libstdc++-v3/python/libstdcxx/v6/printers.py

   1 # Pretty-printers for libstc++.
   2
   3 # Copyright (C) 2008-2014 Free Software Foundation, Inc.
   4
   5 # This program is free software; you can redistribute it and/or modify
   6 # it under the terms of the GNU General Public License as published by
   7 # the Free Software Foundation; either version 3 of the License, or
   8 # (at your option) any later version.
   9 #
  10 # This program is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 # GNU General Public License for more details.
  14 #
  15 # You should have received a copy of the GNU General Public License
  16 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 import gdb
  19 import itertools
  20 import re
  21
  22 # Try to use the new-style pretty-printing if available.
  23 _use_gdb_pp = True
  24 try:
  25     import gdb.printing
  26 except ImportError:
  27     _use_gdb_pp = False
  28
  29 # Try to install type-printers.
  30 _use_type_printing = False
  31 try:
  32     import gdb.types
  33     if hasattr(gdb.types, 'TypePrinter'):
  34         _use_type_printing = True
  35 except ImportError:
  36     pass
  37
  38 # Starting with the type ORIG, search for the member type NAME.  This
  39 # handles searching upward through superclasses.  This is needed to
  40 # work around http://sourceware.org/bugzilla/show_bug.cgi?id=13615.
  41 def find_type(orig, name):
  42     typ = orig.strip_typedefs()
  43     while True:
  44         search = str(typ) + '::' + name
  45         try:
  46             return gdb.lookup_type(search)
  47         except RuntimeError:
  48             pass
  49         # The type was not found, so try the superclass.  We only need
  50         # to check the first superclass, so we don't bother with
  51         # anything fancier here.
  52         field = typ.fields()[0]
  53         if not field.is_base_class:
  54             raise ValueError("Cannot find type %s::%s" % (str(orig), name))
  55         typ = field.type
  56
  57 class SharedPointerPrinter:
  58     "Print a shared_ptr or weak_ptr"
  59
  60     def __init__ (self, typename, val):
  61         self.typename = typename
  62         self.val = val
  63
  64     def to_string (self):
  65         state = 'empty'
  66         refcounts = self.val['_M_refcount']['_M_pi']
  67         if refcounts != 0:
  68             usecount = refcounts['_M_use_count']
  69             weakcount = refcounts['_M_weak_count']
  70             if usecount == 0:
  71                 state = 'expired, weak %d' % weakcount
  72             else:
  73                 state = 'count %d, weak %d' % (usecount, weakcount - 1)
  74         return '%s (%s) %s' % (self.typename, state, self.val['_M_ptr'])
  75
  76 class UniquePointerPrinter:
  77     "Print a unique_ptr"
  78
  79     def __init__ (self, typename, val):
  80         self.val = val
  81
  82     def to_string (self):
  83         v = self.val['_M_t']['_M_head_impl']
  84         return ('std::unique_ptr<%s> containing %s' % (str(v.type.target()),
  85                                                        str(v)))
  86
  87 class StdListPrinter:
  88     "Print a std::list"
  89
  90     class _iterator:
  91         def __init__(self, nodetype, head):
  92             self.nodetype = nodetype
  93             self.base = head['_M_next']
  94             self.head = head.address
  95             self.count = 0
  96
  97         def __iter__(self):
  98             return self
  99
 100         def next(self):
 101             if self.base == self.head:
 102                 raise StopIteration
 103             elt = self.base.cast(self.nodetype).dereference()
 104             self.base = elt['_M_next']
 105             count = self.count
 106             self.count = self.count + 1
 107             return ('[%d]' % count, elt['_M_data'])
 108
 109     def __init__(self, typename, val):
 110         self.typename = typename
 111         self.val = val
 112
 113     def children(self):
 114         nodetype = find_type(self.val.type, '_Node')
 115         nodetype = nodetype.strip_typedefs().pointer()
 116         return self._iterator(nodetype, self.val['_M_impl']['_M_node'])
 117
 118     def to_string(self):
 119         if self.val['_M_impl']['_M_node'].address == self.val['_M_impl']['_M_node']['_M_next']:
 120             return 'empty %s' % (self.typename)
 121         return '%s' % (self.typename)
 122
 123 class StdListIteratorPrinter:
 124     "Print std::list::iterator"
 125
 126     def __init__(self, typename, val):
 127         self.val = val
 128         self.typename = typename
 129
 130     def to_string(self):
 131         nodetype = find_type(self.val.type, '_Node')
 132         nodetype = nodetype.strip_typedefs().pointer()
 133         return self.val['_M_node'].cast(nodetype).dereference()['_M_data']
 134
 135 class StdSlistPrinter:
 136     "Print a __gnu_cxx::slist"
 137
 138     class _iterator:
 139         def __init__(self, nodetype, head):
 140             self.nodetype = nodetype
 141             self.base = head['_M_head']['_M_next']
 142             self.count = 0
 143
 144         def __iter__(self):
 145             return self
 146
 147         def next(self):
 148             if self.base == 0:
 149                 raise StopIteration
 150             elt = self.base.cast(self.nodetype).dereference()
 151             self.base = elt['_M_next']
 152             count = self.count
 153             self.count = self.count + 1
 154             return ('[%d]' % count, elt['_M_data'])
 155
 156     def __init__(self, typename, val):
 157         self.val = val
 158
 159     def children(self):
 160         nodetype = find_type(self.val.type, '_Node')
 161         nodetype = nodetype.strip_typedefs().pointer()
