CUDA: Do not device link if CUDA is not an enabled language

Checks added in commit 81b4d10d8f (CUDA: More exhaustive checks to
determine when to do device linking, 2019-05-09, v3.15.0-rc1~82^2)
assumed that CUDA properties would be set only if CUDA is enabled.

We cannot do a device link step if we do not have the CUDA language
enabled.  This was discovered as some projects unconditionally set CUDA
properties such as `CUDA_RESOLVE_DEVICE_SYMBOLS` even when the CUDA
language has not been enabled.

Fixes: #19432

4 files changed, 29 insertions, 0 deletions

diff --git a/Tests/Cuda/CMakeLists.txt b/Tests/Cuda/CMakeLists.txt
index 1b3daa6..a30071f 100644
--- a/Tests/Cuda/CMakeLists.txt
+++ b/Tests/Cuda/CMakeLists.txt
@@ -3,6 +3,7 @@ ADD_TEST_MACRO(Cuda.Complex CudaComplex)
 ADD_TEST_MACRO(Cuda.ConsumeCompileFeatures CudaConsumeCompileFeatures)
 ADD_TEST_MACRO(Cuda.ObjectLibrary CudaObjectLibrary)
 ADD_TEST_MACRO(Cuda.MixedStandardLevels MixedStandardLevels)
+ADD_TEST_MACRO(Cuda.NotEnabled CudaNotEnabled)
 ADD_TEST_MACRO(Cuda.ToolkitInclude CudaToolkitInclude)
 ADD_TEST_MACRO(Cuda.ProperDeviceLibraries ProperDeviceLibraries)
 ADD_TEST_MACRO(Cuda.ProperLinkFlags ProperLinkFlags)
diff --git a/Tests/Cuda/NotEnabled/CMakeLists.txt b/Tests/Cuda/NotEnabled/CMakeLists.txt
new file mode 100644
index 0000000..968751b
--- /dev/null
+++ b/Tests/Cuda/NotEnabled/CMakeLists.txt
@@ -0,0 +1,14 @@
+cmake_minimum_required(VERSION 3.7)
+project(CudaNotEnabled CXX)
+
+add_library(HasCudaProps lib.cxx)
+
+target_compile_features(HasCudaProps PUBLIC cxx_std_11)
+#Verify that setting this variables in a project that doesn't have CUDA
+#enabled allow for the project to configure and build correctly.
+#Tests the fix for #19432
+set_property(TARGET HasCudaProps PROPERTY CUDA_SEPARABLE_COMPILATION ON)
+set_property(TARGET HasCudaProps PROPERTY CUDA_RESOLVE_DEVICE_SYMBOLS ON)
+
+add_executable(CudaNotEnabled main.cxx)
+target_link_libraries(CudaNotEnabled PRIVATE HasCudaProps)
diff --git a/Tests/Cuda/NotEnabled/lib.cxx b/Tests/Cuda/NotEnabled/lib.cxx
new file mode 100644
index 0000000..5dae5a3
--- /dev/null
+++ b/Tests/Cuda/NotEnabled/lib.cxx
@@ -0,0 +1,5 @@
+
+int cxx_function(int input)
+{
+  return input;
+}
diff --git a/Tests/Cuda/NotEnabled/main.cxx b/Tests/Cuda/NotEnabled/main.cxx
new file mode 100644
index 0000000..a644207
--- /dev/null
+++ b/Tests/Cuda/NotEnabled/main.cxx
@@ -0,0 +1,9 @@
+
+#include <type_traits>
+
+int main(int argc, char** argv)
+{
+  // make sure we have c++11 enabled
+  using returnv = std::integral_constant<int, 0>;
+  return returnv::value;
+}