Fix utils/update_cc_test_checks/check-globals.test on stand-alone builds

[tstellar]

Summary

We want to use LLVM_EXTERNAL_LIT if defined for the %lit substitution.

[jdenny]

Thanks for the fix. LGTM.

clang/test/CMakeLists.txt

configure_lit_site_cfg(
   ${CMAKE_CURRENT_SOURCE_DIR}/lit.cfg.py
   PATHS
   "LLVM_SOURCE_DIR"
   "LLVM_BINARY_DIR"
   "LLVM_TOOLS_DIR"
   "LLVM_LIBS_DIR"
   "SHLIBDIR"
   "LLVM_LIT_TOOLS_DIR"
+  "LLVM_EXTERNAL_LIT"
   "CLANG_BINARY_DIR"
   "CLANG_SOURCE_DIR"
   "CLANG_TOOLS_DIR"
   )
 
 configure_lit_site_cfg(
   ${CMAKE_CURRENT_SOURCE_DIR}/Unit/lit.site.cfg.py.in
   ${CMAKE_CURRENT_BINARY_DIR}/Unit/lit.site.cfg.py

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

 config.enable_backtrace = @ENABLE_BACKTRACES@
 config.enable_experimental_new_pass_manager = @LLVM_ENABLE_NEW_PASS_MANAGER@
 config.enable_threads = @LLVM_ENABLE_THREADS@
 config.host_arch = "@HOST_ARCH@"
 config.python_executable = "@Python3_EXECUTABLE@"
 config.use_z3_solver = lit_config.params.get('USE_Z3_SOLVER', "@USE_Z3_SOLVER@")
 config.has_plugins = @LLVM_ENABLE_PLUGINS@
 config.clang_vendor_uti = "@CLANG_VENDOR_UTI@"
+config.llvm_external_lit = path(r"@LLVM_EXTERNAL_LIT@")
 
 # Support substitution of the tools and libs dirs with user parameters. This is
 # used when we can't determine the tool dir at configuration time.
 try:
     config.clang_tools_dir = config.clang_tools_dir % lit_config.params
     config.llvm_tools_dir = config.llvm_tools_dir % lit_config.params
     config.llvm_shlib_dir = config.llvm_shlib_dir % lit_config.params
     config.llvm_libs_dir = config.llvm_libs_dir % lit_config.params

clang/test/utils/update_cc_test_checks/lit.local.cfg

 
 clang_path = os.path.join(config.clang_tools_dir, 'clang')
 extra_args = '--clang ' + shell_quote(clang_path)
 opt_path = os.path.join(config.llvm_tools_dir, 'opt')
 extra_args += ' --opt ' + shell_quote(opt_path)
 script_path = os.path.join(config.llvm_src_root, 'utils',
                            'update_cc_test_checks.py')
 assert os.path.isfile(script_path)
-lit = shell_quote(os.path.join(config.llvm_src_root, 'utils', 'lit', 'lit.py'))
+lit = config.llvm_external_lit if config.llvm_external_lit else shell_quote(os.path.join(config.llvm_src_root, 'utils', 'lit', 'lit.py'))
 python = shell_quote(config.python_executable)
 config.substitutions.append(
     ('%update_cc_test_checks', "%s %s %s" % (
         python, shell_quote(script_path), extra_args)))
 config.substitutions.append(
     ('%clang_tools_dir', shell_quote(config.clang_tools_dir)))
 config.substitutions.append(
     ('%lit', "%s %s -Dclang_lit_site_cfg=%s -j1 -vv" % (
         python, lit, shell_quote(config.clang_lit_site_cfg))))