 162         return self._iterator(nodetype, self.val)
 163
 164     def to_string(self):
 165         if self.val['_M_head']['_M_next'] == 0:
 166             return 'empty __gnu_cxx::slist'
 167         return '__gnu_cxx::slist'
 168
 169 class StdSlistIteratorPrinter:
 170     "Print __gnu_cxx::slist::iterator"
 171
 172     def __init__(self, typename, val):
 173         self.val = val
 174
 175     def to_string(self):
 176         nodetype = find_type(self.val.type, '_Node')
 177         nodetype = nodetype.strip_typedefs().pointer()
 178         return self.val['_M_node'].cast(nodetype).dereference()['_M_data']
 179
 180 class StdVectorPrinter:
 181     "Print a std::vector"
 182
 183     class _iterator:
 184         def __init__ (self, start, finish, bitvec):
 185             self.bitvec = bitvec
 186             if bitvec:
 187                 self.item   = start['_M_p']
 188                 self.so     = start['_M_offset']
 189                 self.finish = finish['_M_p']
 190                 self.fo     = finish['_M_offset']
 191                 itype = self.item.dereference().type
 192                 self.isize = 8 * itype.sizeof
 193             else:
 194                 self.item = start
 195                 self.finish = finish
 196             self.count = 0
 197
 198         def __iter__(self):
 199             return self
 200
 201         def next(self):
 202             count = self.count
 203             self.count = self.count + 1
 204             if self.bitvec:
 205                 if self.item == self.finish and self.so >= self.fo:
 206                     raise StopIteration
 207                 elt = self.item.dereference()
 208                 if elt & (1 << self.so):
 209                     obit = 1
 210                 else:
 211                     obit = 0
 212                 self.so = self.so + 1
 213                 if self.so >= self.isize:
 214                     self.item = self.item + 1
 215                     self.so = 0
 216                 return ('[%d]' % count, obit)
 217             else:
 218                 if self.item == self.finish:
 219                     raise StopIteration
 220                 elt = self.item.dereference()
 221                 self.item = self.item + 1
 222                 return ('[%d]' % count, elt)
 223
 224     def __init__(self, typename, val):
 225         self.typename = typename
 226         self.val = val
 227         self.is_bool = val.type.template_argument(0).code  == gdb.TYPE_CODE_BOOL
 228
 229     def children(self):
 230         return self._iterator(self.val['_M_impl']['_M_start'],
 231                               self.val['_M_impl']['_M_finish'],
 232                               self.is_bool)
 233
 234     def to_string(self):
 235         start = self.val['_M_impl']['_M_start']
 236         finish = self.val['_M_impl']['_M_finish']
 237         end = self.val['_M_impl']['_M_end_of_storage']
 238         if self.is_bool:
 239             start = self.val['_M_impl']['_M_start']['_M_p']
 240             so    = self.val['_M_impl']['_M_start']['_M_offset']
 241             finish = self.val['_M_impl']['_M_finish']['_M_p']
 242             fo     = self.val['_M_impl']['_M_finish']['_M_offset']
 243             itype = start.dereference().type
 244             bl = 8 * itype.sizeof
 245             length   = (bl - so) + bl * ((finish - start) - 1) + fo
 246             capacity = bl * (end - start)
 247             return ('%s<bool> of length %d, capacity %d'
 248                     % (self.typename, int (length), int (capacity)))
 249         else:
 250             return ('%s of length %d, capacity %d'
 251                     % (self.typename, int (finish - start), int (end - start)))
 252
 253     def display_hint(self):
 254         return 'array'
 255
 256 class StdVectorIteratorPrinter:
 257     "Print std::vector::iterator"
 258
 259     def __init__(self, typename, val):
 260         self.val = val
 261
 262     def to_string(self):
 263         return self.val['_M_current'].dereference()
 264
 265 class StdTuplePrinter:
 266     "Print a std::tuple"
 267
 268     class _iterator:
 269         def __init__ (self, head):
 270             self.head = head
 271
 272             # Set the base class as the initial head of the
 273             # tuple.
 274             nodes = self.head.type.fields ()
 275             if len (nodes) == 1:
 276                 # Set the actual head to the first pair.
 277                 self.head  = self.head.cast (nodes[0].type)
 278             elif len (nodes) != 0:
 279                 raise ValueError("Top of tuple tree does not consist of a single node.")
 280             self.count = 0
 281
 282         def __iter__ (self):
 283             return self
 284
 285         def next (self):
 286             nodes = self.head.type.fields ()
 287             # Check for further recursions in the inheritance tree.
 288             if len (nodes) == 0:
 289                 raise StopIteration
 290             # Check that this iteration has an expected structure.
 291             if len (nodes) != 2:
 292                 raise ValueError("Cannot parse more than 2 nodes in a tuple tree.")
 293
 294             # - Left node is the next recursion parent.
 295             # - Right node is the actual class contained in the tuple.
 296
 297             # Process right node.
 298             impl = self.head.cast (nodes[1].type)
 299
 300             # Process left node and set it as head.
 301             self.head  = self.head.cast (nodes[0].type)
 302             self.count = self.count + 1
 303
 304             # Finally, check the implementation.  If it is
 305             # wrapped in _M_head_impl return that, otherwise return
 306             # the value "as is".
