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binutils-gdb/gdb/ada-varobj.c
Andrew Burgess 9a9a760829 Improve MI -var-info-path-expression for nested struct/union case. 
https://sourceware.org/ml/gdb-patches/2014-05/msg00383.html

The MI command -var-info-path-expression currently does not handle
non-anonymous structs / unions nested within other structs / unions,
it will skip parts of the expression.  Consider this example:

  ## START EXAMPLE ##
  $ cat ex.c
  #include <string.h>

  int
  main ()
  {
    struct s1
    {
      int a;
    };

    struct ss
    {
      struct s1 x;
    };

    struct ss an_ss;
    memset (&an_ss, 0, sizeof (an_ss));
    return 0;
  }
  $ gcc -g -o ex.x ex.c
  $ gdb ex.x
  (gdb) break 18
  Breakpoint 1 at 0x80483ba: file ex.c, line 18.
  (gdb) run
  Starting program: /home/user/ex.x

  Breakpoint 1, main () at ex.c:18
  18	  return 0;
  (gdb) interpreter-exec mi "-var-create an_ss * an_ss"
  (gdb) interpreter-exec mi "-var-list-children an_ss"
  ^done,numchild="1",children=[child={name="an_ss.x",exp="x",numchild="1",type="struct s1",thread-id="1"}],has_more="0"
  (gdb) interpreter-exec mi "-var-list-children an_ss.x"
  ^done,numchild="1",children=[child={name="an_ss.x.a",exp="a",numchild="0",type="int",thread-id="1"}],has_more="0"
  (gdb) interpreter-exec mi "-var-list-children an_ss.x.a"
  ^done,numchild="0",has_more="0"
  (gdb) interpreter-exec mi "-var-info-path-expression an_ss.x.a"
  ^done,path_expr="(an_ss).a"
  (gdb) print (an_ss).a
  There is no member named a.
  ## END EXAMPLE ##

Notice that the path expression returned is wrong, and as a result
the print command fails.

This patch adds a new method to the varobj_ops structure called
is_path_expr_parent, to allow language specific control over finding
the parent varobj, the current logic becomes the C/C++ version and is
extended to handle the nested cases.  No other language currently uses
this code, so all other languages just get a default method.

With this patch, the above example now finishes like this:

  ## START EXAMPLE ##
  $ gdb ex.x
  (gdb) break 18
  Breakpoint 1 at 0x80483ba: file ex.c, line 18.
  (gdb) run
  Starting program: /home/user/ex.x

  Breakpoint 1, main () at ex.c:18
  18	  return 0;
  (gdb) interpreter-exec mi "-var-list-children an_ss"
  ^done,numchild="1",children=[child={name="an_ss.x",exp="x",numchild="1",type="struct s1",thread-id="1"}],has_more="0"
  (gdb) interpreter-exec mi "-var-list-children an_ss.x"
  ^done,numchild="1",children=[child={name="an_ss.x.a",exp="a",numchild="0",type="int",thread-id="1"}],has_more="0"
  (gdb) interpreter-exec mi "-var-list-children an_ss.x.a"
  ^done,numchild="0",has_more="0"
  (gdb) interpreter-exec mi "-var-info-path-expression an_ss.x.a"
  ^done,path_expr="((an_ss).x).a"
  (gdb) print ((an_ss).x).a
  $1 = 0
  ## END EXAMPLE ##

Notice that the path expression is now correct, and the print is a
success.

gdb/ChangeLog:

	* ada-varobj.c (ada_varobj_ops): Fill in is_path_expr_parent
	field.
	* c-varobj.c (c_is_path_expr_parent): New function, moved core
	from varobj.c, with additional checks.
	(c_varobj_ops): Fill in is_path_expr_parent field.
	(cplus_varobj_ops): Fill in is_path_expr_parent field.
	* jv-varobj.c (java_varobj_ops): Fill in is_path_expr_parent
	field.
	* varobj.c (is_path_expr_parent): Call is_path_expr_parent varobj
	ops method.
	(varobj_default_is_path_expr_parent): New function.
	* varobj.h (lang_varobj_ops): Add is_path_expr_parent field.
	(varobj_default_is_path_expr_parent): Declare new function.

gdb/testsuite/ChangeLog:

