Mercurial > hg > CbC > CbC_gcc
diff gcc/cp/method.c @ 111:04ced10e8804
gcc 7
author | kono |
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date | Fri, 27 Oct 2017 22:46:09 +0900 |
parents | |
children | 84e7813d76e9 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/gcc/cp/method.c Fri Oct 27 22:46:09 2017 +0900 @@ -0,0 +1,2479 @@ +/* Handle the hair of processing (but not expanding) inline functions. + Also manage function and variable name overloading. + Copyright (C) 1987-2017 Free Software Foundation, Inc. + Contributed by Michael Tiemann (tiemann@cygnus.com) + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 3, or (at your option) +any later version. + +GCC is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING3. If not see +<http://www.gnu.org/licenses/>. */ + + +/* Handle method declarations. */ +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "target.h" +#include "cp-tree.h" +#include "stringpool.h" +#include "cgraph.h" +#include "varasm.h" +#include "toplev.h" +#include "common/common-target.h" + +/* Various flags to control the mangling process. */ + +enum mangling_flags +{ + /* No flags. */ + mf_none = 0, + /* The thing we are presently mangling is part of a template type, + rather than a fully instantiated type. Therefore, we may see + complex expressions where we would normally expect to see a + simple integer constant. */ + mf_maybe_uninstantiated = 1, + /* When mangling a numeric value, use the form `_XX_' (instead of + just `XX') if the value has more than one digit. */ + mf_use_underscores_around_value = 2 +}; + +static void do_build_copy_assign (tree); +static void do_build_copy_constructor (tree); +static tree make_alias_for_thunk (tree); + +/* Called once to initialize method.c. */ + +void +init_method (void) +{ + init_mangle (); +} + +/* Return a this or result adjusting thunk to FUNCTION. THIS_ADJUSTING + indicates whether it is a this or result adjusting thunk. + FIXED_OFFSET and VIRTUAL_OFFSET indicate how to do the adjustment + (see thunk_adjust). VIRTUAL_OFFSET can be NULL, but FIXED_OFFSET + never is. VIRTUAL_OFFSET is the /index/ into the vtable for this + adjusting thunks, we scale it to a byte offset. For covariant + thunks VIRTUAL_OFFSET is the virtual binfo. You must post process + the returned thunk with finish_thunk. */ + +tree +make_thunk (tree function, bool this_adjusting, + tree fixed_offset, tree virtual_offset) +{ + HOST_WIDE_INT d; + tree thunk; + + gcc_assert (TREE_CODE (function) == FUNCTION_DECL); + /* We can have this thunks to covariant thunks, but not vice versa. */ + gcc_assert (!DECL_THIS_THUNK_P (function)); + gcc_assert (!DECL_RESULT_THUNK_P (function) || this_adjusting); + + /* Scale the VIRTUAL_OFFSET to be in terms of bytes. */ + if (this_adjusting && virtual_offset) + virtual_offset + = size_binop (MULT_EXPR, + virtual_offset, + convert (ssizetype, + TYPE_SIZE_UNIT (vtable_entry_type))); + + d = tree_to_shwi (fixed_offset); + + /* See if we already have the thunk in question. For this_adjusting + thunks VIRTUAL_OFFSET will be an INTEGER_CST, for covariant thunks it + will be a BINFO. */ + for (thunk = DECL_THUNKS (function); thunk; thunk = DECL_CHAIN (thunk)) + if (DECL_THIS_THUNK_P (thunk) == this_adjusting + && THUNK_FIXED_OFFSET (thunk) == d + && !virtual_offset == !THUNK_VIRTUAL_OFFSET (thunk) + && (!virtual_offset + || (this_adjusting + ? tree_int_cst_equal (THUNK_VIRTUAL_OFFSET (thunk), + virtual_offset) + : THUNK_VIRTUAL_OFFSET (thunk) == virtual_offset))) + return thunk; + + /* All thunks must be created before FUNCTION is actually emitted; + the ABI requires that all thunks be emitted together with the + function to which they transfer control. */ + gcc_assert (!TREE_ASM_WRITTEN (function)); + /* Likewise, we can only be adding thunks to a function declared in + the class currently being laid out. */ + gcc_assert (TYPE_SIZE (DECL_CONTEXT (function)) + && TYPE_BEING_DEFINED (DECL_CONTEXT (function))); + + thunk = build_decl (DECL_SOURCE_LOCATION (function), + FUNCTION_DECL, NULL_TREE, TREE_TYPE (function)); + DECL_LANG_SPECIFIC (thunk) = DECL_LANG_SPECIFIC (function); + cxx_dup_lang_specific_decl (thunk); + DECL_VIRTUAL_P (thunk) = true; + SET_DECL_THUNKS (thunk, NULL_TREE); + + DECL_CONTEXT (thunk) = DECL_CONTEXT (function); + TREE_READONLY (thunk) = TREE_READONLY (function); + TREE_THIS_VOLATILE (thunk) = TREE_THIS_VOLATILE (function); + TREE_PUBLIC (thunk) = TREE_PUBLIC (function); + SET_DECL_THUNK_P (thunk, this_adjusting); + THUNK_TARGET (thunk) = function; + THUNK_FIXED_OFFSET (thunk) = d; + THUNK_VIRTUAL_OFFSET (thunk) = virtual_offset; + THUNK_ALIAS (thunk) = NULL_TREE; + + DECL_INTERFACE_KNOWN (thunk) = 1; + DECL_NOT_REALLY_EXTERN (thunk) = 1; + DECL_COMDAT (thunk) = DECL_COMDAT (function); + DECL_SAVED_FUNCTION_DATA (thunk) = NULL; + /* The thunk itself is not a constructor or destructor, even if + the thing it is thunking to is. */ + DECL_CXX_DESTRUCTOR_P (thunk) = 0; + DECL_CXX_CONSTRUCTOR_P (thunk) = 0; + DECL_EXTERNAL (thunk) = 1; + DECL_ARTIFICIAL (thunk) = 1; + /* The THUNK is not a pending inline, even if the FUNCTION is. */ + DECL_PENDING_INLINE_P (thunk) = 0; + DECL_DECLARED_INLINE_P (thunk) = 0; + /* Nor is it a template instantiation. */ + DECL_USE_TEMPLATE (thunk) = 0; + DECL_TEMPLATE_INFO (thunk) = NULL; + + /* Add it to the list of thunks associated with FUNCTION. */ + DECL_CHAIN (thunk) = DECL_THUNKS (function); + SET_DECL_THUNKS (function, thunk); + + return thunk; +} + +/* Finish THUNK, a thunk decl. */ + +void +finish_thunk (tree thunk) +{ + tree function, name; + tree fixed_offset = ssize_int (THUNK_FIXED_OFFSET (thunk)); + tree virtual_offset = THUNK_VIRTUAL_OFFSET (thunk); + + gcc_assert (!DECL_NAME (thunk) && DECL_THUNK_P (thunk)); + if (virtual_offset && DECL_RESULT_THUNK_P (thunk)) + virtual_offset = BINFO_VPTR_FIELD (virtual_offset); + function = THUNK_TARGET (thunk); + name = mangle_thunk (function, DECL_THIS_THUNK_P (thunk), + fixed_offset, virtual_offset, thunk); + + /* We can end up with declarations of (logically) different + covariant thunks, that do identical adjustments. The two thunks + will be adjusting between within different hierarchies, which + happen to have the same layout. We must nullify one of them to + refer to the other. */ + if (DECL_RESULT_THUNK_P (thunk)) + { + tree cov_probe; + + for (cov_probe = DECL_THUNKS (function); + cov_probe; cov_probe = DECL_CHAIN (cov_probe)) + if (DECL_NAME (cov_probe) == name) + { + gcc_assert (!DECL_THUNKS (thunk)); + THUNK_ALIAS (thunk) = (THUNK_ALIAS (cov_probe) + ? THUNK_ALIAS (cov_probe) : cov_probe); + break; + } + } + + DECL_NAME (thunk) = name; + SET_DECL_ASSEMBLER_NAME (thunk, name); +} + +static GTY (()) int thunk_labelno; + +/* Create a static alias to target. */ + +tree +make_alias_for (tree target, tree newid) +{ + tree alias = build_decl (DECL_SOURCE_LOCATION (target), + TREE_CODE (target), newid, TREE_TYPE (target)); + DECL_LANG_SPECIFIC (alias) = DECL_LANG_SPECIFIC (target); + cxx_dup_lang_specific_decl (alias); + DECL_CONTEXT (alias) = NULL; + TREE_READONLY (alias) = TREE_READONLY (target); + TREE_THIS_VOLATILE (alias) = TREE_THIS_VOLATILE (target); + TREE_PUBLIC (alias) = 0; + DECL_INTERFACE_KNOWN (alias) = 1; + if (DECL_LANG_SPECIFIC (alias)) + { + DECL_NOT_REALLY_EXTERN (alias) = 1; + DECL_USE_TEMPLATE (alias) = 0; + DECL_TEMPLATE_INFO (alias) = NULL; + } + DECL_EXTERNAL (alias) = 0; + DECL_ARTIFICIAL (alias) = 1; + DECL_TEMPLATE_INSTANTIATED (alias) = 0; + if (TREE_CODE (alias) == FUNCTION_DECL) + { + DECL_SAVED_FUNCTION_DATA (alias) = NULL; + DECL_CXX_DESTRUCTOR_P (alias) = 0; + DECL_CXX_CONSTRUCTOR_P (alias) = 0; + DECL_PENDING_INLINE_P (alias) = 0; + DECL_DECLARED_INLINE_P (alias) = 0; + DECL_INITIAL (alias) = error_mark_node; + DECL_ARGUMENTS (alias) = copy_list (DECL_ARGUMENTS (target)); + } + else + TREE_STATIC (alias) = 1; + TREE_ADDRESSABLE (alias) = 1; + TREE_USED (alias) = 1; + SET_DECL_ASSEMBLER_NAME (alias, DECL_NAME (alias)); + return alias; +} + +static tree +make_alias_for_thunk (tree function) +{ + tree alias; + char buf[256]; + + targetm.asm_out.generate_internal_label (buf, "LTHUNK", thunk_labelno); + thunk_labelno++; + + alias = make_alias_for (function, get_identifier (buf)); + + if (!flag_syntax_only) + { + struct cgraph_node *funcn, *aliasn; + funcn = cgraph_node::get (function); + gcc_checking_assert (funcn); + aliasn = cgraph_node::create_same_body_alias (alias, function); + DECL_ASSEMBLER_NAME (function); + gcc_assert (aliasn != NULL); + } + + return alias; +} + +/* Emit the definition of a C++ multiple inheritance or covariant + return vtable thunk. If EMIT_P is nonzero, the thunk is emitted + immediately. */ + +void +use_thunk (tree thunk_fndecl, bool emit_p) +{ + tree a, t, function, alias; + tree virtual_offset; + HOST_WIDE_INT fixed_offset, virtual_value; + bool this_adjusting = DECL_THIS_THUNK_P (thunk_fndecl); + struct cgraph_node *funcn, *thunk_node; + + /* We should have called finish_thunk to give it a name. */ + gcc_assert (DECL_NAME (thunk_fndecl)); + + /* We should never be using an alias, always refer to the + aliased thunk. */ + gcc_assert (!THUNK_ALIAS (thunk_fndecl)); + + if (TREE_ASM_WRITTEN (thunk_fndecl)) + return; + + function = THUNK_TARGET (thunk_fndecl); + if (DECL_RESULT (thunk_fndecl)) + /* We already turned this thunk into an ordinary function. + There's no need to process this thunk again. */ + return; + + if (DECL_THUNK_P (function)) + /* The target is itself a thunk, process it now. */ + use_thunk (function, emit_p); + + /* Thunks are always addressable; they only appear in vtables. */ + TREE_ADDRESSABLE (thunk_fndecl) = 1; + + /* Figure out what function is being thunked to. It's referenced in + this translation unit. */ + TREE_ADDRESSABLE (function) = 1; + mark_used (function); + if (!emit_p) + return; + + if (TARGET_USE_LOCAL_THUNK_ALIAS_P (function)) + alias = make_alias_for_thunk (function); + else + alias = function; + + fixed_offset = THUNK_FIXED_OFFSET (thunk_fndecl); + virtual_offset = THUNK_VIRTUAL_OFFSET (thunk_fndecl); + + if (virtual_offset) + { + if (!this_adjusting) + virtual_offset = BINFO_VPTR_FIELD (virtual_offset); + virtual_value = tree_to_shwi (virtual_offset); + gcc_assert (virtual_value); + } + else + virtual_value = 0; + + /* And, if we need to emit the thunk, it's used. */ + mark_used (thunk_fndecl); + /* This thunk is actually defined. */ + DECL_EXTERNAL (thunk_fndecl) = 0; + /* The linkage of the function may have changed. FIXME in linkage + rewrite. */ + gcc_assert (DECL_INTERFACE_KNOWN (function)); + TREE_PUBLIC (thunk_fndecl) = TREE_PUBLIC (function); + DECL_VISIBILITY (thunk_fndecl) = DECL_VISIBILITY (function); + DECL_VISIBILITY_SPECIFIED (thunk_fndecl) + = DECL_VISIBILITY_SPECIFIED (function); + DECL_COMDAT (thunk_fndecl) = DECL_COMDAT (function); + DECL_WEAK (thunk_fndecl) = DECL_WEAK (function); + + if (flag_syntax_only) + { + TREE_ASM_WRITTEN (thunk_fndecl) = 1; + return; + } + + push_to_top_level (); + + if (TARGET_USE_LOCAL_THUNK_ALIAS_P (function) + && targetm_common.have_named_sections) + { + tree fn = function; + struct symtab_node *symbol; + + if ((symbol = symtab_node::get (function)) + && symbol->alias) + { + if (symbol->analyzed) + fn = symtab_node::get (function)->ultimate_alias_target ()->decl; + else + fn = symtab_node::get (function)->alias_target; + } + resolve_unique_section (fn, 0, flag_function_sections); + + if (DECL_SECTION_NAME (fn) != NULL && DECL_ONE_ONLY (fn)) + { + resolve_unique_section (thunk_fndecl, 0, flag_function_sections); + + /* Output the thunk into the same section as function. */ + set_decl_section_name (thunk_fndecl, DECL_SECTION_NAME (fn)); + symtab_node::get (thunk_fndecl)->implicit_section + = symtab_node::get (fn)->implicit_section; + } + } + + /* Set up cloned argument trees for the thunk. */ + t = NULL_TREE; + for (a = DECL_ARGUMENTS (function); a; a = DECL_CHAIN (a)) + { + tree x = copy_node (a); + DECL_CHAIN (x) = t; + DECL_CONTEXT (x) = thunk_fndecl; + SET_DECL_RTL (x, NULL); + DECL_HAS_VALUE_EXPR_P (x) = 0; + TREE_ADDRESSABLE (x) = 0; + t = x; + } + a = nreverse (t); + DECL_ARGUMENTS (thunk_fndecl) = a; + TREE_ASM_WRITTEN (thunk_fndecl) = 1; + funcn = cgraph_node::get (function); + gcc_checking_assert (funcn); + thunk_node = funcn->create_thunk (thunk_fndecl, function, + this_adjusting, fixed_offset, virtual_value, + virtual_offset, alias); + if (DECL_ONE_ONLY (function)) + thunk_node->add_to_same_comdat_group (funcn); + + pop_from_top_level (); +} + +/* Code for synthesizing methods which have default semantics defined. */ + +/* True iff CTYPE has a trivial SFK. */ + +static bool +type_has_trivial_fn (tree ctype, special_function_kind sfk) +{ + switch (sfk) + { + case sfk_constructor: + return !TYPE_HAS_COMPLEX_DFLT (ctype); + case sfk_copy_constructor: + return !TYPE_HAS_COMPLEX_COPY_CTOR (ctype); + case sfk_move_constructor: + return !TYPE_HAS_COMPLEX_MOVE_CTOR (ctype); + case sfk_copy_assignment: + return !TYPE_HAS_COMPLEX_COPY_ASSIGN (ctype); + case sfk_move_assignment: + return !TYPE_HAS_COMPLEX_MOVE_ASSIGN (ctype); + case sfk_destructor: + return !TYPE_HAS_NONTRIVIAL_DESTRUCTOR (ctype); + case sfk_inheriting_constructor: + return false; + default: + gcc_unreachable (); + } +} + +/* Note that CTYPE has a non-trivial SFK even though we previously thought + it was trivial. */ + +static void +type_set_nontrivial_flag (tree ctype, special_function_kind sfk) +{ + switch (sfk) + { + case sfk_constructor: + TYPE_HAS_COMPLEX_DFLT (ctype) = true; + return; + case sfk_copy_constructor: + TYPE_HAS_COMPLEX_COPY_CTOR (ctype) = true; + return; + case sfk_move_constructor: + TYPE_HAS_COMPLEX_MOVE_CTOR (ctype) = true; + return; + case sfk_copy_assignment: + TYPE_HAS_COMPLEX_COPY_ASSIGN (ctype) = true; + return; + case sfk_move_assignment: + TYPE_HAS_COMPLEX_MOVE_ASSIGN (ctype) = true; + return; + case sfk_destructor: + TYPE_HAS_NONTRIVIAL_DESTRUCTOR (ctype) = true; + return; + case sfk_inheriting_constructor: + default: + gcc_unreachable (); + } +} + +/* True iff FN is a trivial defaulted member function ([cd]tor, op=). */ + +bool +trivial_fn_p (tree fn) +{ + if (TREE_CODE (fn) == TEMPLATE_DECL) + return false; + if (!DECL_DEFAULTED_FN (fn)) + return false; + + /* If fn is a clone, get the primary variant. */ + if (tree prim = DECL_CLONED_FUNCTION (fn)) + fn = prim; + return type_has_trivial_fn (DECL_CONTEXT (fn), special_function_p (fn)); +} + +/* PARM is a PARM_DECL for a function which we want to forward to another + function without changing its value category, a la std::forward. */ + +tree +forward_parm (tree parm) +{ + tree exp = convert_from_reference (parm); + tree type = TREE_TYPE (parm); + if (DECL_PACK_P (parm)) + type = PACK_EXPANSION_PATTERN (type); + if (TREE_CODE (type) != REFERENCE_TYPE) + type = cp_build_reference_type (type, /*rval=*/true); + warning_sentinel w (warn_useless_cast); + exp = build_static_cast (type, exp, tf_warning_or_error); + if (DECL_PACK_P (parm)) + exp = make_pack_expansion (exp); + return exp; +} + +/* Strip all inheriting constructors, if any, to return the original + constructor from a (possibly indirect) base class. */ + +tree +strip_inheriting_ctors (tree dfn) +{ + if (!flag_new_inheriting_ctors) + return dfn; + tree fn = dfn; + while (tree inh = DECL_INHERITED_CTOR (fn)) + fn = OVL_FIRST (inh); + + if (TREE_CODE (fn) == TEMPLATE_DECL + && TREE_CODE (dfn) == FUNCTION_DECL) + fn = DECL_TEMPLATE_RESULT (fn); + return fn; +} + +/* Find the binfo for the base subobject of BINFO being initialized by + inherited constructor FNDECL (a member of a direct base of BINFO). */ + +static tree inherited_ctor_binfo (tree, tree); +static tree +inherited_ctor_binfo_1 (tree binfo, tree fndecl) +{ + tree base = DECL_CONTEXT (fndecl); + tree base_binfo; + for (int i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) + if (BINFO_TYPE (base_binfo) == base) + return inherited_ctor_binfo (base_binfo, fndecl); + + gcc_unreachable(); +} + +/* Find the binfo for the base subobject of BINFO being initialized by + inheriting constructor FNDECL (a member of BINFO), or BINFO if FNDECL is not + an inheriting constructor. */ + +static tree +inherited_ctor_binfo (tree binfo, tree fndecl) +{ + tree inh = DECL_INHERITED_CTOR (fndecl); + if (!inh) + return binfo; + + tree results = NULL_TREE; + for (ovl_iterator iter (inh); iter; ++iter) + { + tree one = inherited_ctor_binfo_1 (binfo, *iter); + if (!results) + results = one; + else if (one != results) + results = tree_cons (NULL_TREE, one, results); + } + return results; +} + +/* Find the binfo for the base subobject being initialized by inheriting + constructor FNDECL, or NULL_TREE if FNDECL is not an inheriting + constructor. */ + +tree +inherited_ctor_binfo (tree fndecl) +{ + if (!DECL_INHERITED_CTOR (fndecl)) + return NULL_TREE; + tree binfo = TYPE_BINFO (DECL_CONTEXT (fndecl)); + return inherited_ctor_binfo (binfo, fndecl); +} + +/* True if we should omit all user-declared parameters from constructor FN, + because it is a base clone of a ctor inherited from a virtual base. */ + +bool +ctor_omit_inherited_parms (tree fn) +{ + if (!flag_new_inheriting_ctors) + /* We only optimize away the parameters in the new model. */ + return false; + if (!DECL_BASE_CONSTRUCTOR_P (fn) + || !CLASSTYPE_VBASECLASSES (DECL_CONTEXT (fn))) + return false; + if (FUNCTION_FIRST_USER_PARMTYPE (DECL_ORIGIN (fn)) == void_list_node) + /* No user-declared parameters to omit. */ + return false; + tree binfo = inherited_ctor_binfo (fn); + for (; binfo; binfo = BINFO_INHERITANCE_CHAIN (binfo)) + if (BINFO_VIRTUAL_P (binfo)) + return true; + return false; +} + +/* True iff constructor(s) INH inherited into BINFO initializes INIT_BINFO. + This can be true for multiple virtual bases as well as one direct + non-virtual base. */ + +static bool +binfo_inherited_from (tree binfo, tree init_binfo, tree inh) +{ + /* inh is an OVERLOAD if we inherited the same constructor along + multiple paths, check all of them. */ + for (ovl_iterator iter (inh); iter; ++iter) + { + tree fn = *iter; + tree base = DECL_CONTEXT (fn); + tree base_binfo = NULL_TREE; + for (int i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) + if (BINFO_TYPE (base_binfo) == base) + break; + if (base_binfo == init_binfo + || (flag_new_inheriting_ctors + && binfo_inherited_from (base_binfo, init_binfo, + DECL_INHERITED_CTOR (fn)))) + return true; + } + return false; +} + +/* Subroutine of do_build_copy_constructor: Add a mem-initializer for BINFO + given the parameter or parameters PARM, possibly inherited constructor + base INH, or move flag MOVE_P. */ + +static tree +add_one_base_init (tree binfo, tree parm, bool move_p, tree inh, + tree member_init_list) +{ + tree init; + if (inh) + { + /* An inheriting constructor only has a mem-initializer for + the base it inherits from. */ + if (!binfo_inherited_from (TYPE_BINFO (current_class_type), binfo, inh)) + return member_init_list; + + tree *p = &init; + init = NULL_TREE; + for (; parm; parm = DECL_CHAIN (parm)) + { + tree exp = forward_parm (parm); + *p = build_tree_list (NULL_TREE, exp); + p = &TREE_CHAIN (*p); + } + } + else + { + init = build_base_path (PLUS_EXPR, parm, binfo, 1, + tf_warning_or_error); + if (move_p) + init = move (init); + init = build_tree_list (NULL_TREE, init); + } + return tree_cons (binfo, init, member_init_list); +} + +/* Generate code for default X(X&) or X(X&&) constructor or an inheriting + constructor. */ + +static void +do_build_copy_constructor (tree fndecl) +{ + tree parm = FUNCTION_FIRST_USER_PARM (fndecl); + bool move_p = DECL_MOVE_CONSTRUCTOR_P (fndecl); + bool trivial = trivial_fn_p (fndecl); + tree inh = DECL_INHERITED_CTOR (fndecl); + + if (!inh) + parm = convert_from_reference (parm); + + if (trivial) + { + if (is_empty_class (current_class_type)) + /* Don't copy the padding byte; it might not have been allocated + if *this is a base subobject. */; + else if (tree_int_cst_equal (TYPE_SIZE (current_class_type), + CLASSTYPE_SIZE (current_class_type))) + { + tree t = build2 (INIT_EXPR, void_type_node, current_class_ref, parm); + finish_expr_stmt (t); + } + else + { + /* We must only copy the non-tail padding parts. */ + tree base_size = CLASSTYPE_SIZE_UNIT (current_class_type); + base_size = size_binop (MINUS_EXPR, base_size, size_int (1)); + tree array_type = build_array_type (unsigned_char_type_node, + build_index_type (base_size)); + tree alias_set = build_int_cst (TREE_TYPE (current_class_ptr), 0); + tree lhs = build2 (MEM_REF, array_type, + current_class_ptr, alias_set); + tree rhs = build2 (MEM_REF, array_type, + TREE_OPERAND (parm, 0), alias_set); + tree t = build2 (INIT_EXPR, void_type_node, lhs, rhs); + finish_expr_stmt (t); + } + } + else + { + tree fields = TYPE_FIELDS (current_class_type); + tree member_init_list = NULL_TREE; + int cvquals = cp_type_quals (TREE_TYPE (parm)); + int i; + tree binfo, base_binfo; + tree init; + vec<tree, va_gc> *vbases; + + /* Initialize all the base-classes with the parameter converted + to their type so that we get their copy constructor and not + another constructor that takes current_class_type. We must + deal with the binfo's directly as a direct base might be + inaccessible due to ambiguity. */ + for (vbases = CLASSTYPE_VBASECLASSES (current_class_type), i = 0; + vec_safe_iterate (vbases, i, &binfo); i++) + { + member_init_list = add_one_base_init (binfo, parm, move_p, inh, + member_init_list); + } + + for (binfo = TYPE_BINFO (current_class_type), i = 0; + BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) + { + if (BINFO_VIRTUAL_P (base_binfo)) + continue; + member_init_list = add_one_base_init (base_binfo, parm, move_p, + inh, member_init_list); + } + + for (; fields; fields = DECL_CHAIN (fields)) + { + tree field = fields; + tree expr_type; + + if (TREE_CODE (field) != FIELD_DECL) + continue; + if (inh) + continue; + + expr_type = TREE_TYPE (field); + if (DECL_NAME (field)) + { + if (VFIELD_NAME_P (DECL_NAME (field))) + continue; + } + else if (ANON_AGGR_TYPE_P (expr_type) && TYPE_FIELDS (expr_type)) + /* Just use the field; anonymous types can't have + nontrivial copy ctors or assignment ops or this + function would be deleted. */; + else + continue; + + /* Compute the type of "init->field". If the copy-constructor + parameter is, for example, "const S&", and the type of + the field is "T", then the type will usually be "const + T". (There are no cv-qualified variants of reference + types.) */ + if (TREE_CODE (expr_type) != REFERENCE_TYPE) + { + int quals = cvquals; + + if (DECL_MUTABLE_P (field)) + quals &= ~TYPE_QUAL_CONST; + quals |= cp_type_quals (expr_type); + expr_type = cp_build_qualified_type (expr_type, quals); + } + + init = build3 (COMPONENT_REF, expr_type, parm, field, NULL_TREE); + if (move_p && TREE_CODE (expr_type) != REFERENCE_TYPE + /* 'move' breaks bit-fields, and has no effect for scalars. */ + && !scalarish_type_p (expr_type)) + init = move (init); + init = build_tree_list (NULL_TREE, init); + + member_init_list = tree_cons (field, init, member_init_list); + } + finish_mem_initializers (member_init_list); + } +} + +static void +do_build_copy_assign (tree fndecl) +{ + tree parm = DECL_CHAIN (DECL_ARGUMENTS (fndecl)); + tree compound_stmt; + bool move_p = move_fn_p (fndecl); + bool trivial = trivial_fn_p (fndecl); + int flags = LOOKUP_NORMAL | LOOKUP_NONVIRTUAL | LOOKUP_DEFAULTED; + + compound_stmt = begin_compound_stmt (0); + parm = convert_from_reference (parm); + + if (trivial + && is_empty_class (current_class_type)) + /* Don't copy the padding byte; it might not have been allocated + if *this is a base subobject. */; + else if (trivial) + { + tree t = build2 (MODIFY_EXPR, void_type_node, current_class_ref, parm); + finish_expr_stmt (t); + } + else + { + tree fields; + int cvquals = cp_type_quals (TREE_TYPE (parm)); + int i; + tree binfo, base_binfo; + + /* Assign to each of the direct base classes. */ + for (binfo = TYPE_BINFO (current_class_type), i = 0; + BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) + { + tree converted_parm; + vec<tree, va_gc> *parmvec; + + /* We must convert PARM directly to the base class + explicitly since the base class may be ambiguous. */ + converted_parm = build_base_path (PLUS_EXPR, parm, base_binfo, 1, + tf_warning_or_error); + if (move_p) + converted_parm = move (converted_parm); + /* Call the base class assignment operator. */ + parmvec = make_tree_vector_single (converted_parm); + finish_expr_stmt + (build_special_member_call (current_class_ref, + cp_assignment_operator_id (NOP_EXPR), + &parmvec, + base_binfo, + flags, + tf_warning_or_error)); + release_tree_vector (parmvec); + } + + /* Assign to each of the non-static data members. */ + for (fields = TYPE_FIELDS (current_class_type); + fields; + fields = DECL_CHAIN (fields)) + { + tree comp = current_class_ref; + tree init = parm; + tree field = fields; + tree expr_type; + int quals; + + if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field)) + continue; + + expr_type = TREE_TYPE (field); + + if (CP_TYPE_CONST_P (expr_type)) + { + error ("non-static const member %q#D, can%'t use default " + "assignment operator", field); + continue; + } + else if (TREE_CODE (expr_type) == REFERENCE_TYPE) + { + error ("non-static reference member %q#D, can%'t use " + "default assignment operator", field); + continue; + } + + if (DECL_NAME (field)) + { + if (VFIELD_NAME_P (DECL_NAME (field))) + continue; + } + else if (ANON_AGGR_TYPE_P (expr_type) + && TYPE_FIELDS (expr_type) != NULL_TREE) + /* Just use the field; anonymous types can't have + nontrivial copy ctors or assignment ops or this + function would be deleted. */; + else + continue; + + comp = build3 (COMPONENT_REF, expr_type, comp, field, NULL_TREE); + + /* Compute the type of init->field */ + quals = cvquals; + if (DECL_MUTABLE_P (field)) + quals &= ~TYPE_QUAL_CONST; + expr_type = cp_build_qualified_type (expr_type, quals); + + init = build3 (COMPONENT_REF, expr_type, init, field, NULL_TREE); + if (move_p && TREE_CODE (expr_type) != REFERENCE_TYPE + /* 'move' breaks bit-fields, and has no effect for scalars. */ + && !scalarish_type_p (expr_type)) + init = move (init); + + if (DECL_NAME (field)) + init = cp_build_modify_expr (input_location, comp, NOP_EXPR, init, + tf_warning_or_error); + else + init = build2 (MODIFY_EXPR, TREE_TYPE (comp), comp, init); + finish_expr_stmt (init); + } + } + finish_return_stmt (current_class_ref); + finish_compound_stmt (compound_stmt); +} + +/* Synthesize FNDECL, a non-static member function. */ + +void +synthesize_method (tree fndecl) +{ + bool nested = (current_function_decl != NULL_TREE); + tree context = decl_function_context (fndecl); + bool need_body = true; + tree stmt; + location_t save_input_location = input_location; + int error_count = errorcount; + int warning_count = warningcount + werrorcount; + + /* Reset the source location, we might have been previously + deferred, and thus have saved where we were first needed. */ + DECL_SOURCE_LOCATION (fndecl) + = DECL_SOURCE_LOCATION (TYPE_NAME (DECL_CONTEXT (fndecl))); + + /* If we've been asked to synthesize a clone, just synthesize the + cloned function instead. Doing so will automatically fill in the + body for the clone. */ + if (DECL_CLONED_FUNCTION_P (fndecl)) + fndecl = DECL_CLONED_FUNCTION (fndecl); + + /* We may be in the middle of deferred access check. Disable + it now. */ + push_deferring_access_checks (dk_no_deferred); + + if (! context) + push_to_top_level (); + else if (nested) + push_function_context (); + + input_location = DECL_SOURCE_LOCATION (fndecl); + + start_preparsed_function (fndecl, NULL_TREE, SF_DEFAULT | SF_PRE_PARSED); + stmt = begin_function_body (); + + if (DECL_OVERLOADED_OPERATOR_P (fndecl) == NOP_EXPR) + { + do_build_copy_assign (fndecl); + need_body = false; + } + else if (DECL_CONSTRUCTOR_P (fndecl)) + { + tree arg_chain = FUNCTION_FIRST_USER_PARMTYPE (fndecl); + if (arg_chain != void_list_node) + do_build_copy_constructor (fndecl); + else + finish_mem_initializers (NULL_TREE); + } + + /* If we haven't yet generated the body of the function, just + generate an empty compound statement. */ + if (need_body) + { + tree compound_stmt; + compound_stmt = begin_compound_stmt (BCS_FN_BODY); + finish_compound_stmt (compound_stmt); + } + + finish_function_body (stmt); + expand_or_defer_fn (finish_function (/*inline_p=*/false)); + + input_location = save_input_location; + + if (! context) + pop_from_top_level (); + else if (nested) + pop_function_context (); + + pop_deferring_access_checks (); + + if (error_count != errorcount || warning_count != warningcount + werrorcount) + inform (input_location, "synthesized method %qD first required here ", + fndecl); +} + +/* Build a reference to type TYPE with cv-quals QUALS, which is an + rvalue if RVALUE is true. */ + +static tree +build_stub_type (tree type, int quals, bool rvalue) +{ + tree argtype = cp_build_qualified_type (type, quals); + return cp_build_reference_type (argtype, rvalue); +} + +/* Build a dummy glvalue from dereferencing a dummy reference of type + REFTYPE. */ + +static tree +build_stub_object (tree reftype) +{ + if (TREE_CODE (reftype) != REFERENCE_TYPE) + reftype = cp_build_reference_type (reftype, /*rval*/true); + tree stub = build1 (CONVERT_EXPR, reftype, integer_one_node); + return convert_from_reference (stub); +} + +/* Determine which function will be called when looking up NAME in TYPE, + called with a single ARGTYPE argument, or no argument if ARGTYPE is + null. FLAGS and COMPLAIN are as for build_new_method_call. + + Returns a FUNCTION_DECL if all is well. + Returns NULL_TREE if overload resolution failed. + Returns error_mark_node if the chosen function cannot be called. */ + +static tree +locate_fn_flags (tree type, tree name, tree argtype, int flags, + tsubst_flags_t complain) +{ + tree ob, fn, fns, binfo, rval; + vec<tree, va_gc> *args; + + if (TYPE_P (type)) + binfo = TYPE_BINFO (type); + else + { + binfo = type; + type = BINFO_TYPE (binfo); + } + + ob = build_stub_object (cp_build_reference_type (type, false)); + args = make_tree_vector (); + if (argtype) + { + if (TREE_CODE (argtype) == TREE_LIST) + { + for (tree elt = argtype; elt && elt != void_list_node; + elt = TREE_CHAIN (elt)) + { + tree type = TREE_VALUE (elt); + tree arg = build_stub_object (type); + vec_safe_push (args, arg); + } + } + else + { + tree arg = build_stub_object (argtype); + args->quick_push (arg); + } + } + + fns = lookup_fnfields (binfo, name, 0); + rval = build_new_method_call (ob, fns, &args, binfo, flags, &fn, complain); + + release_tree_vector (args); + if (fn && rval == error_mark_node) + return rval; + else + return fn; +} + +/* Locate the dtor of TYPE. */ + +tree +get_dtor (tree type, tsubst_flags_t complain) +{ + tree fn = locate_fn_flags (type, complete_dtor_identifier, NULL_TREE, + LOOKUP_NORMAL, complain); + if (fn == error_mark_node) + return NULL_TREE; + return fn; +} + +/* Locate the default ctor of TYPE. */ + +tree +locate_ctor (tree type) +{ + tree fn; + + push_deferring_access_checks (dk_no_check); + fn = locate_fn_flags (type, complete_ctor_identifier, NULL_TREE, + LOOKUP_SPECULATIVE, tf_none); + pop_deferring_access_checks (); + if (fn == error_mark_node) + return NULL_TREE; + return fn; +} + +/* Likewise, but give any appropriate errors. */ + +tree +get_default_ctor (tree type) +{ + tree fn = locate_fn_flags (type, complete_ctor_identifier, NULL_TREE, + LOOKUP_NORMAL, tf_warning_or_error); + if (fn == error_mark_node) + return NULL_TREE; + return fn; +} + +/* Locate the copy ctor of TYPE. */ + +tree +get_copy_ctor (tree type, tsubst_flags_t complain) +{ + int quals = (TYPE_HAS_CONST_COPY_CTOR (type) + ? TYPE_QUAL_CONST : TYPE_UNQUALIFIED); + tree argtype = build_stub_type (type, quals, false); + tree fn = locate_fn_flags (type, complete_ctor_identifier, argtype, + LOOKUP_NORMAL, complain); + if (fn == error_mark_node) + return NULL_TREE; + return fn; +} + +/* Locate the copy assignment operator of TYPE. */ + +tree +get_copy_assign (tree type) +{ + int quals = (TYPE_HAS_CONST_COPY_ASSIGN (type) + ? TYPE_QUAL_CONST : TYPE_UNQUALIFIED); + tree argtype = build_stub_type (type, quals, false); + tree fn = locate_fn_flags (type, cp_assignment_operator_id (NOP_EXPR), argtype, + LOOKUP_NORMAL, tf_warning_or_error); + if (fn == error_mark_node) + return NULL_TREE; + return fn; +} + +/* walk_tree helper function for is_trivially_xible. If *TP is a call, + return it if it calls something other than a trivial special member + function. */ + +static tree +check_nontriv (tree *tp, int *, void *) +{ + tree fn = cp_get_callee (*tp); + if (fn == NULL_TREE) + return NULL_TREE; + + if (TREE_CODE (fn) == ADDR_EXPR) + fn = TREE_OPERAND (fn, 0); + + if (TREE_CODE (fn) != FUNCTION_DECL + || !trivial_fn_p (fn)) + return fn; + return NULL_TREE; +} + +/* Return declval<T>() = declval<U>() treated as an unevaluated operand. */ + +static tree +assignable_expr (tree to, tree from) +{ + ++cp_unevaluated_operand; + to = build_stub_object (to); + from = build_stub_object (from); + tree r = cp_build_modify_expr (input_location, to, NOP_EXPR, from, tf_none); + --cp_unevaluated_operand; + return r; +} + +/* The predicate condition for a template specialization + is_constructible<T, Args...> shall be satisfied if and only if the + following variable definition would be well-formed for some invented + variable t: T t(create<Args>()...); + + Return something equivalent in well-formedness and triviality. */ + +static tree +constructible_expr (tree to, tree from) +{ + tree expr; + if (CLASS_TYPE_P (to)) + { + tree ctype = to; + vec<tree, va_gc> *args = NULL; + cp_unevaluated cp_uneval_guard; + if (TREE_CODE (to) != REFERENCE_TYPE) + to = cp_build_reference_type (to, /*rval*/false); + tree ob = build_stub_object (to); + for (; from; from = TREE_CHAIN (from)) + vec_safe_push (args, build_stub_object (TREE_VALUE (from))); + expr = build_special_member_call (ob, complete_ctor_identifier, &args, + ctype, LOOKUP_NORMAL, tf_none); + if (expr == error_mark_node) + return error_mark_node; + /* The current state of the standard vis-a-vis LWG 2116 is that + is_*constructible involves destruction as well. */ + if (type_build_dtor_call (ctype)) + { + tree dtor = build_special_member_call (ob, complete_dtor_identifier, + NULL, ctype, LOOKUP_NORMAL, + tf_none); + if (dtor == error_mark_node) + return error_mark_node; + if (!TYPE_HAS_TRIVIAL_DESTRUCTOR (ctype)) + expr = build2 (COMPOUND_EXPR, void_type_node, expr, dtor); + } + } + else + { + if (from == NULL_TREE) + return build_value_init (strip_array_types (to), tf_none); + else if (TREE_CHAIN (from)) + return error_mark_node; // too many initializers + from = build_stub_object (TREE_VALUE (from)); + expr = perform_direct_initialization_if_possible (to, from, + /*cast*/false, + tf_none); + } + return expr; +} + +/* Returns a tree iff TO is assignable (if CODE is MODIFY_EXPR) or + constructible (otherwise) from FROM, which is a single type for + assignment or a list of types for construction. */ + +static tree +is_xible_helper (enum tree_code code, tree to, tree from, bool trivial) +{ + if (VOID_TYPE_P (to) || ABSTRACT_CLASS_TYPE_P (to) + || (from && FUNC_OR_METHOD_TYPE_P (from) + && (TYPE_READONLY (from) || FUNCTION_REF_QUALIFIED (from)))) + return error_mark_node; + tree expr; + if (code == MODIFY_EXPR) + expr = assignable_expr (to, from); + else if (trivial && from && TREE_CHAIN (from)) + return error_mark_node; // only 0- and 1-argument ctors can be trivial + else + expr = constructible_expr (to, from); + return expr; +} + +/* Returns true iff TO is trivially assignable (if CODE is MODIFY_EXPR) or + constructible (otherwise) from FROM, which is a single type for + assignment or a list of types for construction. */ + +bool +is_trivially_xible (enum tree_code code, tree to, tree from) +{ + tree expr; + expr = is_xible_helper (code, to, from, /*trivial*/true); + + if (expr == error_mark_node) + return false; + tree nt = cp_walk_tree_without_duplicates (&expr, check_nontriv, NULL); + return !nt; +} + +/* Returns true iff TO is assignable (if CODE is MODIFY_EXPR) or + constructible (otherwise) from FROM, which is a single type for + assignment or a list of types for construction. */ + +bool +is_xible (enum tree_code code, tree to, tree from) +{ + tree expr = is_xible_helper (code, to, from, /*trivial*/false); + if (expr == error_mark_node) + return false; + return !!expr; +} + +/* Subroutine of synthesized_method_walk. Update SPEC_P, TRIVIAL_P and + DELETED_P or give an error message MSG with argument ARG. */ + +static void +process_subob_fn (tree fn, tree *spec_p, bool *trivial_p, + bool *deleted_p, bool *constexpr_p, + bool diag, tree arg, bool dtor_from_ctor = false) +{ + if (!fn || fn == error_mark_node) + { + if (deleted_p) + *deleted_p = true; + return; + } + + if (spec_p) + { + maybe_instantiate_noexcept (fn); + tree raises = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (fn)); + *spec_p = merge_exception_specifiers (*spec_p, raises); + } + + if (!trivial_fn_p (fn) && !dtor_from_ctor) + { + if (trivial_p) + *trivial_p = false; + if (TREE_CODE (arg) == FIELD_DECL + && TREE_CODE (DECL_CONTEXT (arg)) == UNION_TYPE) + { + if (deleted_p) + *deleted_p = true; + if (diag) + error ("union member %q+D with non-trivial %qD", arg, fn); + } + } + + if (constexpr_p && !DECL_DECLARED_CONSTEXPR_P (fn)) + { + *constexpr_p = false; + if (diag) + { + inform (DECL_SOURCE_LOCATION (fn), + "defaulted constructor calls non-constexpr %qD", fn); + explain_invalid_constexpr_fn (fn); + } + } +} + +/* Subroutine of synthesized_method_walk to allow recursion into anonymous + aggregates. If DTOR_FROM_CTOR is true, we're walking subobject destructors + called from a synthesized constructor, in which case we don't consider + the triviality of the subobject destructor. */ + +static void +walk_field_subobs (tree fields, tree fnname, special_function_kind sfk, + int quals, bool copy_arg_p, bool move_p, + bool assign_p, tree *spec_p, bool *trivial_p, + bool *deleted_p, bool *constexpr_p, + bool diag, int flags, tsubst_flags_t complain, + bool dtor_from_ctor) +{ + tree field; + for (field = fields; field; field = DECL_CHAIN (field)) + { + tree mem_type, argtype, rval; + + if (TREE_CODE (field) != FIELD_DECL + || DECL_ARTIFICIAL (field)) + continue; + + mem_type = strip_array_types (TREE_TYPE (field)); + if (assign_p) + { + bool bad = true; + if (CP_TYPE_CONST_P (mem_type) && !CLASS_TYPE_P (mem_type)) + { + if (diag) + error ("non-static const member %q#D, can%'t use default " + "assignment operator", field); + } + else if (TREE_CODE (mem_type) == REFERENCE_TYPE) + { + if (diag) + error ("non-static reference member %q#D, can%'t use " + "default assignment operator", field); + } + else + bad = false; + + if (bad && deleted_p) + *deleted_p = true; + } + else if (sfk == sfk_constructor || sfk == sfk_inheriting_constructor) + { + bool bad; + + if (DECL_INITIAL (field)) + { + if (diag && DECL_INITIAL (field) == error_mark_node) + inform (DECL_SOURCE_LOCATION (field), + "initializer for %q#D is invalid", field); + if (trivial_p) + *trivial_p = false; + /* Core 1351: If the field has an NSDMI that could throw, the + default constructor is noexcept(false). */ + if (spec_p) + { + tree nsdmi = get_nsdmi (field, /*ctor*/false, complain); + if (!expr_noexcept_p (nsdmi, complain)) + *spec_p = noexcept_false_spec; + } + /* Don't do the normal processing. */ + continue; + } + + bad = false; + if (CP_TYPE_CONST_P (mem_type) + && default_init_uninitialized_part (mem_type)) + { + if (diag) + { + error ("uninitialized const member in %q#T", + current_class_type); + inform (DECL_SOURCE_LOCATION (field), + "%q#D should be initialized", field); + } + bad = true; + } + else if (TREE_CODE (mem_type) == REFERENCE_TYPE) + { + if (diag) + { + error ("uninitialized reference member in %q#T", + current_class_type); + inform (DECL_SOURCE_LOCATION (field), + "%q#D should be initialized", field); + } + bad = true; + } + + if (bad && deleted_p) + *deleted_p = true; + + /* For an implicitly-defined default constructor to be constexpr, + every member must have a user-provided default constructor or + an explicit initializer. */ + if (constexpr_p && !CLASS_TYPE_P (mem_type) + && TREE_CODE (DECL_CONTEXT (field)) != UNION_TYPE) + { + *constexpr_p = false; + if (diag) + inform (DECL_SOURCE_LOCATION (field), + "defaulted default constructor does not " + "initialize %q#D", field); + } + } + else if (sfk == sfk_copy_constructor) + { + /* 12.8p11b5 */ + if (TREE_CODE (mem_type) == REFERENCE_TYPE + && TYPE_REF_IS_RVALUE (mem_type)) + { + if (diag) + error ("copying non-static data member %q#D of rvalue " + "reference type", field); + if (deleted_p) + *deleted_p = true; + } + } + + if (!CLASS_TYPE_P (mem_type)) + continue; + + if (ANON_AGGR_TYPE_P (mem_type)) + { + walk_field_subobs (TYPE_FIELDS (mem_type), fnname, sfk, quals, + copy_arg_p, move_p, assign_p, spec_p, trivial_p, + deleted_p, constexpr_p, + diag, flags, complain, dtor_from_ctor); + continue; + } + + if (copy_arg_p) + { + int mem_quals = cp_type_quals (mem_type) | quals; + if (DECL_MUTABLE_P (field)) + mem_quals &= ~TYPE_QUAL_CONST; + argtype = build_stub_type (mem_type, mem_quals, move_p); + } + else + argtype = NULL_TREE; + + rval = locate_fn_flags (mem_type, fnname, argtype, flags, complain); + + process_subob_fn (rval, spec_p, trivial_p, deleted_p, + constexpr_p, diag, field, dtor_from_ctor); + } +} + +/* Base walker helper for synthesized_method_walk. Inspect a direct + or virtual base. BINFO is the parent type's binfo. BASE_BINFO is + the base binfo of interests. All other parms are as for + synthesized_method_walk, or its local vars. */ + +static tree +synthesized_method_base_walk (tree binfo, tree base_binfo, + int quals, bool copy_arg_p, + bool move_p, bool ctor_p, + tree *inheriting_ctor, tree inherited_parms, + tree fnname, int flags, bool diag, + tree *spec_p, bool *trivial_p, + bool *deleted_p, bool *constexpr_p) +{ + bool inherited_binfo = false; + tree argtype = NULL_TREE; + deferring_kind defer = dk_no_deferred; + + if (copy_arg_p) + argtype = build_stub_type (BINFO_TYPE (base_binfo), quals, move_p); + else if (inheriting_ctor + && (inherited_binfo + = binfo_inherited_from (binfo, base_binfo, *inheriting_ctor))) + { + argtype = inherited_parms; + /* Don't check access on the inherited constructor. */ + if (flag_new_inheriting_ctors) + defer = dk_deferred; + } + /* To be conservative, ignore access to the base dtor that + DR1658 instructs us to ignore. See the comment in + synthesized_method_walk. */ + else if (cxx_dialect >= cxx14 && fnname == complete_dtor_identifier + && BINFO_VIRTUAL_P (base_binfo) + && ABSTRACT_CLASS_TYPE_P (BINFO_TYPE (binfo))) + defer = dk_no_check; + + if (defer != dk_no_deferred) + push_deferring_access_checks (defer); + tree rval = locate_fn_flags (base_binfo, fnname, argtype, flags, + diag ? tf_warning_or_error : tf_none); + if (defer != dk_no_deferred) + pop_deferring_access_checks (); + + /* Replace an inherited template with the appropriate specialization. */ + if (inherited_binfo && rval + && DECL_P (*inheriting_ctor) && DECL_P (rval) + && DECL_CONTEXT (*inheriting_ctor) == DECL_CONTEXT (rval)) + *inheriting_ctor = DECL_CLONED_FUNCTION (rval); + + process_subob_fn (rval, spec_p, trivial_p, deleted_p, + constexpr_p, diag, BINFO_TYPE (base_binfo)); + if (ctor_p && + (!BINFO_VIRTUAL_P (base_binfo) + || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (BINFO_TYPE (base_binfo)))) + { + /* In a constructor we also need to check the subobject + destructors for cleanup of partially constructed objects. */ + tree dtor = locate_fn_flags (base_binfo, complete_dtor_identifier, + NULL_TREE, flags, + diag ? tf_warning_or_error : tf_none); + /* Note that we don't pass down trivial_p; the subobject + destructors don't affect triviality of the constructor. Nor + do they affect constexpr-ness (a constant expression doesn't + throw) or exception-specification (a throw from one of the + dtors would be a double-fault). */ + process_subob_fn (dtor, NULL, NULL, deleted_p, NULL, false, + BINFO_TYPE (base_binfo), /*dtor_from_ctor*/true); + } + + return rval; +} + +/* The caller wants to generate an implicit declaration of SFK for + CTYPE which is const if relevant and CONST_P is set. If SPEC_P, + TRIVIAL_P, DELETED_P or CONSTEXPR_P are non-null, set their + referent appropriately. If DIAG is true, we're either being called + from maybe_explain_implicit_delete to give errors, or if + CONSTEXPR_P is non-null, from explain_invalid_constexpr_fn. */ + +static void +synthesized_method_walk (tree ctype, special_function_kind sfk, bool const_p, + tree *spec_p, bool *trivial_p, bool *deleted_p, + bool *constexpr_p, bool diag, + tree *inheriting_ctor, tree inherited_parms) +{ + tree binfo, base_binfo, fnname; + int i; + + if (spec_p) + *spec_p = (cxx_dialect >= cxx11 ? noexcept_true_spec : empty_except_spec); + + if (deleted_p) + { + /* "The closure type associated with a lambda-expression has a deleted + default constructor and a deleted copy assignment operator." + This is diagnosed in maybe_explain_implicit_delete. */ + if (LAMBDA_TYPE_P (ctype) + && (sfk == sfk_constructor + || sfk == sfk_copy_assignment)) + { + *deleted_p = true; + return; + } + + *deleted_p = false; + } + + bool ctor_p = false; + bool assign_p = false; + bool check_vdtor = false; + switch (sfk) + { + case sfk_move_assignment: + case sfk_copy_assignment: + assign_p = true; + fnname = cp_assignment_operator_id (NOP_EXPR); + break; + + case sfk_destructor: + check_vdtor = true; + /* The synthesized method will call