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 NodeIteratorPrinter:
 253     def __init__(self, typename, val, contname):
 254         self.val = val
 255         self.typename = typename
 256         self.contname = contname
 257
 258     def to_string(self):
 259         if not self.val['_M_node']:
 260             return 'non-dereferenceable iterator for std::%s' % (self.contname)
 261         nodetype = find_type(self.val.type, '_Node')
 262         nodetype = nodetype.strip_typedefs().pointer()
 263         node = self.val['_M_node'].cast(nodetype).dereference()
 264         return str(get_value_from_list_node(node))
 265
 266 class StdListIteratorPrinter(NodeIteratorPrinter):
 267     "Print std::list::iterator"
 268
 269     def __init__(self, typename, val):
 270         NodeIteratorPrinter.__init__(self, typename, val, 'list')
 271
 272 class StdFwdListIteratorPrinter(NodeIteratorPrinter):
 273     "Print std::forward_list::iterator"
 274
 275     def __init__(self, typename, val):
 276         NodeIteratorPrinter.__init__(self, typename, val, 'forward_list')
 277
 278 class StdSlistPrinter:
 279     "Print a __gnu_cxx::slist"
 280
 281     class _iterator(Iterator):
 282         def __init__(self, nodetype, head):
 283             self.nodetype = nodetype
 284             self.base = head['_M_head']['_M_next']
 285             self.count = 0
 286
 287         def __iter__(self):
 288             return self
 289
 290         def __next__(self):
 291             if self.base == 0:
 292                 raise StopIteration
 293             elt = self.base.cast(self.nodetype).dereference()
 294             self.base = elt['_M_next']
 295             count = self.count
 296             self.count = self.count + 1
 297             return ('[%d]' % count, elt['_M_data'])
 298
 299     def __init__(self, typename, val):
 300         self.val = val
 301
 302     def children(self):
 303         nodetype = find_type(self.val.type, '_Node')
 304         nodetype = nodetype.strip_typedefs().pointer()
 305         return self._iterator(nodetype, self.val)
 306
 307     def to_string(self):
 308         if self.val['_M_head']['_M_next'] == 0:
 309             return 'empty __gnu_cxx::slist'
 310         return '__gnu_cxx::slist'
 311
 312 class StdSlistIteratorPrinter:
 313     "Print __gnu_cxx::slist::iterator"
 314
 315     def __init__(self, typename, val):
 316         self.val = val
 317
 318     def to_string(self):
 319         if not self.val['_M_node']:
 320             return 'non-dereferenceable iterator for __gnu_cxx::slist'
 321         nodetype = find_type(self.val.type, '_Node')
 322         nodetype = nodetype.strip_typedefs().pointer()
 323         return str(self.val['_M_node'].cast(nodetype).dereference()['_M_data'])
 324
 325 class StdVectorPrinter:
 326     "Print a std::vector"
 327
 328     class _iterator(Iterator):
 329         def __init__ (self, start, finish, bitvec):
 330             self.bitvec = bitvec
 331             if bitvec:
 332                 self.item   = start['_M_p']
 333                 self.so     = start['_M_offset']
 334                 self.finish = finish['_M_p']
 335                 self.fo     = finish['_M_offset']
 336                 itype = self.item.dereference().type
 337                 self.isize = 8 * itype.sizeof
 338             else:
 339                 self.item = start
 340                 self.finish = finish
 341             self.count = 0
 342
 343         def __iter__(self):
 344             return self
 345
 346         def __next__(self):
 347             count = self.count
 348             self.count = self.count + 1
 349             if self.bitvec:
 350                 if self.item == self.finish and self.so >= self.fo:
 351                     raise StopIteration
 352                 elt = self.item.dereference()
 353                 if elt & (1 << self.so):
 354                     obit = 1
 355                 else:
 356                     obit = 0
 357                 self.so = self.so + 1
 358                 if self.so >= self.isize:
 359                     self.item = self.item + 1
 360                     self.so = 0
 361                 return ('[%d]' % count, obit)
 362             else:
 363                 if self.item == self.finish:
 364                     raise StopIteration
 365                 elt = self.item.dereference()
 366                 self.item = self.item + 1
 367                 return ('[%d]' % count, elt)
 368
 369     def __init__(self, typename, val):
 370         self.typename = strip_versioned_namespace(typename)
 371         self.val = val
 372         self.is_bool = val.type.template_argument(0).code  == gdb.TYPE_CODE_BOOL
 373
 374     def children(self):
 375         return self._iterator(self.val['_M_impl']['_M_start'],
 376                               self.val['_M_impl']['_M_finish'],
 377                               self.is_bool)
 378
 379     def to_string(self):
 380         start = self.val['_M_impl']['_M_start']
 381         finish = self.val['_M_impl']['_M_finish']
 382         end = self.val['_M_impl']['_M_end_of_storage']
 383         if self.is_bool:
 384             start = self.val['_M_impl']['_M_start']['_M_p']
 385             so    = self.val['_M_impl']['_M_start']['_M_offset']
 386             finish = self.val['_M_impl']['_M_finish']['_M_p']
 387             fo     = self.val['_M_impl']['_M_finish']['_M_offset']
 388             itype = start.dereference().type
 389             bl = 8 * itype.sizeof
 390             length   = (bl - so) + bl * ((finish - start) - 1) + fo
 391             capacity = bl * (end - start)
 392             return ('%s<bool> of length %d, capacity %d'
 393                     % (self.typename, int (length), int (capacity)))
 394         else:
 395             return ('%s of length %d, capacity %d'
 396                     % (self.typename, int (finish - start), int (end - start)))
 397
 398     def display_hint(self):
 399         return 'array'
 400
 401 class StdVectorIteratorPrinter:
 402     "Print std::vector::iterator"
 403
 404     def __init__(self, typename, val):
 405         self.val = val
 406
 407     def to_string(self):
 408         if not self.val['_M_current']:
 409             return 'non-dereferenceable iterator for std::vector'
 410         return str(self.val['_M_current'].dereference())
 411
 412 class StdTuplePrinter:
 413     "Print a std::tuple"
 414
 415     class _iterator(Iterator):
 416         def __init__ (self, head):
 417             self.head = head
 418
 419             # Set the base class as the initial head of the
 420             # tuple.
 421             nodes = self.head.type.fields ()
 422             if len (nodes) == 1:
 423                 # Set the actual head to the first pair.
 424                 self.head  = self.head.cast (nodes[0].type)
 425             elif len (nodes) != 0:
 426                 raise ValueError("Top of tuple tree does not consist of a single node.")
 427             self.count = 0
 428
 429         def __iter__ (self):
 430             return self
 431
 432         def __next__ (self):
 433             # Check for further recursions in the inheritance tree.
 434             # For a GCC 5+ tuple self.head is None after visiting all nodes:
 435             if not self.head:
 436                 raise StopIteration
 437             nodes = self.head.type.fields ()
 438             # For a GCC 4.x tuple there is a final node with no fields:
 439             if len (nodes) == 0:
 440                 raise StopIteration
 441             # Check that this iteration has an expected structure.
 442             if len (nodes) > 2:
 443                 raise ValueError("Cannot parse more than 2 nodes in a tuple tree.")
 444
 445             if len (nodes) == 1:
 446                 # This is the last node of a GCC 5+ std::tuple.
 447                 impl = self.head.cast (nodes[0].type)
 448                 self.head = None
 449             else:
 450                 # Either a node before the last node, or the last node of
 451                 # a GCC 4.x tuple (which has an empty parent).
 452
 453                 # - Left node is the next recursion parent.
 454                 # - Right node is the actual class contained in the tuple.
 455
 456                 # Process right node.
 457                 impl = self.head.cast (nodes[1].type)
 458
 459                 # Process left node and set it as head.
