"""Interface to the compiler's internal symbol tables"""

[0] Fix | Delete

[1] Fix | Delete

import _symtable

[2] Fix | Delete

from _symtable import (USE, DEF_GLOBAL, DEF_LOCAL, DEF_PARAM,

[3] Fix | Delete

DEF_IMPORT, DEF_BOUND, OPT_IMPORT_STAR, OPT_EXEC, OPT_BARE_EXEC,

[4] Fix | Delete

SCOPE_OFF, SCOPE_MASK, FREE, GLOBAL_IMPLICIT, GLOBAL_EXPLICIT, CELL, LOCAL)

[5] Fix | Delete

[6] Fix | Delete

import weakref

[7] Fix | Delete

[8] Fix | Delete

__all__ = ["symtable", "SymbolTable", "Class", "Function", "Symbol"]

[9] Fix | Delete

[10] Fix | Delete

def symtable(code, filename, compile_type):

[11] Fix | Delete

top = _symtable.symtable(code, filename, compile_type)

[12] Fix | Delete

return _newSymbolTable(top, filename)

[13] Fix | Delete

[14] Fix | Delete

class SymbolTableFactory:

[15] Fix | Delete

def __init__(self):

[16] Fix | Delete

self.__memo = weakref.WeakValueDictionary()

[17] Fix | Delete

[18] Fix | Delete

def new(self, table, filename):

[19] Fix | Delete

if table.type == _symtable.TYPE_FUNCTION:

[20] Fix | Delete

return Function(table, filename)

[21] Fix | Delete

if table.type == _symtable.TYPE_CLASS:

[22] Fix | Delete

return Class(table, filename)

[23] Fix | Delete

return SymbolTable(table, filename)

[24] Fix | Delete

[25] Fix | Delete

def __call__(self, table, filename):

[26] Fix | Delete

key = table, filename

[27] Fix | Delete

obj = self.__memo.get(key, None)

[28] Fix | Delete

if obj is None:

[29] Fix | Delete

obj = self.__memo[key] = self.new(table, filename)

[30] Fix | Delete

return obj

[31] Fix | Delete

[32] Fix | Delete

_newSymbolTable = SymbolTableFactory()

[33] Fix | Delete

[34] Fix | Delete

[35] Fix | Delete

class SymbolTable(object):

[36] Fix | Delete

[37] Fix | Delete

def __init__(self, raw_table, filename):

[38] Fix | Delete

self._table = raw_table

[39] Fix | Delete

self._filename = filename

[40] Fix | Delete

self._symbols = {}

[41] Fix | Delete

[42] Fix | Delete

def __repr__(self):

[43] Fix | Delete

if self.__class__ == SymbolTable:

[44] Fix | Delete

kind = ""

[45] Fix | Delete

else:

[46] Fix | Delete

kind = "%s " % self.__class__.__name__

[47] Fix | Delete

[48] Fix | Delete

if self._table.name == "global":

[49] Fix | Delete

return "<{0}SymbolTable for module {1}>".format(kind, self._filename)

[50] Fix | Delete

else:

[51] Fix | Delete

return "<{0}SymbolTable for {1} in {2}>".format(kind,

[52] Fix | Delete

self._table.name,

[53] Fix | Delete

self._filename)

[54] Fix | Delete

[55] Fix | Delete

def get_type(self):

[56] Fix | Delete

if self._table.type == _symtable.TYPE_MODULE:

[57] Fix | Delete

return "module"

[58] Fix | Delete

if self._table.type == _symtable.TYPE_FUNCTION:

[59] Fix | Delete

return "function"

[60] Fix | Delete

if self._table.type == _symtable.TYPE_CLASS:

[61] Fix | Delete

return "class"

[62] Fix | Delete

assert self._table.type in (1, 2, 3), \

[63] Fix | Delete

"unexpected type: {0}".format(self._table.type)

[64] Fix | Delete

[65] Fix | Delete

def get_id(self):

[66] Fix | Delete

return self._table.id

[67] Fix | Delete

[68] Fix | Delete

def get_name(self):

[69] Fix | Delete

return self._table.name

[70] Fix | Delete

[71] Fix | Delete

def get_lineno(self):

[72] Fix | Delete

return self._table.lineno

[73] Fix | Delete

[74] Fix | Delete

def is_optimized(self):

[75] Fix | Delete

return bool(self._table.type == _symtable.TYPE_FUNCTION

[76] Fix | Delete

and not self._table.optimized)

