Fix an infinite recursion by disallowing forward globals in global var defs.

This commit is contained in:
Sei Lisa 2014-07-27 18:42:55 +02:00
parent 716374eb83
commit f3339b0906
2 changed files with 11 additions and 3 deletions

View file

@ -165,9 +165,8 @@ class optimizer(object):
if self.globalmode:
val = self.symtab[code[3]][code[2]][2]
if val is not None:
# WARNING: Possible reference loop here
# TODO: Break reference loop by only accepting globals in order
# of definition during parsing.
# Infinite recursion is prevented at the parser level, by
# not allowing forward globals in global var definitions.
self.FoldTree(val)
if code[1] != 'key' and val is not None:
code[:] = [CONSTANT, code[1], val]

View file

@ -186,6 +186,8 @@ class parser(object):
# return (symtab[symbol][1], symtab[symbol][3])
return symtab[symbol][1]
scope = symtab[-1]
if self.globalmode and symbol not in self.symtab[0]:
return None # Disallow forwards in global var mode
if symbol not in self.globals:
return None
return self.globals[symbol]
@ -1464,7 +1466,9 @@ class parser(object):
if self.tok[0] == '=':
self.NextToken()
if self.extendedglobalexpr:
self.globalmode = True # Var def. Disallow forward globals.
value = tuple(self.Parse_expression()) # Use advanced expression evaluation.
self.globalmode = False # Allow forward globals again.
else:
value = self.Parse_simple_expr() # Use LSL's dull global expression.
self.expect(';')
@ -1713,6 +1717,11 @@ class parser(object):
self.dictorder = 0
# This is a small hack to prevent circular definitions in globals when
# extended expressions are enabled. When false (default), forward
# globals are allowed; if true, only already seen globals are permitted.
self.globalmode = False
# Globals and labels can be referenced before they are defined. That
# includes states.
#