--- ./gdb/breakpoint.c	2011-03-05 07:11:41.000000000 +0100
+++ ./gdb/breakpoint.c	2011-03-05 07:08:59.000000000 +0100
@@ -11730,6 +11730,7 @@ all_tracepoints ()
   return tp_vec;
 }
 
+#if 0
 /* Call type_mark_used for any TYPEs referenced from this GDB source file.  */
 
 static void
@@ -11745,6 +11746,7 @@ breakpoint_types_mark_used (void)
 	type_mark_used (value_type (b->val));
     }
 }
+#endif
 
 
 /* This help string is used for the break, hbreak, tbreak and thbreak commands.
@@ -12441,5 +12443,7 @@ inferior in all-stop mode, gdb behaves a
   automatic_hardware_breakpoints = 1;
 
   observer_attach_about_to_proceed (breakpoint_about_to_proceed);
+#if 0
   observer_attach_mark_used (breakpoint_types_mark_used);
+#endif
 }
--- ./gdb/doc/observer.texi	2011-03-05 07:11:40.000000000 +0100
+++ ./gdb/doc/observer.texi	2011-03-05 07:08:59.000000000 +0100
@@ -223,10 +223,10 @@ Bytes from @var{data} to @var{data} + @v
 to the current inferior at @var{addr}.
 @end deftypefun
 
-@deftypefun void mark_used (void)
-Mark any possibly reclaimable objects as used during a mark-and-sweep garbage
-collector pass.  Currently only @code{type_mark_used} marker is supported.
-@end deftypefun
+@c @deftypefun void mark_used (void)
+@c Mark any possibly reclaimable objects as used during a mark-and-sweep garbage
+@c collector pass.  Currently only @code{type_mark_used} marker is supported.
+@c @end deftypefun
 
 @deftypefun void test_notification (int @var{somearg})
 This observer is used for internal testing.  Do not use.  
--- ./gdb/gdbtypes.c	2011-03-05 07:11:41.000000000 +0100
+++ ./gdb/gdbtypes.c	2011-03-05 07:09:00.000000000 +0100
@@ -126,11 +126,13 @@ static void print_arg_types (struct fiel
 static void dump_fn_fieldlists (struct type *, int);
 static void print_cplus_stuff (struct type *, int);
 
+#if 0
 /* The hash table holding all discardable `struct type *' references.  */
 static htab_t type_discardable_table;
 
 /* Current type_discardable_check pass used for TYPE_DISCARDABLE_AGE.  */
 static int type_discardable_age_current;
+#endif
 
 /* Allocate a new OBJFILE-associated type structure and fill it
    with some defaults.  Space for the type structure is allocated
@@ -161,6 +163,7 @@ alloc_type (struct objfile *objfile)
   return type;
 }
 
+#if 0
 /* Declare TYPE as discardable on next garbage collection by free_all_types.
    You must call type_mark_used during each free_all_types to protect TYPE from
    being deallocated.  */
@@ -179,6 +182,7 @@ set_type_as_discardable (struct type *ty
   gdb_assert (!*slot);
   *slot = type;
 }
+#endif
 
 /* Allocate a new type like alloc_type but preserve for it the discardability
    state of PARENT_TYPE.  */
@@ -188,8 +192,10 @@ alloc_type_as_parent (struct type *paren
 {
   struct type *new_type = alloc_type_copy (parent_type);
 
+#if 0
   if (TYPE_DISCARDABLE (parent_type))
     set_type_as_discardable (new_type);
+#endif
 
   return new_type;
 }
@@ -3219,11 +3225,13 @@ copy_type_recursive_1 (struct objfile *o
   TYPE_OBJFILE_OWNED (new_type) = 0;
   TYPE_OWNER (new_type).gdbarch = get_type_arch (type);
 
+#if 0
   /* TYPE_MAIN_TYPE memory copy above rewrote the TYPE_DISCARDABLE flag so we
      need to initialize it again.  And even if TYPE was already discardable
      NEW_TYPE so far is not registered in TYPE_DISCARDABLE_TABLE.  */
   TYPE_DISCARDABLE (new_type) = 0;
   set_type_as_discardable (new_type);
+#endif
 
   /* Pre-clear the fields processed by delete_main_type.  If DWARF block
      evaluations below call error we would leave an unfreeable TYPE.  */
@@ -3537,6 +3545,7 @@ copy_type (const struct type *type)
   return new_type;
 }
 
