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/* Functions related to building classes and their related objects. Copyright (C) 1987, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009 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/>. */ /* High-level class interface. */ #include "config.h" #include "system.h" #include "coretypes.h" #include "tm.h" #include "tree.h" #include "cp-tree.h" #include "flags.h" #include "rtl.h" #include "output.h" #include "toplev.h" #include "target.h" #include "convert.h" #include "cgraph.h" #include "tree-dump.h" /* The number of nested classes being processed. If we are not in the scope of any class, this is zero. */ int current_class_depth; /* In order to deal with nested classes, we keep a stack of classes. The topmost entry is the innermost class, and is the entry at index CURRENT_CLASS_DEPTH */ typedef struct class_stack_node { /* The name of the class. */ tree name; /* The _TYPE node for the class. */ tree type; /* The access specifier pending for new declarations in the scope of this class. */ tree access; /* If were defining TYPE, the names used in this class. */ splay_tree names_used; /* Nonzero if this class is no longer open, because of a call to push_to_top_level. */ size_t hidden; }* class_stack_node_t; typedef struct vtbl_init_data_s { /* The base for which we're building initializers. */ tree binfo; /* The type of the most-derived type. */ tree derived; /* The binfo for the dynamic type. This will be TYPE_BINFO (derived), unless ctor_vtbl_p is true. */ tree rtti_binfo; /* The negative-index vtable initializers built up so far. These are in order from least negative index to most negative index. */ tree inits; /* The last (i.e., most negative) entry in INITS. */ tree* last_init; /* The binfo for the virtual base for which we're building vcall offset initializers. */ tree vbase; /* The functions in vbase for which we have already provided vcall offsets. */ VEC(tree,gc) *fns; /* The vtable index of the next vcall or vbase offset. */ tree index; /* Nonzero if we are building the initializer for the primary vtable. */ int primary_vtbl_p; /* Nonzero if we are building the initializer for a construction vtable. */ int ctor_vtbl_p; /* True when adding vcall offset entries to the vtable. False when merely computing the indices. */ bool generate_vcall_entries; } vtbl_init_data; /* The type of a function passed to walk_subobject_offsets. */ typedef int (*subobject_offset_fn) (tree, tree, splay_tree); /* The stack itself. This is a dynamically resized array. The number of elements allocated is CURRENT_CLASS_STACK_SIZE. */ static int current_class_stack_size; static class_stack_node_t current_class_stack; /* The size of the largest empty class seen in this translation unit. */ static GTY (()) tree sizeof_biggest_empty_class; /* An array of all local classes present in this translation unit, in declaration order. */ VEC(tree,gc) *local_classes; static tree get_vfield_name (tree); static void finish_struct_anon (tree); static tree get_vtable_name (tree); static tree get_basefndecls (tree, tree); static int build_primary_vtable (tree, tree); static int build_secondary_vtable (tree); static void finish_vtbls (tree); static void modify_vtable_entry (tree, tree, tree, tree, tree *); static void finish_struct_bits (tree); static int alter_access (tree, tree, tree); static void handle_using_decl (tree, tree); static tree dfs_modify_vtables (tree, void *); static tree modify_all_vtables (tree, tree); static void determine_primary_bases (tree); static void finish_struct_methods (tree); static void maybe_warn_about_overly_private_class (tree); static int method_name_cmp (const void *, const void *); static int resort_method_name_cmp (const void *, const void *); static void add_implicitly_declared_members (tree, int, int); static tree fixed_type_or_null (tree, int *, int *); static tree build_simple_base_path (tree expr, tree binfo); static tree build_vtbl_ref_1 (tree, tree); static tree build_vtbl_initializer (tree, tree, tree, tree, int *); static int count_fields (tree); static int add_fields_to_record_type (tree, struct sorted_fields_type*, int); static bool check_bitfield_decl (tree); static void check_field_decl (tree, tree, int *, int *, int *); static void check_field_decls (tree, tree *, int *, int *); static tree *build_base_field (record_layout_info, tree, splay_tree, tree *); static void build_base_fields (record_layout_info, splay_tree, tree *); static void check_methods (tree); static void remove_zero_width_bit_fields (tree); static void check_bases (tree, int *, int *); static void check_bases_and_members (tree); static tree create_vtable_ptr (tree, tree *); static void include_empty_classes (record_layout_info); static void layout_class_type (tree, tree *); static void propagate_binfo_offsets (tree, tree); static void layout_virtual_bases (record_layout_info, splay_tree); static void build_vbase_offset_vtbl_entries (tree, vtbl_init_data *); static void add_vcall_offset_vtbl_entries_r (tree, vtbl_init_data *); static void add_vcall_offset_vtbl_entries_1 (tree, vtbl_init_data *); static void build_vcall_offset_vtbl_entries (tree, vtbl_init_data *); static void add_vcall_offset (tree, tree, vtbl_init_data *); static void layout_vtable_decl (tree, int); static tree dfs_find_final_overrider_pre (tree, void *); static tree dfs_find_final_overrider_post (tree, void *); static tree find_final_overrider (tree, tree, tree); static int make_new_vtable (tree, tree); static tree get_primary_binfo (tree); static int maybe_indent_hierarchy (FILE *, int, int); static tree dump_class_hierarchy_r (FILE *, int, tree, tree, int); static void dump_class_hierarchy (tree); static void dump_class_hierarchy_1 (FILE *, int, tree); static void dump_array (FILE *, tree); static void dump_vtable (tree, tree, tree); static void dump_vtt (tree, tree); static void dump_thunk (FILE *, int, tree); static tree build_vtable (tree, tree, tree); static void initialize_vtable (tree, tree); static void layout_nonempty_base_or_field (record_layout_info, tree, tree, splay_tree); static tree end_of_class (tree, int); static bool layout_empty_base (record_layout_info, tree, tree, splay_tree); static void accumulate_vtbl_inits (tree, tree, tree, tree, tree); static tree dfs_accumulate_vtbl_inits (tree, tree, tree, tree, tree); static void build_rtti_vtbl_entries (tree, vtbl_init_data *); static void build_vcall_and_vbase_vtbl_entries (tree, vtbl_init_data *); static void clone_constructors_and_destructors (tree); static tree build_clone (tree, tree); static void update_vtable_entry_for_fn (tree, tree, tree, tree *, unsigned); static void build_ctor_vtbl_group (tree, tree); static void build_vtt (tree); static tree binfo_ctor_vtable (tree); static tree *build_vtt_inits (tree, tree, tree *, tree *); static tree dfs_build_secondary_vptr_vtt_inits (tree, void *); static tree dfs_fixup_binfo_vtbls (tree, void *); static int record_subobject_offset (tree, tree, splay_tree); static int check_subobject_offset (tree, tree, splay_tree); static int walk_subobject_offsets (tree, subobject_offset_fn, tree, splay_tree, tree, int); static void record_subobject_offsets (tree, tree, splay_tree, bool); static int layout_conflict_p (tree, tree, splay_tree, int); static int splay_tree_compare_integer_csts (splay_tree_key k1, splay_tree_key k2); static void warn_about_ambiguous_bases (tree); static bool type_requires_array_cookie (tree); static bool contains_empty_class_p (tree); static bool base_derived_from (tree, tree); static int empty_base_at_nonzero_offset_p (tree, tree, splay_tree); static tree end_of_base (tree); static tree get_vcall_index (tree, tree); /* Variables shared between class.c and call.c. */ #ifdef GATHER_STATISTICS int n_vtables = 0; int n_vtable_entries = 0; int n_vtable_searches = 0; int n_vtable_elems = 0; int n_convert_harshness = 0; int n_compute_conversion_costs = 0; int n_inner_fields_searched = 0; #endif /* Convert to or from a base subobject. EXPR is an expression of type `A' or `A*', an expression of type `B' or `B*' is returned. To convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for the B base instance within A. To convert base A to derived B, CODE is MINUS_EXPR and BINFO is the binfo for the A instance within B. In this latter case, A must not be a morally virtual base of B. NONNULL is true if EXPR is known to be non-NULL (this is only needed when EXPR is of pointer type). CV qualifiers are preserved from EXPR. */ tree build_base_path (enum tree_code code, tree expr, tree binfo, int nonnull) { tree v_binfo = NULL_TREE; tree d_binfo = NULL_TREE; tree probe; tree offset; tree target_type; tree null_test = NULL; tree ptr_target_type; int fixed_type_p; int want_pointer = TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE; bool has_empty = false; bool virtual_access; if (expr == error_mark_node || binfo == error_mark_node || !binfo) return error_mark_node; for (probe = binfo; probe; probe = BINFO_INHERITANCE_CHAIN (probe)) { d_binfo = probe; if (is_empty_class (BINFO_TYPE (probe))) has_empty = true; if (!v_binfo && BINFO_VIRTUAL_P (probe)) v_binfo = probe; } probe = TYPE_MAIN_VARIANT (TREE_TYPE (expr)); if (want_pointer) probe = TYPE_MAIN_VARIANT (TREE_TYPE (probe)); gcc_assert ((code == MINUS_EXPR && SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), probe)) || (code == PLUS_EXPR && SAME_BINFO_TYPE_P (BINFO_TYPE (d_binfo), probe))); if (binfo == d_binfo) /* Nothing to do. */ return expr; if (code == MINUS_EXPR && v_binfo) { error ("cannot convert from base %qT to derived type %qT via virtual base %qT", BINFO_TYPE (binfo), BINFO_TYPE (d_binfo), BINFO_TYPE (v_binfo)); return error_mark_node; } if (!want_pointer) /* This must happen before the call to save_expr. */ expr = cp_build_unary_op (ADDR_EXPR, expr, 0, tf_warning_or_error); offset = BINFO_OFFSET (binfo); fixed_type_p = resolves_to_fixed_type_p (expr, &nonnull); target_type = code == PLUS_EXPR ? BINFO_TYPE (binfo) : BINFO_TYPE (d_binfo); /* Do we need to look in the vtable for the real offset? */ virtual_access = (v_binfo && fixed_type_p <= 0); /* Don't bother with the calculations inside sizeof; they'll ICE if the source type is incomplete and the pointer value doesn't matter. */ if (cp_unevaluated_operand != 0) { expr = build_nop (build_pointer_type (target_type), expr); if (!want_pointer) expr = build_indirect_ref (EXPR_LOCATION (expr), expr, RO_NULL); return expr; } /* Do we need to check for a null pointer? */ if (want_pointer && !nonnull) { /* If we know the conversion will not actually change the value of EXPR, then we can avoid testing the expression for NULL. We have to avoid generating a COMPONENT_REF for a base class field, because other parts of the compiler know that such expressions are always non-NULL. */ if (!virtual_access && integer_zerop (offset)) { tree class_type; /* TARGET_TYPE has been extracted from BINFO, and, is therefore always cv-unqualified. Extract the cv-qualifiers from EXPR so that the expression returned matches the input. */ class_type = TREE_TYPE (TREE_TYPE (expr)); target_type = cp_build_qualified_type (target_type, cp_type_quals (class_type)); return build_nop (build_pointer_type (target_type), expr); } null_test = error_mark_node; } /* Protect against multiple evaluation if necessary. */ if (TREE_SIDE_EFFECTS (expr) && (null_test || virtual_access)) expr = save_expr (expr); /* Now that we've saved expr, build the real null test. */ if (null_test) { tree zero = cp_convert (TREE_TYPE (expr), integer_zero_node); null_test = fold_build2_loc (input_location, NE_EXPR, boolean_type_node, expr, zero); } /* If this is a simple base reference, express it as a COMPONENT_REF. */ if (code == PLUS_EXPR && !virtual_access /* We don't build base fields for empty bases, and they aren't very interesting to the optimizers anyway. */ && !has_empty) { expr = cp_build_indirect_ref (expr, RO_NULL, tf_warning_or_error); expr = build_simple_base_path (expr, binfo); if (want_pointer) expr = build_address (expr); target_type = TREE_TYPE (expr); goto out; } if (virtual_access) { /* Going via virtual base V_BINFO. We need the static offset from V_BINFO to BINFO, and the dynamic offset from D_BINFO to V_BINFO. That offset is an entry in D_BINFO's vtable. */ tree v_offset; if (fixed_type_p < 0 && in_base_initializer) { /* In a base member initializer, we cannot rely on the vtable being set up. We have to indirect via the vtt_parm. */ tree t; t = TREE_TYPE (TYPE_VFIELD (current_class_type)); t = build_pointer_type (t); v_offset = convert (t, current_vtt_parm); v_offset = cp_build_indirect_ref (v_offset, RO_NULL, tf_warning_or_error); } else v_offset = build_vfield_ref (cp_build_indirect_ref (expr, RO_NULL, tf_warning_or_error), TREE_TYPE (TREE_TYPE (expr))); v_offset = build2 (POINTER_PLUS_EXPR, TREE_TYPE (v_offset), v_offset, fold_convert (sizetype, BINFO_VPTR_FIELD (v_binfo))); v_offset = build1 (NOP_EXPR, build_pointer_type (ptrdiff_type_node), v_offset); v_offset = cp_build_indirect_ref (v_offset, RO_NULL, tf_warning_or_error); TREE_CONSTANT (v_offset) = 1; offset = convert_to_integer (ptrdiff_type_node, size_diffop_loc (input_location, offset, BINFO_OFFSET (v_binfo))); if (!integer_zerop (offset)) v_offset = build2 (code, ptrdiff_type_node, v_offset, offset); if (fixed_type_p < 0) /* Negative fixed_type_p means this is a constructor or destructor; virtual base layout is fixed in in-charge [cd]tors, but not in base [cd]tors. */ offset = build3 (COND_EXPR, ptrdiff_type_node, build2 (EQ_EXPR, boolean_type_node, current_in_charge_parm, integer_zero_node), v_offset, convert_to_integer (ptrdiff_type_node, BINFO_OFFSET (binfo))); else offset = v_offset; } target_type = cp_build_qualified_type (target_type, cp_type_quals (TREE_TYPE (TREE_TYPE (expr)))); ptr_target_type = build_pointer_type (target_type); if (want_pointer) target_type = ptr_target_type; expr = build1 (NOP_EXPR, ptr_target_type, expr); if (!integer_zerop (offset)) { offset = fold_convert (sizetype, offset); if (code == MINUS_EXPR) offset = fold_build1_loc (input_location, NEGATE_EXPR, sizetype, offset); expr = build2 (POINTER_PLUS_EXPR, ptr_target_type, expr, offset); } else null_test = NULL; if (!want_pointer) expr = cp_build_indirect_ref (expr, RO_NULL, tf_warning_or_error); out: if (null_test) expr = fold_build3_loc (input_location, COND_EXPR, target_type, null_test, expr, fold_build1_loc (input_location, NOP_EXPR, target_type, integer_zero_node)); return expr; } /* Subroutine of build_base_path; EXPR and BINFO are as in that function. Perform a derived-to-base conversion by recursively building up a sequence of COMPONENT_REFs to the appropriate base fields. */ static tree build_simple_base_path (tree expr, tree binfo) { tree type = BINFO_TYPE (binfo); tree d_binfo = BINFO_INHERITANCE_CHAIN (binfo); tree field; if (d_binfo == NULL_TREE) { tree temp; gcc_assert (TYPE_MAIN_VARIANT (TREE_TYPE (expr)) == type); /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue in the front end; only _DECLs and _REFs are lvalues in the back end. */ temp = unary_complex_lvalue (ADDR_EXPR, expr); if (temp) expr = cp_build_indirect_ref (temp, RO_NULL, tf_warning_or_error); return expr; } /* Recurse. */ expr = build_simple_base_path (expr, d_binfo); for (field = TYPE_FIELDS (BINFO_TYPE (d_binfo)); field; field = TREE_CHAIN (field)) /* Is this the base field created by build_base_field? */ if (TREE_CODE (field) == FIELD_DECL && DECL_FIELD_IS_BASE (field) && TREE_TYPE (field) == type) { /* We don't use build_class_member_access_expr here, as that has unnecessary checks, and more importantly results in recursive calls to dfs_walk_once. */ int type_quals = cp_type_quals (TREE_TYPE (expr)); expr = build3 (COMPONENT_REF, cp_build_qualified_type (type, type_quals), expr, field, NULL_TREE); expr = fold_if_not_in_template (expr); /* Mark the expression const or volatile, as appropriate. Even though we've dealt with the type above, we still have to mark the expression itself. */ if (type_quals & TYPE_QUAL_CONST) TREE_READONLY (expr) = 1; if (type_quals & TYPE_QUAL_VOLATILE) TREE_THIS_VOLATILE (expr) = 1; return expr; } /* Didn't find the base field?!? */ gcc_unreachable (); } /* Convert OBJECT to the base TYPE. OBJECT is an expression whose type is a class type or a pointer to a class type. In the former case, TYPE is also a class type; in the latter it is another pointer type. If CHECK_ACCESS is true, an error message is emitted if TYPE is inaccessible. If OBJECT has pointer type, the value is assumed to be non-NULL. */ tree convert_to_base (tree object, tree type, bool check_access, bool nonnull) { tree binfo; tree object_type; if (TYPE_PTR_P (TREE_TYPE (object))) { object_type = TREE_TYPE (TREE_TYPE (object)); type = TREE_TYPE (type); } else object_type = TREE_TYPE (object); binfo = lookup_base (object_type, type, check_access ? ba_check : ba_unique, NULL); if (!binfo || binfo == error_mark_node) return error_mark_node; return build_base_path (PLUS_EXPR, object, binfo, nonnull); } /* EXPR is an expression with unqualified class type. BASE is a base binfo of that class type. Returns EXPR, converted to the BASE type. This function assumes that EXPR is the most derived class; therefore virtual bases can be found at their static offsets. */ tree convert_to_base_statically (tree expr, tree base) { tree expr_type; expr_type = TREE_TYPE (expr); if (!SAME_BINFO_TYPE_P (BINFO_TYPE (base), expr_type)) { tree pointer_type; pointer_type = build_pointer_type (expr_type); /* We use fold_build2 and fold_convert below to simplify the trees provided to the optimizers. It is not safe to call these functions when processing a template because they do not handle C++-specific trees. */ gcc_assert (!processing_template_decl); expr = cp_build_unary_op (ADDR_EXPR, expr, /*noconvert=*/1, tf_warning_or_error); if (!integer_zerop (BINFO_OFFSET (base))) expr = fold_build2_loc (input_location, POINTER_PLUS_EXPR, pointer_type, expr, fold_convert (sizetype, BINFO_OFFSET (base))); expr = fold_convert (build_pointer_type (BINFO_TYPE (base)), expr); expr = build_fold_indirect_ref_loc (input_location, expr); } return expr; } tree build_vfield_ref (tree datum, tree type) { tree vfield, vcontext; if (datum == error_mark_node) return error_mark_node; /* First, convert to the requested type. */ if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (datum), type)) datum = convert_to_base (datum, type, /*check_access=*/false, /*nonnull=*/true); /* Second, the requested type may not be the owner of its own vptr. If not, convert to the base class that owns it. We cannot use convert_to_base here, because VCONTEXT may appear more than once in the inheritance hierarchy of TYPE, and thus direct conversion between the types may be ambiguous. Following the path back up one step at a time via primary bases avoids the problem. */ vfield = TYPE_VFIELD (type); vcontext = DECL_CONTEXT (vfield); while (!same_type_ignoring_top_level_qualifiers_p (vcontext, type)) { datum = build_simple_base_path (datum, CLASSTYPE_PRIMARY_BINFO (type)); type = TREE_TYPE (datum); } return build3 (COMPONENT_REF, TREE_TYPE (vfield), datum, vfield, NULL_TREE); } /* Given an object INSTANCE, return an expression which yields the vtable element corresponding to INDEX. There are many special cases for INSTANCE which we take care of here, mainly to avoid creating extra tree nodes when we don't have to. */ static tree build_vtbl_ref_1 (tree instance, tree idx) { tree aref; tree vtbl = NULL_TREE; /* Try to figure out what a reference refers to, and access its virtual function table directly. */ int cdtorp = 0; tree fixed_type = fixed_type_or_null (instance, NULL, &cdtorp); tree basetype = non_reference (TREE_TYPE (instance)); if (fixed_type && !cdtorp) { tree binfo = lookup_base (fixed_type, basetype, ba_unique | ba_quiet, NULL); if (binfo) vtbl = unshare_expr (BINFO_VTABLE (binfo)); } if (!vtbl) vtbl = build_vfield_ref (instance, basetype); aref = build_array_ref (input_location, vtbl, idx); TREE_CONSTANT (aref) |= TREE_CONSTANT (vtbl) && TREE_CONSTANT (idx); return aref; } tree build_vtbl_ref (tree instance, tree idx) { tree aref = build_vtbl_ref_1 (instance, idx); return aref; } /* Given a stable object pointer INSTANCE_PTR, return an expression which yields a function pointer corresponding to vtable element INDEX. */ tree build_vfn_ref (tree instance_ptr, tree idx) { tree aref; aref = build_vtbl_ref_1 (cp_build_indirect_ref (instance_ptr, RO_NULL, tf_warning_or_error), idx); /* When using function descriptors, the address of the vtable entry is treated as a function pointer. */ if (TARGET_VTABLE_USES_DESCRIPTORS) aref = build1 (NOP_EXPR, TREE_TYPE (aref), cp_build_unary_op (ADDR_EXPR, aref, /*noconvert=*/1, tf_warning_or_error)); /* Remember this as a method reference, for later devirtualization. */ aref = build3 (OBJ_TYPE_REF, TREE_TYPE (aref), aref, instance_ptr, idx); return aref; } /* Return the name of the virtual function table (as an IDENTIFIER_NODE) for the given TYPE. */ static tree get_vtable_name (tree type) { return mangle_vtbl_for_type (type); } /* DECL is an entity associated with TYPE, like a virtual table or an implicitly generated constructor. Determine whether or not DECL should have external or internal linkage at the object file level. This routine does not deal with COMDAT linkage and other similar complexities; it simply sets TREE_PUBLIC if it possible for entities in other translation units to contain copies of DECL, in the abstract. */ void set_linkage_according_to_type (tree type, tree decl) { /* If TYPE involves a local class in a function with internal linkage, then DECL should have internal linkage too. Other local classes have no linkage -- but if their containing functions have external linkage, it makes sense for DECL to have external linkage too. That will allow template definitions to be merged, for example. */ if (no_linkage_check (type, /*relaxed_p=*/true)) { TREE_PUBLIC (decl) = 0; DECL_INTERFACE_KNOWN (decl) = 1; } else TREE_PUBLIC (decl) = 1; } /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE. (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.) Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */ static tree build_vtable (tree class_type, tree name, tree vtable_type) { tree decl; decl = build_lang_decl (VAR_DECL, name, vtable_type); /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME now to avoid confusion in mangle_decl. */ SET_DECL_ASSEMBLER_NAME (decl, name); DECL_CONTEXT (decl) = class_type; DECL_ARTIFICIAL (decl) = 1; TREE_STATIC (decl) = 1; TREE_READONLY (decl) = 1; DECL_VIRTUAL_P (decl) = 1; DECL_ALIGN (decl) = TARGET_VTABLE_ENTRY_ALIGN; DECL_VTABLE_OR_VTT_P (decl) = 1; /* At one time the vtable info was grabbed 2 words at a time. This fails on sparc unless you have 8-byte alignment. (tiemann) */ DECL_ALIGN (decl) = MAX (TYPE_ALIGN (double_type_node), DECL_ALIGN (decl)); set_linkage_according_to_type (class_type, decl); /* The vtable has not been defined -- yet. */ DECL_EXTERNAL (decl) = 1; DECL_NOT_REALLY_EXTERN (decl) = 1; /* Mark the VAR_DECL node representing the vtable itself as a "gratuitous" one, thereby forcing dwarfout.c to ignore it. It is rather important that such things be ignored because any effort to actually generate DWARF for them will run into trouble when/if we encounter code like: #pragma interface struct S { virtual void member (); }; because the artificial declaration of the vtable itself (as manufactured by the g++ front end) will say that the vtable is a static member of `S' but only *after* the debug output for the definition of `S' has already been output. This causes grief because the DWARF entry for the definition of the vtable will try to refer back to an earlier *declaration* of the vtable as a static member of `S' and there won't be one. We might be able to arrange to have the "vtable static member" attached to the member list for `S' before the debug info for `S' get written (which would solve the problem) but that would require more intrusive changes to the g++ front end. */ DECL_IGNORED_P (decl) = 1; return decl; } /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic, or even complete. If this does not exist, create it. If COMPLETE is nonzero, then complete the definition of it -- that will render it impossible to actually build the vtable, but is useful to get at those which are known to exist in the runtime. */ tree get_vtable_decl (tree type, int complete) { tree decl; if (CLASSTYPE_VTABLES (type)) return CLASSTYPE_VTABLES (type); decl = build_vtable (type, get_vtable_name (type), vtbl_type_node); CLASSTYPE_VTABLES (type) = decl; if (complete) { DECL_EXTERNAL (decl) = 1; cp_finish_decl (decl, NULL_TREE, false, NULL_TREE, 0); } return decl; } /* Build the primary virtual function table for TYPE. If BINFO is non-NULL, build the vtable starting with the initial approximation that it is the same as the one which is the head of the association list. Returns a nonzero value if a new vtable is actually created. */ static int build_primary_vtable (tree binfo, tree type) { tree decl; tree virtuals; decl = get_vtable_decl (type, /*complete=*/0); if (binfo) { if (BINFO_NEW_VTABLE_MARKED (binfo)) /* We have already created a vtable for this base, so there's no need to do it again. */ return 0; virtuals = copy_list (BINFO_VIRTUALS (binfo)); TREE_TYPE (decl) = TREE_TYPE (get_vtbl_decl_for_binfo (binfo)); DECL_SIZE (decl) = TYPE_SIZE (TREE_TYPE (decl)); DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (TREE_TYPE (decl)); } else { gcc_assert (TREE_TYPE (decl) == vtbl_type_node); virtuals = NULL_TREE; } #ifdef GATHER_STATISTICS n_vtables += 1; n_vtable_elems += list_length (virtuals); #endif /* Initialize the association list for this type, based on our first approximation. */ BINFO_VTABLE (TYPE_BINFO (type)) = decl; BINFO_VIRTUALS (TYPE_BINFO (type)) = virtuals; SET_BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (type)); return 1; } /* Give BINFO a new virtual function table which is initialized with a skeleton-copy of its original initialization. The only entry that changes is the `delta' entry, so we can really share a lot of structure. FOR_TYPE is the most derived type which caused this table to be needed. Returns nonzero if we haven't met BINFO before. The order in which vtables are built (by calling this function) for an object must remain the same, otherwise a binary incompatibility can result. */ static int build_secondary_vtable (tree binfo) { if (BINFO_NEW_VTABLE_MARKED (binfo)) /* We already created a vtable for this base. There's no need to do it again. */ return 0; /* Remember that we've created a vtable for this BINFO, so that we don't try to do so again. */ SET_BINFO_NEW_VTABLE_MARKED (binfo); /* Make fresh virtual list, so we can smash it later. */ BINFO_VIRTUALS (binfo) = copy_list (BINFO_VIRTUALS (binfo)); /* Secondary vtables are laid out as part of the same structure as the primary vtable. */ BINFO_VTABLE (binfo) = NULL_TREE; return 1; } /* Create a new vtable for BINFO which is the hierarchy dominated by T. Return nonzero if we actually created a new vtable. */ static int make_new_vtable (tree t, tree binfo) { if (binfo == TYPE_BINFO (t)) /* In this case, it is *type*'s vtable we are modifying. We start with the approximation that its vtable is that of the immediate base class. */ return build_primary_vtable (binfo, t); else /* This is our very own copy of `basetype' to play with. Later, we will fill in all the virtual functions that override the virtual functions in these base classes which are not defined by the current type. */ return build_secondary_vtable (binfo); } /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO (which is in the hierarchy dominated by T) list FNDECL as its BV_FN. DELTA is the required constant adjustment from the `this' pointer where the vtable entry appears to the `this' required when the function is actually called. */ static void modify_vtable_entry (tree t, tree binfo, tree fndecl, tree delta, tree *virtuals) { tree v; v = *virtuals; if (fndecl != BV_FN (v) || !tree_int_cst_equal (delta, BV_DELTA (v))) { /* We need a new vtable for BINFO. */ if (make_new_vtable (t, binfo)) { /* If we really did make a new vtable, we also made a copy of the BINFO_VIRTUALS list. Now, we have to find the corresponding entry in that list. */ *virtuals = BINFO_VIRTUALS (binfo); while (BV_FN (*virtuals) != BV_FN (v)) *virtuals = TREE_CHAIN (*virtuals); v = *virtuals; } BV_DELTA (v) = delta; BV_VCALL_INDEX (v) = NULL_TREE; BV_FN (v) = fndecl; } } /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is the USING_DECL naming METHOD. Returns true if the method could be added to the method vec. */ bool add_method (tree type, tree method, tree using_decl) { unsigned slot; tree overload; bool template_conv_p = false; bool conv_p; VEC(tree,gc) *method_vec; bool complete_p; bool insert_p = false; tree current_fns; tree fns; if (method == error_mark_node) return false; complete_p = COMPLETE_TYPE_P (type); conv_p = DECL_CONV_FN_P (method); if (conv_p) template_conv_p = (TREE_CODE (method) == TEMPLATE_DECL && DECL_TEMPLATE_CONV_FN_P (method)); method_vec = CLASSTYPE_METHOD_VEC (type); if (!method_vec) { /* Make a new method vector. We start with 8 entries. We must allocate at least two (for constructors and destructors), and we're going to end up with an assignment operator at some point as well. */ method_vec = VEC_alloc (tree, gc, 8); /* Create slots for constructors and destructors. */ VEC_quick_push (tree, method_vec, NULL_TREE); VEC_quick_push (tree, method_vec, NULL_TREE); CLASSTYPE_METHOD_VEC (type) = method_vec; } /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */ grok_special_member_properties (method); /* Constructors and destructors go in special slots. */ if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (method)) slot = CLASSTYPE_CONSTRUCTOR_SLOT; else if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method)) { slot = CLASSTYPE_DESTRUCTOR_SLOT; if (TYPE_FOR_JAVA (type)) { if (!DECL_ARTIFICIAL (method)) error ("Java class %qT cannot have a destructor", type); else if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) error ("Java class %qT cannot have an implicit non-trivial " "destructor", type); } } else { tree m; insert_p = true; /* See if we already have an entry with this name. */ for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT; VEC_iterate (tree, method_vec, slot, m); ++slot) { m = OVL_CURRENT (m); if (template_conv_p) { if (TREE_CODE (m) == TEMPLATE_DECL && DECL_TEMPLATE_CONV_FN_P (m)) insert_p = false; break; } if (conv_p && !DECL_CONV_FN_P (m)) break; if (DECL_NAME (m) == DECL_NAME (method)) { insert_p = false; break; } if (complete_p && !DECL_CONV_FN_P (m) && DECL_NAME (m) > DECL_NAME (method)) break; } } current_fns = insert_p ? NULL_TREE : VEC_index (tree, method_vec, slot); /* Check to see if we've already got this method. */ for (fns = current_fns; fns; fns = OVL_NEXT (fns)) { tree fn = OVL_CURRENT (fns); tree fn_type; tree method_type; tree parms1; tree parms2; if (TREE_CODE (fn) != TREE_CODE (method)) continue; /* [over.load] Member function declarations with the same name and the same parameter types cannot be overloaded if any of them is a static member function declaration. [namespace.udecl] When a using-declaration brings names from a base class into a derived class scope, member functions in the derived class override and/or hide member functions with the same name and parameter types in a base class (rather than conflicting). */ fn_type = TREE_TYPE (fn); method_type = TREE_TYPE (method); parms1 = TYPE_ARG_TYPES (fn_type); parms2 = TYPE_ARG_TYPES (method_type); /* Compare the quals on the 'this' parm. Don't compare the whole types, as used functions are treated as coming from the using class in overload resolution. */ if (! DECL_STATIC_FUNCTION_P (fn) && ! DECL_STATIC_FUNCTION_P (method) && TREE_TYPE (TREE_VALUE (parms1)) != error_mark_node && TREE_TYPE (TREE_VALUE (parms2)) != error_mark_node && (TYPE_QUALS (TREE_TYPE (TREE_VALUE (parms1))) != TYPE_QUALS (TREE_TYPE (TREE_VALUE (parms2))))) continue; /* For templates, the return type and template parameters must be identical. */ if (TREE_CODE (fn) == TEMPLATE_DECL && (!same_type_p (TREE_TYPE (fn_type), TREE_TYPE (method_type)) || !comp_template_parms (DECL_TEMPLATE_PARMS (fn), DECL_TEMPLATE_PARMS (method)))) continue; if (! DECL_STATIC_FUNCTION_P (fn)) parms1 = TREE_CHAIN (parms1); if (! DECL_STATIC_FUNCTION_P (method)) parms2 = TREE_CHAIN (parms2); if (compparms (parms1, parms2) && (!DECL_CONV_FN_P (fn) || same_type_p (TREE_TYPE (fn_type), TREE_TYPE (method_type)))) { if (using_decl) { if (DECL_CONTEXT (fn) == type) /* Defer to the local function. */ return false; if (DECL_CONTEXT (fn) == DECL_CONTEXT (method)) error ("repeated using declaration %q+D", using_decl); else error ("using declaration %q+D conflicts with a previous using declaration", using_decl); } else { error ("%q+#D cannot be overloaded", method); error ("with %q+#D", fn); } /* We don't call duplicate_decls here to merge the declarations because that will confuse things if the methods have inline definitions. In particular, we will crash while processing the definitions. */ return false; } } /* A class should never have more than one destructor. */ if (current_fns && DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method)) return false; /* Add the new binding. */ overload = build_overload (method, current_fns); if (conv_p) TYPE_HAS_CONVERSION (type) = 1; else if (slot >= CLASSTYPE_FIRST_CONVERSION_SLOT && !complete_p) push_class_level_binding (DECL_NAME (method), overload); if (insert_p) { bool reallocated; /* We only expect to add few methods in the COMPLETE_P case, so just make room for one more method in that case. */ if (complete_p) reallocated = VEC_reserve_exact (tree, gc, method_vec, 1); else reallocated = VEC_reserve (tree, gc, method_vec, 1); if (reallocated) CLASSTYPE_METHOD_VEC (type) = method_vec; if (slot == VEC_length (tree, method_vec)) VEC_quick_push (tree, method_vec, overload); else VEC_quick_insert (tree, method_vec, slot, overload); } else /* Replace the current slot. */ VEC_replace (tree, method_vec, slot, overload); return true; } /* Subroutines of finish_struct. */ /* Change the access of FDECL to ACCESS in T. Return 1 if change was legit, otherwise return 0. */ static int alter_access (tree t, tree fdecl, tree access) { tree elem; if (!DECL_LANG_SPECIFIC (fdecl)) retrofit_lang_decl (fdecl); gcc_assert (!DECL_DISCRIMINATOR_P (fdecl)); elem = purpose_member (t, DECL_ACCESS (fdecl)); if (elem) { if (TREE_VALUE (elem) != access) { if (TREE_CODE (TREE_TYPE (fdecl)) == FUNCTION_DECL) error ("conflicting access specifications for method" " %q+D, ignored", TREE_TYPE (fdecl)); else error ("conflicting access specifications for field %qE, ignored", DECL_NAME (fdecl)); } else { /* They're changing the access to the same thing they changed it to before. That's OK. */ ; } } else { perform_or_defer_access_check (TYPE_BINFO (t), fdecl, fdecl); DECL_ACCESS (fdecl) = tree_cons (t, access, DECL_ACCESS (fdecl)); return 1; } return 0; } /* Process the USING_DECL, which is a member of T. */ static void handle_using_decl (tree using_decl, tree t) { tree decl = USING_DECL_DECLS (using_decl); tree name = DECL_NAME (using_decl); tree access = TREE_PRIVATE (using_decl) ? access_private_node : TREE_PROTECTED (using_decl) ? access_protected_node : access_public_node; tree flist = NULL_TREE; tree old_value; gcc_assert (!processing_template_decl && decl); old_value = lookup_member (t, name, /*protect=*/0, /*want_type=*/false); if (old_value) { if (is_overloaded_fn (old_value)) old_value = OVL_CURRENT (old_value); if (DECL_P (old_value) && DECL_CONTEXT (old_value) == t) /* OK */; else old_value = NULL_TREE; } cp_emit_debug_info_for_using (decl, USING_DECL_SCOPE (using_decl)); if (is_overloaded_fn (decl)) flist = decl; if (! old_value) ; else if (is_overloaded_fn (old_value)) { if (flist) /* It's OK to use functions from a base when there are functions with the same name already present in the current class. */; else { error ("%q+D invalid in %q#T", using_decl, t); error (" because of local method %q+#D with same name", OVL_CURRENT (old_value)); return; } } else if (!DECL_ARTIFICIAL (old_value)) { error ("%q+D invalid in %q#T", using_decl, t); error (" because of local member %q+#D with same name", old_value); return; } /* Make type T see field decl FDECL with access ACCESS. */ if (flist) for (; flist; flist = OVL_NEXT (flist)) { add_method (t, OVL_CURRENT (flist), using_decl); alter_access (t, OVL_CURRENT (flist), access); } else alter_access (t, decl, access); } /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P, and NO_CONST_ASN_REF_P. Also set flag bits in T based on properties of the bases. */ static void check_bases (tree t, int* cant_have_const_ctor_p, int* no_const_asn_ref_p) { int i; int seen_non_virtual_nearly_empty_base_p; tree base_binfo; tree binfo; tree field = NULL_TREE; seen_non_virtual_nearly_empty_base_p = 0; if (!CLASSTYPE_NON_STD_LAYOUT (t)) for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field)) if (TREE_CODE (field) == FIELD_DECL) break; for (binfo = TYPE_BINFO (t), i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) { tree basetype = TREE_TYPE (base_binfo); gcc_assert (COMPLETE_TYPE_P (basetype)); /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P here because the case of virtual functions but non-virtual dtor is handled in finish_struct_1. */ if (!TYPE_POLYMORPHIC_P (basetype)) warning (OPT_Weffc__, "base class %q#T has a non-virtual destructor", basetype); /* If the base class doesn't have copy constructors or assignment operators that take const references, then the derived class cannot have such a member automatically generated. */ if (! TYPE_HAS_CONST_INIT_REF (basetype)) *cant_have_const_ctor_p = 1; if (TYPE_HAS_ASSIGN_REF (basetype) && !TYPE_HAS_CONST_ASSIGN_REF (basetype)) *no_const_asn_ref_p = 1; if (BINFO_VIRTUAL_P (base_binfo)) /* A virtual base does not effect nearly emptiness. */ ; else if (CLASSTYPE_NEARLY_EMPTY_P (basetype)) { if (seen_non_virtual_nearly_empty_base_p) /* And if there is more than one nearly empty base, then the derived class is not nearly empty either. */ CLASSTYPE_NEARLY_EMPTY_P (t) = 0; else /* Remember we've seen one. */ seen_non_virtual_nearly_empty_base_p = 1; } else if (!is_empty_class (basetype)) /* If the base class is not empty or nearly empty, then this class cannot be nearly empty. */ CLASSTYPE_NEARLY_EMPTY_P (t) = 0; /* A lot of properties from the bases also apply to the derived class. */ TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (basetype); TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (basetype); TYPE_HAS_COMPLEX_ASSIGN_REF (t) |= TYPE_HAS_COMPLEX_ASSIGN_REF (basetype); TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (basetype); TYPE_POLYMORPHIC_P (t) |= TYPE_POLYMORPHIC_P (basetype); CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) |= CLASSTYPE_CONTAINS_EMPTY_CLASS_P (basetype); TYPE_HAS_COMPLEX_DFLT (t) |= TYPE_HAS_COMPLEX_DFLT (basetype); /* A standard-layout class is a class that: ... * has no non-standard-layout base classes, */ CLASSTYPE_NON_STD_LAYOUT (t) |= CLASSTYPE_NON_STD_LAYOUT (basetype); if (!CLASSTYPE_NON_STD_LAYOUT (t)) { tree basefield; /* ...has no base classes of the same type as the first non-static data member... */ if (field && DECL_CONTEXT (field) == t && (same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (field), basetype))) CLASSTYPE_NON_STD_LAYOUT (t) = 1; else /* ...either has no non-static data members in the most-derived class and at most one base class with non-static data members, or has no base classes with non-static data members */ for (basefield = TYPE_FIELDS (basetype); basefield; basefield = TREE_CHAIN (basefield)) if (TREE_CODE (basefield) == FIELD_DECL) { if (field) CLASSTYPE_NON_STD_LAYOUT (t) = 1; else field = basefield; break; } } } } /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for those that are primaries. Sets BINFO_LOST_PRIMARY_P for those that have had a nearly-empty virtual primary base stolen by some other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for T. */ static void determine_primary_bases (tree t) { unsigned i; tree primary = NULL_TREE; tree type_binfo = TYPE_BINFO (t); tree base_binfo; /* Determine the primary bases of our bases. */ for (base_binfo = TREE_CHAIN (type_binfo); base_binfo; base_binfo = TREE_CHAIN (base_binfo)) { tree primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (base_binfo)); /* See if we're the non-virtual primary of our inheritance chain. */ if (!BINFO_VIRTUAL_P (base_binfo)) { tree parent = BINFO_INHERITANCE_CHAIN (base_binfo); tree parent_primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (parent)); if (parent_primary && SAME_BINFO_TYPE_P (BINFO_TYPE (base_binfo), BINFO_TYPE (parent_primary))) /* We are the primary binfo. */ BINFO_PRIMARY_P (base_binfo) = 1; } /* Determine if we have a virtual primary base, and mark it so. */ if (primary && BINFO_VIRTUAL_P (primary)) { tree this_primary = copied_binfo (primary, base_binfo); if (BINFO_PRIMARY_P (this_primary)) /* Someone already claimed this base. */ BINFO_LOST_PRIMARY_P (base_binfo) = 1; else { tree delta; BINFO_PRIMARY_P (this_primary) = 1; BINFO_INHERITANCE_CHAIN (this_primary) = base_binfo; /* A virtual binfo might have been copied from within another hierarchy. As we're about to use it as a primary base, make sure the offsets match. */ delta = size_diffop_loc (input_location, convert (ssizetype, BINFO_OFFSET (base_binfo)), convert (ssizetype, BINFO_OFFSET (this_primary))); propagate_binfo_offsets (this_primary, delta); } } } /* First look for a dynamic direct non-virtual base. */ for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, base_binfo); i++) { tree basetype = BINFO_TYPE (base_binfo); if (TYPE_CONTAINS_VPTR_P (basetype) && !BINFO_VIRTUAL_P (base_binfo)) { primary = base_binfo; goto found; } } /* A "nearly-empty" virtual base class can be the primary base class, if no non-virtual polymorphic base can be found. Look for a nearly-empty virtual dynamic base that is not already a primary base of something in the hierarchy. If there is no such base, just pick the first nearly-empty virtual base. */ for (base_binfo = TREE_CHAIN (type_binfo); base_binfo; base_binfo = TREE_CHAIN (base_binfo)) if (BINFO_VIRTUAL_P (base_binfo) && CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (base_binfo))) { if (!BINFO_PRIMARY_P (base_binfo)) { /* Found one that is not primary. */ primary = base_binfo; goto found; } else if (!primary) /* Remember the first candidate. */ primary = base_binfo; } found: /* If we've got a primary base, use it. */ if (primary) { tree basetype = BINFO_TYPE (primary); CLASSTYPE_PRIMARY_BINFO (t) = primary; if (BINFO_PRIMARY_P (primary)) /* We are stealing a primary base. */ BINFO_LOST_PRIMARY_P (BINFO_INHERITANCE_CHAIN (primary)) = 1; BINFO_PRIMARY_P (primary) = 1; if (BINFO_VIRTUAL_P (primary)) { tree delta; BINFO_INHERITANCE_CHAIN (primary) = type_binfo; /* A virtual binfo might have been copied from within another hierarchy. As we're about to use it as a primary base, make sure the offsets match. */ delta = size_diffop_loc (input_location, ssize_int (0), convert (ssizetype, BINFO_OFFSET (primary))); propagate_binfo_offsets (primary, delta); } primary = TYPE_BINFO (basetype); TYPE_VFIELD (t) = TYPE_VFIELD (basetype); BINFO_VTABLE (type_binfo) = BINFO_VTABLE (primary); BINFO_VIRTUALS (type_binfo) = BINFO_VIRTUALS (primary); } } /* Update the variant types of T. */ void fixup_type_variants (tree t) { tree variants; if (!t) return; for (variants = TYPE_NEXT_VARIANT (t); variants; variants = TYPE_NEXT_VARIANT (variants)) { /* These fields are in the _TYPE part of the node, not in the TYPE_LANG_SPECIFIC component, so they are not shared. */ TYPE_HAS_USER_CONSTRUCTOR (variants) = TYPE_HAS_USER_CONSTRUCTOR (t); TYPE_NEEDS_CONSTRUCTING (variants) = TYPE_NEEDS_CONSTRUCTING (t); TYPE_HAS_NONTRIVIAL_DESTRUCTOR (variants) = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t); TYPE_POLYMORPHIC_P (variants) = TYPE_POLYMORPHIC_P (t); TYPE_BINFO (variants) = TYPE_BINFO (t); /* Copy whatever these are holding today. */ TYPE_VFIELD (variants) = TYPE_VFIELD (t); TYPE_METHODS (variants) = TYPE_METHODS (t); TYPE_FIELDS (variants) = TYPE_FIELDS (t); /* All variants of a class have the same attributes. */ TYPE_ATTRIBUTES (variants) = TYPE_ATTRIBUTES (t); } } /* Set memoizing fields and bits of T (and its variants) for later use. */ static void finish_struct_bits (tree t) { /* Fix up variants (if any). */ fixup_type_variants (t); if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) && TYPE_POLYMORPHIC_P (t)) /* For a class w/o baseclasses, 'finish_struct' has set CLASSTYPE_PURE_VIRTUALS correctly (by definition). Similarly for a class whose base classes do not have vtables. When neither of these is true, we might have removed abstract virtuals (by providing a definition), added some (by declaring new ones), or redeclared ones from a base class. We need to recalculate what's really an abstract virtual at this point (by looking in the vtables). */ get_pure_virtuals (t); /* If this type has a copy constructor or a destructor, force its mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be nonzero. This will cause it to be passed by invisible reference and prevent it from being returned in a register. */ if (! TYPE_HAS_TRIVIAL_INIT_REF (t) || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)) { tree variants; DECL_MODE (TYPE_MAIN_DECL (t)) = BLKmode; for (variants = t; variants; variants = TYPE_NEXT_VARIANT (variants)) { SET_TYPE_MODE (variants, BLKmode); TREE_ADDRESSABLE (variants) = 1; } } } /* Issue warnings about T having private constructors, but no friends, and so forth. HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any non-private static member functions. */ static void maybe_warn_about_overly_private_class (tree t) { int has_member_fn = 0; int has_nonprivate_method = 0; tree fn; if (!warn_ctor_dtor_privacy /* If the class has friends, those entities might create and access instances, so we should not warn. */ || (CLASSTYPE_FRIEND_CLASSES (t) || DECL_FRIENDLIST (TYPE_MAIN_DECL (t))) /* We will have warned when the template was declared; there's no need to warn on every instantiation. */ || CLASSTYPE_TEMPLATE_INSTANTIATION (t)) /* There's no reason to even consider warning about this class. */ return; /* We only issue one warning, if more than one applies, because otherwise, on code like: class A { // Oops - forgot `public:' A(); A(const A&); ~A(); }; we warn several times about essentially the same problem. */ /* Check to see if all (non-constructor, non-destructor) member functions are private. (Since there are no friends or non-private statics, we can't ever call any of the private member functions.) */ for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn)) /* We're not interested in compiler-generated methods; they don't provide any way to call private members. */ if (!DECL_ARTIFICIAL (fn)) { if (!TREE_PRIVATE (fn)) { if (DECL_STATIC_FUNCTION_P (fn)) /* A non-private static member function is just like a friend; it can create and invoke private member functions, and be accessed without a class instance. */ return; has_nonprivate_method = 1; /* Keep searching for a static member function. */ } else if (!DECL_CONSTRUCTOR_P (fn) && !DECL_DESTRUCTOR_P (fn)) has_member_fn = 1; } if (!has_nonprivate_method && has_member_fn) { /* There are no non-private methods, and there's at least one private member function that isn't a constructor or destructor. (If all the private members are constructors/destructors we want to use the code below that issues error messages specifically referring to constructors/destructors.) */ unsigned i; tree binfo = TYPE_BINFO (t); for (i = 0; i != BINFO_N_BASE_BINFOS (binfo); i++) if (BINFO_BASE_ACCESS (binfo, i) != access_private_node) { has_nonprivate_method = 1; break; } if (!has_nonprivate_method) { warning (OPT_Wctor_dtor_privacy, "all member functions in class %qT are private", t); return; } } /* Even if some of the member functions are non-private, the class won't be useful for much if all the constructors or destructors are private: such an object can never be created or destroyed. */ fn = CLASSTYPE_DESTRUCTORS (t); if (fn && TREE_PRIVATE (fn)) { warning (OPT_Wctor_dtor_privacy, "%q#T only defines a private destructor and has no friends", t); return; } /* Warn about classes that have private constructors and no friends. */ if (TYPE_HAS_USER_CONSTRUCTOR (t) /* Implicitly generated constructors are always public. */ && (!CLASSTYPE_LAZY_DEFAULT_CTOR (t) || !CLASSTYPE_LAZY_COPY_CTOR (t))) { int nonprivate_ctor = 0; /* If a non-template class does not define a copy constructor, one is defined for it, enabling it to avoid this warning. For a template class, this does not happen, and so we would normally get a warning on: template <class T> class C { private: C(); }; To avoid this asymmetry, we check TYPE_HAS_INIT_REF. All complete non-template or fully instantiated classes have this flag set. */ if (!TYPE_HAS_INIT_REF (t)) nonprivate_ctor = 1; else for (fn = CLASSTYPE_CONSTRUCTORS (t); fn; fn = OVL_NEXT (fn)) { tree ctor = OVL_CURRENT (fn); /* Ideally, we wouldn't count copy constructors (or, in fact, any constructor that takes an argument of the class type as a parameter) because such things cannot be used to construct an instance of the class unless you already have one. But, for now at least, we're more generous. */ if (! TREE_PRIVATE (ctor)) { nonprivate_ctor = 1; break; } } if (nonprivate_ctor == 0) { warning (OPT_Wctor_dtor_privacy, "%q#T only defines private constructors and has no friends", t); return; } } } static struct { gt_pointer_operator new_value; void *cookie; } resort_data; /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */ static int method_name_cmp (const void* m1_p, const void* m2_p) { const tree *const m1 = (const tree *) m1_p; const tree *const m2 = (const tree *) m2_p; if (*m1 == NULL_TREE && *m2 == NULL_TREE) return 0; if (*m1 == NULL_TREE) return -1; if (*m2 == NULL_TREE) return 1; if (DECL_NAME (OVL_CURRENT (*m1)) < DECL_NAME (OVL_CURRENT (*m2))) return -1; return 1; } /* This routine compares two fields like method_name_cmp but using the pointer operator in resort_field_decl_data. */ static int resort_method_name_cmp (const void* m1_p, const void* m2_p) { const tree *const m1 = (const tree *) m1_p; const tree *const m2 = (const tree *) m2_p; if (*m1 == NULL_TREE && *m2 == NULL_TREE) return 0; if (*m1 == NULL_TREE) return -1; if (*m2 == NULL_TREE) return 1; { tree d1 = DECL_NAME (OVL_CURRENT (*m1)); tree d2 = DECL_NAME (OVL_CURRENT (*m2)); resort_data.new_value (&d1, resort_data.cookie); resort_data.new_value (&d2, resort_data.cookie); if (d1 < d2) return -1; } return 1; } /* Resort TYPE_METHOD_VEC because pointers have been reordered. */ void resort_type_method_vec (void* obj, void* orig_obj ATTRIBUTE_UNUSED , gt_pointer_operator new_value, void* cookie) { VEC(tree,gc) *method_vec = (VEC(tree,gc) *) obj; int len = VEC_length (tree, method_vec); size_t slot; tree fn; /* The type conversion ops have to live at the front of the vec, so we can't sort them. */ for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT; VEC_iterate (tree, method_vec, slot, fn); ++slot) if (!DECL_CONV_FN_P (OVL_CURRENT (fn))) break; if (len - slot > 1) { resort_data.new_value = new_value; resort_data.cookie = cookie; qsort (VEC_address (tree, method_vec) + slot, len - slot, sizeof (tree), resort_method_name_cmp); } } /* Warn about duplicate methods in fn_fields. Sort methods that are not special (i.e., constructors, destructors, and type conversion operators) so that we can find them faster in search. */ static void finish_struct_methods (tree t) { tree fn_fields; VEC(tree,gc) *method_vec; int slot, len; method_vec = CLASSTYPE_METHOD_VEC (t); if (!method_vec) return; len = VEC_length (tree, method_vec); /* Clear DECL_IN_AGGR_P for all functions. */ for (fn_fields = TYPE_METHODS (t); fn_fields; fn_fields = TREE_CHAIN (fn_fields)) DECL_IN_AGGR_P (fn_fields) = 0; /* Issue warnings about private constructors and such. If there are no methods, then some public defaults are generated. */ maybe_warn_about_overly_private_class (t); /* The type conversion ops have to live at the front of the vec, so we can't sort them. */ for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT; VEC_iterate (tree, method_vec, slot, fn_fields); ++slot) if (!DECL_CONV_FN_P (OVL_CURRENT (fn_fields))) break; if (len - slot > 1) qsort (VEC_address (tree, method_vec) + slot, len-slot, sizeof (tree), method_name_cmp); } /* Make BINFO's vtable have N entries, including RTTI entries, vbase and vcall offsets, etc. Set its type and call the back end to lay it out. */ static void layout_vtable_decl (tree binfo, int n) { tree atype; tree vtable; atype = build_cplus_array_type (vtable_entry_type, build_index_type (size_int (n - 1))); layout_type (atype); /* We may have to grow the vtable. */ vtable = get_vtbl_decl_for_binfo (binfo); if (!same_type_p (TREE_TYPE (vtable), atype)) { TREE_TYPE (vtable) = atype; DECL_SIZE (vtable) = DECL_SIZE_UNIT (vtable) = NULL_TREE; layout_decl (vtable, 0); } } /* True iff FNDECL and BASE_FNDECL (both non-static member functions) have the same signature. */ int same_signature_p (const_tree fndecl, const_tree base_fndecl) { /* One destructor overrides another if they are the same kind of destructor. */ if (DECL_DESTRUCTOR_P (base_fndecl) && DECL_DESTRUCTOR_P (fndecl) && special_function_p (base_fndecl) == special_function_p (fndecl)) return 1; /* But a non-destructor never overrides a destructor, nor vice versa, nor do different kinds of destructors override one-another. For example, a complete object destructor does not override a deleting destructor. */ if (DECL_DESTRUCTOR_P (base_fndecl) || DECL_DESTRUCTOR_P (fndecl)) return 0; if (DECL_NAME (fndecl) == DECL_NAME (base_fndecl) || (DECL_CONV_FN_P (fndecl) && DECL_CONV_FN_P (base_fndecl) && same_type_p (DECL_CONV_FN_TYPE (fndecl), DECL_CONV_FN_TYPE (base_fndecl)))) { tree types, base_types; types = TYPE_ARG_TYPES (TREE_TYPE (fndecl)); base_types = TYPE_ARG_TYPES (TREE_TYPE (base_fndecl)); if ((TYPE_QUALS (TREE_TYPE (TREE_VALUE (base_types))) == TYPE_QUALS (TREE_TYPE (TREE_VALUE (types)))) && compparms (TREE_CHAIN (base_types), TREE_CHAIN (types))) return 1; } return 0; } /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a subobject. */ static bool base_derived_from (tree derived, tree base) { tree probe; for (probe = base; probe; probe = BINFO_INHERITANCE_CHAIN (probe)) { if (probe == derived) return true; else if (BINFO_VIRTUAL_P (probe)) /* If we meet a virtual base, we can't follow the inheritance any more. See if the complete type of DERIVED contains such a virtual base. */ return (binfo_for_vbase (BINFO_TYPE (probe), BINFO_TYPE (derived)) != NULL_TREE); } return false; } typedef struct find_final_overrider_data_s { /* The function for which we are trying to find a final overrider. */ tree fn; /* The base class in which the function was declared. */ tree declaring_base; /* The candidate overriders. */ tree candidates; /* Path to most derived. */ VEC(tree,heap) *path; } find_final_overrider_data; /* Add the overrider along the current path to FFOD->CANDIDATES. Returns true if an overrider was found; false otherwise. */ static bool dfs_find_final_overrider_1 (tree binfo, find_final_overrider_data *ffod, unsigned depth) { tree method; /* If BINFO is not the most derived type, try a more derived class. A definition there will overrider a definition here. */ if (depth) { depth--; if (dfs_find_final_overrider_1 (VEC_index (tree, ffod->path, depth), ffod, depth)) return true; } method = look_for_overrides_here (BINFO_TYPE (binfo), ffod->fn); if (method) { tree *candidate = &ffod->candidates; /* Remove any candidates overridden by this new function. */ while (*candidate) { /* If *CANDIDATE overrides METHOD, then METHOD cannot override anything else on the list. */ if (base_derived_from (TREE_VALUE (*candidate), binfo)) return true; /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */ if (base_derived_from (binfo, TREE_VALUE (*candidate))) *candidate = TREE_CHAIN (*candidate); else candidate = &TREE_CHAIN (*candidate); } /* Add the new function. */ ffod->candidates = tree_cons (method, binfo, ffod->candidates); return true; } return false; } /* Called from find_final_overrider via dfs_walk. */ static tree dfs_find_final_overrider_pre (tree binfo, void *data) { find_final_overrider_data *ffod = (find_final_overrider_data *) data; if (binfo == ffod->declaring_base) dfs_find_final_overrider_1 (binfo, ffod, VEC_length (tree, ffod->path)); VEC_safe_push (tree, heap, ffod->path, binfo); return NULL_TREE; } static tree dfs_find_final_overrider_post (tree binfo ATTRIBUTE_UNUSED, void *data) { find_final_overrider_data *ffod = (find_final_overrider_data *) data; VEC_pop (tree, ffod->path); return NULL_TREE; } /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for FN and whose TREE_VALUE is the binfo for the base where the overriding occurs. BINFO (in the hierarchy dominated by the binfo DERIVED) is the base object in which FN is declared. */ static tree find_final_overrider (tree derived, tree binfo, tree fn) { find_final_overrider_data ffod; /* Getting