Index: llvm/trunk/test/tools/llvm-config/booleans.test
===================================================================
--- llvm/trunk/test/tools/llvm-config/booleans.test
+++ llvm/trunk/test/tools/llvm-config/booleans.test
@@ -0,0 +1,28 @@
+# Check whether boolean options are consistently normalized to ON/OFF.
+RUN: llvm-config --assertion-mode 2>&1 | FileCheck --check-prefix=CHECK-ONOFF %s
+RUN: llvm-config --has-global-isel 2>&1 | FileCheck --check-prefix=CHECK-ONOFF %s
+CHECK-ONOFF: {{ON|OFF}}
+CHECK-ONOFF-NOT: error:
+CHECK-ONOFF-NOT: warning
+
+# ...or to YES/NO.
+RUN: llvm-config --has-rtti 2>&1 | FileCheck --check-prefix=CHECK-YESNO %s
+CHECK-YESNO: {{YES|NO}}
+CHECK-YESNO-NOT: error:
+CHECK-YESNO-NOT: warning
+
+# Also check some other multi-choice options.
+RUN: llvm-config --build-mode 2>&1 | FileCheck --check-prefix=CHECK-BUILD-MODE %s
+CHECK-BUILD-MODE: {{[Dd][Ee][Bb][Uu][Gg]|[Rr][Ee][Ll][Ee][Aa][Ss][Ee]|[Rr][Ee][Ll][Ww][Ii][Tt][Hh][Dd][Ee][Bb][Ii][Nn][Ff][Oo]|[Mm][Ii][Nn][Ss][Ii][Zz][Ee][Rr][Ee][Ll]}}
+CHECK-BUILD-MODE-NOT: error:
+CHECK-BUILD-MODE-NOT: warning
+
+RUN: llvm-config --build-system 2>&1 | FileCheck --check-prefix=CHECK-BUILD-SYSTEM %s
+CHECK-BUILD-SYSTEM: cmake
+CHECK-BUILD-SYSTEM-NOT: error:
+CHECK-BUILD-SYSTEM-NOT: warning
+
+RUN: llvm-config --shared-mode 2>&1 | FileCheck --check-prefix=CHECK-SHARED-MODE %s
+CHECK-SHARED-MODE: {{static|shared}}
+CHECK-SHARED-MODE-NOT: error:
+CHECK-SHARED-MODE-NOT: warning
Index: llvm/trunk/tools/llvm-config/BuildVariables.inc.in
===================================================================
--- llvm/trunk/tools/llvm-config/BuildVariables.inc.in
+++ llvm/trunk/tools/llvm-config/BuildVariables.inc.in
@@ -27,10 +27,10 @@
 #define LLVM_TARGETS_BUILT "@LLVM_TARGETS_BUILT@"
 #define LLVM_SYSTEM_LIBS "@LLVM_SYSTEM_LIBS@"
 #define LLVM_BUILD_SYSTEM "@LLVM_BUILD_SYSTEM@"
-#define LLVM_HAS_RTTI "@LLVM_HAS_RTTI@"
-#define LLVM_ENABLE_DYLIB "@LLVM_BUILD_LLVM_DYLIB@"
-#define LLVM_LINK_DYLIB "@LLVM_LINK_LLVM_DYLIB@"
-#define LLVM_ENABLE_SHARED "@LLVM_ENABLE_SHARED@"
+#define LLVM_HAS_RTTI @LLVM_HAS_RTTI@
+#define LLVM_ENABLE_DYLIB @LLVM_BUILD_LLVM_DYLIB@
+#define LLVM_LINK_DYLIB @LLVM_LINK_LLVM_DYLIB@
+#define LLVM_ENABLE_SHARED @BUILD_SHARED_LIBS@
 #define LLVM_DYLIB_COMPONENTS "@LLVM_DYLIB_COMPONENTS@"
 #define LLVM_DYLIB_VERSION "@LLVM_DYLIB_VERSION@"
-#define LLVM_HAS_GLOBAL_ISEL "@LLVM_HAS_GLOBAL_ISEL@"
+#define LLVM_HAS_GLOBAL_ISEL @LLVM_HAS_GLOBAL_ISEL@
Index: llvm/trunk/tools/llvm-config/CMakeLists.txt
===================================================================
--- llvm/trunk/tools/llvm-config/CMakeLists.txt
+++ llvm/trunk/tools/llvm-config/CMakeLists.txt
@@ -47,12 +47,13 @@
 set(LLVM_LDFLAGS "${CMAKE_CXX_LINK_FLAGS}")
 set(LLVM_BUILDMODE ${CMAKE_BUILD_TYPE})
 set(LLVM_SYSTEM_LIBS ${SYSTEM_LIBS})
-if(BUILD_SHARED_LIBS)
-  set(LLVM_ENABLE_SHARED ON)
-else()
-  set(LLVM_ENABLE_SHARED OFF)
-endif()
 string(REPLACE ";" " " LLVM_TARGETS_BUILT "${LLVM_TARGETS_TO_BUILD}")
+llvm_canonicalize_cmake_booleans(
+  LLVM_BUILD_LLVM_DYLIB
+  LLVM_LINK_LLVM_DYLIB
+  LLVM_HAS_RTTI
+  LLVM_HAS_GLOBAL_ISEL
+  BUILD_SHARED_LIBS)
 configure_file(${BUILDVARIABLES_SRCPATH} ${BUILDVARIABLES_OBJPATH} @ONLY)
 
