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Re: ada/8358: Ada accesses freed memory
- From: Graham Stott <graham dot stott at btinternet dot com>
- To: aj at suse dot de
- Cc: gcc-gnats at gcc dot gnu dot org, gcc-patches at gcc dot gnu dot org
- Date: Fri, 25 Oct 2002 19:59:05 +0100
- Subject: Re: ada/8358: Ada accesses freed memory
- References: <20021025181942.28757.qmail@sources.redhat.com>
Andreas,
Here's a patch which I have bootstraped i686-linux-gnu-pc with
all checking enabled.
This patch introduces a new GC root which is used to prevent
the pending eleaborations from being GC collected while they
are being enumerated by build_unit_elab.
Ok for mainline?
Graham
ada/ChangeLog
* trans.c (gnu_pending_elaboration_lists): New GC root.
(build_unit_elab): Use..
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Index: trans.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/ada/trans.c,v
retrieving revision 1.21
diff -c -p -r1.21 trans.c
*** trans.c 23 Oct 2002 07:33:34 -0000 1.21
--- trans.c 25 Oct 2002 18:52:50 -0000
*************** tree gnu_block_stack;
*** 88,93 ****
--- 88,97 ----
handler. Not used in the zero-cost case. */
static GTY(()) tree gnu_except_ptr_stack;
+ /* List of TREE_LIST nodes containing pending elaborations lists.
+ used to prevent the elaborations being reclaimed by GC. */
+ static GTY(()) tree gnu_pending_elaboration_lists;
+
/* Map GNAT tree codes to GCC tree codes for simple expressions. */
static enum tree_code gnu_codes[Number_Node_Kinds];
*************** build_unit_elab (gnat_unit, body_p, gnu_
*** 5298,5303 ****
--- 5302,5311 ----
if (gnu_elab_list == 0)
return 1;
+ /* Prevent the elaboration list from being reclaimed by the GC. */
+ gnu_pending_elaboration_lists = chainon (gnu_pending_elaboration_lists,
+ gnu_elab_list);
+
/* Set our file and line number to that of the object and set up the
elaboration routine. */
gnu_decl = create_subprog_decl (create_concat_name (gnat_unit,
*************** build_unit_elab (gnat_unit, body_p, gnu_
*** 5357,5362 ****
--- 5365,5373 ----
poplevel (kept_level_p (), 1, 0);
gnu_block_stack = TREE_CHAIN (gnu_block_stack);
end_subprog_body ();
+
+ /* We are finished with the elaboration list it can now be discarded. */
+ gnu_pending_elaboration_lists = TREE_CHAIN (gnu_pending_elaboration_lists);
/* If there were no insns, we don't need an elab routine. It would
be nice to not output this one, but there's no good way to do that. */
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