src/solver.c

   1 /*
   2  * Copyright (c) 2007-2008, Novell Inc.
   3  *
   4  * This program is licensed under the BSD license, read LICENSE.BSD
   5  * for further information
   6  */
   7
   8 /*
   9  * solver.c
  10  *
  11  * SAT based dependency solver
  12  */
  13
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16 #include <unistd.h>
  17 #include <string.h>
  18 #include <assert.h>
  19
  20 #include "solver.h"
  21 #include "bitmap.h"
  22 #include "pool.h"
  23 #include "util.h"
  24 #include "policy.h"
  25 #include "solverdebug.h"
  26
  27 #define RULES_BLOCK 63
  28
  29 /********************************************************************
  30  *
  31  * dependency check helpers
  32  *
  33  */
  34
  35 /*-------------------------------------------------------------------
  36  * handle split provides
  37  */
  38
  39 int
  40 solver_splitprovides(Solver *solv, Id dep)
  41 {
  42   Pool *pool = solv->pool;
  43   Id p, pp;
  44   Reldep *rd;
  45   Solvable *s;
  46
  47   if (!solv->dosplitprovides || !solv->installed)
  48     return 0;
  49   if (!ISRELDEP(dep))
  50     return 0;
  51   rd = GETRELDEP(pool, dep);
  52   if (rd->flags != REL_WITH)
  53     return 0;
  54   FOR_PROVIDES(p, pp, dep)
  55     {
  56       s = pool->solvables + p;
  57       if (s->repo == solv->installed && s->name == rd->name)
  58         return 1;
  59     }
  60   return 0;
  61 }
  62
  63
  64 /*-------------------------------------------------------------------
  65  * solver_dep_installed
  66  */
  67
  68 int
  69 solver_dep_installed(Solver *solv, Id dep)
  70 {
  71 #if 0
  72   Pool *pool = solv->pool;
  73   Id p, pp;
  74
  75   if (ISRELDEP(dep))
  76     {
  77       Reldep *rd = GETRELDEP(pool, dep);
  78       if (rd->flags == REL_AND)
  79         {
  80           if (!solver_dep_installed(solv, rd->name))
  81             return 0;
  82           return solver_dep_installed(solv, rd->evr);
  83         }
  84       if (rd->flags == REL_NAMESPACE && rd->name == NAMESPACE_INSTALLED)
  85         return solver_dep_installed(solv, rd->evr);
  86     }
  87   FOR_PROVIDES(p, pp, dep)
  88     {
  89       if (p == SYSTEMSOLVABLE || (solv->installed && pool->solvables[p].repo == solv->installed))
  90         return 1;
  91     }
  92 #endif
  93   return 0;
  94 }
  95
  96
  97
  98 /************************************************************************/
  99
 100 /*
 101  * make assertion rules into decisions
 102  *
 103  * Go through rules and add direct assertions to the decisionqueue.
 104  * If we find a conflict, disable rules and add them to problem queue.
 105  */
 106
 107 static void
 108 makeruledecisions(Solver *solv)
 109 {
 110   Pool *pool = solv->pool;
 111   int i, ri, ii;
 112   Rule *r, *rr;
 113   Id v, vv;
 114   int decisionstart;
 115
 116   POOL_DEBUG(SAT_DEBUG_SCHUBI, "----- makeruledecisions ; size decisionq: %d -----\n",solv->decisionq.count);
 117
 118   /* The system solvable is always installed first */
 119   assert(solv->decisionq.count == 0);
 120   queue_push(&solv->decisionq, SYSTEMSOLVABLE);
 121   queue_push(&solv->decisionq_why, 0);
 122   solv->decisionmap[SYSTEMSOLVABLE] = 1;        /* installed at level '1' */
 123
 124   decisionstart = solv->decisionq.count;
 125   for (ii = 0; ii < solv->ruleassertions.count; ii++)
 126     {
 127       ri = solv->ruleassertions.elements[ii];
 128       r = solv->rules + ri;
 129
 130       if (r->d < 0 || !r->p || r->w2)   /* disabled, dummy or no assertion */
 131         continue;
 132       /* do weak rules in phase 2 */
 133       if (ri < solv->learntrules && MAPTST(&solv->weakrulemap, ri))
 134         continue;
 135
 136       v = r->p;
 137       vv = v > 0 ? v : -v;
 138
 139       if (!solv->decisionmap[vv])          /* if not yet decided */
 140         {
 141             /*
 142              * decide !
 143              */
 144           queue_push(&solv->decisionq, v);
 145           queue_push(&solv->decisionq_why, r - solv->rules);
 146           solv->decisionmap[vv] = v > 0 ? 1 : -1;
 147           IF_POOLDEBUG (SAT_DEBUG_PROPAGATE)
 148             {
 149               Solvable *s = solv->pool->solvables + vv;
 150               if (v < 0)
 151                 POOL_DEBUG(SAT_DEBUG_PROPAGATE, "conflicting %s (assertion)\n", solvable2str(solv->pool, s));
 152               else
 153                 POOL_DEBUG(SAT_DEBUG_PROPAGATE, "installing  %s (assertion)\n", solvable2str(solv->pool, s));
 154             }
 155           continue;
 156         }
 157         /*
 158          * check previous decision: is it sane ?
 159          */
 160
 161       if (v > 0 && solv->decisionmap[vv] > 0)    /* ok to install */
 162         continue;
 163       if (v < 0 && solv->decisionmap[vv] < 0)    /* ok to remove */
 164         continue;
 165
 166         /*
 167          * found a conflict!
 168          *
 169          * The rule (r) we're currently processing says something
 170          * different (v = r->p) than a previous decision (decisionmap[abs(v)])
 171          * on this literal
 172          */
 173
 174       if (ri >= solv->learntrules)
 175         {
 176           /* conflict with a learnt rule */
 177           /* can happen when packages cannot be installed for
 178            * multiple reasons. */
 179           /* we disable the learnt rule in this case */
 180           solver_disablerule(solv, r);
 181           continue;
 182         }
 183
 184         /*
 185          * find the decision which is the "opposite" of the rule
 186          */
 187
 188       for (i = 0; i < solv->decisionq.count; i++)
 189         if (solv->decisionq.elements[i] == -v)
 190           break;
 191       assert(i < solv->decisionq.count);         /* assert that we found it */
 192
 193       /*
 194        * conflict with system solvable ?
 195        */
 196
 197       if (v == -SYSTEMSOLVABLE) {
 198         /* conflict with system solvable */
 199         queue_push(&solv->problems, solv->learnt_pool.count);
 200         queue_push(&solv->learnt_pool, ri);
 201         queue_push(&solv->learnt_pool, 0);
 202         POOL_DEBUG(SAT_DEBUG_UNSOLVABLE, "conflict with system solvable, disabling rule #%d\n", ri);
 203         if  (ri >= solv->jobrules && ri < solv->jobrules_end)
 204           v = -(solv->ruletojob.elements[ri - solv->jobrules] + 1);
 205         else
 206           v = ri;
 207         queue_push(&solv->problems, v);
 208         queue_push(&solv->problems, 0);
 209         solver_disableproblem(solv, v);
 210         continue;
 211       }
 212
 213       assert(solv->decisionq_why.elements[i] > 0);
 214
 215       /*
 216        * conflict with an rpm rule ?
 217        */
 218
 219       if (solv->decisionq_why.elements[i] < solv->rpmrules_end)
 220         {
 221           /* conflict with rpm rule assertion */
 222           queue_push(&solv->problems, solv->learnt_pool.count);
 223           queue_push(&solv->learnt_pool, ri);
 224           queue_push(&solv->learnt_pool, solv->decisionq_why.elements[i]);
 225           queue_push(&solv->learnt_pool, 0);
 226           assert(v > 0 || v == -SYSTEMSOLVABLE);
 227           POOL_DEBUG(SAT_DEBUG_UNSOLVABLE, "conflict with rpm rule, disabling rule #%d\n", ri);
 228           if (ri >= solv->jobrules && ri < solv->jobrules_end)
 229             v = -(solv->ruletojob.elements[ri - solv->jobrules] + 1);
 230           else
 231             v = ri;
 232           queue_push(&solv->problems, v);
 233           queue_push(&solv->problems, 0);
 234           solver_disableproblem(solv, v);
 235           continue;
 236         }
 237
 238       /*
 239        * conflict with another job or update/feature rule
 240        */
 241
 242       /* record proof */
 243       queue_push(&solv->problems, solv->learnt_pool.count);
 244       queue_push(&solv->learnt_pool, ri);
 245       queue_push(&solv->learnt_pool, solv->decisionq_why.elements[i]);
 246       queue_push(&solv->learnt_pool, 0);
 247
 248       POOL_DEBUG(SAT_DEBUG_UNSOLVABLE, "conflicting update/job assertions over literal %d\n", vv);
 249
 250         /*
 251          * push all of our rules (can only be feature or job rules)
 252          * asserting this literal on the problem stack
 253          */
 254
 255       for (i = solv->featurerules, rr = solv->rules + i; i < solv->learntrules; i++, rr++)
 256         {
 257           if (rr->d < 0                          /* disabled */
 258               || rr->w2)                         /*  or no assertion */
 259             continue;
 260           if (rr->p != vv                        /* not affecting the literal */
 261               && rr->p != -vv)
 262             continue;
 263           if (MAPTST(&solv->weakrulemap, i))     /* weak: silently ignore */
 264             continue;
 265
 266           POOL_DEBUG(SAT_DEBUG_UNSOLVABLE, " - disabling rule #%d\n", i);
 267
 268           solver_printruleclass(solv, SAT_DEBUG_UNSOLVABLE, solv->rules + i);
 269
 270           v = i;
 271             /* is is a job rule ? */
 272           if (i >= solv->jobrules && i < solv->jobrules_end)
 273             v = -(solv->ruletojob.elements[i - solv->jobrules] + 1);
 274
 275           queue_push(&solv->problems, v);
 276           solver_disableproblem(solv, v);
 277         }
 278       queue_push(&solv->problems, 0);
 279
 280       /*
 281        * start over
 282        * (back up from decisions)
 283        */
 284       while (solv->decisionq.count > decisionstart)
 285         {
 286           v = solv->decisionq.elements[--solv->decisionq.count];
 287           --solv->decisionq_why.count;
 288           vv = v > 0 ? v : -v;
 289           solv->decisionmap[vv] = 0;
 290         }
 291       ii = -1; /* restarts loop at 0 */
 292     }
 293
 294   /*
 295    * phase 2: now do the weak assertions
 296    */
 297   for (ii = 0; ii < solv->ruleassertions.count; ii++)
 298     {
 299       ri = solv->ruleassertions.elements[ii];
 300       r = solv->rules + ri;
 301       if (r->d < 0 || r->w2)                     /* disabled or no assertion */
 302         continue;
 303       if (ri >= solv->learntrules || !MAPTST(&solv->weakrulemap, ri))       /* skip non-weak */
 304         continue;
 305       v = r->p;
 306       vv = v > 0 ? v : -v;
 307       /*
 308        * decide !
 309        * (if not yet decided)
 310        */
 311       if (!solv->decisionmap[vv])
 312         {
 313           queue_push(&solv->decisionq, v);
 314           queue_push(&solv->decisionq_why, r - solv->rules);
 315           solv->decisionmap[vv] = v > 0 ? 1 : -1;
 316           IF_POOLDEBUG (SAT_DEBUG_PROPAGATE)
 317             {
 318               Solvable *s = solv->pool->solvables + vv;
 319               if (v < 0)
 320                 POOL_DEBUG(SAT_DEBUG_PROPAGATE, "conflicting %s (weak assertion)\n", solvable2str(solv->pool, s));
 321               else
 322                 POOL_DEBUG(SAT_DEBUG_PROPAGATE, "installing  %s (weak assertion)\n", solvable2str(solv->pool, s));
 323             }
 324           continue;
 325         }
 326       /*
 327        * previously decided, sane ?
 328        */
 329       if (v > 0 && solv->decisionmap[vv] > 0)
 330         continue;
 331       if (v < 0 && solv->decisionmap[vv] < 0)
 332         continue;
 333
 334       POOL_DEBUG(SAT_DEBUG_UNSOLVABLE, "assertion conflict, but I am weak, disabling ");
 335       solver_printrule(solv, SAT_DEBUG_UNSOLVABLE, r);
 336
 337       if (ri >= solv->jobrules && ri < solv->jobrules_end)
 338         v = -(solv->ruletojob.elements[ri - solv->jobrules] + 1);
 339       else
 340         v = ri;
 341       solver_disableproblem(solv, v);
 342       if (v < 0)
 343         solver_reenablepolicyrules(solv, -(v + 1));
 344     }
 345
 346   POOL_DEBUG(SAT_DEBUG_SCHUBI, "----- makeruledecisions end; size decisionq: %d -----\n",solv->decisionq.count);
 347 }
 348
 349
 350 /*-------------------------------------------------------------------
 351  * enable/disable learnt rules
 352  *
 353  * we have enabled or disabled some of our rules. We now reenable all
 354  * of our learnt rules except the ones that were learnt from rules that
 355  * are now disabled.
