Remove extra unnecessary blocks

[jjant]

Description

It should be safe to remove unnecessarily nested blocks when there's no statements in between: {{{ <stmts> }}} => { <stmts> }.

Example

Input:

fn f() {
    {{{{{ g() }}}}};
}

---

Expected output:

fn f() {
  g();
}

Actual output:

fn f() {
    {
        {
            {
                {
                    {
                        g()
                    }
                }
            }
        }
    };
}

[0xSaksham]

Hi, I would like to contribute to this issue, please assign me and point to where I should look for these.

[ytmimi]

@0xSaksham Thanks for your interest in working on this. You can assign yourself by commenting @rustbot claim. I'd encourage you to read the Issue claiming section of the rustc dev guide.

I imagine this option would work just like remove_nested_parens, and you can check out how remove_nested_parens is implemented by looking at rewrite_paren.

Maybe it makes sense to implement this logic in walk_block_stmts, but to be honest I haven't looked into this so you'll need to do some investigating on your own.

[vatsalkeshav]

@rustbot claim

[karolzwolak]

@vats004 Are you working on this? If you are no longer able to work on this issue, I'll try to tackle it.

Edit: It's been a month since you've claimed this, and I implemented it myself.

[vatsalkeshav]

@rustbot release-assignment