make it work with both python2 and python3

I ran 2to3, fixed up the output a tiny bit, and fixed the C module as
well.  I smoke tested with both versions of Python but didn't use it in
anger yet.

Fix #29

Makefile

@@ -1,3 +1,7 @@
+# This is passed to pkg-config to determine which python to use.  It
+# has to match your gdb.
+pyname = python
+
 all: gdb-gui.py gui/fix_signals.so
 	@:
 
@@ -5,7 +9,7 @@ gdb-gui.py: gdb-gui.py.in
 	sed -e "s,HERE,`pwd`," < gdb-gui.py.in > gdb-gui.py
 
 gui/fix_signals.so: gui/fix-signals.c
-	gcc -shared -fPIC -g -o gui/fix_signals.so gui/fix-signals.c `pkg-config --cflags python` `pkg-config --libs python`
+	gcc -shared -fPIC -g -o gui/fix_signals.so gui/fix-signals.c `pkg-config --cflags $(pyname)` `pkg-config --libs $(pyname)`
 
 clean:
 	-rm gdb-gui.py gui/fix_signals.so

gui/adapt.py

@@ -46,10 +46,10 @@ def notify_bug(bugno):
         return
     if not (bugno in bugs):
         return
-    print "################"
-    print bugs[bugno]
-    print _warning % bugno
-    print ""
-    print "You can use 'set gui mention-missing off' to disable this message."
-    print "################"
+    print("################")
+    print(bugs[bugno])
+    print(_warning % bugno)
+    print("")
+    print("You can use 'set gui mention-missing off' to disable this message.")
+    print("################")
     del bugs[bugno]

gui/commands.py

@@ -65,7 +65,7 @@ LINESPEC is a line specification of the form given to 'break'."""
         if sals is None:
             raise gdb.GdbError('not found')
         if len(sals) > 1:
-            print "Ambiguous linespec, only showing first result"
+            print("Ambiguous linespec, only showing first result")
         sal = sals[0]
         if sal.symtab is None or sal.symtab.filename is None:
             raise gdb.GdbError('could not find file for symbol')
@@ -122,7 +122,7 @@ gui print @5 variable"""
     def invoke(self, arg, from_tty):
         self.dont_repeat()
         window = gui.logwindow.LogWindow()
-        print "Created log window %d; now the default" % window.number
+        print("Created log window %d; now the default" % window.number)
 
 class GuiPrintBase(gdb.Command):
     def __init__(self, command):

gui/fix-signals.c

@@ -1,4 +1,4 @@
-/* Copyright (C) 2013 Tom Tromey <tom@tromey.com>
+/* Copyright (C) 2013, 2015 Tom Tromey <tom@tromey.com>
 
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -53,8 +53,33 @@ static PyMethodDef methods[] =
   { NULL, NULL, 0, NULL }
 };
 
+#if PY_MAJOR_VERSION >= 3
+
+static struct PyModuleDef module =
+{
+  PyModuleDef_HEAD_INIT,
+  "fix_signals",
+  NULL,
+  -1,
+  methods,
+  NULL,
+  NULL,
+  NULL,
+  NULL
+};
+
+PyMODINIT_FUNC
+PyInit_fix_signals (void)
+{
+  PyModule_Create (&module);
+}
+
+#else
+
 PyMODINIT_FUNC
 initfix_signals (void)
 {
   Py_InitModule ("fix_signals", methods);
 }
+
+#endif

gui/params.py

@@ -70,7 +70,7 @@ class _StoredParameter(gdb.Parameter):
         elif p_kind is gdb.PARAM_ZINTEGER:
             val = storage.getint(self.storage_name)
         else:
-            raise "WHOOPS"
+            raise Error("missing case in gdb gui code")
         # Don't record the first setting.
         self.storage = None
         if val is None:

gui/startup.py

@@ -15,23 +15,30 @@
 
 import gdb
 import threading
+try:
+    import queue
+except ImportError:
+    # Python 2.
     import Queue
+    queue = Queue
 import os
 import os.path
 import gui
 
-import fix_signals
+from . import fix_signals
 fix_signals.save()
 
 from gi.repository import Gtk, Gdk, GObject, GtkSource, GLib, GdkPixbuf
 
 (read_pipe, write_pipe) = os.pipe()
 
-_event_queue = Queue.Queue()
+_event_queue = queue.Queue()
 
 def send_to_gtk(func):
     _event_queue.put(func)
-    os.write(write_pipe, 'x')
+    # The payload is arbitrary, and bytes(1) is chosen to work on both
+    # Python 2 and Python 3.
+    os.write(write_pipe, bytes(1))
 
 class _GtkThread(threading.Thread):
     def handle_queue(self, source, condition):

gui/storage.py

@@ -18,7 +18,12 @@
 from gi.repository import GLib
 import os
 import errno
+try:
+    import configparser
+except ImportError:
+    # Python 2.
     import ConfigParser
+    configparser = ConfigParser
 import atexit
 
 class StorageManager:
@@ -26,11 +31,11 @@ class StorageManager:
         self.dir = os.path.join(GLib.get_user_config_dir(), 'gdb')
         self.file = os.path.join(self.dir, 'settings')
         try:
-            os.mkdir(self.dir, 0700)
+            os.mkdir(self.dir, 0o700)
         except OSError as exc:
             if exc.errno is not errno.EEXIST:
                 self.file = None
-        self.config = ConfigParser.RawConfigParser()
+        self.config = configparser.RawConfigParser()
         if self.file is not None:
             self.config.read(self.file)
         if not self.config.has_section('general'):
@@ -56,7 +61,7 @@ class StorageManager:
         self.config.set('general', name, value)
 
     def write(self):
-        with open(self.file, 'wb') as save_file:
+        with open(self.file, 'wt') as save_file:
             self.config.write(save_file)
 
 storage_manager = StorageManager()

gui/toplevel.py

@@ -70,15 +70,15 @@ class _ToplevelState(object):
     def display(self):
         with self.toplevel_lock:
             if len(self.toplevels) == 0:
-                print "No windows"
+                print("No windows")
                 return
 
-            print ' Num    Name'
+            print(' Num    Name')
             for winno in range(1, self.next_toplevel):
                 if winno in self.toplevels:
                     window = self.toplevels[winno]
-                    print ' %3d    %s' % (window.number,
-                                          window.window.get_title())
+                    print(' %3d    %s' % (window.number,
+                                          window.window.get_title()))
 
     @in_gtk_thread
     def _do_set_font(self, font_name):
@@ -123,7 +123,7 @@ class _ToplevelState(object):
 
     @in_gtk_thread
     def windows(self):
-        return self.toplevels.values()
+        return list(self.toplevels.values())
 
 state = _ToplevelState()