* flag-types.h (enum sanitize_code): Add SANITIZE_VPTR,
	include SANITIZE_VPTR in SANITIZE_UNDEFINED.
	* opts.c (common_handle_option): Add -fsanitize=vptr.
	* sanitizer.def (BUILT_IN_UBSAN_HANDLE_DYNAMIC_TYPE_CACHE_MISS,
	BUILT_IN_UBSAN_HANDLE_DYNAMIC_TYPE_CACHE_MISS_ABORT): New.
	* ubsan.h (enum ubsan_null_ckind): Add UBSAN_DOWNCAST_POINTER,
	UBSAN_DOWNCAST_REFERENCE, UBSAN_UPCAST and UBSAN_CAST_TO_VBASE.
	(ubsan_expand_vptr_ifn): New prototype.
	* internal-fn.c (expand_ANNOTATE, expand_GOMP_SIMD_LANE,
	expand_GOMP_SIMD_VF, expand_GOMP_SIMD_LAST_LANE, expand_UBSAN_NULL,
	expand_UBSAN_BOUNDS, expand_UBSAN_OBJECT_SIZE, expand_ASAN_CHECK,
	expand_LOOP_VECTORIZED): Make argument nameless, remove
	ATTRIBUTE_UNUSED.
	(expand_UBSAN_VPTR): New function.
	* internal-fn.def (UBSAN_NULL, ASAN_CHECK): Use R instead of W
	in fn spec.
	(UBSAN_VPTR): New internal function.
	* sanopt.c (tree_map_traits): Renamed to ...
	(sanopt_tree_map_traits): ... this.
	(sanopt_tree_triplet, sanopt_tree_triplet_map_traits): New classes.
	(sanopt_ctx): Adjust asan_check_map type for tree_map_traits
	to sanopt_tree_map_traits renaming.  Add vptr_check_map field.
	(maybe_optimize_ubsan_vptr_ifn): New function.
	(sanopt_optimize_walker): Handle IFN_UBSAN_VPTR.
	(pass_sanopt::execute): Likewise.  Call sanopt_optimize even for
	-fsanitize=vptr.
	* tree-ssa-alias.c (call_may_clobber_ref_p_1): Handle certain
	internal calls like pure functions for aliasing, even when they
	have other side-effects that prevent making them ECF_PURE.
	* ubsan.c (ubsan_vptr_type_cache_decl): New variable.
	(ubsan_expand_vptr_ifn): New function.
cp/
	* cp-gimplify.c (cp_genericize_r): Call
	cp_ubsan_maybe_instrument_member_call for member calls.
	(cp_ubsan_check_member_access_r): New function.
	(cp_genericize_tree): Call cp_ubsan_instrument_member_accesses.
	* cp-tree.h (cp_ubsan_maybe_instrument_member_call,
	cp_ubsan_instrument_member_accesses,
	cp_ubsan_maybe_instrument_downcast,
	cp_ubsan_maybe_instrument_cast_to_vbase): New prototypes.
	* cp-ubsan.c: New file.
	* Make-lang.in (CXX_AND_OBJCXX_OBJS): Add cp/cp-ubsan.o.
	* constexpr.c (cxx_eval_call_expression): Return void_node
	for IFN_UBSAN_VPTR.
	(potential_constant_expression_1): Return true for
	UBSAN_NULL, UBSAN_BOUNDS and UBSAN_VPTR internal calls.
	* typeck.c (build_class_member_access_expr): Provide locus
	for COMPONENT_REFs.
	(build_static_cast_1): Instrument downcasts.
	* class.c (build_base_path): For -fsanitize=vptr and !fixed_type_p
	add ubsan instrumentation for virtual_access.
	* call.c: Include internal-fn.h.
	(set_flags_from_callee): Handle internal calls.
gcc/testsuite/
	* g++.dg/ubsan/vptr-1.C: New test.
	* g++.dg/ubsan/vptr-2.C: New test.
	* g++.dg/ubsan/vptr-3.C: New test.
	* g++.dg/ubsan/vptr-4.C: New test.
	* g++.dg/ubsan/vptr-5.C: New test.
	* g++.dg/ubsan/vptr-6.C: New test.
	* g++.dg/ubsan/vptr-7.C: New test.
	* g++.dg/ubsan/vptr-8.C: New test.
	* g++.dg/ubsan/vptr-9.C: New test.

From-SVN: r219695