https://github.com/philogy/huff-stuff

https://github.com/philogy/huff-stuff

Last synced: 11 days ago
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• Host: GitHub
• URL: https://github.com/philogy/huff-stuff
• Owner: Philogy
• Created: 2022-08-02T09:15:29.000Z (over 2 years ago)
• Default Branch: main
• Last Pushed: 2022-08-09T20:05:56.000Z (over 2 years ago)
• Last Synced: 2023-03-10T19:18:31.129Z (over 1 year ago)
• Language: Solidity
• Size: 24.4 KB
• Stars: 10
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# Huff Stuff

A collection of heavily optimized Huff contrats.

## ERC20

Source: `ERC20.huff`

Example use: `src/test/contracts/MockERC20.huff`

**Basic Macros:**

The `_ERC20_SELECTOR_SWITCH` macro inserts the ERC20 selector switch into your

code. It takes 1 stack argument, the selector and returns it, meaning the macro

can seamlessly be added to an existing selector switch. Example:

```huff

GET_SELECTOR()

dup1 __FUNC_SIG(mint) eq mint jumpi

dup1 _ERC20_SELECTOR_SWITCH(decimals, symbol, name)

__FUNC_SIG(burn) eq burn jumpi

```

The `_ERC20_SELECTOR_SWITCH` macro takes the token's decimals and 2 jump labels

as macro arguments. The first jump label being the logic returning the token's

symbol and the second the name.

**Minting / Burning:**

In order to mint / burn tokens in the constructor or elsewhere use the

`ERC20_SAFE_BURN` and `ERC20_SAFE_MINT` macros. They take 2 stack arguments:

\[amount, account\]. They're called "safe" because they do overflow / underflow

checking, meaning that if only these methods are used to adjust the supply,

balances and the total supply cannot not overflow / underflow.

The two macros also take 2 macro arguments `mem1` and `mem2`. These are meant

to be free memory pointers whereby `mem2 = 0x20 + mem1`, `mem2` is passed as a

macro argument to avoid having to calculate it via `mem1 0x20 add` at runtime.

**Other Macros:**

The `ERC20.huff` library currently has no other macros for retrieving

balance / allowance / total supply internally. They may however be added in the

future.

**Storage layout:**

Variable|Slot

------|------

totalSupply|`SLOT_TOTAL_SUPPLY`

balanceOf(account)|`keccak256(SLOT_BALANCE_OF . account)`

allowance(owner, spender)|`keccak256(SLOT_ALLOWANCE . spender . owner)`