xref: /original-bsd/usr.bin/pascal/src/fhdr.c (revision 9087ff44)
1 /*
2  * Copyright (c) 1980 Regents of the University of California.
3  * All rights reserved.  The Berkeley software License Agreement
4  * specifies the terms and conditions for redistribution.
5  */
6 
7 #ifndef lint
8 static char sccsid[] = "@(#)fhdr.c	5.1 (Berkeley) 06/05/85";
9 #endif not lint
10 
11 #include "whoami.h"
12 #include "0.h"
13 #include "tree.h"
14 #include "opcode.h"
15 #include "objfmt.h"
16 #include "align.h"
17 #include "tree_ty.h"
18 
19 /*
20  * this array keeps the pxp counters associated with
21  * functions and procedures, so that they can be output
22  * when their bodies are encountered
23  */
24 int	bodycnts[ DSPLYSZ ];
25 
26 #ifdef PC
27 #   include "pc.h"
28 #endif PC
29 
30 #ifdef OBJ
31 int	cntpatch;
32 int	nfppatch;
33 #endif OBJ
34 
35 /*
36  * Funchdr inserts
37  * declaration of a the
38  * prog/proc/func into the
39  * namelist. It also handles
40  * the arguments and puts out
41  * a transfer which defines
42  * the entry point of a procedure.
43  */
44 
45 struct nl *
46 funchdr(r)
47 	struct tnode *r;
48 {
49 	register struct nl *p;
50 	register struct tnode *rl;
51 	struct nl *cp, *dp, *temp;
52 	int o;
53 
54 	if (inpflist(r->p_dec.id_ptr)) {
55 		opush('l');
56 		yyretrieve();	/* kludge */
57 	}
58 	pfcnt++;
59 	parts[ cbn ] |= RPRT;
60 	line = r->p_dec.line_no;
61 	if (r->p_dec.param_list == TR_NIL &&
62 		(p=lookup1(r->p_dec.id_ptr)) != NIL && bn == cbn) {
63 		/*
64 		 * Symbol already defined
65 		 * in this block. it is either
66 		 * a redeclared symbol (error)
67 		 * a forward declaration,
68 		 * or an external declaration.
69 		 * check that forwards are of the right kind:
70 		 *     if this fails, we are trying to redefine it
71 		 *     and enter() will complain.
72 		 */
73 		if (  ( ( p->nl_flags & NFORWD ) != 0 )
74 		   && (  ( p->class == FUNC && r->tag == T_FDEC )
75 		      || ( p->class == PROC && r->tag == T_PDEC ) ) ) {
76 			/*
77 			 * Grammar doesnt forbid
78 			 * types on a resolution
79 			 * of a forward function
80 			 * declaration.
81 			 */
82 			if (p->class == FUNC && r->p_dec.type)
83 				error("Function type should be given only in forward declaration");
84 			/*
85 			 * get another counter for the actual
86 			 */
87 			if ( monflg ) {
88 			    bodycnts[ cbn ] = getcnt();
89 			}
90 #			ifdef PC
91 			    enclosing[ cbn ] = p -> symbol;
92 #			endif PC
93 #			ifdef PTREE
94 				/*
95 				 *	mark this proc/func as forward
96 				 *	in the pTree.
97 				 */
98 			    pDEF( p -> inTree ).PorFForward = TRUE;
99 #			endif PTREE
100 			return (p);
101 		}
102 	}
103 
104 	/* if a routine segment is being compiled,
105 	 * do level one processing.
