diff options
| -rw-r--r-- | decl.c | 23 | ||||
| -rw-r--r-- | test/struct-packed.c | 9 | ||||
| -rw-r--r-- | test/struct-packed.qbe | 17 |
3 files changed, 42 insertions, 7 deletions
@@ -57,6 +57,7 @@ struct structbuilder { struct type *type; struct member **last; unsigned bits; /* number of bits remaining in the last byte */ + bool pack; }; struct decl * @@ -159,20 +160,24 @@ tagspec(struct scope *s) enum typekind kind; struct decl *d, *enumconsts; struct expr *e; + struct attr a; + enum attrkind allowedattr; struct structbuilder b; unsigned long long value, max, min; bool sign; int i; + allowedattr = 0; switch (tok.kind) { - case TSTRUCT: kind = TYPESTRUCT; break; - case TUNION: kind = TYPEUNION; break; - case TENUM: kind = TYPEENUM; break; + case TSTRUCT: kind = TYPESTRUCT, allowedattr |= ATTRPACKED; break; + case TUNION: kind = TYPEUNION; break; + case TENUM: kind = TYPEENUM; break; default: fatal("internal error: unknown tag kind"); } next(); - attr(NULL, 0); - gnuattr(NULL, 0); + a.kind = 0; + attr(&a, allowedattr); + gnuattr(&a, allowedattr); tag = NULL; t = NULL; et = NULL; @@ -216,12 +221,14 @@ tagspec(struct scope *s) b.type = t; b.last = &t->u.structunion.members; b.bits = 0; + b.pack = a.kind & ATTRPACKED; do structdecl(s, &b); while (tok.kind != TRBRACE); if (!t->u.structunion.members) error(&tok.loc, "struct/union has no members"); next(); - t->size = ALIGNUP(t->size, t->align); + if (!b.pack) + t->size = ALIGNUP(t->size, t->align); break; case TYPEENUM: enumconsts = NULL; @@ -795,7 +802,7 @@ addmember(struct structbuilder *b, struct qualtype mt, char *name, int align, un if (align < mt.type->align) { if (align) error(&tok.loc, "specified alignment of struct member is less strict than is required by type"); - align = mt.type->align; + align = b->pack ? 1 : mt.type->align; } if (t->kind == TYPESTRUCT) { m->offset = ALIGNUP(t->size, align); @@ -811,6 +818,8 @@ addmember(struct structbuilder *b, struct qualtype mt, char *name, int align, un error(&tok.loc, "bit-field has invalid type"); if (align) error(&tok.loc, "alignment specified for bit-field"); + if (b->pack) + error(&tok.loc, "bit-field in packed struct is not supported"); if (!width && name) error(&tok.loc, "bit-field with zero width must not have declarator"); if (width > mt.type->size * 8) diff --git a/test/struct-packed.c b/test/struct-packed.c new file mode 100644 index 0000000..d05bf91 --- /dev/null +++ b/test/struct-packed.c @@ -0,0 +1,9 @@ +struct [[gnu::packed]] { + char a; + long long b; + short c; +} s = {1, 2, 3}; + +int main(void) { + return s.a + s.b - s.c; +} diff --git a/test/struct-packed.qbe b/test/struct-packed.qbe new file mode 100644 index 0000000..ee79301 --- /dev/null +++ b/test/struct-packed.qbe @@ -0,0 +1,17 @@ +export data $s = align 1 { b 1, l 2, h 3, } +export +function w $main() { +@start.1 +@body.2 + %.1 =l add $s, 0 + %.2 =w loadsb %.1 + %.3 =l extsb %.2 + %.4 =l add $s, 1 + %.5 =l loadl %.4 + %.6 =l add %.3, %.5 + %.7 =l add $s, 9 + %.8 =w loadsh %.7 + %.9 =l extsh %.8 + %.10 =l sub %.6, %.9 + ret %.10 +} |