1 files changed, 242 insertions, 0 deletions
diff --git a/lib/python2.7/symtable.py b/lib/python2.7/symtable.py
new file mode 100644
index 0000000..ca73f58
--- /dev/null
+++ b/lib/python2.7/symtable.py
@@ -0,0 +1,242 @@
+"""Interface to the compiler's internal symbol tables"""
+
+import _symtable
+from _symtable import (USE, DEF_GLOBAL, DEF_LOCAL, DEF_PARAM,
+     DEF_IMPORT, DEF_BOUND, OPT_IMPORT_STAR, OPT_EXEC, OPT_BARE_EXEC,
+     SCOPE_OFF, SCOPE_MASK, FREE, GLOBAL_IMPLICIT, GLOBAL_EXPLICIT, CELL, LOCAL)
+
+import weakref
+
+__all__ = ["symtable", "SymbolTable", "Class", "Function", "Symbol"]
+
+def symtable(code, filename, compile_type):
+    raw = _symtable.symtable(code, filename, compile_type)
+    for top in raw.itervalues():
+        if top.name == 'top':
+            break
+    return _newSymbolTable(top, filename)
+
+class SymbolTableFactory:
+    def __init__(self):
+        self.__memo = weakref.WeakValueDictionary()
+
+    def new(self, table, filename):
+        if table.type == _symtable.TYPE_FUNCTION:
+            return Function(table, filename)
+        if table.type == _symtable.TYPE_CLASS:
+            return Class(table, filename)
+        return SymbolTable(table, filename)
+
+    def __call__(self, table, filename):
+        key = table, filename
+        obj = self.__memo.get(key, None)
+        if obj is None:
+            obj = self.__memo[key] = self.new(table, filename)
+        return obj
+
+_newSymbolTable = SymbolTableFactory()
+
+
+class SymbolTable(object):
+
+    def __init__(self, raw_table, filename):
+        self._table = raw_table
+        self._filename = filename
+        self._symbols = {}
+
+    def __repr__(self):
+        if self.__class__ == SymbolTable:
+            kind = ""
+        else:
+            kind = "%s " % self.__class__.__name__
+
+        if self._table.name == "global":
+            return "<{0}SymbolTable for module {1}>".format(kind, self._filename)
+        else:
+            return "<{0}SymbolTable for {1} in {2}>".format(kind,
+                                                            self._table.name,
+                                                            self._filename)
+
+    def get_type(self):
+        if self._table.type == _symtable.TYPE_MODULE:
+            return "module"
+        if self._table.type == _symtable.TYPE_FUNCTION:
+            return "function"
+        if self._table.type == _symtable.TYPE_CLASS:
+            return "class"
+        assert self._table.type in (1, 2, 3), \
+               "unexpected type: {0}".format(self._table.type)
+
+    def get_id(self):
+        return self._table.id
+
+    def get_name(self):
+        return self._table.name
+
+    def get_lineno(self):
+        return self._table.lineno
+
+    def is_optimized(self):
+        return bool(self._table.type == _symtable.TYPE_FUNCTION
+                    and not self._table.optimized)
+
+    def is_nested(self):
+        return bool(self._table.nested)
+
+    def has_children(self):
+        return bool(self._table.children)
+
+    def has_exec(self):
+        """Return true if the scope uses exec"""
+        return bool(self._table.optimized & (OPT_EXEC | OPT_BARE_EXEC))
+
+    def has_import_star(self):
+        """Return true if the scope uses import *"""
+        return bool(self._table.optimized & OPT_IMPORT_STAR)
+
+    def get_identifiers(self):
+        return self._table.symbols.keys()
+
+    def lookup(self, name):
+        sym = self._symbols.get(name)
+        if sym is None:
+            flags = self._table.symbols[name]
+            namespaces = self.__check_children(name)
+            sym = self._symbols[name] = Symbol(name, flags, namespaces)
+        return sym
+
+    def get_symbols(self):
+        return [self.lookup(ident) for ident in self.get_identifiers()]
+
+    def __check_children(self, name):
+        return [_newSymbolTable(st, self._filename)
+                for st in self._table.children
+                if st.name == name]
