Advanced Solidity: Yul and Assembly

Explore how Solidity uses memory, starting with the free memory pointer at 0x40 and progressing through struct and array allocation, and how ABI encoding shapes memory layout.

Explore how mismanaging the free memory pointer in Solidity can overwrite memory and corrupt data, with foo becoming bar and unpacked memory spanning multiple 32-byte slots.

Explore how memory handles data larger than 32 bytes in youll, using explicit memory addressing to return and hash data with keccak256, including scratch space and free memory pointer.

Explore how Solidity logs and events work, including indexed versus non-indexed arguments, event signatures and topics, and emitting logs on a testnet.

Discover calldata in ethereum smart contracts, including function selectors and ABI-encoded arguments, how arbitrary transaction data is structured and gas costs are affected.

Explore how to call other contracts in Solidity using staticcall, regular call, and delegatecall, including function selectors, ABI encoding, memory handling, gas management, and handling return data.

Learn how dynamic length arguments encode in call data, using pointers, lengths, and surrounding fixed data in Solidity. Compare using structs versus arrays for fixed-length tuples to reduce gas costs.

Compare two transfer of value patterns for withdrawing ether: call with a payable recipient and empty abi encoding, highlighting gas costs, bytecode size, and reentrancy considerations.

Learn to imitate a solidity contract in fuel using yul, handling call data, function selectors, and a switch statement, calling get two or get 99, with leave and return semantics.

Explore building a 100% Yul contract with an all-in constructor, using memory slots and data markers, compiling with yield, and interfacing for testing on remix.

Deploy to Rink B and inspect etherscan verification challenges when using yul versus solidity, and prefer writing in solidity with assembly only for small, gas-efficient functions.

Store large data in contract bytecode by embedding strings with the data keyword. Use a static call to retrieve the bytes and convert them into a string, reverting on failure.

Illustrate an ERC-20 example showing constructor storage, function selectors, balance and total supply operations, and non-payable calls with memory and storage access and return behavior.

Examine how balance of derives from decode as address within calldata, including function selectors, offsets, and zero-padding to verify a valid address and revert on invalid or zero address.

Explores total supply in ERC20, how mint updates total supply and balances, owner-only mint enforcement, overflow checks, storage offsets, and emitting transfer events, with reference to OpenZeppelin hooks.

Explore how balanceOf loads a user's ERC20 balance by computing a storage offset from the address into a mapping, using hex 1000, and returning the balance.

Review ERC20 transfer and transfer from flows by examining execute transfer calls, balance deduction, and transfer emission, ensuring nonzero source and destination and proper balance checks.

Examine ERC20 approval via OpenZeppelin, detailing owner and spender allowances and transferFrom. See how storage slots, hashing, and memory choices influence gas efficiency and contract clarity.

Explore rarely used signed arithmetic in yul and assembly, including signed division, modulus, comparisons, and signed shifts, with sign extension and EVM 32-byte word handling.