xref: /llvm-project/llvm/utils/gdb-scripts/prettyprinters.py (revision a36032345ed823414fcee0f9aed43628f4320001)
1from __future__ import print_function
2import struct
3import sys
4
5import gdb.printing
6import gdb.types
7
8class Iterator:
9  def __iter__(self):
10    return self
11
12  if sys.version_info.major == 2:
13      def next(self):
14        return self.__next__()
15
16  def children(self):
17    return self
18
19def escape_bytes(val, l):
20  return '"' + val.string(encoding='Latin-1', length=l).encode('unicode_escape').decode() + '"'
21
22class SmallStringPrinter:
23  """Print an llvm::SmallString object."""
24
25  def __init__(self, val):
26    self.val = val
27
28  def to_string(self):
29    begin = self.val['BeginX']
30    return escape_bytes(begin.cast(gdb.lookup_type('char').pointer()), self.val['Size'])
31
32class StringRefPrinter:
33  """Print an llvm::StringRef object."""
34
35  def __init__(self, val):
36    self.val = val
37
38  def to_string(self):
39    return escape_bytes(self.val['Data'], self.val['Length'])
40
41class SmallVectorPrinter(Iterator):
42  """Print an llvm::SmallVector object."""
43
44  def __init__(self, val):
45    self.val = val
46    t = val.type.template_argument(0).pointer()
47    self.begin = val['BeginX'].cast(t)
48    self.size = val['Size']
49    self.i = 0
50
51  def __next__(self):
52    if self.i == self.size:
53      raise StopIteration
54    ret = '[{}]'.format(self.i), (self.begin+self.i).dereference()
55    self.i += 1
56    return ret
57
58  def to_string(self):
59    return 'llvm::SmallVector of Size {}, Capacity {}'.format(self.size, self.val['Capacity'])
60
61  def display_hint (self):
62    return 'array'
63
64class ArrayRefPrinter:
65  """Print an llvm::ArrayRef object."""
66
67  class _iterator:
68    def __init__(self, begin, end):
69      self.cur = begin
70      self.end = end
71      self.count = 0
72
73    def __iter__(self):
74      return self
75
76    def __next__(self):
77      if self.cur == self.end:
78        raise StopIteration
79      count = self.count
80      self.count = self.count + 1
81      cur = self.cur
82      self.cur = self.cur + 1
83      return '[%d]' % count, cur.dereference()
84
85    if sys.version_info.major == 2:
86        next = __next__
87
88  def __init__(self, val):
89    self.val = val
90
91  def children(self):
92    data = self.val['Data']
93    return self._iterator(data, data + self.val['Length'])
94
95  def to_string(self):
96    return 'llvm::ArrayRef of length %d' % (self.val['Length'])
97
98  def display_hint (self):
99    return 'array'
100
101class ExpectedPrinter(Iterator):
102  """Print an llvm::Expected object."""
103
104  def __init__(self, val):
105    self.val = val
106
107  def __next__(self):
108    val = self.val
109    if val is None:
110      raise StopIteration
111    self.val = None
112    if val['HasError']:
113      return ('error', val['ErrorStorage'].address.cast(
114          gdb.lookup_type('llvm::ErrorInfoBase').pointer()).dereference())
115    return ('value', val['TStorage'].address.cast(
116        val.type.template_argument(0).pointer()).dereference())
117
118  def to_string(self):
119    return 'llvm::Expected{}'.format(' is error' if self.val['HasError'] else '')
120
121class OptionalPrinter(Iterator):
122  """Print an llvm::Optional object."""
123
124  def __init__(self, val):
125    self.val = val
126
127  def __next__(self):
128    val = self.val
129    if val is None:
130      raise StopIteration
131    self.val = None
132    if not val['Storage']['hasVal']:
133      raise StopIteration
134    return ('value', val['Storage']['value'])
135
136  def to_string(self):
137    return 'llvm::Optional{}'.format('' if self.val['Storage']['hasVal'] else ' is not initialized')
138
139class DenseMapPrinter:
140  "Print a DenseMap"
141
142  class _iterator:
143    def __init__(self, key_info_t, begin, end):
144      self.key_info_t = key_info_t
145      self.cur = begin
146      self.end = end
147      self.advancePastEmptyBuckets()
148      self.first = True
149
150    def __iter__(self):
151      return self
152
153    def advancePastEmptyBuckets(self):
154      # disabled until the comments below can be addressed
155      # keeping as notes/posterity/hints for future contributors
156      return
157      n = self.key_info_t.name
158      is_equal = gdb.parse_and_eval(n + '::isEqual')
159      empty = gdb.parse_and_eval(n + '::getEmptyKey()')
160      tombstone = gdb.parse_and_eval(n + '::getTombstoneKey()')
161      # the following is invalid, GDB fails with:
162      #   Python Exception <class 'gdb.error'> Attempt to take address of value
163      #   not located in memory.