	* gdb.mi/var-cmd.c (do_nested_struct_union_tests): New function
	setting up test structures.
	(main): Call new test function.
	* gdb.mi/mi2-var-child.exp: Create additional breakpoint in new
	test function, continue into test function and walk test
	structures.
2014-07-09 14:47:47 +01:00

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/* varobj support for Ada.
Copyright (C) 2012-2014 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 "ada-lang.h"
#include "varobj.h"
#include "language.h"
#include "valprint.h"
/* Implementation principle used in this unit:
For our purposes, the meat of the varobj object is made of two
elements: The varobj's (struct) value, and the varobj's (struct)
type. In most situations, the varobj has a non-NULL value, and
the type becomes redundant, as it can be directly derived from
the value. In the initial implementation of this unit, most
routines would only take a value, and return a value.
But there are many situations where it is possible for a varobj
to have a NULL value. For instance, if the varobj becomes out of
scope. Or better yet, when the varobj is the child of another
NULL pointer varobj. In that situation, we must rely on the type
instead of the value to create the child varobj.
That's why most functions below work with a (value, type) pair.
The value may or may not be NULL. But the type is always expected
to be set. When the value is NULL, then we work with the type
alone, and keep the value NULL. But when the value is not NULL,
then we work using the value, because it provides more information.
But we still always set the type as well, even if that type could
easily be derived from the value. The reason behind this is that
it allows the code to use the type without having to worry about
it being set or not. It makes the code clearer. */
static int ada_varobj_get_number_of_children (struct value *parent_value,
struct type *parent_type);
/* A convenience function that decodes the VALUE_PTR/TYPE_PTR couple:
If there is a value (*VALUE_PTR not NULL), then perform the decoding
using it, and compute the associated type from the resulting value.
Otherwise, compute a static approximation of *TYPE_PTR, leaving
*VALUE_PTR unchanged.
The results are written in place. */
static void
ada_varobj_decode_var (struct value **value_ptr, struct type **type_ptr)
{
if (*value_ptr)
{
*value_ptr = ada_get_decoded_value (*value_ptr);
*type_ptr = ada_check_typedef (value_type (*value_ptr));
}
else
*type_ptr = ada_get_decoded_type (*type_ptr);
}
/* Return a string containing an image of the given scalar value.
VAL is the numeric value, while TYPE is the value's type.
This is useful for plain integers, of course, but even more
so for enumerated types.
The result should be deallocated by xfree after use. */
static char *
ada_varobj_scalar_image (struct type *type, LONGEST val)
{
struct ui_file *buf = mem_fileopen ();
struct cleanup *cleanups = make_cleanup_ui_file_delete (buf);
char *result;
ada_print_scalar (type, val, buf);
result = ui_file_xstrdup (buf, NULL);
do_cleanups (cleanups);
return result;
}
/* Assuming that the (PARENT_VALUE, PARENT_TYPE) pair designates
a struct or union, compute the (CHILD_VALUE, CHILD_TYPE) couple
corresponding to the field number FIELDNO. */
static void
ada_varobj_struct_elt (struct value *parent_value,
struct type *parent_type,
int fieldno,
struct value **child_value,
struct type **child_type)
{
struct value *value = NULL;
struct type *type = NULL;
if (parent_value)
{
value = value_field (parent_value, fieldno);
type = value_type (value);
}
else
type = TYPE_FIELD_TYPE (parent_type, fieldno);
if (child_value)
*child_value = value;
if (child_type)
*child_type = type;
}
/* Assuming that the (PARENT_VALUE, PARENT_TYPE) pair is a pointer or
reference, return a (CHILD_VALUE, CHILD_TYPE) couple corresponding
to the dereferenced value. */
static void
ada_varobj_ind (struct value *parent_value,
struct type *parent_type,
struct value **child_value,
struct type **child_type)
{
struct value *value = NULL;
struct type *type = NULL;
if (ada_is_array_descriptor_type (parent_type))