 307             fields = impl.type.fields ()
 308             if len (fields) < 1 or fields[0].name != "_M_head_impl":
 309                 return ('[%d]' % self.count, impl)
 310             else:
 311                 return ('[%d]' % self.count, impl['_M_head_impl'])
 312
 313     def __init__ (self, typename, val):
 314         self.typename = typename
 315         self.val = val;
 316
 317     def children (self):
 318         return self._iterator (self.val)
 319
 320     def to_string (self):
 321         if len (self.val.type.fields ()) == 0:
 322             return 'empty %s' % (self.typename)
 323         return '%s containing' % (self.typename)
 324
 325 class StdStackOrQueuePrinter:
 326     "Print a std::stack or std::queue"
 327
 328     def __init__ (self, typename, val):
 329         self.typename = typename
 330         self.visualizer = gdb.default_visualizer(val['c'])
 331
 332     def children (self):
 333         return self.visualizer.children()
 334
 335     def to_string (self):
 336         return '%s wrapping: %s' % (self.typename,
 337                                     self.visualizer.to_string())
 338
 339     def display_hint (self):
 340         if hasattr (self.visualizer, 'display_hint'):
 341             return self.visualizer.display_hint ()
 342         return None
 343
 344 class RbtreeIterator:
 345     def __init__(self, rbtree):
 346         self.size = rbtree['_M_t']['_M_impl']['_M_node_count']
 347         self.node = rbtree['_M_t']['_M_impl']['_M_header']['_M_left']
 348         self.count = 0
 349
 350     def __iter__(self):
 351         return self
 352
 353     def __len__(self):
 354         return int (self.size)
 355
 356     def next(self):
 357         if self.count == self.size:
 358             raise StopIteration
 359         result = self.node
 360         self.count = self.count + 1
 361         if self.count < self.size:
 362             # Compute the next node.
 363             node = self.node
 364             if node.dereference()['_M_right']:
 365                 node = node.dereference()['_M_right']
 366                 while node.dereference()['_M_left']:
 367                     node = node.dereference()['_M_left']
 368             else:
 369                 parent = node.dereference()['_M_parent']
 370                 while node == parent.dereference()['_M_right']:
 371                     node = parent
 372                     parent = parent.dereference()['_M_parent']
 373                 if node.dereference()['_M_right'] != parent:
 374                     node = parent
 375             self.node = node
 376         return result
 377
 378 def get_value_from_Rb_tree_node(node):
 379     """Returns the value held in an _Rb_tree_node<_Val>"""
 380     try:
 381         member = node.type.fields()[1].name
 382         if member == '_M_value_field':
 383             # C++03 implementation, node contains the value as a member
 384             return node['_M_value_field']
 385         elif member == '_M_storage':
 386             # C++11 implementation, node stores value in __aligned_buffer
 387             p = node['_M_storage']['_M_storage'].address
 388             p = p.cast(node.type.template_argument(0).pointer())
 389             return p.dereference()
 390     except:
 391         pass
 392     raise ValueError("Unsupported implementation for %s" % str(node.type))
 393
 394 # This is a pretty printer for std::_Rb_tree_iterator (which is
 395 # std::map::iterator), and has nothing to do with the RbtreeIterator
 396 # class above.
 397 class StdRbtreeIteratorPrinter:
 398     "Print std::map::iterator"
 399
 400     def __init__ (self, typename, val):
 401         self.val = val
 402
 403     def to_string (self):
 404         typename = str(self.val.type.strip_typedefs()) + '::_Link_type'
 405         nodetype = gdb.lookup_type(typename).strip_typedefs()
 406         node = self.val.cast(nodetype).dereference()
 407         return get_value_from_Rb_tree_node(node)
 408
 409 class StdDebugIteratorPrinter:
 410     "Print a debug enabled version of an iterator"
 411
 412     def __init__ (self, typename, val):
 413         self.val = val
 414
 415     # Just strip away the encapsulating __gnu_debug::_Safe_iterator
 416     # and return the wrapped iterator value.
 417     def to_string (self):
 418         itype = self.val.type.template_argument(0)
 419         return self.val['_M_current'].cast(itype)
 420
 421 class StdMapPrinter:
 422     "Print a std::map or std::multimap"
 423
 424     # Turn an RbtreeIterator into a pretty-print iterator.
 425     class _iter:
 426         def __init__(self, rbiter, type):
 427             self.rbiter = rbiter
 428             self.count = 0
 429             self.type = type
 430
 431         def __iter__(self):
 432             return self
 433
 434         def next(self):
 435             if self.count % 2 == 0:
 436                 n = self.rbiter.next()
 437                 n = n.cast(self.type).dereference()
 438                 n = get_value_from_Rb_tree_node(n)
 439                 self.pair = n
 440                 item = n['first']
 441             else:
 442                 item = self.pair['second']
 443             result = ('[%d]' % self.count, item)
 444             self.count = self.count + 1
 445             return result
 446
 447     def __init__ (self, typename, val):
 448         self.typename = typename
 449         self.val = val
 450
 451     def to_string (self):
 452         return '%s with %d elements' % (self.typename,
 453                                         len (RbtreeIterator (self.val)))
 454
 455     def children (self):
 456         rep_type = find_type(self.val.type, '_Rep_type')
 457         node = find_type(rep_type, '_Link_type')
 458         node = node.strip_typedefs()
 459         return self._iter (RbtreeIterator (self.val), node)
 460
 461     def display_hint (self):
 462         return 'map'
 463
 464 class StdSetPrinter:
 465     "Print a std::set or std::multiset"
 466
 467     # Turn an RbtreeIterator into a pretty-print iterator.
