diff --git a/compiler-rt/CMakeLists.txt b/compiler-rt/CMakeLists.txt
--- a/compiler-rt/CMakeLists.txt
+++ b/compiler-rt/CMakeLists.txt
@@ -457,7 +457,7 @@
 append_list_if(MINGW -fms-extensions SANITIZER_COMMON_CFLAGS)
 
 # Set common link flags.
-append_list_if(COMPILER_RT_HAS_NODEFAULTLIBS_FLAG -nodefaultlibs SANITIZER_COMMON_LINK_FLAGS)
+append_list_if(C_SUPPORTS_NODEFAULTLIBS_FLAG -nodefaultlibs SANITIZER_COMMON_LINK_FLAGS)
 append_list_if(COMPILER_RT_HAS_Z_TEXT -Wl,-z,text SANITIZER_COMMON_LINK_FLAGS)
 
 if (COMPILER_RT_USE_BUILTINS_LIBRARY)
diff --git a/compiler-rt/cmake/config-ix.cmake b/compiler-rt/cmake/config-ix.cmake
--- a/compiler-rt/cmake/config-ix.cmake
+++ b/compiler-rt/cmake/config-ix.cmake
@@ -23,8 +23,8 @@
   endif()
 endif()
 
-check_c_compiler_flag(-nodefaultlibs COMPILER_RT_HAS_NODEFAULTLIBS_FLAG)
-if (COMPILER_RT_HAS_NODEFAULTLIBS_FLAG)
+check_c_compiler_flag(-nodefaultlibs C_SUPPORTS_NODEFAULTLIBS_FLAG)
+if (C_SUPPORTS_NODEFAULTLIBS_FLAG)
   set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nodefaultlibs")
   if (COMPILER_RT_HAS_LIBC)
     list(APPEND CMAKE_REQUIRED_LIBRARIES c)
diff --git a/libcxx/CMakeLists.txt b/libcxx/CMakeLists.txt
--- a/libcxx/CMakeLists.txt
+++ b/libcxx/CMakeLists.txt
@@ -593,7 +593,7 @@
     target_compile_definitions(${target} PRIVATE -D_LIBCPP_DISABLE_NEW_DELETE_DEFINITIONS)
   endif()
 
-  if (LIBCXX_HAS_COMMENT_LIB_PRAGMA)
+  if (C_SUPPORTS_COMMENT_LIB_PRAGMA)
     if (LIBCXX_HAS_PTHREAD_LIB)
       target_compile_definitions(${target} PRIVATE -D_LIBCPP_LINK_PTHREAD_LIB)
     endif()
@@ -774,7 +774,7 @@
 # Unfortunately this cannot be used universally because for example g++ supports
 # only -nodefaultlibs in which case all libraries will be removed and
 # all libraries but c++ have to be added in manually.
-  if (LIBCXX_SUPPORTS_NOSTDLIBXX_FLAG)
+  if (CXX_SUPPORTS_NOSTDLIBXX_FLAG)
     target_add_link_flags_if_supported(${target} PRIVATE "-nostdlib++")
   else()
     target_add_link_flags_if_supported(${target} PRIVATE "-nodefaultlibs")
@@ -782,7 +782,7 @@
     target_add_link_flags_if_supported(${target} PRIVATE "/nodefaultlib")
   endif()
 
-  if (LIBCXX_SUPPORTS_UNWINDLIB_NONE_FLAG AND LIBCXXABI_USE_LLVM_UNWINDER)
+  if (CXX_SUPPORTS_UNWINDLIB_EQ_NONE_FLAG AND LIBCXXABI_USE_LLVM_UNWINDER)
     # If we're linking directly against the libunwind that we're building
     # in the same invocation, don't try to link in the toolchain's
     # default libunwind (which may be missing still).
diff --git a/libcxx/cmake/Modules/HandleLibcxxFlags.cmake b/libcxx/cmake/Modules/HandleLibcxxFlags.cmake
--- a/libcxx/cmake/Modules/HandleLibcxxFlags.cmake
+++ b/libcxx/cmake/Modules/HandleLibcxxFlags.cmake
@@ -42,7 +42,7 @@
 
 macro(check_flag_supported flag)
     mangle_name("${flag}" flagname)
-    check_cxx_compiler_flag("${flag}" "LIBCXX_SUPPORTS_${flagname}_FLAG")
+    check_cxx_compiler_flag("${flag}" "CXX_SUPPORTS_${flagname}_FLAG")
 endmacro()
 
