lldb/test/API/python_api/watchpoint/watchlocation/TestSetWatchlocation.py

   1 """
   2 Use lldb Python SBValue.WatchPointee() API to create a watchpoint for write of '*g_char_ptr'.
   3 """
   4
   5 import lldb
   6 from lldbsuite.test.decorators import *
   7 from lldbsuite.test.lldbtest import *
   8 from lldbsuite.test import lldbutil
   9
  10
  11 class SetWatchlocationAPITestCase(TestBase):
  12     NO_DEBUG_INFO_TESTCASE = True
  13
  14     def setUp(self):
  15         # Call super's setUp().
  16         TestBase.setUp(self)
  17         # Our simple source filename.
  18         self.source = "main.cpp"
  19         # Find the line number to break inside main().
  20         self.line = line_number(self.source, "// Set break point at this line.")
  21         # This is for verifying that watch location works.
  22         self.violating_func = "do_bad_thing_with_location"
  23
  24     @skipIfWindows  # This test is flaky on Windows
  25     def test_watch_location(self):
  26         """Exercise SBValue.WatchPointee() API to set a watchpoint."""
  27         self.build()
  28         exe = self.getBuildArtifact("a.out")
  29
  30         # Create a target by the debugger.
  31         target = self.dbg.CreateTarget(exe)
  32         self.assertTrue(target, VALID_TARGET)
  33
  34         # Now create a breakpoint on main.c.
  35         breakpoint = target.BreakpointCreateByLocation(self.source, self.line)
  36         self.assertTrue(
  37             breakpoint and breakpoint.GetNumLocations() == 1, VALID_BREAKPOINT
  38         )
  39
  40         # Now launch the process, and do not stop at the entry point.
  41         process = target.LaunchSimple(None, None, self.get_process_working_directory())
  42
  43         # We should be stopped due to the breakpoint.  Get frame #0.
  44         process = target.GetProcess()
  45         self.assertState(process.GetState(), lldb.eStateStopped, PROCESS_STOPPED)
  46         thread = lldbutil.get_stopped_thread(process, lldb.eStopReasonBreakpoint)
  47         frame0 = thread.GetFrameAtIndex(0)
  48
  49         value = frame0.FindValue("g_char_ptr", lldb.eValueTypeVariableGlobal)
  50         pointee = value.CreateValueFromAddress(
  51             "pointee", value.GetValueAsUnsigned(0), value.GetType().GetPointeeType()
  52         )
  53         # Watch for write to *g_char_ptr.
  54         error = lldb.SBError()
  55         watchpoint = value.WatchPointee(True, False, True, error)
  56         self.assertTrue(
  57             value and watchpoint, "Successfully found the pointer and set a watchpoint"
  58         )
  59         self.DebugSBValue(value)
  60         self.DebugSBValue(pointee)
  61
  62         # Check some API calls return expected values
  63         self.assertEqual(
  64             watchpoint.GetWatchValueKind(), lldb.eWatchPointValueKindExpression
  65         )
  66         # FIXME: The spec should probably be 'g_char_ptr'
  67         self.assertEqual(watchpoint.GetWatchSpec(), None)
  68         self.assertEqual(watchpoint.GetType().GetDisplayTypeName(), "char")
  69         self.assertFalse(watchpoint.IsWatchingReads())
  70         self.assertTrue(watchpoint.IsWatchingWrites())
  71
  72         # Hide stdout if not running with '-t' option.
  73         if not self.TraceOn():
  74             self.HideStdout()
  75
  76         print(watchpoint)
  77
  78         # Continue.  Expect the program to stop due to the variable being
  79         # written to.
  80         process.Continue()
  81
  82         if self.TraceOn():
  83             lldbutil.print_stacktraces(process)
  84
  85         thread = lldbutil.get_stopped_thread(process, lldb.eStopReasonWatchpoint)
  86         self.assertTrue(thread, "The thread stopped due to watchpoint")
  87         self.DebugSBValue(value)
  88         self.DebugSBValue(pointee)
  89
  90         self.expect(
  91             lldbutil.print_stacktrace(thread, string_buffer=True),
  92             exe=False,
  93             substrs=[self.violating_func],
  94         )
  95
  96         # This finishes our test.