[CLI] Drop --combined-json option and direct users to standard json

[axic]

Closes #10276.

[chriseth]

I think it has some features that standard json lacks.

[axic]

Can you list those? We should add it to standard json.

[chriseth]

Maybe I confused this with non-json mode.

[axic]

Frameworks:

• Waffle: standard-json
• Truffle: standard-json
• Embark: standard-json
• dapptools: uses --combined-json (as of Standardjson dapphub/dapptools#569 it uses --standard-json)
• brownie: uses py-solc-x uses both --standard-json and --combined-json
• Buidler/Hardhat: uses only --standard-json
• saddle: uses --combined-json as of version 0.1.23. (Tracker: Consider using solc's --standard-json instead of --combined-json compound-finance/saddle#43)

Tools:

• crytic-compile: uses only --combined-json (Tracker: Investigate standard-json for Solidity 0.8 crytic/crytic-compile#140)
• gasol: input/output in --combined-json asm format.
• ethers-rs: standard-json (has dropped --combined-json support recently).
• mythril: uses --standard-json as of v0.22.32.

I'm sure there are more frameworks, just I'm unaware of them.

[axic]

@iamdefinitelyahuman could you explain whether you rely on --combined-json and if yes, why?

@MrChico likewise, could you explain if moving to --standard-json would be debilitating? :)

[cameel]

Buidler/Hardhat: uses only --standard-json

[axic]

@cameel thanks, added to the list above (please feel free to edit my comment if you check other frameworks)

[iamdefinitelyahuman]

Brownie uses --standard-json exclusively . py-solc-x is just wrapping around solc, so it provides access to --combined-json for no reason other than that combined json exists :)

Brownie would not break anywhere if you removed --combined-json, so 👍 from me.

[axic]

@iamdefinitelyahuman thanks for the response! Do you know of any py-solc-x user who makes use of --combined-json?

[MrChico]

I mainly prefer --combined-json for it's easy commandline use – I can get all of the compiler outputs of interest with a relatively simply one liner.
As far as I can foresee there would be nothing fundamentally limiting to migrate dapptools to use --standard-json besides the obvious labor involved in architecturing everything to support the new format. Many features that have been introduced into --standard-json have been neglected in --combined-json, so if that pattern is to continue we would probably migrate anyway.
My preference would of course be to simply get --combined-json up to feature parity, as requested in #10274.

[axic]

The thing is we have three outputs to maintain:

1. standard-json
2. individual options to solc
3. the legacy combined-json (which predates standard-json)

We can barely keep feature parity between individual solc options and standard-json, and since combined-json is so sparsely used (seemingly only by dapphub), it is hard to rationalise keeping it maintained.

See the various open issues regarding CLI issues.

[iamdefinitelyahuman]

@iamdefinitelyahuman thanks for the response! Do you know of any py-solc-x user who makes use of --combined-json?

I took a look through some of the listed dependents, most are using the standard JSON interface. The notable exception is NuCypher. @KPrasch @cygnusv - care to weigh in here?

[vzotova]

@iamdefinitelyahuman @KPrasch and I are working on that, probably will finish moving to standard JSON interface soon

[axic]

@MrChico could you point me to the places in dapptools where --combined-json is used? I am wondering whether the output parsing or the input preparation seems like the bigger hurdle.

The output should be much more nicely formatted (compared to --combined-json), but at the cost of more levels of objects.