lldb/test/API/commands/watchpoints/watchpoint_set_command/TestWatchLocationWithWatchSet.py

"""
Test lldb watchpoint that uses 'watchpoint set -w write -s size' to watch a pointed location with size.
"""


import lldb
from lldbsuite.test.decorators import *
from lldbsuite.test.lldbtest import *
from lldbsuite.test import lldbutil


class WatchLocationUsingWatchpointSetTestCase(TestBase):
    NO_DEBUG_INFO_TESTCASE = True

    # on arm64 targets, lldb has incorrect hit-count / ignore-counts
    # for watchpoints when they are hit with multiple threads at
    # the same time.  Tracked as llvm.org/pr49433
    # or rdar://93863107 inside Apple.
    def affected_by_radar_93863107(self):
        return (
            self.getArchitecture() in ["arm64", "arm64e"]
        ) and self.platformIsDarwin()

    def setUp(self):
        # Call super's setUp().
        TestBase.setUp(self)
        # Our simple source filename.
        self.source = "main.cpp"
        # Find the line number to break inside main().
        self.line = line_number(self.source, "// Set break point at this line.")
        # This is for verifying that watch location works.
        self.violating_func = "do_bad_thing_with_location"
        # Build dictionary to have unique executable names for each test
        # method.

    @skipIf(oslist=["linux"], archs=["aarch64", "arm$"], bugnumber="llvm.org/pr26031")
    @skipIfWindows  # This test is flaky on Windows
    def test_watchlocation_using_watchpoint_set(self):
        """Test watching a location with 'watchpoint set expression -w write -s size' option."""
        self.build()
        self.setTearDownCleanup()

        exe = self.getBuildArtifact("a.out")
        target = self.dbg.CreateTarget(exe)

        # Add a breakpoint to set a watchpoint when stopped on the breakpoint.
        lldbutil.run_break_set_by_file_and_line(
            self, None, self.line, num_expected_locations=1
        )

        # Run the program.
        self.runCmd("run", RUN_SUCCEEDED)

        # We should be stopped again due to the breakpoint.
        # The stop reason of the thread should be breakpoint.
        self.expect(
            "thread list",
            STOPPED_DUE_TO_BREAKPOINT,
            substrs=["stopped", "stop reason = breakpoint"],
        )

        # Now let's set a write-type watchpoint pointed to by 'g_char_ptr' and
        # with offset as 7.
        # The main.cpp, by design, misbehaves by not following the agreed upon
        # protocol of only accessing the allowable index range of [0, 6].
        self.expect(
            "watchpoint set expression -w write -s 1 -- g_char_ptr + 7",
            WATCHPOINT_CREATED,
            substrs=["Watchpoint created", "size = 1", "type = w"],
        )
        self.runCmd("expr unsigned val = g_char_ptr[7]; val")
        self.expect(self.res.GetOutput().splitlines()[0], exe=False, endstr=" = 0")

        # Use the '-v' option to do verbose listing of the watchpoint.
        # The hit count should be 0 initially.
        self.expect("watchpoint list -v", substrs=["hit_count = 0"])

        # Check the underlying SBWatchpoint.
        watchpoint = target.GetWatchpointAtIndex(0)
        self.assertEqual(watchpoint.GetWatchSize(), 1)
        self.assertEqual(watchpoint.GetHitCount(), 0)
        self.assertEqual(watchpoint.GetWatchSpec(), "g_char_ptr + 7")

        self.runCmd("process continue")

        # We should be stopped again due to the watchpoint (write type), but
        # only once.  The stop reason of the thread should be watchpoint.
        self.expect(
            "thread list",
            STOPPED_DUE_TO_WATCHPOINT,
            substrs=[
                "stopped",
                self.violating_func,
                "stop reason = watchpoint",
            ],
        )

        # Switch to the thread stopped due to watchpoint and issue some
        # commands.
        self.switch_to_thread_with_stop_reason(lldb.eStopReasonWatchpoint)
        self.runCmd("thread backtrace")
        self.runCmd("expr unsigned val = g_char_ptr[7]; val")
        self.expect(self.res.GetOutput().splitlines()[0], exe=False, endstr=" = 99")

        # Use the '-v' option to do verbose listing of the watchpoint.
        # The hit count should now be the same as the number of threads that
        # stopped on a watchpoint.
        threads = lldbutil.get_stopped_threads(
            self.process(), lldb.eStopReasonWatchpoint
        )

        if not self.affected_by_radar_93863107():
            self.expect("watchpoint list -v", substrs=["hit_count = %d" % len(threads)])

        self.runCmd("thread backtrace all")