Jeremy Hylton | 816e149 | 2001-03-22 23:32:22 +0000 | [diff] [blame] | 1 | """Interface to the compiler's internal symbol tables""" |
| 2 | from __future__ import nested_scopes |
| 3 | |
| 4 | import _symtable |
| 5 | from _symtable import USE, DEF_GLOBAL, DEF_LOCAL, DEF_PARAM, \ |
| 6 | DEF_STAR, DEF_DOUBLESTAR, DEF_INTUPLE, DEF_FREE, \ |
Jeremy Hylton | 5030cf1 | 2001-04-16 18:43:18 +0000 | [diff] [blame] | 7 | DEF_FREE_GLOBAL, DEF_FREE_CLASS, DEF_IMPORT, DEF_BOUND, \ |
| 8 | OPT_IMPORT_STAR, OPT_EXEC, OPT_BARE_EXEC |
Jeremy Hylton | 816e149 | 2001-03-22 23:32:22 +0000 | [diff] [blame] | 9 | |
| 10 | import weakref |
| 11 | |
Jeremy Hylton | 101651c | 2001-03-23 15:41:14 +0000 | [diff] [blame] | 12 | __all__ = ["symtable", "SymbolTable", "newSymbolTable", "Class", |
| 13 | "Function", "Symbol"] |
Jeremy Hylton | 816e149 | 2001-03-22 23:32:22 +0000 | [diff] [blame] | 14 | |
| 15 | def symtable(code, filename, compile_type): |
| 16 | raw = _symtable.symtable(code, filename, compile_type) |
| 17 | return newSymbolTable(raw[0], filename) |
| 18 | |
| 19 | class SymbolTableFactory: |
| 20 | def __init__(self): |
| 21 | self.__memo = weakref.WeakValueDictionary() |
| 22 | |
| 23 | def new(self, table, filename): |
| 24 | if table.type == _symtable.TYPE_FUNCTION: |
| 25 | return Function(table, filename) |
| 26 | if table.type == _symtable.TYPE_CLASS: |
| 27 | return Class(table, filename) |
| 28 | return SymbolTable(table, filename) |
| 29 | |
| 30 | def __call__(self, table, filename): |
| 31 | key = table, filename |
| 32 | obj = self.__memo.get(key, None) |
| 33 | if obj is None: |
| 34 | obj = self.__memo[key] = self.new(table, filename) |
| 35 | return obj |
| 36 | |
| 37 | newSymbolTable = SymbolTableFactory() |
Tim Peters | a19a168 | 2001-03-29 04:36:09 +0000 | [diff] [blame] | 38 | |
Jeremy Hylton | 816e149 | 2001-03-22 23:32:22 +0000 | [diff] [blame] | 39 | def bool(x): |
| 40 | """Helper to force boolean result to 1 or 0""" |
| 41 | if x: |
| 42 | return 1 |
| 43 | return 0 |
| 44 | |
| 45 | def is_free(flags): |
| 46 | if (flags & (USE | DEF_FREE)) \ |
| 47 | and (flags & (DEF_LOCAL | DEF_PARAM | DEF_GLOBAL)): |
| 48 | return 1 |
| 49 | if flags & DEF_FREE_CLASS: |
| 50 | return 1 |
| 51 | return 0 |
| 52 | |
| 53 | class SymbolTable: |
| 54 | def __init__(self, raw_table, filename): |
| 55 | self._table = raw_table |
| 56 | self._filename = filename |
| 57 | self._symbols = {} |
| 58 | |
| 59 | def __repr__(self): |
| 60 | if self.__class__ == SymbolTable: |
| 61 | kind = "" |
| 62 | else: |
| 63 | kind = "%s " % self.__class__.__name__ |
Tim Peters | a19a168 | 2001-03-29 04:36:09 +0000 | [diff] [blame] | 64 | |
Jeremy Hylton | 816e149 | 2001-03-22 23:32:22 +0000 | [diff] [blame] | 65 | if self._table.name == "global": |
| 66 | return "<%sSymbolTable for module %s>" % (kind, self._filename) |
| 67 | else: |
| 68 | return "<%sSymbolTable for %s in %s>" % (kind, self._table.name, |
| 69 | self._filename) |
| 70 | |
| 71 | def get_type(self): |
| 72 | if self._table.type == _symtable.TYPE_MODULE: |
| 73 | return "module" |
| 74 | if self._table.type == _symtable.TYPE_FUNCTION: |
| 75 | return "function" |
| 76 | if self._table.type == _symtable.TYPE_CLASS: |
| 77 | return "class" |
| 78 | assert self._table.type in (1, 2, 3), \ |
| 79 | "unexpected type: %s" % self._table.type |
| 80 | |
| 81 | def get_id(self): |
| 82 | return self._table.id |