+
+    def get_children(self):
+        return [_newSymbolTable(st, self._filename)
+                for st in self._table.children]
+
+
+class Function(SymbolTable):
+
+    # Default values for instance variables
+    __params = None
+    __locals = None
+    __frees = None
+    __globals = None
+
+    def __idents_matching(self, test_func):
+        return tuple([ident for ident in self.get_identifiers()
+                      if test_func(self._table.symbols[ident])])
+
+    def get_parameters(self):
+        if self.__params is None:
+            self.__params = self.__idents_matching(lambda x:x & DEF_PARAM)
+        return self.__params
+
+    def get_locals(self):
+        if self.__locals is None:
+            locs = (LOCAL, CELL)
+            test = lambda x: ((x >> SCOPE_OFF) & SCOPE_MASK) in locs
+            self.__locals = self.__idents_matching(test)
+        return self.__locals
+
+    def get_globals(self):
+        if self.__globals is None:
+            glob = (GLOBAL_IMPLICIT, GLOBAL_EXPLICIT)
+            test = lambda x:((x >> SCOPE_OFF) & SCOPE_MASK) in glob
+            self.__globals = self.__idents_matching(test)
+        return self.__globals
+
+    def get_frees(self):
+        if self.__frees is None:
+            is_free = lambda x:((x >> SCOPE_OFF) & SCOPE_MASK) == FREE
+            self.__frees = self.__idents_matching(is_free)
+        return self.__frees
+
+
+class Class(SymbolTable):
+
+    __methods = None
+
+    def get_methods(self):
+        if self.__methods is None:
+            d = {}
+            for st in self._table.children:
+                d[st.name] = 1
+            self.__methods = tuple(d)
+        return self.__methods
+
+
+class Symbol(object):
+
+    def __init__(self, name, flags, namespaces=None):
+        self.__name = name
+        self.__flags = flags
+        self.__scope = (flags >> SCOPE_OFF) & SCOPE_MASK # like PyST_GetScope()
+        self.__namespaces = namespaces or ()
+
+    def __repr__(self):
+        return "<symbol {0!r}>".format(self.__name)
+
+    def get_name(self):
+        return self.__name
+
+    def is_referenced(self):
+        return bool(self.__flags & _symtable.USE)
+
+    def is_parameter(self):
+        return bool(self.__flags & DEF_PARAM)
+
+    def is_global(self):
+        return bool(self.__scope in (GLOBAL_IMPLICIT, GLOBAL_EXPLICIT))
+
+    def is_declared_global(self):
+        return bool(self.__scope == GLOBAL_EXPLICIT)
+
+    def is_local(self):
+        return bool(self.__flags & DEF_BOUND)
+
+    def is_free(self):
+        return bool(self.__scope == FREE)
+
+    def is_imported(self):
+        return bool(self.__flags & DEF_IMPORT)
+
+    def is_assigned(self):
+        return bool(self.__flags & DEF_LOCAL)
+
+    def is_namespace(self):
+        """Returns true if name binding introduces new namespace.
+
+        If the name is used as the target of a function or class
+        statement, this will be true.
+
+        Note that a single name can be bound to multiple objects.  If
+        is_namespace() is true, the name may also be bound to other
+        objects, like an int or list, that does not introduce a new
+        namespace.
+        """
+        return bool(self.__namespaces)
+
+    def get_namespaces(self):
+        """Return a list of namespaces bound to this name"""
+        return self.__namespaces
+
+    def get_namespace(self):
+        """Returns the single namespace bound to this name.
+
+        Raises ValueError if the name is bound to multiple namespaces.
+        """
+        if len(self.__namespaces) != 1:
+            raise ValueError, "name is bound to multiple namespaces"
+        return self.__namespaces[0]
+
+if __name__ == "__main__":
+    import os, sys
+    src = open(sys.argv[0]).read()
+    mod = symtable(src, os.path.split(sys.argv[0])[1], "exec")
+    for ident in mod.get_identifiers():
+        info = mod.lookup(ident)
+        print info, info.is_local(), info.is_namespace()