Bug #20285: Stale inline method caches when refinement modules are reopened

• Status: Assigned
• Assignee: jhawthorn (John Hawthorn)
• Target version: -
• Backport: 3.0: DONTNEED, 3.1: DONTNEED, 3.2: DONTNEED, 3.3: REQUIRED

[jhawthorn (John Hawthorn)]

This is essentially the same issue as #11672, but for inline method caches rather than class caches.

In Ruby 3.3 we started using inline caches for refinements. However, we weren't clearing inline caches when defined on a reopened refinement module.

class C
end

module R
  refine C do
    def m
      :foo
    end
  end
end

using R
def m
  C.new.m
end

raise unless :foo == m()

module R
  refine C do
    alias m m
    def m
      :bar
    end
  end
end

v = m()
raise "expected :bar, got #{v.inspect}" unless :bar == v

This will raise in Ruby 3.3 as the inline cache finds a stale refinement, but passes in previous versions.

[jhawthorn (John Hawthorn)]

• Backport changed from 3.0: DONTNEED, 3.1: DONTNEED, 3.2: DONTNEED, 3.3: UNKNOWN to 3.0: DONTNEED, 3.1: DONTNEED, 3.2: DONTNEED, 3.3: REQUIRED

Fixed by https://github.com/ruby/ruby/pull/10037

I'll mark this as requiring a backport for 3.3, but I think there's probably minimal impact from this issue.

[jhawthorn (John Hawthorn)]

• Related to Bug #11672: refinement added

[jhawthorn (John Hawthorn)]

• Subject changed from Stale inline method caches when refinement modules are reloaded to Stale inline method caches when refinement modules are reopened