mirror/gcc
2
0
Fork 0
mirror of git://gcc.gnu.org/git/gcc.git synced 2025-03-09 23:07:27 +08:00
Code Issues Packages Projects Releases Wiki Activity

class.c (layout_empty_base): Handle empty bases with non-byte alignment.

Browse Source 
* class.c (layout_empty_base): Handle empty bases with non-byte
	alignment.
	(build_base_field): Likewise.
	(layout_virtual_bases): Likewise.

	* class.c (finish_struct_1): Fix typo in this change:

	Sat Mar 25 09:12:10 2000  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>

From-SVN: r32750
This commit is contained in:
Mark Mitchell 2000-03-26 18:57:57 +00:00 committed by Mark Mitchell
parent a69beca121
commit ec386958da
2 changed files with 42 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
gcc/cp/ChangeLog
View File

@ -1,3 +1,14 @@
2000-03-26 Mark Mitchell <mark@codesourcery.com>
* class.c (layout_empty_base): Handle empty bases with non-byte
alignment.
(build_base_field): Likewise.
(layout_virtual_bases): Likewise.
* class.c (finish_struct_1): Fix typo in this change:
Sat Mar 25 09:12:10 2000 Richard Kenner <kenner@vlsi1.ultra.nyu.edu>
2000-03-25 Mark Mitchell <mark@codesourcery.com>
* decl.c (grokdeclarator): Count partial specializations when

55
gcc/cp/class.c
View File

@ -4267,8 +4267,9 @@ layout_nonempty_base_or_field (rli, decl, binfo, v)
}
/* Layout the empty base BINFO. EOC indicates the byte currently just
past the end of the class; BINFO_OFFSETS gives the offsets of the
other bases allocated so far. */
past the end of the class, and should be correctly aligned for a
class of the type indicated by BINFO; BINFO_OFFSETS gives the
offsets of the other bases allocated so far. */
static void
layout_empty_base (binfo, eoc, binfo_offsets)
@ -4276,16 +4277,12 @@ layout_empty_base (binfo, eoc, binfo_offsets)
tree eoc;
varray_type binfo_offsets;
{
tree alignment;
tree basetype = BINFO_TYPE (binfo);
/* This routine should only be used for empty classes. */
my_friendly_assert (is_empty_class (basetype), 20000321);
/* This code assumes that zero-sized classes have one-byte
alignment. There might someday be a system where that's not
true. */
my_friendly_assert (TYPE_ALIGN (basetype) == BITS_PER_UNIT,
20000314);
alignment = ssize_int (CLASSTYPE_ALIGN (basetype));
/* This is an empty base class. We first try to put it at offset
zero. */
@ -4301,7 +4298,7 @@ layout_empty_base (binfo, eoc, binfo_offsets)
break;
/* There's overlap here, too. Bump along to the next spot. */
propagate_binfo_offsets (binfo, ssize_int (1));
propagate_binfo_offsets (binfo, alignment);
}
}
}
@ -4360,7 +4357,15 @@ build_base_field (rli, binfo, empty_p, base_align, v)
layout_nonempty_base_or_field (rli, decl, binfo, *v);
}
else
layout_empty_base (binfo, rli_size_unit_so_far (rli), *v);
{
unsigned HOST_WIDE_INT eoc;
/* On some platforms (ARM), even empty classes will not be
byte-aligned. */
eoc = tree_low_cst (rli_size_unit_so_far (rli), 0);
eoc = CEIL (eoc, DECL_ALIGN (decl)) * DECL_ALIGN (decl);
layout_empty_base (binfo, size_int (eoc), *v);
}
/* Check for inaccessible base classes. If the same base class
appears more than once in the hierarchy, but isn't virtual, then
@ -4847,6 +4852,19 @@ layout_virtual_bases (t, base_offsets)
basetype = BINFO_TYPE (vbase);
if (flag_new_abi)
desired_align = CLASSTYPE_ALIGN (basetype);
else
/* Under the old ABI, virtual bases were aligned as for the
entire base object (including its virtual bases). That's
wasteful, in general. */
desired_align = TYPE_ALIGN (basetype);
TYPE_ALIGN (t) = MAX (TYPE_ALIGN (t), desired_align);
/* Add padding so that we can put the virtual base class at an
appropriately aligned offset. */
dsize = CEIL (dsize, desired_align) * desired_align;
/* Under the new ABI, we try to squish empty virtual bases in
just like ordinary empty bases. */
if (flag_new_abi && is_empty_class (basetype))
@ -4855,18 +4873,6 @@ layout_virtual_bases (t, base_offsets)
*base_offsets);
else
{
if (flag_new_abi)
desired_align = CLASSTYPE_ALIGN (basetype);
else
/* Under the old ABI, virtual bases were aligned as for
the entire base object (including its virtual bases).
That's wasteful, in general. */
desired_align = TYPE_ALIGN (basetype);
TYPE_ALIGN (t) = MAX (TYPE_ALIGN (t), desired_align);
/* Add padding so that we can put the virtual base class at an
appropriately aligned offset. */
dsize = CEIL (dsize, desired_align) * desired_align;
/* And compute the offset of the virtual base. */
propagate_binfo_offsets (vbase,
ssize_int (CEIL (dsize, BITS_PER_UNIT)));
@ -5262,14 +5268,15 @@ finish_struct_1 (t)
if (vfield != NULL_TREE
&& DECL_FIELD_CONTEXT (vfield) != t)
{
tree binfo = get_binfo (DECL_FIELD_CONTEXT (vfield), t, 0);
vfield = copy_node (vfield);
copy_lang_decl (vfield);
DECL_FIELD_CONTEXT (vfield) = t;
DECL_FIELD_OFFSET (vfield)
= size_binop (PLUS_EXPR,
BINFO_OFFSET (get_binfo (DECL_FIELD_CONTEXT (vfield),
t, 0)),
BINFO_OFFSET (binfo),
DECL_FIELD_OFFSET (vfield));
TYPE_VFIELD (t) = vfield;
}