+}
+
+static char *debuginfo_path = NULL;
+
+static const Dwfl_Callbacks proc_callbacks =
+  {
+    .find_elf = dwfl_linux_proc_find_elf,
+    .find_debuginfo = dwfl_standard_find_debuginfo,
+    .debuginfo_path = &debuginfo_path,
+  };
+
+static int
+thread_callback (Dwfl_Thread *thread, void *thread_arg)
+{
+  int *threads = (int *) thread_arg;
+  pid_t tid = dwfl_thread_tid (thread);
+  printf ("thread tid: %d\n", tid);
+  (*threads)++;
+
+  return DWARF_CB_OK;
+}
+
+int
+main (int argc __attribute__ ((unused)),
+      char **argv __attribute__ ((unused)))
+{
+  /* Create two extra threads to iterate through.  */
+  int err;
+  if ((err = pthread_create (&thread1, NULL, sleeper, NULL)) != 0)
+    error (-1, err, "Couldn't create thread1");
+  if ((err = pthread_create (&thread2, NULL, sleeper, NULL)) != 0)
+    error (-1, err, "Couldn't create thread2");
+
+  Dwfl *dwfl = dwfl_begin (&proc_callbacks);
+  if (dwfl == NULL)
+    error (-1, 0, "dwfl_begin: %s", dwfl_errmsg (-1));
+
+  pid_t pid = getpid ();
+  /* This used to fail, since we don't have any modules yet.  */
+  if (dwfl_linux_proc_attach (dwfl, pid, false) < 0)
+    error (-1, 0, "dwfl_linux_proc_attach pid %d: %s", pid,
+	   dwfl_errmsg (-1));
+
+  /* Did we see all 3 threads?  */
+  int threads = 0;
+  if (dwfl_getthreads (dwfl, thread_callback, &threads) != DWARF_CB_OK)
+    error (-1, 0, "dwfl_getthreads failed: %s", dwfl_errmsg (-1));
+
+  return (threads == 3) ? 0 : -1;
+}
+
+#endif /* __linux__ */