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

   1 # Pretty-printers for libstdc++.
   2
   3 # Copyright (C) 2008-2018 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 import sys
  22
  23 ### Python 2 + Python 3 compatibility code
  24
  25 # Resources about compatibility:
  26 #
  27 #  * <http://pythonhosted.org/six/>: Documentation of the "six" module
  28
  29 # FIXME: The handling of e.g. std::basic_string (at least on char)
  30 # probably needs updating to work with Python 3's new string rules.
  31 #
  32 # In particular, Python 3 has a separate type (called byte) for
  33 # bytestrings, and a special b"" syntax for the byte literals; the old
  34 # str() type has been redefined to always store Unicode text.
  35 #
  36 # We probably can't do much about this until this GDB PR is addressed:
  37 # <https://sourceware.org/bugzilla/show_bug.cgi?id=17138>
  38
  39 if sys.version_info[0] > 2:
  40     ### Python 3 stuff
  41     Iterator = object
  42     # Python 3 folds these into the normal functions.
  43     imap = map
  44     izip = zip
  45     # Also, int subsumes long
  46     long = int
  47 else:
  48     ### Python 2 stuff
  49     class Iterator:
  50         """Compatibility mixin for iterators
  51
  52         Instead of writing next() methods for iterators, write
  53         __next__() methods and use this mixin to make them work in
  54         Python 2 as well as Python 3.
  55
  56         Idea stolen from the "six" documentation:
  57         <http://pythonhosted.org/six/#six.Iterator>
  58         """
  59
  60         def next(self):
  61             return self.__next__()
  62
  63     # In Python 2, we still need these from itertools
  64     from itertools import imap, izip
  65
  66 # Try to use the new-style pretty-printing if available.
  67 _use_gdb_pp = True
  68 try:
  69     import gdb.printing
  70 except ImportError:
  71     _use_gdb_pp = False
  72
  73 # Try to install type-printers.
  74 _use_type_printing = False
  75 try:
  76     import gdb.types
  77     if hasattr(gdb.types, 'TypePrinter'):
  78         _use_type_printing = True
  79 except ImportError:
  80     pass
  81
  82 # Starting with the type ORIG, search for the member type NAME.  This
  83 # handles searching upward through superclasses.  This is needed to
  84 # work around http://sourceware.org/bugzilla/show_bug.cgi?id=13615.
  85 def find_type(orig, name):
  86     typ = orig.strip_typedefs()
  87     while True:
  88         # Strip cv-qualifiers.  PR 67440.
  89         search = '%s::%s' % (typ.unqualified(), name)
  90         try:
  91             return gdb.lookup_type(search)
  92         except RuntimeError:
  93             pass
  94         # The type was not found, so try the superclass.  We only need
  95         # to check the first superclass, so we don't bother with
  96         # anything fancier here.
  97         field = typ.fields()[0]
  98         if not field.is_base_class:
  99             raise ValueError("Cannot find type %s::%s" % (str(orig), name))
 100         typ = field.type
 101
 102 _versioned_namespace = '__8::'
 103
 104 def is_specialization_of(type, template_name):
 105     "Test if a type is a given template instantiation."
 106     global _versioned_namespace
 107     if _versioned_namespace:
 108         return re.match('^std::(%s)?%s<.*>$' % (_versioned_namespace, template_name), type) is not None
 109     return re.match('^std::%s<.*>$' % template_name, type) is not None
 110
 111 def strip_versioned_namespace(typename):
 112     global _versioned_namespace
 113     if _versioned_namespace:
 114         return typename.replace(_versioned_namespace, '')
 115     return typename
 116
 117 def strip_inline_namespaces(type_str):
 118     "Remove known inline namespaces from the canonical name of a type."
 119     type_str = strip_versioned_namespace(type_str)
 120     type_str = type_str.replace('std::__cxx11::', 'std::')
 121     expt_ns = 'std::experimental::'
 122     for lfts_ns in ('fundamentals_v1', 'fundamentals_v2'):
 123         type_str = type_str.replace(expt_ns+lfts_ns+'::', expt_ns)
 124     fs_ns = expt_ns + 'filesystem::'
 125     type_str = type_str.replace(fs_ns+'v1::', fs_ns)
 126     return type_str
 127
 128 def get_template_arg_list(type_obj):
 129     "Return a type's template arguments as a list"
 130     n = 0
 131     template_args = []
 132     while True:
 133         try:
 134             template_args.append(type_obj.template_argument(n))
 135         except:
 136             return template_args
 137         n += 1
 138
 139 class SmartPtrIterator(Iterator):
 140     "An iterator for smart pointer types with a single 'child' value"
 141
 142     def __init__(self, val):
 143         self.val = val
 144
 145     def __iter__(self):
 146         return self
 147
 148     def __next__(self):
 149         if self.val is None:
 150             raise StopIteration
 151         self.val, val = None, self.val
 152         return ('get()', val)
 153
 154 class SharedPointerPrinter:
 155     "Print a shared_ptr or weak_ptr"
 156
 157     def __init__ (self, typename, val):
 158         self.typename = strip_versioned_namespace(typename)
 159         self.val = val
 160         self.pointer = val['_M_ptr']
 161
 162     def children (self):
 163         return SmartPtrIterator(self.pointer)
 164
 165     def to_string (self):
 166         state = 'empty'
 167         refcounts = self.val['_M_refcount']['_M_pi']
 168         if refcounts != 0:
 169             usecount = refcounts['_M_use_count']
 170             weakcount = refcounts['_M_weak_count']
 171             if usecount == 0:
 172                 state = 'expired, weak count %d' % weakcount
 173             else:
 174                 state = 'use count %d, weak count %d' % (usecount, weakcount - 1)
 175         return '%s<%s> (%s)' % (self.typename, str(self.val.type.template_argument(0)), state)
 176
 177 class UniquePointerPrinter:
 178     "Print a unique_ptr"
 179
 180     def __init__ (self, typename, val):
 181         self.val = val
 182         impl_type = val.type.fields()[0].type.tag
 183         if is_specialization_of(impl_type, '__uniq_ptr_impl'): # New implementation
 184             self.pointer = val['_M_t']['_M_t']['_M_head_impl']
 185         elif is_specialization_of(impl_type, 'tuple'):
 186             self.pointer = val['_M_t']['_M_head_impl']
 187         else:
 188             raise ValueError("Unsupported implementation for unique_ptr: %s" % impl_type)
 189
 190     def children (self):
 191         return SmartPtrIterator(self.pointer)
 192
 193     def to_string (self):
 194         return ('std::unique_ptr<%s>' % (str(self.val.type.template_argument(0))))
 195
 196 def get_value_from_aligned_membuf(buf, valtype):
 197     """Returns the value held in a __gnu_cxx::__aligned_membuf."""
