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8776cfe971
Given the following variable...
BT : Bounded := New_Bounded (Low => 1, High => 3);
... where type Bounded is defined as a simple unconstrained array:
type Bounded is array (Integer range <>) of Integer;
Creating a varobj for that variable, and immediately asking for
varobj updates, GDB says that our varobj changed types!
(gdb)
-var-create bt * bt
^done,name="bt",numchild="3",value="[3]",type="<ref> array (1 .. 3) of integer",has_more="0"
(gdb)
-var-update 1 *
^done,changelist=[{name="bt",value="[3]",in_scope="true",type_changed="true",new_type="<ref> array (1 .. 3) of integer",new_num_children="3",has_more="0"}]
The expected output for the -var-update command is, in this case:
(gdb)
-var-update 1 *
^done,changelist=[]
The problem occurs because the ada-varobj module does not handle
references, and while the references gets stripped when the varobj
gets created, it doesn't when computing varobj updates.
More specifically, when creating the varobj, varobj_create creates
a new value which is a reference to a TYPE_CODE_ARRAY. It then calls
install_new_value which calls coerce_ref with the following comment:
/* We are not interested in the address of references, and given
that in C++ a reference is not rebindable, it cannot
meaningfully change. So, get hold of the real value. */
if (value)
value = coerce_ref (value);
This leaves the varobj's type component still a ref, while
the varobj's value is now our array, without the ref. This explains
why the "value" field in the varobj indicates an array with 3 elements
"[3]" while the "type" field shows a ref to an array. Generally
speaking, most users have said that showing the ref was a useful
piece of information, so this patch is not touching this part.
Next, when the user issues the -var-update request, varobj_update
calls value_of_root to compute the varobj's new value as well as
determine whether the value's type has changed or not. What happens
in a nutshell is that it calls value_of_root_1 (which re-evaluates
the expression and returns the corresponding new value), finds that
the new value is not NULL, and thus asks whether it has mutated:
else if (varobj_value_has_mutated (var, value, value_type (value)))
This then indirectly delegates the determination to the language-specific
callback, which fails, because it does not handle references.
This patch fixes the issue by adjusting varobj_value_has_mutated to
expect references, and strip them when seen. This allows the various
language-specific implementations to remain unaware of references.
gdb/ChangeLog:
* varobj.c (varobj_value_has_mutated): If NEW_VALUE is
a reference, strip the reference layer before calling
the lang_ops value_has_mutated callback.
gdb/testsuite/ChangeLog:
* gdb.ada/mi_dyn_arr: New testcase.
|
||
|---|---|---|
| .. | ||
| aliased_array | ||
| array_bounds | ||
| array_char_idx | ||
| array_return | ||
| array_subscript_addr | ||
| arraydim | ||
| arrayidx | ||
| arrayparam | ||
| arrayptr | ||
| atomic_enum | ||
| bad-task-bp-keyword | ||
| bp_enum_homonym | ||
| bp_on_var | ||
| bp_range_type | ||
| bp_reset | ||
| call_pn | ||
| catch_ex | ||
| char_enum | ||
| char_param | ||
| complete | ||
| cond_lang | ||
| dot_all | ||
| dyn_loc | ||
| enum_idx_packed | ||
| exec_changed | ||
| expr_delims | ||
| exprs | ||
| fixed_cmp | ||
| fixed_points | ||
| float_param | ||
| formatted_ref | ||
| frame_args | ||
| fullname_bp | ||
| fun_addr | ||
| fun_in_declare | ||