 macro(append_flags DEST)
@@ -63,8 +63,8 @@
 macro(append_flags_if_supported DEST)
   foreach(flag ${ARGN})
     mangle_name("${flag}" flagname)
-    check_cxx_compiler_flag("${flag}" "LIBCXX_SUPPORTS_${flagname}_FLAG")
-    append_flags_if(LIBCXX_SUPPORTS_${flagname}_FLAG ${DEST} ${flag})
+    check_cxx_compiler_flag("${flag}" "CXX_SUPPORTS_${flagname}_FLAG")
+    append_flags_if(CXX_SUPPORTS_${flagname}_FLAG ${DEST} ${flag})
   endforeach()
 endmacro()
 
@@ -127,8 +127,8 @@
 macro(add_target_flags_if_supported)
   foreach(flag ${ARGN})
     mangle_name("${flag}" flagname)
-    check_cxx_compiler_flag("${flag}" "LIBCXX_SUPPORTS_${flagname}_FLAG")
-    add_target_flags_if(LIBCXX_SUPPORTS_${flagname}_FLAG ${flag})
+    check_cxx_compiler_flag("${flag}" "CXX_SUPPORTS_${flagname}_FLAG")
+    add_target_flags_if(CXX_SUPPORTS_${flagname}_FLAG ${flag})
   endforeach()
 endmacro()
 
@@ -154,8 +154,8 @@
 macro(add_flags_if_supported)
   foreach(flag ${ARGN})
       mangle_name("${flag}" flagname)
-      check_cxx_compiler_flag("${flag}" "LIBCXX_SUPPORTS_${flagname}_FLAG")
-      add_flags_if(LIBCXX_SUPPORTS_${flagname}_FLAG ${flag})
+      check_cxx_compiler_flag("${flag}" "CXX_SUPPORTS_${flagname}_FLAG")
+      add_flags_if(CXX_SUPPORTS_${flagname}_FLAG ${flag})
   endforeach()
 endmacro()
 
@@ -179,8 +179,8 @@
 macro(add_compile_flags_if_supported)
   foreach(flag ${ARGN})
       mangle_name("${flag}" flagname)
-      check_cxx_compiler_flag("${flag}" "LIBCXX_SUPPORTS_${flagname}_FLAG")
-      add_compile_flags_if(LIBCXX_SUPPORTS_${flagname}_FLAG ${flag})
+      check_cxx_compiler_flag("${flag}" "CXX_SUPPORTS_${flagname}_FLAG")
+      add_compile_flags_if(CXX_SUPPORTS_${flagname}_FLAG ${flag})
   endforeach()
 endmacro()
 
@@ -204,8 +204,8 @@
 macro(add_link_flags_if_supported)
   foreach(flag ${ARGN})
     mangle_name("${flag}" flagname)
-    check_cxx_compiler_flag("${flag}" "LIBCXX_SUPPORTS_${flagname}_FLAG")
-    add_link_flags_if(LIBCXX_SUPPORTS_${flagname}_FLAG ${flag})
+    check_cxx_compiler_flag("${flag}" "CXX_SUPPORTS_${flagname}_FLAG")
+    add_link_flags_if(CXX_SUPPORTS_${flagname}_FLAG ${flag})
   endforeach()
 endmacro()
 
