Bug #12018: Tail call optimization is incorrectly applied in Ruby 2.3.0

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 2.4.0dev (2016-01-25 trunk 53652) [x86_64-linux]
• Backport: 2.0.0: DONTNEED, 2.1: DONTNEED, 2.2: DONTNEED, 2.3: DONE

[rhenium (Kazuki Yamaguchi)]

r51903 changed the operand order of send/invokesuper instructions, but the code applying tail call optimization still looks at the second operand, which is now CALL_CACHE.
The following code causes a segmentation fault:

RubyVM::InstructionSequence.compile_option = { tailcall_optimization: true }

def just_yield
  yield
end

eval "just_yield { }"

I attached a patch to fix it.

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed

Applied in changeset r53658.

---

compile.c: fix tailcall optimization

• compile.c (iseq_peephole_optimize): don't apply tailcall
  optimization to send/invokesuper instructions with blockiseq.
  This is a follow-up to the changes in r51903; blockiseq is now
  the third operand of send/invokesuper instructions.
  [ruby-core:73413] [Bug #12018]

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN, 2.3: UNKNOWN to 2.0.0: DONTNEED, 2.1: DONTNEED, 2.2: DONTNEED, 2.3: REQUIRED

[naruse (Yui NARUSE)]

• Backport changed from 2.0.0: DONTNEED, 2.1: DONTNEED, 2.2: DONTNEED, 2.3: REQUIRED to 2.0.0: DONTNEED, 2.1: DONTNEED, 2.2: DONTNEED, 2.3: DONE

ruby_2_3 r54401 merged revision(s) 53658.