Index: cmake/modules/AddLLVM.cmake
===================================================================
--- cmake/modules/AddLLVM.cmake	(revision 127962)
+++ cmake/modules/AddLLVM.cmake	(working copy)
@@ -119,8 +119,99 @@
 endmacro(add_llvm_example name)
 
 
+macro(add_no_compile_file ofn)
+  # Add a dummy generated output files to enable correct dependency analysis
+  add_custom_command(OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/${ofn}.nocompile
+    COMMAND "${CMAKE_COMMAND}" -E 
+      touch ${CMAKE_CURRENT_BINARY_DIR}/${ofn}.nocompile
+    DEPENDS ${ofn}
+    )
+  set_source_files_properties(${CMAKE_CURRENT_BINARY_DIR}/${ofn}.nocompile
+    PROPERTIES
+    GENERATED TRUE
+    )
+    
+  # Make sure not to try to compile source c/cpp files as the other build dir
+  # dir takes care of the actual compiling
+  set_source_files_properties(${file} PROPERTIES HEADER_FILE_ONLY TRUE)
+  
+  # Clean generated files
+  set_property(DIRECTORY APPEND
+    PROPERTY ADDITIONAL_MAKE_CLEAN_FILES 
+      ${CMAKE_CURRENT_BINARY_DIR}/${ofn}.nocompile)
+endmacro(add_no_compile_file ofn)
+
+# Used to keep track of the last added utility
+set(LLVM_ADD_UTILITY_LAST "" CACHE STRING INTERNAL FORCE)
+
 macro(add_llvm_utility name)
-  add_llvm_executable(${name} ${ARGN})
+  if( LLVM_UTILS_BUILD_DIR )
+  
+    # Figure out project to build
+    if (MSVC_IDE)
+      string(REPLACE "${CMAKE_HOME_DIRECTORY}/" "" 
+        LLVM_TEMP_TARGET "${CMAKE_CURRENT_SOURCE_DIR}")
+      set(LLVM_TEMP_TARGET ${LLVM_TEMP_TARGET}/${name})
+    else()
+      set(LLVM_TEMP_TARGET ${name})
+    endif()
+
+    # Add dummy generated files to force rebuild of project when source c/cpp
+    # files change
+    foreach(file ${ARGN})
+      add_no_compile_file( ${file} )
+      set(LLVM_TEMP_FILES ${LLVM_TEMP_FILES} 
+        ${CMAKE_CURRENT_BINARY_DIR}/${file}.nocompile)
+    endforeach()
+
+    # Add executable to allow resolution of executable path.
+    # Just build a minimal executable with default.c
+    add_executable(${name} ${LLVM_TEMP_FILES} ${ARGN} 
+      "${CMAKE_HOME_DIRECTORY}/utils/default.c")
+    
+    # Try to hide no compile files in it's own directory
+    source_group("No Compile" FILES ${LLVM_TEMP_FILES})
+    
+    # Try to put source files in correct directory even though CMake will
+    # currently put the files in the root when HEADER_FILE_ONLY is set.
+    source_group("Source Files" FILES ${ARGN})
+    
+    if (MSVC_IDE AND MSVC_VERSION GREATER 1599)
+      # When building with msbuild reduce verbosity to a sane level
+      set(LLVM_TEMP_EXTRAPARAMS -- /verbosity:minimal /nologo)
+    endif()
+    
+    # When we are compiling on a multi config generator we need to append
+    # the configuration dir.
+    if( LLVM_UTILS_BUILD_CONFIG )
+      set(LLVM_TEMP_CONFIG_DIR "/${LLVM_UTILS_BUILD_CONFIG}")
+    endif()
+    
+    # Add a custom command to post build that will build the project in the
+    # utils build dir and copy the result to our runtime dir.
+    add_custom_command(TARGET ${name}
+      POST_BUILD
+      COMMAND ${CMAKE_COMMAND} --build . --target ${LLVM_TEMP_TARGET}
+        --config ${LLVM_UTILS_BUILD_CONFIG} ${LLVM_TEMP_EXTRAPARAMS}
+      COMMAND ${CMAKE_COMMAND} -E copy_if_different 
+        "bin${LLVM_TEMP_CONFIG_DIR}/${name}${CMAKE_EXECUTABLE_SUFFIX}" 
+        "${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/${CMAKE_CFG_INTDIR}/"
+      COMMAND ${CMAKE_COMMAND} -E echo 
+        "${LLVM_UTILS_BUILD_DIR}/bin${LLVM_TEMP_CONFIG_DIR}/${name}${CMAKE_EXECUTABLE_SUFFIX}" to 
+        "${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/${CMAKE_CFG_INTDIR}/${name}${CMAKE_EXECUTABLE_SUFFIX}"
+      WORKING_DIRECTORY ${LLVM_UTILS_BUILD_DIR})
+
+    # We need to add dependencies between the different utils, otherwise a race
+    # condition will occur when the projects are bulit at the same time trying
+    # to write to the same files.    
+    if ( LLVM_ADD_UTILITY_LAST )
+      add_dependencies(${name} ${LLVM_ADD_UTILITY_LAST})
+    endif()
+    set(LLVM_ADD_UTILITY_LAST ${name} CACHE STRING INTERNAL FORCE)
+    
+  else()
+    add_llvm_executable(${name} ${ARGN})
+  endif()
   set_target_properties(${name} PROPERTIES FOLDER "Utils")
 endmacro(add_llvm_utility name)
 
Index: CMakeLists.txt
===================================================================
--- CMakeLists.txt	(revision 127962)
+++ CMakeLists.txt	(working copy)
@@ -202,6 +202,28 @@
 # Put this before tblgen. Else we have a circular dependence.
 add_subdirectory(lib/Support)
 