 356  */
 357 static void
 358 enabledisablelearntrules(Solver *solv)
 359 {
 360   Pool *pool = solv->pool;
 361   Rule *r;
 362   Id why, *whyp;
 363   int i;
 364
 365   POOL_DEBUG(SAT_DEBUG_SOLUTIONS, "enabledisablelearntrules called\n");
 366   for (i = solv->learntrules, r = solv->rules + i; i < solv->nrules; i++, r++)
 367     {
 368       whyp = solv->learnt_pool.elements + solv->learnt_why.elements[i - solv->learntrules];
 369       while ((why = *whyp++) != 0)
 370         {
 371           assert(why > 0 && why < i);
 372           if (solv->rules[why].d < 0)
 373             break;
 374         }
 375       /* why != 0: we found a disabled rule, disable the learnt rule */
 376       if (why && r->d >= 0)
 377         {
 378           IF_POOLDEBUG (SAT_DEBUG_SOLUTIONS)
 379             {
 380               POOL_DEBUG(SAT_DEBUG_SOLUTIONS, "disabling ");
 381               solver_printruleclass(solv, SAT_DEBUG_SOLUTIONS, r);
 382             }
 383           solver_disablerule(solv, r);
 384         }
 385       else if (!why && r->d < 0)
 386         {
 387           IF_POOLDEBUG (SAT_DEBUG_SOLUTIONS)
 388             {
 389               POOL_DEBUG(SAT_DEBUG_SOLUTIONS, "re-enabling ");
 390               solver_printruleclass(solv, SAT_DEBUG_SOLUTIONS, r);
 391             }
 392           solver_enablerule(solv, r);
 393         }
 394     }
 395 }
 396
 397
 398 /********************************************************************/
 399 /* watches */
 400
 401
 402 /*-------------------------------------------------------------------
 403  * makewatches
 404  *
 405  * initial setup for all watches
 406  */
 407
 408 static void
 409 makewatches(Solver *solv)
 410 {
 411   Rule *r;
 412   int i;
 413   int nsolvables = solv->pool->nsolvables;
 414
 415   sat_free(solv->watches);
 416                                        /* lower half for removals, upper half for installs */
 417   solv->watches = sat_calloc(2 * nsolvables, sizeof(Id));
 418 #if 1
 419   /* do it reverse so rpm rules get triggered first (XXX: obsolete?) */
 420   for (i = 1, r = solv->rules + solv->nrules - 1; i < solv->nrules; i++, r--)
 421 #else
 422   for (i = 1, r = solv->rules + 1; i < solv->nrules; i++, r++)
 423 #endif
 424     {
 425       if (!r->w2)               /* assertions do not need watches */
 426         continue;
 427
 428       /* see addwatches_rule(solv, r) */
 429       r->n1 = solv->watches[nsolvables + r->w1];
 430       solv->watches[nsolvables + r->w1] = r - solv->rules;
 431
 432       r->n2 = solv->watches[nsolvables + r->w2];
 433       solv->watches[nsolvables + r->w2] = r - solv->rules;
 434     }
 435 }
 436
 437
 438 /*-------------------------------------------------------------------
 439  *
 440  * add watches (for a new learned rule)
 441  * sets up watches for a single rule
 442  *
 443  * see also makewatches() above.
 444  */
 445
 446 static inline void
 447 addwatches_rule(Solver *solv, Rule *r)
 448 {
 449   int nsolvables = solv->pool->nsolvables;
 450
 451   r->n1 = solv->watches[nsolvables + r->w1];
 452   solv->watches[nsolvables + r->w1] = r - solv->rules;
 453
 454   r->n2 = solv->watches[nsolvables + r->w2];
 455   solv->watches[nsolvables + r->w2] = r - solv->rules;
 456 }
 457
 458
 459 /********************************************************************/
 460 /*
 461  * rule propagation
 462  */
 463
 464
 465 /* shortcuts to check if a literal (positive or negative) assignment
 466  * evaluates to 'true' or 'false'
 467  */
 468 #define DECISIONMAP_TRUE(p) ((p) > 0 ? (decisionmap[p] > 0) : (decisionmap[-p] < 0))
 469 #define DECISIONMAP_FALSE(p) ((p) > 0 ? (decisionmap[p] < 0) : (decisionmap[-p] > 0))
 470 #define DECISIONMAP_UNDEF(p) (decisionmap[(p) > 0 ? (p) : -(p)] == 0)
 471
 472 /*-------------------------------------------------------------------
 473  *
 474  * propagate
 475  *
 476  * make decision and propagate to all rules
 477  *
 478  * Evaluate each term affected by the decision (linked through watches)
 479  * If we find unit rules we make new decisions based on them
 480  *
 481  * Everything's fixed there, it's just finding rules that are
 482  * unit.
 483  *
 484  * return : 0 = everything is OK
 485  *          rule = conflict found in this rule
 486  */
 487
 488 static Rule *
 489 propagate(Solver *solv, int level)
 490 {
 491   Pool *pool = solv->pool;
 492   Id *rp, *next_rp;           /* rule pointer, next rule pointer in linked list */
 493   Rule *r;                    /* rule */
 494   Id p, pkg, other_watch;
 495   Id *dp;
 496   Id *decisionmap = solv->decisionmap;
 497
 498   Id *watches = solv->watches + pool->nsolvables;   /* place ptr in middle */
 499
 500   POOL_DEBUG(SAT_DEBUG_PROPAGATE, "----- propagate -----\n");
 501
 502   /* foreach non-propagated decision */
 503   while (solv->propagate_index < solv->decisionq.count)
 504     {
 505         /*
 506          * 'pkg' was just decided
 507          * negate because our watches trigger if literal goes FALSE
 508          */
 509       pkg = -solv->decisionq.elements[solv->propagate_index++];
 510
 511       IF_POOLDEBUG (SAT_DEBUG_PROPAGATE)
 512         {
 513           POOL_DEBUG(SAT_DEBUG_PROPAGATE, "propagate for decision %d level %d\n", -pkg, level);
 514           solver_printruleelement(solv, SAT_DEBUG_PROPAGATE, 0, -pkg);
 515         }
 516
 517       /* foreach rule where 'pkg' is now FALSE */
 518       for (rp = watches + pkg; *rp; rp = next_rp)
 519         {
 520           r = solv->rules + *rp;
 521           if (r->d < 0)
 522             {
 523               /* rule is disabled, goto next */
 524               if (pkg == r->w1)
 525                 next_rp = &r->n1;
 526               else
 527                 next_rp = &r->n2;
 528               continue;
 529             }
 530
 531           IF_POOLDEBUG (SAT_DEBUG_PROPAGATE)
 532             {
 533               POOL_DEBUG(SAT_DEBUG_PROPAGATE,"  watch triggered ");
 534               solver_printrule(solv, SAT_DEBUG_PROPAGATE, r);
 535             }
 536
 537             /* 'pkg' was just decided (was set to FALSE)
 538              *
 539              *  now find other literal watch, check clause
 540              *   and advance on linked list
 541              */
 542           if (pkg == r->w1)
 543             {
 544               other_watch = r->w2;
 545               next_rp = &r->n1;
 546             }
 547           else
 548             {
 549               other_watch = r->w1;
 550               next_rp = &r->n2;
 551             }
 552
 553             /*
 554              * This term is already true (through the other literal)
 555              * so we have nothing to do
 556              */
 557           if (DECISIONMAP_TRUE(other_watch))
 558             continue;
 559
 560             /*
 561              * The other literal is FALSE or UNDEF
 562              *
 563              */
 564
 565           if (r->d)
 566             {
 567               /* Not a binary clause, try to move our watch.
 568                *
 569                * Go over all literals and find one that is
 570                *   not other_watch
 571                *   and not FALSE
 572                *
 573                * (TRUE is also ok, in that case the rule is fulfilled)
 574                */
 575               if (r->p                                /* we have a 'p' */
 576                   && r->p != other_watch              /* which is not watched */
 577                   && !DECISIONMAP_FALSE(r->p))        /* and not FALSE */
 578                 {
 579                   p = r->p;
 580                 }
 581               else                                    /* go find a 'd' to make 'true' */
 582                 {
 583                   /* foreach p in 'd'
 584                      we just iterate sequentially, doing it in another order just changes the order of decisions, not the decisions itself
 585                    */
 586                   for (dp = pool->whatprovidesdata + r->d; (p = *dp++) != 0;)
 587                     {
 588                       if (p != other_watch              /* which is not watched */
 589                           && !DECISIONMAP_FALSE(p))     /* and not FALSE */
 590                         break;
 591                     }
 592                 }
 593
 594               if (p)
 595                 {
 596                   /*
 597                    * if we found some p that is UNDEF or TRUE, move
 598                    * watch to it
 599                    */
 600                   IF_POOLDEBUG (SAT_DEBUG_PROPAGATE)
 601                     {
 602                       if (p > 0)
 603                         POOL_DEBUG(SAT_DEBUG_PROPAGATE, "    -> move w%d to %s\n", (pkg == r->w1 ? 1 : 2), solvid2str(pool, p));
 604                       else
 605                         POOL_DEBUG(SAT_DEBUG_PROPAGATE,"    -> move w%d to !%s\n", (pkg == r->w1 ? 1 : 2), solvid2str(pool, -p));
 606                     }
 607
 608                   *rp = *next_rp;
 609                   next_rp = rp;
 610
 611                   if (pkg == r->w1)
 612                     {
 613                       r->w1 = p;
 614                       r->n1 = watches[p];
 615                     }
 616                   else
 617                     {
 618                       r->w2 = p;
 619                       r->n2 = watches[p];
 620                     }
 621                   watches[p] = r - solv->rules;
 622                   continue;
 623                 }
 624               /* search failed, thus all unwatched literals are FALSE */
 625
 626             } /* not binary */
 627
 628             /*
 629              * unit clause found, set literal other_watch to TRUE
 630              */
 631
 632           if (DECISIONMAP_FALSE(other_watch))      /* check if literal is FALSE */
 633             return r;                              /* eek, a conflict! */
 634
 635           IF_POOLDEBUG (SAT_DEBUG_PROPAGATE)
 636             {
 637               POOL_DEBUG(SAT_DEBUG_PROPAGATE, "   unit ");
 638               solver_printrule(solv, SAT_DEBUG_PROPAGATE, r);
 639             }
 640
 641           if (other_watch > 0)
 642             decisionmap[other_watch] = level;    /* install! */
 643           else
 644             decisionmap[-other_watch] = -level;  /* remove! */
 645
 646           queue_push(&solv->decisionq, other_watch);
 647           queue_push(&solv->decisionq_why, r - solv->rules);
 648
 649           IF_POOLDEBUG (SAT_DEBUG_PROPAGATE)
 650             {
 651               if (other_watch > 0)
 652                 POOL_DEBUG(SAT_DEBUG_PROPAGATE, "    -> decided to install %s\n", solvid2str(pool, other_watch));
 653               else
 654                 POOL_DEBUG(SAT_DEBUG_PROPAGATE, "    -> decided to conflict %s\n", solvid2str(pool, -other_watch));
 655             }
 656
 657         } /* foreach rule involving 'pkg' */
 658
 659     } /* while we have non-decided decisions */
 660
 661   POOL_DEBUG(SAT_DEBUG_PROPAGATE, "----- propagate end-----\n");
 662
 663   return 0;     /* all is well */
 664 }
 665
 666
 667 /********************************************************************/
 668 /* Analysis */
 669
 670 /*-------------------------------------------------------------------
 671  *
 672  * analyze
 673  *   and learn
 674  */
 675
 676 static int
 677 analyze(Solver *solv, int level, Rule *c, int *pr, int *dr, int *whyp)
 678 {
 679   Pool *pool = solv->pool;
 680   Queue r;
 681   int rlevel = 1;
 682   Map seen;             /* global? */
 683   Id d, v, vv, *dp, why;
 684   int l, i, idx;
 685   int num = 0, l1num = 0;
 686   int learnt_why = solv->learnt_pool.count;
 687   Id *decisionmap = solv->decisionmap;
 688
 689   queue_init(&r);
 690
 691   POOL_DEBUG(SAT_DEBUG_ANALYZE, "ANALYZE at %d ----------------------\n", level);
 692   map_init(&seen, pool->nsolvables);
 693   idx = solv->decisionq.count;
 694   for (;;)
 695     {
 696       IF_POOLDEBUG (SAT_DEBUG_ANALYZE)
 697         solver_printruleclass(solv, SAT_DEBUG_ANALYZE, c);
 698       queue_push(&solv->learnt_pool, c - solv->rules);
 699       d = c->d < 0 ? -c->d - 1 : c->d;
 700       dp = d ? pool->whatprovidesdata + d : 0;
 701       /* go through all literals of the rule */
 702       for (i = -1; ; i++)
 703         {
 704           if (i == -1)
 705             v = c->p;
 706           else if (d == 0)
 707             v = i ? 0 : c->w2;
 708           else
 709             v = *dp++;
 710           if (v == 0)
 711             break;
 712
 713           if (DECISIONMAP_TRUE(v))      /* the one true literal */
 714             continue;
 715           vv = v > 0 ? v : -v;
 716           if (MAPTST(&seen, vv))
 717             continue;
 718           l = solv->decisionmap[vv];
 719           if (l < 0)
 720             l = -l;
 721           MAPSET(&seen, vv);
 722           if (l == 1)
 723             l1num++;                    /* need to do this one in level1 pass */
 724           else if (l == level)
 725             num++;                      /* need to do this one as well */
 726           else
 727             {
 728               queue_push(&r, v);        /* not level1 or conflict level, add to new rule */
 729               if (l > rlevel)
 730                 rlevel = l;
 731             }
 732         }
 733 l1retry:
 734       if (!num && !--l1num)
 735         break;  /* all level 1 literals done */
 736       for (;;)
 737         {
 738           assert(idx > 0);
 739           v = solv->decisionq.elements[--idx];
 740           vv = v > 0 ? v : -v;
 741           if (MAPTST(&seen, vv))
 742             break;
 743         }
 744       MAPCLR(&seen, vv);
 745       if (num && --num == 0)
 746         {
 747           *pr = -v;     /* so that v doesn't get lost */
 748           if (!l1num)
 749             break;
 750           POOL_DEBUG(SAT_DEBUG_ANALYZE, "got %d involved level 1 decisions\n", l1num);
 751           for (i = 0; i < r.count; i++)
 752             {
 753               v = r.elements[i];
 754               MAPCLR(&seen, v > 0 ? v : -v);
 755             }
 756           /* only level 1 marks left */
 757           l1num++;
 758           goto l1retry;
 759         }
 760       why = solv->decisionq_why.elements[idx];
 761       if (why <= 0)     /* just in case, maybe for SYSTEMSOLVABLE */
 762         goto l1retry;
 763       c = solv->rules + why;
 764     }
 765   map_free(&seen);
 766
 767   if (r.count == 0)
 768     *dr = 0;
 769   else if (r.count == 1 && r.elements[0] < 0)
 770     *dr = r.elements[0];
 771   else
 772     *dr = pool_queuetowhatprovides(pool, &r);
 773   IF_POOLDEBUG (SAT_DEBUG_ANALYZE)
 774     {
 775       POOL_DEBUG(SAT_DEBUG_ANALYZE, "learned rule for level %d (am %d)\n", rlevel, level);
 776       solver_printruleelement(solv, SAT_DEBUG_ANALYZE, 0, *pr);
 777       for (i = 0; i < r.count; i++)
 778         solver_printruleelement(solv, SAT_DEBUG_ANALYZE, 0, r.elements[i]);
 779     }
 780   /* push end marker on learnt reasons stack */
 781   queue_push(&solv->learnt_pool, 0);
 782   if (whyp)
 783     *whyp = learnt_why;
 784   solv->stats_learned++;
 785   return rlevel;
 786 }
 787
 788
 789 /*-------------------------------------------------------------------
 790  *
 791  * solver_reset
 792  *
 793  * reset the solver decisions to right after the rpm rules.
