/*
 * (c) copyright 1983 by the Vrije Universiteit, Amsterdam, The Netherlands.
 *
 *          This product is part of the Amsterdam Compiler Kit.
 *
 * Permission to use, sell, duplicate or disclose this software must be
 * obtained in writing. Requests for such permissions may be sent to
 *
 *      Dr. Andrew S. Tanenbaum
 *      Wiskundig Seminarium
 *      Vrije Universiteit
 *      Postbox 7161
 *      1007 MC Amsterdam
 *      The Netherlands
 *
 */

#include        "ass00.h"
#include        "assex.h"
#include        "../../h/em_mes.h"
#include        "../../h/em_pseu.h"
#include        "../../h/em_ptyp.h"

/*
 * read compact code and fill in tables
 */

static  int     tabval;
static  cons_t  argval;

static  int     oksizes;        /* MES EMX,.,. seen */

static  enum    m_type { CON, ROM, HOLBSS }     memtype ;
static  int     valtype;        /* Transfer of type information between
				   valsize ans putval
				*/

int table3(i) {

	switch(i) {
	case sp_ilb1:
		tabval = get8();
		break;
	case sp_dlb1:
		make_string(get8());
		i= sp_dnam;
		break;
	case sp_dlb2:
		tabval = get16();
		if ( tabval<0 ) {
			error("illegal data label .%d",tabval);
			tabval=0 ;
		}
		make_string(tabval);
		i= sp_dnam;
		break;
	case sp_cst2:
		argval = get16();
		break;
	case sp_ilb2:
		tabval = get16();
		if ( tabval<0 ) {
			error("illegal instruction label %d",tabval);
			tabval=0 ;
		}
		i = sp_ilb1;
		break;
	case sp_cst4:
		i = sp_cst2;
		argval = get32();
		break;
	case sp_dnam:
	case sp_pnam:
		inident();
		break ;
	case sp_scon:
		getstring() ;
		break;
	case sp_doff:
		getarg(sym_ptyp);
		getarg(cst_ptyp);
		break;
	case sp_icon:
	case sp_ucon:
	case sp_fcon:
		getarg(cst_ptyp);
		consiz = argval;
		if ( consiz<wordsize ?
			wordsize%consiz!=0 : consiz%wordsize!=0 ) {
			fatal("illegal object size") ;
		}
		getstring();
		break;
	}
	return(i);
}

int get16() {
	register int l_byte, h_byte;

	l_byte = get8();
	h_byte = get8();
	if ( h_byte>=128 ) h_byte -= 256 ;
	return l_byte | (h_byte*256) ;
}

int getu16() {
	register int l_byte, h_byte;

	l_byte = get8();
	h_byte = get8();
	return l_byte | (h_byte*256) ;
}

cons_t get32() {
	register cons_t l;
	register int h_byte;

	l = get8(); l |= (unsigned)get8()*256 ; l |= get8()*256L*256L ;
	h_byte = get8() ;
	if ( h_byte>=128 ) h_byte -= 256 ;
	return l | (h_byte*256L*256*256L) ;
}

int table1() {
	register i;

	i = xget8();
	if (i < sp_fmnem+sp_nmnem && i >= sp_fmnem) {
		tabval = i-sp_fmnem;
		return(sp_fmnem);
	}
	if (i < sp_fpseu+sp_npseu && i >= sp_fpseu) {
		tabval = i;
		return(sp_fpseu);
	}
	if (i < sp_filb0+sp_nilb0 && i >= sp_filb0) {
		tabval = i - sp_filb0;
		return(sp_ilb1);
	}
	return(table3(i));
}

int table2() {
	register i;

	i = get8();
	if (i < sp_fcst0+sp_ncst0 && i >= sp_fcst0) {
		argval = i - sp_zcst0;
		return(sp_cst2);
	}
	return(table3(i));
}

int getarg(typset) {
	register t,argtyp;

	argtyp = t = table2();
	t -= sp_fspec;
	t = 1 << t;
	if ((typset & t) == 0)
		error("bad argument type %d",argtyp);
	return(argtyp);
}