@@ -234,8 +234,8 @@
 function(target_add_link_flags_if_supported target visibility)
   foreach(flag ${ARGN})
     mangle_name("${flag}" flagname)
-    check_cxx_compiler_flag("${flag}" "LIBCXX_SUPPORTS_${flagname}_FLAG")
-    if (LIBCXX_SUPPORTS_${flagname}_FLAG)
+    check_cxx_compiler_flag("${flag}" "CXX_SUPPORTS_${flagname}_FLAG")
+    if (CXX_SUPPORTS_${flagname}_FLAG)
       target_link_libraries(${target} ${visibility} ${flag})
     endif()
   endforeach()
@@ -246,8 +246,8 @@
 function(target_add_compile_flags_if_supported target visibility)
   foreach(flag ${ARGN})
     mangle_name("${flag}" flagname)
-    check_cxx_compiler_flag("${flag}" "LIBCXX_SUPPORTS_${flagname}_FLAG")
-    if (LIBCXX_SUPPORTS_${flagname}_FLAG)
+    check_cxx_compiler_flag("${flag}" "CXX_SUPPORTS_${flagname}_FLAG")
+    if (CXX_SUPPORTS_${flagname}_FLAG)
       target_compile_options(${target} ${visibility} ${flag})
     endif()
   endforeach()
diff --git a/libcxx/cmake/config-ix.cmake b/libcxx/cmake/config-ix.cmake
--- a/libcxx/cmake/config-ix.cmake
+++ b/libcxx/cmake/config-ix.cmake
@@ -12,8 +12,8 @@
 # libunwind (and the compiler implicit -lunwind wouldn't succeed as the newly
 # built libunwind isn't installed yet). For those cases, it'd be good to
 # link with --uwnindlib=none. Check if that option works.
-llvm_check_compiler_linker_flag(C "--unwindlib=none" LIBCXX_SUPPORTS_UNWINDLIB_NONE_FLAG)
-if (LIBCXX_SUPPORTS_UNWINDLIB_NONE_FLAG)
+llvm_check_compiler_linker_flag(C "--unwindlib=none" CXX_SUPPORTS_UNWINDLIB_EQ_NONE_FLAG)
+if (CXX_SUPPORTS_UNWINDLIB_EQ_NONE_FLAG)
   set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} --unwindlib=none")
 endif()
 
@@ -46,17 +46,17 @@
 # required for the link to go through. We remove sanitizers from the
 # configuration checks to avoid spurious link errors.
 
-check_c_compiler_flag(-nostdlib++ LIBCXX_SUPPORTS_NOSTDLIBXX_FLAG)
-if (LIBCXX_SUPPORTS_NOSTDLIBXX_FLAG)
+check_cxx_compiler_flag(-nostdlib++ CXX_SUPPORTS_NOSTDLIBXX_FLAG)
+if (CXX_SUPPORTS_NOSTDLIBXX_FLAG)
   set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nostdlib++")
 else()
-  check_c_compiler_flag(-nodefaultlibs LIBCXX_SUPPORTS_NODEFAULTLIBS_FLAG)
-  if (LIBCXX_SUPPORTS_NODEFAULTLIBS_FLAG)
+  check_c_compiler_flag(-nodefaultlibs C_SUPPORTS_NODEFAULTLIBS_FLAG)
+  if (C_SUPPORTS_NODEFAULTLIBS_FLAG)
     set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nodefaultlibs")
   endif()
 endif()
 
-if (LIBCXX_SUPPORTS_NOSTDLIBXX_FLAG OR LIBCXX_SUPPORTS_NODEFAULTLIBS_FLAG)
+if (CXX_SUPPORTS_NOSTDLIBXX_FLAG OR C_SUPPORTS_NODEFAULTLIBS_FLAG)
   if (LIBCXX_HAS_C_LIB)
     list(APPEND CMAKE_REQUIRED_LIBRARIES c)
   endif ()
@@ -98,7 +98,7 @@
   check_c_source_compiles("
 #pragma comment(lib, \"c\")
 int main() { return 0; }
-" LIBCXX_HAS_COMMENT_LIB_PRAGMA)
+" C_SUPPORTS_COMMENT_LIB_PRAGMA)
   cmake_pop_check_state()
 endif()
 
diff --git a/libcxxabi/CMakeLists.txt b/libcxxabi/CMakeLists.txt
--- a/libcxxabi/CMakeLists.txt
+++ b/libcxxabi/CMakeLists.txt
@@ -276,7 +276,7 @@
 # Configure compiler. Must happen after setting the target flags.
 include(config-ix)
 
-if (LIBCXXABI_HAS_NOSTDINCXX_FLAG)
+if (CXX_SUPPORTS_NOSTDINCXX_FLAG)
   list(APPEND LIBCXXABI_COMPILE_FLAGS -nostdinc++)
   # cmake 3.14 and above remove system include paths that are explicitly
   # passed on the command line.  We build with -nostdinc++ and explicitly add
@@ -497,7 +497,7 @@
     add_definitions(-DLIBCXXABI_BAREMETAL)
 endif()
 
