# Copyright (C) 2009, 2010, 2011 Free Software Foundation, Inc. # # This file is part of GDB. # # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 3 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program. If not, see <http://www.gnu.org/licenses/>. import gdb import os.path class TypeFlag: """A class that allows us to store a flag name, its short name, and its value. In the GDB sources, struct type has a component called instance_flags in which the value is the addition of various flags. These flags are defined by two enumerates: type_flag_value, and type_instance_flag_value. This class helps us recreate a list with all these flags that is easy to manipulate and sort. Because all flag names start with either TYPE_FLAG_ or TYPE_INSTANCE_FLAG_, a short_name attribute is provided that strips this prefix. ATTRIBUTES name: The enumeration name (eg: "TYPE_FLAG_UNSIGNED"). value: The associated value. short_name: The enumeration name, with the suffix stripped. """ def __init__(self, name, value): self.name = name self.value = value self.short_name = name.replace("TYPE_FLAG_", '') if self.short_name == name: self.short_name = name.replace("TYPE_INSTANCE_FLAG_", '') def __cmp__(self, other): """Sort by value order.""" return self.value.__cmp__(other.value) # A list of all existing TYPE_FLAGS_* and TYPE_INSTANCE_FLAGS_* # enumerations, stored as TypeFlags objects. Lazy-initialized. TYPE_FLAGS = None class TypeFlagsPrinter: """A class that prints a decoded form of an instance_flags value. This class uses a global named TYPE_FLAGS, which is a list of all defined TypeFlag values. Using a global allows us to compute this list only once. This class relies on a couple of enumeration types being defined. If not, then printing of the instance_flag is going to be degraded, but it's not a fatal error. """ def __init__(self, val): self.val = val def __str__(self): global TYPE_FLAGS if TYPE_FLAGS is None: self.init_TYPE_FLAGS() if not self.val: return "0" if TYPE_FLAGS: flag_list = [flag.short_name for flag in TYPE_FLAGS if self.val & flag.value] else: flag_list = ["???"] return "0x%x [%s]" % (self.val, "|".join(flag_list)) def init_TYPE_FLAGS(self): """Initialize the TYPE_FLAGS global as a list of TypeFlag objects. This operation requires the search of a couple of enumeration types. If not found, a warning is printed on stdout, and TYPE_FLAGS is set to the empty list. The resulting list is sorted by increasing value, to facilitate printing of the list of flags used in an instance_flags value. """ global TYPE_FLAGS TYPE_FLAGS = [] try: flags = gdb.lookup_type("enum type_flag_value") except: print "Warning: Cannot find enum type_flag_value type." print " `struct type' pretty-printer will be degraded" return try: iflags = gdb.lookup_type("enum type_instance_flag_value") except: print "Warning: Cannot find enum type_instance_flag_value type." print " `struct type' pretty-printer will be degraded" return # Note: TYPE_FLAG_MIN is a duplicate of TYPE_FLAG_UNSIGNED, # so exclude it from the list we are building. TYPE_FLAGS = [TypeFlag(field.name, field.bitpos) for field in flags.fields() if field.name != 'TYPE_FLAG_MIN'] TYPE_FLAGS += [TypeFlag(field.name, field.bitpos) for field in iflags.fields()] TYPE_FLAGS.sort() class StructTypePrettyPrinter: """Pretty-print an object of type struct type""" def __init__(self, val): self.val = val def to_string(self): fields = [] fields.append("pointer_type = %s" % self.val['pointer_type']) fields.append("reference_type = %s" % self.val['reference_type']) fields.append("chain = %s" % self.val['reference_type']) fields.append("instance_flags = %s" % TypeFlagsPrinter(self.val['instance_flags'])) fields.append("length = %d" % self.val['length']) fields.append("main_type = %s" % self.val['main_type']) return "\n{" + ",\n ".join(fields) + "}" class StructMainTypePrettyPrinter: """Pretty-print an objet of type main_type""" def __init__(self, val): self.val = val def flags_to_string(self): """struct main_type contains a series of components that are one-bit ints whose name start with "flag_". For instance: flag_unsigned, flag_stub, etc. In essence, these components are really boolean flags, and this method prints a short synthetic version of the value of all these flags. For instance, if flag_unsigned and flag_static are the only components set to 1, this function will return "unsigned|static". """ fields = [field.name.replace("flag_", "") for field in