libacpi: require ACPI_BUILD_DIR to be set

It's better to have a explicit error than a build failure returned by
gcc.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>

diff --git a/tools/libacpi/Makefile b/tools/libacpi/Makefile
index ee8c09506f5bc9b6936193baeb82b3823c398f7d..18a5cd43b81a7502d704192bac707e92d0d57120 100644 (file)
--- a/tools/libacpi/Makefile
+++ b/tools/libacpi/Makefile
@@ -15,6 +15,10 @@
 XEN_ROOT = $(CURDIR)/../..
 include $(XEN_ROOT)/tools/Rules.mk
 
+ifeq ($(ACPI_BUILD_DIR),)
+$(error ACPI_BUILD_DIR not set)
+endif
+
 MK_DSDT = $(ACPI_BUILD_DIR)/mk_dsdt
 
 C_SRC-$(GPL) = dsdt_anycpu.c dsdt_15cpu.c dsdt_anycpu_qemu_xen.c