utils/gdb-scripts/prettyprinters.py

   1 from __future__ import print_function
   2 import sys
   3
   4 import gdb.printing
   5
   6 class Iterator:
   7   def __iter__(self):
   8     return self
   9
  10   if sys.version_info.major == 2:
  11       def next(self):
  12         return self.__next__()
  13
  14   def children(self):
  15     return self
  16
  17 def escape_bytes(val, l):
  18   return '"' + val.string(encoding='Latin-1', length=l).encode('unicode_escape').decode() + '"'
  19
  20 class SmallStringPrinter:
  21   """Print an llvm::SmallString object."""
  22
  23   def __init__(self, val):
  24     self.val = val
  25
  26   def to_string(self):
  27     begin = self.val['BeginX']
  28     return escape_bytes(begin.cast(gdb.lookup_type('char').pointer()), self.val['Size'])
  29
  30 class StringRefPrinter:
  31   """Print an llvm::StringRef object."""
  32
  33   def __init__(self, val):
  34     self.val = val
  35
  36   def to_string(self):
  37     return escape_bytes(self.val['Data'], self.val['Length'])
  38
  39 class SmallVectorPrinter(Iterator):
  40   """Print an llvm::SmallVector object."""
  41
  42   def __init__(self, val):
  43     self.val = val
  44     t = val.type.template_argument(0).pointer()
  45     self.begin = val['BeginX'].cast(t)
  46     self.size = val['Size']
  47     self.i = 0
  48
  49   def __next__(self):
  50     if self.i == self.size:
  51       raise StopIteration
  52     ret = '[{}]'.format(self.i), (self.begin+self.i).dereference()
  53     self.i += 1
  54     return ret
  55
  56   def to_string(self):
  57     return 'llvm::SmallVector of Size {}, Capacity {}'.format(self.size, self.val['Capacity'])
  58
  59   def display_hint (self):
  60     return 'array'
  61
  62 class ArrayRefPrinter:
  63   """Print an llvm::ArrayRef object."""
  64
  65   class _iterator:
  66     def __init__(self, begin, end):
  67       self.cur = begin
  68       self.end = end
  69       self.count = 0
  70
  71     def __iter__(self):
  72       return self
  73
  74     def __next__(self):
  75       if self.cur == self.end:
  76         raise StopIteration
  77       count = self.count
  78       self.count = self.count + 1
  79       cur = self.cur
  80       self.cur = self.cur + 1
  81       return '[%d]' % count, cur.dereference()
  82
  83     if sys.version_info.major == 2:
  84         next = __next__
  85
  86   def __init__(self, val):
  87     self.val = val
  88
  89   def children(self):
  90     data = self.val['Data']
  91     return self._iterator(data, data + self.val['Length'])
  92
  93   def to_string(self):
  94     return 'llvm::ArrayRef of length %d' % (self.val['Length'])
  95
  96   def display_hint (self):
  97     return 'array'
  98
  99 class ExpectedPrinter(Iterator):
 100   """Print an llvm::Expected object."""
 101
 102   def __init__(self, val):
 103     self.val = val
 104
 105   def __next__(self):
 106     val = self.val
 107     if val is None:
 108       raise StopIteration
 109     self.val = None
 110     if val['HasError']:
 111       return ('error', val['ErrorStorage'].address.cast(
 112           gdb.lookup_type('llvm::ErrorInfoBase').pointer()).dereference())
 113     return ('value', val['TStorage'].address.cast(
 114         val.type.template_argument(0).pointer()).dereference())
 115
 116   def to_string(self):
 117     return 'llvm::Expected{}'.format(' is error' if self.val['HasError'] else '')
 118
 119 class OptionalPrinter(Iterator):
 120   """Print an llvm::Optional object."""