 198     return buf['_M_storage'].address.cast(valtype.pointer()).dereference()
 199
 200 def get_value_from_list_node(node):
 201     """Returns the value held in an _List_node<_Val>"""
 202     try:
 203         member = node.type.fields()[1].name
 204         if member == '_M_data':
 205             # C++03 implementation, node contains the value as a member
 206             return node['_M_data']
 207         elif member == '_M_storage':
 208             # C++11 implementation, node stores value in __aligned_membuf
 209             valtype = node.type.template_argument(0)
 210             return get_value_from_aligned_membuf(node['_M_storage'], valtype)
 211     except:
 212         pass
 213     raise ValueError("Unsupported implementation for %s" % str(node.type))
 214
 215 class StdListPrinter:
 216     "Print a std::list"
 217
 218     class _iterator(Iterator):
 219         def __init__(self, nodetype, head):
 220             self.nodetype = nodetype
 221             self.base = head['_M_next']
 222             self.head = head.address
 223             self.count = 0
 224
 225         def __iter__(self):
 226             return self
 227
 228         def __next__(self):
 229             if self.base == self.head:
 230                 raise StopIteration
 231             elt = self.base.cast(self.nodetype).dereference()
 232             self.base = elt['_M_next']
 233             count = self.count
 234             self.count = self.count + 1
 235             val = get_value_from_list_node(elt)
 236             return ('[%d]' % count, val)
 237
 238     def __init__(self, typename, val):
 239         self.typename = strip_versioned_namespace(typename)
 240         self.val = val
 241
 242     def children(self):
 243         nodetype = find_type(self.val.type, '_Node')
 244         nodetype = nodetype.strip_typedefs().pointer()
 245         return self._iterator(nodetype, self.val['_M_impl']['_M_node'])
 246
 247     def to_string(self):
 248         if self.val['_M_impl']['_M_node'].address == self.val['_M_impl']['_M_node']['_M_next']:
 249             return 'empty %s' % (self.typename)
 250         return '%s' % (self.typename)
 251
 252 class StdListIteratorPrinter:
 253     "Print std::list::iterator"
 254
 255     def __init__(self, typename, val):
 256         self.val = val
 257         self.typename = typename
 258
 259     def to_string(self):
 260         if not self.val['_M_node']:
 261             return 'non-dereferenceable iterator for std::list'
 262         nodetype = find_type(self.val.type, '_Node')
 263         nodetype = nodetype.strip_typedefs().pointer()
 264         node = self.val['_M_node'].cast(nodetype).dereference()
 265         return str(get_value_from_list_node(node))
 266
 267 class StdSlistPrinter:
 268     "Print a __gnu_cxx::slist"
 269
 270     class _iterator(Iterator):
 271         def __init__(self, nodetype, head):
 272             self.nodetype = nodetype
 273             self.base = head['_M_head']['_M_next']
 274             self.count = 0
 275
 276         def __iter__(self):
 277             return self
 278
 279         def __next__(self):
 280             if self.base == 0:
 281                 raise StopIteration
 282             elt = self.base.cast(self.nodetype).dereference()
 283             self.base = elt['_M_next']
 284             count = self.count
 285             self.count = self.count + 1
 286             return ('[%d]' % count, elt['_M_data'])
 287
 288     def __init__(self, typename, val):
 289         self.val = val
 290
 291     def children(self):
 292         nodetype = find_type(self.val.type, '_Node')
 293         nodetype = nodetype.strip_typedefs().pointer()
 294         return self._iterator(nodetype, self.val)
 295
 296     def to_string(self):
 297         if self.val['_M_head']['_M_next'] == 0:
 298             return 'empty __gnu_cxx::slist'
 299         return '__gnu_cxx::slist'
 300
 301 class StdSlistIteratorPrinter:
 302     "Print __gnu_cxx::slist::iterator"
 303
 304     def __init__(self, typename, val):
 305         self.val = val
 306
 307     def to_string(self):
 308         if not self.val['_M_node']:
 309             return 'non-dereferenceable iterator for __gnu_cxx::slist'
 310         nodetype = find_type(self.val.type, '_Node')
 311         nodetype = nodetype.strip_typedefs().pointer()
 312         return str(self.val['_M_node'].cast(nodetype).dereference()['_M_data'])
 313
 314 class StdVectorPrinter:
 315     "Print a std::vector"
 316
 317     class _iterator(Iterator):
 318         def __init__ (self, start, finish, bitvec):
 319             self.bitvec = bitvec
 320             if bitvec:
 321                 self.item   = start['_M_p']
 322                 self.so     = start['_M_offset']
 323                 self.finish = finish['_M_p']
 324                 self.fo     = finish['_M_offset']
 325                 itype = self.item.dereference().type
 326                 self.isize = 8 * itype.sizeof
 327             else:
 328                 self.item = start
 329                 self.finish = finish
 330             self.count = 0
 331
 332         def __iter__(self):
 333             return self
 334
 335         def __next__(self):
 336             count = self.count
 337             self.count = self.count + 1
 338             if self.bitvec:
 339                 if self.item == self.finish and self.so >= self.fo:
 340                     raise StopIteration
 341                 elt = self.item.dereference()
 342                 if elt & (1 << self.so):
 343                     obit = 1
 344                 else:
 345                     obit = 0
 346                 self.so = self.so + 1
 347                 if self.so >= self.isize:
 348                     self.item = self.item + 1
 349                     self.so = 0
 350                 return ('[%d]' % count, obit)
 351             else:
 352                 if self.item == self.finish:
 353                     raise StopIteration
 354                 elt = self.item.dereference()
 355                 self.item = self.item + 1
 356                 return ('[%d]' % count, elt)
 357
 358     def __init__(self, typename, val):
 359         self.typename = strip_versioned_namespace(typename)
 360         self.val = val
 361         self.is_bool = val.type.template_argument(0).code  == gdb.TYPE_CODE_BOOL
 362
 363     def children(self):
 364         return self._iterator(self.val['_M_impl']['_M_start'],
 365                               self.val['_M_impl']['_M_finish'],
 366                               self.is_bool)
 367
 368     def to_string(self):
 369         start = self.val['_M_impl']['_M_start']
 370         finish = self.val['_M_impl']['_M_finish']
 371         end = self.val['_M_impl']['_M_end_of_storage']
 372         if self.is_bool:
 373             start = self.val['_M_impl']['_M_start']['_M_p']
 374             so    = self.val['_M_impl']['_M_start']['_M_offset']
 375             finish = self.val['_M_impl']['_M_finish']['_M_p']
 376             fo     = self.val['_M_impl']['_M_finish']['_M_offset']
 377             itype = start.dereference().type
 378             bl = 8 * itype.sizeof
 379             length   = (bl - so) + bl * ((finish - start) - 1) + fo
 380             capacity = bl * (end - start)
 381             return ('%s<bool> of length %d, capacity %d'
 382                     % (self.typename, int (length), int (capacity)))
 383         else:
 384             return ('%s of length %d, capacity %d'
 385                     % (self.typename, int (finish - start), int (end - start)))
 386
 387     def display_hint(self):
 388         return 'array'
 389
 390 class StdVectorIteratorPrinter:
 391     "Print std::vector::iterator"
 392
 393     def __init__(self, typename, val):
 394         self.val = val
 395
 396     def to_string(self):
 397         if not self.val['_M_current']:
 398             return 'non-dereferenceable iterator for std::vector'
 399         return str(self.val['_M_current'].dereference())
 400
 401 class StdTuplePrinter:
 402     "Print a std::tuple"
 403
 404     class _iterator(Iterator):
 405         def __init__ (self, head):
 406             self.head = head
 407
 408             # Set the base class as the initial head of the
 409             # tuple.
 410             nodes = self.head.type.fields ()
 411             if len (nodes) == 1:
 412                 # Set the actual head to the first pair.
 413                 self.head  = self.head.cast (nodes[0].type)
 414             elif len (nodes) != 0:
 415                 raise ValueError("Top of tuple tree does not consist of a single node.")
 416             self.count = 0
 417
 418         def __iter__ (self):
 419             return self
 420
 421         def __next__ (self):
 422             # Check for further recursions in the inheritance tree.
 423             # For a GCC 5+ tuple self.head is None after visiting all nodes:
 424             if not self.head:
 425                 raise StopIteration
 426             nodes = self.head.type.fields ()
 427             # For a GCC 4.x tuple there is a final node with no fields:
 428             if len (nodes) == 0:
 429                 raise StopIteration
 430             # Check that this iteration has an expected structure.
 431             if len (nodes) > 2:
 432                 raise ValueError("Cannot parse more than 2 nodes in a tuple tree.")
 433
 434             if len (nodes) == 1:
 435                 # This is the last node of a GCC 5+ std::tuple.
 436                 impl = self.head.cast (nodes[0].type)
 437                 self.head = None
 438             else:
 439                 # Either a node before the last node, or the last node of
 440                 # a GCC 4.x tuple (which has an empty parent).
 441
 442                 # - Left node is the next recursion parent.
 443                 # - Right node is the actual class contained in the tuple.
 444
 445                 # Process right node.
 446                 impl = self.head.cast (nodes[1].type)
 447
 448                 # Process left node and set it as head.
 449                 self.head  = self.head.cast (nodes[0].type)
 450
 451             self.count = self.count + 1
 452
 453             # Finally, check the implementation.  If it is
 454             # wrapped in _M_head_impl return that, otherwise return
 455             # the value "as is".
 456             fields = impl.type.fields ()
 457             if len (fields) < 1 or fields[0].name != "_M_head_impl":
 458                 return ('[%d]' % self.count, impl)
 459             else:
 460                 return ('[%d]' % self.count, impl['_M_head_impl'])
 461
 462     def __init__ (self, typename, val):
 463         self.typename = strip_versioned_namespace(typename)
 464         self.val = val;
 465
 466     def children (self):
 467         return self._iterator (self.val)
 468
 469     def to_string (self):
 470         if len (self.val.type.fields ()) == 0:
 471             return 'empty %s' % (self.typename)
 472         return '%s containing' % (self.typename)
 473
 474 class StdStackOrQueuePrinter:
 475     "Print a std::stack or std::queue"
 476
 477     def __init__ (self, typename, val):
 478         self.typename = strip_versioned_namespace(typename)
 479         self.visualizer = gdb.default_visualizer(val['c'])
 480
 481     def children (self):
 482         return self.visualizer.children()
 483
 484     def to_string (self):
 485         return '%s wrapping: %s' % (self.typename,
 486                                     self.visualizer.to_string())
 487
 488     def display_hint (self):
 489         if hasattr (self.visualizer, 'display_hint'):
 490             return self.visualizer.display_hint ()
 491         return None
 492
 493 class RbtreeIterator(Iterator):
 494     """
 495     Turn an RB-tree-based container (std::map, std::set etc.) into
 496     a Python iterable object.
