llvm::Constant * IrField::getDefaultInit()
{
if (constInit)
return constInit;
constInit = get_default_initializer(V, V->init);
return constInit;
}
void IrStruct::addBaseClassInits(
std::vector<llvm::Constant*>& constants,
ClassDeclaration* base,
size_t& offset,
size_t& field_index)
{
if (base->baseClass)
{
addBaseClassInits(constants, base->baseClass, offset, field_index);
}
IrTypeClass* tc = stripModifiers(base->type)->irtype->isClass();
assert(tc);
// go through fields
IrTypeAggr::iterator it;
for (it = tc->def_begin(); it != tc->def_end(); ++it)
{
VarDeclaration* vd = *it;
IF_LOG Logger::println("Adding default field %s %s (+%u)", vd->type->toChars(), vd->toChars(), vd->offset);
LOG_SCOPE;
assert(vd->offset >= offset && "default fields not sorted by offset");
// get next aligned offset for this type
size_t alignedoffset = realignOffset(offset, vd->type);
// insert explicit padding?
if (alignedoffset < vd->offset)
{
add_zeros(constants, vd->offset - alignedoffset);
}
// add default type
constants.push_back(get_default_initializer(vd, vd->init));
// advance offset to right past this field
offset = vd->offset + vd->type->size();
}
// has interface vtbls?
if (base->vtblInterfaces && base->vtblInterfaces->dim > 0)
{
// false when it's not okay to use functions from super classes
bool newinsts = (base == aggrdecl->isClassDeclaration());
size_t inter_idx = interfacesWithVtbls.size();
offset = (offset + PTRSIZE - 1) & ~(PTRSIZE - 1);
ArrayIter<BaseClass> it2(*base->vtblInterfaces);
for (; !it2.done(); it2.next())
{
BaseClass* b = it2.get();
constants.push_back(getInterfaceVtbl(b, newinsts, inter_idx));
offset += PTRSIZE;
// add to the interface list
interfacesWithVtbls.push_back(b);
inter_idx++;
}
}
}
void IrAggr::addFieldInitializers(
llvm::SmallVectorImpl<llvm::Constant*>& constants,
const VarInitMap& explicitInitializers,
AggregateDeclaration* decl,
unsigned& offset,
bool populateInterfacesWithVtbls
)
{
if (ClassDeclaration* cd = decl->isClassDeclaration())
{
if (cd->baseClass)
{
addFieldInitializers(constants, explicitInitializers,
cd->baseClass, offset, populateInterfacesWithVtbls);
}
}
// Build up vector with one-to-one mapping to field indices.
const size_t n = decl->fields.dim;
llvm::SmallVector<VarInitConst, 16> data(n);
// Fill in explicit initializers.
for (size_t i = 0; i < n; ++i)
{
VarDeclaration* vd = decl->fields[i];
VarInitMap::const_iterator expl = explicitInitializers.find(vd);
if (expl != explicitInitializers.end())
data[i] = *expl;
}
// Fill in implicit initializers
for (size_t i = 0; i < n; i++)
{
if (data[i].first) continue;
VarDeclaration* vd = decl->fields[i];
/* Skip void initializers for unions. DMD bug 3991:
union X
{
int a = void;
dchar b = 'a';
}
*/
if (decl->isUnionDeclaration() && vd->init && vd->init->isVoidInitializer())
continue;
unsigned vd_begin = vd->offset;
unsigned vd_end = vd_begin + vd->type->size();
/* Skip zero size fields like zero-length static arrays, LDC issue 812:
class B {
ubyte[0] test;
}
*/
if (vd_begin == vd_end)
continue;
// make sure it doesn't overlap any explicit initializers.
bool overlaps = false;
if (type->ty == Tstruct)
{
// Only structs and unions can have overlapping fields.
for (size_t j = 0; j < n; ++j)
{
if (i == j || !data[j].first)
continue;
VarDeclaration* it = decl->fields[j];
unsigned f_begin = it->offset;
unsigned f_end = f_begin + it->type->size();
if (vd_begin >= f_end || vd_end <= f_begin)
continue;
overlaps = true;
break;
}
}
// add if no overlap found
if (!overlaps)
{
IF_LOG Logger::println("Implicit initializer: %s @+%u", vd->toChars(), vd->offset);
LOG_SCOPE;
data[i].first = vd;
data[i].second = get_default_initializer(vd, NULL);
}
}
// Sort data array by offset.
// TODO: Figure out whether this is really necessary, fields should already
// be in offset order. Not having do do this would mean we could use a plain
// llvm::Constant* vector for initializers and avoid all the VarInitConst business.
std::sort(data.begin(), data.end(), struct_init_data_sort);
// build array of constants and make sure explicit zero padding is inserted when necessary.
for (size_t i = 0; i < n; i++)
{
VarDeclaration* vd = data[i].first;
if (vd == NULL)
continue;
// Explicitly zero the padding as per TDPL §7.1.1. Otherwise, it would
// be left uninitialized by LLVM.
if (offset < vd->offset)
{
add_zeros(constants, offset, vd->offset);
offset = vd->offset;
}
IF_LOG Logger::println("adding field %s", vd->toChars());
constants.push_back(FillSArrayDims(vd->type, data[i].second));
offset += getMemberSize(vd->type);
}
if (ClassDeclaration* cd = decl->isClassDeclaration())
{
// has interface vtbls?
if (cd->vtblInterfaces && cd->vtblInterfaces->dim > 0)
{
// Align interface infos to pointer size.
unsigned aligned = (offset + Target::ptrsize - 1) & ~(Target::ptrsize - 1);
if (offset < aligned)
{
add_zeros(constants, offset, aligned);
offset = aligned;
}
// false when it's not okay to use functions from super classes
bool newinsts = (cd == aggrdecl->isClassDeclaration());
size_t inter_idx = interfacesWithVtbls.size();
offset = (offset + Target::ptrsize - 1) & ~(Target::ptrsize - 1);
for (BaseClasses::iterator I = cd->vtblInterfaces->begin(),
E = cd->vtblInterfaces->end();
I != E; ++I)
{
constants.push_back(getInterfaceVtbl(*I, newinsts, inter_idx));
offset += Target::ptrsize;
inter_idx++;
if (populateInterfacesWithVtbls)
interfacesWithVtbls.push_back(*I);
}
}
}
}