this right is a little tricky. This is valid: struct S { virtual void f (); }; struct T { virtual void f (); }; struct U : public S, public T { }; even though calling `f' in `U' is ambiguous. But, struct R { virtual void f(); }; struct S : virtual public R { virtual void f (); }; struct T : virtual public R { virtual void f (); }; struct U : public S, public T { }; is not -- there's no way to decide whether to put `S::f' or `T::f' in the vtable for `R'. The solution is to look at all paths to BINFO. If we find different overriders along any two, then there is a problem. */ if (DECL_THUNK_P (fn)) fn = THUNK_TARGET (fn); /* Determine the depth of the hierarchy. */ ffod.fn = fn; ffod.declaring_base = binfo; ffod.candidates = NULL_TREE; ffod.path = VEC_alloc (tree, heap, 30); dfs_walk_all (derived, dfs_find_final_overrider_pre, dfs_find_final_overrider_post, &ffod); VEC_free (tree, heap, ffod.path); /* If there was no winner, issue an error message. */ if (!ffod.candidates || TREE_CHAIN (ffod.candidates)) return error_mark_node; return ffod.candidates; } /* Return the index of the vcall offset for FN when TYPE is used as a virtual base. */ static tree get_vcall_index (tree fn, tree type) { VEC(tree_pair_s,gc) *indices = CLASSTYPE_VCALL_INDICES (type); tree_pair_p p; unsigned ix; for (ix = 0; VEC_iterate (tree_pair_s, indices, ix, p); ix++) if ((DECL_DESTRUCTOR_P (fn) && DECL_DESTRUCTOR_P (p->purpose)) || same_signature_p (fn, p->purpose)) return p->value; /* There should always be an appropriate index. */ gcc_unreachable (); } /* Update an entry in the vtable for BINFO, which is in the hierarchy dominated by T. FN has been overridden in BINFO; VIRTUALS points to the corresponding position in the BINFO_VIRTUALS list. */ static void update_vtable_entry_for_fn (tree t, tree binfo, tree fn, tree* virtuals, unsigned ix) { tree b; tree overrider; tree delta; tree virtual_base; tree first_defn; tree overrider_fn, overrider_target; tree target_fn = DECL_THUNK_P (fn) ? THUNK_TARGET (fn) : fn; tree over_return, base_return; bool lost = false; /* Find the nearest primary base (possibly binfo itself) which defines this function; this is the class the caller will convert to when calling FN through BINFO. */ for (b = binfo; ; b = get_primary_binfo (b)) { gcc_assert (b); if (look_for_overrides_here (BINFO_TYPE (b), target_fn)) break; /* The nearest definition is from a lost primary. */ if (BINFO_LOST_PRIMARY_P (b)) lost = true; } first_defn = b; /* Find the final overrider. */ overrider = find_final_overrider (TYPE_BINFO (t), b, target_fn); if (overrider == error_mark_node) { error ("no unique final overrider for %qD in %qT", target_fn, t); return; } overrider_target = overrider_fn = TREE_PURPOSE (overrider); /* Check for adjusting covariant return types. */ over_return = TREE_TYPE (TREE_TYPE (overrider_target)); base_return = TREE_TYPE (TREE_TYPE (target_fn)); if (POINTER_TYPE_P (over_return) && TREE_CODE (over_return) == TREE_CODE (base_return) && CLASS_TYPE_P (TREE_TYPE (over_return)) && CLASS_TYPE_P (TREE_TYPE (base_return)) /* If the overrider is invalid, don't even try. */ && !DECL_INVALID_OVERRIDER_P (overrider_target)) { /* If FN is a covariant thunk, we must figure out the adjustment to the final base FN was converting to. As OVERRIDER_TARGET might also be converting to the return type of FN, we have to combine the two conversions here. */ tree fixed_offset, virtual_offset; over_return = TREE_TYPE (over_return); base_return = TREE_TYPE (base_return); if (DECL_THUNK_P (fn)) { gcc_assert (DECL_RESULT_THUNK_P (fn)); fixed_offset = ssize_int (THUNK_FIXED_OFFSET (fn)); virtual_offset = THUNK_VIRTUAL_OFFSET (fn); } else fixed_offset = virtual_offset = NULL_TREE; if (virtual_offset) /* Find the equivalent binfo within the return type of the overriding function. We will want the vbase offset from there. */ virtual_offset = binfo_for_vbase (BINFO_TYPE (virtual_offset), over_return); else if (!same_type_ignoring_top_level_qualifiers_p (over_return, base_return)) { /* There was no existing virtual thunk (which takes precedence). So find the binfo of the base function's return type within the overriding function's return type. We cannot call lookup base here, because we're inside a dfs_walk, and will therefore clobber the BINFO_MARKED flags. Fortunately we know the covariancy is valid (it has already been checked), so we can just iterate along the binfos, which have been chained in inheritance graph order. Of course it is lame that we have to repeat the search here anyway -- we should really be caching pieces of the vtable and avoiding this repeated work. */ tree thunk_binfo, base_binfo; /* Find the base binfo within the overriding function's return type. We will always find a thunk_binfo, except when the covariancy is invalid (which we will have already diagnosed). */ for (base_binfo = TYPE_BINFO (base_return), thunk_binfo = TYPE_BINFO (over_return); thunk_binfo; thunk_binfo = TREE_CHAIN (thunk_binfo)) if (SAME_BINFO_TYPE_P (BINFO_TYPE (thunk_binfo), BINFO_TYPE (base_binfo))) break; /* See if virtual inheritance is involved. */ for (virtual_offset = thunk_binfo; virtual_offset; virtual_offset = BINFO_INHERITANCE_CHAIN (virtual_offset)) if (BINFO_VIRTUAL_P (virtual_offset)) break; if (virtual_offset || (thunk_binfo && !BINFO_OFFSET_ZEROP (thunk_binfo))) { tree offset = convert (ssizetype, BINFO_OFFSET (thunk_binfo)); if (virtual_offset) { /* We convert via virtual base. Adjust the fixed offset to be from there. */ offset = size_diffop (offset, convert (ssizetype, BINFO_OFFSET (virtual_offset))); } if (fixed_offset) /* There was an existing fixed offset, this must be from the base just converted to, and the base the FN was thunking to. */ fixed_offset = size_binop (PLUS_EXPR, fixed_offset, offset); else fixed_offset = offset; } } if (fixed_offset || virtual_offset) /* Replace the overriding function with a covariant thunk. We will emit the overriding function in its own slot as well. */ overrider_fn = make_thunk (overrider_target, /*this_adjusting=*/0, fixed_offset, virtual_offset); } else gcc_assert (DECL_INVALID_OVERRIDER_P (overrider_target) || !DECL_THUNK_P (fn)); /* Assume that we will produce a thunk that convert all the way to the final overrider, and not to an intermediate virtual base. */ virtual_base = NULL_TREE; /* See if we can convert to an intermediate virtual base first, and then use the vcall offset located there to finish the conversion. */ for (; b; b = BINFO_INHERITANCE_CHAIN (b)) { /* If we find the final overrider, then we can stop walking. */ if (SAME_BINFO_TYPE_P (BINFO_TYPE (b), BINFO_TYPE (TREE_VALUE (overrider)))) break; /* If we find a virtual base, and we haven't yet found the overrider, then there is a virtual base between the declaring base (first_defn) and the final overrider. */ if (BINFO_VIRTUAL_P (b)) { virtual_base = b; break; } } if (overrider_fn != overrider_target && !virtual_base) { /* The ABI specifies that a covariant thunk includes a mangling for a this pointer adjustment. This-adjusting thunks that override a function from a virtual base have a vcall adjustment. When the virtual base in question is a primary virtual base, we know the adjustments are zero, (and in the non-covariant case, we would not use the thunk). Unfortunately we didn't notice this could happen, when designing the ABI and so never mandated that such a covariant thunk should be emitted. Because we must use the ABI mandated name, we must continue searching from the binfo where we found the most recent definition of the function, towards the primary binfo which first introduced the function into the vtable. If that enters a virtual base, we must use a vcall this-adjusting thunk. Bleah! */ tree probe = first_defn; while ((probe = get_primary_binfo (probe)) && (unsigned) list_length (BINFO_VIRTUALS (probe)) > ix) if (BINFO_VIRTUAL_P (probe)) virtual_base = probe; if (virtual_base) /* Even if we find a virtual base, the correct delta is between the overrider and the binfo we're building a vtable for. */ goto virtual_covariant; } /* Compute the constant adjustment to the `this' pointer. The `this' pointer, when this function is called, will point at BINFO (or one of its primary bases, which are at the same offset). */ if (virtual_base) /* The `this' pointer needs to be adjusted from the declaration to the nearest virtual base. */ delta = size_diffop_loc (input_location, convert (ssizetype, BINFO_OFFSET (virtual_base)), convert (ssizetype, BINFO_OFFSET (first_defn))); else if (lost) /* If the nearest definition is in a lost primary, we don't need an entry in our vtable. Except possibly in a constructor vtable, if we happen to get our primary back. In that case, the offset will be zero, as it will be a primary base. */ delta = size_zero_node; else /* The `this' pointer needs to be adjusted from pointing to BINFO to pointing at the base where the final overrider appears. */ virtual_covariant: delta = size_diffop_loc (input_location, convert (ssizetype, BINFO_OFFSET (TREE_VALUE (overrider))), convert (ssizetype, BINFO_OFFSET (binfo))); modify_vtable_entry (t, binfo, overrider_fn, delta, virtuals); if (virtual_base) BV_VCALL_INDEX (*virtuals) = get_vcall_index (overrider_target, BINFO_TYPE (virtual_base)); else BV_VCALL_INDEX (*virtuals) = NULL_TREE; } /* Called from modify_all_vtables via dfs_walk. */ static tree dfs_modify_vtables (tree binfo, void* data) { tree t = (tree) data; tree virtuals; tree old_virtuals; unsigned ix; if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo))) /* A base without a vtable needs no modification, and its bases are uninteresting. */ return dfs_skip_bases; if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t) && !CLASSTYPE_HAS_PRIMARY_BASE_P (t)) /* Don't do the primary vtable, if it's new. */ return NULL_TREE; if (BINFO_PRIMARY_P (binfo) && !BINFO_VIRTUAL_P (binfo)) /* There's no need to modify the vtable for a non-virtual primary base; we're not going to use that vtable anyhow. We do still need to do this for virtual primary bases, as they could become non-primary in a construction vtable. */ return NULL_TREE; make_new_vtable (t, binfo); /* Now, go through each of the virtual functions in the virtual function table for BINFO. Find the final overrider, and update the BINFO_VIRTUALS list appropriately. */ for (ix = 0, virtuals = BINFO_VIRTUALS (binfo), old_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo))); virtuals; ix++, virtuals = TREE_CHAIN (virtuals), old_virtuals = TREE_CHAIN (old_virtuals)) update_vtable_entry_for_fn (t, binfo, BV_FN (old_virtuals), &virtuals, ix); return NULL_TREE; } /* Update all of the primary and secondary vtables for T. Create new vtables as required, and initialize their RTTI information. Each of the functions in VIRTUALS is declared in T and may override a virtual function from a base class; find and modify the appropriate entries to point to the overriding functions. Returns a list, in declaration order, of the virtual functions that are declared in T, but do not appear in the primary base class vtable, and which should therefore be appended to the end of the vtable for T. */ static tree modify_all_vtables (tree t, tree virtuals) { tree binfo = TYPE_BINFO (t); tree *fnsp; /* Update all of the vtables. */ dfs_walk_once (binfo, dfs_modify_vtables, NULL, t); /* Add virtual functions not already in our primary vtable. These will be both those introduced by this class, and those overridden from secondary bases. It does not include virtuals merely inherited from secondary bases. */ for (fnsp = &virtuals; *fnsp; ) { tree fn = TREE_VALUE (*fnsp); if (!value_member (fn, BINFO_VIRTUALS (binfo)) || DECL_VINDEX (fn) == error_mark_node) { /* We don't need to adjust the `this' pointer when calling this function. */ BV_DELTA (*fnsp) = integer_zero_node; BV_VCALL_INDEX (*fnsp) = NULL_TREE; /* This is a function not already in our vtable. Keep it. */ fnsp = &TREE_CHAIN (*fnsp); } else /* We've already got an entry for this function. Skip it. */ *fnsp = TREE_CHAIN (*fnsp); } return virtuals; } /* Get the base virtual function declarations in T that have the indicated NAME. */ static tree get_basefndecls (tree name, tree t) { tree methods; tree base_fndecls = NULL_TREE; int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t)); int i; /* Find virtual functions in T with the indicated NAME. */ i = lookup_fnfields_1 (t, name); if (i != -1) for (methods = VEC_index (tree, CLASSTYPE_METHOD_VEC (t), i); methods; methods = OVL_NEXT (methods)) { tree method = OVL_CURRENT (methods); if (TREE_CODE (method) == FUNCTION_DECL && DECL_VINDEX (method)) base_fndecls = tree_cons (NULL_TREE, method, base_fndecls); } if (base_fndecls) return base_fndecls; for (i = 0; i < n_baseclasses; i++) { tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (t), i)); base_fndecls = chainon (get_basefndecls (name, basetype), base_fndecls); } return base_fndecls; } /* If this declaration supersedes the declaration of a method declared virtual in the base class, then mark this field as being virtual as well. */ void check_for_override (tree decl, tree ctype) { if (TREE_CODE (decl) == TEMPLATE_DECL) /* In [temp.mem] we have: A specialization of a member function template does not override a virtual function from a base class. */ return; if ((DECL_DESTRUCTOR_P (decl) || IDENTIFIER_VIRTUAL_P (DECL_NAME (decl)) || DECL_CONV_FN_P (decl)) && look_for_overrides (ctype, decl) && !DECL_STATIC_FUNCTION_P (decl)) /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor the error_mark_node so that we know it is an overriding function. */ DECL_VINDEX (decl) = decl; if (DECL_VIRTUAL_P (decl)) { if (!DECL_VINDEX (decl)) DECL_VINDEX (decl) = error_mark_node; IDENTIFIER_VIRTUAL_P (DECL_NAME (decl)) = 1; } } /* Warn about hidden virtual functions that are not overridden in t. We know that constructors and destructors don't apply. */ static void warn_hidden (tree t) { VEC(tree,gc) *method_vec = CLASSTYPE_METHOD_VEC (t); tree fns; size_t i; /* We go through each separately named virtual function. */ for (i = CLASSTYPE_FIRST_CONVERSION_SLOT; VEC_iterate (tree, method_vec, i, fns); ++i) { tree fn; tree name; tree fndecl; tree base_fndecls; tree base_binfo; tree binfo; int j; /* All functions in this slot in the CLASSTYPE_METHOD_VEC will have the same name. Figure out what name that is. */ name = DECL_NAME (OVL_CURRENT (fns)); /* There are no possibly hidden functions yet. */ base_fndecls = NULL_TREE; /* Iterate through all of the base classes looking for possibly hidden functions. */ for (binfo = TYPE_BINFO (t), j = 0; BINFO_BASE_ITERATE (binfo, j, base_binfo); j++) { tree basetype = BINFO_TYPE (base_binfo); base_fndecls = chainon (get_basefndecls (name, basetype), base_fndecls); } /* If there are no functions to hide, continue. */ if (!base_fndecls) continue; /* Remove any overridden functions. */ for (fn = fns; fn; fn = OVL_NEXT (fn)) { fndecl = OVL_CURRENT (fn); if (DECL_VINDEX (fndecl)) { tree *prev = &base_fndecls; while (*prev) /* If the method from the base class has the same signature as the method from the derived class, it has been overridden. */ if (same_signature_p (fndecl, TREE_VALUE (*prev))) *prev = TREE_CHAIN (*prev); else prev = &TREE_CHAIN (*prev); } } /* Now give a warning for all base functions without overriders, as they are hidden. */ while (base_fndecls) { /* Here we know it is a hider, and no overrider exists. */ warning (OPT_Woverloaded_virtual, "%q+D was hidden", TREE_VALUE (base_fndecls)); warning (OPT_Woverloaded_virtual, " by %q+D", fns); base_fndecls = TREE_CHAIN (base_fndecls); } } } /* Check for things that are invalid. There are probably plenty of other things we should check for also. */ static void finish_struct_anon (tree t) { tree field; for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field)) { if (TREE_STATIC (field)) continue; if (TREE_CODE (field) != FIELD_DECL) continue; if (DECL_NAME (field) == NULL_TREE && ANON_AGGR_TYPE_P (TREE_TYPE (field))) { bool is_union = TREE_CODE (TREE_TYPE (field)) == UNION_TYPE; tree elt = TYPE_FIELDS (TREE_TYPE (field)); for (; elt; elt = TREE_CHAIN (elt)) { /* We're generally only interested in entities the user declared, but we also find nested classes by noticing the TYPE_DECL that we create implicitly. You're allowed to put one anonymous union inside another, though, so we explicitly tolerate that. We use TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that we also allow unnamed types used for defining fields. */ if (DECL_ARTIFICIAL (elt) && (!DECL_IMPLICIT_TYPEDEF_P (elt) || TYPE_ANONYMOUS_P (TREE_TYPE (elt)))) continue; if (TREE_CODE (elt) != FIELD_DECL) { if (is_union) permerror (input_location, "%q+#D invalid; an anonymous union can " "only have non-static data members", elt); else permerror (input_location, "%q+#D invalid; an anonymous struct can " "only have non-static data members", elt); continue; } if (TREE_PRIVATE (elt)) { if (is_union) permerror (input_location, "private member %q+#D in anonymous union", elt); else permerror (input_location, "private member %q+#D in anonymous struct", elt); } else if (TREE_PROTECTED (elt)) { if (is_union) permerror (input_location, "protected member %q+#D in anonymous union", elt); else permerror (input_location, "protected member %q+#D in anonymous struct", elt); } TREE_PRIVATE (elt) = TREE_PRIVATE (field); TREE_PROTECTED (elt) = TREE_PROTECTED (field); } } } } /* Add T to CLASSTYPE_DECL_LIST of current_class_type which will be used later during class template instantiation. When FRIEND_P is zero, T can be a static member data (VAR_DECL), a non-static member data (FIELD_DECL), a member function (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE), a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL) When FRIEND_P is nonzero, T is either a friend class (RECORD_TYPE, TEMPLATE_DECL) or a friend function (FUNCTION_DECL, TEMPLATE_DECL). */ void maybe_add_class_template_decl_list (tree type, tree t, int friend_p) { /* Save some memory by not creating TREE_LIST if TYPE is not template. */ if (CLASSTYPE_TEMPLATE_INFO (type)) CLASSTYPE_DECL_LIST (type) = tree_cons (friend_p ? NULL_TREE : type, t, CLASSTYPE_DECL_LIST (type)); } /* Create default constructors, assignment operators, and so forth for the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR, and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason, the class cannot have a default constructor, copy constructor taking a const reference argument, or an assignment operator taking a const reference, respectively. */ static void add_implicitly_declared_members (tree t, int cant_have_const_cctor, int cant_have_const_assignment) { /* Destructor. */ if (!CLASSTYPE_DESTRUCTORS (t)) { /* In general, we create destructors lazily. */ CLASSTYPE_LAZY_DESTRUCTOR (t) = 1; /* However, if the implicit destructor is non-trivial destructor, we sometimes have to create it at this point. */ if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)) { bool lazy_p = true; if (TYPE_FOR_JAVA (t)) /* If this a Java class, any non-trivial destructor is invalid, even if compiler-generated. Therefore, if the destructor is non-trivial we create it now. */ lazy_p = false; else { tree binfo; tree base_binfo; int ix; /* If the implicit destructor will be virtual, then we must generate it now because (unfortunately) we do not generate virtual tables lazily. */ binfo = TYPE_BINFO (t); for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++) { tree base_type; tree dtor; base_type = BINFO_TYPE (base_binfo); dtor = CLASSTYPE_DESTRUCTORS (base_type); if (dtor && DECL_VIRTUAL_P (dtor)) { lazy_p = false; break; } } } /* If we can't get away with being lazy, generate the destructor now. */ if (!lazy_p) lazily_declare_fn (sfk_destructor, t); } } /* [class.ctor] If there is no user-declared constructor for a class, a default constructor is implicitly declared. */ if (! TYPE_HAS_USER_CONSTRUCTOR (t)) { TYPE_HAS_DEFAULT_CONSTRUCTOR (t) = 1; CLASSTYPE_LAZY_DEFAULT_CTOR (t) = 1; } /* [class.ctor] If a class definition does not explicitly declare a copy constructor, one is declared implicitly. */ if (! TYPE_HAS_INIT_REF (t) && ! TYPE_FOR_JAVA (t)) { TYPE_HAS_INIT_REF (t) = 1; TYPE_HAS_CONST_INIT_REF (t) = !cant_have_const_cctor; CLASSTYPE_LAZY_COPY_CTOR (t) = 1; } /* Currently only lambdas get a lazy move ctor, but N2987 adds them for other classes. */ if (LAMBDA_TYPE_P (t)) CLASSTYPE_LAZY_MOVE_CTOR (t) = 1; /* If there is no assignment operator, one will be created if and when it is needed. For now, just record whether or not the type of the parameter to the assignment operator will be a const or non-const reference. */ if (!TYPE_HAS_ASSIGN_REF (t) && !TYPE_FOR_JAVA (t)) { TYPE_HAS_ASSIGN_REF (t) = 1; TYPE_HAS_CONST_ASSIGN_REF (t) = !cant_have_const_assignment; CLASSTYPE_LAZY_ASSIGNMENT_OP (t) = 1; } } /* Subroutine of finish_struct_1. Recursively count the number of fields in TYPE, including anonymous union members. */ static int count_fields (tree fields) { tree x; int n_fields = 0; for (x = fields; x; x = TREE_CHAIN (x)) { if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x))) n_fields += count_fields (TYPE_FIELDS (TREE_TYPE (x))); else n_fields += 1; } return n_fields; } /* Subroutine of finish_struct_1. Recursively add all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE elts, starting at offset IDX. */ static int add_fields_to_record_type (tree fields, struct sorted_fields_type *field_vec, int idx) { tree x; for (x = fields; x; x = TREE_CHAIN (x)) { if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x))) idx = add_fields_to_record_type (TYPE_FIELDS (TREE_TYPE (x)), field_vec, idx); else field_vec->elts[idx++] = x; } return idx; } /* FIELD is a bit-field. We are finishing the processing for its enclosing type. Issue any appropriate messages and set appropriate flags. Returns false if an error has been diagnosed. */ static bool check_bitfield_decl (tree field) { tree type = TREE_TYPE (field); tree w; /* Extract the declared width of the bitfield, which has been temporarily stashed in DECL_INITIAL. */ w = DECL_INITIAL (field); gcc_assert (w != NULL_TREE); /* Remove the bit-field width indicator so that the rest of the compiler does not treat that value as an initializer. */ DECL_INITIAL (field) = NULL_TREE; /* Detect invalid bit-field type. */ if (!INTEGRAL_OR_ENUMERATION_TYPE_P (type)) { error ("bit-field %q+#D with non-integral type", field); w = error_mark_node; } else { /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */ STRIP_NOPS (w); /* detect invalid field size. */ w = integral_constant_value (w); if (TREE_CODE (w) != INTEGER_CST) { error ("bit-field %q+D width not an integer constant", field); w = error_mark_node; } else if (tree_int_cst_sgn (w) < 0) { error ("negative width in bit-field %q+D", field); w = error_mark_node; } else if (integer_zerop (w) && DECL_NAME (field) != 0) { error ("zero width for bit-field %q+D", field); w = error_mark_node; } else if (compare_tree_int (w, TYPE_PRECISION (type)) > 0 && TREE_CODE (type) != ENUMERAL_TYPE && TREE_CODE (type) != BOOLEAN_TYPE) warning (0, "width of %q+D exceeds its type", field); else if (TREE_CODE (type) == ENUMERAL_TYPE && (0 > compare_tree_int (w, tree_int_cst_min_precision (TYPE_MIN_VALUE (type), TYPE_UNSIGNED (type))) || 0 > compare_tree_int (w, tree_int_cst_min_precision (TYPE_MAX_VALUE (type), TYPE_UNSIGNED (type))))) warning (0, "%q+D is too small to hold all values of %q#T", field, type); } if (w != error_mark_node) { DECL_SIZE (field) = convert (bitsizetype, w); DECL_BIT_FIELD (field) = 1; return true; } else { /* Non-bit-fields are aligned for their type. */ DECL_BIT_FIELD (field) = 0; CLEAR_DECL_C_BIT_FIELD (field); return false; } } /* FIELD is a non bit-field. We are finishing the processing for its enclosing type T. Issue any appropriate messages and set appropriate flags. */ static void check_field_decl (tree field, tree t, int* cant_have_const_ctor, int* no_const_asn_ref, int* any_default_members) { tree type = strip_array_types (TREE_TYPE (field)); /* An anonymous union cannot contain any fields which would change the settings of CANT_HAVE_CONST_CTOR and friends. */ if (ANON_UNION_TYPE_P (type)) ; /* And, we don't set TYPE_HAS_CONST_INIT_REF, etc., for anonymous structs. So, we recurse through their fields here. */ else if (ANON_AGGR_TYPE_P (type)) { tree fields; for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields)) if (TREE_CODE (fields) == FIELD_DECL && !DECL_C_BIT_FIELD (field)) check_field_decl (fields, t, cant_have_const_ctor, no_const_asn_ref, any_default_members); } /* Check members with class type for constructors, destructors, etc. */ else if (CLASS_TYPE_P (type)) { /* Never let anything with uninheritable virtuals make it through without complaint. */ abstract_virtuals_error (field, type); if (TREE_CODE (t) == UNION_TYPE) { if (TYPE_NEEDS_CONSTRUCTING (type)) error ("member %q+#D with constructor not allowed in union", field); if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) error ("member %q+#D with destructor not allowed in union", field); if (TYPE_HAS_COMPLEX_ASSIGN_REF (type)) error ("member %q+#D with copy assignment operator not allowed in union", field); } else { TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (type); TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type); TYPE_HAS_COMPLEX_ASSIGN_REF (t) |= TYPE_HAS_COMPLEX_ASSIGN_REF (type); TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (type); TYPE_HAS_COMPLEX_DFLT (t) |= TYPE_HAS_COMPLEX_DFLT (type); } if (!TYPE_HAS_CONST_INIT_REF (type)) *cant_have_const_ctor = 1; if (!TYPE_HAS_CONST_ASSIGN_REF (type)) *no_const_asn_ref = 1; } if (DECL_INITIAL (field) != NULL_TREE) { /* `build_class_init_list' does not recognize non-FIELD_DECLs. */ if (TREE_CODE (t) == UNION_TYPE && any_default_members != 0) error ("multiple fields in union %qT initialized", t); *any_default_members = 1; } } /* Check the data members (both static and non-static), class-scoped typedefs, etc., appearing in the declaration of T. Issue appropriate diagnostics. Sets ACCESS_DECLS to a list (in declaration order) of access declarations; each TREE_VALUE in this list is a USING_DECL. In addition, set the following flags: EMPTY_P The class is empty, i.e., contains no non-static data members. CANT_HAVE_CONST_CTOR_P This class cannot have an implicitly generated copy constructor taking a const reference. CANT_HAVE_CONST_ASN_REF This class cannot have an implicitly generated assignment operator taking a const reference. All of these flags should be initialized before calling this function. Returns a pointer to the end of the TYPE_FIELDs chain; additional fields can be added by adding to this chain. */ static void check_field_decls (tree t, tree *access_decls, int *cant_have_const_ctor_p, int *no_const_asn_ref_p) { tree *field; tree *next; bool has_pointers; int any_default_members; int cant_pack = 0; int field_access = -1; /* Assume there are no access declarations. */ *access_decls = NULL_TREE; /* Assume this class has no pointer members. */ has_pointers = false; /* Assume none of the members of this class have default initializations. */ any_default_members = 0; for (field = &TYPE_FIELDS (t); *field; field = next) { tree x = *field; tree type = TREE_TYPE (x); int this_field_access; next = &TREE_CHAIN (x); if (TREE_CODE (x) == USING_DECL) { /* Prune the access declaration from the list of fields. */ *field = TREE_CHAIN (x); /* Save the access declarations for our caller. */ *access_decls = tree_cons (NULL_TREE, x, *access_decls); /* Since we've reset *FIELD there's no reason to skip to the next field. */ next = field; continue; } if (TREE_CODE (x) == TYPE_DECL || TREE_CODE (x) == TEMPLATE_DECL) continue; /* If we've gotten this far, it's a data member, possibly static, or an enumerator. */ DECL_CONTEXT (x) = t; /* When this goes into scope, it will be a non-local reference. */ DECL_NONLOCAL (x) = 1; if (TREE_CODE (t) == UNION_TYPE) { /* [class.union] If a union contains a static data member, or a member of reference type, the program is ill-formed. */ if (TREE_CODE (x) == VAR_DECL) { error ("%q+D may not be static because it is a member of a union", x); continue; } if (TREE_CODE (type) == REFERENCE_TYPE) { error ("%q+D may not have reference type %qT because" " it is a member of a union", x, type); continue; } } /* Perform error checking that did not get done in grokdeclarator. */ if (TREE_CODE (type) == FUNCTION_TYPE) { error ("field %q+D invalidly declared function type", x); type = build_pointer_type (type); TREE_TYPE (x) = type; } else if (TREE_CODE (type) == METHOD_TYPE) { error ("field %q+D invalidly declared method type", x); type = build_pointer_type (type); TREE_TYPE (x) = type; } if (type == error_mark_node) continue; if (TREE_CODE (x) == CONST_DECL || TREE_CODE (x) == VAR_DECL) continue; /* Now it can only be a FIELD_DECL. */ if (TREE_PRIVATE (x) || TREE_PROTECTED (x)) CLASSTYPE_NON_AGGREGATE (t) = 1; /* A standard-layout class is a class that: ... has the same access control (Clause 11) for all non-static data members, ... */ this_field_access = TREE_PROTECTED (x) ? 