From 14163d7d6b818ac1add7d467b643abfed8fe7216 Mon Sep 17 00:00:00 2001
From: Raul Tambre <raul@tambre.ee>
Date: Tue, 16 Jun 2020 17:13:56 +0300
Subject: CUDA: Throw error for Clang on Windows

Supporting compiling on Windows is more complicated than initially expected, so
it won't make it into CMake 3.18.
Add a helpful error for users.
---
 Modules/CMakeDetermineCUDACompiler.cmake | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Modules/CMakeDetermineCUDACompiler.cmake b/Modules/CMakeDetermineCUDACompiler.cmake
index a0f7202..e12da45 100644
--- a/Modules/CMakeDetermineCUDACompiler.cmake
+++ b/Modules/CMakeDetermineCUDACompiler.cmake
@@ -198,6 +198,10 @@ if(NOT CMAKE_CUDA_COMPILER_ID_RUN)
       string(APPEND nvcc_test_flags " -ccbin=${CMAKE_CUDA_HOST_COMPILER}")
     endif()
   elseif(CMAKE_CUDA_COMPILER_ID STREQUAL "Clang")
+    if(WIN32)
+      message(FATAL_ERROR "Clang with CUDA is not yet supported on Windows. See CMake issue #20776.")
+    endif()
+
     set(clang_test_flags "--cuda-path=\"${CMAKE_CUDA_COMPILER_LIBRARY_ROOT}\"")
     if(CMAKE_CROSSCOMPILING)
       # Need to pass the host target and include directories if we're crosscompiling.
-- 
cgit v0.12


From fec7dd33d309aeccf870169d957c69f9ee523463 Mon Sep 17 00:00:00 2001
From: Raul Tambre <raul@tambre.ee>
Date: Tue, 16 Jun 2020 20:54:04 +0300
Subject: CUDA: Add issue number to Clang separable compilation error

---
 Source/cmLocalGenerator.cxx | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Source/cmLocalGenerator.cxx b/Source/cmLocalGenerator.cxx
index f748822..3b3f110 100644
--- a/Source/cmLocalGenerator.cxx
+++ b/Source/cmLocalGenerator.cxx
@@ -1997,7 +1997,8 @@ void cmLocalGenerator::AddLanguageFlags(std::string& flags,
       if (separable) {
         this->Makefile->IssueMessage(
           MessageType::FATAL_ERROR,
-          "CUDA_SEPARABLE_COMPILATION isn't supported on Clang.");
+          "CUDA_SEPARABLE_COMPILATION isn't supported on Clang. "
+          "See CMake issue #20726.");
       }
     }
   }
-- 
cgit v0.12


From bdb105ee94046f0b89e60c9fabe4e4a058844005 Mon Sep 17 00:00:00 2001
From: Raul Tambre <raul@tambre.ee>
Date: Tue, 16 Jun 2020 17:18:22 +0300
Subject: Help: Mention CUDA Clang limitations in 3.18 release notes

---
 Help/release/3.18.rst | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Help/release/3.18.rst b/Help/release/3.18.rst
index db5f62a..072f9aa 100644
--- a/Help/release/3.18.rst
+++ b/Help/release/3.18.rst
@@ -13,7 +13,8 @@ New Features
 Languages
 ---------
 
-* The ``CUDA`` language can now be compiled using Clang.
+* The ``CUDA`` language can now be compiled using Clang on non-Windows
+  platforms. Separable compilation is not yet supported on any platform.
 
 Command-Line
 ------------
-- 
cgit v0.12