| """ |
| Make sure the getting a variable path works and doesn't crash. |
| """ |
| |
| import lldb |
| import lldbsuite.test.lldbutil as lldbutil |
| from lldbsuite.test.decorators import * |
| from lldbsuite.test.lldbtest import * |
| |
| |
| class TestVTableValue(TestBase): |
| # If your test case doesn't stress debug info, then |
| # set this to true. That way it won't be run once for |
| # each debug info format. |
| NO_DEBUG_INFO_TESTCASE = True |
| |
| @skipIf(compiler="clang", compiler_version=["<", "9.0"]) |
| @skipUnlessPlatform(["linux", "macosx"]) |
| def test_vtable(self): |
| self.build() |
| lldbutil.run_to_source_breakpoint( |
| self, "At the end", lldb.SBFileSpec("main.cpp") |
| ) |
| |
| # Test a shape instance to make sure we get the vtable correctly. |
| shape = self.frame().FindVariable("shape") |
| vtable = shape.GetVTable() |
| self.assertEqual(vtable.GetName(), "vtable for Shape") |
| self.assertEqual(vtable.GetTypeName(), "vtable for Shape") |
| # Make sure we have the right number of virtual functions in our vtable |
| # for the shape class. |
| self.assertEqual(vtable.GetNumChildren(), 4) |
| |
| # Verify vtable address |
| vtable_addr = vtable.GetValueAsUnsigned(0) |
| expected_addr = self.expected_vtable_addr(shape) |
| self.assertEqual(vtable_addr, expected_addr) |
| |
| for idx, vtable_entry in enumerate(vtable.children): |
| self.verify_vtable_entry(vtable_entry, vtable_addr, idx) |
| |
| # Test a shape reference to make sure we get the vtable correctly. |
| shape = self.frame().FindVariable("shape_ref") |
| vtable = shape.GetVTable() |
| self.assertEqual(vtable.GetName(), "vtable for Shape") |
| self.assertEqual(vtable.GetTypeName(), "vtable for Shape") |
| # Make sure we have the right number of virtual functions in our vtable |
| # for the shape class. |
| self.assertEqual(vtable.GetNumChildren(), 4) |
| |
| # Verify vtable address |
| vtable_addr = vtable.GetValueAsUnsigned(0) |
| expected_addr = self.expected_vtable_addr(shape) |
| self.assertEqual(vtable_addr, expected_addr) |
| |
| for idx, vtable_entry in enumerate(vtable.children): |
| self.verify_vtable_entry(vtable_entry, vtable_addr, idx) |
| |
| # Test we get the right vtable for the Rectangle instance. |
| rect = self.frame().FindVariable("rect") |
| vtable = rect.GetVTable() |
| self.assertEqual(vtable.GetName(), "vtable for Rectangle") |
| self.assertEqual(vtable.GetTypeName(), "vtable for Rectangle") |
| |
| # Make sure we have the right number of virtual functions in our vtable |
| # with the extra virtual function added by the Rectangle class |
| self.assertEqual(vtable.GetNumChildren(), 5) |
| |
| # Verify vtable address |
| vtable_addr = vtable.GetValueAsUnsigned() |
| expected_addr = self.expected_vtable_addr(rect) |
| self.assertEqual(vtable_addr, expected_addr) |
| |
| for idx, vtable_entry in enumerate(vtable.children): |
| self.verify_vtable_entry(vtable_entry, vtable_addr, idx) |
| |
| @skipIf(compiler="clang", compiler_version=["<", "9.0"]) |
| @skipUnlessPlatform(["linux", "macosx"]) |
| def test_base_class_ptr(self): |
| self.build() |
| (target, process, thread, bkpt) = lldbutil.run_to_source_breakpoint( |
| self, "Shape is Rectangle", lldb.SBFileSpec("main.cpp") |
| ) |
| |
| shape = self.frame().FindVariable("shape") |
| rect = self.frame().FindVariable("rect") |
| |
| shape_ptr = self.frame().FindVariable("shape_ptr") |
| shape_ptr_vtable = shape_ptr.GetVTable() |
| self.assertEqual(shape_ptr_vtable.GetName(), "vtable for Rectangle") |
| self.assertEqual(shape_ptr_vtable.GetNumChildren(), 5) |
| self.assertEqual(shape_ptr.GetValueAsUnsigned(0), rect.GetLoadAddress()) |
| lldbutil.continue_to_source_breakpoint( |
| self, process, "Shape is Shape", lldb.SBFileSpec("main.cpp") |
| ) |
| self.assertEqual(shape_ptr.GetValueAsUnsigned(0), shape.GetLoadAddress()) |