 794  * called after rules have been enabled/disabled
 795  */
 796
 797 void
 798 solver_reset(Solver *solv)
 799 {
 800   Pool *pool = solv->pool;
 801   int i;
 802   Id v;
 803
 804   /* rewind all decisions */
 805   for (i = solv->decisionq.count - 1; i >= 0; i--)
 806     {
 807       v = solv->decisionq.elements[i];
 808       solv->decisionmap[v > 0 ? v : -v] = 0;
 809     }
 810   solv->decisionq_why.count = 0;
 811   solv->decisionq.count = 0;
 812   solv->recommends_index = -1;
 813   solv->propagate_index = 0;
 814   solv->recommendations.count = 0;
 815   solv->branches.count = 0;
 816
 817   /* adapt learnt rule status to new set of enabled/disabled rules */
 818   enabledisablelearntrules(solv);
 819
 820   /* redo all job/update decisions */
 821   makeruledecisions(solv);
 822   POOL_DEBUG(SAT_DEBUG_UNSOLVABLE, "decisions so far: %d\n", solv->decisionq.count);
 823 }
 824
 825
 826 /*-------------------------------------------------------------------
 827  *
 828  * analyze_unsolvable_rule
 829  */
 830
 831 static void
 832 analyze_unsolvable_rule(Solver *solv, Rule *r, Id *lastweakp)
 833 {
 834   Pool *pool = solv->pool;
 835   int i;
 836   Id why = r - solv->rules;
 837
 838   IF_POOLDEBUG (SAT_DEBUG_UNSOLVABLE)
 839     solver_printruleclass(solv, SAT_DEBUG_UNSOLVABLE, r);
 840   if (solv->learntrules && why >= solv->learntrules)
 841     {
 842       for (i = solv->learnt_why.elements[why - solv->learntrules]; solv->learnt_pool.elements[i]; i++)
 843         if (solv->learnt_pool.elements[i] > 0)
 844           analyze_unsolvable_rule(solv, solv->rules + solv->learnt_pool.elements[i], lastweakp);
 845       return;
 846     }
 847   if (MAPTST(&solv->weakrulemap, why))
 848     if (!*lastweakp || why > *lastweakp)
 849       *lastweakp = why;
 850   /* do not add rpm rules to problem */
 851   if (why < solv->rpmrules_end)
 852     return;
 853   /* turn rule into problem */
 854   if (why >= solv->jobrules && why < solv->jobrules_end)
 855     why = -(solv->ruletojob.elements[why - solv->jobrules] + 1);
 856   /* normalize dup/infarch rules */
 857   if (why > solv->infarchrules && why < solv->infarchrules_end)
 858     {
 859       Id name = pool->solvables[-solv->rules[why].p].name;
 860       while (why > solv->infarchrules && pool->solvables[-solv->rules[why - 1].p].name == name)
 861         why--;
 862     }
 863   if (why > solv->duprules && why < solv->duprules_end)
 864     {
 865       Id name = pool->solvables[-solv->rules[why].p].name;
 866       while (why > solv->duprules && pool->solvables[-solv->rules[why - 1].p].name == name)
 867         why--;
 868     }
 869
 870   /* return if problem already countains our rule */
 871   if (solv->problems.count)
 872     {
 873       for (i = solv->problems.count - 1; i >= 0; i--)
 874         if (solv->problems.elements[i] == 0)    /* end of last problem reached? */
 875           break;
 876         else if (solv->problems.elements[i] == why)
 877           return;
 878     }
 879   queue_push(&solv->problems, why);
 880 }
 881
 882
 883 /*-------------------------------------------------------------------
 884  *
 885  * analyze_unsolvable
 886  *
 887  * return: 1 - disabled some rules, try again
 888  *         0 - hopeless
 889  */
 890
 891 static int
 892 analyze_unsolvable(Solver *solv, Rule *cr, int disablerules)
 893 {
 894   Pool *pool = solv->pool;
 895   Rule *r;
 896   Map seen;             /* global to speed things up? */
 897   Id d, v, vv, *dp, why;
 898   int l, i, idx;
 899   Id *decisionmap = solv->decisionmap;
 900   int oldproblemcount;
 901   int oldlearntpoolcount;
 902   Id lastweak;
 903
 904   POOL_DEBUG(SAT_DEBUG_UNSOLVABLE, "ANALYZE UNSOLVABLE ----------------------\n");
 905   solv->stats_unsolvable++;
 906   oldproblemcount = solv->problems.count;
 907   oldlearntpoolcount = solv->learnt_pool.count;
 908
 909   /* make room for proof index */
 910   /* must update it later, as analyze_unsolvable_rule would confuse
 911    * it with a rule index if we put the real value in already */
 912   queue_push(&solv->problems, 0);
 913
 914   r = cr;
 915   map_init(&seen, pool->nsolvables);
 916   queue_push(&solv->learnt_pool, r - solv->rules);
 917   lastweak = 0;
 918   analyze_unsolvable_rule(solv, r, &lastweak);
 919   d = r->d < 0 ? -r->d - 1 : r->d;
 920   dp = d ? pool->whatprovidesdata + d : 0;
 921   for (i = -1; ; i++)
 922     {
 923       if (i == -1)
 924         v = r->p;
 925       else if (d == 0)
 926         v = i ? 0 : r->w2;
 927       else
 928         v = *dp++;
 929       if (v == 0)
 930         break;
 931       if (DECISIONMAP_TRUE(v))  /* the one true literal */
 932           continue;
 933       vv = v > 0 ? v : -v;
 934       l = solv->decisionmap[vv];
 935       if (l < 0)
 936         l = -l;
 937       MAPSET(&seen, vv);
 938     }
 939   idx = solv->decisionq.count;
 940   while (idx > 0)
 941     {
 942       v = solv->decisionq.elements[--idx];
 943       vv = v > 0 ? v : -v;
 944       if (!MAPTST(&seen, vv))
 945         continue;
 946       why = solv->decisionq_why.elements[idx];
 947       assert(why > 0);
 948       queue_push(&solv->learnt_pool, why);
 949       r = solv->rules + why;
 950       analyze_unsolvable_rule(solv, r, &lastweak);
 951       d = r->d < 0 ? -r->d - 1 : r->d;
 952       dp = d ? pool->whatprovidesdata + d : 0;
 953       for (i = -1; ; i++)
 954         {
 955           if (i == -1)
 956             v = r->p;
 957           else if (d == 0)
 958             v = i ? 0 : r->w2;
 959           else
 960             v = *dp++;
 961           if (v == 0)
 962             break;
 963           if (DECISIONMAP_TRUE(v))      /* the one true literal */
 964               continue;
 965           vv = v > 0 ? v : -v;
 966           l = solv->decisionmap[vv];
 967           if (l < 0)
 968             l = -l;
 969           MAPSET(&seen, vv);
 970         }
 971     }
 972   map_free(&seen);
 973   queue_push(&solv->problems, 0);       /* mark end of this problem */
 974
 975   if (lastweak)
 976     {
 977       Id v;
 978       extern void disablechoicerules(Solver *solv, Rule *r);
 979       /* disable last weak rule */
 980       solv->problems.count = oldproblemcount;
 981       solv->learnt_pool.count = oldlearntpoolcount;
 982       if (lastweak >= solv->jobrules && lastweak < solv->jobrules_end)
 983         v = -(solv->ruletojob.elements[lastweak - solv->jobrules] + 1);
 984       else
 985         v = lastweak;
 986       POOL_DEBUG(SAT_DEBUG_UNSOLVABLE, "disabling ");
 987       solver_printruleclass(solv, SAT_DEBUG_UNSOLVABLE, solv->rules + lastweak);
 988       if (lastweak >= solv->choicerules && lastweak < solv->choicerules_end)
 989         disablechoicerules(solv, solv->rules + lastweak);
 990       solver_disableproblem(solv, v);
 991       if (v < 0)
 992         solver_reenablepolicyrules(solv, -(v + 1));
 993       solver_reset(solv);
 994       return 1;
 995     }
 996
 997   /* finish proof */
 998   queue_push(&solv->learnt_pool, 0);
 999   solv->problems.elements[oldproblemcount] = oldlearntpoolcount;
1000
1001   if (disablerules)
1002     {
1003       for (i = oldproblemcount + 1; i < solv->problems.count - 1; i++)
1004         solver_disableproblem(solv, solv->problems.elements[i]);
1005       /* XXX: might want to enable all weak rules again */
1006       solver_reset(solv);
1007       return 1;
1008     }
1009   POOL_DEBUG(SAT_DEBUG_UNSOLVABLE, "UNSOLVABLE\n");
1010   return 0;
1011 }
1012
1013
1014 /********************************************************************/
1015 /* Decision revert */
1016
1017 /*-------------------------------------------------------------------
1018  *
1019  * revert
1020  * revert decision at level
1021  */
1022
1023 static void
1024 revert(Solver *solv, int level)
1025 {
1026   Pool *pool = solv->pool;
1027   Id v, vv;
1028   while (solv->decisionq.count)
1029     {
1030       v = solv->decisionq.elements[solv->decisionq.count - 1];
1031       vv = v > 0 ? v : -v;
1032       if (solv->decisionmap[vv] <= level && solv->decisionmap[vv] >= -level)
1033         break;
1034       POOL_DEBUG(SAT_DEBUG_PROPAGATE, "reverting decision %d at %d\n", v, solv->decisionmap[vv]);
1035       if (v > 0 && solv->recommendations.count && v == solv->recommendations.elements[solv->recommendations.count - 1])
1036         solv->recommendations.count--;
1037       solv->decisionmap[vv] = 0;
1038       solv->decisionq.count--;
1039       solv->decisionq_why.count--;
1040       solv->propagate_index = solv->decisionq.count;
1041     }
1042   while (solv->branches.count && solv->branches.elements[solv->branches.count - 1] <= -level)
1043     {
1044       solv->branches.count--;
1045       while (solv->branches.count && solv->branches.elements[solv->branches.count - 1] >= 0)
1046         solv->branches.count--;
1047     }
1048   solv->recommends_index = -1;
1049 }
1050
1051
1052 /*-------------------------------------------------------------------
1053  *
1054  * watch2onhighest - put watch2 on literal with highest level
1055  */
1056
1057 static inline void
1058 watch2onhighest(Solver *solv, Rule *r)
1059 {
1060   int l, wl = 0;
1061   Id d, v, *dp;
1062
1063   d = r->d < 0 ? -r->d - 1 : r->d;
1064   if (!d)
1065     return;     /* binary rule, both watches are set */
1066   dp = solv->pool->whatprovidesdata + d;
1067   while ((v = *dp++) != 0)
1068     {
1069       l = solv->decisionmap[v < 0 ? -v : v];
1070       if (l < 0)
1071         l = -l;
1072       if (l > wl)
1073         {
1074           r->w2 = dp[-1];
1075           wl = l;
1076         }
1077     }
1078 }
1079
1080
1081 /*-------------------------------------------------------------------
1082  *
1083  * setpropagatelearn
1084  *
1085  * add free decision (solvable to install) to decisionq
1086  * increase level and propagate decision
1087  * return if no conflict.
