VS: Add support for per-config sources

Since commit 97cc29c766 (VS: Teach generators how to mark per-config
source files, 2017-04-10, v3.9.0-rc1~268^2~2) the VS generators have
known how to generate per-config sources.  We've now converted most
other code paths to support per-config sources, so drop the check
that disallows it.

This leaves only per-config support for precompiled headers and unity
build transformations, but those are optional features that can be
addressed later.

Fixes: #18233
Issue: #19789

Help/release/dev/vs-per-config-sources.rst

@@ -0,0 +1,5 @@
+vs-per-config-sources
+---------------------
+
+* :ref:`Visual Studio Generators` learned to support per-config sources.
+  Previously only :ref:`Command-Line Build Tool Generators` supported them.

Source/cmGlobalVisualStudioGenerator.cxx

@@ -799,15 +799,6 @@ void RegisterVisualStudioMacros(const std::string& macrosFile,
 bool cmGlobalVisualStudioGenerator::TargetIsFortranOnly(
   cmGeneratorTarget const* gt)
 {
-  // check to see if this is a fortran build
-  {
-    // Issue diagnostic if the source files depend on the config.
-    std::vector<cmSourceFile*> sources;
-    if (!gt->GetConfigCommonSourceFiles(sources)) {
-      return false;
-    }
-  }
-
   // If there's only one source language, Fortran has to be used
   // in order for the sources to compile.
   std::set<std::string> languages = gt->GetAllConfigCompileLanguages();

Tests/CMakeLists.txt

@@ -451,8 +451,12 @@ if(BUILD_TESTING)
   ADD_TEST_MACRO(StagingPrefix StagingPrefix)
   ADD_TEST_MACRO(ImportedSameName ImportedSameName)
   ADD_TEST_MACRO(InterfaceLibrary InterfaceLibrary)
-  if(NOT _isMultiConfig)
+  if(NOT CMAKE_GENERATOR STREQUAL "Xcode")
-    set(ConfigSources_BUILD_OPTIONS -DCMAKE_BUILD_TYPE=$<CONFIGURATION>)
+    if(_isMultiConfig)
+      set(ConfigSources_CTEST_OPTIONS --build-config $<CONFIGURATION>)
+    else()
+      set(ConfigSources_BUILD_OPTIONS -DCMAKE_BUILD_TYPE=$<CONFIGURATION>)
+    endif()
     ADD_TEST_MACRO(ConfigSources ConfigSources)
   endif()
   ADD_TEST_MACRO(SourcesProperty SourcesProperty)

Tests/RunCMake/TargetSources/RunCMakeTest.cmake

@@ -1,6 +1,6 @@
 include(RunCMake)
 
-if(RunCMake_GENERATOR MATCHES "Visual Studio|Xcode")
+if(RunCMake_GENERATOR STREQUAL "Xcode")
   run_cmake(ConfigNotAllowed)
 endif()