| self.assertEqual(shape_ptr_vtable.GetNumChildren(), 4) |
| self.assertEqual(shape_ptr_vtable.GetName(), "vtable for Shape") |
| |
| @skipUnlessPlatform(["linux", "macosx"]) |
| def test_no_vtable(self): |
| self.build() |
| lldbutil.run_to_source_breakpoint( |
| self, "At the end", lldb.SBFileSpec("main.cpp") |
| ) |
| |
| var = self.frame().FindVariable("not_virtual") |
| self.assertEqual( |
| var.GetVTable().GetError().GetCString(), |
| 'type "NotVirtual" doesn\'t have a vtable', |
| ) |
| |
| var = self.frame().FindVariable("argc") |
| self.assertEqual( |
| var.GetVTable().GetError().GetCString(), |
| 'no language runtime support for the language "c"', |
| ) |
| |
| @skipUnlessPlatform(["linux", "macosx"]) |
| def test_overwrite_vtable(self): |
| self.build() |
| (target, process, thread, bkpt) = lldbutil.run_to_source_breakpoint( |
| self, "At the end", lldb.SBFileSpec("main.cpp") |
| ) |
| |
| # Test a shape instance to make sure we get the vtable correctly. |
| shape = self.frame().FindVariable("shape") |
| vtable = shape.GetVTable() |
| self.assertEqual(vtable.GetName(), "vtable for Shape") |
| self.assertEqual(vtable.GetTypeName(), "vtable for Shape") |
| # Make sure we have the right number of virtual functions in our vtable |
| # for the shape class. |
| self.assertEqual(vtable.GetNumChildren(), 4) |
| |
| # Overwrite the first entry in the vtable and make sure we can still |
| # see the bogus value which should have no summary |
| vtable_addr = vtable.GetValueAsUnsigned() |
| |
| is_64bit = self.process().GetAddressByteSize() == 8 |
| data = str( |
| "\x01\x01\x01\x01\x01\x01\x01\x01" if is_64bit else "\x01\x01\x01\x01" |
| ) |
| error = lldb.SBError() |
| bytes_written = process.WriteMemory(vtable_addr, data, error) |
| |
| self.assertSuccess(error) |
| self.assertGreater( |
| bytes_written, 0, "Failed to overwrite first entry in vtable" |
| ) |
| |
| scribbled_child = vtable.GetChildAtIndex(0) |
| self.assertEqual( |
| scribbled_child.GetValueAsUnsigned(0), |
| 0x0101010101010101 if is_64bit else 0x01010101, |
| ) |
| self.assertEqual(scribbled_child.GetSummary(), None) |
| |
| def expected_vtable_addr(self, var: lldb.SBValue) -> int: |
| load_addr = var.GetLoadAddress() |
| read_from_memory_error = lldb.SBError() |
| vtable_addr = self.process().ReadPointerFromMemory( |
| load_addr, read_from_memory_error |
| ) |
| self.assertTrue(read_from_memory_error.Success()) |
| return vtable_addr |
| |
| def expected_vtable_entry_func_ptr(self, vtable_addr: int, idx: int): |
| vtable_entry_addr = vtable_addr + idx * self.process().GetAddressByteSize() |
| read_func_ptr_error = lldb.SBError() |
| func_ptr = self.process().ReadPointerFromMemory( |
| vtable_entry_addr, read_func_ptr_error |
| ) |
| self.assertTrue(read_func_ptr_error.Success()) |
| return func_ptr |
| |
| def verify_vtable_entry( |
| self, vtable_entry: lldb.SBValue, vtable_addr: int, idx: int |
| ): |
| """Verify the vtable entry looks something like: |
| |
| (double ()) [0] = 0x0000000100003a10 a.out`Rectangle::Area() at main.cpp:14 |
| |
| """ |
| # Check function ptr |
| vtable_entry_func_ptr = vtable_entry.GetValueAsUnsigned(0) |
| self.assertEqual( |
| vtable_entry_func_ptr, |
| self.expected_vtable_entry_func_ptr(vtable_addr, idx), |
| ) |
| |
| sb_addr = self.target().ResolveLoadAddress(vtable_entry_func_ptr) |
| sym_ctx = sb_addr.GetSymbolContext(lldb.eSymbolContextEverything) |
| |
| # Make sure the type is the same as the function type |
| func_type = sym_ctx.GetFunction().GetType() |
| if func_type.IsValid(): |
| self.assertEqual(vtable_entry.GetType(), func_type.GetPointerType()) |
| |
| # The summary should be the address description of the function pointer |
| summary = vtable_entry.GetSummary() |
| self.assertEqual(str(sb_addr), summary) |
