[test] Skip a test when using an out-of-tree debugserver

The test "test_fp_special_purpose_register_read" in TestRegisters.py
fails on Darwin machines configured to use an out-of-tree debugserver.

The error message is: 'register read ftag' returns expected result, got
'ftag = 0x80'. This indicates that the debugserver in use is too old.

This commit introduces a decorator which can be used to skip tests which
rely on having a just-built debugserver. This resolves the issue:

$ ./bin/llvm-dotest -p TestRegisters.py -v
  1 out of 617 test suites processed - TestRegisters.py
  Test Methods:          7
  Success:               6
  Skip:                  1
...

llvm-svn: 327052

lldb/packages/Python/lldbsuite/test/decorators.py

@@ -22,6 +22,7 @@ import use_lldb_suite
 import lldb
 from . import configuration
 from . import test_categories
+from . import lldbtest_config
 from lldbsuite.test_event.event_builder import EventBuilder
 from lldbsuite.support import funcutils
 from lldbsuite.test import lldbplatform
@@ -476,6 +477,11 @@ def expectedFlakeyAndroid(bugnumber=None, api_levels=None, archs=None):
             archs),
         bugnumber)
 
+def skipIfOutOfTreeDebugserver(func):
+    """Decorate the item to skip tests if using an out-of-tree debugserver."""
+    def is_out_of_tree_debugserver():
+        return "out-of-tree debugserver" if lldbtest_config.out_of_tree_debugserver else None
+    return skipTestIfFn(is_out_of_tree_debugserver)(func)
 
 def skipIfRemote(func):
     """Decorate the item to skip tests if testing remotely."""

lldb/packages/Python/lldbsuite/test/dotest.py

@@ -307,6 +307,9 @@ def parseOptionsAndInitTestdirs():
     if args.log_success:
         lldbtest_config.log_success = args.log_success
 
+    if args.out_of_tree_debugserver:
+        lldbtest_config.out_of_tree_debugserver = args.out_of_tree_debugserver
+
     # Set SDKROOT if we are using an Apple SDK
     if platform_system == 'Darwin' and args.apple_sdk:
         os.environ['SDKROOT'] = seven.get_command_output(

lldb/packages/Python/lldbsuite/test/dotest_args.py

@@ -126,6 +126,11 @@ def create_parser():
         '--server',
         metavar='server-path',
         help='The path to the debug server executable to use')
+    group.add_argument(
+        '--out-of-tree-debugserver',
+        dest='out_of_tree_debugserver',
+        action='store_true',
+        help='A flag to indicate an out-of-tree debug server is being used')
     group.add_argument(
         '-s',
         metavar='name',

lldb/packages/Python/lldbsuite/test/functionalities/register/register_command/TestRegisters.py

@@ -69,6 +69,7 @@ class RegisterCommandsTestCase(TestBase):
     @expectedFailureAndroid(archs=["i386"])
     @skipIfFreeBSD  # llvm.org/pr25057
     @skipIf(archs=no_match(['amd64', 'i386', 'x86_64']))
+    @skipIfOutOfTreeDebugserver
     def test_fp_special_purpose_register_read(self):
         """Test commands that read fpu special purpose registers."""
         self.build()

lldb/packages/Python/lldbsuite/test/lldbtest_config.py

@@ -16,5 +16,8 @@ channels = []
 # leave logs/traces even for successful test runs
 log_success = False
 
+# Indicate whether we're testing with an out-of-tree debugserver
+out_of_tree_debugserver = False
+
 # path to the lldb command line executable tool
 lldbExec = None

lldb/test/CMakeLists.txt

@@ -113,6 +113,10 @@ if(CMAKE_HOST_APPLE)
   list(APPEND LLDB_TEST_COMMON_ARGS --server ${DEBUGSERVER_PATH})
 endif()
 
+if(SKIP_DEBUGSERVER)
+  list(APPEND LLDB_TEST_COMMON_ARGS --out-of-tree-debugserver)
+endif()
+
 set(LLDB_DOTEST_ARGS ${LLDB_TEST_COMMON_ARGS};${LLDB_TEST_USER_ARGS})
 
 add_python_test_target(check-lldb-single