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[RFA] Better support for DWARF location blocks (was DWARF support for .debug_loc offsets)
- From: Petr Sorfa <petrs at caldera dot com>
- To: "gdb-patches at sources dot redhat dot com" <gdb-patches at sources dot redhat dot com>
- Date: Thu, 11 Jul 2002 16:24:53 -0400
- Subject: [RFA] Better support for DWARF location blocks (was DWARF support for .debug_loc offsets)
- Organization: Caldera
Hi,
This patch provides better error detection when processing certain DWARF
location blocks. Basically an error is given in these cases when the
attribute's form is not a DW_AT_block*.
Again, this patch does not support in read_tag_string_type() the
DW_AT_string_length attribute which is currently being misused by GCC
(it uses it to hold the length, rather than the location to the length)
and GDB supports this incorrect form.
2002-07-11 Petr Sorfa (petrs@caldera.com)
* dwarf2read.c (dwarf2_invalid_attrib_class): New
complaint for invalid attribute class or form.
(read_func_scope): DW_AT_frame_base
better handling of DW_AT_block*.
(dwarf2_add_member_fn): DW_AT_vtable_elem_location
better handling of DW_AT_block*.
(read_common_block): DW_AT_location
better handling of DW_AT_block*.
(read_partial_die): DW_AT_location better handling
of DW_AT_block*.
(new_symbol): DW_AT_external better handling of
DW_AT_block*. Proper initialization of variable
"addr".
Index: dwarf2read.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2read.c,v
retrieving revision 1.60
diff -c -p -r1.60 dwarf2read.c
*** dwarf2read.c 22 Jun 2002 00:05:59 -0000 1.60
--- dwarf2read.c 11 Jul 2002 20:03:34 -0000
*************** static struct complaint dwarf2_macro_spa
*** 658,663 ****
--- 658,667 ----
{
"macro definition contains spaces in formal argument list:\n`%s'", 0, 0
};
+ static struct complaint dwarf2_invalid_attrib_class =
+ {
+ "invalid attribute class or form for '%s' in '%s'", 0, 0
+ };
/* local function prototypes */
*************** read_func_scope (struct die_info *die, s
*** 1870,1876 ****
attr = dwarf_attr (die, DW_AT_frame_base);
if (attr)
{
! CORE_ADDR addr = decode_locdesc (DW_BLOCK (attr), objfile, cu_header);
if (isderef)
complain (&dwarf2_unsupported_at_frame_base, name);
else if (isreg)
--- 1874,1900 ----
attr = dwarf_attr (die, DW_AT_frame_base);
if (attr)
{
! CORE_ADDR addr;
!
! /* Support the .debug_loc offsets */
! if (attr->form == DW_FORM_block1
! || attr->form == DW_FORM_block2
! || attr->form == DW_FORM_block4
! || attr->form == DW_FORM_block)
! {
! addr = decode_locdesc (DW_BLOCK (attr), objfile, cu_header);
! }
! else if (attr->form == DW_FORM_data4 || attr->form == DW_FORM_data8)
! {
! complain (&dwarf2_complex_location_expr);
! addr = 0;
! }
! else
! {
! complain (&dwarf2_invalid_attrib_class, "DW_AT_frame_base", name);
! addr = 0;
! }
!
if (isderef)
complain (&dwarf2_unsupported_at_frame_base, name);
else if (isreg)
*************** dwarf2_add_member_fn (struct field_info
*** 2348,2354 ****
/* Get index in virtual function table if it is a virtual member function. */
attr = dwarf_attr (die, DW_AT_vtable_elem_location);
if (attr)
! fnp->voffset = decode_locdesc (DW_BLOCK (attr), objfile, cu_header) + 2;
}
/* Create the vector of member function fields, and attach it to the type. */
--- 2372,2396 ----
/* Get index in virtual function table if it is a virtual member function. */
attr = dwarf_attr (die, DW_AT_vtable_elem_location);
if (attr)
! {
! /* Support the .debug_loc offsets */
! if (attr->form == DW_FORM_block1
! || attr->form == DW_FORM_block2
! || attr->form == DW_FORM_block4
! || attr->form == DW_FORM_block)
! {
! fnp->voffset = decode_locdesc (DW_BLOCK (attr), objfile, cu_header) + 2;
! }
! else if (attr->form == DW_FORM_data4 || attr->form == DW_FORM_data8)
! {
! complain (&dwarf2_complex_location_expr);
! }
! else
! {
! complain (&dwarf2_invalid_attrib_class, "DW_AT_vtable_elem_location",
! fieldname);
! }
! }
}
