/* $Id$ */
/*
 * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
 * See the copyright notice in the ACK home directory, in the file "Copyright".
 */
/* S H A R E D   F I L E
 *
 * G E T . C
 */

#include <stdio.h>
#include <em_spec.h>
#include <em_mnem.h>
#include <em_pseu.h>
#include <em_mes.h>
#include "types.h"
#include "def.h"
#include "debug.h"
#include "global.h"
#include "lset.h"
#include "cset.h"
#include "get.h"
#include "alloc.h"
#include "map.h"
#include "utils.h"

FILE *curinp;
block_id lastbid;	/* block identifying number */
lab_id	 lastlabid;	/* last label identifier */


/* creating new identifying numbers, i.e. numbers that did not
 * appear in the input.
 */

bblock_p freshblock(void)
{
	bblock_p b;
	b = newbblock();
	b->b_id = ++lastbid;
	return b;
}


lab_id freshlabel(void)
{
	curproc->p_nrlabels++;
	return ++lastlabid;
}


#define getmark()	getbyte()

short getshort(void) {
	register int l_byte, h_byte;

	l_byte = getbyte();
	h_byte = getbyte();
	if ( h_byte>=128 ) h_byte -= 256 ;
	return l_byte | (h_byte*256) ;
}


offset getoff(void) {
	register long l;
	register int h_byte;

	l = getbyte();
	l |= ((unsigned) getbyte())*256 ;
	l |= getbyte()*256L*256L ;
	h_byte = getbyte() ;
	if ( h_byte>=128 ) h_byte -= 256 ;
	return l | (h_byte*256L*256*256L) ;
}

STATIC int getint(void)
{
	/* Read an integer from the input file. This routine is
	 * only used when reading a bitvector-set. We expect  an
	 * integer to be either a short or a long.
	 */

	if (sizeof(int) == sizeof(short)) {
		return getshort();
	} else {
		assert (sizeof(int) == sizeof(offset));
		return getoff();
	}
}

/* getptable */

STATIC void *getloop(loop_id id)
{
	/* Map a loop identifier onto a loop struct.
	 * If no struct was alocated yet for this identifier then
	 * allocate one now and update the loop-map table.
	 */


	assert (id > 0 && id <=lplength);
	if (lpmap[id] == (loop_p) 0) {
		lpmap[id] = newloop();
		lpmap[id]->lp_id = id;
	}
	return (lpmap[id]);
}

STATIC void *getblock(block_id id)
{
	/* Map a basic block identifier onto a block struct
	 * If no struct was alocated yet for this identifier then
	 * allocate one now and update the block-map table.
	 */


	assert (id >= 0 && id <=blength);
	if (id == 0) return (bblock_p) 0;
	if (bmap[id] == (bblock_p) 0) {
		bmap[id] = newbblock();
		bmap[id]->b_id = id;
	}
	return (bmap[id]);
}


STATIC lset getlset(void *(*p)(short))
{
	/* Read a 'long' set. Such a set is represented externally
	 * as a sequence of identifying numbers terminated by a 0.
	 * The procedural parameter p maps such a number onto a
	 * pointer to a struct (bblock_p, loop_p etc.).
	 */

	lset s;
	int id;

	s = Lempty_set();
	while (id = getshort()) {
		Ladd( (*p) (id), &s);
	}
	return s;
}


STATIC cset getcset()
{
	/* Read a 'compact' set. Such a set is represented externally
	 * a row of bytes (its bitvector) preceded by its length.
	 */

	cset s;
	register short i;

	s = Cempty_set(getshort());
	for (i = 0; i <= DIVWL(s->v_size-1);i++) {
		s->v_bits[i] = getint();
	}
	return s;
}


proc_p getptable(const char *pname)
{
	short i;
	proc_p head, p, *pp;
	short all;

	if ((curinp = fopen(pname,"r")) == NULL) {
		error("cannot open %s",pname);
	}

	plength = getshort();  /* table is preceded by its length */
	assert(plength >= 0);
	assert(plength < 1000);  /* See if its a reasonable number */
	pmap = (proc_p *) newmap(plength);   /* allocate the pmap table */

	all = getshort();
	head = (proc_p) 0;
	pp = &head;
	for (i = 0; i < plength; i++) {
		if (feof(curinp)) {
			error("unexpected eof %s", pname);
		}
		p = newproc();
		p->p_id = getshort();
		assert(p->p_id > 0 && p->p_id <= plength);
		pmap[p->p_id] = p;
		p->p_flags1 = getbyte();
		if (p->p_flags1 & PF_BODYSEEN) {
			p->p_nrlabels = getshort();
			p->p_localbytes = getoff();
			p->p_nrformals = getoff();
			if (all) {
				p->p_change = newchange();
				p->p_change->c_ext = getcset();
				p->p_change->c_flags = getshort();
				p->p_use = newuse();
				p->p_use->u_flags = getshort();
				p->p_calling = getcset();
			}
		}
		*pp = p;
		pp = &(p->p_next);
	}
	fclose(curinp);
	OUTTRACE("have read proc table of length %d",plength);
	return head;	/* pointer to first structure of list */
}