106 	 */
107 
108 	 if ((r->tag != T_PROG) && (!progseen))
109 		level1();
110 
111 
112 	/*
113 	 * Declare the prog/proc/func
114 	 */
115 	switch (r->tag) {
116 	    case T_PROG:
117 		    progseen = TRUE;
118 		    if (opt('z'))
119 			    monflg = TRUE;
120 		    program = p = defnl(r->p_dec.id_ptr, PROG, NLNIL, 0);
121 		    p->value[3] = r->p_dec.line_no;
122 		    break;
123 	    case T_PDEC:
124 		    if (r->p_dec.type != TR_NIL)
125 			    error("Procedures do not have types, only functions do");
126 		    p = enter(defnl(r->p_dec.id_ptr, PROC, NLNIL, 0));
127 		    p->nl_flags |= NMOD;
128 #		    ifdef PC
129 			enclosing[ cbn ] = r->p_dec.id_ptr;
130 			p -> extra_flags |= NGLOBAL;
131 #		    endif PC
132 		    break;
133 	    case T_FDEC:
134 		    {
135 			register struct tnode *il;
136 		    il = r->p_dec.type;
137 		    if (il == TR_NIL) {
138 			    temp = NLNIL;
139 			    error("Function type must be specified");
140 		    } else if (il->tag != T_TYID) {
141 			    temp = NLNIL;
142 			    error("Function type can be specified only by using a type identifier");
143 		    } else
144 			    temp = gtype(il);
145 		    }
146 		    p = enter(defnl(r->p_dec.id_ptr, FUNC, temp, NIL));
147 		    p->nl_flags |= NMOD;
148 		    /*
149 		     * An arbitrary restriction
150 		     */
151 		    switch (o = classify(p->type)) {
152 			    case TFILE:
153 			    case TARY:
154 			    case TREC:
155 			    case TSET:
156 			    case TSTR:
157 				    warning();
158 				    if (opt('s')) {
159 					    standard();
160 				    }
161 				    error("Functions should not return %ss", clnames[o]);
162 		    }
163 #		    ifdef PC
164 			enclosing[ cbn ] = r->p_dec.id_ptr;
165 			p -> extra_flags |= NGLOBAL;
166 #		    endif PC
167 		    break;
168 	    default:
169 		    panic("funchdr");
170 	}
171 	if (r->tag != T_PROG) {
172 		/*
173 		 * Mark this proc/func as
174 		 * being forward declared
175 		 */
176 		p->nl_flags |= NFORWD;
177 		/*
178 		 * Enter the parameters
179 		 * in the next block for
180 		 * the time being
181 		 */
182 		if (++cbn >= DSPLYSZ) {
183 			error("Procedure/function nesting too deep");
184 			pexit(ERRS);
185 		}
186 		/*
187 		 * For functions, the function variable
188 		 */
189 		if (p->class == FUNC) {
190 #			ifdef OBJ
191 			    cp = defnl(r->p_dec.id_ptr, FVAR, p->type, 0);
192 #			endif OBJ
193 #			ifdef PC
194 				/*
195 				 * fvars used to be allocated and deallocated
196 				 * by the caller right before the arguments.
197 				 * the offset of the fvar was kept in
198 				 * value[NL_OFFS] of function (very wierd,
199 				 * but see asgnop).
200 				 * now, they are locals to the function
201 				 * with the offset kept in the fvar.
202 				 */
203 
204 			    cp = defnl(r->p_dec.id_ptr, FVAR, p->type,
205 				(int)-leven(roundup(
206 			            (int)(DPOFF1+lwidth(p->type)),
207 				    (long)align(p->type))));
208 			    cp -> extra_flags |= NLOCAL;
209 #			endif PC
210 			cp->chain = p;
211 			p->ptr[NL_FVAR] = cp;
212 		}
213 		/*
214 		 * Enter the parameters
215 		 * and compute total size
216 		 */
217 	        p->value[NL_OFFS] = params(p, r->p_dec.param_list);
218 		/*
219 		 * because NL_LINENO field in the function
220 		 * namelist entry has been used (as have all
221 		 * the other fields), the line number is
222 		 * stored in the NL_LINENO field of its fvar.
223 		 */
224 		if (p->class == FUNC)
225 		    p->ptr[NL_FVAR]->value[NL_LINENO] = r->p_dec.line_no;
226 		else
227 		    p->value[NL_LINENO] = r->p_dec.line_no;
228 		cbn--;
229 	} else {
230 		/*
231 		 * The wonderful
232 		 * program statement!
233 		 */
234 #		ifdef OBJ
235 		    if (monflg) {
236 			    (void) put(1, O_PXPBUF);
237 			    cntpatch = put(2, O_CASE4, (long)0);
238 			    nfppatch = put(2, O_CASE4, (long)0);
239 		    }
240 #		endif OBJ
241 		cp = p;
242 		for (rl = r->p_dec.param_list; rl; rl = rl->list_node.next) {
243 			if (rl->list_node.list == TR_NIL)
244 				continue;
245 			dp = defnl((char *) rl->list_node.list, VAR, NLNIL, 0);
246 			cp->chain = dp;
247 			cp = dp;
248 		}
249 	}
250 	/*
251 	 * Define a branch at
252 	 * the "entry point" of
253 	 * the prog/proc/func.
254 	 */
255 	p->value[NL_ENTLOC] = (int) getlab();
256 	if (monflg) {
257 		bodycnts[ cbn ] = getcnt();
258 		p->value[ NL_CNTR ] = 0;
259 	}
260 #	ifdef OBJ
261 	    (void) put(2, O_TRA4, (long)p->value[NL_ENTLOC]);
262 #	endif OBJ
263 #	ifdef PTREE
264 	    {
265 		pPointer	PF = tCopy( r );
266 
267 		pSeize( PorFHeader[ nesting ] );
268 		if ( r->tag != T_PROG ) {
269 			pPointer	*PFs;
270 
271 			PFs = &( pDEF( PorFHeader[ nesting ] ).PorFPFs );
272 			*PFs = ListAppend( *PFs , PF );
273 		} else {
274 			pDEF( PorFHeader[ nesting ] ).GlobProg = PF;
275 		}
276 		pRelease( PorFHeader[ nesting ] );
277 	    }
278 #	endif PTREE
279 	return (p);
280 }
281 
282 	/*
283 	 * deal with the parameter declaration for a routine.
