Uploaded image for project: 'Qt'
  1. Qt
  2. QTBUG-93814

QVariant is miscompiled if -Ofast, -ffast-math or friends are in the compiler flags

    XMLWordPrintable

    Details

    • Type: Bug
    • Status: Closed
    • Priority: Not Evaluated
    • Resolution: Incomplete
    • Affects Version/s: 5.15.2
    • Fix Version/s: None
    • Component/s: Core: Other
    • Labels:
      None
    • Platform/s:
      All

      Description

      If Qt is built with -Ofast, -ffast-math or other "risky" compiler flags, QVariant gets subtly miscompiled (-ffast-math implies -ffinite-math-only, resulting in NaN not being there, resulting in QVariant thinking anything fed into it could be a floating point number).

      This behavior is not immediately visible, but causes "funny" issues like kmail not displaying HTML messages or plasma-systemmonitor's UI being broken.

      While this is not strictly a Qt bug, it would be nice to catch this with an addition like

      #ifdef _FAST_MATH_
      #error Don't compile QVariant with -ffast-math, it needs NaN
      #endif

        Attachments

        No reviews matched the request. Check your Options in the drop-down menu of this sections header.

          Activity

            People

            Assignee:
            bero Bernhard Rosenkränzer
            Reporter:
            bero Bernhard Rosenkränzer
            Votes:
            0 Vote for this issue
            Watchers:
            4 Start watching this issue

              Dates

              Created:
              Updated:
              Resolved:

                Gerrit Reviews

                There are no open Gerrit changes