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2009-11-12 Daniel Jacobowitz <dan@codesourcery.com>

Browse Source 
Paul Brook  <paul@codesourcery.com>

	* c-typeprint.c (c_type_print_base): Skip artificial fields.
	Use get_vptr_fieldno to skip the vtable pointer.
	* dwarf2read.c (dwarf2_add_field): Set FIELD_ARTIFICIAL on artificial
	fields.
	(dwarf2_add_member_fn): Complain about virtual member functions
	without DW_AT_vtable_elem_location and force TYPE_CPLUS_DYNAMIC.
	* gdbtypes.c (get_vptr_fieldno): Update comment.
	* gdbtypes.h (struct cplus_struct_type): Add is_dynamic.
	(TYPE_CPLUS_DYNAMIC): New macro.
	* gnu-v3-abi.c (gnuv3_dynamic_class): New.
	(gnuv3_get_vtable): Rewrite to use gnuv3_dynamic_class.  Move higher.
	(gnuv3_rtti_type, gnuv3_get_virtual_fn, gnuv3_baseclass_offset): Use
	gnuv3_get_vtable.
	* varobj.c (cplus_class_num_children, cplus_describe_child): Skip
	artificial fields.  Use get_vptr_fieldno to skip the vtable pointer.
This commit is contained in:
Daniel Jacobowitz 2009-11-12 19:47:25 +00:00
parent 87728fa060
commit d48cc9dd6f
7 changed files with 157 additions and 103 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
gdb/ChangeLog
View File

@ -1,3 +1,22 @@
2009-11-12 Daniel Jacobowitz <dan@codesourcery.com>
Paul Brook <paul@codesourcery.com>
* c-typeprint.c (c_type_print_base): Skip artificial fields.
Use get_vptr_fieldno to skip the vtable pointer.
* dwarf2read.c (dwarf2_add_field): Set FIELD_ARTIFICIAL on artificial
fields.
(dwarf2_add_member_fn): Complain about virtual member functions
without DW_AT_vtable_elem_location and force TYPE_CPLUS_DYNAMIC.
* gdbtypes.c (get_vptr_fieldno): Update comment.
* gdbtypes.h (struct cplus_struct_type): Add is_dynamic.
(TYPE_CPLUS_DYNAMIC): New macro.
* gnu-v3-abi.c (gnuv3_dynamic_class): New.
(gnuv3_get_vtable): Rewrite to use gnuv3_dynamic_class. Move higher.
(gnuv3_rtti_type, gnuv3_get_virtual_fn, gnuv3_baseclass_offset): Use
gnuv3_get_vtable.
* varobj.c (cplus_class_num_children, cplus_describe_child): Skip
artificial fields. Use get_vptr_fieldno to skip the vtable pointer.
2009-11-12 Paul Brook <paul@codesourcery.com>
Daniel Jacobowitz <dan@codesourcery.com>

13
gdb/c-typeprint.c
View File

@ -761,6 +761,9 @@ c_type_print_base (struct type *type, struct ui_file *stream, int show,
}
else if (show > 0 || TYPE_TAG_NAME (type) == NULL)
{
struct type *basetype;
int vptr_fieldno;
cp_type_print_derivation_info (stream, type);
fprintf_filtered (stream, "{\n");
@ -848,12 +851,16 @@ c_type_print_base (struct type *type, struct ui_file *stream, int show,
do not print the field that it occupies. */
len = TYPE_NFIELDS (type);
vptr_fieldno = get_vptr_fieldno (type, &basetype);
for (i = TYPE_N_BASECLASSES (type); i < len; i++)
{
QUIT;
/* Don't print out virtual function table. */
if (strncmp (TYPE_FIELD_NAME (type, i), "_vptr", 5) == 0
&& is_cplus_marker ((TYPE_FIELD_NAME (type, i))[5]))
/* If we have a virtual table pointer, omit it. Even if
virtual table pointers are not specifically marked in
the debug info, they should be artificial. */
if ((type == basetype && i == vptr_fieldno)
|| TYPE_FIELD_ARTIFICIAL (type, i))
continue;
/* If this is a C++ class we can print the various C++ section

