d48cc9dd6f
Paul Brook <paul@codesourcery.com> * c-typeprint.c (c_type_print_base): Skip artificial fields. Use get_vptr_fieldno to skip the vtable pointer. * dwarf2read.c (dwarf2_add_field): Set FIELD_ARTIFICIAL on artificial fields. (dwarf2_add_member_fn): Complain about virtual member functions without DW_AT_vtable_elem_location and force TYPE_CPLUS_DYNAMIC. * gdbtypes.c (get_vptr_fieldno): Update comment. * gdbtypes.h (struct cplus_struct_type): Add is_dynamic. (TYPE_CPLUS_DYNAMIC): New macro. * gnu-v3-abi.c (gnuv3_dynamic_class): New. (gnuv3_get_vtable): Rewrite to use gnuv3_dynamic_class. Move higher. (gnuv3_rtti_type, gnuv3_get_virtual_fn, gnuv3_baseclass_offset): Use gnuv3_get_vtable. * varobj.c (cplus_class_num_children, cplus_describe_child): Skip artificial fields. Use get_vptr_fieldno to skip the vtable pointer.
871 lines
29 KiB
C
871 lines
29 KiB
C
/* Abstraction of GNU v3 abi.
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Contributed by Jim Blandy <jimb@redhat.com>
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Copyright (C) 2001, 2002, 2003, 2005, 2006, 2007, 2008, 2009
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Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include "value.h"
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#include "cp-abi.h"
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#include "cp-support.h"
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#include "demangle.h"
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#include "objfiles.h"
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#include "valprint.h"
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#include "gdb_assert.h"
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#include "gdb_string.h"
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static struct cp_abi_ops gnu_v3_abi_ops;
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static int
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gnuv3_is_vtable_name (const char *name)
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{
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return strncmp (name, "_ZTV", 4) == 0;
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}
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static int
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gnuv3_is_operator_name (const char *name)
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{
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return strncmp (name, "operator", 8) == 0;
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}
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/* To help us find the components of a vtable, we build ourselves a
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GDB type object representing the vtable structure. Following the
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V3 ABI, it goes something like this:
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struct gdb_gnu_v3_abi_vtable {
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/ * An array of virtual call and virtual base offsets. The real
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length of this array depends on the class hierarchy; we use
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negative subscripts to access the elements. Yucky, but
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better than the alternatives. * /
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ptrdiff_t vcall_and_vbase_offsets[0];
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/ * The offset from a virtual pointer referring to this table
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to the top of the complete object. * /
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ptrdiff_t offset_to_top;
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/ * The type_info pointer for this class. This is really a
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std::type_info *, but GDB doesn't really look at the
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type_info object itself, so we don't bother to get the type
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exactly right. * /
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void *type_info;
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/ * Virtual table pointers in objects point here. * /
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/ * Virtual function pointers. Like the vcall/vbase array, the
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real length of this table depends on the class hierarchy. * /
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void (*virtual_functions[0]) ();
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};
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The catch, of course, is that the exact layout of this table
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depends on the ABI --- word size, endianness, alignment, etc. So
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the GDB type object is actually a per-architecture kind of thing.
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vtable_type_gdbarch_data is a gdbarch per-architecture data pointer
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which refers to the struct type * for this structure, laid out
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appropriately for the architecture. */
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static struct gdbarch_data *vtable_type_gdbarch_data;
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/* Human-readable names for the numbers of the fields above. */
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enum {
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vtable_field_vcall_and_vbase_offsets,
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vtable_field_offset_to_top,
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vtable_field_type_info,
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vtable_field_virtual_functions
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};
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/* Return a GDB type representing `struct gdb_gnu_v3_abi_vtable',
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described above, laid out appropriately for ARCH.
