/* @(#)stak.h 1.3 */ /* * UNIX shell * * Bell Telephone Laboratories * */ /* To use stack as temporary workspace across * possible storage allocation (eg name lookup) * a) get ptr from `relstak' * b) can now use `pushstak' * c) then reset with `setstak' * d) `absstak' gives real address if needed */ #define relstak() (staktop-stakbot) #define absstak(x) (stakbot+Rcheat(x)) #define zerostak() (*staktop=0) /* Used to address an item left on the top of * the stack (very temporary) */ #define curstak() (staktop) /* `usestak' before `pushstak' then `fixstak' * These routines are safe against heap * being allocated. */ #define usestak() {locstak();} /* for local use only since it hands * out a real address for the stack top */ extern char *locstak(); /* Will allocate the item being used and return its * address (safe now). */ #define fixstak() endstak(staktop) /* For use after `locstak' to hand back * new stack top and then allocate item */ extern char *endstak(); /* Copy a string onto the stack and * allocate the space. */ extern char *cpystak(); /* Allocate given ammount of stack space */ extern char *getstak(); /* A chain of ptrs of stack blocks that * have become covered by heap allocation. * `tdystak' will return them to the heap. */ extern struct blk *stakbsy; /* Base of the entire stack */ extern char *stakbas; /* Top of entire stack */ extern char *brkend; /* Base of current item */ extern char *stakbot; /* Top of current item */ extern char *staktop; /* Used with tdystak */ extern char *savstak(); #ifdef CRAY /* End of Memory */ extern char *endcp; #endif