Yul sources are given id 1 instead of 0 in compiler output (inconsistent with source map & ast)

[haltman-at]

Description

In the sources output in Yul mode (when present), the ID of each source is given as 1, instead of 0. This is inconsistent with Solidity's general practice of 0-indexing sources. Worse yet, it's inconsistent with the numbering elsewhere in the output, namely, the source map and the AST; both of these will give the ID as 0.

Environment

• Compiler version: 0.8.21
• Target EVM version (as per compiler settings): default

Steps to Reproduce

Any Yul source code will do, just make sure to request ASTs in the output (about which see #14452) so that you get sources output. Also good idea to request the source map as well for comparison.

[r0qs]

Hi @haltman-at, thank you very much! Indeed the IDs are inconsistent. The wrong ID was added here: https://github.com/ethereum/solidity/pull/14177/files#diff-ad23dac446ab50b79251aacbae1a5230bacd344588c52241eca0f0b1d815e8acR1528.

I opened a PR to fix it :)

[cameel]

Yes, just like #14452 this is just an oversight from #14177. The IDs are arbitrary, but if they don't match numbers in the AST or source map, it's a bug. And there's no reason for it not to start at 0.