164      # because isEqual took parameter (for the unsigned long key I was testing)
165      # by const ref, and GDB
166      # It's also not entirely general - we should be accessing the "getFirst()"
167      # member function, not the 'first' member variable, but I've yet to figure
168      # out how to find/call member functions (especially (const) overloaded
169      # ones) on a gdb.Value.
170      while self.cur != self.end and (is_equal(self.cur.dereference()['first'], empty) or is_equal(self.cur.dereference()['first'], tombstone)):
171        self.cur = self.cur + 1
172
173    def __next__(self):
174      if self.cur == self.end:
175        raise StopIteration
176      cur = self.cur
177      v = cur.dereference()['first' if self.first else 'second']
178      if not self.first:
179        self.cur = self.cur + 1
180        self.advancePastEmptyBuckets()
181        self.first = True
182      else:
183        self.first = False
184      return 'x', v
185
186    if sys.version_info.major == 2:
187        next = __next__
188
189  def __init__(self, val):
190    self.val = val
191
192  def children(self):
193    t = self.val.type.template_argument(3).pointer()
194    begin = self.val['Buckets'].cast(t)
195    end = (begin + self.val['NumBuckets']).cast(t)
196    return self._iterator(self.val.type.template_argument(2), begin, end)
197
198  def to_string(self):
199    return 'llvm::DenseMap with %d elements' % (self.val['NumEntries'])
200
201  def display_hint(self):
202    return 'map'
203
204class StringMapPrinter:
205  "Print a StringMap"
206
207  def __init__(self, val):
208    self.val = val
209
210  def children(self):
211    it = self.val['TheTable']
212    end = (it + self.val['NumBuckets'])
213    value_ty = self.val.type.template_argument(0)
214    entry_base_ty = gdb.lookup_type('llvm::StringMapEntryBase')
215    tombstone = gdb.parse_and_eval('llvm::StringMapImpl::TombstoneIntVal');
216
217    while it != end:
218      it_deref = it.dereference()
219      if it_deref == 0 or it_deref == tombstone:
220        it = it + 1
221        continue
222
223      entry_ptr = it_deref.cast(entry_base_ty.pointer())
224      entry = entry_ptr.dereference()
225
226      str_len = entry['keyLength']
227      value_ptr = (entry_ptr + 1).cast(value_ty.pointer())
228      str_data = (entry_ptr + 1).cast(gdb.lookup_type('uintptr_t')) + max(value_ty.sizeof, entry_base_ty.alignof)
229      str_data = str_data.cast(gdb.lookup_type('char').const().pointer())
230      string_ref = gdb.Value(struct.pack('PN', int(str_data), int(str_len)), gdb.lookup_type('llvm::StringRef'))
231      yield 'key', string_ref
232
233      value = value_ptr.dereference()
234      yield 'value', value
235
236      it = it + 1
237
238  def to_string(self):
239    return 'llvm::StringMap with %d elements' % (self.val['NumItems'])
240
241  def display_hint(self):
242    return 'map'
243
244class TwinePrinter:
245  "Print a Twine"
246
247  def __init__(self, val):
248    self._val = val
249
250  def display_hint(self):
251    return 'string'
252
253  def string_from_pretty_printer_lookup(self, val):
254    '''Lookup the default pretty-printer for val and use it.
255
256    If no pretty-printer is defined for the type of val, print an error and
257    return a placeholder string.'''
258
259    pp = gdb.default_visualizer(val)
260    if pp:
261      s = pp.to_string()
262
263      # The pretty-printer may return a LazyString instead of an actual Python
264      # string.  Convert it to a Python string.  However, GDB doesn't seem to
265      # register the LazyString type, so we can't check
266      # "type(s) == gdb.LazyString".
267      if 'LazyString' in type(s).__name__:
268        s = s.value().address.string()
269
270    else:
271      print(('No pretty printer for {} found. The resulting Twine ' +
272             'representation will be incomplete.').format(val.type.name))
273      s = '(missing {})'.format(val.type.name)
274
275    return s
276
277  def is_twine_kind(self, kind, expected):
278    if not kind.endswith(expected):
279      return False
280    # apparently some GDB versions add the NodeKind:: namespace
281    # (happens for me on GDB 7.11)
282    return kind in ('llvm::Twine::' + expected,
283                    'llvm::Twine::NodeKind::' + expected)
284
285  def string_from_child(self, child, kind):
286    '''Return the string representation of the Twine::Child child.'''
