add a simple prerequisite check

git-svn-id: svn://svn.openwrt.org/openwrt/branches/buildroot-ng/openwrt@4168 3c298f89-4303-0410-b956-a3cf2f4a3e73

Makefile

@@ -81,11 +81,24 @@ toolchain/%: FORCE
 	@[ -f .config ] || $(NO_TRACE_MAKE) menuconfig
 	@$< -D .config Config.in &> /dev/null
 
+.prereq: $(TOPDIR)/include/prereq.mk .pkginfo
+	@$(NO_TRACE_MAKE) -s -f $(TOPDIR)/include/prereq.mk prereq 2>/dev/null || { \
+		echo "Prerequisite check failed. Use FORCE=1 to override."; \
+		false; \
+	}
+	@touch $@
+
+prereq: .prereq FORCE
+
 download: .config FORCE
 	$(MAKE) toolchain/download
 	$(MAKE) package/download
 	$(MAKE) target/download
 
+ifeq ($(FORCE),)
+world: .prereq
+endif
+
 world: .config FORCE
 	$(MAKE) toolchain/install
 	$(MAKE) target/compile

include/prereq.mk

@@ -0,0 +1,118 @@
+# 
+# Copyright (C) 2006 OpenWrt.org
+#
+# This is free software, licensed under the GNU General Public License v2.
+# See /LICENSE for more information.
+#
+
+include $(TOPDIR)/rules.mk
+include $(INCLUDE_DIR)/verbose.mk
+
+$(TMP_DIR):
+	mkdir -p $@
+
+prereq:
+	@echo
+	@if [ -f $(TMP_DIR)/.prereq-error ]; then \
+		cat $(TMP_DIR)/.prereq-error; \
+		echo; \
+		rm -rf $(TMP_DIR); \
+		false; \
+	fi
+	@rm -rf $(TMP_DIR)
+	@mkdir -p $(TMP_DIR)
+
+define Require
+  ifeq ($$(CHECK_$(1)),)
+    prereq: prereq-$(1)
+
+    prereq-$(1): $(TMP_DIR) FORCE
+		@echo -n "Checking '$(1)'... "
+		@if $(NO_TRACE_MAKE) -f $(INCLUDE_DIR)/prereq.mk check-$(1) >/dev/null 2>/dev/null; then \
+			echo 'ok.'; \
+		else \
+			echo 'failed.'; \
+			echo -e "$(strip $(2))" >> $(TMP_DIR)/.prereq-error; \
+		fi
+
+    check-$(1): FORCE
+	  $(call Require/$(1))
+    CHECK_$(1):=1
+  endif
+endef
+
+
+define RequireCommand
+  define Require/$(1)
+    which $(1)
+  endef
+
+  $$(eval $$(call Require,$(1),$(2)))
+endef
+
+# Required for the toolchain
+define Require/working-make
+	echo 'all: test' > $(TMP_DIR)/check.mk
+	echo 'e0 = $$$$(foreach s,foobar,$$$$(eval $$$$s:))' >> $(TMP_DIR)/check.mk
+	echo 'e1 = $$$$(foreach s,foobar, $$$$(eval $$$$s:))' >> $(TMP_DIR)/check.mk
+	echo 'test: $$$$(strip $$$$(e0)) $$$$(strip $$$$(e1))' >> $(TMP_DIR)/check.mk
+	$(NO_TRACE_MAKE) -f $(TMP_DIR)/check.mk
+endef
+
+$(eval $(call Require,working-make, \
+	Your make version is buggy. Please install GNU make v3.81 or later. \
+))
+
+define Require/working-gcc
+	echo 'int main(int argc, char **argv) { return 0; }' | \
+		gcc -x c -o $(TMP_DIR)/a.out -
+endef
+
+$(eval $(call Require,working-gcc, \
+	No working GNU C Compiler was found on your system. \
+))
+
+define Require/working-g++
+	echo 'int main(int argc, char **argv) { return 0; }' | \
+		g++ -x c++ -o $(TMP_DIR)/a.out -lstdc++ -
+endef
+
+$(eval $(call Require,working-g++, \
+	No working GNU C++ Compiler was found on your system. \
+))
+
+define Require/zlib
+	echo 'int main(int argc, char **argv) { gzdopen(0, "rb"); return 0; }' | \
+		gcc -x c -o $(TMP_DIR)/a.out -lz -
+endef
+
+$(eval $(call Require,zlib, \
+	The development version of zlib was not found on your system. \
+))
+
+
+$(eval $(call RequireCommand,bison, \
+	Please install GNU bison. \
+))
+
+$(eval $(call RequireCommand,flex, \
+	Please install flex. \
+))
+
+$(eval $(call RequireCommand,python, \
+	Please install python. \
+))
+
+$(eval $(call RequireCommand,unzip, \
+	Please install unzip. \
+))
+
+$(eval $(call RequireCommand,bzip2, \
+	Please install bzip2. \
+))
+
+$(eval $(call RequireCommand,patch, \
+	Please install patch. \
+))
+
+

rules.mk

@@ -28,6 +28,7 @@ BIN_DIR:=$(TOPDIR)/bin
 PACKAGE_DIR:=$(BIN_DIR)/packages
 IPKG_TARGET_DIR:=$(PACKAGE_DIR)
 BUILD_DIR:=$(TOPDIR)/build_$(ARCH)
+TMP_DIR:=$(BUILD_DIR)/tmp
 STAMP_DIR:=$(BUILD_DIR)/stamp
 TARGET_DIR:=$(BUILD_DIR)/root
 IPKG_STATE_DIR:=$(TARGET_DIR)/usr/lib/ipkg