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We use this function as the gdbarch per-architecture data
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initialization function. */
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static void *
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build_gdb_vtable_type (struct gdbarch *arch)
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{
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struct type *t;
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struct field *field_list, *field;
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int offset;
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struct type *void_ptr_type
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= builtin_type (arch)->builtin_data_ptr;
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struct type *ptr_to_void_fn_type
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= builtin_type (arch)->builtin_func_ptr;
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/* ARCH can't give us the true ptrdiff_t type, so we guess. */
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struct type *ptrdiff_type
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= arch_integer_type (arch, gdbarch_ptr_bit (arch), 0, "ptrdiff_t");
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/* We assume no padding is necessary, since GDB doesn't know
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anything about alignment at the moment. If this assumption bites
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us, we should add a gdbarch method which, given a type, returns
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the alignment that type requires, and then use that here. */
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/* Build the field list. */
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field_list = xmalloc (sizeof (struct field [4]));
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memset (field_list, 0, sizeof (struct field [4]));
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field = &field_list[0];
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offset = 0;
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/* ptrdiff_t vcall_and_vbase_offsets[0]; */
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FIELD_NAME (*field) = "vcall_and_vbase_offsets";
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FIELD_TYPE (*field) = lookup_array_range_type (ptrdiff_type, 0, -1);
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FIELD_BITPOS (*field) = offset * TARGET_CHAR_BIT;
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offset += TYPE_LENGTH (FIELD_TYPE (*field));
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field++;
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/* ptrdiff_t offset_to_top; */
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FIELD_NAME (*field) = "offset_to_top";
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FIELD_TYPE (*field) = ptrdiff_type;
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FIELD_BITPOS (*field) = offset * TARGET_CHAR_BIT;
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offset += TYPE_LENGTH (FIELD_TYPE (*field));
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field++;
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/* void *type_info; */
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FIELD_NAME (*field) = "type_info";
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FIELD_TYPE (*field) = void_ptr_type;
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FIELD_BITPOS (*field) = offset * TARGET_CHAR_BIT;
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offset += TYPE_LENGTH (FIELD_TYPE (*field));
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field++;
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/* void (*virtual_functions[0]) (); */
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FIELD_NAME (*field) = "virtual_functions";
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FIELD_TYPE (*field) = lookup_array_range_type (ptr_to_void_fn_type, 0, -1);
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FIELD_BITPOS (*field) = offset * TARGET_CHAR_BIT;
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offset += TYPE_LENGTH (FIELD_TYPE (*field));
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field++;
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/* We assumed in the allocation above that there were four fields. */
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gdb_assert (field == (field_list + 4));
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t = arch_type (arch, TYPE_CODE_STRUCT, offset, NULL);
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TYPE_NFIELDS (t) = field - field_list;
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TYPE_FIELDS (t) = field_list;
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TYPE_TAG_NAME (t) = "gdb_gnu_v3_abi_vtable";
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INIT_CPLUS_SPECIFIC (t);
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return t;
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}
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/* Return the ptrdiff_t type used in the vtable type. */
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static struct type *
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vtable_ptrdiff_type (struct gdbarch *gdbarch)
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{
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struct type *vtable_type = gdbarch_data (gdbarch, vtable_type_gdbarch_data);
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/* The "offset_to_top" field has the appropriate (ptrdiff_t) type. */
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return TYPE_FIELD_TYPE (vtable_type, vtable_field_offset_to_top);
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}
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/* Return the offset from the start of the imaginary `struct
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gdb_gnu_v3_abi_vtable' object to the vtable's "address point"
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(i.e., where objects' virtual table pointers point). */
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static int
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vtable_address_point_offset (struct gdbarch *gdbarch)
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{
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struct type *vtable_type = gdbarch_data (gdbarch, vtable_type_gdbarch_data);
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return (TYPE_FIELD_BITPOS (vtable_type, vtable_field_virtual_functions)
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/ TARGET_CHAR_BIT);
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}
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/* Determine whether structure TYPE is a dynamic class. Cache the
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result. */
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static int
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gnuv3_dynamic_class (struct type *type)
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{
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int fieldnum, fieldelem;
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if (TYPE_CPLUS_DYNAMIC (type))
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return TYPE_CPLUS_DYNAMIC (type) == 1;
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ALLOCATE_CPLUS_STRUCT_TYPE (type);
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for (fieldnum = 0; fieldnum < TYPE_N_BASECLASSES (type); fieldnum++)
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if (BASETYPE_VIA_VIRTUAL (type, fieldnum)
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|| gnuv3_dynamic_class (TYPE_FIELD_TYPE (type, fieldnum)))
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{
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TYPE_CPLUS_DYNAMIC (type) = 1;
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return 1;
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}
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for (fieldnum = 0; fieldnum < TYPE_NFN_FIELDS (type); fieldnum++)
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for (fieldelem = 0; fieldelem < TYPE_FN_FIELDLIST_LENGTH (type, fieldnum);
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fieldelem++)
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{
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struct fn_field *f = TYPE_FN_FIELDLIST1 (type, fieldnum);
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if (TYPE_FN_FIELD_VIRTUAL_P (f, fieldelem))
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{
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TYPE_CPLUS_DYNAMIC (type) = 1;
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return 1;
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}
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}
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TYPE_CPLUS_DYNAMIC (type) = -1;
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return 0;
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}
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/* Find the vtable for a value of CONTAINER_TYPE located at
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CONTAINER_ADDR. Return a value of the correct vtable type for this
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architecture, or NULL if CONTAINER does not have a vtable. */
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static struct value *
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gnuv3_get_vtable (struct gdbarch *gdbarch,
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struct type *container_type, CORE_ADDR container_addr)
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{
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struct type *vtable_type = gdbarch_data (gdbarch,
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vtable_type_gdbarch_data);
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struct type *vtable_pointer_type;
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struct value *vtable_pointer;
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CORE_ADDR vtable_address;
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/* If this type does not have a virtual table, don't read the first
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field. */
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if (!gnuv3_dynamic_class (check_typedef (container_type)))
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return NULL;
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/* We do not consult the debug information to find the virtual table.
