diff options
Diffstat (limited to 'miasm2/expression/expression_helper.py')
| -rw-r--r-- | miasm2/expression/expression_helper.py | 30 |
1 files changed, 19 insertions, 11 deletions
diff --git a/miasm2/expression/expression_helper.py b/miasm2/expression/expression_helper.py index 2f0bd4e7..825cad60 100644 --- a/miasm2/expression/expression_helper.py +++ b/miasm2/expression/expression_helper.py @@ -17,7 +17,6 @@ # # Expressions manipulation functions -import re import itertools import collections import random @@ -210,16 +209,20 @@ class Variables_Identifier(object): - original expression with variables translated """ - var_identifier = re.compile("v\d+") + # Attribute used to distinguish created variables from original ones + is_var_ident = "is_var_ident" - def __init__(self, expr): + def __init__(self, expr, var_prefix="v"): """Set the expression @expr to handle and launch variable identification - process""" + process + @expr: Expr instance + @var_prefix: (optional) prefix of the variable name, default is 'v'""" # Init self.var_indice = itertools.count() self.var_asked = set() self._vars = {} # VarID -> Expr + self.var_prefix = var_prefix # Launch recurrence self.find_variables_rec(expr) @@ -254,9 +257,13 @@ class Variables_Identifier(object): ## Build initial needs for var_id, var_expr in self._vars.iteritems(): + ### Handle corner cases while using Variable Identifier on an + ### already computed equation needs[var_id] = [var_name for var_name in var_expr.get_r(mem_read=True) - if self.is_var_identifier(var_name)] + if self.is_var_identifier(var_name) and \ + var_name in todo and \ + var_name != var_id] ## Build order list while todo: @@ -268,7 +275,6 @@ class Variables_Identifier(object): # A dependency is not met all_met = False break - if not all_met: continue @@ -282,12 +288,12 @@ class Variables_Identifier(object): @classmethod def is_var_identifier(cls, expr): - "Return True iff expr seems to be a variable identifier" + "Return True iff @expr is a variable identifier" if not isinstance(expr, m2_expr.ExprId): return False - match = cls.var_identifier.match(expr.name) - return match is not None and match.group(0) == expr.name + return hasattr(expr, cls.is_var_ident) and \ + getattr(expr, cls.is_var_ident) == True def find_variables_rec(self, expr): """Recursive method called by find_variable to expand @expr. @@ -301,8 +307,10 @@ class Variables_Identifier(object): if (expr not in self._vars.values()): # Create var - identifier = m2_expr.ExprId("v%s" % self.var_indice.next(), - size = expr.size) + identifier = m2_expr.ExprId("%s%s" % (self.var_prefix, + self.var_indice.next()), + size = expr.size) + setattr(identifier, self.__class__.is_var_ident, True) self._vars[identifier] = expr # Recursion stop case |