| /* Abstraction of GNU v3 abi. |
| Contributed by Jim Blandy <jimb@redhat.com> |
| |
| Copyright (C) 2001-2021 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 3 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, see <http://www.gnu.org/licenses/>. */ |
| |
| #include "defs.h" |
| #include "value.h" |
| #include "cp-abi.h" |
| #include "cp-support.h" |
| #include "demangle.h" |
| #include "dwarf2.h" |
| #include "objfiles.h" |
| #include "valprint.h" |
| #include "c-lang.h" |
| #include "typeprint.h" |
| #include <algorithm> |
| #include "cli/cli-style.h" |
| #include "dwarf2/loc.h" |
| #include "inferior.h" |
| |
| static struct cp_abi_ops gnu_v3_abi_ops; |
| |
| /* A gdbarch key for std::type_info, in the event that it can't be |
| found in the debug info. */ |
| |
| static struct gdbarch_data *std_type_info_gdbarch_data; |
| |
| |
| static int |
| gnuv3_is_vtable_name (const char *name) |
| { |
| return startswith (name, "_ZTV"); |
| } |
| |
| static int |
| gnuv3_is_operator_name (const char *name) |
| { |
| return startswith (name, CP_OPERATOR_STR); |
| } |
| |
| |
| /* 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. */ |
| static void * |
| build_gdb_vtable_type (struct gdbarch *arch) |
| { |
| struct type *t; |
| struct field *field_list, *field; |
| int offset; |
| |
| struct type *void_ptr_type |
| = builtin_type (arch)->builtin_data_ptr; |
| struct type *ptr_to_void_fn_type |
| = builtin_type (arch)->builtin_func_ptr; |
| |
| /* ARCH can't give us the true ptrdiff_t type, so we guess. */ |
| struct type *ptrdiff_type |
| = arch_integer_type (arch, gdbarch_ptr_bit (arch), 0, "ptrdiff_t"); |
| |
| /* 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 = XCNEWVEC (struct field, 4); |
| field = &field_list[0]; |
| offset = 0; |
| |
| /* ptrdiff_t vcall_and_vbase_offsets[0]; */ |
| field->set_name ("vcall_and_vbase_offsets"); |
| field->set_type (lookup_array_range_type (ptrdiff_type, 0, -1)); |
| field->set_loc_bitpos (offset * TARGET_CHAR_BIT); |
| offset += TYPE_LENGTH (field->type ()); |
| field++; |
| |
| /* ptrdiff_t offset_to_top; */ |
| field->set_name ("offset_to_top"); |
| field->set_type (ptrdiff_type); |
| field->set_loc_bitpos (offset * TARGET_CHAR_BIT); |
| offset += TYPE_LENGTH (field->type ()); |
| field++; |
| |
| /* void *type_info; */ |
| field->set_name ("type_info"); |
| field->set_type (void_ptr_type); |
| field->set_loc_bitpos (offset * TARGET_CHAR_BIT); |
| offset += TYPE_LENGTH (field->type ()); |
| field++; |
| |
| /* void (*virtual_functions[0]) (); */ |
| field->set_name ("virtual_functions"); |
| field->set_type (lookup_array_range_type (ptr_to_void_fn_type, 0, -1)); |
| field->set_loc_bitpos (offset * TARGET_CHAR_BIT); |
| offset += TYPE_LENGTH (field->type ()); |
| field++; |
| |
| /* We assumed in the allocation above that there were four fields. */ |
| gdb_assert (field == (field_list + 4)); |
| |
| t = arch_type (arch, TYPE_CODE_STRUCT, offset * TARGET_CHAR_BIT, NULL); |
| t->set_num_fields (field - field_list); |
| t->set_fields (field_list); |
| t->set_name ("gdb_gnu_v3_abi_vtable"); |
| INIT_CPLUS_SPECIFIC (t); |
| |
| return make_type_with_address_space (t, TYPE_INSTANCE_FLAG_CODE_SPACE); |
| } |
| |
| |
| /* Return the ptrdiff_t type used in the vtable type. */ |
| static struct type * |
| vtable_ptrdiff_type (struct gdbarch *gdbarch) |
| { |
| struct type *vtable_type |
| = (struct type *) gdbarch_data (gdbarch, vtable_type_gdbarch_data); |
| |
| /* The "offset_to_top" field has the appropriate (ptrdiff_t) type. */ |
| return vtable_type->field (vtable_field_offset_to_top).type (); |
| } |
| |
| /* 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 (struct gdbarch *gdbarch) |
| { |
| struct type *vtable_type |
| = (struct type *) gdbarch_data (gdbarch, vtable_type_gdbarch_data); |
| |
| return (TYPE_FIELD_BITPOS (vtable_type, vtable_field_virtual_functions) |
| / TARGET_CHAR_BIT); |
| } |
| |
| |
| /* Determine whether structure TYPE is a dynamic class. Cache the |
| result. */ |
| |
| static int |
| gnuv3_dynamic_class (struct type *type) |
| { |
| int fieldnum, fieldelem; |
| |
| type = check_typedef (type); |
| gdb_assert (type->code () == TYPE_CODE_STRUCT |
| || type->code () == TYPE_CODE_UNION); |
| |
| if (type->code () == TYPE_CODE_UNION) |
| return 0; |
| |
| if (TYPE_CPLUS_DYNAMIC (type)) |
| return TYPE_CPLUS_DYNAMIC (type) == 1; |
| |
| ALLOCATE_CPLUS_STRUCT_TYPE (type); |
| |
| for (fieldnum = 0; fieldnum < TYPE_N_BASECLASSES (type); fieldnum++) |
| if (BASETYPE_VIA_VIRTUAL (type, fieldnum) |
| || gnuv3_dynamic_class (type->field (fieldnum).type ())) |
| { |
| TYPE_CPLUS_DYNAMIC (type) = 1; |