13
gdb/dwarf2read.c
View File

@ -4484,6 +4484,7 @@ dwarf2_add_field (struct field_info *fip, struct die_info *die,
pointer or virtual base class pointer) to private. */
if (dwarf2_attr (die, DW_AT_artificial, cu))
{
FIELD_ARTIFICIAL (*fp) = 1;
new_field->accessibility = DW_ACCESS_private;
fip->non_public_fields = 1;
}
@ -4803,6 +4804,18 @@ dwarf2_add_member_fn (struct field_info *fip, struct die_info *die,
else
dwarf2_complex_location_expr_complaint ();
}
else
{
attr = dwarf2_attr (die, DW_AT_virtuality, cu);
if (attr && DW_UNSND (attr))
{
/* GCC does this, as of 2008-08-25; PR debug/37237. */
complaint (&symfile_complaints,
_("Member function \"%s\" (offset %d) is virtual but the vtable offset is not specified"),
fieldname, die->offset);
TYPE_CPLUS_DYNAMIC (type) = 1;
}
}
}
/* Create the vector of member function fields, and attach it to the type. */

3
gdb/gdbtypes.c
View File

@ -1277,7 +1277,8 @@ lookup_struct_elt_type (struct type *type, char *name, int noerr)
If not found, return -1 and ignore BASETYPEP.
Callers should be aware that in some cases (for example,
the type or one of its baseclasses is a stub type and we are
debugging a .o file), this function will not be able to find the
debugging a .o file, or the compiler uses DWARF-2 and is not GCC),
this function will not be able to find the
virtual function table pointer, and vptr_fieldno will remain -1 and
vptr_basetype will remain NULL or incomplete. */

8
gdb/gdbtypes.h
View File

@ -775,6 +775,13 @@ struct cplus_struct_type
int line;
}
*localtype_ptr;
/* One if this struct is a dynamic class, as defined by the
Itanium C++ ABI: if it requires a virtual table pointer,
because it or any of its base classes have one or more virtual
member functions or virtual base classes. Minus one if not
dynamic. Zero if not yet computed. */
int is_dynamic : 2;
};
/* Struct used in computing virtual base list */
@ -861,6 +868,7 @@ extern void allocate_cplus_struct_type (struct type *);
#define TYPE_BASECLASS_BITPOS(thistype,index) TYPE_FIELD_BITPOS(thistype,index)
#define BASETYPE_VIA_PUBLIC(thistype, index) \
((!TYPE_FIELD_PRIVATE(thistype, index)) && (!TYPE_FIELD_PROTECTED(thistype, index)))
#define TYPE_CPLUS_DYNAMIC(thistype) TYPE_CPLUS_SPECIFIC (thistype)->is_dynamic
#define BASETYPE_VIA_VIRTUAL(thistype, index) \
(TYPE_CPLUS_SPECIFIC(thistype)->virtual_field_bits == NULL ? 0 \

