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Jeremy Hylton816e1492001-03-22 23:32:22 +00001"""Interface to the compiler's internal symbol tables"""
Jeremy Hylton816e1492001-03-22 23:32:22 +00002
3import _symtable
Benjamin Peterson55e00f22008-08-17 18:02:44 +00004from _symtable import (USE, DEF_GLOBAL, DEF_LOCAL, DEF_PARAM,
5 DEF_STAR, DEF_DOUBLESTAR, DEF_INTUPLE, DEF_FREE,
6 DEF_FREE_GLOBAL, DEF_FREE_CLASS, DEF_IMPORT, DEF_BOUND,
7 OPT_IMPORT_STAR, SCOPE_OFF, SCOPE_MASK, FREE,
8 GLOBAL_IMPLICIT, GLOBAL_EXPLICIT)
Jeremy Hylton816e1492001-03-22 23:32:22 +00009
10import weakref
11
Jeremy Hylton101651c2001-03-23 15:41:14 +000012__all__ = ["symtable", "SymbolTable", "newSymbolTable", "Class",
13 "Function", "Symbol"]
Jeremy Hylton816e1492001-03-22 23:32:22 +000014
15def symtable(code, filename, compile_type):
16 raw = _symtable.symtable(code, filename, compile_type)
Guido van Rossumcc2b0162007-02-11 06:12:03 +000017 for top in raw.values():
Neal Norwitz21d19f72005-11-25 03:14:00 +000018 if top.name == 'top':
19 break
20 return newSymbolTable(top, filename)
Jeremy Hylton816e1492001-03-22 23:32:22 +000021
22class SymbolTableFactory:
23 def __init__(self):
24 self.__memo = weakref.WeakValueDictionary()
25
26 def new(self, table, filename):
27 if table.type == _symtable.TYPE_FUNCTION:
28 return Function(table, filename)
29 if table.type == _symtable.TYPE_CLASS:
30 return Class(table, filename)
31 return SymbolTable(table, filename)
32
33 def __call__(self, table, filename):
34 key = table, filename
35 obj = self.__memo.get(key, None)
36 if obj is None:
37 obj = self.__memo[key] = self.new(table, filename)
38 return obj
39
40newSymbolTable = SymbolTableFactory()
Tim Petersa19a1682001-03-29 04:36:09 +000041
Jeremy Hylton816e1492001-03-22 23:32:22 +000042
Benjamin Peterson55e00f22008-08-17 18:02:44 +000043class SymbolTable(object):
44
Jeremy Hylton816e1492001-03-22 23:32:22 +000045 def __init__(self, raw_table, filename):
46 self._table = raw_table
47 self._filename = filename
48 self._symbols = {}
49
50 def __repr__(self):
51 if self.__class__ == SymbolTable:
52 kind = ""
53 else:
54 kind = "%s " % self.__class__.__name__
Tim Petersa19a1682001-03-29 04:36:09 +000055
Jeremy Hylton816e1492001-03-22 23:32:22 +000056 if self._table.name == "global":
Benjamin Peterson55e00f22008-08-17 18:02:44 +000057 return "<{0}SymbolTable for module {1}>".format(kind, self._filename)
Jeremy Hylton816e1492001-03-22 23:32:22 +000058 else:
Benjamin Peterson55e00f22008-08-17 18:02:44 +000059 return "<{0}SymbolTable for {1} in {2}>".format(kind,
60 self._table.name,
61 self._filename)
Jeremy Hylton816e1492001-03-22 23:32:22 +000062
63 def get_type(self):
64 if self._table.type == _symtable.TYPE_MODULE:
65 return "module"
66 if self._table.type == _symtable.TYPE_FUNCTION:
67 return "function"
68 if self._table.type == _symtable.TYPE_CLASS:
69 return "class"
70 assert self._table.type in (1, 2, 3), \
Benjamin Peterson55e00f22008-08-17 18:02:44 +000071 "unexpected type: {0}".format(self._table.type)
Jeremy Hylton816e1492001-03-22 23:32:22 +000072
73 def get_id(self):
74 return self._table.id
75
76 def get_name(self):
77 return self._table.name
78
79 def get_lineno(self):
80 return self._table.lineno
81
82 def is_optimized(self):
83 return bool(self._table.type == _symtable.TYPE_FUNCTION
84 and not self._table.optimized)
85
86 def is_nested(self):
87 return bool(self._table.nested)
88
89 def has_children(self):
90 return bool(self._table.children)
91
92 def has_exec(self):
Guido van Rossum2def5572006-09-06 22:37:15 +000093 """Return true if the scope uses exec. Deprecated method."""
