Commit 720097d8 authored by Sam Ravnborg's avatar Sam Ravnborg
Browse files

kbuild: introduce subdir-ccflags-y 



Following patch introduce support for setting options
to gcc that has effect for current directory and all
subdirectories.

The typical use case are an architecture or a subsystem that
decide to cover all files with -Werror.
Today alpha, mips and sparc uses -Werror in almost all their
Makefile- with subdir-ccflag-y it is now simpler to do so
as only the top-level directories needs to be covered.

Likewise if we decide to cover a full subsystem such
as net/ with -Werror this is done by adding a single
line to net/Makefile.

Signed-off-by: default avatarSam Ravnborg <sam@ravnborg.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
parent f14875a3

Documentation/kbuild/makefiles.txt

+10 −0
Original line number Diff line number Diff line
@@ -316,6 +316,16 @@ more details, with real examples. 
		#arch/m68k/fpsp040/Makefile

		ldflags-y := -x



    subdir-ccflags-y, subdir-asflags-y

	The two flags listed above are similar to ccflags-y and as-falgs-y.

	The difference is that the subdir- variants has effect for the kbuild

	file where tey are present and all subdirectories.

	Options specified using subdir-* are added to the commandline before

	the options specified using the non-subdir variants.



	Example:

		subdir-ccflags-y := -Werror



    CFLAGS_$@, AFLAGS_$@



	CFLAGS_$@ and AFLAGS_$@ only apply to commands in current

scripts/Makefile.build

+3 −0
Original line number Diff line number Diff line
@@ -27,6 +27,9 @@ ccflags-y := 
cppflags-y :=

ldflags-y  :=



subdir-asflags-y :=

subdir-ccflags-y :=



# Read auto.conf if it exists, otherwise ignore

-include include/config/auto.conf

scripts/Makefile.lib

+7 −2
Original line number Diff line number Diff line
@@ -4,6 +4,11 @@ ccflags-y += $(EXTRA_CFLAGS) 
cppflags-y += $(EXTRA_CPPFLAGS)

ldflags-y  += $(EXTRA_LDFLAGS)



#

# flags that take effect in sub directories

export KBUILD_SUBDIR_ASFLAGS := $(KBUILD_SUBDIR_ASFLAGS) $(subdir-asflags-y)

export KBUILD_SUBDIR_CCFLAGS := $(KBUILD_SUBDIR_CCFLAGS) $(subdir-ccflags-y)



# Figure out what we need to build from the various variables

# ===========================================================================
@@ -104,10 +109,10 @@ else 
debug_flags =

endif



orig_c_flags   = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)                     \

orig_c_flags   = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(KBUILD_SUBDIR_CCFLAGS) \

                 $(ccflags-y) $(CFLAGS_$(basetarget).o)

_c_flags       = $(filter-out $(CFLAGS_REMOVE_$(basetarget).o), $(orig_c_flags))

_a_flags       = $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS)                     \

_a_flags       = $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(KBUILD_SUBDIR_ASFLAGS) \

                 $(asflags-y) $(AFLAGS_$(basetarget).o)

_cpp_flags     = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(@F))

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