/*
 * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
 * See the copyright notice in the ACK home directory, in the file "Copyright".
 */
/* $Header$ */
/*	Lint state stack	*/

/* These datastructures are used to implement a stack on which the
 * state of automatic variables (including register variables) is
 * kept.
 * In this way it is possible to account for the flow of
 * control of the program.
 */


struct switch_states {
	struct state *sws_case;
	struct state *sws_break;
	int sws_default_met;
};

struct lint_stack_entry {
	struct lint_stack_entry *next;
	struct lint_stack_entry *ls_previous;
	short ls_class;		/* IF, WHILE, DO, FOR, SWITCH, CASE */
	int ls_level;
	struct state *ls_current;		/* used by all classes */
	union {
		struct state *u_if_state;	/* used for IF-class */
		struct state *u_end;		/* used for loop-classes */
		struct switch_states u_switch;
	} ls_states;	/* not used for CASE-class */
};

/* macros to access the union */
#define LS_IF_STATE 	ls_states.u_if_state
#define LS_END		ls_states.u_end
#define LS_CASE		ls_states.u_switch.sws_case
#define LS_BREAK	ls_states.u_switch.sws_break
#define LS_DEFAULT_MET	ls_states.u_switch.sws_default_met

/* ALLOCDEF "lint_stack_entry" 10 */

struct state {
	struct state *next;		/* only used by memory allocator */
	struct auto_def *st_auto_list;
	int st_notreached;		/* set if not reached */
	int st_warned;			/* set if warning issued */
};

/* ALLOCDEF "state" 15 */

struct auto_def {
	struct auto_def *next;
	struct idf *ad_idf;
	struct def *ad_def;
	int ad_used;
	int ad_set;
	int ad_maybe_set;
};

/* ALLOCDEF "auto_def" 20 */

struct expr_state {
	struct expr_state *next;
	struct idf *es_idf;
	arith es_offset;
	int es_used;
	int es_set;
};

/* ALLOCDEF "expr_state" 20 */