1# SPDX-License-Identifier: GPL-2.0-only
2
3# Unlike the kernel space, exported headers are written in standard C.
4#  - Forbid C++ style comments
5#  - Use '__inline__', '__asm__' instead of 'inline', 'asm'
6#
7# -std=c90 (equivalent to -ansi) catches the violation of those.
8# We cannot go as far as adding -Wpedantic since it emits too many warnings.
9UAPI_CFLAGS := -std=c90 -Wall -Werror=implicit-function-declaration
10
11# In theory, we do not care -m32 or -m64 for header compile tests.
12# It is here just because CONFIG_CC_CAN_LINK is tested with -m32 or -m64.
13UAPI_CFLAGS += $(filter -m32 -m64, $(KBUILD_CFLAGS))
14
15override c_flags = $(UAPI_CFLAGS) -Wp,-MMD,$(depfile) -I$(objtree)/usr/include
16
17# The following are excluded for now because they fail to build.
18#
19# Do not add a new header to the blacklist without legitimate reason.
20# Please consider to fix the header first.
21#
22# Sorted alphabetically.
23no-header-test += asm/shmbuf.h
24no-header-test += asm/signal.h
25no-header-test += asm/ucontext.h
26no-header-test += drm/vmwgfx_drm.h
27no-header-test += linux/am437x-vpfe.h
28no-header-test += linux/android/binder.h
29no-header-test += linux/android/binderfs.h
30no-header-test += linux/coda.h
31no-header-test += linux/errqueue.h
32no-header-test += linux/fsmap.h
33no-header-test += linux/hdlc/ioctl.h
34no-header-test += linux/ivtv.h
35no-header-test += linux/kexec.h
36no-header-test += linux/matroxfb.h
37no-header-test += linux/nfc.h
38no-header-test += linux/omap3isp.h
39no-header-test += linux/omapfb.h
40no-header-test += linux/patchkey.h
41no-header-test += linux/phonet.h
42no-header-test += linux/reiserfs_xattr.h
43no-header-test += linux/sctp.h
44no-header-test += linux/signal.h
45no-header-test += linux/sysctl.h
46no-header-test += linux/usb/audio.h
47no-header-test += linux/v4l2-mediabus.h
48no-header-test += linux/v4l2-subdev.h
49no-header-test += linux/videodev2.h
50no-header-test += linux/vm_sockets.h
51no-header-test += sound/asequencer.h
52no-header-test += sound/asoc.h
53no-header-test += sound/asound.h
54no-header-test += sound/compress_offload.h
55no-header-test += sound/emu10k1.h
56no-header-test += sound/sfnt_info.h
57no-header-test += xen/evtchn.h
58no-header-test += xen/gntdev.h
59no-header-test += xen/privcmd.h
60
61# More headers are broken in some architectures
62
63ifeq ($(SRCARCH),arc)
64no-header-test += linux/bpf_perf_event.h
65endif
66
67ifeq ($(SRCARCH),ia64)
68no-header-test += asm/setup.h
69no-header-test += asm/sigcontext.h
70no-header-test += linux/if_bonding.h
71endif
72
73ifeq ($(SRCARCH),mips)
74no-header-test += asm/stat.h
75endif
76
77ifeq ($(SRCARCH),powerpc)
78no-header-test += asm/stat.h
79no-header-test += linux/bpf_perf_event.h
80endif
81
82ifeq ($(SRCARCH),riscv)
83no-header-test += linux/bpf_perf_event.h
84endif
85
86ifeq ($(SRCARCH),sparc)
87no-header-test += asm/stat.h
88no-header-test += asm/uctx.h
89no-header-test += asm/fbio.h
90endif
91
92# asm-generic/*.h is used by asm/*.h, and should not be included directly
93no-header-test += asm-generic/%
94
95extra-y := $(patsubst $(obj)/%.h,%.hdrtest, $(shell find $(obj) -name '*.h' 2>/dev/null))
96
97# Include the header twice to detect missing include guard.
98quiet_cmd_hdrtest = HDRTEST $<
99      cmd_hdrtest = \
100		$(CC) $(c_flags) -S -o /dev/null -x c /dev/null \
101			$(if $(filter-out $(no-header-test), $*.h), -include $< -include $<); \
102		$(PERL) $(srctree)/scripts/headers_check.pl $(obj) $(SRCARCH) $<; \
103		touch $@
104
105$(obj)/%.hdrtest: $(obj)/%.h FORCE
106	$(call if_changed_dep,hdrtest)
107
108clean-files += $(filter-out Makefile, $(notdir $(wildcard $(obj)/*)))
109