1 : TREE_PRIVATE (x) ? 2 : 0; if (field_access == -1) field_access = this_field_access; else if (this_field_access != field_access) CLASSTYPE_NON_STD_LAYOUT (t) = 1; /* If this is of reference type, check if it needs an init. */ if (TREE_CODE (type) == REFERENCE_TYPE) { CLASSTYPE_NON_LAYOUT_POD_P (t) = 1; CLASSTYPE_NON_STD_LAYOUT (t) = 1; if (DECL_INITIAL (x) == NULL_TREE) SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1); /* ARM $12.6.2: [A member initializer list] (or, for an aggregate, initialization by a brace-enclosed list) is the only way to initialize nonstatic const and reference members. */ TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1; } type = strip_array_types (type); if (TYPE_PACKED (t)) { if (!layout_pod_type_p (type) && !TYPE_PACKED (type)) { warning (0, "ignoring packed attribute because of unpacked non-POD field %q+#D", x); cant_pack = 1; } else if (DECL_C_BIT_FIELD (x) || TYPE_ALIGN (TREE_TYPE (x)) > BITS_PER_UNIT) DECL_PACKED (x) = 1; } if (DECL_C_BIT_FIELD (x) && integer_zerop (DECL_INITIAL (x))) /* We don't treat zero-width bitfields as making a class non-empty. */ ; else { /* The class is non-empty. */ CLASSTYPE_EMPTY_P (t) = 0; /* The class is not even nearly empty. */ CLASSTYPE_NEARLY_EMPTY_P (t) = 0; /* If one of the data members contains an empty class, so does T. */ if (CLASS_TYPE_P (type) && CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type)) CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1; } /* This is used by -Weffc++ (see below). Warn only for pointers to members which might hold dynamic memory. So do not warn for pointers to functions or pointers to members. */ if (TYPE_PTR_P (type) && !TYPE_PTRFN_P (type) && !TYPE_PTR_TO_MEMBER_P (type)) has_pointers = true; if (CLASS_TYPE_P (type)) { if (CLASSTYPE_REF_FIELDS_NEED_INIT (type)) SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1); if (CLASSTYPE_READONLY_FIELDS_NEED_INIT (type)) SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1); } if (DECL_MUTABLE_P (x) || TYPE_HAS_MUTABLE_P (type)) CLASSTYPE_HAS_MUTABLE (t) = 1; if (! layout_pod_type_p (type)) /* DR 148 now allows pointers to members (which are POD themselves), to be allowed in POD structs. */ CLASSTYPE_NON_LAYOUT_POD_P (t) = 1; if (!std_layout_type_p (type)) CLASSTYPE_NON_STD_LAYOUT (t) = 1; if (! zero_init_p (type)) CLASSTYPE_NON_ZERO_INIT_P (t) = 1; /* If any field is const, the structure type is pseudo-const. */ if (CP_TYPE_CONST_P (type)) { C_TYPE_FIELDS_READONLY (t) = 1; if (DECL_INITIAL (x) == NULL_TREE) SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1); /* ARM $12.6.2: [A member initializer list] (or, for an aggregate, initialization by a brace-enclosed list) is the only way to initialize nonstatic const and reference members. */ TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1; } /* A field that is pseudo-const makes the structure likewise. */ else if (CLASS_TYPE_P (type)) { C_TYPE_FIELDS_READONLY (t) |= C_TYPE_FIELDS_READONLY (type); SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, CLASSTYPE_READONLY_FIELDS_NEED_INIT (t) | CLASSTYPE_READONLY_FIELDS_NEED_INIT (type)); } /* Core issue 80: A nonstatic data member is required to have a different name from the class iff the class has a user-declared constructor. */ if (constructor_name_p (DECL_NAME (x), t) && TYPE_HAS_USER_CONSTRUCTOR (t)) permerror (input_location, "field %q+#D with same name as class", x); /* We set DECL_C_BIT_FIELD in grokbitfield. If the type and width are valid, we'll also set DECL_BIT_FIELD. */ if (! DECL_C_BIT_FIELD (x) || ! check_bitfield_decl (x)) check_field_decl (x, t, cant_have_const_ctor_p, no_const_asn_ref_p, &any_default_members); } /* Effective C++ rule 11: if a class has dynamic memory held by pointers, it should also define a copy constructor and an assignment operator to implement the correct copy semantic (deep vs shallow, etc.). As it is not feasible to check whether the constructors do allocate dynamic memory and store it within members, we approximate the warning like this: -- Warn only if there are members which are pointers -- Warn only if there is a non-trivial constructor (otherwise, there cannot be memory allocated). -- Warn only if there is a non-trivial destructor. We assume that the user at least implemented the cleanup correctly, and a destructor is needed to free dynamic memory. This seems enough for practical purposes. */ if (warn_ecpp && has_pointers && TYPE_HAS_USER_CONSTRUCTOR (t) && TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) && !(TYPE_HAS_INIT_REF (t) && TYPE_HAS_ASSIGN_REF (t))) { warning (OPT_Weffc__, "%q#T has pointer data members", t); if (! TYPE_HAS_INIT_REF (t)) { warning (OPT_Weffc__, " but does not override %<%T(const %T&)%>", t, t); if (!TYPE_HAS_ASSIGN_REF (t)) warning (OPT_Weffc__, " or %<operator=(const %T&)%>", t); } else if (! TYPE_HAS_ASSIGN_REF (t)) warning (OPT_Weffc__, " but does not override %<operator=(const %T&)%>", t); } /* If any of the fields couldn't be packed, unset TYPE_PACKED. */ if (cant_pack) TYPE_PACKED (t) = 0; /* Check anonymous struct/anonymous union fields. */ finish_struct_anon (t); /* We've built up the list of access declarations in reverse order. Fix that now. */ *access_decls = nreverse (*access_decls); } /* If TYPE is an empty class type, records its OFFSET in the table of OFFSETS. */ static int record_subobject_offset (tree type, tree offset, splay_tree offsets) { splay_tree_node n; if (!is_empty_class (type)) return 0; /* Record the location of this empty object in OFFSETS. */ n = splay_tree_lookup (offsets, (splay_tree_key) offset); if (!n) n = splay_tree_insert (offsets, (splay_tree_key) offset, (splay_tree_value) NULL_TREE); n->value = ((splay_tree_value) tree_cons (NULL_TREE, type, (tree) n->value)); return 0; } /* Returns nonzero if TYPE is an empty class type and there is already an entry in OFFSETS for the same TYPE as the same OFFSET. */ static int check_subobject_offset (tree type, tree offset, splay_tree offsets) { splay_tree_node n; tree t; if (!is_empty_class (type)) return 0; /* Record the location of this empty object in OFFSETS. */ n = splay_tree_lookup (offsets, (splay_tree_key) offset); if (!n) return 0; for (t = (tree) n->value; t; t = TREE_CHAIN (t)) if (same_type_p (TREE_VALUE (t), type)) return 1; return 0; } /* Walk through all the subobjects of TYPE (located at OFFSET). Call F for every subobject, passing it the type, offset, and table of OFFSETS. If VBASES_P is one, then virtual non-primary bases should be traversed. If MAX_OFFSET is non-NULL, then subobjects with an offset greater than MAX_OFFSET will not be walked. If F returns a nonzero value, the traversal ceases, and that value is returned. Otherwise, returns zero. */ static int walk_subobject_offsets (tree type, subobject_offset_fn f, tree offset, splay_tree offsets, tree max_offset, int vbases_p) { int r = 0; tree type_binfo = NULL_TREE; /* If this OFFSET is bigger than the MAX_OFFSET, then we should stop. */ if (max_offset && INT_CST_LT (max_offset, offset)) return 0; if (type == error_mark_node) return 0; if (!TYPE_P (type)) { if (abi_version_at_least (2)) type_binfo = type; type = BINFO_TYPE (type); } if (CLASS_TYPE_P (type)) { tree field; tree binfo; int i; /* Avoid recursing into objects that are not interesting. */ if (!CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type)) return 0; /* Record the location of TYPE. */ r = (*f) (type, offset, offsets); if (r) return r; /* Iterate through the direct base classes of TYPE. */ if (!type_binfo) type_binfo = TYPE_BINFO (type); for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, binfo); i++) { tree binfo_offset; if (abi_version_at_least (2) && BINFO_VIRTUAL_P (binfo)) continue; if (!vbases_p && BINFO_VIRTUAL_P (binfo) && !BINFO_PRIMARY_P (binfo)) continue; if (!abi_version_at_least (2)) binfo_offset = size_binop (PLUS_EXPR, offset, BINFO_OFFSET (binfo)); else { tree orig_binfo; /* We cannot rely on BINFO_OFFSET being set for the base class yet, but the offsets for direct non-virtual bases can be calculated by going back to the TYPE. */ orig_binfo = BINFO_BASE_BINFO (TYPE_BINFO (type), i); binfo_offset = size_binop (PLUS_EXPR, offset, BINFO_OFFSET (orig_binfo)); } r = walk_subobject_offsets (binfo, f, binfo_offset, offsets, max_offset, (abi_version_at_least (2) ? /*vbases_p=*/0 : vbases_p)); if (r) return r; } if (abi_version_at_least (2) && CLASSTYPE_VBASECLASSES (type)) { unsigned ix; VEC(tree,gc) *vbases; /* Iterate through the virtual base classes of TYPE. In G++ 3.2, we included virtual bases in the direct base class loop above, which results in incorrect results; the correct offsets for virtual bases are only known when working with the most derived type. */ if (vbases_p) for (vbases = CLASSTYPE_VBASECLASSES (type), ix = 0; VEC_iterate (tree, vbases, ix, binfo); ix++) { r = walk_subobject_offsets (binfo, f, size_binop (PLUS_EXPR, offset, BINFO_OFFSET (binfo)), offsets, max_offset, /*vbases_p=*/0); if (r) return r; } else { /* We still have to walk the primary base, if it is virtual. (If it is non-virtual, then it was walked above.) */ tree vbase = get_primary_binfo (type_binfo); if (vbase && BINFO_VIRTUAL_P (vbase) && BINFO_PRIMARY_P (vbase) && BINFO_INHERITANCE_CHAIN (vbase) == type_binfo) { r = (walk_subobject_offsets (vbase, f, offset, offsets, max_offset, /*vbases_p=*/0)); if (r) return r; } } } /* Iterate through the fields of TYPE. */ for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) if (TREE_CODE (field) == FIELD_DECL && !DECL_ARTIFICIAL (field)) { tree field_offset; if (abi_version_at_least (2)) field_offset = byte_position (field); else /* In G++ 3.2, DECL_FIELD_OFFSET was used. */ field_offset = DECL_FIELD_OFFSET (field); r = walk_subobject_offsets (TREE_TYPE (field), f, size_binop (PLUS_EXPR, offset, field_offset), offsets, max_offset, /*vbases_p=*/1); if (r) return r; } } else if (TREE_CODE (type) == ARRAY_TYPE) { tree element_type = strip_array_types (type); tree domain = TYPE_DOMAIN (type); tree index; /* Avoid recursing into objects that are not interesting. */ if (!CLASS_TYPE_P (element_type) || !CLASSTYPE_CONTAINS_EMPTY_CLASS_P (element_type)) return 0; /* Step through each of the elements in the array. */ for (index = size_zero_node; /* G++ 3.2 had an off-by-one error here. */ (abi_version_at_least (2) ? !INT_CST_LT (TYPE_MAX_VALUE (domain), index) : INT_CST_LT (index, TYPE_MAX_VALUE (domain))); index = size_binop (PLUS_EXPR, index, size_one_node)) { r = walk_subobject_offsets (TREE_TYPE (type), f, offset, offsets, max_offset, /*vbases_p=*/1); if (r) return r; offset = size_binop (PLUS_EXPR, offset, TYPE_SIZE_UNIT (TREE_TYPE (type))); /* If this new OFFSET is bigger than the MAX_OFFSET, then there's no point in iterating through the remaining elements of the array. */ if (max_offset && INT_CST_LT (max_offset, offset)) break; } } return 0; } /* Record all of the empty subobjects of TYPE (either a type or a binfo). If IS_DATA_MEMBER is true, then a non-static data member is being placed at OFFSET; otherwise, it is a base class that is being placed at OFFSET. */ static void record_subobject_offsets (tree type, tree offset, splay_tree offsets, bool is_data_member) { tree max_offset; /* If recording subobjects for a non-static data member or a non-empty base class , we do not need to record offsets beyond the size of the biggest empty class. Additional data members will go at the end of the class. Additional base classes will go either at offset zero (if empty, in which case they cannot overlap with offsets past the size of the biggest empty class) or at the end of the class. However, if we are placing an empty base class, then we must record all offsets, as either the empty class is at offset zero (where other empty classes might later be placed) or at the end of the class (where other objects might then be placed, so other empty subobjects might later overlap). */ if (is_data_member || !is_empty_class (BINFO_TYPE (type))) max_offset = sizeof_biggest_empty_class; else max_offset = NULL_TREE; walk_subobject_offsets (type, record_subobject_offset, offset, offsets, max_offset, is_data_member); } /* Returns nonzero if any of the empty subobjects of TYPE (located at OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero, virtual bases of TYPE are examined. */ static int layout_conflict_p (tree type, tree offset, splay_tree offsets, int vbases_p) { splay_tree_node max_node; /* Get the node in OFFSETS that indicates the maximum offset where an empty subobject is located. */ max_node = splay_tree_max (offsets); /* If there aren't any empty subobjects, then there's no point in performing this check. */ if (!max_node) return 0; return walk_subobject_offsets (type, check_subobject_offset, offset, offsets, (tree) (max_node->key), vbases_p); } /* DECL is a FIELD_DECL corresponding either to a base subobject of a non-static data member of the type indicated by RLI. BINFO is the binfo corresponding to the base subobject, OFFSETS maps offsets to types already located at those offsets. This function determines the position of the DECL. */ static void layout_nonempty_base_or_field (record_layout_info rli, tree decl, tree binfo, splay_tree offsets) { tree offset = NULL_TREE; bool field_p; tree type; if (binfo) { /* For the purposes of determining layout conflicts, we want to use the class type of BINFO; TREE_TYPE (DECL) will be the CLASSTYPE_AS_BASE version, which does not contain entries for zero-sized bases. */ type = TREE_TYPE (binfo); field_p = false; } else { type = TREE_TYPE (decl); field_p = true; } /* Try to place the field. It may take more than one try if we have a hard time placing the field without putting two objects of the same type at the same address. */ while (1) { struct record_layout_info_s old_rli = *rli; /* Place this field. */ place_field (rli, decl); offset = byte_position (decl); /* We have to check to see whether or not there is already something of the same type at the offset we're about to use. For example, consider: struct S {}; struct T : public S { int i; }; struct U : public S, public T {}; Here, we put S at offset zero in U. Then, we can't put T at offset zero -- its S component would be at the same address as the S we already allocated. So, we have to skip ahead. Since all data members, including those whose type is an empty class, have nonzero size, any overlap can happen only with a direct or indirect base-class -- it can't happen with a data member. */ /* In a union, overlap is permitted; all members are placed at offset zero. */ if (TREE_CODE (rli->t) == UNION_TYPE) break; /* G++ 3.2 did not check for overlaps when placing a non-empty virtual base. */ if (!abi_version_at_least (2) && binfo && BINFO_VIRTUAL_P (binfo)) break; if (layout_conflict_p (field_p ? type : binfo, offset, offsets, field_p)) { /* Strip off the size allocated to this field. That puts us at the first place we could have put the field with proper alignment. */ *rli = old_rli; /* Bump up by the alignment required for the type. */ rli->bitpos = size_binop (PLUS_EXPR, rli->bitpos, bitsize_int (binfo ? CLASSTYPE_ALIGN (type) : TYPE_ALIGN (type))); normalize_rli (rli); } else /* There was no conflict. We're done laying out this field. */ break; } /* Now that we know where it will be placed, update its BINFO_OFFSET. */ if (binfo && CLASS_TYPE_P (BINFO_TYPE (binfo))) /* Indirect virtual bases may have a nonzero BINFO_OFFSET at this point because their BINFO_OFFSET is copied from another hierarchy. Therefore, we may not need to add the entire OFFSET. */ propagate_binfo_offsets (binfo, size_diffop_loc (input_location, convert (ssizetype, offset), convert (ssizetype, BINFO_OFFSET (binfo)))); } /* Returns true if TYPE is empty and OFFSET is nonzero. */ static int empty_base_at_nonzero_offset_p (tree type, tree offset, splay_tree offsets ATTRIBUTE_UNUSED) { return is_empty_class (type) && !integer_zerop (offset); } /* Layout the empty base BINFO. EOC indicates the byte currently just past the end of the class, and should be correctly aligned for a class of the type indicated by BINFO; OFFSETS gives the offsets of the empty bases allocated so far. T is the most derived type. Return nonzero iff we added it at the end. */ static bool layout_empty_base (record_layout_info rli, tree binfo, tree eoc, splay_tree offsets) { tree alignment; tree basetype = BINFO_TYPE (binfo); bool atend = false; /* This routine should only be used for empty classes. */ gcc_assert (is_empty_class (basetype)); alignment = ssize_int (CLASSTYPE_ALIGN_UNIT (basetype)); if (!integer_zerop (BINFO_OFFSET (binfo))) { if (abi_version_at_least (2)) propagate_binfo_offsets (binfo, size_diffop_loc (input_location, size_zero_node, BINFO_OFFSET (binfo))); else warning (OPT_Wabi, "offset of empty base %qT may not be ABI-compliant and may" "change in a future version of GCC", BINFO_TYPE (binfo)); } /* This is an empty base class. We first try to put it at offset zero. */ if (layout_conflict_p (binfo, BINFO_OFFSET (binfo), offsets, /*vbases_p=*/0)) { /* That didn't work. Now, we move forward from the next available spot in the class. */ atend = true; propagate_binfo_offsets (binfo, convert (ssizetype, eoc)); while (1) { if (!layout_conflict_p (binfo, BINFO_OFFSET (binfo), offsets, /*vbases_p=*/0)) /* We finally found a spot where there's no overlap. */ break; /* There's overlap here, too. Bump along to the next spot. */ propagate_binfo_offsets (binfo, alignment); } } if (CLASSTYPE_USER_ALIGN (basetype)) { rli->record_align = MAX (rli->record_align, CLASSTYPE_ALIGN (basetype)); if (warn_packed) rli->unpacked_align = MAX (rli->unpacked_align, CLASSTYPE_ALIGN (basetype)); TYPE_USER_ALIGN (rli->t) = 1; } return atend; } /* Layout the base given by BINFO in the class indicated by RLI. *BASE_ALIGN is a running maximum of the alignments of any base class. OFFSETS gives the location of empty base subobjects. T is the most derived type. Return nonzero if the new object cannot be nearly-empty. A new FIELD_DECL is inserted at *NEXT_FIELD, unless BINFO is for an empty base class. Returns the location at which the next field should be inserted. */ static tree * build_base_field (record_layout_info rli, tree binfo, splay_tree offsets, tree *next_field) { tree t = rli->t; tree basetype = BINFO_TYPE (binfo); if (!COMPLETE_TYPE_P (basetype)) /* This error is now reported in xref_tag, thus giving better location information. */ return next_field; /* Place the base class. */ if (!is_empty_class (basetype)) { tree decl; /* The containing class is non-empty because it has a non-empty base class. */ CLASSTYPE_EMPTY_P (t) = 0; /* Create the FIELD_DECL. */ decl = build_decl (input_location, FIELD_DECL, NULL_TREE, CLASSTYPE_AS_BASE (basetype)); DECL_ARTIFICIAL (decl) = 1; DECL_IGNORED_P (decl) = 1; DECL_FIELD_CONTEXT (decl) = t; if (CLASSTYPE_AS_BASE (basetype)) { DECL_SIZE (decl) = CLASSTYPE_SIZE (basetype); DECL_SIZE_UNIT (decl) = CLASSTYPE_SIZE_UNIT (basetype); DECL_ALIGN (decl) = CLASSTYPE_ALIGN (basetype); DECL_USER_ALIGN (decl) = CLASSTYPE_USER_ALIGN (basetype); DECL_MODE (decl) = TYPE_MODE (basetype); DECL_FIELD_IS_BASE (decl) = 1; /* Try to place the field. It may take more than one try if we have a hard time placing the field without putting two objects of the same type at the same address. */ layout_nonempty_base_or_field (rli, decl, binfo, offsets); /* Add the new FIELD_DECL to the list of fields for T. */ TREE_CHAIN (decl) = *next_field; *next_field = decl; next_field = &TREE_CHAIN (decl); } } else { tree eoc; bool atend; /* On some platforms (ARM), even empty classes will not be byte-aligned. */ eoc = round_up_loc (input_location, rli_size_unit_so_far (rli), CLASSTYPE_ALIGN_UNIT (basetype)); atend = layout_empty_base (rli, binfo, eoc, offsets); /* A nearly-empty class "has no proper base class that is empty, not morally virtual, and at an offset other than zero." */ if (!BINFO_VIRTUAL_P (binfo) && CLASSTYPE_NEARLY_EMPTY_P (t)) { if (atend) CLASSTYPE_NEARLY_EMPTY_P (t) = 0; /* The check above (used in G++ 3.2) is insufficient because an empty class placed at offset zero might itself have an empty base at a nonzero offset. */ else if (walk_subobject_offsets (basetype, empty_base_at_nonzero_offset_p, size_zero_node, /*offsets=*/NULL, /*max_offset=*/NULL_TREE, /*vbases_p=*/true)) { if (abi_version_at_least (2)) CLASSTYPE_NEARLY_EMPTY_P (t) = 0; else warning (OPT_Wabi, "class %qT will be considered nearly empty in a " "future version of GCC", t); } } /* We do not create a FIELD_DECL for empty base classes because it might overlap some other field. We want to be able to create CONSTRUCTORs for the class by iterating over the FIELD_DECLs, and the back end does not handle overlapping FIELD_DECLs. */ /* An empty virtual base causes a class to be non-empty -- but in that case we do not need to clear CLASSTYPE_EMPTY_P here because that was already done when the virtual table pointer was created. */ } /* Record the offsets of BINFO and its base subobjects. */ record_subobject_offsets (binfo, BINFO_OFFSET (binfo), offsets, /*is_data_member=*/false); return next_field; } /* Layout all of the non-virtual base classes. Record empty subobjects in OFFSETS. T is the most derived type. Return nonzero if the type cannot be nearly empty. The fields created corresponding to the base classes will be inserted at *NEXT_FIELD. */ static void build_base_fields (record_layout_info rli, splay_tree offsets, tree *next_field) { /* Chain to hold all the new FIELD_DECLs which stand in for base class subobjects. */ tree t = rli->t; int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t)); int i; /* The primary base class is always allocated first. */ if (CLASSTYPE_HAS_PRIMARY_BASE_P (t)) next_field = build_base_field (rli, CLASSTYPE_PRIMARY_BINFO (t), offsets, next_field); /* Now allocate the rest of the bases. */ for (i = 0; i < n_baseclasses; ++i) { tree base_binfo; base_binfo = BINFO_BASE_BINFO (TYPE_BINFO (t), i); /* The primary base was already allocated above, so we don't need to allocate it again here. */ if (base_binfo == CLASSTYPE_PRIMARY_BINFO (t)) continue; /* Virtual bases are added at the end (a primary virtual base will have already been added). */ if (BINFO_VIRTUAL_P (base_binfo)) continue; next_field = build_base_field (rli, base_binfo, offsets, next_field); } } /* Go through the TYPE_METHODS of T issuing any appropriate diagnostics, figuring out which methods override which other methods, and so forth. */ static void check_methods (tree t) { tree x; for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x)) { check_for_override (x, t); if (DECL_PURE_VIRTUAL_P (x) && ! DECL_VINDEX (x)) error ("initializer specified for non-virtual method %q+D", x); /* The name of the field is the original field name Save this in auxiliary field for later overloading. */ if (DECL_VINDEX (x)) { TYPE_POLYMORPHIC_P (t) = 1; if (DECL_PURE_VIRTUAL_P (x)) VEC_safe_push (tree, gc, CLASSTYPE_PURE_VIRTUALS (t), x); } /* All user-provided destructors are non-trivial. */ if (DECL_DESTRUCTOR_P (x) && user_provided_p (x)) TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = 1; } } /* FN is a constructor or destructor. Clone the declaration to create a specialized in-charge or not-in-charge version, as indicated by NAME. */ static tree build_clone (tree fn, tree name) { tree parms; tree clone; /* Copy the function. */ clone = copy_decl (fn); /* Reset the function name. */ DECL_NAME (clone) = name; SET_DECL_ASSEMBLER_NAME (clone, NULL_TREE); /* Remember where this function came from. */ DECL_ABSTRACT_ORIGIN (clone) = fn; /* Make it easy to find the CLONE given the FN. */ TREE_CHAIN (clone) = TREE_CHAIN (fn); TREE_CHAIN (fn) = clone; /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */ if (TREE_CODE (clone) == TEMPLATE_DECL) { tree result = build_clone (DECL_TEMPLATE_RESULT (clone), name); DECL_TEMPLATE_RESULT (clone) = result; DECL_TEMPLATE_INFO (result) = copy_node (DECL_TEMPLATE_INFO (result)); DECL_TI_TEMPLATE (result) = clone; TREE_TYPE (clone) = TREE_TYPE (result); return clone; } DECL_CLONED_FUNCTION (clone) = fn; /* There's no pending inline data for this function. */ DECL_PENDING_INLINE_INFO (clone) = NULL; DECL_PENDING_INLINE_P (clone) = 0; /* The base-class destructor is not virtual. */ if (name == base_dtor_identifier) { DECL_VIRTUAL_P (clone) = 0; if (TREE_CODE (clone) != TEMPLATE_DECL) DECL_VINDEX (clone) = NULL_TREE; } /* If there was an in-charge parameter, drop it from the function type. */ if (DECL_HAS_IN_CHARGE_PARM_P (clone)) { tree basetype; tree parmtypes; tree exceptions; exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone)); basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone)); parmtypes = TYPE_ARG_TYPES (TREE_TYPE (clone)); /* Skip the `this' parameter. */ parmtypes = TREE_CHAIN (parmtypes); /* Skip the in-charge parameter. */ parmtypes = TREE_CHAIN (parmtypes); /* And the VTT parm, in a complete [cd]tor. */ if (DECL_HAS_VTT_PARM_P (fn) && ! DECL_NEEDS_VTT_PARM_P (clone)) parmtypes = TREE_CHAIN (parmtypes); /* If this is subobject constructor or destructor, add the vtt parameter. */ TREE_TYPE (clone) = build_method_type_directly (basetype, TREE_TYPE (TREE_TYPE (clone)), parmtypes); if (exceptions) TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone), exceptions); TREE_TYPE (clone) = cp_build_type_attribute_variant (TREE_TYPE (clone), TYPE_ATTRIBUTES (TREE_TYPE (fn))); } /* Copy the function parameters. */ DECL_ARGUMENTS (clone) = copy_list (DECL_ARGUMENTS (clone)); /* Remove the in-charge parameter. */ if (DECL_HAS_IN_CHARGE_PARM_P (clone)) { TREE_CHAIN (DECL_ARGUMENTS (clone)) = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone))); DECL_HAS_IN_CHARGE_PARM_P (clone) = 0; } /* And the VTT parm, in a complete [cd]tor. */ if (DECL_HAS_VTT_PARM_P (fn)) { if (DECL_NEEDS_VTT_PARM_P (clone)) DECL_HAS_VTT_PARM_P (clone) = 1; else { TREE_CHAIN (DECL_ARGUMENTS (clone)) = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone))); DECL_HAS_VTT_PARM_P (clone) = 0; } } for (parms = DECL_ARGUMENTS (clone); parms; parms = TREE_CHAIN (parms)) { DECL_CONTEXT (parms) = clone; cxx_dup_lang_specific_decl (parms); } /* Create the RTL for this function. */ SET_DECL_RTL (clone, NULL_RTX); rest_of_decl_compilation (clone, /*top_level=*/1, at_eof); if (pch_file) note_decl_for_pch (clone); return clone; } /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do not invoke this function directly. For a non-thunk function, returns the address of the slot for storing the function it is a clone of. Otherwise returns NULL_TREE. If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if cloned_function is unset. This is to support the separate DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter on a template makes sense, but not the former. */ tree * decl_cloned_function_p (const_tree decl, bool just_testing) { tree *ptr; if (just_testing) decl = STRIP_TEMPLATE (decl); if (TREE_CODE (decl) != FUNCTION_DECL || !DECL_LANG_SPECIFIC (decl) || DECL_LANG_SPECIFIC (decl)->u.fn.thunk_p) { #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007) if (!just_testing) lang_check_failed (__FILE__, __LINE__, __FUNCTION__); else #endif return NULL; } ptr = &DECL_LANG_SPECIFIC (decl)->u.fn.u5.cloned_function; if (just_testing && *ptr == NULL_TREE) return NULL; else return ptr; } /* Produce declarations for all appropriate clones of FN. If UPDATE_METHOD_VEC_P is nonzero, the clones are added to the CLASTYPE_METHOD_VEC as well. */ void clone_function_decl (tree fn, int update_method_vec_p) { tree clone; /* Avoid inappropriate cloning. */ if (TREE_CHAIN (fn) && DECL_CLONED_FUNCTION_P (TREE_CHAIN (fn))) return; if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn)) { /* For each constructor, we need two variants: an in-charge version and a not-in-charge version. */ clone = build_clone (fn, complete_ctor_identifier); if (update_method_vec_p) add_method (DECL_CONTEXT (clone), clone, NULL_TREE); clone = build_clone (fn, base_ctor_identifier); if (update_method_vec_p) add_method (DECL_CONTEXT (clone), clone, NULL_TREE); } else { gcc_assert (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn)); /* For each destructor, we need three variants: an in-charge version, a not-in-charge version, and an in-charge deleting version. We clone the deleting version first because that means it will go second on the TYPE_METHODS