nsz Git - libfirm/blob - ir/tr/tr_inheritance.c

   1 /*
   2  * Copyright (C) 1995-2011 University of Karlsruhe.  All right reserved.
   3  *
   4  * This file is part of libFirm.
   5  *
   6  * This file may be distributed and/or modified under the terms of the
   7  * GNU General Public License version 2 as published by the Free Software
   8  * Foundation and appearing in the file LICENSE.GPL included in the
   9  * packaging of this file.
  10  *
  11  * Licensees holding valid libFirm Professional Edition licenses may use
  12  * this file in accordance with the libFirm Commercial License.
  13  * Agreement provided with the Software.
  14  *
  15  * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
  16  * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  17  * PURPOSE.
  18  */
  19
  20 /**
  21  * @file    tr_inheritance.c
  22  * @brief   Utility routines for inheritance representation
  23  * @author  Goetz Lindenmaier
  24  */
  25 #include "config.h"
  26
  27 #include "debug.h"
  28 #include "typerep.h"
  29 #include "irgraph_t.h"
  30 #include "irprog_t.h"
  31 #include "irprintf.h"
  32 #include "pset.h"
  33 #include "set.h"
  34 #include "irgwalk.h"
  35 #include "irflag.h"
  36
  37 DEBUG_ONLY(static firm_dbg_module_t *dbg;)
  38
  39 /* ----------------------------------------------------------------------- */
  40 /* Resolve implicit inheritance.                                           */
  41 /* ----------------------------------------------------------------------- */
  42
  43 ident *default_mangle_inherited_name(const ir_entity *super, const ir_type *clss)
  44 {
  45         return id_mangle_u(new_id_from_str("inh"), id_mangle_u(get_class_ident(clss), get_entity_ident(super)));
  46 }
  47
  48 /** Replicates all entities in all super classes that are not overwritten
  49     by an entity of this class. */
  50 static void copy_entities_from_superclass(ir_type *clss, void *env)
  51 {
  52         size_t i;
  53         size_t j;
  54         size_t k;
  55         size_t l;
  56         int overwritten;
  57         ir_type *super;
  58         ir_entity *inhent, *thisent;
  59         mangle_inherited_name_func *mfunc = *(mangle_inherited_name_func **)env;
  60
  61         for (i = 0; i < get_class_n_supertypes(clss); i++) {
  62                 super = get_class_supertype(clss, i);
  63                 assert(is_Class_type(super) && "not a class");
  64                 for (j = 0; j < get_class_n_members(super); j++) {
  65                         inhent = get_class_member(super, j);
  66                         /* check whether inhent is already overwritten */
  67                         overwritten = 0;
  68                         for (k = 0; (k < get_class_n_members(clss)) && (overwritten == 0); k++) {
  69                                 thisent = get_class_member(clss, k);
  70                                 for (l = 0; l < get_entity_n_overwrites(thisent); l++) {
  71                                         if (inhent == get_entity_overwrites(thisent, l)) {
  72                                                 /* overwritten - do not copy */
  73                                                 overwritten = 1;
  74                                                 break;
  75                                         }
  76                                 }
  77                         }
  78                         /* Inherit entity */
  79                         if (!overwritten) {
  80                                 thisent = copy_entity_own(inhent, clss);
  81                                 add_entity_overwrites(thisent, inhent);
  82                                 if (get_entity_peculiarity(inhent) == peculiarity_existent)
  83                                         set_entity_peculiarity(thisent, peculiarity_inherited);
  84                                 set_entity_ld_ident(thisent, mfunc(inhent, clss));
  85                                 if (get_entity_linkage(inhent) & IR_LINKAGE_CONSTANT) {
  86                                         assert(is_atomic_entity(inhent) &&  /* @@@ */
  87                                                 "Inheritance of constant, compound entities not implemented");
  88                                         add_entity_linkage(thisent, IR_LINKAGE_CONSTANT);
  89                                         set_atomic_ent_value(thisent, get_atomic_ent_value(inhent));
  90                                 }
  91                         }
  92                 }
  93         }
  94 }
  95
  96 void resolve_inheritance(mangle_inherited_name_func *mfunc)
  97 {
  98         if (!mfunc)
  99                 mfunc = default_mangle_inherited_name;
