| """ |
| This module provides an abstraction layer over common Rust pretty printing |
| functionality needed by both GDB and LLDB. |
| """ |
| |
| import re |
| |
| # Type codes that indicate the kind of type as it appears in DWARF debug |
| # information. This code alone is not sufficient to determine the Rust type. |
| # For example structs, tuples, fat pointers, or enum variants will all have |
| # DWARF_TYPE_CODE_STRUCT. |
| DWARF_TYPE_CODE_STRUCT = 1 |
| DWARF_TYPE_CODE_UNION = 2 |
| DWARF_TYPE_CODE_PTR = 3 |
| DWARF_TYPE_CODE_ARRAY = 4 |
| DWARF_TYPE_CODE_ENUM = 5 |
| |
| # These constants specify the most specific kind of type that could be |
| # determined for a given value. |
| TYPE_KIND_UNKNOWN = -1 |
| TYPE_KIND_EMPTY = 0 |
| TYPE_KIND_SLICE = 1 |
| TYPE_KIND_REGULAR_STRUCT = 2 |
| TYPE_KIND_TUPLE = 3 |
| TYPE_KIND_TUPLE_STRUCT = 4 |
| TYPE_KIND_CSTYLE_VARIANT = 5 |
| TYPE_KIND_TUPLE_VARIANT = 6 |
| TYPE_KIND_STRUCT_VARIANT = 7 |
| TYPE_KIND_STR_SLICE = 8 |
| TYPE_KIND_STD_VEC = 9 |
| TYPE_KIND_STD_STRING = 10 |
| TYPE_KIND_REGULAR_ENUM = 11 |
| TYPE_KIND_COMPRESSED_ENUM = 12 |
| TYPE_KIND_SINGLETON_ENUM = 13 |
| TYPE_KIND_CSTYLE_ENUM = 14 |
| TYPE_KIND_PTR = 15 |
| TYPE_KIND_FIXED_SIZE_VEC = 16 |
| TYPE_KIND_REGULAR_UNION = 17 |
| TYPE_KIND_OS_STRING = 18 |
| TYPE_KIND_STD_VECDEQUE = 19 |
| TYPE_KIND_STD_BTREESET = 20 |
| TYPE_KIND_STD_BTREEMAP = 21 |
| |
| ENCODED_ENUM_PREFIX = "RUST$ENCODED$ENUM$" |
| ENUM_DISR_FIELD_NAME = "RUST$ENUM$DISR" |
| |
| # Slice related constants |
| SLICE_FIELD_NAME_DATA_PTR = "data_ptr" |
| SLICE_FIELD_NAME_LENGTH = "length" |
| SLICE_FIELD_NAMES = [SLICE_FIELD_NAME_DATA_PTR, SLICE_FIELD_NAME_LENGTH] |
| |
| # std::Vec<> related constants |
| STD_VEC_FIELD_NAME_LENGTH = "len" |
| STD_VEC_FIELD_NAME_BUF = "buf" |
| STD_VEC_FIELD_NAMES = [STD_VEC_FIELD_NAME_BUF, |
| STD_VEC_FIELD_NAME_LENGTH] |
| |
| # std::collections::VecDeque<> related constants |
| STD_VECDEQUE_FIELD_NAME_TAIL = "tail" |
| STD_VECDEQUE_FIELD_NAME_HEAD = "head" |
| STD_VECDEQUE_FIELD_NAME_BUF = "buf" |
| STD_VECDEQUE_FIELD_NAMES = [STD_VECDEQUE_FIELD_NAME_TAIL, |
| STD_VECDEQUE_FIELD_NAME_HEAD, |
| STD_VECDEQUE_FIELD_NAME_BUF] |
| |
| # std::collections::BTreeSet<> related constants |
| STD_BTREESET_FIELD_NAMES = ["map"] |
| |
| # std::collections::BTreeMap<> related constants |
| STD_BTREEMAP_FIELD_NAMES = ["root", "length"] |
| |
| # std::String related constants |
| STD_STRING_FIELD_NAMES = ["vec"] |
| |
| # std::ffi::OsString related constants |
| OS_STRING_FIELD_NAMES = ["inner"] |
| |
| |
| class Type(object): |
| """ |
| This class provides a common interface for type-oriented operations. |
| Sub-classes are supposed to wrap a debugger-specific type-object and |
| provide implementations for the abstract methods in this class. |
| """ |
| |
| def __init__(self): |
| self.__type_kind = None |
| |
| def get_unqualified_type_name(self): |
| """ |
| Implementations of this method should return the unqualified name of the |
| type-object they are wrapping. Some examples: |
| |
| 'int' -> 'int' |
| 'std::vec::Vec<std::string::String>' -> 'Vec<std::string::String>' |
| '&std::option::Option<std::string::String>' -> '&std::option::Option<std::string::String>' |
| |
| As you can see, type arguments stay fully qualified. |
| """ |
| raise NotImplementedError("Override this method") |
| |
| def get_dwarf_type_kind(self): |
| """ |
| Implementations of this method should return the correct |
| DWARF_TYPE_CODE_* value for the wrapped type-object. |
| """ |
