Revert "[lit] Force site configs to run before source-tree configs"

This patch is still breaking several multi-stage compiler-rt bots.
I already know what the fix is, but I want to get the bots green
for now and then try re-applying in the morning.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@313335 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 63 insertions, 4 deletions

diff --git a/test/Unit/lit.cfg b/test/Unit/lit.cfg
index c4794ccbe5..90eb2ac604 100644
--- a/test/Unit/lit.cfg
+++ b/test/Unit/lit.cfg
@@ -17,11 +17,14 @@ config.suffixes = []
 
 # test_source_root: The root path where tests are located.
 # test_exec_root: The root path where tests should be run.
-config.test_exec_root = os.path.join(config.clang_obj_root, 'unittests')
-config.test_source_root = config.test_exec_root
+clang_obj_root = getattr(config, 'clang_obj_root', None)
+if clang_obj_root is not None:
+    config.test_exec_root = os.path.join(clang_obj_root, 'unittests')
+    config.test_source_root = config.test_exec_root
 
 # testFormat: The test format to use to interpret tests.
-config.test_format = lit.formats.GoogleTest(config.llvm_build_mode, 'Tests')
+llvm_build_mode = getattr(config, 'llvm_build_mode', "Debug")
+config.test_format = lit.formats.GoogleTest(llvm_build_mode, 'Tests')
 
 # Propagate the temp directory. Windows requires this because it uses \Windows\
 # if none of these are present.
@@ -35,6 +38,55 @@ for symbolizer in ['ASAN_SYMBOLIZER_PATH', 'MSAN_SYMBOLIZER_PATH']:
     if symbolizer in os.environ:
         config.environment[symbolizer] = os.environ[symbolizer]
 
+###
+
+# Check that the object root is known.
+if config.test_exec_root is None:
+    # Otherwise, we haven't loaded the site specific configuration (the user is
+    # probably trying to run on a test file directly, and either the site
+    # configuration hasn't been created by the build system, or we are in an
+    # out-of-tree build situation).
+
+    # Check for 'clang_unit_site_config' user parameter, and use that if available.
+    site_cfg = lit_config.params.get('clang_unit_site_config', None)
+    if site_cfg and os.path.exists(site_cfg):
+        lit_config.load_config(config, site_cfg)
+        raise SystemExit
+
+    # Try to detect the situation where we are using an out-of-tree build by
+    # looking for 'llvm-config'.
+    #
+    # FIXME: I debated (i.e., wrote and threw away) adding logic to
+    # automagically generate the lit.site.cfg if we are in some kind of fresh
+    # build situation. This means knowing how to invoke the build system
+    # though, and I decided it was too much magic.
+
+    llvm_config = lit.util.which('llvm-config', config.environment['PATH'])
+    if not llvm_config:
+        lit_config.fatal('No site specific configuration available!')
+
+    # Get the source and object roots.
+    llvm_src_root = subprocess.check_output(['llvm-config', '--src-root']).strip()
+    llvm_obj_root = subprocess.check_output(['llvm-config', '--obj-root']).strip()
+    clang_src_root = os.path.join(llvm_src_root, "tools", "clang")
+    clang_obj_root = os.path.join(llvm_obj_root, "tools", "clang")
+
+    # Validate that we got a tree which points to here, using the standard
+    # tools/clang layout.
+    this_src_root = os.path.join(os.path.dirname(__file__),'..','..')
+    if os.path.realpath(clang_src_root) != os.path.realpath(this_src_root):
+        lit_config.fatal('No site specific configuration available!')
+
+    # Check that the site specific configuration exists.
+    site_cfg = os.path.join(clang_obj_root, 'test', 'Unit', 'lit.site.cfg')
+    if not os.path.exists(site_cfg):
+        lit_config.fatal('No site specific configuration available!')
+
+    # Okay, that worked. Notify the user of the automagic, and reconfigure.
+    lit_config.note('using out-of-tree build at %r' % clang_obj_root)
+    lit_config.load_config(config, site_cfg)
+    raise SystemExit
+
 shlibpath_var = ''
 if platform.system() == 'Linux':
     shlibpath_var = 'LD_LIBRARY_PATH'
@@ -45,7 +97,14 @@ elif platform.system() == 'Windows':
 
 # in stand-alone builds, shlibdir is clang's build tree
 # while llvm_libs_dir is installed LLVM (and possibly older clang)
-shlibpath = os.path.pathsep.join((config.shlibdir, config.llvm_libs_dir,
+llvm_shlib_dir = getattr(config, 'shlibdir', None)
+if not llvm_shlib_dir:
+    lit_config.fatal('No shlibdir set!')
+# Point the dynamic loader at dynamic libraries in 'lib'.
+llvm_libs_dir = getattr(config, 'llvm_libs_dir', None)
+if not llvm_libs_dir:
+    lit_config.fatal('No LLVM libs dir set!')
+shlibpath = os.path.pathsep.join((llvm_shlib_dir, llvm_libs_dir,
                                  config.environment.get(shlibpath_var,'')))
 
 config.environment[shlibpath_var] = shlibpath