list -- and that corresponds to the correct layout order in the virtual function table. For a non-virtual destructor, we do not build a deleting destructor. */ if (DECL_VIRTUAL_P (fn)) { clone = build_clone (fn, deleting_dtor_identifier); if (update_method_vec_p) add_method (DECL_CONTEXT (clone), clone, NULL_TREE); } clone = build_clone (fn, complete_dtor_identifier); if (update_method_vec_p) add_method (DECL_CONTEXT (clone), clone, NULL_TREE); clone = build_clone (fn, base_dtor_identifier); if (update_method_vec_p) add_method (DECL_CONTEXT (clone), clone, NULL_TREE); } /* Note that this is an abstract function that is never emitted. */ DECL_ABSTRACT (fn) = 1; } /* DECL is an in charge constructor, which is being defined. This will have had an in class declaration, from whence clones were declared. An out-of-class definition can specify additional default arguments. As it is the clones that are involved in overload resolution, we must propagate the information from the DECL to its clones. */ void adjust_clone_args (tree decl) { tree clone; for (clone = TREE_CHAIN (decl); clone && DECL_CLONED_FUNCTION_P (clone); clone = TREE_CHAIN (clone)) { tree orig_clone_parms = TYPE_ARG_TYPES (TREE_TYPE (clone)); tree orig_decl_parms = TYPE_ARG_TYPES (TREE_TYPE (decl)); tree decl_parms, clone_parms; clone_parms = orig_clone_parms; /* Skip the 'this' parameter. */ orig_clone_parms = TREE_CHAIN (orig_clone_parms); orig_decl_parms = TREE_CHAIN (orig_decl_parms); if (DECL_HAS_IN_CHARGE_PARM_P (decl)) orig_decl_parms = TREE_CHAIN (orig_decl_parms); if (DECL_HAS_VTT_PARM_P (decl)) orig_decl_parms = TREE_CHAIN (orig_decl_parms); clone_parms = orig_clone_parms; if (DECL_HAS_VTT_PARM_P (clone)) clone_parms = TREE_CHAIN (clone_parms); for (decl_parms = orig_decl_parms; decl_parms; decl_parms = TREE_CHAIN (decl_parms), clone_parms = TREE_CHAIN (clone_parms)) { gcc_assert (same_type_p (TREE_TYPE (decl_parms), TREE_TYPE (clone_parms))); if (TREE_PURPOSE (decl_parms) && !TREE_PURPOSE (clone_parms)) { /* A default parameter has been added. Adjust the clone's parameters. */ tree exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone)); tree attrs = TYPE_ATTRIBUTES (TREE_TYPE (clone)); tree basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone)); tree type; clone_parms = orig_decl_parms; if (DECL_HAS_VTT_PARM_P (clone)) { clone_parms = tree_cons (TREE_PURPOSE (orig_clone_parms), TREE_VALUE (orig_clone_parms), clone_parms); TREE_TYPE (clone_parms) = TREE_TYPE (orig_clone_parms); } type = build_method_type_directly (basetype, TREE_TYPE (TREE_TYPE (clone)), clone_parms); if (exceptions) type = build_exception_variant (type, exceptions); if (attrs) type = cp_build_type_attribute_variant (type, attrs); TREE_TYPE (clone) = type; clone_parms = NULL_TREE; break; } } gcc_assert (!clone_parms); } } /* For each of the constructors and destructors in T, create an in-charge and not-in-charge variant. */ static void clone_constructors_and_destructors (tree t) { tree fns; /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail out now. */ if (!CLASSTYPE_METHOD_VEC (t)) return; for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns)) clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1); for (fns = CLASSTYPE_DESTRUCTORS (t); fns; fns = OVL_NEXT (fns)) clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1); } /* Returns true iff class T has a user-defined constructor other than the default constructor. */ bool type_has_user_nondefault_constructor (tree t) { tree fns; if (!TYPE_HAS_USER_CONSTRUCTOR (t)) return false; for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns)) { tree fn = OVL_CURRENT (fns); if (!DECL_ARTIFICIAL (fn) && (TREE_CODE (fn) == TEMPLATE_DECL || (skip_artificial_parms_for (fn, DECL_ARGUMENTS (fn)) != NULL_TREE))) return true; } return false; } /* Returns true iff FN is a user-provided function, i.e. user-declared and not defaulted at its first declaration; or explicit, private, protected, or non-const. */ bool user_provided_p (tree fn) { if (TREE_CODE (fn) == TEMPLATE_DECL) return true; else return (!DECL_ARTIFICIAL (fn) && !DECL_DEFAULTED_IN_CLASS_P (fn)); } /* Returns true iff class T has a user-provided constructor. */ bool type_has_user_provided_constructor (tree t) { tree fns; if (!CLASS_TYPE_P (t)) return false; if (!TYPE_HAS_USER_CONSTRUCTOR (t)) return false; /* This can happen in error cases; avoid crashing. */ if (!CLASSTYPE_METHOD_VEC (t)) return false; for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns)) if (user_provided_p (OVL_CURRENT (fns))) return true; return false; } /* Returns true iff class T has a user-provided default constructor. */ bool type_has_user_provided_default_constructor (tree t) { tree fns, args; if (!TYPE_HAS_USER_CONSTRUCTOR (t)) return false; for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns)) { tree fn = OVL_CURRENT (fns); if (TREE_CODE (fn) == FUNCTION_DECL && user_provided_p (fn)) { args = FUNCTION_FIRST_USER_PARMTYPE (fn); while (args && TREE_PURPOSE (args)) args = TREE_CHAIN (args); if (!args || args == void_list_node) return true; } } return false; } /* Remove all zero-width bit-fields from T. */ static void remove_zero_width_bit_fields (tree t) { tree *fieldsp; fieldsp = &TYPE_FIELDS (t); while (*fieldsp) { if (TREE_CODE (*fieldsp) == FIELD_DECL && DECL_C_BIT_FIELD (*fieldsp) /* We should not be confused by the fact that grokbitfield temporarily sets the width of the bit field into DECL_INITIAL (*fieldsp). check_bitfield_decl eventually sets DECL_SIZE (*fieldsp) to that width. */ && integer_zerop (DECL_SIZE (*fieldsp))) *fieldsp = TREE_CHAIN (*fieldsp); else fieldsp = &TREE_CHAIN (*fieldsp); } } /* Returns TRUE iff we need a cookie when dynamically allocating an array whose elements have the indicated class TYPE. */ static bool type_requires_array_cookie (tree type) { tree fns; bool has_two_argument_delete_p = false; gcc_assert (CLASS_TYPE_P (type)); /* If there's a non-trivial destructor, we need a cookie. In order to iterate through the array calling the destructor for each element, we'll have to know how many elements there are. */ if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) return true; /* If the usual deallocation function is a two-argument whose second argument is of type `size_t', then we have to pass the size of the array to the deallocation function, so we will need to store a cookie. */ fns = lookup_fnfields (TYPE_BINFO (type), ansi_opname (VEC_DELETE_EXPR), /*protect=*/0); /* If there are no `operator []' members, or the lookup is ambiguous, then we don't need a cookie. */ if (!fns || fns == error_mark_node) return false; /* Loop through all of the functions. */ for (fns = BASELINK_FUNCTIONS (fns); fns; fns = OVL_NEXT (fns)) { tree fn; tree second_parm; /* Select the current function. */ fn = OVL_CURRENT (fns); /* See if this function is a one-argument delete function. If it is, then it will be the usual deallocation function. */ second_parm = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (fn))); if (second_parm == void_list_node) return false; /* Do not consider this function if its second argument is an ellipsis. */ if (!second_parm) continue; /* Otherwise, if we have a two-argument function and the second argument is `size_t', it will be the usual deallocation function -- unless there is one-argument function, too. */ if (TREE_CHAIN (second_parm) == void_list_node && same_type_p (TREE_VALUE (second_parm), size_type_node)) has_two_argument_delete_p = true; } return has_two_argument_delete_p; } /* Check the validity of the bases and members declared in T. Add any implicitly-generated functions (like copy-constructors and assignment operators). Compute various flag bits (like CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++ level: i.e., independently of the ABI in use. */ static void check_bases_and_members (tree t) { /* Nonzero if the implicitly generated copy constructor should take a non-const reference argument. */ int cant_have_const_ctor; /* Nonzero if the implicitly generated assignment operator should take a non-const reference argument. */ int no_const_asn_ref; tree access_decls; bool saved_complex_asn_ref; bool saved_nontrivial_dtor; tree fn; /* By default, we use const reference arguments and generate default constructors. */ cant_have_const_ctor = 0; no_const_asn_ref = 0; /* Check all the base-classes. */ check_bases (t, &cant_have_const_ctor, &no_const_asn_ref); /* Check all the method declarations. */ check_methods (t); /* Save the initial values of these flags which only indicate whether or not the class has user-provided functions. As we analyze the bases and members we can set these flags for other reasons. */ saved_complex_asn_ref = TYPE_HAS_COMPLEX_ASSIGN_REF (t); saved_nontrivial_dtor = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t); /* Check all the data member declarations. We cannot call check_field_decls until we have called check_bases check_methods, as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR being set appropriately. */ check_field_decls (t, &access_decls, &cant_have_const_ctor, &no_const_asn_ref); /* A nearly-empty class has to be vptr-containing; a nearly empty class contains just a vptr. */ if (!TYPE_CONTAINS_VPTR_P (t)) CLASSTYPE_NEARLY_EMPTY_P (t) = 0; /* Do some bookkeeping that will guide the generation of implicitly declared member functions. */ TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_CONTAINS_VPTR_P (t); /* We need to call a constructor for this class if it has a user-provided constructor, or if the default constructor is going to initialize the vptr. (This is not an if-and-only-if; TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members themselves need constructing.) */ TYPE_NEEDS_CONSTRUCTING (t) |= (type_has_user_provided_constructor (t) || TYPE_CONTAINS_VPTR_P (t)); /* [dcl.init.aggr] An aggregate is an array or a class with no user-provided constructors ... and no virtual functions. Again, other conditions for being an aggregate are checked elsewhere. */ CLASSTYPE_NON_AGGREGATE (t) |= (type_has_user_provided_constructor (t) || TYPE_POLYMORPHIC_P (t)); /* This is the C++98/03 definition of POD; it changed in C++0x, but we retain the old definition internally for ABI reasons. */ CLASSTYPE_NON_LAYOUT_POD_P (t) |= (CLASSTYPE_NON_AGGREGATE (t) || saved_nontrivial_dtor || saved_complex_asn_ref); CLASSTYPE_NON_STD_LAYOUT (t) |= TYPE_CONTAINS_VPTR_P (t); TYPE_HAS_COMPLEX_ASSIGN_REF (t) |= TYPE_CONTAINS_VPTR_P (t); TYPE_HAS_COMPLEX_DFLT (t) |= TYPE_CONTAINS_VPTR_P (t); /* If the class has no user-declared constructor, but does have non-static const or reference data members that can never be initialized, issue a warning. */ if (warn_uninitialized /* Classes with user-declared constructors are presumed to initialize these members. */ && !TYPE_HAS_USER_CONSTRUCTOR (t) /* Aggregates can be initialized with brace-enclosed initializers. */ && CLASSTYPE_NON_AGGREGATE (t)) { tree field; for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field)) { tree type; if (TREE_CODE (field) != FIELD_DECL) continue; type = TREE_TYPE (field); if (TREE_CODE (type) == REFERENCE_TYPE) warning (OPT_Wuninitialized, "non-static reference %q+#D " "in class without a constructor", field); else if (CP_TYPE_CONST_P (type) && (!CLASS_TYPE_P (type) || !TYPE_HAS_DEFAULT_CONSTRUCTOR (type))) warning (OPT_Wuninitialized, "non-static const member %q+#D " "in class without a constructor", field); } } /* Synthesize any needed methods. */ add_implicitly_declared_members (t, cant_have_const_ctor, no_const_asn_ref); /* Check defaulted declarations here so we have cant_have_const_ctor and don't need to worry about clones. */ for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn)) if (DECL_DEFAULTED_IN_CLASS_P (fn)) { int copy = copy_fn_p (fn); if (copy > 0) { bool imp_const_p = (DECL_CONSTRUCTOR_P (fn) ? !cant_have_const_ctor : !no_const_asn_ref); bool fn_const_p = (copy == 2); if (fn_const_p && !imp_const_p) /* If the function is defaulted outside the class, we just give the synthesis error. */ error ("%q+D declared to take const reference, but implicit " "declaration would take non-const", fn); else if (imp_const_p && !fn_const_p) error ("%q+D declared to take non-const reference cannot be " "defaulted in the class body", fn); } defaulted_late_check (fn); } if (LAMBDA_TYPE_P (t)) { /* "The closure type associated with a lambda-expression has a deleted default constructor and a deleted copy assignment operator." */ TYPE_NEEDS_CONSTRUCTING (t) = 1; TYPE_HAS_DEFAULT_CONSTRUCTOR (t) = 0; CLASSTYPE_LAZY_DEFAULT_CTOR (t) = 0; TYPE_HAS_ASSIGN_REF (t) = 0; CLASSTYPE_LAZY_ASSIGNMENT_OP (t) = 0; /* "This class type is not an aggregate." */ CLASSTYPE_NON_AGGREGATE (t) = 1; } /* Create the in-charge and not-in-charge variants of constructors and destructors. */ clone_constructors_and_destructors (t); /* Process the using-declarations. */ for (; access_decls; access_decls = TREE_CHAIN (access_decls)) handle_using_decl (TREE_VALUE (access_decls), t); /* Build and sort the CLASSTYPE_METHOD_VEC. */ finish_struct_methods (t); /* Figure out whether or not we will need a cookie when dynamically allocating an array of this type. */ TYPE_LANG_SPECIFIC (t)->u.c.vec_new_uses_cookie = type_requires_array_cookie (t); } /* If T needs a pointer to its virtual function table, set TYPE_VFIELD accordingly. If a new vfield was created (because T doesn't have a primary base class), then the newly created field is returned. It is not added to the TYPE_FIELDS list; it is the caller's responsibility to do that. Accumulate declared virtual functions on VIRTUALS_P. */ static tree create_vtable_ptr (tree t, tree* virtuals_p) { tree fn; /* Collect the virtual functions declared in T. */ for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn)) if (DECL_VINDEX (fn) && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn) && TREE_CODE (DECL_VINDEX (fn)) != INTEGER_CST) { tree new_virtual = make_node (TREE_LIST); BV_FN (new_virtual) = fn; BV_DELTA (new_virtual) = integer_zero_node; BV_VCALL_INDEX (new_virtual) = NULL_TREE; TREE_CHAIN (new_virtual) = *virtuals_p; *virtuals_p = new_virtual; } /* If we couldn't find an appropriate base class, create a new field here. Even if there weren't any new virtual functions, we might need a new virtual function table if we're supposed to include vptrs in all classes that need them. */ if (!TYPE_VFIELD (t) && (*virtuals_p || TYPE_CONTAINS_VPTR_P (t))) { /* We build this decl with vtbl_ptr_type_node, which is a `vtable_entry_type*'. It might seem more precise to use `vtable_entry_type (*)[N]' where N is the number of virtual functions. However, that would require the vtable pointer in base classes to have a different type than the vtable pointer in derived classes. We could make that happen, but that still wouldn't solve all the problems. In particular, the type-based alias analysis code would decide that assignments to the base class vtable pointer can't alias assignments to the derived class vtable pointer, since they have different types. Thus, in a derived class destructor, where the base class constructor was inlined, we could generate bad code for setting up the vtable pointer. Therefore, we use one type for all vtable pointers. We still use a type-correct type; it's just doesn't indicate the array bounds. That's better than using `void*' or some such; it's cleaner, and it let's the alias analysis code know that these stores cannot alias stores to void*! */ tree field; field = build_decl (input_location, FIELD_DECL, get_vfield_name (t), vtbl_ptr_type_node); DECL_VIRTUAL_P (field) = 1; DECL_ARTIFICIAL (field) = 1; DECL_FIELD_CONTEXT (field) = t; DECL_FCONTEXT (field) = t; if (TYPE_PACKED (t)) DECL_PACKED (field) = 1; TYPE_VFIELD (t) = field; /* This class is non-empty. */ CLASSTYPE_EMPTY_P (t) = 0; return field; } return NULL_TREE; } /* Add OFFSET to all base types of BINFO which is a base in the hierarchy dominated by T. OFFSET, which is a type offset, is number of bytes. */ static void propagate_binfo_offsets (tree binfo, tree offset) { int i; tree primary_binfo; tree base_binfo; /* Update BINFO's offset. */ BINFO_OFFSET (binfo) = convert (sizetype, size_binop (PLUS_EXPR, convert (ssizetype, BINFO_OFFSET (binfo)), offset)); /* Find the primary base class. */ primary_binfo = get_primary_binfo (binfo); if (primary_binfo && BINFO_INHERITANCE_CHAIN (primary_binfo) == binfo) propagate_binfo_offsets (primary_binfo, offset); /* Scan all of the bases, pushing the BINFO_OFFSET adjust downwards. */ for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) { /* Don't do the primary base twice. */ if (base_binfo == primary_binfo) continue; if (BINFO_VIRTUAL_P (base_binfo)) continue; propagate_binfo_offsets (base_binfo, offset); } } /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of empty subobjects of T. */ static void layout_virtual_bases (record_layout_info rli, splay_tree offsets) { tree vbase; tree t = rli->t; bool first_vbase = true; tree *next_field; if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) == 0) return; if (!abi_version_at_least(2)) { /* In G++ 3.2, we incorrectly rounded the size before laying out the virtual bases. */ finish_record_layout (rli, /*free_p=*/false); #ifdef STRUCTURE_SIZE_BOUNDARY /* Packed structures don't need to have minimum size. */ if (! TYPE_PACKED (t)) TYPE_ALIGN (t) = MAX (TYPE_ALIGN (t), (unsigned) STRUCTURE_SIZE_BOUNDARY); #endif rli->offset = TYPE_SIZE_UNIT (t); rli->bitpos = bitsize_zero_node; rli->record_align = TYPE_ALIGN (t); } /* Find the last field. The artificial fields created for virtual bases will go after the last extant field to date. */ next_field = &TYPE_FIELDS (t); while (*next_field) next_field = &TREE_CHAIN (*next_field); /* Go through the virtual bases, allocating space for each virtual base that is not already a primary base class. These are allocated in inheritance graph order. */ for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase)) { if (!BINFO_VIRTUAL_P (vbase)) continue; if (!BINFO_PRIMARY_P (vbase)) { tree basetype = TREE_TYPE (vbase); /* This virtual base is not a primary base of any class in the hierarchy, so we have to add space for it. */ next_field = build_base_field (rli, vbase, offsets, next_field); /* If the first virtual base might have been placed at a lower address, had we started from CLASSTYPE_SIZE, rather than TYPE_SIZE, issue a warning. There can be both false positives and false negatives from this warning in rare cases; to deal with all the possibilities would probably require performing both layout algorithms and comparing the results which is not particularly tractable. */ if (warn_abi && first_vbase && (tree_int_cst_lt (size_binop (CEIL_DIV_EXPR, round_up_loc (input_location, CLASSTYPE_SIZE (t), CLASSTYPE_ALIGN (basetype)), bitsize_unit_node), BINFO_OFFSET (vbase)))) warning (OPT_Wabi, "offset of virtual base %qT is not ABI-compliant and " "may change in a future version of GCC", basetype); first_vbase = false; } } } /* Returns the offset of the byte just past the end of the base class BINFO. */ static tree end_of_base (tree binfo) { tree size; if (!CLASSTYPE_AS_BASE (BINFO_TYPE (binfo))) size = TYPE_SIZE_UNIT (char_type_node); else if (is_empty_class (BINFO_TYPE (binfo))) /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to allocate some space for it. It cannot have virtual bases, so TYPE_SIZE_UNIT is fine. */ size = TYPE_SIZE_UNIT (BINFO_TYPE (binfo)); else size = CLASSTYPE_SIZE_UNIT (BINFO_TYPE (binfo)); return size_binop (PLUS_EXPR, BINFO_OFFSET (binfo), size); } /* Returns the offset of the byte just past the end of the base class with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then only non-virtual bases are included. */ static tree end_of_class (tree t, int include_virtuals_p) { tree result = size_zero_node; VEC(tree,gc) *vbases; tree binfo; tree base_binfo; tree offset; int i; for (binfo = TYPE_BINFO (t), i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) { if (!include_virtuals_p && BINFO_VIRTUAL_P (base_binfo) && (!BINFO_PRIMARY_P (base_binfo) || BINFO_INHERITANCE_CHAIN (base_binfo) != TYPE_BINFO (t))) continue; offset = end_of_base (base_binfo); if (INT_CST_LT_UNSIGNED (result, offset)) result = offset; } /* G++ 3.2 did not check indirect virtual bases. */ if (abi_version_at_least (2) && include_virtuals_p) for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0; VEC_iterate (tree, vbases, i, base_binfo); i++) { offset = end_of_base (base_binfo); if (INT_CST_LT_UNSIGNED (result, offset)) result = offset; } return result; } /* Warn about bases of T that are inaccessible because they are ambiguous. For example: struct S {}; struct T : public S {}; struct U : public S, public T {}; Here, `(S*) new U' is not allowed because there are two `S' subobjects of U. */ static void warn_about_ambiguous_bases (tree t) { int i; VEC(tree,gc) *vbases; tree basetype; tree binfo; tree base_binfo; /* If there are no repeated bases, nothing can be ambiguous. */ if (!CLASSTYPE_REPEATED_BASE_P (t)) return; /* Check direct bases. */ for (binfo = TYPE_BINFO (t), i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) { basetype = BINFO_TYPE (base_binfo); if (!lookup_base (t, basetype, ba_unique | ba_quiet, NULL)) warning (0, "direct base %qT inaccessible in %qT due to ambiguity", basetype, t); } /* Check for ambiguous virtual bases. */ if (extra_warnings) for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0; VEC_iterate (tree, vbases, i, binfo); i++) { basetype = BINFO_TYPE (binfo); if (!lookup_base (t, basetype, ba_unique | ba_quiet, NULL)) warning (OPT_Wextra, "virtual base %qT inaccessible in %qT due to ambiguity", basetype, t); } } /* Compare two INTEGER_CSTs K1 and K2. */ static int splay_tree_compare_integer_csts (splay_tree_key k1, splay_tree_key k2) { return tree_int_cst_compare ((tree) k1, (tree) k2); } /* Increase the size indicated in RLI to account for empty classes that are "off the end" of the class. */ static void include_empty_classes (record_layout_info rli) { tree eoc; tree rli_size; /* It might be the case that we grew the class to allocate a zero-sized base class. That won't be reflected in RLI, yet, because we are willing to overlay multiple bases at the same offset. However, now we need to make sure that RLI is big enough to reflect the entire class. */ eoc = end_of_class (rli->t, CLASSTYPE_AS_BASE (rli->t) != NULL_TREE); rli_size = rli_size_unit_so_far (rli); if (TREE_CODE (rli_size) == INTEGER_CST && INT_CST_LT_UNSIGNED (rli_size, eoc)) { if (!abi_version_at_least (2)) /* In version 1 of the ABI, the size of a class that ends with a bitfield was not rounded up to a whole multiple of a byte. Because rli_size_unit_so_far returns only the number of fully allocated bytes, any extra bits were not included in the size. */ rli->bitpos = round_down (rli->bitpos, BITS_PER_UNIT); else /* The size should have been rounded to a whole byte. */ gcc_assert (tree_int_cst_equal (rli->bitpos, round_down (rli->bitpos, BITS_PER_UNIT))); rli->bitpos = size_binop (PLUS_EXPR, rli->bitpos, size_binop (MULT_EXPR, convert (bitsizetype, size_binop (MINUS_EXPR, eoc, rli_size)), bitsize_int (BITS_PER_UNIT))); normalize_rli (rli); } } /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate BINFO_OFFSETs for all of the base-classes. Position the vtable pointer. Accumulate declared virtual functions on VIRTUALS_P. */ static void layout_class_type (tree t, tree *virtuals_p) { tree non_static_data_members; tree field; tree vptr; record_layout_info rli; /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of types that appear at that offset. */ splay_tree empty_base_offsets; /* True if the last field layed out was a bit-field. */ bool last_field_was_bitfield = false; /* The location at which the next field should be inserted. */ tree *next_field; /* T, as a base class. */ tree base_t; /* Keep track of the first non-static data member. */ non_static_data_members = TYPE_FIELDS (t); /* Start laying out the record. */ rli = start_record_layout (t); /* Mark all the primary bases in the hierarchy. */ determine_primary_bases (t); /* Create a pointer to our virtual function table. */ vptr = create_vtable_ptr (t, virtuals_p); /* The vptr is always the first thing in the class. */ if (vptr) { TREE_CHAIN (vptr) = TYPE_FIELDS (t); TYPE_FIELDS (t) = vptr; next_field = &TREE_CHAIN (vptr); place_field (rli, vptr); } else next_field = &TYPE_FIELDS (t); /* Build FIELD_DECLs for all of the non-virtual base-types. */ empty_base_offsets = splay_tree_new (splay_tree_compare_integer_csts, NULL, NULL); build_base_fields (rli, empty_base_offsets, next_field); /* Layout the non-static data members. */ for (field = non_static_data_members; field; field = TREE_CHAIN (field)) { tree type; tree padding; /* We still pass things that aren't non-static data members to the back end, in case it wants to do something with them. */ if (TREE_CODE (field) != FIELD_DECL) { place_field (rli, field); /* If the static data member has incomplete type, keep track of it so that it can be completed later. (The handling of pending statics in finish_record_layout is insufficient; consider: struct S1; struct S2 { static S1 s1; }; At this point, finish_record_layout will be called, but S1 is still incomplete.) */ if (TREE_CODE (field) == VAR_DECL) { maybe_register_incomplete_var (field); /* The visibility of static data members is determined at their point of declaration, not their point of definition. */ determine_visibility (field); } continue; } type = TREE_TYPE (field); if (type == error_mark_node) continue; padding = NULL_TREE; /* If this field is a bit-field whose width is greater than its type, then there are some special rules for allocating it. */ if (DECL_C_BIT_FIELD (field) && INT_CST_LT (TYPE_SIZE (type), DECL_SIZE (field))) { unsigned int itk; tree integer_type; bool was_unnamed_p = false; /* We must allocate the bits as if suitably aligned for the longest integer type that fits in this many bits. type of the field. Then, we are supposed to use the left over bits as additional padding. */ for (itk = itk_char; itk != itk_none; ++itk) if (INT_CST_LT (DECL_SIZE (field), TYPE_SIZE (integer_types[itk]))) break; /* ITK now indicates a type that is too large for the field. We have to back up by one to find the largest type that fits. */ integer_type = integer_types[itk - 1]; /* Figure out how much additional padding is required. GCC 3.2 always created a padding field, even if it had zero width. */ if (!abi_version_at_least (2) || INT_CST_LT (TYPE_SIZE (integer_type), DECL_SIZE (field))) { if (abi_version_at_least (2) && TREE_CODE (t) == UNION_TYPE) /* In a union, the padding field must have the full width of the bit-field; all fields start at offset zero. */ padding = DECL_SIZE (field); else { if (TREE_CODE (t) == UNION_TYPE) warning (OPT_Wabi, "size assigned to %qT may not be " "ABI-compliant and may change in a future " "version of GCC", t); padding = size_binop (MINUS_EXPR, DECL_SIZE (field), TYPE_SIZE (integer_type)); } } #ifdef PCC_BITFIELD_TYPE_MATTERS /* An unnamed bitfield does not normally affect the alignment of the containing class on a target where PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not make any exceptions for unnamed bitfields when the bitfields are longer than their types. Therefore, we temporarily give the field a name. */ if (PCC_BITFIELD_TYPE_MATTERS && !DECL_NAME (field)) { was_unnamed_p = true; DECL_NAME (field) = make_anon_name (); } #endif DECL_SIZE (field) = TYPE_SIZE (integer_type); DECL_ALIGN (field) = TYPE_ALIGN (integer_type); DECL_USER_ALIGN (field) = TYPE_USER_ALIGN (integer_type); layout_nonempty_base_or_field (rli, field, NULL_TREE, empty_base_offsets); if (was_unnamed_p) DECL_NAME (field) = NULL_TREE; /* Now that layout has been performed, set the size of the field to the size of its declared type; the rest of the field is effectively invisible. */ DECL_SIZE (field) = TYPE_SIZE (type); /* We must also reset the DECL_MODE of the field. */ if (abi_version_at_least (2)) DECL_MODE (field) = TYPE_MODE (type); else if (warn_abi && DECL_MODE (field) != TYPE_MODE (type)) /* Versions of G++ before G++ 3.4 did not reset the DECL_MODE. */ warning (OPT_Wabi, "the offset of %qD may not be ABI-compliant and may " "change in a future version of GCC", field); } else layout_nonempty_base_or_field (rli, field, NULL_TREE, empty_base_offsets); /* Remember the location of any empty classes in FIELD. */ if (abi_version_at_least (2)) record_subobject_offsets (TREE_TYPE (field), byte_position(field), empty_base_offsets, /*is_data_member=*/true); /* If a bit-field does not immediately follow another bit-field, and yet it starts in the middle of a byte, we have failed to comply