[wxwidgets] Fix #4756

[ras0219]

Alternative approach compared to #13023

• What does your PR fix?
  Fixes wxwidgets installed but not detected by FindwxWidgets.cmake #4756

I'm able to successfully compile https://docs.wxwidgets.org/trunk/overview_helloworld.html with the following CMakeLists.txt:

cmake_minimum_required(VERSION 3.17)
project(foo)

add_executable(foo foo.cpp)

find_package(wxWidgets REQUIRED COMPONENTS core qa html xml aui adv stc webview base scintilla)
include(${wxWidgets_USE_FILE})
target_link_libraries(foo ${wxWidgets_LIBRARIES})

The source also required modification to add wxIMPLEMENT_WXWIN_MAIN_CONSOLE since our built copy of wxwidgets targets GUIs.

[marekr]

This seems like a very awkward hack with removing WXUSINGDLL and replacing it with #if 1 or 0.........

You are supposed to define WXUSINGDLL in your application. Your code would never compile outside VCPKG and this encourages people to make that (minor) error.

Edit:
Normally in cmake land, FindWxWidgets.cmake is supposed to append WXUSINGDLL automatically on Windows. I believe the stock findwxwidgets cmake module is where your problems lie.

We at the KiCad project have our own corrected copy of FindWxwidgets that fixes compatibility with vcpkg and have no need to violate the source of wxwidgets.
https://gitlab.com/kicad/code/kicad/-/blob/master/CMakeModules/FindwxWidgets.cmake#L513

[ras0219]

@marekr I'm really happy you've been able to work around these issues with a custom file!

However, in upstream vcpkg,

1. We really don't want to force every user to write a custom FindwxWidgets.cmake
2. We have to support more buildsystems than just CMake

Because vcpkg always deploys exactly one version of wxwidgets (either DLL or static) we can statically encode the linkage in the package, which removes a source of error on the consumption side. If the user correctly set the macro in their project, there will be no observable difference in the build. This is a technique we apply broadly across vcpkg for libraries to handle ABI-affecting macros.

[NancyLi1013]

/azp run

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Azure Pipelines successfully started running 1 pipeline(s).

[NancyLi1013]

The control file for wxchartdir has been delated. vcpkg.json seems missing in this PR.

[NancyLi1013]

The failure on osx:

There should be no bin\ directory in a static build, but /Users/vagrant/Data/packages/wxwidgets_x64-osx/bin is present.
There should be no debug\bin\ directory in a static build, but /Users/vagrant/Data/packages/wxwidgets_x64-osx/debug/bin is present.
If the creation of bin\ and/or debug\bin\ cannot be disabled, use this in the portfile to remove them

    if(VCPKG_LIBRARY_LINKAGE STREQUAL "static")
        file(REMOVE_RECURSE "${CURRENT_PACKAGES_DIR}/bin" "${CURRENT_PACKAGES_DIR}/debug/bin")
    endif()

[ras0219-msft]