Mini Shell
# Pretty-printer commands.
# Copyright (C) 2010-2018 Free Software Foundation, Inc.
# This program 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 of the License, or
# (at your option) any later version.
#
# This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
"""GDB commands for working with pretty-printers."""
import copy
import gdb
import re
def parse_printer_regexps(arg):
"""Internal utility to parse a pretty-printer command argv.
Arguments:
arg: The arguments to the command. The format is:
[object-regexp [name-regexp]].
Individual printers in a collection are named as
printer-name;subprinter-name.
Returns:
The result is a 3-tuple of compiled regular expressions, except that
the resulting compiled subprinter regexp is None if not provided.
Raises:
SyntaxError: an error processing ARG
"""
argv = gdb.string_to_argv(arg);
argc = len(argv)
object_regexp = "" # match everything
name_regexp = "" # match everything
subname_regexp = None
if argc > 3:
raise SyntaxError("too many arguments")
if argc >= 1:
object_regexp = argv[0]
if argc >= 2:
name_subname = argv[1].split(";", 1)
name_regexp = name_subname[0]
if len(name_subname) == 2:
subname_regexp = name_subname[1]
# That re.compile raises SyntaxError was determined empirically.
# We catch it and reraise it to provide a slightly more useful
# error message for the user.
try:
object_re = re.compile(object_regexp)
except SyntaxError:
raise SyntaxError("invalid object regexp: %s" % object_regexp)
try:
name_re = re.compile (name_regexp)
except SyntaxError:
raise SyntaxError("invalid name regexp: %s" % name_regexp)
if subname_regexp is not None:
try:
subname_re = re.compile(subname_regexp)
except SyntaxError:
raise SyntaxError("invalid subname regexp: %s" % subname_regexp)
else:
subname_re = None
return(object_re, name_re, subname_re)
def printer_enabled_p(printer):
"""Internal utility to see if printer (or subprinter) is enabled."""
if hasattr(printer, "enabled"):
return printer.enabled
else:
return True
class InfoPrettyPrinter(gdb.Command):
"""GDB command to list all registered pretty-printers.
Usage: info pretty-printer [object-regexp [name-regexp]]
OBJECT-REGEXP is a regular expression matching the objects to list.
Objects are "global", the program space's file, and the objfiles within
that program space.
NAME-REGEXP matches the name of the pretty-printer.
Individual printers in a collection are named as
printer-name;subprinter-name.
"""
def __init__ (self):
super(InfoPrettyPrinter, self).__init__("info pretty-printer",
gdb.COMMAND_DATA)
@staticmethod
def enabled_string(printer):
"""Return "" if PRINTER is enabled, otherwise " [disabled]"."""
if printer_enabled_p(printer):
return ""
else:
return " [disabled]"
@staticmethod
def printer_name(printer):
"""Return the printer's name."""
if hasattr(printer, "name"):
return printer.name
if hasattr(printer, "__name__"):
return printer.__name__
# This "shouldn't happen", but the public API allows for
# direct additions to the pretty-printer list, and we shouldn't
# crash because someone added a bogus printer.
# Plus we want to give the user a way to list unknown printers.
return "unknown"
def list_pretty_printers(self, pretty_printers, name_re, subname_re):
"""Print a list of pretty-printers."""
# A potential enhancement is to provide an option to list printers in
# "lookup order" (i.e. unsorted).
sorted_pretty_printers = sorted (copy.copy(pretty_printers),
key = self.printer_name)
for printer in sorted_pretty_printers:
name = self.printer_name(printer)
enabled = self.enabled_string(printer)
if name_re.match(name):
print (" %s%s" % (name, enabled))
if (hasattr(printer, "subprinters") and
printer.subprinters is not None):
sorted_subprinters = sorted (copy.copy(printer.subprinters),
key = self.printer_name)
for subprinter in sorted_subprinters:
if (not subname_re or
subname_re.match(subprinter.name)):
print (" %s%s" %
(subprinter.name,
self.enabled_string(subprinter)))
def invoke1(self, title, printer_list,
obj_name_to_match, object_re, name_re, subname_re):
"""Subroutine of invoke to simplify it."""
if printer_list and object_re.match(obj_name_to_match):
print (title)
self.list_pretty_printers(printer_list, name_re, subname_re)
def invoke(self, arg, from_tty):
"""GDB calls this to perform the command."""
(object_re, name_re, subname_re) = parse_printer_regexps(arg)
self.invoke1("global pretty-printers:", gdb.pretty_printers,
"global", object_re, name_re, subname_re)
cp = gdb.current_progspace()
self.invoke1("progspace %s pretty-printers:" % cp.filename,
cp.pretty_printers, "progspace",
object_re, name_re, subname_re)
for objfile in gdb.objfiles():
self.invoke1(" objfile %s pretty-printers:" % objfile.filename,
objfile.pretty_printers, objfile.filename,
object_re, name_re, subname_re)
def count_enabled_printers(pretty_printers):
"""Return a 2-tuple of number of enabled and total printers."""
enabled = 0
total = 0
for printer in pretty_printers:
if (hasattr(printer, "subprinters")
and printer.subprinters is not None):
if printer_enabled_p(printer):
for subprinter in printer.subprinters:
if printer_enabled_p(subprinter):
enabled += 1
total += len(printer.subprinters)
else:
if printer_enabled_p(printer):
enabled += 1
total += 1
return (enabled, total)
def count_all_enabled_printers():
"""Return a 2-tuble of the enabled state and total number of all printers.
This includes subprinters.
