After r13-332-g88459c3965e2a2, it looks like we can safely remove the NULL test from TMPL_ARGS_HAVE_MULTIPLE_LEVELS, which simplifies its semantics.
And TMPL_ARGS_LEVEL should verify the level argument is sane in the one-dimensional vector case. This change uncovered a couple of latent bugs: in try_class_unification, we weren't correctly copying multidimensional targs, and in unify_pack_expansion it seems an inequality test needs to be reversed (not sure about this latter fix, the test was added in r8-6178-g2625472ffa519e FWIW). Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for trunk? Also tested on cmcstl2 and range-v3. gcc/cp/ChangeLog: * cp-tree.h (TMPL_ARGS_HAVE_MULTIPLE_LEVELS): Remove NULL test. (TMPL_ARGS_LEVEL): Assert LEVEL is 1 when TMPL_ARGS_HAVE_MULTIPLE_LEVELS is false. * pt.cc (try_class_unification): Correctly copy multidimensional targs. (unify_pack_expansion): Fix level comparison. --- gcc/cp/cp-tree.h | 5 +++-- gcc/cp/pt.cc | 12 ++++++------ 2 files changed, 9 insertions(+), 8 deletions(-) diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h index b6961a796af..f681d32ac93 100644 --- a/gcc/cp/cp-tree.h +++ b/gcc/cp/cp-tree.h @@ -3766,7 +3766,7 @@ struct GTY(()) lang_decl { /* Nonzero if the template arguments is actually a vector of vectors, rather than just a vector. */ #define TMPL_ARGS_HAVE_MULTIPLE_LEVELS(NODE) \ - (NODE && TREE_VEC_LENGTH (NODE) && TREE_VEC_ELT (NODE, 0) \ + (TREE_VEC_LENGTH (NODE) && TREE_VEC_ELT (NODE, 0) \ && TREE_CODE (TREE_VEC_ELT (NODE, 0)) == TREE_VEC) /* The depth of a template argument vector. When called directly by @@ -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 2c7c5f8bb5d..75b21e5c88a 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) @@ -23438,17 +23436,19 @@ 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<I, I, I>. 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; if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM) { - if (unify_bound_ttp_args (tparms, copy_of_targs, parm, arg, explain_p)) + if (unify_bound_ttp_args (tparms, targs, parm, arg, explain_p)) return NULL_TREE; return arg; } /* If unification failed, we're done. */ - if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm), + if (unify (tparms, targs, CLASSTYPE_TI_ARGS (parm), CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE, explain_p)) return NULL_TREE; @@ -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 -- 2.36.1.63.gef9b086d95