On 09/18/2014 10:12 AM, Jakub Jelinek wrote:
Clobber stmts, being artificial statements, were certainly never meant to be instrumented. In 4.8 when asan has been introduced into gcc, the lhs of clobber could be only a decl and as a whole decl store would not be really instrumented, but with *this clobbers in 4.9 that is no longer the case.
And this patch fixes the clobber to only clobber the as-base part of the class, since any virtual bases might not be destroyed yet. This patch also fixes Jakub's testcase (without his patch).
Tested x86_64-pc-linux-gnu, applying to trunk.
commit e8c36b9fe6c1534925d809a7a15e599770466ee3 Author: Jason Merrill <ja...@redhat.com> Date: Thu Sep 18 11:15:57 2014 -0400 PR c++/62017 * decl.c (begin_destructor_body): Only clobber the as-base part of *this. diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c index 59dada7..fe5a4af 100644 --- a/gcc/cp/decl.c +++ b/gcc/cp/decl.c @@ -13808,10 +13808,12 @@ begin_destructor_body (void) /* Insert a cleanup to let the back end know that the object is dead when we exit the destructor, either normally or via exception. */ - tree clobber = build_constructor (current_class_type, NULL); + tree btype = CLASSTYPE_AS_BASE (current_class_type); + tree clobber = build_constructor (btype, NULL); TREE_THIS_VOLATILE (clobber) = true; - tree exprstmt = build2 (MODIFY_EXPR, current_class_type, - current_class_ref, clobber); + tree bref = build_nop (build_reference_type (btype), current_class_ptr); + bref = convert_from_reference (bref); + tree exprstmt = build2 (MODIFY_EXPR, btype, bref, clobber); finish_decl_cleanup (NULL_TREE, exprstmt); /* And insert cleanups for our bases and members so that they