cons_t getint() {
	getarg(cst_ptyp);
	return(argval);
}

glob_t *getlab(status) {
	getarg(sym_ptyp);
	return(glo2lookup(string,status));
}

char *getdig(str,number) char *str; register unsigned number; {
	register int remain;

	remain= number%10;
	number /= 10;
	if ( number ) str= getdig(str,number) ;
	*str++ = '0'+remain ;
	return str ;
}

make_string(n) unsigned n ; {
	string[0] = '.';
	*getdig(&string[1],n)= 0;
}


getstring() {
	register char *p;
	register n;

	getarg(cst_ptyp);
	if ( argval < 0 || argval >= MAXSTRING-1 )
		fatal("string/identifier too long");
	strlngth = n = argval;
	p = string;
	while (--n >= 0)
		*p++ = get8();
	*p = 0 ;
}

inident() {
	getstring();
	string[IDLENGTH] = '\0';
}

char *inproname() {
	getarg(ptyp(sp_pnam));
	return(string);
}

int needed() {
	register glob_t *g;
	register proc_t *p;

	for(;;){
		switch ( table2() ) {
		case sp_dnam :
			if (g = xglolookup(string,SEARCHING)) {
				if ((g->g_status&DEF) != 0)
					continue ;
			} else continue ;
			break ;
		case sp_pnam :
			p = searchproc(string,xprocs,oursize->n_xproc);
			if (p->p_name[0]) {
				if ((p->p_status & DEF) != 0)
					continue ;
			} else continue ;
			break ;
		default :
			error("Unexpected byte after ms_ext") ;
		case sp_cend :
			return FALSE ;
		}
		while ( table2()!=sp_cend ) ;
		return TRUE ;
	}
}

cons_t valsize() {
	switch(valtype=table2()) { /* valtype is used by putval */
	case sp_cst2:
		return wordsize ;
	case sp_ilb1:
	case sp_dnam:
	case sp_doff:
	case sp_pnam:
		return ptrsize ;
	case sp_scon:
		/* Pad the string with zeros up to the wordsize */
		while ( strlngth%wordsize ) {
			if ( strlngth>=MAXSTRING )
				fatal("string too long") ;
			string[strlngth]=0 ;
			strlngth++ ;
		}
		return strlngth ;
	case sp_fcon:
	case sp_icon:
	case sp_ucon:
		return consiz ;
	case sp_cend:
		return 0 ;
	default:
		fatal("value expected") ;
		/* NOTREACHED */
	}
}

newline(type) {
	register line_t *n_lnp ;

	if ( type>VALLOW ) type=VALLOW ;
	n_lnp = lnp_cast getarea((unsigned)linesize[type]) ;
	n_lnp->l_next = pstate.s_fline ;
	pstate.s_fline = n_lnp ;
	n_lnp->type1 = type ;
	n_lnp->opoff = NO_OFF ;
}

read_compact() {

	/*
	 * read module in compact EM1 code
	 */
	init_module();
	pass = 1;
	eof_seen = 0;
	do {
		compact_line() ;
		line_num++;
	} while (!eof_seen) ;
	endproc() ; /* Throw away unwanted garbage */
	if ( mod_sizes ) end_module();
		/* mod_sizes is only false for rejected library modules */
}

int compact_line() {
	register instr_no ;