 121
 122   def __init__(self, val):
 123     self.val = val
 124
 125   def __next__(self):
 126     val = self.val
 127     if val is None:
 128       raise StopIteration
 129     self.val = None
 130     if not val['Storage']['hasVal']:
 131       raise StopIteration
 132     return ('value', val['Storage']['storage']['buffer'].address.cast(
 133         val.type.template_argument(0).pointer()).dereference())
 134
 135   def to_string(self):
 136     return 'llvm::Optional{}'.format('' if self.val['Storage']['hasVal'] else ' is not initialized')
 137
 138 class DenseMapPrinter:
 139   "Print a DenseMap"
 140
 141   class _iterator:
 142     def __init__(self, key_info_t, begin, end):
 143       self.key_info_t = key_info_t
 144       self.cur = begin
 145       self.end = end
 146       self.advancePastEmptyBuckets()
 147       self.first = True
 148
 149     def __iter__(self):
 150       return self
 151
 152     def advancePastEmptyBuckets(self):
 153       # disabled until the comments below can be addressed
 154       # keeping as notes/posterity/hints for future contributors
 155       return
 156       n = self.key_info_t.name
 157       is_equal = gdb.parse_and_eval(n + '::isEqual')
 158       empty = gdb.parse_and_eval(n + '::getEmptyKey()')
 159       tombstone = gdb.parse_and_eval(n + '::getTombstoneKey()')
 160       # the following is invalid, GDB fails with:
 161       #   Python Exception <class 'gdb.error'> Attempt to take address of value
 162       #   not located in memory.
 163       # because isEqual took parameter (for the unsigned long key I was testing)
 164       # by const ref, and GDB
 165       # It's also not entirely general - we should be accessing the "getFirst()"
 166       # member function, not the 'first' member variable, but I've yet to figure
 167       # out how to find/call member functions (especially (const) overloaded
 168       # ones) on a gdb.Value.
 169       while self.cur != self.end and (is_equal(self.cur.dereference()['first'], empty) or is_equal(self.cur.dereference()['first'], tombstone)):
 170         self.cur = self.cur + 1
 171
 172     def __next__(self):
 173       if self.cur == self.end:
 174         raise StopIteration
 175       cur = self.cur
 176       v = cur.dereference()['first' if self.first else 'second']
 177       if not self.first:
 178         self.cur = self.cur + 1
 179         self.advancePastEmptyBuckets()
 180         self.first = True
 181       else:
 182         self.first = False
 183       return 'x', v
 184
 185     if sys.version_info.major == 2:
 186         next = __next__
 187
 188   def __init__(self, val):
 189     self.val = val
 190
 191   def children(self):
 192     t = self.val.type.template_argument(3).pointer()
 193     begin = self.val['Buckets'].cast(t)
 194     end = (begin + self.val['NumBuckets']).cast(t)
 195     return self._iterator(self.val.type.template_argument(2), begin, end)
 196
 197   def to_string(self):
 198     return 'llvm::DenseMap with %d elements' % (self.val['NumEntries'])
 199
 200   def display_hint(self):
 201     return 'map'
 202
 203 class TwinePrinter:
 204   "Print a Twine"
 205
 206   def __init__(self, val):
 207     self._val = val
 208
 209   def display_hint(self):
 210     return 'string'
 211
 212   def string_from_pretty_printer_lookup(self, val):
 213     '''Lookup the default pretty-printer for val and use it.
 214
 215     If no pretty-printer is defined for the type of val, print an error and
 216     return a placeholder string.'''
 217
 218     pp = gdb.default_visualizer(val)
 219     if pp:
 220       s = pp.to_string()
 221
 222       # The pretty-printer may return a LazyString instead of an actual Python
 223       # string.  Convert it to a Python string.  However, GDB doesn't seem to
 224       # register the LazyString type, so we can't check
 225       # "type(s) == gdb.LazyString".
 226       if 'LazyString' in type(s).__name__:
 227         s = s.value().address.string()
 228
 229     else:
 230       print(('No pretty printer for {} found. The resulting Twine ' +
 231              'representation will be incomplete.').format(val.type.name))
 232       s = '(missing {})'.format(val.type.name)
 233
 234     return s
 235
 236   def is_twine_kind(self, kind, expected):
 237     if not kind.endswith(expected):
 238       return False
 239     # apparently some GDB versions add the NodeKind:: namespace
 240     # (happens for me on GDB 7.11)
 241     return kind in ('llvm::Twine::' + expected,
 242                     'llvm::Twine::NodeKind::' + expected)
 243
 244   def string_from_child(self, child, kind):
 245     '''Return the string representation of the Twine::Child child.'''
