diff options
Diffstat (limited to 'tccgen.c')
| -rw-r--r-- | tccgen.c | 30 |
1 files changed, 23 insertions, 7 deletions
@@ -3154,7 +3154,7 @@ static void parse_attribute(AttributeDef *ad) /* enum/struct/union declaration. u is either VT_ENUM or VT_STRUCT */ static void struct_decl(CType *type, AttributeDef *ad, int u) { - int a, v, size, align, maxalign, c, offset, flexible; + int a, v, size, align, maxalign, c, offset, flexible, extra_bytes; int bit_size, bit_pos, bsize, bt, lbit_pos, prevbt; Sym *s, *ss, *ass, **ps; AttributeDef ad1; @@ -3235,6 +3235,7 @@ static void struct_decl(CType *type, AttributeDef *ad, int u) while (tok != '}') { parse_btype(&btype, &ad1); while (1) { + extra_bytes = 0; if (flexible) tcc_error("flexible array member '%s' not at the end of struct", get_tok_str(v, NULL)); @@ -3310,9 +3311,9 @@ static void struct_decl(CType *type, AttributeDef *ad, int u) /* zero size: means to pad */ bit_pos = 0; } else { - /* we do not have enough room ? - did the type change? - is it a union? */ + /* if type change, union, or will overrun + * allignment slot, start at a newly + * alligned slot */ if ((bit_pos + bit_size) > bsize || bt != prevbt || a == TOK_UNION) bit_pos = 0; @@ -3322,15 +3323,30 @@ static void struct_decl(CType *type, AttributeDef *ad, int u) (bit_pos << VT_STRUCT_SHIFT) | (bit_size << (VT_STRUCT_SHIFT + 6)); bit_pos += bit_size; + /* without ms-bitfields, allocate the + * minimum number of bytes necessary, + * adding single bytes as needed */ + if (!tcc_state->ms_bitfields) { + if (lbit_pos == 0) + /* minimum bytes for new bitfield */ + size = (bit_size + 7) / 8; + else { + /* enough spare bits already allocated? */ + bit_size = (lbit_pos - 1) % 8 + 1 + bit_size; + if (bit_size > 8) /* doesn't fit */ + extra_bytes = (bit_size - 1) / 8; + } + } } prevbt = bt; } else { bit_pos = 0; } if (v != 0 || (type1.t & VT_BTYPE) == VT_STRUCT) { - /* add new memory data only if starting - bit field */ - if (lbit_pos == 0) { + /* add new memory data only if starting bit + field or adding bytes to existing bit field */ + if (extra_bytes) c += extra_bytes; + else if (lbit_pos == 0) { if (a == TOK_STRUCT) { c = (c + align - 1) & -align; offset = c; |