[opencv3] Update to 3.4.8

[JackBoosY]

Update opencv3 to 3.4.8.

Related: #8641.

[cenit]

Variables that are defined using ocv_update can be modified setting them through vcpkg_configure_cmake instead of patching them in the source code

[JackBoosY]

In SOURCE/cmake/OpenCVVersion.cmake:

SET(OPENCV_VERSION_FILE "${CMAKE_CURRENT_SOURCE_DIR}/modules/core/include/opencv2/core/version.hpp")
file(STRINGS "${OPENCV_VERSION_FILE}" OPENCV_VERSION_PARTS REGEX "#define CV_VERSION_[A-Z]+[ ]+" )

string(REGEX REPLACE ".+CV_VERSION_MAJOR[ ]+([0-9]+).*" "\\1" OPENCV_VERSION_MAJOR "${OPENCV_VERSION_PARTS}")
string(REGEX REPLACE ".+CV_VERSION_MINOR[ ]+([0-9]+).*" "\\1" OPENCV_VERSION_MINOR "${OPENCV_VERSION_PARTS}")
string(REGEX REPLACE ".+CV_VERSION_REVISION[ ]+([0-9]+).*" "\\1" OPENCV_VERSION_PATCH "${OPENCV_VERSION_PARTS}")
string(REGEX REPLACE ".+CV_VERSION_STATUS[ ]+\"([^\"]*)\".*" "\\1" OPENCV_VERSION_STATUS "${OPENCV_VERSION_PARTS}")

We cannot pass OPENCV_VERSION MAJOR into vcpkg_configure_cmake because it will be overwritten here.

[cenit]

Sorry I don't understand. I was telling you to pass value from the port file because it is much easier to maintain, instead of patching source code. Those variables became managed through ocv_update exactly because we were patching them (they were not supposed to be modified by users in the beginning), in order to ease our work here :)

[cenit]

Pass OPENCV_DLLVERSION="" from the portfile :)

[cenit]

They are skipped because they conflict with opencv/opencv4.

[cenit]

If you want to use CI to test opencv3 you have to skip opencv4, but I am not sure that you would trigger an automatic removal in the installed folder in this way... So I fear that it's impossible to test opencv3 in CI

[JackBoosY]

If CI cannot test these features, I worry that this PR will last a long time.

[JackBoosY]

Once this PR is done, I will revert these changes.

[JackBoosY]

@Neumann-A When I build opencv3[qt], I found error message:

CMake Error at F:/vcpkg/installed/x86-windows/debug/lib/cmake/Qt5Widgets/Qt5WidgetsConfig.cmake:15 (message):
  The imported target "Qt5::Widgets" references the file

     "F:/vcpkg/installed/x86-windows/debug/tools/qt5/uic.exe"

  but this file does not exist.  Possible reasons include:

  * The file was deleted, renamed, or moved to another location.

  * An install or uninstall procedure did not complete successfully.

  * The installation package was faulty and contained

     "F:/vcpkg/installed/x86-windows/debug/lib/cmake/Qt5Widgets/Qt5WidgetsConfigExtras.cmake"

  but not all the files it references.

I cannot find uic.exe in path F:/vcpkg/installed/x86-windows/debug/tools.
So should this issue be a qt5 bug?

[Neumann-A]

@JackBoosY

F:/vcpkg/installed/x86-windows/debug/lib/cmake/Qt5Widgets/Qt5WidgetsConfig.cmake:15 (message):

This file should not exist at all. Delete the cmake folder in debug/lib

And I don't understand why it even exists since qt5-base has the line:
file(REMOVE_RECURSE ${CURRENT_PACKAGES_DIR}/debug/lib/cmake) # TODO: check if important debug information for cmake is lost

[JackBoosY]

@Neumann-A I guess my installed/x86-windows is not clean.

[JackBoosY]

@cenit
I found that opencv3 installs dynamic libraries in ${OpenCV_ARCH}/${OpenCV_RUNTIME} by default. Should we continue to use this setting?
It caused some problems in OpenCVModules-debug.cmake.

Nope, I found it was added in this release.

[JackBoosY]

It looks like we only have problems with static builds.

[cenit]

Together with @alalek we helped reviewing the #8557 which might contain the answer for your problem (and also the same comments about using portfile instead of patches for "ocv_update- managed" variables 😅)

[JackBoosY]

Same as before, instead of patching the source, pass the proper OPENCV_BIN_INSTALL_PATH from the port file

I hope it works. Because when I try to pass -DOPENCV_INSTALL_BINARIES_PREFIX=""to vcpkg_configure_cmake, the configuration process reports errors.

[cenit]

you have to pass them with the proper quotation sintax. The opencv4 port should contain an example :)

[Neumann-A]

with the proper quotation syntax

and proper escaping syntax if you want to pass a list of elements (7 or 9 backslashes needed for passing a list)..... all due to cmake_parse_arguments using the ARGN version. Would like to see a change to cmake_parse_arguments(PARSE_ARGV

[JackBoosY]

Since Opencv3 is updated to 3.4.10, I think this PR is no longer available.