 497     """
 498
 499     def __init__(self, rbtree):
 500         self.size = rbtree['_M_t']['_M_impl']['_M_node_count']
 501         self.node = rbtree['_M_t']['_M_impl']['_M_header']['_M_left']
 502         self.count = 0
 503
 504     def __iter__(self):
 505         return self
 506
 507     def __len__(self):
 508         return int (self.size)
 509
 510     def __next__(self):
 511         if self.count == self.size:
 512             raise StopIteration
 513         result = self.node
 514         self.count = self.count + 1
 515         if self.count < self.size:
 516             # Compute the next node.
 517             node = self.node
 518             if node.dereference()['_M_right']:
 519                 node = node.dereference()['_M_right']
 520                 while node.dereference()['_M_left']:
 521                     node = node.dereference()['_M_left']
 522             else:
 523                 parent = node.dereference()['_M_parent']
 524                 while node == parent.dereference()['_M_right']:
 525                     node = parent
 526                     parent = parent.dereference()['_M_parent']
 527                 if node.dereference()['_M_right'] != parent:
 528                     node = parent
 529             self.node = node
 530         return result
 531
 532 def get_value_from_Rb_tree_node(node):
 533     """Returns the value held in an _Rb_tree_node<_Val>"""
 534     try:
 535         member = node.type.fields()[1].name
 536         if member == '_M_value_field':
 537             # C++03 implementation, node contains the value as a member
 538             return node['_M_value_field']
 539         elif member == '_M_storage':
 540             # C++11 implementation, node stores value in __aligned_membuf
 541             valtype = node.type.template_argument(0)
 542             return get_value_from_aligned_membuf(node['_M_storage'], valtype)
 543     except:
 544         pass
 545     raise ValueError("Unsupported implementation for %s" % str(node.type))
 546
 547 # This is a pretty printer for std::_Rb_tree_iterator (which is
 548 # std::map::iterator), and has nothing to do with the RbtreeIterator
 549 # class above.
 550 class StdRbtreeIteratorPrinter:
 551     "Print std::map::iterator, std::set::iterator, etc."
 552
 553     def __init__ (self, typename, val):
 554         self.val = val
 555         valtype = self.val.type.template_argument(0).strip_typedefs()
 556         nodetype = '_Rb_tree_node<' + str(valtype) + '>'
 557         if _versioned_namespace and typename.startswith('std::' + _versioned_namespace):
 558             nodetype = _versioned_namespace + nodetype
 559         nodetype = gdb.lookup_type('std::' + nodetype)
 560         self.link_type = nodetype.strip_typedefs().pointer()
 561
 562     def to_string (self):
 563         if not self.val['_M_node']:
 564             return 'non-dereferenceable iterator for associative container'
 565         node = self.val['_M_node'].cast(self.link_type).dereference()
 566         return str(get_value_from_Rb_tree_node(node))
 567
 568 class StdDebugIteratorPrinter:
 569     "Print a debug enabled version of an iterator"
 570
 571     def __init__ (self, typename, val):
 572         self.val = val
 573
 574     # Just strip away the encapsulating __gnu_debug::_Safe_iterator
 575     # and return the wrapped iterator value.
 576     def to_string (self):
 577         base_type = gdb.lookup_type('__gnu_debug::_Safe_iterator_base')
 578         safe_seq = self.val.cast(base_type)['_M_sequence']
 579         if not safe_seq or self.val['_M_version'] != safe_seq['_M_version']:
 580             return "invalid iterator"
 581         itype = self.val.type.template_argument(0)
 582         return str(self.val.cast(itype))
 583
 584 def num_elements(num):
 585     """Return either "1 element" or "N elements" depending on the argument."""
 586     return '1 element' if num == 1 else '%d elements' % num
 587
 588 class StdMapPrinter:
 589     "Print a std::map or std::multimap"
 590
 591     # Turn an RbtreeIterator into a pretty-print iterator.
 592     class _iter(Iterator):
 593         def __init__(self, rbiter, type):
 594             self.rbiter = rbiter
 595             self.count = 0
 596             self.type = type
 597
 598         def __iter__(self):
 599             return self
 600
 601         def __next__(self):
 602             if self.count % 2 == 0:
 603                 n = next(self.rbiter)
 604                 n = n.cast(self.type).dereference()
 605                 n = get_value_from_Rb_tree_node(n)
 606                 self.pair = n
 607                 item = n['first']
 608             else:
 609                 item = self.pair['second']
 610             result = ('[%d]' % self.count, item)
 611             self.count = self.count + 1
 612             return result
 613
 614     def __init__ (self, typename, val):
 615         self.typename = strip_versioned_namespace(typename)
 616         self.val = val
 617
 618     def to_string (self):
 619         return '%s with %s' % (self.typename,
 620                                num_elements(len(RbtreeIterator (self.val))))
 621
 622     def children (self):
 623         rep_type = find_type(self.val.type, '_Rep_type')
 624         node = find_type(rep_type, '_Link_type')
 625         node = node.strip_typedefs()
 626         return self._iter (RbtreeIterator (self.val), node)
 627
 628     def display_hint (self):
 629         return 'map'
 630
 631 class StdSetPrinter:
 632     "Print a std::set or std::multiset"
 633
 634     # Turn an RbtreeIterator into a pretty-print iterator.
 635     class _iter(Iterator):
 636         def __init__(self, rbiter, type):
 637             self.rbiter = rbiter
 638             self.count = 0
 639             self.type = type
 640
 641         def __iter__(self):
 642             return self
 643
 644         def __next__(self):
 645             item = next(self.rbiter)
 646             item = item.cast(self.type).dereference()
 647             item = get_value_from_Rb_tree_node(item)
 648             # FIXME: this is weird ... what to do?
 649             # Maybe a 'set' display hint?
 650             result = ('[%d]' % self.count, item)
 651             self.count = self.count + 1
 652             return result
 653
 654     def __init__ (self, typename, val):
 655         self.typename = strip_versioned_namespace(typename)
 656         self.val = val
 657
 658     def to_string (self):
 659         return '%s with %s' % (self.typename,
 660                                num_elements(len(RbtreeIterator (self.val))))
 661
 662     def children (self):
 663         rep_type = find_type(self.val.type, '_Rep_type')
 664         node = find_type(rep_type, '_Link_type')
 665         node = node.strip_typedefs()
 666         return self._iter (RbtreeIterator (self.val), node)
 667
 668 class StdBitsetPrinter:
 669     "Print a std::bitset"
 670
 671     def __init__(self, typename, val):
 672         self.typename = strip_versioned_namespace(typename)
 673         self.val = val
 674
 675     def to_string (self):
 676         # If template_argument handled values, we could print the
 677         # size.  Or we could use a regexp on the type.
 678         return '%s' % (self.typename)
 679
 680     def children (self):
 681         words = self.val['_M_w']
 682         wtype = words.type
 683
 684         # The _M_w member can be either an unsigned long, or an
 685         # array.  This depends on the template specialization used.
 686         # If it is a single long, convert to a single element list.
 687         if wtype.code == gdb.TYPE_CODE_ARRAY:
 688             tsize = wtype.target ().sizeof
 689         else:
 690             words = [words]
 691             tsize = wtype.sizeof
 692
 693         nwords = wtype.sizeof / tsize
 694         result = []
 695         byte = 0
 696         while byte < nwords:
 697             w = words[byte]
 698             bit = 0
 699             while w != 0:
 700                 if (w & 1) != 0:
 701                     # Another spot where we could use 'set'?
 702                     result.append(('[%d]' % (byte * tsize * 8 + bit), 1))
 703                 bit = bit + 1
 704                 w = w >> 1
 705             byte = byte + 1
 706         return result
 707
 708 class StdDequePrinter:
 709     "Print a std::deque"
 710
 711     class _iter(Iterator):
 712         def __init__(self, node, start, end, last, buffer_size):
 713             self.node = node
 714             self.p = start
 715             self.end = end
 716             self.last = last
 717             self.buffer_size = buffer_size
 718             self.count = 0
 719
 720         def __iter__(self):
 721             return self
 722
 723         def __next__(self):
 724             if self.p == self.last:
 725                 raise StopIteration
 726
 727             result = ('[%d]' % self.count, self.p.dereference())
 728             self.count = self.count + 1
 729
 730             # Advance the 'cur' pointer.
 731             self.p = self.p + 1
 732             if self.p == self.end:
 733                 # If we got to the end of this bucket, move to the
 734                 # next bucket.