 460                 self.head  = self.head.cast (nodes[0].type)
 461
 462             self.count = self.count + 1
 463
 464             # Finally, check the implementation.  If it is
 465             # wrapped in _M_head_impl return that, otherwise return
 466             # the value "as is".
 467             fields = impl.type.fields ()
 468             if len (fields) < 1 or fields[0].name != "_M_head_impl":
 469                 return ('[%d]' % self.count, impl)
 470             else:
 471                 return ('[%d]' % self.count, impl['_M_head_impl'])
 472
 473     def __init__ (self, typename, val):
 474         self.typename = strip_versioned_namespace(typename)
 475         self.val = val;
 476
 477     def children (self):
 478         return self._iterator (self.val)
 479
 480     def to_string (self):
 481         if len (self.val.type.fields ()) == 0:
 482             return 'empty %s' % (self.typename)
 483         return '%s containing' % (self.typename)
 484
 485 class StdStackOrQueuePrinter:
 486     "Print a std::stack or std::queue"
 487
 488     def __init__ (self, typename, val):
 489         self.typename = strip_versioned_namespace(typename)
 490         self.visualizer = gdb.default_visualizer(val['c'])
 491
 492     def children (self):
 493         return self.visualizer.children()
 494
 495     def to_string (self):
 496         return '%s wrapping: %s' % (self.typename,
 497                                     self.visualizer.to_string())
 498
 499     def display_hint (self):
 500         if hasattr (self.visualizer, 'display_hint'):
 501             return self.visualizer.display_hint ()
 502         return None
 503
 504 class RbtreeIterator(Iterator):
 505     """
 506     Turn an RB-tree-based container (std::map, std::set etc.) into
 507     a Python iterable object.
 508     """
 509
 510     def __init__(self, rbtree):
 511         self.size = rbtree['_M_t']['_M_impl']['_M_node_count']
 512         self.node = rbtree['_M_t']['_M_impl']['_M_header']['_M_left']
 513         self.count = 0
 514
 515     def __iter__(self):
 516         return self
 517
 518     def __len__(self):
 519         return int (self.size)
 520
 521     def __next__(self):
 522         if self.count == self.size:
 523             raise StopIteration
 524         result = self.node
 525         self.count = self.count + 1
 526         if self.count < self.size:
 527             # Compute the next node.
 528             node = self.node
 529             if node.dereference()['_M_right']:
 530                 node = node.dereference()['_M_right']
 531                 while node.dereference()['_M_left']:
 532                     node = node.dereference()['_M_left']
 533             else:
 534                 parent = node.dereference()['_M_parent']
 535                 while node == parent.dereference()['_M_right']:
 536                     node = parent
 537                     parent = parent.dereference()['_M_parent']
 538                 if node.dereference()['_M_right'] != parent:
 539                     node = parent
 540             self.node = node
 541         return result
 542
 543 def get_value_from_Rb_tree_node(node):
 544     """Returns the value held in an _Rb_tree_node<_Val>"""
 545     try:
 546         member = node.type.fields()[1].name
 547         if member == '_M_value_field':
 548             # C++03 implementation, node contains the value as a member
 549             return node['_M_value_field']
 550         elif member == '_M_storage':
 551             # C++11 implementation, node stores value in __aligned_membuf
 552             valtype = node.type.template_argument(0)
 553             return get_value_from_aligned_membuf(node['_M_storage'], valtype)
 554     except:
 555         pass
 556     raise ValueError("Unsupported implementation for %s" % str(node.type))
 557
 558 # This is a pretty printer for std::_Rb_tree_iterator (which is
 559 # std::map::iterator), and has nothing to do with the RbtreeIterator
 560 # class above.
 561 class StdRbtreeIteratorPrinter:
 562     "Print std::map::iterator, std::set::iterator, etc."
 563
 564     def __init__ (self, typename, val):
 565         self.val = val
 566         valtype = self.val.type.template_argument(0).strip_typedefs()
 567         nodetype = '_Rb_tree_node<' + str(valtype) + '>'
 568         if _versioned_namespace and typename.startswith('std::' + _versioned_namespace):
 569             nodetype = _versioned_namespace + nodetype
 570         nodetype = gdb.lookup_type('std::' + nodetype)
 571         self.link_type = nodetype.strip_typedefs().pointer()
 572
 573     def to_string (self):
 574         if not self.val['_M_node']:
 575             return 'non-dereferenceable iterator for associative container'
 576         node = self.val['_M_node'].cast(self.link_type).dereference()
 577         return str(get_value_from_Rb_tree_node(node))
 578
 579 class StdDebugIteratorPrinter:
 580     "Print a debug enabled version of an iterator"
 581
 582     def __init__ (self, typename, val):
 583         self.val = val
 584
 585     # Just strip away the encapsulating __gnu_debug::_Safe_iterator
 586     # and return the wrapped iterator value.
 587     def to_string (self):
 588         base_type = gdb.lookup_type('__gnu_debug::_Safe_iterator_base')
 589         itype = self.val.type.template_argument(0)
 590         safe_seq = self.val.cast(base_type)['_M_sequence']
 591         if not safe_seq:
 592             return str(self.val.cast(itype))
 593         if self.val['_M_version'] != safe_seq['_M_version']:
 594             return "invalid iterator"
 595         return str(self.val.cast(itype))
 596
 597 def num_elements(num):
 598     """Return either "1 element" or "N elements" depending on the argument."""
 599     return '1 element' if num == 1 else '%d elements' % num
 600
 601 class StdMapPrinter:
 602     "Print a std::map or std::multimap"
 603
 604     # Turn an RbtreeIterator into a pretty-print iterator.
 605     class _iter(Iterator):
 606         def __init__(self, rbiter, type):
 607             self.rbiter = rbiter
 608             self.count = 0
 609             self.type = type
 610
 611         def __iter__(self):
 612             return self
 613
 614         def __next__(self):
 615             if self.count % 2 == 0:
 616                 n = next(self.rbiter)
 617                 n = n.cast(self.type).dereference()
 618                 n = get_value_from_Rb_tree_node(n)
 619                 self.pair = n
 620                 item = n['first']
 621             else:
 622                 item = self.pair['second']
 623             result = ('[%d]' % self.count, item)
 624             self.count = self.count + 1
 625             return result
 626
 627     def __init__ (self, typename, val):
 628         self.typename = strip_versioned_namespace(typename)
 629         self.val = val
 630
 631     def to_string (self):
 632         return '%s with %s' % (self.typename,
 633                                num_elements(len(RbtreeIterator (self.val))))
 634
 635     def children (self):
 636         rep_type = find_type(self.val.type, '_Rep_type')
 637         node = find_type(rep_type, '_Link_type')
 638         node = node.strip_typedefs()
 639         return self._iter (RbtreeIterator (self.val), node)
 640
 641     def display_hint (self):
 642         return 'map'
 643
 644 class StdSetPrinter:
 645     "Print a std::set or std::multiset"
 646
 647     # Turn an RbtreeIterator into a pretty-print iterator.
 648     class _iter(Iterator):
 649         def __init__(self, rbiter, type):
 650             self.rbiter = rbiter
 651             self.count = 0
 652             self.type = type
 653
 654         def __iter__(self):
 655             return self
 656
 657         def __next__(self):
 658             item = next(self.rbiter)
 659             item = item.cast(self.type).dereference()
 660             item = get_value_from_Rb_tree_node(item)
 661             # FIXME: this is weird ... what to do?
 662             # Maybe a 'set' display hint?
