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| | # Copyright (C) 2022 Free Software Foundation, Inc.
#
# This file is part of GNU Emacs.
#
# GNU Emacs is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3, or (at your option)
# any later version.
#
# GNU Emacs is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
# Load this module in LLDB with
#
# (lldb) command script import emacs_lldb
#
# Available commands start with 'x' and can be seen with
#
# (lldb) help
import lldb
\f
########################################################################
# Utilties
########################################################################
# Return the Lisp_Type of Lisp_Object OBJ.
def get_lisp_type(obj):
int_value = obj.GetValueAsUnsigned()
return obj.GetFrame().EvaluateExpression(
f"(enum Lisp_Type) ((EMACS_INT) {int_value} "
"& (1 << GCTYPEBITS) - 1)")
# Return the Lisp_Type or pseudo-vector type of OBJ.
def get_lisp_type_or_vectorlike(obj):
lisp_type = get_lisp_type(obj)
if enumerator_name(lisp_type) == "Lisp_Vectorlike":
vector = get_lisp_pointer(obj, "struct Lisp_Vector")
header_size = vector.GetValueForExpressionPath(
"->header.size").GetValueAsUnsigned()
frame = obj.GetFrame()
pseudo = frame.EvaluateExpression(
f"{header_size} & PSEUDOVECTOR_FLAG")
if pseudo.GetValueAsUnsigned() != 0:
return frame.EvaluateExpression(
f"(enum pvec_type) (({header_size} "
"& More_Lisp_Bits::PVEC_TYPE_MASK) "
">> More_Lisp_Bits::PSEUDOVECTOR_AREA_BITS)")
return frame.EvaluateExpression("pvec_type::PVEC_NORMAL_VECTOR")
return lisp_type
# Return Lisp_Object OBJ as pointer to TYP *.
def get_lisp_pointer(obj, typ):
return obj.GetFrame().EvaluateExpression(
f"({typ}*) (((EMACS_INT) {obj.GetValueAsUnsigned()}) & VALMASK)")
# Return Lisp_Object OBJ as pointer to Lisp_Symbol.
def get_lisp_symbol(obj):
ptr = get_lisp_pointer(obj, "char")
offset = ptr.GetValueAsUnsigned()
return obj.GetFrame().EvaluateExpression(
f"(struct Lisp_Symbol *) ((char *) &lispsym + {offset})")
# Return Lisp_Object OBJ as pointer to Lisp_String
def get_lisp_string(obj):
return get_lisp_pointer(obj, "struct Lisp_String")
# Return the string data of Lisp_Object OBJ which denotes a Lisp_String.
def get_lisp_string_data(obj):
string = get_lisp_string(obj)
return string.GetValueForExpressionPath("->u.s.data")
# Assuming OBJ denotes a Lisp_Symbol, return the name of the symbol.
def get_lisp_symbol_name(obj):
sym = get_lisp_symbol(obj)
name = sym.GetValueForExpressionPath("->u.s.name")
return get_lisp_string_data(name)
# Return a string for the enuerator ENUM.
def enumerator_name(enum):
enumerators = enum.GetType().GetEnumMembers()
return enumerators[enum.GetValueAsUnsigned()].GetName()
\f
########################################################################
# LLDB Commands
########################################################################
def xbacktrace(debugger, command, ctx, result, internal_dict):
"""Print Emacs Lisp backtrace"""
frame = ctx.GetFrame()
n = frame.EvaluateExpression(
"current_thread->m_specpdl_ptr - current_thread->m_specpdl")
for i in reversed(range(0, n.GetValueAsUnsigned())):
s = frame.EvaluateExpression(f"current_thread->m_specpdl[{i}]")
kind = enumerator_name(s.GetChildMemberWithName("kind"))
if kind == "SPECPDL_BACKTRACE":
function = s.GetValueForExpressionPath(".bt.function")
function_type = enumerator_name(get_lisp_type(function))
if function_type == "Lisp_Symbol":
sym_name = get_lisp_symbol_name(function)
result.AppendMessage(str(sym_name))
elif function_type == "Lisp_Vectorlike":
subtype = get_lisp_type_or_vectorlike(function)
result.AppendMessage(str(subtype))
else:
result.AppendMessage(function_type)
def xdebug_print(debugger, command, result, internal_dict):
"""Print Lisp_Objects using safe_debug_print()"""
debugger.HandleCommand(f"expr safe_debug_print({command})")
\f
########################################################################
# Formatters
########################################################################
# Return a type summary for Lisp_Objects.
def format_Lisp_Object(obj, internal_dict):
lisp_type = get_lisp_type_or_vectorlike(obj)
kind = enumerator_name(lisp_type)
summary = "-> "
if kind == "PVEC_FRAME":
ptr = get_lisp_pointer(obj, "struct frame")
summary += str(ptr)
elif kind == "PVEC_WINDOW":
ptr = get_lisp_pointer(obj, "struct window")
summary += str(ptr)
return summary
\f
########################################################################
# Initialization
########################################################################
# Define Python FUNCTION as an LLDB command.
def define_command (debugger, function):
lldb_command = function.__name__
python_function = __name__ + "." + function.__name__
debugger.HandleCommand(f"command script add "
f"--overwrite "
f"--function {python_function} "
f"{lldb_command}")
# Define Python FUNCTION as an LLDB type formatter.
def define_formatter(debugger, regex, function):
python_function = __name__ + "." + function.__name__
debugger.HandleCommand(f"type summary add "
f"--cascade true "
f'--regex "{regex}" '
f"--python-function {python_function}")
# This function is called by LLDB to initialize the module.
def __lldb_init_module(debugger, internal_dict):
define_command(debugger, xbacktrace)
define_command(debugger, xdebug_print)
define_formatter(debugger, "Lisp_Object", format_Lisp_Object)
print('Emacs debugging support has been installed.')
# end.
|