[XEN PATCH v6 02/31] build: introduce cpp_flags macro

[Anthony PERARD <anthony.perard@citrix.com>]

Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
---

Notes:
    v6:
    - switch to a macro as suggested
      which allows to be used with both a_flags and c_flags
    
    v5:
    - new patch

 xen/Rules.mk                    | 7 +++++--
 xen/arch/x86/mm/Makefile        | 2 +-
 xen/arch/x86/mm/hap/Makefile    | 2 +-
 xen/arch/x86/mm/shadow/Makefile | 2 +-
 4 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/xen/Rules.mk b/xen/Rules.mk
index d65d6a48993b..f778058f80a6 100644
--- a/xen/Rules.mk
+++ b/xen/Rules.mk
@@ -133,6 +133,9 @@ endif
 # Always build obj-bin files as binary even if they come from C source. 
 $(obj-bin-y): XEN_CFLAGS := $(filter-out -flto,$(XEN_CFLAGS))
 
+# To be use with $(a_flags) or $(c_flags) to produce CPP flags
+cpp_flags = $(filter-out -Wa$(comma)%,$(1))
+
 # Calculation of flags, first the generic flags, then the arch specific flags,
 # and last the flags modified for a target or a directory.
 
@@ -222,13 +225,13 @@ $(filter %.init.o,$(obj-y) $(obj-bin-y) $(extra-y)): %.init.o: %.o FORCE
 	$(call if_changed,obj_init_o)
 
 quiet_cmd_cpp_i_c = CPP     $@
-cmd_cpp_i_c = $(CPP) $(filter-out -Wa$(comma)%,$(c_flags)) -MQ $@ -o $@ $<
+cmd_cpp_i_c = $(CPP) $(call cpp_flags,$(c_flags)) -MQ $@ -o $@ $<
 
 quiet_cmd_cc_s_c = CC      $@
 cmd_cc_s_c = $(CC) $(filter-out -Wa$(comma)%,$(c_flags)) -S $< -o $@
 
 quiet_cmd_cpp_s_S = CPP     $@
-cmd_cpp_s_S = $(CPP) $(filter-out -Wa$(comma)%,$(a_flags)) -MQ $@ -o $@ $<
+cmd_cpp_s_S = $(CPP) $(call cpp_flags,$(a_flags)) -MQ $@ -o $@ $<
 
 %.i: %.c FORCE
 	$(call if_changed,cpp_i_c)
diff --git a/xen/arch/x86/mm/Makefile b/xen/arch/x86/mm/Makefile
index b31041644fe8..2818c066f76a 100644
--- a/xen/arch/x86/mm/Makefile
+++ b/xen/arch/x86/mm/Makefile
@@ -15,7 +15,7 @@ guest_walk_%.o: guest_walk.c Makefile
 	$(CC) $(c_flags) -DGUEST_PAGING_LEVELS=$* -c $< -o $@
 
 guest_walk_%.i: guest_walk.c Makefile
-	$(CPP) $(filter-out -Wa$(comma)%,$(c_flags)) -DGUEST_PAGING_LEVELS=$* -c $< -o $@
+	$(CPP) $(call cpp_flags,$(c_flags)) -DGUEST_PAGING_LEVELS=$* -c $< -o $@
 
 guest_walk_%.s: guest_walk.c Makefile
 	$(CC) $(filter-out -Wa$(comma)%,$(c_flags)) -DGUEST_PAGING_LEVELS=$* -S $< -o $@
diff --git a/xen/arch/x86/mm/hap/Makefile b/xen/arch/x86/mm/hap/Makefile
index 22e7ad54bd33..c6d296b51720 100644
--- a/xen/arch/x86/mm/hap/Makefile
+++ b/xen/arch/x86/mm/hap/Makefile
@@ -9,7 +9,7 @@ guest_walk_%level.o: guest_walk.c Makefile
 	$(CC) $(c_flags) -DGUEST_PAGING_LEVELS=$* -c $< -o $@
 
 guest_walk_%level.i: guest_walk.c Makefile
-	$(CPP) $(filter-out -Wa$(comma)%,$(c_flags)) -DGUEST_PAGING_LEVELS=$* -c $< -o $@
+	$(CPP) $(call cpp_flags,$(c_flags)) -DGUEST_PAGING_LEVELS=$* -c $< -o $@
 
 guest_walk_%level.s: guest_walk.c Makefile
 	$(CC) $(filter-out -Wa$(comma)%,$(c_flags)) -DGUEST_PAGING_LEVELS=$* -S $< -o $@
diff --git a/xen/arch/x86/mm/shadow/Makefile b/xen/arch/x86/mm/shadow/Makefile
index 770213fe9d84..fd64b4dda925 100644
--- a/xen/arch/x86/mm/shadow/Makefile
+++ b/xen/arch/x86/mm/shadow/Makefile
@@ -10,7 +10,7 @@ guest_%.o: multi.c Makefile
 	$(CC) $(c_flags) -DGUEST_PAGING_LEVELS=$* -c $< -o $@
 
 guest_%.i: multi.c Makefile
-	$(CPP) $(filter-out -Wa$(comma)%,$(c_flags)) -DGUEST_PAGING_LEVELS=$* -c $< -o $@
+	$(CPP) $(call cpp_flags,$(c_flags)) -DGUEST_PAGING_LEVELS=$* -c $< -o $@
 
 guest_%.s: multi.c Makefile
 	$(CC) $(filter-out -Wa$(comma)%,$(c_flags)) -DGUEST_PAGING_LEVELS=$* -S $< -o $@
-- 
Anthony PERARD