{
/* This can only happen when PARENT_VALUE is NULL. Otherwise,
ada_get_decoded_value would have transformed our parent_type
into a simple array pointer type. */
gdb_assert (parent_value == NULL);
gdb_assert (TYPE_CODE (parent_type) == TYPE_CODE_TYPEDEF);
/* Decode parent_type by the equivalent pointer to (decoded)
array. */
while (TYPE_CODE (parent_type) == TYPE_CODE_TYPEDEF)
parent_type = TYPE_TARGET_TYPE (parent_type);
parent_type = ada_coerce_to_simple_array_type (parent_type);
parent_type = lookup_pointer_type (parent_type);
}
/* If parent_value is a null pointer, then only perform static
dereferencing. We cannot dereference null pointers. */
if (parent_value && value_as_address (parent_value) == 0)
parent_value = NULL;
if (parent_value)
{
value = ada_value_ind (parent_value);
type = value_type (value);
}
else
type = TYPE_TARGET_TYPE (parent_type);
if (child_value)
*child_value = value;
if (child_type)
*child_type = type;
}
/* Assuming that the (PARENT_VALUE, PARENT_TYPE) pair is a simple
array (TYPE_CODE_ARRAY), return the (CHILD_VALUE, CHILD_TYPE)
pair corresponding to the element at ELT_INDEX. */
static void
ada_varobj_simple_array_elt (struct value *parent_value,
struct type *parent_type,
int elt_index,
struct value **child_value,
struct type **child_type)
{
struct value *value = NULL;
struct type *type = NULL;
if (parent_value)
{
struct value *index_value =
value_from_longest (TYPE_INDEX_TYPE (parent_type), elt_index);
value = ada_value_subscript (parent_value, 1, &index_value);
type = value_type (value);
}
else
type = TYPE_TARGET_TYPE (parent_type);
if (child_value)
*child_value = value;
if (child_type)
*child_type = type;
}
/* Given the decoded value and decoded type of a variable object,
adjust the value and type to those necessary for getting children
of the variable object.
The replacement is performed in place. */
static void
ada_varobj_adjust_for_child_access (struct value **value,
struct type **type)
{
/* Pointers to struct/union types are special: Instead of having
one child (the struct), their children are the components of
the struct/union type. We handle this situation by dereferencing
the (value, type) couple. */
if (TYPE_CODE (*type) == TYPE_CODE_PTR
&& (TYPE_CODE (TYPE_TARGET_TYPE (*type)) == TYPE_CODE_STRUCT
|| TYPE_CODE (TYPE_TARGET_TYPE (*type)) == TYPE_CODE_UNION)
&& !ada_is_array_descriptor_type (TYPE_TARGET_TYPE (*type))
&& !ada_is_constrained_packed_array_type (TYPE_TARGET_TYPE (*type)))
ada_varobj_ind (*value, *type, value, type);
/* If this is a tagged type, we need to transform it a bit in order
to be able to fetch its full view. As always with tagged types,
we can only do that if we have a value. */
if (*value != NULL && ada_is_tagged_type (*type, 1))
{
*value = ada_tag_value_at_base_address (*value);
*type = value_type (*value);
}
}
/* Assuming that the (PARENT_VALUE, PARENT_TYPE) pair is an array
(any type of array, "simple" or not), return the number of children
that this array contains. */
static int
ada_varobj_get_array_number_of_children (struct value *parent_value,
struct type *parent_type)
{
LONGEST lo, hi;
if (!get_array_bounds (parent_type, &lo, &hi))
{
/* Could not get the array bounds. Pretend this is an empty array. */
warning (_("unable to get bounds of array, assuming null array"));
return 0;
}
/* Ada allows the upper bound to be less than the lower bound,
in order to specify empty arrays... */
if (hi < lo)
return 0;
return hi - lo + 1;
}
/* Assuming that the (PARENT_VALUE, PARENT_TYPE) pair is a struct or
union, return the number of children this struct contains. */
static int
ada_varobj_get_struct_number_of_children (struct value *parent_value,
struct type *parent_type)
{
int n_children = 0;
int i;
gdb_assert (TYPE_CODE (parent_type) == TYPE_CODE_STRUCT
|| TYPE_CODE (parent_type) == TYPE_CODE_UNION);
for (i = 0; i < TYPE_NFIELDS (parent_type); i++)
{
if (ada_is_ignored_field (parent_type, i))
continue;
if (ada_is_wrapper_field (parent_type, i))
{
struct value *elt_value;
struct type *elt_type;
ada_varobj_struct_elt (parent_value, parent_type, i,
