xref: /llvm-project/lldb/test/API/python_api/watchpoint/watchlocation/TestSetWatchlocation.py (revision 2238dcc39358353cac21df75c3c3286ab20b8f53) 
1"""
2Use lldb Python SBValue.WatchPointee() API to create a watchpoint for write of '*g_char_ptr'.
3"""
4
5import lldb
6from lldbsuite.test.decorators import *
7from lldbsuite.test.lldbtest import *
8from lldbsuite.test import lldbutil
9
10
11class 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.
97