284 	 * p is the namelist entry of the routine.
285 	 * formalist is the parse tree for the parameter declaration.
286 	 * formalist	[0]	T_LISTPP
287 	 *		[1]	pointer to a formal
288 	 *		[2]	pointer to next formal
289 	 * for by-value or by-reference formals, the formal is
290 	 * formal	[0]	T_PVAL or T_PVAR
291 	 *		[1]	pointer to id_list
292 	 *		[2]	pointer to type (error if not typeid)
293 	 * for function and procedure formals, the formal is
294 	 * formal	[0]	T_PFUNC or T_PPROC
295 	 *		[1]	pointer to id_list (error if more than one)
296 	 *		[2]	pointer to type (error if not typeid, or proc)
297 	 *		[3]	pointer to formalist for this routine.
298 	 */
299 fparams(p, formal)
300 	register struct nl *p;
301 	struct tnode *formal;		/* T_PFUNC or T_PPROC */
302 {
303 	(void) params(p, formal->pfunc_node.param_list);
304 	p -> value[ NL_LINENO ] = formal->pfunc_node.line_no;
305 	p -> ptr[ NL_FCHAIN ] = p -> chain;
306 	p -> chain = NIL;
307 }
308 
309 params(p, formalist)
310 	register struct nl *p;
311 	struct tnode *formalist;	/* T_LISTPP */
312 {
313 	struct nl *chainp, *savedp;
314 	struct nl *dp;
315 	register struct tnode *formalp;	/* an element of the formal list */
316 	register struct tnode *formal;	/* a formal */
317 	struct tnode *r, *s, *t, *typ, *idlist;
318 	int w, o;
319 
320 	/*
321 	 * Enter the parameters
322 	 * and compute total size
323 	 */
324 	chainp = savedp = p;
325 
326 #	ifdef OBJ
327 	    o = 0;
328 #	endif OBJ
329 #	ifdef PC
330 		/*
331 		 * parameters used to be allocated backwards,
332 		 * then fixed.  for pc, they are allocated correctly.
333 		 * also, they are aligned.
334 		 */
335 	    o = DPOFF2;
336 #	endif PC
337 	for (formalp = formalist; formalp != TR_NIL;
338 			formalp = formalp->list_node.next) {
339 		p = NLNIL;
340 		formal = formalp->list_node.list;
341 		if (formal == TR_NIL)
342 			continue;
343 		/*
344 		 * Parametric procedures
345 		 * don't have types !?!
346 		 */
347 		typ = formal->pfunc_node.type;
348 		if ( typ == TR_NIL ) {
349 		    if ( formal->tag != T_PPROC ) {
350 			error("Types must be specified for arguments");
351 			p = NLNIL;
352 		    }
353 		} else {
354 		    if ( formal->tag == T_PPROC ) {
355 			error("Procedures cannot have types");
356 			p = NLNIL;
357 		    } else {
358 			p = gtype(typ);
359 		    }
360 		}
361 		for (idlist = formal->param.id_list; idlist != TR_NIL;
362 				idlist = idlist->list_node.next) {
363 			switch (formal->tag) {
364 			    default:
365 				    panic("funchdr2");
366 			    case T_PVAL:
367 				    if (p != NLNIL) {
368 					    if (p->class == FILET)
369 						    error("Files cannot be passed by value");
370 					    else if (p->nl_flags & NFILES)
371 						    error("Files cannot be a component of %ss passed by value",
372 							    nameof(p));
373 				    }
374 #				    ifdef OBJ
375 					w = lwidth(p);
376 					o -= even(w);
377 #					ifdef DEC11
378 					    dp = defnl((char *) idlist->list_node.list,
379 								VAR, p, o);
380 #					else
381 					    dp = defnl((char *) idlist->list_node.list,
382 						    VAR,p, (w < 2) ? o + 1 : o);
383 #					endif DEC11
384 #				    endif OBJ
385 #				    ifdef PC
386 					o = roundup(o, (long) A_STACK);
387 					w = lwidth(p);
388 #					ifndef DEC11
389 					    if (w <= sizeof(int)) {
390 						o += sizeof(int) - w;
391 					    }
392 #					endif not DEC11
393 					dp = defnl((char *) idlist->list_node.list,VAR,
394 							p, o);
395 					o += w;
396 #				    endif PC
397 				    dp->nl_flags |= NMOD;
398 				    break;
