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: Sam Ravnborg <sam@ravnborg.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt
index d4b0567..d76cfd8 100644
--- a/Documentation/kbuild/makefiles.txt
+++ b/Documentation/kbuild/makefiles.txt
@@ -316,6 +316,16 @@
#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
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 39a9642..5c4b7a4 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -27,6 +27,9 @@
cppflags-y :=
ldflags-y :=
+subdir-asflags-y :=
+subdir-ccflags-y :=
+
# Read auto.conf if it exists, otherwise ignore
-include include/config/auto.conf
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 9796195..cba61ca 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -4,6 +4,11 @@
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 @@
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))