New python module gdb.types.

* NEWS: Document it.
	* data-directory/Makefile.in (PYTHON_FILES): Add gdb/types.py.
	* python/lib/gdb/types.py: New file.

	testsuite/
	* lib/gdb-python.exp (gdb_check_python_config): New function.
	* gdb.python/Makefile.in (EXECUTABLES): Add lib-types.
	* gdb.python/lib-types.cc: New file.
	* gdb.python/lib-types.exp: New file.

	doc/
	* gdb.texinfo (Python): Add "Python modules".
	(Types in Python): Add reference to gdb.types section.
	(Python modules): New node.

gdb/python/lib/gdb/types.py

@@ -0,0 +1,91 @@
+# Type utilities.
+# Copyright (C) 2010 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""Utilities for working with gdb.Types."""
+
+import gdb
+
+
+def get_basic_type(type_):
+    """Return the "basic" type of a type.
+
+    Arguments:
+        type_: The type to reduce to its basic type.
+
+    Returns:
+        type_ with const/volatile is stripped away,
+        and typedefs/references converted to the underlying type.
+    """
+
+    while (type_.code == gdb.TYPE_CODE_REF or
+           type_.code == gdb.TYPE_CODE_TYPEDEF):
+        if type_.code == gdb.TYPE_CODE_REF:
+            type_ = type_.target()
+        else:
+            type_ = type_.strip_typedefs()
+    return type_.unqualified()
+
+
+def has_field(type_, field):
+    """Return True if a type has the specified field.
+
+    Arguments:
+        type_: The type to examine.
+            It must be one of gdb.TYPE_CODE_STRUCT, gdb.TYPE_CODE_UNION.
+        field: The name of the field to look up.
+
+    Returns:
+        True if the field is present either in type_ or any baseclass.
+
+    Raises:
+        TypeError: The type is not a struct or union.
+    """
+
+    type_ = get_basic_type(type_)
+    if (type_.code != gdb.TYPE_CODE_STRUCT and
+        type_.code != gdb.TYPE_CODE_UNION):
+        raise TypeError("not a struct or union")
+    for f in type_.fields():
+        if f.is_base_class:
+            if has_field(f.type, field):
+                return True
+        else:
+            # NOTE: f.name could be None
+            if f.name == field:
+                return True
+    return False
+
+
+def make_enum_dict(enum_type):
+    """Return a dictionary from a program's enum type.
+
+    Arguments:
+        enum_type: The enum to compute the dictionary for.
+
+    Returns:
+        The dictionary of the enum.
+
+    Raises:
+        TypeError: The type is not an enum.
+    """
+
+    if enum_type.code != gdb.TYPE_CODE_ENUM:
+        raise TypeError("not an enum type")
+    enum_dict = {}
+    for field in enum_type.fields():
+        # The enum's value is stored in "bitpos".
+        enum_dict[field.name] = field.bitpos
+    return enum_dict