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Bug #22533
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Peephole optimizer infinite loop
Bug #22533:
Peephole optimizer infinite loop
Description
The following code compiles a small loop with and without the peephole optimizer. It spawns a subprocess and waits 5 seconds before killing it to demonstrate the hang.
SRC = "while true; if true then 1 end; end"
pid = fork do
RubyVM::InstructionSequence.compile(SRC)
exit!(0)
end
deadline = Time.now + 5
status = nil
while Time.now < deadline
break if (status = Process.waitpid2(pid, Process::WNOHANG))
sleep 0.05
end
if status
puts "compiled (#{status[1].inspect}): not reproduced"
else
Process.kill(:KILL, pid)
Process.wait(pid)
puts "compile_parsey(#{SRC.inspect}) still running after 5s: killed (hang)"
end
ok = RubyVM::InstructionSequence.compile(SRC, nil, nil, 1, peephole_optimization: false)
puts "without the peephole pass it compiles: #{ok.to_a[13].size} body entries"
It also happens with .compile_parsey. This affects at least 3.4+ through master.
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