As mentioned in the other thread, I think this option is less attractive because it introduces more complexity to the EVM, in the form of new opcodes, and another form of memory with new semantics. I think changing gas accounting around SSTORE/SLOAD is much simpler and more versatile.
Further, a change to SSTORE/SLOAD gas accounting will reduce gas costs for contracts already using storage for transient or repeated updates. Examples include contracts using storage to implement locks, and ERC20 tokens using ‘approve’ between contracts. If transient storage is implemented instead, new standards would need to be developed to permit the use of transient storage for these purposes.
When implementing contract-proxies using
DELEGATECALL, all direct arguments are relayed from the caller to the callee via the
CALLDATA, leaving no room for meta-data between the proxy and the proxee. Also, the proxy must be careful about
storage access to avoid collision with
transient storage would be shared, it would be possible to use
transient storage to pass information between the
proxy and the
It’s not clear to me why you can’t just pass the metadata along with the call data. Further, this approach would not work if you may end up with recursive calls; it’s the equivalent of using global variables.
Transient storage does not interact with reverts or invalid transactions, that means if a frame reverts, its effects on the transient storage remain until the end of the transaction.
I think this is a really bad idea. Every other state change is reverted when a call reverts or throws; introducing a new semantic for this one type of storage would be counterintuitive, and creates a special case that is likely to lead to a great number of nonobvious bugs and security issues.