blob: 7548a7f359bedbfe42f3bf9acdd96f6a2f7880b7 [file] [log] [blame]
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 Peterson55e00f22008-08-17 18:02:44 +00005 DEF_FREE_GLOBAL, DEF_FREE_CLASS, DEF_IMPORT, DEF_BOUND,
6 OPT_IMPORT_STAR, SCOPE_OFF, SCOPE_MASK, FREE,
7 GLOBAL_IMPLICIT, GLOBAL_EXPLICIT)
Jeremy Hylton816e1492001-03-22 23:32:22 +00008
9import weakref
10
Benjamin Peterson3938a902008-08-20 02:33:00 +000011__all__ = ["symtable", "SymbolTable", "Class", "Function", "Symbol"]
Jeremy Hylton816e1492001-03-22 23:32:22 +000012
13def symtable(code, filename, compile_type):
14 raw = _symtable.symtable(code, filename, compile_type)
Guido van Rossumcc2b0162007-02-11 06:12:03 +000015 for top in raw.values():
Neal Norwitz21d19f72005-11-25 03:14:00 +000016 if top.name == 'top':
17 break
Benjamin Peterson3938a902008-08-20 02:33:00 +000018 return _newSymbolTable(top, filename)
Jeremy Hylton816e1492001-03-22 23:32:22 +000019
20class SymbolTableFactory:
21 def __init__(self):
22 self.__memo = weakref.WeakValueDictionary()
23
24 def new(self, table, filename):
25 if table.type == _symtable.TYPE_FUNCTION:
26 return Function(table, filename)
27 if table.type == _symtable.TYPE_CLASS:
28 return Class(table, filename)
29 return SymbolTable(table, filename)
30
31 def __call__(self, table, filename):
32 key = table, filename
33 obj = self.__memo.get(key, None)
34 if obj is None:
35 obj = self.__memo[key] = self.new(table, filename)
36 return obj
37
Benjamin Peterson3938a902008-08-20 02:33:00 +000038_newSymbolTable = SymbolTableFactory()
Tim Petersa19a1682001-03-29 04:36:09 +000039
Jeremy Hylton816e1492001-03-22 23:32:22 +000040
Benjamin Peterson55e00f22008-08-17 18:02:44 +000041class SymbolTable(object):
42
Jeremy Hylton816e1492001-03-22 23:32:22 +000043 def __init__(self, raw_table, filename):
44 self._table = raw_table
45 self._filename = filename
46 self._symbols = {}
47
48 def __repr__(self):
49 if self.__class__ == SymbolTable:
50 kind = ""
51 else:
52 kind = "%s " % self.__class__.__name__
Tim Petersa19a1682001-03-29 04:36:09 +000053
Jeremy Hylton816e1492001-03-22 23:32:22 +000054 if self._table.name == "global":
Benjamin Peterson55e00f22008-08-17 18:02:44 +000055 return "<{0}SymbolTable for module {1}>".format(kind, self._filename)
Jeremy Hylton816e1492001-03-22 23:32:22 +000056 else:
Benjamin Peterson55e00f22008-08-17 18:02:44 +000057 return "<{0}SymbolTable for {1} in {2}>".format(kind,
58 self._table.name,
59 self._filename)
Jeremy Hylton816e1492001-03-22 23:32:22 +000060
61 def get_type(self):
62 if self._table.type == _symtable.TYPE_MODULE:
63 return "module"
64 if self._table.type == _symtable.TYPE_FUNCTION:
65 return "function"
66 if self._table.type == _symtable.TYPE_CLASS:
67 return "class"
68 assert self._table.type in (1, 2, 3), \
Benjamin Peterson55e00f22008-08-17 18:02:44 +000069 "unexpected type: {0}".format(self._table.type)
Jeremy Hylton816e1492001-03-22 23:32:22 +000070
71 def get_id(self):
72 return self._table.id
73
74 def get_name(self):
75 return self._table.name
76
77 def get_lineno(self):
78 return self._table.lineno
79
80 def is_optimized(self):
81 return bool(self._table.type == _symtable.TYPE_FUNCTION
82 and not self._table.optimized)
83
84 def is_nested(self):
85 return bool(self._table.nested)
86
87 def has_children(self):
88 return bool(self._table.children)
89
90 def has_exec(self):
Guido van Rossum2def5572006-09-06 22:37:15 +000091 """Return true if the scope uses exec. Deprecated method."""
