/****************************************
* Count the number of fields starting at firstIndex which are part of the
* same union as field[firstIndex]. If not a union, return 1.
*/
int AggregateDeclaration::numFieldsInUnion(int firstIndex)
{
VarDeclaration * vd = fields[firstIndex];
/* If it is a zero-length field, AND we can't find an earlier non-zero
* sized field with the same offset, we assume it's not part of a union.
*/
if (vd->size(loc) == 0 && !isUnionDeclaration() &&
firstFieldInUnion(firstIndex) == firstIndex)
return 1;
int count = 1;
for (size_t i = firstIndex+1; i < fields.dim; ++i)
{
VarDeclaration * v = fields[i];
// If offsets are different, they are not in the same union
if (v->offset != vd->offset)
break;
++count;
}
return count;
}
/****************************************
* If field[indx] is not part of a union, return indx.
* Otherwise, return the lowest field index of the union.
*/
int AggregateDeclaration::firstFieldInUnion(int indx)
{
if (isUnionDeclaration())
return 0;
VarDeclaration * vd = fields[indx];
int firstNonZero = indx; // first index in the union with non-zero size
for (; ;)
{
if (indx == 0)
return firstNonZero;
VarDeclaration * v = fields[indx - 1];
if (v->offset != vd->offset)
return firstNonZero;
--indx;
/* If it is a zero-length field, it's ambiguous: we don't know if it is
* in the union unless we find an earlier non-zero sized field with the
* same offset.
*/
if (v->size(loc) != 0)
firstNonZero = indx;
}
}