 468     class _iter:
 469         def __init__(self, rbiter, type):
 470             self.rbiter = rbiter
 471             self.count = 0
 472             self.type = type
 473
 474         def __iter__(self):
 475             return self
 476
 477         def next(self):
 478             item = self.rbiter.next()
 479             item = item.cast(self.type).dereference()
 480             item = get_value_from_Rb_tree_node(item)
 481             # FIXME: this is weird ... what to do?
 482             # Maybe a 'set' display hint?
 483             result = ('[%d]' % self.count, item)
 484             self.count = self.count + 1
 485             return result
 486
 487     def __init__ (self, typename, val):
 488         self.typename = typename
 489         self.val = val
 490
 491     def to_string (self):
 492         return '%s with %d elements' % (self.typename,
 493                                         len (RbtreeIterator (self.val)))
 494
 495     def children (self):
 496         rep_type = find_type(self.val.type, '_Rep_type')
 497         node = find_type(rep_type, '_Link_type')
 498         node = node.strip_typedefs()
 499         return self._iter (RbtreeIterator (self.val), node)
 500
 501 class StdBitsetPrinter:
 502     "Print a std::bitset"
 503
 504     def __init__(self, typename, val):
 505         self.typename = typename
 506         self.val = val
 507
 508     def to_string (self):
 509         # If template_argument handled values, we could print the
 510         # size.  Or we could use a regexp on the type.
 511         return '%s' % (self.typename)
 512
 513     def children (self):
 514         words = self.val['_M_w']
 515         wtype = words.type
 516
 517         # The _M_w member can be either an unsigned long, or an
 518         # array.  This depends on the template specialization used.
 519         # If it is a single long, convert to a single element list.
 520         if wtype.code == gdb.TYPE_CODE_ARRAY:
 521             tsize = wtype.target ().sizeof
 522         else:
 523             words = [words]
 524             tsize = wtype.sizeof
 525
 526         nwords = wtype.sizeof / tsize
 527         result = []
 528         byte = 0
 529         while byte < nwords:
 530             w = words[byte]
 531             bit = 0
 532             while w != 0:
 533                 if (w & 1) != 0:
 534                     # Another spot where we could use 'set'?
 535                     result.append(('[%d]' % (byte * tsize * 8 + bit), 1))
 536                 bit = bit + 1
 537                 w = w >> 1
 538             byte = byte + 1
 539         return result
 540
 541 class StdDequePrinter:
 542     "Print a std::deque"
 543
 544     class _iter:
 545         def __init__(self, node, start, end, last, buffer_size):
 546             self.node = node
 547             self.p = start
 548             self.end = end
 549             self.last = last
 550             self.buffer_size = buffer_size
 551             self.count = 0
 552
 553         def __iter__(self):
 554             return self
 555
 556         def next(self):
 557             if self.p == self.last:
 558                 raise StopIteration
 559
 560             result = ('[%d]' % self.count, self.p.dereference())
 561             self.count = self.count + 1
 562
 563             # Advance the 'cur' pointer.
 564             self.p = self.p + 1
 565             if self.p == self.end:
 566                 # If we got to the end of this bucket, move to the
 567                 # next bucket.
 568                 self.node = self.node + 1
 569                 self.p = self.node[0]
 570                 self.end = self.p + self.buffer_size
 571
 572             return result
 573
 574     def __init__(self, typename, val):
 575         self.typename = typename
 576         self.val = val
 577         self.elttype = val.type.template_argument(0)
 578         size = self.elttype.sizeof
 579         if size < 512:
 580             self.buffer_size = int (512 / size)
 581         else:
 582             self.buffer_size = 1
 583
 584     def to_string(self):
 585         start = self.val['_M_impl']['_M_start']
 586         end = self.val['_M_impl']['_M_finish']
 587
 588         delta_n = end['_M_node'] - start['_M_node'] - 1
 589         delta_s = start['_M_last'] - start['_M_cur']
 590         delta_e = end['_M_cur'] - end['_M_first']
 591
 592         size = self.buffer_size * delta_n + delta_s + delta_e
 593
 594         return '%s with %d elements' % (self.typename, long (size))
 595
 596     def children(self):
 597         start = self.val['_M_impl']['_M_start']
 598         end = self.val['_M_impl']['_M_finish']
 599         return self._iter(start['_M_node'], start['_M_cur'], start['_M_last'],
 600                           end['_M_cur'], self.buffer_size)
 601
 602     def display_hint (self):
 603         return 'array'
 604
 605 class StdDequeIteratorPrinter:
 606     "Print std::deque::iterator"
 607
 608     def __init__(self, typename, val):
 609         self.val = val
 610
 611     def to_string(self):
 612         return self.val['_M_cur'].dereference()
 613
 614 class StdStringPrinter:
 615     "Print a std::basic_string of some kind"
 616
 617     def __init__(self, typename, val):
 618         self.val = val
 619
 620     def to_string(self):
 621         # Make sure &string works, too.
 622         type = self.val.type
 623         if type.code == gdb.TYPE_CODE_REF:
 624             type = type.target ()
 625
 626         # Calculate the length of the string so that to_string returns
 627         # the string according to length, not according to first null
 628         # encountered.