399 			    case T_PVAR:
400 #				    ifdef OBJ
401 					dp = defnl((char *) idlist->list_node.list, REF,
402 						    p, o -= sizeof ( int * ) );
403 #				    endif OBJ
404 #				    ifdef PC
405 					dp = defnl( (char *) idlist->list_node.list, REF,
406 						    p ,
407 					    o = roundup( o , (long)A_STACK ) );
408 					o += sizeof(char *);
409 #				    endif PC
410 				    break;
411 			    case T_PFUNC:
412 				    if (idlist->list_node.next != TR_NIL) {
413 					error("Each function argument must be declared separately");
414 					idlist->list_node.next = TR_NIL;
415 				    }
416 #				    ifdef OBJ
417 					dp = defnl((char *) idlist->list_node.list,FFUNC,
418 						p, o -= sizeof ( int * ) );
419 #				    endif OBJ
420 #				    ifdef PC
421 					dp = defnl( (char *) idlist->list_node.list ,
422 						FFUNC , p ,
423 						o = roundup( o , (long)A_STACK ) );
424 					o += sizeof(char *);
425 #				    endif PC
426 				    dp -> nl_flags |= NMOD;
427 				    fparams(dp, formal);
428 				    break;
429 			    case T_PPROC:
430 				    if (idlist->list_node.next != TR_NIL) {
431 					error("Each procedure argument must be declared separately");
432 					idlist->list_node.next = TR_NIL;
433 				    }
434 #				    ifdef OBJ
435 					dp = defnl((char *) idlist->list_node.list,
436 					    FPROC, p, o -= sizeof ( int * ) );
437 #				    endif OBJ
438 #				    ifdef PC
439 					dp = defnl( (char *) idlist->list_node.list ,
440 						FPROC , p,
441 						o = roundup( o , (long)A_STACK ) );
442 					o += sizeof(char *);
443 #				    endif PC
444 				    dp -> nl_flags |= NMOD;
445 				    fparams(dp, formal);
446 				    break;
447 			    }
448 			if (dp != NLNIL) {
449 #				ifdef PC
450 				    dp -> extra_flags |= NPARAM;
451 #				endif PC
452 				chainp->chain = dp;
453 				chainp = dp;
454 			}
455 		}
456 		if (typ->tag == T_TYCARY) {
457 #		    ifdef OBJ
458 			w = -even(lwidth(p->chain));
459 #			ifndef DEC11
460 			    w = (w > -2)? w + 1 : w;
461 #			endif
462 #		    endif OBJ
463 #		    ifdef PC
464 			w = lwidth(p->chain);
465 			o = roundup(o, (long)A_STACK);
466 #		    endif PC
467 		    /*
468 		     * Allocate space for upper and
469 		     * lower bounds and width.
470 		     */
471 		    for (s=typ; s->tag == T_TYCARY; s = s->ary_ty.type) {
472 			for (r=s->ary_ty.type_list; r != TR_NIL;
473 						r = r->list_node.next) {
474 			    t = r->list_node.list;
475 			    p = p->chain;
476 #			    ifdef OBJ
477 				o += w;
478 #			    endif OBJ
479 			    chainp->chain = defnl(t->crang_ty.lwb_var,
480 								VAR, p, o);
481 			    chainp = chainp->chain;
482 			    chainp->nl_flags |= (NMOD | NUSED);
483 			    p->nptr[0] = chainp;
484 			    o += w;
485 			    chainp->chain = defnl(t->crang_ty.upb_var,
486 								VAR, p, o);
487 			    chainp = chainp->chain;
488 			    chainp->nl_flags |= (NMOD | NUSED);
489 			    p->nptr[1] = chainp;
490 			    o += w;
491 			    chainp->chain  = defnl(0, VAR, p, o);
492 			    chainp = chainp->chain;
493 			    chainp->nl_flags |= (NMOD | NUSED);
494 			    p->nptr[2] = chainp;
495 #			    ifdef PC
496 				o += w;
497 #			    endif PC
498 			}
499 		    }
500 		}
501 	}
502 	p = savedp;
503 #	ifdef OBJ
504 		/*
505 		 * Correct the naivete (naivety)
506 		 * of our above code to
507 		 * calculate offsets
508 		 */
509 	    for (dp = p->chain; dp != NLNIL; dp = dp->chain)
510 		    dp->value[NL_OFFS] += -o + DPOFF2;
511 	    return (-o + DPOFF2);
512 #	endif OBJ
513 #	ifdef PC
514 	    return roundup( o , (long)A_STACK );
515 #	endif PC
516 }
517