Index: cmake/modules/GenerateVersionFromCVS.cmake
===================================================================
--- /dev/null
+++ cmake/modules/GenerateVersionFromCVS.cmake
@@ -0,0 +1,39 @@
+# CMake project that writes Subversion revision information to a header.
+#
+# Input variables:
+#   SRC               - Source directory
+#   HEADER_FILE       - The header file to write
+#
+# The output header will contain macros FIRST_REPOSITORY and FIRST_REVISION,
+# and SECOND_REPOSITORY and SECOND_REVISION if requested, where "FIRST" and
+# "SECOND" are substituted with the names specified in the input variables.
+
+
+
+# Chop off cmake/modules/GetSVN.cmake
+get_filename_component(LLVM_DIR "${CMAKE_SCRIPT_MODE_FILE}" PATH)
+get_filename_component(LLVM_DIR "${LLVM_DIR}" PATH)
+get_filename_component(LLVM_DIR "${LLVM_DIR}" PATH)
+
+set(CMAKE_MODULE_PATH
+  ${CMAKE_MODULE_PATH}
+  "${LLVM_DIR}/cmake/modules")
+include(VersionFromVCS)
+
+# Handle strange terminals
+set(ENV{TERM} "dumb")
+
+function(append_info name path)
+  add_version_info_from_vcs(REVISION ${path})
+  string(STRIP "${REVISION}" REVISION)
+  file(APPEND "${HEADER_FILE}.txt"
+    "#define ${name} \"${REVISION}\"\n")
+endfunction()
+
+append_info(${NAME} "${SOURCE_DIR}")
+
+# Copy the file only if it has changed.
+execute_process(COMMAND ${CMAKE_COMMAND} -E copy_if_different
+  "${HEADER_FILE}.txt" "${HEADER_FILE}")
+file(REMOVE "${HEADER_FILE}.txt")
+
Index: cmake/modules/VersionFromVCS.cmake
===================================================================
--- cmake/modules/VersionFromVCS.cmake
+++ cmake/modules/VersionFromVCS.cmake
@@ -1,17 +1,22 @@
 # Adds version control information to the variable VERS. For
 # determining the Version Control System used (if any) it inspects the
-# existence of certain subdirectories under CMAKE_CURRENT_SOURCE_DIR.
+# existence of certain subdirectories under SOURCE_DIR (if provided as an
+# extra argument, otherwise uses CMAKE_CURRENT_SOURCE_DIR).
 
 function(add_version_info_from_vcs VERS)
+  SET(SOURCE_DIR ${ARGV1})
+  if("${SOURCE_DIR}" STREQUAL "")
+      SET(SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
+  endif()
   string(REPLACE "svn" "" result "${${VERS}}")
-  if( EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/.svn" )
+  if( EXISTS "${SOURCE_DIR}/.svn" )
     set(result "${result}svn")
     # FindSubversion does not work with symlinks. See PR 8437
-    if( NOT IS_SYMLINK "${CMAKE_CURRENT_SOURCE_DIR}" )
+    if( NOT IS_SYMLINK "${SOURCE_DIR}" )
       find_package(Subversion)
     endif()
     if( Subversion_FOUND )
-      subversion_wc_info( ${CMAKE_CURRENT_SOURCE_DIR} Project )
+      subversion_wc_info( ${SOURCE_DIR} Project )
       if( Project_WC_REVISION )
         set(SVN_REVISION ${Project_WC_REVISION} PARENT_SCOPE)
         set(result "${result}-r${Project_WC_REVISION}")
@@ -20,16 +25,16 @@
         set(LLVM_REPOSITORY ${Project_WC_URL} PARENT_SCOPE)
       endif()
     endif()
-  elseif( EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/.git )
+  elseif( EXISTS ${SOURCE_DIR}/.git )
     set(result "${result}git")
     # Try to get a ref-id
-    if( EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/.git/svn )
+    if( EXISTS ${SOURCE_DIR}/.git/svn )
       find_program(git_executable NAMES git git.exe git.cmd)
       if( git_executable )
         set(is_git_svn_rev_exact false)
         execute_process(COMMAND
           ${git_executable} svn info
-          WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+          WORKING_DIRECTORY ${SOURCE_DIR}
           TIMEOUT 5
           RESULT_VARIABLE git_result
           OUTPUT_VARIABLE git_output)
@@ -46,7 +51,7 @@
 
