# `EEVM.Interpreter.Instructions.System.Creation`
[🔗](https://github.com/mw2000/eevm/blob/v0.1.0/lib/eevm/interpreter/instructions/system/creation.ex#L1)

Contract creation opcodes.

This module handles the most complex EVM operations — those that spawn nested
execution frames and interact with the world state.

## Contract Creation

- **CREATE** (0xF0) — deploys a new contract at an address derived from
  the sender's address and nonce (RLP-encoded, then Keccak-256 hashed).
- **CREATE2** (0xF5) — deploys at a deterministic address derived from
  the sender, a salt value, and the initcode hash (EIP-1014).

Both enforce EIP-3860 initcode size limits (`max_initcode_size = 49,152 bytes`)
and EIP-170 runtime code size limits (`max_code_size = 24,576 bytes`).
Oversized initcode halts the calling frame with `:initcode_too_large`.

Creation fails and pushes 0 without touching the creator's nonce at the
1,024 call-depth limit, when its balance can't cover the endowment, or when
its nonce is already 2^64 - 1 (EIP-2681). A collision with an existing
account (EIP-684, EIP-7610) also pushes 0, but keeps the nonce bump and
consumes the gas meant for the init code.

# `address_collision?`

```elixir
@spec address_collision?(EEVM.Database.t(), non_neg_integer()) :: boolean()
```

Returns true when contract creation at `address` collides with an existing
account: one with a nonzero nonce, non-empty code (EIP-684), or non-empty
storage (EIP-7610). A collision fails the creation.

# `execute`

```elixir
@spec execute(non_neg_integer(), EEVM.Interpreter.MachineState.t()) ::
  {:ok, EEVM.Interpreter.MachineState.t()}
  | {:error, atom(), EEVM.Interpreter.MachineState.t()}
```

Executes CREATE (0xF0) or CREATE2 (0xF5) against the current frame.

Pushes the new contract's address on success and 0 on any creation failure
(depth limit, static context, insufficient balance, address collision, or a
failed or rejected initcode run). Oversized initcode (EIP-3860) halts the
frame with `{:error, :initcode_too_large, state}`. Any other opcode halts as
`:invalid`.

---

*Consult [api-reference.md](api-reference.md) for complete listing*