/* vim: set ts=4 sw=4 tw=99 et:

  *

  * Copyright (C) 2012 David Anderson

  *

  * This file is part of SourcePawn.

  *

  * SourcePawn is free software: you can redistribute it and/or modify it under

  * the terms of the GNU General Public License as published by the Free

  * Software Foundation, either version 3 of the License, or (at your option)

  * any later version.

  * 

  * SourcePawn is distributed in the hope that it will be useful, but WITHOUT ANY

  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

  * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

  *

  * You should have received a copy of the GNU General Public License along with

  * SourcePawn. If not, see http://www.gnu.org/licenses/.

  */

 #include <string.h>

 #include "Structures.h"

 #include "Zone.h"

 #include "Types.h"

 #include "Array.h"

 #include "Spaces-inl.h"

 #include "Heap-inl.h"

 using namespace ke;

 StructureBufferBuilder::StructureBufferBuilder()

   : size_(0)

 {

 }

 bool

 StructureBufferBuilder::add(Handle<Type> type, unsigned *offset)

 {

     *offset = size_;

     if (!type->isTraceable()) {

         // For now, assume the alignment of all primitive storage is 4 bytes,

         // and that all need <= 4 bytes of storage.

         assert(type->isInt32() ||

                type->isFloat() ||

                type->isBool() ||

                type->isChar() ||

                type->isEnum());

         size_ += 4;

         return true;

     }

     if (!offsets_.append(size_))

         return false;

     size_ += sizeof(Object *);

     return true;

 }

 Descriptor *

 Descriptor::New(Zone *zone, Handle<String> name, Handle<Type> type)

 {

     Local<Descriptor> desc(zone,

         Descriptor::cast(zone->allocate(MapKind_Descriptor, sizeof(Descriptor), Heap::Tenure_Old)));

     if (!desc)

         return NULL;

     desc->name_ = name;

     desc->type_ = type;

     desc->offset_ = unsigned(-1);

     return desc;

 }

 StructMap *

 StructMap::New(Zone *zone, const StructureBufferBuilder &builder, Handle<StructType> type)

 {

     Vector<unsigned> composedIndexes;

     for (size_t i = 0; i < type->fields()->length(); i++) {

         Descriptor *desc = Descriptor::cast(type->fields()->at(i));

         if (desc->type()->isArray() || desc->type()->isStruct()) {

             if (!composedIndexes.append(i))

                 return NULL;

         }

     }

     Local<FixedArray> composed(zone, FixedArray::New(zone, composedIndexes.length(), Heap::Tenure_Old));

     if (!composed)

         return NULL;

     for (size_t i = 0; i < composedIndexes.length(); i++) {

         Descriptor *desc = Descriptor::cast(type->fields()->at(composedIndexes[i]));

         composed->set(zone, i, desc);

     }

     size_t bytesNeeded = sizeof(StructMap) +

                          (builder.traceableOffsetCount() * sizeof(unsigned));

     Local<StructMap> map(zone);

     map = StructMap::cast(zone->allocateMap(MapKind_Struct, bytesNeeded, MapKind_MetaStruct));

     if (!map)

         return NULL;

     map->structureSize_ = builder.structureSize();

     map->traceOffsetCount_ = builder.traceableOffsetCount();

     map->type_ = type;

     map->composed_ = composed;

     memcpy(const_cast<unsigned *>(map->traceOffsets()), builder.offsets(),

            sizeof(unsigned) * builder.traceableOffsetCount());

     return map;

 }

 Struct *

 Struct::New(Zone *zone, Handle<StructMap> map, Heap::Tenure tenure)

 {

     size_t bytesNeeded = sizeof(Struct) + map->structureSize();

     Local<Struct> obj(zone, Struct::cast(zone->allocate(map, bytesNeeded, tenure)));

     if (!obj)

         return NULL;

     memset((Struct *)obj + 1, 0, map->structureSize());

     // Initialize any sub-structures. Right now, this is performed as part of

     // struct allocation, rather than inlined in bytecode, for simplicity.

     if (map->composed()) {

         Local<Descriptor> desc(zone);

         Local<Object> child(zone);

         Local<StructMap> childStructMap(zone);

         Local<ArrayMap> childArrayMap(zone);

         for (unsigned i = 0; i < map->composed()->length(); i++) {

             desc = Descriptor::cast(map->composed()->at(i));

             if (desc->type()->isStruct()) {

                 childStructMap = StructMap::cast(StructType::cast(desc->type())->newMap());

                 child = Struct::New(zone, childStructMap, tenure);

             } else if (desc->type()->isArray()) {

                 // :TODO: don't create empty arrays for ref slots here.

                 // Instead, make a separate Initialize function, so we

                 // can avoid double-creating arrays for module globals.

                 //  (const char:x[] = "x")

                 ArrayType *type = ArrayType::cast(desc->type());

                 childArrayMap = ArrayMap::cast(type->newMap());

                 if (type->isFixedLength())

                     child = Array::NewFixed(zone, childArrayMap, tenure);

                 else

                     child = Array::NewEmpty(zone, childArrayMap, tenure);

             }

             if (!child)

                 return NULL;

             obj->set(zone, desc, child);

         }

     }

     return obj;

 }

 bool

 Struct::Copy(Zone *zone, Handle<Struct> left, Handle<Struct> right)

 {

     assert(left->map()->type() == right->map()->type());

     Local<StructType> type(zone, StructType::cast(left->map()->type()));

     Local<Struct> leftStruct(zone);

     Local<Struct> rightStruct(zone);

     Local<Array> leftArray(zone);

     Local<Array> rightArray(zone);

     for (unsigned i = 0; i < type->fields()->length(); i++) {

         Descriptor *desc = Descriptor::cast(type->fields()->at(i));

         // If the field is a struct, we need to deep-copy.

         if (desc->type()->isStruct()) {

             leftStruct = Struct::cast(left->get<Object *>(desc));

             rightStruct = Struct::cast(right->get<Object *>(desc));

             if (!Struct::Copy(zone, leftStruct, rightStruct))

                 return false;

         } else if (desc->type()->isArray()) {

             leftArray = Array::cast(left->get<Object *>(desc));

             rightArray = Array::cast(right->get<Object *>(desc));

             if (!Array::ShallowCopy(zone, leftArray, rightArray))

                 return false;

         } else if (desc->type()->isTraceable()) {

             Object *obj = right->get<Object *>(desc);

             left->set(zone, desc, obj);

         } else {

             switch (desc->type()->pod()) {

               case PrimitiveType_Int32:

               case PrimitiveType_Char:

               case PrimitiveType_Bool:

                 left->set(desc, right->get<int>(desc));

                 break;

               case PrimitiveType_Float:

                 left->set(desc, right->get<float>(desc));

                 break;

               default:

                 assert(false);

             }

         }

     }

     return true;

 }