 100         class_walk_super2sub(copy_entities_from_superclass, NULL, (void *)&mfunc);
 101 }
 102
 103
 104 /* ----------------------------------------------------------------------- */
 105 /* The transitive closure of the subclass/superclass and                   */
 106 /* overwrites/overwrittenby relation.                                      */
 107 /*                                                                         */
 108 /* A walk over the ir (O(#types+#entities)) computes the transitive        */
 109 /* closure.  Adding a new type/entity or changing the basic relations in   */
 110 /* some other way invalidates the transitive closure, i.e., it is not      */
 111 /* updated by the basic functions.                                         */
 112 /*                                                                         */
 113 /* All functions are named as their counterparts for the basic relations,  */
 114 /* adding the infix 'trans_'.                                              */
 115 /* ----------------------------------------------------------------------- */
 116
 117 void                        set_irp_inh_transitive_closure_state(inh_transitive_closure_state s)
 118 {
 119         irp->inh_trans_closure_state = s;
 120 }
 121 void                        invalidate_irp_inh_transitive_closure_state(void)
 122 {
 123         if (irp->inh_trans_closure_state == inh_transitive_closure_valid)
 124                 irp->inh_trans_closure_state = inh_transitive_closure_invalid;
 125 }
 126 inh_transitive_closure_state get_irp_inh_transitive_closure_state(void)
 127 {
 128         return irp->inh_trans_closure_state;
 129 }
 130
 131 static void assert_valid_state(void)
 132 {
 133         assert(irp->inh_trans_closure_state == inh_transitive_closure_valid ||
 134                irp->inh_trans_closure_state == inh_transitive_closure_invalid);
 135 }
 136
 137 /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
 138 /* There is a set that extends each entity/type with two new               */
 139 /* fields:  one for the upwards directed relation: 'up' (supertype,        */
 140 /* overwrites) and one for the downwards directed relation: 'down' (sub-   */
 141 /* type, overwrittenby.  These fields contain psets (and maybe later       */
 142 /* arrays) listing all subtypes...                                         */
 143 /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
 144
 145 typedef enum {
 146         d_up   = 0,
 147         d_down = 1,
 148 } dir;
 149
 150 typedef struct {
 151         const firm_kind *kind;   /**< An entity or type. */
 152         pset *directions[2];
 153 } tr_inh_trans_tp;
 154
 155 /* We use this set for all types and entities.  */
 156 static set *tr_inh_trans_set = NULL;
 157
 158 /**
 159  * Compare two tr_inh_trans_tp entries.
 160  */
 161 static int tr_inh_trans_cmp(const void *e1, const void *e2, size_t size)
 162 {
 163         const tr_inh_trans_tp *ef1 = (const tr_inh_trans_tp*)e1;
 164         const tr_inh_trans_tp *ef2 = (const tr_inh_trans_tp*)e2;
 165         (void) size;
 166
 167         return ef1->kind != ef2->kind;
 168 }
 169
 170 /**
 171  * calculate the hash value of an tr_inh_trans_tp
 172  */
 173 static inline unsigned int tr_inh_trans_hash(const tr_inh_trans_tp *v)
 174 {
 175         return hash_ptr(v->kind);
 176 }
 177
 178 /* This always completes successfully. */
 179 static tr_inh_trans_tp *get_firm_kind_entry(const firm_kind *k)
 180 {
 181         tr_inh_trans_tp a, *found;
 182         a.kind = k;
 183
 184         if (!tr_inh_trans_set) tr_inh_trans_set = new_set(tr_inh_trans_cmp, 128);
 185
 186         found = (tr_inh_trans_tp*)set_find(tr_inh_trans_set, &a, sizeof(a), tr_inh_trans_hash(&a));
 187         if (!found) {
 188                 a.directions[d_up]   = pset_new_ptr(16);
 189                 a.directions[d_down] = pset_new_ptr(16);
 190                 found = (tr_inh_trans_tp*)set_insert(tr_inh_trans_set, &a, sizeof(a), tr_inh_trans_hash(&a));
 191         }
 192         return found;
 193 }
 194
 195 static pset *get_entity_map(const ir_entity *ent, dir d)
 196 {
 197         tr_inh_trans_tp *found;
 198
 199         assert(is_entity(ent));
 200         found = get_firm_kind_entry((const firm_kind *)ent);
 201         return found->directions[d];
 202 }
 203
 204 static pset *get_type_map(const ir_type *tp, dir d)
 205 {
 206         tr_inh_trans_tp *found;
 207
 208         assert(is_type(tp));
 209         found = get_firm_kind_entry((const firm_kind *)tp);
 210         return found->directions[d];
 211 }
 212
 213
 214 /**
 215  * Walk over all types reachable from tp in the sub/supertype
 216  * relation and compute the closure for the two downwards directed
 217  * relations.
