llvm::Type* IrTypeClass::buildType()
{
IF_LOG Logger::println("Building class type %s @ %s", cd->toPrettyChars(), cd->loc.toChars());
LOG_SCOPE;
IF_LOG Logger::println("Instance size: %u", cd->structsize);
// find the fields that contribute to the default initializer.
// these will define the default type.
std::vector<llvm::Type*> defaultTypes;
defaultTypes.reserve(32);
// add vtbl
defaultTypes.push_back(llvm::PointerType::get(vtbl_type, 0));
// interfaces are just a vtable
if (cd->isInterfaceDeclaration())
{
num_interface_vtbls = cd->vtblInterfaces ? cd->vtblInterfaces->dim : 0;
}
// classes have monitor and fields
else
{
// add monitor
defaultTypes.push_back(llvm::PointerType::get(llvm::Type::getInt8Ty(gIR->context()), 0));
// we start right after the vtbl and monitor
size_t offset = PTRSIZE * 2;
size_t field_index = 2;
// add data members recursively
addBaseClassData(defaultTypes, cd, offset, field_index);
#if 1
// tail padding?
if (offset < cd->structsize)
{
field_index += add_zeros(defaultTypes, cd->structsize - offset);
offset = cd->structsize;
}
#endif
}
// errors are fatal during codegen
if (global.errors)
fatal();
// set struct body
isaStruct(type)->setBody(defaultTypes, false);
// VTBL
// set vtbl type body
vtbl_type->setBody(buildVtblType(ClassDeclaration::classinfo->type, &cd->vtbl));
IF_LOG Logger::cout() << "class type: " << *type << std::endl;
return get();
}
void IrTypeClass::addClassData(AggrTypeBuilder &builder,
ClassDeclaration *currCd) {
// First, recursively add the fields for our base class and interfaces, if
// any.
if (currCd->baseClass) {
addClassData(builder, currCd->baseClass);
}
if (currCd->vtblInterfaces && currCd->vtblInterfaces->dim > 0) {
// KLUDGE: The first pointer in the vtbl will be of type object.Interface;
// extract that from the "well-known" object.TypeInfo_Class definition.
// For C++ interfaces, this vtbl entry has to be omitted
const auto interfaceArrayType = Type::typeinfoclass->fields[3]->type;
const auto interfacePtrType = interfaceArrayType->nextOf()->pointerTo();
builder.alignCurrentOffset(Target::ptrsize);
for (auto b : *currCd->vtblInterfaces) {
IF_LOG Logger::println("Adding interface vtbl for %s",
b->sym->toPrettyChars());
FuncDeclarations arr;
b->fillVtbl(cd, &arr, currCd == cd);
// add to the interface map
addInterfaceToMap(b->sym, builder.currentFieldIndex());
Type* first = b->sym->isCPPinterface() ? nullptr : interfacePtrType;
const auto ivtblType =
llvm::StructType::get(gIR->context(), buildVtblType(first, &arr));
builder.addType(llvm::PointerType::get(ivtblType, 0), Target::ptrsize);
++num_interface_vtbls;
}
}
// Finally, the data members for this class.
builder.addAggregate(currCd);
}
void IrTypeClass::addBaseClassData(
std::vector<llvm::Type *> & defaultTypes,
ClassDeclaration * base,
size_t & offset,
size_t & field_index)
{
if (base->baseClass)
{
addBaseClassData(defaultTypes, base->baseClass, offset, field_index);
}
// FIXME: merge code with structs in IrTypeAggr
// mirror the sd->fields array but only fill in contributors
size_t n = base->fields.dim;
LLSmallVector<VarDeclaration*, 16> data(n, NULL);
default_fields.reserve(n);
// first fill in the fields with explicit initializers
VarDeclarationIter field_it(base->fields);
for (; field_it.more(); field_it.next())
{
// init is !null for explicit inits
if (field_it->init != NULL)
{
IF_LOG Logger::println("adding explicit initializer for struct field %s",
field_it->toChars());
data[field_it.index] = *field_it;
size_t f_begin = field_it->offset;
size_t f_end = f_begin + field_it->type->size();
// make sure there is no overlap
for (size_t i = 0; i < field_it.index; i++)
{
if (data[i] != NULL)
{
VarDeclaration* vd = data[i];
size_t v_begin = vd->offset;
size_t v_end = v_begin + vd->type->size();
if (v_begin >= f_end || v_end <= f_begin)
continue;
base->error(vd->loc, "has overlapping initialization for %s and %s",
field_it->toChars(), vd->toChars());
}
}
}
}
if (global.errors)
{
fatal();
}
// fill in default initializers
field_it = VarDeclarationIter(base->fields);
for (;field_it.more(); field_it.next())
{
if (data[field_it.index])
continue;
size_t f_begin = field_it->offset;
size_t f_end = f_begin + field_it->type->size();
// make sure it doesn't overlap anything explicit
bool overlaps = false;
for (size_t i = 0; i < n; i++)
{
if (data[i])
{
size_t v_begin = data[i]->offset;
size_t v_end = v_begin + data[i]->type->size();
if (v_begin >= f_end || v_end <= f_begin)
continue;
overlaps = true;
break;
}
}
// if no overlap was found, add the default initializer
if (!overlaps)
{
IF_LOG Logger::println("adding default initializer for struct field %s",
field_it->toChars());
data[field_it.index] = *field_it;
}
}
// ok. now we can build a list of llvm types. and make sure zeros are inserted if necessary.
