mirrors/binutils-gdb
0
0
Fork 0
mirror of https://sourceware.org/git/binutils-gdb.git synced 2025-01-18 22:13:40 +08:00
Code Issues Actions Packages Projects Releases Wiki Activity

Compute proper length for dynamic types of TYPE_CODE_TYPEDEF

Browse Source 
This patch fixes gdb/21356 in which we hit an assertion in
value_contents_bits_eq:

(gdb) p container_object2
(gdb) p container_object2
$1 = {_container_member2 = 15, _vla_struct_object2 = {_some_member = 0,
    _vla_field = {
../../src/gdb/value.c:829: internal-error: \
  int value_contents_bits_eq(const value*, int, const value*, int, int): \
  Assertion `offset1 + length \
             <= TYPE_LENGTH (val1->enclosing_type) * TARGET_CHAR_BIT' failed.

This is happening because TYPE_LENGTH (val1->enclosing_type) is erroneously
based on enclosing_type, which is a typedef, instead of the actual underlying
type.

This can be traced back to resolve_dynamic_struct, where the size of the
type is computed:
...
        TYPE_FIELD_TYPE (resolved_type, i)
          = resolve_dynamic_type_internal (TYPE_FIELD_TYPE (resolved_type, i),
                                           &pinfo, 0);
        gdb_assert (TYPE_FIELD_LOC_KIND (resolved_type, i)
                    == FIELD_LOC_KIND_BITPOS);

        new_bit_length = TYPE_FIELD_BITPOS (resolved_type, i);
        if (TYPE_FIELD_BITSIZE (resolved_type, i) != 0)
          new_bit_length += TYPE_FIELD_BITSIZE (resolved_type, i);
        else
          new_bit_length += (TYPE_LENGTH (TYPE_FIELD_TYPE (resolved_type, i))
                             * TARGET_CHAR_BIT);
...

In this function, resolved_type is TYPE_CODE_TYPEDEF which is not what we
want to use to calculate the size of the actual field.

This patch fixes this and the similar problem in resolve_dynamic_union.

gdb/ChangeLog:
2020-06-11  Keith Seitz  <keiths@redhat.com>

	PR gdb/21356
	* gdbtypes.c (resolve_dynamic_union, resolve_dynamic_struct):
	Resolve typedefs for type length calculations.

gdb/testsuite/ChangeLog:
2020-06-11  Keith Seitz  <keiths@redhat.com>

	PR gdb/21356
	* gdb.base/vla-datatypes.c (vla_factory): Add typedef for struct
	vla_struct.
	Add new struct vla_typedef and union vla_typedef_union and
	corresponding instantiation objects.
	Initialize new objects.
	* gdb.base/vla-datatypes.exp: Add tests for vla_typedef_struct_object
	and vla_typedef_union_object.
	Fixup type for vla_struct_object.
This commit is contained in:
Keith Seitz 2020-06-11 14:34:44 +02:00 committed by Tom de Vries
parent a8baf0a32b
commit 2f33032a93
5 changed files with 60 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
gdb/ChangeLog
View File

@ -1,3 +1,9 @@
2020-06-11 Keith Seitz <keiths@redhat.com>
PR gdb/21356
* gdbtypes.c (resolve_dynamic_union, resolve_dynamic_struct):
Resolve typedefs for type length calculations.
2020-06-10 Tom de Vries <tdevries@suse.de>
PR ada/24713

14
gdb/gdbtypes.c
View File

@ -2264,8 +2264,10 @@ resolve_dynamic_union (struct type *type,
t = resolve_dynamic_type_internal (resolved_type->field (i).type (),
addr_stack, 0);
resolved_type->field (i).set_type (t);
if (TYPE_LENGTH (t) > max_len)
max_len = TYPE_LENGTH (t);
struct type *real_type = check_typedef (t);
if (TYPE_LENGTH (real_type) > max_len)
max_len = TYPE_LENGTH (real_type);
}
TYPE_LENGTH (resolved_type) = max_len;
@ -2521,8 +2523,12 @@ resolve_dynamic_struct (struct type *type,
if (TYPE_FIELD_BITSIZE (resolved_type, i) != 0)
new_bit_length += TYPE_FIELD_BITSIZE (resolved_type, i);
else
new_bit_length += (TYPE_LENGTH (resolved_type->field (i).type ())
* TARGET_CHAR_BIT);
{
struct type *real_type
= check_typedef (resolved_type->field (i).type ());
new_bit_length += (TYPE_LENGTH (real_type) * TARGET_CHAR_BIT);
}
/* Normally, we would use the position and size of the last field
to determine the size of the enclosing structure. But GCC seems