 218  *
 219  * The walk in the dag formed by the relation is tricky:  We must visit
 220  * all subtypes before visiting the supertypes.  So we first walk down.
 221  * Then we can compute the closure for this type.  Then we walk up.
 222  * As we call ourselves recursive, and walk in both directions, there
 223  * can be cycles.  So we have to make sure, that if we visit a node
 224  * a second time (in a walk up) we do nothing.  For this we increment
 225  * the master visited flag twice.
 226  * If the type is marked with master_flag_visited-1 it is on the stack.
 227  * If it is marked with master_flag_visited it is fully processed.
 228  *
 229  * Well, we still miss some candidates ... */
 230 static void compute_down_closure(ir_type *tp)
 231 {
 232         pset *myset, *subset;
 233         size_t i, n_subtypes, n_members, n_supertypes;
 234         ir_visited_t master_visited = get_master_type_visited();
 235
 236         assert(is_Class_type(tp));
 237
 238         set_type_visited(tp, master_visited-1);
 239
 240         /* Recursive descend. */
 241         n_subtypes = get_class_n_subtypes(tp);
 242         for (i = 0; i < n_subtypes; ++i) {
 243                 ir_type *stp = get_class_subtype(tp, i);
 244                 if (get_type_visited(stp) < master_visited-1) {
 245                         compute_down_closure(stp);
 246                 }
 247         }
 248
 249         /* types */
 250         myset = get_type_map(tp, d_down);
 251         for (i = 0; i < n_subtypes; ++i) {
 252                 ir_type *stp = get_class_subtype(tp, i);
 253                 subset = get_type_map(stp, d_down);
 254                 pset_insert_ptr(myset, stp);
 255                 pset_insert_pset_ptr(myset, subset);
 256         }
 257
 258         /* entities */
 259         n_members = get_class_n_members(tp);
 260         for (i = 0; i < n_members; ++i) {
 261                 ir_entity *mem = get_class_member(tp, i);
 262                 size_t j, n_overwrittenby = get_entity_n_overwrittenby(mem);
 263
 264                 myset = get_entity_map(mem, d_down);
 265                 for (j = 0; j < n_overwrittenby; ++j) {
 266                         ir_entity *ov = get_entity_overwrittenby(mem, j);
 267                         subset = get_entity_map(ov, d_down);
 268                         pset_insert_ptr(myset, ov);
 269                         pset_insert_pset_ptr(myset, subset);
 270                 }
 271         }
 272
 273         mark_type_visited(tp);
 274
 275         /* Walk up. */
 276         n_supertypes = get_class_n_supertypes(tp);
 277         for (i = 0; i < n_supertypes; ++i) {
 278                 ir_type *stp = get_class_supertype(tp, i);
 279                 if (get_type_visited(stp) < master_visited-1) {
 280                         compute_down_closure(stp);
 281                 }
 282         }
 283 }
 284
 285 static void compute_up_closure(ir_type *tp)
 286 {
 287         pset *myset, *subset;
 288         size_t i, n_subtypes, n_members, n_supertypes;
 289         ir_visited_t master_visited = get_master_type_visited();
 290
 291         assert(is_Class_type(tp));
 292
 293         set_type_visited(tp, master_visited-1);
 294
 295         /* Recursive descend. */
 296         n_supertypes = get_class_n_supertypes(tp);
 297         for (i = 0; i < n_supertypes; ++i) {
 298                 ir_type *stp = get_class_supertype(tp, i);
 299                 if (get_type_visited(stp) < get_master_type_visited()-1) {
 300                         compute_up_closure(stp);
 301                 }
 302         }
 303
 304         /* types */
 305         myset = get_type_map(tp, d_up);
 306         for (i = 0; i < n_supertypes; ++i) {
 307                 ir_type *stp = get_class_supertype(tp, i);
 308                 subset = get_type_map(stp, d_up);
 309                 pset_insert_ptr(myset, stp);
