Makefile: Check $CC variable returned from xcompile is not empty.

If xcompile can't find out suitable GCC compiler for i386/armv7, it
will not set $CC_i386/$CC_armv7 variable. Makefile sets $CC variable
from xcompile, and will print strange error messages when executing
$CC program if $CC is empty.

Add checking to avoid this problem. If $CC is empty, also delete
invalid .xcompile file, so Make can recreate this file next time.

Change-Id: Ia8d481d76ca52f3351cb99f05779d06947161c5d
Signed-off-by: Andrew Wu <>
Tested-by: build bot (Jenkins)
Reviewed-by: Jonathan A. Kollasch <>
Reviewed-by: Patrick Georgi <>
2 files changed