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  1. Qt
  2. QTBUG-97816

Prevent linker from discarding unused shared libraries

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Details

    • Bug
    • Resolution: Unresolved
    • P3: Somewhat important
    • None
    • 6.2.1
    • Build System: CMake

    Description

      There are scenarios where we want to link to a shared library, but we don't actually use any symbols from it (e.g. with QML modules where the consumer may want to link only to the backing library and not need the associated plugin at all). Some linkers will discard that library as an optimization, since they think it is unused. We want some way of conveniently telling the linker not to discard a library in this situation, but currently there is no easy way to do that. Different linkers use different linker flags, some don't allow you to specify it at per-library level and only at a whole-of-link level (e.g. the MSVC linker).

      Reported as a specific use case in the broader upstream CMake issue for linker decorations: https://gitlab.kitware.com/cmake/cmake/-/issues/22812#note_1074118

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        Issue Links

          relates to

          Bug - A problem which impairs or prevents the functions of the product. QTBUG-128568 [REG Qt 6.7.0-> 6.8.0 beta4] QML module linked as library doesn't work anymore

          • P1: Critical - Urgent and Important, will STOP the release if matched with set FixVersion field. This includes regressions from the last version that are not edge cases; Data loss; Build issues; All but the most unlikely crashes/lockups/hanging; Serious usability issues and embarrassing bugs & Bugs critical to a deliverable. This is the highest possible priority for requirements.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. QTBUG-80863 [cmake] excessive compilation of Import.cpp files for static plugins

          • P3: Somewhat important - Should be fixed, but doesn't affect the release in any way.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. QTBUG-91448 Undefined resource symbols when linking app with a static Qt without qmake and CMake

          • P2: Important - Urgent, should be fixed, but will not stop the release.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. QTBUG-110243 Resources are lost when linking static libraries using CMake build system in a separate project

          • P2: Important - Urgent, should be fixed, but will not stop the release.
          • Closed

          Technical task - A technical task. QTBUG-95149 Fix use case of linking an executable to a shared library QML module backing target

          • P2: Important - Urgent, should be fixed, but will not stop the release.
          • Reported
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              qtbuildsystem Qt Build System Team
              crscott Craig Scott
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              Dates

                Created:
                Updated:

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