Consider using CMake AUTOMOC property instead of qt_wrap_cpp

[uilianries]

Hello!

We are just packaging the Node Editor project in Conan (PR conan-io/conan-center-index#24751) and it fails to be built when using Qt full dynamic libraries, so moc executable can not find its dependencies libraries due to a misconfiguration of ld library path. Of course, it will not happen in case Qt is fully static, or moc and rcc executables at least.

However, Nodeeditor is using qt_wrap_cpp which is marked as deprecated by CMake page, but still working. The CMake's page also recommends:

Consider updating the project to use the AUTOMOC target property instead for a more automated way of invoking the moc tool.

The CMake's suggestion here will not only reduce your CMakeLists.txt size, but also its maintenance as well.

I did a patch locally to validate this theory and it looks to be working: 0001-configure-automoc.patch

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9c9285b..a2e366c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -60,16 +60,6 @@ if (${QT_VERSION} VERSION_LESS 5.11.0)
   message(FATAL_ERROR "Requires qt version >= 5.11.0, Your current version is ${QT_VERSION}")
 endif()
 
-if (${QT_VERSION_MAJOR} EQUAL 6)
-  qt_add_resources(RESOURCES ./resources/resources.qrc)
-else()
-  qt5_add_resources(RESOURCES ./resources/resources.qrc)
-endif()
-
-# Unfortunately, as we have a split include/src, AUTOMOC doesn't work.
-# We'll have to manually specify some files
-set(CMAKE_AUTOMOC ON)
-
 set(CPP_SOURCE_FILES
   src/AbstractGraphModel.cpp
   src/AbstractNodeGeometry.cpp
@@ -95,6 +85,7 @@ set(CPP_SOURCE_FILES
   src/StyleCollection.cpp
   src/UndoCommands.cpp
   src/locateNode.cpp
+  resources/resources.qrc
 )
 
 set(HPP_HEADER_FILES
@@ -203,24 +194,8 @@ set_target_properties(QtNodes
 ######
 # Moc
 ##
+set_target_properties(QtNodes PROPERTIES AUTOMOC ON AUTORCC ON)
 
-file(GLOB_RECURSE HEADERS_TO_MOC include/QtNodes/internal/*.hpp)
-
-if (${QT_VERSION_MAJOR} EQUAL 6)
-  qt_wrap_cpp(nodes_moc
-      ${HEADERS_TO_MOC}
-      TARGET QtNodes
-    OPTIONS --no-notes # Don't display a note for the headers which don't produce a moc_*.cpp
-  )
-else()
-  qt5_wrap_cpp(nodes_moc
-  ${HEADERS_TO_MOC}
-  TARGET QtNodes
-  OPTIONS --no-notes # Don't display a note for the headers which don't produce a moc_*.cpp
-  )
-endif()
-
-target_sources(QtNodes PRIVATE ${nodes_moc})
 
 ###########
 # Examples

As a result, the build log still generates the qrc_resources.cpp, but now is automatically done by CMake:

[21/29] /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++ -DNODE_EDITOR_EXPORTS -DNODE_EDITOR_SHARED -DQT_CORE_LIB -DQT_GUI_LIB -DQT_NO_DEBUG -DQT_NO_KEYWORDS -DQT_OPENGL_LIB -DQT_WIDGETS_LIB -DQtNodes_EXPORTS -I/Users/uilian/.conan2/p/b/nodee61d0ab45eaa0f/b/build/Release/QtNodes_autogen/include -I/Users/uilian/.conan2/p/b/nodee61d0ab45eaa0f/b/src/include -I/Users/uilian/.conan2/p/b/nodee61d0ab45eaa0f/b/src/src -I/Users/uilian/.conan2/p/b/nodee61d0ab45eaa0f/b/src/include/QtNodes/internal -isystem /Users/uilian/.conan2/p/b/qt47cbbe2bd005f/p/include -isystem /Users/uilian/.conan2/p/b/qt47cbbe2bd005f/p/include/QtCore -isystem /Users/uilian/.conan2/p/b/qt47cbbe2bd005f/p/include/QtWidgets -isystem /Users/uilian/.conan2/p/b/qt47cbbe2bd005f/p/include/QtGui -isystem /Users/uilian/.conan2/p/b/qt47cbbe2bd005f/p/include/QtOpenGL -stdlib=libc++ -O3 -DNDEBUG -std=c++17 -arch arm64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX15.2.sdk -fPIC -Wall -Wextra -Werror -fPIC -MD -MT CMakeFiles/QtNodes.dir/QtNodes_autogen/3YJK5W5UP7/qrc_resources.cpp.o -MF CMakeFiles/QtNodes.dir/QtNodes_autogen/3YJK5W5UP7/qrc_resources.cpp.o.d -o CMakeFiles/QtNodes.dir/QtNodes_autogen/3YJK5W5UP7/qrc_resources.cpp.o -c /Users/uilian/.conan2/p/b/nodee61d0ab45eaa0f/b/build/Release/QtNodes_autogen/3YJK5W5UP7/qrc_resources.cpp

Here is my full build log, so you can visualize everything:

nodeeditor-3.0.11-macos-shared-patched.log

I see the comment in your CMakeLists.txt as well:

Unfortunately, as we have a split include/src, AUTOMOC doesn't work.

However, it was 7 years ago (PR #142) and many features changed in CMake since then.

Please, feel free to share your ideas about using AUTOMOC now. I could open a PR if needed.