	/*
	 * read one "line" of compact code.
	 */
	curglosym=0;
	switch (table1()) {
	default:
		fatal("unknown byte at start of \"line\""); /* NOTREACHED */
	case EOF:
		eof_seen++ ;
		while ( pstate.s_prevstat != pst_cast 0 ) {
			error("missing end") ; do_proc() ;
		}
		return ;
	case sp_fmnem:
		if ( pstate.s_curpro == prp_cast 0) {
			error("instruction outside procedure");
		}
		instr_no = tabval;
		if ( (em_flag[instr_no]&EM_PAR)==PAR_NO ) {
			newline(MISSING) ;
			pstate.s_fline->instr_num= instr_no ;
			return ;
		}
		/*
		 * This instruction should have an opcode, so read it after
		 * this switch.
		 */
		break;
	case sp_dnam:
		chkstart() ;
		align(wordsize) ;
		curglosym = glo2lookup(string,DEFINING);
		curglosym->g_val.g_addr = databytes;
		lastglosym = curglosym;
		setline() ; line_num++ ;
		if (table1() != sp_fpseu)
			fatal("no pseudo after data label");
	case sp_fpseu:
		inpseudo(tabval);
		setline() ;
		return ;
	case sp_ilb1:
		newline(LOCSYM) ;
		pstate.s_fline->ad.ad_lp = loclookup(tabval,DEFINING);
		pstate.s_fline->instr_num = sp_ilb1;
		return ;
	}

	/*
	 * Now process argument
	 */

	switch(table2()) {
	default:
		fatal("unknown byte at start of argument"); /*NOTREACHED*/
	case sp_cst2:
		if ( (em_flag[instr_no]&EM_PAR)==PAR_B ) {
			/* value indicates a label */
			newline(LOCSYM) ;
			pstate.s_fline->ad.ad_lp=
				loclookup((int)argval,OCCURRING) ;
		} else {
			if ( argval>=VAL1(VALLOW) && argval<=VAL1(VALHIGH)) {
				newline(VALLOW) ;
				pstate.s_fline->type1 = argval+VALMID ;
			} else {
				newline(CONST) ;
				pstate.s_fline->ad.ad_i = argval;
				pstate.s_fline->type1 = CONST;
			}
		}
		break;
	case sp_ilb1:
		newline(LOCSYM) ;
		pstate.s_fline->ad.ad_lp = loclookup(tabval,OCCURRING);
		break;
	case sp_dnam:
		newline(GLOSYM) ;
		pstate.s_fline->ad.ad_gp = glo2lookup(string,OCCURRING);
		break;
	case sp_pnam:
		newline(PROCNAME) ;
		pstate.s_fline->ad.ad_pp=prolookup(string,PRO_OCC);
		break;
	case sp_cend:
		if ( (em_flag[instr_no]&EM_PAR)!=PAR_W ) {
			fatal("missing operand") ;
		}
		newline(MISSING) ;
		break ;
	case sp_doff:
		newline(GLOOFF) ;
		pstate.s_fline->ad.ad_df.df_i = argval ;
		pstate.s_fline->ad.ad_df.df_gp= glo2lookup(string,OCCURRING) ;
		break ;
	}
	pstate.s_fline->instr_num= instr_no ;
	return ;
}

inpseudo(instr_no) {
	cons_t cst;
	register proc_t *prptr;
	cons_t objsize;
	cons_t par1,par2;
	register char *pars;