-if (LIBCXXABI_HAS_COMMENT_LIB_PRAGMA)
+if (C_SUPPORTS_COMMENT_LIB_PRAGMA)
   if (LIBCXXABI_HAS_PTHREAD_LIB)
     add_definitions(-D_LIBCXXABI_LINK_PTHREAD_LIB)
   endif()
diff --git a/libcxxabi/cmake/Modules/HandleLibcxxabiFlags.cmake b/libcxxabi/cmake/Modules/HandleLibcxxabiFlags.cmake
--- a/libcxxabi/cmake/Modules/HandleLibcxxabiFlags.cmake
+++ b/libcxxabi/cmake/Modules/HandleLibcxxabiFlags.cmake
@@ -41,7 +41,7 @@
 
 macro(check_flag_supported flag)
     mangle_name("${flag}" flagname)
-    check_cxx_compiler_flag("${flag}" "LIBCXXABI_SUPPORTS_${flagname}_FLAG")
+    check_cxx_compiler_flag("${flag}" "CXX_SUPPORTS_${flagname}_FLAG")
 endmacro()
 
 macro(append_flags DEST)
@@ -62,8 +62,8 @@
 macro(append_flags_if_supported DEST)
   foreach(flag ${ARGN})
     mangle_name("${flag}" flagname)
-    check_cxx_compiler_flag("${flag}" "LIBCXXABI_SUPPORTS_${flagname}_FLAG")
-    append_flags_if(LIBCXXABI_SUPPORTS_${flagname}_FLAG ${DEST} ${flag})
+    check_cxx_compiler_flag("${flag}" "CXX_SUPPORTS_${flagname}_FLAG")
+    append_flags_if(CXX_SUPPORTS_${flagname}_FLAG ${DEST} ${flag})
   endforeach()
 endmacro()
 
@@ -129,8 +129,8 @@
 macro(add_target_flags_if_supported)
   foreach(flag ${ARGN})
     mangle_name("${flag}" flagname)
-    check_cxx_compiler_flag("${flag}" "LIBCXXABI_SUPPORTS_${flagname}_FLAG")
-    add_target_flags_if(LIBCXXABI_SUPPORTS_${flagname}_FLAG ${flag})
+    check_cxx_compiler_flag("${flag}" "CXX_SUPPORTS_${flagname}_FLAG")
+    add_target_flags_if(CXX_SUPPORTS_${flagname}_FLAG ${flag})
   endforeach()
 endmacro()
 
@@ -156,8 +156,8 @@
 macro(add_flags_if_supported)
   foreach(flag ${ARGN})
       mangle_name("${flag}" flagname)
-      check_cxx_compiler_flag("${flag}" "LIBCXXABI_SUPPORTS_${flagname}_FLAG")
-      add_flags_if(LIBCXXABI_SUPPORTS_${flagname}_FLAG ${flag})
+      check_cxx_compiler_flag("${flag}" "CXX_SUPPORTS_${flagname}_FLAG")
+      add_flags_if(CXX_SUPPORTS_${flagname}_FLAG ${flag})
   endforeach()
 endmacro()
 
@@ -181,8 +181,8 @@
 macro(add_compile_flags_if_supported)
   foreach(flag ${ARGN})
       mangle_name("${flag}" flagname)
-      check_cxx_compiler_flag("${flag}" "LIBCXXABI_SUPPORTS_${flagname}_FLAG")
-      add_compile_flags_if(LIBCXXABI_SUPPORTS_${flagname}_FLAG ${flag})
+      check_cxx_compiler_flag("${flag}" "CXX_SUPPORTS_${flagname}_FLAG")
+      add_compile_flags_if(CXX_SUPPORTS_${flagname}_FLAG ${flag})
   endforeach()
 endmacro()
 
@@ -191,8 +191,8 @@
 macro(add_c_compile_flags_if_supported)
   foreach(flag ${ARGN})
       mangle_name("${flag}" flagname)
-      check_c_compiler_flag("${flag}" "LIBCXXABI_SUPPORTS_${flagname}_FLAG")
-      add_compile_flags_if(LIBCXXABI_SUPPORTS_${flagname}_FLAG ${flag})
+      check_c_compiler_flag("${flag}" "C_SUPPORTS_${flagname}_FLAG")
+      add_compile_flags_if(CXX_SUPPORTS_${flagname}_FLAG ${flag})
   endforeach()
 endmacro()
 