185
gdb/gnu-v3-abi.c
View File

@ -190,23 +190,96 @@ vtable_address_point_offset (struct gdbarch *gdbarch)
}
/* Determine whether structure TYPE is a dynamic class. Cache the
result. */
static int
gnuv3_dynamic_class (struct type *type)
{
int fieldnum, fieldelem;
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_TYPE (type, fieldnum)))
{
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 = gdbarch_data (gdbarch,
vtable_type_gdbarch_data);
struct type *vtable_pointer_type;
struct value *vtable_pointer;
CORE_ADDR vtable_address;
/* If this type does not have a virtual table, don't read the first
field. */
if (!gnuv3_dynamic_class (check_typedef (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, int *top_p, int *using_enc_p)
{
struct gdbarch *gdbarch;
struct type *vtable_type;
struct type *values_type = check_typedef (value_type (value));
CORE_ADDR vtable_address;
struct value *vtable;
struct minimal_symbol *vtable_symbol;
const char *vtable_symbol_name;
const char *class_name;
struct type *run_time_type;
struct type *base_type;
LONGEST offset_to_top;
struct type *values_type_vptr_basetype;
int values_type_vptr_fieldno;
/* We only have RTTI for class objects. */
if (TYPE_CODE (values_type) != TYPE_CODE_CLASS)
@ -214,33 +287,15 @@ gnuv3_rtti_type (struct value *value,
/* Determine architecture. */
gdbarch = get_type_arch (values_type);
vtable_type = gdbarch_data (gdbarch, vtable_type_gdbarch_data);
/* If we can't find the virtual table pointer for values_type, we
can't find the RTTI. */
values_type_vptr_fieldno = get_vptr_fieldno (values_type,
&values_type_vptr_basetype);
if (values_type_vptr_fieldno == -1)
return NULL;
if (using_enc_p)
*using_enc_p = 0;
/* Fetch VALUE's virtual table pointer, and tweak it to point at
an instance of our imaginary gdb_gnu_v3_abi_vtable structure. */
base_type = check_typedef (values_type_vptr_basetype);
if (values_type != base_type)
{
value = value_cast (base_type, value);
if (using_enc_p)
*using_enc_p = 1;
}
vtable_address
= value_as_address (value_field (value, values_type_vptr_fieldno));
vtable
= value_at_lazy (vtable_type,
vtable_address - vtable_address_point_offset (gdbarch));
vtable = gnuv3_get_vtable (gdbarch, value_type (value),
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)
@ -282,45 +337,9 @@ gnuv3_rtti_type (struct value *value,
>= TYPE_LENGTH (run_time_type)));
if (top_p)
*top_p = - offset_to_top;
return run_time_type;
}
/* Find the vtable for CONTAINER and return a value of the correct
vtable type for this architecture. */
static struct value *
gnuv3_get_vtable (struct gdbarch *gdbarch, struct value *container)
{
struct type *vtable_type = gdbarch_data (gdbarch, vtable_type_gdbarch_data);
struct type *vtable_pointer_type;
struct value *vtable_pointer;
CORE_ADDR vtable_pointer_address, vtable_address;
/* We do not consult the debug information to find the virtual table.
The ABI specifies that it is always at offset zero in any class,
and debug information may not represent it. We won't issue an
error if there's a class with virtual functions but no virtual table
pointer, but something's already gone seriously wrong if that
happens.
We avoid using value_contents on principle, because the object might
be large. */
/* Find the type "pointer to virtual table". */
vtable_pointer_type = lookup_pointer_type (vtable_type);
/* Load it from the start of the class. */
vtable_pointer_address = value_as_address (value_addr (container));
vtable_pointer = value_at (vtable_pointer_type, vtable_pointer_address);
vtable_address = value_as_address (vtable_pointer);
/* Correct it to point at the start of the virtual table, rather
than the address point. */
return value_at_lazy (vtable_type,
vtable_address - vtable_address_point_offset (gdbarch));
}
/* Return a function pointer for CONTAINER's VTABLE_INDEX'th virtual
function, of type FNTYPE. */
@ -328,8 +347,12 @@ static struct value *
gnuv3_get_virtual_fn (struct gdbarch *gdbarch, struct value *container,
struct type *fntype, int vtable_index)
{
struct value *vtable = gnuv3_get_vtable (gdbarch, container);
struct value *vfn;
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),
@ -389,18 +412,13 @@ gnuv3_baseclass_offset (struct type *type, int index, const bfd_byte *valaddr,
CORE_ADDR address)
{
struct gdbarch *gdbarch;
struct type *vtable_type;
struct type *ptr_type;
struct value *vtable;
struct type *vbasetype;
struct value *vbase_array;
CORE_ADDR vtable_address;
long int cur_base_offset, base_offset;
int vbasetype_vptr_fieldno;
/* Determine architecture. */
gdbarch = get_type_arch (type);
vtable_type = gdbarch_data (gdbarch, vtable_type_gdbarch_data);
ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
/* If it isn't a virtual base, this is easy. The offset is in the
@ -422,29 +440,8 @@ gnuv3_baseclass_offset (struct type *type, int index, const bfd_byte *valaddr,
error (_("Misaligned vbase offset."));
cur_base_offset = cur_base_offset / ((int) TYPE_LENGTH (ptr_type));
/* We're now looking for the cur_base_offset'th entry (negative index)
in the vcall_and_vbase_offsets array. We used to cast the object to
its TYPE_VPTR_BASETYPE, and reference the vtable as TYPE_VPTR_FIELDNO;
however, that cast can not be done without calling baseclass_offset again
if the TYPE_VPTR_BASETYPE is a virtual base class, as described in the
v3 C++ ABI Section 2.4.I.2.b. Fortunately the ABI guarantees that the
vtable pointer will be located at the beginning of the object, so we can
bypass the casting. Verify that the TYPE_VPTR_FIELDNO is in fact at the
start of whichever baseclass it resides in, as a sanity measure - iff
we have debugging information for that baseclass. */
vbasetype = check_typedef (TYPE_VPTR_BASETYPE (type));
vbasetype_vptr_fieldno = get_vptr_fieldno (vbasetype, NULL);
if (vbasetype_vptr_fieldno >= 0
&& TYPE_FIELD_BITPOS (vbasetype, vbasetype_vptr_fieldno) != 0)
error (_("Illegal vptr offset in class %s"),
TYPE_NAME (vbasetype) ? TYPE_NAME (vbasetype) : "<unknown>");
vtable_address = value_as_address (value_at_lazy (ptr_type, address));
vtable
= value_at_lazy (vtable_type,
vtable_address - vtable_address_point_offset (gdbarch));
vtable = gnuv3_get_vtable (gdbarch, type, address);
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;