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The ABI specifies that it is always at offset zero in any class,
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and debug information may not represent it.
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We avoid using value_contents on principle, because the object might
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be large. */
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/* Find the type "pointer to virtual table". */
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vtable_pointer_type = lookup_pointer_type (vtable_type);
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/* Load it from the start of the class. */
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vtable_pointer = value_at (vtable_pointer_type, container_addr);
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vtable_address = value_as_address (vtable_pointer);
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/* Correct it to point at the start of the virtual table, rather
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than the address point. */
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return value_at_lazy (vtable_type,
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vtable_address - vtable_address_point_offset (gdbarch));
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}
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static struct type *
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gnuv3_rtti_type (struct value *value,
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int *full_p, int *top_p, int *using_enc_p)
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{
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struct gdbarch *gdbarch;
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struct type *values_type = check_typedef (value_type (value));
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struct value *vtable;
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struct minimal_symbol *vtable_symbol;
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const char *vtable_symbol_name;
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const char *class_name;
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struct type *run_time_type;
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LONGEST offset_to_top;
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/* We only have RTTI for class objects. */
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if (TYPE_CODE (values_type) != TYPE_CODE_CLASS)
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return NULL;
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/* Determine architecture. */
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gdbarch = get_type_arch (values_type);
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if (using_enc_p)
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*using_enc_p = 0;
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vtable = gnuv3_get_vtable (gdbarch, value_type (value),
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value_as_address (value_addr (value)));
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if (vtable == NULL)
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return NULL;
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/* Find the linker symbol for this vtable. */
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vtable_symbol
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= lookup_minimal_symbol_by_pc (value_address (vtable)
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+ value_embedded_offset (vtable));
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if (! vtable_symbol)
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return NULL;
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/* The symbol's demangled name should be something like "vtable for
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CLASS", where CLASS is the name of the run-time type of VALUE.
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If we didn't like this approach, we could instead look in the
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type_info object itself to get the class name. But this way
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should work just as well, and doesn't read target memory. */
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vtable_symbol_name = SYMBOL_DEMANGLED_NAME (vtable_symbol);
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if (vtable_symbol_name == NULL
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|| strncmp (vtable_symbol_name, "vtable for ", 11))
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{
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warning (_("can't find linker symbol for virtual table for `%s' value"),
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TYPE_NAME (values_type));
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if (vtable_symbol_name)
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warning (_(" found `%s' instead"), vtable_symbol_name);
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return NULL;
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}
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class_name = vtable_symbol_name + 11;
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/* Try to look up the class name as a type name. */
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/* FIXME: chastain/2003-11-26: block=NULL is bogus. See pr gdb/1465. */
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run_time_type = cp_lookup_rtti_type (class_name, NULL);
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if (run_time_type == NULL)
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return NULL;
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/* Get the offset from VALUE to the top of the complete object.
