Restore mono build (#7377)

* Add mono build back into C# build

* Add mono build back into C# build

* Add mono build back into C# build

* Don't do mono build on Linux if dotnet is used

* CSharp dotnet build always on windows. Enable dotnet testing in vs_build_swit

* Fix typos

.azure-pipelines/vs_build_swig.yml

@@ -1,4 +1,9 @@
 steps:
+- task: UseDotNet@2
+  displayName: 'Install .NET Core 8 SDK'
+  inputs:
+    version: 8.x
+    performMultiLevelLookup: true
 - powershell: Write-Host "##vso[task.prependpath]$env:CONDA\Scripts"
   displayName: Setup build environment
 - script: |
@@ -53,7 +58,7 @@ steps:
     set PYTHONPATH=%RDBASE%;%PYTHONPATH%
     set PATH=%RDBASE%\lib;%PATH%
     cd build
-    ctest -C Release -j $(number_of_cores) --output-on-failure -T Test
+    ctest -R CSharpTests -C Release -T test --output-on-failure --verbose 
   displayName: Run tests
 - task: PublishTestResults@2
   inputs:

CMakeLists.txt

@@ -40,7 +40,7 @@ option(RDK_BUILD_SLN_SUPPORT "include support for the SLN format" ON )
 option(RDK_TEST_MULTITHREADED "run some tests of multithreading" ON )
 option(RDK_BUILD_SWIG_JAVA_WRAPPER "build the SWIG JAVA wrappers (does nothing if RDK_BUILD_SWIG_WRAPPERS is not set)" ON )
 option(RDK_BUILD_SWIG_CSHARP_WRAPPER "build the experimental SWIG C# wrappers (does nothing if RDK_BUILD_SWIG_WRAPPERS is not set)" OFF )
-option(RDK_BUILD_DOTNET_CSHARP_TESTS "build the DotNet Core tests for C# wrappers (does nothing if RDK_BUILD_SWIG_CSHARP_WRAPPER is not set)" OFF )
+option(RDK_BUILD_DOTNET_CSHARP_TESTS "build the DotNet Core tests for C# wrappers on Linux (does nothing if RDK_BUILD_SWIG_CSHARP_WRAPPER is not set and is ignored on Windows)" OFF )
 option(RDK_SWIG_STATIC "statically link rdkit libraries into the SWIG wrappers" ON )
 option(RDK_TEST_MMFF_COMPLIANCE "run MMFF compliance tests (requires tar/gzip)" ON )
 option(RDK_BUILD_CPP_TESTS "build the c++ tests (disabing can speed up builds" ON)

Code/JavaWrappers/csharp_wrapper/CMakeLists.txt

@@ -81,7 +81,7 @@ SWIG_LINK_LIBRARIES(RDKFuncs ${RDKit_Wrapper_Libs}
 INSTALL(TARGETS RDKFuncs
         DESTINATION ${CMAKE_CURRENT_SOURCE_DIR} )
 
-if (RDK_BUILD_DOTNET_CSHARP_TESTS)
+if (RDK_BUILD_DOTNET_CSHARP_TESTS OR MSVC)
 
   find_program(DOTNET_EXE dotnet)
   if (NOT DOTNET_EXE)
@@ -108,5 +108,26 @@ if (RDK_BUILD_DOTNET_CSHARP_TESTS)
     COMMAND ${DOTNET_EXE} test RDKitDotNetCore.sln "-l:console$<SEMICOLON>verbosity=normal" 
     WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
   )
+else(RDK_BUILD_DOTNET_CSHARP_TESTS OR MSVC)
+  # find the mcs executable on non-windows systems, if dotnet is not used:
+  find_program(GMCS_EXE mcs)
+  if (NOT GMCS_EXE)
+	MESSAGE ("mcs (executable) is not found. Please add it to PATH and rerun cmake.")
+	MESSAGE(FATAL_ERROR "Cannot find required executable mcs")
+  endif (NOT GMCS_EXE)
+
+  # code adapted from the wrapper code for
+  # GDCM: http://gdcm.svn.sf.net/viewvc/gdcm/trunk/Wrapping/Java/CMakeLists.txt?view=markup
+  ADD_CUSTOM_COMMAND(
+    OUTPUT ${CMAKE_CURRENT_SOURCE_DIR}/RDKit2DotNet.dll
+    ## 1. run this custom command only after swig has been run.
+    COMMAND ${GMCS_EXE} -platform:${PLATFORM} -out:RDKit2DotNet.dll -t:library "swig_csharp/*.cs"
+    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+    DEPENDS "${swig_generated_file_fullname}"
+  )
+  ADD_CUSTOM_TARGET(RDKFuncsDLL ALL
+    DEPENDS RDKFuncs ${CMAKE_CURRENT_SOURCE_DIR}/RDKit2DotNet.dll
+    COMMENT "building mono dll"
+  )
+endif(RDK_BUILD_DOTNET_CSHARP_TESTS OR MSVC)
 
-endif()