 629         ptr = self.val ['_M_dataplus']['_M_p']
 630         realtype = type.unqualified ().strip_typedefs ()
 631         reptype = gdb.lookup_type (str (realtype) + '::_Rep').pointer ()
 632         header = ptr.cast(reptype) - 1
 633         len = header.dereference ()['_M_length']
 634         if hasattr(ptr, "lazy_string"):
 635             return ptr.lazy_string (length = len)
 636         return ptr.string (length = len)
 637
 638     def display_hint (self):
 639         return 'string'
 640
 641 class Tr1HashtableIterator:
 642     def __init__ (self, hash):
 643         self.buckets = hash['_M_buckets']
 644         self.bucket = 0
 645         self.bucket_count = hash['_M_bucket_count']
 646         self.node_type = find_type(hash.type, '_Node').pointer()
 647         self.node = 0
 648         while self.bucket != self.bucket_count:
 649             self.node = self.buckets[self.bucket]
 650             if self.node:
 651                 break
 652             self.bucket = self.bucket + 1
 653
 654     def __iter__ (self):
 655         return self
 656
 657     def next (self):
 658         if self.node == 0:
 659             raise StopIteration
 660         node = self.node.cast(self.node_type)
 661         result = node.dereference()['_M_v']
 662         self.node = node.dereference()['_M_next'];
 663         if self.node == 0:
 664             self.bucket = self.bucket + 1
 665             while self.bucket != self.bucket_count:
 666                 self.node = self.buckets[self.bucket]
 667                 if self.node:
 668                     break
 669                 self.bucket = self.bucket + 1
 670         return result
 671
 672 class StdHashtableIterator:
 673     def __init__(self, hash):
 674         self.node = hash['_M_before_begin']['_M_nxt']
 675         self.node_type = find_type(hash.type, '__node_type').pointer()
 676
 677     def __iter__(self):
 678         return self
 679
 680     def next(self):
 681         if self.node == 0:
 682             raise StopIteration
 683         elt = self.node.cast(self.node_type).dereference()
 684         self.node = elt['_M_nxt']
 685         valptr = elt['_M_storage'].address
 686         valptr = valptr.cast(elt.type.template_argument(0).pointer())
 687         return valptr.dereference()
 688
 689 class Tr1UnorderedSetPrinter:
 690     "Print a tr1::unordered_set"
 691
 692     def __init__ (self, typename, val):
 693         self.typename = typename
 694         self.val = val
 695
 696     def hashtable (self):
 697         if self.typename.startswith('std::tr1'):
 698             return self.val
 699         return self.val['_M_h']
 700
 701     def to_string (self):
 702         return '%s with %d elements' % (self.typename, self.hashtable()['_M_element_count'])
 703
 704     @staticmethod
 705     def format_count (i):
 706         return '[%d]' % i
 707
 708     def children (self):
 709         counter = itertools.imap (self.format_count, itertools.count())
 710         if self.typename.startswith('std::tr1'):
 711             return itertools.izip (counter, Tr1HashtableIterator (self.hashtable()))
 712         return itertools.izip (counter, StdHashtableIterator (self.hashtable()))
 713
 714 class Tr1UnorderedMapPrinter:
 715     "Print a tr1::unordered_map"
 716
 717     def __init__ (self, typename, val):
 718         self.typename = typename
 719         self.val = val
 720
 721     def hashtable (self):
 722         if self.typename.startswith('std::tr1'):
 723             return self.val
 724         return self.val['_M_h']
 725
 726     def to_string (self):
 727         return '%s with %d elements' % (self.typename, self.hashtable()['_M_element_count'])
 728
 729     @staticmethod
 730     def flatten (list):
 731         for elt in list:
 732             for i in elt:
 733                 yield i
 734
 735     @staticmethod
 736     def format_one (elt):
 737         return (elt['first'], elt['second'])
 738
 739     @staticmethod
 740     def format_count (i):
 741         return '[%d]' % i
 742
 743     def children (self):
 744         counter = itertools.imap (self.format_count, itertools.count())
 745         # Map over the hash table and flatten the result.
 746         if self.typename.startswith('std::tr1'):
 747             data = self.flatten (itertools.imap (self.format_one, Tr1HashtableIterator (self.hashtable())))
 748             # Zip the two iterators together.
 749             return itertools.izip (counter, data)
 750         data = self.flatten (itertools.imap (self.format_one, StdHashtableIterator (self.hashtable())))
 751         # Zip the two iterators together.
 752         return itertools.izip (counter, data)
 753
 754
 755     def display_hint (self):
 756         return 'map'
 757
 758 class StdForwardListPrinter:
 759     "Print a std::forward_list"
 760
 761     class _iterator:
 762         def __init__(self, nodetype, head):
 763             self.nodetype = nodetype
 764             self.base = head['_M_next']
 765             self.count = 0
 766
 767         def __iter__(self):
 768             return self
 769
 770         def next(self):
 771             if self.base == 0:
 772                 raise StopIteration
 773             elt = self.base.cast(self.nodetype).dereference()
 774             self.base = elt['_M_next']
 775             count = self.count
 776             self.count = self.count + 1
 777             valptr = elt['_M_storage'].address
 778             valptr = valptr.cast(elt.type.template_argument(0).pointer())
 779             return ('[%d]' % count, valptr.dereference())
 780
 781     def __init__(self, typename, val):
 782         self.val = val
 783         self.typename = typename
 784
 785     def children(self):
 786         nodetype = find_type(self.val.type, '_Node')
 787         nodetype = nodetype.strip_typedefs().pointer()
 788         return self._iterator(nodetype, self.val['_M_impl']['_M_head'])
 789
 790     def to_string(self):
 791         if self.val['_M_impl']['_M_head']['_M_next'] == 0:
 792             return 'empty %s' % (self.typename)
 793         return '%s' % (self.typename)
 794
 795
 796 # A "regular expression" printer which conforms to the
 797 # "SubPrettyPrinter" protocol from gdb.printing.
