"""
Use lldb Python SBValue API to create a watchpoint for read_write of 'globl' var.
"""

from __future__ import print_function


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


class SetWatchpointAPITestCase(TestBase):

    mydir = TestBase.compute_mydir(__file__)

    def setUp(self):
        # Call super's setUp().
        TestBase.setUp(self)
        # Our simple source filename.
        self.source = 'main.c'
        # Find the line number to break inside main().
        self.line = line_number(
            self.source, '// Set break point at this line.')

    @add_test_categories(['pyapi'])
    @expectedFailureAll(
        oslist=["windows"],
        bugnumber="llvm.org/pr24446: WINDOWS XFAIL TRIAGE - Watchpoints not supported on Windows")
    # Read-write watchpoints not supported on SystemZ
    @expectedFailureAll(archs=['s390x'])
    def test_watch_val(self):
        """Exercise SBValue.Watch() API to set a watchpoint."""
        self.build()
        exe = self.getBuildArtifact("a.out")

        # Create a target by the debugger.
        target = self.dbg.CreateTarget(exe)
        self.assertTrue(target, VALID_TARGET)

        # Now create a breakpoint on main.c.
        breakpoint = target.BreakpointCreateByLocation(self.source, self.line)
        self.assertTrue(breakpoint and
                        breakpoint.GetNumLocations() == 1,
                        VALID_BREAKPOINT)

        # Now launch the process, and do not stop at the entry point.
        process = target.LaunchSimple(
            None, None, self.get_process_working_directory())

        # We should be stopped due to the breakpoint.  Get frame #0.
        process = target.GetProcess()
        self.assertTrue(process.GetState() == lldb.eStateStopped,
                        PROCESS_STOPPED)
        thread = lldbutil.get_stopped_thread(
            process, lldb.eStopReasonBreakpoint)
        frame0 = thread.GetFrameAtIndex(0)

        # Watch 'global' for read and write.
        value = frame0.FindValue('global', lldb.eValueTypeVariableGlobal)
        error = lldb.SBError()
        watchpoint = value.Watch(True, True, True, error)
        self.assertTrue(value and watchpoint,
                        "Successfully found the variable and set a watchpoint")
        self.DebugSBValue(value)

        # Hide stdout if not running with '-t' option.
        if not self.TraceOn():
            self.HideStdout()

        print(watchpoint)

        # Continue.  Expect the program to stop due to the variable being
        # written to.
        process.Continue()

        if (self.TraceOn()):
            lldbutil.print_stacktraces(process)

        thread = lldbutil.get_stopped_thread(
            process, lldb.eStopReasonWatchpoint)
        self.assertTrue(thread, "The thread stopped due to watchpoint")
        self.DebugSBValue(value)

        # Continue.  Expect the program to stop due to the variable being read
        # from.
        process.Continue()

        if (self.TraceOn()):
            lldbutil.print_stacktraces(process)

        thread = lldbutil.get_stopped_thread(
            process, lldb.eStopReasonWatchpoint)
        self.assertTrue(thread, "The thread stopped due to watchpoint")
        self.DebugSBValue(value)

        # Continue the process.  We don't expect the program to be stopped
        # again.
        process.Continue()

        # At this point, the inferior process should have exited.
        self.assertTrue(
            process.GetState() == lldb.eStateExited,
            PROCESS_EXITED)

        self.dbg.DeleteTarget(target)
        self.assertFalse(watchpoint.IsValid())
