[Bug]: calls-loop does not report the context of the loop

[itinance]

Describe the issue:

Slither reports "has external calls inside a loop" although the corresponding function only contains an if -statement.

Code example to reproduce the issue:

Example 1:

    function _hasRole(uint256 tokenId, address account) internal view virtual returns (bool) {
        if (_permissions.balanceOf(account, tokenId) > 0) {
            return true;
        }

        return false;
    }

Example 2:

    function _doSafeTransferAcceptanceCheck(
        address operator,
        address from,
        address to,
        uint256 id,
        uint256 amount,
        bytes memory data
    ) private {
        if (to.isContract()) {
            try IERC1155Receiver(to).onERC1155Received(operator, from, id, amount, data) returns (bytes4 response) {
                if (response != IERC1155Receiver.onERC1155Received.selector) {
                    revert("ERC1155: ERC1155Receiver rejected tokens");
                }
            } catch Error(string memory reason) {
                revert(reason);
            } catch {
                revert("ERC1155: transfer to non ERC1155Receiver implementer");
            }
        }
    }

Version:

0.8.3

Relevant log output:

PermissionsAware._hasRole(uint256,address) (contracts/permissions/PermissionsAware.sol#44-50) has external calls inside a loop: _permissions.balanceOf(account,tokenId) > 0 (contracts/permissions/PermissionsAware.sol#45)
ERC1155._doSafeTransferAcceptanceCheck(address,address,address,uint256,uint256,bytes) (node_modules/@openzeppelin/contracts/token/ERC1155/ERC1155.sol#467-486) has external calls inside a loop: IERC1155Receiver(to).onERC1155Received(operator,from,id,amount,data) (node_modules/@openzeppelin/contracts/token/ERC1155/ERC1155.sol#476-484)
Reference: https://github.com/crytic/slither/wiki/Detector-Documentation/#calls-inside-a-loop

[0xalpharush]

Are _hasRole or _doSafeTransferAcceptanceCheck called within loops anywhere in the codebase?

[itinance]

Are _hasRole or _doSafeTransferAcceptanceCheck called within loops anywhere in the codebase?

No, definitely no loops. But calls like that:

if (!_hasRole(TOKEN_ROLE_ISSUER, from) && !_hasRole(TOKEN_ROLE_ADMIN, from)) {

Could it be that this counts as "loop" because _hasRole was called twice?

The second example with _doSafeTransferAcceptanceCheck is from OpenZeppelin (ERC1155-contract). I couldn't find a loop also in their repository.

[PaulRBerg]

Here's another example that triggers this bug:

function _cancel(uint256 streamId) internal override onlySenderOrRecipient(streamId) {
    // beginning of function clipped
    // ...
    if (msg.sender == sender) {
        if (recipient.code.length > 0) {
            try ISablierV2LockupRecipient(recipient).onStreamCanceled({
                streamId: streamId,
                senderAmount: senderAmount,
                recipientAmount: recipientAmount
            }) { } catch { }
        }
    }
    else {
        if (sender.code.length > 0) {
            try ISablierV2LockupSender(sender).onStreamCanceled({
                streamId: streamId,
                senderAmount: senderAmount,
                recipientAmount: recipientAmount
            }) { } catch { }
        }
    }
}

_cancel is called by other functions in the code base, some of which do contain loops. But those loop-containing functions are not reported.