| 83 | |
| 84 | def get_name(self): |
| 85 | return self._table.name |
| 86 | |
| 87 | def get_lineno(self): |
| 88 | return self._table.lineno |
| 89 | |
| 90 | def is_optimized(self): |
| 91 | return bool(self._table.type == _symtable.TYPE_FUNCTION |
| 92 | and not self._table.optimized) |
| 93 | |
| 94 | def is_nested(self): |
| 95 | return bool(self._table.nested) |
| 96 | |
| 97 | def has_children(self): |
| 98 | return bool(self._table.children) |
| 99 | |
| 100 | def has_exec(self): |
Jeremy Hylton | 5030cf1 | 2001-04-16 18:43:18 +0000 | [diff] [blame] | 101 | """Return true if the scope uses exec""" |
| 102 | return bool(self._table.optimized & (OPT_EXEC | OPT_BARE_EXEC)) |
| 103 | |
| 104 | def has_import_star(self): |
| 105 | """Return true if the scope uses import *""" |
| 106 | return bool(self._table.optimized & OPT_IMPORT_STAR) |
Jeremy Hylton | 816e149 | 2001-03-22 23:32:22 +0000 | [diff] [blame] | 107 | |
| 108 | def get_identifiers(self): |
| 109 | return self._table.symbols.keys() |
| 110 | |
| 111 | def lookup(self, name): |
| 112 | sym = self._symbols.get(name) |
| 113 | if sym is None: |
| 114 | flags = self._table.symbols[name] |
| 115 | namespaces = self.__check_children(name) |
| 116 | sym = self._symbols[name] = Symbol(name, flags, namespaces) |
| 117 | return sym |
| 118 | |
| 119 | def get_symbols(self): |
| 120 | return [self.lookup(ident) for ident in self.get_identifiers()] |
| 121 | |
| 122 | def __check_children(self, name): |
| 123 | return [newSymbolTable(st, self._filename) |
| 124 | for st in self._table.children |
| 125 | if st.name == name] |
| 126 | |
Jeremy Hylton | 101651c | 2001-03-23 15:41:14 +0000 | [diff] [blame] | 127 | def get_children(self): |
| 128 | return [newSymbolTable(st, self._filename) |
| 129 | for st in self._table.children] |
| 130 | |
Jeremy Hylton | 816e149 | 2001-03-22 23:32:22 +0000 | [diff] [blame] | 131 | class Function(SymbolTable): |
| 132 | |
| 133 | # Default values for instance variables |
| 134 | __params = None |
| 135 | __locals = None |
| 136 | __frees = None |
| 137 | __globals = None |
| 138 | |
| 139 | def __idents_matching(self, test_func): |
| 140 | return tuple([ident for ident in self.get_identifiers() |
| 141 | if test_func(self._table.symbols[ident])]) |
| 142 | |
| 143 | def get_parameters(self): |
| 144 | if self.__params is None: |
| 145 | self.__params = self.__idents_matching(lambda x:x & DEF_PARAM) |
| 146 | return self.__params |
| 147 | |
| 148 | def get_locals(self): |
| 149 | if self.__locals is None: |
| 150 | self.__locals = self.__idents_matching(lambda x:x & DEF_BOUND) |
| 151 | return self.__locals |
Tim Peters | a19a168 | 2001-03-29 04:36:09 +0000 | [diff] [blame] | 152 | |
Jeremy Hylton | 816e149 | 2001-03-22 23:32:22 +0000 | [diff] [blame] | 153 | def get_globals(self): |
| 154 | if self.__globals is None: |
| 155 | glob = DEF_GLOBAL | DEF_FREE_GLOBAL |
| 156 | self.__globals = self.__idents_matching(lambda x:x & glob) |
| 157 | return self.__globals |
| 158 | |
| 159 | def get_frees(self): |
| 160 | if self.__frees is None: |
| 161 | self.__frees = self.__idents_matching(is_free) |
| 162 | return self.__frees |
| 163 | |
| 164 | class Class(SymbolTable): |
| 165 | |
| 166 | __methods = None |
| 167 | |
| 168 | def get_methods(self): |
| 169 | if self.__methods is None: |
| 170 | d = {} |
| 171 | for st in self._table.children: |
