diff --git a/llvm/CMakeLists.txt b/llvm/CMakeLists.txt
--- a/llvm/CMakeLists.txt
+++ b/llvm/CMakeLists.txt
@@ -788,6 +788,9 @@
   endif()
 endforeach(t)
 
+# Provide an LLVM_ namespaced alias for use in #cmakedefine.
+set(LLVM_BUILD_SHARED_LIBS ${BUILD_SHARED_LIBS})
+
 # Produce the target definition files, which provide a way for clients to easily
 # include various classes of targets.
 configure_file(
diff --git a/llvm/include/llvm/Config/llvm-config.h.cmake b/llvm/include/llvm/Config/llvm-config.h.cmake
--- a/llvm/include/llvm/Config/llvm-config.h.cmake
+++ b/llvm/include/llvm/Config/llvm-config.h.cmake
@@ -103,4 +103,10 @@
 /* Define if the xar_open() function is supported on this platform. */
 #cmakedefine LLVM_HAVE_LIBXAR ${LLVM_HAVE_LIBXAR}
 
+/* Define if building libLLVM shared library */
+#cmakedefine LLVM_BUILD_LLVM_DYLIB
+
+/* Define if building LLVM with BUILD_SHARED_LIBS */
+#cmakedefine LLVM_BUILD_SHARED_LIBS
+
 #endif
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
@@ -126,7 +126,11 @@
 #if __has_attribute(visibility) && !defined(__MINGW32__) &&                    \
     !defined(__CYGWIN__) && !defined(_WIN32)
 #define LLVM_LIBRARY_VISIBILITY __attribute__ ((visibility("hidden")))
-#define LLVM_EXTERNAL_VISIBILITY __attribute__ ((visibility("default")))
+#if defined(LLVM_BUILD_LLVM_DYLIB) || defined(LLVM_BUILD_SHARED_LIBS)
+#define LLVM_EXTERNAL_VISIBILITY __attribute__((visibility("default")))
+#else
+#define LLVM_EXTERNAL_VISIBILITY
+#endif
 #else
 #define LLVM_LIBRARY_VISIBILITY
 #define LLVM_EXTERNAL_VISIBILITY