gdb/python/lib/gdb/command/pretty_printers.py

   1 # Pretty-printer commands.
   2 # Copyright (C) 2010-2019 Free Software Foundation, Inc.
   3
   4 # This program is free software; you can redistribute it and/or modify
   5 # it under the terms of the GNU General Public License as published by
   6 # the Free Software Foundation; either version 3 of the License, or
   7 # (at your option) any later version.
   8 #
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU General Public License
  15 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 """GDB commands for working with pretty-printers."""
  18
  19 import copy
  20 import gdb
  21 import re
  22
  23
  24 def parse_printer_regexps(arg):
  25     """Internal utility to parse a pretty-printer command argv.
  26
  27     Arguments:
  28         arg: The arguments to the command.  The format is:
  29              [object-regexp [name-regexp]].
  30              Individual printers in a collection are named as
  31              printer-name;subprinter-name.
  32
  33     Returns:
  34         The result is a 3-tuple of compiled regular expressions, except that
  35         the resulting compiled subprinter regexp is None if not provided.
  36
  37     Raises:
  38         SyntaxError: an error processing ARG
  39     """
  40
  41     argv = gdb.string_to_argv(arg);
  42     argc = len(argv)
  43     object_regexp = ""  # match everything
  44     name_regexp = ""  # match everything
  45     subname_regexp = None
  46     if argc > 3:
  47         raise SyntaxError("too many arguments")
  48     if argc >= 1:
  49         object_regexp = argv[0]
  50     if argc >= 2:
  51         name_subname = argv[1].split(";", 1)
  52         name_regexp = name_subname[0]
  53         if len(name_subname) == 2:
  54             subname_regexp = name_subname[1]
  55     # That re.compile raises SyntaxError was determined empirically.
  56     # We catch it and reraise it to provide a slightly more useful
  57     # error message for the user.
  58     try:
  59         object_re = re.compile(object_regexp)
  60     except SyntaxError:
  61         raise SyntaxError("invalid object regexp: %s" % object_regexp)
  62     try:
  63         name_re = re.compile (name_regexp)
  64     except SyntaxError:
  65         raise SyntaxError("invalid name regexp: %s" % name_regexp)
  66     if subname_regexp is not None:
  67         try:
  68             subname_re = re.compile(subname_regexp)
  69         except SyntaxError:
  70             raise SyntaxError("invalid subname regexp: %s" % subname_regexp)
  71     else:
  72         subname_re = None
  73     return(object_re, name_re, subname_re)
  74
  75
  76 def printer_enabled_p(printer):
  77     """Internal utility to see if printer (or subprinter) is enabled."""
  78     if hasattr(printer, "enabled"):
  79         return printer.enabled
  80     else:
  81         return True
  82
  83
  84 class InfoPrettyPrinter(gdb.Command):
  85     """GDB command to list all registered pretty-printers.
  86
  87 Usage: info pretty-printer [OBJECT-REGEXP [NAME-REGEXP]]
  88
  89 OBJECT-REGEXP is a regular expression matching the objects to list.
  90 Objects are "global", the program space's file, and the objfiles within
  91 that program space.
  92
  93 NAME-REGEXP matches the name of the pretty-printer.
  94 Individual printers in a collection are named as
  95 printer-name;subprinter-name."""
  96
  97     def __init__ (self):
  98         super(InfoPrettyPrinter, self).__init__("info pretty-printer",
  99                                                  gdb.COMMAND_DATA)
 100
 101     @staticmethod
 102     def enabled_string(printer):
 103         """Return "" if PRINTER is enabled, otherwise " [disabled]"."""
 104         if printer_enabled_p(printer):
 105             return ""
 106         else:
 107             return " [disabled]"
 108
 109     @staticmethod
 110     def printer_name(printer):
 111         """Return the printer's name."""
 112         if hasattr(printer, "name"):
 113             return printer.name
 114         if hasattr(printer, "__name__"):
 115             return printer.__name__
 116         # This "shouldn't happen", but the public API allows for
 117         # direct additions to the pretty-printer list, and we shouldn't
 118         # crash because someone added a bogus printer.
 119         # Plus we want to give the user a way to list unknown printers.
 120         return "unknown"
 121
 122     def list_pretty_printers(self, pretty_printers, name_re, subname_re):
 123         """Print a list of pretty-printers."""
 124         # A potential enhancement is to provide an option to list printers in
 125         # "lookup order" (i.e. unsorted).
