H. EVM-Specific Features

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These features reference EVM runtime concepts. The compiler maps them to Neo equivalents where possible, blocks them where no safe equivalent exists, and emits warnings for approximate mappings.

Feature	Status	Neo Mapping
msg.sender	✅	Runtime.GetCallingScriptHash()
msg.value	⚠️	Only mapped inside onNEP17Payment callback.
msg.data	⚠️	Approximated as selector | abi.encode(current args) outside onNEP17Payment.
msg.sig	⚠️	Approximated as the current function selector with warning; internal-call propagation still differs from EVM.
block.timestamp	✅	Runtime.GetTime() (normalized to seconds).
block.number	✅	Ledger.CurrentIndex().
block.chainid	✅	Neo network magic number.
block.coinbase	✅	Auto-mapped to address(0) with warning (dBFT has no miner).
block.difficulty / block.prevrandao	✅	Auto-mapped to Runtime.getRandom() with warning.
block.gaslimit	✅	Auto-mapped to Policy.getExecFeeFactor() with warning.
block.basefee	✅	Auto-mapped to Policy.getFeePerByte() with warning.
tx.origin	⚠️	Parsed. Warning about authorization risks. Maps to first signer script hash.
tx.gasprice	✅	Auto-mapped to Policy.getFeePerByte() with warning.
gasleft()	✅	System.Runtime.GasLeft syscall.
blockhash(n)	✅	Auto-mapped to Ledger.getBlockHash() with warning.
block.sha3	⚠️	Auto-mapped to Ledger.currentHash. Deprecated in Solidity 0.8+.
keccak256(...)	✅	CryptoLib.keccak256.
sha256(...)	✅	CryptoLib.sha256.
ecrecover(...)	✅	CryptoLib.recoverSecp256K1, followed by keccak256 and rightmost-20-byte address derivation.
selfdestruct(addr)	✅	Auto-mapped to ContractManagement.destroy() with warning.
address.call(...)	⚠️	System.Contract.Call; return wrapping and ABI payload parity differ from EVM and need Neo-Express validation.
address.staticcall(...)	⚠️	System.Contract.Call with read-only flag; return wrapping and ABI payload parity differ from EVM.
address.delegatecall(...) / callcode(...)	🚫	Blocked at compile time; NeoVM has no equivalent caller-storage execution semantics.
address.transfer(amount)	✅	Auto-mapped to GAS.transfer(from,to,amount,data); aborts on transfer failure.
address.send(amount)	✅	Auto-mapped to GAS.transfer(from,to,amount,data); returns bool.
address.balance	✅	Auto-mapped to GAS.balanceOf(address).
address.code	⚠️	Returns Neo contract script bytes via ContractManagement.getContract(); non-contract addresses return empty bytes.
address.codehash	✅	Auto-mapped to contract script hash with warning. Non-contract returns bytes32(0).
Ether units (wei, gwei, ether)	⚠️	Parsed. Warning that Neo uses GAS token (10^8 decimals).
Time units (seconds, minutes, etc.)	✅	Compile-time constants normalized to seconds.
this keyword	✅	Runtime.GetExecutingScriptHash().
type(X).creationCode	⚠️	Emits deterministic NEF3-shaped bytes for hashing compatibility; not EVM bytecode.
type(X).runtimeCode	⚠️	Same deterministic Neo-shaped payload model as creationCode; not production bytecode introspection.

Partial EVM feature details

msg.value — Neo does not attach native value to contract calls. The msg.value expression is only meaningful inside onNEP17Payment() callbacks, where it maps to the amount parameter. Outside that context, the compiler emits a warning (W111) and returns 0 at runtime.

// ✅ Works — msg.value inside payment callback
function onNEP17Payment(address from, uint256 amount, bytes memory data) external {
    require(msg.value >= minDeposit, "insufficient deposit");
    // msg.value maps to the `amount` parameter
}

// ⚠️ Warning — msg.value outside payment context returns 0
function deposit() public payable {
    balances[msg.sender] += msg.value; // msg.value is always 0 on Neo
}

tx.origin — Maps to the first signer's script hash in the Neo transaction. The compiler emits a warning because tx.origin-based authorization is considered an anti-pattern on both EVM and Neo. Use msg.sender (which maps to Runtime.GetCallingScriptHash()) or Runtime.checkWitness() instead.

Ether units — The literal multipliers (1 ether = 10^18, 1 gwei = 10^9, etc.) are parsed for source compatibility, but a warning is emitted because Neo GAS uses 10^8 decimals, not 10^18. Adjust your constants accordingly.

address.code — On Neo this now lowers to the contract script bytes fetched through ContractManagement.getContract(). This is closer to EVM runtime bytecode access than the old empty-byte placeholder, but it is still Neo contract script rather than EVM bytecode. Non-contract addresses return empty bytes. address.code.length remains the fast contract-existence approximation (0 for non-contract, 1 for contract).

address.delegatecall(...) / callcode(...) — On NeoVM, each contract has isolated storage. These EVM operations execute callee code in the caller's storage context, which has no Neo equivalent. The compiler rejects them instead of compiling them with unsafe changed semantics. Redesign proxy and library patterns around explicit calls, inlined libraries, or ContractManagement.update().

// 🚫 Rejected by neo-solc
(bool success, bytes memory data) = target.delegatecall(abi.encodeWithSignature("foo()"));
// Use explicit calls or ContractManagement.update() depending on the upgrade pattern.

type(X).creationCode / type(X).runtimeCode — Neo does not expose EVM bytecode. For compatibility with CREATE2-style hashing patterns, the compiler emits deterministic NEF3-shaped byte payloads that are stable per referenced contract/type when the target is available in the compilation graph. Treat these bytes as hashing artifacts, not deployable EVM bytecode.

bytes32 childCodeHash = keccak256(type(Child).creationCode);

Auto-mapping warnings

Several EVM globals are auto-mapped to approximate Neo equivalents. The compiler emits warnings for each to ensure developers understand the semantic differences:

EVM Global	Auto-Mapped To	Why It Warns
block.coinbase	address(0)	dBFT consensus has no block miner.
block.difficulty / block.prevrandao	Runtime.getRandom()	Different randomness model.
block.gaslimit	Policy.getExecFeeFactor()	Different gas accounting.
block.basefee	Policy.getFeePerByte()	Different fee model.
tx.gasprice	Policy.getFeePerByte()	Different fee model.
blockhash(n)	Ledger.getBlockHash()	Semantic match but different chain.
block.sha3	Ledger.currentHash	Deprecated in Solidity 0.8+; Neo uses current block hash.
selfdestruct(addr)	ContractManagement.destroy()	No refund mechanism. Permanent.
address.codehash	Contract script hash	Non-contract addresses return bytes32(0).

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