CUDA/Clang: Add support for MSVC ABI on Windows using GNU-like frontend

Fixes: #20776

Help/release/dev/cuda-clang-windows.rst

@@ -0,0 +1,5 @@
+cuda-clang-windows
+------------------
+
+* The ``CUDA`` language can now be compiled with Clang on Windows
+  using its GNU-like frontend, ``clang++``.

Modules/CMakeDetermineCUDACompiler.cmake

@@ -74,10 +74,6 @@ if(NOT CMAKE_CUDA_COMPILER_ID_RUN)
     set(CMAKE_CUDA_COMPILER_ID_VENDOR_REGEX_Clang "(clang version)")
     CMAKE_DETERMINE_COMPILER_ID_VENDOR(CUDA "--version")
 
-    if(CMAKE_CUDA_COMPILER_ID STREQUAL "Clang" AND WIN32)
-      message(FATAL_ERROR "Clang with CUDA is not yet supported on Windows. See CMake issue #20776.")
-    endif()
-
     # Find the CUDA toolkit to get:
     # - CMAKE_CUDA_COMPILER_TOOLKIT_VERSION
     # - CMAKE_CUDA_COMPILER_TOOLKIT_ROOT

Modules/Compiler/Clang.cmake

@@ -17,6 +17,7 @@ set(__pch_header_OBJCXX "objective-c++-header")
 
 if("x${CMAKE_C_SIMULATE_ID}" STREQUAL "xMSVC"
     OR "x${CMAKE_CXX_SIMULATE_ID}" STREQUAL "xMSVC"
+    OR "x${CMAKE_CUDA_SIMULATE_ID}" STREQUAL "xMSVC"
     OR "x${CMAKE_Fortran_SIMULATE_ID}" STREQUAL "xMSVC")
   macro(__compiler_clang lang)
   endmacro()

Modules/Platform/Windows-Clang-CUDA.cmake

@@ -0,0 +1,16 @@
+include(Platform/Windows-Clang)
+__windows_compiler_clang(CUDA)
+
+# Tell Clang where to find the CUDA libraries.
+set(__IMPLICIT_LINKS)
+foreach(dir ${CMAKE_CUDA_HOST_IMPLICIT_LINK_DIRECTORIES})
+  string(APPEND __IMPLICIT_LINKS " -L\"${dir}\"")
+endforeach()
+string(APPEND CMAKE_CUDA_LINK_EXECUTABLE "${__IMPLICIT_LINKS}")
+string(APPEND CMAKE_CUDA_CREATE_SHARED_LIBRARY "${__IMPLICIT_LINKS}")
+string(APPEND CMAKE_CUDA_CREATE_SHARED_MODULE "${__IMPLICIT_LINKS}")
+unset(__IMPLICIT_LINKS)
+
+# Device linking is just regular linking so these are the same.
+set(CMAKE_CUDA_DEVICE_LINKER_WRAPPER_FLAG ${CMAKE_CUDA_LINKER_WRAPPER_FLAG})
+set(CMAKE_CUDA_DEVICE_LINKER_WRAPPER_FLAG_SEP ${CMAKE_CUDA_LINKER_WRAPPER_FLAG_SEP})

Modules/Platform/Windows-Clang.cmake

@@ -53,6 +53,7 @@ macro(__windows_compiler_clang_gnu lang)
   set(CMAKE_${lang}_LINK_OPTIONS_PIE "")
   set(CMAKE_${lang}_LINK_OPTIONS_NO_PIE "")
   set(CMAKE_SHARED_LIBRARY_${lang}_FLAGS "")
+  set(CMAKE_SHARED_LIBRARY_CREATE_${lang}_FLAGS "-shared")
 
   set(CMAKE_${lang}_LINK_LIBRARIES_PROCESSING ORDER=FORWARD UNICITY=ALL)
 
@@ -184,18 +185,19 @@ endmacro()
 
 if("x${CMAKE_C_SIMULATE_ID}" STREQUAL "xMSVC"
     OR "x${CMAKE_CXX_SIMULATE_ID}" STREQUAL "xMSVC"
+    OR "x${CMAKE_CUDA_SIMULATE_ID}" STREQUAL "xMSVC"
     OR "x${CMAKE_HIP_SIMULATE_ID}" STREQUAL "xMSVC")
 
   __verify_same_language_values(COMPILER_ID
                                 "The current configuration mixes Clang and MSVC or "
                                 "some other CL compatible compiler tool. This is not supported. "
-                                "Use either clang or MSVC as both C, C++ and/or HIP compilers.")
+                                "Use either Clang or MSVC as the compiler for all of C, C++, CUDA and/or HIP.")
 
   __verify_same_language_values(COMPILER_FRONTEND_VARIANT
                                 "The current configuration uses the Clang compiler "
                                 "tool with mixed frontend variants, both the GNU and in MSVC CL "
                                 "like variants. This is not supported. Use either clang/clang++ "
-                                "or clang-cl as both C, C++ and/or HIP compilers.")
+                                "or clang-cl as all C, C++, CUDA and/or HIP compilers.")
 
   if(NOT CMAKE_RC_COMPILER_INIT)
     # Check if rc is already in the path
@@ -217,6 +219,7 @@ if("x${CMAKE_C_SIMULATE_ID}" STREQUAL "xMSVC"
 
   if ( "x${CMAKE_CXX_COMPILER_FRONTEND_VARIANT}" STREQUAL "xMSVC"
       OR "x${CMAKE_C_COMPILER_FRONTEND_VARIANT}" STREQUAL "xMSVC"
+      OR "x${CMAKE_CUDA_COMPILER_FRONTEND_VARIANT}" STREQUAL "xMSVC"
       OR "x${CMAKE_HIP_COMPILER_FRONTEND_VARIANT}" STREQUAL "xMSVC")
 
     include(Platform/Windows-MSVC)