| 172 | d[st.name] = 1 |
| 173 | self.__methods = tuple(d.keys()) |
| 174 | return self.__methods |
| 175 | |
| 176 | class Symbol: |
| 177 | def __init__(self, name, flags, namespaces=None): |
| 178 | self.__name = name |
| 179 | self.__flags = flags |
| 180 | self.__namespaces = namespaces or () |
| 181 | |
| 182 | def __repr__(self): |
| 183 | return "<symbol '%s'>" % self.__name |
| 184 | |
| 185 | def get_name(self): |
| 186 | return self.__name |
| 187 | |
| 188 | def is_referenced(self): |
| 189 | return bool(self.__flags & _symtable.USE) |
| 190 | |
| 191 | def is_parameter(self): |
| 192 | return bool(self.__flags & DEF_PARAM) |
| 193 | |
| 194 | def is_global(self): |
Tim Peters | a19a168 | 2001-03-29 04:36:09 +0000 | [diff] [blame] | 195 | return bool((self.__flags & DEF_GLOBAL) |
Jeremy Hylton | 816e149 | 2001-03-22 23:32:22 +0000 | [diff] [blame] | 196 | or (self.__flags & DEF_FREE_GLOBAL)) |
| 197 | |
| 198 | def is_vararg(self): |
Jeremy Hylton | 5030cf1 | 2001-04-16 18:43:18 +0000 | [diff] [blame] | 199 | return bool(self.__flags & DEF_STAR) |
Jeremy Hylton | 816e149 | 2001-03-22 23:32:22 +0000 | [diff] [blame] | 200 | |
| 201 | def is_keywordarg(self): |
Jeremy Hylton | 5030cf1 | 2001-04-16 18:43:18 +0000 | [diff] [blame] | 202 | return bool(self.__flags & DEF_DOUBLESTAR) |
Jeremy Hylton | 816e149 | 2001-03-22 23:32:22 +0000 | [diff] [blame] | 203 | |
| 204 | def is_local(self): |
| 205 | return bool(self.__flags & DEF_BOUND) |
| 206 | |
| 207 | def is_free(self): |
| 208 | if (self.__flags & (USE | DEF_FREE)) \ |
| 209 | and (self.__flags & (DEF_LOCAL | DEF_PARAM | DEF_GLOBAL)): |
| 210 | return 1 |
| 211 | if self.__flags & DEF_FREE_CLASS: |
| 212 | return 1 |
| 213 | return 0 |
| 214 | |
| 215 | def is_imported(self): |
| 216 | return bool(self.__flags & DEF_IMPORT) |
| 217 | |
| 218 | def is_assigned(self): |
| 219 | return bool(self.__flags & DEF_LOCAL) |
| 220 | |
| 221 | def is_in_tuple(self): |
| 222 | return bool(self.__flags & DEF_INTUPLE) |
| 223 | |
| 224 | def is_namespace(self): |
| 225 | """Returns true if name binding introduces new namespace. |
| 226 | |
| 227 | If the name is used as the target of a function or class |
| 228 | statement, this will be true. |
| 229 | |
| 230 | Note that a single name can be bound to multiple objects. If |
| 231 | is_namespace() is true, the name may also be bound to other |
| 232 | objects, like an int or list, that does not introduce a new |
| 233 | namespace. |
| 234 | """ |
| 235 | return bool(self.__namespaces) |
| 236 | |
| 237 | def get_namespaces(self): |
| 238 | """Return a list of namespaces bound to this name""" |
| 239 | return self.__namespaces |
| 240 | |
| 241 | def get_namespace(self): |
| 242 | """Returns the single namespace bound to this name. |
| 243 | |
| 244 | Raises ValueError if the name is bound to multiple namespaces. |
| 245 | """ |
| 246 | if len(self.__namespaces) != 1: |
| 247 | raise ValueError, "name is bound to multiple namespaces" |
| 248 | return self.__namespaces[0] |
| 249 | |
Jeremy Hylton | 816e149 | 2001-03-22 23:32:22 +0000 | [diff] [blame] | 250 | if __name__ == "__main__": |
| 251 | import os, sys |
| 252 | src = open(sys.argv[0]).read() |
| 253 | mod = symtable(src, os.path.split(sys.argv[0])[1], "exec") |
| 254 | for ident in mod.get_identifiers(): |
| 255 | info = mod.lookup(ident) |
| 256 | print info, info.is_local(), info.is_namespace() |