Fix finding of file info for magics and decorated functions.

Refactored some of the oinspect logic into standalone functions and
added tests.

IPython/core/oinspect.py

@@ -230,6 +230,77 b' def call_tip(oinfo, format_call=True):'
     return call_line, doc
 
 
+def find_file(obj):
+    """Find the absolute path to the file where an object was defined.
+
+    This is essentially a robust wrapper around `inspect.getabsfile`.
+
+    Returns None if no file can be found.
+
+    Parameters
+    ----------
+    obj : any Python object
+
+    Returns
+    -------
+    fname : str
+      The absolute path to the file where the object was defined.
+    """
+    try:
+        fname = inspect.getabsfile(obj)
+    except TypeError:
+        # For an instance, the file that matters is where its class was
+        # declared.
+        if hasattr(obj,'__class__'):
+            try:
+                fname = inspect.getabsfile(obj.__class__)
+            except TypeError:
+                # Can happen for builtins
+                fname = None
+    except:
+        fname = None
+    else:
+        if fname.endswith('<string>') and hasattr(obj, '__wrapped__'):
+            # Analyze decorated functions and methods correctly
+            fname = inspect.getabsfile(obj.__wrapped__)
+    return fname
+
+
+def find_source_lines(obj):
+    """Find the line number in a file where an object was defined.
+
+    This is essentially a robust wrapper around `inspect.getsourcelines`.
+
+    Returns None if no file can be found.
+
+    Parameters
+    ----------
+    obj : any Python object
+
+    Returns
+    -------
+    lineno : int
+      The line number where the object definition starts.
+    """
+    try:
+        try:
+            lineno = inspect.getsourcelines(obj)[1]
+        except TypeError:
+            # For instances, try the class object like getsource() does
+            if hasattr(obj,'__class__'):
+                lineno = inspect.getsourcelines(obj.__class__)[1]
+                # Adjust the inspected object so getabsfile() below works
+                obj = obj.__class__
+        except IOError:
+            if hasattr(obj, '__wrapped__'):
+                obj = obj.__wrapped__
+                lineno = inspect.getsourcelines(obj)[1]
+    except:
+        return None
+
+    return lineno
+
+
 class Inspector:
     def __init__(self, color_table=InspectColors,
                  code_color_table=PyColorize.ANSICodeColors,
@@ -369,25 +440,15 b' class Inspector:'
     def pfile(self,obj,oname=''):
         """Show the whole file where an object was defined."""
 
-        try:
-            try:
-                lineno = inspect.getsourcelines(obj)[1]
-            except TypeError:
-                # For instances, try the class object like getsource() does
-                if hasattr(obj,'__class__'):
-                    lineno = inspect.getsourcelines(obj.__class__)[1]
-                    # Adjust the inspected object so getabsfile() below works
-                    obj = obj.__class__
-        except:
+        lineno = find_source_lines(obj)
+        if lineno is None:
             self.noinfo('file',oname)
             return
 
-        # We only reach this point if object was successfully queried
-
-        # run contents of file through pager starting at line
-        # where the object is defined
-        ofile = inspect.getabsfile(obj)
-
+        ofile = find_file(obj)
+        # run contents of file through pager starting at line where the object
+        # is defined, as long as the file isn't binary and is actually on the
+        # filesystem.
         if ofile.endswith(('.so', '.dll', '.pyd')):
             print 'File %r is binary, not printing.' % ofile
         elif not os.path.isfile(ofile):
@@ -570,23 +631,17 b' class Inspector:'
 
         # Filename where object was defined
         binary_file = False
-        try:
-            try:
-                fname = inspect.getabsfile(obj)
-            except TypeError:
-                # For an instance, the file that matters is where its class was
-                # declared.
-                if hasattr(obj,'__class__'):
-                    fname = inspect.getabsfile(obj.__class__)
-            if fname.endswith('<string>'):
-                fname = 'Dynamically generated function. No source code available.'
-            if fname.endswith(('.so', '.dll', '.pyd')):
-                binary_file = True
-            out['file'] = fname
-        except:
+        fname = find_file(obj)
+        if fname is None:
             # if anything goes wrong, we don't want to show source, so it's as
             # if the file was binary
             binary_file = True
+        else:
+            if fname.endswith(('.so', '.dll', '.pyd')):
+                binary_file = True
+            elif fname.endswith('<string>'):
+                fname = 'Dynamically generated function. No source code available.'
+            out['file'] = fname
 
         # reconstruct the function definition and print it:
         defln = self._getdef(obj, oname)

IPython/core/tests/test_oinspect.py

@@ -14,6 +14,7 b''
 from __future__ import print_function
 
 # Stdlib imports
+import os
 
 # Third-party imports
 import nose.tools as nt
@@ -37,6 +38,26 b' ip = get_ipython()'
 # Local utilities
 #-----------------------------------------------------------------------------
 
+# WARNING: since this test checks the line number where a function is
+# defined, if any code is inserted above, the following line will need to be
+# updated.  Do NOT insert any whitespace between the next line and the function
+# definition below.
+THIS_LINE_NUMBER = 45  # Put here the actual number of this line
+def test_find_source_lines():
+    nt.assert_equal(oinspect.find_source_lines(test_find_source_lines), 
+                    THIS_LINE_NUMBER+1)
+
+
+def test_find_file():
+    nt.assert_equal(oinspect.find_file(test_find_file),
+                    os.path.abspath(__file__))
+
+
+def test_find_file_magic():
+    run = ip.find_line_magic('run')
+    nt.assert_not_equal(oinspect.find_file(run), None)
+
+
 # A few generic objects we can then inspect in the tests below
 
 class Call(object):