| return 1; |
| } |
| |
| for (fieldnum = 0; fieldnum < TYPE_NFN_FIELDS (type); fieldnum++) |
| for (fieldelem = 0; fieldelem < TYPE_FN_FIELDLIST_LENGTH (type, fieldnum); |
| fieldelem++) |
| { |
| struct fn_field *f = TYPE_FN_FIELDLIST1 (type, fieldnum); |
| |
| if (TYPE_FN_FIELD_VIRTUAL_P (f, fieldelem)) |
| { |
| TYPE_CPLUS_DYNAMIC (type) = 1; |
| return 1; |
| } |
| } |
| |
| TYPE_CPLUS_DYNAMIC (type) = -1; |
| return 0; |
| } |
| |
| /* Find the vtable for a value of CONTAINER_TYPE located at |
| CONTAINER_ADDR. Return a value of the correct vtable type for this |
| architecture, or NULL if CONTAINER does not have a vtable. */ |
| |
| static struct value * |
| gnuv3_get_vtable (struct gdbarch *gdbarch, |
| struct type *container_type, CORE_ADDR container_addr) |
| { |
| struct type *vtable_type |
| = (struct type *) gdbarch_data (gdbarch, vtable_type_gdbarch_data); |
| struct type *vtable_pointer_type; |
| struct value *vtable_pointer; |
| CORE_ADDR vtable_address; |
| |
| container_type = check_typedef (container_type); |
| gdb_assert (container_type->code () == TYPE_CODE_STRUCT); |
| |
| /* If this type does not have a virtual table, don't read the first |
| field. */ |
| if (!gnuv3_dynamic_class (container_type)) |
| return NULL; |
| |
| /* 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 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 = value_at (vtable_pointer_type, container_addr); |
| 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 (gdbarch)); |
| } |
| |
| |
| static struct type * |
| gnuv3_rtti_type (struct value *value, |
| int *full_p, LONGEST *top_p, int *using_enc_p) |
| { |
| struct gdbarch *gdbarch; |
| struct type *values_type = check_typedef (value_type (value)); |
| struct value *vtable; |
| struct minimal_symbol *vtable_symbol; |
| const char *vtable_symbol_name; |
| const char *class_name; |
| struct type *run_time_type; |
| LONGEST offset_to_top; |
| const char *atsign; |
| |
| /* We only have RTTI for dynamic class objects. */ |
| if (values_type->code () != TYPE_CODE_STRUCT |
| || !gnuv3_dynamic_class (values_type)) |
| return NULL; |
| |
| /* Determine architecture. */ |
| gdbarch = values_type->arch (); |
| |
| if (using_enc_p) |
| *using_enc_p = 0; |
| |
| vtable = gnuv3_get_vtable (gdbarch, values_type, |
| value_as_address (value_addr (value))); |
| if (vtable == NULL) |
| return NULL; |
| |
| /* Find the linker symbol for this vtable. */ |
| vtable_symbol |
| = lookup_minimal_symbol_by_pc (value_address (vtable) |
| + value_embedded_offset (vtable)).minsym; |
| 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 = vtable_symbol->demangled_name (); |
| if (vtable_symbol_name == NULL |
| || !startswith (vtable_symbol_name, "vtable for ")) |
| { |
| warning (_("can't find linker symbol for virtual table for `%s' value"), |
| TYPE_SAFE_NAME (values_type)); |
| if (vtable_symbol_name) |
| warning (_(" found `%s' instead"), vtable_symbol_name); |
| return NULL; |
| } |
| class_name = vtable_symbol_name + 11; |
| |
| /* Strip off @plt and version suffixes. */ |
| atsign = strchr (class_name, '@'); |
| if (atsign != NULL) |
| { |
| char *copy; |
| |
| copy = (char *) alloca (atsign - class_name + 1); |
| memcpy (copy, class_name, atsign - class_name); |
| copy[atsign - class_name] = '\0'; |
| class_name = copy; |
| } |
| |
| /* 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; |
| } |
| |
| /* Return a function pointer for CONTAINER's VTABLE_INDEX'th virtual |
| function, of type FNTYPE. */ |
| |
| static struct value * |
| gnuv3_get_virtual_fn (struct gdbarch *gdbarch, struct value *container, |
| struct type *fntype, int vtable_index) |
| { |
| struct value *vtable, *vfn; |
| |
| /* Every class with virtual functions must have a vtable. */ |
| vtable = gnuv3_get_vtable (gdbarch, value_type (container), |
| value_as_address (value_addr (container))); |
| gdb_assert (vtable != NULL); |
| |
| /* Fetch the appropriate function pointer from the vtable. */ |
| vfn = value_subscript (value_field (vtable, vtable_field_virtual_functions), |
| 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 outputting |
| debug information. */ |
| if (gdbarch_vtable_function_descriptors (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)); |
| struct gdbarch *gdbarch; |
| |
| /* Some simple sanity checks. */ |
| if (values_type->code () != TYPE_CODE_STRUCT) |
| error (_("Only classes can have virtual functions.")); |
| |
| /* Determine architecture. */ |
| gdbarch = values_type->arch (); |
| |
| /* 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 (gdbarch, *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, LONGEST embedded_offset, |
| CORE_ADDR address, const struct value *val) |
| { |
| struct gdbarch *gdbarch; |
| struct type *ptr_type; |
| struct value *vtable; |
| struct value *vbase_array; |
| long int cur_base_offset, base_offset; |
| |
| /* Determine architecture. */ |
| gdbarch = type->arch (); |
| ptr_type = builtin_type (gdbarch)->builtin_data_ptr; |
| |
| /* 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; |
| |
| /* If we have a DWARF expression for the offset, evaluate it. */ |
| if (TYPE_FIELD_LOC_KIND (type, index) == FIELD_LOC_KIND_DWARF_BLOCK) |
| { |
| struct dwarf2_property_baton baton; |
| baton.property_type |
| = lookup_pointer_type (type->field (index).type ()); |
| baton.locexpr = *TYPE_FIELD_DWARF_BLOCK (type, index); |
| |
| struct dynamic_prop prop; |
| prop.set_locexpr (&baton); |
| |
| struct property_addr_info addr_stack; |
| addr_stack.type = type; |
| /* Note that we don't set "valaddr" here. Doing so causes |
| regressions. FIXME. */ |
| addr_stack.addr = address + embedded_offset; |
| addr_stack.next = nullptr; |
| |
| CORE_ADDR result; |
| if (dwarf2_evaluate_property (&prop, nullptr, &addr_stack, &result, |
| true)) |
| return (int) (result - addr_stack.addr); |
| } |
| |
| /* 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 (gdbarch)) |
| error (_("Expected a negative vbase offset (old compiler?)")); |
| |
| cur_base_offset = cur_base_offset + vtable_address_point_offset (gdbarch); |
| if ((- cur_base_offset) % TYPE_LENGTH (ptr_type) != 0) |
| error (_("Misaligned vbase offset.")); |
| cur_base_offset = cur_base_offset / ((int) TYPE_LENGTH (ptr_type)); |
| |
| vtable = gnuv3_get_vtable (gdbarch, type, address + embedded_offset); |
| gdb_assert (vtable != NULL); |
| vbase_array = value_field (vtable, vtable_field_vcall_and_vbase_offsets); |
| base_offset = value_as_long (value_subscript (vbase_array, cur_base_offset)); |
| 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. */ |
| |
| static const char * |
| gnuv3_find_method_in (struct type *domain, CORE_ADDR voffset, |
| LONGEST adjustment) |
| { |
| int i; |
| |
| /* Search this class first. */ |
| 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 = domain->field (i).type (); |
| /* 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 *self_type = TYPE_SELF_TYPE (type); |
| struct gdbarch *gdbarch = self_type->arch (); |
| 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 (self_type, 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) |
| { |
| gdb::unique_xmalloc_ptr<char> demangled_name |
| = gdb_demangle (physname, DMGL_ANSI | DMGL_PARAMS); |
| |
| fprintf_filtered (stream, "&virtual "); |
| if (demangled_name == NULL) |
| fputs_filtered (physname, stream); |
| else |
| fputs_filtered (demangled_name.get (), stream); |
| return; |
| } |
| } |
| else if (ptr_value != 0) |
| { |
| /* Found a non-virtual function: print out the type. */ |
| fputs_filtered ("(", stream); |
| c_print_type (type, "", stream, -1, 0, &type_print_raw_options); |
| fputs_filtered (") ", stream); |
| } |
| |
| /* 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 |
| { |
| struct value_print_options opts; |
| |
| get_user_print_options (&opts); |
| print_address_demangle (&opts, 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) |
| { |
| return 2 * TYPE_LENGTH (builtin_type (type->arch ())->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 gdbarch *gdbarch = type->arch (); |
| int size = TYPE_LENGTH (builtin_type (gdbarch)->builtin_data_ptr); |
| enum bfd_endian byte_order = type_byte_order (type); |
| |
| /* 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 *self_type, *final_type, *method_type; |
| LONGEST adjustment; |
| int vbit; |
| |
| self_type = TYPE_SELF_TYPE (check_typedef (value_type (method_ptr))); |
| final_type = lookup_pointer_type (self_type); |
| |
| method_type = TYPE_TARGET_TYPE (check_typedef (value_type (method_ptr))); |
| |
| /* Extract the pointer to member. */ |
| gdbarch = self_type->arch (); |
| 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); |
| } |
| |
| /* Objects of this type are stored in a hash table and a vector when |
| printing the vtables for a class. */ |
| |
| struct value_and_voffset |
| { |
| /* The value representing the object. */ |
| struct value *value; |
| |
| /* The maximum vtable offset we've found for any object at this |
| offset in the outermost object. */ |
| int max_voffset; |
| }; |
| |
| /* Hash function for value_and_voffset. */ |
| |
| static hashval_t |
| hash_value_and_voffset (const void *p) |
| { |
| const struct value_and_voffset *o = (const struct value_and_voffset *) p; |
| |
