Another GC problem I noticed while looking at something else: when we
freed a duplicate typedef, we were leaving its type in the variants
list, with its TYPE_NAME still pointing to the now-freed TYPE_DECL,
leading to a crash.
Tested x86_64-pc-linux-gnu, applying to trunk.
commit e36d7607f157b5c90b56afe22786a2a0ff1711c8
Author: Jason Merrill <ja...@redhat.com>
Date: Wed Nov 11 15:17:42 2015 -0500
* decl.c (duplicate_decls): When combining typedefs, remove the
new type from the variants list.
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 76cc1d1..383b47d 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -2014,7 +2014,22 @@ duplicate_decls (tree newdecl, tree olddecl, bool newdecl_is_friend)
/* For typedefs use the old type, as the new type's DECL_NAME points
at newdecl, which will be ggc_freed. */
if (TREE_CODE (newdecl) == TYPE_DECL)
- newtype = oldtype;
+ {
+ newtype = oldtype;
+
+ /* And remove the new type from the variants list. */
+ if (TYPE_NAME (TREE_TYPE (newdecl)) == newdecl)
+ {
+ tree remove = TREE_TYPE (newdecl);
+ for (tree t = TYPE_MAIN_VARIANT (remove); ;
+ t = TYPE_NEXT_VARIANT (t))
+ if (TYPE_NEXT_VARIANT (t) == remove)
+ {
+ TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (remove);
+ break;
+ }
+ }
+ }
else
/* Merge the data types specified in the two decls. */
newtype = merge_types (TREE_TYPE (newdecl), TREE_TYPE (olddecl));