1088  *
1089  * in conflict case, analyze conflict rule, add resulting
1090  * rule to learnt rule set, make decision from learnt
1091  * rule (always unit) and re-propagate.
1092  *
1093  * returns the new solver level or 0 if unsolvable
1094  *
1095  */
1096
1097 static int
1098 setpropagatelearn(Solver *solv, int level, Id decision, int disablerules, Id ruleid)
1099 {
1100   Pool *pool = solv->pool;
1101   Rule *r;
1102   Id p = 0, d = 0;
1103   int l, why;
1104
1105   assert(ruleid >= 0);
1106   if (decision)
1107     {
1108       level++;
1109       if (decision > 0)
1110         solv->decisionmap[decision] = level;
1111       else
1112         solv->decisionmap[-decision] = -level;
1113       queue_push(&solv->decisionq, decision);
1114       queue_push(&solv->decisionq_why, -ruleid);        /* <= 0 -> free decision */
1115     }
1116   for (;;)
1117     {
1118       r = propagate(solv, level);
1119       if (!r)
1120         break;
1121       if (level == 1)
1122         return analyze_unsolvable(solv, r, disablerules);
1123       POOL_DEBUG(SAT_DEBUG_ANALYZE, "conflict with rule #%d\n", (int)(r - solv->rules));
1124       l = analyze(solv, level, r, &p, &d, &why);        /* learnt rule in p and d */
1125       assert(l > 0 && l < level);
1126       POOL_DEBUG(SAT_DEBUG_ANALYZE, "reverting decisions (level %d -> %d)\n", level, l);
1127       level = l;
1128       revert(solv, level);
1129       r = solver_addrule(solv, p, d);
1130       assert(r);
1131       assert(solv->learnt_why.count == (r - solv->rules) - solv->learntrules);
1132       queue_push(&solv->learnt_why, why);
1133       if (d)
1134         {
1135           /* at least 2 literals, needs watches */
1136           watch2onhighest(solv, r);
1137           addwatches_rule(solv, r);
1138         }
1139       else
1140         {
1141           /* learnt rule is an assertion */
1142           queue_push(&solv->ruleassertions, r - solv->rules);
1143         }
1144       /* the new rule is unit by design */
1145       solv->decisionmap[p > 0 ? p : -p] = p > 0 ? level : -level;
1146       queue_push(&solv->decisionq, p);
1147       queue_push(&solv->decisionq_why, r - solv->rules);
1148       IF_POOLDEBUG (SAT_DEBUG_ANALYZE)
1149         {
1150           POOL_DEBUG(SAT_DEBUG_ANALYZE, "decision: ");
1151           solver_printruleelement(solv, SAT_DEBUG_ANALYZE, 0, p);
1152           POOL_DEBUG(SAT_DEBUG_ANALYZE, "new rule: ");
1153           solver_printrule(solv, SAT_DEBUG_ANALYZE, r);
1154         }
1155     }
1156   return level;
1157 }
1158
1159
1160 /*-------------------------------------------------------------------
1161  *
1162  * select and install
1163  *
1164  * install best package from the queue. We add an extra package, inst, if
1165  * provided. See comment in weak install section.
1166  *
1167  * returns the new solver level or 0 if unsolvable
1168  *
1169  */
1170
1171 static int
1172 selectandinstall(Solver *solv, int level, Queue *dq, int disablerules, Id ruleid)
1173 {
1174   Pool *pool = solv->pool;
1175   Id p;
1176   int i;
1177
1178   if (dq->count > 1)
1179     policy_filter_unwanted(solv, dq, POLICY_MODE_CHOOSE);
1180   if (dq->count > 1)
1181     {
1182       /* XXX: didn't we already do that? */
1183       /* XXX: shouldn't we prefer installed packages? */
1184       /* XXX: move to policy.c? */
1185       /* choose the supplemented one */
1186       for (i = 0; i < dq->count; i++)
1187         if (solver_is_supplementing(solv, pool->solvables + dq->elements[i]))
1188           {
1189             dq->elements[0] = dq->elements[i];
1190             dq->count = 1;
1191             break;
1192           }
1193     }
1194   if (dq->count > 1)
1195     {
1196       /* multiple candidates, open a branch */
1197       for (i = 1; i < dq->count; i++)
1198         queue_push(&solv->branches, dq->elements[i]);
1199       queue_push(&solv->branches, -level);
1200     }
1201   p = dq->elements[0];
1202
1203   POOL_DEBUG(SAT_DEBUG_POLICY, "installing %s\n", solvid2str(pool, p));
1204
1205   return setpropagatelearn(solv, level, p, disablerules, ruleid);
1206 }
1207
1208
1209 /********************************************************************/
1210 /* Main solver interface */
1211
1212
1213 /*-------------------------------------------------------------------
1214  *
1215  * solver_create
1216  * create solver structure
1217  *
1218  * pool: all available solvables
1219  * installed: installed Solvables
1220  *
1221  *
1222  * Upon solving, rules are created to flag the Solvables
1223  * of the 'installed' Repo as installed.
1224  */
1225
1226 Solver *
1227 solver_create(Pool *pool)
1228 {
1229   Solver *solv;
1230   solv = (Solver *)sat_calloc(1, sizeof(Solver));
1231   solv->pool = pool;
1232   solv->installed = pool->installed;
1233
1234   transaction_init(&solv->trans, pool);
1235   queue_init(&solv->ruletojob);
1236   queue_init(&solv->decisionq);
1237   queue_init(&solv->decisionq_why);
1238   queue_init(&solv->problems);
1239   queue_init(&solv->suggestions);
1240   queue_init(&solv->recommendations);
1241   queue_init(&solv->orphaned);
1242   queue_init(&solv->learnt_why);
1243   queue_init(&solv->learnt_pool);
1244   queue_init(&solv->branches);
1245   queue_init(&solv->covenantq);
1246   queue_init(&solv->weakruleq);
1247   queue_init(&solv->ruleassertions);
1248
1249   map_init(&solv->recommendsmap, pool->nsolvables);
1250   map_init(&solv->suggestsmap, pool->nsolvables);
1251   map_init(&solv->noupdate, solv->installed ? solv->installed->end - solv->installed->start : 0);
1252   solv->recommends_index = 0;
1253
1254   solv->decisionmap = (Id *)sat_calloc(pool->nsolvables, sizeof(Id));
1255   solv->nrules = 1;
1256   solv->rules = sat_extend_resize(solv->rules, solv->nrules, sizeof(Rule), RULES_BLOCK);
1257   memset(solv->rules, 0, sizeof(Rule));
1258
1259   return solv;
1260 }
1261
1262
1263 /*-------------------------------------------------------------------
1264  *
1265  * solver_free
1266  */
1267
1268 void
1269 solver_free(Solver *solv)
1270 {
1271   transaction_free(&solv->trans);
1272   queue_free(&solv->job);
1273   queue_free(&solv->ruletojob);
1274   queue_free(&solv->decisionq);
1275   queue_free(&solv->decisionq_why);
1276   queue_free(&solv->learnt_why);
1277   queue_free(&solv->learnt_pool);
1278   queue_free(&solv->problems);
1279   queue_free(&solv->solutions);
1280   queue_free(&solv->suggestions);
1281   queue_free(&solv->recommendations);
1282   queue_free(&solv->orphaned);
1283   queue_free(&solv->branches);
1284   queue_free(&solv->covenantq);
1285   queue_free(&solv->weakruleq);
1286   queue_free(&solv->ruleassertions);
1287
1288   map_free(&solv->recommendsmap);
1289   map_free(&solv->suggestsmap);
1290   map_free(&solv->noupdate);
1291   map_free(&solv->weakrulemap);
1292   map_free(&solv->noobsoletes);
1293
1294   map_free(&solv->updatemap);
1295   map_free(&solv->fixmap);
1296   map_free(&solv->dupmap);
1297   map_free(&solv->dupinvolvedmap);
1298
1299   sat_free(solv->decisionmap);
1300   sat_free(solv->rules);
1301   sat_free(solv->watches);
1302   sat_free(solv->obsoletes);
1303   sat_free(solv->obsoletes_data);
1304   sat_free(solv->multiversionupdaters);
1305   sat_free(solv->choicerules_ref);
1306   sat_free(solv);
1307 }
1308
1309
1310 /*-------------------------------------------------------------------
1311  *
1312  * solver_run_sat
1313  *
1314  * all rules have been set up, now actually run the solver
1315  *
1316  */
1317
1318 void
1319 solver_run_sat(Solver *solv, int disablerules, int doweak)
1320 {
1321   Queue dq;             /* local decisionqueue */
1322   Queue dqs;            /* local decisionqueue for supplements */
1323   int systemlevel;
1324   int level, olevel;
1325   Rule *r;
1326   int i, j, n;
1327   Solvable *s;
1328   Pool *pool = solv->pool;
1329   Id p, *dp;
1330   int minimizationsteps;
1331   int installedpos = solv->installed ? solv->installed->start : 0;
1332
1333   IF_POOLDEBUG (SAT_DEBUG_RULE_CREATION)
1334     {
1335       POOL_DEBUG (SAT_DEBUG_RULE_CREATION, "number of rules: %d\n", solv->nrules);
1336       for (i = 1; i < solv->nrules; i++)
1337         solver_printruleclass(solv, SAT_DEBUG_RULE_CREATION, solv->rules + i);
1338     }
1339
1340   POOL_DEBUG(SAT_DEBUG_SOLVER, "initial decisions: %d\n", solv->decisionq.count);
1341
1342   IF_POOLDEBUG (SAT_DEBUG_SCHUBI)
1343     solver_printdecisions(solv);
1344
1345   /* start SAT algorithm */
1346   level = 1;
1347   systemlevel = level + 1;
1348   POOL_DEBUG(SAT_DEBUG_SOLVER, "solving...\n");
1349
1350   queue_init(&dq);
1351   queue_init(&dqs);
1352
1353   /*
1354    * here's the main loop:
1355    * 1) propagate new decisions (only needed once)
1356    * 2) fulfill jobs
1357    * 3) try to keep installed packages
1358    * 4) fulfill all unresolved rules
1359    * 5) install recommended packages
1360    * 6) minimalize solution if we had choices
1361    * if we encounter a problem, we rewind to a safe level and restart
1362    * with step 1
1363    */
1364
1365   minimizationsteps = 0;
1366   for (;;)
1367     {
1368       /*
1369        * initial propagation of the assertions
1370        */
1371       if (level == 1)
1372         {
1373           POOL_DEBUG(SAT_DEBUG_PROPAGATE, "propagating (propagate_index: %d;  size decisionq: %d)...\n", solv->propagate_index, solv->decisionq.count);
1374           if ((r = propagate(solv, level)) != 0)
1375             {
1376               if (analyze_unsolvable(solv, r, disablerules))
1377                 continue;
1378               queue_free(&dq);
1379               queue_free(&dqs);
1380               return;
1381             }
1382         }
1383
1384       /*
1385        * resolve jobs first
1386        */
1387      if (level < systemlevel)
1388         {
1389           POOL_DEBUG(SAT_DEBUG_SOLVER, "resolving job rules\n");
1390           for (i = solv->jobrules, r = solv->rules + i; i < solv->jobrules_end; i++, r++)
1391             {
1392               Id l;
1393               if (r->d < 0)             /* ignore disabled rules */
1394                 continue;
1395               queue_empty(&dq);
1396               FOR_RULELITERALS(l, dp, r)
1397                 {
1398                   if (l < 0)
1399                     {
1400                       if (solv->decisionmap[-l] <= 0)
1401                         break;
1402                     }
1403                   else
1404                     {
1405                       if (solv->decisionmap[l] > 0)
1406                         break;
1407                       if (solv->decisionmap[l] == 0)
1408                         queue_push(&dq, l);
1409                     }
1410                 }
1411               if (l || !dq.count)
1412                 continue;
1413               /* prune to installed if not updating */
1414               if (!solv->updatesystem && solv->installed && dq.count > 1)
1415                 {
1416                   int j, k;
1417                   for (j = k = 0; j < dq.count; j++)
1418                     {
1419                       Solvable *s = pool->solvables + dq.elements[j];
1420                       if (s->repo == solv->installed)
1421                         dq.elements[k++] = dq.elements[j];
1422                     }
1423                   if (k)
1424                     dq.count = k;
1425                 }
1426               olevel = level;
1427               level = selectandinstall(solv, level, &dq, disablerules, i);
1428               if (level == 0)
1429                 {
1430                   queue_free(&dq);
1431                   queue_free(&dqs);
1432                   return;
1433                 }
1434               if (level <= olevel)
1435                 break;
1436             }
1437           systemlevel = level + 1;
1438           if (i < solv->jobrules_end)
1439             continue;
1440         }
1441
1442
1443       /*
1444        * installed packages
1445        */
1446       if (level < systemlevel && solv->installed && solv->installed->nsolvables && !solv->installed->disabled)
1447         {
1448           Repo *installed = solv->installed;
1449           int pass;
1450
1451           POOL_DEBUG(SAT_DEBUG_SOLVER, "resolving installed packages\n");
1452           /* we use two passes if we need to update packages
1453            * to create a better user experience */
1454           for (pass = solv->updatemap.size ? 0 : 1; pass < 2; pass++)
1455             {
1456               int passlevel = level;
1457               /* start with installedpos, the position that gave us problems last time */
1458               for (i = installedpos, n = installed->start; n < installed->end; i++, n++)
1459                 {
1460                   Rule *rr;
1461                   Id d;
1462
1463                   if (i == installed->end)
1464                     i = installed->start;
1465                   s = pool->solvables + i;
1466                   if (s->repo != installed)
1467                     continue;
1468
1469                   if (solv->decisionmap[i] > 0)
1470                     continue;
1471                   /* XXX: noupdate check is probably no longer needed, as all jobs should
1472                    * already be satisfied */
1473                   if (MAPTST(&solv->noupdate, i - installed->start))
1474                     continue;
1475                   if (!pass && solv->updatemap.size && !MAPTST(&solv->updatemap, i - installed->start))
1476                     continue;           /* updates first */
1477                   r = solv->rules + solv->updaterules + (i - installed->start);
1478                   rr = r;
1479                   if (!rr->p || rr->d < 0)      /* disabled -> look at feature rule */
1480                     rr -= solv->installed->end - solv->installed->start;
1481                   if (!rr->p)           /* identical to update rule? */
1482                     rr = r;