	/*
	 * get operands of pseudo (if needed) and process it.
	 */

	switch ( ctrunc(instr_no) ) {
	case ps_bss:
		chkstart() ;
		typealign(HOLBSS) ;
		cst = getint();   /* number of bytes */
		extbss(cst);
		break;
	case ps_hol:
		chkstart() ;
		typealign(HOLBSS) ;
		holsize=getint();
		holbase=databytes;
		extbss(holsize);
		break;
	case ps_rom:
	case ps_con:
		chkstart() ;
		typealign( ctrunc(instr_no)==ps_rom ? ROM : CON ) ;
		while( (objsize=valsize())!=0 ) {
			sizealign(objsize) ;
			putval() ;
			databytes+=objsize ;
		}
		break;
	case ps_end:
		prptr= pstate.s_curpro ;
		if ( prptr == prp_cast 0 ) fatal("unexpected END") ;
		proctab[prptr->p_num].pr_off = textbytes;
		if (procflag) {
			printf("%6lu\t%6lo\t%5d\t%-12s\t%s",
				textbytes,textbytes,
					prptr->p_num,prptr->p_name,curfile);
			if (archmode)
				printf("(%.14s)",archhdr.ar_name);
			printf("\n");
		}
		par2 = proctab[prptr->p_num].pr_loc ;
		if ( getarg(cst_ptyp|ptyp(sp_cend))==sp_cend ) {
			if ( par2 == -1 ) {
				fatal("size of local area unspecified") ;
			}
		} else {
			if ( par2 != -1 && argval!=par2 ) {
				fatal("inconsistent local area size") ;
			}
			proctab[prptr->p_num].pr_loc = argval ;
		}
		setline();
		do_proc();
		break;
	case ps_mes:
		switch( int_cast getint() ) {
		case ms_err:
			error("module with error") ; ertrap();
			/* NOTREACHED */
		case ms_emx:
			if ( oksizes ) {
				if ( wordsize!=getint() ) {
					fatal("Inconsistent word size");
				}
				if ( ptrsize!=getint() ) {
					fatal("Inconsistent pointer size");
				}
			} else {
				oksizes++ ;
				wordsize=getint();ptrsize=getint();
				if ( wordsize!=2 && wordsize!=4 ) {
					fatal("Illegal word size");
				}
				if ( ptrsize!=2 && ptrsize!=4 ) {
					fatal("Illegal pointer size");
				}
				setsizes() ;
			}
			++mod_sizes ;
			break;
		case ms_src:
			break;
		case ms_flt:
			intflags |= 020; break;  /*floats used*/
		case ms_ext:
			if ( !needed() ) {
				eof_seen++ ;
			}
			if ( line_num!=1 ) {
				werror("mes ms_ext must be first pseudo") ;
			}
			return ;
		}
		while (table2() != sp_cend)
			;
		break;
	case ps_exc:
		par1 = getint();
		par2 = getint();
		if (par1 == 0 || par2 == 0)
			break;
		exchange((int)par2,(int)par1) ;
		break;
	case ps_exa:
		getlab(EXTERNING);
		break;
	case ps_ina:
		getlab(INTERNING);
		break;
	case ps_pro:
		chkstart() ;
		initproc();
		pars = inproname();
		if ( getarg(cst_ptyp|ptyp(sp_cend))==sp_cend ) {
			par2 = -1 ;
		} else {
			par2 = argval ;
		}
		prptr = prolookup(pars,PRO_DEF);
		proctab[prptr->p_num].pr_loc = par2;
		pstate.s_curpro=prptr;
		break;
	case ps_inp:
		prptr = prolookup(inproname(),PRO_INT);
		break;
	case ps_exp:
		prptr = prolookup(inproname(),PRO_EXT);
		break;
	default:
		fatal("unknown pseudo");
	}
	if ( !mod_sizes ) fatal("Missing size specification");
	if ( databytes>maxadr ) error("Maximum data area size exceeded") ;
}

setline() {

	/* Get line numbers correct */

	if ( pstate.s_fline &&
	     ctrunc(pstate.s_fline->instr_num) == sp_fpseu ) {
		/* Already one present */
		pstate.s_fline->ad.ad_ln.ln_extra++ ;
	} else {
		newline(LINES) ;
		pstate.s_fline->instr_num= sp_fpseu ;
		pstate.s_fline->ad.ad_ln.ln_extra= 0 ;
		pstate.s_fline->ad.ad_ln.ln_first= line_num ;
	}

}

cons_t maxval(bits) int bits ; {
	/* find the maximum positive value,
	 * fitting in 'bits' bits AND
	 * fitting in a 'cons_t' .
	 */

	cons_t val ;
	val=1 ;
	while ( bits-- ) {
		val<<= 1 ;
		if ( val<0 ) return ~val ;
	}
	return val-1 ;
}

setsizes() {
	maxadr    = maxval(8*ptrsize)      ;
	maxint    = maxval(8*wordsize-1)   ;
	maxunsig  = maxval(8*wordsize)     ;
	maxdint   = maxval(2*8*wordsize-1) ;
	maxdunsig = maxval(2*8*wordsize)   ;
}

exchange(p1,p2) {
	int size, line ;
	int l_of_p1, l_of_p2, l_of_before ;
	register line_t *t_lnp,*a_lnp, *b_lnp ;

