Make:Diagnostic fail if no eval

To help diagnose make problems, we report an error if the make
program used does not provide the $(eval ) make functionality.
This will detect early versions of GNU make and other make programs.

Change-Id: I0ebb0f63694cf0b04eaeb7ea1e9e172fb9770ce0

diff --git a/make_helpers/build_macros.mk b/make_helpers/build_macros.mk
index 274f365a42dc9647ce40754a9576a782cd5687c0..42e11b3f9acfeb2e90c6db606ce6b6a59f6be451 100644 (file)
--- a/make_helpers/build_macros.mk
+++ b/make_helpers/build_macros.mk
@@ -28,6 +28,12 @@
 # POSSIBILITY OF SUCH DAMAGE.
 #
 
+# Report an error if the eval make function is not available.
+$(eval eval_available := T)
+ifneq (${eval_available},T)
+    $(error This makefile only works with a Make program that supports $$(eval))
+endif
+
 # Some utility macros for manipulating awkward (whitespace) characters.
 blank                  :=
 space                  :=${blank} ${blank}