auto import from //depot/cupcake/@135843
diff --git a/libc/kernel/tools/defaults.py b/libc/kernel/tools/defaults.py
new file mode 100644
index 0000000..aad0092
--- /dev/null
+++ b/libc/kernel/tools/defaults.py
@@ -0,0 +1,101 @@
+# this module contains all the defaults used by the generation of cleaned-up headers
+# for the Bionic C library
+#
+
+import time, os, sys
+from utils import *
+
+# the list of supported architectures
+#
+kernel_archs = [ 'arm', 'x86' ]
+
+# the list of include directories that belong to the kernel
+# tree. used when looking for sources...
+#
+kernel_dirs = [ "linux", "asm", "asm-generic", "mtd" ]
+
+# path to the directory containing the original kernel headers
+#
+kernel_original_path = os.path.normpath( find_program_dir() + '/../original' )
+
+# a special value that is used to indicate that a given macro is known to be
+# undefined during optimization
+kCppUndefinedMacro = "<<<undefined>>>"
+
+# this is the set of known macros we want to totally optimize out from the
+# final headers
+kernel_known_macros = {
+ "__KERNEL__": kCppUndefinedMacro,
+ "__KERNEL_STRICT_NAMES":"1",
+ "__CHECKER__": kCppUndefinedMacro,
+ "__CHECK_ENDIAN__": kCppUndefinedMacro,
+ }
+
+# define to true if you want to remove all defined(CONFIG_FOO) tests
+# from the clean headers. testing shows that this is not strictly necessary
+# but just generates cleaner results
+kernel_remove_config_macros = True
+
+# maps an architecture to a set of default macros that would be provided by
+# toolchain preprocessor
+kernel_default_arch_macros = {
+ "arm": {},
+ "x86": {"__i386__": "1"},
+ }
+
+# this is the set of known static inline functions that we want to keep
+# in the final ARM headers. this is only used to keep optimized byteswapping
+# static functions and stuff like that.
+kernel_known_arm_statics = set(
+ [ "___arch__swab32", # asm-arm/byteorder.h
+ ]
+ )
+
+kernel_known_x86_statics = set(
+ [ "___arch__swab32", # asm-x86/byteorder.h
+ "___arch__swab64", # asm-x86/byteorder.h
+ ]
+ )
+
+kernel_known_generic_statics = set(
+ [ "__invalid_size_argument_for_IOC", # asm-generic/ioctl.h
+ "__cmsg_nxthdr", # linux/socket.h
+ "cmsg_nxthdr", # linux/socket.h
+ "ipt_get_target",
+ ]
+ )
+
+# this maps an architecture to the set of static inline functions that
+# we want to keep in the final headers
+#
+kernel_known_statics = {
+ "arm" : kernel_known_arm_statics,
+ "x86" : kernel_known_x86_statics
+ }
+
+# this is a list of macros which we want to specifically exclude from
+# the generated files.
+#
+kernel_ignored_macros = set(
+ [ "MAXHOSTNAMELEN", # for some reason, Linux defines it to 64
+ # while most of the BSD code expects this to be 256
+ # so ignore the kernel-provided definition and
+ # define it in the Bionic headers instead
+ ]
+ )
+
+# this is the standard disclaimer
+#
+kernel_disclaimer = """\
+/****************************************************************************
+ ****************************************************************************
+ ***
+ *** This header was automatically generated from a Linux kernel header
+ *** of the same name, to make information necessary for userspace to
+ *** call into the kernel available to libc. It contains only constants,
+ *** structures, and macros generated from the original header, and thus,
+ *** contains no copyrightable information.
+ ***
+ ****************************************************************************
+ ****************************************************************************/
+"""