Tests/Cuda/CMakeLists.txt

@@ -9,8 +9,10 @@ add_cuda_test_macro(Cuda.ObjectLibrary CudaObjectLibrary)
 add_cuda_test_macro(Cuda.MixedStandardLevels1 MixedStandardLevels1)
 add_cuda_test_macro(Cuda.MixedStandardLevels2 MixedStandardLevels2)
 add_cuda_test_macro(Cuda.MixedStandardLevels3 MixedStandardLevels3)
-add_cuda_test_macro(Cuda.MixedStandardLevels4 MixedStandardLevels4)
-add_cuda_test_macro(Cuda.MixedStandardLevels5 MixedStandardLevels5)
+if(NOT WIN32 OR NOT CMake_TEST_CUDA STREQUAL "Clang") # MSVC std lib needs C++14
+  add_cuda_test_macro(Cuda.MixedStandardLevels4 MixedStandardLevels4)
+  add_cuda_test_macro(Cuda.MixedStandardLevels5 MixedStandardLevels5)
+endif()
 add_cuda_test_macro(Cuda.NotEnabled CudaNotEnabled)
 add_cuda_test_macro(Cuda.SeparableCompCXXOnly SeparableCompCXXOnly)
 add_cuda_test_macro(Cuda.StubRPATH StubRPATH)

Tests/CudaOnly/CMakeLists.txt

@@ -11,7 +11,9 @@ add_cuda_test_macro(CudaOnly.EnableStandard CudaOnlyEnableStandard)
 add_cuda_test_macro(CudaOnly.ExportPTX CudaOnlyExportPTX)
 add_cuda_test_macro(CudaOnly.SharedRuntimePlusToolkit CudaOnlySharedRuntimePlusToolkit)
 add_cuda_test_macro(CudaOnly.StaticRuntimePlusToolkit CudaOnlyStaticRuntimePlusToolkit)
-add_cuda_test_macro(CudaOnly.Standard98 CudaOnlyStandard98)
+if(NOT WIN32 OR NOT CMake_TEST_CUDA STREQUAL "Clang") # MSVC std lib needs C++14
+  add_cuda_test_macro(CudaOnly.Standard98 CudaOnlyStandard98)
+endif()
 set(CudaOnly.Toolkit_BUILD_OPTIONS -DHAS_CUPTI:BOOL=${CMake_TEST_CUDA_CUPTI})
 add_cuda_test_macro(CudaOnly.Toolkit CudaOnlyToolkit)
 add_cuda_test_macro(CudaOnly.ToolkitBeforeLang CudaOnlyToolkitBeforeLang)

Tests/MSVCDebugInformationFormat/override-CUDA.cmake

@@ -1,5 +1,6 @@
 set(var "CMAKE_CUDA_COMPILE_OPTIONS_MSVC_DEBUG_INFORMATION_FORMAT_Embedded")
 string(REPLACE "-Z7" "-Z7;-DTEST_Z7" "${var}" "${${var}}")
+string(REPLACE "-gcodeview" "-gcodeview;-DTEST_Z7" "${var}" "${${var}}")
 set(var "CMAKE_CUDA_COMPILE_OPTIONS_MSVC_DEBUG_INFORMATION_FORMAT_ProgramDatabase")
 string(REPLACE "-Zi" "-Zi;-DTEST_Zi" "${var}" "${${var}}")
 set(var "CMAKE_CUDA_COMPILE_OPTIONS_MSVC_DEBUG_INFORMATION_FORMAT_EditAndContinue")

Tests/RunCMake/NinjaMultiConfig/Common.cmake

@@ -37,7 +37,7 @@ function(generate_output_files)
       set(exe_file " [==[$<TARGET_FILE_DIR:${tgt}>/$<TARGET_FILE_PREFIX:${tgt}>$<TARGET_FILE_BASE_NAME:${tgt}>$<TARGET_FILE_SUFFIX:${tgt}>]==]")
       set(exe_filename " [==[$<TARGET_FILE_PREFIX:${tgt}>$<TARGET_FILE_BASE_NAME:${tgt}>$<TARGET_FILE_SUFFIX:${tgt}>]==]")
 
-      if(WIN32)
+      if(WIN32 AND NOT generate_output_files_NO_EXE_LIB)
         set(exe_lib_file " [==[$<TARGET_FILE_DIR:${tgt}>/$<TARGET_FILE_PREFIX:${tgt}>$<TARGET_FILE_BASE_NAME:${tgt}>.lib]==]")
         string(APPEND content "set(TARGET_EXE_LIB_FILE_${tgt}_$<CONFIG>${exe_lib_file})\n")
       endif()

Tests/RunCMake/NinjaMultiConfig/CudaSimple.cmake

@@ -16,6 +16,9 @@ set_target_properties(simplecudaobj simplecudashared
 add_executable(simplecudaexe main.cu )
 target_link_libraries(simplecudaexe PRIVATE simplecudashared)
 
+if(WIN32 AND CMAKE_CUDA_COMPILER_ID STREQUAL "Clang")
+  set(generate_output_files_NO_EXE_LIB 1)
+endif()
 include(${CMAKE_CURRENT_LIST_DIR}/Common.cmake)
 generate_output_files(simplecudaexe simplecudashared simplecudaobj)