| #!/usr/bin/env python3 |
| # -*- coding: utf-8 -*- |
| # |
| # Copyright (C) 2018 Apple Inc. All rights reserved. |
| # |
| # Redistribution and use in source and binary forms, with or without |
| # modification, are permitted provided that the following conditions |
| # are met: |
| # 1. Redistributions of source code must retain the above copyright |
| # notice, this list of conditions and the following disclaimer. |
| # 2. Redistributions in binary form must reproduce the above copyright |
| # notice, this list of conditions and the following disclaimer in the |
| # documentation and/or other materials provided with the distribution. |
| # |
| # THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY |
| # EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
| # WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| # DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY |
| # DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| # (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| # LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON |
| # ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| # SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| import os |
| import re |
| import subprocess |
| import sys |
| |
| from webkitpy.common.system.systemhost import SystemHost |
| sys.path.append(SystemHost().path_to_lldb_python_directory()) |
| import lldb |
| |
| # lldb Python reference: |
| # <https://lldb.llvm.org/python_reference/> |
| |
| |
| class AnsiColors: |
| BLUE = '\033[94m' |
| WARNING = '\033[93m' |
| ENDCOLOR = '\033[0m' |
| |
| |
| class ClassLayoutBase(object): |
| |
| MEMBER_NAME_KEY = 'name' |
| MEMBER_TYPE_KEY = 'type' |
| MEMBER_TYPE_CLASS = 'type_class' # lldb.eTypeClassStruct etc. Values here: <https://lldb.llvm.org/python_reference/_lldb%27-module.html#eTypeClassAny> |
| MEMBER_CLASS_INSTANCE = 'class_instance' |
| MEMBER_BYTE_SIZE = 'byte_size' |
| MEMBER_OFFSET = 'offset' # offset is local to this class. |
| MEMBER_OFFSET_IN_BITS = 'offset_in_bits' |
| MEMBER_IS_BITFIELD = 'is_bitfield' |
| MEMBER_BITFIELD_BIT_SIZE = 'bit_size' |
| PADDING_BYTES_TYPE = 'padding' |
| PADDING_BITS_TYPE = 'padding_bits' |
| PADDING_BITS_SIZE = 'padding_bits_size' |
| PADDING_NAME = '' |
| |
| def __init__(self, typename): |
| self.typename = typename |
| self.total_byte_size = 0 |
| self.total_pad_bytes = 0 |
| self.data_members = [] |
| |
| def __ne__(self, other): |
| return not self.__eq__(other) |
| |
| def __eq__(self, other): |
| if not isinstance(other, self.__class__): |
| return False |
| |
| if self.total_byte_size != other.total_byte_size: |
| return False |
| |
| if self.total_pad_bytes != other.total_pad_bytes: |
| return False |
| |
| if len(self.data_members) != other.data_members: |
| return False |
| |
| for i in range(len(self.data_members)): |
| self_member = self.data_members[i] |
| other_member = other.data_members[i] |
| if self_member != other_member: |
| return False |
| |
| return True |
| |
| def _to_string_recursive(self, str_list, colorize, member_name=None, depth=0, total_offset=0): |
| type_start = AnsiColors.BLUE if colorize else '' |
| warn_start = AnsiColors.WARNING if colorize else '' |
| color_end = AnsiColors.ENDCOLOR if colorize else '' |
| |
| if member_name: |
| str_list.append('%+4u <%3u> %s%s%s%s %s' % (total_offset, self.total_byte_size, ' ' * depth, type_start, self.typename, color_end, member_name)) |
| else: |
| str_list.append('%+4u <%3u> %s%s%s%s' % (total_offset, self.total_byte_size, ' ' * depth, type_start, self.typename, color_end)) |
| |
| start_offset = total_offset |
| |
| for data_member in self.data_members: |
| member_total_offset = start_offset + data_member[self.MEMBER_OFFSET] |
| if self.MEMBER_CLASS_INSTANCE in data_member: |
| data_member[self.MEMBER_CLASS_INSTANCE]._to_string_recursive(str_list, colorize, data_member[self.MEMBER_NAME_KEY], depth + 1, member_total_offset) |
| else: |
| byte_size = data_member[self.MEMBER_BYTE_SIZE] |
