[PyChecker-checkins] CVS: pychecker/pychecker checker.py,1.74,1.75

[Skip M. <mon...@us...>]

Update of /cvsroot/pychecker/pychecker/pychecker
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv10421/pychecker

Modified Files:
	checker.py 
Log Message:
Python spells "abstract method" as "raise NotImplementedError...".  This
patch more-or-less enforces that dictum.  If a "LOAD_GLOBAL
NotImplementedError" is seen before the raise statement that triggers a
return, assume "raise NotImplementedError" was executed.

This can obviously be fooled:

    def f(self):
	x = NotImplementedError
	raise SystemError

and note that arbitrarily complex expressions can be involved in the raise
statement:

    def f(self):
	raise NotImplementedError, "*"*14 + " msg " + "*"*14

so the distance between LOAD_GLOBAL "NotImplementedError" and RAISE_VARARGS
can vary.  Still, this seems like a better approximation to the truth than
assuming a priori that all raise statements imply abstract methods.



Index: checker.py
===================================================================
RCS file: /cvsroot/pychecker/pychecker/pychecker/checker.py,v
retrieving revision 1.74
retrieving revision 1.75
diff -C2 -d -r1.74 -r1.75
*** checker.py	6 Jun 2004 15:12:24 -0000	1.74
--- checker.py	15 Jul 2004 03:39:44 -0000	1.75
***************
*** 361,369 ****
          func_code, bytes, i, maxCode, extended_arg = \
                     OP.initFuncCode(self.methods[m].function)
!         # abstract if the first conditional is RAISE_VARARGS
          while i < maxCode:
              op, oparg, i, extended_arg = OP.getInfo(bytes, i, extended_arg)
!             if OP.RAISE_VARARGS(op):
!                 return 1
              if OP.conditional(op):
                  break
--- 361,375 ----
          func_code, bytes, i, maxCode, extended_arg = \
                     OP.initFuncCode(self.methods[m].function)
!         # abstract if the first opcode is RAISE_VARARGS and it raises
!         # NotImplementedError
!         arg = ""
          while i < maxCode:
              op, oparg, i, extended_arg = OP.getInfo(bytes, i, extended_arg)
!             if OP.LOAD_GLOBAL(op):
!                 arg = func_code.co_names[oparg]
!             elif OP.RAISE_VARARGS(op):
!                 # if we saw NotImplementedError sometime before the raise
!                 # assume it's related to this raise stmt
!                 return arg == "NotImplementedError"
              if OP.conditional(op):
                  break