 798 class RxPrinter(object):
 799     def __init__(self, name, function):
 800         super(RxPrinter, self).__init__()
 801         self.name = name
 802         self.function = function
 803         self.enabled = True
 804
 805     def invoke(self, value):
 806         if not self.enabled:
 807             return None
 808
 809         if value.type.code == gdb.TYPE_CODE_REF:
 810             if hasattr(gdb.Value,"referenced_value"):
 811                 value = value.referenced_value()
 812
 813         return self.function(self.name, value)
 814
 815 # A pretty-printer that conforms to the "PrettyPrinter" protocol from
 816 # gdb.printing.  It can also be used directly as an old-style printer.
 817 class Printer(object):
 818     def __init__(self, name):
 819         super(Printer, self).__init__()
 820         self.name = name
 821         self.subprinters = []
 822         self.lookup = {}
 823         self.enabled = True
 824         self.compiled_rx = re.compile('^([a-zA-Z0-9_:]+)<.*>$')
 825
 826     def add(self, name, function):
 827         # A small sanity check.
 828         # FIXME
 829         if not self.compiled_rx.match(name + '<>'):
 830             raise ValueError('libstdc++ programming error: "%s" does not match' % name)
 831         printer = RxPrinter(name, function)
 832         self.subprinters.append(printer)
 833         self.lookup[name] = printer
 834
 835     # Add a name using _GLIBCXX_BEGIN_NAMESPACE_VERSION.
 836     def add_version(self, base, name, function):
 837         self.add(base + name, function)
 838         self.add(base + '__7::' + name, function)
 839
 840     # Add a name using _GLIBCXX_BEGIN_NAMESPACE_CONTAINER.
 841     def add_container(self, base, name, function):
 842         self.add_version(base, name, function)
 843         self.add_version(base + '__cxx1998::', name, function)
 844
 845     @staticmethod
 846     def get_basic_type(type):
 847         # If it points to a reference, get the reference.
 848         if type.code == gdb.TYPE_CODE_REF:
 849             type = type.target ()
 850
 851         # Get the unqualified type, stripped of typedefs.
 852         type = type.unqualified ().strip_typedefs ()
 853
 854         return type.tag
 855
 856     def __call__(self, val):
 857         typename = self.get_basic_type(val.type)
 858         if not typename:
 859             return None
 860
 861         # All the types we match are template types, so we can use a
 862         # dictionary.
 863         match = self.compiled_rx.match(typename)
 864         if not match:
 865             return None
 866
 867         basename = match.group(1)
 868
 869         if val.type.code == gdb.TYPE_CODE_REF:
 870             if hasattr(gdb.Value,"referenced_value"):
 871                 val = val.referenced_value()
 872
 873         if basename in self.lookup:
 874             return self.lookup[basename].invoke(val)
 875
 876         # Cannot find a pretty printer.  Return None.
 877         return None
 878
 879 libstdcxx_printer = None
 880
 881 class FilteringTypePrinter(object):
 882     def __init__(self, match, name):
 883         self.match = match
 884         self.name = name
 885         self.enabled = True
 886
 887     class _recognizer(object):
 888         def __init__(self, match, name):
 889             self.match = match
 890             self.name = name
 891             self.type_obj = None
 892
 893         def recognize(self, type_obj):
 894             if type_obj.tag is None:
 895                 return None
 896
 897             if self.type_obj is None:
 898                 if not self.match in type_obj.tag:
 899                     # Filter didn't match.
 900                     return None
 901                 try:
 902                     self.type_obj = gdb.lookup_type(self.name).strip_typedefs()
 903                 except:
 904                     pass
 905             if self.type_obj == type_obj:
 906                 return self.name
 907             return None
 908
 909     def instantiate(self):
 910         return self._recognizer(self.match, self.name)
 911
 912 def add_one_type_printer(obj, match, name):
 913     printer = FilteringTypePrinter(match, 'std::' + name)
 914     gdb.types.register_type_printer(obj, printer)
 915
 916 def register_type_printers(obj):
 917     global _use_type_printing
 918
 919     if not _use_type_printing:
 920         return
 921
 922     for pfx in ('', 'w'):
 923         add_one_type_printer(obj, 'basic_string', pfx + 'string')
 924         add_one_type_printer(obj, 'basic_ios', pfx + 'ios')
 925         add_one_type_printer(obj, 'basic_streambuf', pfx + 'streambuf')
 926         add_one_type_printer(obj, 'basic_istream', pfx + 'istream')
 927         add_one_type_printer(obj, 'basic_ostream', pfx + 'ostream')
 928         add_one_type_printer(obj, 'basic_iostream', pfx + 'iostream')
 929         add_one_type_printer(obj, 'basic_stringbuf', pfx + 'stringbuf')
 930         add_one_type_printer(obj, 'basic_istringstream',
 931                                  pfx + 'istringstream')
 932         add_one_type_printer(obj, 'basic_ostringstream',
 933                                  pfx + 'ostringstream')
 934         add_one_type_printer(obj, 'basic_stringstream',
 935                                  pfx + 'stringstream')
 936         add_one_type_printer(obj, 'basic_filebuf', pfx + 'filebuf')
 937         add_one_type_printer(obj, 'basic_ifstream', pfx + 'ifstream')
 938         add_one_type_printer(obj, 'basic_ofstream', pfx + 'ofstream')
 939         add_one_type_printer(obj, 'basic_fstream', pfx + 'fstream')
 940         add_one_type_printer(obj, 'basic_regex', pfx + 'regex')
 941         add_one_type_printer(obj, 'sub_match', pfx + 'csub_match')
 942         add_one_type_printer(obj, 'sub_match', pfx + 'ssub_match')
 943         add_one_type_printer(obj, 'match_results', pfx + 'cmatch')
 944         add_one_type_printer(obj, 'match_results', pfx + 'smatch')
 945         add_one_type_printer(obj, 'regex_iterator', pfx + 'cregex_iterator')
 946         add_one_type_printer(obj, 'regex_iterator', pfx + 'sregex_iterator')
 947         add_one_type_printer(obj, 'regex_token_iterator',
 948                                  pfx + 'cregex_token_iterator')
 949         add_one_type_printer(obj, 'regex_token_iterator',
 950                                  pfx + 'sregex_token_iterator')
 951
 952     # Note that we can't have a printer for std::wstreampos, because
 953     # it shares the same underlying type as std::streampos.
