[commit v4] PR 16113: Allow gdb.Field objects as subscripts on gdb.Value objects

[Siva Chandra <sivachandra at google dot com>]

I have pushed the attached patch after addressing Eli's and Tom's nits.

    2013-12-12  Siva Chandra Reddy  <sivachandra@google.com>

        PR python/16113
        * NEWS (Python Scripting): Add entry for the new feature and the
        new attribute of gdb.Field objects.
        * python/py-type.c (gdbpy_is_field): New function
        (convert_field): Add 'parent_type' attribute to gdb.Field
        objects.
        * python/py-value.c (valpy_getitem): Allow subscript value to be
        a gdb.Field object.
        (value_has_field): New function
        (get_field_flag): New function
        * python/python-internal.h (gdbpy_is_field): Add declaration.

        testsuite/
        * gdb.python/py-value-cc.cc: Improve test case.
        * gdb.python/py-value-cc.exp: Add new tests to test usage of
        gdb.Field objects as subscripts on gdb.Value objects.

        doc/
        * gdb.texinfo (Values From Inferior): Add a note about using
        gdb.Field objects as subscripts on gdb.Value objects.
        (Types In Python): Add description about the new attribute
        "parent_type" of gdb.Field objects.

Attachment: value_field_subscript_patch_v4.txt
Description: Text document