From 3e948d645bc9086eee28407fcc67d05b3450bb78 Mon Sep 17 00:00:00 2001 From: Patrick Palka Date: Thu, 12 May 2022 16:52:06 -0400 Subject: [PATCH] c++: tighten TMPL_ARGS_LEVEL macro This patch makes TMPL_ARGS_LEVEL verify the level argument is valid when the one-dimensional vector case. Doing so uncovered a couple of latent issues: in try_class_unification, we weren't correctly copying targs when it's two-dimensional, and in unify_pack_expansion it seems an inequality test needs to be reversed. This patch fixes both issues, and in passing makes the former function free the temporary copy of targs. gcc/cp/ChangeLog: * cp-tree.h (TMPL_ARGS_LEVEL): Assert LEVEL is 1 when TMPL_ARGS_HAVE_MULTIPLE_LEVELS is false. * pt.cc (try_class_unification): Correctly copy multidimensional targs. Free the copy of targs. (unify_pack_expansion): Fix level comparison. --- gcc/cp/cp-tree.h | 3 ++- gcc/cp/pt.cc | 28 ++++++++++++++-------------- 2 files changed, 16 insertions(+), 15 deletions(-) diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h index b6961a7..b2df6fc 100644 --- a/gcc/cp/cp-tree.h +++ b/gcc/cp/cp-tree.h @@ -3783,7 +3783,8 @@ struct GTY(()) lang_decl { args is level 1, not level 0. */ #define TMPL_ARGS_LEVEL(ARGS, LEVEL) \ (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (ARGS) \ - ? TREE_VEC_ELT (ARGS, (LEVEL) - 1) : (ARGS)) + ? TREE_VEC_ELT (ARGS, (LEVEL) - 1) \ + : (gcc_checking_assert ((LEVEL) == 1), (ARGS))) /* Set the LEVELth level of the template ARGS to VAL. This macro does not work with single-level argument vectors. */ diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index 06b4a7d..fa05e91 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -23398,8 +23398,6 @@ static tree try_class_unification (tree tparms, tree targs, tree parm, tree arg, bool explain_p) { - tree copy_of_targs; - if (!CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg)) return NULL_TREE; else if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM) @@ -23438,21 +23436,23 @@ try_class_unification (tree tparms, tree targs, tree parm, tree arg, because there are two ways to unify base classes of S<0, 1, 2> with S. If we kept the already deduced knowledge, we would reject the possibility I=1. */ - copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs)); + targs = copy_template_args (targs); + for (tree& targ : tree_vec_range (INNERMOST_TEMPLATE_ARGS (targs))) + targ = NULL_TREE; + int err; if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM) - { - if (unify_bound_ttp_args (tparms, copy_of_targs, parm, arg, explain_p)) - return NULL_TREE; - return arg; - } + err = unify_bound_ttp_args (tparms, targs, parm, arg, explain_p); + else + err = unify (tparms, targs, CLASSTYPE_TI_ARGS (parm), + CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE, explain_p); - /* If unification failed, we're done. */ - if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm), - CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE, explain_p)) - return NULL_TREE; + if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs)) + for (tree level : tree_vec_range (targs)) + ggc_free (level); + ggc_free (targs); - return arg; + return err ? NULL_TREE : arg; } /* Given a template type PARM and a class type ARG, find the unique @@ -23649,7 +23649,7 @@ unify_pack_expansion (tree tparms, tree targs, tree packed_parms, /* Determine the index and level of this parameter pack. */ template_parm_level_and_index (parm_pack, &level, &idx); - if (level < levels) + if (level > levels) continue; /* Keep track of the parameter packs and their corresponding -- 2.7.4