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 -Werror=implicit-function-declaration 10 11override c_flags = $(KBUILD_USERCFLAGS) $(UAPI_CFLAGS) -Wp,-MMD,$(depfile) -I $(obj) -I $(srctree)/usr/dummy-include 12 13# The following are excluded for now because they fail to build. 14# 15# Do not add a new header to the blacklist without legitimate reason. 16# Please consider to fix the header first. 17# 18# Sorted alphabetically. 19no-header-test += asm/ucontext.h 20no-header-test += drm/vmwgfx_drm.h 21no-header-test += linux/am437x-vpfe.h 22no-header-test += linux/coda.h 23no-header-test += linux/cyclades.h 24no-header-test += linux/errqueue.h 25no-header-test += linux/hdlc/ioctl.h 26no-header-test += linux/ivtv.h 27no-header-test += linux/matroxfb.h 28no-header-test += linux/omap3isp.h 29no-header-test += linux/omapfb.h 30no-header-test += linux/patchkey.h 31no-header-test += linux/phonet.h 32no-header-test += linux/sctp.h 33no-header-test += linux/sysctl.h 34no-header-test += linux/usb/audio.h 35no-header-test += linux/v4l2-mediabus.h 36no-header-test += linux/v4l2-subdev.h 37no-header-test += linux/videodev2.h 38no-header-test += linux/vm_sockets.h 39no-header-test += sound/asequencer.h 40no-header-test += sound/asoc.h 41no-header-test += sound/asound.h 42no-header-test += sound/compress_offload.h 43no-header-test += sound/emu10k1.h 44no-header-test += sound/sfnt_info.h 45no-header-test += xen/evtchn.h 46no-header-test += xen/gntdev.h 47no-header-test += xen/privcmd.h 48 49# More headers are broken in some architectures 50 51ifeq ($(SRCARCH),arc) 52no-header-test += linux/bpf_perf_event.h 53endif 54 55ifeq ($(SRCARCH),openrisc) 56no-header-test += linux/bpf_perf_event.h 57endif 58 59ifeq ($(SRCARCH),powerpc) 60no-header-test += linux/bpf_perf_event.h 61endif 62 63ifeq ($(SRCARCH),sparc) 64no-header-test += asm/uctx.h 65no-header-test += asm/fbio.h 66endif 67 68# asm-generic/*.h is used by asm/*.h, and should not be included directly 69no-header-test += asm-generic/% 70 71always-y := $(patsubst $(obj)/%.h,%.hdrtest, $(shell find $(obj) -name '*.h' 2>/dev/null)) 72 73# Include the header twice to detect missing include guard. 74quiet_cmd_hdrtest = HDRTEST $< 75 cmd_hdrtest = \ 76 $(CC) $(c_flags) -fsyntax-only -Werror -x c /dev/null \ 77 $(if $(filter-out $(no-header-test), $*.h), -include $< -include $<); \ 78 $(PERL) $(src)/headers_check.pl $(obj) $<; \ 79 touch $@ 80 81$(obj)/%.hdrtest: $(obj)/%.h $(src)/headers_check.pl FORCE 82 $(call if_changed_dep,hdrtest) 83 84# Since GNU Make 4.3, $(patsubst $(obj)/%/,%,$(wildcard $(obj)/*/)) works. 85# To support older Make versions, use a somewhat tedious way. 86clean-files += $(filter-out Makefile headers_check.pl, $(notdir $(wildcard $(obj)/*))) 87