1483                   if (!rr->p)
1484                     continue;           /* orpaned package */
1485
1486                   queue_empty(&dq);
1487                   if (solv->decisionmap[i] < 0 || solv->updatesystem || (solv->updatemap.size && MAPTST(&solv->updatemap, i - installed->start)) || rr->p != i)
1488                     {
1489                       if (solv->noobsoletes.size && solv->multiversionupdaters
1490                              && (d = solv->multiversionupdaters[i - installed->start]) != 0)
1491                         {
1492                           /* special multiversion handling, make sure best version is chosen */
1493                           queue_push(&dq, i);
1494                           while ((p = pool->whatprovidesdata[d++]) != 0)
1495                             if (solv->decisionmap[p] >= 0)
1496                               queue_push(&dq, p);
1497                           policy_filter_unwanted(solv, &dq, POLICY_MODE_CHOOSE);
1498                           p = dq.elements[0];
1499                           if (p != i && solv->decisionmap[p] == 0)
1500                             {
1501                               rr = solv->rules + solv->featurerules + (i - solv->installed->start);
1502                               if (!rr->p)               /* update rule == feature rule? */
1503                                 rr = rr - solv->featurerules + solv->updaterules;
1504                               dq.count = 1;
1505                             }
1506                           else
1507                             dq.count = 0;
1508                         }
1509                       else
1510                         {
1511                           /* update to best package */
1512                           FOR_RULELITERALS(p, dp, rr)
1513                             {
1514                               if (solv->decisionmap[p] > 0)
1515                                 {
1516                                   dq.count = 0;         /* already fulfilled */
1517                                   break;
1518                                 }
1519                               if (!solv->decisionmap[p])
1520                                 queue_push(&dq, p);
1521                             }
1522                         }
1523                     }
1524                   /* install best version */
1525                   if (dq.count)
1526                     {
1527                       olevel = level;
1528                       level = selectandinstall(solv, level, &dq, disablerules, rr - solv->rules);
1529                       if (level == 0)
1530                         {
1531                           queue_free(&dq);
1532                           queue_free(&dqs);
1533                           return;
1534                         }
1535                       if (level <= olevel)
1536                         {
1537                           if (level == 1 || level < passlevel)
1538                             break;      /* trouble */
1539                           if (level < olevel)
1540                             n = installed->start;       /* redo all */
1541                           i--;
1542                           n--;
1543                           continue;
1544                         }
1545                     }
1546                   /* if still undecided keep package */
1547                   if (solv->decisionmap[i] == 0)
1548                     {
1549                       olevel = level;
1550                       POOL_DEBUG(SAT_DEBUG_POLICY, "keeping %s\n", solvid2str(pool, i));
1551                       level = setpropagatelearn(solv, level, i, disablerules, r - solv->rules);
1552                       if (level == 0)
1553                         {
1554                           queue_free(&dq);
1555                           queue_free(&dqs);
1556                           return;
1557                         }
1558                       if (level <= olevel)
1559                         {
1560                           if (level == 1 || level < passlevel)
1561                             break;      /* trouble */
1562                           if (level < olevel)
1563                             n = installed->start;       /* redo all */
1564                           i--;
1565                           n--;
1566                           continue; /* retry with learnt rule */
1567                         }
1568                     }
1569                 }
1570               if (n < installed->end)
1571                 {
1572                   installedpos = i;     /* retry problem solvable next time */
1573                   break;                /* ran into trouble */
1574                 }
1575               installedpos = installed->start;  /* reset installedpos */
1576             }
1577           systemlevel = level + 1;
1578           if (pass < 2)
1579             continue;           /* had trouble, retry */
1580         }
1581
1582       if (level < systemlevel)
1583         systemlevel = level;
1584
1585       /*
1586        * decide
1587        */
1588       POOL_DEBUG(SAT_DEBUG_POLICY, "deciding unresolved rules\n");
1589       for (i = 1, n = 1; n < solv->nrules; i++, n++)
1590         {
1591           if (i == solv->nrules)
1592             i = 1;
1593           r = solv->rules + i;
1594           if (r->d < 0)         /* ignore disabled rules */
1595             continue;
1596           queue_empty(&dq);
1597           if (r->d == 0)
1598             {
1599               /* binary or unary rule */
1600               /* need two positive undecided literals */
1601               if (r->p < 0 || r->w2 <= 0)
1602                 continue;
1603               if (solv->decisionmap[r->p] || solv->decisionmap[r->w2])
1604                 continue;
1605               queue_push(&dq, r->p);
1606               queue_push(&dq, r->w2);
1607             }
1608           else
1609             {
1610               /* make sure that
1611                * all negative literals are installed
1612                * no positive literal is installed
1613                * i.e. the rule is not fulfilled and we
1614                * just need to decide on the positive literals
1615                */
1616               if (r->p < 0)
1617                 {
1618                   if (solv->decisionmap[-r->p] <= 0)
1619                     continue;
1620                 }
1621               else
1622                 {
1623                   if (solv->decisionmap[r->p] > 0)
1624                     continue;
1625                   if (solv->decisionmap[r->p] == 0)
1626                     queue_push(&dq, r->p);
1627                 }
1628               dp = pool->whatprovidesdata + r->d;
1629               while ((p = *dp++) != 0)
1630                 {
1631                   if (p < 0)
1632                     {
1633                       if (solv->decisionmap[-p] <= 0)
1634                         break;
1635                     }
1636                   else
1637                     {
1638                       if (solv->decisionmap[p] > 0)
1639                         break;
1640                       if (solv->decisionmap[p] == 0)
1641                         queue_push(&dq, p);
1642                     }
1643                 }
1644               if (p)
1645                 continue;
1646             }
1647           IF_POOLDEBUG (SAT_DEBUG_PROPAGATE)
1648             {
1649               POOL_DEBUG(SAT_DEBUG_PROPAGATE, "unfulfilled ");
1650               solver_printruleclass(solv, SAT_DEBUG_PROPAGATE, r);
1651             }
1652           /* dq.count < 2 cannot happen as this means that
1653            * the rule is unit */
1654           assert(dq.count > 1);
1655
1656           olevel = level;
1657           level = selectandinstall(solv, level, &dq, disablerules, r - solv->rules);
1658           if (level == 0)
1659             {
1660               queue_free(&dq);
1661               queue_free(&dqs);
1662               return;
1663             }
1664           if (level < systemlevel || level == 1)
1665             break;              /* trouble */
1666           /* something changed, so look at all rules again */
1667           n = 0;
1668         }
1669
1670       if (n != solv->nrules)    /* ran into trouble, restart */
1671         continue;
1672
1673       /* at this point we have a consistent system. now do the extras... */
1674
1675       if (doweak)
1676         {
1677           int qcount;
1678
1679           POOL_DEBUG(SAT_DEBUG_POLICY, "installing recommended packages\n");
1680           queue_empty(&dq);     /* recommended packages */
1681           queue_empty(&dqs);    /* supplemented packages */
1682           for (i = 1; i < pool->nsolvables; i++)
1683             {
1684               if (solv->decisionmap[i] < 0)
1685                 continue;
1686               if (solv->decisionmap[i] > 0)
1687                 {
1688                   /* installed, check for recommends */
1689                   Id *recp, rec, pp, p;
1690                   s = pool->solvables + i;
1691                   if (solv->ignorealreadyrecommended && s->repo == solv->installed)
1692                     continue;
1693                   /* XXX need to special case AND ? */
1694                   if (s->recommends)
1695                     {
1696                       recp = s->repo->idarraydata + s->recommends;
1697                       while ((rec = *recp++) != 0)
1698                         {
1699                           qcount = dq.count;
1700                           FOR_PROVIDES(p, pp, rec)
1701                             {
1702                               if (solv->decisionmap[p] > 0)
1703                                 {
1704                                   dq.count = qcount;
1705                                   break;
1706                                 }
1707                               else if (solv->decisionmap[p] == 0)
1708                                 {
1709                                   queue_pushunique(&dq, p);
1710                                 }
1711                             }
1712                         }
1713                     }
1714                 }
1715               else
1716                 {
1717                   s = pool->solvables + i;
1718                   if (!s->supplements)
1719                     continue;
1720                   if (!pool_installable(pool, s))
1721                     continue;
1722                   if (!solver_is_supplementing(solv, s))
1723                     continue;
1724                   queue_push(&dqs, i);
1725                 }
1726             }
1727
1728           /* filter out all packages obsoleted by installed packages */
1729           /* this is no longer needed if we have reverse obsoletes */
1730           if ((dqs.count || dq.count) && solv->installed)
1731             {
1732               Map obsmap;
1733               Id obs, *obsp, po, ppo;
1734
1735               map_init(&obsmap, pool->nsolvables);
1736               for (p = solv->installed->start; p < solv->installed->end; p++)
1737                 {
1738                   s = pool->solvables + p;
1739                   if (s->repo != solv->installed || !s->obsoletes)
1740                     continue;
1741                   if (solv->decisionmap[p] <= 0)
1742                     continue;
1743                   if (solv->noobsoletes.size && MAPTST(&solv->noobsoletes, p))
1744                     continue;
1745                   obsp = s->repo->idarraydata + s->obsoletes;
1746                   /* foreach obsoletes */
1747                   while ((obs = *obsp++) != 0)
1748                     FOR_PROVIDES(po, ppo, obs)
1749                       MAPSET(&obsmap, po);
1750                 }
1751               for (i = j = 0; i < dqs.count; i++)
1752                 if (!MAPTST(&obsmap, dqs.elements[i]))
1753                   dqs.elements[j++] = dqs.elements[i];
1754               dqs.count = j;
1755               for (i = j = 0; i < dq.count; i++)
1756                 if (!MAPTST(&obsmap, dq.elements[i]))
1757                   dq.elements[j++] = dq.elements[i];
1758               dq.count = j;
1759               map_free(&obsmap);
1760             }
1761
1762           /* filter out all already supplemented packages if requested */
1763           if (solv->ignorealreadyrecommended && dqs.count)
1764             {
1765               /* turn off all new packages */
1766               for (i = 0; i < solv->decisionq.count; i++)
1767                 {
1768                   p = solv->decisionq.elements[i];
1769                   if (p < 0)
1770                     continue;
1771                   s = pool->solvables + p;
1772                   if (s->repo && s->repo != solv->installed)
1773                     solv->decisionmap[p] = -solv->decisionmap[p];
1774                 }
1775               /* filter out old supplements */
1776               for (i = j = 0; i < dqs.count; i++)
1777                 {
1778                   p = dqs.elements[i];
1779                   s = pool->solvables + p;
1780                   if (!s->supplements)
1781                     continue;
1782                   if (!solver_is_supplementing(solv, s))
1783                     dqs.elements[j++] = p;
1784                 }
1785               dqs.count = j;
1786               /* undo turning off */
1787               for (i = 0; i < solv->decisionq.count; i++)
1788                 {
1789                   p = solv->decisionq.elements[i];
1790                   if (p < 0)
1791                     continue;
1792                   s = pool->solvables + p;
1793                   if (s->repo && s->repo != solv->installed)
1794                     solv->decisionmap[p] = -solv->decisionmap[p];
1795                 }
1796             }
1797
1798           /* multiversion doesn't mix well with supplements.
