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252367af DF |
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 | */ | |
9f7cd8aa | 6 | |
72fbef68 | 7 | #ifndef lint |
95f51977 | 8 | static char sccsid[] = "@(#)rec.c 5.1 (Berkeley) 6/5/85"; |
252367af | 9 | #endif not lint |
9f7cd8aa PK |
10 | |
11 | #include "whoami.h" | |
12 | #include "0.h" | |
13 | #include "tree.h" | |
14 | #include "opcode.h" | |
d25ca1ea | 15 | #include "align.h" |
72fbef68 | 16 | #include "tree_ty.h" |
d25ca1ea PK |
17 | |
18 | /* | |
19 | * set this to TRUE with adb to turn on record alignment/offset debugging. | |
20 | */ | |
21 | bool debug_records = FALSE; | |
22 | #define DEBUG_RECORDS(x) if (debug_records) { x ; } else | |
9f7cd8aa PK |
23 | |
24 | /* | |
25 | * Build a record namelist entry. | |
26 | * Some of the processing here is somewhat involved. | |
27 | * The basic structure we are building is as follows. | |
28 | * | |
d25ca1ea PK |
29 | * Each record has a main RECORD entry, |
30 | * with an attached chain of fields as ->chain; | |
72fbef68 | 31 | * these enclude all the fields in all the variants of this record. |
d25ca1ea PK |
32 | * Fields are cons'ed to the front of the ->chain list as they are discovered. |
33 | * This is for reclook(), but not for sizing and aligning offsets. | |
9f7cd8aa | 34 | * |
d25ca1ea PK |
35 | * If there are variants to the record, NL_TAG points to the field which |
36 | * is the tag. If its name is NIL, the tag field is unnamed, and is not | |
37 | * allocated any space in the record. | |
9f7cd8aa PK |
38 | * Attached to NL_VARNT is a chain of VARNT structures |
39 | * describing each of the variants. These are further linked | |
40 | * through ->chain. Each VARNT has, in ->range[0] the value of | |
41 | * the associated constant, and each points at a RECORD describing | |
42 | * the subrecord through NL_VTOREC. These pointers are not unique, | |
43 | * more than one VARNT may reference the same RECORD. | |
44 | * | |
d25ca1ea PK |
45 | * On the first pass, we traverse the parse tree and construct the namelist |
46 | * entries. This pass fills in the alignment of each record (including | |
47 | * subrecords (the alignment of a record is the maximum of the alignments | |
48 | * of any of its fields). | |
49 | * A second pass over the namelist entries fills in the offsets of each field | |
50 | * based on the alignments required. This second pass uses the NL_FIELDLIST | |
51 | * chaining of fields, and the NL_TAG pointer and the NL_VARNT pointer to get | |
52 | * to fields in the order in which they were declared. | |
53 | * This second pass can not be folded into the first pass, | |
54 | * as the starting offset of all variants is the same, | |
55 | * so we must see all the variants (and especially must know their alignments) | |
56 | * before assigning offsets. With the alignments calculated (by the first | |
57 | * pass) this can be done in one top down pass, max'ing over the alignment of | |
58 | * variants before assigning offsets to any of them. | |
9f7cd8aa PK |
59 | */ |
60 | ||
61 | /* | |
62 | * P0 points to the outermost RECORD for name searches. | |
63 | */ | |
64 | struct nl *P0; | |
65 | ||
d25ca1ea | 66 | struct nl * |
9f7cd8aa | 67 | tyrec(r, off) |
72fbef68 RT |
68 | struct tnode *r; |
69 | int off; | |
9f7cd8aa | 70 | { |
d25ca1ea | 71 | struct nl *recp; |
9f7cd8aa | 72 | |
d25ca1ea PK |
73 | DEBUG_RECORDS(fprintf(stderr,"[tyrec] off=%d\n", off)); |
