Better support compiling cells with separate __future__ environments

IPython/core/compilerop.py

@@ -1,144 +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
+        linecache.checkcache = check_linecache_ipython
         
     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)
+def check_linecache_ipython(*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/core/tests/test_compilerop.py

@@ -1,75 +1,75 b''
 # coding: utf-8
 """Tests for the compilerop module.
 """
 #-----------------------------------------------------------------------------
 #  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 linecache
 import sys
 
 # Third-party imports
 import nose.tools as nt
 
 # Our own imports
 from IPython.core import compilerop
 from IPython.utils import py3compat
 
 #-----------------------------------------------------------------------------
 # Test functions
 #-----------------------------------------------------------------------------
 
 def test_code_name():
     code = 'x=1'
     name = compilerop.code_name(code)
     nt.assert_true(name.startswith('<ipython-input-0'))
 
 
 def test_code_name2():
     code = 'x=1'
     name = compilerop.code_name(code, 9)
     nt.assert_true(name.startswith('<ipython-input-9'))
 
 
 def test_cache():
     """Test the compiler correctly compiles and caches inputs
     """
     cp = compilerop.CachingCompiler()
     ncache = len(linecache.cache)
     cp.cache('x=1')
     nt.assert_true(len(linecache.cache) > ncache)
 
 def setUp():
     # Check we're in a proper Python 2 environment (some imports, such
     # as GTK, can change the default encoding, which can hide bugs.)
     nt.assert_equal(sys.getdefaultencoding(), "utf-8" if py3compat.PY3 else "ascii")
 
 def test_cache_unicode():
     cp = compilerop.CachingCompiler()
     ncache = len(linecache.cache)
     cp.cache(u"t = 'žćčšđ'")
     nt.assert_true(len(linecache.cache) > ncache)
 
 def test_compiler_check_cache():
     """Test the compiler properly manages the cache.
     """
     # Rather simple-minded tests that just exercise the API
     cp = compilerop.CachingCompiler()
     cp.cache('x=1', 99)
     # Ensure now that after clearing the cache, our entries survive
-    cp.check_cache()
+    linecache.checkcache()
     for k in linecache.cache:
         if k.startswith('<ipython-input-99'):
             break
     else:
         raise AssertionError('Entry for input-99 missing from linecache')