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

   1 # Pretty-printer commands.
   2 # Copyright (C) 2010-2014 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
  98     def __init__ (self):
  99         super(InfoPrettyPrinter, self).__init__("info pretty-printer",
 100                                                  gdb.COMMAND_DATA)
 101
 102     @staticmethod
 103     def enabled_string(printer):
 104         """Return "" if PRINTER is enabled, otherwise " [disabled]"."""
 105         if printer_enabled_p(printer):
 106             return ""
 107         else:
 108             return " [disabled]"
 109
 110     @staticmethod
 111     def printer_name(printer):
 112         """Return the printer's name."""
 113         if hasattr(printer, "name"):
 114             return printer.name
 115         if hasattr(printer, "__name__"):
 116             return printer.__name__
 117         # This "shouldn't happen", but the public API allows for
 118         # direct additions to the pretty-printer list, and we shouldn't
 119         # crash because someone added a bogus printer.
 120         # Plus we want to give the user a way to list unknown printers.
 121         return "unknown"
 122
 123     def list_pretty_printers(self, pretty_printers, name_re, subname_re):
 124         """Print a list of pretty-printers."""
 125         # A potential enhancement is to provide an option to list printers in
 126         # "lookup order" (i.e. unsorted).
 127         sorted_pretty_printers = sorted (copy.copy(pretty_printers),
 128                                          key = self.printer_name)
 129         for printer in sorted_pretty_printers:
 130             name = self.printer_name(printer)
 131             enabled = self.enabled_string(printer)
 132             if name_re.match(name):
 133                 print ("  %s%s" % (name, enabled))
 134                 if (hasattr(printer, "subprinters") and
 135                     printer.subprinters is not None):
 136                     sorted_subprinters = sorted (copy.copy(printer.subprinters),
 137                                                  key = self.printer_name)
 138                     for subprinter in sorted_subprinters:
 139                         if (not subname_re or
 140                             subname_re.match(subprinter.name)):
 141                             print ("    %s%s" %
 142                                    (subprinter.name,
 143                                     self.enabled_string(subprinter)))
 144
 145     def invoke1(self, title, printer_list,
 146                 obj_name_to_match, object_re, name_re, subname_re):
 147         """Subroutine of invoke to simplify it."""
 148         if printer_list and object_re.match(obj_name_to_match):
 149             print (title)
 150             self.list_pretty_printers(printer_list, name_re, subname_re)
 151
 152     def invoke(self, arg, from_tty):
 153         """GDB calls this to perform the command."""
 154         (object_re, name_re, subname_re) = parse_printer_regexps(arg)
 155         self.invoke1("global pretty-printers:", gdb.pretty_printers,
 156                      "global", object_re, name_re, subname_re)
 157         cp = gdb.current_progspace()
 158         self.invoke1("progspace %s pretty-printers:" % cp.filename,
 159                      cp.pretty_printers, "progspace",
 160                      object_re, name_re, subname_re)
 161         for objfile in gdb.objfiles():
 162             self.invoke1("  objfile %s pretty-printers:" % objfile.filename,
 163                          objfile.pretty_printers, objfile.filename,
 164                          object_re, name_re, subname_re)
 165
 166
 167 def count_enabled_printers(pretty_printers):
 168     """Return a 2-tuple of number of enabled and total printers."""
 169     enabled = 0
 170     total = 0
 171     for printer in pretty_printers:
 172         if (hasattr(printer, "subprinters")
 173             and printer.subprinters is not None):
 174             if printer_enabled_p(printer):
 175                 for subprinter in printer.subprinters:
 176                     if printer_enabled_p(subprinter):
 177                         enabled += 1
 178             total += len(printer.subprinters)
 179         else:
 180             if printer_enabled_p(printer):
 181                 enabled += 1
 182             total += 1
 183     return (enabled, total)
 184
 185
 186 def count_all_enabled_printers():
 187     """Return a 2-tuble of the enabled state and total number of all printers.
 188     This includes subprinters.
 189     """
 190     enabled_count = 0
 191     total_count = 0
 192     (t_enabled, t_total) = count_enabled_printers(gdb.pretty_printers)
 193     enabled_count += t_enabled
 194     total_count += t_total
 195     (t_enabled, t_total) = count_enabled_printers(gdb.current_progspace().pretty_printers)
 196     enabled_count += t_enabled
 197     total_count += t_total
 198     for objfile in gdb.objfiles():
 199         (t_enabled, t_total) = count_enabled_printers(objfile.pretty_printers)
 200         enabled_count += t_enabled
 201         total_count += t_total
 202     return (enabled_count, total_count)
 203
 204
 205 def pluralize(text, n, suffix="s"):
 206     """Return TEXT pluralized if N != 1."""
 207     if n != 1:
 208         return "%s%s" % (text, suffix)
 209     else:
 210         return text
 211
 212
 213 def show_pretty_printer_enabled_summary():
 214     """Print the number of printers enabled/disabled.
 215     We count subprinters individually.
 216     """
 217     (enabled_count, total_count) = count_all_enabled_printers()
 218     print ("%d of %d printers enabled" % (enabled_count, total_count))
 219
 220
 221 def do_enable_pretty_printer_1 (pretty_printers, name_re, subname_re, flag):
 222     """Worker for enabling/disabling pretty-printers.
