Config.mk: evaluate XEN_COMPILE_ARCH and XEN_OS on first use

With GNU make 4.4, the number of execution of the command present in
these $(shell ) increased greatly. This is probably because as of make
4.4, exported variable are also added to the environment of $(shell )
construct.

So, to avoid having these command been run more than necessery, we
will use a construct to evaluate on first use.

Reported-by: Jason Andryuk <jandryuk@gmail.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Tested-by: Jason Andryuk <jandryuk@gmail.com>

diff --git a/Config.mk b/Config.mk
index c529b1ba19cd5729d310fc49d4a6d9dfa09bf79a..5fbdbc4500d216f9886f91e2e42e85a06fc1ce93 100644 (file)
--- a/Config.mk
+++ b/Config.mk
@@ -19,13 +19,13 @@ or       = $(if $(strip $(1)),$(1),$(if $(strip $(2)),$(2),$(if $(strip $(3)),$(
 
 -include $(XEN_ROOT)/.config
 
-XEN_COMPILE_ARCH    ?= $(shell uname -m | sed -e s/i.86/x86_32/ \
+XEN_COMPILE_ARCH    ?= $(eval XEN_COMPILE_ARCH := $(shell uname -m | sed -e s/i.86/x86_32/ \
                          -e s/i86pc/x86_32/ -e s/amd64/x86_64/ \
                          -e s/armv7.*/arm32/ -e s/armv8.*/arm64/ \
-                         -e s/aarch64/arm64/)
+                         -e s/aarch64/arm64/))$(XEN_COMPILE_ARCH)
 
 XEN_TARGET_ARCH     ?= $(XEN_COMPILE_ARCH)
-XEN_OS              ?= $(shell uname -s)
+XEN_OS              ?= $(eval XEN_OS := $(shell uname -s))$(XEN_OS)
 
 CONFIG_$(XEN_OS) := y