| /* Abstraction of GNU v3 abi. |
| Contributed by Jim Blandy <jimb@redhat.com> |
| |
| Copyright (C) 2001, 2002, 2003, 2005, 2006, 2007 |
| Free Software Foundation, Inc. |
| |
| This file is part of GDB. |
| |
| This program 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 2 of the |
| License, or (at your option) any later version. |
| |
| This program 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 this program; if not, write to the Free Software |
| Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| Boston, MA 02110-1301, USA. */ |
| |
| #include "defs.h" |
| #include "value.h" |
| #include "cp-abi.h" |
| #include "cp-support.h" |
| #include "demangle.h" |
| #include "valprint.h" |
| |
| #include "gdb_assert.h" |
| #include "gdb_string.h" |
| |
| static struct cp_abi_ops gnu_v3_abi_ops; |
| |
| static int |
| gnuv3_is_vtable_name (const char *name) |
| { |
| return strncmp (name, "_ZTV", 4) == 0; |
| } |
| |
| static int |
| gnuv3_is_operator_name (const char *name) |
| { |
| return strncmp (name, "operator", 8) == 0; |
| } |
| |
| |
| /* To help us find the components of a vtable, we build ourselves a |
| GDB type object representing the vtable structure. Following the |
| V3 ABI, it goes something like this: |
| |
| struct gdb_gnu_v3_abi_vtable { |
| |
| / * An array of virtual call and virtual base offsets. The real |
| length of this array depends on the class hierarchy; we use |
| negative subscripts to access the elements. Yucky, but |
| better than the alternatives. * / |
| ptrdiff_t vcall_and_vbase_offsets[0]; |
| |
| / * The offset from a virtual pointer referring to this table |
| to the top of the complete object. * / |
| ptrdiff_t offset_to_top; |
| |
| / * The type_info pointer for this class. This is really a |
| std::type_info *, but GDB doesn't really look at the |
| type_info object itself, so we don't bother to get the type |
| exactly right. * / |
| void *type_info; |
| |
| / * Virtual table pointers in objects point here. * / |
| |
| / * Virtual function pointers. Like the vcall/vbase array, the |
| real length of this table depends on the class hierarchy. * / |
| void (*virtual_functions[0]) (); |
| |
| }; |
| |
| The catch, of course, is that the exact layout of this table |
| depends on the ABI --- word size, endianness, alignment, etc. So |
| the GDB type object is actually a per-architecture kind of thing. |
| |
| vtable_type_gdbarch_data is a gdbarch per-architecture data pointer |
| which refers to the struct type * for this structure, laid out |
| appropriately for the architecture. */ |
| static struct gdbarch_data *vtable_type_gdbarch_data; |
| |
| |
| /* Human-readable names for the numbers of the fields above. */ |
| enum { |
| vtable_field_vcall_and_vbase_offsets, |
| vtable_field_offset_to_top, |
| vtable_field_type_info, |
| vtable_field_virtual_functions |
| }; |
| |
| |
| /* Return a GDB type representing `struct gdb_gnu_v3_abi_vtable', |
| described above, laid out appropriately for ARCH. |
| |
| We use this function as the gdbarch per-architecture data |
| initialization function. We assume that the gdbarch framework |
| calls the per-architecture data initialization functions after it |
| sets current_gdbarch to the new architecture. */ |
| static void * |
| build_gdb_vtable_type (struct gdbarch *arch) |
| { |
| struct type *t; |
| struct field *field_list, *field; |
| int offset; |
| |
| struct type *void_ptr_type |
| = lookup_pointer_type (builtin_type_void); |
| struct type *ptr_to_void_fn_type |
| = lookup_pointer_type (lookup_function_type (builtin_type_void)); |
| |
| /* ARCH can't give us the true ptrdiff_t type, so we guess. */ |
| struct type *ptrdiff_type |
| = init_type (TYPE_CODE_INT, TARGET_PTR_BIT / TARGET_CHAR_BIT, 0, |
| "ptrdiff_t", 0); |
| |
| /* We assume no padding is necessary, since GDB doesn't know |
| anything about alignment at the moment. If this assumption bites |
