diff --git a/llvm/cmake/modules/HandleLLVMOptions.cmake b/llvm/cmake/modules/HandleLLVMOptions.cmake
--- a/llvm/cmake/modules/HandleLLVMOptions.cmake
+++ b/llvm/cmake/modules/HandleLLVMOptions.cmake
@@ -1019,8 +1019,9 @@
   endif()
 endif()
 
+set(LLVM_SOURCE_PREFIX "" CACHE STRING "Use prefix for sources")
+
 option(LLVM_USE_RELATIVE_PATHS_IN_DEBUG_INFO "Use relative paths in debug info" OFF)
-set(LLVM_SOURCE_PREFIX "" CACHE STRING "Use prefix for sources in debug info")
 
 if(LLVM_USE_RELATIVE_PATHS_IN_DEBUG_INFO)
   check_c_compiler_flag("-fdebug-prefix-map=foo=bar" SUPPORTS_FDEBUG_PREFIX_MAP)
@@ -1034,3 +1035,18 @@
   append_if(SUPPORTS_FDEBUG_PREFIX_MAP "-fdebug-prefix-map=${source_root}/=${LLVM_SOURCE_PREFIX}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
   add_flag_if_supported("-no-canonical-prefixes" NO_CANONICAL_PREFIXES)
 endif()
+
+option(LLVM_USE_RELATIVE_PATHS_IN_FILES "Use relative paths in sources and debug info" OFF)
+
+if(LLVM_USE_RELATIVE_PATHS_IN_FILES)
+  check_c_compiler_flag("-ffile-prefix-map=foo=bar" SUPPORTS_FFILE_PREFIX_MAP)
+  if(LLVM_ENABLE_PROJECTS_USED)
+    get_filename_component(source_root "${LLVM_MAIN_SRC_DIR}/.." ABSOLUTE)
+  else()
+    set(source_root "${LLVM_MAIN_SRC_DIR}")
+  endif()
+  file(RELATIVE_PATH relative_root "${source_root}" "${CMAKE_BINARY_DIR}")
+  append_if(SUPPORTS_FFILE_PREFIX_MAP "-ffile-prefix-map=${CMAKE_BINARY_DIR}=${relative_root}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
+  append_if(SUPPORTS_FFILE_PREFIX_MAP "-ffile-prefix-map=${source_root}/=${LLVM_SOURCE_PREFIX}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
+  add_flag_if_supported("-no-canonical-prefixes" NO_CANONICAL_PREFIXES)
+endif()
diff --git a/llvm/cmake/modules/LLVMExternalProjectUtils.cmake b/llvm/cmake/modules/LLVMExternalProjectUtils.cmake
--- a/llvm/cmake/modules/LLVMExternalProjectUtils.cmake
+++ b/llvm/cmake/modules/LLVMExternalProjectUtils.cmake
@@ -239,6 +239,7 @@
                -DLLVM_HOST_TRIPLE=${LLVM_HOST_TRIPLE}
                -DLLVM_HAVE_LINK_VERSION_SCRIPT=${LLVM_HAVE_LINK_VERSION_SCRIPT}
                -DLLVM_USE_RELATIVE_PATHS_IN_DEBUG_INFO=${LLVM_USE_RELATIVE_PATHS_IN_DEBUG_INFO}
+               -DLLVM_USE_RELATIVE_PATHS_IN_FILES=${LLVM_USE_RELATIVE_PATHS_IN_FILES}
                -DLLVM_SOURCE_PREFIX=${LLVM_SOURCE_PREFIX}
                -DPACKAGE_VERSION=${PACKAGE_VERSION}
                -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
diff --git a/llvm/docs/CMake.rst b/llvm/docs/CMake.rst
--- a/llvm/docs/CMake.rst
+++ b/llvm/docs/CMake.rst
@@ -631,6 +631,14 @@
   If enabled, the Z3 constraint solver is activated for the Clang static analyzer.
   A recent version of the z3 library needs to be available on the system.
 
+**LLVM_USE_RELATIVE_PATHS_IN_DEBUG_INFO**:BOOL
+  Rewrite absolute source paths in debug info to relative ones. The source prefix
+  can be adjusted via the LLVM_SOURCE_PREFIX variable.
+
+**LLVM_USE_RELATIVE_PATHS_IN_FILES**:BOOL
+  Rewrite absolute source paths in sources and debug info to relative ones. The
+  source prefix can be adjusted via the LLVM_SOURCE_PREFIX variable.
+
 CMake Caches
 ============