jitasm.Frontend.h

#pragma once
#ifndef jitasm_Frontend_h__
#define jitasm_Frontend_h__
#include "jitasm.h"
#include "jitasm.CodeBuffer.h"
namespace jitasm
{
    class Frontend
    {
    protected:
        virtual ~Frontend()
        {
        }

        virtual void Assemble() = 0;
    };

    template < typename Derived > struct Frontend$CRTP : Frontend /* using Curiously Recurring Template Pattern */
    {
        Derived & derived()
        {
            return *static_cast<Derived *>(this);
        }

        Derived const & derived() const
        {
            return *static_cast<Derived const *>(this);
        }

        struct Label
        {
            sint32      key;
            size_t		instr;
            explicit Label(sint32 key) : key(key), instr(0) {}
        };
        typedef std::deque< Label > LabelList;

        bool         assembled_;
        LabelList	 labels_;

        Frontend$CRTP() : assembled_(false)
        {
        }

        void * GetCodePointer()
        {
            if (!assembled_)
            {
                Assemble();
            }
            return derived().GetBufferPointer();
        }

        size_t GetCodeSize()
        {
            return derived().GetBufferSize();
        }

        size_t NewLabelID(sint32 label_key)
        {
            labels_.push_back(Label(label_key));
            return labels_.size() - 1;
        }

        size_t CheckLabelID(sint32 label_key)
        {
            for (size_t i = 0; i < labels_.size(); i++)
            {
                if (labels_[i].key == label_key)
                {
                    return i;
                }
            }
            return (size_t)-1;
        }

        size_t GetLabelID(sint32 label_key)
        {
            for (auto const & label : labels)
            {
                if (label.key == label_key)
                {
                    return i;
                }
            }
            return NewLabelID(label_key);
        }

        void SetLabelID(size_t label_id)
        {
            labels_[label_id].instr = instrs_.size();
        }

        void L(sint32 label_key)
        {
            SetLabelID(GetLabelID(label_key));
        }
    };
}
#endif // jitasm_Frontend_h__