diff --git a/llvm/cmake/modules/HandleLLVMOptions.cmake b/llvm/cmake/modules/HandleLLVMOptions.cmake
--- a/llvm/cmake/modules/HandleLLVMOptions.cmake
+++ b/llvm/cmake/modules/HandleLLVMOptions.cmake
@@ -351,8 +351,11 @@
   endif()
 endif()
 
-if(NOT WIN32 AND NOT CYGWIN AND NOT (${CMAKE_SYSTEM_NAME} MATCHES "AIX"))
-  # MinGW warns if -fvisibility-inlines-hidden is used.
+if((NOT (${CMAKE_SYSTEM_NAME} MATCHES "AIX")) AND
+   (NOT (WIN32 OR CYGWIN) OR (MINGW AND CMAKE_CXX_COMPILER_ID MATCHES "Clang")))
+  # GCC for MinGW does nothing about -fvisibility-inlines-hidden, but warns
+  # about use of the attributes. As long as we don't use the attributes (to
+  # override the default) we shouldn't set the command line options either.
   # GCC on AIX warns if -fvisibility-inlines-hidden is used and Clang on AIX doesn't currently support visibility.
   check_cxx_compiler_flag("-fvisibility-inlines-hidden" SUPPORTS_FVISIBILITY_INLINES_HIDDEN_FLAG)
   append_if(SUPPORTS_FVISIBILITY_INLINES_HIDDEN_FLAG "-fvisibility-inlines-hidden" CMAKE_CXX_FLAGS)
diff --git a/llvm/include/llvm/Support/Compiler.h b/llvm/include/llvm/Support/Compiler.h
--- a/llvm/include/llvm/Support/Compiler.h
+++ b/llvm/include/llvm/Support/Compiler.h
@@ -113,8 +113,9 @@
 /// LLVM_EXTERNAL_VISIBILITY - classes, functions, and variables marked with
 /// this attribute will be made public and visible outside of any shared library
 /// they are linked in to.
-#if __has_attribute(visibility) && !defined(__MINGW32__) &&                    \
-    !defined(__CYGWIN__) && !defined(_WIN32)
+#if __has_attribute(visibility) &&                                             \
+    (!(defined(_WIN32) || defined(__CYGWIN__)) ||                              \
+     (defined(__MINGW32__) && defined(__clang__)))
 #define LLVM_LIBRARY_VISIBILITY __attribute__ ((visibility("hidden")))
 #if defined(LLVM_BUILD_LLVM_DYLIB) || defined(LLVM_BUILD_SHARED_LIBS)
 #define LLVM_EXTERNAL_VISIBILITY __attribute__((visibility("default")))
diff --git a/llvm/lib/Target/CMakeLists.txt b/llvm/lib/Target/CMakeLists.txt
--- a/llvm/lib/Target/CMakeLists.txt
+++ b/llvm/lib/Target/CMakeLists.txt
@@ -22,7 +22,7 @@
 # When building shared objects for each target there are some internal APIs
 # that are used across shared objects which we can't hide.
 if (NOT BUILD_SHARED_LIBS AND NOT APPLE AND
-    NOT MINGW AND
+    (NOT (WIN32 OR CYGWIN) OR (MINGW AND CMAKE_CXX_COMPILER_ID MATCHES "Clang")) AND
     NOT (${CMAKE_SYSTEM_NAME} MATCHES "AIX") AND
     NOT DEFINED CMAKE_CXX_VISIBILITY_PRESET)
   # Set default visibility to hidden, so we don't export all the Target classes