solidity/test/libsolidity/semanticTests/modifiers/function_modifier.sol

contract C {
    function getOne() public payable nonFree returns (uint256 r) {
        return 1;
    }

    modifier nonFree {
        if (msg.value > 0) _;
    }
}

// ====
// compileViaYul: also
// ----
// getOne() -> 0
// getOne(), 1 wei -> 1