[lldb] Add a testcase for MainThreadCheckerRuntime plugin

[kubamracek]

Summary

This adds a simple testcase for MainThreadCheckerRuntime. The tool (Main Thread Checker) is only available on Darwin and in very new Xcode versions, so the test also detects the presence of libMainThreadChecker.dylib and is skipped if the tool is not available.

[kubamracek]

Actually, I think I need to extract the detection of libMainThreadChecker.dylib into a helper function, because I want to add more tests that will use it.

[kubamracek]

Landed in r307170.

[SeanChense]

Hi there, I am here to find help. Is there a way to get libMainThreadChecker.dylib output ? Then we can analyze the output to generate a report ?

[kubamracek]

In D34774#907636, @SeanChense wrote:

Hi there, I am here to find help. Is there a way to get libMainThreadChecker.dylib output ? Then we can analyze the output to generate a report ?

Hi, what are you trying to do? What info are you missing that the LLDB plugin doesn't provide? I don't think parsing the text output (in stderr) from libMainThreadChecker.dylib is a good idea, as it's likely to change.

[SeanChense]

In D34774#908084, @kubamracek wrote:

In D34774#907636, @SeanChense wrote:

Hi there, I am here to find help. Is there a way to get libMainThreadChecker.dylib output ? Then we can analyze the output to generate a report ?

Hi, what are you trying to do? What info are you missing that the LLDB plugin doesn't provide? I don't think parsing the text output (in stderr) from libMainThreadChecker.dylib is a good idea, as it's likely to change.

I am an iOS developer. We are using XCTest to run automated testing twice per day and to generate a report. In Xcode 9, I notice that libMainThreadChecker.dylib which documented in https://developer.apple.com/documentation/code_diagnostics/main_thread_checker. It seems that there is no API for libMainThreadChecker.dylib we can use to collect warning to append in report. So I wanna analyze the log to extract libMainThreadChecker.dylib output. Since you are saying parsing the text output is a bad idea, is there a better way to do that ?

packages/Python/lldbsuite/test/functionalities/mtc/simple/Makefile

+LEVEL = ../../../make
+
+OBJC_SOURCES := main.m
+LDFLAGS = $(CFLAGS) -lobjc -framework Foundation -framework AppKit
+
+include $(LEVEL)/Makefile.rules

packages/Python/lldbsuite/test/functionalities/mtc/simple/TestMTCSimple.py

+"""
+Tests basic Main Thread Checker support (detecting a main-thread-only violation).
+"""
+
+import os
+import time
+import lldb
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test.decorators import *
+import lldbsuite.test.lldbutil as lldbutil
+from lldbsuite.test.lldbplatformutil import *
+import json
+
+
+class MTCSimpleTestCase(TestBase):
+
+    mydir = TestBase.compute_mydir(__file__)
+
+    @skipUnlessDarwin
+    def test(self):
+        self.mtc_dylib_path = findMainThreadCheckerDylib()
+        if self.mtc_dylib_path == "":
+            self.skipTest("This test requires libMainThreadChecker.dylib.")
+
+        self.build()
+        self.mtc_tests()
+
+    def setUp(self):
+        # Call super's setUp().
+        TestBase.setUp(self)
+
+    def mtc_tests(self):
+        # Load the test
+        exe = os.path.join(os.getcwd(), "a.out")
+        self.expect("file " + exe, patterns=["Current executable set to .*a.out"])
+
+        self.runCmd("env DYLD_INSERT_LIBRARIES=%s" % self.mtc_dylib_path)
+        self.runCmd("run")
+
+        process = self.dbg.GetSelectedTarget().process
+        thread = process.GetSelectedThread()
+        frame = thread.GetSelectedFrame()
+
+        self.expect("thread info", substrs=['stop reason = -[NSView superview] must be called from main thread only'])
+
+        self.expect(
+            "thread info -s",
+            substrs=["instrumentation_class", "api_name", "class_name", "selector", "description"])
+        self.assertEqual(thread.GetStopReason(), lldb.eStopReasonInstrumentation)
+        output_lines = self.res.GetOutput().split('\n')
+        json_line = '\n'.join(output_lines[2:])
+        data = json.loads(json_line)
+        self.assertEqual(data["instrumentation_class"], "MainThreadChecker")
+        self.assertEqual(data["api_name"], "-[NSView superview]")
+        self.assertEqual(data["class_name"], "NSView")
+        self.assertEqual(data["selector"], "superview")
+        self.assertEqual(data["description"], "-[NSView superview] must be called from main thread only")

packages/Python/lldbsuite/test/functionalities/mtc/simple/main.m

+#import <Foundation/Foundation.h>
+#import <AppKit/AppKit.h>
+
+int main() {
+  NSView *view = [[NSView alloc] init];
+  dispatch_group_t g = dispatch_group_create();
+  dispatch_group_enter(g);
+  [NSThread detachNewThreadWithBlock:^{
+    @autoreleasepool {
+      [view superview];
+    }
+    dispatch_group_leave(g);
+  }];
+  dispatch_group_wait(g, DISPATCH_TIME_FOREVER);
+}

packages/Python/lldbsuite/test/lldbplatformutil.py

 """ This module contains functions used by the test cases to hide the
 architecture and/or the platform dependent nature of the tests. """
 
 from __future__ import absolute_import
 
 # System modules
 import itertools
 import re
 import subprocess
 import sys
+import os
 
 # Third-party modules
 import six
 from six.moves.urllib import parse as urlparse
 
 # LLDB modules
 from . import configuration
 import use_lldb_suite
def getPlatform():
     return platform
 
 
 def platformIsDarwin():
     """Returns true if the OS triple for the selected platform is any valid apple OS"""
     return getPlatform() in getDarwinOSTriples()
 
 
+def findMainThreadCheckerDylib():
+    if not platformIsDarwin():
+        return ""
+
+    with os.popen('xcode-select -p') as output:
+        xcode_developer_path = output.read().strip()
+        mtc_dylib_path = '%s/usr/lib/libMainThreadChecker.dylib' % xcode_developer_path
+        if os.path.isfile(mtc_dylib_path):
+            return mtc_dylib_path
+
+    return ""
+
+
 class _PlatformContext(object):
     """Value object class which contains platform-specific options."""
 
     def __init__(self, shlib_environment_var, shlib_prefix, shlib_extension):
         self.shlib_environment_var = shlib_environment_var
         self.shlib_prefix = shlib_prefix
         self.shlib_extension = shlib_extension