+#if 0
 /* Callback type for main_type_crawl.  */
 typedef int (*main_type_crawl_iter) (struct type *type, void *data);
 
@@ -3730,6 +3739,7 @@ free_all_types (void)
 
   htab_traverse (type_discardable_table, type_discardable_remove, NULL);
 }
+#endif
 
 /* Helper functions to initialize architecture-specific types.  */
 
@@ -4261,9 +4271,11 @@ _initialize_gdbtypes (void)
 {
   gdbtypes_data = gdbarch_data_register_post_init (gdbtypes_post_init);
 
+#if 0
   type_discardable_table = htab_create_alloc (20, type_discardable_hash,
 					     type_discardable_equal, NULL,
 					     xcalloc, xfree);
+#endif
 
   objfile_type_data = register_objfile_data ();
 
--- ./gdb/gdbtypes.h	2011-03-05 07:11:41.000000000 +0100
+++ ./gdb/gdbtypes.h	2011-03-05 07:09:00.000000000 +0100
@@ -297,6 +297,7 @@ enum type_instance_flag_value
 
 #define TYPE_DECLARED_CLASS(t) (TYPE_MAIN_TYPE (t)->flag_declared_class)
 
+#if 0
 /* Define this type as being reclaimable during free_all_types.  Type is
    required to be have TYPE_OBJFILE set to NULL.  Setting this flag requires
    initializing TYPE_DISCARDABLE_AGE, see alloc_type_discardable.  */
@@ -308,6 +309,7 @@ enum type_instance_flag_value
    by TYPE_DISCARDABLE_AGE_CURRENT.  */
 
 #define TYPE_DISCARDABLE_AGE(t)	(TYPE_MAIN_TYPE (t)->flag_discardable_age)
+#endif
 
 /* Is HIGH_BOUND a low-bound relative count (1) or the high bound itself (0)?  */
 
@@ -450,8 +452,10 @@ struct main_type
   /* True if this type was declared with "class" rather than
      "struct".  */
   unsigned int flag_declared_class : 1;
+#if 0
   unsigned int flag_discardable : 1;
   unsigned int flag_discardable_age : 1;
+#endif
   unsigned int flag_dynamic : 1;
   unsigned int flag_range_high_bound_is_count : 1;
   unsigned int flag_not_allocated : 1;
@@ -1519,7 +1523,9 @@ extern int is_public_ancestor (struct ty
 
 extern int is_unique_ancestor (struct type *, struct value *);
 
+#if 0
 extern void type_mark_used (struct type *type);
+#endif
 
 /* Overload resolution */
 
@@ -1588,6 +1594,8 @@ extern struct type *copy_type_recursive 
 
 extern struct type *copy_type (const struct type *type);
 
+#if 0
 extern void free_all_types (void);
+#endif
 
 #endif /* GDBTYPES_H */
--- ./gdb/parse.c	2011-03-05 07:11:41.000000000 +0100
+++ ./gdb/parse.c	2011-03-05 07:09:00.000000000 +0100
@@ -1584,6 +1584,7 @@ exp_uses_objfile (struct expression *exp
 
 /* Helper for exp_types_mark_used.  */
 
+#if 0
 static int
 exp_types_mark_used_iter (struct type *type, void *unused)
 {
@@ -1600,6 +1601,7 @@ exp_types_mark_used (struct expression *
 {
   exp_iterate (exp, exp_types_mark_used_iter, NULL, NULL);
 }
+#endif
 
 void
 _initialize_parse (void)
--- ./gdb/parser-defs.h	2011-03-05 07:11:40.000000000 +0100
+++ ./gdb/parser-defs.h	2011-03-05 07:09:00.000000000 +0100
@@ -328,6 +328,8 @@ extern int exp_uses_objfile (struct expr
 
 extern int exp_uses_objfile (struct expression *exp, struct objfile *objfile);
 
+#if 0
 extern void exp_types_mark_used (struct expression *exp);
+#endif
 
 #endif /* PARSER_DEFS_H */
--- ./gdb/printcmd.c	2011-03-05 07:11:40.000000000 +0100
+++ ./gdb/printcmd.c	2011-03-05 07:09:00.000000000 +0100
@@ -1485,6 +1485,7 @@ x_command (char *exp, int from_tty)
     }
 }
 
