make: Switch main Makefile to simplified form

This is a bit tricky since the build infrastructure
we're switching to is targeted to per-directory targets
if simplified Makefiles are used.

So I did the following

 - move rules to compile general sources to Makefile.crtools
 - main Makefiles now simply calls for scritps/Makefile.build
   help to generate built-in.o target

Also note that we clean up suffixes for implicit rules with

	.SUFFIXES:

this is done on purpose to eliminate any possible side effect
in future -- all rules _must_ be described explicitly.

Because of implicit rules used in zdtm building procedure
I can't use of stict makefile mode and add

	MAKEFLAGS := -r

to the top of the general Makefile. This should be done
one day latter (if ever).
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Makefile

 #
-# Common definitions
+# FIXME zdtm building procedure requires implicit rules
+# so I can't use strict make file mode and drop completely
+# all of implicit rules, so I tuned only .SUFFIXES:
+#
+# In future zdtm makefiles need to be fixed and the line below
+# may be uncommented.
 #
+#MAKEFLAGS := -r -R --no-print-directory
 
+#
+# Common definitions
+#
 ifeq ($(strip $(V)),)
 	E = @echo
 	Q = @
@@ -89,58 +98,16 @@ export SRC_DIR SYSCALL-LIB SH RM ARCH_DIR OBJCOPY LDARCH LD
 
 include scripts/Makefile.version
 include scripts/Makefile.rules
+
+.SUFFIXES:
+
 #
 # shorthand
-build := -s -r -R --no-print-directory -f scripts/Makefile.build makefile=Makefile obj
+build := -r -R --no-print-directory -f scripts/Makefile.build makefile=Makefile obj
+build-crtools := -r -R --no-print-directory -f scripts/Makefile.build makefile=Makefile.crtools obj
 
 PROGRAM		:= crtools
 
-OBJS		+= parasite-syscall.o
-OBJS		+= cr-restore.o
-OBJS		+= crtools.o
-OBJS		+= image.o
-OBJS		+= net.o
-OBJS		+= proc_parse.o
-OBJS		+= cr-dump.o
-OBJS		+= cr-show.o
-OBJS		+= cr-check.o
-OBJS		+= util.o
-OBJS		+= sysctl.o
-OBJS		+= ptrace.o
-OBJS		+= kcmp-ids.o
-OBJS		+= rbtree.o
-OBJS		+= log.o
-OBJS		+= libnetlink.o
-OBJS		+= sockets.o
-OBJS		+= sk-inet.o
-OBJS		+= sk-tcp.o
-OBJS		+= sk-unix.o
-OBJS		+= sk-packet.o
-OBJS		+= sk-queue.o
-OBJS		+= files.o
-OBJS		+= files-reg.o
-OBJS		+= pipes.o
-OBJS		+= fifo.o
-OBJS		+= file-ids.o
-OBJS		+= namespaces.o
-OBJS		+= uts_ns.o
-OBJS		+= ipc_ns.o
-OBJS		+= netfilter.o
-OBJS		+= shmem.o
-OBJS		+= eventfd.o
-OBJS		+= eventpoll.o
-OBJS		+= mount.o
-OBJS		+= fsnotify.o
-OBJS		+= signalfd.o
-OBJS		+= pstree.o
-OBJS		+= protobuf.o
-OBJS		+= tty.o
-OBJS		+= cr-exec.o
-OBJS		+= cpu.o
-OBJS		+= file-lock.o
-
-DEPS		:= $(patsubst %.o,%.d,$(OBJS))
-
 .PHONY: all zdtm test rebuild clean distclean tags cscope	\
 	docs help pie protobuf arch/$(ARCH)
 
@@ -166,23 +133,12 @@ pie/%:: arch/$(ARCH)
 pie: arch/$(ARCH)
 	$(Q) $(MAKE) $(build)=pie all
 