| return value_address (o->value) + value_embedded_offset (o->value); |
| } |
| |
| /* Equality function for value_and_voffset. */ |
| |
| static int |
| eq_value_and_voffset (const void *a, const void *b) |
| { |
| const struct value_and_voffset *ova = (const struct value_and_voffset *) a; |
| const struct value_and_voffset *ovb = (const struct value_and_voffset *) b; |
| |
| return (value_address (ova->value) + value_embedded_offset (ova->value) |
| == value_address (ovb->value) + value_embedded_offset (ovb->value)); |
| } |
| |
| /* Comparison function for value_and_voffset. */ |
| |
| static bool |
| compare_value_and_voffset (const struct value_and_voffset *va, |
| const struct value_and_voffset *vb) |
| { |
| CORE_ADDR addra = (value_address (va->value) |
| + value_embedded_offset (va->value)); |
| CORE_ADDR addrb = (value_address (vb->value) |
| + value_embedded_offset (vb->value)); |
| |
| return addra < addrb; |
| } |
| |
| /* A helper function used when printing vtables. This determines the |
| key (most derived) sub-object at each address and also computes the |
| maximum vtable offset seen for the corresponding vtable. Updates |
| OFFSET_HASH and OFFSET_VEC with a new value_and_voffset object, if |
| needed. VALUE is the object to examine. */ |
| |
| static void |
| compute_vtable_size (htab_t offset_hash, |
| std::vector<value_and_voffset *> *offset_vec, |
| struct value *value) |
| { |
| int i; |
| struct type *type = check_typedef (value_type (value)); |
| void **slot; |
| struct value_and_voffset search_vo, *current_vo; |
| |
| gdb_assert (type->code () == TYPE_CODE_STRUCT); |
| |
| /* If the object is not dynamic, then we are done; as it cannot have |
| dynamic base types either. */ |
| if (!gnuv3_dynamic_class (type)) |
| return; |
| |
| /* Update the hash and the vec, if needed. */ |
| search_vo.value = value; |
| slot = htab_find_slot (offset_hash, &search_vo, INSERT); |
| if (*slot) |
| current_vo = (struct value_and_voffset *) *slot; |
| else |
| { |
| current_vo = XNEW (struct value_and_voffset); |
| current_vo->value = value; |
| current_vo->max_voffset = -1; |
| *slot = current_vo; |
| offset_vec->push_back (current_vo); |
| } |
| |
| /* Update the value_and_voffset object with the highest vtable |
| offset from this class. */ |
| for (i = 0; i < TYPE_NFN_FIELDS (type); ++i) |
| { |
| int j; |
| struct fn_field *fn = TYPE_FN_FIELDLIST1 (type, i); |
| |
| for (j = 0; j < TYPE_FN_FIELDLIST_LENGTH (type, i); ++j) |
| { |
| if (TYPE_FN_FIELD_VIRTUAL_P (fn, j)) |
| { |
| int voffset = TYPE_FN_FIELD_VOFFSET (fn, j); |
| |
| if (voffset > current_vo->max_voffset) |
| current_vo->max_voffset = voffset; |
| } |
| } |
| } |
| |
| /* Recurse into base classes. */ |
| for (i = 0; i < TYPE_N_BASECLASSES (type); ++i) |
| compute_vtable_size (offset_hash, offset_vec, value_field (value, i)); |
| } |
| |
| /* Helper for gnuv3_print_vtable that prints a single vtable. */ |
| |
| static void |
| print_one_vtable (struct gdbarch *gdbarch, struct value *value, |
| int max_voffset, |
| struct value_print_options *opts) |
| { |
| int i; |
| struct type *type = check_typedef (value_type (value)); |
| struct value *vtable; |
| CORE_ADDR vt_addr; |
| |
| vtable = gnuv3_get_vtable (gdbarch, type, |
| value_address (value) |
| + value_embedded_offset (value)); |
| vt_addr = value_address (value_field (vtable, |
| vtable_field_virtual_functions)); |
| |
| printf_filtered (_("vtable for '%s' @ %s (subobject @ %s):\n"), |
| TYPE_SAFE_NAME (type), |
| paddress (gdbarch, vt_addr), |
| paddress (gdbarch, (value_address (value) |
| + value_embedded_offset (value)))); |
| |
| for (i = 0; i <= max_voffset; ++i) |
| { |
| /* Initialize it just to avoid a GCC false warning. */ |
| CORE_ADDR addr = 0; |
| int got_error = 0; |
| struct value *vfn; |
| |
| printf_filtered ("[%d]: ", i); |
| |
| vfn = value_subscript (value_field (vtable, |
| vtable_field_virtual_functions), |
| i); |
| |
| if (gdbarch_vtable_function_descriptors (gdbarch)) |
| vfn = value_addr (vfn); |
| |
| try |
| { |
| addr = value_as_address (vfn); |
| } |
| catch (const gdb_exception_error &ex) |
| { |
| fprintf_styled (gdb_stdout, metadata_style.style (), |
| _("<error: %s>"), ex.what ()); |
| got_error = 1; |
| } |
| |
| if (!got_error) |
| print_function_pointer_address (opts, gdbarch, addr, gdb_stdout); |
| printf_filtered ("\n"); |
| } |
| } |
| |
| /* Implementation of the print_vtable method. */ |
| |
| static void |
| gnuv3_print_vtable (struct value *value) |
| { |
| struct gdbarch *gdbarch; |
| struct type *type; |
| struct value *vtable; |
| struct value_print_options opts; |
| int count; |
| |
| value = coerce_ref (value); |