 663             result = ('[%d]' % self.count, item)
 664             self.count = self.count + 1
 665             return result
 666
 667     def __init__ (self, typename, val):
 668         self.typename = strip_versioned_namespace(typename)
 669         self.val = val
 670
 671     def to_string (self):
 672         return '%s with %s' % (self.typename,
 673                                num_elements(len(RbtreeIterator (self.val))))
 674
 675     def children (self):
 676         rep_type = find_type(self.val.type, '_Rep_type')
 677         node = find_type(rep_type, '_Link_type')
 678         node = node.strip_typedefs()
 679         return self._iter (RbtreeIterator (self.val), node)
 680
 681 class StdBitsetPrinter:
 682     "Print a std::bitset"
 683
 684     def __init__(self, typename, val):
 685         self.typename = strip_versioned_namespace(typename)
 686         self.val = val
 687
 688     def to_string (self):
 689         # If template_argument handled values, we could print the
 690         # size.  Or we could use a regexp on the type.
 691         return '%s' % (self.typename)
 692
 693     def children (self):
 694         words = self.val['_M_w']
 695         wtype = words.type
 696
 697         # The _M_w member can be either an unsigned long, or an
 698         # array.  This depends on the template specialization used.
 699         # If it is a single long, convert to a single element list.
 700         if wtype.code == gdb.TYPE_CODE_ARRAY:
 701             tsize = wtype.target ().sizeof
 702         else:
 703             words = [words]
 704             tsize = wtype.sizeof
 705
 706         nwords = wtype.sizeof / tsize
 707         result = []
 708         byte = 0
 709         while byte < nwords:
 710             w = words[byte]
 711             bit = 0
 712             while w != 0:
 713                 if (w & 1) != 0:
 714                     # Another spot where we could use 'set'?
 715                     result.append(('[%d]' % (byte * tsize * 8 + bit), 1))
 716                 bit = bit + 1
 717                 w = w >> 1
 718             byte = byte + 1
 719         return result
 720
 721 class StdDequePrinter:
 722     "Print a std::deque"
 723
 724     class _iter(Iterator):
 725         def __init__(self, node, start, end, last, buffer_size):
 726             self.node = node
 727             self.p = start
 728             self.end = end
 729             self.last = last
 730             self.buffer_size = buffer_size
 731             self.count = 0
 732
 733         def __iter__(self):
 734             return self
 735
 736         def __next__(self):
 737             if self.p == self.last:
 738                 raise StopIteration
 739
 740             result = ('[%d]' % self.count, self.p.dereference())
 741             self.count = self.count + 1
 742
 743             # Advance the 'cur' pointer.
 744             self.p = self.p + 1
 745             if self.p == self.end:
 746                 # If we got to the end of this bucket, move to the
 747                 # next bucket.
 748                 self.node = self.node + 1
 749                 self.p = self.node[0]
 750                 self.end = self.p + self.buffer_size
 751
 752             return result
 753
 754     def __init__(self, typename, val):
 755         self.typename = strip_versioned_namespace(typename)
 756         self.val = val
 757         self.elttype = val.type.template_argument(0)
 758         size = self.elttype.sizeof
 759         if size < 512:
 760             self.buffer_size = int (512 / size)
 761         else:
 762             self.buffer_size = 1
 763
 764     def to_string(self):
 765         start = self.val['_M_impl']['_M_start']
 766         end = self.val['_M_impl']['_M_finish']
 767
 768         delta_n = end['_M_node'] - start['_M_node'] - 1
 769         delta_s = start['_M_last'] - start['_M_cur']
 770         delta_e = end['_M_cur'] - end['_M_first']
 771
 772         size = self.buffer_size * delta_n + delta_s + delta_e
 773
 774         return '%s with %s' % (self.typename, num_elements(long(size)))
 775
 776     def children(self):
 777         start = self.val['_M_impl']['_M_start']
 778         end = self.val['_M_impl']['_M_finish']
 779         return self._iter(start['_M_node'], start['_M_cur'], start['_M_last'],
 780                           end['_M_cur'], self.buffer_size)
 781
 782     def display_hint (self):
 783         return 'array'
 784
 785 class StdDequeIteratorPrinter:
 786     "Print std::deque::iterator"
 787
 788     def __init__(self, typename, val):
 789         self.val = val
 790
 791     def to_string(self):
 792         if not self.val['_M_cur']:
 793             return 'non-dereferenceable iterator for std::deque'
 794         return str(self.val['_M_cur'].dereference())
 795
 796 class StdStringPrinter:
 797     "Print a std::basic_string of some kind"
 798
 799     def __init__(self, typename, val):
 800         self.val = val
 801         self.new_string = typename.find("::__cxx11::basic_string") != -1
 802
 803     def to_string(self):
 804         # Make sure &string works, too.
 805         type = self.val.type
 806         if type.code == gdb.TYPE_CODE_REF:
 807             type = type.target ()
 808
 809         # Calculate the length of the string so that to_string returns
 810         # the string according to length, not according to first null
 811         # encountered.
 812         ptr = self.val ['_M_dataplus']['_M_p']
 813         if self.new_string:
 814             length = self.val['_M_string_length']
 815             # https://sourceware.org/bugzilla/show_bug.cgi?id=17728
 816             ptr = ptr.cast(ptr.type.strip_typedefs())
 817         else:
 818             realtype = type.unqualified ().strip_typedefs ()
 819             reptype = gdb.lookup_type (str (realtype) + '::_Rep').pointer ()
 820             header = ptr.cast(reptype) - 1
 821             length = header.dereference ()['_M_length']
 822         if hasattr(ptr, "lazy_string"):
 823             return ptr.lazy_string (length = length)
 824         return ptr.string (length = length)
 825
 826     def display_hint (self):
 827         return 'string'
 828
 829 class Tr1HashtableIterator(Iterator):
 830     def __init__ (self, hash):
 831         self.buckets = hash['_M_buckets']
 832         self.bucket = 0
 833         self.bucket_count = hash['_M_bucket_count']
 834         self.node_type = find_type(hash.type, '_Node').pointer()
 835         self.node = 0
 836         while self.bucket != self.bucket_count:
 837             self.node = self.buckets[self.bucket]
 838             if self.node:
 839                 break
 840             self.bucket = self.bucket + 1
 841
 842     def __iter__ (self):
 843         return self
 844
 845     def __next__ (self):
 846         if self.node == 0:
 847             raise StopIteration
 848         node = self.node.cast(self.node_type)
 849         result = node.dereference()['_M_v']
 850         self.node = node.dereference()['_M_next'];
 851         if self.node == 0:
 852             self.bucket = self.bucket + 1
 853             while self.bucket != self.bucket_count:
 854                 self.node = self.buckets[self.bucket]
 855                 if self.node:
 856                     break
 857                 self.bucket = self.bucket + 1
 858         return result
 859
 860 class StdHashtableIterator(Iterator):
 861     def __init__(self, hash):
 862         self.node = hash['_M_before_begin']['_M_nxt']
 863         self.node_type = find_type(hash.type, '__node_type').pointer()
 864
 865     def __iter__(self):
 866         return self
 867
 868     def __next__(self):
 869         if self.node == 0:
 870             raise StopIteration
 871         elt = self.node.cast(self.node_type).dereference()
 872         self.node = elt['_M_nxt']
 873         valptr = elt['_M_storage'].address
 874         valptr = valptr.cast(elt.type.template_argument(0).pointer())
 875         return valptr.dereference()
 876
 877 class Tr1UnorderedSetPrinter:
 878     "Print a tr1::unordered_set"
 879
 880     def __init__ (self, typename, val):
 881         self.typename = strip_versioned_namespace(typename)
 882         self.val = val
 883
 884     def hashtable (self):
 885         if self.typename.startswith('std::tr1'):
 886             return self.val
 887         return self.val['_M_h']
 888
 889     def to_string (self):
 890         count = self.hashtable()['_M_element_count']
 891         return '%s with %s' % (self.typename, num_elements(count))
 892
 893     @staticmethod
 894     def format_count (i):
 895         return '[%d]' % i
 896
 897     def children (self):
 898         counter = imap (self.format_count, itertools.count())
 899         if self.typename.startswith('std::tr1'):
 900             return izip (counter, Tr1HashtableIterator (self.hashtable()))
 901         return izip (counter, StdHashtableIterator (self.hashtable()))
 902
 903 class Tr1UnorderedMapPrinter:
 904     "Print a tr1::unordered_map"
 905
 906     def __init__ (self, typename, val):
 907         self.typename = strip_versioned_namespace(typename)
 908         self.val = val
 909
 910     def hashtable (self):
 911         if self.typename.startswith('std::tr1'):
 912             return self.val
 913         return self.val['_M_h']
 914
 915     def to_string (self):
 916         count = self.hashtable()['_M_element_count']
 917         return '%s with %s' % (self.typename, num_elements(count))
 918
 919     @staticmethod
 920     def flatten (list):
 921         for elt in list:
 922             for i in elt:
 923                 yield i
 924
 925     @staticmethod
 926     def format_one (elt):
 927         return (elt['first'], elt['second'])
 928
 929     @staticmethod
 930     def format_count (i):
 931         return '[%d]' % i
 932
 933     def children (self):
 934         counter = imap (self.format_count, itertools.count())
 935         # Map over the hash table and flatten the result.