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NOTE: this is the reverse of the meaning of *TOP_P. */
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offset_to_top
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= value_as_long (value_field (vtable, vtable_field_offset_to_top));
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if (full_p)
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*full_p = (- offset_to_top == value_embedded_offset (value)
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&& (TYPE_LENGTH (value_enclosing_type (value))
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>= TYPE_LENGTH (run_time_type)));
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if (top_p)
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*top_p = - offset_to_top;
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return run_time_type;
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}
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/* Return a function pointer for CONTAINER's VTABLE_INDEX'th virtual
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function, of type FNTYPE. */
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static struct value *
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gnuv3_get_virtual_fn (struct gdbarch *gdbarch, struct value *container,
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struct type *fntype, int vtable_index)
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{
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struct value *vtable, *vfn;
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/* Every class with virtual functions must have a vtable. */
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vtable = gnuv3_get_vtable (gdbarch, value_type (container),
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value_as_address (value_addr (container)));
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gdb_assert (vtable != NULL);
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/* Fetch the appropriate function pointer from the vtable. */
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vfn = value_subscript (value_field (vtable, vtable_field_virtual_functions),
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vtable_index);
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/* If this architecture uses function descriptors directly in the vtable,
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then the address of the vtable entry is actually a "function pointer"
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(i.e. points to the descriptor). We don't need to scale the index
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by the size of a function descriptor; GCC does that before outputing
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debug information. */
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if (gdbarch_vtable_function_descriptors (gdbarch))
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vfn = value_addr (vfn);
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/* Cast the function pointer to the appropriate type. */
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vfn = value_cast (lookup_pointer_type (fntype), vfn);
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return vfn;
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}
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/* GNU v3 implementation of value_virtual_fn_field. See cp-abi.h
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for a description of the arguments. */
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static struct value *
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gnuv3_virtual_fn_field (struct value **value_p,
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struct fn_field *f, int j,
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struct type *vfn_base, int offset)
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{
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struct type *values_type = check_typedef (value_type (*value_p));
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struct gdbarch *gdbarch;
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/* Some simple sanity checks. */
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if (TYPE_CODE (values_type) != TYPE_CODE_CLASS)
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error (_("Only classes can have virtual functions."));
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/* Determine architecture. */
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gdbarch = get_type_arch (values_type);
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/* Cast our value to the base class which defines this virtual
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function. This takes care of any necessary `this'
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adjustments. */
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if (vfn_base != values_type)
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*value_p = value_cast (vfn_base, *value_p);
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return gnuv3_get_virtual_fn (gdbarch, *value_p, TYPE_FN_FIELD_TYPE (f, j),
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TYPE_FN_FIELD_VOFFSET (f, j));
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}
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/* Compute the offset of the baseclass which is
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the INDEXth baseclass of class TYPE,
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for value at VALADDR (in host) at ADDRESS (in target).
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The result is the offset of the baseclass value relative
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to (the address of)(ARG) + OFFSET.
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-1 is returned on error. */
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static int