| funcall_param | ||
| homonym | ||
| info_exc | ||
| info_locals_renaming | ||
| int_deref | ||
| interface | ||
| iwide | ||
| lang_switch | ||
| mi_catch_ex | ||
| mi_dyn_arr | ||
| mi_ex_cond | ||
| mi_exc_info | ||
| mi_interface | ||
| mi_task_arg | ||
| mi_task_info | ||
| mod_from_name | ||
| nested | ||
| null_array | ||
| null_record | ||
| O2_float_param | ||
| operator_bp | ||
| optim_drec | ||
| packed_array | ||
| packed_tagged | ||
| pckd_arr_ren | ||
| pp-rec-component | ||
| print_chars | ||
| ptr_typedef | ||
| ptype_field | ||
| ptype_tagged_param | ||
| py_range | ||
| rdv_wait | ||
| rec_return | ||
| ref_param | ||
| ref_tick_size | ||
| same_enum | ||
| set_pckd_arr_elt | ||
| set_wstr | ||
| small_reg_param | ||
| start | ||
| str_ref_cmp | ||
| sym_print_name | ||
| taft_type | ||
| tagged | ||
| tagged_access | ||
| tagged_not_init | ||
| task_bp | ||
| tasks | ||
| tick_last_segv | ||
| tick_length_array_enum_idx | ||
| type_coercion | ||
| unc_arr_ptr_in_var_rec | ||
| uninitialized_vars | ||
| variant_record_packed_array | ||
| watch_arg | ||
| whatis_array_val | ||
| widewide | ||
| win_fu_syms | ||
| aliased_array.exp | ||
| array_bounds.exp | ||
| array_char_idx.exp | ||
| array_return.exp | ||
| array_subscript_addr.exp | ||
| arraydim.exp | ||
| arrayidx.exp | ||
| arrayparam.exp | ||
| arrayptr.exp | ||
| assign_1.exp | ||
| atomic_enum.exp | ||
| bad-task-bp-keyword.exp | ||
| boolean_expr.exp | ||
| bp_enum_homonym.exp | ||
| bp_on_var.exp | ||
| bp_range_type.exp | ||
| bp_reset.exp | ||
| call_pn.exp | ||
| catch_ex.exp | ||
| char_enum.exp | ||
| char_param.exp | ||
| complete.exp | ||
| cond_lang.exp | ||
| dot_all.exp | ||
| dyn_loc.exp | ||
| enum_idx_packed.exp | ||
| exec_changed.exp | ||
| expr_delims.exp | ||
| exprs.exp | ||
| fixed_cmp.exp | ||
| fixed_points.exp | ||
| float_param.exp | ||
| formatted_ref.exp | ||
| frame_args.exp | ||
| fullname_bp.exp | ||
| fun_addr.exp | ||
| fun_in_declare.exp | ||
| funcall_param.exp | ||
| gnat_ada.gpr | ||
| homonym.exp | ||
| info_exc.exp | ||
| info_locals_renaming.exp | ||
| info_types.c | ||
| info_types.exp | ||
| int_deref.exp | ||
| interface.exp | ||
| iwide.exp | ||
| lang_switch.exp | ||
| Makefile.in | ||
| mi_catch_ex.exp | ||
| mi_dyn_arr.exp | ||
| mi_ex_cond.exp | ||
| mi_exc_info.exp | ||
| mi_interface.exp | ||
| mi_task_arg.exp | ||
| mi_task_info.exp | ||
| mod_from_name.exp | ||
| nested.exp | ||
| null_array.exp | ||
| null_record.exp | ||
| O2_float_param.exp | ||
| operator_bp.exp | ||
| optim_drec.exp | ||
| packed_array.exp | ||
| packed_tagged.exp | ||
| pckd_arr_ren.exp | ||
| pp-rec-component.exp | ||
| pp-rec-component.py | ||
| print_chars.exp | ||
| print_pc.exp | ||
| ptr_typedef.exp | ||
| ptype_arith_binop.exp | ||
| ptype_field.exp | ||
| ptype_tagged_param.exp | ||
| py_range.exp | ||
| rdv_wait.exp | ||
| rec_return.exp | ||
| ref_param.exp | ||
| ref_tick_size.exp | ||
| same_enum.exp | ||
| set_pckd_arr_elt.exp | ||
| set_wstr.exp | ||
| small_reg_param.exp | ||
| start.exp | ||
| str_ref_cmp.exp | ||
| sym_print_name.exp | ||
| taft_type.exp | ||
| tagged_access.exp | ||
| tagged_not_init.exp | ||
| tagged.exp | ||
| task_bp.exp | ||
| tasks.exp | ||
| tick_last_segv.exp | ||
| tick_length_array_enum_idx.exp | ||
| type_coercion.exp | ||
| unc_arr_ptr_in_var_rec.exp | ||
| uninitialized_vars.exp | ||
| variant_record_packed_array.exp | ||
| watch_arg.exp | ||
| whatis_array_val.exp | ||
| widewide.exp | ||
| win_fu_syms.exp | ||