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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,
Benjamin Peterson78565b22009-06-28 19:19:51 +00005 DEF_IMPORT, DEF_BOUND, OPT_IMPORT_STAR, SCOPE_OFF, SCOPE_MASK, FREE,
Benjamin Peterson500c6ef2009-06-28 19:30:36 +00006 LOCAL, GLOBAL_IMPLICIT, GLOBAL_EXPLICIT, CELL)
Jeremy Hylton816e1492001-03-22 23:32:22 +00007
8import weakref
9
Benjamin Peterson3938a902008-08-20 02:33:00 +000010__all__ = ["symtable", "SymbolTable", "Class", "Function", "Symbol"]
Jeremy Hylton816e1492001-03-22 23:32:22 +000011
12def symtable(code, filename, compile_type):
13 raw = _symtable.symtable(code, filename, compile_type)
Guido van Rossumcc2b0162007-02-11 06:12:03 +000014 for top in raw.values():
Neal Norwitz21d19f72005-11-25 03:14:00 +000015 if top.name == 'top':
16 break
Benjamin Peterson3938a902008-08-20 02:33:00 +000017 return _newSymbolTable(top, filename)
Jeremy Hylton816e1492001-03-22 23:32:22 +000018
19class 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
Benjamin Peterson3938a902008-08-20 02:33:00 +000037_newSymbolTable = SymbolTableFactory()
Tim Petersa19a1682001-03-29 04:36:09 +000038
Jeremy Hylton816e1492001-03-22 23:32:22 +000039
Benjamin Peterson55e00f22008-08-17 18:02:44 +000040class SymbolTable(object):
41
Jeremy Hylton816e1492001-03-22 23:32:22 +000042 def __init__(self, raw_table, filename):
43 self._table = raw_table
44 self._filename = filename
45 self._symbols = {}
46
47 def __repr__(self):
48 if self.__class__ == SymbolTable:
49 kind = ""
50 else:
51 kind = "%s " % self.__class__.__name__
Tim Petersa19a1682001-03-29 04:36:09 +000052
Jeremy Hylton816e1492001-03-22 23:32:22 +000053 if self._table.name == "global":
Benjamin Peterson55e00f22008-08-17 18:02:44 +000054 return "<{0}SymbolTable for module {1}>".format(kind, self._filename)
Jeremy Hylton816e1492001-03-22 23:32:22 +000055 else:
Benjamin Peterson55e00f22008-08-17 18:02:44 +000056 return "<{0}SymbolTable for {1} in {2}>".format(kind,
57 self._table.name,
58 self._filename)
Jeremy Hylton816e1492001-03-22 23:32:22 +000059
60 def get_type(self):
61 if self._table.type == _symtable.TYPE_MODULE:
62 return "module"
63 if self._table.type == _symtable.TYPE_FUNCTION:
64 return "function"
65 if self._table.type == _symtable.TYPE_CLASS:
66 return "class"
67 assert self._table.type in (1, 2, 3), \
Benjamin Peterson55e00f22008-08-17 18:02:44 +000068 "unexpected type: {0}".format(self._table.type)
Jeremy Hylton816e1492001-03-22 23:32:22 +000069
70 def get_id(self):
71 return self._table.id
72
73 def get_name(self):
74 return self._table.name
75
76 def get_lineno(self):
77 return self._table.lineno
78
79 def is_optimized(self):
80 return bool(self._table.type == _symtable.TYPE_FUNCTION
81 and not self._table.optimized)
82
83 def is_nested(self):
84 return bool(self._table.nested)
85
86 def has_children(self):
87 return bool(self._table.children)
88
89 def has_exec(self):
Guido van Rossum2def5572006-09-06 22:37:15 +000090 """Return true if the scope uses exec. Deprecated method."""
91 return False
Jeremy Hylton5030cf12001-04-16 18:43:18 +000092
93 def has_import_star(self):
94 """Return true if the scope uses import *"""
95 return bool(self._table.optimized & OPT_IMPORT_STAR)
Jeremy Hylton816e1492001-03-22 23:32:22 +000096
97 def get_identifiers(self):
98 return self._table.symbols.keys()
99
100 def lookup(self, name):
101 sym = self._symbols.get(name)
102 if sym is None:
103 flags = self._table.symbols[name]
104 namespaces = self.__check_children(name)
105 sym = self._symbols[name] = Symbol(name, flags, namespaces)
106 return sym
107
108 def get_symbols(self):
109 return [self.lookup(ident) for ident in self.get_identifiers()]
110
111 def __check_children(self, name):
Benjamin Peterson3938a902008-08-20 02:33:00 +0000112 return [_newSymbolTable(st, self._filename)
Jeremy Hylton816e1492001-03-22 23:32:22 +0000113 for st in self._table.children
114 if st.name == name]
115
Jeremy Hylton101651c2001-03-23 15:41:14 +0000116 def get_children(self):
Benjamin Peterson3938a902008-08-20 02:33:00 +0000117 return [_newSymbolTable(st, self._filename)
Jeremy Hylton101651c2001-03-23 15:41:14 +0000118 for st in self._table.children]
119
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000120
Jeremy Hylton816e1492001-03-22 23:32:22 +0000121class Function(SymbolTable):
122
123 # Default values for instance variables
124 __params = None
125 __locals = None
126 __frees = None
127 __globals = None
128
129 def __idents_matching(self, test_func):
Benjamin Petersonb71caf12008-08-20 12:55:31 +0000130 return tuple([ident for ident in self.get_identifiers()
131 if test_func(self._table.symbols[ident])])