	/* Since the lines are linked backwards it is easy
	 * to count the number of lines backwards.
	 * Each instr counts for 1, each pseudo for ln_extra + 1.
	 * The line numbers in error messages etc. are INCORRECT
	 * If exc's are used.
	 */

	line= line_num ; size=0 ;
	newline(LINES) ; a_lnp=pstate.s_fline ;
	a_lnp->instr_num= sp_fpseu ;
	a_lnp->ad.ad_ln.ln_first= line ;
	a_lnp->ad.ad_ln.ln_extra= -1 ;
	for ( ; a_lnp ; a_lnp= a_lnp->l_next ) {
		line-- ;
		switch ( ctrunc(a_lnp->instr_num) ) {
		case sp_fpseu :
			line= a_lnp->ad.ad_ln.ln_first ;
			size += a_lnp->ad.ad_ln.ln_extra ;
			break ;
		case sp_ilb1 :
			a_lnp->ad.ad_lp->l_min -= p2 ;
			break ;
		}
		size++ ;
		if ( size>=p1 ) break ;
	}
	if ( ( size-= p1 )>0 ) {
		if ( ctrunc(a_lnp->instr_num) !=sp_fpseu ) {
			fatal("EXC inconsistency") ;
		}
		doinsert(a_lnp,line,size-1) ;
		a_lnp->ad.ad_ln.ln_extra -= size ;
		size=0 ;
	} else  {
		if( a_lnp) doinsert(a_lnp,line,-1) ;
	}
	b_lnp= a_lnp ;
	while ( b_lnp ) {
		b_lnp= b_lnp->l_next ;
		line-- ;
		switch ( ctrunc(b_lnp->instr_num) ) {
		case sp_fpseu :
			size += b_lnp->ad.ad_ln.ln_extra ;
			line = b_lnp->ad.ad_ln.ln_first ;
			break ;
		case sp_ilb1 :
			b_lnp->ad.ad_lp->l_min += p1 ;
			break ;
		}
		size++ ;
		if ( size>=p2 ) break ;
	}
	if ( !b_lnp ) { /* if a_lnp==0, so is b_lnp */
		fatal("Cannot perform exchange") ;
	}
	if ( ( size-= p2 )>0 ) {
		if ( ctrunc(b_lnp->instr_num) !=sp_fpseu ) {
			fatal("EXC inconsistency") ;
		}
		doinsert(b_lnp,line,size-1) ;
		b_lnp->ad.ad_ln.ln_extra -= size ;
	} else  {
		doinsert(b_lnp,line,-1) ;
	}
	t_lnp = b_lnp->l_next ;
	b_lnp->l_next = pstate.s_fline ;
	pstate.s_fline= a_lnp->l_next ;
	a_lnp->l_next=t_lnp ;
}

doinsert(lnp,first,extra) line_t *lnp ; {
	/* Beware : s_fline will be clobbered and restored */
	register line_t *t_lnp ;

	t_lnp= pstate.s_fline;
	pstate.s_fline= lnp->l_next ;
	newline(LINES) ;
	pstate.s_fline->instr_num= sp_fpseu ;
	pstate.s_fline->ad.ad_ln.ln_first= first ;
	pstate.s_fline->ad.ad_ln.ln_extra= extra ;
	lnp->l_next= pstate.s_fline ;
	pstate.s_fline= t_lnp; /* restore */
}

putval() {
	switch(valtype){
	case sp_cst2:
		extconst(argval);
		return ;
	case sp_ilb1:
		extloc(loclookup(tabval,OCCURRING));
		return ;
	case sp_dnam:
		extglob(glo2lookup(string,OCCURRING),(cons_t)0);
		return ;
	case sp_doff:
		extglob(glo2lookup(string,OCCURRING),argval);
		return ;
	case sp_pnam:
		extpro(prolookup(string,PRO_OCC));
		return ;
	case sp_scon:
		extstring() ;
		return ;
	case sp_fcon:
		extxcon(DATA_FCON) ;
		return ;
	case sp_icon:
		extvcon(DATA_ICON) ;
		return ;
	case sp_ucon:
		extvcon(DATA_UCON) ;
		return ;
	default:
		fatal("putval notreached") ;
		/* NOTREACHED */
	}
}