| type = check_typedef (value_type (value)); |
| if (type->code () == TYPE_CODE_PTR) |
| { |
| value = value_ind (value); |
| type = check_typedef (value_type (value)); |
| } |
| |
| get_user_print_options (&opts); |
| |
| /* Respect 'set print object'. */ |
| if (opts.objectprint) |
| { |
| value = value_full_object (value, NULL, 0, 0, 0); |
| type = check_typedef (value_type (value)); |
| } |
| |
| gdbarch = type->arch (); |
| |
| vtable = NULL; |
| if (type->code () == TYPE_CODE_STRUCT) |
| vtable = gnuv3_get_vtable (gdbarch, type, |
| value_as_address (value_addr (value))); |
| |
| if (!vtable) |
| { |
| printf_filtered (_("This object does not have a virtual function table\n")); |
| return; |
| } |
| |
| htab_up offset_hash (htab_create_alloc (1, hash_value_and_voffset, |
| eq_value_and_voffset, |
| xfree, xcalloc, xfree)); |
| std::vector<value_and_voffset *> result_vec; |
| |
| compute_vtable_size (offset_hash.get (), &result_vec, value); |
| std::sort (result_vec.begin (), result_vec.end (), |
| compare_value_and_voffset); |
| |
| count = 0; |
| for (value_and_voffset *iter : result_vec) |
| { |
| if (iter->max_voffset >= 0) |
| { |
| if (count > 0) |
| printf_filtered ("\n"); |
| print_one_vtable (gdbarch, iter->value, iter->max_voffset, &opts); |
| ++count; |
| } |
| } |
| } |
| |
| /* Return a GDB type representing `struct std::type_info', laid out |
| appropriately for ARCH. |
| |
| We use this function as the gdbarch per-architecture data |
| initialization function. */ |
| |
| static void * |
| build_std_type_info_type (struct gdbarch *arch) |
| { |
| struct type *t; |
| struct field *field_list, *field; |
| int offset; |
| struct type *void_ptr_type |
| = builtin_type (arch)->builtin_data_ptr; |
| struct type *char_type |
| = builtin_type (arch)->builtin_char; |
| struct type *char_ptr_type |
| = make_pointer_type (make_cv_type (1, 0, char_type, NULL), NULL); |
| |
| field_list = XCNEWVEC (struct field, 2); |
| field = &field_list[0]; |
| offset = 0; |
| |
| /* The vtable. */ |
| field->set_name ("_vptr.type_info"); |
| field->set_type (void_ptr_type); |
| field->set_loc_bitpos (offset * TARGET_CHAR_BIT); |
| offset += TYPE_LENGTH (field->type ()); |
| field++; |
| |
| /* The name. */ |
| field->set_name ("__name"); |
| field->set_type (char_ptr_type); |
| field->set_loc_bitpos (offset * TARGET_CHAR_BIT); |
| offset += TYPE_LENGTH (field->type ()); |
| field++; |
| |
| gdb_assert (field == (field_list + 2)); |
| |
| t = arch_type (arch, TYPE_CODE_STRUCT, offset * TARGET_CHAR_BIT, NULL); |
| t->set_num_fields (field - field_list); |
| t->set_fields (field_list); |
| t->set_name ("gdb_gnu_v3_type_info"); |
| INIT_CPLUS_SPECIFIC (t); |
| |
| return t; |
| } |
| |
| /* Implement the 'get_typeid_type' method. */ |
| |
| static struct type * |
| gnuv3_get_typeid_type (struct gdbarch *gdbarch) |
| { |
| struct symbol *typeinfo; |
| struct type *typeinfo_type; |
| |
| typeinfo = lookup_symbol ("std::type_info", NULL, STRUCT_DOMAIN, |
| NULL).symbol; |
| if (typeinfo == NULL) |
| typeinfo_type |
| = (struct type *) gdbarch_data (gdbarch, std_type_info_gdbarch_data); |
| else |
| typeinfo_type = SYMBOL_TYPE (typeinfo); |
| |
| return typeinfo_type; |
| } |
| |
| /* Implement the 'get_typeid' method. */ |
| |
| static struct value * |
| gnuv3_get_typeid (struct value *value) |
| { |
| struct type *typeinfo_type; |
| struct type *type; |
| struct gdbarch *gdbarch; |
| struct value *result; |
| std::string type_name; |
| gdb::unique_xmalloc_ptr<char> canonical; |
| |
| /* We have to handle values a bit trickily here, to allow this code |
| to work properly with non_lvalue values that are really just |
| disguised types. */ |
| if (value_lval_const (value) == lval_memory) |
| value = coerce_ref (value); |
| |
| type = check_typedef (value_type (value)); |
| |
| /* In the non_lvalue case, a reference might have slipped through |
| here. */ |
| if (type->code () == TYPE_CODE_REF) |
| type = check_typedef (TYPE_TARGET_TYPE (type)); |
| |
| /* Ignore top-level cv-qualifiers. */ |
| type = make_cv_type (0, 0, type, NULL); |
| gdbarch = type->arch (); |
| |
| type_name = type_to_string (type); |
| if (type_name.empty ()) |
| error (_("cannot find typeinfo for unnamed type")); |
| |
| /* We need to canonicalize the type name here, because we do lookups |
| using the demangled name, and so we must match the format it |
| uses. E.g., GDB tends to use "const char *" as a type name, but |
| the demangler uses "char const *". */ |
| canonical = cp_canonicalize_string (type_name.c_str ()); |
| const char *name = (canonical == nullptr |
| ? type_name.c_str () |