Jeremy Hylton816e1492001-03-22 23:32:22 +0000132
133 def get_parameters(self):
134 if self.__params is None:
135 self.__params = self.__idents_matching(lambda x:x & DEF_PARAM)
136 return self.__params
137
138 def get_locals(self):
139 if self.__locals is None:
Benjamin Peterson500c6ef2009-06-28 19:30:36 +0000140 locs = (LOCAL, CELL)
141 test = lambda x: ((x >> SCOPE_OFF) & SCOPE_MASK) in locs
Benjamin Peterson78565b22009-06-28 19:19:51 +0000142 self.__locals = self.__idents_matching(test)
Jeremy Hylton816e1492001-03-22 23:32:22 +0000143 return self.__locals
Tim Petersa19a1682001-03-29 04:36:09 +0000144
Jeremy Hylton816e1492001-03-22 23:32:22 +0000145 def get_globals(self):
146 if self.__globals is None:
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000147 glob = (GLOBAL_IMPLICIT, GLOBAL_EXPLICIT)
148 test = lambda x:((x >> SCOPE_OFF) & SCOPE_MASK) in glob
149 self.__globals = self.__idents_matching(test)
Jeremy Hylton816e1492001-03-22 23:32:22 +0000150 return self.__globals
151
152 def get_frees(self):
153 if self.__frees is None:
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000154 is_free = lambda x:((x >> SCOPE_OFF) & SCOPE_MASK) == FREE
Jeremy Hylton816e1492001-03-22 23:32:22 +0000155 self.__frees = self.__idents_matching(is_free)
156 return self.__frees
157
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000158
Jeremy Hylton816e1492001-03-22 23:32:22 +0000159class Class(SymbolTable):
160
161 __methods = None
162
163 def get_methods(self):
164 if self.__methods is None:
165 d = {}
166 for st in self._table.children:
167 d[st.name] = 1
Benjamin Petersonb71caf12008-08-20 12:55:31 +0000168 self.__methods = tuple(d)
Jeremy Hylton816e1492001-03-22 23:32:22 +0000169 return self.__methods
170
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000171
172class Symbol(object):
173
Jeremy Hylton816e1492001-03-22 23:32:22 +0000174 def __init__(self, name, flags, namespaces=None):
175 self.__name = name
176 self.__flags = flags
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000177 self.__scope = (flags >> SCOPE_OFF) & SCOPE_MASK # like PyST_GetScope()
Jeremy Hylton816e1492001-03-22 23:32:22 +0000178 self.__namespaces = namespaces or ()
179
180 def __repr__(self):
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000181 return "<symbol {0!r}>".format(self.__name)
Jeremy Hylton816e1492001-03-22 23:32:22 +0000182
183 def get_name(self):
184 return self.__name
185
186 def is_referenced(self):
187 return bool(self.__flags & _symtable.USE)
188
189 def is_parameter(self):
190 return bool(self.__flags & DEF_PARAM)
191
192 def is_global(self):
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000193 return bool(self.__scope in (GLOBAL_IMPLICIT, GLOBAL_EXPLICIT))
Jeremy Hylton816e1492001-03-22 23:32:22 +0000194
Jeremy Hyltonf37708e2009-03-31 15:26:37 +0000195 def is_declared_global(self):
196 return bool(self.__scope == GLOBAL_EXPLICIT)
197
Jeremy Hylton816e1492001-03-22 23:32:22 +0000198 def is_local(self):
199 return bool(self.__flags & DEF_BOUND)
200
201 def is_free(self):
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000202 return bool(self.__scope == FREE)
Jeremy Hylton816e1492001-03-22 23:32:22 +0000203
204 def is_imported(self):
205 return bool(self.__flags & DEF_IMPORT)
206
207 def is_assigned(self):
208 return bool(self.__flags & DEF_LOCAL)
209
Jeremy Hylton816e1492001-03-22 23:32:22 +0000210 def is_namespace(self):
211 """Returns true if name binding introduces new namespace.
212
213 If the name is used as the target of a function or class
214 statement, this will be true.
215
216 Note that a single name can be bound to multiple objects. If
217 is_namespace() is true, the name may also be bound to other
218 objects, like an int or list, that does not introduce a new
219 namespace.
220 """
221 return bool(self.__namespaces)
222
223 def get_namespaces(self):
224 """Return a list of namespaces bound to this name"""
225 return self.__namespaces
226
227 def get_namespace(self):
228 """Returns the single namespace bound to this name.
229
230 Raises ValueError if the name is bound to multiple namespaces.
231 """
232 if len(self.__namespaces) != 1:
Collin Winterce36ad82007-08-30 01:19:48 +0000233 raise ValueError("name is bound to multiple namespaces")
Jeremy Hylton816e1492001-03-22 23:32:22 +0000234 return self.__namespaces[0]
235
Jeremy Hylton816e1492001-03-22 23:32:22 +0000236if __name__ == "__main__":
237 import os, sys
238 src = open(sys.argv[0]).read()
239 mod = symtable(src, os.path.split(sys.argv[0])[1], "exec")
240 for ident in mod.get_identifiers():
241 info = mod.lookup(ident)
Guido van Rossumbe19ed72007-02-09 05:37:30 +0000242 print(info, info.is_local(), info.is_namespace())