287
288    if self.is_twine_kind(kind, 'EmptyKind') or self.is_twine_kind(kind, 'NullKind'):
289      return ''
290
291    if self.is_twine_kind(kind, 'TwineKind'):
292      return self.string_from_twine_object(child['twine'].dereference())
293
294    if self.is_twine_kind(kind, 'CStringKind'):
295      return child['cString'].string()
296
297    if self.is_twine_kind(kind, 'StdStringKind'):
298      val = child['stdString'].dereference()
299      return self.string_from_pretty_printer_lookup(val)
300
301    if self.is_twine_kind(kind, 'PtrAndLengthKind'):
302      val = child['ptrAndLength']
303      return val['ptr'].string(encoding='Latin-1', length=val['length']).encode('unicode_escape').decode()
304
305    if self.is_twine_kind(kind, 'SmallStringKind'):
306      val = child['smallString'].dereference()
307      pp = SmallStringPrinter(val)
308      return pp.to_string()
309
310    if self.is_twine_kind(kind, 'CharKind'):
311      return chr(child['character'])
312
313    if self.is_twine_kind(kind, 'DecUIKind'):
314      return str(child['decUI'])
315
316    if self.is_twine_kind(kind, 'DecIKind'):
317      return str(child['decI'])
318
319    if self.is_twine_kind(kind, 'DecULKind'):
320      return str(child['decUL'].dereference())
321
322    if self.is_twine_kind(kind, 'DecLKind'):
323      return str(child['decL'].dereference())
324
325    if self.is_twine_kind(kind, 'DecULLKind'):
326      return str(child['decULL'].dereference())
327
328    if self.is_twine_kind(kind, 'DecLLKind'):
329      return str(child['decLL'].dereference())
330
331    if self.is_twine_kind(kind, 'UHexKind'):
332      val = child['uHex'].dereference()
333      return hex(int(val))
334
335    print(('Unhandled NodeKind {} in Twine pretty-printer. The result will be '
336           'incomplete.').format(kind))
337
338    return '(unhandled {})'.format(kind)
339
340  def string_from_twine_object(self, twine):
341    '''Return the string representation of the Twine object twine.'''
342
343    lhs_str = ''
344    rhs_str = ''
345
346    lhs = twine['LHS']
347    rhs = twine['RHS']
348    lhs_kind = str(twine['LHSKind'])
349    rhs_kind = str(twine['RHSKind'])
350
351    lhs_str = self.string_from_child(lhs, lhs_kind)
352    rhs_str = self.string_from_child(rhs, rhs_kind)
353
354    return lhs_str + rhs_str
355
356  def to_string(self):
357    return self.string_from_twine_object(self._val)
358
359def get_pointer_int_pair(val):
360  """Get tuple from llvm::PointerIntPair."""
361  info_name = val.type.template_argument(4).strip_typedefs().name
362  # Note: this throws a gdb.error if the info type is not used (by means of a
363  # call to getPointer() or similar) in the current translation unit.
364  enum_type = gdb.lookup_type(info_name + '::MaskAndShiftConstants')
365  enum_dict = gdb.types.make_enum_dict(enum_type)
366  ptr_mask = enum_dict[info_name + '::PointerBitMask']
367  int_shift = enum_dict[info_name + '::IntShift']
368  int_mask = enum_dict[info_name + '::IntMask']
369  pair_union = val['Value']
370  pointer = (pair_union & ptr_mask)
371  value = ((pair_union >> int_shift) & int_mask)
372  return (pointer, value)
373
374class PointerIntPairPrinter:
375  """Print a PointerIntPair."""
376
377  def __init__(self, pointer, value):
378    self.pointer = pointer
379    self.value = value
380
381  def children(self):
382    yield ('pointer', self.pointer)
383    yield ('value', self.value)
384
385def make_pointer_int_pair_printer(val):
386  """Factory for an llvm::PointerIntPair printer."""
387  try:
388    pointer, value = get_pointer_int_pair(val)
389  except gdb.error:
390    return None  # If PointerIntPair cannot be analyzed, print as raw value.
391  pointer_type = val.type.template_argument(0)
392  value_type = val.type.template_argument(2)
393  return PointerIntPairPrinter(pointer.cast(pointer_type),
394                               value.cast(value_type))
395
396class PointerUnionPrinter:
397  """Print a PointerUnion."""