12
gdb/testsuite/ChangeLog
View File

@ -1,3 +1,15 @@
2020-06-11 Keith Seitz <keiths@redhat.com>
PR gdb/21356
* gdb.base/vla-datatypes.c (vla_factory): Add typedef for struct
vla_struct.
Add new struct vla_typedef and union vla_typedef_union and
corresponding instantiation objects.
Initialize new objects.
* gdb.base/vla-datatypes.exp: Add tests for vla_typedef_struct_object
and vla_typedef_union_object.
Fixup type for vla_struct_object.
2020-06-11 Tom de Vries <tdevries@suse.de>
* lib/gdb.exp (with_override): New proc, factored out of ...

28
gdb/testsuite/gdb.base/vla-datatypes.c
View File

@ -50,7 +50,10 @@ vla_factory (int n)
{
int something;
int vla_field[n];
} vla_struct_object;
};
/* Define a typedef for a VLA structure. */
typedef struct vla_struct vla_struct_typedef;
vla_struct_typedef vla_struct_object;
struct inner_vla_struct
{
@ -59,14 +62,33 @@ vla_factory (int n)
int after;
} inner_vla_struct_object;
/* Define a structure which uses a typedef for the VLA field
to make sure that GDB creates the proper type for this field,
preventing a possible assertion failure (see gdb/21356). */
struct vla_struct_typedef_struct_member
{
int something;
vla_struct_typedef vla_object;
} vla_struct_typedef_struct_member_object;
union vla_union
{
int vla_field[n];
} vla_union_object;
/* Like vla_struct_typedef_struct_member but a union type. */
union vla_struct_typedef_union_member
{
int something;
vla_struct_typedef vla_object;
} vla_struct_typedef_union_member_object;
vla_struct_object.something = n;
inner_vla_struct_object.something = n;
inner_vla_struct_object.after = n;
vla_struct_typedef_struct_member_object.something = n * 2;
vla_struct_typedef_struct_member_object.vla_object.something = n * 3;
vla_struct_typedef_union_member_object.vla_object.something = n + 1;
for (i = 0; i < n; i++)
{
int_vla[i] = i*2;
@ -85,6 +107,10 @@ vla_factory (int n)
vla_struct_object.vla_field[i] = i*2;
vla_union_object.vla_field[i] = i*2;
inner_vla_struct_object.vla_field[i] = i*2;
vla_struct_typedef_struct_member_object.vla_object.vla_field[i]
= i * 3;
vla_struct_typedef_union_member_object.vla_object.vla_field[i]
= i * 3 - 1;
}
size_t int_size = sizeof(int_vla); /* vlas_filled */

6
gdb/testsuite/gdb.base/vla-datatypes.exp
View File

@ -45,6 +45,10 @@ gdb_test "print vla_struct_object" \
"\\\{something = 5, vla_field = \\\{0, 2, 4, 6, 8\\\}\\\}"
gdb_test "print vla_union_object" \
"\\\{vla_field = \\\{0, 2, 4, 6, 8\\\}\\\}"
gdb_test "print vla_struct_typedef_struct_member_object" \
"\\\{something = 10, vla_object = \\\{something = 15, vla_field = \\\{0, 3, 6, 9, 12\\\}\\\}\\\}"
gdb_test "print vla_struct_typedef_union_member_object" \
"\\\{something = 6, vla_object = \\\{something = 6, vla_field = \\\{-1, 2, 5, 8, 11\\\}\\\}\\\}"
# Check whatis of VLA's.
gdb_test "whatis int_vla" "type = int \\\[5\\\]"
@ -61,7 +65,7 @@ gdb_test "whatis unsigned_short_vla" \
gdb_test "whatis unsigned_char_vla" "type = unsigned char \\\[5\\\]"
gdb_test "whatis foo_vla" "type = struct foo \\\[5\\\]"
gdb_test "whatis bar_vla" "type = BAR \\\[5\\\]"
gdb_test "whatis vla_struct_object" "type = struct vla_struct"
gdb_test "whatis vla_struct_object" "type = vla_struct_typedef"
gdb_test "whatis vla_union_object" "type = union vla_union"
# Check ptype of VLA's.