@@ -216,8 +216,8 @@
 macro(add_link_flags_if_supported)
   foreach(flag ${ARGN})
     mangle_name("${flag}" flagname)
-    check_cxx_compiler_flag("${flag}" "LIBCXXABI_SUPPORTS_${flagname}_FLAG")
-    add_link_flags_if(LIBCXXABI_SUPPORTS_${flagname}_FLAG ${flag})
+    check_cxx_compiler_flag("${flag}" "CXX_SUPPORTS_${flagname}_FLAG")
+    add_link_flags_if(CXX_SUPPORTS_${flagname}_FLAG ${flag})
   endforeach()
 endmacro()
 
diff --git a/libcxxabi/cmake/config-ix.cmake b/libcxxabi/cmake/config-ix.cmake
--- a/libcxxabi/cmake/config-ix.cmake
+++ b/libcxxabi/cmake/config-ix.cmake
@@ -23,17 +23,17 @@
 # required for the link to go through. We remove sanitizers from the
 # configuration checks to avoid spurious link errors.
 
-check_c_compiler_flag(-nostdlib++ LIBCXXABI_SUPPORTS_NOSTDLIBXX_FLAG)
-if (LIBCXXABI_SUPPORTS_NOSTDLIBXX_FLAG)
+check_cxx_compiler_flag(-nostdlib++ CXX_SUPPORTS_NOSTDLIBXX_FLAG)
+if (CXX_SUPPORTS_NOSTDLIBXX_FLAG)
   set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nostdlib++")
 else()
-  check_c_compiler_flag(-nodefaultlibs LIBCXXABI_SUPPORTS_NODEFAULTLIBS_FLAG)
-  if (LIBCXXABI_SUPPORTS_NODEFAULTLIBS_FLAG)
+  check_c_compiler_flag(-nodefaultlibs C_SUPPORTS_NODEFAULTLIBS_FLAG)
+  if (C_SUPPORTS_NODEFAULTLIBS_FLAG)
     set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nodefaultlibs")
   endif()
 endif()
 
-if (LIBCXXABI_SUPPORTS_NOSTDLIBXX_FLAG OR LIBCXXABI_SUPPORTS_NODEFAULTLIBS_FLAG)
+if (CXX_SUPPORTS_NOSTDLIBXX_FLAG OR C_SUPPORTS_NODEFAULTLIBS_FLAG)
   if (LIBCXXABI_HAS_C_LIB)
     list(APPEND CMAKE_REQUIRED_LIBRARIES c)
   endif ()
@@ -78,12 +78,12 @@
   check_c_source_compiles("
 #pragma comment(lib, \"c\")
 int main() { return 0; }
-" LIBCXXABI_HAS_COMMENT_LIB_PRAGMA)
+" C_SUPPORTS_COMMENT_LIB_PRAGMA)
   cmake_pop_check_state()
 endif()
 
 # Check compiler flags
-check_cxx_compiler_flag(-nostdinc++ LIBCXXABI_HAS_NOSTDINCXX_FLAG)
+check_cxx_compiler_flag(-nostdinc++ CXX_SUPPORTS_NOSTDINCXX_FLAG)
 
 # Check libraries
 if(FUCHSIA)
diff --git a/libcxxabi/src/CMakeLists.txt b/libcxxabi/src/CMakeLists.txt
--- a/libcxxabi/src/CMakeLists.txt
+++ b/libcxxabi/src/CMakeLists.txt
@@ -116,7 +116,7 @@
 endif ()
 
 # Setup flags.
-if (LIBCXXABI_SUPPORTS_NOSTDLIBXX_FLAG)
+if (CXX_SUPPORTS_NOSTDLIBXX_FLAG)
   add_link_flags_if_supported(-nostdlib++)
 else()
   add_link_flags_if_supported(-nodefaultlibs)
diff --git a/libunwind/CMakeLists.txt b/libunwind/CMakeLists.txt
--- a/libunwind/CMakeLists.txt
+++ b/libunwind/CMakeLists.txt
@@ -276,7 +276,7 @@
 add_compile_flags_if_supported(-funwind-tables)
 set(CMAKE_TRY_COMPILE_TARGET_TYPE ${_previous_CMAKE_TRY_COMPILE_TARGET_TYPE})
 
