path: root/usr
diff options
authorMasahiro Yamada <>2019-12-19 00:34:21 +0900
committerMasahiro Yamada <>2020-01-07 02:18:38 +0900
commit551197864ad5d8ed01137b7008448bd18b9731d5 (patch)
treee54d330ff582e53aa9e2900ab580db2261dd77ec /usr
parentc79f46a282390e0f5b306007bf7b11a46d529538 (diff)
kbuild: detect missing include guard for exported headers
Adding an include guard to every header file is good practice in case it is included multiple times. Exported headers are compile-tested for the comprehensive sanity checks. Let's include the same header twice. If an include guard is missing, the header will fail to build due to redefinition of something. Signed-off-by: Masahiro Yamada <> Reviewed-by: Sam Ravnborg <>
Diffstat (limited to 'usr')
1 files changed, 2 insertions, 1 deletions
diff --git a/usr/include/Makefile b/usr/include/Makefile
index 84598469e6ff..e90f5f7903bb 100644
--- a/usr/include/Makefile
+++ b/usr/include/Makefile
@@ -93,10 +93,11 @@ header-test- += asm-generic/%
extra-y := $(patsubst $(obj)/%.h,%.hdrtest, $(shell find $(obj) -name '*.h' 2>/dev/null))
+# Include the header to detect missing include guard.
quiet_cmd_hdrtest = HDRTEST $<
cmd_hdrtest = \
$(CC) $(c_flags) -S -o /dev/null -x c /dev/null \
- $(if $(filter-out $(header-test-), $*.h), -include $<); \
+ $(if $(filter-out $(header-test-), $*.h), -include $< -include $<); \
$(PERL) $(srctree)/scripts/ $(obj) $(SRCARCH) $<; \
touch $@