 954     add_one_type_printer(obj, 'fpos', 'streampos')
 955     add_one_type_printer(obj, 'basic_string', 'u16string')
 956     add_one_type_printer(obj, 'basic_string', 'u32string')
 957
 958     for dur in ('nanoseconds', 'microseconds', 'milliseconds',
 959                 'seconds', 'minutes', 'hours'):
 960         add_one_type_printer(obj, 'duration', dur)
 961
 962     add_one_type_printer(obj, 'linear_congruential_engine', 'minstd_rand0')
 963     add_one_type_printer(obj, 'linear_congruential_engine', 'minstd_rand')
 964     add_one_type_printer(obj, 'mersenne_twister_engine', 'mt19937')
 965     add_one_type_printer(obj, 'mersenne_twister_engine', 'mt19937_64')
 966     add_one_type_printer(obj, 'subtract_with_carry_engine', 'ranlux24_base')
 967     add_one_type_printer(obj, 'subtract_with_carry_engine', 'ranlux48_base')
 968     add_one_type_printer(obj, 'discard_block_engine', 'ranlux24')
 969     add_one_type_printer(obj, 'discard_block_engine', 'ranlux48')
 970     add_one_type_printer(obj, 'shuffle_order_engine', 'knuth_b')
 971
 972 def register_libstdcxx_printers (obj):
 973     "Register libstdc++ pretty-printers with objfile Obj."
 974
 975     global _use_gdb_pp
 976     global libstdcxx_printer
 977
 978     if _use_gdb_pp:
 979         gdb.printing.register_pretty_printer(obj, libstdcxx_printer)
 980     else:
 981         if obj is None:
 982             obj = gdb
 983         obj.pretty_printers.append(libstdcxx_printer)
 984
 985     register_type_printers(obj)
 986
 987 def build_libstdcxx_dictionary ():
 988     global libstdcxx_printer
 989
 990     libstdcxx_printer = Printer("libstdc++-v6")
 991
 992     # For _GLIBCXX_BEGIN_NAMESPACE_VERSION.
 993     vers = '(__7::)?'
 994     # For _GLIBCXX_BEGIN_NAMESPACE_CONTAINER.
 995     container = '(__cxx1998::' + vers + ')?'
 996
 997     # libstdc++ objects requiring pretty-printing.
 998     # In order from:
 999     # http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/a01847.html
1000     libstdcxx_printer.add_version('std::', 'basic_string', StdStringPrinter)
1001     libstdcxx_printer.add_container('std::', 'bitset', StdBitsetPrinter)
1002     libstdcxx_printer.add_container('std::', 'deque', StdDequePrinter)
1003     libstdcxx_printer.add_container('std::', 'list', StdListPrinter)
1004     libstdcxx_printer.add_container('std::', 'map', StdMapPrinter)
1005     libstdcxx_printer.add_container('std::', 'multimap', StdMapPrinter)
1006     libstdcxx_printer.add_container('std::', 'multiset', StdSetPrinter)
1007     libstdcxx_printer.add_version('std::', 'priority_queue',
1008                                   StdStackOrQueuePrinter)
1009     libstdcxx_printer.add_version('std::', 'queue', StdStackOrQueuePrinter)
1010     libstdcxx_printer.add_version('std::', 'tuple', StdTuplePrinter)
1011     libstdcxx_printer.add_container('std::', 'set', StdSetPrinter)
1012     libstdcxx_printer.add_version('std::', 'stack', StdStackOrQueuePrinter)
1013     libstdcxx_printer.add_version('std::', 'unique_ptr', UniquePointerPrinter)
1014     libstdcxx_printer.add_container('std::', 'vector', StdVectorPrinter)
1015     # vector<bool>
1016
1017     # Printer registrations for classes compiled with -D_GLIBCXX_DEBUG.
