src/llvm-project/lldb/test/API/commands/watchpoints/hello_watchlocation/TestWatchLocation.py

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


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


class HelloWatchLocationTestCase(TestBase):
    NO_DEBUG_INFO_TESTCASE = True

    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.
        self.exe_name = self.testMethodName
        self.d = {"CXX_SOURCES": self.source, "EXE": self.exe_name}

    # 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()

    # Most of the MIPS boards provide only one H/W watchpoints, and S/W
    # watchpoints are not supported yet
    @expectedFailureAll(triple=re.compile("^mips"))
    # SystemZ and PowerPC also currently supports only one H/W watchpoint
    @expectedFailureAll(archs=["powerpc64le", "s390x"])
    @skipIfWindows  # This test is flaky on Windows
    def test_hello_watchlocation(self):
        """Test watching a location with '-s size' option."""
        self.build(dictionary=self.d)
        self.setTearDownCleanup(dictionary=self.d)
        exe = self.getBuildArtifact(self.exe_name)
        self.runCmd("file " + exe, CURRENT_EXECUTABLE_SET)

        # 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, loc_exact=False
        )

        # 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'.
        self.expect(
            "watchpoint set expression -w write -s 1 -- g_char_ptr",
            WATCHPOINT_CREATED,
            substrs=["Watchpoint created", "size = 1", "type = w"],
        )
        # Get a hold of the watchpoint id just created, it is used later on to
        # match the watchpoint id which is expected to be fired.
        match = re.match(
            "Watchpoint created: Watchpoint (.*):", self.res.GetOutput().splitlines()[0]
        )
        if match:
            expected_wp_id = int(match.group(1), 0)
        else:
            self.fail("Grokking watchpoint id faailed!")

        self.runCmd("expr unsigned val = *g_char_ptr; val")
        self.expect(self.res.GetOutput().splitlines()[0], exe=False, endstr=" = 0")

        self.runCmd("watchpoint set expression -w write -s 4 -- &threads[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"])

        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", "stop reason = watchpoint %d" % expected_wp_id],
        )

        # 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.expect("frame info", substrs=[self.violating_func])

        # 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")