&elt_value, &elt_type);
if (ada_is_tagged_type (elt_type, 0))
{
/* We must not use ada_varobj_get_number_of_children
to determine is element's number of children, because
this function first calls ada_varobj_decode_var,
which "fixes" the element. For tagged types, this
includes reading the object's tag to determine its
real type, which happens to be the parent_type, and
leads to an infinite loop (because the element gets
fixed back into the parent). */
n_children += ada_varobj_get_struct_number_of_children
(elt_value, elt_type);
}
else
n_children += ada_varobj_get_number_of_children (elt_value, elt_type);
}
else if (ada_is_variant_part (parent_type, i))
{
/* In normal situations, the variant part of the record should
have been "fixed". Or, in other words, it should have been
replaced by the branch of the variant part that is relevant
for our value. But there are still situations where this
can happen, however (Eg. when our parent is a NULL pointer).
We do not support showing this part of the record for now,
so just pretend this field does not exist. */
}
else
n_children++;
}
return n_children;
}
/* Assuming that the (PARENT_VALUE, PARENT_TYPE) pair designates
a pointer, return the number of children this pointer has. */
static int
ada_varobj_get_ptr_number_of_children (struct value *parent_value,
struct type *parent_type)
{
struct type *child_type = TYPE_TARGET_TYPE (parent_type);
/* Pointer to functions and to void do not have a child, since
you cannot print what they point to. */
if (TYPE_CODE (child_type) == TYPE_CODE_FUNC
|| TYPE_CODE (child_type) == TYPE_CODE_VOID)
return 0;
/* All other types have 1 child. */
return 1;
}
/* Return the number of children for the (PARENT_VALUE, PARENT_TYPE)
pair. */
static int
ada_varobj_get_number_of_children (struct value *parent_value,
struct type *parent_type)
{
ada_varobj_decode_var (&parent_value, &parent_type);
ada_varobj_adjust_for_child_access (&parent_value, &parent_type);
/* A typedef to an array descriptor in fact represents a pointer
to an unconstrained array. These types always have one child
(the unconstrained array). */
if (ada_is_array_descriptor_type (parent_type)
&& TYPE_CODE (parent_type) == TYPE_CODE_TYPEDEF)
return 1;
if (TYPE_CODE (parent_type) == TYPE_CODE_ARRAY)
return ada_varobj_get_array_number_of_children (parent_value,
parent_type);
if (TYPE_CODE (parent_type) == TYPE_CODE_STRUCT
|| TYPE_CODE (parent_type) == TYPE_CODE_UNION)
return ada_varobj_get_struct_number_of_children (parent_value,
parent_type);
if (TYPE_CODE (parent_type) == TYPE_CODE_PTR)
return ada_varobj_get_ptr_number_of_children (parent_value,
parent_type);
/* All other types have no child. */
return 0;
}
/* Describe the child of the (PARENT_VALUE, PARENT_TYPE) pair
whose index is CHILD_INDEX:
- If CHILD_NAME is not NULL, then a copy of the child's name
is saved in *CHILD_NAME. This copy must be deallocated
with xfree after use.
- If CHILD_VALUE is not NULL, then save the child's value
in *CHILD_VALUE. Same thing for the child's type with
CHILD_TYPE if not NULL.
- If CHILD_PATH_EXPR is not NULL, then compute the child's
path expression. The resulting string must be deallocated
after use with xfree.
Computing the child's path expression requires the PARENT_PATH_EXPR
to be non-NULL. Otherwise, PARENT_PATH_EXPR may be null if
CHILD_PATH_EXPR is NULL.
PARENT_NAME is the name of the parent, and should never be NULL. */
static void ada_varobj_describe_child (struct value *parent_value,
struct type *parent_type,
const char *parent_name,
const char *parent_path_expr,
int child_index,
char **child_name,
struct value **child_value,
struct type **child_type,
char **child_path_expr);
/* Same as ada_varobj_describe_child, but limited to struct/union
objects. */
static void
ada_varobj_describe_struct_child (struct value *parent_value,
struct type *parent_type,
const char *parent_name,
const char *parent_path_expr,
int child_index,
char **child_name,
struct value **child_value,
struct type **child_type,
char **child_path_expr)
{
int fieldno;
int childno = 0;
gdb_assert (TYPE_CODE (parent_type) == TYPE_CODE_STRUCT);