 310                 pset_insert_pset_ptr(myset, subset);
 311         }
 312
 313         /* entities */
 314         n_members = get_class_n_members(tp);
 315         for (i = 0; i < n_members; ++i) {
 316                 ir_entity *mem = get_class_member(tp, i);
 317                 size_t j, n_overwrites = get_entity_n_overwrites(mem);
 318
 319                 myset = get_entity_map(mem, d_up);
 320                 for (j = 0; j < n_overwrites; ++j) {
 321                         ir_entity *ov = get_entity_overwrites(mem, j);
 322                         subset = get_entity_map(ov, d_up);
 323                         pset_insert_pset_ptr(myset, subset);
 324                         pset_insert_ptr(myset, ov);
 325                 }
 326         }
 327
 328         mark_type_visited(tp);
 329
 330         /* Walk down. */
 331         n_subtypes = get_class_n_subtypes(tp);
 332         for (i = 0; i < n_subtypes; ++i) {
 333                 ir_type *stp = get_class_subtype(tp, i);
 334                 if (get_type_visited(stp) < master_visited-1) {
 335                         compute_up_closure(stp);
 336                 }
 337         }
 338 }
 339
 340 void compute_inh_transitive_closure(void)
 341 {
 342         size_t i, n_types = get_irp_n_types();
 343         free_inh_transitive_closure();
 344
 345         /* The 'down' relation */
 346         irp_reserve_resources(irp, IRP_RESOURCE_TYPE_VISITED);
 347         inc_master_type_visited();  /* Inc twice: one if on stack, second if values computed. */
 348         inc_master_type_visited();
 349         for (i = 0; i < n_types; ++i) {
 350                 ir_type *tp = get_irp_type(i);
 351                 if (is_Class_type(tp) && type_not_visited(tp)) { /* For others there is nothing to accumulate. */
 352                         size_t j, n_subtypes = get_class_n_subtypes(tp);
 353                         int has_unmarked_subtype = 0;
 354
 355                         assert(get_type_visited(tp) < get_master_type_visited()-1);
 356                         for (j = 0; j < n_subtypes; ++j) {
 357                                 ir_type *stp = get_class_subtype(tp, j);
 358                                 if (type_not_visited(stp)) {
 359                                         has_unmarked_subtype = 1;
 360                                         break;
 361                                 }
 362                         }
 363
 364                         /* This is a good starting point. */
 365                         if (!has_unmarked_subtype)
 366                                 compute_down_closure(tp);
 367                 }
 368         }
 369
 370         /* The 'up' relation */
 371         inc_master_type_visited();
 372         inc_master_type_visited();
 373         for (i = 0; i < n_types; ++i) {
 374                 ir_type *tp = get_irp_type(i);
 375                 if (is_Class_type(tp) && type_not_visited(tp)) { /* For others there is nothing to accumulate. */
 376                         size_t j, n_supertypes = get_class_n_supertypes(tp);
 377                         int has_unmarked_supertype = 0;
 378
 379                         assert(get_type_visited(tp) < get_master_type_visited()-1);
 380                         for (j = 0; j < n_supertypes; ++j) {
 381                                 ir_type *stp = get_class_supertype(tp, j);
 382                                 if (type_not_visited(stp)) {
 383                                         has_unmarked_supertype = 1;
 384                                         break;
 385                                 }
 386                         }
 387
 388                         /* This is a good starting point. */
 389                         if (!has_unmarked_supertype)
 390                                 compute_up_closure(tp);
 391                 }