74 | /* | |
75 | * build namelist structure for the outermost record type. | |
76 | * then calculate offsets (starting at 0) of the fields | |
77 | * in this record and its variant subrecords. | |
78 | */ | |
79 | recp = tyrec1(r, TRUE); | |
72fbef68 | 80 | rec_offsets(recp, (long) 0); |
d25ca1ea | 81 | return recp; |
9f7cd8aa PK |
82 | } |
83 | ||
84 | /* | |
85 | * Define a record namelist entry. | |
d25ca1ea PK |
86 | * r is the tree for the record to be built. |
87 | * first is a boolean indicating whether this is an outermost record, | |
88 | * for name lookups. | |
89 | * p is the record we define here. | |
90 | * P0was is a local which stacks the enclosing value of P0 in the stack frame, | |
91 | * since tyrec1() is recursive. | |
9f7cd8aa PK |
92 | */ |
93 | struct nl * | |
d25ca1ea | 94 | tyrec1(r, first) |
72fbef68 | 95 | register struct tnode *r; /* T_FLDLST */ |
d25ca1ea | 96 | bool first; |
9f7cd8aa PK |
97 | { |
98 | register struct nl *p, *P0was; | |
99 | ||
d25ca1ea | 100 | DEBUG_RECORDS(fprintf(stderr,"[tyrec1] first=%d\n", first)); |
72fbef68 | 101 | p = defnl((char *) 0, RECORD, NLNIL, 0); |
9f7cd8aa PK |
102 | P0was = P0; |
103 | if (first) | |
104 | P0 = p; | |
105 | #ifndef PI0 | |
d25ca1ea | 106 | p->align_info = A_MIN; |
9f7cd8aa | 107 | #endif |
72fbef68 RT |
108 | if (r != TR_NIL) { |
109 | fields(p, r->fldlst.fix_list); | |
110 | variants(p, r->fldlst.variant); | |
9f7cd8aa | 111 | } |
9f7cd8aa PK |
112 | P0 = P0was; |
113 | return (p); | |
114 | } | |
115 | ||
116 | /* | |
117 | * Define the fixed part fields for p. | |
d25ca1ea PK |
118 | * hang them, in order, from the record entry, through ->ptr[NL_FIELDLIST]. |
119 | * the fieldlist is a tconc structure, and is manipulated | |
120 | * just like newlist(), addlist(), fixlist() in the parser. | |
9f7cd8aa | 121 | */ |
9f7cd8aa PK |
122 | fields(p, r) |
123 | struct nl *p; | |
72fbef68 | 124 | struct tnode *r; /* T_LISTPP */ |
9f7cd8aa | 125 | { |
72fbef68 | 126 | register struct tnode *fp, *tp, *ip; |
d25ca1ea PK |
127 | struct nl *jp; |
128 | struct nl *fieldnlp; | |
9f7cd8aa | 129 | |
d25ca1ea | 130 | DEBUG_RECORDS(fprintf(stderr,"[fields]\n")); |
72fbef68 RT |
131 | for (fp = r; fp != TR_NIL; fp = fp->list_node.next) { |
132 | tp = fp->list_node.list; | |
133 | if (tp == TR_NIL) | |
9f7cd8aa | 134 | continue; |
72fbef68 RT |
135 | jp = gtype(tp->rfield.type); |
136 | line = tp->rfield.line_no; | |
137 | for (ip = tp->rfield.id_list; ip != TR_NIL; | |
138 | ip = ip->list_node.next) { | |
139 | fieldnlp = deffld(p, (char *) ip->list_node.list, jp); | |
d25ca1ea PK |
140 | if ( p->ptr[NL_FIELDLIST] == NIL ) { |
141 | /* newlist */ | |
142 | p->ptr[NL_FIELDLIST] = fieldnlp; | |
143 | fieldnlp->ptr[NL_FIELDLIST] = fieldnlp; | |
144 | } else { | |
145 | /* addlist */ | |
146 | fieldnlp->ptr[NL_FIELDLIST] = | |
147 | p->ptr[NL_FIELDLIST]->ptr[NL_FIELDLIST]; | |
148 | p->ptr[NL_FIELDLIST]->ptr[NL_FIELDLIST] = fieldnlp; | |
149 | p->ptr[NL_FIELDLIST] = fieldnlp; | |
150 | } | |
151 | } | |
152 | } | |
153 | if ( p->ptr[NL_FIELDLIST] != NIL ) { | |
154 | /* fixlist */ | |
155 | fieldnlp = p->ptr[NL_FIELDLIST]->ptr[NL_FIELDLIST]; | |
156 | p->ptr[NL_FIELDLIST]->ptr[NL_FIELDLIST] = NIL; | |
157 | p->ptr[NL_FIELDLIST] = fieldnlp; | |
9f7cd8aa PK |
158 | } |
159 | } | |
160 | ||
161 | /* | |
162 | * Define the variants for RECORD p. | |
163 | */ | |
9f7cd8aa PK |
164 | variants(p, r) |
