Revert "Make it possible for lit.site.cfg to contain relative paths, and use it for llvm and clang"

This reverts commit fb80b6b2d58c476747a3206bd4371b787108591b and
follow-up 631ee8b24adf36359b61ecb47484e8e82de35be8.

Seems to not work on Windows:
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-windows10pro-fast/builds/31684
http://lab.llvm.org:8011/builders/llvm-clang-win-x-aarch64/builds/6512

Let's revert while I investigate.

cmake/modules/AddLLVM.cmake

@@ -1396,14 +1396,8 @@ endmacro()
 # variables needed for the 'lit.site.cfg' files. This function bundles the
 # common variables that any Lit instance is likely to need, and custom
 # variables can be passed in.
-# The keyword PATHS is followed by a list of cmake variable names that are
-# mentioned as `path("@varname@")` in the lit.cfg.py.in file. Variables in that
-# list are treated as paths that are relative to the directory the generated
-# lit.cfg.py file is in, and the `path()` function converts the relative
-# path back to absolute form. This makes it possible to move a build directory
-# containing lit.cfg.py files from one machine to another.
 function(configure_lit_site_cfg site_in site_out)
-  cmake_parse_arguments(ARG "" "" "MAIN_CONFIG;OUTPUT_MAPPING;PATHS" ${ARGN})
+  cmake_parse_arguments(ARG "" "" "MAIN_CONFIG;OUTPUT_MAPPING" ${ARGN})
 
   if ("${ARG_MAIN_CONFIG}" STREQUAL "")
     get_filename_component(INPUT_DIR ${site_in} DIRECTORY)
@@ -1453,17 +1447,12 @@ function(configure_lit_site_cfg site_in site_out)
   set(HOST_CXX "${CMAKE_CXX_COMPILER} ${CMAKE_CXX_COMPILER_ARG1}")
   set(HOST_LDFLAGS "${CMAKE_EXE_LINKER_FLAGS}")
 
-  set(LIT_SITE_CFG_IN_HEADER  "# Autogenerated from ${site_in}\n# Do not edit!")
-
-  string(CONCAT LIT_SITE_CFG_IN_HEADER "${LIT_SITE_CFG_IN_HEADER}\n\n"
-    "# Allow generated lit.site.cfg.py to be relocatable.\n"
-    "def path(p): return os.path.join(os.path.dirname(__file__), p) if p else ''\n"
-    )
+  set(LIT_SITE_CFG_IN_HEADER  "## Autogenerated from ${site_in}\n## Do not edit!")
 
   # Override config_target_triple (and the env)
   if(LLVM_TARGET_TRIPLE_ENV)
     # This is expanded into the heading.
-    string(CONCAT LIT_SITE_CFG_IN_HEADER "${LIT_SITE_CFG_IN_HEADER}"
+    string(CONCAT LIT_SITE_CFG_IN_HEADER "${LIT_SITE_CFG_IN_HEADER}\n\n"
       "import os\n"
       "target_env = \"${LLVM_TARGET_TRIPLE_ENV}\"\n"
       "config.target_triple = config.environment[target_env] = os.environ.get(target_env, \"${TARGET_TRIPLE}\")\n"
@@ -1473,45 +1462,7 @@ function(configure_lit_site_cfg site_in site_out)
     set(TARGET_TRIPLE "\"+config.target_triple+\"")
   endif()
 