for (fieldno = 0; fieldno < TYPE_NFIELDS (parent_type); fieldno++)
{
if (ada_is_ignored_field (parent_type, fieldno))
continue;
if (ada_is_wrapper_field (parent_type, fieldno))
{
struct value *elt_value;
struct type *elt_type;
int elt_n_children;
ada_varobj_struct_elt (parent_value, parent_type, fieldno,
&elt_value, &elt_type);
if (ada_is_tagged_type (elt_type, 0))
{
/* Same as in ada_varobj_get_struct_number_of_children:
For tagged types, we must be careful to not call
ada_varobj_get_number_of_children, to prevent our
element from being fixed back into the parent. */
elt_n_children = ada_varobj_get_struct_number_of_children
(elt_value, elt_type);
}
else
elt_n_children =
ada_varobj_get_number_of_children (elt_value, elt_type);
/* Is the child we're looking for one of the children
of this wrapper field? */
if (child_index - childno < elt_n_children)
{
if (ada_is_tagged_type (elt_type, 0))
{
/* Same as in ada_varobj_get_struct_number_of_children:
For tagged types, we must be careful to not call
ada_varobj_describe_child, to prevent our element
from being fixed back into the parent. */
ada_varobj_describe_struct_child
(elt_value, elt_type, parent_name, parent_path_expr,
child_index - childno, child_name, child_value,
child_type, child_path_expr);
}
else
ada_varobj_describe_child (elt_value, elt_type,
parent_name, parent_path_expr,
child_index - childno,
child_name, child_value,
child_type, child_path_expr);
return;
}
/* The child we're looking for is beyond this wrapper
field, so skip all its children. */
childno += elt_n_children;
continue;
}
else if (ada_is_variant_part (parent_type, fieldno))
{
/* In normal situations, the variant part of the record should
have been "fixed". Or, in other words, it should have been
replaced by the branch of the variant part that is relevant
for our value. But there are still situations where this
can happen, however (Eg. when our parent is a NULL pointer).
We do not support showing this part of the record for now,
so just pretend this field does not exist. */
continue;
}
if (childno == child_index)
{
if (child_name)
{
/* The name of the child is none other than the field's
name, except that we need to strip suffixes from it.
For instance, fields with alignment constraints will
have an __XVA suffix added to them. */
const char *field_name = TYPE_FIELD_NAME (parent_type, fieldno);
int child_name_len = ada_name_prefix_len (field_name);
*child_name = xstrprintf ("%.*s", child_name_len, field_name);
}
if (child_value && parent_value)
ada_varobj_struct_elt (parent_value, parent_type, fieldno,
child_value, NULL);
if (child_type)
ada_varobj_struct_elt (parent_value, parent_type, fieldno,
NULL, child_type);
if (child_path_expr)
{
/* The name of the child is none other than the field's
name, except that we need to strip suffixes from it.
For instance, fields with alignment constraints will
have an __XVA suffix added to them. */
const char *field_name = TYPE_FIELD_NAME (parent_type, fieldno);
int child_name_len = ada_name_prefix_len (field_name);
*child_path_expr =
xstrprintf ("(%s).%.*s", parent_path_expr,
child_name_len, field_name);
}
return;
}
childno++;
}
/* Something went wrong. Either we miscounted the number of
children, or CHILD_INDEX was too high. But we should never
reach here. We don't have enough information to recover
nicely, so just raise an assertion failure. */
gdb_assert_not_reached ("unexpected code path");
}
/* Same as ada_varobj_describe_child, but limited to pointer objects.
Note that CHILD_INDEX is unused in this situation, but still provided
for consistency of interface with other routines describing an object's
child. */
static void
ada_varobj_describe_ptr_child (struct value *parent_value,
struct type *parent_type,
const char *parent_name,
const char *parent_path_expr,
int child_index,
char **child_name,
struct value **child_value,
struct type **child_type,
char **child_path_expr)
{
if (child_name)
*child_name = xstrprintf ("%s.all", parent_name);
if (child_value && parent_value)
ada_varobj_ind (parent_value, parent_type, child_value, NULL);
if (child_type)
