[XEN PATCH v5 11/16] xen/build: factorise generation of the linker scripts

[Anthony PERARD <anthony.perard@xxxxxxxxxx>]

In Arm and X86 makefile, generating the linker script is the same, so
we can simply have both call the same macro.

We need to add *.lds files into extra-y so that Rules.mk can find the
.*.cmd dependency file and load it.

Change made to the command line:
- Use of $(CPP) instead of $(CC) -E
- Remove -Ui386.
  We don't compile Xen for i386 anymore, so that macro is never
  defined. Also it doesn't make sense on Arm.
- Use $(cpp_flags) which simply filter -Wa,% options from $(a_flags).

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

Notes:
    v5:
    - rename cc_lds_S to cpp_lds_S as the binary runned is now CPP
    - Use new cpp_flags instead of the open-coded filter of a_flags.
    
    v4:
    - fix rebuild by adding FORCE as dependency
    - Use $(CPP)
    - remove -Ui386
    - avoid using "define" for cmd_cc_lds_S, as adding '; \' on each line is
      still mandatory for if_changed (or cmd) macro to work.

 xen/Rules.mk          | 6 ++++++
 xen/arch/arm/Makefile | 8 ++++----
 xen/arch/x86/Makefile | 8 ++++----
 3 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/xen/Rules.mk b/xen/Rules.mk
index 9150911296de..877f52d871fa 100644
--- a/xen/Rules.mk
+++ b/xen/Rules.mk
@@ -236,6 +236,12 @@ cmd_s_S = $(CPP) $(cpp_flags) $< -o $@
 %.s: %.S FORCE
        $(call if_changed,cpp_s_S)
 
+# Linker scripts, .lds.S -> .lds
+quiet_cmd_cpp_lds_S = LDS     $@
+cmd_cpp_lds_S = $(CPP) -P $(cpp_flags) -o $@ $<; \
+    sed -e 's/.*\.lds\.o:/$(@F):/g' <$(dot-target).d >$(dot-target).d.new; \
+    mv -f $(dot-target).d.new $(dot-target).d
+
 # Add intermediate targets:
 # When building objects with specific suffix patterns, add intermediate
 # targets that the final targets are derived from.
diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
index b79ad55646bd..68cb258870eb 100644
--- a/xen/arch/arm/Makefile
+++ b/xen/arch/arm/Makefile
@@ -64,6 +64,8 @@ obj-y += vpsci.o
 obj-y += vuart.o
 extra-y += $(TARGET_SUBARCH)/head.o
 
+extra-y += xen.lds
+
 #obj-bin-y += ....o
 
 ifdef CONFIG_DTB_FILE
@@ -122,10 +124,8 @@ $(TARGET)-syms: prelink.o xen.lds
 asm-offsets.s: $(TARGET_SUBARCH)/asm-offsets.c
        $(CC) $(filter-out -flto,$(c_flags)) -S -o $@ $<
 
-xen.lds: xen.lds.S
-       $(CC) -P -E -Ui386 $(a_flags) -o $@ $<
-       sed -e 's/xen\.lds\.o:/xen\.lds:/g' <.xen.lds.d >.xen.lds.d.new
-       mv -f .xen.lds.d.new .xen.lds.d
+xen.lds: xen.lds.S FORCE
+       $(call if_changed,cpp_lds_S)
 
 dtb.o: $(CONFIG_DTB_FILE)
 
diff --git a/xen/arch/x86/Makefile b/xen/arch/x86/Makefile
index 44137d919b66..92430192a74e 100644
--- a/xen/arch/x86/Makefile
+++ b/xen/arch/x86/Makefile
@@ -72,6 +72,7 @@ obj-y += hpet.o
 obj-y += vm_event.o
 obj-y += xstate.o
 extra-y += asm-macros.i
+extra-y += xen.lds
 
 x86_emulate.o: x86_emulate/x86_emulate.c x86_emulate/x86_emulate.h
 
@@ -173,6 +174,7 @@ export XEN_BUILD_EFI := $(shell $(CC) $(XEN_CFLAGS) -c 
efi/check.c -o efi/check.
 # Check if the linker supports PE.
 XEN_BUILD_PE := $(if $(XEN_BUILD_EFI),$(shell $(LD) -mi386pep --subsystem=10 
-o efi/check.efi efi/check.o 2>/dev/null && echo y))
 CFLAGS-$(XEN_BUILD_EFI) += -DXEN_BUILD_EFI
+extra-$(XEN_BUILD_PE) += efi.lds
 
 $(TARGET).efi: VIRT_BASE = 0x$(shell $(NM) efi/relocs-dummy.o | sed -n 's, A 
VIRT_START$$,,p')
 $(TARGET).efi: ALT_BASE = 0x$(shell $(NM) efi/relocs-dummy.o | sed -n 's, A 
ALT_START$$,,p')
@@ -240,10 +242,8 @@ $(BASEDIR)/include/asm-x86/asm-macros.h: asm-macros.i 
Makefile
        $(call move-if-changed,$@.new,$@)
 
 efi.lds: AFLAGS-y += -DEFI
-xen.lds efi.lds: xen.lds.S
-       $(CC) -P -E -Ui386 $(filter-out -Wa$(comma)%,$(a_flags)) -o $@ $<
-       sed -e 's/.*\.lds\.o:/$(@F):/g' <.$(@F).d >.$(@F).d.new
-       mv -f .$(@F).d.new .$(@F).d
+xen.lds efi.lds: xen.lds.S FORCE
+       $(call if_changed,cpp_lds_S)
 
 boot/mkelf32: boot/mkelf32.c
        $(HOSTCC) $(HOSTCFLAGS) -o $@ $<
-- 
Anthony PERARD