-if (LIBUNWIND_USES_ARM_EHABI AND NOT LIBUNWIND_SUPPORTS_FUNWIND_TABLES_FLAG)
+if (LIBUNWIND_USES_ARM_EHABI AND NOT CXX_SUPPORTS_FUNWIND_TABLES_FLAG)
   message(SEND_ERROR "The -funwind-tables flag must be supported "
                      "because this target uses ARM Exception Handling ABI")
 endif()
@@ -285,7 +285,7 @@
 add_cxx_compile_flags_if_supported(-fno-rtti)
 
 # Ensure that we don't depend on C++ standard library.
-if (LIBUNWIND_HAS_NOSTDINCXX_FLAG)
+if (CXX_SUPPORTS_NOSTDINCXX_FLAG)
   list(APPEND LIBUNWIND_COMPILE_FLAGS -nostdinc++)
   # Remove -stdlib flags to prevent them from causing an unused flag warning.
   string(REPLACE "--stdlib=libc++" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
@@ -354,7 +354,7 @@
   add_definitions(-D_LIBUNWIND_HIDE_SYMBOLS)
 endif()
 
-if (LIBUNWIND_HAS_COMMENT_LIB_PRAGMA)
+if (C_SUPPORTS_COMMENT_LIB_PRAGMA)
   if (LIBUNWIND_HAS_DL_LIB)
     add_definitions(-D_LIBUNWIND_LINK_DL_LIB)
   endif()
diff --git a/libunwind/cmake/Modules/HandleLibunwindFlags.cmake b/libunwind/cmake/Modules/HandleLibunwindFlags.cmake
--- a/libunwind/cmake/Modules/HandleLibunwindFlags.cmake
+++ b/libunwind/cmake/Modules/HandleLibunwindFlags.cmake
@@ -42,7 +42,7 @@
 
 macro(check_flag_supported flag)
     mangle_name("${flag}" flagname)
-    check_cxx_compiler_flag("${flag}" "LIBUNWIND_SUPPORTS_${flagname}_FLAG")
+    check_cxx_compiler_flag("${flag}" "CXX_SUPPORTS_${flagname}_FLAG")
 endmacro()
 
 macro(append_flags DEST)
@@ -63,8 +63,8 @@
 macro(append_flags_if_supported DEST)
   foreach(flag ${ARGN})
     mangle_name("${flag}" flagname)
-    check_cxx_compiler_flag("${flag}" "LIBUNWIND_SUPPORTS_${flagname}_FLAG")
-    append_flags_if(LIBUNWIND_SUPPORTS_${flagname}_FLAG ${DEST} ${flag})
+    check_cxx_compiler_flag("${flag}" "CXX_SUPPORTS_${flagname}_FLAG")
+    append_flags_if(CXX_SUPPORTS_${flagname}_FLAG ${DEST} ${flag})
   endforeach()
 endmacro()
 
@@ -130,8 +130,8 @@
 macro(add_target_flags_if_supported)
   foreach(flag ${ARGN})
     mangle_name("${flag}" flagname)
-    check_cxx_compiler_flag("${flag}" "LIBUNWIND_SUPPORTS_${flagname}_FLAG")
-    add_target_flags_if(LIBUNWIND_SUPPORTS_${flagname}_FLAG ${flag})
+    check_cxx_compiler_flag("${flag}" "CXX_SUPPORTS_${flagname}_FLAG")
+    add_target_flags_if(CXX_SUPPORTS_${flagname}_FLAG ${flag})
   endforeach()
 endmacro()
 
@@ -157,8 +157,8 @@
 macro(add_flags_if_supported)
   foreach(flag ${ARGN})
       mangle_name("${flag}" flagname)
-      check_cxx_compiler_flag("${flag}" "LIBUNWIND_SUPPORTS_${flagname}_FLAG")
-      add_flags_if(LIBUNWIND_SUPPORTS_${flagname}_FLAG ${flag})
+      check_cxx_compiler_flag("${flag}" "CXX_SUPPORTS_${flagname}_FLAG")
+      add_flags_if(CXX_SUPPORTS_${flagname}_FLAG ${flag})
   endforeach()
 endmacro()
 
