[Bug]: No tuple variable assigned when call destination is compound expression

[kevinclancy]

Describe the issue:

When I invoke a multi-return method on a cast expression, the generated IR does not contain a HighLevelCall operation to initialize a tuple variable.

I think this only happens if the method has at least one parameter.

Code example to reproduce the issue:

pragma solidity ^0.8.19;

interface ISomeInterface {
    function value(uint z) external returns (uint, uint);
}

contract Test {

    function test(address a) external {
        (uint256 w, uint256 x) = ISomeInterface(a).value(3);
    }
}

Version:

0.9.3

Relevant log output:

INFO:Printers:Contract ISomeInterface
        Function ISomeInterface.value(uint256) (*)
Contract Test
        Function Test.test(address) (*)
                Expression: (w,x) = ISomeInterface(a).value(3)
                IRs:
                        TMP_0 = CONVERT a to ISomeInterface
                        w(uint256)= UNPACK TUPLE_0 index: 0 
                        x(uint256)= UNPACK TUPLE_0 index: 1 
                Expression: ()
                IRs:
                        RETURN

[0xalpharush]

I think it only happens when the method is named "value" because it's incorrectly is treated as a function call option ({value:..}) by is_value here

slither/slither/slithir/convert.py

Line 336 in 79ff12a

if is_value(ins) and isinstance(prev_ins, Argument):

[kevinclancy]

It seems this is an inherent problem with solc versions prior to 0.7.0.

For solc versions 0.7.0 and higher, slither could refrain from performing the filtering that is causing this issue.

For versions prior to 0.7.0, it's probably possible to distinguish call options from functions called value and gas from inside solc_parsing. Another approach would be to halt and produce an error message if it encounters declarations for functions named "value" or "gas".