embed(): Default to the future compile flags of the calling frame.

IPython/core/compilerop.py

@@ -1,131 +1,144 b''
 """Compiler tools with improved interactive support.
 
 Provides compilation machinery similar to codeop, but with caching support so
 we can provide interactive tracebacks.
 
 Authors
 -------
 * Robert Kern
 * Fernando Perez
 * Thomas Kluyver
 """
 
 # Note: though it might be more natural to name this module 'compiler', that
 # name is in the stdlib and name collisions with the stdlib tend to produce
 # weird problems (often with third-party tools).
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2010-2011 The IPython Development Team.
 #
 #  Distributed under the terms of the BSD License.
 #
 #  The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 from __future__ import print_function
 
 # Stdlib imports
+import __future__
 from ast import PyCF_ONLY_AST
 import codeop
+import functools
 import hashlib
 import linecache
+import operator
 import time
 
 #-----------------------------------------------------------------------------
+# Constants
+#-----------------------------------------------------------------------------
+
+# Roughtly equal to PyCF_MASK | PyCF_MASK_OBSOLETE as defined in pythonrun.h,
+# this is used as a bitmask to extract future-related code flags.
+PyCF_MASK = functools.reduce(operator.or_,
+                             (getattr(__future__, fname).compiler_flag
+                              for fname in __future__.all_feature_names))
+
+#-----------------------------------------------------------------------------
 # Local utilities
 #-----------------------------------------------------------------------------
 
 def code_name(code, number=0):
     """ Compute a (probably) unique name for code for caching.
     
     This now expects code to be unicode.
     """
     hash_digest = hashlib.md5(code.encode("utf-8")).hexdigest()
     # Include the number and 12 characters of the hash in the name.  It's
     # pretty much impossible that in a single session we'll have collisions
     # even with truncated hashes, and the full one makes tracebacks too long
     return '<ipython-input-{0}-{1}>'.format(number, hash_digest[:12])
 
 #-----------------------------------------------------------------------------
 # Classes and functions
 #-----------------------------------------------------------------------------
 
 class CachingCompiler(codeop.Compile):
     """A compiler that caches code compiled from interactive statements.
     """
 
     def __init__(self):
         codeop.Compile.__init__(self)
         
         # This is ugly, but it must be done this way to allow multiple
         # simultaneous ipython instances to coexist.  Since Python itself
         # directly accesses the data structures in the linecache module, and
         # the cache therein is global, we must work with that data structure.
         # We must hold a reference to the original checkcache routine and call
         # that in our own check_cache() below, but the special IPython cache
         # must also be shared by all IPython instances.  If we were to hold
         # separate caches (one in each CachingCompiler instance), any call made
         # by Python itself to linecache.checkcache() would obliterate the
         # cached data from the other IPython instances.
         if not hasattr(linecache, '_ipython_cache'):
             linecache._ipython_cache = {}
         if not hasattr(linecache, '_checkcache_ori'):
             linecache._checkcache_ori = linecache.checkcache
         # Now, we must monkeypatch the linecache directly so that parts of the
         # stdlib that call it outside our control go through our codepath
         # (otherwise we'd lose our tracebacks).
         linecache.checkcache = self.check_cache
         
     def ast_parse(self, source, filename='<unknown>', symbol='exec'):
         """Parse code to an AST with the current compiler flags active.
         
         Arguments are exactly the same as ast.parse (in the standard library),
         and are passed to the built-in compile function."""
         return compile(source, filename, symbol, self.flags | PyCF_ONLY_AST, 1)
     
     def reset_compiler_flags(self):
         """Reset compiler flags to default state."""
         # This value is copied from codeop.Compile.__init__, so if that ever
         # changes, it will need to be updated.
         self.flags = codeop.PyCF_DONT_IMPLY_DEDENT
 
     @property
     def compiler_flags(self):
         """Flags currently active in the compilation process.
         """
         return self.flags
         
     def cache(self, code, number=0):
         """Make a name for a block of code, and cache the code.
         
         Parameters
         ----------
         code : str
           The Python source code to cache.
         number : int
           A number which forms part of the code's name. Used for the execution
           counter.
           
         Returns
         -------
         The name of the cached code (as a string). Pass this as the filename
         argument to compilation, so that tracebacks are correctly hooked up.
         """
         name = code_name(code, number)
         entry = (len(code), time.time(),
                  [line+'\n' for line in code.splitlines()], name)
         linecache.cache[name] = entry
         linecache._ipython_cache[name] = entry
         return name
 
     def check_cache(self, *args):
         """Call linecache.checkcache() safely protecting our cached values.
         """
         # First call the orignal checkcache as intended
         linecache._checkcache_ori(*args)
         # Then, update back the cache with our data, so that tracebacks related
         # to our compiled codes can be produced.
         linecache.cache.update(linecache._ipython_cache)

IPython/frontend/terminal/embed.py

@@ -1,283 +1,296 b''
 # encoding: utf-8
 """
 An embedded IPython shell.
 
