New compiled files extensions

[mkaput]

Hello everyone!

We (@starkware-libs & @software-mansion) are considering changing compiled files extension convention, as we are going to introduce new kinds of compiled artifacts in Cairo/Sierra/CASM/Starknet. We'd like to gather quick feedback on this idea.

Context

Currently, the Cairo compiler and Scarb are capable of producing the following file types:

• Textual Sierra representation, meant for debugging use and compiler tests: crate.sierra
• Textual CASM code of compiled Sierra, executable in Cairo VM: crate.casm
• JSON containing Sierra code of Starknet contract class: contract.sierra.json
• JSON containing CASM code of Starknet contract class: contract.casm.json

We want to introduce the following new file type:

• JSON representation of Sierra, used to be much more reliable than textual dump. For example, for consumption by test frameworks, or Cairo runner.
• and leave us space for other serialization formats, for example binary.

Proposal

It happens to be unfortunate that we have named Starknet compiler contract classes in a way that clashes with non-Starknet targets, so we propose to introduce a change that is a potentially breaking change for tools that rely on existing state of things (for example by listing files with specific extension):

• Textual Sierra representation, meant for debugging use and compiler tests stays as: crate.sierra
• Textual CASM code of compiled Sierra, executable in Cairo VM stays as: crate.casm
• JSON representation of Sierra, used to be much more reliable than textual dump becomes: crate.sierra.json
  • alternative serialization formats will naturally be crate.sierra.X
• JSON containing Sierra code of Starknet contract class becomes: contract.contract_class.json
• JSON containing CASM code of Starknet contract class becomes: contract.compiled_contract_class.json

Notable changes to Cairo compiler

• Cairo compiler binaries never assume any file extensions.
• The cairo-compile binary will still produce textual Sierra representation, as this is an internal tool.

Notable changes to Scarb

Note

Scarb emits Starknet Artifacts files which, if treated as the only source of truth about generated artifacts, should make this convention change transparent for you tool!

If the community reaches consensus on this manner, the following changes will be implemented immediately:

• The starknet-contract target will start naming files accordingly to the new convention.
• The lib target will start generating sierra.json files if the lib.sierra field will be true (which it is by default)
• The lib target will generate sierra files only if the lib.sierra-text field will be true (which will be not by default)

[mkaput]

To these two kind folks who voted yes: what will you have to change in your workflows?

[mkaput]

Scarb 2.3.0-rc0 implements this change 🎉