[N.B. this is a corrected version of https://gcc.gnu.org/pipermail/gcc-patches/2022-November/607443.html ]
This patch factors out the TYPENAME_TYPE case of tsubst into a separate function tsubst_typename_type. It also factors out the two tsubst flags controlling TYPENAME_TYPE substitution, tf_keep_type_decl and tf_tst_ok, into distinct boolean parameters of this new function (and of make_typename_type). Consequently, callers which used to pass tf_tst_ok to tsubst now instead must directly call tsubst_typename_type when appropriate. In a subsequent patch we'll add another flag to tsubst_typename_type controlling whether we want to ignore non-types during the qualified lookup. gcc/cp/ChangeLog: * cp-tree.h (enum tsubst_flags): Remove tf_keep_type_decl and tf_tst_ok. (make_typename_type): Add two trailing boolean parameters defaulted to false. * decl.cc (make_typename_type): Replace uses of tf_keep_type_decl and tf_tst_ok with the corresponding new boolean parameters. * pt.cc (tsubst_typename_type): New, factored out from tsubst and adjusted after removing tf_keep_type_decl and tf_tst_ok. (tsubst_decl) <case VAR_DECL>: Conditionally call tsubst_typename_type directly instead of using tf_tst_ok. (tsubst) <case TYPENAME_TYPE>: Call tsubst_typename_type. (tsubst_copy) <case CAST_EXPR>: Conditionally call tsubst_typename_type directly instead of using tf_tst_ok. (tsubst_copy_and_build) <case CAST_EXPR>: Likewise. <case CONSTRUCTOR>: Likewise. --- gcc/cp/cp-tree.h | 9 +- gcc/cp/decl.cc | 17 ++-- gcc/cp/pt.cc | 223 +++++++++++++++++++++++++---------------------- 3 files changed, 134 insertions(+), 115 deletions(-) diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h index 06bc64a6b8d..a7c5765fc33 100644 --- a/gcc/cp/cp-tree.h +++ b/gcc/cp/cp-tree.h @@ -5573,8 +5573,7 @@ enum tsubst_flags { tf_error = 1 << 0, /* give error messages */ tf_warning = 1 << 1, /* give warnings too */ tf_ignore_bad_quals = 1 << 2, /* ignore bad cvr qualifiers */ - tf_keep_type_decl = 1 << 3, /* retain typedef type decls - (make_typename_type use) */ + /* 1 << 3 available */ tf_ptrmem_ok = 1 << 4, /* pointers to member ok (internal instantiate_type use) */ tf_user = 1 << 5, /* found template must be a user template @@ -5594,8 +5593,7 @@ enum tsubst_flags { (build_target_expr and friends) */ tf_norm = 1 << 11, /* Build diagnostic information during constraint normalization. */ - tf_tst_ok = 1 << 12, /* Allow a typename-specifier to name - a template (C++17 or later). */ + /* 1 << 12 available */ tf_dguide = 1 << 13, /* Building a deduction guide from a ctor. */ /* Convenient substitution flags combinations. */ tf_warning_or_error = tf_warning | tf_error @@ -6846,7 +6844,8 @@ extern tree declare_local_label (tree); extern tree define_label (location_t, tree); extern void check_goto (tree); extern bool check_omp_return (void); -extern tree make_typename_type (tree, tree, enum tag_types, tsubst_flags_t); +extern tree make_typename_type (tree, tree, enum tag_types, tsubst_flags_t, + bool = false, bool = false); extern tree build_typename_type (tree, tree, tree, tag_types); extern tree make_unbound_class_template (tree, tree, tree, tsubst_flags_t); extern tree make_unbound_class_template_raw (tree, tree, tree); diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc index d606b31d7a7..430533606b0 100644 --- a/gcc/cp/decl.cc +++ b/gcc/cp/decl.cc @@ -4228,14 +4228,17 @@ build_typename_type (tree context, tree name, tree fullname, /* Resolve `typename CONTEXT::NAME'. TAG_TYPE indicates the tag provided to name the type. Returns an appropriate type, unless an error occurs, in which case error_mark_node is returned. If we - locate a non-artificial TYPE_DECL and TF_KEEP_TYPE_DECL is set, we + locate a non-artificial TYPE_DECL and KEEP_TYPE_DECL is true, we return that, rather than the _TYPE it corresponds to, in other - cases we look through the type decl. If TF_ERROR is set, complain - about errors, otherwise be quiet. */ + cases we look through the type decl. If TEMPLATE_OK is true and + we found a TEMPLATE_DECL then we return a CTAD placeholder for the + TEMPLATE_DECL. If TF_ERROR is set, complain about errors, otherwise + be quiet. */ tree make_typename_type (tree context, tree name, enum tag_types tag_type, - tsubst_flags_t complain) + tsubst_flags_t complain, bool keep_type_decl /* = false */, + bool template_ok /* = false */) { tree fullname; tree t; @@ -4352,8 +4355,8 @@ make_typename_type (tree context, tree name, enum tag_types tag_type, } if (!want_template && TREE_CODE (t) != TYPE_DECL) { - if ((complain & tf_tst_ok) && cxx_dialect >= cxx17 - && DECL_TYPE_TEMPLATE_P (t)) + if (template_ok && DECL_TYPE_TEMPLATE_P (t) + && cxx_dialect >= cxx17) /* The caller permits this typename-specifier to name a template (because it appears in a CTAD-enabled context). */; else @@ -4383,7 +4386,7 @@ make_typename_type (tree context, tree name, enum tag_types tag_type, t = TYPE_NAME (t); } - if (DECL_ARTIFICIAL (t) || !