 392         }
 393
 394         irp->inh_trans_closure_state = inh_transitive_closure_valid;
 395         irp_free_resources(irp, IRP_RESOURCE_TYPE_VISITED);
 396 }
 397
 398 void free_inh_transitive_closure(void)
 399 {
 400         if (tr_inh_trans_set) {
 401                 tr_inh_trans_tp *elt;
 402                 for (elt = (tr_inh_trans_tp*)set_first(tr_inh_trans_set); elt != NULL;
 403                      elt = (tr_inh_trans_tp*)set_next(tr_inh_trans_set)) {
 404                         del_pset(elt->directions[d_up]);
 405                         del_pset(elt->directions[d_down]);
 406                 }
 407                 del_set(tr_inh_trans_set);
 408                 tr_inh_trans_set = NULL;
 409         }
 410         irp->inh_trans_closure_state = inh_transitive_closure_none;
 411 }
 412
 413 /* - subtype ------------------------------------------------------------- */
 414
 415 ir_type *get_class_trans_subtype_first(const ir_type *tp)
 416 {
 417         assert_valid_state();
 418         return (ir_type*)pset_first(get_type_map(tp, d_down));
 419 }
 420
 421 ir_type *get_class_trans_subtype_next(const ir_type *tp)
 422 {
 423         assert_valid_state();
 424         return (ir_type*)pset_next(get_type_map(tp, d_down));
 425 }
 426
 427 int is_class_trans_subtype(const ir_type *tp, const ir_type *subtp)
 428 {
 429         assert_valid_state();
 430         return (pset_find_ptr(get_type_map(tp, d_down), subtp) != NULL);
 431 }
 432
 433 /* - supertype ----------------------------------------------------------- */
 434
 435 ir_type *get_class_trans_supertype_first(const ir_type *tp)
 436 {
 437         assert_valid_state();
 438         return (ir_type*)pset_first(get_type_map(tp, d_up));
 439 }
 440
 441 ir_type *get_class_trans_supertype_next(const ir_type *tp)
 442 {
 443         assert_valid_state();
 444         return (ir_type*)pset_next(get_type_map(tp, d_up));
 445 }
 446
 447 /* - overwrittenby ------------------------------------------------------- */
 448
 449 ir_entity *get_entity_trans_overwrittenby_first(const ir_entity *ent)
 450 {
 451         assert_valid_state();
 452         return (ir_entity*)pset_first(get_entity_map(ent, d_down));
 453 }
 454
 455 ir_entity *get_entity_trans_overwrittenby_next(const ir_entity *ent)
 456 {
 457         assert_valid_state();
 458         return (ir_entity*)pset_next(get_entity_map(ent, d_down));
 459 }
 460
 461 /* - overwrites ---------------------------------------------------------- */
 462
 463
 464 ir_entity *get_entity_trans_overwrites_first(const ir_entity *ent)
 465 {
 466         assert_valid_state();
 467         return (ir_entity*)pset_first(get_entity_map(ent, d_up));
 468 }
 469
 470 ir_entity *get_entity_trans_overwrites_next(const ir_entity *ent)
 471 {
 472         assert_valid_state();
 473         return (ir_entity*)pset_next(get_entity_map(ent, d_up));
 474 }
 475
 476
 477 /* ----------------------------------------------------------------------- */
 478 /* Classify pairs of types/entities in the inheritance relations.          */
 479 /* ----------------------------------------------------------------------- */
 480
 481 /** Returns true if low is subclass of high. */
 482 static int check_is_SubClass_of(ir_type *low, ir_type *high)
 483 {
 484         size_t i, n_subtypes;
 485
 486         /* depth first search from high downwards. */
 487         n_subtypes = get_class_n_subtypes(high);
 488         for (i = 0; i < n_subtypes; i++) {
 489                 ir_type *stp = get_class_subtype(high, i);
 490                 if (low == stp) return 1;
 491                 if (is_SubClass_of(low, stp))
 492                         return 1;
 493         }
 494         return 0;
 495 }
 496
 497 int is_SubClass_of(ir_type *low, ir_type *high)
 498 {
 499         assert(is_Class_type(low) && is_Class_type(high));
 500
