* NEWS: Update.

* data-directory/Makefile.in (PYTHON_FILES): Add
	type_printers.py.
	* python/lib/gdb/command/type_printers.py: New file.
	* python/lib/gdb/command/types.py (TypePrinter): New class.
	(_get_some_type_recognizers, get_type_recognizers,
	apply_type_recognizers, register_type_printer): New
	functions.
	* python/py-objfile.c (objfile_object) <type_printers>: New
	field.
	(objfpy_dealloc): Decref new field.
	(objfpy_new): Set new field.
	(objfpy_get_type_printers, objfpy_set_type_printers): New
	functions.
	(objfile_to_objfile_object): Set new field.
	(objfile_getset): Add "type_printers".
	* python/py-progspace.c (pspace_object) <type_printers>: New
	field.
	(pspy_dealloc): Decref new field.
	(pspy_new): Set new field.
	(pspy_get_type_printers, pspy_set_type_printers): New functions.
	(pspace_to_pspace_object): Set new field.
	(pspace_getset): Add "type_printers".
	* python/python.c (start_type_printers, apply_type_printers,
	free_type_printers): New functions.
	(_initialize_python): Set gdb.type_printers.
	* python/python.h (start_type_printers, apply_type_printers,
	free_type_printers): Declare.
	* typeprint.c (type_print_raw_options, default_ptype_flags):
	Update for new fields.
	(do_free_global_table, create_global_typedef_table,
	find_global_typedef): New functions.
	(find_typedef_in_hash): Use find_global_typedef.
	(whatis_exp): Use create_global_typedef_table.  Change cleanup
	handling.
	* typeprint.h (struct type_print_options) <global_typedefs,
	global_printers>: New fields.
doc
	* gdb.texinfo (Symbols): Document "info type-printers",
	"enable type-printer" and "disable type-printer".
	(Python API): Add new node to menu.
	(Type Printing API): New node.
	(Progspaces In Python): Document type_printers field.
	(Objfiles In Python): Likewise.
	(gdb.types) <get_type_recognizers, apply_type_recognizers,
	register_type_printer, TypePrinter>: Document.
testsuite
	* gdb.base/completion.exp: Update for "info type-printers".
	* gdb.python/py-typeprint.cc: New file.
	* gdb.python/py-typeprint.exp: New file.
	* gdb.python/py-typeprint.py: New file.

gdb/python/lib/gdb/__init__.py

@@ -70,6 +70,9 @@ sys.argv = ['']
 # Initial pretty printers.
 pretty_printers = []
 
+# Initial type printers.
+type_printers = []
+
 # Convenience variable to GDB's python directory
 PYTHONDIR = os.path.dirname(os.path.dirname(__file__))
 