+#if 0
 /* Call type_mark_used for any TYPEs referenced from this GDB source file.  */
 
 static void
@@ -1499,6 +1500,7 @@ print_types_mark_used (void)
     if (d->exp)
       exp_types_mark_used (d->exp);
 }
+#endif
 
 
 
@@ -2899,5 +2901,7 @@ Show printing of source filename and lin
 Convert \"printf format string\", arg1, arg2, arg3, ..., argn to\n\
 a command line, and call it."));
 
+#if 0
   observer_attach_mark_used (print_types_mark_used);
+#endif
 }
--- ./gdb/python/py-type.c	2011-03-05 07:11:40.000000000 +0100
+++ ./gdb/python/py-type.c	2011-03-05 07:09:00.000000000 +0100
@@ -45,8 +45,10 @@ typedef struct pyty_type_object
   struct pyty_type_object *next;
 } type_object;
 
+#if 0
 /* First element of a doubly-linked list of TYPE_DISCARDABLE Types.  */
 static type_object *pyty_objects_discardable;
+#endif
 
 static PyTypeObject type_object_type;
 
@@ -647,6 +649,7 @@ typy_link (type_object *type_obj)
 	type_obj->next->prev = type_obj;
       set_objfile_data (objfile, typy_objfile_data_key, type_obj);
     }
+#if 0
   else if (type_obj->type && TYPE_DISCARDABLE (type_obj->type))
     {
       type_obj->next = pyty_objects_discardable;
@@ -654,6 +657,7 @@ typy_link (type_object *type_obj)
 	type_obj->next->prev = type_obj;
       pyty_objects_discardable = type_obj;
     }
+#endif
   else
     type_obj->next = NULL;
 }
@@ -672,8 +676,10 @@ typy_unlink (type_object *type_obj)
 
       set_objfile_data (objfile, typy_objfile_data_key, type_obj->next);
     }
+#if 0
   else if (pyty_objects_discardable == type_obj)
     pyty_objects_discardable = type_obj->next;
+#endif
 
   if (type_obj->next)
     type_obj->next->prev = type_obj->prev;
@@ -722,6 +728,7 @@ typy_dealloc (PyObject *obj)
   type_obj->ob_type->tp_free (obj);
 }
 
+#if 0
 /* Call type_mark_used for any TYPEs referenced from this GDB source file.  */
 static void
 typy_types_mark_used (void)
@@ -733,6 +740,7 @@ typy_types_mark_used (void)
        type_obj = type_obj->next)
     type_mark_used (type_obj->type);
 }
+#endif
 
 /* Create a new Type referring to TYPE.  */
 PyObject *
@@ -820,7 +828,9 @@ gdbpy_initialize_types (void)
   Py_INCREF (&field_object_type);
   PyModule_AddObject (gdb_module, "Field", (PyObject *) &field_object_type);
 
+#if 0
   observer_attach_mark_used (typy_types_mark_used);
+#endif
 }
 
 
--- ./gdb/python/py-value.c	2011-03-05 07:11:41.000000000 +0100
+++ ./gdb/python/py-value.c	2011-03-05 07:09:00.000000000 +0100
@@ -1071,6 +1071,7 @@ gdbpy_is_value_object (PyObject *obj)
   return PyObject_TypeCheck (obj, &value_object_type);
 }
 
+#if 0
 /* Call type_mark_used for any TYPEs referenced from this GDB source file.  */
 
 static void
@@ -1081,6 +1082,7 @@ python_types_mark_used (void)
   for (iter = values_in_python; iter; iter = iter->next)
     type_mark_used (value_type (iter->value));
 }
+#endif
 
 void
 gdbpy_initialize_values (void)
@@ -1093,7 +1095,9 @@ gdbpy_initialize_values (void)
 
   values_in_python = NULL;
 
+#if 0
   observer_attach_mark_used (python_types_mark_used);
+#endif
 }
 
 
--- ./gdb/top.c	2011-03-05 07:11:41.000000000 +0100
+++ ./gdb/top.c	2011-03-05 07:09:00.000000000 +0100
@@ -337,7 +337,9 @@ void
 prepare_execute_command (void)
 {
   free_all_values ();
+#if 0
   free_all_types ();
+#endif
 