 501         if (low == high) return 1;
 502
 503         if (get_irp_inh_transitive_closure_state() == inh_transitive_closure_valid) {
 504                 pset *m = get_type_map(high, d_down);
 505                 return pset_find_ptr(m, low) ? 1 : 0;
 506         }
 507         return check_is_SubClass_of(low, high);
 508 }
 509
 510 int is_SubClass_ptr_of(ir_type *low, ir_type *high)
 511 {
 512         while (is_Pointer_type(low) && is_Pointer_type(high)) {
 513                 low  = get_pointer_points_to_type(low);
 514                 high = get_pointer_points_to_type(high);
 515         }
 516
 517         if (is_Class_type(low) && is_Class_type(high))
 518                 return is_SubClass_of(low, high);
 519         return 0;
 520 }
 521
 522 int is_overwritten_by(ir_entity *high, ir_entity *low)
 523 {
 524         size_t i, n_overwrittenby;
 525         assert(is_entity(low) && is_entity(high));
 526
 527         if (get_irp_inh_transitive_closure_state() == inh_transitive_closure_valid) {
 528                 pset *m = get_entity_map(high, d_down);
 529                 return pset_find_ptr(m, low) ? 1 : 0;
 530         }
 531
 532         /* depth first search from high downwards. */
 533         n_overwrittenby = get_entity_n_overwrittenby(high);
 534         for (i = 0; i < n_overwrittenby; i++) {
 535                 ir_entity *ov = get_entity_overwrittenby(high, i);
 536                 if (low == ov) return 1;
 537                 if (is_overwritten_by(low, ov))
 538                         return 1;
 539         }
 540         return 0;
 541 }
 542
 543 /** Resolve polymorphy in the inheritance relation.
 544  *
 545  * Returns the dynamically referenced entity if the static entity and the
 546  * dynamic type are given.
 547  * Search downwards in overwritten tree.
 548  *
 549  * Need two routines because I want to assert the result.
 550  */
 551 static ir_entity *do_resolve_ent_polymorphy(ir_type *dynamic_class, ir_entity *static_ent)
 552 {
 553         size_t i, n_overwrittenby;
 554
 555         ir_type *owner = get_entity_owner(static_ent);
 556         if (owner == dynamic_class) return static_ent;
 557
 558         // if the owner of the static_ent already is more special than the dynamic
 559         // type to check against - stop here.
 560         if (! is_SubClass_of(dynamic_class, owner)) return NULL;
 561
 562         n_overwrittenby = get_entity_n_overwrittenby(static_ent);
 563         for (i = 0; i < n_overwrittenby; ++i) {
 564                 ir_entity *ent = get_entity_overwrittenby(static_ent, i);
 565                 ent = do_resolve_ent_polymorphy(dynamic_class, ent);
 566                 if (ent) return ent;
 567         }
 568
 569         // No further specialization of static_ent has been found
 570         return static_ent;
 571 }
 572
 573 ir_entity *resolve_ent_polymorphy(ir_type *dynamic_class, ir_entity *static_ent)
 574 {
 575         ir_entity *res;
 576         assert(static_ent && is_entity(static_ent));
 577
 578         res = do_resolve_ent_polymorphy(dynamic_class, static_ent);
 579         assert(res);
 580
 581         return res;
 582 }
 583
 584
 585
 586 /* ----------------------------------------------------------------------- */
 587 /* Class cast state handling.                                              */
 588 /* ----------------------------------------------------------------------- */
 589
 590 /* - State handling. ----------------------------------------- */
 591
 592 void set_irg_class_cast_state(ir_graph *irg, ir_class_cast_state s)
 593 {
 594         if (get_irp_class_cast_state() > s)
 595                 set_irp_class_cast_state(s);
 596         irg->class_cast_state = s;
 597 }
 598
 599 ir_class_cast_state get_irg_class_cast_state(const ir_graph *irg)
 600 {
 601         return irg->class_cast_state;
 602 }
 603
