path: root/lldb/test/API/lang/cpp/dynamic-value/TestDynamicValue.py

"""
Use lldb Python API to test dynamic values in C++
"""


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


class DynamicValueTestCase(TestBase):
    def setUp(self):
        # Call super's setUp().
        TestBase.setUp(self)

        # Find the line number to break for main.c.

        self.do_something_line = line_number(
            "pass-to-base.cpp", "// Break here in doSomething."
        )
        self.main_first_call_line = line_number(
            "pass-to-base.cpp",
            "// Break here and get real addresses of myB and otherB.",
        )
        self.main_second_call_line = line_number(
            "pass-to-base.cpp", "// Break here and get real address of reallyA."
        )

    @add_test_categories(["pyapi"])
    @expectedFailureAll(oslist=["windows"], bugnumber="llvm.org/pr24663")
    def test_get_dynamic_vals(self):
        """Test fetching C++ dynamic values from pointers & references."""
        self.build()
        exe = self.getBuildArtifact("a.out")

        # Create a target from the debugger.

        target = self.dbg.CreateTarget(exe)
        self.assertTrue(target, VALID_TARGET)

        # Set up our breakpoints:

        do_something_bpt = target.BreakpointCreateByLocation(
            "pass-to-base.cpp", self.do_something_line
        )
        self.assertTrue(do_something_bpt, VALID_BREAKPOINT)

        first_call_bpt = target.BreakpointCreateByLocation(
            "pass-to-base.cpp", self.main_first_call_line
        )
        self.assertTrue(first_call_bpt, VALID_BREAKPOINT)

        second_call_bpt = target.BreakpointCreateByLocation(
            "pass-to-base.cpp", self.main_second_call_line
        )
        self.assertTrue(second_call_bpt, VALID_BREAKPOINT)

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

        self.assertState(process.GetState(), lldb.eStateStopped, PROCESS_STOPPED)

        threads = lldbutil.get_threads_stopped_at_breakpoint(process, first_call_bpt)
        self.assertEqual(len(threads), 1)
        thread = threads[0]

        frame = thread.GetFrameAtIndex(0)

        # Now find the dynamic addresses of myB and otherB so we can compare them
        # with the dynamic values we get in doSomething:

        use_dynamic = lldb.eDynamicCanRunTarget
        no_dynamic = lldb.eNoDynamicValues

        myB = frame.FindVariable("myB", no_dynamic)
        self.assertTrue(myB)
        myB_loc = int(myB.GetLocation(), 16)

        otherB = frame.FindVariable("otherB", no_dynamic)
        self.assertTrue(otherB)
        otherB_loc = int(otherB.GetLocation(), 16)

        # Okay now run to doSomething:

        threads = lldbutil.continue_to_breakpoint(process, do_something_bpt)
        self.assertEqual(len(threads), 1)
        thread = threads[0]

        frame = thread.GetFrameAtIndex(0)

        # Get "this" using FindVariable:

        this_static = frame.FindVariable("this", no_dynamic)
        this_dynamic = frame.FindVariable("this", use_dynamic)
        self.examine_value_object_of_this_ptr(this_static, this_dynamic, myB_loc)

        # Now make sure that the "GetDynamicValue" works:
        # This doesn't work currently because we can't get dynamic values from
        # ConstResult objects.
        fetched_dynamic_value = this_static.GetDynamicValue(use_dynamic)
        self.examine_value_object_of_this_ptr(
            this_static, fetched_dynamic_value, myB_loc
        )

        # And conversely that the GetDynamicValue() interface also works:
        fetched_static_value = this_dynamic.GetStaticValue()
        self.examine_value_object_of_this_ptr(
            fetched_static_value, this_dynamic, myB_loc
        )

        # Get "this" using FindValue, make sure that works too:
        this_static = frame.FindValue(
            "this", lldb.eValueTypeVariableArgument, no_dynamic
        )
        this_dynamic = frame.FindValue(
            "this", lldb.eValueTypeVariableArgument, use_dynamic
        )
        self.examine_value_object_of_this_ptr(this_static, this_dynamic, myB_loc)

        # Get "this" using the EvaluateExpression:
        this_static = frame.EvaluateExpression("this", False)
        this_dynamic = frame.EvaluateExpression("this", True)
        self.examine_value_object_of_this_ptr(this_static, this_dynamic, myB_loc)