165 | struct nl *p; | |
72fbef68 | 166 | register struct tnode *r; /* T_TYVARPT */ |
9f7cd8aa | 167 | { |
72fbef68 RT |
168 | register struct tnode *vc, *v; |
169 | struct nl *vr; | |
9f7cd8aa PK |
170 | struct nl *ct; |
171 | ||
d25ca1ea | 172 | DEBUG_RECORDS(fprintf(stderr,"[variants]\n")); |
72fbef68 | 173 | if (r == TR_NIL) |
9f7cd8aa | 174 | return; |
72fbef68 RT |
175 | ct = gtype(r->varpt.type_id); |
176 | if ( ( ct != NLNIL ) && ( isnta( ct , "bcsi" ) ) ) { | |
9f7cd8aa PK |
177 | error("Tag fields cannot be %ss" , nameof( ct ) ); |
178 | } | |
72fbef68 | 179 | line = r->varpt.line_no; |
9f7cd8aa PK |
180 | /* |
181 | * Want it even if r[2] is NIL so | |
182 | * we check its type in "new" and "dispose" | |
183 | * calls -- link it to NL_TAG. | |
184 | */ | |
72fbef68 RT |
185 | p->ptr[NL_TAG] = deffld(p, r->varpt.cptr, ct); |
186 | for (vc = r->varpt.var_list; vc != TR_NIL; vc = vc->list_node.next) { | |
187 | v = vc->list_node.list; | |
188 | if (v == TR_NIL) | |
9f7cd8aa | 189 | continue; |
72fbef68 | 190 | vr = tyrec1(v->tyvarnt.fld_list, FALSE); |
9f7cd8aa | 191 | #ifndef PI0 |
d25ca1ea PK |
192 | DEBUG_RECORDS( |
193 | fprintf(stderr, | |
194 | "[variants] p->align_info %d vr->align_info %d\n", | |
195 | p->align_info, vr->align_info)); | |
196 | if (vr->align_info > p->align_info) { | |
197 | p->align_info = vr->align_info; | |
198 | } | |
9f7cd8aa | 199 | #endif |
72fbef68 RT |
200 | line = v->tyvarnt.line_no; |
201 | for (v = v->tyvarnt.const_list; v != TR_NIL; | |
202 | v = v->list_node.next) | |
203 | (void) defvnt(p, v->list_node.list, vr, ct); | |
9f7cd8aa PK |
204 | } |
205 | } | |
206 | ||
207 | /* | |
208 | * Define a field in subrecord p of record P0 | |
209 | * with name s and type t. | |
210 | */ | |
211 | struct nl * | |
212 | deffld(p, s, t) | |
213 | struct nl *p; | |
214 | register char *s; | |
215 | register struct nl *t; | |
216 | { | |
217 | register struct nl *fp; | |
218 | ||
d25ca1ea | 219 | DEBUG_RECORDS(fprintf(stderr,"[deffld] s=<%s>\n", s)); |
9f7cd8aa PK |
220 | if (reclook(P0, s) != NIL) { |
221 | #ifndef PI1 | |
222 | error("%s is a duplicate field name in this record", s); | |
223 | #endif | |
224 | s = NIL; | |
225 | } | |
9f7cd8aa | 226 | /* |
d25ca1ea | 227 | * enter the field with its type |
9f7cd8aa | 228 | */ |
9f7cd8aa | 229 | fp = enter(defnl(s, FIELD, t, 0)); |
d25ca1ea PK |
230 | /* |
231 | * if no name, then this is an unnamed tag, | |
232 | * so don't link it into reclook()'s chain. | |
233 | */ | |
9f7cd8aa PK |
234 | if (s != NIL) { |
235 | fp->chain = P0->chain; | |
236 | P0->chain = fp; | |
237 | #ifndef PI0 | |
238 | /* | |
d25ca1ea | 239 | * and the alignment is propagated back. |
9f7cd8aa | 240 | */ |
d25ca1ea PK |
241 | fp->align_info = align(t); |
242 | DEBUG_RECORDS( | |
243 | fprintf(stderr, | |
244 | "[deffld] fp->align_info %d p->align_info %d \n", | |
245 | fp->align_info, p->align_info)); | |
246 | if (fp->align_info > p->align_info) { | |
247 | p->align_info = fp->align_info; | |
248 | } | |
9f7cd8aa PK |
249 | #endif |
250 | if (t != NIL) { | |
251 | P0->nl_flags |= t->nl_flags & NFILES; | |
252 | p->nl_flags |= t->nl_flags & NFILES; | |
253 | } | |
9f7cd8aa PK |
254 | } |
255 | return (fp); | |
256 | } | |
257 | ||
258 | /* | |
259 | * Define a variant from the constant tree of t | |
260 | * in subrecord p of record P0 where the casetype | |
261 | * is ct and the variant record to be associated is vr. | |