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gnuv3_baseclass_offset (struct type *type, int index, const bfd_byte *valaddr,
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CORE_ADDR address)
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{
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struct gdbarch *gdbarch;
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struct type *ptr_type;
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struct value *vtable;
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struct value *vbase_array;
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long int cur_base_offset, base_offset;
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/* Determine architecture. */
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gdbarch = get_type_arch (type);
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ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
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/* If it isn't a virtual base, this is easy. The offset is in the
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type definition. */
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if (!BASETYPE_VIA_VIRTUAL (type, index))
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return TYPE_BASECLASS_BITPOS (type, index) / 8;
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/* To access a virtual base, we need to use the vbase offset stored in
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our vtable. Recent GCC versions provide this information. If it isn't
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available, we could get what we needed from RTTI, or from drawing the
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complete inheritance graph based on the debug info. Neither is
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worthwhile. */
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cur_base_offset = TYPE_BASECLASS_BITPOS (type, index) / 8;
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if (cur_base_offset >= - vtable_address_point_offset (gdbarch))
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error (_("Expected a negative vbase offset (old compiler?)"));
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cur_base_offset = cur_base_offset + vtable_address_point_offset (gdbarch);
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if ((- cur_base_offset) % TYPE_LENGTH (ptr_type) != 0)
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error (_("Misaligned vbase offset."));
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cur_base_offset = cur_base_offset / ((int) TYPE_LENGTH (ptr_type));
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vtable = gnuv3_get_vtable (gdbarch, type, address);
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gdb_assert (vtable != NULL);
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vbase_array = value_field (vtable, vtable_field_vcall_and_vbase_offsets);
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base_offset = value_as_long (value_subscript (vbase_array, cur_base_offset));
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return base_offset;
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}
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/* Locate a virtual method in DOMAIN or its non-virtual base classes
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which has virtual table index VOFFSET. The method has an associated
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"this" adjustment of ADJUSTMENT bytes. */
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static const char *
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gnuv3_find_method_in (struct type *domain, CORE_ADDR voffset,
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LONGEST adjustment)
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{
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int i;
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const char *physname;
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/* Search this class first. */
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physname = NULL;
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if (adjustment == 0)
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{
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int len;
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len = TYPE_NFN_FIELDS (domain);
|
|
for (i = 0; i < len; i++)
|
|
{
|
|
int len2, j;
|
|
struct fn_field *f;
|
|
|
|
f = TYPE_FN_FIELDLIST1 (domain, i);
|
|
len2 = TYPE_FN_FIELDLIST_LENGTH (domain, i);
|
|
|
|
check_stub_method_group (domain, i);
|
|
for (j = 0; j < len2; j++)
|
|
if (TYPE_FN_FIELD_VOFFSET (f, j) == voffset)
|
|
return TYPE_FN_FIELD_PHYSNAME (f, j);
|
|
}
|
|
}
|
|
|
|
/* Next search non-virtual bases. If it's in a virtual base,
|
|
we're out of luck. */
|
|
for (i = 0; i < TYPE_N_BASECLASSES (domain); i++)
|
|
{
|
|
int pos;
|
|
struct type *basetype;
|
|
|
|
if (BASETYPE_VIA_VIRTUAL (domain, i))
|
|
continue;
|
|
|
|
pos = TYPE_BASECLASS_BITPOS (domain, i) / 8;
|
|
basetype = TYPE_FIELD_TYPE (domain, i);
|
|
/* Recurse with a modified adjustment. We don't need to adjust
|
|
voffset. */
|
|
if (adjustment >= pos && adjustment < pos + TYPE_LENGTH (basetype))
|
|
return gnuv3_find_method_in (basetype, voffset, adjustment - pos);
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/* Decode GNU v3 method pointer. */
|
|
|
|
static int
|
|
gnuv3_decode_method_ptr (struct gdbarch *gdbarch,
|
|
const gdb_byte *contents,
|
|
CORE_ADDR *value_p,
|
|
LONGEST *adjustment_p)
|
|
{
|
|
struct type *funcptr_type = builtin_type (gdbarch)->builtin_func_ptr;
|
|
struct type *offset_type = vtable_ptrdiff_type (gdbarch);
|
|
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
|
|
CORE_ADDR ptr_value;
|
|
LONGEST voffset, adjustment;
|
|
int vbit;
|
|
|
|
/* Extract the pointer to member. The first element is either a pointer
|
|
or a vtable offset. For pointers, we need to use extract_typed_address
|
|
