Index: CMakeLists.txt
===================================================================
--- CMakeLists.txt
+++ CMakeLists.txt
@@ -458,6 +458,12 @@
   option(LLVM_BUILD_32_BITS "Build 32 bits executables and libraries." OFF)
 endif()
 
+# If building on a 32-bit system, make sure off_t can store offsets > 2GB
+if( CMAKE_SIZEOF_VOID_P EQUAL 4 )
+  add_definitions( -D_LARGEFILE_SOURCE )
+  add_definitions( -D_FILE_OFFSET_BITS=64 )
+endif()
+
 # Define the default arguments to use with 'lit', and an option for the user to
 # override.
 set(LIT_ARGS_DEFAULT "-sv")