build: detect broken make version on macOS

Apple ships a broken make version with the Xcode command line tools.
Homebrew installs make as gmake by default in order to not collide with
Apple's version.
Exit with an error if the broken one is used accidentally

Signed-off-by: Felix Fietkau <[email protected]>

include/toplevel.mk

@@ -29,6 +29,12 @@ export GNU_HOST_NAME:=$(shell $(TOPDIR)/scripts/config.guess)
 export HOST_OS:=$(shell uname)
 export HOST_ARCH:=$(shell uname -m)
 
+ifeq ($(HOST_OS),Darwin)
+  ifneq ($(filter /Applications/Xcode.app/% /Library/Developer/%,$(MAKE)),)
+    $(error Please use a newer version of GNU make. The version shipped by Apple is not supported)
+  endif
+endif
+
 # prevent perforce from messing with the patch utility
 unexport P4PORT P4USER P4CONFIG P4CLIENT