 246
 247     if self.is_twine_kind(kind, 'EmptyKind') or self.is_twine_kind(kind, 'NullKind'):
 248       return ''
 249
 250     if self.is_twine_kind(kind, 'TwineKind'):
 251       return self.string_from_twine_object(child['twine'].dereference())
 252
 253     if self.is_twine_kind(kind, 'CStringKind'):
 254       return child['cString'].string()
 255
 256     if self.is_twine_kind(kind, 'StdStringKind'):
 257       val = child['stdString'].dereference()
 258       return self.string_from_pretty_printer_lookup(val)
 259
 260     if self.is_twine_kind(kind, 'StringRefKind'):
 261       val = child['stringRef'].dereference()
 262       pp = StringRefPrinter(val)
 263       return pp.to_string()
 264
 265     if self.is_twine_kind(kind, 'SmallStringKind'):
 266       val = child['smallString'].dereference()
 267       pp = SmallStringPrinter(val)
 268       return pp.to_string()
 269
 270     if self.is_twine_kind(kind, 'CharKind'):
 271       return chr(child['character'])
 272
 273     if self.is_twine_kind(kind, 'DecUIKind'):
 274       return str(child['decUI'])
 275
 276     if self.is_twine_kind(kind, 'DecIKind'):
 277       return str(child['decI'])
 278
 279     if self.is_twine_kind(kind, 'DecULKind'):
 280       return str(child['decUL'].dereference())
 281
 282     if self.is_twine_kind(kind, 'DecLKind'):
 283       return str(child['decL'].dereference())
 284
 285     if self.is_twine_kind(kind, 'DecULLKind'):
 286       return str(child['decULL'].dereference())
 287
 288     if self.is_twine_kind(kind, 'DecLLKind'):
 289       return str(child['decLL'].dereference())
 290
 291     if self.is_twine_kind(kind, 'UHexKind'):
 292       val = child['uHex'].dereference()
 293       return hex(int(val))
 294
 295     print(('Unhandled NodeKind {} in Twine pretty-printer. The result will be '
 296            'incomplete.').format(kind))
 297
 298     return '(unhandled {})'.format(kind)
 299
 300   def string_from_twine_object(self, twine):
 301     '''Return the string representation of the Twine object twine.'''
 302
 303     lhs_str = ''
 304     rhs_str = ''
 305
 306     lhs = twine['LHS']
 307     rhs = twine['RHS']
 308     lhs_kind = str(twine['LHSKind'])
 309     rhs_kind = str(twine['RHSKind'])
 310
 311     lhs_str = self.string_from_child(lhs, lhs_kind)
 312     rhs_str = self.string_from_child(rhs, rhs_kind)
 313
 314     return lhs_str + rhs_str
 315
 316   def to_string(self):
 317     return self.string_from_twine_object(self._val)
 318
 319 pp = gdb.printing.RegexpCollectionPrettyPrinter("LLVMSupport")
 320 pp.add_printer('llvm::SmallString', '^llvm::SmallString<.*>$', SmallStringPrinter)
 321 pp.add_printer('llvm::StringRef', '^llvm::StringRef$', StringRefPrinter)
 322 pp.add_printer('llvm::SmallVectorImpl', '^llvm::SmallVector(Impl)?<.*>$', SmallVectorPrinter)
 323 pp.add_printer('llvm::ArrayRef', '^llvm::(Const)?ArrayRef<.*>$', ArrayRefPrinter)
 324 pp.add_printer('llvm::Expected', '^llvm::Expected<.*>$', ExpectedPrinter)
 325 pp.add_printer('llvm::Optional', '^llvm::Optional<.*>$', OptionalPrinter)
 326 pp.add_printer('llvm::DenseMap', '^llvm::DenseMap<.*>$', DenseMapPrinter)
 327 pp.add_printer('llvm::Twine', '^llvm::Twine$', TwinePrinter)
 328 gdb.printing.register_pretty_printer(gdb.current_objfile(), pp)