| raise NotImplementedError("Override this method") |
| |
| def get_fields(self): |
| """ |
| Implementations of this method should return a list of field-objects of |
| this type. For Rust-enums (i.e. with DWARF_TYPE_CODE_UNION) these field- |
| objects represent the variants of the enum. Field-objects must have a |
| `name` attribute that gives their name as specified in DWARF. |
| """ |
| assert ((self.get_dwarf_type_kind() == DWARF_TYPE_CODE_STRUCT) or |
| (self.get_dwarf_type_kind() == DWARF_TYPE_CODE_UNION)) |
| raise NotImplementedError("Override this method") |
| |
| def get_wrapped_value(self): |
| """ |
| Returns the debugger-specific type-object wrapped by this object. This |
| is sometimes needed for doing things like pointer-arithmetic in GDB. |
| """ |
| raise NotImplementedError("Override this method") |
| |
| def get_type_kind(self): |
| """This method returns the TYPE_KIND_* value for this type-object.""" |
| if self.__type_kind is None: |
| dwarf_type_code = self.get_dwarf_type_kind() |
| |
| if dwarf_type_code == DWARF_TYPE_CODE_STRUCT: |
| self.__type_kind = self.__classify_struct() |
| elif dwarf_type_code == DWARF_TYPE_CODE_UNION: |
| self.__type_kind = self.__classify_union() |
| elif dwarf_type_code == DWARF_TYPE_CODE_PTR: |
| self.__type_kind = TYPE_KIND_PTR |
| elif dwarf_type_code == DWARF_TYPE_CODE_ARRAY: |
| self.__type_kind = TYPE_KIND_FIXED_SIZE_VEC |
| else: |
| self.__type_kind = TYPE_KIND_UNKNOWN |
| return self.__type_kind |
| |
| def __classify_struct(self): |
| assert self.get_dwarf_type_kind() == DWARF_TYPE_CODE_STRUCT |
| |
| unqualified_type_name = self.get_unqualified_type_name() |
| |
| # STR SLICE |
| if unqualified_type_name == "&str": |
| return TYPE_KIND_STR_SLICE |
| |
| # REGULAR SLICE |
| if (unqualified_type_name.startswith(("&[", "&mut [")) and |
| unqualified_type_name.endswith("]") and |
| self.__conforms_to_field_layout(SLICE_FIELD_NAMES)): |
| return TYPE_KIND_SLICE |
| |
| fields = self.get_fields() |
| field_count = len(fields) |
| |
| # EMPTY STRUCT |
| if field_count == 0: |
| return TYPE_KIND_EMPTY |
| |
| # STD VEC |
| if (unqualified_type_name.startswith("Vec<") and |
| self.__conforms_to_field_layout(STD_VEC_FIELD_NAMES)): |
| return TYPE_KIND_STD_VEC |
| |
| # STD COLLECTION VECDEQUE |
| if (unqualified_type_name.startswith("VecDeque<") and |
| self.__conforms_to_field_layout(STD_VECDEQUE_FIELD_NAMES)): |
| return TYPE_KIND_STD_VECDEQUE |
| |
| # STD COLLECTION BTREESET |
| if (unqualified_type_name.startswith("BTreeSet<") and |
| self.__conforms_to_field_layout(STD_BTREESET_FIELD_NAMES)): |
| return TYPE_KIND_STD_BTREESET |
| |
| # STD COLLECTION BTREEMAP |
| if (unqualified_type_name.startswith("BTreeMap<") and |
| self.__conforms_to_field_layout(STD_BTREEMAP_FIELD_NAMES)): |
| return TYPE_KIND_STD_BTREEMAP |
| |
| # STD STRING |
| if (unqualified_type_name.startswith("String") and |
| self.__conforms_to_field_layout(STD_STRING_FIELD_NAMES)): |
| return TYPE_KIND_STD_STRING |
| |
| # OS STRING |
| if (unqualified_type_name == "OsString" and |
| self.__conforms_to_field_layout(OS_STRING_FIELD_NAMES)): |
| return TYPE_KIND_OS_STRING |
| |
| # ENUM VARIANTS |
| if fields[0].name == ENUM_DISR_FIELD_NAME: |
| if field_count == 1: |
| return TYPE_KIND_CSTYLE_VARIANT |
| elif self.__all_fields_conform_to_tuple_field_naming(1): |
| return TYPE_KIND_TUPLE_VARIANT |
| else: |
| return TYPE_KIND_STRUCT_VARIANT |
| |
| # TUPLE |
| if self.__all_fields_conform_to_tuple_field_naming(0): |
| if unqualified_type_name.startswith("("): |
