diff --git a/clang/runtime/CMakeLists.txt b/clang/runtime/CMakeLists.txt
--- a/clang/runtime/CMakeLists.txt
+++ b/clang/runtime/CMakeLists.txt
@@ -75,6 +75,7 @@
     CMAKE_ARGS ${CLANG_COMPILER_RT_CMAKE_ARGS}
                -DCMAKE_C_COMPILER=${LLVM_RUNTIME_OUTPUT_INTDIR}/clang
                -DCMAKE_CXX_COMPILER=${LLVM_RUNTIME_OUTPUT_INTDIR}/clang++
+               -DCMAKE_ASM_COMPILER=${LLVM_RUNTIME_OUTPUT_INTDIR}/clang
                -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
                -DCMAKE_MAKE_PROGRAM=${CMAKE_MAKE_PROGRAM}
                -DLLVM_CONFIG_PATH=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-config
diff --git a/compiler-rt/cmake/Modules/AddCompilerRT.cmake b/compiler-rt/cmake/Modules/AddCompilerRT.cmake
--- a/compiler-rt/cmake/Modules/AddCompilerRT.cmake
+++ b/compiler-rt/cmake/Modules/AddCompilerRT.cmake
@@ -109,11 +109,11 @@
 
 function(add_asm_sources output)
   set(${output} ${ARGN} PARENT_SCOPE)
-  # Xcode will try to compile asm files as C ('clang -x c'), and that will fail.
-  if (${CMAKE_GENERATOR} STREQUAL "Xcode")
-    enable_language(ASM)
-  else()
-    # Pass ASM file directly to the C++ compiler.
+  # CMake doesn't pass the correct architecture for Apple prior to CMake 3.19. https://gitlab.kitware.com/cmake/cmake/-/issues/20771
+  # MinGW didn't work correctly with assembly prior to CMake 3.17. https://gitlab.kitware.com/cmake/cmake/-/merge_requests/4287 and https://reviews.llvm.org/rGb780df052dd2b246a760d00e00f7de9ebdab9d09
+  # Workaround these two issues by compiling as C.
+  # Same workaround used in libunwind. Also update there if changed here.
+  if((APPLE AND CMAKE_VERSION VERSION_LESS 3.19) OR (MINGW AND CMAKE_VERSION VERSION_LESS 3.17))
     set_source_files_properties(${ARGN} PROPERTIES LANGUAGE C)
   endif()
 endfunction()
diff --git a/libunwind/src/CMakeLists.txt b/libunwind/src/CMakeLists.txt
--- a/libunwind/src/CMakeLists.txt
+++ b/libunwind/src/CMakeLists.txt
@@ -24,14 +24,10 @@
     UnwindRegistersRestore.S
     UnwindRegistersSave.S
     )
-if (MINGW OR APPLE)
-  # CMake doesn't build assembly sources for windows/gnu targets properly
-  # (up to current CMake, 3.16), so treat them as C files.
-  # Additionally, CMake ignores OSX_ARCHITECTURE for ASM files when targeting
-  # Apple platforms.
-  set_source_files_properties(${LIBUNWIND_ASM_SOURCES}
-                              PROPERTIES
-                                LANGUAGE C)
+
+# See add_asm_sources() in compiler-rt for explanation of this workaround.
+if((APPLE AND CMAKE_VERSION VERSION_LESS 3.19) OR (MINGW AND CMAKE_VERSION VERSION_LESS 3.17))
+  set_source_files_properties(${LIBUNWIND_ASM_SOURCES} PROPERTIES LANGUAGE C)
 endif()
 
 set(LIBUNWIND_HEADERS