 126         sorted_pretty_printers = sorted (copy.copy(pretty_printers),
 127                                          key = self.printer_name)
 128         for printer in sorted_pretty_printers:
 129             name = self.printer_name(printer)
 130             enabled = self.enabled_string(printer)
 131             if name_re.match(name):
 132                 print ("  %s%s" % (name, enabled))
 133                 if (hasattr(printer, "subprinters") and
 134                     printer.subprinters is not None):
 135                     sorted_subprinters = sorted (copy.copy(printer.subprinters),
 136                                                  key = self.printer_name)
 137                     for subprinter in sorted_subprinters:
 138                         if (not subname_re or
 139                             subname_re.match(subprinter.name)):
 140                             print ("    %s%s" %
 141                                    (subprinter.name,
 142                                     self.enabled_string(subprinter)))
 143
 144     def invoke1(self, title, printer_list,
 145                 obj_name_to_match, object_re, name_re, subname_re):
 146         """Subroutine of invoke to simplify it."""
 147         if printer_list and object_re.match(obj_name_to_match):
 148             print (title)
 149             self.list_pretty_printers(printer_list, name_re, subname_re)
 150
 151     def invoke(self, arg, from_tty):
 152         """GDB calls this to perform the command."""
 153         (object_re, name_re, subname_re) = parse_printer_regexps(arg)
 154         self.invoke1("global pretty-printers:", gdb.pretty_printers,
 155                      "global", object_re, name_re, subname_re)
 156         cp = gdb.current_progspace()
 157         self.invoke1("progspace %s pretty-printers:" % cp.filename,
 158                      cp.pretty_printers, "progspace",
 159                      object_re, name_re, subname_re)
 160         for objfile in gdb.objfiles():
 161             self.invoke1("objfile %s pretty-printers:" % objfile.filename,
 162                          objfile.pretty_printers, objfile.filename,
 163                          object_re, name_re, subname_re)
 164
 165
 166 def count_enabled_printers(pretty_printers):
 167     """Return a 2-tuple of number of enabled and total printers."""
 168     enabled = 0
 169     total = 0
 170     for printer in pretty_printers:
 171         if (hasattr(printer, "subprinters")
 172             and printer.subprinters is not None):
 173             if printer_enabled_p(printer):
 174                 for subprinter in printer.subprinters:
 175                     if printer_enabled_p(subprinter):
 176                         enabled += 1
 177             total += len(printer.subprinters)
 178         else:
 179             if printer_enabled_p(printer):
 180                 enabled += 1
 181             total += 1
 182     return (enabled, total)
 183
 184
 185 def count_all_enabled_printers():
 186     """Return a 2-tuble of the enabled state and total number of all printers.
 187     This includes subprinters.
 188     """
 189     enabled_count = 0
 190     total_count = 0
 191     (t_enabled, t_total) = count_enabled_printers(gdb.pretty_printers)
 192     enabled_count += t_enabled
 193     total_count += t_total
 194     (t_enabled, t_total) = count_enabled_printers(gdb.current_progspace().pretty_printers)
 195     enabled_count += t_enabled
 196     total_count += t_total
 197     for objfile in gdb.objfiles():
 198         (t_enabled, t_total) = count_enabled_printers(objfile.pretty_printers)
 199         enabled_count += t_enabled
 200         total_count += t_total
 201     return (enabled_count, total_count)
 202
 203
 204 def pluralize(text, n, suffix="s"):
 205     """Return TEXT pluralized if N != 1."""
 206     if n != 1:
 207         return "%s%s" % (text, suffix)
 208     else:
 209         return text
 210
 211
 212 def show_pretty_printer_enabled_summary():
 213     """Print the number of printers enabled/disabled.
 214     We count subprinters individually.
 215     """
 216     (enabled_count, total_count) = count_all_enabled_printers()
 217     print ("%d of %d printers enabled" % (enabled_count, total_count))
 218
 219
 220 def do_enable_pretty_printer_1 (pretty_printers, name_re, subname_re, flag):
 221     """Worker for enabling/disabling pretty-printers.
 222
 223     Arguments:
 224         pretty_printers: list of pretty-printers
 225         name_re: regular-expression object to select printers
 226         subname_re: regular expression object to select subprinters or None
 227                     if all are affected
 228         flag: True for Enable, False for Disable
 229
 230     Returns:
 231         The number of printers affected.
 232         This is just for informational purposes for the user.
 233     """
 234     total = 0
 235     for printer in pretty_printers:
 236         if (hasattr(printer, "name") and name_re.match(printer.name) or
 237             hasattr(printer, "__name__") and name_re.match(printer.__name__)):
 238             if (hasattr(printer, "subprinters") and
 239                 printer.subprinters is not None):
 240                 if not subname_re:
 241                     # Only record printers that change state.
 242                     if printer_enabled_p(printer) != flag:
 243                         for subprinter in printer.subprinters:
 244                             if printer_enabled_p(subprinter):
 245                                 total += 1
 246                     # NOTE: We preserve individual subprinter settings.