 936         if self.typename.startswith('std::tr1'):
 937             data = self.flatten (imap (self.format_one, Tr1HashtableIterator (self.hashtable())))
 938             # Zip the two iterators together.
 939             return izip (counter, data)
 940         data = self.flatten (imap (self.format_one, StdHashtableIterator (self.hashtable())))
 941         # Zip the two iterators together.
 942         return izip (counter, data)
 943
 944
 945     def display_hint (self):
 946         return 'map'
 947
 948 class StdForwardListPrinter:
 949     "Print a std::forward_list"
 950
 951     class _iterator(Iterator):
 952         def __init__(self, nodetype, head):
 953             self.nodetype = nodetype
 954             self.base = head['_M_next']
 955             self.count = 0
 956
 957         def __iter__(self):
 958             return self
 959
 960         def __next__(self):
 961             if self.base == 0:
 962                 raise StopIteration
 963             elt = self.base.cast(self.nodetype).dereference()
 964             self.base = elt['_M_next']
 965             count = self.count
 966             self.count = self.count + 1
 967             valptr = elt['_M_storage'].address
 968             valptr = valptr.cast(elt.type.template_argument(0).pointer())
 969             return ('[%d]' % count, valptr.dereference())
 970
 971     def __init__(self, typename, val):
 972         self.val = val
 973         self.typename = strip_versioned_namespace(typename)
 974
 975     def children(self):
 976         nodetype = find_type(self.val.type, '_Node')
 977         nodetype = nodetype.strip_typedefs().pointer()
 978         return self._iterator(nodetype, self.val['_M_impl']['_M_head'])
 979
 980     def to_string(self):
 981         if self.val['_M_impl']['_M_head']['_M_next'] == 0:
 982             return 'empty %s' % self.typename
 983         return '%s' % self.typename
 984
 985 class SingleObjContainerPrinter(object):
 986     "Base class for printers of containers of single objects"
 987
 988     def __init__ (self, val, viz, hint = None):
 989         self.contained_value = val
 990         self.visualizer = viz
 991         self.hint = hint
 992
 993     def _recognize(self, type):
 994         """Return TYPE as a string after applying type printers"""
 995         global _use_type_printing
 996         if not _use_type_printing:
 997             return str(type)
 998         return gdb.types.apply_type_recognizers(gdb.types.get_type_recognizers(),
 999                                                 type) or str(type)
1000
1001     class _contained(Iterator):
1002         def __init__ (self, val):
1003             self.val = val
1004
1005         def __iter__ (self):
1006             return self
1007
1008         def __next__(self):
1009             if self.val is None:
1010                 raise StopIteration
1011             retval = self.val
1012             self.val = None
1013             return ('[contained value]', retval)
1014
1015     def children (self):
1016         if self.contained_value is None:
1017             return self._contained (None)
1018         if hasattr (self.visualizer, 'children'):
1019             return self.visualizer.children ()
1020         return self._contained (self.contained_value)
1021
1022     def display_hint (self):
1023         # if contained value is a map we want to display in the same way
1024         if hasattr (self.visualizer, 'children') and hasattr (self.visualizer, 'display_hint'):
1025             return self.visualizer.display_hint ()
1026         return self.hint
1027
1028 class StdExpAnyPrinter(SingleObjContainerPrinter):
1029     "Print a std::any or std::experimental::any"
1030
1031     def __init__ (self, typename, val):
1032         self.typename = strip_versioned_namespace(typename)
1033         self.typename = re.sub('^std::experimental::fundamentals_v\d::', 'std::experimental::', self.typename, 1)
1034         self.val = val
1035         self.contained_type = None
1036         contained_value = None
1037         visualizer = None
1038         mgr = self.val['_M_manager']
1039         if mgr != 0:
1040             func = gdb.block_for_pc(int(mgr.cast(gdb.lookup_type('intptr_t'))))
1041             if not func:
1042                 raise ValueError("Invalid function pointer in %s" % self.typename)
1043             rx = r"""({0}::_Manager_\w+<.*>)::_S_manage\({0}::_Op, {0} const\*, {0}::_Arg\*\)""".format(typename)
1044             m = re.match(rx, func.function.name)
1045             if not m:
1046                 raise ValueError("Unknown manager function in %s" % self.typename)
1047
1048             mgrname = m.group(1)
1049             # FIXME need to expand 'std::string' so that gdb.lookup_type works
1050             if 'std::string' in mgrname:
1051                 mgrname = re.sub("std::string(?!\w)", str(gdb.lookup_type('std::string').strip_typedefs()), m.group(1))
1052
1053             mgrtype = gdb.lookup_type(mgrname)
1054             self.contained_type = mgrtype.template_argument(0)
1055             valptr = None
1056             if '::_Manager_internal' in mgrname:
1057                 valptr = self.val['_M_storage']['_M_buffer'].address
1058             elif '::_Manager_external' in mgrname:
1059                 valptr = self.val['_M_storage']['_M_ptr']
1060             else:
1061                 raise ValueError("Unknown manager function in %s" % self.typename)
1062             contained_value = valptr.cast(self.contained_type.pointer()).dereference()
1063             visualizer = gdb.default_visualizer(contained_value)
1064         super(StdExpAnyPrinter, self).__init__ (contained_value, visualizer)
1065
1066     def to_string (self):
1067         if self.contained_type is None:
1068             return '%s [no contained value]' % self.typename
1069         desc = "%s containing " % self.typename
1070         if hasattr (self.visualizer, 'children'):
1071             return desc + self.visualizer.to_string ()
1072         valtype = self._recognize (self.contained_type)
1073         return desc + strip_versioned_namespace(str(valtype))
1074
1075 class StdExpOptionalPrinter(SingleObjContainerPrinter):
1076     "Print a std::optional or std::experimental::optional"
1077
1078     def __init__ (self, typename, val):
1079         valtype = self._recognize (val.type.template_argument(0))
1080         self.typename = strip_versioned_namespace(typename)
1081         self.typename = re.sub('^std::(experimental::|)(fundamentals_v\d::|)(.*)', r'std::\1\3<%s>' % valtype, self.typename, 1)
1082         if not self.typename.startswith('std::experimental'):
1083             val = val['_M_payload']
1084         self.val = val
1085         contained_value = val['_M_payload'] if self.val['_M_engaged'] else None
1086         visualizer = gdb.default_visualizer (val['_M_payload'])
1087         super (StdExpOptionalPrinter, self).__init__ (contained_value, visualizer)
1088
1089     def to_string (self):
1090         if self.contained_value is None:
1091             return "%s [no contained value]" % self.typename
1092         if hasattr (self.visualizer, 'children'):
1093             return "%s containing %s" % (self.typename,
1094                                          self.visualizer.to_string())
1095         return self.typename
1096
1097 class StdVariantPrinter(SingleObjContainerPrinter):
1098     "Print a std::variant"
1099
1100     def __init__(self, typename, val):
1101         alternatives = get_template_arg_list(val.type)
1102         self.typename = strip_versioned_namespace(typename)
1103         self.typename = "%s<%s>" % (self.typename, ', '.join([self._recognize(alt) for alt in alternatives]))