| |
| if self.MEMBER_IS_BITFIELD in data_member: |
| num_bits = data_member[self.MEMBER_BITFIELD_BIT_SIZE] |
| str_list.append('%+4u < :%1u> %s %s %s : %d' % (member_total_offset, num_bits, ' ' * depth, data_member[self.MEMBER_TYPE_KEY], data_member[self.MEMBER_NAME_KEY], num_bits)) |
| elif data_member[self.MEMBER_TYPE_KEY] == self.PADDING_BYTES_TYPE: |
| str_list.append('%+4u <%3u> %s %s<PADDING: %d %s>%s' % (member_total_offset, byte_size, ' ' * depth, warn_start, byte_size, 'bytes' if byte_size > 1 else 'byte', color_end)) |
| elif data_member[self.MEMBER_TYPE_KEY] == self.PADDING_BITS_TYPE: |
| padding_bits = data_member[self.PADDING_BITS_SIZE] |
| str_list.append('%+4u < :%1u> %s %s<UNUSED BITS: %d %s>%s' % (member_total_offset, padding_bits, ' ' * depth, warn_start, padding_bits, 'bits' if padding_bits > 1 else 'bit', color_end)) |
| else: |
| str_list.append('%+4u <%3u> %s %s %s' % (member_total_offset, byte_size, ' ' * depth, data_member[self.MEMBER_TYPE_KEY], data_member[self.MEMBER_NAME_KEY])) |
| |
| def as_string_list(self, colorize=False): |
| str_list = [] |
| self._to_string_recursive(str_list, colorize) |
| str_list.append('Total byte size: %d' % (self.total_byte_size)) |
| str_list.append('Total pad bytes: %d' % (self.total_pad_bytes)) |
| if self.total_pad_bytes > 0: |
| str_list.append('Padding percentage: %2.2f %%' % ((float(self.total_pad_bytes) / float(self.total_byte_size)) * 100.0)) |
| return str_list |
| |
| def as_string(self, colorize=False): |
| return '\n'.join(self.as_string_list(colorize)) |
| |
| def dump(self, colorize=True): |
| print(self.as_string(colorize)) |
| |
| |
| class ClassLayout(ClassLayoutBase): |
| "Stores the layout of a class or struct." |
| |
| def __init__(self, target, type, containerClass=None, derivedClass=None): |
| super(ClassLayout, self).__init__(type.GetName()) |
| |
| self.target = target |
| self.type = type |
| self.total_byte_size = self.type.GetByteSize() |
| self.pointer_size = self.target.GetAddressByteSize() |
| self.total_pad_bytes = 0 |
| self.data_members = [] |
| self.virtual_base_classes = self._virtual_base_classes_dictionary() |
| self._parse(containerClass, derivedClass) |
| if containerClass == None and derivedClass == None: |
| self.total_pad_bytes = self._compute_padding() |
| |
| def _has_polymorphic_non_virtual_base_class(self): |
| num_base_classes = self.type.GetNumberOfDirectBaseClasses() |
| for i in range(num_base_classes): |
| base_class = self.type.GetDirectBaseClassAtIndex(i) |
| if base_class.GetName() in self.virtual_base_classes: |
| continue |
| |
| if base_class.GetType().IsPolymorphicClass(): |
| return True |
| |
| return False |
| |
| def _virtual_base_classes_dictionary(self): |
| result = {} |
| num_virtual_base_classes = self.type.GetNumberOfVirtualBaseClasses() |
| for i in range(num_virtual_base_classes): |
| virtual_base = self.type.GetVirtualBaseClassAtIndex(i) |
| result[virtual_base.GetName()] = ClassLayout(self.target, virtual_base.GetType(), self) |
| return result |
| |
| def _parse(self, containerClass=None, derivedClass=None): |
| # It's moot where we actually show the vtable pointer, but to match clang -fdump-record-layouts, assign it to the |
| # base-most polymorphic class (unless virtual inheritance is involved). |
| if self.type.IsPolymorphicClass() and not self._has_polymorphic_non_virtual_base_class(): |
| data_member = { |
| self.MEMBER_NAME_KEY : '__vtbl_ptr_type * _vptr', |
| self.MEMBER_TYPE_KEY : '', |
| self.MEMBER_BYTE_SIZE : self.pointer_size, |
| self.MEMBER_OFFSET : 0 |
| } |
| self.data_members.append(data_member) |
| |
| num_direct_base_classes = self.type.GetNumberOfDirectBaseClasses() |
| if num_direct_base_classes > 0: |
| for i in range(num_direct_base_classes): |
| direct_base = self.type.GetDirectBaseClassAtIndex(i) |
| |
| # virtual base classes are also considered direct base classes, but we need to skip those here. |
| if direct_base.GetName() in self.virtual_base_classes: |
