[Python-checkins] CVS: python/dist/src/Python ceval.c,2.300,2.301

[Tim Peters]

Update of /cvsroot/python/python/dist/src/Python
In directory usw-pr-cvs1:/tmp/cvs-serv24281/python/Python

Modified Files:
	ceval.c 
Log Message:
SF bug #494668:  PUSH() should assert-fail on overflow.
eval_frame():  Added asserts to the top of the eval loop, to verify
that the eval stack pointer is in bounds, plus some comments.  


Index: ceval.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Python/ceval.c,v
retrieving revision 2.300
retrieving revision 2.301
diff -C2 -d -r2.300 -r2.301
*** ceval.c	2001/12/18 22:36:40	2.300
--- ceval.c	2001/12/19 04:11:07	2.301
***************
*** 498,502 ****
  	int lastopcode = 0;
  #endif
! 	PyObject **stack_pointer;
  	register unsigned char *next_instr;
  	register int opcode=0;	/* Current opcode */
--- 498,502 ----
  	int lastopcode = 0;
  #endif
! 	PyObject **stack_pointer; /* Next free slot in value stack */
  	register unsigned char *next_instr;
  	register int opcode=0;	/* Current opcode */
***************
*** 587,591 ****
  	stack_pointer = f->f_stacktop;
  	assert(stack_pointer != NULL);
! 	f->f_stacktop = NULL;
  
  	if (tstate->use_tracing) {
--- 587,591 ----
  	stack_pointer = f->f_stacktop;
  	assert(stack_pointer != NULL);
! 	f->f_stacktop = NULL;	/* remains NULL unless yield suspends frame */
  
  	if (tstate->use_tracing) {
***************
*** 635,638 ****
--- 635,640 ----
  
  	for (;;) {
+ 		assert(stack_pointer >= f->f_valuestack);	/* else underflow */
+ 		assert(STACK_LEVEL() <= f->f_stacksize);	/* else overflow */
  		/* Do periodic things.  Doing this every time through
  		   the loop would add too much overhead, so we do it