1104         self.index = val['_M_index']
1105         if self.index >= len(alternatives):
1106             self.contained_type = None
1107             contained_value = None
1108             visualizer = None
1109         else:
1110             self.contained_type = alternatives[int(self.index)]
1111             addr = val['_M_u']['_M_first']['_M_storage'].address
1112             contained_value = addr.cast(self.contained_type.pointer()).dereference()
1113             visualizer = gdb.default_visualizer(contained_value)
1114         super (StdVariantPrinter, self).__init__(contained_value, visualizer, 'array')
1115
1116     def to_string(self):
1117         if self.contained_value is None:
1118             return "%s [no contained value]" % self.typename
1119         if hasattr(self.visualizer, 'children'):
1120             return "%s [index %d] containing %s" % (self.typename, self.index,
1121                                                     self.visualizer.to_string())
1122         return "%s [index %d]" % (self.typename, self.index)
1123
1124 class StdNodeHandlePrinter(SingleObjContainerPrinter):
1125     "Print a container node handle"
1126
1127     def __init__(self, typename, val):
1128         self.value_type = val.type.template_argument(1)
1129         nodetype = val.type.template_argument(2).template_argument(0)
1130         self.is_rb_tree_node = is_specialization_of(nodetype.name, '_Rb_tree_node')
1131         self.is_map_node = val.type.template_argument(0) != self.value_type
1132         nodeptr = val['_M_ptr']
1133         if nodeptr:
1134             if self.is_rb_tree_node:
1135                 contained_value = get_value_from_Rb_tree_node(nodeptr.dereference())
1136             else:
1137                 contained_value = get_value_from_aligned_membuf(nodeptr['_M_storage'],
1138                                                                 self.value_type)
1139             visualizer = gdb.default_visualizer(contained_value)
1140         else:
1141             contained_value = None
1142             visualizer = None
1143         optalloc = val['_M_alloc']
1144         self.alloc = optalloc['_M_payload'] if optalloc['_M_engaged'] else None
1145         super(StdNodeHandlePrinter, self).__init__(contained_value, visualizer,
1146                                                    'array')
1147
1148     def to_string(self):
1149         desc = 'node handle for '
1150         if not self.is_rb_tree_node:
1151             desc += 'unordered '
1152         if self.is_map_node:
1153             desc += 'map';
1154         else:
1155             desc += 'set';
1156
1157         if self.contained_value:
1158             desc += ' with element'
1159             if hasattr(self.visualizer, 'children'):
1160                 return "%s = %s" % (desc, self.visualizer.to_string())
1161             return desc
1162         else:
1163             return 'empty %s' % desc
1164
1165 class StdExpStringViewPrinter:
1166     "Print a std::basic_string_view or std::experimental::basic_string_view"
1167
1168     def __init__ (self, typename, val):
1169         self.val = val
1170
1171     def to_string (self):
1172         ptr = self.val['_M_str']
1173         len = self.val['_M_len']
1174         if hasattr (ptr, "lazy_string"):
1175             return ptr.lazy_string (length = len)
1176         return ptr.string (length = len)
1177
1178     def display_hint (self):
1179         return 'string'
1180
1181 class StdExpPathPrinter:
1182     "Print a std::experimental::filesystem::path"
1183
1184     def __init__ (self, typename, val):
1185         self.val = val
1186         start = self.val['_M_cmpts']['_M_impl']['_M_start']
1187         finish = self.val['_M_cmpts']['_M_impl']['_M_finish']
1188         self.num_cmpts = int (finish - start)
1189
1190     def _path_type(self):
1191         t = str(self.val['_M_type'])
1192         if t[-9:] == '_Root_dir':
1193             return "root-directory"
1194         if t[-10:] == '_Root_name':
1195             return "root-name"
1196         return None
1197
1198     def to_string (self):
1199         path = "%s" % self.val ['_M_pathname']
1200         if self.num_cmpts == 0:
1201             t = self._path_type()
1202             if t:
1203                 path = '%s [%s]' % (path, t)
1204         return "filesystem::path %s" % path
1205
1206     class _iterator(Iterator):
1207         def __init__(self, cmpts):
1208             self.item = cmpts['_M_impl']['_M_start']
1209             self.finish = cmpts['_M_impl']['_M_finish']
1210             self.count = 0
1211
1212         def __iter__(self):
1213             return self
1214
1215         def __next__(self):
1216             if self.item == self.finish:
1217                 raise StopIteration
1218             item = self.item.dereference()
1219             count = self.count
1220             self.count = self.count + 1
1221             self.item = self.item + 1
1222             path = item['_M_pathname']
1223             t = StdExpPathPrinter(item.type.name, item)._path_type()
1224             if not t:
1225                 t = count
1226             return ('[%s]' % t, path)
1227
1228     def children(self):
1229         return self._iterator(self.val['_M_cmpts'])
1230
1231
1232 # A "regular expression" printer which conforms to the
1233 # "SubPrettyPrinter" protocol from gdb.printing.
1234 class RxPrinter(object):
1235     def __init__(self, name, function):
1236         super(RxPrinter, self).__init__()
1237         self.name = name
1238         self.function = function
1239         self.enabled = True
1240
1241     def invoke(self, value):
1242         if not self.enabled:
1243             return None
1244
1245         if value.type.code == gdb.TYPE_CODE_REF:
1246             if hasattr(gdb.Value,"referenced_value"):
1247                 value = value.referenced_value()
1248
1249         return self.function(self.name, value)
1250
1251 # A pretty-printer that conforms to the "PrettyPrinter" protocol from
1252 # gdb.printing.  It can also be used directly as an old-style printer.
1253 class Printer(object):
1254     def __init__(self, name):
1255         super(Printer, self).__init__()
1256         self.name = name
1257         self.subprinters = []
1258         self.lookup = {}
1259         self.enabled = True
1260         self.compiled_rx = re.compile('^([a-zA-Z0-9_:]+)(<.*>)?$')
1261
1262     def add(self, name, function):
1263         # A small sanity check.
1264         # FIXME
1265         if not self.compiled_rx.match(name):
1266             raise ValueError('libstdc++ programming error: "%s" does not match' % name)
1267         printer = RxPrinter(name, function)
1268         self.subprinters.append(printer)
1269         self.lookup[name] = printer
1270
1271     # Add a name using _GLIBCXX_BEGIN_NAMESPACE_VERSION.
1272     def add_version(self, base, name, function):
1273         self.add(base + name, function)
1274         if _versioned_namespace:
1275             vbase = re.sub('^(std|__gnu_cxx)::', r'\g<0>%s' % _versioned_namespace, base)
1276             self.add(vbase + name, function)
1277
1278     # Add a name using _GLIBCXX_BEGIN_NAMESPACE_CONTAINER.
1279     def add_container(self, base, name, function):
1280         self.add_version(base, name, function)
1281         self.add_version(base + '__cxx1998::', name, function)
1282
1283     @staticmethod
1284     def get_basic_type(type):
1285         # If it points to a reference, get the reference.
1286         if type.code == gdb.TYPE_CODE_REF:
1287             type = type.target ()
1288
1289         # Get the unqualified type, stripped of typedefs.
