create_forwarder_to does not revert on creation failure

[charles-cooper]

Version Information

• vyper Version (output of vyper --version): 90e3d20
• Python Version (output of python --version): v3.8.10

What's your issue about?

while implementing create() and create_copy_of() (see #2889), i realized that CREATE and CREATE2 opcodes don't bubble up failure of the initcode, instead they return a zero address. for safety, i decided the implementation should check the zero address case. but, the existing implementation of create_forwarder_to() (see below) does not check for the zero case. i'm actually not sure what the ideal behavior here is, because if there is a collision, it most likely means that the code you intended to deploy is already deployed.

vyper/vyper/builtin_functions/functions.py

Lines 1731 to 1741 in 90e3d20

	return IRnode.from_list(
	[
	"seq",
	["mstore", placeholder, forwarder_preamble],
	["mstore", ["add", placeholder, preamble_length], target_address],
	["mstore", ["add", placeholder, preamble_length + 20], forwarder_post],
	[op, *op_args],
	],
	typ=BaseType("address"),
	add_gas_estimate=11000,
	)

How can it be fixed?

[charles-cooper]

meeting notes: should revert

[charles-cooper]

todo: add allow_failure= flag of some sort to allow customization of the behavior