build: Create a better definition of LLVM deps

Author: brson

mk/llvm.mk

@@ -1,13 +1,17 @@
+# Recursive wildcard function
+# http://blog.jgc.org/2011/07/gnu-make-recursive-wildcard-function.html
+rwildcard=$(foreach d,$(wildcard $1*),$(call rwildcard,$d/,$2) \
+  $(filter $(subst *,%,$2),$d))
+
 # This is just a rough approximation of LLVM deps
-LLVM_DEPS:=$(wildcard $(addprefix $(CFG_LLVM_SRC_DIR)/, \
-                        * */*h */*/*h */*/*/*h */*cpp */*/*cpp */*/*/*cpp))
+LLVM_DEPS=$(call rwildcard,$(CFG_LLVM_SRC_DIR),*cpp *hpp)
 
 define DEF_LLVM_RULES
 
 # If CFG_LLVM_ROOT is defined then we don't build LLVM ourselves
 ifeq ($(CFG_LLVM_ROOT),)
 
-$$(LLVM_CONFIG_$(1)): $$(LLVM_DEPS_$(1))
+$$(LLVM_CONFIG_$(1)): $$(LLVM_DEPS)
 	@$$(call E, make: llvm)
 	$$(Q)$$(MAKE) -C $$(CFG_LLVM_BUILD_DIR_$(1)) $$(CFG_LLVM_BUILD_ENV)