1799            * filter supplemented packages where we already decided
1800            * to install a different version (see bnc#501088) */
1801           if (dqs.count && solv->noobsoletes.size)
1802             {
1803               for (i = j = 0; i < dqs.count; i++)
1804                 {
1805                   p = dqs.elements[i];
1806                   if (MAPTST(&solv->noobsoletes, p))
1807                     {
1808                       Id p2, pp2;
1809                       s = pool->solvables + p;
1810                       FOR_PROVIDES(p2, pp2, s->name)
1811                         if (solv->decisionmap[p2] > 0 && pool->solvables[p2].name == s->name)
1812                           break;
1813                       if (p2)
1814                         continue;       /* ignore this package */
1815                     }
1816                   dqs.elements[j++] = p;
1817                 }
1818               dqs.count = j;
1819             }
1820
1821           /* make dq contain both recommended and supplemented pkgs */
1822           if (dqs.count)
1823             {
1824               for (i = 0; i < dqs.count; i++)
1825                 queue_pushunique(&dq, dqs.elements[i]);
1826             }
1827
1828           if (dq.count)
1829             {
1830               Map dqmap;
1831               int decisioncount = solv->decisionq.count;
1832
1833               if (dq.count == 1)
1834                 {
1835                   /* simple case, just one package. no need to choose  */
1836                   p = dq.elements[0];
1837                   if (dqs.count)
1838                     POOL_DEBUG(SAT_DEBUG_POLICY, "installing supplemented %s\n", solvid2str(pool, p));
1839                   else
1840                     POOL_DEBUG(SAT_DEBUG_POLICY, "installing recommended %s\n", solvid2str(pool, p));
1841                   queue_push(&solv->recommendations, p);
1842                   level = setpropagatelearn(solv, level, p, 0, 0);
1843                   continue;     /* back to main loop */
1844                 }
1845
1846               /* filter packages, this gives us the best versions */
1847               policy_filter_unwanted(solv, &dq, POLICY_MODE_RECOMMEND);
1848
1849               /* create map of result */
1850               map_init(&dqmap, pool->nsolvables);
1851               for (i = 0; i < dq.count; i++)
1852                 MAPSET(&dqmap, dq.elements[i]);
1853
1854               /* install all supplemented packages */
1855               for (i = 0; i < dqs.count; i++)
1856                 {
1857                   p = dqs.elements[i];
1858                   if (solv->decisionmap[p] || !MAPTST(&dqmap, p))
1859                     continue;
1860                   POOL_DEBUG(SAT_DEBUG_POLICY, "installing supplemented %s\n", solvid2str(pool, p));
1861                   queue_push(&solv->recommendations, p);
1862                   olevel = level;
1863                   level = setpropagatelearn(solv, level, p, 0, 0);
1864                   if (level <= olevel)
1865                     break;
1866                 }
1867               if (i < dqs.count || solv->decisionq.count < decisioncount)
1868                 {
1869                   map_free(&dqmap);
1870                   continue;
1871                 }
1872
1873               /* install all recommended packages */
1874               /* more work as we want to created branches if multiple
1875                * choices are valid */
1876               for (i = 0; i < decisioncount; i++)
1877                 {
1878                   Id rec, *recp, pp;
1879                   p = solv->decisionq.elements[i];
1880                   if (p < 0)
1881                     continue;
1882                   s = pool->solvables + p;
1883                   if (!s->repo || (solv->ignorealreadyrecommended && s->repo == solv->installed))
1884                     continue;
1885                   if (!s->recommends)
1886                     continue;
1887                   recp = s->repo->idarraydata + s->recommends;
1888                   while ((rec = *recp++) != 0)
1889                     {
1890                       queue_empty(&dq);
1891                       FOR_PROVIDES(p, pp, rec)
1892                         {
1893                           if (solv->decisionmap[p] > 0)
1894                             {
1895                               dq.count = 0;
1896                               break;
1897                             }
1898                           else if (solv->decisionmap[p] == 0 && MAPTST(&dqmap, p))
1899                             queue_pushunique(&dq, p);
1900                         }
1901                       if (!dq.count)
1902                         continue;
1903                       if (dq.count > 1)
1904                         {
1905                           /* multiple candidates, open a branch */
1906                           for (i = 1; i < dq.count; i++)
1907                             queue_push(&solv->branches, dq.elements[i]);
1908                           queue_push(&solv->branches, -level);
1909                         }
1910                       p = dq.elements[0];
1911                       POOL_DEBUG(SAT_DEBUG_POLICY, "installing recommended %s\n", solvid2str(pool, p));
1912                       queue_push(&solv->recommendations, p);
1913                       olevel = level;
1914                       level = setpropagatelearn(solv, level, p, 0, 0);
1915                       if (level <= olevel || solv->decisionq.count < decisioncount)
1916                         break;  /* we had to revert some decisions */
1917                     }
1918                   if (rec)
1919                     break;      /* had a problem above, quit loop */
1920                 }
1921               map_free(&dqmap);
1922
1923               continue;         /* back to main loop so that all deps are checked */
1924             }
1925         }
1926
1927      if (solv->distupgrade && solv->installed)
1928         {
1929           int installedone = 0;
1930
1931           /* let's see if we can install some unsupported package */
1932           POOL_DEBUG(SAT_DEBUG_SOLVER, "deciding unsupported packages\n");
1933           for (i = 0; i < solv->orphaned.count; i++)
1934             {
1935               p = solv->orphaned.elements[i];
1936               if (solv->decisionmap[p])
1937                 continue;       /* already decided */
1938               olevel = level;
1939               if (solv->distupgrade_removeunsupported)
1940                 {
1941                   POOL_DEBUG(SAT_DEBUG_SOLVER, "removing unsupported %s\n", solvid2str(pool, p));
1942                   level = setpropagatelearn(solv, level, -p, 0, 0);
1943                 }
1944               else
1945                 {
1946                   POOL_DEBUG(SAT_DEBUG_SOLVER, "keeping unsupported %s\n", solvid2str(pool, p));
1947                   level = setpropagatelearn(solv, level, p, 0, 0);
1948                   installedone = 1;
1949                 }
1950               if (level < olevel)
1951                 break;
1952             }
1953           if (installedone || i < solv->orphaned.count)
1954             continue;           /* back to main loop */
1955         }
1956
1957      if (solv->solution_callback)
1958         {
1959           solv->solution_callback(solv, solv->solution_callback_data);
1960           if (solv->branches.count)
1961             {
1962               int i = solv->branches.count - 1;
1963               int l = -solv->branches.elements[i];
1964               Id why;
1965
1966               for (; i > 0; i--)
1967                 if (solv->branches.elements[i - 1] < 0)
1968                   break;
1969               p = solv->branches.elements[i];
1970               POOL_DEBUG(SAT_DEBUG_SOLVER, "branching with %s\n", solvid2str(pool, p));
1971               queue_empty(&dq);
1972               for (j = i + 1; j < solv->branches.count; j++)
1973                 queue_push(&dq, solv->branches.elements[j]);
1974               solv->branches.count = i;
1975               level = l;
1976               revert(solv, level);
1977               if (dq.count > 1)
1978                 for (j = 0; j < dq.count; j++)
1979                   queue_push(&solv->branches, dq.elements[j]);
1980               olevel = level;
1981               why = -solv->decisionq_why.elements[solv->decisionq_why.count];
1982               assert(why >= 0);
1983               level = setpropagatelearn(solv, level, p, disablerules, why);
1984               if (level == 0)
1985                 {
1986                   queue_free(&dq);
1987                   queue_free(&dqs);
1988                   return;
1989                 }
1990               continue;
1991             }
1992           /* all branches done, we're finally finished */
1993           break;
1994         }
1995
1996       /* minimization step */
1997      if (solv->branches.count)
1998         {
1999           int l = 0, lasti = -1, lastl = -1;
2000           Id why;
2001
2002           p = 0;
2003           for (i = solv->branches.count - 1; i >= 0; i--)
2004             {
2005               p = solv->branches.elements[i];
2006               if (p < 0)
2007                 l = -p;
2008               else if (p > 0 && solv->decisionmap[p] > l + 1)
2009                 {
2010                   lasti = i;
2011                   lastl = l;
2012                 }
2013             }
2014           if (lasti >= 0)
2015             {
2016               /* kill old solvable so that we do not loop */
2017               p = solv->branches.elements[lasti];
2018               solv->branches.elements[lasti] = 0;
2019               POOL_DEBUG(SAT_DEBUG_SOLVER, "minimizing %d -> %d with %s\n", solv->decisionmap[p], lastl, solvid2str(pool, p));
2020               minimizationsteps++;
2021
2022               level = lastl;
2023               revert(solv, level);
2024               why = -solv->decisionq_why.elements[solv->decisionq_why.count];
2025               assert(why >= 0);
2026               olevel = level;
2027               level = setpropagatelearn(solv, level, p, disablerules, why);
2028               if (level == 0)
2029                 {
2030                   queue_free(&dq);
2031                   queue_free(&dqs);
2032                   return;
2033                 }
2034               continue;         /* back to main loop */
2035             }
2036         }
2037       /* no minimization found, we're finally finished! */
2038       break;
2039     }
2040
2041   POOL_DEBUG(SAT_DEBUG_STATS, "solver statistics: %d learned rules, %d unsolvable, %d minimization steps\n", solv->stats_learned, solv->stats_unsolvable, minimizationsteps);
2042
2043   POOL_DEBUG(SAT_DEBUG_STATS, "done solving.\n\n");
2044   queue_free(&dq);
2045   queue_free(&dqs);
2046 #if 0
2047   solver_printdecisionq(solv, SAT_DEBUG_RESULT);
2048 #endif
2049 }
2050
2051
2052 /*-------------------------------------------------------------------
2053  *
2054  * remove disabled conflicts
2055  *
2056  * purpose: update the decisionmap after some rules were disabled.
2057  * this is used to calculate the suggested/recommended package list.
2058  * Also returns a "removed" list to undo the discisionmap changes.
