VS: Provide an option to specify CUDA toolset version

The NVIDIA CUDA Toolkit provides MSBuild toolset files for integration
with Visual Studio.  Multiple versions may be installed so we need a way
to tell our VS generators which CUDA toolset to use.  Extend the
`CMAKE_GENERATOR_TOOLSET` specification to provide a `cuda=...` field
specifying the version number.

Help/manual/cmake-variables.7.rst

@@ -82,6 +82,7 @@ Variables that Provide Information
    /variable/CMAKE_VS_NsightTegra_VERSION
    /variable/CMAKE_VS_PLATFORM_NAME
    /variable/CMAKE_VS_PLATFORM_TOOLSET
+   /variable/CMAKE_VS_PLATFORM_TOOLSET_CUDA
    /variable/CMAKE_VS_PLATFORM_TOOLSET_HOST_ARCHITECTURE
    /variable/CMAKE_VS_WINDOWS_TARGET_PLATFORM_VERSION
    /variable/CMAKE_XCODE_PLATFORM_TOOLSET

Help/variable/CMAKE_VS_PLATFORM_TOOLSET_CUDA.rst

+CMAKE_VS_PLATFORM_TOOLSET_CUDA
+------------------------------
+
+NVIDIA CUDA Toolkit version whose Visual Studio toolset to use.
+
+The :ref:`Visual Studio Generators` for VS 2010 and above support using
+a CUDA toolset provided by a CUDA Toolkit.  The toolset version number
+may be specified by a field in :variable:`CMAKE_GENERATOR_TOOLSET` of
+the form ``cuda=8.0``.  CMake provides the selected CUDA toolset version
+in this variable.  The value may be empty if no version was specified.

Source/cmGlobalVisualStudio10Generator.cxx

@@ -186,6 +186,9 @@ bool cmGlobalVisualStudio10Generator::SetGeneratorToolset(
   if (const char* hostArch = this->GetPlatformToolsetHostArchitecture()) {
     mf->AddDefinition("CMAKE_VS_PLATFORM_TOOLSET_HOST_ARCHITECTURE", hostArch);
   }
+  if (const char* cuda = this->GetPlatformToolsetCuda()) {
+    mf->AddDefinition("CMAKE_VS_PLATFORM_TOOLSET_CUDA", cuda);
+  }
   return true;
 }
 
@@ -261,8 +264,10 @@ bool cmGlobalVisualStudio10Generator::ParseGeneratorToolset(
 bool cmGlobalVisualStudio10Generator::ProcessGeneratorToolsetField(
   std::string const& key, std::string const& value)
 {
-  static_cast<void>(key);
-  static_cast<void>(value);
+  if (key == "cuda") {
+    this->GeneratorToolsetCuda = value;
+    return true;
+  }
   return false;
 }
 
@@ -463,6 +468,20 @@ cmGlobalVisualStudio10Generator::GetPlatformToolsetHostArchitecture() const
   return CM_NULLPTR;
 }
 
+const char* cmGlobalVisualStudio10Generator::GetPlatformToolsetCuda() const
+{
+  if (!this->GeneratorToolsetCuda.empty()) {
+    return this->GeneratorToolsetCuda.c_str();
+  }
+  return CM_NULLPTR;
+}
+
+std::string const&
+cmGlobalVisualStudio10Generator::GetPlatformToolsetCudaString() const
+{
+  return this->GeneratorToolsetCuda;
+}
+
 bool cmGlobalVisualStudio10Generator::FindMakeProgram(cmMakefile* mf)
 {
   if (!this->cmGlobalVisualStudio8Generator::FindMakeProgram(mf)) {

Source/cmGlobalVisualStudio10Generator.h

@@ -53,6 +53,10 @@ public:
   /** The toolset host architecture name (e.g. x64 for 64-bit host tools).  */
   const char* GetPlatformToolsetHostArchitecture() const;
 
+  /** The cuda toolset version.  */
+  const char* GetPlatformToolsetCuda() const;
+  std::string const& GetPlatformToolsetCudaString() const;
+
   /** Return the CMAKE_SYSTEM_NAME.  */
   std::string const& GetSystemName() const { return this->SystemName; }
 
@@ -118,6 +122,7 @@ protected:
 
   std::string GeneratorToolset;
   std::string GeneratorToolsetHostArchitecture;
+  std::string GeneratorToolsetCuda;
   std::string DefaultPlatformToolset;
   std::string WindowsTargetPlatformVersion;
   std::string SystemName;

Tests/RunCMake/GeneratorToolset/RunCMakeTest.cmake

@@ -6,6 +6,12 @@ run_cmake(NoToolset)
 if("${RunCMake_GENERATOR}" MATCHES "Visual Studio 1[01245]")
   set(RunCMake_GENERATOR_TOOLSET "Test Toolset")
   run_cmake(TestToolset)
+  set(RunCMake_GENERATOR_TOOLSET "Test Toolset,cuda=Test Cuda")
+  run_cmake(TestToolsetCudaBoth)
+  set(RunCMake_GENERATOR_TOOLSET ",cuda=Test Cuda")
+  run_cmake(TestToolsetCudaOnly)
+  set(RunCMake_GENERATOR_TOOLSET "cuda=Test Cuda")
+  run_cmake(TestToolsetCudaOnly)
   if("${RunCMake_GENERATOR}" MATCHES "Visual Studio 1[245]")
     set(RunCMake_GENERATOR_TOOLSET "Test Toolset,host=x64")
     run_cmake(TestToolsetHostArchBoth)

Tests/RunCMake/GeneratorToolset/TestToolsetCudaBoth-stdout.txt

+-- CMAKE_VS_PLATFORM_TOOLSET='Test Toolset'
+-- CMAKE_VS_PLATFORM_TOOLSET_CUDA='Test Cuda'

Tests/RunCMake/GeneratorToolset/TestToolsetCudaBoth.cmake

+message(STATUS "CMAKE_VS_PLATFORM_TOOLSET='${CMAKE_VS_PLATFORM_TOOLSET}'")
+message(STATUS "CMAKE_VS_PLATFORM_TOOLSET_CUDA='${CMAKE_VS_PLATFORM_TOOLSET_CUDA}'")

Tests/RunCMake/GeneratorToolset/TestToolsetCudaOnly-stdout.txt

+-- CMAKE_VS_PLATFORM_TOOLSET='(v[0-9]+|Windows7.1SDK)'
+-- CMAKE_VS_PLATFORM_TOOLSET_CUDA='Test Cuda'

Tests/RunCMake/GeneratorToolset/TestToolsetCudaOnly.cmake

+message(STATUS "CMAKE_VS_PLATFORM_TOOLSET='${CMAKE_VS_PLATFORM_TOOLSET}'")
+message(STATUS "CMAKE_VS_PLATFORM_TOOLSET_CUDA='${CMAKE_VS_PLATFORM_TOOLSET_CUDA}'")