// return a constant array of type arrTypeD initialized with a constant value, or that constant value
LLConstant* FillSArrayDims(Type* arrTypeD, LLConstant* init)
{
if (arrTypeD->ty == Tsarray)
{
init = FillSArrayDims(arrTypeD->nextOf(), init);
size_t dim = static_cast<TypeSArray*>(arrTypeD)->dim->toUInteger();
LLArrayType* arrty = LLArrayType::get(init->getType(), dim);
return LLConstantArray::get(arrty, std::vector<LLConstant*>(dim, init));
}
return init;
}
// return a constant array of type arrTypeD initialized with a constant value,
// or that constant value
static llvm::Constant *FillSArrayDims(Type *arrTypeD, llvm::Constant *init) {
// Check whether we actually need to expand anything.
// KLUDGE: We don't have the initializer type here, so we can only check
// the size without doing an expensive recursive D <-> LLVM type comparison.
// The better way to solve this would be to just fix the initializer
// codegen in any place where a scalar initializer might still be generated.
if (gDataLayout->getTypeStoreSize(init->getType()) >= arrTypeD->size()) {
return init;
}
if (arrTypeD->ty == Tsarray) {
init = FillSArrayDims(arrTypeD->nextOf(), init);
size_t dim = static_cast<TypeSArray *>(arrTypeD)->dim->toUInteger();
llvm::ArrayType *arrty = llvm::ArrayType::get(init->getType(), dim);
return llvm::ConstantArray::get(arrty,
std::vector<llvm::Constant *>(dim, init));
}
return init;
}
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);
}
// 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();
for (auto bc : *cd->vtblInterfaces) {
constants.push_back(getInterfaceVtbl(bc, newinsts, inter_idx));
offset += Target::ptrsize;
inter_idx++;
if (populateInterfacesWithVtbls)
interfacesWithVtbls.push_back(bc);
}
}
}
AggrTypeBuilder b(false, offset);
b.addAggregate(decl, &explicitInitializers, AggrTypeBuilder::Aliases::Skip);
offset = b.currentOffset();
const size_t baseLLFieldIndex = constants.size();
const size_t numNewLLFields = b.defaultTypes().size();
constants.resize(constants.size() + numNewLLFields, nullptr);
// add explicit and non-overlapping implicit initializers
for (const auto &pair : b.varGEPIndices()) {
const auto field = pair.first;
const size_t fieldIndex = pair.second;
const auto explicitIt = explicitInitializers.find(field);
llvm::Constant *init = (explicitIt != explicitInitializers.end()
? explicitIt->second
: getDefaultInitializer(field));
constants[baseLLFieldIndex + fieldIndex] =
FillSArrayDims(field->type, init);
}
// zero out remaining padding fields
for (size_t i = 0; i < numNewLLFields; i++) {
auto &init = constants[baseLLFieldIndex + i];
if (!init)
init = llvm::Constant::getNullValue(b.defaultTypes()[i]);
}
}
std::vector<LLConstant*> DtoStructLiteralValues(const StructDeclaration* sd,
const std::vector<LLConstant*>& inits)
{
// get arrays
size_t nvars = sd->fields.dim;
VarDeclaration** vars = (VarDeclaration**)sd->fields.data;
assert(inits.size() == nvars);
// first locate all explicit initializers
std::vector<VarDeclaration*> explicitInits;
for (size_t i=0; i < nvars; i++)
{
if (inits[i])
{
explicitInits.push_back(vars[i]);
}
}
// vector of values to build aggregate from
std::vector<LLConstant*> values;
// offset trackers
size_t lastoffset = 0;
size_t lastsize = 0;
// index of next explicit init
size_t exidx = 0;
// number of explicit inits
size_t nex = explicitInits.size();
// for through each field and build up the struct, padding with zeros
size_t i;
for (i=0; i<nvars; i++)
{
VarDeclaration* var = vars[i];
// get var info
size_t os = var->offset;
size_t sz = var->type->size();
// get next explicit
VarDeclaration* nextVar = NULL;
size_t nextOs = 0;
if (exidx < nex)
{
nextVar = explicitInits[exidx];
nextOs = nextVar->offset;
}
// none, rest is defaults
else
{
break;
}
// not explicit initializer, default initialize if there is room, otherwise skip
if (!inits[i])
{
// default init if there is room
// (past current offset) and (small enough to fit before next explicit)
if ((os >= lastoffset + lastsize) && (os+sz <= nextOs))
{
// add any 0 padding needed before this field
if (os > lastoffset + lastsize)
{
//printf("1added %lu zeros\n", os - lastoffset - lastsize);
add_zeros(values, os - lastoffset - lastsize);
}
// get field default init
IrField* f = var->ir.irField;
assert(f);
values.push_back(f->getDefaultInit());
lastoffset = os;
lastsize = sz;
//printf("added default: %s : %lu (%lu)\n", var->toChars(), os, sz);
}
// skip
continue;
}
assert(nextVar == var);
LLConstant* init = FillSArrayDims(var->type, inits[i]);
values.push_back(init);
// update offsets
lastoffset = os;
// sometimes size of the initializer is less than size of the variable,
// so make sure that lastsize is correct
if (inits[i]->getType()->isSized())
sz = ceil(gDataLayout->getTypeSizeInBits(init->getType()) / 8.0);
lastsize = sz;
// go to next explicit init
exidx++;
//printf("added field: %s : %lu (%lu)\n", var->toChars(), os, sz);
}
// fill out rest with default initializers
LLType* structtype = DtoType(sd->type);
size_t structsize = getTypePaddedSize(structtype);
// FIXME: this could probably share some code with the above
if (structsize > lastoffset+lastsize)
{
for (/*continue from first loop*/; i < nvars; i++)
{
VarDeclaration* var = vars[i];
// get var info
size_t os = var->offset;
size_t sz = var->type->size();
// skip?
if (os < lastoffset + lastsize)
continue;
// add any 0 padding needed before this field
if (os > lastoffset + lastsize)
{
//printf("2added %lu zeros\n", os - lastoffset - lastsize);
add_zeros(values, os - lastoffset - lastsize);
}
// get field default init
IrField* f = var->ir.irField;
assert(f);
values.push_back(f->getDefaultInit());
lastoffset = os;
lastsize = sz;
//printf("2added default: %s : %lu (%lu)\n", var->toChars(), os, sz);
}
}
// add any 0 padding needed at the end of the literal
if (structsize > lastoffset+lastsize)
{
//printf("3added %lu zeros\n", structsize - lastoffset - lastsize);
add_zeros(values, structsize - lastoffset - lastsize);
}
return values;
}
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 ยง7.1.1. 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);
}
}
}
}