| return TYPE_KIND_TUPLE |
| else: |
| return TYPE_KIND_TUPLE_STRUCT |
| |
| # REGULAR STRUCT |
| return TYPE_KIND_REGULAR_STRUCT |
| |
| def __classify_union(self): |
| assert self.get_dwarf_type_kind() == DWARF_TYPE_CODE_UNION |
| |
| union_members = self.get_fields() |
| union_member_count = len(union_members) |
| if union_member_count == 0: |
| return TYPE_KIND_EMPTY |
| |
| first_variant_name = union_members[0].name |
| if first_variant_name is None: |
| if union_member_count == 1: |
| return TYPE_KIND_SINGLETON_ENUM |
| else: |
| return TYPE_KIND_REGULAR_ENUM |
| elif first_variant_name.startswith(ENCODED_ENUM_PREFIX): |
| assert union_member_count == 1 |
| return TYPE_KIND_COMPRESSED_ENUM |
| else: |
| return TYPE_KIND_REGULAR_UNION |
| |
| def __conforms_to_field_layout(self, expected_fields): |
| actual_fields = self.get_fields() |
| actual_field_count = len(actual_fields) |
| |
| if actual_field_count != len(expected_fields): |
| return False |
| |
| for i in range(0, actual_field_count): |
| if actual_fields[i].name != expected_fields[i]: |
| return False |
| |
| return True |
| |
| def __all_fields_conform_to_tuple_field_naming(self, start_index): |
| fields = self.get_fields() |
| field_count = len(fields) |
| |
| for i in range(start_index, field_count): |
| field_name = fields[i].name |
| if (field_name is None) or (re.match(r"__\d+$", field_name) is None): |
| return False |
| return True |
| |
| |
| class Value(object): |
| """ |
| This class provides a common interface for value-oriented operations. |
| Sub-classes are supposed to wrap a debugger-specific value-object and |
| provide implementations for the abstract methods in this class. |
| """ |
| def __init__(self, ty): |
| self.type = ty |
| |
| def get_child_at_index(self, index): |
| """Returns the value of the field, array element or variant at the given index""" |
| raise NotImplementedError("Override this method") |
| |
| def as_integer(self): |
| """ |
| Try to convert the wrapped value into a Python integer. This should |
| always succeed for values that are pointers or actual integers. |
| """ |
| raise NotImplementedError("Override this method") |
| |
| def get_wrapped_value(self): |
| """ |
| Returns the debugger-specific value-object wrapped by this object. This |
| is sometimes needed for doing things like pointer-arithmetic in GDB. |
| """ |
| raise NotImplementedError("Override this method") |
| |
| |
| class EncodedEnumInfo(object): |
| """ |
| This class provides facilities for handling enum values with compressed |
| encoding where a non-null field in one variant doubles as the discriminant. |
| """ |
| |
| def __init__(self, enum_val): |
| assert enum_val.type.get_type_kind() == TYPE_KIND_COMPRESSED_ENUM |
| variant_name = enum_val.type.get_fields()[0].name |
| last_separator_index = variant_name.rfind("$") |
| start_index = len(ENCODED_ENUM_PREFIX) |
| indices_substring = variant_name[start_index:last_separator_index].split("$") |
| self.__enum_val = enum_val |
| self.__disr_field_indices = [int(index) for index in indices_substring] |
| self.__null_variant_name = variant_name[last_separator_index + 1:] |
| |
| def is_null_variant(self): |
| ty = self.__enum_val.type |
| sole_variant_val = self.__enum_val.get_child_at_index(0) |
| discriminant_val = sole_variant_val |
| for disr_field_index in self.__disr_field_indices: |
| discriminant_val = discriminant_val.get_child_at_index(disr_field_index) |
| |
| # If the discriminant field is a fat pointer we have to consider the |