| : canonical.get ()); |
| |
| typeinfo_type = gnuv3_get_typeid_type (gdbarch); |
| |
| /* We check for lval_memory because in the "typeid (type-id)" case, |
| the type is passed via a not_lval value object. */ |
| if (type->code () == TYPE_CODE_STRUCT |
| && value_lval_const (value) == lval_memory |
| && gnuv3_dynamic_class (type)) |
| { |
| struct value *vtable, *typeinfo_value; |
| CORE_ADDR address = value_address (value) + value_embedded_offset (value); |
| |
| vtable = gnuv3_get_vtable (gdbarch, type, address); |
| if (vtable == NULL) |
| error (_("cannot find typeinfo for object of type '%s'"), |
| name); |
| typeinfo_value = value_field (vtable, vtable_field_type_info); |
| result = value_ind (value_cast (make_pointer_type (typeinfo_type, NULL), |
| typeinfo_value)); |
| } |
| else |
| { |
| std::string sym_name = std::string ("typeinfo for ") + name; |
| bound_minimal_symbol minsym |
| = lookup_minimal_symbol (sym_name.c_str (), NULL, NULL); |
| |
| if (minsym.minsym == NULL) |
| error (_("could not find typeinfo symbol for '%s'"), name); |
| |
| result = value_at_lazy (typeinfo_type, BMSYMBOL_VALUE_ADDRESS (minsym)); |
| } |
| |
| return result; |
| } |
| |
| /* Implement the 'get_typename_from_type_info' method. */ |
| |
| static std::string |
| gnuv3_get_typename_from_type_info (struct value *type_info_ptr) |
| { |
| struct gdbarch *gdbarch = value_type (type_info_ptr)->arch (); |
| struct bound_minimal_symbol typeinfo_sym; |
| CORE_ADDR addr; |
| const char *symname; |
| const char *class_name; |
| const char *atsign; |
| |
| addr = value_as_address (type_info_ptr); |
| typeinfo_sym = lookup_minimal_symbol_by_pc (addr); |
| if (typeinfo_sym.minsym == NULL) |
| error (_("could not find minimal symbol for typeinfo address %s"), |
| paddress (gdbarch, addr)); |
| |
| #define TYPEINFO_PREFIX "typeinfo for " |
| #define TYPEINFO_PREFIX_LEN (sizeof (TYPEINFO_PREFIX) - 1) |
| symname = typeinfo_sym.minsym->demangled_name (); |
| if (symname == NULL || strncmp (symname, TYPEINFO_PREFIX, |
| TYPEINFO_PREFIX_LEN)) |
| error (_("typeinfo symbol '%s' has unexpected name"), |
| typeinfo_sym.minsym->linkage_name ()); |
| class_name = symname + TYPEINFO_PREFIX_LEN; |
| |
| /* Strip off @plt and version suffixes. */ |
| atsign = strchr (class_name, '@'); |
| if (atsign != NULL) |
| return std::string (class_name, atsign - class_name); |
| return class_name; |
| } |
| |
| /* Implement the 'get_type_from_type_info' method. */ |
| |
| static struct type * |
| gnuv3_get_type_from_type_info (struct value *type_info_ptr) |
| { |
| /* We have to parse the type name, since in general there is not a |
| symbol for a type. This is somewhat bogus since there may be a |
| mis-parse. Another approach might be to re-use the demangler's |
| internal form to reconstruct the type somehow. */ |
| std::string type_name = gnuv3_get_typename_from_type_info (type_info_ptr); |
| expression_up expr (parse_expression (type_name.c_str ())); |
| struct value *type_val = evaluate_type (expr.get ()); |
| return value_type (type_val); |
| } |
| |
| /* 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, func_addr; |
| struct gdbarch *gdbarch = get_frame_arch (frame); |
| struct bound_minimal_symbol thunk_sym, fn_sym; |
| struct obj_section *section; |
| const 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.minsym == 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 = thunk_sym.minsym->demangled_name (); |
| 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.minsym == NULL) |
| return 0; |
| |
| method_stop_pc = BMSYMBOL_VALUE_ADDRESS (fn_sym); |
| |
| /* Some targets have minimal symbols pointing to function descriptors |
| (powerpc 64 for example). Make sure to retrieve the address |
| of the real function from the function descriptor before passing on |
| the address to other layers of GDB. */ |
| func_addr = gdbarch_convert_from_func_ptr_addr |
| (gdbarch, method_stop_pc, current_inferior ()->top_target ()); |
| if (func_addr != 0) |
| method_stop_pc = func_addr; |
| |
| 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; |
| } |
| |
| /* A member function is in one these states. */ |
| |
| enum definition_style |
| { |
| DOES_NOT_EXIST_IN_SOURCE, |
| DEFAULTED_INSIDE, |
| DEFAULTED_OUTSIDE, |
| DELETED, |
| EXPLICIT, |
| }; |
| |
| /* Return how the given field is defined. */ |
| |
| static definition_style |
| get_def_style (struct fn_field *fn, int fieldelem) |
| { |
| if (TYPE_FN_FIELD_DELETED (fn, fieldelem)) |
| return DELETED; |
| |
| if (TYPE_FN_FIELD_ARTIFICIAL (fn, fieldelem)) |
| return DOES_NOT_EXIST_IN_SOURCE; |
| |
| switch (TYPE_FN_FIELD_DEFAULTED (fn, fieldelem)) |
