diff options
| author | Jason Merrill <jason@redhat.com> | 2020-05-29 11:59:33 -0400 |
|---|---|---|
| committer | Jason Merrill <jason@redhat.com> | 2020-05-29 12:21:21 -0400 |
| commit | 8e915901deb3518d4bef73ea52eab2ece7a2bbf6 (patch) | |
| tree | 2ef890b17ce82be48d3d6ae010a321f0ca2799c5 /gcc/cp | |
| parent | 83c34c4452b2d5fea4536c865e34b3c63f9acff6 (diff) | |
c++: vptr ubsan and derived class [PR95311].
We weren't able to find OBJ_TYPE_REF_OBJECT walking through
OBJ_TYPE_REF_EXPR because we had folded away the ADDR_EXPR.
gcc/cp/ChangeLog:
PR c++/95311
PR c++/95221
* class.c (build_vfn_ref): Don't fold the INDIRECT_REF.
gcc/testsuite/ChangeLog:
PR c++/95311
* g++.dg/ubsan/vptr-16.C: New test.
Diffstat (limited to 'gcc/cp')
| -rw-r--r-- | gcc/cp/class.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/gcc/cp/class.c b/gcc/cp/class.c index bab15524a60..ca492cdbd40 100644 --- a/gcc/cp/class.c +++ b/gcc/cp/class.c @@ -729,9 +729,13 @@ build_vtbl_ref (tree instance, tree idx) tree build_vfn_ref (tree instance_ptr, tree idx) { - tree aref; + tree obtype = TREE_TYPE (TREE_TYPE (instance_ptr)); + + /* Leave the INDIRECT_REF unfolded so cp_ubsan_maybe_instrument_member_call + can find instance_ptr. */ + tree ind = build1 (INDIRECT_REF, obtype, instance_ptr); - aref = build_vtbl_ref (cp_build_fold_indirect_ref (instance_ptr), idx); + tree aref = build_vtbl_ref (ind, idx); /* When using function descriptors, the address of the vtable entry is treated as a function pointer. */ |