| continue |
| |
| member_type = direct_base.GetType() |
| member_typename = member_type.GetName() |
| member_canonical_type = member_type.GetCanonicalType() |
| member_type_class = member_canonical_type.GetTypeClass() |
| |
| member_name = direct_base.GetName() |
| member_offset = direct_base.GetOffsetInBytes() |
| member_byte_size = member_type.GetByteSize() |
| |
| base_class = ClassLayout(self.target, member_type, None, self) |
| |
| data_member = { |
| self.MEMBER_NAME_KEY : member_name, |
| self.MEMBER_TYPE_KEY : member_typename, |
| self.MEMBER_TYPE_CLASS : member_type_class, |
| self.MEMBER_CLASS_INSTANCE : base_class, |
| self.MEMBER_BYTE_SIZE : member_byte_size, |
| self.MEMBER_OFFSET : member_offset, |
| } |
| |
| self.data_members.append(data_member) |
| |
| num_fields = self.type.GetNumberOfFields() |
| for i in range(num_fields): |
| field = self.type.GetFieldAtIndex(i) |
| |
| member_type = field.GetType() |
| member_typename = member_type.GetName() |
| member_canonical_type = member_type.GetCanonicalType() |
| member_type_class = member_canonical_type.GetTypeClass() |
| |
| member_name = field.GetName() |
| member_offset = field.GetOffsetInBytes() |
| member_byte_size = member_type.GetByteSize() |
| |
| data_member = { |
| self.MEMBER_NAME_KEY : member_name, |
| self.MEMBER_TYPE_KEY : member_typename, |
| self.MEMBER_TYPE_CLASS : member_type_class, |
| self.MEMBER_BYTE_SIZE : member_byte_size, |
| self.MEMBER_OFFSET : member_offset, |
| } |
| |
| if field.IsBitfield(): |
| data_member[self.MEMBER_IS_BITFIELD] = True |
| data_member[self.MEMBER_BITFIELD_BIT_SIZE] = field.GetBitfieldSizeInBits() |
| data_member[self.MEMBER_OFFSET_IN_BITS] = field.GetOffsetInBits() |
| # For bitfields, member_byte_size was computed based on the field type without the bitfield modifiers, so compute from the number of bits. |
| data_member[self.MEMBER_BYTE_SIZE] = (field.GetBitfieldSizeInBits() + 7) / 8 |
| elif member_type_class == lldb.eTypeClassStruct or member_type_class == lldb.eTypeClassClass: |
| nested_class = ClassLayout(self.target, member_type, self) |
| data_member[self.MEMBER_CLASS_INSTANCE] = nested_class |
| |
| self.data_members.append(data_member) |
| |
| # "For each distinct base class that is specified virtual, the most derived object contains only one base class subobject of that type, |
| # even if the class appears many times in the inheritance hierarchy (as long as it is inherited virtual every time)." |
| num_virtual_base_classes = self.type.GetNumberOfVirtualBaseClasses() |
| if derivedClass == None and num_virtual_base_classes > 0: |
| for i in range(num_virtual_base_classes): |
| virtual_base = self.type.GetVirtualBaseClassAtIndex(i) |
| member_type = virtual_base.GetType() |
| member_typename = member_type.GetName() |
| member_canonical_type = member_type.GetCanonicalType() |
| member_type_class = member_canonical_type.GetTypeClass() |
| |
| member_name = virtual_base.GetName() |
| member_offset = virtual_base.GetOffsetInBytes() |
| member_byte_size = member_type.GetByteSize() |
| |
| nested_class = ClassLayout(self.target, member_type, None, self) |
| |
| data_member = { |
| self.MEMBER_NAME_KEY : member_name, |
| self.MEMBER_TYPE_KEY : member_typename, |
| self.MEMBER_TYPE_CLASS : member_type_class, |
| self.MEMBER_CLASS_INSTANCE : nested_class, |
| self.MEMBER_BYTE_SIZE : member_byte_size, |
| self.MEMBER_OFFSET : member_offset, |
| } |
| |
| self.data_members.append(data_member) |
| |
| # clang -fdump-record-layouts shows "(empty)" for such classes, but I can't find any way to access this information via lldb. |
| def _probably_has_empty_base_class_optimization(self): |
| if self.total_byte_size > 1: |
| return False |
| |
| if len(self.data_members) > 1: |
| return False |
| |
| if len(self.data_members) == 1: |
| data_member = self.data_members[0] |
| if self.MEMBER_CLASS_INSTANCE in data_member: |
| return data_member[self.MEMBER_CLASS_INSTANCE]._probably_has_empty_base_class_optimization() |
