Update scripts to python3, replacing imp.

Debian bullseye will not ship python2 by default anymore, and at any rate
there is not going to be just /usr/bin/python. So we might as well go
ahead and update our scripts.

4 files changed, 22 insertions, 8 deletions

diff --git a/scripts/gen_ir.py b/scripts/gen_ir.py
index 16127cf..6ce0adb 100755
--- a/scripts/gen_ir.py
+++ b/scripts/gen_ir.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # This file is part of libFirm.
 # Copyright (C) 2012 Karlsruhe Institute of Technology.
@@ -8,9 +8,24 @@ sys.dont_write_bytecode = True
 import argparse
 from jinja2 import Environment
 import filters
-import imp
 import jinjautil
 
+# Since python3, importing an arbitrary file became somewhat more involved. This piece of code is from "spack" at
+# https://github.com/epfl-scitas/spack/blob/releases/humagne/lib/spack/llnl/util/lang.py
+# and licensed under Apache-2.0.
+def load_module_from_file(module_name, module_path):
+    if sys.version_info[0] == 3 and sys.version_info[1] >= 5:
+        import importlib.util
+        spec = importlib.util.spec_from_file_location(module_name, module_path)
+        module = importlib.util.module_from_spec(spec)
+        spec.loader.exec_module(module)
+    else:
+        import importlib.machinery
+        loader = importlib.machinery.SourceFileLoader(module_name, module_path)
+        module = loader.load_module()
+
+    return module
+
 
 def main(argv):
     description = 'Generate code/docu from node specification'
@@ -38,9 +53,9 @@ def main(argv):
     loader.includedirs += config.includedirs
 
     # Load specfile
-    imp.load_source('spec', config.specfile)
+    load_module_from_file('spec', config.specfile)
     for num, extrafile in enumerate(config.extra):
-        imp.load_source('extra%s' % (num,), extrafile)
+        load_module_from_file('extra%s' % (num,), extrafile)
 
     env = Environment(loader=loader, keep_trailing_newline=True)
     env.globals.update(jinjautil.exports)
diff --git a/scripts/irops.py b/scripts/irops.py
index 8d65ad7..b9ca48c 100644
--- a/scripts/irops.py
+++ b/scripts/irops.py
@@ -1,7 +1,6 @@
 from jinjautil import export_filter, export
 from jinja2._compat import string_types
 from filters import arguments
-import imp
 import sys
 
 
diff --git a/scripts/jinja2/environment.py b/scripts/jinja2/environment.py
index 06156b8..feb6df3 100644
--- a/scripts/jinja2/environment.py
+++ b/scripts/jinja2/environment.py
@@ -637,9 +637,9 @@ class Environment(object):
                 warn(Warning('py_compile has no effect on pypy or Python 3'))
                 py_compile = False
             else:
-                import imp
+                import importlib.util
                 import marshal
-                py_header = imp.get_magic() + \
+                py_header = importlib.util.MAGIC_NUMBER + \
                     u'\xff\xff\xff\xff'.encode('iso-8859-15')
 
                 # Python 3.3 added a source filesize to the header
diff --git a/support/statev_sql.py b/support/statev_sql.py
index 666b4c5..0e2c85a 100755
--- a/support/statev_sql.py
+++ b/support/statev_sql.py
@@ -1,4 +1,4 @@
-#! /usr/bin/env python
+#! /usr/bin/env python3
 #
 # This file is part of libFirm.
 # Copyright (C) 2012 Karlsruhe Institute of Technology.