ada_varobj_ind (parent_value, parent_type, NULL, child_type);
if (child_path_expr)
*child_path_expr = xstrprintf ("(%s).all", parent_path_expr);
}
/* Same as ada_varobj_describe_child, limited to simple array objects
(TYPE_CODE_ARRAY only).
Assumes that the (PARENT_VALUE, PARENT_TYPE) pair is properly decoded.
This is done by ada_varobj_describe_child before calling us. */
static void
ada_varobj_describe_simple_array_child (struct value *parent_value,
struct type *parent_type,
const char *parent_name,
const char *parent_path_expr,
int child_index,
char **child_name,
struct value **child_value,
struct type **child_type,
char **child_path_expr)
{
struct type *index_type;
int real_index;
gdb_assert (TYPE_CODE (parent_type) == TYPE_CODE_ARRAY);
index_type = TYPE_INDEX_TYPE (parent_type);
real_index = child_index + ada_discrete_type_low_bound (index_type);
if (child_name)
*child_name = ada_varobj_scalar_image (index_type, real_index);
if (child_value && parent_value)
ada_varobj_simple_array_elt (parent_value, parent_type, real_index,
child_value, NULL);
if (child_type)
ada_varobj_simple_array_elt (parent_value, parent_type, real_index,
NULL, child_type);
if (child_path_expr)
{
char *index_img = ada_varobj_scalar_image (index_type, real_index);
struct cleanup *cleanups = make_cleanup (xfree, index_img);
/* Enumeration litterals by themselves are potentially ambiguous.
For instance, consider the following package spec:
package Pck is
type Color is (Red, Green, Blue, White);
type Blood_Cells is (White, Red);
end Pck;
In this case, the litteral "red" for instance, or even
the fully-qualified litteral "pck.red" cannot be resolved
by itself. Type qualification is needed to determine which
enumeration litterals should be used.
The following variable will be used to contain the name
of the array index type when such type qualification is
needed. */
const char *index_type_name = NULL;
/* If the index type is a range type, find the base type. */
while (TYPE_CODE (index_type) == TYPE_CODE_RANGE)
index_type = TYPE_TARGET_TYPE (index_type);
if (TYPE_CODE (index_type) == TYPE_CODE_ENUM
|| TYPE_CODE (index_type) == TYPE_CODE_BOOL)
{
index_type_name = ada_type_name (index_type);
if (index_type_name)
index_type_name = ada_decode (index_type_name);
}
if (index_type_name != NULL)
*child_path_expr =
xstrprintf ("(%s)(%.*s'(%s))", parent_path_expr,
ada_name_prefix_len (index_type_name),
index_type_name, index_img);
else
*child_path_expr =
xstrprintf ("(%s)(%s)", parent_path_expr, index_img);
do_cleanups (cleanups);
}
}
/* See description at declaration above. */
static void
ada_varobj_describe_child (struct value *parent_value,
struct type *parent_type,
const char *parent_name,
const char *parent_path_expr,
int child_index,
char **child_name,
struct value **child_value,
struct type **child_type,
char **child_path_expr)
{
/* We cannot compute the child's path expression without
the parent's path expression. This is a pre-condition
for calling this function. */
if (child_path_expr)
gdb_assert (parent_path_expr != NULL);
ada_varobj_decode_var (&parent_value, &parent_type);
ada_varobj_adjust_for_child_access (&parent_value, &parent_type);
if (child_name)
*child_name = NULL;
if (child_value)
*child_value = NULL;
if (child_type)
*child_type = NULL;
if (child_path_expr)
*child_path_expr = NULL;
if (ada_is_array_descriptor_type (parent_type)
&& TYPE_CODE (parent_type) == TYPE_CODE_TYPEDEF)
{
ada_varobj_describe_ptr_child (parent_value, parent_type,
parent_name, parent_path_expr,
child_index, child_name,
child_value, child_type,
child_path_expr);
return;
}
if (TYPE_CODE (parent_type) == TYPE_CODE_ARRAY)
{
ada_varobj_describe_simple_array_child
(parent_value, parent_type, parent_name, parent_path_expr,
child_index, child_name, child_value, child_type,
child_path_expr);
return;
}
if (TYPE_CODE (parent_type) == TYPE_CODE_STRUCT)
{
ada_varobj_describe_struct_child (parent_value, parent_type,
parent_name, parent_path_expr,
child_index, child_name,
child_value, child_type,
child_path_expr);
return;
}
if (TYPE_CODE (parent_type) == TYPE_CODE_PTR)
{