// first we sort the list by offset
std::sort(data.begin(), data.end(), var_offset_sort_cb);
// add types to list
for (size_t i = 0; i < n; i++)
{
VarDeclaration* vd = data[i];
if (vd == NULL)
continue;
assert(vd->offset >= offset && "it's a bug... most likely DMD bug 2481");
// add to default field list
if (cd == base)
default_fields.push_back(vd);
// get next aligned offset for this type
size_t alignedoffset = realignOffset(offset, vd->type);
// insert explicit padding?
if (alignedoffset < vd->offset)
{
field_index += add_zeros(defaultTypes, vd->offset - alignedoffset);
}
// add default type
defaultTypes.push_back(DtoType(vd->type));
// advance offset to right past this field
offset = vd->offset + vd->type->size();
// create ir field
vd->aggrIndex = (unsigned)field_index;
++field_index;
}
// any interface implementations?
if (base->vtblInterfaces && base->vtblInterfaces->dim > 0)
{
bool new_instances = (base == cd);
ArrayIter<BaseClass> it2(*base->vtblInterfaces);
VarDeclarationIter interfaces_idx(ClassDeclaration::classinfo->fields, 3);
Type* first = interfaces_idx->type->nextOf()->pointerTo();
// align offset
offset = (offset + PTRSIZE - 1) & ~(PTRSIZE - 1);
for (; !it2.done(); it2.next())
{
BaseClass* b = it2.get();
IF_LOG Logger::println("Adding interface vtbl for %s", b->base->toPrettyChars());
FuncDeclarations arr;
b->fillVtbl(cd, &arr, new_instances);
llvm::Type* ivtbl_type = llvm::StructType::get(gIR->context(), buildVtblType(first, &arr));
defaultTypes.push_back(llvm::PointerType::get(ivtbl_type, 0));
offset += PTRSIZE;
// add to the interface map
addInterfaceToMap(b->base, field_index);
field_index++;
// inc count
num_interface_vtbls++;
}
}
#if 0
// tail padding?
if (offset < base->structsize)
{
field_index += add_zeros(defaultTypes, base->structsize - offset);
offset = base->structsize;
}
#endif
}
IrTypeClass *IrTypeClass::get(ClassDeclaration *cd) {
const auto t = new IrTypeClass(cd);
cd->type->ctype = t;
IF_LOG Logger::println("Building class type %s @ %s", cd->toPrettyChars(),
cd->loc.toChars());
LOG_SCOPE;
IF_LOG Logger::println("Instance size: %u", cd->structsize);
// This class may contain an align declaration. See GitHub #726.
t->packed = false;
for (auto base = cd; base != nullptr && !t->packed; base = base->baseClass) {
t->packed = isPacked(base);
}
AggrTypeBuilder builder(t->packed);
// add vtbl
builder.addType(llvm::PointerType::get(t->vtbl_type, 0), Target::ptrsize);
if (cd->isInterfaceDeclaration()) {
// interfaces are just a vtable
t->num_interface_vtbls = cd->vtblInterfaces ? cd->vtblInterfaces->dim : 0;
} else {
// classes have monitor and fields
if (!cd->isCPPclass() && !cd->isCPPinterface()) {
// add monitor
builder.addType(
llvm::PointerType::get(llvm::Type::getInt8Ty(gIR->context()), 0),
Target::ptrsize);
}
// add data members recursively
t->addClassData(builder, cd);
// add tail padding
builder.addTailPadding(cd->structsize);
}
if (global.errors) {
fatal();
}
// set struct body and copy GEP indices
isaStruct(t->type)->setBody(builder.defaultTypes(), t->packed);
t->varGEPIndices = builder.varGEPIndices();
// set vtbl type body
FuncDeclarations vtbl;
vtbl.reserve(cd->vtbl.dim);
if (!cd->isCPPclass())
vtbl.push(nullptr);
for (size_t i = cd->vtblOffset(); i < cd->vtbl.dim; ++i) {
FuncDeclaration *fd = cd->vtbl[i]->isFuncDeclaration();
assert(fd);
vtbl.push(fd);
}
Type* first = cd->isCPPclass() ? nullptr : Type::typeinfoclass->type;
t->vtbl_type->setBody(t->buildVtblType(first, &vtbl));
IF_LOG Logger::cout() << "class type: " << *t->type << std::endl;
return t;
}