Break out utils to separate file

utils.h

@@ -0,0 +1,128 @@
+/* build-root
+ * Copyright (C) 2016 Alexander Larsson
+ *
+ * This program 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 of the License, or (at your option) any later version.
+ *
+ * This 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 this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef __UTILS_H__
+#define __UTILS_H__
+
+#include <assert.h>
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#if 0
+#define __debug__(x) printf x
+#else
+#define __debug__(x)
+#endif
+
+#define N_ELEMENTS(arr)		(sizeof (arr) / sizeof ((arr)[0]))
+
+#define TRUE 1
+#define FALSE 0
+typedef int bool;
+
+#define PIPE_READ_END 0
+#define PIPE_WRITE_END 1
+
+void  strfreev       (char       **str_array);
+void  die_with_error (const char  *format,
+                      ...);
+void  die            (const char  *format,
+                      ...);
+void  die_oom        (void);
+void *xmalloc        (size_t       size);
+void *xcalloc        (size_t       size);
+void *xrealloc       (void        *ptr,
+                      size_t       size);
+char *xstrdup        (const char  *str);
+void  xsetenv        (const char  *name,
+                      const char  *value,
+                      int          overwrite);
+void  xunsetenv      (const char  *name);
+char *strconcat      (const char  *s1,
+                      const char  *s2);
+char *strconcat3     (const char  *s1,
+                      const char  *s2,
+                      const char  *s3);
+char* strdup_printf  (const char  *format,
+                      ...);
+int   fdwalk         (int          proc_fd,
+                      int        (*cb)(void *data, int fd),
+                      void        *data);
+
+/* syscall wrappers */
+int   raw_clone      (unsigned long flags,
+                      void         *child_stack);
+int   pivot_root     (const char   *new_root,
+                      const char   *put_old);
+
+static inline void
+cleanup_freep (void *p)
+{
+  void **pp = (void**)p;
+  if (*pp)
+    free (*pp);
+}
+
+static inline void
+cleanup_strvp (void *p)
+{
+  void **pp = (void**)p;
+  strfreev (*pp);
+}
+
+static inline void
+cleanup_fdp (int *fdp)
+{
+  int fd;
+
+  assert (fdp);
+
+  fd = *fdp;
+  if (fd != -1)
+    (void) close (fd);
+}
+
+#define cleanup_free __attribute__((cleanup(cleanup_freep)))
+#define cleanup_fd __attribute__((cleanup(cleanup_fdp)))
+#define cleanup_strv __attribute__((cleanup(cleanup_strvp)))
+
+static inline void *
+steal_pointer (void *pp)
+{
+  void **ptr = (void **) pp;
+  void *ref;
+
+  ref = *ptr;
+  *ptr = NULL;
+
+  return ref;
+}
+
+/* type safety */
+#define steal_pointer(pp) \
+  (0 ? (*(pp)) : (steal_pointer) (pp))
+
+#endif /* __UTILS_H__ */