diff options
Diffstat (limited to 'gcc/cp/class.c')
| -rw-r--r-- | gcc/cp/class.c | 55 |
1 files changed, 31 insertions, 24 deletions
diff --git a/gcc/cp/class.c b/gcc/cp/class.c index 789ce45..fe636a2 100644 --- a/gcc/cp/class.c +++ b/gcc/cp/class.c @@ -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; } |