262 | */ | |
263 | struct nl * | |
264 | defvnt(p, t, vr, ct) | |
265 | struct nl *p, *vr; | |
72fbef68 | 266 | struct tnode *t; /* CHAR_CONST or SIGN_CONST */ |
9f7cd8aa PK |
267 | register struct nl *ct; |
268 | { | |
269 | register struct nl *av; | |
270 | ||
271 | gconst(t); | |
272 | if (ct != NIL && incompat(con.ctype, ct , t )) { | |
273 | #ifndef PI1 | |
274 | cerror("Variant label type incompatible with selector type"); | |
275 | #endif | |
276 | ct = NIL; | |
277 | } | |
72fbef68 | 278 | av = defnl((char *) 0, VARNT, ct, 0); |
9f7cd8aa PK |
279 | #ifndef PI1 |
280 | if (ct != NIL) | |
281 | uniqv(p); | |
d25ca1ea | 282 | #endif not PI1 |
9f7cd8aa PK |
283 | av->chain = p->ptr[NL_VARNT]; |
284 | p->ptr[NL_VARNT] = av; | |
285 | av->ptr[NL_VTOREC] = vr; | |
286 | av->range[0] = con.crval; | |
287 | return (av); | |
288 | } | |
289 | ||
290 | #ifndef PI1 | |
291 | /* | |
292 | * Check that the constant label value | |
293 | * is unique among the labels in this variant. | |
294 | */ | |
295 | uniqv(p) | |
296 | struct nl *p; | |
297 | { | |
298 | register struct nl *vt; | |
299 | ||
300 | for (vt = p->ptr[NL_VARNT]; vt != NIL; vt = vt->chain) | |
301 | if (vt->range[0] == con.crval) { | |
302 | error("Duplicate variant case label in record"); | |
303 | return; | |
304 | } | |
305 | } | |
306 | #endif | |
307 | ||
308 | /* | |
309 | * See if the field name s is defined | |
310 | * in the record p, returning a pointer | |
311 | * to it namelist entry if it is. | |
312 | */ | |
313 | struct nl * | |
314 | reclook(p, s) | |
315 | register struct nl *p; | |
316 | char *s; | |
317 | { | |
318 | ||
319 | if (p == NIL || s == NIL) | |
320 | return (NIL); | |
321 | for (p = p->chain; p != NIL; p = p->chain) | |
322 | if (p->symbol == s) | |
323 | return (p); | |
324 | return (NIL); | |
325 | } | |
d25ca1ea PK |
326 | |
327 | /* | |
328 | * descend namelist entry for a record and assign offsets. | |
329 | * fields go at the next higher offset that suits their alignment. | |
330 | * all variants of a record start at the same offset, which is suitable | |
331 | * for the alignment of their worst aligned field. thus the size of a | |
332 | * record is independent of whether or not it is a variant | |
333 | * (a desirable property). | |
334 | * records come to us in the namelist, where they have been annotated | |
335 | * with the maximum alignment their fields require. | |
336 | * the starting offset is passed to us, and is passed recursively for | |
337 | * variant records within records. | |
338 | * the final maximum size of each record is recorded in the namelist | |
339 | * in the value[NL_OFFS] field of the namelist for the record. | |
340 | * | |
341 | * this is supposed to match the offsets used by the c compiler | |
342 | * so people can share records between modules in both languages. | |
343 | */ | |
344 | rec_offsets(recp, offset) | |
345 | struct nl *recp; /* pointer to the namelist record */ | |
346 | long offset; /* starting offset for this record/field */ | |
347 | { | |
348 | long origin; /* offset of next field */ | |
349 | struct nl *fieldnlp; /* the current field */ | |
350 | struct nl *varntnlp; /* the current variant */ | |
351 | struct nl *vrecnlp; /* record for the current variant */ | |
d25ca1ea PK |
352 | |
353 | if ( recp == NIL ) { | |
354 | return; | |
355 | } | |
72fbef68 | 356 | origin = roundup((int) offset,(long) recp->align_info); |
d25ca1ea PK |