| { |
| case DW_DEFAULTED_no: |
| return EXPLICIT; |
| case DW_DEFAULTED_in_class: |
| return DEFAULTED_INSIDE; |
| case DW_DEFAULTED_out_of_class: |
| return DEFAULTED_OUTSIDE; |
| default: |
| break; |
| } |
| |
| return EXPLICIT; |
| } |
| |
| /* Helper functions to determine whether the given definition style |
| denotes that the definition is user-provided or implicit. |
| Being defaulted outside the class decl counts as an explicit |
| user-definition, while being defaulted inside is implicit. */ |
| |
| static bool |
| is_user_provided_def (definition_style def) |
| { |
| return def == EXPLICIT || def == DEFAULTED_OUTSIDE; |
| } |
| |
| static bool |
| is_implicit_def (definition_style def) |
| { |
| return def == DOES_NOT_EXIST_IN_SOURCE || def == DEFAULTED_INSIDE; |
| } |
| |
| /* Helper function to decide if METHOD_TYPE is a copy/move |
| constructor type for CLASS_TYPE. EXPECTED is the expected |
| type code for the "right-hand-side" argument. |
| This function is supposed to be used by the IS_COPY_CONSTRUCTOR_TYPE |
| and IS_MOVE_CONSTRUCTOR_TYPE functions below. Normally, you should |
| not need to call this directly. */ |
| |
| static bool |
| is_copy_or_move_constructor_type (struct type *class_type, |
| struct type *method_type, |
| type_code expected) |
| { |
| /* The method should take at least two arguments... */ |
| if (method_type->num_fields () < 2) |
| return false; |
| |
| /* ...and the second argument should be the same as the class |
| type, with the expected type code... */ |
| struct type *arg_type = method_type->field (1).type (); |
| |
| if (arg_type->code () != expected) |
| return false; |
| |
| struct type *target = check_typedef (TYPE_TARGET_TYPE (arg_type)); |
| if (!(class_types_same_p (target, class_type))) |
| return false; |
| |
| /* ...and if any of the remaining arguments don't have a default value |
| then this is not a copy or move constructor, but just a |
| constructor. */ |
| for (int i = 2; i < method_type->num_fields (); i++) |
| { |
| arg_type = method_type->field (i).type (); |
| /* FIXME aktemur/2019-10-31: As of this date, neither |
| clang++-7.0.0 nor g++-8.2.0 produce a DW_AT_default_value |
| attribute. GDB is also not set to read this attribute, yet. |
| Hence, we immediately return false if there are more than |
| 2 parameters. |
| GCC bug link: |
| https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42959 |
| */ |
| return false; |
| } |
| |
| return true; |
| } |
| |
| /* Return true if METHOD_TYPE is a copy ctor type for CLASS_TYPE. */ |
| |
| static bool |
| is_copy_constructor_type (struct type *class_type, |
| struct type *method_type) |
| { |
| return is_copy_or_move_constructor_type (class_type, method_type, |
| TYPE_CODE_REF); |
| } |
| |
| /* Return true if METHOD_TYPE is a move ctor type for CLASS_TYPE. */ |
| |
| static bool |
| is_move_constructor_type (struct type *class_type, |
| struct type *method_type) |
| { |
| return is_copy_or_move_constructor_type (class_type, method_type, |
| TYPE_CODE_RVALUE_REF); |
| } |
| |
| /* Return pass-by-reference information for the given TYPE. |
| |
| 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/move 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 DWARF5 debug |
| information, we can check the calling_convention attribute, |
| the 'artificial' flag, the 'defaulted' attribute, and the |
| 'deleted' attribute. */ |
| |
| static struct language_pass_by_ref_info |
| gnuv3_pass_by_reference (struct type *type) |
| { |
| int fieldnum, fieldelem; |
| |
| type = check_typedef (type); |
| |
| /* Start with the default values. */ |
| struct language_pass_by_ref_info info; |
| |
| bool has_cc_attr = false; |
| bool is_pass_by_value = false; |
| bool is_dynamic = false; |
| definition_style cctor_def = DOES_NOT_EXIST_IN_SOURCE; |
| definition_style dtor_def = DOES_NOT_EXIST_IN_SOURCE; |
| definition_style mctor_def = DOES_NOT_EXIST_IN_SOURCE; |
| |
| /* We're only interested in things that can have methods. */ |
| if (type->code () != TYPE_CODE_STRUCT |
| && type->code () != TYPE_CODE_UNION) |
| return info; |
| |
| /* The compiler may have emitted the calling convention attribute. |
| Note: GCC does not produce this attribute as of version 9.2.1. |
| Bug link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92418 */ |
| if (TYPE_CPLUS_CALLING_CONVENTION (type) == DW_CC_pass_by_value) |
| { |
| has_cc_attr = true; |
| is_pass_by_value = true; |
| /* Do not return immediately. We have to find out if this type |
| is copy_constructible and destructible. */ |
| } |
| |
| if (TYPE_CPLUS_CALLING_CONVENTION (type) == DW_CC_pass_by_reference) |
| { |