[77] Fix | Delete

[78] Fix | Delete

def is_nested(self):

[79] Fix | Delete

return bool(self._table.nested)

[80] Fix | Delete

[81] Fix | Delete

def has_children(self):

[82] Fix | Delete

return bool(self._table.children)

[83] Fix | Delete

[84] Fix | Delete

def has_exec(self):

[85] Fix | Delete

"""Return true if the scope uses exec"""

[86] Fix | Delete

return bool(self._table.optimized & (OPT_EXEC | OPT_BARE_EXEC))

[87] Fix | Delete

[88] Fix | Delete

def has_import_star(self):

[89] Fix | Delete

"""Return true if the scope uses import *"""

[90] Fix | Delete

return bool(self._table.optimized & OPT_IMPORT_STAR)

[91] Fix | Delete

[92] Fix | Delete

def get_identifiers(self):

[93] Fix | Delete

return self._table.symbols.keys()

[94] Fix | Delete

[95] Fix | Delete

def lookup(self, name):

[96] Fix | Delete

sym = self._symbols.get(name)

[97] Fix | Delete

if sym is None:

[98] Fix | Delete

flags = self._table.symbols[name]

[99] Fix | Delete

namespaces = self.__check_children(name)

[100] Fix | Delete

sym = self._symbols[name] = Symbol(name, flags, namespaces)

[101] Fix | Delete

return sym

[102] Fix | Delete

[103] Fix | Delete

def get_symbols(self):

[104] Fix | Delete

return [self.lookup(ident) for ident in self.get_identifiers()]

[105] Fix | Delete

[106] Fix | Delete

def __check_children(self, name):

[107] Fix | Delete

return [_newSymbolTable(st, self._filename)

[108] Fix | Delete

for st in self._table.children

[109] Fix | Delete

if st.name == name]

[110] Fix | Delete

[111] Fix | Delete

def get_children(self):

[112] Fix | Delete

return [_newSymbolTable(st, self._filename)

[113] Fix | Delete

for st in self._table.children]

[114] Fix | Delete

[115] Fix | Delete

[116] Fix | Delete

class Function(SymbolTable):

[117] Fix | Delete

[118] Fix | Delete

# Default values for instance variables

[119] Fix | Delete

__params = None

[120] Fix | Delete

__locals = None

[121] Fix | Delete

__frees = None

[122] Fix | Delete

__globals = None

[123] Fix | Delete

[124] Fix | Delete

def __idents_matching(self, test_func):

[125] Fix | Delete

return tuple([ident for ident in self.get_identifiers()

[126] Fix | Delete

if test_func(self._table.symbols[ident])])

[127] Fix | Delete

[128] Fix | Delete

def get_parameters(self):

[129] Fix | Delete

if self.__params is None:

[130] Fix | Delete

self.__params = self.__idents_matching(lambda x:x & DEF_PARAM)

[131] Fix | Delete

return self.__params

[132] Fix | Delete

[133] Fix | Delete

def get_locals(self):

[134] Fix | Delete

if self.__locals is None:

[135] Fix | Delete

locs = (LOCAL, CELL)

[136] Fix | Delete

test = lambda x: ((x >> SCOPE_OFF) & SCOPE_MASK) in locs

[137] Fix | Delete

self.__locals = self.__idents_matching(test)

[138] Fix | Delete

return self.__locals

[139] Fix | Delete

[140] Fix | Delete

def get_globals(self):

[141] Fix | Delete

if self.__globals is None:

[142] Fix | Delete

glob = (GLOBAL_IMPLICIT, GLOBAL_EXPLICIT)

[143] Fix | Delete

test = lambda x:((x >> SCOPE_OFF) & SCOPE_MASK) in glob

[144] Fix | Delete

self.__globals = self.__idents_matching(test)

[145] Fix | Delete

return self.__globals

[146] Fix | Delete

[147] Fix | Delete

def get_frees(self):

[148] Fix | Delete

if self.__frees is None:

[149] Fix | Delete

is_free = lambda x:((x >> SCOPE_OFF) & SCOPE_MASK) == FREE

[150] Fix | Delete

self.__frees = self.__idents_matching(is_free)

[151] Fix | Delete

return self.__frees

[152] Fix | Delete

[153] Fix | Delete

[154] Fix | Delete

class Class(SymbolTable):

[155] Fix | Delete

[156] Fix | Delete

__methods = None

[157] Fix | Delete

[158] Fix | Delete

def get_methods(self):