19
gdb/varobj.c
View File

@ -3103,16 +3103,21 @@ cplus_number_of_children (struct varobj *var)
static void
cplus_class_num_children (struct type *type, int children[3])
{
int i;
int i, vptr_fieldno;
struct type *basetype = NULL;
children[v_public] = 0;
children[v_private] = 0;
children[v_protected] = 0;
vptr_fieldno = get_vptr_fieldno (type, &basetype);
for (i = TYPE_N_BASECLASSES (type); i < TYPE_NFIELDS (type); i++)
{
/* If we have a virtual table pointer, omit it. */
if (TYPE_VPTR_BASETYPE (type) == type && TYPE_VPTR_FIELDNO (type) == i)
/* If we have a virtual table pointer, omit it. Even if virtual
table pointers are not specifically marked in the debug info,
they should be artificial. */
if ((type == basetype && i == vptr_fieldno)
|| TYPE_FIELD_ARTIFICIAL (type, i))
continue;
if (TYPE_FIELD_PROTECTED (type, i))
@ -3199,6 +3204,10 @@ cplus_describe_child (struct varobj *parent, int index,
find the indexed field. */
int type_index = TYPE_N_BASECLASSES (type);
enum accessibility acc = public_field;
int vptr_fieldno;
struct type *basetype = NULL;
vptr_fieldno = get_vptr_fieldno (type, &basetype);
if (strcmp (parent->name, "private") == 0)
acc = private_field;
else if (strcmp (parent->name, "protected") == 0)
@ -3206,8 +3215,8 @@ cplus_describe_child (struct varobj *parent, int index,
while (index >= 0)
{
if (TYPE_VPTR_BASETYPE (type) == type
&& type_index == TYPE_VPTR_FIELDNO (type))
if ((type == basetype && type_index == vptr_fieldno)
|| TYPE_FIELD_ARTIFICIAL (type, type_index))
; /* ignore vptr */
else if (match_accessibility (type, type_index, acc))
--index;