 223
 224     Arguments:
 225         pretty_printers: list of pretty-printers
 226         name_re: regular-expression object to select printers
 227         subname_re: regular expression object to select subprinters or None
 228                     if all are affected
 229         flag: True for Enable, False for Disable
 230
 231     Returns:
 232         The number of printers affected.
 233         This is just for informational purposes for the user.
 234     """
 235     total = 0
 236     for printer in pretty_printers:
 237         if (hasattr(printer, "name") and name_re.match(printer.name) or
 238             hasattr(printer, "__name__") and name_re.match(printer.__name__)):
 239             if (hasattr(printer, "subprinters") and
 240                 printer.subprinters is not None):
 241                 if not subname_re:
 242                     # Only record printers that change state.
 243                     if printer_enabled_p(printer) != flag:
 244                         for subprinter in printer.subprinters:
 245                             if printer_enabled_p(subprinter):
 246                                 total += 1
 247                     # NOTE: We preserve individual subprinter settings.
 248                     printer.enabled = flag
 249                 else:
 250                     # NOTE: Whether this actually disables the subprinter
 251                     # depends on whether the printer's lookup function supports
 252                     # the "enable" API.  We can only assume it does.
 253                     for subprinter in printer.subprinters:
 254                         if subname_re.match(subprinter.name):
 255                             # Only record printers that change state.
 256                            if (printer_enabled_p(printer) and
 257                                printer_enabled_p(subprinter) != flag):
 258                                total += 1
 259                            subprinter.enabled = flag
 260             else:
 261                 # This printer has no subprinters.
 262                 # If the user does "disable pretty-printer .* .* foo"
 263                 # should we disable printers that don't have subprinters?
 264                 # How do we apply "foo" in this context?  Since there is no
 265                 # "foo" subprinter it feels like we should skip this printer.
 266                 # There's still the issue of how to handle
 267                 # "disable pretty-printer .* .* .*", and every other variation
 268                 # that can match everything.  For now punt and only support
 269                 # "disable pretty-printer .* .*" (i.e. subname is elided)
 270                 # to disable everything.
 271                 if not subname_re:
 272                     # Only record printers that change state.
 273                     if printer_enabled_p(printer) != flag:
 274                         total += 1
 275                     printer.enabled = flag
 276     return total
 277
 278
 279 def do_enable_pretty_printer (arg, flag):
 280     """Internal worker for enabling/disabling pretty-printers."""
 281     (object_re, name_re, subname_re) = parse_printer_regexps(arg)
 282
 283     total = 0
 284     if object_re.match("global"):
 285         total += do_enable_pretty_printer_1(gdb.pretty_printers,
 286                                             name_re, subname_re, flag)
 287     cp = gdb.current_progspace()
 288     if object_re.match("progspace"):
 289         total += do_enable_pretty_printer_1(cp.pretty_printers,
 290                                             name_re, subname_re, flag)
 291     for objfile in gdb.objfiles():
 292         if object_re.match(objfile.filename):
 293             total += do_enable_pretty_printer_1(objfile.pretty_printers,
 294                                                 name_re, subname_re, flag)
 295
 296     if flag:
 297         state = "enabled"
 298     else:
 299         state = "disabled"
 300     print ("%d %s %s" % (total, pluralize("printer", total), state))
 301
 302     # Print the total list of printers currently enabled/disabled.
 303     # This is to further assist the user in determining whether the result
 304     # is expected.  Since we use regexps to select it's useful.
 305     show_pretty_printer_enabled_summary()
 306
 307
 308 # Enable/Disable one or more pretty-printers.
 309 #
 310 # This is intended for use when a broken pretty-printer is shipped/installed
 311 # and the user wants to disable that printer without disabling all the other
 312 # printers.
 313 #
 314 # A useful addition would be -v (verbose) to show each printer affected.
 315
 316 class EnablePrettyPrinter (gdb.Command):
 317     """GDB command to enable the specified pretty-printer.
 318
 319     Usage: enable pretty-printer [object-regexp [name-regexp]]
 320
 321     OBJECT-REGEXP is a regular expression matching the objects to examine.
 322     Objects are "global", the program space's file, and the objfiles within
 323     that program space.
 324
 325     NAME-REGEXP matches the name of the pretty-printer.
 326     Individual printers in a collection are named as
 327     printer-name;subprinter-name.
 328     """
 329
 330     def __init__(self):
 331         super(EnablePrettyPrinter, self).__init__("enable pretty-printer",
 332                                                    gdb.COMMAND_DATA)
 333
 334     def invoke(self, arg, from_tty):
 335         """GDB calls this to perform the command."""
 336         do_enable_pretty_printer(arg, True)
 337
 338
 339 class DisablePrettyPrinter (gdb.Command):
 340     """GDB command to disable the specified pretty-printer.
 341
 342     Usage: disable pretty-printer [object-regexp [name-regexp]]
 343
 344     OBJECT-REGEXP is a regular expression matching the objects to examine.
 345     Objects are "global", the program space's file, and the objfiles within
 346     that program space.
 347
 348     NAME-REGEXP matches the name of the pretty-printer.
 349     Individual printers in a collection are named as
 350     printer-name;subprinter-name.
 351     """
 352
 353     def __init__(self):
 354         super(DisablePrettyPrinter, self).__init__("disable pretty-printer",
 355                                                    gdb.COMMAND_DATA)
 356
 357     def invoke(self, arg, from_tty):
 358         """GDB calls this to perform the command."""
 359         do_enable_pretty_printer(arg, False)
 360
 361
 362 def register_pretty_printer_commands():
 363     """Call from a top level script to install the pretty-printer commands."""
 364     InfoPrettyPrinter()
 365     EnablePrettyPrinter()
 366     DisablePrettyPrinter()
 367
 368 register_pretty_printer_commands()