/* getdtable */

dblock_p getdtable(const char *dname)
{
	/* Read the data block table. Every data block may
	 * have a list of objects and a list of values (arguments),
	 * each of which is also represented by a structure.
	 * So the input file contains a mixture of dblock,
	 * obj and arg records, each one having its own
	 * attributes. A mark indicates which one comes next.
	 * We assume that the syntactic structure of the input
	 * is correct.
	 */

	dblock_p head, d = 0, *dp = &head;
	obj_p    obj, *op = 0;
	arg_p    arg, *ap = 0;
	/* dp, op an ap tell how the next dblock/obj/arg
	 * has to be linked.
	 */
	int n;

	head = (dblock_p) 0;
	if ((curinp = fopen(dname,"r")) == NULL) {
		error("cannot open %s", dname);
	}
	olength = getshort();
	assert(olength >= 0);
	assert(olength < 5000);  /* See if its a reasonable number */
	/* total number of objects */
	omap = (obj_p *) newmap(olength);  /* allocate omap table */

	while (TRUE) {
		n = getmark();
		if (feof(curinp)) break;
		switch(n) {
			case MARK_DBLOCK:
				d = *dp = newdblock();
				op = &d->d_objlist;
				ap = &d->d_values;
				dp = &d->d_next;
				d->d_id = getshort();
				d->d_pseudo = getbyte();
				d->d_size = getoff();
				d->d_fragmnr = getshort();
				d->d_flags1 = getbyte();
				break;
			case MARK_OBJ:
				obj = *op = newobject();
				op = &obj->o_next;
				obj->o_dblock = d;
				obj->o_id = getshort();
				assert(obj->o_id >0);
				assert(obj->o_id <= olength);
				omap[obj->o_id] = obj;
				obj->o_size = getoff();
				obj->o_off = getoff();
				break;
			case MARK_ARG:
				arg = *ap = newarg(ARGOFF);
				ap = &arg->a_next;
				arg->a_a.a_offset = getoff();
				break;
			default:
				assert(FALSE);
		}
	}
	OUTTRACE("have read data table, %d objects",olength);
	return head;
}



/* getbblocks */

STATIC void argstring(short length, argb_p abp)
{

	while (length--) {
		if (abp->ab_index == NARGBYTES)
			abp = abp->ab_next = newargb();
		abp->ab_contents[abp->ab_index++] = getbyte();
	}
}



STATIC arg_p readargs(void)
{
	/* Read a list of arguments and allocate structures
	 * for them. Return a pointer to the head of the list.
	 */

	arg_p head, arg, *ap;
	byte  t;
	short length;

	ap = &head;
	for (;;) {
		/* every argument list is terminated by an
		 * ARGCEND byte in Intermediate Code.
		 */
		t = getbyte();
		if (t == (byte) ARGCEND) {
			return head;
		}
		arg = *ap = newarg(t);
		ap = &arg->a_next;
		switch((short) t) {
			case ARGOFF:
				arg->a_a.a_offset = getoff();
				break;
			case ARGINSTRLAB:
				arg->a_a.a_instrlab = getshort();
				break;
			case ARGOBJECT:
				arg->a_a.a_obj = omap[getshort()];
				/* Read an object identifier (o_id)
				 * and use the omap table to obtain
				 * a pointer to the rigth obj struct.
				 */
				break;
			case ARGPROC:
				arg->a_a.a_proc = pmap[getshort()];
				/* Read a procedure identifier (p_id) */
				break;
			case ARGSTRING:
				length = getshort();
				argstring(length, &arg->a_a.a_string);
				break;
			case ARGICN:
			case ARGUCN:
			case ARGFCN:
				length = getshort();
				arg->a_a.a_con.ac_length = length;
				/* size of the constant */
				argstring(getshort(),
					  &arg->a_a.a_con.ac_con);
				break;
			default:
				assert(FALSE);
		}
	}
}


line_p read_line(proc_p *p_out)
{
	/* Read a line of EM code (i.e. one instruction)
	 * and its arguments (if any).
	 * In Intermediate Code, the first byte is the
	 * instruction code and the second byte denotes the kind
	 * of operand(s) that follow.
	 */

	line_p lnp;
	byte   instr;