92 return False
Jeremy Hylton5030cf12001-04-16 18:43:18 +000093
94 def has_import_star(self):
95 """Return true if the scope uses import *"""
96 return bool(self._table.optimized & OPT_IMPORT_STAR)
Jeremy Hylton816e1492001-03-22 23:32:22 +000097
98 def get_identifiers(self):
99 return self._table.symbols.keys()
100
101 def lookup(self, name):
102 sym = self._symbols.get(name)
103 if sym is None:
104 flags = self._table.symbols[name]
105 namespaces = self.__check_children(name)
106 sym = self._symbols[name] = Symbol(name, flags, namespaces)
107 return sym
108
109 def get_symbols(self):
110 return [self.lookup(ident) for ident in self.get_identifiers()]
111
112 def __check_children(self, name):
Benjamin Peterson3938a902008-08-20 02:33:00 +0000113 return [_newSymbolTable(st, self._filename)
Jeremy Hylton816e1492001-03-22 23:32:22 +0000114 for st in self._table.children
115 if st.name == name]
116
Jeremy Hylton101651c2001-03-23 15:41:14 +0000117 def get_children(self):
Benjamin Peterson3938a902008-08-20 02:33:00 +0000118 return [_newSymbolTable(st, self._filename)
Jeremy Hylton101651c2001-03-23 15:41:14 +0000119 for st in self._table.children]
120
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000121
Jeremy Hylton816e1492001-03-22 23:32:22 +0000122class Function(SymbolTable):
123
124 # Default values for instance variables
125 __params = None
126 __locals = None
127 __frees = None
128 __globals = None
129
130 def __idents_matching(self, test_func):
Benjamin Petersonb71caf12008-08-20 12:55:31 +0000131 return tuple([ident for ident in self.get_identifiers()
132 if test_func(self._table.symbols[ident])])
Jeremy Hylton816e1492001-03-22 23:32:22 +0000133
134 def get_parameters(self):
135 if self.__params is None:
136 self.__params = self.__idents_matching(lambda x:x & DEF_PARAM)
137 return self.__params
138
139 def get_locals(self):
140 if self.__locals is None:
141 self.__locals = self.__idents_matching(lambda x:x & DEF_BOUND)
142 return self.__locals
Tim Petersa19a1682001-03-29 04:36:09 +0000143
Jeremy Hylton816e1492001-03-22 23:32:22 +0000144 def get_globals(self):
145 if self.__globals is None:
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000146 glob = (GLOBAL_IMPLICIT, GLOBAL_EXPLICIT)
147 test = lambda x:((x >> SCOPE_OFF) & SCOPE_MASK) in glob
148 self.__globals = self.__idents_matching(test)
Jeremy Hylton816e1492001-03-22 23:32:22 +0000149 return self.__globals
150
151 def get_frees(self):
152 if self.__frees is None:
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000153 is_free = lambda x:((x >> SCOPE_OFF) & SCOPE_MASK) == FREE
Jeremy Hylton816e1492001-03-22 23:32:22 +0000154 self.__frees = self.__idents_matching(is_free)
155 return self.__frees
156
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000157
Jeremy Hylton816e1492001-03-22 23:32:22 +0000158class Class(SymbolTable):
159
160 __methods = None
161
162 def get_methods(self):
163 if self.__methods is None:
164 d = {}
165 for st in self._table.children:
166 d[st.name] = 1
Benjamin Petersonb71caf12008-08-20 12:55:31 +0000167 self.__methods = tuple(d)
Jeremy Hylton816e1492001-03-22 23:32:22 +0000168 return self.__methods
169
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000170
171class Symbol(object):
172
Jeremy Hylton816e1492001-03-22 23:32:22 +0000173 def __init__(self, name, flags, namespaces=None):
174 self.__name = name
175 self.__flags = flags
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000176 self.__scope = (flags >> SCOPE_OFF) & SCOPE_MASK # like PyST_GetScope()
Jeremy Hylton816e1492001-03-22 23:32:22 +0000177 self.__namespaces = namespaces or ()
178
179 def __repr__(self):
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000180 return "<symbol {0!r}>".format(self.__name)
Jeremy Hylton816e1492001-03-22 23:32:22 +0000181
182 def get_name(self):
183 return self.__name
184
185 def is_referenced(self):
186 return bool(self.__flags & _symtable.USE)
187
188 def is_parameter(self):
189 return bool(self.__flags & DEF_PARAM)
190
191 def is_global(self):
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000192 return bool(self.__scope in (GLOBAL_IMPLICIT, GLOBAL_EXPLICIT))
Jeremy Hylton816e1492001-03-22 23:32:22 +0000193
Jeremy Hyltonf37708e2009-03-31 15:26:37 +0000194 def is_declared_global(self):
195 return bool(self.__scope == GLOBAL_EXPLICIT)
196
Jeremy Hylton816e1492001-03-22 23:32:22 +0000197 def is_local(self):
198 return bool(self.__flags & DEF_BOUND)
199
200 def is_free(self):
Benjamin Peterson55e00f22008-08-17 18:02:44 +0000201 return bool(self.__scope == FREE)
Jeremy Hylton816e1492001-03-22 23:32:22 +0000202
203 def is_imported(self):
204 return bool(self.__flags & DEF_IMPORT)
205
206 def is_assigned(self):
207 return bool(self.__flags & DEF_LOCAL)
208
Jeremy Hylton816e1492001-03-22 23:32:22 +0000209 def is_namespace(self):
210 """Returns true if name binding introduces new namespace.
211
212 If the name is used as the target of a function or class
213 statement, this will be true.
214
215 Note that a single name can be bound to multiple objects. If
216 is_namespace() is true, the name may also be bound to other
217 objects, like an int or list, that does not introduce a new
218 namespace.
219 """
220 return bool(self.__namespaces)
221
222 def get_namespaces(self):
223 """Return a list of namespaces bound to this name"""
224 return self.__namespaces
225
226 def get_namespace(self):
227 """Returns the single namespace bound to this name.
228
229 Raises ValueError if the name is bound to multiple namespaces.
230 """
231 if len(self.__namespaces) != 1:
Collin Winterce36ad82007-08-30 01:19:48 +0000232 raise ValueError("name is bound to multiple namespaces")
Jeremy Hylton816e1492001-03-22 23:32:22 +0000233 return self.__namespaces[0]
234
Jeremy Hylton816e1492001-03-22 23:32:22 +0000235if __name__ == "__main__":
236 import os, sys
237 src = open(sys.argv[0]).read()
238 mod = symtable(src, os.path.split(sys.argv[0])[1], "exec")
239 for ident in mod.get_identifiers():
240 info = mod.lookup(ident)
Guido van Rossumbe19ed72007-02-09 05:37:30 +0000241 print(info, info.is_local(), info.is_namespace())