File: CrossDomainMessenger.sol
176:     function sendMessage(address _target, bytes calldata _message, uint32 _minGasLimit) external payable {
177:         if (isCustomGasToken()) {
178:             require(msg.value == 0, "CrossDomainMessenger: cannot send value with custom gas token");
179:         }
180: 
181:         // Triggers a message to the other messenger. Note that the amount of gas provided to the
182:         // message is the amount of gas requested by the user PLUS the base gas value. We want to
183:         // guarantee the property that the call to the target contract will always have at least
184:         // the minimum gas limit specified by the user.
185:         _sendMessage({
186:             _to: address(otherMessenger),
187:             _gasLimit: baseGas(_message, _minGasLimit),
188:             _value: msg.value,
189:             _data: abi.encodeWithSelector(
190:                 this.relayMessage.selector, messageNonce(), msg.sender, _target, msg.value, _minGasLimit, _message
191:             )
192:         });
File: CrossDomainMessenger.sol
211:     function relayMessage(
212:         uint256 _nonce,
213:         address _sender,
214:         address _target,
215:         uint256 _value,
216:         uint256 _minGasLimit,
217:         bytes calldata _message
218:     )
219:         external
220:         payable
221:     {

			 ...

287:         bool success = SafeCall.call(_target, gasleft() - RELAY_RESERVED_GAS, _value, _message);