gdb/python/lib/gdb/command/type_printers.py

@@ -0,0 +1,125 @@
+# Type printer commands.
+# Copyright (C) 2010-2012 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/>.
+
+import copy
+import gdb
+
+"""GDB commands for working with type-printers."""
+
+class InfoTypePrinter(gdb.Command):
+    """GDB command to list all registered type-printers.
+
+    Usage: info type-printers
+    """
+
+    def __init__ (self):
+        super(InfoTypePrinter, self).__init__("info type-printers",
+                                              gdb.COMMAND_DATA)
+
+    def list_type_printers(self, type_printers):
+        """Print a list of type printers."""
+        # A potential enhancement is to provide an option to list printers in
+        # "lookup order" (i.e. unsorted).
+        sorted_type_printers = copy.copy(type_printers)
+        sorted_type_printers.sort(lambda x, y: cmp(x.name, y.name))
+        for printer in sorted_type_printers:
+            if printer.enabled:
+                enabled = ''
+            else:
+                enabled = " [disabled]"
+            print "  %s%s" % (printer.name, enabled)
+
+    def invoke(self, arg, from_tty):
+        """GDB calls this to perform the command."""
+        sep = ''
+        for objfile in gdb.objfiles():
+            if objfile.type_printers:
+                print "%sType printers for %s:" % (sep, objfile.name)
+                self.list_type_printers(objfile.type_printers)
+                sep = '\n'
+        if gdb.current_progspace().type_printers:
+            print "%sType printers for program space:" % sep
+            self.list_type_printers(gdb.current_progspace().type_printers)
+            sep = '\n'
+        if gdb.type_printers:
+            print "%sGlobal type printers:" % sep
+            self.list_type_printers(gdb.type_printers)
+
+class _EnableOrDisableCommand(gdb.Command):
+    def __init__(self, setting, name):
+        super(_EnableOrDisableCommand, self).__init__(name, gdb.COMMAND_DATA)
+        self.setting = setting
+
+    def set_some(self, name, printers):
+        result = False
+        for p in printers:
+            if name == p.name:
+                p.enabled = self.setting
+                result = True
+        return result
+
+    def invoke(self, arg, from_tty):
+        """GDB calls this to perform the command."""
+        for name in arg.split():
+            ok = False
+            for objfile in gdb.objfiles():
+                if self.set_some(name, objfile.type_printers):
+                    ok = True
+            if self.set_some(name, gdb.current_progspace().type_printers):
+                ok = True
+            if self.set_some(name, gdb.type_printers):
+                ok = True
+            if not ok:
+                print "No type printer named '%s'" % name
+
+    def add_some(self, result, word, printers):
+        for p in printers:
+            if p.name.startswith(word):
+                result.append(p.name)
+
+    def complete(self, text, word):
+        result = []
+        for objfile in gdb.objfiles():
+            self.add_some(result, word, objfile.type_printers)
+        self.add_some(result, word, gdb.current_progspace().type_printers)
+        self.add_some(result, word, gdb.type_printers)
+        return result
+
+class EnableTypePrinter(_EnableOrDisableCommand):
+    """GDB command to enable the specified type printer.
+
+    Usage: enable type-printer NAME
+
+    NAME is the name of the type-printer.
+    """
+
+    def __init__(self):
+        super(EnableTypePrinter, self).__init__(True, "enable type-printer")
+
+class DisableTypePrinter(_EnableOrDisableCommand):
+    """GDB command to disable the specified type-printer.
+
+    Usage: disable type-printer NAME
+
+    NAME is the name of the type-printer.
+    """
+
+    def __init__(self):
+        super(DisableTypePrinter, self).__init__(False, "disable type-printer")
+
+InfoTypePrinter()
+EnableTypePrinter()
+DisableTypePrinter()

gdb/python/lib/gdb/types.py

@@ -109,3 +109,68 @@ def deep_items (type_):
         else:
             for i in deep_items (v.type):
                 yield i
+
+class TypePrinter(object):
+    """The base class for type printers.
+
+    Instances of this type can be used to substitute type names during
+    'ptype'.
+
+    A type printer must have at least 'name' and 'enabled' attributes,
+    and supply an 'instantiate' method.
+
+    The 'instantiate' method must either return None, or return an
+    object which has a 'recognize' method.  This method must accept a
+    gdb.Type argument and either return None, meaning that the type
+    was not recognized, or a string naming the type.
+    """
+
+    def __init__(self, name):
+        self.name = name
+        self.enabled = True
+
+    def instantiate(self):
+        return None
+
+# Helper function for computing the list of type recognizers.
+def _get_some_type_recognizers(result, plist):
+    for printer in plist:
+        if printer.enabled:
+            inst = printer.instantiate()
+            if inst is not None:
+                result.append(inst)
+    return None
+
+def get_type_recognizers():
+    "Return a list of the enabled type recognizers for the current context."
+    result = []
+
+    # First try the objfiles.
+    for objfile in gdb.objfiles():
+        _get_some_type_recognizers(result, objfile.type_printers)
+    # Now try the program space.
+    _get_some_type_recognizers(result, gdb.current_progspace().type_printers)
+    # Finally, globals.
+    _get_some_type_recognizers(result, gdb.type_printers)
+
+    return result
+
+def apply_type_recognizers(recognizers, type_obj):
+    """Apply the given list of type recognizers to the type TYPE_OBJ.
+    If any recognizer in the list recognizes TYPE_OBJ, returns the name
+    given by the recognizer.  Otherwise, this returns None."""
+    for r in recognizers:
+        result = r.recognize(type_obj)
+        if result is not None:
+            return result
+    return None
+
+def register_type_printer(locus, printer):
+    """Register a type printer.
+    PRINTER is the type printer instance.
+    LOCUS is either an objfile, a program space, or None, indicating
+    global registration."""
+
+    if locus is None:
+        locus = gdb
+    locus.type_printers.insert(0, printer)