 735                 self.node = self.node + 1
 736                 self.p = self.node[0]
 737                 self.end = self.p + self.buffer_size
 738
 739             return result
 740
 741     def __init__(self, typename, val):
 742         self.typename = strip_versioned_namespace(typename)
 743         self.val = val
 744         self.elttype = val.type.template_argument(0)
 745         size = self.elttype.sizeof
 746         if size < 512:
 747             self.buffer_size = int (512 / size)
 748         else:
 749             self.buffer_size = 1
 750
 751     def to_string(self):
 752         start = self.val['_M_impl']['_M_start']
 753         end = self.val['_M_impl']['_M_finish']
 754
 755         delta_n = end['_M_node'] - start['_M_node'] - 1
 756         delta_s = start['_M_last'] - start['_M_cur']
 757         delta_e = end['_M_cur'] - end['_M_first']
 758
 759         size = self.buffer_size * delta_n + delta_s + delta_e
 760
 761         return '%s with %s' % (self.typename, num_elements(long(size)))
 762
 763     def children(self):
 764         start = self.val['_M_impl']['_M_start']
 765         end = self.val['_M_impl']['_M_finish']
 766         return self._iter(start['_M_node'], start['_M_cur'], start['_M_last'],
 767                           end['_M_cur'], self.buffer_size)
 768
 769     def display_hint (self):
 770         return 'array'
 771
 772 class StdDequeIteratorPrinter:
 773     "Print std::deque::iterator"
 774
 775     def __init__(self, typename, val):
 776         self.val = val
 777
 778     def to_string(self):
 779         if not self.val['_M_cur']:
 780             return 'non-dereferenceable iterator for std::deque'
 781         return str(self.val['_M_cur'].dereference())
 782
 783 class StdStringPrinter:
 784     "Print a std::basic_string of some kind"
 785
 786     def __init__(self, typename, val):
 787         self.val = val
 788         self.new_string = typename.find("::__cxx11::basic_string") != -1
 789
 790     def to_string(self):
 791         # Make sure &string works, too.
 792         type = self.val.type
 793         if type.code == gdb.TYPE_CODE_REF:
 794             type = type.target ()
 795
 796         # Calculate the length of the string so that to_string returns
 797         # the string according to length, not according to first null
 798         # encountered.
 799         ptr = self.val ['_M_dataplus']['_M_p']
 800         if self.new_string:
 801             length = self.val['_M_string_length']
 802             # https://sourceware.org/bugzilla/show_bug.cgi?id=17728
 803             ptr = ptr.cast(ptr.type.strip_typedefs())
 804         else:
 805             realtype = type.unqualified ().strip_typedefs ()
 806             reptype = gdb.lookup_type (str (realtype) + '::_Rep').pointer ()
 807             header = ptr.cast(reptype) - 1
 808             length = header.dereference ()['_M_length']
 809         if hasattr(ptr, "lazy_string"):
 810             return ptr.lazy_string (length = length)
 811         return ptr.string (length = length)
 812
 813     def display_hint (self):
 814         return 'string'
 815
 816 class Tr1HashtableIterator(Iterator):
 817     def __init__ (self, hash):
 818         self.buckets = hash['_M_buckets']
 819         self.bucket = 0
 820         self.bucket_count = hash['_M_bucket_count']
 821         self.node_type = find_type(hash.type, '_Node').pointer()
 822         self.node = 0
 823         while self.bucket != self.bucket_count:
 824             self.node = self.buckets[self.bucket]
 825             if self.node:
 826                 break
 827             self.bucket = self.bucket + 1
 828
 829     def __iter__ (self):
 830         return self
 831
 832     def __next__ (self):
 833         if self.node == 0:
 834             raise StopIteration
 835         node = self.node.cast(self.node_type)
 836         result = node.dereference()['_M_v']
 837         self.node = node.dereference()['_M_next'];
 838         if self.node == 0:
 839             self.bucket = self.bucket + 1
 840             while self.bucket != self.bucket_count:
 841                 self.node = self.buckets[self.bucket]
 842                 if self.node:
 843                     break
 844                 self.bucket = self.bucket + 1
 845         return result
 846
 847 class StdHashtableIterator(Iterator):
 848     def __init__(self, hash):
 849         self.node = hash['_M_before_begin']['_M_nxt']
 850         self.node_type = find_type(hash.type, '__node_type').pointer()
 851
 852     def __iter__(self):
 853         return self
 854
 855     def __next__(self):
 856         if self.node == 0:
 857             raise StopIteration
 858         elt = self.node.cast(self.node_type).dereference()
 859         self.node = elt['_M_nxt']
 860         valptr = elt['_M_storage'].address
 861         valptr = valptr.cast(elt.type.template_argument(0).pointer())
 862         return valptr.dereference()
 863
 864 class Tr1UnorderedSetPrinter:
 865     "Print a tr1::unordered_set"
 866
 867     def __init__ (self, typename, val):
 868         self.typename = strip_versioned_namespace(typename)
 869         self.val = val
 870
 871     def hashtable (self):
 872         if self.typename.startswith('std::tr1'):
 873             return self.val
 874         return self.val['_M_h']
 875
 876     def to_string (self):
 877         count = self.hashtable()['_M_element_count']
 878         return '%s with %s' % (self.typename, num_elements(count))
 879
 880     @staticmethod
 881     def format_count (i):
 882         return '[%d]' % i
 883
 884     def children (self):
 885         counter = imap (self.format_count, itertools.count())
 886         if self.typename.startswith('std::tr1'):
 887             return izip (counter, Tr1HashtableIterator (self.hashtable()))
 888         return izip (counter, StdHashtableIterator (self.hashtable()))
 889
 890 class Tr1UnorderedMapPrinter:
 891     "Print a tr1::unordered_map"
 892
 893     def __init__ (self, typename, val):
 894         self.typename = strip_versioned_namespace(typename)
 895         self.val = val
 896
 897     def hashtable (self):
 898         if self.typename.startswith('std::tr1'):
 899             return self.val
 900         return self.val['_M_h']
 901
 902     def to_string (self):
 903         count = self.hashtable()['_M_element_count']
 904         return '%s with %s' % (self.typename, num_elements(count))
 905
 906     @staticmethod
 907     def flatten (list):
 908         for elt in list:
 909             for i in elt:
 910                 yield i
 911
 912     @staticmethod
 913     def format_one (elt):
 914         return (elt['first'], elt['second'])
 915
 916     @staticmethod
 917     def format_count (i):
 918         return '[%d]' % i
 919
 920     def children (self):
 921         counter = imap (self.format_count, itertools.count())
 922         # Map over the hash table and flatten the result.
 923         if self.typename.startswith('std::tr1'):
 924             data = self.flatten (imap (self.format_one, Tr1HashtableIterator (self.hashtable())))
 925             # Zip the two iterators together.
 926             return izip (counter, data)
 927         data = self.flatten (imap (self.format_one, StdHashtableIterator (self.hashtable())))
 928         # Zip the two iterators together.