with the ABI. */ if (warn_abi && DECL_C_BIT_FIELD (field) /* The TREE_NO_WARNING flag gets set by Objective-C when laying out an Objective-C class. The ObjC ABI differs from the C++ ABI, and so we do not want a warning here. */ && !TREE_NO_WARNING (field) && !last_field_was_bitfield && !integer_zerop (size_binop (TRUNC_MOD_EXPR, DECL_FIELD_BIT_OFFSET (field), bitsize_unit_node))) warning (OPT_Wabi, "offset of %q+D is not ABI-compliant and may " "change in a future version of GCC", field); /* G++ used to use DECL_FIELD_OFFSET as if it were the byte offset of the field. */ if (warn_abi && !abi_version_at_least (2) && !tree_int_cst_equal (DECL_FIELD_OFFSET (field), byte_position (field)) && contains_empty_class_p (TREE_TYPE (field))) warning (OPT_Wabi, "%q+D contains empty classes which may cause base " "classes to be placed at different locations in a " "future version of GCC", field); /* The middle end uses the type of expressions to determine the possible range of expression values. In order to optimize "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end must be made aware of the width of "i", via its type. Because C++ does not have integer types of arbitrary width, we must (for the purposes of the front end) convert from the type assigned here to the declared type of the bitfield whenever a bitfield expression is used as an rvalue. Similarly, when assigning a value to a bitfield, the value must be converted to the type given the bitfield here. */ if (DECL_C_BIT_FIELD (field)) { unsigned HOST_WIDE_INT width; tree ftype = TREE_TYPE (field); width = tree_low_cst (DECL_SIZE (field), /*unsignedp=*/1); if (width != TYPE_PRECISION (ftype)) { TREE_TYPE (field) = c_build_bitfield_integer_type (width, TYPE_UNSIGNED (ftype)); TREE_TYPE (field) = cp_build_qualified_type (TREE_TYPE (field), TYPE_QUALS (ftype)); } } /* If we needed additional padding after this field, add it now. */ if (padding) { tree padding_field; padding_field = build_decl (input_location, FIELD_DECL, NULL_TREE, char_type_node); DECL_BIT_FIELD (padding_field) = 1; DECL_SIZE (padding_field) = padding; DECL_CONTEXT (padding_field) = t; DECL_ARTIFICIAL (padding_field) = 1; DECL_IGNORED_P (padding_field) = 1; layout_nonempty_base_or_field (rli, padding_field, NULL_TREE, empty_base_offsets); } last_field_was_bitfield = DECL_C_BIT_FIELD (field); } if (abi_version_at_least (2) && !integer_zerop (rli->bitpos)) { /* Make sure that we are on a byte boundary so that the size of the class without virtual bases will always be a round number of bytes. */ rli->bitpos = round_up_loc (input_location, rli->bitpos, BITS_PER_UNIT); normalize_rli (rli); } /* G++ 3.2 does not allow virtual bases to be overlaid with tail padding. */ if (!abi_version_at_least (2)) include_empty_classes(rli); /* Delete all zero-width bit-fields from the list of fields. Now that the type is laid out they are no longer important. */ remove_zero_width_bit_fields (t); /* Create the version of T used for virtual bases. We do not use make_class_type for this version; this is an artificial type. For a POD type, we just reuse T. */ if (CLASSTYPE_NON_LAYOUT_POD_P (t) || CLASSTYPE_EMPTY_P (t)) { base_t = make_node (TREE_CODE (t)); /* Set the size and alignment for the new type. In G++ 3.2, all empty classes were considered to have size zero when used as base classes. */ if (!abi_version_at_least (2) && CLASSTYPE_EMPTY_P (t)) { TYPE_SIZE (base_t) = bitsize_zero_node; TYPE_SIZE_UNIT (base_t) = size_zero_node; if (warn_abi && !integer_zerop (rli_size_unit_so_far (rli))) warning (OPT_Wabi, "layout of classes derived from empty class %qT " "may change in a future version of GCC", t); } else { tree eoc; /* If the ABI version is not at least two, and the last field was a bit-field, RLI may not be on a byte boundary. In particular, rli_size_unit_so_far might indicate the last complete byte, while rli_size_so_far indicates the total number of bits used. Therefore, rli_size_so_far, rather than rli_size_unit_so_far, is used to compute TYPE_SIZE_UNIT. */ eoc = end_of_class (t, /*include_virtuals_p=*/0); TYPE_SIZE_UNIT (base_t) = size_binop (MAX_EXPR, convert (sizetype, size_binop (CEIL_DIV_EXPR, rli_size_so_far (rli), bitsize_int (BITS_PER_UNIT))), eoc); TYPE_SIZE (base_t) = size_binop (MAX_EXPR, rli_size_so_far (rli), size_binop (MULT_EXPR, convert (bitsizetype, eoc), bitsize_int (BITS_PER_UNIT))); } TYPE_ALIGN (base_t) = rli->record_align; TYPE_USER_ALIGN (base_t) = TYPE_USER_ALIGN (t); /* Copy the fields from T. */ next_field = &TYPE_FIELDS (base_t); for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field)) if (TREE_CODE (field) == FIELD_DECL) { *next_field = build_decl (input_location, FIELD_DECL, DECL_NAME (field), TREE_TYPE (field)); DECL_CONTEXT (*next_field) = base_t; DECL_FIELD_OFFSET (*next_field) = DECL_FIELD_OFFSET (field); DECL_FIELD_BIT_OFFSET (*next_field) = DECL_FIELD_BIT_OFFSET (field); DECL_SIZE (*next_field) = DECL_SIZE (field); DECL_MODE (*next_field) = DECL_MODE (field); next_field = &TREE_CHAIN (*next_field); } /* Record the base version of the type. */ CLASSTYPE_AS_BASE (t) = base_t; TYPE_CONTEXT (base_t) = t; } else CLASSTYPE_AS_BASE (t) = t; /* Every empty class contains an empty class. */ if (CLASSTYPE_EMPTY_P (t)) CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1; /* Set the TYPE_DECL for this type to contain the right value for DECL_OFFSET, so that we can use it as part of a COMPONENT_REF for multiple inheritance. */ layout_decl (TYPE_MAIN_DECL (t), 0); /* Now fix up any virtual base class types that we left lying around. We must get these done before we try to lay out the virtual function table. As a side-effect, this will remove the base subobject fields. */ layout_virtual_bases (rli, empty_base_offsets); /* Make sure that empty classes are reflected in RLI at this point. */ include_empty_classes(rli); /* Make sure not to create any structures with zero size. */ if (integer_zerop (rli_size_unit_so_far (rli)) && CLASSTYPE_EMPTY_P (t)) place_field (rli, build_decl (input_location, FIELD_DECL, NULL_TREE, char_type_node)); /* If this is a non-POD, declaring it packed makes a difference to how it can be used as a field; don't let finalize_record_size undo it. */ if (TYPE_PACKED (t) && !layout_pod_type_p (t)) rli->packed_maybe_necessary = true; /* Let the back end lay out the type. */ finish_record_layout (rli, /*free_p=*/true); /* Warn about bases that can't be talked about due to ambiguity. */ warn_about_ambiguous_bases (t); /* Now that we're done with layout, give the base fields the real types. */ for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field)) if (DECL_ARTIFICIAL (field) && IS_FAKE_BASE_TYPE (TREE_TYPE (field))) TREE_TYPE (field) = TYPE_CONTEXT (TREE_TYPE (field)); /* Clean up. */ splay_tree_delete (empty_base_offsets); if (CLASSTYPE_EMPTY_P (t) && tree_int_cst_lt (sizeof_biggest_empty_class, TYPE_SIZE_UNIT (t))) sizeof_biggest_empty_class = TYPE_SIZE_UNIT (t); } /* Determine the "key method" for the class type indicated by TYPE, and set CLASSTYPE_KEY_METHOD accordingly. */ void determine_key_method (tree type) { tree method; if (TYPE_FOR_JAVA (type) || processing_template_decl || CLASSTYPE_TEMPLATE_INSTANTIATION (type) || CLASSTYPE_INTERFACE_KNOWN (type)) return; /* The key method is the first non-pure virtual function that is not inline at the point of class definition. On some targets the key function may not be inline; those targets should not call this function until the end of the translation unit. */ for (method = TYPE_METHODS (type); method != NULL_TREE; method = TREE_CHAIN (method)) if (DECL_VINDEX (method) != NULL_TREE && ! DECL_DECLARED_INLINE_P (method) && ! DECL_PURE_VIRTUAL_P (method)) { CLASSTYPE_KEY_METHOD (type) = method; break; } return; } /* Perform processing required when the definition of T (a class type) is complete. */ void finish_struct_1 (tree t) { tree x; /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */ tree virtuals = NULL_TREE; int n_fields = 0; if (COMPLETE_TYPE_P (t)) { gcc_assert (MAYBE_CLASS_TYPE_P (t)); error ("redefinition of %q#T", t); popclass (); return; } /* If this type was previously laid out as a forward reference, make sure we lay it out again. */ TYPE_SIZE (t) = NULL_TREE; CLASSTYPE_PRIMARY_BINFO (t) = NULL_TREE; /* Make assumptions about the class; we'll reset the flags if necessary. */ CLASSTYPE_EMPTY_P (t) = 1; CLASSTYPE_NEARLY_EMPTY_P (t) = 1; CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 0; /* Do end-of-class semantic processing: checking the validity of the bases and members and add implicitly generated methods. */ check_bases_and_members (t); /* Find the key method. */ if (TYPE_CONTAINS_VPTR_P (t)) { /* The Itanium C++ ABI permits the key method to be chosen when the class is defined -- even though the key method so selected may later turn out to be an inline function. On some systems (such as ARM Symbian OS) the key method cannot be determined until the end of the translation unit. On such systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which will cause the class to be added to KEYED_CLASSES. Then, in finish_file we will determine the key method. */ if (targetm.cxx.key_method_may_be_inline ()) determine_key_method (t); /* If a polymorphic class has no key method, we may emit the vtable in every translation unit where the class definition appears. */ if (CLASSTYPE_KEY_METHOD (t) == NULL_TREE) keyed_classes = tree_cons (NULL_TREE, t, keyed_classes); } /* Layout the class itself. */ layout_class_type (t, &virtuals); if (CLASSTYPE_AS_BASE (t) != t) /* We use the base type for trivial assignments, and hence it needs a mode. */ compute_record_mode (CLASSTYPE_AS_BASE (t)); virtuals = modify_all_vtables (t, nreverse (virtuals)); /* If necessary, create the primary vtable for this class. */ if (virtuals || TYPE_CONTAINS_VPTR_P (t)) { /* We must enter these virtuals into the table. */ if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t)) build_primary_vtable (NULL_TREE, t); else if (! BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (t))) /* Here we know enough to change the type of our virtual function table, but we will wait until later this function. */ build_primary_vtable (CLASSTYPE_PRIMARY_BINFO (t), t); } if (TYPE_CONTAINS_VPTR_P (t)) { int vindex; tree fn; if (BINFO_VTABLE (TYPE_BINFO (t))) gcc_assert (DECL_VIRTUAL_P (BINFO_VTABLE (TYPE_BINFO (t)))); if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t)) gcc_assert (BINFO_VIRTUALS (TYPE_BINFO (t)) == NULL_TREE); /* Add entries for virtual functions introduced by this class. */ BINFO_VIRTUALS (TYPE_BINFO (t)) = chainon (BINFO_VIRTUALS (TYPE_BINFO (t)), virtuals); /* Set DECL_VINDEX for all functions declared in this class. */ for (vindex = 0, fn = BINFO_VIRTUALS (TYPE_BINFO (t)); fn; fn = TREE_CHAIN (fn), vindex += (TARGET_VTABLE_USES_DESCRIPTORS ? TARGET_VTABLE_USES_DESCRIPTORS : 1)) { tree fndecl = BV_FN (fn); if (DECL_THUNK_P (fndecl)) /* A thunk. We should never be calling this entry directly from this vtable -- we'd use the entry for the non thunk base function. */ DECL_VINDEX (fndecl) = NULL_TREE; else if (TREE_CODE (DECL_VINDEX (fndecl)) != INTEGER_CST) DECL_VINDEX (fndecl) = build_int_cst (NULL_TREE, vindex); } } finish_struct_bits (t); /* Complete the rtl for any static member objects of the type we're working on. */ for (x = TYPE_FIELDS (t); x; x = TREE_CHAIN (x)) if (TREE_CODE (x) == VAR_DECL && TREE_STATIC (x) && TREE_TYPE (x) != error_mark_node && same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (x)), t)) DECL_MODE (x) = TYPE_MODE (t); /* Done with FIELDS...now decide whether to sort these for faster lookups later. We use a small number because most searches fail (succeeding ultimately as the search bores through the inheritance hierarchy), and we want this failure to occur quickly. */ n_fields = count_fields (TYPE_FIELDS (t)); if (n_fields > 7) { struct sorted_fields_type *field_vec = GGC_NEWVAR (struct sorted_fields_type, sizeof (struct sorted_fields_type) + n_fields * sizeof (tree)); field_vec->len = n_fields; add_fields_to_record_type (TYPE_FIELDS (t), field_vec, 0); qsort (field_vec->elts, n_fields, sizeof (tree), field_decl_cmp); CLASSTYPE_SORTED_FIELDS (t) = field_vec; } /* Complain if one of the field types requires lower visibility. */ constrain_class_visibility (t); /* Make the rtl for any new vtables we have created, and unmark the base types we marked. */ finish_vtbls (t); /* Build the VTT for T. */ build_vtt (t); /* This warning does not make sense for Java classes, since they cannot have destructors. */ if (!TYPE_FOR_JAVA (t) && warn_nonvdtor && TYPE_POLYMORPHIC_P (t)) { tree dtor; dtor = CLASSTYPE_DESTRUCTORS (t); if (/* An implicitly declared destructor is always public. And, if it were virtual, we would have created it by now. */ !dtor || (!DECL_VINDEX (dtor) && (/* public non-virtual */ (!TREE_PRIVATE (dtor) && !TREE_PROTECTED (dtor)) || (/* non-public non-virtual with friends */ (TREE_PRIVATE (dtor) || TREE_PROTECTED (dtor)) && (CLASSTYPE_FRIEND_CLASSES (t) || DECL_FRIENDLIST (TYPE_MAIN_DECL (t))))))) warning (OPT_Wnon_virtual_dtor, "%q#T has virtual functions and accessible" " non-virtual destructor", t); } complete_vars (t); if (warn_overloaded_virtual) warn_hidden (t); /* Class layout, assignment of virtual table slots, etc., is now complete. Give the back end a chance to tweak the visibility of the class or perform any other required target modifications. */ targetm.cxx.adjust_class_at_definition (t); maybe_suppress_debug_info (t); dump_class_hierarchy (t); /* Finish debugging output for this type. */ rest_of_type_compilation (t, ! LOCAL_CLASS_P (t)); } /* When T was built up, the member declarations were added in reverse order. Rearrange them to declaration order. */ void unreverse_member_declarations (tree t) { tree next; tree prev; tree x; /* The following lists are all in reverse order. Put them in declaration order now. */ TYPE_METHODS (t) = nreverse (TYPE_METHODS (t)); CLASSTYPE_DECL_LIST (t) = nreverse (CLASSTYPE_DECL_LIST (t)); /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in reverse order, so we can't just use nreverse. */ prev = NULL_TREE; for (x = TYPE_FIELDS (t); x && TREE_CODE (x) != TYPE_DECL; x = next) { next = TREE_CHAIN (x); TREE_CHAIN (x) = prev; prev = x; } if (prev) { TREE_CHAIN (TYPE_FIELDS (t)) = x; if (prev) TYPE_FIELDS (t) = prev; } } tree finish_struct (tree t, tree attributes) { location_t saved_loc = input_location; /* Now that we've got all the field declarations, reverse everything as necessary. */ unreverse_member_declarations (t); cplus_decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE); /* Nadger the current location so that diagnostics point to the start of the struct, not the end. */ input_location = DECL_SOURCE_LOCATION (TYPE_NAME (t)); if (processing_template_decl) { tree x; finish_struct_methods (t); TYPE_SIZE (t) = bitsize_zero_node; TYPE_SIZE_UNIT (t) = size_zero_node; /* We need to emit an error message if this type was used as a parameter and it is an abstract type, even if it is a template. We construct a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into account and we call complete_vars with this type, which will check the PARM_DECLS. Note that while the type is being defined, CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */ CLASSTYPE_PURE_VIRTUALS (t) = NULL; for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x)) if (DECL_PURE_VIRTUAL_P (x)) VEC_safe_push (tree, gc, CLASSTYPE_PURE_VIRTUALS (t), x); complete_vars (t); /* Remember current #pragma pack value. */ TYPE_PRECISION (t) = maximum_field_alignment; } else finish_struct_1 (t); input_location = saved_loc; TYPE_BEING_DEFINED (t) = 0; if (current_class_type) popclass (); else error ("trying to finish struct, but kicked out due to previous parse errors"); if (processing_template_decl && at_function_scope_p ()) add_stmt (build_min (TAG_DEFN, t)); return t; } /* Return the dynamic type of INSTANCE, if known. Used to determine whether the virtual function table is needed or not. *NONNULL is set iff INSTANCE can be known to be nonnull, regardless of our knowledge of its type. *NONNULL should be initialized before this function is called. */ static tree fixed_type_or_null (tree instance, int *nonnull, int *cdtorp) { #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp) switch (TREE_CODE (instance)) { case INDIRECT_REF: if (POINTER_TYPE_P (TREE_TYPE (instance))) return NULL_TREE; else return RECUR (TREE_OPERAND (instance, 0)); case CALL_EXPR: /* This is a call to a constructor, hence it's never zero. */ if (TREE_HAS_CONSTRUCTOR (instance)) { if (nonnull) *nonnull = 1; return TREE_TYPE (instance); } return NULL_TREE; case SAVE_EXPR: /* This is a call to a constructor, hence it's never zero. */ if (TREE_HAS_CONSTRUCTOR (instance)) { if (nonnull) *nonnull = 1; return TREE_TYPE (instance); } return RECUR (TREE_OPERAND (instance, 0)); case POINTER_PLUS_EXPR: case PLUS_EXPR: case MINUS_EXPR: if (TREE_CODE (TREE_OPERAND (instance, 0)) == ADDR_EXPR) return RECUR (TREE_OPERAND (instance, 0)); if (TREE_CODE (TREE_OPERAND (instance, 1)) == INTEGER_CST) /* Propagate nonnull. */ return RECUR (TREE_OPERAND (instance, 0)); return NULL_TREE; CASE_CONVERT: return RECUR (TREE_OPERAND (instance, 0)); case ADDR_EXPR: instance = TREE_OPERAND (instance, 0); if (nonnull) { /* Just because we see an ADDR_EXPR doesn't mean we're dealing with a real object -- given &p->f, p can still be null. */ tree t = get_base_address (instance); /* ??? Probably should check DECL_WEAK here. */ if (t && DECL_P (t)) *nonnull = 1; } return RECUR (instance); case COMPONENT_REF: /* If this component is really a base class reference, then the field itself isn't definitive. */ if (DECL_FIELD_IS_BASE (TREE_OPERAND (instance, 1))) return RECUR (TREE_OPERAND (instance, 0)); return RECUR (TREE_OPERAND (instance, 1)); case VAR_DECL: case FIELD_DECL: if (TREE_CODE (TREE_TYPE (instance)) == ARRAY_TYPE && MAYBE_CLASS_TYPE_P (TREE_TYPE (TREE_TYPE (instance)))) { if (nonnull) *nonnull = 1; return TREE_TYPE (TREE_TYPE (instance)); } /* fall through... */ case TARGET_EXPR: case PARM_DECL: case RESULT_DECL: if (MAYBE_CLASS_TYPE_P (TREE_TYPE (instance))) { if (nonnull) *nonnull = 1; return TREE_TYPE (instance); } else if (instance == current_class_ptr) { if (nonnull) *nonnull = 1; /* if we're in a ctor or dtor, we know our type. */ if (DECL_LANG_SPECIFIC (current_function_decl) && (DECL_CONSTRUCTOR_P (current_function_decl) || DECL_DESTRUCTOR_P (current_function_decl))) { if (cdtorp) *cdtorp = 1; return TREE_TYPE (TREE_TYPE (instance)); } } else if (TREE_CODE (TREE_TYPE (instance)) == REFERENCE_TYPE) { /* We only need one hash table because it is always left empty. */ static htab_t ht; if (!ht) ht = htab_create (37, htab_hash_pointer, htab_eq_pointer, /*htab_del=*/NULL); /* Reference variables should be references to objects. */ if (nonnull) *nonnull = 1; /* Enter the INSTANCE in a table to prevent recursion; a variable's initializer may refer to the variable itself. */ if (TREE_CODE (instance) == VAR_DECL && DECL_INITIAL (instance) && !htab_find (ht, instance)) { tree type; void **slot; slot = htab_find_slot (ht, instance, INSERT); *slot = instance; type = RECUR (DECL_INITIAL (instance)); htab_remove_elt (ht, instance); return type; } } return NULL_TREE; default: return NULL_TREE; } #undef RECUR } /* Return nonzero if the dynamic type of INSTANCE is known, and equivalent to the static type. We also handle the case where INSTANCE is really a pointer. Return negative if this is a ctor/dtor. There the dynamic type is known, but this might not be the most derived base of the original object, and hence virtual bases may not be layed out according to this type. Used to determine whether the virtual function table is needed or not. *NONNULL is set iff INSTANCE can be known to be nonnull, regardless of our knowledge of its type. *NONNULL should be initialized before this function is called. */ int resolves_to_fixed_type_p (tree instance, int* nonnull) { tree t = TREE_TYPE (instance); int cdtorp = 0; tree fixed = fixed_type_or_null (instance, nonnull, &cdtorp); if (fixed == NULL_TREE) return 0; if (POINTER_TYPE_P (t)) t = TREE_TYPE (t); if (!same_type_ignoring_top_level_qualifiers_p (t, fixed)) return 0; return cdtorp ? -1 : 1; } void init_class_processing (void) { current_class_depth = 0; current_class_stack_size = 10; current_class_stack = XNEWVEC (struct class_stack_node, current_class_stack_size); local_classes = VEC_alloc (tree, gc, 8); sizeof_biggest_empty_class = size_zero_node; ridpointers[(int) RID_PUBLIC] = access_public_node; ridpointers[(int) RID_PRIVATE] = access_private_node; ridpointers[(int) RID_PROTECTED] = access_protected_node; } /* Restore the cached PREVIOUS_CLASS_LEVEL. */ static void restore_class_cache (void) { tree type; /* We are re-entering the same class we just left, so we don't have to search the whole inheritance matrix to find all the decls to bind again. Instead, we install the cached class_shadowed list and walk through it binding names. */ push_binding_level (previous_class_level); class_binding_level = previous_class_level; /* Restore IDENTIFIER_TYPE_VALUE. */ for (type = class_binding_level->type_shadowed; type; type = TREE_CHAIN (type)) SET_IDENTIFIER_TYPE_VALUE (TREE_PURPOSE (type), TREE_TYPE (type)); } /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as appropriate for TYPE. So that we may avoid calls to lookup_name, we cache the _TYPE nodes of local TYPE_DECLs in the TREE_TYPE field of the name. For multiple inheritance, we perform a two-pass depth-first search of the type lattice. */ void pushclass (tree type) { class_stack_node_t csn; type = TYPE_MAIN_VARIANT (type); /* Make sure there is enough room for the new entry on the stack. */ if (current_class_depth + 1 >= current_class_stack_size) { current_class_stack_size *= 2; current_class_stack = XRESIZEVEC (struct class_stack_node, current_class_stack, current_class_stack_size); } /* Insert a new entry on the class stack. */ csn = current_class_stack + current_class_depth; csn->name = current_class_name; csn->type = current_class_type; csn->access = current_access_specifier; csn->names_used = 0; csn->hidden = 0; current_class_depth++; /* Now set up the new type. */ current_class_name = TYPE_NAME (type); if (TREE_CODE (current_class_name) == TYPE_DECL) current_class_name = DECL_NAME (current_class_name); current_class_type = type; /* By default, things in classes are private, while things in structures or unions are public. */ current_access_specifier = (CLASSTYPE_DECLARED_CLASS (type) ? access_private_node : access_public_node); if (previous_class_level && type != previous_class_level->this_entity && current_class_depth == 1) { /* Forcibly remove any old class remnants. */ invalidate_class_lookup_cache (); } if (!previous_class_level || type != previous_class_level->this_entity || current_class_depth > 1) pushlevel_class (); else restore_class_cache (); } /* When we exit a toplevel class scope, we save its binding level so that we can restore it quickly. Here, we've entered some other class, so we must invalidate our cache. */ void invalidate_class_lookup_cache (void) { previous_class_level = NULL; } /* Get out of the current class scope. If we were in a class scope previously, that is the one popped to. */ void popclass (void) { poplevel_class (); current_class_depth--; current_class_name = current_class_stack[current_class_depth].name; current_class_type = current_class_stack[current_class_depth].type; current_access_specifier = current_class_stack[current_class_depth].access; if (current_class_stack[current_class_depth].names_used) splay_tree_delete (current_class_stack[current_class_depth].names_used); } /* Mark the top of the class stack as hidden. */ void push_class_stack (void) { if (current_class_depth) ++current_class_stack[current_class_depth - 1].hidden; } /* Mark the top of the class stack as un-hidden. */ void pop_class_stack (void) { if (current_class_depth) --current_class_stack[current_class_depth - 1].hidden; } /* Returns 1 if the class type currently being defined is either T or a nested type of T. */ bool currently_open_class (tree t) { int i; if (!CLASS_TYPE_P (t)) return false; t = TYPE_MAIN_VARIANT (t); /* We start looking from 1 because entry 0 is from global scope, and has no type. */ for (i = current_class_depth; i > 0; --i) { tree c; if (i == current_class_depth) c = current_class_type; else { if (current_class_stack[i].hidden) break; c = current_class_stack[i].type; } if (!c) continue; if (same_type_p (c, t)) return true; } return false; } /* If either current_class_type or one of its enclosing classes are derived from T, return the appropriate type. Used to determine how we found something via unqualified lookup. */ tree currently_open_derived_class (tree t) { int i; /* The bases of a dependent type are unknown. */ if (dependent_type_p (t)) return NULL_TREE; if (!current_class_type) return NULL_TREE; if (DERIVED_FROM_P (t, current_class_type)) return current_class_type; for (i = current_class_depth - 1; i > 0; --i) { if (current_class_stack[i].hidden) break; if (DERIVED_FROM_P (t, current_class_stack[i].type)) return current_class_stack[i].type; } return NULL_TREE; } /* When entering a class scope, all enclosing class scopes' names with static meaning (static variables, static functions, types and enumerators) have to be visible. This recursive function calls pushclass for all enclosing class contexts until global or a local scope is reached. TYPE is the enclosed class. */ void push_nested_class (tree type) { /* A namespace might be passed in error cases, like A::B:C. */ if (type == NULL_TREE || !CLASS_TYPE_P (type)) return; push_nested_class (DECL_CONTEXT (TYPE_MAIN_DECL (type))); pushclass (type); } /* Undoes a push_nested_class call. */ void pop_nested_class (void) { tree context = DECL_CONTEXT (TYPE_MAIN_DECL (current_class_type)); popclass (); if (context && CLASS_TYPE_P (context)) pop_nested_class (); } /* Returns the number of extern "LANG" blocks we are nested within. */ int current_lang_depth (void) { return VEC_length (tree, current_lang_base); } /* Set global variables CURRENT_LANG_NAME to appropriate value so that behavior of name-mangling machinery is correct. */ void push_lang_context (tree name) { VEC_safe_push (tree, gc, current_lang_base, current_lang_name); if (name == lang_name_cplusplus) { current_lang_name = name; } else if (name == lang_name_java) { current_lang_name = name; /* DECL_IGNORED_P is initially set for these types, to avoid clutter. (See record_builtin_java_type in decl.c.) However, that causes incorrect debug entries if these types are actually used. So we re-enable debug output after extern "Java". */ DECL_IGNORED_P (TYPE_NAME (java_byte_type_node)) = 0; DECL_IGNORED_P (TYPE_NAME (java_short_type_node)) = 0; DECL_IGNORED_P (TYPE_NAME (java_int_type_node)) = 0; DECL_IGNORED_P (TYPE_NAME (java_long_type_node)) = 0; DECL_IGNORED_P (TYPE_NAME (java_float_type_node)) = 0; DECL_IGNORED_P (TYPE_NAME (java_double_type_node)) = 0; DECL_IGNORED_P (TYPE_NAME (java_char_type_node)) = 0; DECL_IGNORED_P (TYPE_NAME (java_boolean_type_node)) = 0; } else if (name == lang_name_c) { current_lang_name = name; } else error ("language string %<\"%E\"%> not recognized", name); } /* Get out of the current language scope. */ void pop_lang_context (void) { current_lang_name = VEC_pop (tree, current_lang_base); } /* Type instantiation routines. */ /* Given an OVERLOAD and a TARGET_TYPE, return the function that matches the TARGET_TYPE. If there is no satisfactory match, return error_mark_node, and issue an error & warning messages under control of FLAGS. Permit pointers to member function if FLAGS permits. If TEMPLATE_ONLY, the name of the overloaded function was a template-id, and EXPLICIT_TARGS are the explicitly provided template arguments. If OVERLOAD is for one or more member functions, then ACCESS_PATH is the base path used to reference those member functions. If TF_NO_ACCESS_CONTROL is not set in FLAGS, and the address is resolved to a member function, access checks will be performed and errors issued if appropriate. */ static tree resolve_address_of_overloaded_function (tree target_type, tree overload, tsubst_flags_t flags, bool template_only, tree explicit_targs, tree access_path) { /* Here's what the standard says: [over.over] If the name is a function template, template argument deduction is done, and if the argument deduction succeeds, the deduced arguments are used to generate a single template function, which is added to the set of overloaded functions considered. Non-member functions and static member functions match targets of type "pointer-to-function" or "reference-to-function." Nonstatic member functions match targets of type "pointer-to-member function;" the function type of the pointer to member is used to select the member function from the set of overloaded member functions. If a nonstatic member function is selected, the reference to the overloaded function name is required to have the form of a pointer to member as described in 5.3.1. If more than one function is selected, any template functions in the set are eliminated if the set also contains a non-template function, and any given template function is eliminated if the set contains a second template function that is more specialized than the first according to the partial ordering rules 14.5.5.2. After such eliminations, if any, there shall remain exactly one selected function. */ int is_ptrmem = 0; /* We store the matches in a TREE_LIST rooted here. The functions are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy interoperability with most_specialized_instantiation. */ tree matches = NULL_TREE; tree fn; tree target_fn_type; /* By the time we get here, we should be seeing only real pointer-to-member types, not the internal POINTER_TYPE to METHOD_TYPE representation. */ gcc_assert (TREE_CODE (target_type) != POINTER_TYPE || TREE_CODE (TREE_TYPE (target_type)) != METHOD_TYPE); gcc_assert (is_overloaded_fn (overload)); /* Check that the TARGET_TYPE is reasonable. */ if (TYPE_PTRFN_P (target_type)) /* This is OK. */; else if (TYPE_PTRMEMFUNC_P (target_type)) /* This is OK, too. */ is_ptrmem = 1; else if (TREE_CODE (target_type) == FUNCTION_TYPE) /* This is OK, too. This comes from a conversion to reference type. */ target_type = build_reference_type (target_type); else { if (flags & tf_error) error ("cannot resolve overloaded function %qD based on" " conversion to type %qT", DECL_NAME (OVL_FUNCTION (overload)), target_type); return error_mark_node; } /* Non-member functions and static member functions match targets of type "pointer-to-function" or "reference-to-function." Nonstatic member functions match targets of type "pointer-to-member-function;" the function type of the pointer to member is used to select the member function from the set of overloaded member functions. So figure out the FUNCTION_TYPE that we want to match against. */ target_fn_type = static_fn_type (target_type); /* If we can find a non-template function that matches, we can just use it. There's no point in generating template instantiations if we're just going to throw them out anyhow. But, of course, we can only do this when we don't *need* a template function. */ if (!template_only) { tree fns; for (fns = overload; fns; fns = OVL_NEXT (fns)) { tree fn = OVL_CURRENT (fns); if (TREE_CODE (fn) == TEMPLATE_DECL) /* We're not looking for templates just yet. */ continue; if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE) != is_ptrmem) /* We're looking for a non-static member, and this isn't one, or vice versa. */ continue; /* Ignore functions which haven't been explicitly declared. */ if (DECL_ANTICIPATED (fn)) continue; /* See if there's a match. */ if (same_type_p (target_fn_type, static_fn_type (fn))) matches = tree_cons (fn, NULL_TREE, matches); } } /* Now, if we've already got a match (or matches), there's no need to proceed to the template functions. But, if we don't have a match we need to look at them, too. */ if (!matches) { tree target_arg_types; tree target_ret_type; tree fns; tree *args; unsigned int nargs, ia; tree arg; target_arg_types = TYPE_ARG_TYPES (target_fn_type); target_ret_type = TREE_TYPE (target_fn_type); nargs = list_length (target_arg_types); args = XALLOCAVEC (tree, nargs); for (arg = target_arg_types, ia = 0; arg != NULL_TREE && arg != void_list_node; arg = TREE_CHAIN (arg), ++ia) args[ia] = TREE_VALUE (arg); nargs = ia; for (fns = overload; fns; fns = OVL_NEXT (fns)) { tree fn = OVL_CURRENT (fns); tree instantiation; tree targs; if (TREE_CODE (fn) != TEMPLATE_DECL) /* We're only looking for templates. */ continue; if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE) != is_ptrmem) /* We're not looking for a non-static member, and this is one, or vice versa. */ continue; /* Try to do argument deduction. */ targs = make_tree_vec (DECL_NTPARMS (fn)); if (fn_type_unification (fn, explicit_targs, targs, args, nargs, target_ret_type, DEDUCE_EXACT, LOOKUP_NORMAL)) /* Argument deduction failed. */ continue; /* Instantiate the template. */ instantiation = instantiate_template (fn, targs, flags); if (instantiation == error_mark_node) /* Instantiation failed. */ continue; /* See if there's a match. */ if (same_type_p (target_fn_type, static_fn_type (instantiation))) matches = tree_cons (instantiation, fn, matches); } /* Now, remove all but the most specialized of the matches. */ if (matches) { tree match = most_specialized_instantiation (matches); if (match != error_mark_node) matches = tree_cons (TREE_PURPOSE (match), NULL_TREE, NULL_TREE); } } /* Now we should have exactly one function in MATCHES. */ if (matches == NULL_TREE) { /* There were *no* matches. */ if (flags & tf_error) { error ("no matches converting function %qD to type %q#T", DECL_NAME (OVL_CURRENT (overload)), target_type); /* print_candidates expects a chain with the functions in TREE_VALUE slots, so we cons one up here (we're losing anyway, so why be clever?). */ for (; overload; overload = OVL_NEXT (overload)) matches = tree_cons (NULL_TREE, OVL_CURRENT (overload), matches); print_candidates (matches); } return error_mark_node; } else if (TREE_CHAIN (matches)) { /* There were too many matches. First check if they're all the same function. */ tree match; fn = TREE_PURPOSE (matches); for (match = TREE_CHAIN (matches); match; match = TREE_CHAIN (match)) if (!decls_match (fn, TREE_PURPOSE (match))) break; if (match) { if (flags & tf_error) { error ("converting overloaded function %qD to type %q#T is ambiguous", DECL_NAME (OVL_FUNCTION (overload)), target_type); /* Since print_candidates expects the functions in the TREE_VALUE slot, we flip them here. */ for (match = matches; match; match = TREE_CHAIN (match)) TREE_VALUE (match) = TREE_PURPOSE (match); print_candidates (matches); } return error_mark_node; } } /* Good, exactly one match. Now, convert it to the correct type. */ fn = TREE_PURPOSE (matches); if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn) && !(flags & tf_ptrmem_ok) && !flag_ms_extensions) { static int explained; if (!(flags & tf_error)) return error_mark_node; permerror (input_location, "assuming pointer to member %qD", fn); if (!explained) { inform (input_location, "(a pointer to member can only be formed with %<&%E%>)", fn); explained = 1; } } /* If we're doing overload resolution purely for the purpose of determining conversion sequences, we should not consider the function used. If this conversion sequence is selected, the function will be marked as used at this point. */ if (!(flags & tf_conv)) { /* Make =delete work with SFINAE. */ if (DECL_DELETED_FN (fn) && !(flags & tf_error)) return error_mark_node; mark_used (fn); } /* We could not check access to member functions when this expression was originally created since we did not know at that time to which function the expression referred. */ if (!(flags & tf_no_access_control) && DECL_FUNCTION_MEMBER_P (fn)) { gcc_assert (access_path); perform_or_defer_access_check (access_path, fn, fn); } if (TYPE_PTRFN_P (target_type) || TYPE_PTRMEMFUNC_P (target_type)) return cp_build_unary_op (ADDR_EXPR, fn, 0, flags); else { /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op will mark the function as addressed, but here we must do it explicitly. */ cxx_mark_addressable (fn); return fn; } } /* This function will instantiate the type of the expression given in RHS to match the type of LHSTYPE. If errors exist, then return error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then we complain on errors. If we are not complaining, never modify rhs, as overload resolution wants to try many possible instantiations, in the hope that at least one will work. For non-recursive calls, LHSTYPE should be a function, pointer to function, or a pointer to member function. */ tree instantiate_type (tree lhstype, tree rhs, tsubst_flags_t flags) { tsubst_flags_t flags_in = flags; tree access_path = NULL_TREE; flags &= ~tf_ptrmem_ok; if (TREE_CODE (lhstype) == UNKNOWN_TYPE) { if (flags & tf_error) error ("not enough type information"); return error_mark_node; } if (TREE_TYPE (rhs) != NULL_TREE && ! (type_unknown_p (rhs))) { if (same_type_p (lhstype, TREE_TYPE (rhs))) return rhs; if (flag_ms_extensions && TYPE_PTRMEMFUNC_P (lhstype) && !TYPE_PTRMEMFUNC_P (TREE_TYPE (rhs))) /* Microsoft allows `A::f' to be resolved to a pointer-to-member. */ ; else { if (flags & tf_error) error ("argument of type %qT does not match %qT", TREE_TYPE (rhs), lhstype); return error_mark_node; } } if (TREE_CODE (rhs) == BASELINK) { access_path = BASELINK_ACCESS_BINFO (rhs); rhs = BASELINK_FUNCTIONS (rhs); } /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot deduce any type information. */ if (TREE_CODE (rhs) == NON_DEPENDENT_EXPR) { if (flags & tf_error) error ("not enough type information"); return error_mark_node; } /* There only a few kinds of expressions that may have a type dependent on overload resolution. */ gcc_assert (TREE_CODE (rhs) == ADDR_EXPR || TREE_CODE (rhs) == COMPONENT_REF || really_overloaded_fn (rhs) || (flag_ms_extensions && TREE_CODE (rhs) == FUNCTION_DECL)); /* This should really only be used when attempting to distinguish what sort of a pointer to function we have. For now, any arithmetic operation which is not supported on pointers is rejected as an error. */ switch (TREE_CODE (rhs)) { case COMPONENT_REF: { tree member = TREE_OPERAND (rhs, 1); member = instantiate_type (lhstype, member, flags); if (member != error_mark_node && TREE_SIDE_EFFECTS (TREE_OPERAND (rhs, 0))) /* Do not lose object's side effects. */ return build2 (COMPOUND_EXPR, TREE_TYPE (member), TREE_OPERAND (rhs, 0), member); return member; } case OFFSET_REF: rhs = TREE_OPERAND (rhs, 1); if (BASELINK_P (rhs)) return instantiate_type (lhstype, rhs, flags_in); /* This can happen if we are forming a pointer-to-member for a member template. */ gcc_assert (TREE_CODE (rhs) == TEMPLATE_ID_EXPR); /* Fall through. */ case TEMPLATE_ID_EXPR: { tree fns = TREE_OPERAND (rhs, 0); tree args = TREE_OPERAND (rhs, 1); return resolve_address_of_overloaded_function (lhstype, fns, flags_in, /*template_only=*/true, args, access_path); } case OVERLOAD: case FUNCTION_DECL: return resolve_address_of_overloaded_function (lhstype, rhs, flags_in, /*template_only=*/false, /*explicit_targs=*/NULL_TREE, access_path); case ADDR_EXPR: { if (PTRMEM_OK_P (rhs)) flags |= tf_ptrmem_ok; return instantiate_type (lhstype, TREE_OPERAND (rhs, 0), flags); } case ERROR_MARK: return error_mark_node; default: gcc_unreachable (); } return error_mark_node; } /* Return the name of the virtual function pointer field (as an IDENTIFIER_NODE) for the given TYPE. Note that this may have to look back through base types to find the ultimate field name. (For single inheritance, these could all be the same name. Who knows for multiple inheritance). */ static tree get_vfield_name (tree type) { tree binfo, base_binfo; char *buf; for (binfo = TYPE_BINFO (type); BINFO_N_BASE_BINFOS (binfo); binfo = base_binfo) { base_binfo = BINFO_BASE_BINFO (binfo, 0); if (BINFO_VIRTUAL_P (base_binfo) || !TYPE_CONTAINS_VPTR_P (BINFO_TYPE (base_binfo))) break; } type = BINFO_TYPE (binfo); buf = (char *) alloca (sizeof (VFIELD_NAME_FORMAT) + TYPE_NAME_LENGTH (type) + 2); sprintf (buf, VFIELD_NAME_FORMAT, IDENTIFIER_POINTER (constructor_name (type))); return get_identifier (buf); } void print_class_statistics (void) { #ifdef GATHER_STATISTICS fprintf (stderr, "convert_harshness = %d\n", n_convert_harshness); fprintf (stderr, "compute_conversion_costs = %d\n", n_compute_conversion_costs); if (n_vtables) { fprintf (stderr, "vtables = %d; vtable searches = %d\n", n_vtables, n_vtable_searches); fprintf (stderr, "vtable entries = %d; vtable elems = %d\n", n_vtable_entries, n_vtable_elems); } #endif } /* Build a dummy reference to ourselves so Derived::Base (and A::A) works, according to [class]: The class-name is also inserted into the scope of the class itself. For purposes of access checking, the inserted class name is treated as if it were a public member name. */ void build_self_reference (void) { tree name = constructor_name (current_class_type); tree value = build_lang_decl (TYPE_DECL, name, current_class_type); tree saved_cas; DECL_NONLOCAL (value) = 1; DECL_CONTEXT (value) = current_class_type; DECL_ARTIFICIAL (value) = 1; SET_DECL_SELF_REFERENCE_P (value); cp_set_underlying_type (value); if (processing_template_decl) value = push_template_decl (value); saved_cas = current_access_specifier; current_access_specifier = access_public_node; finish_member_declaration (value); current_access_specifier = saved_cas; } /* Returns 1 if TYPE contains only padding bytes. */ int is_empty_class (tree type) { if (type == error_mark_node) return 0; if (! CLASS_TYPE_P (type)) return 0; /* In G++ 3.2, whether or not a class was empty was determined by looking at its size. */ if (abi_version_at_least (2)) return CLASSTYPE_EMPTY_P (type); else return integer_zerop (CLASSTYPE_SIZE (type)); } /* Returns true if TYPE contains an empty class. */ static bool contains_empty_class_p (tree type) { if (is_empty_class (type)) return true; if (CLASS_TYPE_P (type)) { tree field; tree binfo; tree base_binfo; int i; for (binfo = TYPE_BINFO (type), i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) if (contains_empty_class_p (BINFO_TYPE (base_binfo))) return true; for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) if (TREE_CODE (field) == FIELD_DECL && !DECL_ARTIFICIAL (field) && is_empty_class (TREE_TYPE (field))) return true; } else if (TREE_CODE (type) == ARRAY_TYPE) return contains_empty_class_p (TREE_TYPE (type)); return false; } /* Returns true if TYPE contains no actual data, just various possible combinations of empty classes. */ bool is_really_empty_class (tree type) { if (is_empty_class (type)) return true; if (CLASS_TYPE_P (type)) { tree field; tree binfo; tree base_binfo; int i; for (binfo = TYPE_BINFO (type), i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) if (!is_really_empty_class (BINFO_TYPE (base_binfo))) return false; for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) if (TREE_CODE (field) == FIELD_DECL && !DECL_ARTIFICIAL (field) && !is_really_empty_class (TREE_TYPE (field))) return false; return true; } else if (TREE_CODE (type) == ARRAY_TYPE) return is_really_empty_class (TREE_TYPE (type)); return false; } /* Note that NAME was looked up while the current class was being defined and that the result of that lookup was DECL. */ void maybe_note_name_used_in_class (tree name, tree decl) { splay_tree names_used; /* If we're not defining a class, there's nothing to do. */ if (!(innermost_scope_kind() == sk_class && TYPE_BEING_DEFINED (current_class_type) && !LAMBDA_TYPE_P (current_class_type))) return; /* If there's already a binding for this NAME, then we don't have anything to worry about. */ if (lookup_member (current_class_type, name, /*protect=*/0, /*want_type=*/false)) return; if (!current_class_stack[current_class_depth - 1].names_used) current_class_stack[current_class_depth - 1].names_used = splay_tree_new (splay_tree_compare_pointers, 0, 0); names_used = current_class_stack[current_class_depth - 1].names_used; splay_tree_insert (names_used, (splay_tree_key) name, (splay_tree_value) decl); } /* Note that NAME was declared (as DECL) in the current class. Check to see that the declaration is valid. */ void note_name_declared_in_class (tree name, tree decl) { splay_tree names_used; splay_tree_node n; /* Look to see if we ever used this name. */ names_used = current_class_stack[current_class_depth - 1].names_used; if (!names_used) return; n = splay_tree_lookup (names_used, (splay_tree_key) name); if (n) { /* [basic.scope.class] A name N used in a class S shall refer to the same declaration in its context and when re-evaluated in the completed scope of S. */ permerror (input_location, "declaration of %q#D", decl); permerror (input_location, "changes meaning of %qD from %q+#D", DECL_NAME (OVL_CURRENT (decl)), (tree) n->value); } } /* Returns the VAR_DECL for the complete vtable associated with BINFO. Secondary vtables are merged with primary vtables; this function will return the VAR_DECL for the primary vtable. */ tree get_vtbl_decl_for_binfo (tree binfo) { tree decl; decl = BINFO_VTABLE (binfo); if (decl && TREE_CODE (decl) == POINTER_PLUS_EXPR) { gcc_assert (TREE_CODE (TREE_OPERAND (decl, 0)) == ADDR_EXPR); decl = TREE_OPERAND (TREE_OPERAND (decl, 0), 0); } if (decl) gcc_assert (TREE_CODE (decl) == VAR_DECL); return decl; } /* Returns the binfo for the primary base of BINFO. If the resulting BINFO is a virtual base, and it is inherited elsewhere in the hierarchy, then the returned binfo might not be the primary base of BINFO in the complete object. Check BINFO_PRIMARY_P or BINFO_LOST_PRIMARY_P to be sure. */ static tree get_primary_binfo (tree binfo) { tree primary_base; primary_base = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (binfo)); if (!primary_base) return NULL_TREE; return copied_binfo (primary_base, binfo); } /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */ static int maybe_indent_hierarchy (FILE * stream, int indent, int indented_p) { if (!indented_p) fprintf (stream, "%*s", indent, ""); return 1; } /* Dump the offsets of all the bases rooted at BINFO to STREAM. INDENT should be zero when called from the top level; it is incremented recursively. IGO indicates the next expected BINFO in inheritance graph ordering. */ static tree dump_class_hierarchy_r (FILE *stream, int flags, tree binfo, tree igo, int indent) { int indented = 0; tree base_binfo; int i; indented = maybe_indent_hierarchy (stream, indent, 0); fprintf (stream, "%s (0x%lx) ", type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER), (unsigned long) binfo); if (binfo != igo) { fprintf (stream, "alternative-path\n"); return igo; } igo = TREE_CHAIN (binfo); fprintf (stream, HOST_WIDE_INT_PRINT_DEC, tree_low_cst (BINFO_OFFSET (binfo), 0)); if (is_empty_class (BINFO_TYPE (binfo))) fprintf (stream, " empty"); else if (CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (binfo))) fprintf (stream, " nearly-empty"); if (BINFO_VIRTUAL_P (binfo)) fprintf (stream, " virtual"); fprintf (stream, "\n"); indented = 0; if (BINFO_PRIMARY_P (binfo)) { indented = maybe_indent_hierarchy (stream, indent + 3, indented); fprintf (stream, " primary-for %s (0x%lx)", type_as_string (BINFO_TYPE (BINFO_INHERITANCE_CHAIN (binfo)), TFF_PLAIN_IDENTIFIER), (unsigned long)BINFO_INHERITANCE_CHAIN (binfo)); } if (BINFO_LOST_PRIMARY_P (binfo)) { indented = maybe_indent_hierarchy (stream, indent + 3, indented); fprintf (stream, " lost-primary"); } if (indented) fprintf (stream, "\n"); if (!(flags & TDF_SLIM)) { int indented = 0; if (BINFO_SUBVTT_INDEX (binfo)) { indented = maybe_indent_hierarchy (stream, indent + 3, indented); fprintf (stream, " subvttidx=%s", expr_as_string (BINFO_SUBVTT_INDEX (binfo), TFF_PLAIN_IDENTIFIER)); } if (BINFO_VPTR_INDEX (binfo)) { indented = maybe_indent_hierarchy (stream, indent + 3, indented); fprintf (stream, " vptridx=%s", expr_as_string (BINFO_VPTR_INDEX (binfo), TFF_PLAIN_IDENTIFIER)); } if (BINFO_VPTR_FIELD (binfo)) { indented = maybe_indent_hierarchy (stream, indent + 3, indented); fprintf (stream, " vbaseoffset=%s", expr_as_string (BINFO_VPTR_FIELD (binfo), TFF_PLAIN_IDENTIFIER)); } if (BINFO_VTABLE (binfo)) { indented = maybe_indent_hierarchy (stream, indent + 3, indented); fprintf (stream, " vptr=%s", expr_as_string (BINFO_VTABLE (binfo), TFF_PLAIN_IDENTIFIER)); } if (indented) fprintf (stream, "\n"); } for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) igo = dump_class_hierarchy_r (stream, flags, base_binfo, igo, indent + 2); return igo; } /* Dump the BINFO hierarchy for T. */ static void dump_class_hierarchy_1 (FILE *stream, int flags, tree t) { fprintf (stream, "Class %s\n", type_as_string (t, TFF_PLAIN_IDENTIFIER)); fprintf (stream, " size=%lu align=%lu\n", (unsigned long)(tree_low_cst (TYPE_SIZE (t), 0) / BITS_PER_UNIT), (unsigned long)(TYPE_ALIGN (t) / BITS_PER_UNIT)); fprintf (stream, " base size=%lu base align=%lu\n", (unsigned long)(tree_low_cst (TYPE_SIZE (CLASSTYPE_AS_BASE (t)), 0) / BITS_PER_UNIT), (unsigned long)(TYPE_ALIGN (CLASSTYPE_AS_BASE (t)) / BITS_PER_UNIT)); dump_class_hierarchy_r (stream, flags, TYPE_BINFO (t), TYPE_BINFO (t), 0); fprintf (stream, "\n"); } /* Debug interface to hierarchy dumping. */ void debug_class (tree t) { dump_class_hierarchy_1 (stderr, TDF_SLIM, t); } static void dump_class_hierarchy (tree t) { int flags; FILE *stream = dump_begin (TDI_class, &flags); if (stream) { dump_class_hierarchy_1 (stream, flags, t); dump_end (TDI_class, stream); } } static void dump_array (FILE * stream, tree decl) { tree value; unsigned HOST_WIDE_INT ix; HOST_WIDE_INT elt; tree size = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (decl))); elt = (tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (decl))), 0) / BITS_PER_UNIT); fprintf (stream, "%s:", decl_as_string (decl, TFF_PLAIN_IDENTIFIER)); fprintf (stream, " %s entries", expr_as_string (size_binop (PLUS_EXPR, size, size_one_node), TFF_PLAIN_IDENTIFIER)); fprintf (stream, "\n"); FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (DECL_INITIAL (decl)), ix, value) fprintf (stream, "%-4ld %s\n", (long)(ix * elt), expr_as_string (value, TFF_PLAIN_IDENTIFIER)); } static void dump_vtable (tree t, tree binfo, tree vtable) { int flags; FILE *stream = dump_begin (TDI_class, &flags); if (!stream) return; if (!(flags & TDF_SLIM)) { int ctor_vtbl_p = TYPE_BINFO (t) != binfo; fprintf (stream, "%s for %s", ctor_vtbl_p ? "Construction vtable" : "Vtable", type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER)); if (ctor_vtbl_p) { if (!BINFO_VIRTUAL_P (binfo)) fprintf (stream, " (0x%lx instance)", (unsigned long)binfo); fprintf (stream, " in %s", type_as_string (t, TFF_PLAIN_IDENTIFIER)); } fprintf (stream, "\n"); dump_array (stream, vtable); fprintf (stream, "\n"); } dump_end (TDI_class, stream); } static void dump_vtt (tree t, tree vtt) { int flags; FILE *stream = dump_begin (TDI_class, &flags); if (!stream) return; if (!(flags & TDF_SLIM)) { fprintf (stream, "VTT for %s\n", type_as_string (t, TFF_PLAIN_IDENTIFIER)); dump_array (stream, vtt); fprintf (stream, "\n"); } dump_end (TDI_class, stream); } /* Dump a function or thunk and its thunkees. */ static void dump_thunk (FILE *stream, int indent, tree thunk) { static const char spaces[] = " "; tree name = DECL_NAME (thunk); tree thunks; fprintf (stream, "%.*s%p %s %s", indent, spaces, (void *)thunk, !DECL_THUNK_P (thunk) ? "function" : DECL_THIS_THUNK_P (thunk) ? "this-thunk" : "covariant-thunk", name ? IDENTIFIER_POINTER (name) : "<unset>"); if (DECL_THUNK_P (thunk)) { HOST_WIDE_INT fixed_adjust = THUNK_FIXED_OFFSET (thunk); tree virtual_adjust = THUNK_VIRTUAL_OFFSET (thunk); fprintf (stream, " fixed=" HOST_WIDE_INT_PRINT_DEC, fixed_adjust); if (!virtual_adjust) /*NOP*/; else if (DECL_THIS_THUNK_P (thunk)) fprintf (stream, " vcall=" HOST_WIDE_INT_PRINT_DEC, tree_low_cst (virtual_adjust, 0)); else fprintf (stream, " vbase=" HOST_WIDE_INT_PRINT_DEC "(%s)", tree_low_cst (BINFO_VPTR_FIELD (virtual_adjust), 0), type_as_string (BINFO_TYPE (virtual_adjust), TFF_SCOPE)); if (THUNK_ALIAS (thunk)) fprintf (stream, " alias to %p", (void *)THUNK_ALIAS (thunk)); } fprintf (stream, "\n"); for (thunks = DECL_THUNKS (thunk); thunks; thunks = TREE_CHAIN (thunks)) dump_thunk (stream, indent + 2, thunks); } /* Dump the thunks for FN. */ void debug_thunks (tree fn) { dump_thunk (stderr, 0, fn); } /* Virtual function table initialization. */ /* Create all the necessary vtables for T and its base classes. */ static void finish_vtbls (tree t) { tree list; tree vbase; /* We lay out the primary and secondary vtables in one contiguous vtable. The primary vtable is first, followed by the non-virtual secondary vtables in inheritance graph order. */ list = build_tree_list (BINFO_VTABLE (TYPE_BINFO (t)), NULL_TREE); accumulate_vtbl_inits (TYPE_BINFO (t), TYPE_BINFO (t), TYPE_BINFO (t), t, list); /* Then come the virtual bases, also in inheritance graph order. */ for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase)) { if (!BINFO_VIRTUAL_P (vbase)) continue; accumulate_vtbl_inits (vbase, vbase, TYPE_BINFO (t), t, list); } if (BINFO_VTABLE (TYPE_BINFO (t))) initialize_vtable (TYPE_BINFO (t), TREE_VALUE (list)); } /* Initialize the vtable for BINFO with the INITS. */ static void initialize_vtable (tree binfo, tree inits) { tree decl; layout_vtable_decl (binfo, list_length (inits)); decl = get_vtbl_decl_for_binfo (binfo); initialize_artificial_var (decl, inits); dump_vtable (BINFO_TYPE (binfo), binfo, decl); } /* Build the VTT (virtual table table) for T. A class requires a VTT if it has virtual bases. This holds 1 - primary virtual pointer for complete object T 2 - secondary VTTs for each direct non-virtual base of T which requires a VTT 3 - secondary virtual pointers for each direct or indirect base of T which has virtual bases or is reachable via a virtual path from T. 4 - secondary VTTs for each direct or indirect virtual base of T. Secondary VTTs look like complete object VTTs without part 4. */ static void build_vtt (tree t) { tree inits; tree type; tree vtt; tree index; /* Build up the initializers for the VTT. */ inits = NULL_TREE; index = size_zero_node; build_vtt_inits (TYPE_BINFO (t), t, &inits, &index); /* If we didn't need a VTT, we're done. */ if (!inits) return; /* Figure out the type of the VTT. */ type = build_index_type (size_int (list_length (inits) - 1)); type = build_cplus_array_type (const_ptr_type_node, type); /* Now, build the VTT object itself. */ vtt = build_vtable (t, mangle_vtt_for_type (t), type); initialize_artificial_var (vtt, inits); /* Add the VTT to the vtables list. */ TREE_CHAIN (vtt) = TREE_CHAIN (CLASSTYPE_VTABLES (t)); TREE_CHAIN (CLASSTYPE_VTABLES (t)) = vtt; dump_vtt (t, vtt); } /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo, and CHAIN the vtable pointer for this binfo after construction is complete. VALUE can also be another BINFO, in which case we recurse. */ static tree binfo_ctor_vtable (tree binfo) { tree vt; while (1) { vt = BINFO_VTABLE (binfo); if (TREE_CODE (vt) == TREE_LIST) vt = TREE_VALUE (vt); if (TREE_CODE (vt) == TREE_BINFO) binfo = vt; else break; } return vt; } /* Data for secondary VTT initialization. */ typedef struct secondary_vptr_vtt_init_data_s { /* Is this the primary VTT? */ bool top_level_p; /* Current index into the VTT. */ tree index; /* TREE_LIST of initializers built up. */ tree inits; /* The type being constructed by this secondary VTT. */ tree type_being_constructed; } secondary_vptr_vtt_init_data; /* Recursively build the VTT-initializer for BINFO (which is in the hierarchy dominated by T). INITS points to the end of the initializer list to date. INDEX is the VTT index where the next element will be replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e. not a subvtt for some base of T). When that is so, we emit the sub-VTTs for virtual bases of T. When it is not so, we build the constructor vtables for the BINFO-in-T variant. */ static tree * build_vtt_inits (tree binfo, tree t, tree *inits, tree *index) { int i; tree b; tree init; tree secondary_vptrs; secondary_vptr_vtt_init_data data; int top_level_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t); /* We only need VTTs for subobjects with virtual bases. */ if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))) return inits; /* We need to use a construction vtable if this is not the primary VTT. */ if (!top_level_p) { build_ctor_vtbl_group (binfo, t); /* Record the offset in the VTT where this sub-VTT can be found. */ BINFO_SUBVTT_INDEX (binfo) = *index; } /* Add the address of the primary vtable for the complete object. */ init = binfo_ctor_vtable (binfo); *inits = build_tree_list (NULL_TREE, init); inits = &TREE_CHAIN (*inits); if (top_level_p) { gcc_assert (!BINFO_VPTR_INDEX (binfo)); BINFO_VPTR_INDEX (binfo) = *index; } *index = size_binop (PLUS_EXPR, *index, TYPE_SIZE_UNIT (ptr_type_node)); /* Recursively add the secondary VTTs for non-virtual bases. */ for (i = 0; BINFO_BASE_ITERATE (binfo, i, b); ++i) if (!BINFO_VIRTUAL_P (b)) inits = build_vtt_inits (b, t, inits, index); /* Add secondary virtual pointers for all subobjects of BINFO with either virtual bases or reachable along a virtual path, except subobjects that are non-virtual primary bases. */ data.top_level_p = top_level_p; data.index = *index; data.inits = NULL; data.type_being_constructed = BINFO_TYPE (binfo); dfs_walk_once (binfo, dfs_build_secondary_vptr_vtt_inits, NULL, &data); *index = data.index; /* The secondary vptrs come back in reverse order. After we reverse them, and add the INITS, the last init will be the first element of the chain. */ secondary_vptrs = data.inits; if (secondary_vptrs) { *inits = nreverse (secondary_vptrs); inits = &TREE_CHAIN (secondary_vptrs); gcc_assert (*inits == NULL_TREE); } if (top_level_p) /* Add the secondary VTTs for virtual bases in inheritance graph order. */ for (b = TYPE_BINFO (BINFO_TYPE (binfo)); b; b = TREE_CHAIN (b)) { if (!BINFO_VIRTUAL_P (b)) continue; inits = build_vtt_inits (b, t, inits, index); } else /* Remove the ctor vtables we created. */ dfs_walk_all (binfo, dfs_fixup_binfo_vtbls, NULL, binfo); return inits; } /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */ static tree dfs_build_secondary_vptr_vtt_inits (tree binfo, void *data_) { secondary_vptr_vtt_init_data *data = (secondary_vptr_vtt_init_data *)data_; /* We don't care about bases that don't have vtables. */ if (!TYPE_VFIELD (BINFO_TYPE (binfo))) return dfs_skip_bases; /* We're only interested in proper subobjects of the type being constructed. */ if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), data->type_being_constructed)) return NULL_TREE; /* We're only interested in bases with virtual bases or reachable via a virtual path from the type being constructed. */ if (!(CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)) || binfo_via_virtual (binfo, data->type_being_constructed))) return dfs_skip_bases; /* We're not interested in non-virtual primary bases. */ if (!BINFO_VIRTUAL_P (binfo) && BINFO_PRIMARY_P (binfo)) return NULL_TREE; /* Record the index where this secondary vptr can be found. */ if (data->top_level_p) { gcc_assert (!BINFO_VPTR_INDEX (binfo)); BINFO_VPTR_INDEX (binfo) = data->index; if (BINFO_VIRTUAL_P (binfo)) { /* It's a primary virtual base, and this is not a construction vtable. Find the base this is primary of in the inheritance graph, and use that base's vtable now. */ while (BINFO_PRIMARY_P (binfo)) binfo = BINFO_INHERITANCE_CHAIN (binfo); } } /* Add the initializer for the secondary vptr itself. */ data->inits = tree_cons (NULL_TREE, binfo_ctor_vtable (binfo), data->inits); /* Advance the vtt index. */ data->index = size_binop (PLUS_EXPR, data->index, TYPE_SIZE_UNIT (ptr_type_node)); return NULL_TREE; } /* Called from build_vtt_inits via dfs_walk. After building constructor vtables and generating the sub-vtt from them, we need to restore the BINFO_VTABLES that were scribbled on. DATA is the binfo of the base whose sub vtt was generated. */ static tree dfs_fixup_binfo_vtbls (tree binfo, void* data) { tree vtable = BINFO_VTABLE (binfo); if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo))) /* If this class has no vtable, none of its bases do. */ return dfs_skip_bases; if (!vtable) /* This might be a primary base, so have no vtable in this hierarchy. */ return NULL_TREE; /* If we scribbled the construction vtable vptr into BINFO, clear it out now. */ if (TREE_CODE (vtable) == TREE_LIST && (TREE_PURPOSE (vtable) == (tree) data)) BINFO_VTABLE (binfo) = TREE_CHAIN (vtable); return NULL_TREE; } /* Build the construction vtable group for BINFO which is in the hierarchy dominated by T. */ static void build_ctor_vtbl_group (tree binfo, tree t) { tree list; tree type; tree vtbl; tree inits; tree id; tree vbase; /* See if we've already created this construction vtable group. */ id = mangle_ctor_vtbl_for_type (t, binfo); if (IDENTIFIER_GLOBAL_VALUE (id)) return; gcc_assert (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t)); /* Build a version of VTBL (with the wrong type) for use in constructing the addresses of secondary vtables in the construction vtable group. */ vtbl = build_vtable (t, id, ptr_type_node); DECL_CONSTRUCTION_VTABLE_P (vtbl) = 1; list = build_tree_list (vtbl, NULL_TREE); accumulate_vtbl_inits (binfo, TYPE_BINFO (TREE_TYPE (binfo)), binfo, t, list); /* Add the vtables for each of our virtual bases using the vbase in T binfo. */ for (vbase = TYPE_BINFO (BINFO_TYPE (binfo)); vbase; vbase = TREE_CHAIN (vbase)) { tree b; if (!BINFO_VIRTUAL_P (vbase)) continue; b = copied_binfo (vbase, binfo); accumulate_vtbl_inits (b, vbase, binfo, t, list); } inits = TREE_VALUE (list); /* Figure out the type of the construction vtable. */ type = build_index_type (size_int (list_length (inits) - 1)); type = build_cplus_array_type (vtable_entry_type, type); layout_type (type); TREE_TYPE (vtbl) = type; DECL_SIZE (vtbl) = DECL_SIZE_UNIT (vtbl) = NULL_TREE; layout_decl (vtbl, 0); /* Initialize the construction vtable. */ CLASSTYPE_VTABLES (t) = chainon (CLASSTYPE_VTABLES (t), vtbl); initialize_artificial_var (vtbl, inits); dump_vtable (t, binfo, vtbl); } /* Add the vtbl initializers for BINFO (and its bases other than non-virtual primaries) to the list of INITS. BINFO is in the hierarchy dominated by T. RTTI_BINFO is the binfo within T of the constructor the vtbl inits should be accumulated for. (If this is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).) ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO). BINFO is the active base equivalent of ORIG_BINFO in the inheritance graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE, but are not necessarily the same in terms of layout. */ static void accumulate_vtbl_inits (tree binfo, tree orig_binfo, tree rtti_binfo, tree t, tree inits) { int i; tree base_binfo; int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t); gcc_assert (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), BINFO_TYPE (orig_binfo))); /* If it doesn't have a vptr, we don't do anything. */ if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo))) return; /* If we're building a construction vtable, we're not interested in subobjects that don't require construction vtables. */ if (ctor_vtbl_p && !CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)) && !binfo_via_virtual (orig_binfo, BINFO_TYPE (rtti_binfo))) return; /* Build the initializers for the BINFO-in-T vtable. */ TREE_VALUE (inits) = chainon (TREE_VALUE (inits), dfs_accumulate_vtbl_inits (binfo, orig_binfo, rtti_binfo, t, inits)); /* Walk the BINFO and its bases. We walk in preorder so that as we initialize each vtable we can figure out at what offset the secondary vtable lies from the primary vtable. We can't use dfs_walk here because we need to iterate through bases of BINFO and RTTI_BINFO simultaneously. */ for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) { /* Skip virtual bases. */ if (BINFO_VIRTUAL_P (base_binfo)) continue; accumulate_vtbl_inits (base_binfo, BINFO_BASE_BINFO (orig_binfo, i), rtti_binfo, t, inits); } } /* Called from accumulate_vtbl_inits. Returns the initializers for the BINFO vtable. */ static tree dfs_accumulate_vtbl_inits (tree binfo, tree orig_binfo, tree rtti_binfo, tree t, tree l) { tree inits = NULL_TREE; tree vtbl = NULL_TREE; int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t); if (ctor_vtbl_p && BINFO_VIRTUAL_P (orig_binfo) && BINFO_PRIMARY_P (orig_binfo)) { /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a primary virtual base. If it is not the same primary in the hierarchy of T, we'll need to generate a ctor vtable for it, to place at its location in T. If it is the same primary, we still need a VTT entry for the vtable, but it should point to the ctor vtable for the base it is a primary for within the sub-hierarchy of RTTI_BINFO. There are three possible cases: 1) We are in the same place. 2) We are a primary base within a lost primary virtual base of RTTI_BINFO. 3) We are primary to something not a base of RTTI_BINFO. */ tree b; tree last = NULL_TREE; /* First, look through the bases we are primary to for RTTI_BINFO or a virtual base. */ b = binfo; while (BINFO_PRIMARY_P (b)) { b = BINFO_INHERITANCE_CHAIN (b); last = b; if (BINFO_VIRTUAL_P (b) || b == rtti_binfo) goto found; } /* If we run out of primary links, keep looking down our inheritance chain; we might be an indirect primary. */ for (b = last; b; b = BINFO_INHERITANCE_CHAIN (b)) if (BINFO_VIRTUAL_P (b) || b == rtti_binfo) break; found: /* If we found RTTI_BINFO, this is case 1. If we found a virtual base B and it is a base of RTTI_BINFO, this is case 2. In either case, we share our vtable with LAST, i.e. the derived-most base within B of which we are a primary. */ if (b == rtti_binfo || (b && binfo_for_vbase (BINFO_TYPE (b), BINFO_TYPE (rtti_binfo)))) /* Just set our BINFO_VTABLE to point to LAST, as we may not have set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in binfo_ctor_vtable after everything's been set up. */ vtbl = last; /* Otherwise, this is case 3 and we get our own. */ } else if (!BINFO_NEW_VTABLE_MARKED (orig_binfo)) return inits; if (!vtbl) { tree index; int non_fn_entries; /* Compute the initializer for this vtable. */ inits = build_vtbl_initializer (binfo, orig_binfo, t, rtti_binfo, &non_fn_entries); /* Figure out the position to which the VPTR should point. */ vtbl = TREE_PURPOSE (l); vtbl = build1 (ADDR_EXPR, vtbl_ptr_type_node, vtbl); index = size_binop (PLUS_EXPR, size_int (non_fn_entries), size_int (list_length (TREE_VALUE (l)))); index = size_binop (MULT_EXPR, TYPE_SIZE_UNIT (vtable_entry_type), index); vtbl = build2 (POINTER_PLUS_EXPR, TREE_TYPE (vtbl), vtbl, index); } if (ctor_vtbl_p) /* For a construction vtable, we can't overwrite BINFO_VTABLE. So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will straighten this out. */ BINFO_VTABLE (binfo) = tree_cons (rtti_binfo, vtbl, BINFO_VTABLE (binfo)); else if (BINFO_PRIMARY_P (binfo) && BINFO_VIRTUAL_P (binfo)) inits = NULL_TREE; else /* For an ordinary vtable, set BINFO_VTABLE. */ BINFO_VTABLE (binfo) = vtbl; return inits; } static GTY(()) tree abort_fndecl_addr; /* Construct the initializer for BINFO's virtual function table. BINFO is part of the hierarchy dominated by T. If we're building a construction vtable, the ORIG_BINFO is the binfo we should use to find the actual function pointers to put in the vtable - but they can be overridden on the path to most-derived in the graph that ORIG_BINFO belongs. Otherwise, ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the BINFO that should be indicated by the RTTI information in the vtable; it will be a base class of T, rather than T itself, if we are building a construction vtable. The value returned is a TREE_LIST suitable for wrapping in a CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the number of non-function entries in the vtable. It might seem that this function should never be called with a BINFO for which BINFO_PRIMARY_P holds, the vtable for such a base is always subsumed by a derived class vtable. However, when we are building construction vtables, we do build vtables for primary bases; we need these while the primary base is being constructed. */ static tree build_vtbl_initializer (tree binfo, tree orig_binfo, tree t, tree rtti_binfo, int* non_fn_entries_p) { tree v, b; tree vfun_inits; vtbl_init_data vid; unsigned ix; tree vbinfo; VEC(tree,gc) *vbases; /* Initialize VID. */ memset (&vid, 0, sizeof (vid)); vid.binfo = binfo; vid.derived = t; vid.rtti_binfo = rtti_binfo; vid.last_init = &vid.inits; vid.primary_vtbl_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t); vid.ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t); vid.generate_vcall_entries = true; /* The first vbase or vcall offset is at index -3 in the vtable. */ vid.index = ssize_int(-3 * TARGET_VTABLE_DATA_ENTRY_DISTANCE); /* Add entries to the vtable for RTTI. */ build_rtti_vtbl_entries (binfo, &vid); /* Create an array for keeping track of the functions we've processed. When we see multiple functions with the same signature, we share the vcall offsets. */ vid.fns = VEC_alloc (tree, gc, 32); /* Add the vcall and vbase offset entries. */ build_vcall_and_vbase_vtbl_entries (binfo, &vid); /* Clear BINFO_VTABLE_PATH_MARKED; it's set by build_vbase_offset_vtbl_entries. */ for (vbases = CLASSTYPE_VBASECLASSES (t), ix = 0; VEC_iterate (tree, vbases, ix, vbinfo); ix++) BINFO_VTABLE_PATH_MARKED (vbinfo) = 0; /* If the target requires padding between data entries, add that now. */ if (TARGET_VTABLE_DATA_ENTRY_DISTANCE > 1) { tree cur, *prev; for (prev = &vid.inits; (cur = *prev); prev = &TREE_CHAIN (cur)) { tree add = cur; int i; for (i = 1; i < TARGET_VTABLE_DATA_ENTRY_DISTANCE; ++i) add = tree_cons (NULL_TREE, build1 (NOP_EXPR, vtable_entry_type, null_pointer_node), add); *prev = add; } } if (non_fn_entries_p) *non_fn_entries_p = list_length (vid.inits); /* Go through all the ordinary virtual functions, building up initializers. */ vfun_inits = NULL_TREE; for (v = BINFO_VIRTUALS (orig_binfo); v; v = TREE_CHAIN (v)) { tree delta; tree vcall_index; tree fn, fn_original; tree init = NULL_TREE; fn = BV_FN (v); fn_original = fn; if (DECL_THUNK_P (fn)) { if (!DECL_NAME (fn)) finish_thunk (fn); if (THUNK_ALIAS (fn)) { fn = THUNK_ALIAS (fn); BV_FN (v) = fn; } fn_original = THUNK_TARGET (fn); } /* If the only definition of this function signature along our primary base chain is from a lost primary, this vtable slot will never be used, so just zero it out. This is important to avoid requiring extra thunks which cannot be generated with the function. We first check this in update_vtable_entry_for_fn, so we handle restored primary bases properly; we also need to do it here so we zero out unused slots in ctor vtables, rather than filling them with erroneous values (though harmless, apart from relocation costs). */ for (b = binfo; ; b = get_primary_binfo (b)) { /* We found a defn before a lost primary; go ahead as normal. */ if (look_for_overrides_here (BINFO_TYPE (b), fn_original)) break; /* The nearest definition is from a lost primary; clear the slot. */ if (BINFO_LOST_PRIMARY_P (b)) { init = size_zero_node; break; } } if (! init) { /* Pull the offset for `this', and the function to call, out of the list. */ delta = BV_DELTA (v); vcall_index = BV_VCALL_INDEX (v); gcc_assert (TREE_CODE (delta) == INTEGER_CST); gcc_assert (TREE_CODE (fn) == FUNCTION_DECL); /* You can't call an abstract virtual function; it's abstract. So, we replace these functions with __pure_virtual. */ if (DECL_PURE_VIRTUAL_P (fn_original)) { fn = abort_fndecl; if (abort_fndecl_addr == NULL) abort_fndecl_addr = build1 (ADDR_EXPR, vfunc_ptr_type_node, fn); init = abort_fndecl_addr; } else { if (!integer_zerop (delta) || vcall_index) { fn = make_thunk (fn, /*this_adjusting=*/1, delta, vcall_index); if (!DECL_NAME (fn)) finish_thunk (fn); } /* Take the address of the function, considering it to be of an appropriate generic type. */ init = build1 (ADDR_EXPR, vfunc_ptr_type_node, fn); } } /* And add it to the chain of initializers. */ if (TARGET_VTABLE_USES_DESCRIPTORS) { int i; if (init == size_zero_node) for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i) vfun_inits = tree_cons (NULL_TREE, init, vfun_inits); else for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i) { tree fdesc = build2 (FDESC_EXPR, vfunc_ptr_type_node, TREE_OPERAND (init, 0), build_int_cst (NULL_TREE, i)); TREE_CONSTANT (fdesc) = 1; vfun_inits = tree_cons (NULL_TREE, fdesc, vfun_inits); } } else vfun_inits = tree_cons (NULL_TREE, init, vfun_inits); } /* The initializers for virtual functions were built up in reverse order; straighten them out now. */ vfun_inits = nreverse (vfun_inits); /* The negative offset initializers are also in reverse order. */ vid.inits = nreverse (vid.inits); /* Chain the two together. */ return chainon (vid.inits, vfun_inits); } /* Adds to vid->inits the initializers for the vbase and vcall offsets in BINFO, which is in the hierarchy dominated by T. */ static void build_vcall_and_vbase_vtbl_entries (tree binfo, vtbl_init_data* vid) { tree b; /* If this is a derived class, we must first create entries corresponding to the primary base class. */ b = get_primary_binfo (binfo); if (b) build_vcall_and_vbase_vtbl_entries (b, vid); /* Add the vbase entries for this base. */ build_vbase_offset_vtbl_entries (binfo, vid); /* Add the vcall entries for this base. */ build_vcall_offset_vtbl_entries (binfo, vid); } /* Returns the initializers for the vbase offset entries in the vtable for BINFO (which is part of the class hierarchy dominated by T), in reverse order. VBASE_OFFSET_INDEX gives the vtable index where the next vbase offset will go. */ static void build_vbase_offset_vtbl_entries (tree binfo, vtbl_init_data* vid) { tree vbase; tree t; tree non_primary_binfo; /* If there are no virtual baseclasses, then there is nothing to do. */ if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))) return; t = vid->derived; /* We might be a primary base class. Go up the inheritance hierarchy until we find the most derived class of which we are a primary base: it is the offset of that which we need to use. */ non_primary_binfo = binfo; while (BINFO_INHERITANCE_CHAIN (non_primary_binfo)) { tree b; /* If we have reached a virtual base, then it must be a primary base (possibly multi-level) of vid->binfo, or we wouldn't have called build_vcall_and_vbase_vtbl_entries for it. But it might be a lost primary, so just skip down to vid->binfo. */ if (BINFO_VIRTUAL_P (non_primary_binfo)) { non_primary_binfo = vid->binfo; break; } b = BINFO_INHERITANCE_CHAIN (non_primary_binfo); if (get_primary_binfo (b) != non_primary_binfo) break; non_primary_binfo = b; } /* Go through the virtual bases, adding the offsets. */ for (vbase = TYPE_BINFO (BINFO_TYPE (binfo)); vbase; vbase = TREE_CHAIN (vbase)) { tree b; tree delta; if (!BINFO_VIRTUAL_P (vbase)) continue; /* Find the instance of this virtual base in the complete object. */ b = copied_binfo (vbase, binfo); /* If we've already got an offset for this virtual base, we don't need another one. */ if (BINFO_VTABLE_PATH_MARKED (b)) continue; BINFO_VTABLE_PATH_MARKED (b) = 1; /* Figure out where we can find this vbase offset. */ delta = size_binop (MULT_EXPR, vid->index, convert (ssizetype, TYPE_SIZE_UNIT (vtable_entry_type))); if (vid->primary_vtbl_p) BINFO_VPTR_FIELD (b) = delta; if (binfo != TYPE_BINFO (t)) /* The vbase offset had better be the same. */ gcc_assert (tree_int_cst_equal (delta, BINFO_VPTR_FIELD (vbase))); /* The next vbase will come at a more negative offset. */ vid->index = size_binop (MINUS_EXPR, vid->index, ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE)); /* The initializer is the delta from BINFO to this virtual base. The vbase offsets go in reverse inheritance-graph order, and we are walking in inheritance graph order so these end up in the right order. */ delta = size_diffop_loc (input_location, BINFO_OFFSET (b), BINFO_OFFSET (non_primary_binfo)); *vid->last_init = build_tree_list (NULL_TREE, fold_build1_loc (input_location, NOP_EXPR, vtable_entry_type, delta)); vid->last_init = &TREE_CHAIN (*vid->last_init); } } /* Adds the initializers for the vcall offset entries in the vtable for BINFO (which is part of the class hierarchy dominated by VID->DERIVED) to VID->INITS. */ static void build_vcall_offset_vtbl_entries (tree binfo, vtbl_init_data* vid) { /* We only need these entries if this base is a virtual base. We compute the indices -- but do not add to the vtable -- when building the main vtable for a class. */ if (binfo == TYPE_BINFO (vid->derived) || (BINFO_VIRTUAL_P (binfo) /* If BINFO is RTTI_BINFO, then (since BINFO does not correspond to VID->DERIVED), we are building a primary construction virtual table. Since this is a primary virtual table, we do not need the vcall offsets for BINFO. */ && binfo != vid->rtti_binfo)) { /* We need a vcall offset for each of the virtual functions in this vtable. For example: class A { virtual void f (); }; class B1 : virtual public A { virtual void f (); }; class B2 : virtual public A { virtual void f (); }; class C: public B1, public B2 { virtual void f (); }; A C object has a primary base of B1, which has a primary base of A. A C also has a secondary base of B2, which no longer has a primary base of A. So the B2-in-C construction vtable needs a secondary vtable for A, which will adjust the A* to a B2* to call f. We have no way of knowing what (or even whether) this offset will be when we define B2, so we store this "vcall offset" in the A sub-vtable and look it up in a "virtual thunk" for B2::f. We need entries for all the functions in our primary vtable and in our non-virtual bases' secondary vtables. */ vid->vbase = binfo; /* If we are just computing the vcall indices -- but do not need the actual entries -- not that. */ if (!BINFO_VIRTUAL_P (binfo)) vid->generate_vcall_entries = false; /* Now, walk through the non-virtual bases, adding vcall offsets. */ add_vcall_offset_vtbl_entries_r (binfo, vid); } } /* Build vcall offsets, starting with those for BINFO. */ static void add_vcall_offset_vtbl_entries_r (tree binfo, vtbl_init_data* vid) { int i; tree primary_binfo; tree base_binfo; /* Don't walk into virtual bases -- except, of course, for the virtual base for which we are building vcall offsets. Any primary virtual base will have already had its offsets generated through the recursion in build_vcall_and_vbase_vtbl_entries. */ if (BINFO_VIRTUAL_P (binfo) && vid->vbase != binfo) return; /* If BINFO has a primary base, process it first. */ primary_binfo = get_primary_binfo (binfo); if (primary_binfo) add_vcall_offset_vtbl_entries_r (primary_binfo, vid); /* Add BINFO itself to the list. */ add_vcall_offset_vtbl_entries_1 (binfo, vid); /* Scan the non-primary bases of BINFO. */ for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) if (base_binfo != primary_binfo) add_vcall_offset_vtbl_entries_r (base_binfo, vid); } /* Called from build_vcall_offset_vtbl_entries_r. */ static void add_vcall_offset_vtbl_entries_1 (tree binfo, vtbl_init_data* vid) { /* Make entries for the rest of the virtuals. */ if (abi_version_at_least (2)) { tree orig_fn; /* The ABI requires that the methods be processed in declaration order. G++ 3.2 used the order in the vtable. */ for (orig_fn = TYPE_METHODS (BINFO_TYPE (binfo)); orig_fn; orig_fn = TREE_CHAIN (orig_fn)) if (DECL_VINDEX (orig_fn)) add_vcall_offset (orig_fn, binfo, vid); } else { tree derived_virtuals; tree base_virtuals; tree orig_virtuals; /* If BINFO is a primary base, the most derived class which has BINFO as a primary base; otherwise, just BINFO. */ tree non_primary_binfo; /* We might be a primary base class. Go up the inheritance hierarchy until we find the most derived class of which we are a primary base: it is the BINFO_VIRTUALS there that we need to consider. */ non_primary_binfo = binfo; while (BINFO_INHERITANCE_CHAIN (non_primary_binfo)) { tree b; /* If we have reached a virtual base, then it must be vid->vbase, because we ignore other virtual bases in add_vcall_offset_vtbl_entries_r. In turn, it must be a primary base (possibly multi-level) of vid->binfo, or we wouldn't have called build_vcall_and_vbase_vtbl_entries for it. But it might be a lost primary, so just skip down to vid->binfo. */ if (BINFO_VIRTUAL_P (non_primary_binfo)) { gcc_assert (non_primary_binfo == vid->vbase); non_primary_binfo = vid->binfo; break; } b = BINFO_INHERITANCE_CHAIN (non_primary_binfo); if (get_primary_binfo (b) != non_primary_binfo) break; non_primary_binfo = b; } if (vid->ctor_vtbl_p) /* For a ctor vtable we need the equivalent binfo within the hierarchy where rtti_binfo is the most derived type. */ non_primary_binfo = original_binfo (non_primary_binfo, vid->rtti_binfo); for (base_virtuals = BINFO_VIRTUALS (binfo), derived_virtuals = BINFO_VIRTUALS (non_primary_binfo), orig_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo))); base_virtuals; base_virtuals = TREE_CHAIN (base_virtuals), derived_virtuals = TREE_CHAIN (derived_virtuals), orig_virtuals = TREE_CHAIN (orig_virtuals)) { tree orig_fn; /* Find the declaration that originally caused this function to be present in BINFO_TYPE (binfo). */ orig_fn = BV_FN (orig_virtuals); /* When processing BINFO, we only want to generate vcall slots for function slots introduced in BINFO. So don't try to generate one if the function isn't even defined in BINFO. */ if (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), DECL_CONTEXT (orig_fn))) continue; add_vcall_offset (orig_fn, binfo, vid); } } } /* Add a vcall offset entry for ORIG_FN to the vtable. */ static void add_vcall_offset (tree orig_fn, tree binfo, vtbl_init_data *vid) { size_t i; tree vcall_offset; tree derived_entry; /* If there is already an entry for a function with the same signature as FN, then we do not need a second vcall offset. Check the list of functions already present in the derived class vtable. */ for (i = 0; VEC_iterate (tree, vid->fns, i, derived_entry); ++i) { if (same_signature_p (derived_entry, orig_fn) /* We only use one vcall offset for virtual destructors, even though there are two virtual table entries. */ || (DECL_DESTRUCTOR_P (derived_entry) && DECL_DESTRUCTOR_P (orig_fn))) return; } /* If we are building these vcall offsets as part of building the vtable for the most derived class, remember the vcall offset. */ if (vid->binfo == TYPE_BINFO (vid->derived)) { tree_pair_p elt = VEC_safe_push (tree_pair_s, gc, CLASSTYPE_VCALL_INDICES (vid->derived), NULL); elt->purpose = orig_fn; elt->value = vid->index; } /* The next vcall offset will be found at a more negative offset. */ vid->index = size_binop (MINUS_EXPR, vid->index, ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE)); /* Keep track of this function. */ VEC_safe_push (tree, gc, vid->fns, orig_fn); if (vid->generate_vcall_entries) { tree base; tree fn; /* Find the overriding function. */ fn = find_final_overrider (vid->rtti_binfo, binfo, orig_fn); if (fn == error_mark_node) vcall_offset = build1 (NOP_EXPR, vtable_entry_type, integer_zero_node); else { base = TREE_VALUE (fn); /* The vbase we're working on is a primary base of vid->binfo. But it might be a lost primary, so its BINFO_OFFSET might be wrong, so we just use the BINFO_OFFSET from vid->binfo. */ vcall_offset = size_diffop_loc (input_location, BINFO_OFFSET (base), BINFO_OFFSET (vid->binfo)); vcall_offset = fold_build1_loc (input_location, NOP_EXPR, vtable_entry_type, vcall_offset); } /* Add the initializer to the vtable. */ *vid->last_init = build_tree_list (NULL_TREE, vcall_offset); vid->last_init = &TREE_CHAIN (*vid->last_init); } } /* Return vtbl initializers for the RTTI entries corresponding to the BINFO's vtable. The RTTI entries should indicate the object given by VID->rtti_binfo. */ static void build_rtti_vtbl_entries (tree binfo, vtbl_init_data* vid) { tree b; tree t; tree offset; tree decl; tree init; t = BINFO_TYPE (vid->rtti_binfo); /* To find the complete object, we will first convert to our most primary base, and then add the offset in the vtbl to that value. */ b = binfo; while (CLASSTYPE_HAS_PRIMARY_BASE_P (BINFO_TYPE (b)) && !BINFO_LOST_PRIMARY_P (b)) { tree primary_base; primary_base = get_primary_binfo (b); gcc_assert (BINFO_PRIMARY_P (primary_base) && BINFO_INHERITANCE_CHAIN (primary_base) == b); b = primary_base; } offset = size_diffop_loc (input_location, BINFO_OFFSET (vid->rtti_binfo), BINFO_OFFSET (b)); /* The second entry is the address of the typeinfo object. */ if (flag_rtti) decl = build_address (get_tinfo_decl (t)); else decl = integer_zero_node; /* Convert the declaration to a type that can be stored in the vtable. */ init = build_nop (vfunc_ptr_type_node, decl); *vid->last_init = build_tree_list (NULL_TREE, init); vid->last_init = &TREE_CHAIN (*vid->last_init); /* Add the offset-to-top entry. It comes earlier in the vtable than the typeinfo entry. Convert the offset to look like a function pointer, so that we can put it in the vtable. */ init = build_nop (vfunc_ptr_type_node, offset); *vid->last_init = build_tree_list (NULL_TREE, init); vid->last_init = &TREE_CHAIN (*vid->last_init); } /* Fold a OBJ_TYPE_REF expression to the address of a function. KNOWN_TYPE carries the true type of OBJ_TYPE_REF_OBJECT(REF). */ tree cp_fold_obj_type_ref (tree ref, tree known_type) { HOST_WIDE_INT index = tree_low_cst (OBJ_TYPE_REF_TOKEN (ref), 1); HOST_WIDE_INT i = 0; tree v = BINFO_VIRTUALS (TYPE_BINFO (known_type)); tree fndecl; while (i != index) { i += (TARGET_VTABLE_USES_DESCRIPTORS ? TARGET_VTABLE_USES_DESCRIPTORS : 1); v = TREE_CHAIN (v); } fndecl = BV_FN (v); #ifdef ENABLE_CHECKING gcc_assert (tree_int_cst_equal (OBJ_TYPE_REF_TOKEN (ref), DECL_VINDEX (fndecl))); #endif cgraph_node (fndecl)->local.vtable_method = true; return build_address (fndecl); } #include "gt-cp-class.h"
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