@@ -182,8 +182,8 @@
 macro(add_compile_flags_if_supported)
   foreach(flag ${ARGN})
       mangle_name("${flag}" flagname)
-      check_cxx_compiler_flag("${flag}" "LIBUNWIND_SUPPORTS_${flagname}_FLAG")
-      add_compile_flags_if(LIBUNWIND_SUPPORTS_${flagname}_FLAG ${flag})
+      check_cxx_compiler_flag("${flag}" "CXX_SUPPORTS_${flagname}_FLAG")
+      add_compile_flags_if(CXX_SUPPORTS_${flagname}_FLAG ${flag})
   endforeach()
 endmacro()
 
@@ -207,8 +207,8 @@
 macro(add_c_compile_flags_if_supported)
   foreach(flag ${ARGN})
       mangle_name("${flag}" flagname)
-      check_c_compiler_flag("${flag}" "LIBUNWIND_SUPPORTS_${flagname}_FLAG")
-      add_c_flags_if(LIBUNWIND_SUPPORTS_${flagname}_FLAG ${flag})
+      check_c_compiler_flag("${flag}" "C_SUPPORTS_${flagname}_FLAG")
+      add_c_flags_if(C_SUPPORTS_${flagname}_FLAG ${flag})
   endforeach()
 endmacro()
 
@@ -232,8 +232,8 @@
 macro(add_cxx_compile_flags_if_supported)
   foreach(flag ${ARGN})
       mangle_name("${flag}" flagname)
-      check_cxx_compiler_flag("${flag}" "LIBUNWIND_SUPPORTS_${flagname}_FLAG")
-      add_cxx_flags_if(LIBUNWIND_SUPPORTS_${flagname}_FLAG ${flag})
+      check_cxx_compiler_flag("${flag}" "CXX_SUPPORTS_${flagname}_FLAG")
+      add_cxx_flags_if(CXX_SUPPORTS_${flagname}_FLAG ${flag})
   endforeach()
 endmacro()
 
@@ -257,8 +257,8 @@
 macro(add_link_flags_if_supported)
   foreach(flag ${ARGN})
     mangle_name("${flag}" flagname)
-    check_cxx_compiler_flag("${flag}" "LIBUNWIND_SUPPORTS_${flagname}_FLAG")
-    add_link_flags_if(LIBUNWIND_SUPPORTS_${flagname}_FLAG ${flag})
+    check_cxx_compiler_flag("${flag}" "CXX_SUPPORTS_${flagname}_FLAG")
+    add_link_flags_if(CXX_SUPPORTS_${flagname}_FLAG ${flag})
   endforeach()
 endmacro()
 
diff --git a/libunwind/cmake/config-ix.cmake b/libunwind/cmake/config-ix.cmake
--- a/libunwind/cmake/config-ix.cmake
+++ b/libunwind/cmake/config-ix.cmake
@@ -9,8 +9,8 @@
 # The compiler driver may be implicitly trying to link against libunwind, which
 # might not work if libunwind doesn't exist yet. Try to check if
 # --unwindlib=none is supported, and use that if possible.
-llvm_check_compiler_linker_flag(C "--unwindlib=none" LIBUNWIND_SUPPORTS_UNWINDLIB_NONE_FLAG)
-if (LIBUNWIND_SUPPORTS_UNWINDLIB_NONE_FLAG)
+llvm_check_compiler_linker_flag(C "--unwindlib=none" CXX_SUPPORTS_UNWINDLIB_EQ_NONE_FLAG)
+if (CXX_SUPPORTS_UNWINDLIB_EQ_NONE_FLAG)
   set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} --unwindlib=none")
 endif()
 
@@ -34,17 +34,17 @@
 # required for the link to go through. We remove sanitizers from the
 # configuration checks to avoid spurious link errors.
 
-llvm_check_compiler_linker_flag(C "-nostdlib++" LIBUNWIND_SUPPORTS_NOSTDLIBXX_FLAG)
-if (LIBUNWIND_SUPPORTS_NOSTDLIBXX_FLAG)
+llvm_check_compiler_linker_flag(C "-nostdlib++" CXX_SUPPORTS_NOSTDLIBXX_FLAG)
+if (CXX_SUPPORTS_NOSTDLIBXX_FLAG)
   set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nostdlib++")
 else()
   llvm_check_compiler_linker_flag(C "-nodefaultlibs" LIBUNWIND_SUPPORTS_NODEFAULTLIBS_FLAG)
-  if (LIBUNWIND_SUPPORTS_NODEFAULTLIBS_FLAG)
+  if (C_SUPPORTS_NODEFAULTLIBS_FLAG)
     set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nodefaultlibs")
   endif()
 endif()
 