1290         type = type.unqualified ().strip_typedefs ()
1291
1292         return type.tag
1293
1294     def __call__(self, val):
1295         typename = self.get_basic_type(val.type)
1296         if not typename:
1297             return None
1298
1299         # All the types we match are template types, so we can use a
1300         # dictionary.
1301         match = self.compiled_rx.match(typename)
1302         if not match:
1303             return None
1304
1305         basename = match.group(1)
1306
1307         if val.type.code == gdb.TYPE_CODE_REF:
1308             if hasattr(gdb.Value,"referenced_value"):
1309                 val = val.referenced_value()
1310
1311         if basename in self.lookup:
1312             return self.lookup[basename].invoke(val)
1313
1314         # Cannot find a pretty printer.  Return None.
1315         return None
1316
1317 libstdcxx_printer = None
1318
1319 class TemplateTypePrinter(object):
1320     r"""
1321     A type printer for class templates with default template arguments.
1322
1323     Recognizes specializations of class templates and prints them without
1324     any template arguments that use a default template argument.
1325     Type printers are recursively applied to the template arguments.
1326
1327     e.g. replace "std::vector<T, std::allocator<T> >" with "std::vector<T>".
1328     """
1329
1330     def __init__(self, name, defargs):
1331         self.name = name
1332         self.defargs = defargs
1333         self.enabled = True
1334
1335     class _recognizer(object):
1336         "The recognizer class for TemplateTypePrinter."
1337
1338         def __init__(self, name, defargs):
1339             self.name = name
1340             self.defargs = defargs
1341             # self.type_obj = None
1342
1343         def recognize(self, type_obj):
1344             """
1345             If type_obj is a specialization of self.name that uses all the
1346             default template arguments for the class template, then return
1347             a string representation of the type without default arguments.
1348             Otherwise, return None.
1349             """
1350
1351             if type_obj.tag is None:
1352                 return None
1353
1354             if not type_obj.tag.startswith(self.name):
1355                 return None
1356
1357             template_args = get_template_arg_list(type_obj)
1358             displayed_args = []
1359             require_defaulted = False
1360             for n in range(len(template_args)):
1361                 # The actual template argument in the type:
1362                 targ = template_args[n]
1363                 # The default template argument for the class template:
1364                 defarg = self.defargs.get(n)
1365                 if defarg is not None:
1366                     # Substitute other template arguments into the default:
1367                     defarg = defarg.format(*template_args)
1368                     # Fail to recognize the type (by returning None)
1369                     # unless the actual argument is the same as the default.
1370                     try:
1371                         if targ != gdb.lookup_type(defarg):
1372                             return None
1373                     except gdb.error:
1374                         # Type lookup failed, just use string comparison:
1375                         if targ.tag != defarg:
1376                             return None
1377                     # All subsequent args must have defaults:
1378                     require_defaulted = True
1379                 elif require_defaulted:
1380                     return None
1381                 else:
1382                     # Recursively apply recognizers to the template argument
1383                     # and add it to the arguments that will be displayed:
1384                     displayed_args.append(self._recognize_subtype(targ))
1385
1386             # This assumes no class templates in the nested-name-specifier:
1387             template_name = type_obj.tag[0:type_obj.tag.find('<')]
1388             template_name = strip_inline_namespaces(template_name)
1389
1390             return template_name + '<' + ', '.join(displayed_args) + '>'
1391
1392         def _recognize_subtype(self, type_obj):
1393             """Convert a gdb.Type to a string by applying recognizers,
1394             or if that fails then simply converting to a string."""
1395
1396             if type_obj.code == gdb.TYPE_CODE_PTR:
1397                 return self._recognize_subtype(type_obj.target()) + '*'
1398             if type_obj.code == gdb.TYPE_CODE_ARRAY:
1399                 type_str = self._recognize_subtype(type_obj.target())
1400                 if str(type_obj.strip_typedefs()).endswith('[]'):
1401                     return type_str + '[]' # array of unknown bound
1402                 return "%s[%d]" % (type_str, type_obj.range()[1] + 1)
1403             if type_obj.code == gdb.TYPE_CODE_REF:
1404                 return self._recognize_subtype(type_obj.target()) + '&'
1405             if hasattr(gdb, 'TYPE_CODE_RVALUE_REF'):
1406                 if type_obj.code == gdb.TYPE_CODE_RVALUE_REF:
1407                     return self._recognize_subtype(type_obj.target()) + '&&'
1408
1409             type_str = gdb.types.apply_type_recognizers(
1410                     gdb.types.get_type_recognizers(), type_obj)
1411             if type_str:
1412                 return type_str
1413             return str(type_obj)
1414
1415     def instantiate(self):
1416         "Return a recognizer object for this type printer."
1417         return self._recognizer(self.name, self.defargs)
1418
1419 def add_one_template_type_printer(obj, name, defargs):
1420     r"""
1421     Add a type printer for a class template with default template arguments.
1422
1423     Args:
1424         name (str): The template-name of the class template.
1425         defargs (dict int:string) The default template arguments.
1426
1427     Types in defargs can refer to the Nth template-argument using {N}
1428     (with zero-based indices).
1429
1430     e.g. 'unordered_map' has these defargs:
1431     { 2: 'std::hash<{0}>',
1432       3: 'std::equal_to<{0}>',
1433       4: 'std::allocator<std::pair<const {0}, {1}> >' }
1434
1435     """
1436     printer = TemplateTypePrinter('std::'+name, defargs)
1437     gdb.types.register_type_printer(obj, printer)
1438     if _versioned_namespace:
1439         # Add second type printer for same type in versioned namespace:
1440         ns = 'std::' + _versioned_namespace
1441         # PR 86112 Cannot use dict comprehension here:
1442         defargs = dict((n, d.replace('std::', ns)) for (n,d) in defargs.items())
1443         printer = TemplateTypePrinter(ns+name, defargs)
1444         gdb.types.register_type_printer(obj, printer)
1445
1446 class FilteringTypePrinter(object):
1447     r"""
1448     A type printer that uses typedef names for common template specializations.
1449
1450     Args:
1451         match (str): The class template to recognize.
1452         name (str): The typedef-name that will be used instead.
1453
1454     Checks if a specialization of the class template 'match' is the same type
1455     as the typedef 'name', and prints it as 'name' instead.
1456
1457     e.g. if an instantiation of std::basic_istream<C, T> is the same type as
1458     std::istream then print it as std::istream.
1459     """
1460
1461     def __init__(self, match, name):
1462         self.match = match
1463         self.name = name
1464         self.enabled = True
1465
1466     class _recognizer(object):
1467         "The recognizer class for TemplateTypePrinter."
1468
1469         def __init__(self, match, name):
1470             self.match = match
1471             self.name = name
1472             self.type_obj = None
1473
1474         def recognize(self, type_obj):
1475             """
1476             If type_obj starts with self.match and is the same type as
1477             self.name then return self.name, otherwise None.
1478             """
1479             if type_obj.tag is None:
1480                 return None
1481
1482             if self.type_obj is None:
1483                 if not type_obj.tag.startswith(self.match):
1484                     # Filter didn't match.
1485                     return None
1486                 try:
1487                     self.type_obj = gdb.lookup_type(self.name).strip_typedefs()
1488                 except:
1489                     pass
1490             if self.type_obj == type_obj:
1491                 return strip_inline_namespaces(self.name)
1492             return None
1493
1494     def instantiate(self):
1495         "Return a recognizer object for this type printer."
