Index: CMakeLists.txt
===================================================================
--- CMakeLists.txt
+++ CMakeLists.txt
@@ -7,9 +7,14 @@
 
   # Rely on llvm-config.
   set(CONFIG_OUTPUT)
-  find_program(LLVM_CONFIG "llvm-config")
   if(LLVM_CONFIG)
+    set (LLVM_CONFIG_FOUND 1)
     message(STATUS "Found LLVM_CONFIG as ${LLVM_CONFIG}")
+    message(WARNING "Using llvm-config to detect the LLVM installation is \
+          deprecated.  The installed cmake files should be used \
+          instead.  CMake should be able to detect your LLVM install \
+          automatically, but you can also use LLVM_DIR to specify \
+          the path containing LLVMConfig.cmake.")
     set(CONFIG_COMMAND ${LLVM_CONFIG}
       "--assertion-mode"
       "--bindir"
@@ -32,17 +37,20 @@
       message(STATUS "${CONFIG_COMMAND_STR}")
       message(FATAL_ERROR "llvm-config failed with status ${HAD_ERROR}")
     endif()
-  else()
-    message(FATAL_ERROR "llvm-config not found -- ${LLVM_CONFIG}")
+
+    list(GET CONFIG_OUTPUT 0 ENABLE_ASSERTIONS)
+    list(GET CONFIG_OUTPUT 1 TOOLS_BINARY_DIR)
+    list(GET CONFIG_OUTPUT 2 LIBRARY_DIR)
+    list(GET CONFIG_OUTPUT 3 INCLUDE_DIR)
+    list(GET CONFIG_OUTPUT 4 LLVM_OBJ_ROOT)
+    list(GET CONFIG_OUTPUT 5 MAIN_SRC_DIR)
+    list(GET CONFIG_OUTPUT 6 LLVM_CONFIG_CMAKE_PATH)
+
+    # Normalize LLVM_CMAKE_PATH. --cmakedir might contain backslashes.
+    # CMake assumes slashes as PATH.
+    file(TO_CMAKE_PATH ${LLVM_CONFIG_CMAKE_PATH} LLVM_CMAKE_PATH)
   endif()
 
-  list(GET CONFIG_OUTPUT 0 ENABLE_ASSERTIONS)
-  list(GET CONFIG_OUTPUT 1 TOOLS_BINARY_DIR)
-  list(GET CONFIG_OUTPUT 2 LIBRARY_DIR)
-  list(GET CONFIG_OUTPUT 3 INCLUDE_DIR)
-  list(GET CONFIG_OUTPUT 4 LLVM_OBJ_ROOT)
-  list(GET CONFIG_OUTPUT 5 MAIN_SRC_DIR)
-  list(GET CONFIG_OUTPUT 6 LLVM_CONFIG_CMAKE_PATH)
 
   if(NOT MSVC_IDE)
     set(LLVM_ENABLE_ASSERTIONS ${ENABLE_ASSERTIONS}
@@ -51,22 +59,29 @@
     mark_as_advanced(LLVM_ENABLE_ASSERTIONS)
   endif()
 
+  find_package(LLVM REQUIRED HINTS "${LLVM_CMAKE_PATH}")
+  list(APPEND CMAKE_MODULE_PATH ${LLVM_DIR})
+
+  # We can't check LLVM_CONFIG here, because find_package(LLVM ...) also sets
+  # LLVM_CONFIG.
+  if (NOT LLVM_CONFIG_FOUND)
+    # Pull values from LLVMConfig.cmake.  We can drop this once the llvm-config
+    # path is removed.
+    set(TOOLS_BINARY_DIR ${LLVM_TOOLS_BINARY_DIR})
+    set(LIBRARY_DIR ${LLVM_LIBRARY_DIR})
+    set(INCLUDE_DIR ${LLVM_INCLUDE_DIR})
+    set(LLVM_OBJ_DIR ${LLVM_BINARY_DIR})
+  endif()
+
   set(LLVM_TOOLS_BINARY_DIR ${TOOLS_BINARY_DIR} CACHE PATH "Path to llvm/bin")
   set(LLVM_LIBRARY_DIR ${LIBRARY_DIR} CACHE PATH "Path to llvm/lib")
   set(LLVM_MAIN_INCLUDE_DIR ${INCLUDE_DIR} CACHE PATH "Path to llvm/include")
   set(LLVM_BINARY_DIR ${LLVM_OBJ_ROOT} CACHE PATH "Path to LLVM build tree")
   set(LLVM_MAIN_SRC_DIR ${MAIN_SRC_DIR} CACHE PATH "Path to LLVM source tree")
 
-  # Normalize LLVM_CMAKE_PATH. --cmakedir might contain backslashes.
-  # CMake assumes slashes as PATH.
-  file(TO_CMAKE_PATH ${LLVM_CONFIG_CMAKE_PATH} LLVM_CMAKE_PATH)
-
   find_program(LLVM_TABLEGEN_EXE "llvm-tblgen" ${LLVM_TOOLS_BINARY_DIR}
     NO_DEFAULT_PATH)
 
-  find_package(LLVM REQUIRED HINTS "${LLVM_CMAKE_PATH}")
-  list(APPEND CMAKE_MODULE_PATH ${LLVM_DIR})
-
   # They are used as destination of target generators.
   set(LLVM_RUNTIME_OUTPUT_INTDIR ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin)
   set(LLVM_LIBRARY_OUTPUT_INTDIR ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/lib${LLVM_LIBDIR_SUFFIX})