Sometimes it's useful to be able to explicitly ensure certain headers remain self-contained, i.e. that they are compilable as standalone units, by including and/or forward declaring everything they depend on. Add special target header-test-y where individual Makefiles can add headers to be tested if CONFIG_HEADER_TEST is enabled. This will generate a dummy C file per header that gets built as part of extra-y. Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Cc: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> Cc: Michal Marek <michal.lkml@xxxxxxxxxxx> Cc: Sam Ravnborg <sam@xxxxxxxxxxxx> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> --- v2: changes suggested by Masahiro: http://mid.mail-archive.com/CAK7LNAT=nB0=at0X4OnHVKB=y7WwHGm4LXkrQnCw9HpjB5LooA@xxxxxxxxxxxxxx --- .gitignore | 1 + Documentation/dontdiff | 1 + Documentation/kbuild/makefiles.txt | 7 +++++++ Makefile | 1 + init/Kconfig | 9 +++++++++ scripts/Makefile.build | 9 +++++++++ scripts/Makefile.lib | 3 +++ 7 files changed, 31 insertions(+) diff --git a/.gitignore b/.gitignore index 7587ef56b92d..4bb60f0fa23b 100644 --- a/.gitignore +++ b/.gitignore @@ -22,6 +22,7 @@ *.elf *.gcno *.gz +*.hdrtest.c *.i *.ko *.lex.c diff --git a/Documentation/dontdiff b/Documentation/dontdiff index 5eba889ea84d..554dfe4883d2 100644 --- a/Documentation/dontdiff +++ b/Documentation/dontdiff @@ -19,6 +19,7 @@ *.grep *.grp *.gz +*.hdrtest.c *.html *.i *.jpeg diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt index d65ad5746f94..a31e54bd9ddd 100644 --- a/Documentation/kbuild/makefiles.txt +++ b/Documentation/kbuild/makefiles.txt @@ -1022,6 +1022,13 @@ When kbuild executes, the following steps are followed (roughly): In this example, extra-y is used to list object files that shall be built, but shall not be linked as part of built-in.a. + header-test-y + + header-test-y specifies headers (*.h) in the current directory that + should be compile tested to ensure they are self-contained, + i.e. compilable as standalone units. If CONFIG_HEADER_TEST is enabled, + this autogenerates dummy sources to include the headers, and builds them + as part of extra-y. --- 6.7 Commands useful for building a boot image diff --git a/Makefile b/Makefile index 11358153d8f2..b347be697fbb 100644 --- a/Makefile +++ b/Makefile @@ -1646,6 +1646,7 @@ clean: $(clean-dirs) -o -name '*.dwo' -o -name '*.lst' \ -o -name '*.su' \ -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \ + -o -name '*.hdrtest.c' \ -o -name '*.lex.c' -o -name '*.tab.[ch]' \ -o -name '*.asn1.[ch]' \ -o -name '*.symtypes' -o -name 'modules.order' \ diff --git a/init/Kconfig b/init/Kconfig index 36894c9fb420..02d8897b91fb 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -96,6 +96,15 @@ config COMPILE_TEST here. If you are a user/distributor, say N here to exclude useless drivers to be distributed. +config HEADER_TEST + bool "Compile test headers that should be standalone compilable" + help + Compile test headers listed in header-test-y target to ensure they are + self-contained, i.e. compilable as standalone units. + + If you are a developer or tester and want to ensure the requested + headers are self-contained, say Y here. Otherwise, choose N. + config LOCALVERSION string "Local version - append to kernel release" help diff --git a/scripts/Makefile.build b/scripts/Makefile.build index ae9cf740633e..ee0319560513 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -294,6 +294,15 @@ quiet_cmd_cc_lst_c = MKLST $@ $(obj)/%.lst: $(src)/%.c FORCE $(call if_changed_dep,cc_lst_c) +# Dummy C sources for header test (header-test-y target) +# --------------------------------------------------------------------------- + +quiet_cmd_header_test = HDRTEST $@ + cmd_header_test = echo "\#include \"$*.h\"" > $@ + +$(obj)/%.hdrtest.c: + $(call cmd,header_test) + # Compile assembler sources (.S) # --------------------------------------------------------------------------- diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index f1f38c8cdc74..3e630fcaffd1 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -66,6 +66,9 @@ extra-y += $(patsubst %.dtb,%.dt.yaml, $(dtb-y)) extra-$(CONFIG_OF_ALL_DTBS) += $(patsubst %.dtb,%.dt.yaml, $(dtb-)) endif +# Test self-contained headers +extra-$(CONFIG_HEADER_TEST) += $(patsubst %.h,%.hdrtest.o,$(header-test-y)) + # Add subdir path extra-y := $(addprefix $(obj)/,$(extra-y)) -- 2.20.1
