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  1. Swift
  2. SR-8276

Garbage witness table causes runtime crash while testing conditional conformance on i386 / iphonesimulator

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    Details

    • Type: Bug
    • Status: Open
    • Priority: Medium
    • Resolution: Unresolved
    • Component/s: Compiler
    • Labels:
      None
    • Environment:

      The failing target is the i386 / iphonesimulator target.

      x86_64 and the x86_64 / iphonesimulator both work fine.

      Description

      The PR https://github.com/apple/swift/pull/16238 triggers a runtime error when the swift CI runs on the i386 / iphonesimulator target.

       

      As can be seen from the investigation on the PR thread, the crash appears to have to do with a witness table containing garbage data.

      On a higher level, this witness table relates to the conditional conformance of a 'marker' protocol - and the crash occurs when an `is` check is made for conformance to the marker protocol. 

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            • Assignee:
              Unassigned
              Reporter:
              mortenbekditlevsen Morten Bek Ditlevsen
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              Dates

              • Created:
                Updated: