[ruby-core:114377] [Ruby master Bug#19835] Parser leaks memory for incomplete tokens

9 Aug 2023

      Issue #19835 has been reported by peterzhu2118 (Peter Zhu).

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Bug #19835: Parser leaks memory for incomplete tokens
https://bugs.ruby-lang.org/issues/19835

* Author: peterzhu2118 (Peter Zhu)
* Status: Open
* Priority: Normal
* Backport: 3.0: REQUIRED, 3.1: REQUIRED, 3.2: REQUIRED
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GitHub Pull Request: https://github.com/ruby/ruby/pull/8192

The parser does not free the `tbl` of the `struct vtable` when there are leftover `lvtbl` in the parser. This causes a memory leak.

The following script reproduces this issue:

```ruby
10.times do
  100_000.times do
    Ripper.parse("class Foo")
  end

  puts `ps -o rss= -p #{$$}`
end
```

-- 
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