data/gdb/mono-gdb.py

   1 #
   2 # Author: Zoltan Varga (vargaz@gmail.com)
   3 # License: MIT/X11
   4 #
   5
   6 #
   7 # This is a mono support mode for gdb 7.0 and later
   8 # Usage:
   9 # - copy/symlink this file to the directory where the mono executable lives.
  10 # - run mono under gdb, or attach to a mono process started with --debug=gdb using gdb.
  11 #
  12
  13 import os
  14
  15 class StringPrinter:
  16     "Print a C# string"
  17
  18     def __init__(self, val):
  19         self.val = val
  20
  21     def to_string(self):
  22         if int(self.val.cast (gdb.lookup_type ("guint64"))) == 0:
  23             return "null"
  24
  25         obj = self.val.cast (gdb.lookup_type ("MonoString").pointer ()).dereference ()
  26         len = obj ['length']
  27         chars = obj ['chars']
  28         i = 0
  29         res = ['"']
  30         while i < len:
  31             val = (chars.cast(gdb.lookup_type ("gint64")) + (i * 2)).cast(gdb.lookup_type ("gunichar2").pointer ()).dereference ()
  32             if val >= 256:
  33                 c = "\u%X" % val
  34             else:
  35                 c = chr (val)
  36             res.append (c)
  37             i = i + 1
  38         res.append ('"')
  39         return ''.join (res)
  40
  41 def stringify_class_name(ns, name):
  42     if ns == "System":
  43         if name == "Byte":
  44             return "byte"
  45         if name == "String":
  46             return "string"
  47     if ns == "":
  48         return name
  49     else:
  50         return "%s.%s" % (ns, name)
  51
  52 class ArrayPrinter:
  53     "Print a C# array"
  54
  55     def __init__(self, val, class_ns, class_name):
  56         self.val = val
  57         self.class_ns = class_ns
  58         self.class_name = class_name
  59
  60     def to_string(self):
  61         obj = self.val.cast (gdb.lookup_type ("MonoArray").pointer ()).dereference ()
  62         length = obj ['max_length']
  63         return "%s [%d]" % (stringify_class_name (self.class_ns, self.class_name [0:len(self.class_name) - 2]), int(length))
  64
  65 class ObjectPrinter:
  66     "Print a C# object"
  67
  68     def __init__(self, val):
  69         if str(val.type)[-1] == "&":
  70             self.val = val.address.cast (gdb.lookup_type ("MonoObject").pointer ())
  71         else:
  72             self.val = val.cast (gdb.lookup_type ("MonoObject").pointer ())
  73
  74     class _iterator:
  75         def __init__(self,obj):
  76             self.obj = obj
  77             self.iter = self.obj.type.fields ().__iter__ ()
  78             pass
  79
  80         def __iter__(self):
  81             return self
  82
  83         def next(self):
  84             field = self.iter.next ()
  85             try:
  86                 if str(self.obj [field.name].type) == "object":
  87                     # Avoid recursion
  88                     return (field.name, self.obj [field.name].cast (gdb.lookup_type ("void").pointer ()))
  89                 else:
  90                     return (field.name, self.obj [field.name])
  91             except:
  92                 # Superclass
  93                 return (field.name, self.obj.cast (gdb.lookup_type ("%s" % (field.name))))
  94
  95     def children(self):
  96         # FIXME: It would be easier if gdb.Value would support iteration itself
  97         # It would also be better if we could return None
  98         if int(self.val.cast (gdb.lookup_type ("guint64"))) == 0:
  99             return {}.__iter__ ()
 100         try:
 101             obj = self.val.dereference ()
 102             class_ns = obj ['vtable'].dereference ()['klass'].dereference ()['name_space'].string ()
 103             class_name = obj ['vtable'].dereference ()['klass'].dereference ()['name'].string ()
 104             if class_name [-2:len(class_name)] == "[]":
 105                 return {}.__iter__ ()
 106             gdb_type = gdb.lookup_type ("struct %s_%s" % (class_ns.replace (".", "_"), class_name))
 107             return self._iterator(obj.cast (gdb_type))
 108         except:
 109             print sys.exc_info ()[0]
 110             print sys.exc_info ()[1]