to allow the back-end to convert the pointer to a GDB address -- but
|
|
vtable offsets we must handle as integers. At this point, we do not
|
|
yet know which case we have, so we extract the value under both
|
|
interpretations and choose the right one later on. */
|
|
ptr_value = extract_typed_address (contents, funcptr_type);
|
|
voffset = extract_signed_integer (contents,
|
|
TYPE_LENGTH (funcptr_type), byte_order);
|
|
contents += TYPE_LENGTH (funcptr_type);
|
|
adjustment = extract_signed_integer (contents,
|
|
TYPE_LENGTH (offset_type), byte_order);
|
|
|
|
if (!gdbarch_vbit_in_delta (gdbarch))
|
|
{
|
|
vbit = voffset & 1;
|
|
voffset = voffset ^ vbit;
|
|
}
|
|
else
|
|
{
|
|
vbit = adjustment & 1;
|
|
adjustment = adjustment >> 1;
|
|
}
|
|
|
|
*value_p = vbit? voffset : ptr_value;
|
|
*adjustment_p = adjustment;
|
|
return vbit;
|
|
}
|
|
|
|
/* GNU v3 implementation of cplus_print_method_ptr. */
|
|
|
|
static void
|
|
gnuv3_print_method_ptr (const gdb_byte *contents,
|
|
struct type *type,
|
|
struct ui_file *stream)
|
|
{
|
|
struct type *domain = TYPE_DOMAIN_TYPE (type);
|
|
struct gdbarch *gdbarch = get_type_arch (domain);
|
|
CORE_ADDR ptr_value;
|
|
LONGEST adjustment;
|
|
int vbit;
|
|
|
|
/* Extract the pointer to member. */
|
|
vbit = gnuv3_decode_method_ptr (gdbarch, contents, &ptr_value, &adjustment);
|
|
|
|
/* Check for NULL. */
|
|
if (ptr_value == 0 && vbit == 0)
|
|
{
|
|
fprintf_filtered (stream, "NULL");
|
|
return;
|
|
}
|
|
|
|
/* Search for a virtual method. */
|
|
if (vbit)
|
|
{
|
|
CORE_ADDR voffset;
|
|
const char *physname;
|
|
|
|
/* It's a virtual table offset, maybe in this class. Search
|
|
for a field with the correct vtable offset. First convert it
|
|
to an index, as used in TYPE_FN_FIELD_VOFFSET. */
|
|
voffset = ptr_value / TYPE_LENGTH (vtable_ptrdiff_type (gdbarch));
|
|
|
|
physname = gnuv3_find_method_in (domain, voffset, adjustment);
|
|
|
|
/* If we found a method, print that. We don't bother to disambiguate
|
|
possible paths to the method based on the adjustment. */
|
|
if (physname)
|
|
{
|
|
char *demangled_name = cplus_demangle (physname,
|
|
DMGL_ANSI | DMGL_PARAMS);
|
|
if (demangled_name != NULL)
|
|
{
|
|
fprintf_filtered (stream, "&virtual ");
|
|
fputs_filtered (demangled_name, stream);
|
|
xfree (demangled_name);
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* We didn't find it; print the raw data. */
|
|
if (vbit)
|
|
{
|
|
fprintf_filtered (stream, "&virtual table offset ");
|
|
print_longest (stream, 'd', 1, ptr_value);
|
|
}
|
|
else
|
|
print_address_demangle (gdbarch, ptr_value, stream, demangle);
|
|
|
|
if (adjustment)
|
|
{
|
|
fprintf_filtered (stream, ", this adjustment ");
|
|
print_longest (stream, 'd', 1, adjustment);
|
|
}
|
|
}
|
|
|
|
/* GNU v3 implementation of cplus_method_ptr_size. */
|
|
|
|
static int
|
|
gnuv3_method_ptr_size (struct type *type)
|
|
{
|
|
struct type *domain_type = check_typedef (TYPE_DOMAIN_TYPE (type));
|
|
struct gdbarch *gdbarch = get_type_arch (domain_type);
|
|
return 2 * TYPE_LENGTH (builtin_type (gdbarch)->builtin_data_ptr);
|
|
}
|
|
|
|
/* GNU v3 implementation of cplus_make_method_ptr. */
|
|
|
|
static void
|
|
gnuv3_make_method_ptr (struct type *type, gdb_byte *contents,
|
|
CORE_ADDR value, int is_virtual)
|
|
{
|
|
struct type *domain_type = check_typedef (TYPE_DOMAIN_TYPE (type));
|
|
struct gdbarch *gdbarch = get_type_arch (domain_type);
|
|
int size = TYPE_LENGTH (builtin_type (gdbarch)->builtin_data_ptr);
|
|
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
|
|
|
|
/* FIXME drow/2006-12-24: The adjustment of "this" is currently
|
|
always zero, since the method pointer is of the correct type.
|
|
But if the method pointer came from a base class, this is
|
|
incorrect - it should be the offset to the base. The best
|
|
fix might be to create the pointer to member pointing at the
|
|
base class and cast it to the derived class, but that requires
|
|
support for adjusting pointers to members when casting them -
|
|
not currently supported by GDB. */
|
|
|
|
if (!gdbarch_vbit_in_delta (gdbarch))
|
|
{
|
|
store_unsigned_integer (contents, size, byte_order, value | is_virtual);
|
|
store_unsigned_integer (contents + size, size, byte_order, 0);
|
|
}
|
|
else
|
|
{
|
|
store_unsigned_integer (contents, size, byte_order, value);
|
|
store_unsigned_integer (contents + size, size, byte_order, is_virtual);
|
|
}
|
|
}
|
|
|
|
/* GNU v3 implementation of cplus_method_ptr_to_value. */
|
|
|
|
static struct value *
|
|
gnuv3_method_ptr_to_value (struct value **this_p, struct value *method_ptr)
|
|
{
|
|
struct gdbarch *gdbarch;
|
|
const gdb_byte *contents = value_contents (method_ptr);
|
|
CORE_ADDR ptr_value;
|
|
struct type *domain_type, *final_type, *method_type;
|
|
LONGEST adjustment;
|
|
int vbit;
|
|
|
|
domain_type = TYPE_DOMAIN_TYPE (check_typedef (value_type (method_ptr)));
|
|
final_type = lookup_pointer_type (domain_type);
|
|
|
|
method_type = TYPE_TARGET_TYPE (check_typedef (value_type (method_ptr)));
|
|
|
|
/* Extract the pointer to member. */
|
|
gdbarch = get_type_arch (domain_type);
|
|
vbit = gnuv3_decode_method_ptr (gdbarch, contents, &ptr_value, &adjustment);
|
|
|
|
/* First convert THIS to match the containing type of the pointer to
|
|
member. This cast may adjust the value of THIS. */
|
|
*this_p = value_cast (final_type, *this_p);
|
|
|
|
/* Then apply whatever adjustment is necessary. This creates a somewhat
|
|
strange pointer: it claims to have type FINAL_TYPE, but in fact it
|
|
might not be a valid FINAL_TYPE. For instance, it might be a
|
|
base class of FINAL_TYPE. And if it's not the primary base class,
|
|
then printing it out as a FINAL_TYPE object would produce some pretty
|
|
garbage.
|
|
|
|
But we don't really know the type of the first argument in
|
|
METHOD_TYPE either, which is why this happens. We can't
|
|
dereference this later as a FINAL_TYPE, but once we arrive in the
|
|
called method we'll have debugging information for the type of
|
|
"this" - and that'll match the value we produce here.