 604 void set_irp_class_cast_state(ir_class_cast_state s)
 605 {
 606 #ifndef NDEBUG
 607         size_t i, n;
 608         for (i = 0, n = get_irp_n_irgs(); i < n; ++i)
 609                 assert(get_irg_class_cast_state(get_irp_irg(i)) >= s);
 610 #endif
 611         irp->class_cast_state = s;
 612 }
 613
 614 ir_class_cast_state get_irp_class_cast_state(void)
 615 {
 616         return irp->class_cast_state;
 617 }
 618
 619 const char *get_class_cast_state_string(ir_class_cast_state s)
 620 {
 621 #define X(a)    case a: return #a
 622         switch (s) {
 623         X(ir_class_casts_any);
 624         X(ir_class_casts_transitive);
 625         X(ir_class_casts_normalized);
 626         X(ir_class_casts_state_max);
 627         default: return "invalid class cast state";
 628         }
 629 #undef X
 630 }
 631
 632 /* - State verification. ------------------------------------- */
 633
 634 typedef struct ccs_env {
 635         ir_class_cast_state expected_state;
 636         ir_class_cast_state worst_situation;
 637 } ccs_env;
 638
 639 /**
 640  * Walker: check Casts.
 641  */
 642 static void verify_irn_class_cast_state(ir_node *n, void *env)
 643 {
 644         ccs_env             *ccs = (ccs_env *)env;
 645         ir_class_cast_state this_state = ir_class_casts_any;
 646         ir_type             *fromtype, *totype;
 647
 648         if (!is_Cast(n)) return;
 649
 650         fromtype = get_irn_typeinfo_type(get_Cast_op(n));
 651         totype   = get_Cast_type(n);
 652
 653         while (is_Pointer_type(totype) && is_Pointer_type(fromtype)) {
 654                 totype   = get_pointer_points_to_type(totype);
 655                 fromtype = get_pointer_points_to_type(fromtype);
 656         }
 657
 658         if (!is_Class_type(totype)) return;
 659
 660         if (is_SubClass_of(totype, fromtype) ||
 661                 is_SubClass_of(fromtype, totype)) {
 662                 this_state = ir_class_casts_transitive;
 663                 if ((get_class_supertype_index(totype, fromtype) != (size_t)-1) ||
 664                     (get_class_supertype_index(fromtype, totype) != (size_t)-1) ||
 665                     fromtype == totype) {
 666                         this_state = ir_class_casts_normalized;
 667                 }
 668         }
 669
 670         if (!(this_state >= ccs->expected_state)) {
 671                 ir_printf("  Node is %+F\n", n);
 672                 ir_printf("    totype   %+F\n", totype);
 673                 ir_printf("    fromtype %+F\n", fromtype);
 674                 ir_printf("    this_state: %s, exp. state: %s\n",
 675                         get_class_cast_state_string(this_state),
 676                         get_class_cast_state_string(ccs->expected_state));
 677                 assert(this_state >= ccs->expected_state &&
 678                         "invalid state class cast state setting in graph");
 679         }
 680
 681         if (this_state < ccs->worst_situation)
 682                 ccs->worst_situation = this_state;
 683 }
 684
 685 void verify_irg_class_cast_state(ir_graph *irg)
 686 {
 687         ccs_env env;
 688
 689         FIRM_DBG_REGISTER(dbg, "firm.tr.inheritance");
 690
 691         env.expected_state  = get_irg_class_cast_state(irg);
 692         env.worst_situation = ir_class_casts_normalized;
 693
 694         irg_walk_graph(irg, NULL, verify_irn_class_cast_state, &env);
 695
 696         if ((env.worst_situation > env.expected_state)) {
 697                 DB((dbg, LEVEL_1, "Note:  class cast state is set lower than reqired "
 698                     "in graph \n\t%+F\n", irg));
 699                 DB((dbg, LEVEL_1, "       state is %s, reqired is %s\n",
 700                         get_class_cast_state_string(env.expected_state),
 701                         get_class_cast_state_string(env.worst_situation)));
 702         }
 703 }