/* Create the vector of member function fields, and attach it to the type. */
*************** read_common_block (struct die_info *die,
*** 2812,2818 ****
attr = dwarf_attr (die, DW_AT_location);
if (attr)
{
! base = decode_locdesc (DW_BLOCK (attr), objfile, cu_header);
}
if (die->has_children)
{
--- 2854,2876 ----
attr = dwarf_attr (die, DW_AT_location);
if (attr)
{
! /* Support the .debug_loc offsets */
! if (attr->form == DW_FORM_block1
! || attr->form == DW_FORM_block2
! || attr->form == DW_FORM_block4
! || attr->form == DW_FORM_block)
! {
! base = decode_locdesc (DW_BLOCK (attr), objfile, cu_header);
! }
! else if (attr->form == DW_FORM_data4 || attr->form == DW_FORM_data8)
! {
! complain (&dwarf2_complex_location_expr);
! }
! else
! {
! complain (&dwarf2_invalid_attrib_class, "DW_AT_location",
! "common block member");
! }
}
if (die->has_children)
{
*************** read_partial_die (struct partial_die_inf
*** 3458,3464 ****
part_die->highpc = DW_ADDR (&attr);
break;
case DW_AT_location:
! part_die->locdesc = DW_BLOCK (&attr);
break;
case DW_AT_language:
part_die->language = DW_UNSND (&attr);
--- 3516,3538 ----
part_die->highpc = DW_ADDR (&attr);
break;
case DW_AT_location:
! /* Support the .debug_loc offsets */
! if (attr.form == DW_FORM_block1
! || attr.form == DW_FORM_block2
! || attr.form == DW_FORM_block4
! || attr.form == DW_FORM_block)
! {
! part_die->locdesc = DW_BLOCK (&attr);
! }
! else if (attr.form == DW_FORM_data4 || attr.form == DW_FORM_data8)
! {
! complain (&dwarf2_complex_location_expr);
! }
! else
! {
! complain (&dwarf2_invalid_attrib_class, "DW_AT_location",
! "partial symbol information");
! }
break;
case DW_AT_language:
part_die->language = DW_UNSND (&attr);
*************** new_symbol (struct die_info *die, struct
*** 4522,4528 ****
char *name;
struct attribute *attr = NULL;
struct attribute *attr2 = NULL;
! CORE_ADDR addr;
name = dwarf2_linkage_name (die);
if (name)
--- 4596,4602 ----
char *name;
struct attribute *attr = NULL;
struct attribute *attr2 = NULL;
! CORE_ADDR addr = 0;
name = dwarf2_linkage_name (die);
if (name)
*************** new_symbol (struct die_info *die, struct
*** 4606,4613 ****
attr2 = dwarf_attr (die, DW_AT_external);
if (attr2 && (DW_UNSND (attr2) != 0))
{
! SYMBOL_VALUE_ADDRESS (sym) =
! decode_locdesc (DW_BLOCK (attr), objfile, cu_header);
add_symbol_to_list (sym, &global_symbols);
/* In shared libraries the address of the variable
--- 4680,4704 ----
attr2 = dwarf_attr (die, DW_AT_external);
if (attr2 && (DW_UNSND (attr2) != 0))
{
! /* Support the .debug_loc offsets */
! if (attr->form == DW_FORM_block1
! || attr->form == DW_FORM_block2
! || attr->form == DW_FORM_block4
! || attr->form == DW_FORM_block)
! {
! SYMBOL_VALUE_ADDRESS (sym) =
! decode_locdesc (DW_BLOCK (attr), objfile, cu_header);
! }
! else if (attr->form == DW_FORM_data4
! || attr->form == DW_FORM_data8)
! {
! complain (&dwarf2_complex_location_expr);
! }
! else
! {
! complain (&dwarf2_invalid_attrib_class, "DW_AT_location",
! "external variable");
! }
add_symbol_to_list (sym, &global_symbols);
/* In shared libraries the address of the variable
*************** new_symbol (struct die_info *die, struct
*** 4630,4637 ****
}
else
{
! SYMBOL_VALUE (sym) = addr =
! decode_locdesc (DW_BLOCK (attr), objfile, cu_header);
add_symbol_to_list (sym, list_in_scope);
if (optimized_out)
{
--- 4721,4746 ----
}
else
{
! /* Support the .debug_loc offsets */
! if (attr->form == DW_FORM_block1
! || attr->form == DW_FORM_block2
! || attr->form == DW_FORM_block4
! || attr->form == DW_FORM_block)
! {
! SYMBOL_VALUE (sym) = addr =
! decode_locdesc (DW_BLOCK (attr), objfile, cu_header);
! }
! else if (attr->form == DW_FORM_data4
! || attr->form == DW_FORM_data8)
! {
! complain (&dwarf2_complex_location_expr);
! }
! else
! {
! complain (&dwarf2_invalid_attrib_class, "DW_AT_location",
! "external variable");
! addr = 0;
! }
add_symbol_to_list (sym, list_in_scope);
if (optimized_out)
{