Ben Cheng | 6e5a1b6 | 2014-04-08 14:53:42 -0700 | [diff] [blame^] | 1 | # Type utilities. |
| 2 | # Copyright (C) 2010-2014 Free Software Foundation, Inc. |
| 3 | |
| 4 | # This program is free software; you can redistribute it and/or modify |
| 5 | # it under the terms of the GNU General Public License as published by |
| 6 | # the Free Software Foundation; either version 3 of the License, or |
| 7 | # (at your option) any later version. |
| 8 | # |
| 9 | # This program is distributed in the hope that it will be useful, |
| 10 | # but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | # GNU General Public License for more details. |
| 13 | # |
| 14 | # You should have received a copy of the GNU General Public License |
| 15 | # along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 16 | |
| 17 | """Utilities for working with gdb.Types.""" |
| 18 | |
| 19 | import gdb |
| 20 | |
| 21 | |
| 22 | def get_basic_type(type_): |
| 23 | """Return the "basic" type of a type. |
| 24 | |
| 25 | Arguments: |
| 26 | type_: The type to reduce to its basic type. |
| 27 | |
| 28 | Returns: |
| 29 | type_ with const/volatile is stripped away, |
| 30 | and typedefs/references converted to the underlying type. |
| 31 | """ |
| 32 | |
| 33 | while (type_.code == gdb.TYPE_CODE_REF or |
| 34 | type_.code == gdb.TYPE_CODE_TYPEDEF): |
| 35 | if type_.code == gdb.TYPE_CODE_REF: |
| 36 | type_ = type_.target() |
| 37 | else: |
| 38 | type_ = type_.strip_typedefs() |
| 39 | return type_.unqualified() |
| 40 | |
| 41 | |
| 42 | def has_field(type_, field): |
| 43 | """Return True if a type has the specified field. |
| 44 | |
| 45 | Arguments: |
| 46 | type_: The type to examine. |
| 47 | It must be one of gdb.TYPE_CODE_STRUCT, gdb.TYPE_CODE_UNION. |
| 48 | field: The name of the field to look up. |
| 49 | |
| 50 | Returns: |
| 51 | True if the field is present either in type_ or any baseclass. |
| 52 | |
| 53 | Raises: |
| 54 | TypeError: The type is not a struct or union. |
| 55 | """ |
| 56 | |
| 57 | type_ = get_basic_type(type_) |
| 58 | if (type_.code != gdb.TYPE_CODE_STRUCT and |
| 59 | type_.code != gdb.TYPE_CODE_UNION): |
| 60 | raise TypeError("not a struct or union") |
| 61 | for f in type_.fields(): |
| 62 | if f.is_base_class: |
| 63 | if has_field(f.type, field): |
| 64 | return True |
| 65 | else: |
| 66 | # NOTE: f.name could be None |
| 67 | if f.name == field: |
| 68 | return True |
| 69 | return False |
| 70 | |
| 71 | |
| 72 | def make_enum_dict(enum_type): |
| 73 | """Return a dictionary from a program's enum type. |
| 74 | |
| 75 | Arguments: |
| 76 | enum_type: The enum to compute the dictionary for. |
| 77 | |
| 78 | Returns: |
| 79 | The dictionary of the enum. |
| 80 | |
| 81 | Raises: |
| 82 | TypeError: The type is not an enum. |
| 83 | """ |
| 84 | |
| 85 | if enum_type.code != gdb.TYPE_CODE_ENUM: |
| 86 | raise TypeError("not an enum type") |
| 87 | enum_dict = {} |
| 88 | for field in enum_type.fields(): |
| 89 | # The enum's value is stored in "enumval". |
| 90 | enum_dict[field.name] = field.enumval |
| 91 | return enum_dict |
| 92 | |
| 93 | |
| 94 | def deep_items (type_): |
| 95 | """Return an iterator that recursively traverses anonymous fields. |
| 96 | |
| 97 | Arguments: |
| 98 | type_: The type to traverse. It should be one of |
| 99 | gdb.TYPE_CODE_STRUCT or gdb.TYPE_CODE_UNION. |
| 100 | |
| 101 | Returns: |
| 102 | an iterator similar to gdb.Type.iteritems(), i.e., it returns |
| 103 | pairs of key, value, but for any anonymous struct or union |
| 104 | field that field is traversed recursively, depth-first. |
| 105 | """ |
| 106 | for k, v in type_.iteritems (): |
| 107 | if k: |
| 108 | yield k, v |
| 109 | else: |
| 110 | for i in deep_items (v.type): |
| 111 | yield i |
| 112 | |
| 113 | class TypePrinter(object): |
| 114 | """The base class for type printers. |
| 115 | |
| 116 | Instances of this type can be used to substitute type names during |
| 117 | 'ptype'. |
| 118 | |
| 119 | A type printer must have at least 'name' and 'enabled' attributes, |
| 120 | and supply an 'instantiate' method. |
| 121 | |
| 122 | The 'instantiate' method must either return None, or return an |
| 123 | object which has a 'recognize' method. This method must accept a |
| 124 | gdb.Type argument and either return None, meaning that the type |
| 125 | was not recognized, or a string naming the type. |
| 126 | """ |
| 127 | |
| 128 | def __init__(self, name): |
| 129 | self.name = name |
| 130 | self.enabled = True |
| 131 | |
| 132 | def instantiate(self): |
| 133 | return None |
| 134 | |
| 135 | # Helper function for computing the list of type recognizers. |
| 136 | def _get_some_type_recognizers(result, plist): |
| 137 | for printer in plist: |
| 138 | if printer.enabled: |
| 139 | inst = printer.instantiate() |
| 140 | if inst is not None: |
| 141 | result.append(inst) |
| 142 | return None |
| 143 | |
| 144 | def get_type_recognizers(): |
| 145 | "Return a list of the enabled type recognizers for the current context." |
| 146 | result = [] |
| 147 | |
| 148 | # First try the objfiles. |
| 149 | for objfile in gdb.objfiles(): |
| 150 | _get_some_type_recognizers(result, objfile.type_printers) |
| 151 | # Now try the program space. |
| 152 | _get_some_type_recognizers(result, gdb.current_progspace().type_printers) |
| 153 | # Finally, globals. |
| 154 | _get_some_type_recognizers(result, gdb.type_printers) |
| 155 | |
| 156 | return result |
| 157 | |
| 158 | def apply_type_recognizers(recognizers, type_obj): |
| 159 | """Apply the given list of type recognizers to the type TYPE_OBJ. |
| 160 | If any recognizer in the list recognizes TYPE_OBJ, returns the name |
| 161 | given by the recognizer. Otherwise, this returns None.""" |
| 162 | for r in recognizers: |
| 163 | result = r.recognize(type_obj) |
| 164 | if result is not None: |
| 165 | return result |
| 166 | return None |
| 167 | |
| 168 | def register_type_printer(locus, printer): |
| 169 | """Register a type printer. |
| 170 | PRINTER is the type printer instance. |
| 171 | LOCUS is either an objfile, a program space, or None, indicating |
| 172 | global registration.""" |
| 173 | |
| 174 | if locus is None: |
| 175 | locus = gdb |
| 176 | locus.type_printers.insert(0, printer) |