Bug 914482 - Allow overrides from the command line for variables defined in moz.build. r=gps

config/rules.mk

@@ -54,11 +54,11 @@ ifndef EXTERNALLY_MANAGED_MAKE_FILE
 # scenarios.
 _current_makefile = $(CURDIR)/$(firstword $(MAKEFILE_LIST))
 
-$(foreach var,$(_MOZBUILD_EXTERNAL_VARIABLES),$(if $($(var)),\
+$(foreach var,$(_MOZBUILD_EXTERNAL_VARIABLES),$(if $(filter file override,$(subst $(NULL) ,_,$(origin $(var)))),\
     $(error Variable $(var) is defined in $(_current_makefile). It should only be defined in moz.build files),\
     ))
 
-$(foreach var,$(_DEPRECATED_VARIABLES),$(if $($(var)),\
+$(foreach var,$(_DEPRECATED_VARIABLES),$(if $(filter file override,$(subst $(NULL) ,_,$(origin $(var)))),\
     $(error Variable $(var) is defined in $(_current_makefile). This variable has been deprecated. It does nothing. It must be removed in order to build)\
     ))
 

js/src/config/rules.mk

@@ -54,11 +54,11 @@ ifndef EXTERNALLY_MANAGED_MAKE_FILE
 # scenarios.
 _current_makefile = $(CURDIR)/$(firstword $(MAKEFILE_LIST))
 
-$(foreach var,$(_MOZBUILD_EXTERNAL_VARIABLES),$(if $($(var)),\
+$(foreach var,$(_MOZBUILD_EXTERNAL_VARIABLES),$(if $(filter file override,$(subst $(NULL) ,_,$(origin $(var)))),\
     $(error Variable $(var) is defined in $(_current_makefile). It should only be defined in moz.build files),\
     ))
 
-$(foreach var,$(_DEPRECATED_VARIABLES),$(if $($(var)),\
+$(foreach var,$(_DEPRECATED_VARIABLES),$(if $(filter file override,$(subst $(NULL) ,_,$(origin $(var)))),\
     $(error Variable $(var) is defined in $(_current_makefile). This variable has been deprecated. It does nothing. It must be removed in order to build)\
     ))