        # The "frame var" code uses another path to get into children, so let's
        # make sure that works as well:

        self.expect(
            "frame var -d run-target --ptr-depth=2 --show-types anotherA.m_client_A",
            "frame var finds its way into a child member",
            patterns=[r"\(B \*\)"],
        )

        # Now make sure we also get it right for a reference as well:

        anotherA_static = frame.FindVariable("anotherA", False)
        self.assertTrue(anotherA_static)
        anotherA_static_addr = int(anotherA_static.GetValue(), 16)

        anotherA_dynamic = frame.FindVariable("anotherA", True)
        self.assertTrue(anotherA_dynamic)
        anotherA_dynamic_addr = int(anotherA_dynamic.GetValue(), 16)
        anotherA_dynamic_typename = anotherA_dynamic.GetTypeName()
        self.assertNotEqual(anotherA_dynamic_typename.find("B"), -1)

        self.assertLess(anotherA_dynamic_addr, anotherA_static_addr)

        anotherA_m_b_value_dynamic = anotherA_dynamic.GetChildMemberWithName(
            "m_b_value", True
        )
        self.assertTrue(anotherA_m_b_value_dynamic)
        anotherA_m_b_val = int(anotherA_m_b_value_dynamic.GetValue(), 10)
        self.assertEqual(anotherA_m_b_val, 300)

        anotherA_m_b_value_static = anotherA_static.GetChildMemberWithName(
            "m_b_value", True
        )
        self.assertFalse(anotherA_m_b_value_static)

        # Okay, now continue again, and when we hit the second breakpoint in
        # main

        threads = lldbutil.continue_to_breakpoint(process, second_call_bpt)
        self.assertEqual(len(threads), 1)
        thread = threads[0]

        frame = thread.GetFrameAtIndex(0)
        reallyA_value = frame.FindVariable("reallyA", False)
        self.assertTrue(reallyA_value)
        reallyA_loc = int(reallyA_value.GetLocation(), 16)

        # Continue to doSomething again, and make sure we get the right value for anotherA,
        # which this time around is just an "A".

        threads = lldbutil.continue_to_breakpoint(process, do_something_bpt)
        self.assertEqual(len(threads), 1)
        thread = threads[0]

        frame = thread.GetFrameAtIndex(0)
        anotherA_value = frame.FindVariable("anotherA", True)
        self.assertTrue(anotherA_value)
        anotherA_loc = int(anotherA_value.GetValue(), 16)
        self.assertEqual(anotherA_loc, reallyA_loc)
        self.assertEqual(anotherA_value.GetTypeName().find("B"), -1)

        # Finally do the same with a B in an anonymous namespace.
        threads = lldbutil.continue_to_breakpoint(process, do_something_bpt)
        self.assertEqual(len(threads), 1)
        thread = threads[0]

        frame = thread.GetFrameAtIndex(0)
        anotherA_value = frame.FindVariable("anotherA", use_dynamic)
        self.assertTrue(anotherA_value)
        self.assertIn("B", anotherA_value.GetTypeName())
        anon_b_value = anotherA_value.GetChildMemberWithName("m_anon_b_value")
        self.assertTrue(anon_b_value)
        self.assertEqual(anon_b_value.GetValueAsSigned(), 47)

    def examine_value_object_of_this_ptr(
        self, this_static, this_dynamic, dynamic_location
    ):
        # Get "this" as its static value
        self.assertTrue(this_static)
        this_static_loc = int(this_static.GetValue(), 16)

        # Get "this" as its dynamic value

        self.assertTrue(this_dynamic)
        this_dynamic_typename = this_dynamic.GetTypeName()
        self.assertNotEqual(this_dynamic_typename.find("B"), -1)
        this_dynamic_loc = int(this_dynamic.GetValue(), 16)

        # Make sure we got the right address for "this"

        self.assertEqual(this_dynamic_loc, dynamic_location)

        # And that the static address is greater than the dynamic one

        self.assertGreater(this_static_loc, this_dynamic_loc)