 929         return izip (counter, data)
 930
 931
 932     def display_hint (self):
 933         return 'map'
 934
 935 class StdForwardListPrinter:
 936     "Print a std::forward_list"
 937
 938     class _iterator(Iterator):
 939         def __init__(self, nodetype, head):
 940             self.nodetype = nodetype
 941             self.base = head['_M_next']
 942             self.count = 0
 943
 944         def __iter__(self):
 945             return self
 946
 947         def __next__(self):
 948             if self.base == 0:
 949                 raise StopIteration
 950             elt = self.base.cast(self.nodetype).dereference()
 951             self.base = elt['_M_next']
 952             count = self.count
 953             self.count = self.count + 1
 954             valptr = elt['_M_storage'].address
 955             valptr = valptr.cast(elt.type.template_argument(0).pointer())
 956             return ('[%d]' % count, valptr.dereference())
 957
 958     def __init__(self, typename, val):
 959         self.val = val
 960         self.typename = strip_versioned_namespace(typename)
 961
 962     def children(self):
 963         nodetype = find_type(self.val.type, '_Node')
 964         nodetype = nodetype.strip_typedefs().pointer()
 965         return self._iterator(nodetype, self.val['_M_impl']['_M_head'])
 966
 967     def to_string(self):
 968         if self.val['_M_impl']['_M_head']['_M_next'] == 0:
 969             return 'empty %s' % self.typename
 970         return '%s' % self.typename
 971
 972 class SingleObjContainerPrinter(object):
 973     "Base class for printers of containers of single objects"
 974
 975     def __init__ (self, val, viz, hint = None):
 976         self.contained_value = val
 977         self.visualizer = viz
 978         self.hint = hint
 979
 980     def _recognize(self, type):
 981         """Return TYPE as a string after applying type printers"""
 982         global _use_type_printing
 983         if not _use_type_printing:
 984             return str(type)
 985         return gdb.types.apply_type_recognizers(gdb.types.get_type_recognizers(),
 986                                                 type) or str(type)
 987
 988     class _contained(Iterator):
 989         def __init__ (self, val):
 990             self.val = val
 991
 992         def __iter__ (self):
 993             return self
 994
 995         def __next__(self):
 996             if self.val is None:
 997                 raise StopIteration
 998             retval = self.val
 999             self.val = None
1000             return ('[contained value]', retval)
1001
1002     def children (self):
1003         if self.contained_value is None:
1004             return self._contained (None)
1005         if hasattr (self.visualizer, 'children'):
1006             return self.visualizer.children ()
1007         return self._contained (self.contained_value)
1008
1009     def display_hint (self):
1010         # if contained value is a map we want to display in the same way
1011         if hasattr (self.visualizer, 'children') and hasattr (self.visualizer, 'display_hint'):
1012             return self.visualizer.display_hint ()
1013         return self.hint
1014
1015 class StdExpAnyPrinter(SingleObjContainerPrinter):
1016     "Print a std::any or std::experimental::any"
1017
1018     def __init__ (self, typename, val):
1019         self.typename = strip_versioned_namespace(typename)
1020         self.typename = re.sub('^std::experimental::fundamentals_v\d::', 'std::experimental::', self.typename, 1)
1021         self.val = val
1022         self.contained_type = None
1023         contained_value = None
1024         visualizer = None
1025         mgr = self.val['_M_manager']
1026         if mgr != 0:
1027             func = gdb.block_for_pc(int(mgr.cast(gdb.lookup_type('intptr_t'))))
1028             if not func:
1029                 raise ValueError("Invalid function pointer in %s" % self.typename)
1030             rx = r"""({0}::_Manager_\w+<.*>)::_S_manage\({0}::_Op, {0} const\*, {0}::_Arg\*\)""".format(typename)
1031             m = re.match(rx, func.function.name)
1032             if not m:
1033                 raise ValueError("Unknown manager function in %s" % self.typename)
1034
1035             mgrname = m.group(1)
1036             # FIXME need to expand 'std::string' so that gdb.lookup_type works
1037             if 'std::string' in mgrname:
1038                 mgrname = re.sub("std::string(?!\w)", str(gdb.lookup_type('std::string').strip_typedefs()), m.group(1))
1039
1040             mgrtype = gdb.lookup_type(mgrname)
1041             self.contained_type = mgrtype.template_argument(0)
1042             valptr = None
1043             if '::_Manager_internal' in mgrname:
1044                 valptr = self.val['_M_storage']['_M_buffer'].address
1045             elif '::_Manager_external' in mgrname:
1046                 valptr = self.val['_M_storage']['_M_ptr']
1047             else:
1048                 raise ValueError("Unknown manager function in %s" % self.typename)
1049             contained_value = valptr.cast(self.contained_type.pointer()).dereference()
1050             visualizer = gdb.default_visualizer(contained_value)
1051         super(StdExpAnyPrinter, self).__init__ (contained_value, visualizer)
1052
1053     def to_string (self):
1054         if self.contained_type is None:
1055             return '%s [no contained value]' % self.typename
1056         desc = "%s containing " % self.typename
1057         if hasattr (self.visualizer, 'children'):
1058             return desc + self.visualizer.to_string ()
1059         valtype = self._recognize (self.contained_type)
1060         return desc + strip_versioned_namespace(str(valtype))
1061
1062 class StdExpOptionalPrinter(SingleObjContainerPrinter):
1063     "Print a std::optional or std::experimental::optional"
1064
1065     def __init__ (self, typename, val):
1066         valtype = self._recognize (val.type.template_argument(0))
1067         self.typename = strip_versioned_namespace(typename)
1068         self.typename = re.sub('^std::(experimental::|)(fundamentals_v\d::|)(.*)', r'std::\1\3<%s>' % valtype, self.typename, 1)
1069         if not self.typename.startswith('std::experimental'):
1070             val = val['_M_payload']
1071         self.val = val
1072         contained_value = val['_M_payload'] if self.val['_M_engaged'] else None
1073         visualizer = gdb.default_visualizer (val['_M_payload'])
1074         super (StdExpOptionalPrinter, self).__init__ (contained_value, visualizer)
1075
1076     def to_string (self):
1077         if self.contained_value is None:
1078             return "%s [no contained value]" % self.typename
1079         if hasattr (self.visualizer, 'children'):
1080             return "%s containing %s" % (self.typename,
1081                                          self.visualizer.to_string())
1082         return self.typename
1083
1084 class StdVariantPrinter(SingleObjContainerPrinter):
1085     "Print a std::variant"
1086
1087     def __init__(self, typename, val):
1088         alternatives = get_template_arg_list(val.type)
1089         self.typename = strip_versioned_namespace(typename)
1090         self.typename = "%s<%s>" % (self.typename, ', '.join([self._recognize(alt) for alt in alternatives]))
1091         self.index = val['_M_index']
1092         if self.index >= len(alternatives):
1093             self.contained_type = None
1094             contained_value = None
1095             visualizer = None
1096         else:
1097             self.contained_type = alternatives[int(self.index)]
1098             addr = val['_M_u']['_M_first']['_M_storage'].address
1099             contained_value = addr.cast(self.contained_type.pointer()).dereference()
1100             visualizer = gdb.default_visualizer(contained_value)
1101         super (StdVariantPrinter, self).__init__(contained_value, visualizer, 'array')
1102
1103     def to_string(self):
1104         if self.contained_value is None:
1105             return "%s [no contained value]" % self.typename
1106         if hasattr(self.visualizer, 'children'):
1107             return "%s [index %d] containing %s" % (self.typename, self.index,
1108                                                     self.visualizer.to_string())
1109         return "%s [index %d]" % (self.typename, self.index)
1110
1111 class StdNodeHandlePrinter(SingleObjContainerPrinter):
1112     "Print a container node handle"
1113
1114     def __init__(self, typename, val):
1115         self.value_type = val.type.template_argument(1)
1116         nodetype = val.type.template_argument(2).template_argument(0)
1117         self.is_rb_tree_node = is_specialization_of(nodetype.name, '_Rb_tree_node')
1118         self.is_map_node = val.type.template_argument(0) != self.value_type
1119         nodeptr = val['_M_ptr']
1120         if nodeptr:
1121             if self.is_rb_tree_node:
1122                 contained_value = get_value_from_Rb_tree_node(nodeptr.dereference())
1123             else:
1124                 contained_value = get_value_from_aligned_membuf(nodeptr['_M_storage'],
1125                                                                 self.value_type)
1126             visualizer = gdb.default_visualizer(contained_value)
1127         else:
1128             contained_value = None
1129             visualizer = None
1130         optalloc = val['_M_alloc']
1131         self.alloc = optalloc['_M_payload'] if optalloc['_M_engaged'] else None
1132         super(StdNodeHandlePrinter, self).__init__(contained_value, visualizer,
1133                                                    'array')
1134
1135     def to_string(self):
1136         desc = 'node handle for '
1137         if not self.is_rb_tree_node:
1138             desc += 'unordered '
1139         if self.is_map_node:
1140             desc += 'map';
1141         else:
1142             desc += 'set';
1143
1144         if self.contained_value:
1145             desc += ' with element'
1146             if hasattr(self.visualizer, 'children'):
1147                 return "%s = %s" % (desc, self.visualizer.to_string())
1148             return desc
1149         else:
1150             return 'empty %s' % desc
1151
1152 class StdExpStringViewPrinter:
1153     "Print a std::basic_string_view or std::experimental::basic_string_view"
1154
1155     def __init__ (self, typename, val):
1156         self.val = val
1157
1158     def to_string (self):
1159         ptr = self.val['_M_str']
1160         len = self.val['_M_len']
1161         if hasattr (ptr, "lazy_string"):
1162             return ptr.lazy_string (length = len)
1163         return ptr.string (length = len)
1164
1165     def display_hint (self):
1166         return 'string'
1167
1168 class StdExpPathPrinter:
1169     "Print a std::experimental::filesystem::path"
1170
1171     def __init__ (self, typename, val):
1172         self.val = val
1173         start = self.val['_M_cmpts']['_M_impl']['_M_start']
1174         finish = self.val['_M_cmpts']['_M_impl']['_M_finish']
1175         self.num_cmpts = int (finish - start)
1176
1177     def _path_type(self):
1178         t = str(self.val['_M_type'])
1179         if t[-9:] == '_Root_dir':
1180             return "root-directory"
1181         if t[-10:] == '_Root_name':
1182             return "root-name"
1183         return None
1184
1185     def to_string (self):
1186         path = "%s" % self.val ['_M_pathname']
1187         if self.num_cmpts == 0:
1188             t = self._path_type()
1189             if t:
1190                 path = '%s [%s]' % (path, t)
1191         return "filesystem::path %s" % path
1192
1193     class _iterator(Iterator):
1194         def __init__(self, cmpts):
1195             self.item = cmpts['_M_impl']['_M_start']
1196             self.finish = cmpts['_M_impl']['_M_finish']
1197             self.count = 0
1198
1199         def __iter__(self):
1200             return self
1201
1202         def __next__(self):
1203             if self.item == self.finish:
1204                 raise StopIteration
1205             item = self.item.dereference()
1206             count = self.count
1207             self.count = self.count + 1
1208             self.item = self.item + 1
1209             path = item['_M_pathname']
1210             t = StdExpPathPrinter(item.type.name, item)._path_type()
1211             if not t:
1212                 t = count
1213             return ('[%s]' % t, path)
1214
1215     def children(self):
1216         return self._iterator(self.val['_M_cmpts'])
1217
1218
1219 # A "regular expression" printer which conforms to the
1220 # "SubPrettyPrinter" protocol from gdb.printing.
