Initialize the static variables without main method.

[ShawnYun]

As #219 , we add abi offset for every method. But if there are static variables, we need to load them first.

[erikzhang]

@lightszero What do you think?

[shargon]

We should call the static constructor first

[Tommo-L]

Maybe we need a constructor method for each contract, like c# class?

[lightszero]

简洁的修改方式 是 懒汉模式，在每个入口函数插入一个检查。

[shargon]

But it should be executed once, if we call a recursive method, it should be executed only once.

Exec(int a, int b, int counter)
{
 // STATIC INIT
 if (counter>10)return a+b;
 return Exec(a+b,b+1,counter+1);
}

[Tommo-L]

简洁的修改方式 是 懒汉模式，在每个入口函数插入一个检查。

Translate to EN:

A simple way is to use lazy mode, insert a check method to init those static variables at the entry of each function.

[Tommo-L]

But it should be executed once, if we call a recursive method, we should be executed only once.

If we use lazy mode, it's not a problem.

[Tommo-L]

@erikzhang If we want to use lazy mode, could we add a new opcode SFCOUNT, which return the total amount of static field slot. Then we can use it to determine whether static variables have been loaded.

if static field slot is null return null
else return slot.count

[Tommo-L]

Another way is that when we deploy a contract at the begining, we should call its constructor to complete its initialization(including static variables)

[erikzhang]

My solution is that we allow the contract to have an optional special method: _initsslot().

When an contract is invoked, we check its ABI first. If it has the method _initsslot(), we call it first.

[shargon]

we can call it in other execution context, and after it, call the user method

[Tommo-L]

allow the contract to have an optional special method: _initsslot().

Personally, I don't want to see that we have too many special functions, we already have one. I think we can adjust NEF format, make NEF like window's exe format, which have different segments.

[Tommo-L]

I think we can implement the __initsslot now. I have read the windows PE format, it has a function address table and function name table for mapping. By using .ctor as object instance entry, .cctor as class static methods and variables initialization. It also has a .data sgement, but it's for user-define.

[shargon]

It's a good idea, if we process the static constructor, and after it, we save the static variables in the nef file, it could be easier to execute.

[erikzhang]

neo-project/neo#1572

[lightszero]

got it

[ShawnYun]

close it via #219 .