ada_varobj_describe_ptr_child (parent_value, parent_type,
parent_name, parent_path_expr,
child_index, child_name,
child_value, child_type,
child_path_expr);
return;
}
/* It should never happen. But rather than crash, report dummy names
and return a NULL child_value. */
if (child_name)
*child_name = xstrdup ("???");
}
/* Return the name of the child number CHILD_INDEX of the (PARENT_VALUE,
PARENT_TYPE) pair. PARENT_NAME is the name of the PARENT.
The result should be deallocated after use with xfree. */
static char *
ada_varobj_get_name_of_child (struct value *parent_value,
struct type *parent_type,
const char *parent_name, int child_index)
{
char *child_name;
ada_varobj_describe_child (parent_value, parent_type, parent_name,
NULL, child_index, &child_name, NULL,
NULL, NULL);
return child_name;
}
/* Return the path expression of the child number CHILD_INDEX of
the (PARENT_VALUE, PARENT_TYPE) pair. PARENT_NAME is the name
of the parent, and PARENT_PATH_EXPR is the parent's path expression.
Both must be non-NULL.
The result must be deallocated after use with xfree. */
static char *
ada_varobj_get_path_expr_of_child (struct value *parent_value,
struct type *parent_type,
const char *parent_name,
const char *parent_path_expr,
int child_index)
{
char *child_path_expr;
ada_varobj_describe_child (parent_value, parent_type, parent_name,
parent_path_expr, child_index, NULL,
NULL, NULL, &child_path_expr);
return child_path_expr;
}
/* Return the value of child number CHILD_INDEX of the (PARENT_VALUE,
PARENT_TYPE) pair. PARENT_NAME is the name of the parent. */
static struct value *
ada_varobj_get_value_of_child (struct value *parent_value,
struct type *parent_type,
const char *parent_name, int child_index)
{
struct value *child_value;
ada_varobj_describe_child (parent_value, parent_type, parent_name,
NULL, child_index, NULL, &child_value,
NULL, NULL);
return child_value;
}
/* Return the type of child number CHILD_INDEX of the (PARENT_VALUE,
PARENT_TYPE) pair. */
static struct type *
ada_varobj_get_type_of_child (struct value *parent_value,
struct type *parent_type,
int child_index)
{
struct type *child_type;
ada_varobj_describe_child (parent_value, parent_type, NULL, NULL,
child_index, NULL, NULL, &child_type, NULL);
return child_type;
}
/* Return a string that contains the image of the given VALUE, using
the print options OPTS as the options for formatting the result.
The resulting string must be deallocated after use with xfree. */
static char *
ada_varobj_get_value_image (struct value *value,
struct value_print_options *opts)
{
char *result;
struct ui_file *buffer;
struct cleanup *old_chain;
buffer = mem_fileopen ();
old_chain = make_cleanup_ui_file_delete (buffer);
common_val_print (value, buffer, 0, opts, current_language);
result = ui_file_xstrdup (buffer, NULL);
do_cleanups (old_chain);
return result;
}
/* Assuming that the (VALUE, TYPE) pair designates an array varobj,
return a string that is suitable for use in the "value" field of
the varobj output. Most of the time, this is the number of elements
in the array inside square brackets, but there are situations where
it's useful to add more info.
OPTS are the print options used when formatting the result.
The result should be deallocated after use using xfree. */
static char *
ada_varobj_get_value_of_array_variable (struct value *value,
struct type *type,
struct value_print_options *opts)
{
char *result;
const int numchild = ada_varobj_get_array_number_of_children (value, type);
/* If we have a string, provide its contents in the "value" field.
Otherwise, the only other way to inspect the contents of the string
is by looking at the value of each element, as in any other array,
which is not very convenient... */
if (value
&& ada_is_string_type (type)
&& (opts->format == 0 || opts->format == 's'))
{
char *str;
struct cleanup *old_chain;
str = ada_varobj_get_value_image (value, opts);
old_chain = make_cleanup (xfree, str);
result = xstrprintf ("[%d] %s", numchild, str);
do_cleanups (old_chain);
}
else
result = xstrprintf ("[%d]", numchild);
return result;
}
