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$(objtree)/usr/include 16 17# The following are excluded for now because they fail to build. 18# 19# Do not add a new header to the blacklist without legitimate reason. 20# Please consider to fix the header first. 21# 22# Sorted alphabetically. 23no-header-test += asm/ucontext.h 24no-header-test += drm/vmwgfx_drm.h 25no-header-test += linux/am437x-vpfe.h 26no-header-test += linux/coda.h 27no-header-test += linux/cyclades.h 28no-header-test += linux/errqueue.h 29no-header-test += linux/hdlc/ioctl.h 30no-header-test += linux/ivtv.h 31no-header-test += linux/matroxfb.h 32no-header-test += linux/omap3isp.h 33no-header-test += linux/omapfb.h 34no-header-test += linux/patchkey.h 35no-header-test += linux/phonet.h 36no-header-test += linux/reiserfs_xattr.h 37no-header-test += linux/sctp.h 38no-header-test += linux/sysctl.h 39no-header-test += linux/usb/audio.h 40no-header-test += linux/v4l2-mediabus.h 41no-header-test += linux/v4l2-subdev.h 42no-header-test += linux/videodev2.h 43no-header-test += linux/vm_sockets.h 44no-header-test += sound/asequencer.h 45no-header-test += sound/asoc.h 46no-header-test += sound/asound.h 47no-header-test += sound/compress_offload.h 48no-header-test += sound/emu10k1.h 49no-header-test += sound/sfnt_info.h 50no-header-test += xen/evtchn.h 51no-header-test += xen/gntdev.h 52no-header-test += xen/privcmd.h 53 54# More headers are broken in some architectures 55 56ifeq ($(SRCARCH),arc) 57no-header-test += linux/bpf_perf_event.h 58endif 59 60ifeq ($(SRCARCH),ia64) 61no-header-test += asm/setup.h 62no-header-test += asm/sigcontext.h 63no-header-test += linux/if_bonding.h 64endif 65 66ifeq ($(SRCARCH),mips) 67no-header-test += asm/stat.h 68endif 69 70ifeq ($(SRCARCH),powerpc) 71no-header-test += asm/stat.h 72no-header-test += linux/bpf_perf_event.h 73endif 74 75ifeq ($(SRCARCH),riscv) 76no-header-test += linux/bpf_perf_event.h 77endif 78 79ifeq ($(SRCARCH),sparc) 80no-header-test += asm/stat.h 81no-header-test += asm/uctx.h 82no-header-test += asm/fbio.h 83endif 84 85# asm-generic/*.h is used by asm/*.h, and should not be included directly 86no-header-test += asm-generic/% 87 88extra-y := $(patsubst $(obj)/%.h,%.hdrtest, $(shell find $(obj) -name '*.h' 2>/dev/null)) 89 90# Include the header twice to detect missing include guard. 91quiet_cmd_hdrtest = HDRTEST $< 92 cmd_hdrtest = \ 93 $(CC) $(c_flags) -S -o /dev/null -x c /dev/null \ 94 $(if $(filter-out $(no-header-test), $*.h), -include $< -include $<); \ 95 $(PERL) $(srctree)/$(src)/headers_check.pl $(obj) $(SRCARCH) $<; \ 96 touch $@ 97 98$(obj)/%.hdrtest: $(obj)/%.h FORCE 99 $(call if_changed_dep,hdrtest) 100 101# Since GNU Make 4.3, $(patsubst $(obj)/%/,%,$(wildcard $(obj)/*/)) works. 102# To support older Make versions, use a somewhat tedious way. 103clean-files += $(filter-out Makefile headers_check.pl, $(notdir $(wildcard $(obj)/*))) 104