type conversions should be represented explicitly in the AST

[0xalpharush]

Version Information

• vyper Version (output of vyper --version): 0.3.7
• OS: osx
• Python Version (output of python --version): 3.11

What's your issue about?

The conversion of x to Test is represented as a Call and must be handle specially as Test is not a function name but rather an interface. Instead, there should be a type conversion node that converts x to type Test. Additionally, the Hex literal 0x0000000000000000000000000000000000000000 should have have a type conversion to address as it could also be bytes20. Representing these semantics explicitly will increase the accuracy of tools that attempt to model Vyper's semantics faithfully.

interface Test:
    def foo() -> (int128, uint256): nonpayable

@internal
def foo() -> (int128, int128):
    return 2, 3

@external
def bar():
    a: int128 = 0
    b: int128 = 0
    (a, b) = self.foo()

    x: address = 0x0000000000000000000000000000000000000000
    c: uint256 = 0
    a, c = Test(x).foo()

How can it be fixed?

Create explicit type conversion nodes in the AST