Wireshark-dev: Re: [Wireshark-dev] Qt link errors (Q_INIT_RESOURCE)

From: Gerald Combs <gerald@xxxxxxxxxxxxx>
Date: Wed, 31 Mar 2021 11:45:04 -0700
I was able to replicate this using an opensuse/leap:42.3 docker image with a default build environment, which includes CMake 3.5.2 and Qt 5.6.2. I also installed various CMake versions and got the following results:

CMake 3.5.2: CMake succeeded, ninja failed
CMake 3.8.2: CMake succeeded, ninja failed
CMake 3.9.6: CMake succeeded, ninja failed
CMake 3.10.3: CMake + ninja succeeded
CMake 3.11.4: CMake + ninja succeeded
CMake 3.14.7: CMake + ninja succeeded
CMake 3.20.0: CMake + ninja succeeded

Fix inbound in MR 2578.

On 3/31/21 1:55 AM, Martin Mathieson wrote:
cmake --version
cmake version 3.5.2

qmake-qt5 --version
QMake version 3.0
Using Qt version 5.6.2 in /usr/lib64

This is an old VM that will be retired in around a month when a new machine arrives.


At the very end of running cmake I was getting this:

- Configuring done
Warning: Source file "/home/martin/wireshark_gl-build/ui/qt/CMakeFiles/qtui.dir/qrc_languages.cpp" is listed multiple times for target "qtui".
Warning: Source file "/home/martin/wireshark_gl-build/ui/qt/CMakeFiles/qtui.dir/qrc_layout.cpp" is listed multiple times for target "qtui".
Warning: Source file "/home/martin/wireshark_gl-build/ui/qt/CMakeFiles/qtui.dir/qrc_stock_icons.cpp" is listed multiple times for target "qtui".
Warning: Source file "/home/martin/wireshark_gl-build/ui/qt/CMakeFiles/qtui.dir/qrc_wsicon.cpp" is listed multiple times for target "qtui".
Warning: Source file "/home/martin/wireshark_gl-build/ui/qt/CMakeFiles/qtui.dir/qrc_i18n.cpp" is listed multiple times for target "qtui".
-- Generating done
-- Build files have been written to: /home/martin/wireshark_gl-build

If I move the Q_INIT_RESOURCE() calls to main.cpp (just before ws_app is created), I still get the link error.



Moving the CMAKE_AUTO stuff back to the top-level CMakeLists.txt does fix this for me, i.e.

diff --git a/CMakeLists.txt b/CMakeLists.txt
index ebc42d736b..161e978ce2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1135,9 +1135,6 @@ ws_find_package(Systemd BUILD_sdjournal HAVE_SYSTEMD)

  # Build the Qt GUI?
  if(BUILD_wireshark)
-       set(CMAKE_AUTOMOC ON)
-       set(CMAKE_AUTOUIC ON)
-       set(CMAKE_AUTORCC ON)

         # Untested, may not work if CMAKE_PREFIX_PATH gets overwritten
         # somewhere. The if WIN32 in this place is annoying as well.
diff --git a/ui/qt/CMakeLists.txt b/ui/qt/CMakeLists.txt
index 2e08d60832..a63829eb61 100644
--- a/ui/qt/CMakeLists.txt
+++ b/ui/qt/CMakeLists.txt
@@ -630,6 +630,11 @@ set(WIRESHARK_QT_QRC
         ${CMAKE_CURRENT_BINARY_DIR}/i18n.qrc
  )

+set(CMAKE_AUTOMOC TRUE)
+set(CMAKE_AUTOUIC TRUE)
+set(CMAKE_AUTORCC TRUE)
+
+
  if(NOT Qt5Widgets_VERSION VERSION_LESS "5.9")
         # Drop the file modification time of source files from generated files
         # to help with reproducible builds. We do not use QFileInfo.lastModified


Martin


On Wed, Mar 31, 2021 at 12:38 AM Gerald Combs <gerald@xxxxxxxxxxxxx <mailto:gerald@xxxxxxxxxxxxx>> wrote:

    What versions of CMake and Qt are you using? I enabled CMAKE_AUTORCC earlier on in the configuration process in be2b0fc810, which might have caused this. You might try moving `set(CMAKE_AUTO...` back to ui/qt/CMakeLists.txt, but if that fixes the problem then we might have to enable CMAKE_AUTO* earlier or later depending on our CMake version.

    I also noticed that https://doc.qt.io/qt-5/qdir.html#Q_INIT_RESOURCE <https://doc.qt.io/qt-5/qdir.html#Q_INIT_RESOURCE> says

    "This macro cannot be used in a namespace. It should be called from main()."

    Maybe we need to move our Q_INIT_RESOURCE calls from wireshark_application.cpp to main.cpp?

    On 3/30/21 2:15 AM, Martin Mathieson via Wireshark-dev wrote:
     > I started getting this link error a day or 2 back:
     >
     > [ 98%] Linking CXX executable run/wireshark
     > /usr/lib64/gcc/x86_64-suse-linux/8/../../../../x86_64-suse-linux/bin/ld: ui/qt/CMakeFiles/qtui.dir/wireshark_application.cpp.o: in function `WiresharkApplication::WiresharkApplication(int&, char**)':
     > /home/martin/wireshark_gl/ui/qt/wireshark_application.cpp:639: undefined reference to `qInitResources_about()'
     > /usr/lib64/gcc/x86_64-suse-linux/8/../../../../x86_64-suse-linux/bin/ld: /home/martin/wireshark_gl/ui/qt/wireshark_application.cpp:640: undefined reference to `qInitResources_i18n()'
     > /usr/lib64/gcc/x86_64-suse-linux/8/../../../../x86_64-suse-linux/bin/ld: /home/martin/wireshark_gl/ui/qt/wireshark_application.cpp:641: undefined reference to `qInitResources_layout()'
     > /usr/lib64/gcc/x86_64-suse-linux/8/../../../../x86_64-suse-linux/bin/ld: /home/martin/wireshark_gl/ui/qt/wireshark_application.cpp:642: undefined reference to `qInitResources_stock_icons()'
     > /usr/lib64/gcc/x86_64-suse-linux/8/../../../../x86_64-suse-linux/bin/ld: /home/martin/wireshark_gl/ui/qt/wireshark_application.cpp:643: undefined reference to `qInitResources_wsicon()'
     > /usr/lib64/gcc/x86_64-suse-linux/8/../../../../x86_64-suse-linux/bin/ld: /home/martin/wireshark_gl/ui/qt/wireshark_application.cpp:644: undefined reference to `qInitResources_languages()'
     > collect2: error: ld returned 1 exit status
     >
     > Haven't worked out exactly why this is happening (or at which commit it started to fail).  If I do need to update Qt, the minimum version check in CMake isn't catching it.
     >
     > Martin
     >
     >
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