 Authors:
 
 * Brian Granger
 * Fernando Perez
 
 Notes
 -----
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 from __future__ import with_statement
 
 import sys
 import warnings
 
 # We need to use nested to support python 2.6, once we move to >=2.7, we can
 # use the with keyword's new builtin support for nested managers
 try:
     from contextlib import nested
 except:
     from IPython.utils.nested_context import nested
 
-from IPython.core import ultratb
+from IPython.core import ultratb, compilerop
 from IPython.core.magic import Magics, magics_class, line_magic
 from IPython.frontend.terminal.interactiveshell import TerminalInteractiveShell
 from IPython.frontend.terminal.ipapp import load_default_config
 
 from IPython.utils.traitlets import Bool, CBool, Unicode
 from IPython.utils.io import ask_yes_no
 
 
 #-----------------------------------------------------------------------------
 # Classes and functions
 #-----------------------------------------------------------------------------
 
 # This is an additional magic that is exposed in embedded shells.
 @magics_class
 class EmbeddedMagics(Magics):
 
     @line_magic
     def kill_embedded(self, parameter_s=''):
         """%kill_embedded : deactivate for good the current embedded IPython.
 
         This function (after asking for confirmation) sets an internal flag so
         that an embedded IPython will never activate again.  This is useful to
         permanently disable a shell that is being called inside a loop: once
         you've figured out what you needed from it, you may then kill it and
         the program will then continue to run without the interactive shell
         interfering again.
         """
 
         kill = ask_yes_no("Are you sure you want to kill this embedded instance "
                          "(y/n)? [y/N] ",'n')
         if kill:
             self.shell.embedded_active = False
             print ("This embedded IPython will not reactivate anymore "
                    "once you exit.")
 
 
 class InteractiveShellEmbed(TerminalInteractiveShell):
 
     dummy_mode = Bool(False)
     exit_msg = Unicode('')
     embedded = CBool(True)
     embedded_active = CBool(True)
     # Like the base class display_banner is not configurable, but here it
     # is True by default.
     display_banner = CBool(True)
 
     def __init__(self, config=None, ipython_dir=None, user_ns=None,
                  user_module=None, custom_exceptions=((),None),
                  usage=None, banner1=None, banner2=None,
                  display_banner=None, exit_msg=u'', user_global_ns=None):
     
         if user_global_ns is not None:
             warnings.warn("user_global_ns has been replaced by user_module. The\
                            parameter will be ignored.", DeprecationWarning)
 
         super(InteractiveShellEmbed,self).__init__(
             config=config, ipython_dir=ipython_dir, user_ns=user_ns,
             user_module=user_module, custom_exceptions=custom_exceptions,
             usage=usage, banner1=banner1, banner2=banner2,
             display_banner=display_banner
         )
 
         self.exit_msg = exit_msg
 
         # don't use the ipython crash handler so that user exceptions aren't
         # trapped
         sys.excepthook = ultratb.FormattedTB(color_scheme=self.colors,
                                              mode=self.xmode,
                                              call_pdb=self.pdb)
 
     def init_sys_modules(self):
         pass
 
     def init_magics(self):
         super(InteractiveShellEmbed, self).init_magics()
         self.register_magics(EmbeddedMagics)
 
     def __call__(self, header='', local_ns=None, module=None, dummy=None,
                  stack_depth=1, global_ns=None):
         """Activate the interactive interpreter.
 
         __call__(self,header='',local_ns=None,module=None,dummy=None) -> Start
         the interpreter shell with the given local and global namespaces, and
         optionally print a header string at startup.
 
         The shell can be globally activated/deactivated using the
         dummy_mode attribute. This allows you to turn off a shell used
         for debugging globally.
 
         However, *each* time you call the shell you can override the current
         state of dummy_mode with the optional keyword parameter 'dummy'. For
         example, if you set dummy mode on with IPShell.dummy_mode = True, you
         can still have a specific call work by making it as IPShell(dummy=False).
         """
 
         # If the user has turned it off, go away
         if not self.embedded_active:
             return
 
         # Normal exits from interactive mode set this flag, so the shell can't
         # re-enter (it checks this variable at the start of interactive mode).
         self.exit_now = False
 
         # Allow the dummy parameter to override the global __dummy_mode
         if dummy or (dummy != 0 and self.dummy_mode):
             return
 
         if self.has_readline:
             self.set_readline_completer()
 
         # self.banner is auto computed
         if header:
             self.old_banner2 = self.banner2
             self.banner2 = self.banner2 + '\n' + header + '\n'
         else:
             self.old_banner2 = ''
 
         # Call the embedding code with a stack depth of 1 so it can skip over
         # our call and get the original caller's namespaces.
         self.mainloop(local_ns, module, stack_depth=stack_depth, global_ns=global_ns)
 
         self.banner2 = self.old_banner2
 
         if self.exit_msg is not None:
             print self.exit_msg
 
     def mainloop(self, local_ns=None, module=None, stack_depth=0,
-                 display_banner=None, global_ns=None):
+                 display_banner=None, global_ns=None, compile_flags=None):
         """Embeds IPython into a running python program.
 
         Input:
 
           - header: An optional header message can be specified.
 
           - local_ns, module: working local namespace (a dict) and module (a
           module or similar object). If given as None, they are automatically
           taken from the scope where the shell was called, so that
           program variables become visible.
 
           - stack_depth: specifies how many levels in the stack to go to
           looking for namespaces (when local_ns or module is None).  This
           allows an intermediate caller to make sure that this function gets
           the namespace from the intended level in the stack.  By default (0)
           it will get its locals and globals from the immediate caller.
 
+          - compile_flags: A bit field identifying the __future__ features
+          that are enabled, as passed to the builtin `compile` function. If
+          given as None, they are automatically taken from the scope where the
+          shell was called.
+
         Warning: it's possible to use this in a program which is being run by
         IPython itself (via %run), but some funny things will happen (a few
         globals get overwritten). In the future this will be cleaned up, as
         there is no fundamental reason why it can't work perfectly."""
         
         if (global_ns is not None) and (module is None):
             class DummyMod(object):
                 """A dummy module object for embedded IPython."""
                 pass
             warnings.warn("global_ns is deprecated, use module instead.", DeprecationWarning)
             module = DummyMod()
             module.__dict__ = global_ns
 
         # Get locals and globals from caller
         if (local_ns is None or module is None) and self.default_user_namespaces:
             call_frame = sys._getframe(stack_depth).f_back
 
             if local_ns is None:
                 local_ns = call_frame.f_locals
             if module is None:
                 global_ns = call_frame.f_globals
                 module = sys.modules[global_ns['__name__']]
+            if compile_flags is None:
+                compile_flags = (call_frame.f_code.co_flags &
+                                 compilerop.PyCF_MASK)
         
         # Save original namespace and module so we can restore them after 
         # embedding; otherwise the shell doesn't shut down correctly.
         orig_user_module = self.user_module
         orig_user_ns = self.user_ns
+        orig_compile_flags = self.compile.flags
         
         # Update namespaces and fire up interpreter
         
         # The global one is easy, we can just throw it in
         if module is not None:
             self.user_module = module
 
         # But the user/local one is tricky: ipython needs it to store internal
         # data, but we also need the locals. We'll throw our hidden variables
         # like _ih and get_ipython() into the local namespace, but delete them
         # later.
         if local_ns is not None:
             self.user_ns = local_ns
             self.init_user_ns()
 
+        # Compiler flags
+        self.compile.flags = compile_flags
+
         # Patch for global embedding to make sure that things don't overwrite
         # user globals accidentally. Thanks to Richard <[e-mail]>
         # FIXME. Test this a bit more carefully (the if.. is new)
         # N.B. This can't now ever be called. Not sure what it was for.
         # And now, since it wasn't called in the previous version, I'm
         # commenting out these lines so they can't be called with my new changes
         # --TK, 2011-12-10
         #if local_ns is None and module is None:
         #    self.user_global_ns.update(__main__.__dict__)
 
         # make sure the tab-completer has the correct frame information, so it
         # actually completes using the frame's locals/globals
         self.set_completer_frame()
 
         with nested(self.builtin_trap, self.display_trap):
             self.interact(display_banner=display_banner)
         
         # now, purge out the local namespace of IPython's hidden variables.
         if local_ns is not None:
             for name in self.user_ns_hidden:
                 local_ns.pop(name, None)
         
         # Restore original namespace so shell can shut down when we exit.
         self.user_module = orig_user_module
         self.user_ns = orig_user_ns
+        self.compile.flags = orig_compile_flags
 
 _embedded_shell = None
 
 
 def embed(**kwargs):
     """Call this to embed IPython at the current point in your program.
 
     The first invocation of this will create an :class:`InteractiveShellEmbed`
     instance and then call it.  Consecutive calls just call the already
     created instance.
 
     Here is a simple example::
 
         from IPython import embed
         a = 10
         b = 20
         embed('First time')
         c = 30
         d = 40
         embed
 
     Full customization can be done by passing a :class:`Struct` in as the
     config argument.
     """
     config = kwargs.get('config')
     header = kwargs.pop('header', u'')
     if config is None:
         config = load_default_config()
         config.InteractiveShellEmbed = config.TerminalInteractiveShell
         kwargs['config'] = config
     global _embedded_shell
     if _embedded_shell is None:
         _embedded_shell = InteractiveShellEmbed(**kwargs)
     _embedded_shell(header=header, stack_depth=2)