1221 class RxPrinter(object):
1222     def __init__(self, name, function):
1223         super(RxPrinter, self).__init__()
1224         self.name = name
1225         self.function = function
1226         self.enabled = True
1227
1228     def invoke(self, value):
1229         if not self.enabled:
1230             return None
1231
1232         if value.type.code == gdb.TYPE_CODE_REF:
1233             if hasattr(gdb.Value,"referenced_value"):
1234                 value = value.referenced_value()
1235
1236         return self.function(self.name, value)
1237
1238 # A pretty-printer that conforms to the "PrettyPrinter" protocol from
1239 # gdb.printing.  It can also be used directly as an old-style printer.
1240 class Printer(object):
1241     def __init__(self, name):
1242         super(Printer, self).__init__()
1243         self.name = name
1244         self.subprinters = []
1245         self.lookup = {}
1246         self.enabled = True
1247         self.compiled_rx = re.compile('^([a-zA-Z0-9_:]+)(<.*>)?$')
1248
1249     def add(self, name, function):
1250         # A small sanity check.
1251         # FIXME
1252         if not self.compiled_rx.match(name):
1253             raise ValueError('libstdc++ programming error: "%s" does not match' % name)
1254         printer = RxPrinter(name, function)
1255         self.subprinters.append(printer)
1256         self.lookup[name] = printer
1257
1258     # Add a name using _GLIBCXX_BEGIN_NAMESPACE_VERSION.
1259     def add_version(self, base, name, function):
1260         self.add(base + name, function)
1261         if _versioned_namespace:
1262             vbase = re.sub('^(std|__gnu_cxx)::', r'\g<0>%s' % _versioned_namespace, base)
1263             self.add(vbase + name, function)
1264
1265     # Add a name using _GLIBCXX_BEGIN_NAMESPACE_CONTAINER.
1266     def add_container(self, base, name, function):
1267         self.add_version(base, name, function)
1268         self.add_version(base + '__cxx1998::', name, function)
1269
1270     @staticmethod
1271     def get_basic_type(type):
1272         # If it points to a reference, get the reference.
1273         if type.code == gdb.TYPE_CODE_REF:
1274             type = type.target ()
1275
1276         # Get the unqualified type, stripped of typedefs.
1277         type = type.unqualified ().strip_typedefs ()
1278
1279         return type.tag
1280
1281     def __call__(self, val):
1282         typename = self.get_basic_type(val.type)
1283         if not typename:
1284             return None
1285
1286         # All the types we match are template types, so we can use a
1287         # dictionary.
1288         match = self.compiled_rx.match(typename)
1289         if not match:
1290             return None
1291
1292         basename = match.group(1)
1293
1294         if val.type.code == gdb.TYPE_CODE_REF:
1295             if hasattr(gdb.Value,"referenced_value"):
1296                 val = val.referenced_value()
1297
1298         if basename in self.lookup:
1299             return self.lookup[basename].invoke(val)
1300
1301         # Cannot find a pretty printer.  Return None.
1302         return None
1303
1304 libstdcxx_printer = None
1305
1306 class TemplateTypePrinter(object):
1307     r"""
1308     A type printer for class templates with default template arguments.
1309
1310     Recognizes specializations of class templates and prints them without
1311     any template arguments that use a default template argument.
1312     Type printers are recursively applied to the template arguments.
1313
1314     e.g. replace "std::vector<T, std::allocator<T> >" with "std::vector<T>".
1315     """
1316
1317     def __init__(self, name, defargs):
1318         self.name = name
1319         self.defargs = defargs
1320         self.enabled = True
1321
1322     class _recognizer(object):
1323         "The recognizer class for TemplateTypePrinter."
1324
1325         def __init__(self, name, defargs):
1326             self.name = name
1327             self.defargs = defargs
1328             # self.type_obj = None
1329
1330         def recognize(self, type_obj):
1331             """
1332             If type_obj is a specialization of self.name that uses all the
1333             default template arguments for the class template, then return
1334             a string representation of the type without default arguments.
1335             Otherwise, return None.
1336             """
1337
1338             if type_obj.tag is None:
1339                 return None
1340
1341             if not type_obj.tag.startswith(self.name):
1342                 return None
1343
1344             template_args = get_template_arg_list(type_obj)
1345             displayed_args = []
1346             require_defaulted = False
1347             for n in range(len(template_args)):
1348                 # The actual template argument in the type:
1349                 targ = template_args[n]
1350                 # The default template argument for the class template:
1351                 defarg = self.defargs.get(n)
1352                 if defarg is not None:
1353                     # Substitute other template arguments into the default:
1354                     defarg = defarg.format(*template_args)
1355                     # Fail to recognize the type (by returning None)
1356                     # unless the actual argument is the same as the default.
1357                     try:
1358                         if targ != gdb.lookup_type(defarg):
1359                             return None
1360                     except gdb.error:
1361                         # Type lookup failed, just use string comparison:
1362                         if targ.tag != defarg:
1363                             return None
1364                     # All subsequent args must have defaults:
1365                     require_defaulted = True
1366                 elif require_defaulted:
1367                     return None
1368                 else:
1369                     # Recursively apply recognizers to the template argument
1370                     # and add it to the arguments that will be displayed:
1371                     displayed_args.append(self._recognize_subtype(targ))
1372
1373             # This assumes no class templates in the nested-name-specifier:
1374             template_name = type_obj.tag[0:type_obj.tag.find('<')]
1375             template_name = strip_inline_namespaces(template_name)
1376
1377             return template_name + '<' + ', '.join(displayed_args) + '>'
1378
1379         def _recognize_subtype(self, type_obj):
1380             """Convert a gdb.Type to a string by applying recognizers,
1381             or if that fails then simply converting to a string."""
1382
1383             if type_obj.code == gdb.TYPE_CODE_PTR:
1384                 return self._recognize_subtype(type_obj.target()) + '*'
1385             if type_obj.code == gdb.TYPE_CODE_ARRAY:
1386                 type_str = self._recognize_subtype(type_obj.target())
1387                 if str(type_obj.strip_typedefs()).endswith('[]'):
1388                     return type_str + '[]' # array of unknown bound
1389                 return "%s[%d]" % (type_str, type_obj.range()[1] + 1)
1390             if type_obj.code == gdb.TYPE_CODE_REF:
1391                 return self._recognize_subtype(type_obj.target()) + '&'
1392             if hasattr(gdb, 'TYPE_CODE_RVALUE_REF'):
1393                 if type_obj.code == gdb.TYPE_CODE_RVALUE_REF:
1394                     return self._recognize_subtype(type_obj.target()) + '&&'
1395
1396             type_str = gdb.types.apply_type_recognizers(
1397                     gdb.types.get_type_recognizers(), type_obj)
1398             if type_str:
1399                 return type_str
1400             return str(type_obj)
1401
1402     def instantiate(self):
1403         "Return a recognizer object for this type printer."
1404         return self._recognizer(self.name, self.defargs)
1405
1406 def add_one_template_type_printer(obj, name, defargs):
1407     r"""
1408     Add a type printer for a class template with default template arguments.
1409
1410     Args:
1411         name (str): The template-name of the class template.
1412         defargs (dict int:string) The default template arguments.
1413
1414     Types in defargs can refer to the Nth template-argument using {N}
1415     (with zero-based indices).
1416
1417     e.g. 'unordered_map' has these defargs:
1418     { 2: 'std::hash<{0}>',
1419       3: 'std::equal_to<{0}>',
1420       4: 'std::allocator<std::pair<const {0}, {1}> >' }
1421
1422     """
1423     printer = TemplateTypePrinter('std::'+name, defargs)
1424     gdb.types.register_type_printer(obj, printer)
1425     if _versioned_namespace:
1426         # Add second type printer for same type in versioned namespace:
1427         ns = 'std::' + _versioned_namespace
1428         defargs = { n: d.replace('std::', ns) for n,d in defargs.items() }
1429         printer = TemplateTypePrinter(ns+name, defargs)
1430         gdb.types.register_type_printer(obj, printer)
1431
1432 class FilteringTypePrinter(object):
1433     r"""
1434     A type printer that uses typedef names for common template specializations.
1435
1436     Args:
1437         match (str): The class template to recognize.