-%.o: %.c
-	$(E) "  CC      " $@
-	$(Q) $(CC) -c $(CFLAGS) $< -o $@
-
-%.i: %.c
-	$(E) "  CC      " $@
-	$(Q) $(CC) -E $(CFLAGS) $< -o $@
+%.o %.i %.s %.d: $(VERSION_HEADER) pie
+	$(Q) $(MAKE) $(build-crtools)=. $@
+built-in.o: $(VERSION_HEADER) pie
+	$(Q) $(MAKE) $(build-crtools)=. $@
 
-%.s: %.c
-	$(E) "  CC      " $@
-	$(Q) $(CC) -S $(CFLAGS) -fverbose-asm $< -o $@
-
-%.d: %.c
-	$(E) "  DEP     " $@
-	$(Q) $(CC) -M -MT $@ -MT $(patsubst %.d,%.o,$@) $(CFLAGS) $< -o $@
-
-$(PROGRAM): $(SYSCALL-LIB) $(ARCH-LIB) pie/util-net.o protobuf/built-in.o $(OBJS)
+$(PROGRAM): $(SYSCALL-LIB) $(ARCH-LIB) pie/util-net.o protobuf/built-in.o built-in.o
 	$(E) "  LINK    " $@
 	$(Q) $(CC) $(CFLAGS) $^ $(LIBS) -o $@
 
@@ -206,9 +162,7 @@ clean:
 	$(Q) $(MAKE) $(build)=arch/$(ARCH) clean
 	$(Q) $(MAKE) $(build)=protobuf clean
 	$(Q) $(MAKE) $(build)=pie clean
-	$(Q) $(RM) ./*.o
-	$(Q) $(RM) ./*.d
-	$(Q) $(RM) ./*.i
+	$(Q) $(MAKE) $(build-crtools)=. clean
 	$(Q) $(RM) ./*.img
 	$(Q) $(RM) ./*.out
 	$(Q) $(RM) ./*.bin
@@ -264,14 +218,4 @@ gcov:
 	lcov -a crtools.l.info -a crtools.ns.info -o crtools.info && \
 	genhtml -o html crtools.info
 
-deps-targets := $(OBJS) $(patsubst %.o,%.s,$(OBJS)) $(patsubst %.o,%.i,$(OBJS)) $(PROGRAM)
-
 .DEFAULT_GOAL	:= all
-
-ifneq ($(filter $(deps-targets), $(MAKECMDGOALS)),)
-	INCDEPS := 1
-endif
-
-ifeq ($(INCDEPS),1)
--include $(DEPS)
-endif

Makefile.crtools

+obj-y	+= parasite-syscall.o
+obj-y	+= cr-restore.o
+obj-y	+= crtools.o
+obj-y	+= image.o
+obj-y	+= net.o
+obj-y	+= proc_parse.o
+obj-y	+= cr-dump.o
+obj-y	+= cr-show.o
+obj-y	+= cr-check.o
+obj-y	+= util.o
+obj-y	+= sysctl.o
+obj-y	+= ptrace.o
+obj-y	+= kcmp-ids.o
+obj-y	+= rbtree.o
+obj-y	+= log.o
+obj-y	+= libnetlink.o
+obj-y	+= sockets.o
+obj-y	+= sk-inet.o
+obj-y	+= sk-tcp.o
+obj-y	+= sk-unix.o
+obj-y	+= sk-packet.o
+obj-y	+= sk-queue.o
+obj-y	+= files.o
+obj-y	+= files-reg.o
+obj-y	+= pipes.o
+obj-y	+= fifo.o
+obj-y	+= file-ids.o
+obj-y	+= namespaces.o
+obj-y	+= uts_ns.o
+obj-y	+= ipc_ns.o
+obj-y	+= netfilter.o
+obj-y	+= shmem.o
+obj-y	+= eventfd.o
+obj-y	+= eventpoll.o
+obj-y	+= mount.o
+obj-y	+= fsnotify.o
+obj-y	+= signalfd.o
+obj-y	+= pstree.o
+obj-y	+= protobuf.o
+obj-y	+= tty.o
+obj-y	+= cr-exec.o
+obj-y	+= cpu.o
+obj-y	+= file-lock.o
+
+ifneq ($(MAKECMDGOALS),clean)
+incdeps := y
+endif