|
|
|
|
You can provoke this case by casting a Base::* to a Derived::*, for
|
|
instance. */
|
|
*this_p = value_cast (builtin_type (gdbarch)->builtin_data_ptr, *this_p);
|
|
*this_p = value_ptradd (*this_p, adjustment);
|
|
*this_p = value_cast (final_type, *this_p);
|
|
|
|
if (vbit)
|
|
{
|
|
LONGEST voffset;
|
|
voffset = ptr_value / TYPE_LENGTH (vtable_ptrdiff_type (gdbarch));
|
|
return gnuv3_get_virtual_fn (gdbarch, value_ind (*this_p),
|
|
method_type, voffset);
|
|
}
|
|
else
|
|
return value_from_pointer (lookup_pointer_type (method_type), ptr_value);
|
|
}
|
|
|
|
/* Determine if we are currently in a C++ thunk. If so, get the address
|
|
of the routine we are thunking to and continue to there instead. */
|
|
|
|
static CORE_ADDR
|
|
gnuv3_skip_trampoline (struct frame_info *frame, CORE_ADDR stop_pc)
|
|
{
|
|
CORE_ADDR real_stop_pc, method_stop_pc;
|
|
struct gdbarch *gdbarch = get_frame_arch (frame);
|
|
struct minimal_symbol *thunk_sym, *fn_sym;
|
|
struct obj_section *section;
|
|
char *thunk_name, *fn_name;
|
|
|
|
real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
|
|
if (real_stop_pc == 0)
|
|
real_stop_pc = stop_pc;
|
|
|
|
/* Find the linker symbol for this potential thunk. */
|
|
thunk_sym = lookup_minimal_symbol_by_pc (real_stop_pc);
|
|
section = find_pc_section (real_stop_pc);
|
|
if (thunk_sym == NULL || section == NULL)
|
|
return 0;
|
|
|
|
/* The symbol's demangled name should be something like "virtual
|
|
thunk to FUNCTION", where FUNCTION is the name of the function
|
|
being thunked to. */
|
|
thunk_name = SYMBOL_DEMANGLED_NAME (thunk_sym);
|
|
if (thunk_name == NULL || strstr (thunk_name, " thunk to ") == NULL)
|
|
return 0;
|
|
|
|
fn_name = strstr (thunk_name, " thunk to ") + strlen (" thunk to ");
|
|
fn_sym = lookup_minimal_symbol (fn_name, NULL, section->objfile);
|
|
if (fn_sym == NULL)
|
|
return 0;
|
|
|
|
method_stop_pc = SYMBOL_VALUE_ADDRESS (fn_sym);
|
|
real_stop_pc = gdbarch_skip_trampoline_code
|
|
(gdbarch, frame, method_stop_pc);
|
|
if (real_stop_pc == 0)
|
|
real_stop_pc = method_stop_pc;
|
|
|
|
return real_stop_pc;
|
|
}
|
|
|
|
/* Return nonzero if a type should be passed by reference.
|
|
|
|
The rule in the v3 ABI document comes from section 3.1.1. If the
|
|
type has a non-trivial copy constructor or destructor, then the
|
|
caller must make a copy (by calling the copy constructor if there
|
|
is one or perform the copy itself otherwise), pass the address of
|
|
the copy, and then destroy the temporary (if necessary).
|
|
|
|
For return values with non-trivial copy constructors or
|
|
destructors, space will be allocated in the caller, and a pointer
|
|
will be passed as the first argument (preceding "this").
|
|
|
|
We don't have a bulletproof mechanism for determining whether a
|
|
constructor or destructor is trivial. For GCC and DWARF2 debug
|
|
information, we can check the artificial flag.
|
|
|
|
We don't do anything with the constructors or destructors,
|
|
but we have to get the argument passing right anyway. */
|
|
static int
|
|
gnuv3_pass_by_reference (struct type *type)
|
|
{
|
|
int fieldnum, fieldelem;
|
|
|
|
CHECK_TYPEDEF (type);
|
|
|
|
/* We're only interested in things that can have methods. */
|
|
if (TYPE_CODE (type) != TYPE_CODE_STRUCT
|
|
&& TYPE_CODE (type) != TYPE_CODE_CLASS
|
|
&& TYPE_CODE (type) != TYPE_CODE_UNION)
|
|
return 0;
|
|
|
|
for (fieldnum = 0; fieldnum < TYPE_NFN_FIELDS (type); fieldnum++)
|
|
for (fieldelem = 0; fieldelem < TYPE_FN_FIELDLIST_LENGTH (type, fieldnum);
|
|
fieldelem++)
|
|
{
|
|
struct fn_field *fn = TYPE_FN_FIELDLIST1 (type, fieldnum);
|
|
char *name = TYPE_FN_FIELDLIST_NAME (type, fieldnum);
|
|
struct type *fieldtype = TYPE_FN_FIELD_TYPE (fn, fieldelem);
|
|
|
|
/* If this function is marked as artificial, it is compiler-generated,
|
|
and we assume it is trivial. */
|
|
if (TYPE_FN_FIELD_ARTIFICIAL (fn, fieldelem))
|
|
continue;
|
|
|
|
/* If we've found a destructor, we must pass this by reference. */
|
|
if (name[0] == '~')
|
|
return 1;
|
|
|
|
/* If the mangled name of this method doesn't indicate that it
|
|
is a constructor, we're not interested.