1018     libstdcxx_printer.add('std::__debug::bitset', StdBitsetPrinter)
1019     libstdcxx_printer.add('std::__debug::deque', StdDequePrinter)
1020     libstdcxx_printer.add('std::__debug::list', StdListPrinter)
1021     libstdcxx_printer.add('std::__debug::map', StdMapPrinter)
1022     libstdcxx_printer.add('std::__debug::multimap', StdMapPrinter)
1023     libstdcxx_printer.add('std::__debug::multiset', StdSetPrinter)
1024     libstdcxx_printer.add('std::__debug::priority_queue',
1025                           StdStackOrQueuePrinter)
1026     libstdcxx_printer.add('std::__debug::queue', StdStackOrQueuePrinter)
1027     libstdcxx_printer.add('std::__debug::set', StdSetPrinter)
1028     libstdcxx_printer.add('std::__debug::stack', StdStackOrQueuePrinter)
1029     libstdcxx_printer.add('std::__debug::unique_ptr', UniquePointerPrinter)
1030     libstdcxx_printer.add('std::__debug::vector', StdVectorPrinter)
1031
1032     # These are the TR1 and C++0x printers.
1033     # For array - the default GDB pretty-printer seems reasonable.
1034     libstdcxx_printer.add_version('std::', 'shared_ptr', SharedPointerPrinter)
1035     libstdcxx_printer.add_version('std::', 'weak_ptr', SharedPointerPrinter)
1036     libstdcxx_printer.add_container('std::', 'unordered_map',
1037                                     Tr1UnorderedMapPrinter)
1038     libstdcxx_printer.add_container('std::', 'unordered_set',
1039                                     Tr1UnorderedSetPrinter)
1040     libstdcxx_printer.add_container('std::', 'unordered_multimap',
1041                                     Tr1UnorderedMapPrinter)
1042     libstdcxx_printer.add_container('std::', 'unordered_multiset',
1043                                     Tr1UnorderedSetPrinter)
1044     libstdcxx_printer.add_container('std::', 'forward_list',
1045                                     StdForwardListPrinter)
1046
1047     libstdcxx_printer.add_version('std::tr1::', 'shared_ptr', SharedPointerPrinter)
1048     libstdcxx_printer.add_version('std::tr1::', 'weak_ptr', SharedPointerPrinter)
1049     libstdcxx_printer.add_version('std::tr1::', 'unordered_map',
1050                                   Tr1UnorderedMapPrinter)
1051     libstdcxx_printer.add_version('std::tr1::', 'unordered_set',
1052                                   Tr1UnorderedSetPrinter)
1053     libstdcxx_printer.add_version('std::tr1::', 'unordered_multimap',
1054                                   Tr1UnorderedMapPrinter)
1055     libstdcxx_printer.add_version('std::tr1::', 'unordered_multiset',
1056                                   Tr1UnorderedSetPrinter)
1057
1058     # These are the C++0x printer registrations for -D_GLIBCXX_DEBUG cases.
1059     # The tr1 namespace printers do not seem to have any debug
1060     # equivalents, so do no register them.
1061     libstdcxx_printer.add('std::__debug::unordered_map',
1062                           Tr1UnorderedMapPrinter)
1063     libstdcxx_printer.add('std::__debug::unordered_set',
1064                           Tr1UnorderedSetPrinter)
1065     libstdcxx_printer.add('std::__debug::unordered_multimap',
1066                           Tr1UnorderedMapPrinter)
1067     libstdcxx_printer.add('std::__debug::unordered_multiset',
1068                           Tr1UnorderedSetPrinter)
1069     libstdcxx_printer.add('std::__debug::forward_list',
1070                           StdForwardListPrinter)
1071
1072
1073     # Extensions.
1074     libstdcxx_printer.add_version('__gnu_cxx::', 'slist', StdSlistPrinter)
1075
1076     if True:
1077         # These shouldn't be necessary, if GDB "print *i" worked.
1078         # But it often doesn't, so here they are.
1079         libstdcxx_printer.add_container('std::', '_List_iterator',
1080                                         StdListIteratorPrinter)
1081         libstdcxx_printer.add_container('std::', '_List_const_iterator',
1082                                         StdListIteratorPrinter)
1083         libstdcxx_printer.add_version('std::', '_Rb_tree_iterator',
1084                                       StdRbtreeIteratorPrinter)
1085         libstdcxx_printer.add_version('std::', '_Rb_tree_const_iterator',
1086                                       StdRbtreeIteratorPrinter)
1087         libstdcxx_printer.add_container('std::', '_Deque_iterator',
1088                                         StdDequeIteratorPrinter)
1089         libstdcxx_printer.add_container('std::', '_Deque_const_iterator',
1090                                         StdDequeIteratorPrinter)
1091         libstdcxx_printer.add_version('__gnu_cxx::', '__normal_iterator',
1092                                       StdVectorIteratorPrinter)
1093         libstdcxx_printer.add_version('__gnu_cxx::', '_Slist_iterator',
1094                                       StdSlistIteratorPrinter)
1095
1096         # Debug (compiled with -D_GLIBCXX_DEBUG) printer
1097         # registrations.  The Rb_tree debug iterator when unwrapped
1098         # from the encapsulating __gnu_debug::_Safe_iterator does not
1099         # have the __norm namespace. Just use the existing printer
1100         # registration for that.
1101         libstdcxx_printer.add('__gnu_debug::_Safe_iterator',
1102                               StdDebugIteratorPrinter)
1103         libstdcxx_printer.add('std::__norm::_List_iterator',
1104                               StdListIteratorPrinter)
1105         libstdcxx_printer.add('std::__norm::_List_const_iterator',
1106                               StdListIteratorPrinter)
1107         libstdcxx_printer.add('std::__norm::_Deque_const_iterator',
1108                               StdDequeIteratorPrinter)
1109         libstdcxx_printer.add('std::__norm::_Deque_iterator',
1110                               StdDequeIteratorPrinter)
1111
1112 build_libstdcxx_dictionary ()