+
+set(LLVM_UTILS_ONLY OFF CACHE
+  OPTION "Build only utils and nothing else.")
+
+if( CMAKE_VERSION STRGREATER "2.8." )
+  set(LLVM_UTILS_BUILD_DIR "" CACHE STRING 
+    "Use separate build dir for utils. Allows you to specify different compile options for utils to for example speed up compile time.")
+  if( CMAKE_CONFIGURATION_TYPES )
+    set(LLVM_UTILS_BUILD_CONFIG "Release" CACHE STRING 
+      "When specifying a separate build dir with LLVM_UTILS_BUILD_DIR use this config when building recursively.")
+  else()
+    set(LLVM_UTILS_BUILD_CONFIG "" CACHE STRING 
+      "When specifying a separate build dir with LLVM_UTILS_BUILD_DIR use this config when building recursively.")
+  endif()  
+else()
+  if( LLVM_UTILS_BUILD_DIR )
+    message(FATAL_ERROR 
+      "LLVM_UTILS_BUILD_DIR is only supported for CMake 2.8 and later")
+  endif()
+endif()  
+
+
 set(LLVM_TABLEGEN "tblgen" CACHE
   STRING "Native TableGen executable. Saves building one when cross-compiling.")
 # Effective tblgen executable to be used:
@@ -216,7 +238,9 @@
 
 add_subdirectory(include/llvm)
 
-add_subdirectory(lib)
+if (NOT LLVM_UTILS_ONLY)
+  add_subdirectory(lib)
+endif()
 
 add_subdirectory(utils/FileCheck)
 add_subdirectory(utils/FileUpdate)
@@ -224,37 +248,46 @@
 add_subdirectory(utils/not)
 add_subdirectory(utils/llvm-lit)
 
-add_subdirectory(projects)
+if (NOT LLVM_UTILS_ONLY)
+  add_subdirectory(projects)
+endif()
 
 option(LLVM_BUILD_TOOLS
   "Build the LLVM tools. If OFF, just generate build targets." ON)
 option(LLVM_INCLUDE_TOOLS "Generate build targets for the LLVM tools." ON)
-if( LLVM_INCLUDE_TOOLS )
+if( LLVM_INCLUDE_TOOLS AND NOT LLVM_UTILS_ONLY)
   add_subdirectory(tools)
 endif()
 
 option(LLVM_BUILD_EXAMPLES
   "Build the LLVM example programs. If OFF, just generate build targets." OFF)
 option(LLVM_INCLUDE_EXAMPLES "Generate build targets for the LLVM examples" ON)
-if( LLVM_INCLUDE_EXAMPLES )
+if( LLVM_INCLUDE_EXAMPLES AND NOT LLVM_UTILS_ONLY)
   add_subdirectory(examples)
 endif()
 
 option(LLVM_BUILD_TESTS
   "Build LLVM unit tests. If OFF, just generate build targes." OFF)
-if( LLVM_INCLUDE_TESTS )
-  add_subdirectory(test)
+
+if( LLVM_INCLUDE_TESTS OR LLVM_UTILS_ONLY )
   add_subdirectory(utils/unittest)
-  add_subdirectory(unittests)
-  if (MSVC)
+  if ( MSVC )
     # This utility is used to prevent chrashing tests from calling Dr. Watson on
     # Windows.
     add_subdirectory(utils/KillTheDoctor)
   endif()
 endif()
 
-add_subdirectory(cmake/modules)
+if( LLVM_INCLUDE_TESTS AND NOT LLVM_UTILS_ONLY)
+  add_subdirectory(test)
+  add_subdirectory(unittests)
+endif()
 
+
+if (NOT LLVM_UTILS_ONLY)
+  add_subdirectory(cmake/modules)
+endif()
+
 install(DIRECTORY include/
   DESTINATION include
   FILES_MATCHING
Index: docs/CMake.html
===================================================================
--- docs/CMake.html	(revision 127962)
+++ docs/CMake.html	(working copy)
@@ -350,6 +350,25 @@
     Function Interface library. If the library or its headers are
     installed on a custom location, you can set the variables
     FFI_INCLUDE_DIR and FFI_LIBRARY_DIR. Defaults to OFF.</dd>
+
+  <dt><b>LLVM_UTILS_ONLY</b>:BOOL</dt>
+  <dd>Build only utils and nothing else. This can be useful in 
+    combination with LLVM_UTILS_BUILD_DIR to minimize the required
+    CMake build system generation.</dd>
+
+  <dt><b>LLVM_UTILS_BUILD_DIR</b>:STRING</dt>
+  <dd>Use separate build directory for utils. Allows you to specify different 
+    build options for utils. Useful when you for example want to speed up Debug 
+    compile time. The utilities in this directory will be built automatically 
+    when needed.</dd>
+
+  <dt><b>LLVM_UTILS_BUILD_CONFIG</b>:STRING</dt>
+  <dd>The target type to build when using LLVM_UTILS_BUILD_DIR. This is needed
+    on CMake generators that support generation of multiple target types such as
+    Visual Studio and Xcode. When set to "" utils build dir will be assumed to 
+    not be multi targeted. Defaults to Release for generators that support
+    generation of multible targets, otherwise "".</dd>
+    
 </dl>
 
 </div>
Index: utils/default.c
===================================================================
--- utils/default.c	(revision 0)
+++ utils/default.c	(revision 0)
@@ -0,0 +1,12 @@
+/*===- defalt.c - Default file for utils -----------------------------------===*\
+ *
+ *                     The LLVM Compiler Infrastructure
+ *
+ * This file is distributed under the University of Illinois Open Source
+ * License. See LICENSE.TXT for details.
+ *
+\*===----------------------------------------------------------------------===*/
+
+int main(int argc, char **argv) {
+  return 0;
+}