[Bug middle-end/127783] New: genmatch should allow anonymous leafs

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127783

            Bug ID: 127783
           Summary: genmatch should allow anonymous leafs
           Product: gcc
           Version: 17.0
            Status: UNCONFIRMED
          Keywords: internal-improvement
          Severity: enhancement
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---

As mentioned in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127748#c4.
genmatch requires named captured leafs.  Maybe we should allow anonymous leafs.
Like:
```
(match x
 (plus @ @)
```

Then we can warn if a named leaf is not used in the result/if.