| # first word as the true discriminant |
| if discriminant_val.type.get_dwarf_type_kind() == DWARF_TYPE_CODE_STRUCT: |
| discriminant_val = discriminant_val.get_child_at_index(0) |
| |
| return discriminant_val.as_integer() == 0 |
| |
| def get_non_null_variant_val(self): |
| return self.__enum_val.get_child_at_index(0) |
| |
| def get_null_variant_name(self): |
| return self.__null_variant_name |
| |
| |
| def get_discriminant_value_as_integer(enum_val): |
| assert enum_val.type.get_dwarf_type_kind() == DWARF_TYPE_CODE_UNION |
| # we can take any variant here because the discriminant has to be the same |
| # for all of them. |
| variant_val = enum_val.get_child_at_index(0) |
| disr_val = variant_val.get_child_at_index(0) |
| return disr_val.as_integer() |
| |
| |
| def extract_length_ptr_and_cap_from_std_vec(vec_val): |
| assert vec_val.type.get_type_kind() == TYPE_KIND_STD_VEC |
| length_field_index = STD_VEC_FIELD_NAMES.index(STD_VEC_FIELD_NAME_LENGTH) |
| buf_field_index = STD_VEC_FIELD_NAMES.index(STD_VEC_FIELD_NAME_BUF) |
| |
| length = vec_val.get_child_at_index(length_field_index).as_integer() |
| buf = vec_val.get_child_at_index(buf_field_index) |
| |
| vec_ptr_val = buf.get_child_at_index(0) |
| capacity = buf.get_child_at_index(1).as_integer() |
| data_ptr = vec_ptr_val.get_child_at_index(0) |
| assert data_ptr.type.get_dwarf_type_kind() == DWARF_TYPE_CODE_PTR |
| return (length, data_ptr, capacity) |
| |
| |
| def extract_tail_head_ptr_and_cap_from_std_vecdeque(vec_val): |
| assert vec_val.type.get_type_kind() == TYPE_KIND_STD_VECDEQUE |
| tail_field_index = STD_VECDEQUE_FIELD_NAMES.index(STD_VECDEQUE_FIELD_NAME_TAIL) |
| head_field_index = STD_VECDEQUE_FIELD_NAMES.index(STD_VECDEQUE_FIELD_NAME_HEAD) |
| buf_field_index = STD_VECDEQUE_FIELD_NAMES.index(STD_VECDEQUE_FIELD_NAME_BUF) |
| |
| tail = vec_val.get_child_at_index(tail_field_index).as_integer() |
| head = vec_val.get_child_at_index(head_field_index).as_integer() |
| buf = vec_val.get_child_at_index(buf_field_index) |
| |
| vec_ptr_val = buf.get_child_at_index(0) |
| capacity = buf.get_child_at_index(1).as_integer() |
| data_ptr = vec_ptr_val.get_child_at_index(0) |
| assert data_ptr.type.get_dwarf_type_kind() == DWARF_TYPE_CODE_PTR |
| return (tail, head, data_ptr, capacity) |
| |
| |
| def extract_length_and_ptr_from_slice(slice_val): |
| assert (slice_val.type.get_type_kind() == TYPE_KIND_SLICE or |
| slice_val.type.get_type_kind() == TYPE_KIND_STR_SLICE) |
| |
| length_field_index = SLICE_FIELD_NAMES.index(SLICE_FIELD_NAME_LENGTH) |
| ptr_field_index = SLICE_FIELD_NAMES.index(SLICE_FIELD_NAME_DATA_PTR) |
| |
| length = slice_val.get_child_at_index(length_field_index).as_integer() |
| data_ptr = slice_val.get_child_at_index(ptr_field_index) |
| |
| assert data_ptr.type.get_dwarf_type_kind() == DWARF_TYPE_CODE_PTR |
| return (length, data_ptr) |
| |
| |
| UNQUALIFIED_TYPE_MARKERS = frozenset(["(", "[", "&", "*"]) |
| |
| |
| def extract_type_name(qualified_type_name): |
| """Extracts the type name from a fully qualified path""" |
| if qualified_type_name[0] in UNQUALIFIED_TYPE_MARKERS: |
| return qualified_type_name |
| |
| end_of_search = qualified_type_name.find("<") |
| if end_of_search < 0: |
| end_of_search = len(qualified_type_name) |
| |
| index = qualified_type_name.rfind("::", 0, end_of_search) |
| if index < 0: |
| return qualified_type_name |
| else: |
| return qualified_type_name[index + 2:] |
| |
| |
| try: |
| compat_str = unicode # Python 2 |
| except NameError: |
| compat_str = str |