base dtors, but check complete + here to avoid having to deal with VTT. */ + fnname = complete_dtor_identifier; + break; + + case sfk_constructor: + case sfk_move_constructor: + case sfk_copy_constructor: + case sfk_inheriting_constructor: + ctor_p = true; + fnname = complete_ctor_identifier; + break; + + default: + gcc_unreachable (); + } + + gcc_assert ((sfk == sfk_inheriting_constructor) + == (inheriting_ctor && *inheriting_ctor != NULL_TREE)); + + /* If that user-written default constructor would satisfy the + requirements of a constexpr constructor (7.1.5), the + implicitly-defined default constructor is constexpr. + + The implicitly-defined copy/move assignment operator is constexpr if + - X is a literal type, and + - the assignment operator selected to copy/move each direct base class + subobject is a constexpr function, and + - for each non-static data member of X that is of class type (or array + thereof), the assignment operator selected to copy/move that + member is a constexpr function. */ + if (constexpr_p) + *constexpr_p = ctor_p || (assign_p && cxx_dialect >= cxx14); + + bool move_p = false; + bool copy_arg_p = false; + switch (sfk) + { + case sfk_constructor: + case sfk_destructor: + case sfk_inheriting_constructor: + break; + + case sfk_move_constructor: + case sfk_move_assignment: + move_p = true; + /* FALLTHRU */ + case sfk_copy_constructor: + case sfk_copy_assignment: + copy_arg_p = true; + break; + + default: + gcc_unreachable (); + } + + bool expected_trivial = type_has_trivial_fn (ctype, sfk); + if (trivial_p) + *trivial_p = expected_trivial; + + /* The TYPE_HAS_COMPLEX_* flags tell us about constraints from base + class versions and other properties of the type. But a subobject + class can be trivially copyable and yet have overload resolution + choose a template constructor for initialization, depending on + rvalueness and cv-quals. And furthermore, a member in a base might + be trivial but deleted or otherwise not callable. So we can't exit + early in C++0x. The same considerations apply in C++98/03, but + there the definition of triviality does not consider overload + resolution, so a constructor can be trivial even if it would otherwise + call a non-trivial constructor. */ + if (expected_trivial + && (!copy_arg_p || cxx_dialect < cxx11)) + { + if (constexpr_p && sfk == sfk_constructor) + { + bool cx = trivial_default_constructor_is_constexpr (ctype); + *constexpr_p = cx; + if (diag && !cx && TREE_CODE (ctype) == UNION_TYPE) + /* A trivial constructor doesn't have any NSDMI. */ + inform (input_location, "defaulted default constructor does " + "not initialize any non-static data member"); + } + if (!diag && cxx_dialect < cxx11) + return; + } + + ++cp_unevaluated_operand; + ++c_inhibit_evaluation_warnings; + push_deferring_access_checks (dk_no_deferred); + + tree scope = push_scope (ctype); + + int flags = LOOKUP_NORMAL | LOOKUP_SPECULATIVE; + if (sfk != sfk_inheriting_constructor) + flags |= LOOKUP_DEFAULTED; + + tsubst_flags_t complain = diag ? tf_warning_or_error : tf_none; + if (diag && spec_p) + /* We're in get_defaulted_eh_spec; we don't actually want any walking + diagnostics, we just want complain set. */ + diag = false; + int quals = const_p ? TYPE_QUAL_CONST : TYPE_UNQUALIFIED; + + for (binfo = TYPE_BINFO (ctype), i = 0; + BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) + { + if (!assign_p && BINFO_VIRTUAL_P (base_binfo)) + /* We'll handle virtual bases below. */ + continue; + + tree fn = synthesized_method_base_walk (binfo, base_binfo, quals, + copy_arg_p, move_p, ctor_p, + inheriting_ctor, + inherited_parms, + fnname, flags, diag, + spec_p, trivial_p, + deleted_p, constexpr_p); + + if (diag && assign_p && move_p + && BINFO_VIRTUAL_P (base_binfo) + && fn && TREE_CODE (fn) == FUNCTION_DECL + && move_fn_p (fn) && !trivial_fn_p (fn) + && vbase_has_user_provided_move_assign (BINFO_TYPE (base_binfo))) + warning (OPT_Wvirtual_move_assign, + "defaulted move assignment for %qT calls a non-trivial " + "move assignment operator for virtual base %qT", + ctype, BINFO_TYPE (base_binfo)); + + if (check_vdtor && type_has_virtual_destructor (BINFO_TYPE (base_binfo))) + { + /* Unlike for base ctor/op=/dtor, for operator delete it's fine + to have a null fn (no class-specific op delete). */ + fn = locate_fn_flags (ctype, cp_operator_id (DELETE_EXPR), + ptr_type_node, flags, tf_none); + if (fn && fn == error_mark_node) + { + if (complain & tf_error) + locate_fn_flags (ctype, cp_operator_id (DELETE_EXPR), + ptr_type_node, flags, complain); + if (deleted_p) + *deleted_p = true; + } + check_vdtor = false; + } + } + + vec<tree, va_gc> *vbases = CLASSTYPE_VBASECLASSES (ctype); + if (assign_p) + /* Already examined vbases above. */; + else if (vec_safe_is_empty (vbases)) + /* No virtual bases to worry about. */; + else if (ABSTRACT_CLASS_TYPE_P (ctype) && cxx_dialect >= cxx14 + /* DR 1658 specifies that vbases of abstract classes are + ignored for both ctors and dtors. However, that breaks + virtual dtor overriding when the ignored base has a + throwing destructor. So, ignore that piece of 1658. A + defect has been filed (no number yet). */ + && sfk != sfk_destructor) + /* Vbase cdtors are not relevant. */; + else + { + if (constexpr_p) + *constexpr_p = false; + + FOR_EACH_VEC_ELT (*vbases, i, base_binfo) + synthesized_method_base_walk (binfo, base_binfo, quals, + copy_arg_p, move_p, ctor_p, + inheriting_ctor, inherited_parms, + fnname, flags, diag, + spec_p, trivial_p, + deleted_p, constexpr_p); + } + + /* Now handle the non-static data members. */ + walk_field_subobs (TYPE_FIELDS (ctype), fnname, sfk, quals, + copy_arg_p, move_p, assign_p, spec_p, trivial_p, + deleted_p, constexpr_p, + diag, flags, complain, /*dtor_from_ctor*/false); + if (ctor_p) + walk_field_subobs (TYPE_FIELDS (ctype), complete_dtor_identifier, + sfk_destructor, TYPE_UNQUALIFIED, false, + false, false, NULL, NULL, + deleted_p, NULL, + false, flags, complain, /*dtor_from_ctor*/true); + + pop_scope (scope); + + pop_deferring_access_checks (); + --cp_unevaluated_operand; + --c_inhibit_evaluation_warnings; +} + +/* DECL is a defaulted function whose exception specification is now + needed. Return what it should be. */ + +tree +get_defaulted_eh_spec (tree decl, tsubst_flags_t complain) +{ + if (DECL_CLONED_FUNCTION_P (decl)) + decl = DECL_CLONED_FUNCTION (decl); + special_function_kind sfk = special_function_p (decl); + tree ctype = DECL_CONTEXT (decl); + tree parms = FUNCTION_FIRST_USER_PARMTYPE (decl); + tree parm_type = TREE_VALUE (parms); + bool const_p = CP_TYPE_CONST_P (non_reference (parm_type)); + tree spec = empty_except_spec; + bool diag = !DECL_DELETED_FN (decl) && (complain & tf_error); + tree inh = DECL_INHERITED_CTOR (decl); + synthesized_method_walk (ctype, sfk, const_p, &spec, NULL, NULL, + NULL, diag, &inh, parms); + return spec; +} + +/* DECL is a deleted function. If it's implicitly deleted, explain why and + return true; else return false. */ + +bool +maybe_explain_implicit_delete (tree decl) +{ + /* If decl is a clone, get the primary variant. */ + decl = DECL_ORIGIN (decl); + gcc_assert (DECL_DELETED_FN (decl)); + if (DECL_DEFAULTED_FN (decl)) + { + /* Not marked GTY; it doesn't need to be GC'd or written to PCH. */ + static hash_set<tree> *explained; + + special_function_kind sfk; + location_t loc; + bool informed; + tree ctype; + + if (!explained) + explained = new hash_set<tree>; + if (explained->add (decl)) + return true; + + sfk = special_function_p (decl); + ctype = DECL_CONTEXT (decl); + loc = input_location; + input_location = DECL_SOURCE_LOCATION (decl); + + informed = false; + if (LAMBDA_TYPE_P (ctype)) + { + informed = true; + if (sfk == sfk_constructor) + inform (DECL_SOURCE_LOCATION (decl), + "a lambda closure type has a deleted default constructor"); + else if (sfk == sfk_copy_assignment) + inform (DECL_SOURCE_LOCATION (decl), + "a lambda closure type has a deleted copy assignment operator"); + else + informed = false; + } + else if (DECL_ARTIFICIAL (decl) + && (sfk == sfk_copy_assignment || sfk == sfk_copy_constructor) + && classtype_has_move_assign_or_move_ctor_p (ctype, true)) + { + inform (DECL_SOURCE_LOCATION (decl), + "%q#D is implicitly declared as deleted because %qT " + "declares a move constructor or move assignment operator", + decl, ctype); + informed = true; + } + else if (sfk == sfk_inheriting_constructor) + { + tree binfo = inherited_ctor_binfo (decl); + if (TREE_CODE (binfo) != TREE_BINFO) + { + inform (DECL_SOURCE_LOCATION (decl), + "%q#D inherits from multiple base subobjects", + decl); + informed = true; + } + } + if (!informed) + { + tree parms = FUNCTION_FIRST_USER_PARMTYPE (decl); + tree parm_type = TREE_VALUE (parms); + bool const_p = CP_TYPE_CONST_P (non_reference (parm_type)); + tree raises = NULL_TREE; + bool deleted_p = false; + tree scope = push_scope (ctype); + tree inh = DECL_INHERITED_CTOR (decl); + + synthesized_method_walk (ctype, sfk, const_p, + &raises, NULL, &deleted_p, NULL, false, + &inh, parms); + if (deleted_p) + { + inform (DECL_SOURCE_LOCATION (decl), + "%q#D is implicitly deleted because the default " + "definition would be ill-formed:", decl); + synthesized_method_walk (ctype, sfk, const_p, + NULL, NULL, NULL, NULL, true, + &inh, parms); + } + else if (!comp_except_specs + (TYPE_RAISES_EXCEPTIONS (TREE_TYPE (decl)), + raises, ce_normal)) + inform (DECL_SOURCE_LOCATION (decl), "%q#F is implicitly " + "deleted because its exception-specification does not " + "match the implicit exception-specification %qX", + decl, raises); + else if (flag_checking) + gcc_unreachable (); + + pop_scope (scope); + } + + input_location = loc; + return true; + } + return false; +} + +/* DECL is a defaulted function which was declared constexpr. Explain why + it can't be constexpr. */ + +void +explain_implicit_non_constexpr (tree decl) +{ + tree parm_type = TREE_VALUE (FUNCTION_FIRST_USER_PARMTYPE (decl)); + bool const_p = CP_TYPE_CONST_P (non_reference (parm_type)); + tree inh = DECL_INHERITED_CTOR (decl); + bool dummy; + synthesized_method_walk (DECL_CLASS_CONTEXT (decl), + special_function_p (decl), const_p, + NULL, NULL, NULL, &dummy, true, + &inh, + FUNCTION_FIRST_USER_PARMTYPE (decl)); +} + +/* DECL is an instantiation of an inheriting constructor template. Deduce + the correct exception-specification and deletedness for this particular + specialization. */ + +void +deduce_inheriting_ctor (tree decl) +{ + decl = DECL_ORIGIN (decl); + gcc_assert (DECL_INHERITED_CTOR (decl)); + tree spec; + bool trivial, constexpr_, deleted; + tree inh = DECL_INHERITED_CTOR (decl); + synthesized_method_walk (DECL_CONTEXT (decl), sfk_inheriting_constructor, + false, &spec, &trivial, &deleted, &constexpr_, + /*diag*/false, + &inh, + FUNCTION_FIRST_USER_PARMTYPE (decl)); + if (TREE_CODE (inherited_ctor_binfo (decl)) != TREE_BINFO) + /* Inherited the same constructor from different base subobjects. */ + deleted = true; + DECL_DELETED_FN (decl) = deleted; + TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl), spec); + SET_DECL_INHERITED_CTOR (decl, inh); + + tree clone; + FOR_EACH_CLONE (clone, decl) + { + DECL_DELETED_FN (clone) = deleted; + TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone), spec); + SET_DECL_INHERITED_CTOR (clone, inh); + } +} + +/* Implicitly declare the special function indicated by KIND, as a + member of TYPE. For copy constructors and assignment operators, + CONST_P indicates whether these functions should take a const + reference argument or a non-const reference. Returns the + FUNCTION_DECL for the implicitly declared function. */ + +tree +implicitly_declare_fn (special_function_kind kind, tree type, + bool const_p, tree inherited_ctor, + tree inherited_parms) +{ + tree fn; + tree parameter_types = void_list_node; + tree return_type; + tree fn_type; + tree raises = empty_except_spec; + tree rhs_parm_type = NULL_TREE; + tree this_parm; + tree name; + HOST_WIDE_INT saved_processing_template_decl; + bool deleted_p; + bool constexpr_p; + + /* Because we create declarations for implicitly declared functions + lazily, we may be creating the declaration for a member of TYPE + while in some completely different context. However, TYPE will + never be a dependent class (because we never want to do lookups + for implicitly defined functions in a dependent class). + Furthermore, we must set PROCESSING_TEMPLATE_DECL to zero here + because we only create clones for constructors and destructors + when not in a template. */ + gcc_assert (!dependent_type_p (type)); + saved_processing_template_decl = processing_template_decl; + processing_template_decl = 0; + + type = TYPE_MAIN_VARIANT (type); + + if (targetm.cxx.cdtor_returns_this ()) + { + if (kind == sfk_destructor) + /* See comment in check_special_function_return_type. */ + return_type = build_pointer_type (void_type_node); + else + return_type = build_pointer_type (type); + } + else + return_type = void_type_node; + + switch (kind) + { + case sfk_destructor: + /* Destructor. */ + name = dtor_identifier; + break; + + case sfk_constructor: + /* Default constructor. */ + name = ctor_identifier; + break; + + case sfk_copy_constructor: + case sfk_copy_assignment: + case sfk_move_constructor: + case sfk_move_assignment: + case sfk_inheriting_constructor: + { + if (kind == sfk_copy_assignment + || kind == sfk_move_assignment) + { + return_type = build_reference_type (type); + name = cp_assignment_operator_id (NOP_EXPR); + } + else + name = ctor_identifier; + + if (kind == sfk_inheriting_constructor) + parameter_types = inherited_parms; + else + { + if (const_p) + rhs_parm_type = cp_build_qualified_type (type, TYPE_QUAL_CONST); + else + rhs_parm_type = type; + bool move_p = (kind == sfk_move_assignment + || kind == sfk_move_constructor); + rhs_parm_type = cp_build_reference_type (rhs_parm_type, move_p); + + parameter_types = tree_cons (NULL_TREE, rhs_parm_type, parameter_types); + } + break; + } + default: + gcc_unreachable (); + } + + bool trivial_p = false; + + if (inherited_ctor) + { + /* For an inheriting constructor, just copy these flags from the + inherited constructor until deduce_inheriting_ctor. */ + raises = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (inherited_ctor)); + deleted_p = DECL_DELETED_FN (inherited_ctor); + constexpr_p = DECL_DECLARED_CONSTEXPR_P (inherited_ctor); + } + else if (cxx_dialect >= cxx11) + { + raises = noexcept_deferred_spec; + synthesized_method_walk (type, kind, const_p, NULL, &trivial_p, + &deleted_p, &constexpr_p, false, + &inherited_ctor, inherited_parms); + } + else + synthesized_method_walk (type, kind, const_p, &raises, &trivial_p, + &deleted_p, &constexpr_p, false, + &inherited_ctor, inherited_parms); + /* Don't bother marking a deleted constructor as constexpr. */ + if (deleted_p) + constexpr_p = false; + /* A trivial copy/move constructor is also a constexpr constructor, + unless the class has virtual bases (7.1.5p4). */ + else if (trivial_p && cxx_dialect >= cxx11 + && (kind == sfk_copy_constructor + || kind == sfk_move_constructor) + && !CLASSTYPE_VBASECLASSES (type)) + gcc_assert (constexpr_p); + + if (!trivial_p && type_has_trivial_fn (type, kind)) + type_set_nontrivial_flag (type, kind); + + /* Create the function. */ + fn_type = build_method_type_directly (type, return_type, parameter_types); + if (raises) + fn_type = build_exception_variant (fn_type, raises); + fn = build_lang_decl (FUNCTION_DECL, name, fn_type); + if (kind != sfk_inheriting_constructor) + DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (TYPE_NAME (type)); + + if (!IDENTIFIER_CDTOR_P (name)) + /* Assignment operator. */ + SET_OVERLOADED_OPERATOR_CODE (fn, NOP_EXPR); + else if (IDENTIFIER_CTOR_P (name)) + DECL_CXX_CONSTRUCTOR_P (fn) = true; + else + DECL_CXX_DESTRUCTOR_P (fn) = true; + + SET_DECL_ALIGN (fn, MINIMUM_METHOD_BOUNDARY); + + /* Create the explicit arguments. */ + if (rhs_parm_type) + { + /* Note that this parameter is *not* marked DECL_ARTIFICIAL; we + want its type to be included in the mangled function + name. */ + tree decl = cp_build_parm_decl (fn, NULL_TREE, rhs_parm_type); + TREE_READONLY (decl) = 1; + retrofit_lang_decl (decl); + DECL_PARM_INDEX (decl) = DECL_PARM_LEVEL (decl) = 1; + DECL_ARGUMENTS (fn) = decl; + } + else if (kind == sfk_inheriting_constructor) + { + tree *p = &DECL_ARGUMENTS (fn); + int index = 1; + for (tree parm = inherited_parms; parm && parm != void_list_node; + parm = TREE_CHAIN (parm)) + { + *p = cp_build_parm_decl (fn, NULL_TREE, TREE_VALUE (parm)); + retrofit_lang_decl (*p); + DECL_PARM_LEVEL (*p) = 1; + DECL_PARM_INDEX (*p) = index++; + p = &DECL_CHAIN (*p); + } + SET_DECL_INHERITED_CTOR (fn, inherited_ctor); + DECL_NONCONVERTING_P (fn) = DECL_NONCONVERTING_P (inherited_ctor); + /* A constructor so declared has the same access as the corresponding + constructor in X. */ + TREE_PRIVATE (fn) = TREE_PRIVATE (inherited_ctor); + TREE_PROTECTED (fn) = TREE_PROTECTED (inherited_ctor); + /* Copy constexpr from the inherited constructor even if the + inheriting constructor doesn't satisfy the requirements. */ + constexpr_p = DECL_DECLARED_CONSTEXPR_P (inherited_ctor); + } + /* Add the "this" parameter. */ + this_parm = build_this_parm (fn, fn_type, TYPE_UNQUALIFIED); + DECL_CHAIN (this_parm) = DECL_ARGUMENTS (fn); + DECL_ARGUMENTS (fn) = this_parm; + + grokclassfn (type, fn, kind == sfk_destructor ? DTOR_FLAG : NO_SPECIAL); + DECL_IN_AGGR_P (fn) = 1; + DECL_ARTIFICIAL (fn) = 1; + DECL_DEFAULTED_FN (fn) = 1; + if (cxx_dialect >= cxx11) + { + DECL_DELETED_FN (fn) = deleted_p; + DECL_DECLARED_CONSTEXPR_P (fn) = constexpr_p; + } + DECL_EXTERNAL (fn) = true; + DECL_NOT_REALLY_EXTERN (fn) = 1; + DECL_DECLARED_INLINE_P (fn) = 1; + set_linkage_according_to_type (type, fn); + if (TREE_PUBLIC (fn)) + DECL_COMDAT (fn) = 1; + rest_of_decl_compilation (fn, namespace_bindings_p (), at_eof); + gcc_assert (!TREE_USED (fn)); + + /* Propagate constraints from the inherited constructor. */ + if (flag_concepts && inherited_ctor) + if (tree orig_ci = get_constraints (inherited_ctor)) + { + tree new_ci = copy_node (orig_ci); + set_constraints (fn, new_ci); + } + + /* Restore PROCESSING_TEMPLATE_DECL. */ + processing_template_decl = saved_processing_template_decl; + + if (inherited_ctor && TREE_CODE (inherited_ctor) == TEMPLATE_DECL) + fn = add_inherited_template_parms (fn, inherited_ctor); + + /* Warn about calling a non-trivial move assignment in a virtual base. */ + if (kind == sfk_move_assignment && !deleted_p && !trivial_p + && CLASSTYPE_VBASECLASSES (type)) + { + location_t loc = input_location; + input_location = DECL_SOURCE_LOCATION (fn); + synthesized_method_walk (type, kind, const_p, + NULL, NULL, NULL, NULL, true, + NULL, NULL_TREE); + input_location = loc; + } + + return fn; +} + +/* Gives any errors about defaulted functions which need to be deferred + until the containing class is complete. */ + +void +defaulted_late_check (tree fn) +{ + /* Complain about invalid signature for defaulted fn. */ + tree ctx = DECL_CONTEXT (fn); + special_function_kind kind = special_function_p (fn); + bool fn_const_p = (copy_fn_p (fn) == 2); + tree implicit_fn = implicitly_declare_fn (kind, ctx, fn_const_p, + NULL, NULL); + tree eh_spec = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (implicit_fn)); + + if (!same_type_p (TREE_TYPE (TREE_TYPE (fn)), + TREE_TYPE (TREE_TYPE (implicit_fn))) + || !compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)), + TYPE_ARG_TYPES (TREE_TYPE (implicit_fn)))) + { + error ("defaulted declaration %q+D does not match the " + "expected signature", fn); + inform (DECL_SOURCE_LOCATION (fn), + "expected signature: %qD", implicit_fn); + return; + } + + if (DECL_DELETED_FN (implicit_fn)) + { + DECL_DELETED_FN (fn) = 1; + return; + } + + /* 8.4.2/2: An explicitly-defaulted function (...) may have an explicit + exception-specification only if it is compatible (15.4) with the + exception-specification on the implicit declaration. If a function + is explicitly defaulted on its first declaration, (...) it is + implicitly considered to have the same exception-specification as if + it had been implicitly declared. */ + maybe_instantiate_noexcept (fn); + tree fn_spec = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (fn)); + if (!fn_spec) + { + if (DECL_DEFAULTED_IN_CLASS_P (fn)) + TREE_TYPE (fn) = build_exception_variant (TREE_TYPE (fn), eh_spec); + } + else if (UNEVALUATED_NOEXCEPT_SPEC_P (fn_spec)) + /* Equivalent to the implicit spec. */; + else if (DECL_DEFAULTED_IN_CLASS_P (fn) + && !CLASSTYPE_TEMPLATE_INSTANTIATION (ctx)) + /* We can't compare an explicit exception-specification on a + constructor defaulted in the class body to the implicit + exception-specification until after we've parsed any NSDMI; see + after_nsdmi_defaulted_late_checks. */; + else + { + tree eh_spec = get_defaulted_eh_spec (fn); + if (!comp_except_specs (fn_spec, eh_spec, ce_normal)) + { + if (DECL_DEFAULTED_IN_CLASS_P (fn)) + DECL_DELETED_FN (fn) = true; + else + error ("function %q+D defaulted on its redeclaration " + "with an exception-specification that differs from " + "the implicit exception-specification %qX", fn, eh_spec); + } + } + + if (DECL_DEFAULTED_IN_CLASS_P (fn) + && DECL_DECLARED_CONSTEXPR_P (implicit_fn)) + { + /* Hmm...should we do this for out-of-class too? Should it be OK to + add constexpr later like inline, rather than requiring + declarations to match? */ + DECL_DECLARED_CONSTEXPR_P (fn) = true; + if (kind == sfk_constructor) + TYPE_HAS_CONSTEXPR_CTOR (ctx) = true; + } + + if (!DECL_DECLARED_CONSTEXPR_P (implicit_fn) + && DECL_DECLARED_CONSTEXPR_P (fn)) + { + if (!CLASSTYPE_TEMPLATE_INSTANTIATION (ctx)) + { + error ("explicitly defaulted function %q+D cannot be declared " + "as constexpr because the implicit declaration is not " + "constexpr:", fn); + explain_implicit_non_constexpr (fn); + } + DECL_DECLARED_CONSTEXPR_P (fn) = false; + } +} + +/* OK, we've parsed the NSDMI for class T, now we can check any explicit + exception-specifications on functions defaulted in the class body. */ + +void +after_nsdmi_defaulted_late_checks (tree t) +{ + if (uses_template_parms (t)) + return; + if (t == error_mark_node) + return; + for (tree fn = TYPE_FIELDS (t); fn; fn = DECL_CHAIN (fn)) + if (!DECL_ARTIFICIAL (fn) + && DECL_DECLARES_FUNCTION_P (fn) + && DECL_DEFAULTED_IN_CLASS_P (fn)) + { + tree fn_spec = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (fn)); + if (UNEVALUATED_NOEXCEPT_SPEC_P (fn_spec)) + continue; + + tree eh_spec = get_defaulted_eh_spec (fn); + if (!comp_except_specs (TYPE_RAISES_EXCEPTIONS (TREE_TYPE (fn)), + eh_spec, ce_normal)) + DECL_DELETED_FN (fn) = true; + } +} + +/* Returns true iff FN can be explicitly defaulted, and gives any + errors if defaulting FN is ill-formed. */ + +bool +defaultable_fn_check (tree fn) +{ + special_function_kind kind = sfk_none; + + if (template_parm_scope_p ()) + { + error ("a template cannot be defaulted"); + return false; + } + + if (DECL_CONSTRUCTOR_P (fn)) + { + if (FUNCTION_FIRST_USER_PARMTYPE (fn) == void_list_node) + kind = sfk_constructor; + else if (copy_fn_p (fn) > 0 + && (TREE_CHAIN (FUNCTION_FIRST_USER_PARMTYPE (fn)) + == void_list_node)) + kind = sfk_copy_constructor; + else if (move_fn_p (fn)) + kind = sfk_move_constructor; + } + else if (DECL_DESTRUCTOR_P (fn)) + kind = sfk_destructor; + else if (DECL_ASSIGNMENT_OPERATOR_P (fn) + && DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR) + { + if (copy_fn_p (fn)) + kind = sfk_copy_assignment; + else if (move_fn_p (fn)) + kind = sfk_move_assignment; + } + + if (kind == sfk_none) + { + error ("%qD cannot be defaulted", fn); + return false; + } + else + { + for (tree t = FUNCTION_FIRST_USER_PARMTYPE (fn); + t && t != void_list_node; t = TREE_CHAIN (t)) + if (TREE_PURPOSE (t)) + { + error ("defaulted function %q+D with default argument", fn); + break; + } + + /* Avoid do_warn_unused_parameter warnings. */ + for (tree p = FUNCTION_FIRST_USER_PARM (fn); p; p = DECL_CHAIN (p)) + if (DECL_NAME (p)) + TREE_NO_WARNING (p) = 1; + + if (TYPE_BEING_DEFINED (DECL_CONTEXT (fn))) + /* Defer checking. */; + else if (!processing_template_decl) + defaulted_late_check (fn); + + return true; + } +} + +/* Add an implicit declaration to TYPE for the kind of function + indicated by SFK. Return the FUNCTION_DECL for the new implicit + declaration. */ + +tree +lazily_declare_fn (special_function_kind sfk, tree type) +{ + tree fn; + /* Whether or not the argument has a const reference type. */ + bool const_p = false; + + type = TYPE_MAIN_VARIANT (type); + + switch (sfk) + { + case sfk_constructor: + CLASSTYPE_LAZY_DEFAULT_CTOR (type) = 0; + break; + case sfk_copy_constructor: + const_p = TYPE_HAS_CONST_COPY_CTOR (type); + CLASSTYPE_LAZY_COPY_CTOR (type) = 0; + break; + case sfk_move_constructor: + CLASSTYPE_LAZY_MOVE_CTOR (type) = 0; + break; + case sfk_copy_assignment: + const_p = TYPE_HAS_CONST_COPY_ASSIGN (type); + CLASSTYPE_LAZY_COPY_ASSIGN (type) = 0; + break; + case sfk_move_assignment: + CLASSTYPE_LAZY_MOVE_ASSIGN (type) = 0; + break; + case sfk_destructor: + CLASSTYPE_LAZY_DESTRUCTOR (type) = 0; + break; + default: + gcc_unreachable (); + } + + /* Declare the function. */ + fn = implicitly_declare_fn (sfk, type, const_p, NULL, NULL); + + /* [class.copy]/8 If the class definition declares a move constructor or + move assignment operator, the implicitly declared copy constructor is + defined as deleted.... */ + if ((sfk == sfk_copy_assignment || sfk == sfk_copy_constructor) + && classtype_has_move_assign_or_move_ctor_p (type, true)) + DECL_DELETED_FN (fn) = true; + + /* Destructors and assignment operators may be virtual. */ + if (sfk == sfk_destructor + || sfk == sfk_move_assignment + || sfk == sfk_copy_assignment) + check_for_override (fn, type); + + /* Add it to the class */ + bool added = add_method (type, fn, false); + gcc_assert (added); + + /* Add it to TYPE_FIELDS. */ + if (sfk == sfk_destructor + && DECL_VIRTUAL_P (fn)) + /* The ABI requires that a virtual destructor go at the end of the + vtable. */ + TYPE_FIELDS (type) = chainon (TYPE_FIELDS (type), fn); + else + { + DECL_CHAIN (fn) = TYPE_FIELDS (type); + TYPE_FIELDS (type) = fn; + } + /* Propagate TYPE_FIELDS. */ + fixup_type_variants (type); + + maybe_add_class_template_decl_list (type, fn, /*friend_p=*/0); + if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn) + || DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn)) + /* Create appropriate clones. */ + clone_function_decl (fn, /*update_methods=*/true); + + return fn; +} + +/* Given a FUNCTION_DECL FN and a chain LIST, skip as many elements of LIST + as there are artificial parms in FN. */ + +tree +skip_artificial_parms_for (const_tree fn, tree list) +{ + if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)) + list = TREE_CHAIN (list); + else + return list; + + if (DECL_HAS_IN_CHARGE_PARM_P (fn)) + list = TREE_CHAIN (list); + if (DECL_HAS_VTT_PARM_P (fn)) + list = TREE_CHAIN (list); + return list; +} + +/* Given a FUNCTION_DECL FN and a chain LIST, return the number of + artificial parms in FN. */ + +int +num_artificial_parms_for (const_tree fn) +{ + int count = 0; + + if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)) + count++; + else + return 0; + + if (DECL_HAS_IN_CHARGE_PARM_P (fn)) + count++; + if (DECL_HAS_VTT_PARM_P (fn)) + count++; + return count; +} + + +#include "gt-cp-method.h"