| us, we should add a gdbarch method which, given a type, returns |
| the alignment that type requires, and then use that here. */ |
| |
| /* Build the field list. */ |
| field_list = xmalloc (sizeof (struct field [4])); |
| memset (field_list, 0, sizeof (struct field [4])); |
| field = &field_list[0]; |
| offset = 0; |
| |
| /* ptrdiff_t vcall_and_vbase_offsets[0]; */ |
| FIELD_NAME (*field) = "vcall_and_vbase_offsets"; |
| FIELD_TYPE (*field) |
| = create_array_type (0, ptrdiff_type, |
| create_range_type (0, builtin_type_int, 0, -1)); |
| FIELD_BITPOS (*field) = offset * TARGET_CHAR_BIT; |
| offset += TYPE_LENGTH (FIELD_TYPE (*field)); |
| field++; |
| |
| /* ptrdiff_t offset_to_top; */ |
| FIELD_NAME (*field) = "offset_to_top"; |
| FIELD_TYPE (*field) = ptrdiff_type; |
| FIELD_BITPOS (*field) = offset * TARGET_CHAR_BIT; |
| offset += TYPE_LENGTH (FIELD_TYPE (*field)); |
| field++; |
| |
| /* void *type_info; */ |
| FIELD_NAME (*field) = "type_info"; |
| FIELD_TYPE (*field) = void_ptr_type; |
| FIELD_BITPOS (*field) = offset * TARGET_CHAR_BIT; |
| offset += TYPE_LENGTH (FIELD_TYPE (*field)); |
| field++; |
| |
| /* void (*virtual_functions[0]) (); */ |
| FIELD_NAME (*field) = "virtual_functions"; |
| FIELD_TYPE (*field) |
| = create_array_type (0, ptr_to_void_fn_type, |
| create_range_type (0, builtin_type_int, 0, -1)); |
| FIELD_BITPOS (*field) = offset * TARGET_CHAR_BIT; |
| offset += TYPE_LENGTH (FIELD_TYPE (*field)); |
| field++; |
| |
| /* We assumed in the allocation above that there were four fields. */ |
| gdb_assert (field == (field_list + 4)); |
| |
| t = init_type (TYPE_CODE_STRUCT, offset, 0, 0, 0); |
| TYPE_NFIELDS (t) = field - field_list; |
| TYPE_FIELDS (t) = field_list; |
| TYPE_TAG_NAME (t) = "gdb_gnu_v3_abi_vtable"; |
| |
| return t; |
| } |
| |
| |
| /* Return the offset from the start of the imaginary `struct |
| gdb_gnu_v3_abi_vtable' object to the vtable's "address point" |
| (i.e., where objects' virtual table pointers point). */ |
| static int |
| vtable_address_point_offset (void) |
| { |
| struct type *vtable_type = gdbarch_data (current_gdbarch, |
| vtable_type_gdbarch_data); |
| |
| return (TYPE_FIELD_BITPOS (vtable_type, vtable_field_virtual_functions) |
| / TARGET_CHAR_BIT); |
| } |
| |
| |
| static struct type * |
| gnuv3_rtti_type (struct value *value, |
| int *full_p, int *top_p, int *using_enc_p) |
| { |
| struct type *vtable_type = gdbarch_data (current_gdbarch, |
| vtable_type_gdbarch_data); |
| struct type *values_type = check_typedef (value_type (value)); |
| CORE_ADDR vtable_address; |
| struct value *vtable; |
| struct minimal_symbol *vtable_symbol; |
| const char *vtable_symbol_name; |
| const char *class_name; |
| struct type *run_time_type; |
| struct type *base_type; |
| LONGEST offset_to_top; |
| |
| /* We only have RTTI for class objects. */ |
| if (TYPE_CODE (values_type) != TYPE_CODE_CLASS) |
| return NULL; |
| |
| /* If we can't find the virtual table pointer for values_type, we |
| can't find the RTTI. */ |
| fill_in_vptr_fieldno (values_type); |
| if (TYPE_VPTR_FIELDNO (values_type) == -1) |
| return NULL; |
| |
| if (using_enc_p) |
| *using_enc_p = 0; |
| |
| /* Fetch VALUE's virtual table pointer, and tweak it to point at |
| an instance of our imaginary gdb_gnu_v3_abi_vtable structure. */ |
| base_type = check_typedef (TYPE_VPTR_BASETYPE (values_type)); |
| if (values_type != base_type) |
| { |
| value = value_cast (base_type, value); |
| if (using_enc_p) |
| *using_enc_p = 1; |
| } |
| vtable_address |
| = value_as_address (value_field (value, TYPE_VPTR_FIELDNO (values_type))); |
| vtable = value_at_lazy (vtable_type, |
| vtable_address - vtable_address_point_offset ()); |
| |
| /* Find the linker symbol for this vtable. */ |
| vtable_symbol |
| = lookup_minimal_symbol_by_pc (VALUE_ADDRESS (vtable) |
| + value_offset (vtable) |
| + value_embedded_offset (vtable)); |
