rust/src/etc/lldb_rust_formatters.py
Michael Woerister 98a0f9166c debuginfo: Don't mark struct fields as artificial.
LLDB doesn't allow for reading 'artifical' fields (fields that are generated by the compiler). So do not mark, slice fields, enum discriminants, and GcBox value fields as artificial.
2014-10-08 11:52:06 +02:00

246 lines
8.1 KiB
Python

# Copyright 2014 The Rust Project Developers. See the COPYRIGHT
# file at the top-level directory of this distribution and at
# http://rust-lang.org/COPYRIGHT.
#
# Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
# http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
# <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
# option. This file may not be copied, modified, or distributed
# except according to those terms.
import lldb
def print_val(val, internal_dict):
'''Prints the given value with Rust syntax'''
type_class = val.GetType().GetTypeClass()
if type_class == lldb.eTypeClassStruct:
return print_struct_val(val, internal_dict)
if type_class == lldb.eTypeClassUnion:
return print_enum_val(val, internal_dict)
if type_class == lldb.eTypeClassPointer:
return print_pointer_val(val, internal_dict)
if type_class == lldb.eTypeClassArray:
return print_fixed_size_vec_val(val, internal_dict)
return val.GetValue()
#=--------------------------------------------------------------------------------------------------
# Type-Specialized Printing Functions
#=--------------------------------------------------------------------------------------------------
def print_struct_val(val, internal_dict):
'''Prints a struct, tuple, or tuple struct value with Rust syntax'''
assert val.GetType().GetTypeClass() == lldb.eTypeClassStruct
if is_vec_slice(val):
return print_vec_slice_val(val, internal_dict)
else:
return print_struct_val_starting_from(0, val, internal_dict)
def print_vec_slice_val(val, internal_dict):
output = "&["
length = val.GetChildAtIndex(1).GetValueAsUnsigned()
data_ptr_val = val.GetChildAtIndex(0)
data_ptr_type = data_ptr_val.GetType()
assert data_ptr_type.IsPointerType()
element_type = data_ptr_type.GetPointeeType()
element_type_size = element_type.GetByteSize()
start_address = data_ptr_val.GetValueAsUnsigned()
for i in range(length):
address = start_address + i * element_type_size
element_val = val.CreateValueFromAddress( val.GetName() + ("[%s]" % i), address, element_type )
output += print_val(element_val, internal_dict)
if i != length - 1:
output += ", "
output += "]"
return output
def print_struct_val_starting_from(field_start_index, val, internal_dict):
'''
Prints a struct, tuple, or tuple struct value with Rust syntax.
Ignores any fields before field_start_index.
'''
assert val.GetType().GetTypeClass() == lldb.eTypeClassStruct
t = val.GetType()
has_field_names = type_has_field_names(t)
type_name = extract_type_name(t.GetName())
output = ""
if not type_name.startswith("("):
# this is a tuple, so don't print the type name
output += type_name
if has_field_names:
output += " { \n"
else:
output += "("
num_children = val.num_children
for child_index in range(field_start_index, num_children):
if has_field_names:
field_name = t.GetFieldAtIndex(child_index).GetName()
output += field_name + ": "
field_val = val.GetChildAtIndex(child_index)
output += print_val(field_val, internal_dict)
if child_index != num_children - 1:
output += ", "
if has_field_names:
output += "\n"
if has_field_names:
output += "}"
else:
output += ")"
return output
def print_enum_val(val, internal_dict):
'''Prints an enum value with Rust syntax'''
assert val.GetType().GetTypeClass() == lldb.eTypeClassUnion
if val.num_children == 1:
# This is either an enum with just one variant, or it is an Option-like enum
# where the discriminant is encoded in a non-nullable pointer field. We find
# out which one it is by looking at the member name of the sole union
# variant. If it starts with "RUST$ENCODED$ENUM$" then we have an
# Option-like enum.
first_variant_name = val.GetChildAtIndex(0).GetName()
if first_variant_name and first_variant_name.startswith("RUST$ENCODED$ENUM$"):
# This is an Option-like enum. The position of the discriminator field is
# encoded in the name which has the format:
# RUST$ENCODED$ENUM$<index of discriminator field>$<name of null variant>
last_separator_index = first_variant_name.rfind("$")
if last_separator_index == -1:
return "<invalid enum encoding: %s>" % first_variant_name
second_last_separator_index = first_variant_name.rfind("$", 0, last_separator_index)
if second_last_separator_index == -1:
return "<invalid enum encoding: %s>" % first_variant_name
# Extract index of the discriminator field
try:
disr_field_index = first_variant_name[second_last_separator_index + 1 :
last_separator_index]
disr_field_index = int(disr_field_index)
except:
return "<invalid enum encoding: %s>" % first_variant_name
# Read the discriminant
disr_val = val.GetChildAtIndex(0).GetChildAtIndex(disr_field_index).GetValueAsUnsigned()
if disr_val == 0:
# Null case: Print the name of the null-variant
null_variant_name = first_variant_name[last_separator_index + 1:]
return null_variant_name
else:
# Non-null case: Interpret the data as a value of the non-null variant type
return print_struct_val_starting_from(0, val.GetChildAtIndex(0), internal_dict)
else:
# This is just a regular uni-variant enum without discriminator field
return print_struct_val_starting_from(0, val.GetChildAtIndex(0), internal_dict)
# If we are here, this is a regular enum with more than one variant
disr_val = val.GetChildAtIndex(0).GetChildMemberWithName("RUST$ENUM$DISR")
disr_type = disr_val.GetType()
if disr_type.GetTypeClass() != lldb.eTypeClassEnumeration:
return "<Invalid enum value encountered: Discriminator is not an enum>"
variant_index = disr_val.GetValueAsUnsigned()
return print_struct_val_starting_from(1, val.GetChildAtIndex(variant_index), internal_dict)
def print_pointer_val(val, internal_dict):
'''Prints a pointer value with Rust syntax'''
assert val.GetType().IsPointerType()
sigil = "&"
type_name = extract_type_name(val.GetType().GetName())
if type_name and type_name[0:1] in ["&", "~", "*"]:
sigil = type_name[0:1]
return sigil + hex(val.GetValueAsUnsigned()) #print_val(val.Dereference(), internal_dict)
def print_fixed_size_vec_val(val, internal_dict):
assert val.GetType().GetTypeClass() == lldb.eTypeClassArray
output = "["
for i in range(val.num_children):
output += print_val(val.GetChildAtIndex(i), internal_dict)
if i != val.num_children - 1:
output += ", "
output += "]"
return output
#=--------------------------------------------------------------------------------------------------
# Helper Functions
#=--------------------------------------------------------------------------------------------------
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:]
def type_has_field_names(ty):
'''Returns true of this is a type with field names (struct, struct-like enum variant)'''
# This may also be an enum variant where the first field doesn't have a name but the rest has
if ty.GetNumberOfFields() > 1:
return ty.GetFieldAtIndex(1).GetName() != None
else:
return ty.GetFieldAtIndex(0).GetName() != None
def is_vec_slice(val):
ty = val.GetType()
if ty.GetTypeClass() != lldb.eTypeClassStruct:
return False
if ty.GetNumberOfFields() != 2:
return False
if ty.GetFieldAtIndex(0).GetName() != "data_ptr":
return False
if ty.GetFieldAtIndex(1).GetName() != "length":
return False
type_name = extract_type_name(ty.GetName()).replace("&'static", "&").replace(" ", "")
return type_name.startswith("&[") and type_name.endswith("]")