The attached patch fixes two small problems with the current vtable verification code: it makes the libvtv function decls globally visible, and it updates all uses of the verified vtable pointer with the verification results, rather than just the first use.
I have bootstrapped the compiler with this patch, both with and without vtable verification enabled, and have run the regression testsuites, both with and without vtable verification enabled, with no regressions. I have only tested this on Linux. Is this patch OK to commit? -- Caroline Tice cmt...@google.com gcc ChangeLog: 2013-12-06 Caroline Tice <cmt...@google.com> Submitting patch from Stephen Checkoway, s...@cs.jhu.edu * vtable-class-hierarchy.c (init_functions): Make the libvtv function decls externally visible. gcc/cp ChangeLog: 2013-12-06 Caroline Tice <cmt...@google.com> Submitting patch from Stephen Checkoway, s...@cs.jhu.edu * vtable-class-hierarchy.c (init_functions): Make the libvtv function decls externally visible.
Index: gcc/cp/vtable-class-hierarchy.c =================================================================== --- gcc/cp/vtable-class-hierarchy.c (revision 205756) +++ gcc/cp/vtable-class-hierarchy.c (working copy) @@ -258,6 +258,7 @@ init_functions (void) DECL_ATTRIBUTES (vlt_register_set_fndecl) = tree_cons (get_identifier ("leaf"), NULL, DECL_ATTRIBUTES (vlt_register_set_fndecl)); + DECL_EXTERNAL(vlt_register_set_fndecl) = 1; TREE_PUBLIC (vlt_register_set_fndecl) = 1; DECL_PRESERVE_P (vlt_register_set_fndecl) = 1; SET_DECL_LANGUAGE (vlt_register_set_fndecl, lang_cplusplus); @@ -301,6 +302,7 @@ init_functions (void) DECL_ATTRIBUTES (vlt_register_pairs_fndecl) = tree_cons (get_identifier ("leaf"), NULL, DECL_ATTRIBUTES (vlt_register_pairs_fndecl)); + DECL_EXTERNAL(vlt_register_pairs_fndecl) = 1; TREE_PUBLIC (vlt_register_pairs_fndecl) = 1; DECL_PRESERVE_P (vlt_register_pairs_fndecl) = 1; SET_DECL_LANGUAGE (vlt_register_pairs_fndecl, lang_cplusplus); Index: gcc/vtable-verify.c =================================================================== --- gcc/vtable-verify.c (revision 205756) +++ gcc/vtable-verify.c (working copy) @@ -646,9 +646,6 @@ verify_bb_vtables (basic_block bb) if (vtable_map_node && vtable_map_node->vtbl_map_decl) { - use_operand_p use_p; - ssa_op_iter iter; - vtable_map_node->is_used = true; vtbl_var_decl = vtable_map_node->vtbl_map_decl; @@ -695,35 +692,27 @@ verify_bb_vtables (basic_block bb) gimple_call_set_lhs (call_stmt, tmp0); update_stmt (call_stmt); - /* Find the next stmt, after the vptr assignment - statememt, which should use the result of the - vptr assignment statement value. */ - gsi_next (&gsi_vtbl_assign); - gimple next_stmt = gsi_stmt (gsi_vtbl_assign); - - if (!next_stmt) - return; - - /* Find any/all uses of 'lhs' in next_stmt, and - replace them with 'tmp0'. */ + /* Replace all uses of lhs with tmp0. */ found = false; - FOR_EACH_PHI_OR_STMT_USE (use_p, next_stmt, iter, - SSA_OP_ALL_USES) + imm_use_iterator iterator; + gimple use_stmt; + FOR_EACH_IMM_USE_STMT (use_stmt, iterator, lhs) { - tree op = USE_FROM_PTR (use_p); - if (op == lhs) - { - SET_USE (use_p, tmp0); - found = true; - } + use_operand_p use_p; + if (use_stmt == call_stmt) + continue; + FOR_EACH_IMM_USE_ON_STMT (use_p, iterator) + SET_USE (use_p, tmp0); + update_stmt (use_stmt); + found = true; } - update_stmt (next_stmt); + gcc_assert (found); /* Insert the new verification call just after the statement that gets the vtable pointer out of the object. */ - gsi_vtbl_assign = gsi_for_stmt (stmt); + gcc_assert (gsi_stmt (gsi_vtbl_assign) == stmt); gsi_insert_after (&gsi_vtbl_assign, call_stmt, GSI_NEW_STMT);