dotest.py: Add option to pass extra lldb settings to dotest

[aprantl]

Summary

The primary motivation for this is to add another dimension to the Swift LLDB test matrix, but this seems generally useful.

[JDevlieghere]

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

52

To initialize settings to a empty dictionary this should be {} or dict().

[labath]

Seems reasonable.

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

52

True, though that depends on what you really want out of this. I can see how executing the commands in the order that the user set them could be more predictable....

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

787

Maybe you could even put this as the default value for the settings variable?

[jingham]

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

787

Not sure what you meant by this, but I don't think "no dynamic values" is the right setting for prefer-dynamic-value for ordinary users of lldb. For ObjC it is definitely the wrong value (too many things get passed as "id" which is not useful). But also, every time we break dynamic value determination for C++ we get lots of complaints, so I think this is a feature people really rely on.

[labath]

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

787

I just meant putting settings = [("target.prefer-dynamic-value", "no-dynamic-values")] above in configuration.py. That way the setting would be applied automatically, without needing to manually call disabledynamics().

[aprantl]

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

52

This is intentionally *not* a dictionary :-)

You're supposed to be able to write

--setting foo=bar --setting foo=baz

and have both of them applied, in that order.

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

 
 # The 'arch' and 'compiler' can be specified via command line.
 arch = None        # Must be initialized after option parsing
 compiler = None    # Must be initialized after option parsing
 
 # The overriden dwarf verison.
 dwarf_version = 0
 
+# Any overridden settings.
+settings = []
+
 # Path to the FileCheck testing tool. Not optional.
 filecheck = None
 
 # The arch might dictate some specific CFLAGS to be passed to the toolchain to build
 # the inferior programs.  The global variable cflags_extras provides a hook to do
 # just that.
 cflags_extras = ''
 

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

if args.E:
         os.environ['CFLAGS_EXTRAS'] = args.E
 
     if args.dwarf_version:
         configuration.dwarf_version = args.dwarf_version
         # We cannot modify CFLAGS_EXTRAS because they're used in test cases
         # that explicitly require no debug info.
         os.environ['CFLAGS'] = '-gdwarf-{}'.format(configuration.dwarf_version)
 
+    if args.settings:
+        for setting in args.settings:
+            if not len(setting) == 1 or not setting[0].count('='):
+                logging.error('"%s" is not a setting in the form "key=value"',
+                              setting[0])
+                sys.exit(-1)
+            configuration.settings.append(setting[0].split('=', 1))
+
     if args.d:
         sys.stdout.write(
             "Suspending the process %d to wait for debugger to attach...\n" %
             os.getpid())
         sys.stdout.flush()
         os.kill(os.getpid(), signal.SIGSTOP)
 
     if args.f:
for name in python_test_files:
 
                 # Generate the test event.
                 configuration.results_formatter_object.handle_event(
                     EventBuilder.event_for_job_test_add_error(
                         test_filename, ex, backtrace))
             raise
 
 
-def disabledynamics():
+def setSetting(setting, value):
     import lldb
     ci = lldb.DBG.GetCommandInterpreter()
     res = lldb.SBCommandReturnObject()
-    ci.HandleCommand(
-        "setting set target.prefer-dynamic-value no-dynamic-values",
-        res,
-        False)
+    cmd = 'setting set %s %s'%(setting, value)
+    print(cmd)
+    ci.HandleCommand(cmd, res, False)
     if not res.Succeeded():
-        raise Exception('disabling dynamic type support failed')
+        raise Exception('failed to run "%s"'%cmd)
+
+def disabledynamics():
+    setSetting('target.prefer-dynamic-value', 'no-dynamic-values')
 
 
 # ======================================== #
 #                                          #
 # Execution of the test driver starts here #
 #                                          #
 # ======================================== #
 
def run_suite():
 
     #
     # Now that we have loaded all the test cases, run the whole test suite.
     #
 
     # Disable default dynamic types for testing purposes
     disabledynamics()
 
+    # Set any user-overridden settings.
+    for key, value in configuration.settings:
+        setSetting(key, value)
+
     # Install the control-c handler.
     unittest2.signals.installHandler()
 
     lldbutil.mkdir_p(configuration.sdir_name)
     os.environ["LLDB_SESSION_DIRNAME"] = configuration.sdir_name
 
     sys.stderr.write(
         "\nSession logs for test failures/errors/unexpected successes"

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

group.add_argument(
         help='A flag to indicate an out-of-tree debug server is being used')
     group.add_argument(
         '--dwarf-version',
         metavar='dwarf_version',
         dest='dwarf_version',
         type=int,
         help='Override the DWARF version.')
     group.add_argument(
+        '--setting',
+        metavar='SETTING=VALUE',
+        dest='settings',
+        type=str,
+        nargs=1,
+        action='append',
+        help='Run "setting set SETTING VALUE" before executing any test.')
+    group.add_argument(
         '-s',
         metavar='name',
         help='Specify the name of the dir created to store the session files of tests with errored or failed status. If not specified, the test driver uses the timestamp as the session dir name')
     group.add_argument(
         '-S',
         '--session-file-format',
         default=configuration.session_file_format,
         metavar='format',