        # Now read m_b_value which is only in the dynamic value:

        use_dynamic = lldb.eDynamicCanRunTarget
        no_dynamic = lldb.eNoDynamicValues

        this_dynamic_m_b_value = this_dynamic.GetChildMemberWithName(
            "m_b_value", use_dynamic
        )
        self.assertTrue(this_dynamic_m_b_value)

        m_b_value = int(this_dynamic_m_b_value.GetValue(), 0)
        self.assertEqual(m_b_value, 10)

        # Make sure it is not in the static version

        this_static_m_b_value = this_static.GetChildMemberWithName(
            "m_b_value", no_dynamic
        )
        self.assertFalse(this_static_m_b_value)

        # Okay, now let's make sure that we can get the dynamic type of a child
        # element:

        contained_auto_ptr = this_dynamic.GetChildMemberWithName(
            "m_client_A", use_dynamic
        )
        self.assertTrue(contained_auto_ptr)
        contained_b = contained_auto_ptr.GetChildMemberWithName("_M_ptr", use_dynamic)
        if not contained_b:
            contained_b = contained_auto_ptr.GetChildMemberWithName(
                "__ptr_", use_dynamic
            )
        self.assertTrue(contained_b)

        contained_b_static = contained_auto_ptr.GetChildMemberWithName(
            "_M_ptr", no_dynamic
        )
        if not contained_b_static:
            contained_b_static = contained_auto_ptr.GetChildMemberWithName(
                "__ptr_", no_dynamic
            )
        self.assertTrue(contained_b_static)

        contained_b_addr = int(contained_b.GetValue(), 16)
        contained_b_static_addr = int(contained_b_static.GetValue(), 16)

        self.assertLess(contained_b_addr, contained_b_static_addr)

    @no_debug_info_test
    @expectedFailureAll(oslist=["windows"], bugnumber="llvm.org/pr24663")
    def test_from_forward_decl(self):
        """Test fetching C++ dynamic values forward-declared types. It's
        imperative that this is a separate test so that we don't end up parsing
        a definition of A from somewhere else."""
        self.build()
        lldbutil.run_to_name_breakpoint(self, "take_A")
        self.expect(
            "frame var -d run-target --ptr-depth=1 --show-types a",
            substrs=["(B *) a", "m_b_value = 10"],
        )

    @no_debug_info_test
    @expectedFailureAll(oslist=["windows"], bugnumber="llvm.org/pr24663")
    @expectedFailureAll(archs=["arm$"]) # Minidump saving not implemented
    def test_from_core_file(self):
        """Test fetching C++ dynamic values from core files. Specifically, test
        that we can determine the dynamic type of the value if the core file
        does not contain the type vtable."""
        self.build()
        lldbutil.run_to_name_breakpoint(self, "take_A")

        # Get the address of our object and its vtable
        a = self.frame().FindVariable("a")
        self.assertSuccess(a.GetError())
        vtable = a.GetVTable()
        self.assertSuccess(vtable.GetError())
        a = a.GetValueAsAddress()
        vtable = vtable.GetValueAsAddress()

        # Create a core file which will only contain the memory region
        # containing `a`. The object is on the stack, so this will automatically
        # include the stack of the main thread.
        core = self.getBuildArtifact("a.dmp")
        options = lldb.SBSaveCoreOptions()
        options.SetPluginName("minidump")
        options.SetStyle(lldb.eSaveCoreCustomOnly)
        options.SetOutputFile(lldb.SBFileSpec(core))
        region = lldb.SBMemoryRegionInfo()
        self.assertSuccess(self.process().GetMemoryRegionInfo(a, region))
        self.assertSuccess(options.AddMemoryRegionToSave(region))

        # Save the core file and load it.
        self.assertSuccess(self.process().SaveCore(options))
        self.process().Kill()
        error = lldb.SBError()
        self.target().LoadCore(core, error)
        self.assertSuccess(error)

        # Sanity check -- the process should be able to read the object but not
        # its vtable..
        self.process().ReadPointerFromMemory(a, error)
        self.assertSuccess(error)
        self.process().ReadPointerFromMemory(vtable, error)
        self.assertTrue(error.Fail())

        # .. but we should still be able to see the dynamic type by reading the
        # vtable from the executable file.
        self.expect(
            "frame var -d run-target --ptr-depth=1 --show-types a",
            substrs=["(B *) a", "m_b_value = 10"],
        )