⚙️ LearnEVM.com @LearnEVM

The comprehensive EVM deep dive for Solidity developers. Made by @0xMacroSecurity learnevm.com Joined January 2023

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⚙️ LearnEVM.com @LearnEVM

8 months ago

@Arvolear Definitely the best part of the ecosystem

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Adding to this, the 1 word used for the dynamic array is the length of the array Specifically, the length is zero, so there is no more data in memory following it! If the length were (for example) three, then the total size of the dynamic array would be 4 words in memory 😀

vectorized.eth @optimizoor

9 months ago

Solidity memory lesson 9 (for Fantasy top fans): Implicit memory allocation of dynamic vs static arrays. - Dynamic array is initialized to 0x60, pointing to the zero pointer. No memory is allocated. - Static array is initialized by setting it to the location of newly allocated

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shafu @shafu0x

9 months ago

All EVM opcodes in one diagram by @LearnEVM

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Macro Security @0xMacroSecurity

10 months ago

Building on the Solana virtual machine (SVM) is very different than building on the EVM. Differences include: - Data cannot be encapsulated - External call depth capped at 4 - All account reads and writes must be known ahead of time and much more (tighter transaction limits, built-in upgradability, program-derived accounts and their ability to be signers, and so on). If you're looking to build on Solana and could use an expert opinion to accelerate your development, contact us via telegram, or via inquiry form on our website. Up to 50% of your pre-audit security reviews can be applied to a future audit (limited time only). Stay secure out there 👊 - Macro Security team

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⚙️ LearnEVM.com @LearnEVM

a year ago

Learn more about how EVM Memory works by reading our free lesson on the topic here: learnevm.com/chapters/evm/m…

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⚙️ LearnEVM.com @LearnEVM

a year ago

A perfect example of why it's important to know EVM 🤓

kaden.eth @0xKaden

a year ago

🧵How memory works under the hood in the EVM and how this knowledge led me to recently discover a ✨critical vulnerability✨ Oh and if you're new to assembly, don't worry, it's simpler than you think Memory Layout Starting with the basics, Solidity reserves the following 4

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Solidity @solidity_lang

a year ago

The Solidity Developer Survey 2024 has gotten 500+ responses so far. If you're yet to take the survey, you've got one last week to let us know... ✨ how you are using Solidity. 🆕 which recent changes impact(ed) you the most. 🔮 which features you anticipate the most. It takes ~10min to contribute to the future of Solidity. 🔗cryptpad.fr/form/#/2/form/…

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⚙️ LearnEVM.com @LearnEVM

a year ago

Eth is moving forward 🫡

JOSΞPH 🌳 @CupOJoseph

a year ago

EIP-7907 was just approved It will more than 10X the contract size limit, significantly improving the developer experience on Ethereum. I expect it will be included in the next upgrade after Pectra

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⚙️ LearnEVM.com @LearnEVM

a year ago

this may seem like a lot of opcodes but that's just how expensive the keccak256 operation can be 👀

vectorized.eth @optimizoor

a year ago

Compile-time zero-cost abstraction for Solidity. When compiled (with or without --via-ir), this function gives very optimized bytecode that is faster than using `keccak256` to compare two strings.

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⚙️ LearnEVM.com @LearnEVM

a year ago

@real_philogy 👀👀👀

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⚙️ LearnEVM.com @LearnEVM

a year ago

Gas efficiency *without* writing in opcodes? Have to admit this is kind of impressive🙈🙊🙉

ross.wei @z0r0zzz

a year ago

Zolidity ERC20 is 52 lines of code. But still very gas efficient without assembly, vs. Solady ER20 (613 LOC):

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⚙️ LearnEVM.com @LearnEVM

a year ago

To learn more about how contract storage works, check out our FREE material on the topic 😃 learnevm.com/chapters/evm/s…

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⚙️ LearnEVM.com @LearnEVM

a year ago

What's the significance of Custom Storage Layouts? By default, Solidity starts all storage variables at slot 0. For example, if you have this contract: contract Example { uint256 x; uint256 y; } then reading x will compile to SLOAD with a key of 0x00, and reading y will compile to an SLOAD with a key of 0x01. (If you have smaller values, such as two uint128's, then Solidity will compact those into the same storage slot. But that's a discussion for another day!) Essentially, all your storage variables live right next to each other, starting at zero and incrementing onwards. However... with Custom Storage Layouts, you can now start at a *different* point than zero! contract Example layout at 0xFAFA { uint256 x; uint256 y; } In this modified example, reading x now compiles to SLOAD with a key of 0xFAFA, and y now compiles to an SLOAD with a key of 0xFAFB! This is useful for EIP-7702, which allows an EOA to "become" a smart contract! The EOA can change which smart contract it becomes multiple times, so it's important for each one to have its own isolated storage space to avoid clashing.

Macro Security @0xMacroSecurity

a year ago

Solidity just added support for Custom Storage Layouts! This allows specifying that your contract storage starts at a point *other than* zero. However, this still doesn't cover the popular Namespaced Storage Layout that modern contracts often use (EIP-7201). For now, you will

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⚙️ LearnEVM.com @LearnEVM

a year ago

missing from the list: S - CODECOPY A - CREATE2 - EXTCODECOPY B - KECCAK256 C - CALLDATALOAD D - DIFFICULTY F - PREVRANDAO

karma @0xkarmacoma

a year ago

EVM opcodes ranked

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vectorized.eth @optimizoor

a year ago

I have a monopoly on arranging EVM opcodes beautifully and optimally. And it’s free and open source. Milady.

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shafu @shafu0x

a year ago

The simplicity of the EVM is beautiful.

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⚙️ LearnEVM.com @LearnEVM

a year ago

you can use bytecode as storage.

Gilbert @0xgib

a year ago

Diamond compat is complete! The grand total is... 889 bytes! This is 5x smaller than the Solidity equivalent 🤯 And thanks to my previously conservative math, the router contract *still* supports over 4000 function selectors! 😁 As wise @optimizoor once said, "you can use

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cottons.eth ✊️🇺🇸 @claracottontail

a year ago

you can use bytecode as storage

⚙️ LearnEVM.com @LearnEVM

a year ago

@ghadi8798 @optimizoor you can use bytecode as storage.

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⚙️ LearnEVM.com @LearnEVM

a year ago

@ghadi8798 @optimizoor you can use bytecode as storage.

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⚙️ LearnEVM.com @LearnEVM

a year ago

To learn more about how EVM contract storage works, visit our FREE chapter on the topic 🤓 That's all for now, folks! Keep shifting those bits like a pro 😎 learnevm.com/chapters/evm/s…

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⚙️ LearnEVM.com @LearnEVM

a year ago

What @optimizoor is suggesting is reducing the key size for this pattern! This allows us to only require 10 bytes of bytecode, instead of the usual 33 – giving us a savings of 69% 😎 Best of all, the chance of collision is still ridiculously low – 1 in 2^72, or 4.72×10²¹

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⚙️ LearnEVM.com @LearnEVM

a year ago

what does bro mean by this? ERC-7201 is Namespaced Storage Layout. It's a standard for modular, isolated storage layouts. Why is this pattern necessary? To fully understand, you first need to know a bit of how Solidity works... 🧵

vectorized.eth @optimizoor

a year ago

ERC-7201, namespaced storage, is good but bad at the same time. The solution is to just use the first 9-bytes of the keccak. Stop wasting 32 bytes of precious bytecode space everywhere. No, I don’t think we need an ERC for this. Just code from first-principles.