	instr = getbyte();
	if (feof(curinp)) return (line_p) 0;
	lnp = newline(getbyte());
	linecount++;
	lnp->l_instr = instr;
	switch(TYPE(lnp)) {
		/* read the operand(s) */
		case OPSHORT:
			SHORT(lnp) = getshort();
			break;
		case OPOFFSET:
			OFFSET(lnp) = getoff();
			break;
		case OPINSTRLAB:
			INSTRLAB(lnp) = getshort();
			if ((instr & BMASK) == op_lab) {
				/* defining occurrence of an
				 * instruction label.
				 */
				lmap[INSTRLAB(lnp)] = lnp;
			}
			break;
		case OPOBJECT:
			OBJ(lnp) = omap[getshort()];
			break;
		case OPPROC:
			PROC(lnp) = pmap[getshort()];
			if ((instr & BMASK) == ps_pro) {
				/* enter new procedure: allocate a
				 * label map and a label-block map table.
				 */
				*p_out = PROC(lnp);
				llength = (*p_out)->p_nrlabels;
				lmap = (line_p *) newmap(llength);
				/* maps lab_id to line structure */
				lbmap = (bblock_p *) newmap(llength);
				/* maps lab_id to bblock structure */
				lastlabid = llength;
			}
			break;
		case OPLIST:
			ARG(lnp) = readargs();
			break;
		default:
			assert(TYPE(lnp) == OPNO);
	}
	return lnp;
}


void message(line_p lnp)
{
	/* See if  lnp is some useful message.
	 * (e.g. a message telling that a certain local variable
	 * will never be referenced indirectly, so it may be put
	 * in a register. If so, add it to the mesregs set.)
	 */

	assert(ARG(lnp)->a_type == ARGOFF);
	switch((int) aoff(ARG(lnp),0)) {
		case ms_reg:
			if (ARG(lnp)->a_next != (arg_p) 0) {
				/* take only "mes 3" with further arguments */
				Ladd((Lelem_t) lnp,&mesregs);
			}
			break;
		case ms_err:
			error("ms_err encountered");
		case ms_opt:
			error("ms_opt encountered");
		case ms_emx:
			ws = aoff(ARG(lnp),1);
			ps = aoff(ARG(lnp),2);
			break;
	}
}



line_p getlines(FILE *lf, int n, proc_p *p_out, bool collect_mes)
{
	/* Read n lines of EM text and doubly link them.
	 * Also process messages.
	 */

	line_p head, *pp, l, lprev;

	curinp = lf; /* EM input file */
	pp = &head;
	lprev = (line_p) 0;
	while (n--) {
		l = *pp = read_line(p_out);
		PREV(l) = lprev;
		pp = &l->l_next;
		lprev = l;
		if (collect_mes && INSTR(l) == ps_mes) {
			message(l);
		}
	}
	*pp = (line_p) 0;
	return head;
}



bool getunit(FILE *gf, FILE *lf, short *kind_out, bblock_p *g_out,
	     line_p *l_out, proc_p *p_out, bool collect_mes)
{
	/* Read control flow graph (gf) and EM text (lf) of the next procedure.
	 * A pointer to the proctable entry of the read procedure is
	 * returned via p_out.
	 * This routine also constructs the bmap and lpmap tables.
	 * Note that we allocate structs for basic blocks and loops
	 * at their first reference rather than at when we read them.
	 */

	int n,i;
	bblock_p head, *pp, b;
	loop_p lp;

	curinp = gf;
	blength = getshort(); /* # basic blocks in this procedure */
	if (feof(curinp)) return FALSE;
	if (blength == 0) {
		/* data unit */
		*kind_out = LDATA;
		n = getshort();
		*l_out = getlines(lf,n,p_out,collect_mes);
		return TRUE;
	}
	*kind_out = LTEXT;
	bmap = (bblock_p *) newmap(blength); /* maps block_id on bblock_p */
	lplength = getshort(); /* # loops in this procedure */
	lpmap = (loop_p *) newmap(lplength); /* maps loop_id on loop_p */

	/* Read the basic blocks and the EM text */
	pp = &head; /* we use a pointer-to-a-pointer to link the structs */
	for (i = 0; i < blength; i++) {
		b = getblock(getshort());
		n = getshort();  /* #instructions in the block */
		b->b_succ = getlset(getblock);
		b->b_pred = getlset(getblock);
		b->b_idom = getblock(getshort());
		b->b_loops = getlset(getloop);
		b->b_flags = getshort();
		b->b_start = getlines(lf,n,p_out,collect_mes);  /* read EM text */
		*pp = b;
		pp = &b->b_next;
		curinp = gf;
	}
	lastbid = blength; /* last block_id */

	/* read the information about loops */
	curproc->p_loops = Lempty_set();
	for (i = 0; i < lplength; i++) {
		lp = getloop(getshort());
		lp->lp_level = getshort(); /* nesting level */
		lp->lp_entry = getblock(getshort()); /* entry block of the loop */
		lp->lp_end = getblock(getshort()); /* tail of back edge of loop */
		Ladd((Lelem_t)lp,&curproc->p_loops);
	}
	*g_out = head;
	return TRUE;
}