| if (! vtable_symbol) |
| return NULL; |
| |
| /* The symbol's demangled name should be something like "vtable for |
| CLASS", where CLASS is the name of the run-time type of VALUE. |
| If we didn't like this approach, we could instead look in the |
| type_info object itself to get the class name. But this way |
| should work just as well, and doesn't read target memory. */ |
| vtable_symbol_name = SYMBOL_DEMANGLED_NAME (vtable_symbol); |
| if (vtable_symbol_name == NULL |
| || strncmp (vtable_symbol_name, "vtable for ", 11)) |
| { |
| warning (_("can't find linker symbol for virtual table for `%s' value"), |
| TYPE_NAME (values_type)); |
| if (vtable_symbol_name) |
| warning (_(" found `%s' instead"), vtable_symbol_name); |
| return NULL; |
| } |
| class_name = vtable_symbol_name + 11; |
| |
| /* Try to look up the class name as a type name. */ |
| /* FIXME: chastain/2003-11-26: block=NULL is bogus. See pr gdb/1465. */ |
| run_time_type = cp_lookup_rtti_type (class_name, NULL); |
| if (run_time_type == NULL) |
| return NULL; |
| |
| /* Get the offset from VALUE to the top of the complete object. |
| NOTE: this is the reverse of the meaning of *TOP_P. */ |
| offset_to_top |
| = value_as_long (value_field (vtable, vtable_field_offset_to_top)); |
| |
| if (full_p) |
| *full_p = (- offset_to_top == value_embedded_offset (value) |
| && (TYPE_LENGTH (value_enclosing_type (value)) |
| >= TYPE_LENGTH (run_time_type))); |
| if (top_p) |
| *top_p = - offset_to_top; |
| |
| return run_time_type; |
| } |
| |
| /* Find the vtable for CONTAINER and return a value of the correct |
| vtable type for this architecture. */ |
| |
| static struct value * |
| gnuv3_get_vtable (struct value *container) |
| { |
| struct type *vtable_type = gdbarch_data (current_gdbarch, |
| vtable_type_gdbarch_data); |
| struct type *vtable_pointer_type; |
| struct value *vtable_pointer; |
| CORE_ADDR vtable_pointer_address, vtable_address; |
| |
| /* We do not consult the debug information to find the virtual table. |
| The ABI specifies that it is always at offset zero in any class, |
| and debug information may not represent it. We won't issue an |
| error if there's a class with virtual functions but no virtual table |
| pointer, but something's already gone seriously wrong if that |
| happens. |
| |
| We avoid using value_contents on principle, because the object might |
| be large. */ |
| |
| /* Find the type "pointer to virtual table". */ |
| vtable_pointer_type = lookup_pointer_type (vtable_type); |
| |
| /* Load it from the start of the class. */ |
| vtable_pointer_address = value_as_address (value_addr (container)); |
| vtable_pointer = value_at (vtable_pointer_type, vtable_pointer_address); |
| vtable_address = value_as_address (vtable_pointer); |
| |
| /* Correct it to point at the start of the virtual table, rather |
| than the address point. */ |
| return value_at_lazy (vtable_type, |
| vtable_address - vtable_address_point_offset ()); |
| } |
| |
| /* Return a function pointer for CONTAINER's VTABLE_INDEX'th virtual |
| function, of type FNTYPE. */ |
| |
| static struct value * |
| gnuv3_get_virtual_fn (struct value *container, struct type *fntype, |
| int vtable_index) |
| { |
| struct value *vtable = gnuv3_get_vtable (container); |
| struct value *vfn; |
| |
| /* Fetch the appropriate function pointer from the vtable. */ |
| vfn = value_subscript (value_field (vtable, vtable_field_virtual_functions), |
| value_from_longest (builtin_type_int, vtable_index)); |
| |
| /* If this architecture uses function descriptors directly in the vtable, |
| then the address of the vtable entry is actually a "function pointer" |
| (i.e. points to the descriptor). We don't need to scale the index |
| by the size of a function descriptor; GCC does that before outputing |
| debug information. */ |
| if (gdbarch_vtable_function_descriptors (current_gdbarch)) |
| vfn = value_addr (vfn); |
