Merge topic 'cuda_clang_toolkit_path' into release-3.18

ec59fb6c31 CUDA: Determine CUDA toolkit location for NVCC
0a056246a1 CUDA: Pass toolkit path to Clang
9c43972127 FindCUDAToolkit: Avoid unnecessary temporary variable computing binary dir
9eebb5b8b2 FindCUDAToolkit: Remove unnecessary checks around searches
8f01fe7bf1 FindCUDAToolkit: Use list(SORT) to sort in natural order
8c144fe9ad FindCUDAToolkit: Compute CUDAToolkit_INCLUDE_DIR instead of searching
403f8d31e3 FindCUDAToolkit: Add CUDAToolkit_LIBRARY_ROOT
6636693134 FindCUDAToolkit: Re-unify with Internal/CUDAToolkit

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !4828

Source/cmGeneratorTarget.cxx

@@ -37,6 +37,7 @@
 #include "cmLocalGenerator.h"
 #include "cmMakefile.h"
 #include "cmMessageType.h"
+#include "cmOutputConverter.h"
 #include "cmPropertyMap.h"
 #include "cmRange.h"
 #include "cmSourceFile.h"
@@ -3152,6 +3153,28 @@ void cmGeneratorTarget::AddCUDAArchitectureFlags(std::string& flags) const
   }
 }
 
+void cmGeneratorTarget::AddCUDAToolkitFlags(std::string& flags) const
+{
+  std::string const& compiler =
+    this->Makefile->GetSafeDefinition("CMAKE_CUDA_COMPILER_ID");
+
+  if (compiler == "Clang") {
+    // Pass CUDA toolkit explicitly to Clang.
+    // Clang's searching for the system CUDA toolkit isn't very good and it's
+    // expected the user will explicitly pass the toolkit path.
+    // This also avoids Clang having to search for the toolkit on every
+    // invocation.
+    std::string toolkitRoot =
+      this->Makefile->GetSafeDefinition("CMAKE_CUDA_COMPILER_LIBRARY_ROOT");
+
+    if (!toolkitRoot.empty()) {
+      flags += " --cuda-path=" +
+        this->LocalGenerator->ConvertToOutputFormat(toolkitRoot,
+                                                    cmOutputConverter::SHELL);
+    }
+  }
+}
+
 //----------------------------------------------------------------------------
 std::string cmGeneratorTarget::GetFeatureSpecificLinkRuleVariable(
   std::string const& var, std::string const& lang,

Source/cmGeneratorTarget.h

@@ -426,6 +426,7 @@ public:
                      std::vector<std::string>& archVec) const;
 
   void AddCUDAArchitectureFlags(std::string& flags) const;
+  void AddCUDAToolkitFlags(std::string& flags) const;
 
   std::string GetFeatureSpecificLinkRuleVariable(
     std::string const& var, std::string const& lang,

Source/cmLocalGenerator.cxx

@@ -1986,6 +1986,7 @@ void cmLocalGenerator::AddLanguageFlags(std::string& flags,
     }
   } else if (lang == "CUDA") {
     target->AddCUDAArchitectureFlags(flags);
+    target->AddCUDAToolkitFlags(flags);
 
     std::string const& compiler =
       this->Makefile->GetSafeDefinition("CMAKE_CUDA_COMPILER_ID");