chkstart() {
	static int absout = 0 ;

	if ( absout ) return ;
	if ( !oksizes ) fatal("missing size specification") ;
	setmode(DATA_CONST) ;
	extconst((cons_t)0) ;
	databytes= wordsize ;
	setmode(DATA_REP) ;
	if ( wordsize<ABSSIZE ) {
		register factor = ABSSIZE/wordsize - 1 ;
		extadr( (cons_t) factor ) ;
		databytes += factor * wordsize ;
	}
	absout++ ;
	memtype= HOLBSS ;
}

typealign(new) enum m_type new ; {
	if ( memtype==new ) return ;
	align(wordsize);
	memtype=new ;
}

sizealign(size) cons_t size ; {
	align( size>wordsize ? wordsize : (int)size ) ;
}

align(size) int size ; {
	while ( databytes%size ) {
		setmode(DATA_BYTES) ;
		ext8(0) ;
		databytes++ ;
	}
}

extconst(n) cons_t n ; {
	setmode(DATA_CONST);
	extword(n);
}

extbss(n) cons_t n ; {
	cons_t objsize,amount ;

	if ( n<=0 ) {
		if ( n<0 ) werror("negative bss/hol size") ;
		if ( table2()==sp_cend || table2()==sp_cend) {
			werror("Unexpected end-of-line") ;
		}
		return ;
	}
	setmode(DATA_NUL) ; /* flush descriptor */
	objsize= valsize();
	if ( objsize==0 ) {
		werror("Unexpected end-of-line");
		return;
	}
	if ( n%objsize != 0 ) error("BSS/HOL incompatible sizes");
	putval();
	amount= n/objsize ;
	if ( amount>1 ) {
		setmode(DATA_REP);
		extadr(amount-1) ;
	}
	databytes +=n ;
	getarg(sp_cst2);
	if ( argval<0 || argval>1 ) error("illegal last argument") ;
}

extloc(lbp) register locl_t *lbp; {

	/*
	 * assemble a pointer constant from a local label.
	 * For example  con *1
	 */
	setmode(DATA_IPTR);
	data_reloc( chp_cast lbp,dataoff,RELLOC);
	extadr((cons_t)0);
}

extglob(agbp,off) glob_t *agbp; cons_t off; {
	register glob_t *gbp;

	/*
	 * generate a word of data that is defined by a global symbol.
	 * Various relocation has to be prepared here in some cases
	 */
	gbp=agbp;
	setmode(DATA_DPTR);
	if ( gbp->g_status&DEF ) {
		extadr(gbp->g_val.g_addr+off);
	} else {
		data_reloc( chp_cast gbp,dataoff,RELGLO);
		extadr(off);
	}
}

extpro(aprp) proc_t *aprp; {
	/*
	 * generate a addres that is defined by a procedure descriptor.
	 */
	consiz= ptrsize ; setmode(DATA_UCON);
	extarb((int)ptrsize,(long)(aprp->p_num));
}

extstring() {
	register char *s;
	register n ;

	/*
	 * generate data for a string.
	 */
	for(n=strlngth,s=string ; n--; ) {
		setmode(DATA_BYTES) ;
		ext8(*s++);
	}
	return ;
}

extxcon(header) {
	register char *s ;
	register n;

	/*
	 * generate data for a floating constant initialized by a string.
	 */

	setmode(header);
	s = string ;
	for (n=strlngth ; n-- ;) {
		if ( *s==0 ) error("Zero byte in initializer") ;
		ext8(*s++);
	}
	ext8(0);
	return ;
}

extvcon(header) {
	extern long atol() ;
	/*
	 * generate data for a constant initialized by a string.
	 */

	setmode(header);
	if ( consiz>4 ) {
		error("Size of initializer exceeds loader capability") ;
	}
	extarb((int)consiz,atol(string)) ;
	return ;
}