94 return False
Jeremy Hylton5030cf12001-04-16 18:43:18 +000095
96 def has_import_star(self):
97 """Return true if the scope uses import *"""
98 return bool(self._table.optimized & OPT_IMPORT_STAR)
Jeremy Hylton816e1492001-03-22 23:32:22 +000099
100 def get_identifiers(self):
101 return self._table.symbols.keys()
102
103 def lookup(self, name):
104 sym = self._symbols.get(name)
105 if sym is None:
106 flags = self._table.symbols[name]
107 namespaces = self.__check_children(name)
108 sym = self._symbols[name] = Symbol(name, flags, namespaces)
109 return sym
110
111 def get_symbols(self):
112 return [self.lookup(ident) for ident in self.get_identifiers()]
113
114 def __check_children(self, name):
115 return [newSymbolTable(st, self._filename)
116 for st in self._table.children
117 if st.name == name]
118
Jeremy Hylton101651c2001-03-23 15:41:14 +0000119 def get_children(self):
120 return [newSymbolTable(st, self._filename)
121 for st in self._table.children]
122
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000123
Jeremy Hylton816e1492001-03-22 23:32:22 +0000124class Function(SymbolTable):
125
126 # Default values for instance variables
127 __params = None
128 __locals = None
129 __frees = None
130 __globals = None
131
132 def __idents_matching(self, test_func):
133 return tuple([ident for ident in self.get_identifiers()
134 if test_func(self._table.symbols[ident])])
135
136 def get_parameters(self):
137 if self.__params is None:
138 self.__params = self.__idents_matching(lambda x:x & DEF_PARAM)
139 return self.__params
140
141 def get_locals(self):
142 if self.__locals is None:
143 self.__locals = self.__idents_matching(lambda x:x & DEF_BOUND)
144 return self.__locals
Tim Petersa19a1682001-03-29 04:36:09 +0000145
Jeremy Hylton816e1492001-03-22 23:32:22 +0000146 def get_globals(self):
147 if self.__globals is None:
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000148 glob = (GLOBAL_IMPLICIT, GLOBAL_EXPLICIT)
149 test = lambda x:((x >> SCOPE_OFF) & SCOPE_MASK) in glob
150 self.__globals = self.__idents_matching(test)
Jeremy Hylton816e1492001-03-22 23:32:22 +0000151 return self.__globals
152
153 def get_frees(self):
154 if self.__frees is None:
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000155 is_free = lambda x:((x >> SCOPE_OFF) & SCOPE_MASK) == FREE
Jeremy Hylton816e1492001-03-22 23:32:22 +0000156 self.__frees = self.__idents_matching(is_free)
157 return self.__frees
158
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000159
Jeremy Hylton816e1492001-03-22 23:32:22 +0000160class Class(SymbolTable):
161
162 __methods = None
163
164 def get_methods(self):
165 if self.__methods is None:
166 d = {}
167 for st in self._table.children:
168 d[st.name] = 1
Raymond Hettingere0d49722002-06-02 18:55:56 +0000169 self.__methods = tuple(d)
Jeremy Hylton816e1492001-03-22 23:32:22 +0000170 return self.__methods
171
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000172
173class Symbol(object):
174
Jeremy Hylton816e1492001-03-22 23:32:22 +0000175 def __init__(self, name, flags, namespaces=None):
176 self.__name = name
177 self.__flags = flags
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000178 self.__scope = (flags >> SCOPE_OFF) & SCOPE_MASK # like PyST_GetScope()
Jeremy Hylton816e1492001-03-22 23:32:22 +0000179 self.__namespaces = namespaces or ()
180
181 def __repr__(self):
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000182 return "<symbol {0!r}>".format(self.__name)
Jeremy Hylton816e1492001-03-22 23:32:22 +0000183
184 def get_name(self):
185 return self.__name
186
187 def is_referenced(self):
188 return bool(self.__flags & _symtable.USE)
189
190 def is_parameter(self):
191 return bool(self.__flags & DEF_PARAM)
192
193 def is_global(self):
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000194 return bool(self.__scope in (GLOBAL_IMPLICIT, GLOBAL_EXPLICIT))
Jeremy Hylton816e1492001-03-22 23:32:22 +0000195
196 def is_vararg(self):
Jeremy Hylton5030cf12001-04-16 18:43:18 +0000197 return bool(self.__flags & DEF_STAR)
Jeremy Hylton816e1492001-03-22 23:32:22 +0000198
199 def is_keywordarg(self):
Jeremy Hylton5030cf12001-04-16 18:43:18 +0000200 return bool(self.__flags & DEF_DOUBLESTAR)
Jeremy Hylton816e1492001-03-22 23:32:22 +0000201
202 def is_local(self):
203 return bool(self.__flags & DEF_BOUND)
204
205 def is_free(self):
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000206 return bool(self.__scope == FREE)
Jeremy Hylton816e1492001-03-22 23:32:22 +0000207
208 def is_imported(self):
209 return bool(self.__flags & DEF_IMPORT)
210
211 def is_assigned(self):
212 return bool(self.__flags & DEF_LOCAL)
213
214 def is_in_tuple(self):
215 return bool(self.__flags & DEF_INTUPLE)
216
217 def is_namespace(self):
218 """Returns true if name binding introduces new namespace.
219
220 If the name is used as the target of a function or class
221 statement, this will be true.
222
223 Note that a single name can be bound to multiple objects. If
224 is_namespace() is true, the name may also be bound to other
225 objects, like an int or list, that does not introduce a new
226 namespace.
227 """
228 return bool(self.__namespaces)
229
230 def get_namespaces(self):
231 """Return a list of namespaces bound to this name"""
232 return self.__namespaces
233
234 def get_namespace(self):
235 """Returns the single namespace bound to this name.
236
237 Raises ValueError if the name is bound to multiple namespaces.
238 """
239 if len(self.__namespaces) != 1:
Collin Winterce36ad82007-08-30 01:19:48 +0000240 raise ValueError("name is bound to multiple namespaces")
Jeremy Hylton816e1492001-03-22 23:32:22 +0000241 return self.__namespaces[0]
242
Jeremy Hylton816e1492001-03-22 23:32:22 +0000243if __name__ == "__main__":
244 import os, sys
245 src = open(sys.argv[0]).read()
246 mod = symtable(src, os.path.split(sys.argv[0])[1], "exec")
247 for ident in mod.get_identifiers():
248 info = mod.lookup(ident)
Guido van Rossumbe19ed72007-02-09 05:37:30 +0000249 print(info, info.is_local(), info.is_namespace())