VIP: allow revert_on_failure for regular extcalls

[charles-cooper]

Simple Summary

per title

Motivation

so that users do not need to drop down into raw_call() to use revert_on_failure=False

Specification

allow revert_on_failure in extcall (and also staticcall) position. e.g.,

interface Foo:
    def foo() -> uint256: nonpayable

def call_foo(f: Foo):
    success: bool = empty(bool)
    s: uint256 = empty(uint256)
    success, s  = extcall f.foo(revert_on_failure = False)

Backwards Compatibility

new feature, no breaking changes

Dependencies

References

Copyright

Copyright and related rights waived via CC0

[cyberthirst]

i'm in favor of this approach.

listing some other ideas for future discussion..

1. make the call machinery more general then the current evm-dependent semantics (i think i discussed smth similar w Charles like a year ago):

q: Query = query target.foo()
if res.sucess():
  return abi_decode(q.return_payload)
return 0

2. or maybe context managers

with target.foo() as call:
   if call.success:
       return abi_decode(call.return_payload)
   return 0