[XEN PATCH v8 45/47] WIP, no-VPATH: build xen, out-of-tree!

[Anthony PERARD <anthony.perard@xxxxxxxxxx>]

From: Anthony PERARD <anthony.perard@xxxxxxxxx>

We can retire VPATH now, and $(srctree) to prerequisite of generic
rules.

(targets %.i and %.s and %.E are updated but may not work as
expected.)

Signed-off-by: Anthony PERARD <anthony.perard@xxxxxxxxxx>
---
 xen/Makefile |  3 +--
 xen/Rules.mk | 12 ++++++------
 2 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/xen/Makefile b/xen/Makefile
index fbce0f6771fb..32c36426ed7c 100644
--- a/xen/Makefile
+++ b/xen/Makefile
@@ -188,9 +188,8 @@ else
 endif
 
 objtree := .
-VPATH := $(srctree)
 
-export building_out_of_srctree srctree objtree VPATH
+export building_out_of_srctree srctree objtree
 
 export XEN_ROOT := $(abs_srctree)/..
 
diff --git a/xen/Rules.mk b/xen/Rules.mk
index 0ef45d2c7087..6fcb1f6b769f 100644
--- a/xen/Rules.mk
+++ b/xen/Rules.mk
@@ -268,7 +268,7 @@ ifdef building_out_of_srctree
 $(gen-objs-S) $(obj-gen-y): $(obj)/%.o: $(obj)/%.S FORCE
        $(call if_changed_dep,cc_o_S)
 endif
-$(obj)/%.o: $(src)/%.S FORCE
+$(obj)/%.o: $(srctree)/$(src)/%.S FORCE
        $(call if_changed_dep,cc_o_S)
 
 
@@ -298,18 +298,18 @@ cmd_cc_s_c = $(CC) $(filter-out -Wa$(comma)%,$(c_flags)) 
-S $< -o $@
 quiet_cmd_cpp_s_S = CPP     $@
 cmd_cpp_s_S = $(CPP) $(call cpp_flags,$(a_flags)) -MQ $@ -o $@ $<
 
-$(obj)/%.i: $(src)/%.c FORCE
+$(obj)/%.i: $(srctree)/$(src)/%.c FORCE
        $(call if_changed_dep,cpp_i_c)
 
-$(obj)/%.s: $(src)/%.c FORCE
+$(obj)/%.s: $(srctree)/$(src)/%.c FORCE
        $(call if_changed_dep,cc_s_c)
 
-$(obj)/%.s: $(src)/%.S FORCE
+$(obj)/%.s: $(srctree)/$(src)/%.S FORCE
        $(call if_changed_dep,cpp_s_S)
 
-$(obj)/%.E: $(src)/%.c FORCE
+$(obj)/%.E: $(srctree)/$(src)/%.c FORCE
        $(call if_changed_dep,cpp_i_c)
-$(obj)/%.E: $(src)/%.S FORCE
+$(obj)/%.E: $(srctree)/$(src)/%.S FORCE
        $(call if_changed_dep,cpp_s_S)
 
 # Linker scripts, .lds.S -> .lds
-- 
Anthony PERARD