2059  */
2060
2061 static void
2062 removedisabledconflicts(Solver *solv, Queue *removed)
2063 {
2064   Pool *pool = solv->pool;
2065   int i, n;
2066   Id p, why, *dp;
2067   Id new;
2068   Rule *r;
2069   Id *decisionmap = solv->decisionmap;
2070
2071   POOL_DEBUG(SAT_DEBUG_SCHUBI, "removedisabledconflicts\n");
2072   queue_empty(removed);
2073   for (i = 0; i < solv->decisionq.count; i++)
2074     {
2075       p = solv->decisionq.elements[i];
2076       if (p > 0)
2077         continue;
2078       /* a conflict. we never do conflicts on free decisions, so there
2079        * must have been an unit rule */
2080       why = solv->decisionq_why.elements[i];
2081       assert(why > 0);
2082       r = solv->rules + why;
2083       if (r->d < 0 && decisionmap[-p])
2084         {
2085           /* rule is now disabled, remove from decisionmap */
2086           POOL_DEBUG(SAT_DEBUG_SCHUBI, "removing conflict for package %s[%d]\n", solvid2str(pool, -p), -p);
2087           queue_push(removed, -p);
2088           queue_push(removed, decisionmap[-p]);
2089           decisionmap[-p] = 0;
2090         }
2091     }
2092   if (!removed->count)
2093     return;
2094   /* we removed some confliced packages. some of them might still
2095    * be in conflict, so search for unit rules and re-conflict */
2096   new = 0;
2097   for (i = n = 1, r = solv->rules + i; n < solv->nrules; i++, r++, n++)
2098     {
2099       if (i == solv->nrules)
2100         {
2101           i = 1;
2102           r = solv->rules + i;
2103         }
2104       if (r->d < 0)
2105         continue;
2106       if (!r->w2)
2107         {
2108           if (r->p < 0 && !decisionmap[-r->p])
2109             new = r->p;
2110         }
2111       else if (!r->d)
2112         {
2113           /* binary rule */
2114           if (r->p < 0 && decisionmap[-r->p] == 0 && DECISIONMAP_FALSE(r->w2))
2115             new = r->p;
2116           else if (r->w2 < 0 && decisionmap[-r->w2] == 0 && DECISIONMAP_FALSE(r->p))
2117             new = r->w2;
2118         }
2119       else
2120         {
2121           if (r->p < 0 && decisionmap[-r->p] == 0)
2122             new = r->p;
2123           if (new || DECISIONMAP_FALSE(r->p))
2124             {
2125               dp = pool->whatprovidesdata + r->d;
2126               while ((p = *dp++) != 0)
2127                 {
2128                   if (new && p == new)
2129                     continue;
2130                   if (p < 0 && decisionmap[-p] == 0)
2131                     {
2132                       if (new)
2133                         {
2134                           new = 0;
2135                           break;
2136                         }
2137                       new = p;
2138                     }
2139                   else if (!DECISIONMAP_FALSE(p))
2140                     {
2141                       new = 0;
2142                       break;
2143                     }
2144                 }
2145             }
2146         }
2147       if (new)
2148         {
2149           POOL_DEBUG(SAT_DEBUG_SCHUBI, "re-conflicting package %s[%d]\n", solvid2str(pool, -new), -new);
2150           decisionmap[-new] = -1;
2151           new = 0;
2152           n = 0;        /* redo all rules */
2153         }
2154     }
2155 }
2156
2157 static inline void
2158 undo_removedisabledconflicts(Solver *solv, Queue *removed)
2159 {
2160   int i;
2161   for (i = 0; i < removed->count; i += 2)
2162     solv->decisionmap[removed->elements[i]] = removed->elements[i + 1];
2163 }
2164
2165
2166 /*-------------------------------------------------------------------
2167  *
2168  * weaken solvable dependencies
2169  */
2170
2171 static void
2172 weaken_solvable_deps(Solver *solv, Id p)
2173 {
2174   int i;
2175   Rule *r;
2176
2177   for (i = 1, r = solv->rules + i; i < solv->rpmrules_end; i++, r++)
2178     {
2179       if (r->p != -p)
2180         continue;
2181       if ((r->d == 0 || r->d == -1) && r->w2 < 0)
2182         continue;       /* conflict */
2183       queue_push(&solv->weakruleq, i);
2184     }
2185 }
2186
2187
2188 /********************************************************************/
2189 /* main() */
2190
2191
2192 static void
2193 findrecommendedsuggested(Solver *solv)
2194 {
2195   Pool *pool = solv->pool;
2196   Queue redoq, disabledq;
2197   int goterase, i;
2198   Solvable *s;
2199   Rule *r;
2200   Map obsmap;
2201
2202   map_init(&obsmap, pool->nsolvables);
2203   if (solv->installed)
2204     {
2205       Id obs, *obsp, p, po, ppo;
2206       for (p = solv->installed->start; p < solv->installed->end; p++)
2207         {
2208           s = pool->solvables + p;
2209           if (s->repo != solv->installed || !s->obsoletes)
2210             continue;
2211           if (solv->decisionmap[p] <= 0)
2212             continue;
2213           if (solv->noobsoletes.size && MAPTST(&solv->noobsoletes, p))
2214             continue;
2215           obsp = s->repo->idarraydata + s->obsoletes;
2216           /* foreach obsoletes */
2217           while ((obs = *obsp++) != 0)
2218             FOR_PROVIDES(po, ppo, obs)
2219               MAPSET(&obsmap, po);
2220         }
2221     }
2222
2223   queue_init(&redoq);
2224   queue_init(&disabledq);
2225   goterase = 0;
2226   /* disable all erase jobs (including weak "keep uninstalled" rules) */
2227   for (i = solv->jobrules, r = solv->rules + i; i < solv->jobrules_end; i++, r++)
2228     {
2229       if (r->d < 0)     /* disabled ? */
2230         continue;
2231       if (r->p >= 0)    /* install job? */
2232         continue;
2233       queue_push(&disabledq, i);
2234       solver_disablerule(solv, r);
2235       goterase++;
2236     }
2237
2238   if (goterase)
2239     {
2240       enabledisablelearntrules(solv);
2241       removedisabledconflicts(solv, &redoq);
2242     }
2243
2244   /*
2245    * find recommended packages
2246    */
2247
2248   /* if redoq.count == 0 we already found all recommended in the
2249    * solver run */
2250   if (redoq.count || solv->dontinstallrecommended || !solv->dontshowinstalledrecommended || solv->ignorealreadyrecommended)
2251     {
2252       Id rec, *recp, p, pp;
2253
2254       /* create map of all recommened packages */
2255       solv->recommends_index = -1;
2256       MAPZERO(&solv->recommendsmap);
2257       for (i = 0; i < solv->decisionq.count; i++)
2258         {
2259           p = solv->decisionq.elements[i];
2260           if (p < 0)
2261             continue;
2262           s = pool->solvables + p;
2263           if (s->recommends)
2264             {
2265               recp = s->repo->idarraydata + s->recommends;
2266               while ((rec = *recp++) != 0)
2267                 {
2268                   FOR_PROVIDES(p, pp, rec)
2269                     if (solv->decisionmap[p] > 0)
2270                       break;
2271                   if (p)
2272                     {
2273                       if (!solv->dontshowinstalledrecommended)
2274                         {
2275                           FOR_PROVIDES(p, pp, rec)
2276                             if (solv->decisionmap[p] > 0)
2277                               MAPSET(&solv->recommendsmap, p);
2278                         }
2279                       continue; /* p != 0: already fulfilled */
2280                     }
2281                   FOR_PROVIDES(p, pp, rec)
2282                     MAPSET(&solv->recommendsmap, p);
2283                 }
2284             }
2285         }
2286       for (i = 1; i < pool->nsolvables; i++)
2287         {
2288           if (solv->decisionmap[i] < 0)
2289             continue;
2290           if (solv->decisionmap[i] > 0 && solv->dontshowinstalledrecommended)
2291             continue;
2292           if (MAPTST(&obsmap, i))
2293             continue;
2294           s = pool->solvables + i;
2295           if (!MAPTST(&solv->recommendsmap, i))
2296             {
2297               if (!s->supplements)
2298                 continue;
2299               if (!pool_installable(pool, s))
2300                 continue;
2301               if (!solver_is_supplementing(solv, s))
2302                 continue;
2303             }
2304           if (solv->dontinstallrecommended)
2305             queue_push(&solv->recommendations, i);
2306           else
2307             queue_pushunique(&solv->recommendations, i);
2308         }
2309       /* we use MODE_SUGGEST here so that repo prio is ignored */
2310       policy_filter_unwanted(solv, &solv->recommendations, POLICY_MODE_SUGGEST);
2311     }
2312
2313   /*
2314    * find suggested packages
2315    */
2316
2317   if (1)
2318     {
2319       Id sug, *sugp, p, pp;
2320
2321       /* create map of all suggests that are still open */
2322       solv->recommends_index = -1;
2323       MAPZERO(&solv->suggestsmap);
2324       for (i = 0; i < solv->decisionq.count; i++)
2325         {
2326           p = solv->decisionq.elements[i];
2327           if (p < 0)
2328             continue;
2329           s = pool->solvables + p;
2330           if (s->suggests)
2331             {
2332               sugp = s->repo->idarraydata + s->suggests;
2333               while ((sug = *sugp++) != 0)
2334                 {
2335                   FOR_PROVIDES(p, pp, sug)
2336                     if (solv->decisionmap[p] > 0)
2337                       break;
2338                   if (p)
2339                     {
2340                       if (!solv->dontshowinstalledrecommended)
2341                         {
2342                           FOR_PROVIDES(p, pp, sug)
2343                             if (solv->decisionmap[p] > 0)
2344                               MAPSET(&solv->suggestsmap, p);
2345                         }
2346                       continue; /* already fulfilled */
2347                     }
2348                   FOR_PROVIDES(p, pp, sug)
2349                     MAPSET(&solv->suggestsmap, p);
2350                 }
2351             }
2352         }
2353       for (i = 1; i < pool->nsolvables; i++)
2354         {
2355           if (solv->decisionmap[i] < 0)
2356             continue;
2357           if (solv->decisionmap[i] > 0 && solv->dontshowinstalledrecommended)
2358             continue;
2359           if (MAPTST(&obsmap, i))
2360             continue;
2361           s = pool->solvables + i;
2362           if (!MAPTST(&solv->suggestsmap, i))
2363             {
2364               if (!s->enhances)
2365                 continue;
2366               if (!pool_installable(pool, s))
2367                 continue;
2368               if (!solver_is_enhancing(solv, s))
2369                 continue;
2370             }
2371           queue_push(&solv->suggestions, i);
2372         }
2373       policy_filter_unwanted(solv, &solv->suggestions, POLICY_MODE_SUGGEST);
2374     }
2375
2376   /* undo removedisabledconflicts */
2377   if (redoq.count)
2378     undo_removedisabledconflicts(solv, &redoq);
2379   queue_free(&redoq);
2380
2381   /* undo job rule disabling */
2382   for (i = 0; i < disabledq.count; i++)
2383     solver_enablerule(solv, solv->rules + disabledq.elements[i]);
2384   queue_free(&disabledq);
2385   map_free(&obsmap);
2386 }
2387
2388 void
2389 solver_calculate_noobsmap(Pool *pool, Queue *job, Map *noobsmap)
2390 {
2391   int i;
2392   Id how, what, select;
2393   Id p, pp;
2394   for (i = 0; i < job->count; i += 2)
2395     {
2396       how = job->elements[i];
2397       if ((how & SOLVER_JOBMASK) != SOLVER_NOOBSOLETES)
2398         continue;
2399       what = job->elements[i + 1];
2400       select = how & SOLVER_SELECTMASK;
2401       if (!noobsmap->size)
2402         map_grow(noobsmap, pool->nsolvables);
2403       FOR_JOB_SELECT(p, pp, select, what)
2404         MAPSET(noobsmap, p);
2405     }
2406 }
2407
2408 /*
2409  *
2410  * solve job queue
2411  *
2412  */
2413
2414 void
2415 solver_solve(Solver *solv, Queue *job)
2416 {
2417   Pool *pool = solv->pool;
2418   Repo *installed = solv->installed;
2419   int i;
2420   int oldnrules;
2421   Map addedmap;                /* '1' == have rpm-rules for solvable */
2422   Map installcandidatemap;
2423   Id how, what, select, name, weak, p, pp, d;
2424   Queue q;
2425   Solvable *s;
2426   Rule *r;
2427   int now, solve_start;
2428   int hasdupjob = 0;
2429
2430   solve_start = sat_timems(0);
2431
2432   /* log solver options */
2433   POOL_DEBUG(SAT_DEBUG_STATS, "solver started\n");
2434   POOL_DEBUG(SAT_DEBUG_STATS, "fixsystem=%d updatesystem=%d dosplitprovides=%d, noupdateprovide=%d noinfarchcheck=%d\n", solv->fixsystem, solv->updatesystem, solv->dosplitprovides, solv->noupdateprovide, solv->noinfarchcheck);
2435   POOL_DEBUG(SAT_DEBUG_STATS, "distupgrade=%d distupgrade_removeunsupported=%d\n", solv->distupgrade, solv->distupgrade_removeunsupported);
2436   POOL_DEBUG(SAT_DEBUG_STATS, "allowuninstall=%d, allowdowngrade=%d, allowarchchange=%d, allowvendorchange=%d\n", solv->allowuninstall, solv->allowdowngrade, solv->allowarchchange, solv->allowvendorchange);
