diff --git a/libc/private/debug_format.h b/libc/private/debug_format.h
new file mode 100644
index 0000000..0bc1148
--- /dev/null
+++ b/libc/private/debug_format.h
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef _DEBUG_FORMAT_H
+#define _DEBUG_FORMAT_H
+
+#include <sys/cdefs.h>
+#include <stdarg.h>
+#include <stddef.h>
+
+__BEGIN_DECLS
+
+// Formatting routines for the C library's internal debugging.
+// Unlike the usual alternatives, these don't allocate.
+
+__LIBC_HIDDEN__ int __libc_format_buffer(char* buffer, size_t buffer_size, const char* format, ...)
+    __attribute__((__format__(printf, 3, 4)));
+
+__LIBC_HIDDEN__ int __libc_format_fd(int fd, const char* format, ...)
+    __attribute__((__format__(printf, 2, 3)));
+
+__LIBC_HIDDEN__ int __libc_format_log(int priority, const char* tag, const char* format, ...)
+    __attribute__((__format__(printf, 3, 4)));
+
+__LIBC_HIDDEN__ int __libc_format_log_va_list(int priority, const char* tag, const char* format,
+                                              va_list ap);
+
+__END_DECLS
+
+#endif /* _DEBUG_FORMAT_H */