           # Determine if the HEAD points directly at a subversion revision.
           execute_process(COMMAND ${git_executable} svn find-rev HEAD
-            WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+            WORKING_DIRECTORY ${SOURCE_DIR}
             TIMEOUT 5
             RESULT_VARIABLE git_result
             OUTPUT_VARIABLE git_output)
@@ -61,10 +66,11 @@
         endif()
         execute_process(COMMAND
           ${git_executable} rev-parse --short HEAD
-          WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+          WORKING_DIRECTORY ${SOURCE_DIR}
           TIMEOUT 5
           RESULT_VARIABLE git_result
           OUTPUT_VARIABLE git_output)
+
         if( git_result EQUAL 0 AND NOT is_git_svn_rev_exact )
           string(STRIP "${git_output}" git_ref_id)
           set(GIT_COMMIT ${git_ref_id} PARENT_SCOPE)
Index: lib/LTO/CMakeLists.txt
===================================================================
--- lib/LTO/CMakeLists.txt
+++ lib/LTO/CMakeLists.txt
@@ -1,8 +1,58 @@
+# Figure out if we can track VC revisions.
+function(find_first_existing_file out_var)
+  foreach(file ${ARGN})
+    if(EXISTS "${file}")
+      set(${out_var} "${file}" PARENT_SCOPE)
+      return()
+    endif()
+  endforeach()
+endfunction()
+
+macro(find_first_existing_vc_file out_var path)
+  find_first_existing_file(${out_var}
+    "${path}/.git/logs/HEAD" # Git
+    "${path}/.svn/wc.db"     # SVN 1.7
+    "${path}/.svn/entries"   # SVN 1.6
+    )
+endmacro()
+
+find_first_existing_vc_file(llvm_vc "${LLVM_MAIN_SRC_DIR}")
+
+# The VC revision include that we want to generate.
+set(version_inc "${CMAKE_CURRENT_BINARY_DIR}/LLVMLTORevision.h")
+
+set(get_svn_script "${LLVM_MAIN_SRC_DIR}/cmake/modules/GenerateVersionFromCVS.cmake")
+
+if(DEFINED llvm_vc)
+  # Create custom target to generate the VC revision include.
+  add_custom_command(OUTPUT "${version_inc}"
+    DEPENDS "${llvm_vc}" "${get_svn_script}"
+    COMMAND
+    ${CMAKE_COMMAND} "-DSOURCE_DIR=${LLVM_MAIN_SRC_DIR}"
+                     "-DNAME=LLVM_REVISION"
+                     "-DHEADER_FILE=${version_inc}"
+                     -P "${get_svn_script}")
+
+  # Mark the generated header as being generated.
+  set_source_files_properties("${version_inc}"
+    PROPERTIES GENERATED TRUE
+               HEADER_FILE_ONLY TRUE)
+
+  # Tell Version.cpp that it needs to build with -DHAVE_SVN_VERSION_INC.
+  set_source_files_properties(Version.cpp
+    PROPERTIES COMPILE_DEFINITIONS "HAVE_SVN_VERSION_INC")
+else()
+  # Not producing a VC revision include.
+  set(version_inc)
+endif()
+
+
 add_llvm_library(LLVMLTO
   LTOModule.cpp
   LTOCodeGenerator.cpp
   UpdateCompilerUsed.cpp
   ThinLTOCodeGenerator.cpp
+  ${version_inc}
 
   ADDITIONAL_HEADER_DIRS
   ${LLVM_MAIN_INCLUDE_DIR}/llvm/LTO
Index: lib/LTO/ThinLTOCodeGenerator.cpp
===================================================================
--- lib/LTO/ThinLTOCodeGenerator.cpp
+++ lib/LTO/ThinLTOCodeGenerator.cpp
@@ -13,6 +13,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/LTO/ThinLTOCodeGenerator.h"
+#include "LLVMLTORevision.h"
 
 #include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/StringExtras.h"