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class.c (record_subobject_offsets): Don't record offsets past biggest empty class for non-empty base classes.

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* class.c (record_subobject_offsets): Don't record offsets past
	biggest empty class for non-empty base classes.
	(layout_class_type): Use TYPE_SIZE_UNIT, not TYPE_SIZE, when
	keeping track of the size of emptyclasses.

From-SVN: r106580
This commit is contained in:
Mark Mitchell 2005-11-07 03:47:34 +00:00 committed by Mark Mitchell
parent 405a3684f5
commit c0572427ed
2 changed files with 20 additions and 12 deletions
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5
gcc/cp/ChangeLog
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@ -1,5 +1,10 @@
2005-11-06 Mark Mitchell <mark@codesourcery.com>
* class.c (record_subobject_offsets): Don't record offsets past
biggest empty class for non-empty base classes.
(layout_class_type): Use TYPE_SIZE_UNIT, not TYPE_SIZE, when
keeping track of the size of emptyclasses.
PR c++/21308
* class.c (sizeof_biggest_empty_class): New variable.
(record_subobject_offsets): Don't record offsets past biggest

27
gcc/cp/class.c
View File

@ -3286,8 +3286,8 @@ walk_subobject_offsets (tree type,
return 0;
}
/* Record all of the empty subobjects of TYPE (located at OFFSET) in
OFFSETS. If IS_DATA_MEMBER is true, then a non-static data member
/* Record all of the empty subobjects of TYPE (either a type or a
binfo). If IS_DATA_MEMBER is true, then a non-static data member
is being placed at OFFSET; otherwise, it is a base class that is
being placed at OFFSET. */
@ -3298,19 +3298,21 @@ record_subobject_offsets (tree type,
bool is_data_member)
{
tree max_offset;
/* If recording subobjects for a non-static data member, do not need
to record offsets beyond the size of the biggest empty class.
Additional data members will go at the end of the class.
Additional base classes will go either at offset zero (if empty,
in which case they cannot overlap with offsets past the size of
the biggest empty class) or at the end of the class.
/* If recording subobjects for a non-static data member or a
non-empty base class , we do not need to record offsets beyond
the size of the biggest empty class. Additional data members
will go at the end of the class. Additional base classes will go
either at offset zero (if empty, in which case they cannot
overlap with offsets past the size of the biggest empty class) or
at the end of the class.
However, if we are placing an empty class, then we must record
However, if we are placing an empty base class, then we must record
all offsets, as either the empty class is at offset zero (where
other empty classes might later be placed) or at the end of the
class (where other objects might then be placed, so other empty
subobjects might later overlap). */
if (is_data_member)
if (is_data_member
|| !is_empty_class (BINFO_TYPE (type)))
max_offset = sizeof_biggest_empty_class;
else
max_offset = NULL_TREE;
@ -4850,8 +4852,9 @@ layout_class_type (tree t, tree *virtuals_p)
splay_tree_delete (empty_base_offsets);
if (CLASSTYPE_EMPTY_P (t)
&& tree_int_cst_lt (sizeof_biggest_empty_class, TYPE_SIZE (t)))
sizeof_biggest_empty_class = TYPE_SIZE (t);
&& tree_int_cst_lt (sizeof_biggest_empty_class,
TYPE_SIZE_UNIT (t)))
sizeof_biggest_empty_class = TYPE_SIZE_UNIT (t);
}
/* Determine the "key method" for the class type indicated by TYPE,