1496         return self._recognizer(self.match, self.name)
1497
1498 def add_one_type_printer(obj, match, name):
1499     printer = FilteringTypePrinter('std::' + match, 'std::' + name)
1500     gdb.types.register_type_printer(obj, printer)
1501     if _versioned_namespace:
1502         ns = 'std::' + _versioned_namespace
1503         printer = FilteringTypePrinter(ns + match, ns + name)
1504         gdb.types.register_type_printer(obj, printer)
1505
1506 def register_type_printers(obj):
1507     global _use_type_printing
1508
1509     if not _use_type_printing:
1510         return
1511
1512     # Add type printers for typedefs std::string, std::wstring etc.
1513     for ch in ('', 'w', 'u16', 'u32'):
1514         add_one_type_printer(obj, 'basic_string', ch + 'string')
1515         add_one_type_printer(obj, '__cxx11::basic_string',
1516                              '__cxx11::' + ch + 'string')
1517         add_one_type_printer(obj, 'basic_string_view', ch + 'string_view')
1518
1519     # Add type printers for typedefs std::istream, std::wistream etc.
1520     for ch in ('', 'w'):
1521         for x in ('ios', 'streambuf', 'istream', 'ostream', 'iostream',
1522                   'filebuf', 'ifstream', 'ofstream', 'fstream'):
1523             add_one_type_printer(obj, 'basic_' + x, ch + x)
1524         for x in ('stringbuf', 'istringstream', 'ostringstream',
1525                   'stringstream'):
1526             add_one_type_printer(obj, 'basic_' + x, ch + x)
1527             # <sstream> types are in __cxx11 namespace, but typedefs aren'x:
1528             add_one_type_printer(obj, '__cxx11::basic_' + x, ch + x)
1529
1530     # Add type printers for typedefs regex, wregex, cmatch, wcmatch etc.
1531     for abi in ('', '__cxx11::'):
1532         for ch in ('', 'w'):
1533             add_one_type_printer(obj, abi + 'basic_regex', abi + ch + 'regex')
1534         for ch in ('c', 's', 'wc', 'ws'):
1535             add_one_type_printer(obj, abi + 'match_results', abi + ch + 'match')
1536             for x in ('sub_match', 'regex_iterator', 'regex_token_iterator'):
1537                 add_one_type_printer(obj, abi + x, abi + ch + x)
1538
1539     # Note that we can't have a printer for std::wstreampos, because
1540     # it is the same type as std::streampos.
1541     add_one_type_printer(obj, 'fpos', 'streampos')
1542
1543     # Add type printers for <chrono> typedefs.
1544     for dur in ('nanoseconds', 'microseconds', 'milliseconds',
1545                 'seconds', 'minutes', 'hours'):
1546         add_one_type_printer(obj, 'duration', dur)
1547
1548     # Add type printers for <random> typedefs.
1549     add_one_type_printer(obj, 'linear_congruential_engine', 'minstd_rand0')
1550     add_one_type_printer(obj, 'linear_congruential_engine', 'minstd_rand')
1551     add_one_type_printer(obj, 'mersenne_twister_engine', 'mt19937')
1552     add_one_type_printer(obj, 'mersenne_twister_engine', 'mt19937_64')
1553     add_one_type_printer(obj, 'subtract_with_carry_engine', 'ranlux24_base')
1554     add_one_type_printer(obj, 'subtract_with_carry_engine', 'ranlux48_base')
1555     add_one_type_printer(obj, 'discard_block_engine', 'ranlux24')
1556     add_one_type_printer(obj, 'discard_block_engine', 'ranlux48')
1557     add_one_type_printer(obj, 'shuffle_order_engine', 'knuth_b')
1558
1559     # Add type printers for experimental::basic_string_view typedefs.
1560     ns = 'experimental::fundamentals_v1::'
1561     for ch in ('', 'w', 'u16', 'u32'):
1562         add_one_type_printer(obj, ns + 'basic_string_view',
1563                              ns + ch + 'string_view')
1564
1565     # Do not show defaulted template arguments in class templates.
1566     add_one_template_type_printer(obj, 'unique_ptr',
1567             { 1: 'std::default_delete<{0}>' })
1568     add_one_template_type_printer(obj, 'deque', { 1: 'std::allocator<{0}>'})
1569     add_one_template_type_printer(obj, 'forward_list', { 1: 'std::allocator<{0}>'})
1570     add_one_template_type_printer(obj, 'list', { 1: 'std::allocator<{0}>'})
1571     add_one_template_type_printer(obj, '__cxx11::list', { 1: 'std::allocator<{0}>'})
1572     add_one_template_type_printer(obj, 'vector', { 1: 'std::allocator<{0}>'})
1573     add_one_template_type_printer(obj, 'map',
1574             { 2: 'std::less<{0}>',
1575               3: 'std::allocator<std::pair<{0} const, {1}>>' })
1576     add_one_template_type_printer(obj, 'multimap',
1577             { 2: 'std::less<{0}>',
1578               3: 'std::allocator<std::pair<{0} const, {1}>>' })
1579     add_one_template_type_printer(obj, 'set',
1580             { 1: 'std::less<{0}>', 2: 'std::allocator<{0}>' })
1581     add_one_template_type_printer(obj, 'multiset',
1582             { 1: 'std::less<{0}>', 2: 'std::allocator<{0}>' })
1583     add_one_template_type_printer(obj, 'unordered_map',
1584             { 2: 'std::hash<{0}>',
1585               3: 'std::equal_to<{0}>',
1586               4: 'std::allocator<std::pair<{0} const, {1}>>'})
1587     add_one_template_type_printer(obj, 'unordered_multimap',
1588             { 2: 'std::hash<{0}>',
1589               3: 'std::equal_to<{0}>',
1590               4: 'std::allocator<std::pair<{0} const, {1}>>'})
1591     add_one_template_type_printer(obj, 'unordered_set',
1592             { 1: 'std::hash<{0}>',
1593               2: 'std::equal_to<{0}>',
1594               3: 'std::allocator<{0}>'})
1595     add_one_template_type_printer(obj, 'unordered_multiset',
1596             { 1: 'std::hash<{0}>',
1597               2: 'std::equal_to<{0}>',
1598               3: 'std::allocator<{0}>'})
1599
1600 def register_libstdcxx_printers (obj):
1601     "Register libstdc++ pretty-printers with objfile Obj."
1602
1603     global _use_gdb_pp
1604     global libstdcxx_printer
1605
1606     if _use_gdb_pp:
1607         gdb.printing.register_pretty_printer(obj, libstdcxx_printer)
1608     else:
1609         if obj is None:
1610             obj = gdb
1611         obj.pretty_printers.append(libstdcxx_printer)
1612
1613     register_type_printers(obj)
1614
1615 def build_libstdcxx_dictionary ():
1616     global libstdcxx_printer
1617
1618     libstdcxx_printer = Printer("libstdc++-v6")
1619
1620     # libstdc++ objects requiring pretty-printing.
1621     # In order from:
1622     # http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/a01847.html
1623     libstdcxx_printer.add_version('std::', 'basic_string', StdStringPrinter)
1624     libstdcxx_printer.add_version('std::__cxx11::', 'basic_string', StdStringPrinter)
1625     libstdcxx_printer.add_container('std::', 'bitset', StdBitsetPrinter)
1626     libstdcxx_printer.add_container('std::', 'deque', StdDequePrinter)
1627     libstdcxx_printer.add_container('std::', 'list', StdListPrinter)
1628     libstdcxx_printer.add_container('std::__cxx11::', 'list', StdListPrinter)
1629     libstdcxx_printer.add_container('std::', 'map', StdMapPrinter)
1630     libstdcxx_printer.add_container('std::', 'multimap', StdMapPrinter)
1631     libstdcxx_printer.add_container('std::', 'multiset', StdSetPrinter)
1632     libstdcxx_printer.add_version('std::', 'priority_queue',
1633                                   StdStackOrQueuePrinter)
1634     libstdcxx_printer.add_version('std::', 'queue', StdStackOrQueuePrinter)
1635     libstdcxx_printer.add_version('std::', 'tuple', StdTuplePrinter)
1636     libstdcxx_printer.add_container('std::', 'set', StdSetPrinter)
1637     libstdcxx_printer.add_version('std::', 'stack', StdStackOrQueuePrinter)
1638     libstdcxx_printer.add_version('std::', 'unique_ptr', UniquePointerPrinter)
1639     libstdcxx_printer.add_container('std::', 'vector', StdVectorPrinter)
1640     # vector<bool>
1641
1642     # Printer registrations for classes compiled with -D_GLIBCXX_DEBUG.
