crit: enable python2 or python3 based crit

With this last commit of the crit with python3 series it is possible to
either use python2 or python3 with CRIU.

Now the basic build system functionality (make and make install) are
python2/python3 aware. zdtm.py and criu-coredump are still python2, but
as they are not part of 'make install' those parts have not yet been
ported from python2 to python3.

Signed-off-by: Adrian Reber <areber@redhat.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

.gitignore

@@ -24,6 +24,7 @@ images/google/protobuf/*.c
 images/google/protobuf/*.h
 .gitid
 criu/criu
+crit/crit
 criu/arch/*/sys-exec-tbl*.c
 # x86 syscalls-table is not generated
 !criu/arch/x86/sys-exec-tbl.c

Makefile

@@ -127,7 +127,7 @@ HOSTCFLAGS		+= $(WARNINGS) $(DEFINES) -iquote include/
 export CFLAGS USERCLFAGS HOSTCFLAGS
 
 # Default target
-all: criu lib
+all: criu lib crit
 .PHONY: all
 
 #
@@ -228,14 +228,22 @@ criu: $(criu-deps)
 	$(Q) $(MAKE) $(build)=criu all
 .PHONY: criu
 
+crit/Makefile: ;
+crit/%: criu .FORCE
+	$(Q) $(MAKE) $(build)=crit $@
+crit: criu
+	$(Q) $(MAKE) $(build)=crit all
+.PHONY: crit
+
+
 #
-# Libraries next once criu it ready
+# Libraries next once crit it ready
 # (we might generate headers and such
 # when building criu itself).
 lib/Makefile: ;
-lib/%: criu .FORCE
+lib/%: crit .FORCE
 	$(Q) $(MAKE) $(build)=lib $@
-lib: criu
+lib: crit
 	$(Q) $(MAKE) $(build)=lib all
 .PHONY: lib
 
@@ -247,6 +255,7 @@ clean mrproper:
 	$(Q) $(MAKE) $(build)=compel $@
 	$(Q) $(MAKE) $(build)=compel/plugins $@
 	$(Q) $(MAKE) $(build)=lib $@
+	$(Q) $(MAKE) $(build)=crit $@
 .PHONY: clean mrproper
 
 clean-top:

crit/Makefile

@@ -0,0 +1,13 @@
+
+all-y	+= crit
+
+crit/crit: crit/crit-$(PYTHON)
+	$(Q) cp $^ $@
+crit: crit/crit
+.PHONY: crit
+
+clean-crit:
+	$(Q) $(RM) crit/crit
+.PHONY: clean-crit
+clean: clean-crit
+mrproper: clean

crit/crit-python2

@@ -0,0 +1,6 @@
+#!/usr/bin/env python2
+
+from pycriu import cli
+
+if __name__ == '__main__':
+	cli.main()

crit/crit-python3

@@ -0,0 +1,6 @@
+#!/usr/bin/env python3
+
+from pycriu import cli
+
+if __name__ == '__main__':
+	cli.main()

lib/py/cli.py

@@ -1,4 +1,3 @@
-#!/usr/bin/env python2
 from __future__ import print_function
 import argparse
 import sys