"""
enabled_count = 0
total_count = 0
(t_enabled, t_total) = count_enabled_printers(gdb.pretty_printers)
enabled_count += t_enabled
total_count += t_total
(t_enabled, t_total) = count_enabled_printers(gdb.current_progspace().pretty_printers)
enabled_count += t_enabled
total_count += t_total
for objfile in gdb.objfiles():
(t_enabled, t_total) = count_enabled_printers(objfile.pretty_printers)
enabled_count += t_enabled
total_count += t_total
return (enabled_count, total_count)
def pluralize(text, n, suffix="s"):
"""Return TEXT pluralized if N != 1."""
if n != 1:
return "%s%s" % (text, suffix)
else:
return text
def show_pretty_printer_enabled_summary():
"""Print the number of printers enabled/disabled.
We count subprinters individually.
"""
(enabled_count, total_count) = count_all_enabled_printers()
print ("%d of %d printers enabled" % (enabled_count, total_count))
def do_enable_pretty_printer_1 (pretty_printers, name_re, subname_re, flag):
"""Worker for enabling/disabling pretty-printers.
Arguments:
pretty_printers: list of pretty-printers
name_re: regular-expression object to select printers
subname_re: regular expression object to select subprinters or None
if all are affected
flag: True for Enable, False for Disable
Returns:
The number of printers affected.
This is just for informational purposes for the user.
"""
total = 0
for printer in pretty_printers:
if (hasattr(printer, "name") and name_re.match(printer.name) or
hasattr(printer, "__name__") and name_re.match(printer.__name__)):
if (hasattr(printer, "subprinters") and
printer.subprinters is not None):
if not subname_re:
# Only record printers that change state.
if printer_enabled_p(printer) != flag:
for subprinter in printer.subprinters:
if printer_enabled_p(subprinter):
total += 1
# NOTE: We preserve individual subprinter settings.
printer.enabled = flag
else:
# NOTE: Whether this actually disables the subprinter
# depends on whether the printer's lookup function supports
# the "enable" API. We can only assume it does.
for subprinter in printer.subprinters:
if subname_re.match(subprinter.name):
# Only record printers that change state.
if (printer_enabled_p(printer) and
printer_enabled_p(subprinter) != flag):
total += 1
subprinter.enabled = flag
else:
# This printer has no subprinters.
# If the user does "disable pretty-printer .* .* foo"
# should we disable printers that don't have subprinters?
# How do we apply "foo" in this context? Since there is no
# "foo" subprinter it feels like we should skip this printer.
# There's still the issue of how to handle
# "disable pretty-printer .* .* .*", and every other variation
# that can match everything. For now punt and only support
# "disable pretty-printer .* .*" (i.e. subname is elided)
# to disable everything.
if not subname_re:
# Only record printers that change state.
if printer_enabled_p(printer) != flag:
total += 1
printer.enabled = flag
return total
def do_enable_pretty_printer (arg, flag):
"""Internal worker for enabling/disabling pretty-printers."""
(object_re, name_re, subname_re) = parse_printer_regexps(arg)
total = 0
if object_re.match("global"):
total += do_enable_pretty_printer_1(gdb.pretty_printers,
name_re, subname_re, flag)
cp = gdb.current_progspace()
if object_re.match("progspace"):
total += do_enable_pretty_printer_1(cp.pretty_printers,
name_re, subname_re, flag)
for objfile in gdb.objfiles():
if object_re.match(objfile.filename):
total += do_enable_pretty_printer_1(objfile.pretty_printers,
name_re, subname_re, flag)
if flag:
state = "enabled"
else:
state = "disabled"
print ("%d %s %s" % (total, pluralize("printer", total), state))
# Print the total list of printers currently enabled/disabled.
# This is to further assist the user in determining whether the result
# is expected. Since we use regexps to select it's useful.
show_pretty_printer_enabled_summary()
# Enable/Disable one or more pretty-printers.
#
# This is intended for use when a broken pretty-printer is shipped/installed
# and the user wants to disable that printer without disabling all the other
# printers.
#
# A useful addition would be -v (verbose) to show each printer affected.
class EnablePrettyPrinter (gdb.Command):
"""GDB command to enable the specified pretty-printer.
Usage: enable pretty-printer [object-regexp [name-regexp]]
OBJECT-REGEXP is a regular expression matching the objects to examine.
Objects are "global", the program space's file, and the objfiles within
that program space.
NAME-REGEXP matches the name of the pretty-printer.
Individual printers in a collection are named as
printer-name;subprinter-name.
"""
def __init__(self):
super(EnablePrettyPrinter, self).__init__("enable pretty-printer",
gdb.COMMAND_DATA)
def invoke(self, arg, from_tty):
"""GDB calls this to perform the command."""
do_enable_pretty_printer(arg, True)
class DisablePrettyPrinter (gdb.Command):
"""GDB command to disable the specified pretty-printer.
Usage: disable pretty-printer [object-regexp [name-regexp]]
OBJECT-REGEXP is a regular expression matching the objects to examine.
Objects are "global", the program space's file, and the objfiles within
that program space.
NAME-REGEXP matches the name of the pretty-printer.
Individual printers in a collection are named as
printer-name;subprinter-name.
"""
def __init__(self):
super(DisablePrettyPrinter, self).__init__("disable pretty-printer",
gdb.COMMAND_DATA)
def invoke(self, arg, from_tty):
"""GDB calls this to perform the command."""
do_enable_pretty_printer(arg, False)
def register_pretty_printer_commands():
"""Call from a top level script to install the pretty-printer commands."""
InfoPrettyPrinter()
EnablePrettyPrinter()
DisablePrettyPrinter()
register_pretty_printer_commands()
Zerion Mini Shell 1.0