1# this module contains all the defaults used by the generation of cleaned-up headers
2# for the Bionic C library
3#
4
5import time, os, sys
6from utils import *
7
8# the list of supported architectures
9kernel_archs = [ 'arm', 'arm64', 'x86' ]
10
11# the list of include directories that belong to the kernel
12# tree. used when looking for sources...
13kernel_dirs = [ "linux", "asm", "asm-generic", "mtd" ]
14
15# a special value that is used to indicate that a given macro is known to be
16# undefined during optimization
17kCppUndefinedMacro = "<<<undefined>>>"
18
19# this is the set of known macros we want to totally optimize out from the
20# final headers
21kernel_known_macros = {
22    "__KERNEL__": kCppUndefinedMacro,
23    "__KERNEL_STRICT_NAMES":"1",
24    "__CHECKER__": kCppUndefinedMacro,
25    "__CHECK_ENDIAN__": kCppUndefinedMacro,
26    "CONFIG_64BIT": "__LP64__",
27    "CONFIG_X86_32": "__i386__",
28    "__EXPORTED_HEADERS__": "1",
29    "__HAVE_BUILTIN_BSWAP16__": "1",
30    "__HAVE_BUILTIN_BSWAP32__": "1",
31    "__HAVE_BUILTIN_BSWAP64__": "1",
32    # Use this to remove the struct __kernel_old_timeval definition.
33    # Otherwise, there will be two struct timeval definitions when
34    # __kernel_old_timeval is renamed to timeval.
35    "__kernel_old_timeval": "1",
36    }
37
38# this is the set of known kernel data structures we want to remove from
39# the final headers
40kernel_structs_to_remove = set(
41        [
42          # Remove the structures since they are still the same as
43          # timeval, itimerval.
44          "__kernel_old_timeval",
45          "__kernel_old_itimerval",
46        ]
47    )
48
49# define to true if you want to remove all defined(CONFIG_FOO) tests
50# from the clean headers. testing shows that this is not strictly necessary
51# but just generates cleaner results
52kernel_remove_config_macros = True
53
54# maps an architecture to a set of default macros that would be provided by
55# toolchain preprocessor
56kernel_default_arch_macros = {
57    "arm": {"__ARMEB__": kCppUndefinedMacro, "__ARM_EABI__": "1"},
58    "arm64": {},
59    "x86": {},
60    }
61
62kernel_arch_token_replacements = {
63    "arm": {},
64    "arm64": {},
65    "x86": {},
66    }
67
68# Replace tokens in the output according to this mapping.
69kernel_token_replacements = {
70    # The kernel usage of __unused for unused struct fields conflicts with the macro defined in <sys/cdefs.h>.
71    "__unused": "__linux_unused",
72    # The kernel usage of C++ keywords causes problems for C++ code so rename.
73    "private": "__linux_private",
74    "virtual": "__linux_virtual",
75    # The non-64 stuff is legacy; msqid64_ds/ipc64_perm is what userspace wants.
76    "msqid_ds": "__kernel_legacy_msqid_ds",
77    "semid_ds": "__kernel_legacy_semid_ds",
78    "shmid_ds": "__kernel_legacy_shmid_ds",
79    "ipc_perm": "__kernel_legacy_ipc_perm",
80    # The kernel semun isn't usable (https://github.com/android-ndk/ndk/issues/400).
81    "semun": "__kernel_legacy_semun",
82    # The kernel's _NSIG/NSIG are one less than the userspace value, so we need to move them aside.
83    "_NSIG": "_KERNEL__NSIG",
84    "NSIG": "_KERNEL_NSIG",
85    # The kernel's SIGRTMIN/SIGRTMAX are absolute limits; userspace steals a few.
86    "SIGRTMIN": "__SIGRTMIN",
87    "SIGRTMAX": "__SIGRTMAX",
88    # We want to support both BSD and Linux member names in struct udphdr.
89    "udphdr": "__kernel_udphdr",
90    # This causes problems when trying to export the headers for the ndk.
91    "__attribute_const__": "__attribute__((__const__))",
92    # In this case the kernel tries to keep out of our way, but we're happy to use its definition.
93    "__kernel_sockaddr_storage": "sockaddr_storage",
94    # The kernel started using struct __kernel_old_timeval in some places,
95    # which is the exact same as struct timeval. Replace that name with
96    # timeval so that kernel structures all use the same named structure.
97    # If struct __kernel_old_timeval and struct timeval become different,
98    # then a different solution needs to be implemented.
99    "__kernel_old_timeval": "timeval",
100    # Do the same for __kernel_old_itimerval as for timeval.
101    "__kernel_old_itimerval": "itimerval",
102    }
103
104
105# This is the set of struct definitions that we want to replace with
106# a #include of <bits/struct.h> instead.
107kernel_struct_replacements = set(
108        [
109          "epoll_event",
110          "flock",
111          "flock64",
112          "in_addr",
113          "ip_mreq_source",
114          "ip_msfilter",
115        ]
116    )
117
118
119# This is the set of known static inline functions that we want to keep
120# in the final kernel headers.
121kernel_known_generic_statics = set(
122        [
123          "ipt_get_target",  # uapi/linux/netfilter_ipv4/ip_tables.h
124          "ip6t_get_target", # uapi/linux/netfilter_ipv6/ip6_tables.h
125          # Byte swapping inlines from uapi/linux/swab.h
126          # The below functions are the ones we are guaranting we export.
127          "__swab16",
128          "__swab32",
129          "__swab64",
130          "__swab16p",
131          "__swab32p",
132          "__swab64p",
133          "__swab16s",
134          "__swab32s",
135          "__swab64s",
136          "__swahw32",
137          "__swahb32",
138          "__swahw32p",
139          "__swahb32p",
140          "__swahw32s",
141          "__swahb32s",
142          # These are required to support the above functions.
143          "__fswahw32",
144          "__fswahb32",
145        ]
146    )
147
148# this is the standard disclaimer
149#
150kernel_disclaimer = """\
151/****************************************************************************
152 ****************************************************************************
153 ***
154 ***   This header was automatically generated from a Linux kernel header
155 ***   of the same name, to make information necessary for userspace to
156 ***   call into the kernel available to libc.  It contains only constants,
157 ***   structures, and macros generated from the original header, and thus,
158 ***   contains no copyrightable information.
159 ***
160 ***   To edit the content of this header, modify the corresponding
161 ***   source file (e.g. under external/kernel-headers/original/) then
162 ***   run bionic/libc/kernel/tools/update_all.py
163 ***
164 ***   Any manual change here will be lost the next time this script will
165 ***   be run. You've been warned!
166 ***
167 ****************************************************************************
168 ****************************************************************************/
169"""
170