|
|
|
|
FIXME drow/2007-09-23: We could do this using the name of
|
|
the method and the name of the class instead of dealing
|
|
with the mangled name. We don't have a convenient function
|
|
to strip off both leading scope qualifiers and trailing
|
|
template arguments yet. */
|
|
if (!is_constructor_name (TYPE_FN_FIELD_PHYSNAME (fn, fieldelem)))
|
|
continue;
|
|
|
|
/* If this method takes two arguments, and the second argument is
|
|
a reference to this class, then it is a copy constructor. */
|
|
if (TYPE_NFIELDS (fieldtype) == 2
|
|
&& TYPE_CODE (TYPE_FIELD_TYPE (fieldtype, 1)) == TYPE_CODE_REF
|
|
&& check_typedef (TYPE_TARGET_TYPE (TYPE_FIELD_TYPE (fieldtype, 1))) == type)
|
|
return 1;
|
|
}
|
|
|
|
/* Even if all the constructors and destructors were artificial, one
|
|
of them may have invoked a non-artificial constructor or
|
|
destructor in a base class. If any base class needs to be passed
|
|
by reference, so does this class. Similarly for members, which
|
|
are constructed whenever this class is. We do not need to worry
|
|
about recursive loops here, since we are only looking at members
|
|
of complete class type. */
|
|
for (fieldnum = 0; fieldnum < TYPE_NFIELDS (type); fieldnum++)
|
|
if (gnuv3_pass_by_reference (TYPE_FIELD_TYPE (type, fieldnum)))
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
init_gnuv3_ops (void)
|
|
{
|
|
vtable_type_gdbarch_data = gdbarch_data_register_post_init (build_gdb_vtable_type);
|
|
|
|
gnu_v3_abi_ops.shortname = "gnu-v3";
|
|
gnu_v3_abi_ops.longname = "GNU G++ Version 3 ABI";
|
|
gnu_v3_abi_ops.doc = "G++ Version 3 ABI";
|
|
gnu_v3_abi_ops.is_destructor_name =
|
|
(enum dtor_kinds (*) (const char *))is_gnu_v3_mangled_dtor;
|
|
gnu_v3_abi_ops.is_constructor_name =
|
|
(enum ctor_kinds (*) (const char *))is_gnu_v3_mangled_ctor;
|
|
gnu_v3_abi_ops.is_vtable_name = gnuv3_is_vtable_name;
|
|
gnu_v3_abi_ops.is_operator_name = gnuv3_is_operator_name;
|
|
gnu_v3_abi_ops.rtti_type = gnuv3_rtti_type;
|
|
gnu_v3_abi_ops.virtual_fn_field = gnuv3_virtual_fn_field;
|
|
gnu_v3_abi_ops.baseclass_offset = gnuv3_baseclass_offset;
|
|
gnu_v3_abi_ops.print_method_ptr = gnuv3_print_method_ptr;
|
|
gnu_v3_abi_ops.method_ptr_size = gnuv3_method_ptr_size;
|
|
gnu_v3_abi_ops.make_method_ptr = gnuv3_make_method_ptr;
|
|
gnu_v3_abi_ops.method_ptr_to_value = gnuv3_method_ptr_to_value;
|
|
gnu_v3_abi_ops.skip_trampoline = gnuv3_skip_trampoline;
|
|
gnu_v3_abi_ops.pass_by_reference = gnuv3_pass_by_reference;
|
|
}
|
|
|
|
extern initialize_file_ftype _initialize_gnu_v3_abi; /* -Wmissing-prototypes */
|
|
|
|
void
|
|
_initialize_gnu_v3_abi (void)
|
|
{
|
|
init_gnuv3_ops ();
|
|
|
|
register_cp_abi (&gnu_v3_abi_ops);
|
|
}
|