Index: CMakeLists.txt
===================================================================
--- CMakeLists.txt
+++ CMakeLists.txt
@@ -347,6 +347,8 @@
 
 option(LLVM_ENABLE_ZLIB "Use zlib for compression/decompression if available." ON)
 
+option(LLVM_ENABLE_DIA_SDK "Use MSVC DIA SDK for debugging if available." ON)
+
 if( LLVM_TARGETS_TO_BUILD STREQUAL "all" )
   set( LLVM_TARGETS_TO_BUILD ${LLVM_ALL_TARGETS} )
 endif()
Index: cmake/config-ix.cmake
===================================================================
--- cmake/config-ix.cmake
+++ cmake/config-ix.cmake
@@ -416,7 +416,7 @@
   endif ()
 endif ()
 
-if( MSVC )
+if( MSVC AND LLVM_ENABLE_DIA_SDK )
   set(SHLIBEXT ".lib")
   set(stricmp "_stricmp")
   set(strdup "_strdup")
@@ -432,13 +432,13 @@
   # the DIA SDK folder exists.  Should this happen you will need to
   # uninstall VS 2012 and then re-install VS 2013.
   if (IS_DIRECTORY ${MSVC_DIA_SDK_DIR})
-    set(HAVE_DIA_SDK 1)
+    set(LLVM_ENABLE_DIA_SDK 1)
   else()
-    set(HAVE_DIA_SDK 0)
+    set(LLVM_ENABLE_DIA_SDK 0)
   endif()
 else()
-  set(HAVE_DIA_SDK 0)
-endif( MSVC )
+  set(LLVM_ENABLE_DIA_SDK 0)
+endif()
 
 # FIXME: Signal handler return type, currently hardcoded to 'void'
 set(RETSIGTYPE void)
Index: cmake/modules/LLVMConfig.cmake.in
===================================================================
--- cmake/modules/LLVMConfig.cmake.in
+++ cmake/modules/LLVMConfig.cmake.in
@@ -37,6 +37,8 @@
 
 set(LLVM_ENABLE_ZLIB @LLVM_ENABLE_ZLIB@)
 
+set(LLVM_ENABLE_DIA_SDK @LLVM_ENABLE_DIA_SDK@)
+
 set(LLVM_NATIVE_ARCH @LLVM_NATIVE_ARCH@)
 
 set(LLVM_ENABLE_PIC @LLVM_ENABLE_PIC@)
Index: docs/CMake.rst
===================================================================
--- docs/CMake.rst
+++ docs/CMake.rst
@@ -366,6 +366,10 @@
   Enable building with zlib to support compression/uncompression in LLVM tools.
   Defaults to ON.
 
+**LLVM_ENABLE_DIA_SDK**:BOOL
+  Enable building with MSVC DIA SDK for PDB debugging support. Available
+  only with MSVC. Defaults to ON.
+
 **LLVM_USE_SANITIZER**:STRING
   Define the sanitizer used to build LLVM binaries and tests. Possible values
   are ``Address``, ``Memory``, ``MemoryWithOrigins``, ``Undefined``, ``Thread``,
Index: include/llvm/Config/config.h.cmake
===================================================================
--- include/llvm/Config/config.h.cmake
+++ include/llvm/Config/config.h.cmake
@@ -39,7 +39,7 @@
 #cmakedefine01 HAVE_DECL_STRERROR_S
 
 /* Define to 1 if you have the DIA SDK installed, and to 0 if you don't. */
-#cmakedefine01 HAVE_DIA_SDK
+#define HAVE_DIA_SDK ${LLVM_ENABLE_DIA_SDK}
 
 /* Define to 1 if you have the <dirent.h> header file, and it defines `DIR'.
    */
Index: lib/DebugInfo/PDB/CMakeLists.txt
===================================================================
--- lib/DebugInfo/PDB/CMakeLists.txt
+++ lib/DebugInfo/PDB/CMakeLists.txt
@@ -3,7 +3,7 @@
   source_group(${group} FILES ${ARGN})
 endmacro()
 
-if(HAVE_DIA_SDK)
+if(LLVM_ENABLE_DIA_SDK)
   include_directories(${MSVC_DIA_SDK_DIR}/include)
   set(LIBPDB_LINK_FOLDERS "${MSVC_DIA_SDK_DIR}\\lib")
   if (CMAKE_SIZEOF_VOID_P EQUAL 8)
Index: test/lit.site.cfg.in
===================================================================
--- test/lit.site.cfg.in
+++ test/lit.site.cfg.in
@@ -35,7 +35,7 @@
 config.llvm_use_sanitizer = "@LLVM_USE_SANITIZER@"
 config.have_zlib = "@HAVE_LIBZ@"
 config.have_libxar = "@HAVE_LIBXAR@"
-config.have_dia_sdk = @HAVE_DIA_SDK@
+config.have_dia_sdk = @LLVM_ENABLE_DIA_SDK@
 config.enable_ffi = "@LLVM_ENABLE_FFI@"
 config.test_examples = "@ENABLE_EXAMPLES@"