1 files changed, 16 insertions, 2 deletions

diff --git a/Makefile b/Makefile
index 169fcbc..c4cd926 100644
--- a/Makefile
+++ b/Makefile
@@ -13,8 +13,22 @@ FILE_VERSION = 6
 
 MAKEFLAGS += --no-print-directory
 
-CC ?= $(CROSS_COMPILE)gcc
-AR ?= $(CROSS_COMPILE)ar
+
+# Makefiles suck: This macro sets a default value of $(2) for the
+# variable named by $(1), unless the variable has been set by
+# environment or command line. This is necessary for CC and AR
+# because make sets default values, so the simpler ?= approach
+# won't work as expected.
+define allow-override
+  $(if $(or $(findstring environment,$(origin $(1))),\
+            $(findstring command line,$(origin $(1)))),,\
+    $(eval $(1) = $(2)))
+endef
+
+# Allow setting CC and AR, or setting CROSS_COMPILE as a prefix.
+$(call allow-override,CC,$(CROSS_COMPILE)gcc)
+$(call allow-override,AR,$(CROSS_COMPILE)ar)
+
 EXT = -std=gnu99
 INSTALL = install