(complain & tf_keep_type_decl)) + if (DECL_ARTIFICIAL (t) || !keep_type_decl) t = TREE_TYPE (t); maybe_record_typedef_use (t); diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index e89dbf47097..bc47bf15d38 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -13949,6 +13949,94 @@ tsubst_aggr_type_1 (tree t, return t; } +/* Substitute ARGS into the TYPENAME_TYPE T. The flag TEMPLATE_OK + is passed to make_typename_type. */ + +static tree +tsubst_typename_type (tree t, tree args, tsubst_flags_t complain, tree in_decl, + bool template_ok = false) +{ + tree ctx = TYPE_CONTEXT (t); + if (TREE_CODE (ctx) == TYPE_PACK_EXPANSION) + { + ctx = tsubst_pack_expansion (ctx, args, complain, in_decl); + if (ctx == error_mark_node + || TREE_VEC_LENGTH (ctx) > 1) + return error_mark_node; + if (TREE_VEC_LENGTH (ctx) == 0) + { + if (complain & tf_error) + error ("%qD is instantiated for an empty pack", + TYPENAME_TYPE_FULLNAME (t)); + return error_mark_node; + } + ctx = TREE_VEC_ELT (ctx, 0); + } + else + ctx = tsubst_aggr_type (ctx, args, complain, in_decl, + /*entering_scope=*/1); + if (ctx == error_mark_node) + return error_mark_node; + + tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args, + complain, in_decl); + if (f == error_mark_node) + return error_mark_node; + + if (!MAYBE_CLASS_TYPE_P (ctx)) + { + if (complain & tf_error) + error ("%qT is not a class, struct, or union type", ctx); + return error_mark_node; + } + else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx)) + { + /* Normally, make_typename_type does not require that the CTX + have complete type in order to allow things like: + + template <class T> struct S { typename S<T>::X Y; }; + + But, such constructs have already been resolved by this + point, so here CTX really should have complete type, unless + it's a partial instantiation. */ + if (!complete_type_or_maybe_complain (ctx, NULL_TREE, complain)) + return error_mark_node; + } + + f = make_typename_type (ctx, f, typename_type, complain, + /*keep_type_decl=*/true, template_ok); + if (f == error_mark_node) + return f; + if (TREE_CODE (f) == TYPE_DECL) + { + complain |= tf_ignore_bad_quals; + f = TREE_TYPE (f); + } + + if (TREE_CODE (f) != TYPENAME_TYPE) + { + if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE) + { + if (complain & tf_error) + error ("%qT resolves to %qT, which is not an enumeration type", + t, f); + else + return error_mark_node; + } + else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f)) + { + if (complain & tf_error) + error ("%qT resolves to %qT, which is not a class type", + t, f); + else + return error_mark_node; + } + } + + return cp_build_qualified_type + (f, cp_type_quals (f) | cp_type_quals (t), complain); +} + /* Map from a FUNCTION_DECL to a vec of default argument instantiations, indexed in reverse order of the parameters. */ @@ -15193,10 +15281,13 @@ tsubst_decl (tree t, tree args, tsubst_flags_t complain) && VAR_HAD_UNKNOWN_BOUND (t) && type != error_mark_node) type = strip_array_domain (type); - tsubst_flags_t tcomplain = complain; - if (VAR_P (t)) - tcomplain |= tf_tst_ok; - type = tsubst (type, args, tcomplain, in_decl); + if (VAR_P (t) + && TREE_CODE (type) == TYPENAME_TYPE + && !typedef_variant_p (type)) + type = tsubst_typename_type (type, args, complain, in_decl, + /*template_ok=*/true); + else + type = tsubst (type, args, complain, in_decl); /* Substituting the type might have recursively instantiated this same alias (c++/86171). */ if (gen_tmpl && DECL_ALIAS_TEMPLATE_P (gen_tmpl) @@ -15889,9 +15980,6 @@ tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl) bool fndecl_type = (complain & tf_fndecl_type); complain &= ~tf_fndecl_type; - bool tst_ok = (complain & tf_tst_ok); - complain &= ~tf_tst_ok; - if (type && code != TYPENAME_TYPE && code != TEMPLATE_TYPE_PARM @@ -16424,89 +16512,7 @@ tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl) } case TYPENAME_TYPE: - { - tree ctx = TYPE_CONTEXT (t); - if (TREE_CODE (ctx) == TYPE_PACK_EXPANSION) - { - ctx = tsubst_pack_expansion (ctx, args, complain, in_decl); - if (ctx == error_mark_node - || TREE_VEC_LENGTH (ctx) > 1) - return error_mark_node; - if (TREE_VEC_LENGTH (ctx) == 0) - { - if (complain & tf_error) - error ("%qD is instantiated for an empty pack", - TYPENAME_TYPE_FULLNAME (t)); - return error_mark_node; - } - ctx = TREE_VEC_ELT (ctx, 0); - } - else - ctx = tsubst_aggr_type (ctx, args, complain, in_decl, - /*entering_scope=*/1); - if (ctx == error_mark_node) - return error_mark_node; - - tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args, - complain, in_decl); - if (f == error_mark_node) - return error_mark_node; - - if (!MAYBE_CLASS_TYPE_P (ctx)) - { - if (complain & tf_error) - error ("%qT is not a class, struct, or union type", ctx); - return error_mark_node; - } - else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx)) - { - /* Normally, make_typename_type does not require that the CTX - have complete type in order to allow things like: - - template <class T> struct S { typename S<T>::X Y; }; - - But, such constructs have already been resolved by this - point, so here CTX really should have complete type, unless - it's a partial instantiation. */ - if (!complete_type_or_maybe_complain (ctx, NULL_TREE, complain)) - return error_mark_node; - } - - tsubst_flags_t tcomplain = complain | tf_keep_type_decl; - if (tst_ok) - tcomplain |= tf_tst_ok; - f = make_typename_type (ctx, f, typename_type, tcomplain); - if (f == error_mark_node) - return f; - if (TREE_CODE (f) == TYPE_DECL) - { - complain |= tf_ignore_bad_quals; - f = TREE_TYPE (f); - } - - if (TREE_CODE (f) != TYPENAME_TYPE) - { - if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE) - { - if (complain & tf_error) - error ("%qT resolves to %qT, which is not an enumeration type", - t, f); - else - return error_mark_node; - } - else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f)) - { - if (complain & tf_error) - error ("%qT resolves to %qT, which is not a class type", - t, f); - else - return error_mark_node; - } - } - - return cp_build_qualified_type - (f, cp_type_quals (f) | cp_type_quals (t), complain); - } + return tsubst_typename_type (t, args, complain, in_decl); case UNBOUND_CLASS_TEMPLATE: { @@ -17391,10 +17397,14 @@ tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl) case IMPLICIT_CONV_EXPR: CASE_CONVERT: { - tsubst_flags_t tcomplain = complain; - if (code == CAST_EXPR) - tcomplain |= tf_tst_ok; - tree type = tsubst (TREE_TYPE (t), args, tcomplain, in_decl); + tree type = TREE_TYPE (t); + if (code == CAST_EXPR + && TREE_CODE (type) == TYPENAME_TYPE + && !typedef_variant_p (type)) + type = tsubst_typename_type (type, args, complain, in_decl, + /*template_ok=*/true); + else + type = tsubst (type, args, complain, in_decl); tree op0 = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl); return build1 (code, type, op0); } @@ -20430,13 +20440,16 @@ tsubst_copy_and_build (tree t, case DYNAMIC_CAST_EXPR: case STATIC_CAST_EXPR: { - tree type; + tree type = TREE_TYPE (t); tree op, r = NULL_TREE; - tsubst_flags_t tcomplain = complain; - if (TREE_CODE (t) == CAST_EXPR) - tcomplain |= tf_tst_ok; - type = tsubst (TREE_TYPE (t), args, tcomplain, in_decl); + if (TREE_CODE (t) == CAST_EXPR + && TREE_CODE (type) == TYPENAME_TYPE + && !typedef_variant_p (type)) + type = tsubst_typename_type (type, args, complain, in_decl, + /*template_ok=*/true); + else + type = tsubst (type, args, complain, in_decl); op = RECUR (TREE_OPERAND (t, 0)); @@ -21421,10 +21434,14 @@ tsubst_copy_and_build (tree t, bool need_copy_p = false; tree r; - tsubst_flags_t tcomplain = complain; - if (COMPOUND_LITERAL_P (t)) - tcomplain |= tf_tst_ok; - tree type = tsubst (TREE_TYPE (t), args, tcomplain, in_decl); + tree type = TREE_TYPE (t); + if (COMPOUND_LITERAL_P (t) + && TREE_CODE (type) == TYPENAME_TYPE + && !typedef_variant_p (type)) + type = tsubst_typename_type (type, args, complain, in_decl, + /*template_ok=*/true); + else + type = tsubst (type, args, complain, in_decl); if (type == error_mark_node) RETURN (error_mark_node); -- 2.39.1.433.g23c56f7bd5