From 4a85ff0ec4ceb98ad87bec6002f6e67788b06d00 Mon Sep 17 00:00:00 2001
From: Victor Stinner <vstinner@redhat.com>
Date: Tue, 29 Nov 2016 10:56:57 +0100
Subject: [PATCH] Use inspect.signature() if available

inspect.signature() was added to Python 3.3. inspect.getargspec() is
deprecated since Python 3.0 and doesn't support keyword-only
parameters.

Change-Id: I09dd8a38cc3166bc55917bc0813185457b43a971
---
 mox3/mox.py | 75 +++++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 59 insertions(+), 16 deletions(-)

diff --git a/mox3/mox.py b/mox3/mox.py
index 85d4e0c..9034661 100644
--- a/mox3/mox.py
+++ b/mox3/mox.py
@@ -905,15 +905,7 @@ class MethodSignatureChecker(object):
                         possible. Some methods and functions like built-ins
                         can't be inspected.
         """
-        try:
-            self._args, varargs, varkw, defaults = inspect.getargspec(method)
-        except TypeError:
-            raise ValueError('Could not get argument specification for %r'
-                             % (method,))
-        if (inspect.ismethod(method) or class_to_bind or (
-                hasattr(self, '_args') and len(self._args) > 0
-                and self._args[0] == 'self')):
-            self._args = self._args[1:]    # Skip 'self'.
+
         self._method = method
         self._instance = None    # May contain the instance this is bound to.
         self._instance = getattr(method, "__self__", None)
@@ -925,14 +917,65 @@ class MethodSignatureChecker(object):
             self._bounded_to = class_to_bind or getattr(method, "im_class",
                                                         None)
 
-        self._has_varargs = varargs is not None
-        self._has_varkw = varkw is not None
-        if defaults is None:
-            self._required_args = self._args
-            self._default_args = []
+        # inspect.getargspec() is deprecated since Python 3.0, prefer
+        # inspect.signature() (available since Python 3.3) which supports
+        # also Python 3 keyword-only arguments.
+        if hasattr(inspect, 'signature'):
+            try:
+                signature = inspect.signature(method)
+                params = list(signature.parameters.values())
+            except TypeError:
+                raise ValueError('Could not get signature for %r'
+                                 % (method,))
+
+            Parameter = inspect.Parameter
+            self._has_varargs = any(param.kind == Parameter.VAR_POSITIONAL
+                                    for param in params)
+            self._has_varkw = any(param.kind == Parameter.VAR_KEYWORD
+                                  for param in params)
+
+            if (inspect.ismethod(method) or class_to_bind
+               or (params and params[0].name == 'self')):
+                params = params[1:]
+
+            # Truncate params at the first *args or **kwargs parameter
+            for index, param in enumerate(params):
+                if param.kind in (Parameter.VAR_POSITIONAL,
+                                  Parameter.VAR_KEYWORD):
+                    del params[index:]
+                    break
+
+            required = 0
+            for param in params:
+                if param.default is not Parameter.empty:
+                    break
+                required += 1
+
+            self._args = [param.name for param in params]
+            self._required_args = self._args[:required]
+            self._default_args = self._args[required:]
         else:
-            self._required_args = self._args[:-len(defaults)]
-            self._default_args = self._args[-len(defaults):]
+            try:
+                argspec = inspect.getargspec(method)
+            except TypeError:
+                raise ValueError('Could not get argument specification for %r'
+                                 % (method,))
+
+            args = argspec.args
+            if (inspect.ismethod(method) or class_to_bind or (
+                    args and args[0] == 'self')):
+                args = args[1:]    # Skip 'self'.
+
+            self._has_varargs = (argspec.varargs is not None)
+            self._has_varkw = (argspec.keywords is not None)
+            self._args = args
+            if argspec.defaults:
+                pos = -len(argspec.defaults)
+                self._required_args = args[:pos]
+                self._default_args = args[pos:]
+            else:
+                self._required_args = args
+                self._default_args = []
 
     def _RecordArgumentGiven(self, arg_name, arg_status):
         """Mark an argument as being given.