libxl: make python scripts work with python 2.6 and up

Go through transformations suggested by 2to3 and pick the necessary
ones.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

tools/libxl/gentest.py

@@ -1,5 +1,7 @@
 #!/usr/bin/python
 
+from __future__ import print_function
+
 import os
 import sys
 import re
@@ -86,7 +88,7 @@ def gen_rand_init(ty, v, indent = "    ", parent = None):
 
 if __name__ == '__main__':
     if len(sys.argv) < 3:
-        print >>sys.stderr, "Usage: gentest.py <idl> <implementation>"
+        print("Usage: gentest.py <idl> <implementation>", file=sys.stderr)
         sys.exit(1)
 
     random.seed(os.getenv('LIBXL_TESTIDL_SEED'))

tools/libxl/gentypes.py

@@ -1,5 +1,7 @@
 #!/usr/bin/python
 
+from __future__ import print_function
+
 import sys
 import re
 
@@ -576,14 +578,14 @@ def libxl_C_enum_from_string(ty, str, e, indent = "    "):
 
 if __name__ == '__main__':
     if len(sys.argv) != 6:
-        print >>sys.stderr, "Usage: gentypes.py <idl> <header> <header-private> <header-json> <implementation>"
+        print("Usage: gentypes.py <idl> <header> <header-private> <header-json> <implementation>", file=sys.stderr)
         sys.exit(1)
 
     (_, idlname, header, header_private, header_json, impl) = sys.argv
 
     (builtins,types) = idl.parse(idlname)
 
-    print "outputting libxl type definitions to %s" % header
+    print("outputting libxl type definitions to %s" % header)
 
     f = open(header, "w")
 
@@ -633,7 +635,7 @@ if __name__ == '__main__':
     f.write("""#endif /* %s */\n""" % (header_define))
     f.close()
 
-    print "outputting libxl JSON definitions to %s" % header_json
+    print("outputting libxl JSON definitions to %s" % header_json)
 
     f = open(header_json, "w")
 
@@ -657,7 +659,7 @@ if __name__ == '__main__':
     f.write("""#endif /* %s */\n""" % header_json_define)
     f.close()
 
-    print "outputting libxl type internal definitions to %s" % header_private
+    print("outputting libxl type internal definitions to %s" % header_private)
 
     f = open(header_private, "w")
 
@@ -683,7 +685,7 @@ if __name__ == '__main__':
     f.write("""#endif /* %s */\n""" % header_json_define)
     f.close()
 
-    print "outputting libxl type implementations to %s" % impl
+    print("outputting libxl type implementations to %s" % impl)
 
     f = open(impl, "w")
     f.write("""

tools/libxl/idl.py

@@ -1,3 +1,5 @@
+from __future__ import print_function
+
 import sys
 
 PASS_BY_VALUE = 1
@@ -11,7 +13,7 @@ DIR_BOTH = 3
 _default_namespace = ""
 def namespace(s):
     if type(s) != str:
-        raise TypeError, "Require a string for the default namespace."
+        raise TypeError("Require a string for the default namespace.")
     global _default_namespace
     _default_namespace = s
 
@@ -346,7 +348,7 @@ class OrderedDict(dict):
         return [(x,self[x]) for x in self.__ordered]
 
 def parse(f):
-    print >>sys.stderr, "Parsing %s" % f
+    print("Parsing %s" % f, file=sys.stderr)
 
     globs = {}
     locs = OrderedDict()
@@ -362,11 +364,10 @@ def parse(f):
             globs[n] = t
 
     try:
-        execfile(f, globs, locs)
-    except SyntaxError,e:
-        raise SyntaxError, \
-              "Errors were found at line %d while processing %s:\n\t%s"\
-              %(e.lineno,f,e.text)
+        exec(compile(open(f).read(), f, 'exec'), globs, locs)
+    except SyntaxError as e:
+        raise SyntaxError("Errors were found at line %d while processing %s:\n\t%s"
+                          % (e.lineno, f, e.text))
 
     types = [t for t in locs.ordered_values() if isinstance(t,Type)]