1438         name (str): The typedef-name that will be used instead.
1439
1440     Checks if a specialization of the class template 'match' is the same type
1441     as the typedef 'name', and prints it as 'name' instead.
1442
1443     e.g. if an instantiation of std::basic_istream<C, T> is the same type as
1444     std::istream then print it as std::istream.
1445     """
1446
1447     def __init__(self, match, name):
1448         self.match = match
1449         self.name = name
1450         self.enabled = True
1451
1452     class _recognizer(object):
1453         "The recognizer class for TemplateTypePrinter."
1454
1455         def __init__(self, match, name):
1456             self.match = match
1457             self.name = name
1458             self.type_obj = None
1459
1460         def recognize(self, type_obj):
1461             """
1462             If type_obj starts with self.match and is the same type as
1463             self.name then return self.name, otherwise None.
1464             """
1465             if type_obj.tag is None:
1466                 return None
1467
1468             if self.type_obj is None:
1469                 if not type_obj.tag.startswith(self.match):
1470                     # Filter didn't match.
1471                     return None
1472                 try:
1473                     self.type_obj = gdb.lookup_type(self.name).strip_typedefs()
1474                 except:
1475                     pass
1476             if self.type_obj == type_obj:
1477                 return strip_inline_namespaces(self.name)
1478             return None
1479
1480     def instantiate(self):
1481         "Return a recognizer object for this type printer."
1482         return self._recognizer(self.match, self.name)
1483
1484 def add_one_type_printer(obj, match, name):
1485     printer = FilteringTypePrinter('std::' + match, 'std::' + name)
1486     gdb.types.register_type_printer(obj, printer)
1487     if _versioned_namespace:
1488         ns = 'std::' + _versioned_namespace
1489         printer = FilteringTypePrinter(ns + match, ns + name)
1490         gdb.types.register_type_printer(obj, printer)
1491
1492 def register_type_printers(obj):
1493     global _use_type_printing
1494
1495     if not _use_type_printing:
1496         return
1497
1498     # Add type printers for typedefs std::string, std::wstring etc.
1499     for ch in ('', 'w', 'u16', 'u32'):
1500         add_one_type_printer(obj, 'basic_string', ch + 'string')
1501         add_one_type_printer(obj, '__cxx11::basic_string',
1502                              '__cxx11::' + ch + 'string')
1503         add_one_type_printer(obj, 'basic_string_view', ch + 'string_view')
1504
1505     # Add type printers for typedefs std::istream, std::wistream etc.
1506     for ch in ('', 'w'):
1507         for x in ('ios', 'streambuf', 'istream', 'ostream', 'iostream',
1508                   'filebuf', 'ifstream', 'ofstream', 'fstream'):
1509             add_one_type_printer(obj, 'basic_' + x, ch + x)
1510         for x in ('stringbuf', 'istringstream', 'ostringstream',
1511                   'stringstream'):
1512             add_one_type_printer(obj, 'basic_' + x, ch + x)
1513             # <sstream> types are in __cxx11 namespace, but typedefs aren'x:
1514             add_one_type_printer(obj, '__cxx11::basic_' + x, ch + x)
1515
1516     # Add type printers for typedefs regex, wregex, cmatch, wcmatch etc.
1517     for abi in ('', '__cxx11::'):
1518         for ch in ('', 'w'):
1519             add_one_type_printer(obj, abi + 'basic_regex', abi + ch + 'regex')
1520         for ch in ('c', 's', 'wc', 'ws'):
1521             add_one_type_printer(obj, abi + 'match_results', abi + ch + 'match')
1522             for x in ('sub_match', 'regex_iterator', 'regex_token_iterator'):
1523                 add_one_type_printer(obj, abi + x, abi + ch + x)
1524
1525     # Note that we can't have a printer for std::wstreampos, because
1526     # it is the same type as std::streampos.
1527     add_one_type_printer(obj, 'fpos', 'streampos')
1528
1529     # Add type printers for <chrono> typedefs.
1530     for dur in ('nanoseconds', 'microseconds', 'milliseconds',
1531                 'seconds', 'minutes', 'hours'):
1532         add_one_type_printer(obj, 'duration', dur)
1533
1534     # Add type printers for <random> typedefs.
1535     add_one_type_printer(obj, 'linear_congruential_engine', 'minstd_rand0')
1536     add_one_type_printer(obj, 'linear_congruential_engine', 'minstd_rand')
1537     add_one_type_printer(obj, 'mersenne_twister_engine', 'mt19937')
1538     add_one_type_printer(obj, 'mersenne_twister_engine', 'mt19937_64')
1539     add_one_type_printer(obj, 'subtract_with_carry_engine', 'ranlux24_base')
1540     add_one_type_printer(obj, 'subtract_with_carry_engine', 'ranlux48_base')
1541     add_one_type_printer(obj, 'discard_block_engine', 'ranlux24')
1542     add_one_type_printer(obj, 'discard_block_engine', 'ranlux48')
1543     add_one_type_printer(obj, 'shuffle_order_engine', 'knuth_b')
1544
1545     # Add type printers for experimental::basic_string_view typedefs.
1546     ns = 'experimental::fundamentals_v1::'
1547     for ch in ('', 'w', 'u16', 'u32'):
1548         add_one_type_printer(obj, ns + 'basic_string_view',
1549                              ns + ch + 'string_view')
1550
1551     # Do not show defaulted template arguments in class templates.
1552     add_one_template_type_printer(obj, 'unique_ptr',
1553             { 1: 'std::default_delete<{0}>' })
1554     add_one_template_type_printer(obj, 'deque', { 1: 'std::allocator<{0}>'})
1555     add_one_template_type_printer(obj, 'forward_list', { 1: 'std::allocator<{0}>'})
1556     add_one_template_type_printer(obj, 'list', { 1: 'std::allocator<{0}>'})
1557     add_one_template_type_printer(obj, '__cxx11::list', { 1: 'std::allocator<{0}>'})
1558     add_one_template_type_printer(obj, 'vector', { 1: 'std::allocator<{0}>'})
1559     add_one_template_type_printer(obj, 'map',
1560             { 2: 'std::less<{0}>',
1561               3: 'std::allocator<std::pair<{0} const, {1}>>' })
1562     add_one_template_type_printer(obj, 'multimap',
1563             { 2: 'std::less<{0}>',
1564               3: 'std::allocator<std::pair<{0} const, {1}>>' })
1565     add_one_template_type_printer(obj, 'set',
1566             { 1: 'std::less<{0}>', 2: 'std::allocator<{0}>' })
1567     add_one_template_type_printer(obj, 'multiset',
1568             { 1: 'std::less<{0}>', 2: 'std::allocator<{0}>' })
1569     add_one_template_type_printer(obj, 'unordered_map',
1570             { 2: 'std::hash<{0}>',
1571               3: 'std::equal_to<{0}>',
1572               4: 'std::allocator<std::pair<{0} const, {1}>>'})
1573     add_one_template_type_printer(obj, 'unordered_multimap',
1574             { 2: 'std::hash<{0}>',
1575               3: 'std::equal_to<{0}>',
1576               4: 'std::allocator<std::pair<{0} const, {1}>>'})
1577     add_one_template_type_printer(obj, 'unordered_set',
1578             { 1: 'std::hash<{0}>',
1579               2: 'std::equal_to<{0}>',
1580               3: 'std::allocator<{0}>'})
1581     add_one_template_type_printer(obj, 'unordered_multiset',
1582             { 1: 'std::hash<{0}>',
1583               2: 'std::equal_to<{0}>',
1584               3: 'std::allocator<{0}>'})
1585
1586 def register_libstdcxx_printers (obj):
1587     "Register libstdc++ pretty-printers with objfile Obj."
1588
1589     global _use_gdb_pp
1590     global libstdcxx_printer
1591
1592     if _use_gdb_pp:
1593         gdb.printing.register_pretty_printer(obj, libstdcxx_printer)
1594     else:
1595         if obj is None:
1596             obj = gdb
1597         obj.pretty_printers.append(libstdcxx_printer)
1598
1599     register_type_printers(obj)
1600
1601 def build_libstdcxx_dictionary ():
1602     global libstdcxx_printer
1603
1604     libstdcxx_printer = Printer("libstdc++-v6")
1605
1606     # libstdc++ objects requiring pretty-printing.