-  if (ARG_PATHS)
-    # Walk ARG_PATHS and collect the current value of the variables in there.
-    foreach(path ${ARG_PATHS})
-      list(APPEND ARG_PATH_VALUES "${${path}}")
-    endforeach()
-
-    # Compute paths relative to the directory containing output lit.site.cfg.py.
-    # Passing ARG_PATH_VALUES as-is to execute_process() makes cmake strip
-    # empty list entries. So escape the ;s in the list and do the splitting
-    # outselves. cmake has no relpath function, so use Python for that.
-    string(REPLACE ";" "\\;" ARG_PATH_VALUES_ESCAPED "${ARG_PATH_VALUES}")
-    get_filename_component(OUTPUT_DIR ${site_out} DIRECTORY)
-    execute_process(COMMAND "${PYTHON_EXECUTABLE}" "-c"
-      "import os, sys; sys.stdout.write(';'.join(os.path.relpath(p, sys.argv[1]) if p else '' for p in sys.argv[2].split(';')))"
-      ${OUTPUT_DIR}
-      ${ARG_PATH_VALUES_ESCAPED}
-      OUTPUT_VARIABLE ARG_PATH_VALUES_RELATIVE)
-
-    list(LENGTH ARG_PATHS len_paths)
-    list(LENGTH ARG_PATH_VALUES len_path_values)
-    list(LENGTH ARG_PATH_VALUES_RELATIVE len_path_value_rels)
-    if ((NOT ${len_paths} EQUAL ${len_path_values}) OR
-        (NOT ${len_paths} EQUAL ${len_path_value_rels}))
-      message(SEND_ERROR "PATHS lengths got confused")
-    endif()
-
-    # Transform variables mentioned in ARG_PATHS to relative paths for
-    # the configure_file() call. Variables are copied to subscopeds by cmake,
-    # so this only modifies the local copy of the variables.
-    math(EXPR arg_path_limit "${len_paths} - 1")
-    foreach(i RANGE ${arg_path_limit})
-      list(GET ARG_PATHS ${i} val1)
-      list(GET ARG_PATH_VALUES_RELATIVE ${i} val2)
-      set(${val1} ${val2})
-    endforeach()
-  endif()
-
   configure_file(${site_in} ${site_out} @ONLY)
-
   if (EXISTS "${ARG_MAIN_CONFIG}")
     set(PYTHON_STATEMENT "map_config('${ARG_MAIN_CONFIG}', '${site_out}')")
     get_property(LLVM_LIT_CONFIG_MAP GLOBAL PROPERTY LLVM_LIT_CONFIG_MAP)

test/CMakeLists.txt

@@ -22,23 +22,12 @@ configure_lit_site_cfg(
   ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg.py
   MAIN_CONFIG
   ${CMAKE_CURRENT_SOURCE_DIR}/lit.cfg.py
-  PATHS
-  "LLVM_SOURCE_DIR"
-  "LLVM_BINARY_DIR"
-  "LLVM_TOOLS_DIR"
-  "LLVM_LIBRARY_DIR"
-  "SHLIBDIR"
   )
 configure_lit_site_cfg(
   ${CMAKE_CURRENT_SOURCE_DIR}/Unit/lit.site.cfg.py.in
   ${CMAKE_CURRENT_BINARY_DIR}/Unit/lit.site.cfg.py
   MAIN_CONFIG
   ${CMAKE_CURRENT_SOURCE_DIR}/Unit/lit.cfg.py
-  PATHS
-  "LLVM_SOURCE_DIR"
-  "LLVM_BINARY_DIR"
-  "LLVM_TOOLS_DIR"
-  "SHLIBDIR"
   )
 
 # Set the depends list as a variable so that it can grow conditionally.

test/Unit/lit.site.cfg.py.in

@@ -2,12 +2,12 @@
 
 import sys
 
-config.llvm_src_root = path("@LLVM_SOURCE_DIR@")
-config.llvm_obj_root = path("@LLVM_BINARY_DIR@")
-config.llvm_tools_dir = path("@LLVM_TOOLS_DIR@")
+config.llvm_src_root = "@LLVM_SOURCE_DIR@"
+config.llvm_obj_root = "@LLVM_BINARY_DIR@"
+config.llvm_tools_dir = "@LLVM_TOOLS_DIR@"
 config.llvm_build_mode = "@LLVM_BUILD_MODE@"
 config.enable_shared = @ENABLE_SHARED@
-config.shlibdir = path("@SHLIBDIR@")
+config.shlibdir = "@SHLIBDIR@"
 