self.val.type.fields() if field.name.startswith("flag_") and self.val[field.name]] return "|".join(fields) def owner_to_string(self): """Return an image of component "owner". """ if self.val['flag_objfile_owned'] != 0: return "%s (objfile)" % self.val['owner']['objfile'] else: return "%s (gdbarch)" % self.val['owner']['gdbarch'] def struct_field_location_img(self, field_val): """Return an image of the loc component inside the given field gdb.Value. """ loc_val = field_val['loc'] loc_kind = str(field_val['loc_kind']) if loc_kind == "FIELD_LOC_KIND_BITPOS": return 'bitpos = %d' % loc_val['bitpos'] elif loc_kind == "FIELD_LOC_KIND_PHYSADDR": return 'physaddr = 0x%x' % loc_val['physaddr'] elif loc_kind == "FIELD_LOC_KIND_PHYSNAME": return 'physname = %s' % loc_val['physname'] else: return 'loc = ??? (unsupported loc_kind value)' def struct_field_img(self, fieldno): """Return an image of the main_type field number FIELDNO. """ f = self.val['flds_bnds']['fields'][fieldno] label = "field[%d]:" % fieldno if f['artificial']: label += " (artificial)" fields = [] fields.append("name = %s" % f['name']) fields.append("type = %s" % f['type']) fields.append("loc_kind = %s" % f['loc_kind']) fields.append("bitsize = %d" % f['bitsize']) fields.append(self.struct_field_location_img(f)) return label + "\n" + " {" + ",\n ".join(fields) + "}" def bounds_img(self): """Return an image of the main_type bounds. """ b = self.val['flds_bnds']['bounds'].dereference() low = str(b['low']) if b['low_undefined'] != 0: low += " (undefined)" high = str(b['high']) if b['high_undefined'] != 0: high += " (undefined)" return "bounds = {%s, %s}" % (low, high) def type_specific_img(self): """Return a string image of the main_type type_specific union. Only the relevant component of that union is printed (based on the value of the type_specific_kind field. """ type_specific_kind = str(self.val['type_specific_field']) type_specific = self.val['type_specific'] if type_specific_kind == "TYPE_SPECIFIC_NONE": img = 'type_specific_field = %s' % type_specific_kind elif type_specific_kind == "TYPE_SPECIFIC_CPLUS_STUFF": img = "cplus_stuff = %s" % type_specific['cplus_stuff'] elif type_specific_kind == "TYPE_SPECIFIC_GNAT_STUFF": img = ("gnat_stuff = {descriptive_type = %s}" % type_specific['gnat_stuff']['descriptive_type']) elif type_specific_kind == "TYPE_SPECIFIC_FLOATFORMAT": img = "floatformat[0..1] = %s" % type_specific['floatformat'] elif type_specific_kind == "TYPE_SPECIFIC_CALLING_CONVENTION": img = ("calling_convention = %d" % type_specific['calling_convention']) else: img = ("type_specific = ??? (unknown type_secific_kind: %s)" % type_specific_kind) return img def to_string(self): """Return a pretty-printed image of our main_type. """ fields = [] fields.append("name = %s" % self.val['name']) fields.append("tag_name = %s" % self.val['tag_name']) fields.append("code = %s" % self.val['code']) fields.append("flags = [%s]" % self.flags_to_string()) fields.append("owner = %s" % self.owner_to_string()) fields.append("target_type = %s" % self.val['target_type']) fields.append("vptr_basetype = %s" % self.val['vptr_basetype']) if self.val['nfields'] > 0: for fieldno in range(self.val['nfields']): fields.append(self.struct_field_img(fieldno)) if self.val['code'] == gdb.TYPE_CODE_RANGE: fields.append(self.bounds_img()) fields.append(self.type_specific_img()) return "\n{" + ",\n ".join(fields) + "}" def type_lookup_function(val): """A routine that returns the correct pretty printer for VAL if appropriate. Returns None otherwise. """ if val.type.tag == "type": return StructTypePrettyPrinter(val) elif val.type.tag == "main_type": return StructMainTypePrettyPrinter(val) return None def register_pretty_printer(objfile): """A routine to register a pretty-printer against the given OBJFILE. """ objfile.pretty_printers.append(type_lookup_function) if __name__ == "__main__": if gdb.current_objfile() is not None: # This is the case where this script is being "auto-loaded" # for a given objfile. Register the pretty-printer for that # objfile. register_pretty_printer(gdb.current_objfile()) else: # We need to locate the objfile corresponding to the GDB # executable, and register the pretty-printer for that objfile. # FIXME: The condition used to match the objfile is too simplistic # and will not work on Windows. for objfile in gdb.objfiles(): if os.path.basename(objfile.filename) == "gdb": objfile.pretty_printers.append(type_lookup_function)