| |
| return True |
| |
| def _compute_padding_recursive(self, total_offset=0, depth=0, containerClass=None): |
| padding_bytes = 0 |
| start_offset = total_offset |
| current_offset = total_offset |
| |
| i = 0 |
| while i < len(self.data_members): |
| data_member = self.data_members[i] |
| member_offset = data_member[self.MEMBER_OFFSET] |
| |
| probably_empty_base_class = False |
| if self.MEMBER_CLASS_INSTANCE in data_member: |
| probably_empty_base_class = member_offset == 0 and data_member[self.MEMBER_CLASS_INSTANCE]._probably_has_empty_base_class_optimization() |
| |
| byte_size = data_member[self.MEMBER_BYTE_SIZE] |
| |
| if not probably_empty_base_class: |
| padding_size = start_offset + member_offset - current_offset |
| |
| if padding_size > 0: |
| padding_member = { |
| self.MEMBER_NAME_KEY : self.PADDING_NAME, |
| self.MEMBER_TYPE_KEY : self.PADDING_BYTES_TYPE, |
| self.MEMBER_BYTE_SIZE : padding_size, |
| self.MEMBER_OFFSET : current_offset - start_offset, |
| } |
| |
| self.data_members.insert(i, padding_member) |
| padding_bytes += padding_size |
| i += 1 |
| |
| if self.MEMBER_IS_BITFIELD in data_member: |
| next_member_is_bitfield = False |
| if i < len(self.data_members) - 1: |
| next_data_member = self.data_members[i + 1] |
| next_member_is_bitfield = self.MEMBER_IS_BITFIELD in next_data_member |
| |
| if not next_member_is_bitfield: |
| end_bit_offset = data_member[self.MEMBER_OFFSET_IN_BITS] + data_member[self.MEMBER_BITFIELD_BIT_SIZE] |
| unused_bits = (8 - end_bit_offset) % 8 |
| if unused_bits: |
| bit_padding_member = { |
| self.MEMBER_NAME_KEY : self.PADDING_NAME, |
| self.MEMBER_TYPE_KEY : self.PADDING_BITS_TYPE, |
| self.MEMBER_BYTE_SIZE : data_member[self.MEMBER_BYTE_SIZE], |
| self.PADDING_BITS_SIZE : unused_bits, |
| self.MEMBER_OFFSET : data_member[self.MEMBER_OFFSET], |
| } |
| self.data_members.insert(i + 1, bit_padding_member) |
| i += 1 |
| |
| current_offset = start_offset + member_offset |
| |
| if self.MEMBER_CLASS_INSTANCE in data_member: |
| [padding, offset] = data_member[self.MEMBER_CLASS_INSTANCE]._compute_padding_recursive(current_offset, depth + 1, self) |
| padding_bytes += padding |
| current_offset = offset |
| else: |
| current_offset += byte_size |
| |
| i += 1 |
| |
| # Look for padding at the end. |
| if containerClass == None: |
| padding_size = self.total_byte_size - current_offset |
| if padding_size > 0: |
| padding_member = { |
| self.MEMBER_NAME_KEY : self.PADDING_NAME, |
| self.MEMBER_TYPE_KEY : self.PADDING_BYTES_TYPE, |
| self.MEMBER_BYTE_SIZE : padding_size, |
| self.MEMBER_OFFSET : current_offset - start_offset, |
| } |
| self.data_members.append(padding_member) |
| padding_bytes += padding_size |
| |
| return [padding_bytes, current_offset] |
| |
| def _compute_padding(self): |
| [padding, offset] = self._compute_padding_recursive() |
| return padding |
| |
| |
| class LLDBDebuggerInstance: |
| "Wraps an instance of lldb.SBDebugger and vends ClassLayouts" |
| |
| def __init__(self, binary_path, architecture): |
| self.binary_path = binary_path |
| self.architecture = architecture |
| |
| self.debugger = lldb.SBDebugger.Create() |
| self.debugger.SetAsync(False) |
| self.target = self.debugger.CreateTargetWithFileAndArch(str(self.binary_path), self.architecture) |
| if not self.target: |
| print("Failed to make target for " + self.binary_path) |
| |
| self.module = self.target.GetModuleAtIndex(0) |
| if not self.module: |
| print("Failed to get first module in " + self.binary_path) |
| |
| def __del__(self): |
| if lldb: |
| lldb.SBDebugger.Destroy(self.debugger) |
| |
| def layout_for_classname(self, classname): |
| types = self.module.FindTypes(classname) |
| if types.GetSize(): |
| # There can be more that one type with a given name, but for now just return the first one. |
| return ClassLayout(self.target, types.GetTypeAtIndex(0)) |
| |
| print('error: no type matches "%s" in "%s"' % (classname, self.module.file)) |
| return None |