   /* With multiple threads running while the one we're examining is stopped,
      the dcache can get stale without us being able to detect it.
--- ./gdb/value.c	2011-03-05 07:11:41.000000000 +0100
+++ ./gdb/value.c	2011-03-05 07:09:00.000000000 +0100
@@ -1004,7 +1004,9 @@ value_history_cleanup (void *unused)
 
   /* Free the unreferenced types above.  */
   free_all_values ();
+#if 0
   free_all_types ();
+#endif
 }
 
 /* Internal variables.  These are variables within the debugger
@@ -1484,6 +1486,7 @@ call_internal_function (struct gdbarch *
   return (*ifn->handler) (gdbarch, language, ifn->cookie, argc, argv);
 }
 
+#if 0
 /* Call type_mark_used for any TYPEs referenced from this GDB source file.  */
 
 static void
@@ -1517,6 +1520,7 @@ value_types_mark_used (void)
 	  type_mark_used (value_type (chunk->values[i]));
     }
 }
+#endif
 
 /* The 'function' command.  This does nothing -- it is just a
    placeholder to let "help function NAME" work.  This is also used as
@@ -2573,5 +2577,7 @@ Placeholder command for showing help on 
 
   make_final_cleanup (value_history_cleanup, NULL);
 
+#if 0
   observer_attach_mark_used (value_types_mark_used);
+#endif
 }
commit b20c7d74a7e132186e7d80525eae8ed08ca4d5b8
Author: Jan Kratochvil <jan.kratochvil@redhat.com>
Date:   Tue Mar 8 08:50:33 2011 +0100

    New testcase for the garbage collector MI incompleteness.

diff --git a/gdb/testsuite/gdb.mi/mi2-var-stale-type.c b/gdb/testsuite/gdb.mi/mi2-var-stale-type.c
new file mode 100644
index 0000000..ebced3c
--- /dev/null
+++ b/gdb/testsuite/gdb.mi/mi2-var-stale-type.c
@@ -0,0 +1,26 @@
+/* Copyright 2011 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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/>.  */
+
+int
+main (int argc, char **argv)
+{
+  char vla[argc];
+
+  vla[0] = 0;	/* break-here */
+
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.mi/mi2-var-stale-type.exp b/gdb/testsuite/gdb.mi/mi2-var-stale-type.exp
new file mode 100644
index 0000000..74a104e
--- /dev/null
+++ b/gdb/testsuite/gdb.mi/mi2-var-stale-type.exp
@@ -0,0 +1,57 @@
+# Copyright 2011 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/>.
+
+load_lib mi-support.exp
+set MIFLAGS "-i=mi2"
+
+gdb_exit
+if [mi_gdb_start] {
+    continue
+}
+
+set testfile "mi2-var-stale-type"
+set srcfile ${testfile}.c
+set binfile ${objdir}/${subdir}/${testfile}
+if {[build_executable ${testfile}.exp $testfile $srcfile] == -1} {
+    return -1
+}
+
+mi_delete_breakpoints
+mi_gdb_reinitialize_dir $srcdir/$subdir
+mi_gdb_load ${binfile}
+
+mi_gdb_test {-interpreter-exec console "maintenance set internal-error quit yes"} \
+  {\^done} \
+  "maintenance set internal-error quit yes"
+
+mi_gdb_test {-interpreter-exec console "maintenance set internal-error corefile yes"} \
+  {\^done} \
+  "maintenance set internal-error corefile yes"
+
+set line [gdb_get_line_number "break-here"]
+set func "main"
+
+mi_gdb_test "-break-insert -t $srcfile:$line" \
+  "\\^done,bkpt=\{number=\"\[0-9\]+\",type=\"breakpoint\",disp=\"del\",enabled=\"y\",addr=\"$hex\",func=\"$func\(\\\(.*\\\)\)?\",file=\".*\",line=\"$line\",times=\"0\",original-location=\".*\"\}" \
+  "breakpoint at $func"
+
+if { [mi_run_cmd] < 0 } {
+    return -1
+}
+mi_expect_stop "breakpoint-hit" $func ".*" ".*" "\[0-9\]+" { "" "disp=\"del\"" } "stop after initializing vla"
+
+mi_create_varobj "vla" "vla" "create local variable vla"
+
+mi_gdb_test "-var-update *" "\\^done,changelist=.*" "-var-update *"