 111             return {}.__iter__ ()
 112
 113     def to_string(self):
 114         if int(self.val.cast (gdb.lookup_type ("guint64"))) == 0:
 115             return "null"
 116         try:
 117             obj = self.val.dereference ()
 118             class_ns = obj ['vtable'].dereference ()['klass'].dereference ()['name_space'].string ()
 119             class_name = obj ['vtable'].dereference ()['klass'].dereference ()['name'].string ()
 120             if class_ns == "System" and class_name == "String":
 121                 return StringPrinter (self.val).to_string ()
 122             if class_name [-2:len(class_name)] == "[]":
 123                 return ArrayPrinter (self.val,class_ns,class_name).to_string ()
 124             if class_ns != "":
 125                 try:
 126                     gdb_type = gdb.lookup_type ("struct %s.%s" % (class_ns, class_name))
 127                 except:
 128                     # Maybe there is no debug info for that type
 129                     return "%s.%s" % (class_ns, class_name)
 130                 #return obj.cast (gdb_type)
 131                 return "%s.%s" % (class_ns, class_name)
 132             return class_name
 133         except:
 134             print sys.exc_info ()[0]
 135             print sys.exc_info ()[1]
 136             # FIXME: This can happen because we don't have liveness information
 137             return self.val.cast (gdb.lookup_type ("guint64"))
 138
 139 class MonoMethodPrinter:
 140     "Print a MonoMethod structure"
 141
 142     def __init__(self, val):
 143         self.val = val
 144
 145     def to_string(self):
 146         if int(self.val.cast (gdb.lookup_type ("guint64"))) == 0:
 147             return "0x0"
 148         val = self.val.dereference ()
 149         klass = val ["klass"].dereference ()
 150         class_name = stringify_class_name (klass ["name_space"].string (), klass ["name"].string ())
 151         return "\"%s:%s ()\"" % (class_name, val ["name"].string ())
 152         # This returns more info but requires calling into the inferior
 153         #return "\"%s\"" % (gdb.parse_and_eval ("mono_method_full_name (%s, 1)" % (str (int (self.val.cast (gdb.lookup_type ("guint64")))))).string ())
 154
 155 class MonoClassPrinter:
 156     "Print a MonoClass structure"
 157
 158     def __init__(self, val):
 159         self.val = val
 160
 161     def to_string(self):
 162         if int(self.val.cast (gdb.lookup_type ("guint64"))) == 0:
 163             return "0x0"
 164         klass = self.val.dereference ()
 165         class_name = stringify_class_name (klass ["name_space"].string (), klass ["name"].string ())
 166         return "\"%s\"" % (class_name)
 167         # This returns more info but requires calling into the inferior
 168         #return "\"%s\"" % (gdb.parse_and_eval ("mono_type_full_name (&((MonoClass*)%s)->byval_arg)" % (str (int ((self.val).cast (gdb.lookup_type ("guint64")))))))
 169
 170 def lookup_pretty_printer(val):
 171     t = str (val.type)
 172     if t == "object":
 173         return ObjectPrinter (val)
 174     if t[0:5] == "class" and t[-1] == "&":
 175         return ObjectPrinter (val)
 176     if t == "string":
 177         return StringPrinter (val)
 178     if t == "MonoMethod *":
 179         return MonoMethodPrinter (val)
 180     if t == "MonoClass *":
 181         return MonoClassPrinter (val)
 182     return None
 183
 184 def register_csharp_printers(obj):
 185     "Register C# pretty-printers with objfile Obj."
 186
 187     if obj == None:
 188         obj = gdb
 189
 190     obj.pretty_printers.append (lookup_pretty_printer)
 191
 192 # This command will flush the debugging info collected by the runtime
 193 class XdbCommand (gdb.Command):
 194     def __init__ (self):
 195         super (XdbCommand, self).__init__ ("xdb", gdb.COMMAND_NONE,
 196                                            gdb.COMPLETE_COMMAND)
 197
 198     def invoke(self, arg, from_tty):
 199         gdb.execute ("call mono_xdebug_flush ()")
 200
 201 register_csharp_printers (gdb.current_objfile())
 202
 203 XdbCommand ()
 204
 205 gdb.execute ("set environment MONO_XDEBUG gdb")
 206
 207 print "Mono support loaded."
 208
 209