[159] Fix | Delete

if self.__methods is None:

[160] Fix | Delete

d = {}

[161] Fix | Delete

for st in self._table.children:

[162] Fix | Delete

d[st.name] = 1

[163] Fix | Delete

self.__methods = tuple(d)

[164] Fix | Delete

return self.__methods

[165] Fix | Delete

[166] Fix | Delete

[167] Fix | Delete

class Symbol(object):

[168] Fix | Delete

[169] Fix | Delete

def __init__(self, name, flags, namespaces=None):

[170] Fix | Delete

self.__name = name

[171] Fix | Delete

self.__flags = flags

[172] Fix | Delete

self.__scope = (flags >> SCOPE_OFF) & SCOPE_MASK # like PyST_GetScope()

[173] Fix | Delete

self.__namespaces = namespaces or ()

[174] Fix | Delete

[175] Fix | Delete

def __repr__(self):

[176] Fix | Delete

return "<symbol {0!r}>".format(self.__name)

[177] Fix | Delete

[178] Fix | Delete

def get_name(self):

[179] Fix | Delete

return self.__name

[180] Fix | Delete

[181] Fix | Delete

def is_referenced(self):

[182] Fix | Delete

return bool(self.__flags & _symtable.USE)

[183] Fix | Delete

[184] Fix | Delete

def is_parameter(self):

[185] Fix | Delete

return bool(self.__flags & DEF_PARAM)

[186] Fix | Delete

[187] Fix | Delete

def is_global(self):

[188] Fix | Delete

return bool(self.__scope in (GLOBAL_IMPLICIT, GLOBAL_EXPLICIT))

[189] Fix | Delete

[190] Fix | Delete

def is_declared_global(self):

[191] Fix | Delete

return bool(self.__scope == GLOBAL_EXPLICIT)

[192] Fix | Delete

[193] Fix | Delete

def is_local(self):

[194] Fix | Delete

return bool(self.__flags & DEF_BOUND)

[195] Fix | Delete

[196] Fix | Delete

def is_free(self):

[197] Fix | Delete

return bool(self.__scope == FREE)

[198] Fix | Delete

[199] Fix | Delete

def is_imported(self):

[200] Fix | Delete

return bool(self.__flags & DEF_IMPORT)

[201] Fix | Delete

[202] Fix | Delete

def is_assigned(self):

[203] Fix | Delete

return bool(self.__flags & DEF_LOCAL)

[204] Fix | Delete

[205] Fix | Delete

def is_namespace(self):

[206] Fix | Delete

"""Returns true if name binding introduces new namespace.

[207] Fix | Delete

[208] Fix | Delete

If the name is used as the target of a function or class

[209] Fix | Delete

statement, this will be true.

[210] Fix | Delete

[211] Fix | Delete

Note that a single name can be bound to multiple objects. If

[212] Fix | Delete

is_namespace() is true, the name may also be bound to other

[213] Fix | Delete

objects, like an int or list, that does not introduce a new

[214] Fix | Delete

namespace.

[215] Fix | Delete

"""

[216] Fix | Delete

return bool(self.__namespaces)

[217] Fix | Delete

[218] Fix | Delete

def get_namespaces(self):

[219] Fix | Delete

"""Return a list of namespaces bound to this name"""

[220] Fix | Delete

return self.__namespaces

[221] Fix | Delete

[222] Fix | Delete

def get_namespace(self):

[223] Fix | Delete

"""Returns the single namespace bound to this name.

[224] Fix | Delete

[225] Fix | Delete

Raises ValueError if the name is bound to multiple namespaces.

[226] Fix | Delete

"""

[227] Fix | Delete

if len(self.__namespaces) != 1:

[228] Fix | Delete

raise ValueError, "name is bound to multiple namespaces"

[229] Fix | Delete

return self.__namespaces[0]

[230] Fix | Delete

[231] Fix | Delete

if __name__ == "__main__":

[232] Fix | Delete

import os, sys

[233] Fix | Delete

src = open(sys.argv[0]).read()

[234] Fix | Delete

mod = symtable(src, os.path.split(sys.argv[0])[1], "exec")

[235] Fix | Delete

for ident in mod.get_identifiers():

[236] Fix | Delete

info = mod.lookup(ident)

[237] Fix | Delete

print info, info.is_local(), info.is_namespace()

[238] Fix | Delete

[239] Fix | Delete