/* Return a string representation of the (VALUE, TYPE) pair, using
the given print options OPTS as our formatting options. */
static char *
ada_varobj_get_value_of_variable (struct value *value,
struct type *type,
struct value_print_options *opts)
{
char *result = NULL;
ada_varobj_decode_var (&value, &type);
switch (TYPE_CODE (type))
{
case TYPE_CODE_STRUCT:
case TYPE_CODE_UNION:
result = xstrdup ("{...}");
break;
case TYPE_CODE_ARRAY:
result = ada_varobj_get_value_of_array_variable (value, type, opts);
break;
default:
if (!value)
result = xstrdup ("");
else
result = ada_varobj_get_value_image (value, opts);
break;
}
return result;
}
/* Ada specific callbacks for VAROBJs. */
static int
ada_number_of_children (struct varobj *var)
{
return ada_varobj_get_number_of_children (var->value, var->type);
}
static char *
ada_name_of_variable (struct varobj *parent)
{
return c_varobj_ops.name_of_variable (parent);
}
static char *
ada_name_of_child (struct varobj *parent, int index)
{
return ada_varobj_get_name_of_child (parent->value, parent->type,
parent->name, index);
}
static char*
ada_path_expr_of_child (struct varobj *child)
{
struct varobj *parent = child->parent;
const char *parent_path_expr = varobj_get_path_expr (parent);
return ada_varobj_get_path_expr_of_child (parent->value,
parent->type,
parent->name,
parent_path_expr,
child->index);
}
static struct value *
ada_value_of_child (struct varobj *parent, int index)
{
return ada_varobj_get_value_of_child (parent->value, parent->type,
parent->name, index);
}
static struct type *
ada_type_of_child (struct varobj *parent, int index)
{
return ada_varobj_get_type_of_child (parent->value, parent->type,
index);
}
static char *
ada_value_of_variable (struct varobj *var, enum varobj_display_formats format)
{
struct value_print_options opts;
varobj_formatted_print_options (&opts, format);
return ada_varobj_get_value_of_variable (var->value, var->type, &opts);
}
/* Implement the "value_is_changeable_p" routine for Ada. */
static int
ada_value_is_changeable_p (struct varobj *var)
{
struct type *type = var->value ? value_type (var->value) : var->type;
if (ada_is_array_descriptor_type (type)
&& TYPE_CODE (type) == TYPE_CODE_TYPEDEF)
{
/* This is in reality a pointer to an unconstrained array.
its value is changeable. */
return 1;
}
if (ada_is_string_type (type))
{
/* We display the contents of the string in the array's
"value" field. The contents can change, so consider
that the array is changeable. */
return 1;
}
return varobj_default_value_is_changeable_p (var);
}
/* Implement the "value_has_mutated" routine for Ada. */
static int
ada_value_has_mutated (struct varobj *var, struct value *new_val,
struct type *new_type)
{
int i;
int from = -1;
int to = -1;
/* If the number of fields have changed, then for sure the type
has mutated. */
if (ada_varobj_get_number_of_children (new_val, new_type)
!= var->num_children)
return 1;
/* If the number of fields have remained the same, then we need
to check the name of each field. If they remain the same,
then chances are the type hasn't mutated. This is technically
an incomplete test, as the child's type might have changed
despite the fact that the name remains the same. But we'll
handle this situation by saying that the child has mutated,
not this value.
If only part (or none!) of the children have been fetched,
then only check the ones we fetched. It does not matter
to the frontend whether a child that it has not fetched yet
has mutated or not. So just assume it hasn't. */
varobj_restrict_range (var->children, &from, &to);
for (i = from; i < to; i++)
if (strcmp (ada_varobj_get_name_of_child (new_val, new_type,
var->name, i),
VEC_index (varobj_p, var->children, i)->name) != 0)
return 1;
return 0;
}
/* varobj operations for ada. */
const struct lang_varobj_ops ada_varobj_ops =
{
ada_number_of_children,
ada_name_of_variable,
ada_name_of_child,
ada_path_expr_of_child,
ada_value_of_child,
ada_type_of_child,
ada_value_of_variable,
ada_value_is_changeable_p,
ada_value_has_mutated,
varobj_default_is_path_expr_parent
};
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