1643     libstdcxx_printer.add('std::__debug::bitset', StdBitsetPrinter)
1644     libstdcxx_printer.add('std::__debug::deque', StdDequePrinter)
1645     libstdcxx_printer.add('std::__debug::list', StdListPrinter)
1646     libstdcxx_printer.add('std::__debug::map', StdMapPrinter)
1647     libstdcxx_printer.add('std::__debug::multimap', StdMapPrinter)
1648     libstdcxx_printer.add('std::__debug::multiset', StdSetPrinter)
1649     libstdcxx_printer.add('std::__debug::priority_queue',
1650                           StdStackOrQueuePrinter)
1651     libstdcxx_printer.add('std::__debug::queue', StdStackOrQueuePrinter)
1652     libstdcxx_printer.add('std::__debug::set', StdSetPrinter)
1653     libstdcxx_printer.add('std::__debug::stack', StdStackOrQueuePrinter)
1654     libstdcxx_printer.add('std::__debug::unique_ptr', UniquePointerPrinter)
1655     libstdcxx_printer.add('std::__debug::vector', StdVectorPrinter)
1656
1657     # These are the TR1 and C++11 printers.
1658     # For array - the default GDB pretty-printer seems reasonable.
1659     libstdcxx_printer.add_version('std::', 'shared_ptr', SharedPointerPrinter)
1660     libstdcxx_printer.add_version('std::', 'weak_ptr', SharedPointerPrinter)
1661     libstdcxx_printer.add_container('std::', 'unordered_map',
1662                                     Tr1UnorderedMapPrinter)
1663     libstdcxx_printer.add_container('std::', 'unordered_set',
1664                                     Tr1UnorderedSetPrinter)
1665     libstdcxx_printer.add_container('std::', 'unordered_multimap',
1666                                     Tr1UnorderedMapPrinter)
1667     libstdcxx_printer.add_container('std::', 'unordered_multiset',
1668                                     Tr1UnorderedSetPrinter)
1669     libstdcxx_printer.add_container('std::', 'forward_list',
1670                                     StdForwardListPrinter)
1671
1672     libstdcxx_printer.add_version('std::tr1::', 'shared_ptr', SharedPointerPrinter)
1673     libstdcxx_printer.add_version('std::tr1::', 'weak_ptr', SharedPointerPrinter)
1674     libstdcxx_printer.add_version('std::tr1::', 'unordered_map',
1675                                   Tr1UnorderedMapPrinter)
1676     libstdcxx_printer.add_version('std::tr1::', 'unordered_set',
1677                                   Tr1UnorderedSetPrinter)
1678     libstdcxx_printer.add_version('std::tr1::', 'unordered_multimap',
1679                                   Tr1UnorderedMapPrinter)
1680     libstdcxx_printer.add_version('std::tr1::', 'unordered_multiset',
1681                                   Tr1UnorderedSetPrinter)
1682
1683     # These are the C++11 printer registrations for -D_GLIBCXX_DEBUG cases.
1684     # The tr1 namespace containers do not have any debug equivalents,
1685     # so do not register printers for them.
1686     libstdcxx_printer.add('std::__debug::unordered_map',
1687                           Tr1UnorderedMapPrinter)
1688     libstdcxx_printer.add('std::__debug::unordered_set',
1689                           Tr1UnorderedSetPrinter)
1690     libstdcxx_printer.add('std::__debug::unordered_multimap',
1691                           Tr1UnorderedMapPrinter)
1692     libstdcxx_printer.add('std::__debug::unordered_multiset',
1693                           Tr1UnorderedSetPrinter)
1694     libstdcxx_printer.add('std::__debug::forward_list',
1695                           StdForwardListPrinter)
1696
1697     # Library Fundamentals TS components
1698     libstdcxx_printer.add_version('std::experimental::fundamentals_v1::',
1699                                   'any', StdExpAnyPrinter)
1700     libstdcxx_printer.add_version('std::experimental::fundamentals_v1::',
1701                                   'optional', StdExpOptionalPrinter)
1702     libstdcxx_printer.add_version('std::experimental::fundamentals_v1::',
1703                                   'basic_string_view', StdExpStringViewPrinter)
1704     # Filesystem TS components
1705     libstdcxx_printer.add_version('std::experimental::filesystem::v1::',
1706                                   'path', StdExpPathPrinter)
1707     libstdcxx_printer.add_version('std::experimental::filesystem::v1::__cxx11::',
1708                                   'path', StdExpPathPrinter)
1709     libstdcxx_printer.add_version('std::filesystem::',
1710                                   'path', StdExpPathPrinter)
1711     libstdcxx_printer.add_version('std::filesystem::__cxx11::',
1712                                   'path', StdExpPathPrinter)
1713
1714     # C++17 components
1715     libstdcxx_printer.add_version('std::',
1716                                   'any', StdExpAnyPrinter)
1717     libstdcxx_printer.add_version('std::',
1718                                   'optional', StdExpOptionalPrinter)
1719     libstdcxx_printer.add_version('std::',
1720                                   'basic_string_view', StdExpStringViewPrinter)
1721     libstdcxx_printer.add_version('std::',
1722                                   'variant', StdVariantPrinter)
1723     libstdcxx_printer.add_version('std::',
1724                                   '_Node_handle', StdNodeHandlePrinter)
1725
1726     # Extensions.
1727     libstdcxx_printer.add_version('__gnu_cxx::', 'slist', StdSlistPrinter)
1728
1729     if True:
1730         # These shouldn't be necessary, if GDB "print *i" worked.
1731         # But it often doesn't, so here they are.
1732         libstdcxx_printer.add_container('std::', '_List_iterator',
1733                                         StdListIteratorPrinter)
1734         libstdcxx_printer.add_container('std::', '_List_const_iterator',
1735                                         StdListIteratorPrinter)
1736         libstdcxx_printer.add_version('std::', '_Rb_tree_iterator',
1737                                       StdRbtreeIteratorPrinter)
1738         libstdcxx_printer.add_version('std::', '_Rb_tree_const_iterator',
1739                                       StdRbtreeIteratorPrinter)
1740         libstdcxx_printer.add_container('std::', '_Deque_iterator',
1741                                         StdDequeIteratorPrinter)
1742         libstdcxx_printer.add_container('std::', '_Deque_const_iterator',
1743                                         StdDequeIteratorPrinter)
1744         libstdcxx_printer.add_version('__gnu_cxx::', '__normal_iterator',
1745                                       StdVectorIteratorPrinter)
1746         libstdcxx_printer.add_version('__gnu_cxx::', '_Slist_iterator',
1747                                       StdSlistIteratorPrinter)
1748         libstdcxx_printer.add_container('std::', '_Fwd_list_iterator',
1749                                         StdFwdListIteratorPrinter)
1750         libstdcxx_printer.add_container('std::', '_Fwd_list_const_iterator',
1751                                         StdFwdListIteratorPrinter)
1752
1753         # Debug (compiled with -D_GLIBCXX_DEBUG) printer
1754         # registrations.
1755         libstdcxx_printer.add('__gnu_debug::_Safe_iterator',
1756                               StdDebugIteratorPrinter)
1757
1758 build_libstdcxx_dictionary ()