diff options
Diffstat (limited to 'tccgen.c')
| -rw-r--r-- | tccgen.c | 51 |
1 files changed, 28 insertions, 23 deletions
@@ -3267,6 +3267,7 @@ static void struct_add_offset (Sym *s, int offset) static void struct_layout(CType *type, AttributeDef *ad) { int align, maxalign, offset, c, bit_pos, bt, prevbt; + int pcc = !tcc_state->ms_bitfields; Sym *f; if (ad->a.aligned) maxalign = ad->a.aligned; @@ -3280,13 +3281,12 @@ static void struct_layout(CType *type, AttributeDef *ad) int extra_bytes = 0; int typealign, bit_size; int size = type_size(&f->type, &typealign); - int pcc = !tcc_state->ms_bitfields; if (f->type.t & VT_BITFIELD) { bit_size = (f->type.t >> (VT_STRUCT_SHIFT + 6)) & 0x3f; /* without ms-bitfields, allocate the * minimum number of bytes necessary, * adding single bytes as needed */ - if (!tcc_state->ms_bitfields) { + if (0 && !tcc_state->ms_bitfields) { if (bit_pos == 0) /* minimum bytes for new bitfield */ size = (bit_size + 7) / 8; @@ -3311,55 +3311,59 @@ static void struct_layout(CType *type, AttributeDef *ad) } else { align = typealign; } - /*if (extra_bytes) c += extra_bytes; - else*/ if (bit_size < 0) { - int addbytes = pcc ? (bit_pos + 7) >> 3 : 0; + if (extra_bytes) c += extra_bytes; + else if (bit_size < 0) { + prevbt = VT_STRUCT; if (type->ref->type.t == TOK_STRUCT) { + int addbytes = pcc ? (bit_pos + 7) >> 3 : 0; c = (c + addbytes + align - 1) & -align; offset = c; if (size > 0) c += size; } else { + union_tail: offset = 0; - if (addbytes > c) - c = addbytes; if (size > c) c = size; } if (align > maxalign) maxalign = align; bit_pos = 0; - prevbt = VT_STRUCT; + } else if (type->ref->type.t != TOK_STRUCT) { + if (pcc) + size = (bit_size + 7) >> 3; + f->type.t = (f->type.t & ~(0x3f << VT_STRUCT_SHIFT)) + | (0 << VT_STRUCT_SHIFT); + goto union_tail; } else { /* A bit-field. Layout is more complicated. There are two options TCC implements: PCC compatible and MS compatible (PCC compatible is what GCC uses for almost all targets). */ - if (!bit_pos) { - if (type->ref->type.t == TOK_STRUCT) { - /* Don't align c here. That's only to be done - in certain cases. */ - offset = c; - } else { - offset = 0; - } - } if (pcc) { /* In PCC layout a non-packed bit-field is placed adjacent to the preceding bit-fields, except if it would overflow its container (depending on base type) or it's a zero-width bit-field. Packed non-zero-width bit-fields always are placed adjacent. */ - if ((typealign != 1 && - bit_pos + bit_size > size * 8) || - bit_size == 0) { + int ofs = (c * 8 + bit_pos) % (typealign * 8); + int ofs2 = ofs + bit_size + (typealign * 8) - 1; + /*if ((typealign != 1 && + //bit_pos + bit_size > size * 8) || + (((c + ((bit_pos + 7) >> 3) + typealign - 1) & -typealign) + != ((c + ((bit_pos + bit_size + 7) >> 3) + typealign - 1) & -typealign))) || + bit_size == 0 || + (bit_pos + bit_size > size * 8) + ) {*/ + if (bit_size == 0 || + (typealign != 1 && (ofs2 / (typealign * 8)) > ((size*8)/(typealign*8)))) { c = (c + ((bit_pos + 7) >> 3) + typealign - 1) & -typealign; - offset = c; bit_pos = 0; } + offset = c; /* In PCC layout named bit-fields influence the alignment of the containing struct using the base types alignment, except for packed fields or zero-width fields. */ - if (bit_size > 0) { + if (!(f->v & SYM_FIRST_ANOM)) { if (align > maxalign) maxalign = align; if (typealign > maxalign) @@ -3444,7 +3448,8 @@ static void struct_layout(CType *type, AttributeDef *ad) f->r = 0; } /* store size and alignment */ - type->ref->c = (c + ((bit_pos + 7) >> 3) + maxalign - 1) & -maxalign; + type->ref->c = (c + (pcc ? (bit_pos + 7) >> 3 : 0) + + maxalign - 1) & -maxalign; type->ref->r = maxalign; } |