 # Set build-time environment(s).
Index: llvm/trunk/tools/llvm-config/llvm-config.cpp
===================================================================
--- llvm/trunk/tools/llvm-config/llvm-config.cpp
+++ llvm/trunk/tools/llvm-config/llvm-config.cpp
@@ -212,7 +212,7 @@
   --assertion-mode  Print assertion mode of LLVM tree (ON or OFF).\n\
   --build-system    Print the build system used to build LLVM (always cmake).\n\
   --has-rtti        Print whether or not LLVM was built with rtti (YES or NO).\n\
-  --has-global-isel Print whether or not LLVM was built with global-isel support (YES or NO).\n\
+  --has-global-isel Print whether or not LLVM was built with global-isel support (ON or OFF).\n\
   --shared-mode     Print how the provided components can be collectively linked (`shared` or `static`).\n\
   --link-shared     Link the components as shared libraries.\n\
   --link-static     Link the component libraries statically.\n\
@@ -383,10 +383,10 @@
     StaticPrefix = SharedPrefix = "lib";
   }
 
-  const bool BuiltDyLib = (std::strcmp(LLVM_ENABLE_DYLIB, "ON") == 0);
+  const bool BuiltDyLib = !!LLVM_ENABLE_DYLIB;
 
   /// CMake style shared libs, ie each component is in a shared library.
-  const bool BuiltSharedLibs = std::strcmp(LLVM_ENABLE_SHARED, "ON") == 0;
+  const bool BuiltSharedLibs = !!LLVM_ENABLE_SHARED;
 
   bool DyLibExists = false;
   const std::string DyLibName =
@@ -395,7 +395,7 @@
   // If LLVM_LINK_DYLIB is ON, the single shared library will be returned
   // for "--libs", etc, if they exist. This behaviour can be overridden with
   // --link-static or --link-shared.
-  bool LinkDyLib = (std::strcmp(LLVM_LINK_DYLIB, "ON") == 0);
+  bool LinkDyLib = !!LLVM_LINK_DYLIB;
 
   if (BuiltDyLib) {
     std::string path((SharedDir + DirSep + DyLibName).str());
@@ -549,9 +549,9 @@
       } else if (Arg == "--build-system") {
         OS << LLVM_BUILD_SYSTEM << '\n';
       } else if (Arg == "--has-rtti") {
-        OS << LLVM_HAS_RTTI << '\n';
+        OS << (LLVM_HAS_RTTI ? "YES" : "NO") << '\n';
       } else if (Arg == "--has-global-isel") {
-        OS << LLVM_HAS_GLOBAL_ISEL << '\n';
+        OS << (LLVM_HAS_GLOBAL_ISEL ? "ON" : "OFF") << '\n';
       } else if (Arg == "--shared-mode") {
         PrintSharedMode = true;
       } else if (Arg == "--obj-root") {