improve support for building on mac os x by improving detection of missing components

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@14180 3c298f89-4303-0410-b956-a3cf2f4a3e73

include/prereq-build.mk

@@ -37,6 +37,20 @@ $(eval $(call Require,case-sensitive-fs, \
 	OpenWrt can only be built on a case-sensitive filesystem \
 ))
 
+define Require/getopt
+	getopt --help 2>&1 | grep long >/dev/null
+endef
+$(eval $(call Require,getopt, \
+	Please install GNU getopt \
+))
+
+define Require/fileutils
+	gcp --help || cp --help
+endef
+$(eval $(call Require,fileutils, \
+	Please install GNU fileutils \
+))
+
 define Require/working-gcc
 	echo 'int main(int argc, char **argv) { return 0; }' | \
 		gcc -x c -o $(TMP_DIR)/a.out -

scripts/md5sum

+#!/bin/sh
+cat "$@" | md5

tools/Makefile

@@ -27,23 +27,20 @@ $(STAGING_DIR)/.prepared: $(TMP_DIR)/.build
 	$(INSTALL_DATA) $(TOPDIR)/tools/include/*.h $(STAGING_DIR_HOST)/include/
 	touch $@
 
-$(STAGING_DIR_HOST)/bin/md5sum: $(STAGING_DIR)/.prepared
-	@MD5SUM=`which md5sum 2>/dev/null`; \
-	if [ "$@" != "$$MD5SUM" ]; then \
-		if [ -x "$$MD5SUM" ]; then \
-			ln -sf "$$MD5SUM" "$@"; \
-		else \
-			cp $(SCRIPT_DIR)/md5sum $(STAGING_DIR_HOST)/bin/; \
-		fi; \
-	fi
-
-$(STAGING_DIR_HOST)/bin/find: $(STAGING_DIR)/.prepared
-	if [ -x "$(FIND)" -a "$(FIND)" != "$@" ]; then \
-		ln -sf "$(FIND)" $@; \
-	fi
-
-
-$(curdir)/cmddeps = $(patsubst %,$(STAGING_DIR_HOST)/bin/%,find md5sum)
+define PrepareCommand
+$(STAGING_DIR_HOST)/bin/$(1): $(STAGING_DIR)/.prepared
+	@mkdir -p "$$(dir $$@)"; rm -f "$$@"
+	@export FILE="$$$$(which $(2) 2>/dev/null | grep -v 'not found' | head -n1)"; [ -n "$$$$FILE" ] || { \
+		echo "Command $(1) not found."; false; \
+	}; ln -s "$$$$FILE" "$$@"
+
+endef
+
+$(eval $(call PrepareCommand,find,gfind find))
+$(eval $(call PrepareCommand,md5sum,md5sum $(SCRIPT_DIR)/md5sum))
+$(eval $(call PrepareCommand,cp,gcp cp))
+
+$(curdir)/cmddeps = $(patsubst %,$(STAGING_DIR_HOST)/bin/%,find md5sum cp)
 $(curdir)//prepare = $(STAGING_DIR)/.prepared $($(curdir)/cmddeps)
 $(curdir)//compile = $(STAGING_DIR)/.prepared $($(curdir)/cmddeps)