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[C++ PATCH] Fix rtti ICE (4.1 regression, PR c++/23947)
- From: Jakub Jelinek <jakub at redhat dot com>
- To: gcc-patches at gcc dot gnu dot org
- Cc: Nathan Sidwell <nathan at codesourcery dot com>
- Date: Tue, 20 Sep 2005 07:22:59 -0400
- Subject: [C++ PATCH] Fix rtti ICE (4.1 regression, PR c++/23947)
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
Hi!
Since Nathan's 2005-06-15 rtti patch the following testcase crashes
on HEAD.
The problem is that in some cases the tinfo_descs vector is reallocated,
but get_pseudo_ti_init keeps holding pointers into the old array, which
in case of luck might be the same, but without luck can contain garbage
as well. I have spotted just two places where a tinfo_s * pointer
into the tinfo_descs vector can be live accross reallocation,
which can happen when calling get_tinfo_ptr via.
get_tinfo_decl/get_pseudo_ti_index.
Ok for HEAD if bootstrap/regtesting succeeds (just started)?
Alternatively, rtti.c could stop passing around tinfo_s *
pointers and pass indexes into the tinfo_descs vector instead
and just use VEC_index (tinfo_s, tinfo_descs, xx) immediately
before each use.
2005-09-20 Jakub Jelinek <jakub@redhat.com>
PR c++/23947
* rtti.c (get_pseudo_ti_init): Recompute ti pointer after
get_tinfo_ptr calls.
* g++.dg/rtti/crash3.C: New test.
--- gcc/cp/rtti.c.jj 2005-09-20 12:54:59.000000000 +0200
+++ gcc/cp/rtti.c 2005-09-20 12:58:48.000000000 +0200
@@ -1020,7 +1020,9 @@ get_pseudo_ti_init (tree type, unsigned
tree base_binfo = BINFO_BASE_BINFO (TYPE_BINFO (type), 0);
tree tinfo = get_tinfo_ptr (BINFO_TYPE (base_binfo));
tree base_inits = tree_cons (NULL_TREE, tinfo, NULL_TREE);
-
+
+ /* get_tinfo_ptr might have reallocated the tinfo_descs vector. */
+ ti = VEC_index (tinfo_s, tinfo_descs, tk_index);
return class_initializer (ti, type, base_inits);
}
@@ -1079,6 +1081,9 @@ get_pseudo_ti_init (tree type, unsigned
base_inits = tree_cons (NULL_TREE,
build_int_cst (NULL_TREE, hint),
base_inits);
+
+ /* get_tinfo_ptr might have reallocated the tinfo_descs vector. */
+ ti = VEC_index (tinfo_s, tinfo_descs, tk_index);
return class_initializer (ti, type, base_inits);
}
}
--- gcc/testsuite/g++.dg/rtti/crash3.C.jj 2005-09-20 13:06:25.000000000 +0200
+++ gcc/testsuite/g++.dg/rtti/crash3.C 2005-09-20 13:07:03.000000000 +0200
@@ -0,0 +1,10 @@
+// PR c++/23947
+// { dg-do compile }
+
+class A {};
+class B {};
+class C : public A, public B {};
+class D : public C {};
+void f () throw (D)
+{
+}
Jakub