398
399  def __init__(self, pointer):
400    self.pointer = pointer
401
402  def children(self):
403    yield ('pointer', self.pointer)
404
405  def to_string(self):
406    return "Containing %s" % self.pointer.type
407
408def make_pointer_union_printer(val):
409  """Factory for an llvm::PointerUnion printer."""
410  try:
411    pointer, value = get_pointer_int_pair(val['Val'])
412  except gdb.error:
413    return None  # If PointerIntPair cannot be analyzed, print as raw value.
414  pointer_type = val.type.template_argument(int(value))
415  return PointerUnionPrinter(pointer.cast(pointer_type))
416
417class IlistNodePrinter:
418  """Print an llvm::ilist_node object."""
419
420  def __init__(self, val):
421    impl_type = val.type.fields()[0].type
422    base_type = impl_type.fields()[0].type
423    derived_type = val.type.template_argument(0)
424
425    def get_prev_and_sentinel(base):
426      # One of Prev and PrevAndSentinel exists. Depending on #defines used to
427      # compile LLVM, the base_type's template argument is either true of false.
428      if base_type.template_argument(0):
429        return get_pointer_int_pair(base['PrevAndSentinel'])
430      return base['Prev'], None
431
432    # Casts a base_type pointer to the appropriate derived type.
433    def cast_pointer(pointer):
434      sentinel = get_prev_and_sentinel(pointer.dereference())[1]
435      pointer = pointer.cast(impl_type.pointer())
436      if sentinel:
437          return pointer
438      return pointer.cast(derived_type.pointer())
439
440    # Repeated cast becaue val.type's base_type is ambiguous when using tags.
441    base = val.cast(impl_type).cast(base_type)
442    (prev, sentinel) = get_prev_and_sentinel(base)
443    prev = prev.cast(base_type.pointer())
444    self.prev = cast_pointer(prev)
445    self.next = cast_pointer(val['Next'])
446    self.sentinel = sentinel
447
448  def children(self):
449    if self.sentinel:
450      yield 'sentinel', 'yes'
451    yield 'prev', self.prev
452    yield 'next', self.next
453
454class IlistPrinter:
455  """Print an llvm::simple_ilist or llvm::iplist object."""
456
457  def __init__(self, val):
458    self.node_type = val.type.template_argument(0)
459    sentinel = val['Sentinel']
460    # First field is common base type of sentinel and ilist_node.
461    base_type = sentinel.type.fields()[0].type
462    self.sentinel = sentinel.address.cast(base_type.pointer())
463
464  def _pointers(self):
465    pointer = self.sentinel
466    while True:
467      pointer = pointer['Next'].cast(pointer.type)
468      if pointer == self.sentinel:
469        return
470      yield pointer.cast(self.node_type.pointer())
471
472  def children(self):
473    for k, v in enumerate(self._pointers()):
474      yield ('[%d]' % k, v.dereference())
475
476
477pp = gdb.printing.RegexpCollectionPrettyPrinter("LLVMSupport")
478pp.add_printer('llvm::SmallString', '^llvm::SmallString<.*>$', SmallStringPrinter)
479pp.add_printer('llvm::StringRef', '^llvm::StringRef$', StringRefPrinter)
480pp.add_printer('llvm::SmallVectorImpl', '^llvm::SmallVector(Impl)?<.*>$', SmallVectorPrinter)
481pp.add_printer('llvm::ArrayRef', '^llvm::(Mutable)?ArrayRef<.*>$', ArrayRefPrinter)
482pp.add_printer('llvm::Expected', '^llvm::Expected<.*>$', ExpectedPrinter)
483pp.add_printer('llvm::Optional', '^llvm::Optional<.*>$', OptionalPrinter)
484pp.add_printer('llvm::DenseMap', '^llvm::DenseMap<.*>$', DenseMapPrinter)
485pp.add_printer('llvm::StringMap', '^llvm::StringMap<.*>$', StringMapPrinter)
486pp.add_printer('llvm::Twine', '^llvm::Twine$', TwinePrinter)
487pp.add_printer('llvm::PointerIntPair', '^llvm::PointerIntPair<.*>$', make_pointer_int_pair_printer)
488pp.add_printer('llvm::PointerUnion', '^llvm::PointerUnion<.*>$', make_pointer_union_printer)
489pp.add_printer('llvm::ilist_node', '^llvm::ilist_node<.*>$', IlistNodePrinter)
490pp.add_printer('llvm::iplist', '^llvm::iplist<.*>$', IlistPrinter)
491pp.add_printer('llvm::simple_ilist', '^llvm::simple_ilist<.*>$', IlistPrinter)
492gdb.printing.register_pretty_printer(gdb.current_objfile(), pp)
493