-if (LIBUNWIND_SUPPORTS_NOSTDLIBXX_FLAG OR LIBUNWIND_SUPPORTS_NODEFAULTLIBS_FLAG)
+if (CXX_SUPPORTS_NOSTDLIBXX_FLAG OR C_SUPPORTS_NODEFAULTLIBS_FLAG)
   if (LIBUNWIND_HAS_C_LIB)
     list(APPEND CMAKE_REQUIRED_LIBRARIES c)
   endif ()
@@ -89,12 +89,12 @@
   check_c_source_compiles("
 #pragma comment(lib, \"c\")
 int main() { return 0; }
-" LIBUNWIND_HAS_COMMENT_LIB_PRAGMA)
+" C_SUPPORTS_COMMENT_LIB_PRAGMA)
   cmake_pop_check_state()
 endif()
 
 # Check compiler flags
-check_cxx_compiler_flag(-nostdinc++ LIBUNWIND_HAS_NOSTDINCXX_FLAG)
+check_cxx_compiler_flag(-nostdinc++ CXX_SUPPORTS_NOSTDINCXX_FLAG)
 
 # Check symbols
 check_symbol_exists(__arm__ "" LIBUNWIND_TARGET_ARM)
diff --git a/libunwind/src/CMakeLists.txt b/libunwind/src/CMakeLists.txt
--- a/libunwind/src/CMakeLists.txt
+++ b/libunwind/src/CMakeLists.txt
@@ -93,8 +93,8 @@
 endif()
 
 # Setup flags.
-add_link_flags_if(LIBUNWIND_SUPPORTS_UNWINDLIB_NONE_FLAG --unwindlib=none)
-if (LIBUNWIND_SUPPORTS_NOSTDLIBXX_FLAG)
+add_link_flags_if(CXX_SUPPORTS_UNWINDLIB_EQ_NONE_FLAG --unwindlib=none)
+if (CXX_SUPPORTS_NOSTDLIBXX_FLAG)
   add_link_flags_if_supported(-nostdlib++)
 else()
   add_link_flags_if_supported(-nodefaultlibs)
@@ -104,8 +104,8 @@
 add_library_flags_if(MINGW "${MINGW_LIBRARIES}")
 
 if (LIBUNWIND_ENABLE_SHARED AND
-    NOT (LIBUNWIND_SUPPORTS_FNO_EXCEPTIONS_FLAG AND
-         LIBUNWIND_SUPPORTS_FUNWIND_TABLES_FLAG))
+    NOT (CXX_SUPPORTS_FNO_EXCEPTIONS_FLAG AND
+         CXX_SUPPORTS_FUNWIND_TABLES_FLAG))
   message(FATAL_ERROR
           "Compiler doesn't support generation of unwind tables if exception "
           "support is disabled.  Building libunwind DSO with runtime dependency "
diff --git a/runtimes/CMakeLists.txt b/runtimes/CMakeLists.txt
--- a/runtimes/CMakeLists.txt
+++ b/runtimes/CMakeLists.txt
@@ -110,12 +110,12 @@
 # Check for -nostdlib++ first; if there's no C++ standard library yet,
 # all check_cxx_compiler_flag commands will fail until we add -nostdlib++
 # (or -nodefaultlibs).
-llvm_check_compiler_linker_flag(C "-nostdlib++" LLVM_RUNTIMES_SUPPORT_NOSTDLIBXX_FLAG)
-if (LLVM_RUNTIMES_SUPPORT_NOSTDLIBXX_FLAG)
+llvm_check_compiler_linker_flag(C "-nostdlib++" CXX_SUPPORTS_NOSTDLIBXX_FLAG)
+if (CXX_SUPPORTS_NOSTDLIBXX_FLAG)
   set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nostdlib++")
 endif()
-check_cxx_compiler_flag(-nostdinc++ LLVM_RUNTIMES_SUPPORT_NOSTDINCXX_FLAG)
-if (LLVM_RUNTIMES_SUPPORT_NOSTDINCXX_FLAG)
+check_cxx_compiler_flag(-nostdinc++ CXX_SUPPORTS_NOSTDINCXX_FLAG)
+if (CXX_SUPPORTS_NOSTDINCXX_FLAG)
   set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nostdinc++")
 endif()