357 | if (origin != offset) { |
358 | fprintf(stderr, | |
359 | "[rec_offsets] offset=%d recp->align_info=%d origin=%d\n", | |
360 | offset, recp->align_info, origin); | |
361 | panic("rec_offsets"); | |
362 | } | |
363 | DEBUG_RECORDS( | |
364 | fprintf(stderr, | |
365 | "[rec_offsets] offset %d recp->align %d origin %d\n", | |
366 | offset, recp->align_info, origin)); | |
367 | /* | |
368 | * fixed fields are forward linked though ->ptr[NL_FIELDLIST] | |
369 | * give them all suitable offsets. | |
370 | */ | |
371 | for ( fieldnlp = recp->ptr[NL_FIELDLIST]; | |
372 | fieldnlp != NIL; | |
373 | fieldnlp = fieldnlp->ptr[NL_FIELDLIST] ) { | |
72fbef68 | 374 | origin = roundup((int) origin,(long) align(fieldnlp->type)); |
d25ca1ea PK |
375 | fieldnlp->value[NL_OFFS] = origin; |
376 | DEBUG_RECORDS( | |
377 | fprintf(stderr,"[rec_offsets] symbol %s origin %d\n", | |
378 | fieldnlp->symbol, origin)); | |
379 | origin += lwidth(fieldnlp->type); | |
380 | } | |
381 | /* | |
382 | * this is the extent of the record, so far | |
383 | */ | |
384 | recp->value[NL_OFFS] = origin; | |
385 | /* | |
386 | * if we have a tag field, we have variants to deal with | |
387 | */ | |
388 | if ( recp->ptr[NL_TAG] ) { | |
389 | /* | |
390 | * if tag field is unnamed, then don't allocate space for it. | |
391 | */ | |
392 | fieldnlp = recp->ptr[NL_TAG]; | |
393 | if ( fieldnlp->symbol != NIL ) { | |
72fbef68 | 394 | origin = roundup((int) origin,(long) align(fieldnlp->type)); |
d25ca1ea PK |
395 | fieldnlp->value[NL_OFFS] = origin; |
396 | DEBUG_RECORDS(fprintf(stderr,"[rec_offsets] tag %s origin\n", | |
397 | fieldnlp->symbol, origin)); | |
398 | origin += lwidth(fieldnlp->type); | |
399 | } | |
400 | /* | |
401 | * find maximum alignment of records of variants | |
402 | */ | |
403 | for ( varntnlp = recp->ptr[NL_VARNT]; | |
404 | varntnlp != NIL; | |
405 | varntnlp = varntnlp -> chain ) { | |
406 | vrecnlp = varntnlp->ptr[NL_VTOREC]; | |
407 | DEBUG_RECORDS( | |
408 | fprintf(stderr, | |
409 | "[rec_offsets] maxing variant %d align_info %d\n", | |
410 | varntnlp->value[0], vrecnlp->align_info)); | |
72fbef68 | 411 | origin = roundup((int) origin,(long) vrecnlp->align_info); |
d25ca1ea PK |
412 | } |
413 | DEBUG_RECORDS( | |
414 | fprintf(stderr, "[rec_offsets] origin of variants %d\n", origin)); | |
415 | /* | |
416 | * assign offsets to fields of records of the variants | |
417 | * keep maximum length of the current record. | |
418 | */ | |
419 | for ( varntnlp = recp->ptr[NL_VARNT]; | |
420 | varntnlp != NIL; | |
421 | varntnlp = varntnlp -> chain ) { | |
422 | vrecnlp = varntnlp->ptr[NL_VTOREC]; | |
423 | /* | |
424 | * assign offsets to fields of the variant. | |
425 | * recursive call on rec_offsets. | |
426 | */ | |
427 | rec_offsets(vrecnlp,origin); | |
428 | /* | |
429 | * extent of the record is the | |
430 | * maximum extent of all variants | |
431 | */ | |
432 | if ( vrecnlp->value[NL_OFFS] > recp->value[NL_OFFS] ) { | |
433 | recp->value[NL_OFFS] = vrecnlp->value[NL_OFFS]; | |
434 | } | |
435 | } | |
436 | } | |
437 | /* | |
438 | * roundup the size of the record to its alignment | |
439 | */ | |
440 | DEBUG_RECORDS( | |
441 | fprintf(stderr, | |
442 | "[rec_offsets] recp->value[NL_OFFS] %d ->align_info %d\n", | |
443 | recp->value[NL_OFFS], recp->align_info)); | |
72fbef68 | 444 | recp->value[NL_OFFS] = roundup(recp->value[NL_OFFS],(long) recp->align_info); |
d25ca1ea | 445 | } |