| |
| /* Cast the function pointer to the appropriate type. */ |
| vfn = value_cast (lookup_pointer_type (fntype), vfn); |
| |
| return vfn; |
| } |
| |
| /* GNU v3 implementation of value_virtual_fn_field. See cp-abi.h |
| for a description of the arguments. */ |
| |
| static struct value * |
| gnuv3_virtual_fn_field (struct value **value_p, |
| struct fn_field *f, int j, |
| struct type *vfn_base, int offset) |
| { |
| struct type *values_type = check_typedef (value_type (*value_p)); |
| |
| /* Some simple sanity checks. */ |
| if (TYPE_CODE (values_type) != TYPE_CODE_CLASS) |
| error (_("Only classes can have virtual functions.")); |
| |
| /* Cast our value to the base class which defines this virtual |
| function. This takes care of any necessary `this' |
| adjustments. */ |
| if (vfn_base != values_type) |
| *value_p = value_cast (vfn_base, *value_p); |
| |
| return gnuv3_get_virtual_fn (*value_p, TYPE_FN_FIELD_TYPE (f, j), |
| TYPE_FN_FIELD_VOFFSET (f, j)); |
| } |
| |
| /* Compute the offset of the baseclass which is |
| the INDEXth baseclass of class TYPE, |
| for value at VALADDR (in host) at ADDRESS (in target). |
| The result is the offset of the baseclass value relative |
| to (the address of)(ARG) + OFFSET. |
| |
| -1 is returned on error. */ |
| static int |
| gnuv3_baseclass_offset (struct type *type, int index, const bfd_byte *valaddr, |
| CORE_ADDR address) |
| { |
| struct type *vtable_type = gdbarch_data (current_gdbarch, |
| vtable_type_gdbarch_data); |
| struct value *vtable; |
| struct type *vbasetype; |
| struct value *offset_val, *vbase_array; |
| CORE_ADDR vtable_address; |
| long int cur_base_offset, base_offset; |
| |
| /* If it isn't a virtual base, this is easy. The offset is in the |
| type definition. */ |
| if (!BASETYPE_VIA_VIRTUAL (type, index)) |
| return TYPE_BASECLASS_BITPOS (type, index) / 8; |
| |
| /* To access a virtual base, we need to use the vbase offset stored in |
| our vtable. Recent GCC versions provide this information. If it isn't |
| available, we could get what we needed from RTTI, or from drawing the |
| complete inheritance graph based on the debug info. Neither is |
| worthwhile. */ |
| cur_base_offset = TYPE_BASECLASS_BITPOS (type, index) / 8; |
| if (cur_base_offset >= - vtable_address_point_offset ()) |
| error (_("Expected a negative vbase offset (old compiler?)")); |
| |
| cur_base_offset = cur_base_offset + vtable_address_point_offset (); |
| if ((- cur_base_offset) % TYPE_LENGTH (builtin_type_void_data_ptr) != 0) |
| error (_("Misaligned vbase offset.")); |
| cur_base_offset = cur_base_offset |
| / ((int) TYPE_LENGTH (builtin_type_void_data_ptr)); |
| |
| /* We're now looking for the cur_base_offset'th entry (negative index) |
| in the vcall_and_vbase_offsets array. We used to cast the object to |
| its TYPE_VPTR_BASETYPE, and reference the vtable as TYPE_VPTR_FIELDNO; |
| however, that cast can not be done without calling baseclass_offset again |
| if the TYPE_VPTR_BASETYPE is a virtual base class, as described in the |
| v3 C++ ABI Section 2.4.I.2.b. Fortunately the ABI guarantees that the |
| vtable pointer will be located at the beginning of the object, so we can |
| bypass the casting. Verify that the TYPE_VPTR_FIELDNO is in fact at the |
| start of whichever baseclass it resides in, as a sanity measure - iff |
| we have debugging information for that baseclass. */ |
| |
| vbasetype = TYPE_VPTR_BASETYPE (type); |
| if (TYPE_VPTR_FIELDNO (vbasetype) < 0) |
| fill_in_vptr_fieldno (vbasetype); |
| |
| if (TYPE_VPTR_FIELDNO (vbasetype) >= 0 |
| && TYPE_FIELD_BITPOS (vbasetype, TYPE_VPTR_FIELDNO (vbasetype)) != 0) |
| error (_("Illegal vptr offset in class %s"), |
| TYPE_NAME (vbasetype) ? TYPE_NAME (vbasetype) : "<unknown>"); |
| |
| vtable_address = value_as_address (value_at_lazy (builtin_type_void_data_ptr, |
| address)); |
| vtable = value_at_lazy (vtable_type, |