 247                     printer.enabled = flag
 248                 else:
 249                     # NOTE: Whether this actually disables the subprinter
 250                     # depends on whether the printer's lookup function supports
 251                     # the "enable" API.  We can only assume it does.
 252                     for subprinter in printer.subprinters:
 253                         if subname_re.match(subprinter.name):
 254                             # Only record printers that change state.
 255                            if (printer_enabled_p(printer) and
 256                                printer_enabled_p(subprinter) != flag):
 257                                total += 1
 258                            subprinter.enabled = flag
 259             else:
 260                 # This printer has no subprinters.
 261                 # If the user does "disable pretty-printer .* .* foo"
 262                 # should we disable printers that don't have subprinters?
 263                 # How do we apply "foo" in this context?  Since there is no
 264                 # "foo" subprinter it feels like we should skip this printer.
 265                 # There's still the issue of how to handle
 266                 # "disable pretty-printer .* .* .*", and every other variation
 267                 # that can match everything.  For now punt and only support
 268                 # "disable pretty-printer .* .*" (i.e. subname is elided)
 269                 # to disable everything.
 270                 if not subname_re:
 271                     # Only record printers that change state.
 272                     if printer_enabled_p(printer) != flag:
 273                         total += 1
 274                     printer.enabled = flag
 275     return total
 276
 277
 278 def do_enable_pretty_printer (arg, flag):
 279     """Internal worker for enabling/disabling pretty-printers."""
 280     (object_re, name_re, subname_re) = parse_printer_regexps(arg)
 281
 282     total = 0
 283     if object_re.match("global"):
 284         total += do_enable_pretty_printer_1(gdb.pretty_printers,
 285                                             name_re, subname_re, flag)
 286     cp = gdb.current_progspace()
 287     if object_re.match("progspace"):
 288         total += do_enable_pretty_printer_1(cp.pretty_printers,
 289                                             name_re, subname_re, flag)
 290     for objfile in gdb.objfiles():
 291         if object_re.match(objfile.filename):
 292             total += do_enable_pretty_printer_1(objfile.pretty_printers,
 293                                                 name_re, subname_re, flag)
 294
 295     if flag:
 296         state = "enabled"
 297     else:
 298         state = "disabled"
 299     print ("%d %s %s" % (total, pluralize("printer", total), state))
 300
 301     # Print the total list of printers currently enabled/disabled.
 302     # This is to further assist the user in determining whether the result
 303     # is expected.  Since we use regexps to select it's useful.
 304     show_pretty_printer_enabled_summary()
 305
 306
 307 # Enable/Disable one or more pretty-printers.
 308 #
 309 # This is intended for use when a broken pretty-printer is shipped/installed
 310 # and the user wants to disable that printer without disabling all the other
 311 # printers.
 312 #
 313 # A useful addition would be -v (verbose) to show each printer affected.
 314
 315 class EnablePrettyPrinter (gdb.Command):
 316     """GDB command to enable the specified pretty-printer.
 317
 318 Usage: enable pretty-printer [OBJECT-REGEXP [NAME-REGEXP]]
 319
 320 OBJECT-REGEXP is a regular expression matching the objects to examine.
 321 Objects are "global", the program space's file, and the objfiles within
 322 that program space.
 323
 324 NAME-REGEXP matches the name of the pretty-printer.
 325 Individual printers in a collection are named as
 326 printer-name;subprinter-name."""
 327
 328     def __init__(self):
 329         super(EnablePrettyPrinter, self).__init__("enable pretty-printer",
 330                                                    gdb.COMMAND_DATA)
 331
 332     def invoke(self, arg, from_tty):
 333         """GDB calls this to perform the command."""
 334         do_enable_pretty_printer(arg, True)
 335
 336
 337 class DisablePrettyPrinter (gdb.Command):
 338     """GDB command to disable the specified pretty-printer.
 339
 340 Usage: disable pretty-printer [OBJECT-REGEXP [NAME-REGEXP]]
 341
 342 OBJECT-REGEXP is a regular expression matching the objects to examine.
 343 Objects are "global", the program space's file, and the objfiles within
 344 that program space.
 345
 346 NAME-REGEXP matches the name of the pretty-printer.
 347 Individual printers in a collection are named as
 348 printer-name;subprinter-name."""
 349
 350     def __init__(self):
 351         super(DisablePrettyPrinter, self).__init__("disable pretty-printer",
 352                                                    gdb.COMMAND_DATA)
 353
 354     def invoke(self, arg, from_tty):
 355         """GDB calls this to perform the command."""
 356         do_enable_pretty_printer(arg, False)
 357
 358
 359 def register_pretty_printer_commands():
 360     """Call from a top level script to install the pretty-printer commands."""
 361     InfoPrettyPrinter()
 362     EnablePrettyPrinter()
 363     DisablePrettyPrinter()
 364
 365 register_pretty_printer_commands()