VMFrame *VMFrameStack::PopFrame()
{
if (Blocks == NULL)
{
return NULL;
}
VMFrame *frame = Blocks->LastFrame;
if (frame == NULL)
{
return NULL;
}
auto Func = static_cast<VMScriptFunction *>(frame->Func);
if (Func->SpecialInits.Size())
{
Func->DestroyExtra(frame->GetExtra());
}
// Free any string registers this frame had.
FString *regs = frame->GetRegS();
for (int i = frame->NumRegS; i != 0; --i)
{
(regs++)->~FString();
}
VMFrame *parent = frame->ParentFrame;
if (parent == NULL)
{
// Popping the last frame off the stack.
if (Blocks != NULL)
{
assert(Blocks->NextBlock == NULL);
Blocks->LastFrame = NULL;
Blocks->InitFreeSpace();
}
return NULL;
}
if ((VM_UBYTE *)parent < (VM_UBYTE *)Blocks || (VM_UBYTE *)parent >= (VM_UBYTE *)Blocks + Blocks->BlockSize)
{ // Parent frame is in a different block, so move this one to the unused list.
BlockHeader *next = Blocks->NextBlock;
assert(next != NULL);
assert((VM_UBYTE *)parent >= (VM_UBYTE *)next && (VM_UBYTE *)parent < (VM_UBYTE *)next + next->BlockSize);
Blocks->NextBlock = UnusedBlocks;
UnusedBlocks = Blocks;
Blocks = next;
}
else
{
Blocks->LastFrame = parent;
Blocks->FreeSpace = (VM_UBYTE *)frame;
}
return parent;
}
VMFrame *VMFrameStack::AllocFrame(VMScriptFunction *func)
{
VMFrame *frame = Alloc(func->StackSize);
frame->Func = func;
frame->NumRegD = func->NumRegD;
frame->NumRegF = func->NumRegF;
frame->NumRegS = func->NumRegS;
frame->NumRegA = func->NumRegA;
frame->MaxParam = func->MaxParam;
frame->Func = func;
frame->InitRegS();
if (func->SpecialInits.Size())
{
func->InitExtra(frame->GetExtra());
}
return frame;
}