| has_cc_attr = true; |
| is_pass_by_value = false; |
| } |
| |
| /* A dynamic class has a non-trivial copy constructor. |
| See c++98 section 12.8 Copying class objects [class.copy]. */ |
| if (gnuv3_dynamic_class (type)) |
| is_dynamic = true; |
| |
| 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); |
| const char *name = TYPE_FN_FIELDLIST_NAME (type, fieldnum); |
| struct type *fieldtype = TYPE_FN_FIELD_TYPE (fn, fieldelem); |
| |
| if (name[0] == '~') |
| { |
| /* We've found a destructor. |
| There should be at most one dtor definition. */ |
| gdb_assert (dtor_def == DOES_NOT_EXIST_IN_SOURCE); |
| dtor_def = get_def_style (fn, fieldelem); |
| } |
| else if (is_constructor_name (TYPE_FN_FIELD_PHYSNAME (fn, fieldelem)) |
| || TYPE_FN_FIELD_CONSTRUCTOR (fn, fieldelem)) |
| { |
| /* 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_copy_constructor_type (type, fieldtype)) |
| { |
| /* There may be more than one cctors. E.g.: one that |
| take a const parameter and another that takes a |
| non-const parameter. Such as: |
| |
| class K { |
| K (const K &k)... |
| K (K &k)... |
| }; |
| |
| It is sufficient for the type to be non-trivial |
| even only one of the cctors is explicit. |
| Therefore, update the cctor_def value in the |
| implicit -> explicit direction, not backwards. */ |
| |
| if (is_implicit_def (cctor_def)) |
| cctor_def = get_def_style (fn, fieldelem); |
| } |
| else if (is_move_constructor_type (type, fieldtype)) |
| { |
| /* Again, there may be multiple move ctors. Update the |
| mctor_def value if we found an explicit def and the |
| existing one is not explicit. Otherwise retain the |
| existing value. */ |
| if (is_implicit_def (mctor_def)) |
| mctor_def = get_def_style (fn, fieldelem); |
| } |
| } |
| } |
| |
| bool cctor_implicitly_deleted |
| = (mctor_def != DOES_NOT_EXIST_IN_SOURCE |
| && cctor_def == DOES_NOT_EXIST_IN_SOURCE); |
| |
| bool cctor_explicitly_deleted = (cctor_def == DELETED); |
| |
| if (cctor_implicitly_deleted || cctor_explicitly_deleted) |
| info.copy_constructible = false; |
| |
| if (dtor_def == DELETED) |
| info.destructible = false; |
| |
| info.trivially_destructible = is_implicit_def (dtor_def); |
| |
| info.trivially_copy_constructible |
| = (is_implicit_def (cctor_def) |
| && !is_dynamic); |
| |
| info.trivially_copyable |
| = (info.trivially_copy_constructible |
| && info.trivially_destructible |
| && !is_user_provided_def (mctor_def)); |
| |
| /* 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. Also ignore any static members. */ |
| for (fieldnum = 0; fieldnum < type->num_fields (); fieldnum++) |
| if (!field_is_static (&type->field (fieldnum))) |
| { |
| struct type *field_type = type->field (fieldnum).type (); |
| |
| /* For arrays, make the decision based on the element type. */ |
| if (field_type->code () == TYPE_CODE_ARRAY) |
| field_type = check_typedef (TYPE_TARGET_TYPE (field_type)); |
| |
| struct language_pass_by_ref_info field_info |
| = gnuv3_pass_by_reference (field_type); |
| |
| if (!field_info.copy_constructible) |
| info.copy_constructible = false; |
| if (!field_info.destructible) |
| info.destructible = false; |
| if (!field_info.trivially_copyable) |
| info.trivially_copyable = false; |
| if (!field_info.trivially_copy_constructible) |
| info.trivially_copy_constructible = false; |
| if (!field_info.trivially_destructible) |
| info.trivially_destructible = false; |
| } |
| |
| /* Consistency check. */ |
| if (has_cc_attr && info.trivially_copyable != is_pass_by_value) |
| { |
| /* DWARF CC attribute is not the same as the inferred value; |
| use the DWARF attribute. */ |
| info.trivially_copyable = is_pass_by_value; |
| } |
| |
| return info; |
| } |
| |
| static void |
| init_gnuv3_ops (void) |
| { |
| vtable_type_gdbarch_data |
| = gdbarch_data_register_post_init (build_gdb_vtable_type); |
| std_type_info_gdbarch_data |
| = gdbarch_data_register_post_init (build_std_type_info_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.print_vtable = gnuv3_print_vtable; |
| gnu_v3_abi_ops.get_typeid = gnuv3_get_typeid; |
| gnu_v3_abi_ops.get_typeid_type = gnuv3_get_typeid_type; |
| gnu_v3_abi_ops.get_type_from_type_info = gnuv3_get_type_from_type_info; |
| gnu_v3_abi_ops.get_typename_from_type_info |
| = gnuv3_get_typename_from_type_info; |
| gnu_v3_abi_ops.skip_trampoline = gnuv3_skip_trampoline; |
| gnu_v3_abi_ops.pass_by_reference = gnuv3_pass_by_reference; |
| } |
| |
| void _initialize_gnu_v3_abi (); |
| void |
| _initialize_gnu_v3_abi () |
| { |
| init_gnuv3_ops (); |
| |
| register_cp_abi (&gnu_v3_abi_ops); |
| set_cp_abi_as_auto_default (gnu_v3_abi_ops.shortname); |
| } |