🚀 go-pugleaf

I have been looking at and modifying GCC 2.2.2 for the project I am
working on here at UMass. I have found what I consider to be a slight
error in the file stmt.c. Specifically the macro POPSTACK does not
correctly adjust the value of nesting_depth. The original macro is:

#define POPSTACK(STACK)					\
do { int initial_depth = nesting_stack->depth;		\
     do { struct nesting *this = STACK;			\
	  STACK = this->next;				\
	  nesting_stack = this->all;			\
	  nesting_depth = this->depth;			\
	  obstack_free (&stmt_obstack, this); }		\
     while (nesting_depth > initial_depth); } while (0)

I have added to the last line a decrementation of nesting_depth as follows:

#define POPSTACK(STACK)					\
do { int initial_depth = nesting_stack->depth;		\
     do { struct nesting *this = STACK;			\
	  STACK = this->next;				\
	  nesting_stack = this->all;			\
	  nesting_depth = this->depth;			\
	  obstack_free (&stmt_obstack, this); }		\
     while (nesting_depth > initial_depth);  --nesting_depth; } while (0)

Given the following program:

main ()
{
  int x, y, z;

  y = 0;
  z = 0;

  for (x=1 ; x<10; x++) {
    y++;
  }

  for (x=1 ; x<10; x++) {
    z++;
  }

}

the value of nesting_depth while parsing both y++ and z++ should be 2.
Without the change the value is correct while parsing y++ but is 3
while parsing z++.

Is this a bug or a feature?

Please feel free to contact me about this if I can provide more
information. I can be reached via email at pasieka@cs.umass.edu or by
phone at 413/545-2447.

-- Michael