| vtable_address - vtable_address_point_offset ()); |
| offset_val = value_from_longest(builtin_type_int, cur_base_offset); |
| vbase_array = value_field (vtable, vtable_field_vcall_and_vbase_offsets); |
| base_offset = value_as_long (value_subscript (vbase_array, offset_val)); |
| return base_offset; |
| } |
| |
| /* Locate a virtual method in DOMAIN or its non-virtual base classes |
| which has virtual table index VOFFSET. The method has an associated |
| "this" adjustment of ADJUSTMENT bytes. */ |
| |
| const char * |
| gnuv3_find_method_in (struct type *domain, CORE_ADDR voffset, |
| LONGEST adjustment) |
| { |
| int i; |
| const char *physname; |
| |
| /* Search this class first. */ |
| physname = NULL; |
| if (adjustment == 0) |
| { |
| int len; |
| |
| 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; |
| } |
| |
| /* 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) |
| { |
| CORE_ADDR ptr_value; |
| LONGEST adjustment; |
| struct type *domain; |
| int vbit; |
| |
| domain = TYPE_DOMAIN_TYPE (type); |
| |
| /* Extract the pointer to member. */ |
| ptr_value = extract_typed_address (contents, builtin_type_void_func_ptr); |
| contents += TYPE_LENGTH (builtin_type_void_func_ptr); |
| adjustment = extract_signed_integer (contents, |
| TYPE_LENGTH (builtin_type_long)); |
| |
| if (!gdbarch_vbit_in_delta (current_gdbarch)) |
| { |
| vbit = ptr_value & 1; |
| ptr_value = ptr_value ^ vbit; |
| } |
| else |
| { |
| vbit = adjustment & 1; |
| adjustment = adjustment >> 1; |
| } |
| |
| /* 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 (builtin_type_long); |
| |
| 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 (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 (void) |
| { |
| return 2 * TYPE_LENGTH (builtin_type_void_data_ptr); |
| } |
| |
| /* GNU v3 implementation of cplus_make_method_ptr. */ |
| |
| static void |
| gnuv3_make_method_ptr (gdb_byte *contents, CORE_ADDR value, int is_virtual) |
| { |
| int size = TYPE_LENGTH (builtin_type_void_data_ptr); |
| |
| /* 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 (current_gdbarch)) |
| { |
| store_unsigned_integer (contents, size, value | is_virtual); |
| store_unsigned_integer (contents + size, size, 0); |
| } |
| else |
| { |
| store_unsigned_integer (contents, size, value); |
| store_unsigned_integer (contents + size, size, 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) |
| { |
| const gdb_byte *contents = value_contents (method_ptr); |
| CORE_ADDR ptr_value; |
| struct type *final_type, *method_type; |
| LONGEST adjustment; |
| struct value *adjval; |
| int vbit; |
| |
| final_type = TYPE_DOMAIN_TYPE (check_typedef (value_type (method_ptr))); |
| final_type = lookup_pointer_type (final_type); |
| |
| method_type = TYPE_TARGET_TYPE (check_typedef (value_type (method_ptr))); |
| |
| ptr_value = extract_typed_address (contents, builtin_type_void_func_ptr); |
| contents += TYPE_LENGTH (builtin_type_void_func_ptr); |
| adjustment = extract_signed_integer (contents, |
| TYPE_LENGTH (builtin_type_long)); |
| |
| if (!gdbarch_vbit_in_delta (current_gdbarch)) |
| { |
| vbit = ptr_value & 1; |
| ptr_value = ptr_value ^ vbit; |
| } |
| else |
| { |
| vbit = adjustment & 1; |
| adjustment = adjustment >> 1; |
| } |
| |
| /* 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_void_data_ptr, *this_p); |
| adjval = value_from_longest (builtin_type_long, adjustment); |
| *this_p = value_add (*this_p, adjval); |
| *this_p = value_cast (final_type, *this_p); |
| |
| if (vbit) |
| { |
| LONGEST voffset = ptr_value / TYPE_LENGTH (builtin_type_long); |
| return gnuv3_get_virtual_fn (value_ind (*this_p), method_type, voffset); |
| } |
| else |
| return value_from_pointer (lookup_pointer_type (method_type), ptr_value); |
| } |
| |
| 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; |
| } |
| |
| 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); |
| } |