1607     # In order from:
1608     # http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/a01847.html
1609     libstdcxx_printer.add_version('std::', 'basic_string', StdStringPrinter)
1610     libstdcxx_printer.add_version('std::__cxx11::', 'basic_string', StdStringPrinter)
1611     libstdcxx_printer.add_container('std::', 'bitset', StdBitsetPrinter)
1612     libstdcxx_printer.add_container('std::', 'deque', StdDequePrinter)
1613     libstdcxx_printer.add_container('std::', 'list', StdListPrinter)
1614     libstdcxx_printer.add_container('std::__cxx11::', 'list', StdListPrinter)
1615     libstdcxx_printer.add_container('std::', 'map', StdMapPrinter)
1616     libstdcxx_printer.add_container('std::', 'multimap', StdMapPrinter)
1617     libstdcxx_printer.add_container('std::', 'multiset', StdSetPrinter)
1618     libstdcxx_printer.add_version('std::', 'priority_queue',
1619                                   StdStackOrQueuePrinter)
1620     libstdcxx_printer.add_version('std::', 'queue', StdStackOrQueuePrinter)
1621     libstdcxx_printer.add_version('std::', 'tuple', StdTuplePrinter)
1622     libstdcxx_printer.add_container('std::', 'set', StdSetPrinter)
1623     libstdcxx_printer.add_version('std::', 'stack', StdStackOrQueuePrinter)
1624     libstdcxx_printer.add_version('std::', 'unique_ptr', UniquePointerPrinter)
1625     libstdcxx_printer.add_container('std::', 'vector', StdVectorPrinter)
1626     # vector<bool>
1627
1628     # Printer registrations for classes compiled with -D_GLIBCXX_DEBUG.
1629     libstdcxx_printer.add('std::__debug::bitset', StdBitsetPrinter)
1630     libstdcxx_printer.add('std::__debug::deque', StdDequePrinter)
1631     libstdcxx_printer.add('std::__debug::list', StdListPrinter)
1632     libstdcxx_printer.add('std::__debug::map', StdMapPrinter)
1633     libstdcxx_printer.add('std::__debug::multimap', StdMapPrinter)
1634     libstdcxx_printer.add('std::__debug::multiset', StdSetPrinter)
1635     libstdcxx_printer.add('std::__debug::priority_queue',
1636                           StdStackOrQueuePrinter)
1637     libstdcxx_printer.add('std::__debug::queue', StdStackOrQueuePrinter)
1638     libstdcxx_printer.add('std::__debug::set', StdSetPrinter)
1639     libstdcxx_printer.add('std::__debug::stack', StdStackOrQueuePrinter)
1640     libstdcxx_printer.add('std::__debug::unique_ptr', UniquePointerPrinter)
1641     libstdcxx_printer.add('std::__debug::vector', StdVectorPrinter)
1642
1643     # These are the TR1 and C++11 printers.
1644     # For array - the default GDB pretty-printer seems reasonable.
1645     libstdcxx_printer.add_version('std::', 'shared_ptr', SharedPointerPrinter)
1646     libstdcxx_printer.add_version('std::', 'weak_ptr', SharedPointerPrinter)
1647     libstdcxx_printer.add_container('std::', 'unordered_map',
1648                                     Tr1UnorderedMapPrinter)
1649     libstdcxx_printer.add_container('std::', 'unordered_set',
1650                                     Tr1UnorderedSetPrinter)
1651     libstdcxx_printer.add_container('std::', 'unordered_multimap',
1652                                     Tr1UnorderedMapPrinter)
1653     libstdcxx_printer.add_container('std::', 'unordered_multiset',
1654                                     Tr1UnorderedSetPrinter)
1655     libstdcxx_printer.add_container('std::', 'forward_list',
1656                                     StdForwardListPrinter)
1657
1658     libstdcxx_printer.add_version('std::tr1::', 'shared_ptr', SharedPointerPrinter)
1659     libstdcxx_printer.add_version('std::tr1::', 'weak_ptr', SharedPointerPrinter)
1660     libstdcxx_printer.add_version('std::tr1::', 'unordered_map',
1661                                   Tr1UnorderedMapPrinter)
1662     libstdcxx_printer.add_version('std::tr1::', 'unordered_set',
1663                                   Tr1UnorderedSetPrinter)
1664     libstdcxx_printer.add_version('std::tr1::', 'unordered_multimap',
1665                                   Tr1UnorderedMapPrinter)
1666     libstdcxx_printer.add_version('std::tr1::', 'unordered_multiset',
1667                                   Tr1UnorderedSetPrinter)
1668
1669     # These are the C++11 printer registrations for -D_GLIBCXX_DEBUG cases.
1670     # The tr1 namespace containers do not have any debug equivalents,
1671     # so do not register printers for them.
1672     libstdcxx_printer.add('std::__debug::unordered_map',
1673                           Tr1UnorderedMapPrinter)
1674     libstdcxx_printer.add('std::__debug::unordered_set',
1675                           Tr1UnorderedSetPrinter)
1676     libstdcxx_printer.add('std::__debug::unordered_multimap',
1677                           Tr1UnorderedMapPrinter)
1678     libstdcxx_printer.add('std::__debug::unordered_multiset',
1679                           Tr1UnorderedSetPrinter)
1680     libstdcxx_printer.add('std::__debug::forward_list',
1681                           StdForwardListPrinter)
1682
1683     # Library Fundamentals TS components
1684     libstdcxx_printer.add_version('std::experimental::fundamentals_v1::',
1685                                   'any', StdExpAnyPrinter)
1686     libstdcxx_printer.add_version('std::experimental::fundamentals_v1::',
1687                                   'optional', StdExpOptionalPrinter)
1688     libstdcxx_printer.add_version('std::experimental::fundamentals_v1::',
1689                                   'basic_string_view', StdExpStringViewPrinter)
1690     # Filesystem TS components
1691     libstdcxx_printer.add_version('std::experimental::filesystem::v1::',
1692                                   'path', StdExpPathPrinter)
1693     libstdcxx_printer.add_version('std::experimental::filesystem::v1::__cxx11::',
1694                                   'path', StdExpPathPrinter)
1695     libstdcxx_printer.add_version('std::filesystem::',
1696                                   'path', StdExpPathPrinter)
1697     libstdcxx_printer.add_version('std::filesystem::__cxx11::',
1698                                   'path', StdExpPathPrinter)
1699
1700     # C++17 components
1701     libstdcxx_printer.add_version('std::',
1702                                   'any', StdExpAnyPrinter)
1703     libstdcxx_printer.add_version('std::',
1704                                   'optional', StdExpOptionalPrinter)
1705     libstdcxx_printer.add_version('std::',
1706                                   'basic_string_view', StdExpStringViewPrinter)
1707     libstdcxx_printer.add_version('std::',
1708                                   'variant', StdVariantPrinter)
1709     libstdcxx_printer.add_version('std::',
1710                                   '_Node_handle', StdNodeHandlePrinter)
1711
1712     # Extensions.
1713     libstdcxx_printer.add_version('__gnu_cxx::', 'slist', StdSlistPrinter)
1714
1715     if True:
1716         # These shouldn't be necessary, if GDB "print *i" worked.
1717         # But it often doesn't, so here they are.
1718         libstdcxx_printer.add_container('std::', '_List_iterator',
1719                                         StdListIteratorPrinter)
1720         libstdcxx_printer.add_container('std::', '_List_const_iterator',
1721                                         StdListIteratorPrinter)
1722         libstdcxx_printer.add_version('std::', '_Rb_tree_iterator',
1723                                       StdRbtreeIteratorPrinter)
1724         libstdcxx_printer.add_version('std::', '_Rb_tree_const_iterator',
1725                                       StdRbtreeIteratorPrinter)
1726         libstdcxx_printer.add_container('std::', '_Deque_iterator',
1727                                         StdDequeIteratorPrinter)
1728         libstdcxx_printer.add_container('std::', '_Deque_const_iterator',
1729                                         StdDequeIteratorPrinter)
1730         libstdcxx_printer.add_version('__gnu_cxx::', '__normal_iterator',
1731                                       StdVectorIteratorPrinter)
1732         libstdcxx_printer.add_version('__gnu_cxx::', '_Slist_iterator',
1733                                       StdSlistIteratorPrinter)
1734
1735         # Debug (compiled with -D_GLIBCXX_DEBUG) printer
1736         # registrations.  The Rb_tree debug iterator when unwrapped
1737         # from the encapsulating __gnu_debug::_Safe_iterator does not
1738         # have the __norm namespace. Just use the existing printer
1739         # registration for that.
1740         libstdcxx_printer.add('__gnu_debug::_Safe_iterator',
1741                               StdDebugIteratorPrinter)
1742         libstdcxx_printer.add('std::__norm::_List_iterator',
1743                               StdListIteratorPrinter)
1744         libstdcxx_printer.add('std::__norm::_List_const_iterator',
1745                               StdListIteratorPrinter)
1746         libstdcxx_printer.add('std::__norm::_Deque_const_iterator',
1747                               StdDequeIteratorPrinter)
1748         libstdcxx_printer.add('std::__norm::_Deque_iterator',
1749                               StdDequeIteratorPrinter)
1750
1751 build_libstdcxx_dictionary ()