 # Support substitution of the tools_dir and build_mode with user parameters.
 # This is used when we can't determine the tool dir at configuration time.
@@ -20,5 +20,4 @@ except KeyError:
     lit_config.fatal("unable to find %r parameter, use '--param=%s=VALUE'" % (key,key))
 
 # Let the main config do the real work.
-lit_config.load_config(
-    config, os.path.join(config.llvm_src_root, "test/Unit/lit.cfg.py"))
+lit_config.load_config(config, "@LLVM_SOURCE_DIR@/test/Unit/lit.cfg.py")

test/lit.site.cfg.py.in

@@ -4,14 +4,14 @@ import sys
 
 config.host_triple = "@LLVM_HOST_TRIPLE@"
 config.target_triple = "@TARGET_TRIPLE@"
-config.llvm_src_root = path("@LLVM_SOURCE_DIR@")
-config.llvm_obj_root = path("@LLVM_BINARY_DIR@")
-config.llvm_tools_dir = path("@LLVM_TOOLS_DIR@")
-config.llvm_lib_dir = path("@LLVM_LIBRARY_DIR@")
-config.llvm_shlib_dir = path("@SHLIBDIR@")
+config.llvm_src_root = "@LLVM_SOURCE_DIR@"
+config.llvm_obj_root = "@LLVM_BINARY_DIR@"
+config.llvm_tools_dir = "@LLVM_TOOLS_DIR@"
+config.llvm_lib_dir = "@LLVM_LIBRARY_DIR@"
+config.llvm_shlib_dir = "@SHLIBDIR@"
 config.llvm_shlib_ext = "@SHLIBEXT@"
 config.llvm_exe_ext = "@EXEEXT@"
-config.lit_tools_dir = path("@LLVM_LIT_TOOLS_DIR@")
+config.lit_tools_dir = "@LLVM_LIT_TOOLS_DIR@"
 config.python_executable = "@PYTHON_EXECUTABLE@"
 config.gold_executable = "@GOLD_EXECUTABLE@"
 config.ld64_executable = "@LD64_EXECUTABLE@"
@@ -63,5 +63,4 @@ import lit.llvm
 lit.llvm.initialize(lit_config, config)
 
 # Let the main config do the real work.
-lit_config.load_config(
-    config, os.path.join(config.llvm_src_root, "test/lit.cfg.py"))
+lit_config.load_config(config, "@LLVM_SOURCE_DIR@/test/lit.cfg.py")

utils/gn/secondary/clang/test/BUILD.gn

@@ -12,10 +12,7 @@ template("write_lit_config") {
     input = invoker.input
     output = invoker.output
     values = [
-      # FIXME: Write relative paths for path()s.
-      "LIT_SITE_CFG_IN_HEADER=" +
-          "## Autogenerated from $input, do not edit\n\n" +
-          "def path(p): return p if p else \"\"",
+      "LIT_SITE_CFG_IN_HEADER=## Autogenerated from $input, do not edit",
       "CLANG_BINARY_DIR=" +
           rebase_path(get_label_info("//clang", "target_out_dir")),
       "CLANG_SOURCE_DIR=" + rebase_path("//clang"),

utils/gn/secondary/llvm/test/BUILD.gn

@@ -14,10 +14,7 @@ template("write_lit_config") {
     input = invoker.input
     output = invoker.output
     values = [
-      # FIXME: Write relative paths for path()s.
-      "LIT_SITE_CFG_IN_HEADER=" +
-          "## Autogenerated from $input, do not edit\n\n" +
-          "def path(p): return p if p else \"\"",
+      "LIT_SITE_CFG_IN_HEADER=## Autogenerated from $input, do not edit",
       "ENABLE_SHARED=0",
       "LLVM_BINARY_DIR=" +
           rebase_path(get_label_info("//llvm", "target_out_dir")),