2437   POOL_DEBUG(SAT_DEBUG_STATS, "promoteepoch=%d, novirtualconflicts=%d, allowselfconflicts=%d\n", pool->promoteepoch, pool->novirtualconflicts, pool->allowselfconflicts);
2438   POOL_DEBUG(SAT_DEBUG_STATS, "obsoleteusesprovides=%d, implicitobsoleteusesprovides=%d, obsoleteusescolors=%d\n", pool->obsoleteusesprovides, pool->implicitobsoleteusesprovides, pool->obsoleteusescolors);
2439   POOL_DEBUG(SAT_DEBUG_STATS, "dontinstallrecommended=%d, ignorealreadyrecommended=%d, dontshowinstalledrecommended=%d\n", solv->dontinstallrecommended, solv->ignorealreadyrecommended, solv->dontshowinstalledrecommended);
2440
2441   /* create whatprovides if not already there */
2442   if (!pool->whatprovides)
2443     pool_createwhatprovides(pool);
2444
2445   /* create obsolete index */
2446   policy_create_obsolete_index(solv);
2447
2448   /* remember job */
2449   queue_free(&solv->job);
2450   queue_init_clone(&solv->job, job);
2451
2452   /*
2453    * create basic rule set of all involved packages
2454    * use addedmap bitmap to make sure we don't create rules twice
2455    */
2456
2457   /* create noobsolete map if needed */
2458   solver_calculate_noobsmap(pool, job, &solv->noobsoletes);
2459
2460   map_init(&addedmap, pool->nsolvables);
2461   MAPSET(&addedmap, SYSTEMSOLVABLE);
2462
2463   map_init(&installcandidatemap, pool->nsolvables);
2464   queue_init(&q);
2465
2466   now = sat_timems(0);
2467   /*
2468    * create rules for all package that could be involved with the solving
2469    * so called: rpm rules
2470    *
2471    */
2472   if (installed)
2473     {
2474       /* check for verify jobs */
2475       for (i = 0; i < job->count; i += 2)
2476         {
2477           how = job->elements[i];
2478           what = job->elements[i + 1];
2479           select = how & SOLVER_SELECTMASK;
2480           switch (how & SOLVER_JOBMASK)
2481             {
2482             case SOLVER_VERIFY:
2483               FOR_JOB_SELECT(p, pp, select, what)
2484                 {
2485                   s = pool->solvables + p;
2486                   if (!solv->installed || s->repo != solv->installed)
2487                     continue;
2488                   if (!solv->fixmap.size)
2489                     map_grow(&solv->fixmap, solv->installed->end - solv->installed->start);
2490                   MAPSET(&solv->fixmap, p - solv->installed->start);
2491                 }
2492               break;
2493             default:
2494               break;
2495             }
2496         }
2497
2498       oldnrules = solv->nrules;
2499       POOL_DEBUG(SAT_DEBUG_SCHUBI, "*** create rpm rules for installed solvables ***\n");
2500       FOR_REPO_SOLVABLES(installed, p, s)
2501         solver_addrpmrulesforsolvable(solv, s, &addedmap);
2502       POOL_DEBUG(SAT_DEBUG_STATS, "added %d rpm rules for installed solvables\n", solv->nrules - oldnrules);
2503       POOL_DEBUG(SAT_DEBUG_SCHUBI, "*** create rpm rules for updaters of installed solvables ***\n");
2504       oldnrules = solv->nrules;
2505       FOR_REPO_SOLVABLES(installed, p, s)
2506         solver_addrpmrulesforupdaters(solv, s, &addedmap, 1);
2507       POOL_DEBUG(SAT_DEBUG_STATS, "added %d rpm rules for updaters of installed solvables\n", solv->nrules - oldnrules);
2508     }
2509
2510   /*
2511    * create rules for all packages involved in the job
2512    * (to be installed or removed)
2513    */
2514
2515   POOL_DEBUG(SAT_DEBUG_SCHUBI, "*** create rpm rules for packages involved with a job ***\n");
2516   oldnrules = solv->nrules;
2517   for (i = 0; i < job->count; i += 2)
2518     {
2519       how = job->elements[i];
2520       what = job->elements[i + 1];
2521       select = how & SOLVER_SELECTMASK;
2522
2523       switch (how & SOLVER_JOBMASK)
2524         {
2525         case SOLVER_INSTALL:
2526           FOR_JOB_SELECT(p, pp, select, what)
2527             {
2528               MAPSET(&installcandidatemap, p);
2529               solver_addrpmrulesforsolvable(solv, pool->solvables + p, &addedmap);
2530             }
2531           break;
2532         case SOLVER_DISTUPGRADE:
2533           if (!solv->distupgrade)
2534             hasdupjob = 1;
2535           break;
2536         default:
2537           break;
2538         }
2539     }
2540   POOL_DEBUG(SAT_DEBUG_STATS, "added %d rpm rules for packages involved in a job\n", solv->nrules - oldnrules);
2541
2542
2543   /*
2544    * add rules for suggests, enhances
2545    */
2546   POOL_DEBUG(SAT_DEBUG_SCHUBI, "*** create rpm rules for suggested/enhanced packages ***\n");
2547   oldnrules = solv->nrules;
2548   solver_addrpmrulesforweak(solv, &addedmap);
2549   POOL_DEBUG(SAT_DEBUG_STATS, "added %d rpm rules because of weak dependencies\n", solv->nrules - oldnrules);
2550
2551   /*
2552    * first pass done, we now have all the rpm rules we need.
2553    * unify existing rules before going over all job rules and
2554    * policy rules.
2555    * at this point the system is always solvable,
2556    * as an empty system (remove all packages) is a valid solution
2557    */
2558
2559   IF_POOLDEBUG (SAT_DEBUG_STATS)
2560     {
2561       int possible = 0, installable = 0;
2562       for (i = 1; i < pool->nsolvables; i++)
2563         {
2564           if (pool_installable(pool, pool->solvables + i))
2565             installable++;
2566           if (MAPTST(&addedmap, i))
2567             possible++;
2568         }
2569       POOL_DEBUG(SAT_DEBUG_STATS, "%d of %d installable solvables considered for solving\n", possible, installable);
2570     }
2571
2572   solver_unifyrules(solv);                          /* remove duplicate rpm rules */
2573   solv->rpmrules_end = solv->nrules;              /* mark end of rpm rules */
2574
2575   POOL_DEBUG(SAT_DEBUG_STATS, "rpm rule memory usage: %d K\n", solv->nrules * (int)sizeof(Rule) / 1024);
2576   POOL_DEBUG(SAT_DEBUG_STATS, "rpm rule creation took %d ms\n", sat_timems(now));
2577
2578   /* create dup maps if needed. We need the maps early to create our
2579    * update rules */
2580   if (hasdupjob)
2581     solver_createdupmaps(solv);
2582
2583   /*
2584    * create feature rules
2585    *
2586    * foreach installed:
2587    *   create assertion (keep installed, if no update available)
2588    *   or
2589    *   create update rule (A|update1(A)|update2(A)|...)
2590    *
2591    * those are used later on to keep a version of the installed packages in
2592    * best effort mode
2593    */
2594
2595   POOL_DEBUG(SAT_DEBUG_SCHUBI, "*** Add feature rules ***\n");
2596   solv->featurerules = solv->nrules;              /* mark start of feature rules */
2597   if (installed)
2598     {
2599       /* foreach possibly installed solvable */
2600       for (i = installed->start, s = pool->solvables + i; i < installed->end; i++, s++)
2601         {
2602           if (s->repo != installed)
2603             {
2604               solver_addrule(solv, 0, 0);       /* create dummy rule */
2605               continue;
2606             }
2607           solver_addupdaterule(solv, s, 1);    /* allow s to be updated */
2608         }
2609       /* make sure we accounted for all rules */
2610       assert(solv->nrules - solv->featurerules == installed->end - installed->start);
2611     }
2612   solv->featurerules_end = solv->nrules;
2613
2614     /*
2615      * Add update rules for installed solvables
2616      *
2617      * almost identical to feature rules
2618      * except that downgrades/archchanges/vendorchanges are not allowed
2619      */
2620
2621   POOL_DEBUG(SAT_DEBUG_SCHUBI, "*** Add update rules ***\n");
2622   solv->updaterules = solv->nrules;
2623
2624   if (installed)
2625     { /* foreach installed solvables */
2626       /* we create all update rules, but disable some later on depending on the job */
2627       for (i = installed->start, s = pool->solvables + i; i < installed->end; i++, s++)
2628         {
2629           Rule *sr;
2630
2631           if (s->repo != installed)
2632             {
2633               solver_addrule(solv, 0, 0);       /* create dummy rule */
2634               continue;
2635             }
2636           solver_addupdaterule(solv, s, 0);     /* allowall = 0: downgrades not allowed */
2637           /*
2638            * check for and remove duplicate
2639            */
2640           r = solv->rules + solv->nrules - 1;           /* r: update rule */
2641           sr = r - (installed->end - installed->start); /* sr: feature rule */
2642           /* it's orphaned if there is no feature rule or the feature rule
2643            * consists just of the installed package */
2644           if (!sr->p || (sr->p == i && !sr->d && !sr->w2))
2645             queue_push(&solv->orphaned, i);
2646           if (!r->p)
2647             {
2648               assert(solv->distupgrade && !sr->p);
2649               continue;
2650             }
2651           if (!solver_samerule(solv, r, sr))
2652             {
2653               /* identical rule, kill unneeded one */
2654               if (solv->allowuninstall)
2655                 {
2656                   /* keep feature rule, make it weak */
2657                   memset(r, 0, sizeof(*r));
2658                   queue_push(&solv->weakruleq, sr - solv->rules);
2659                 }
2660               else
2661                 {
2662                   /* keep update rule */
2663                   memset(sr, 0, sizeof(*sr));
2664                 }
2665             }
2666           else if (solv->allowuninstall)
2667             {
2668               /* make both feature and update rule weak */
2669               queue_push(&solv->weakruleq, r - solv->rules);
2670               queue_push(&solv->weakruleq, sr - solv->rules);
2671             }
2672           else
2673             solver_disablerule(solv, sr);
2674         }
2675       /* consistency check: we added a rule for _every_ installed solvable */
2676       assert(solv->nrules - solv->updaterules == installed->end - installed->start);
2677     }
2678   solv->updaterules_end = solv->nrules;
2679
2680
2681   /*
2682    * now add all job rules
2683    */
2684
2685   POOL_DEBUG(SAT_DEBUG_SCHUBI, "*** Add JOB rules ***\n");
2686
2687   solv->jobrules = solv->nrules;
2688   for (i = 0; i < job->count; i += 2)
2689     {
2690       oldnrules = solv->nrules;
2691
2692       how = job->elements[i];
2693       what = job->elements[i + 1];
2694       weak = how & SOLVER_WEAK;
2695       select = how & SOLVER_SELECTMASK;
2696       switch (how & SOLVER_JOBMASK)
2697         {
2698         case SOLVER_INSTALL:
2699           POOL_DEBUG(SAT_DEBUG_JOB, "job: %sinstall %s\n", weak ? "weak " : "", solver_select2str(solv, select, what));
2700           if (select == SOLVER_SOLVABLE)
2701             {
2702               p = what;
2703               d = 0;
2704             }
2705           else
2706             {
2707               queue_empty(&q);
2708               FOR_JOB_SELECT(p, pp, select, what)
2709                 queue_push(&q, p);
2710               if (!q.count)
2711                 {
2712                   /* no candidate found, make this an impossible rule */
2713                   queue_push(&q, -SYSTEMSOLVABLE);
2714                 }
2715               p = queue_shift(&q);      /* get first candidate */
2716               d = !q.count ? 0 : pool_queuetowhatprovides(pool, &q);    /* internalize */
2717             }
2718           solver_addrule(solv, p, d);           /* add install rule */
2719           queue_push(&solv->ruletojob, i);
2720           if (weak)
2721             queue_push(&solv->weakruleq, solv->nrules - 1);
2722           break;
2723         case SOLVER_ERASE:
2724           POOL_DEBUG(SAT_DEBUG_JOB, "job: %serase %s\n", weak ? "weak " : "", solver_select2str(solv, select, what));
2725           if (select == SOLVER_SOLVABLE && solv->installed && pool->solvables[what].repo == solv->installed)
2726             {
2727               /* special case for "erase a specific solvable": we also
2728                * erase all other solvables with that name, so that they
2729                * don't get picked up as replacement */
2730               name = pool->solvables[what].name;
2731               FOR_PROVIDES(p, pp, name)
2732                 {
2733                   if (p == what)
2734                     continue;
2735                   s = pool->solvables + p;
2736                   if (s->name != name)
2737                     continue;
2738                   /* keep other versions installed */
2739                   if (s->repo == solv->installed)
2740                     continue;
2741                   /* keep installcandidates of other jobs */
2742                   if (MAPTST(&installcandidatemap, p))
2743                     continue;
2744                   solver_addrule(solv, -p, 0);                  /* remove by Id */
2745                   queue_push(&solv->ruletojob, i);
2746                   if (weak)
2747                     queue_push(&solv->weakruleq, solv->nrules - 1);
2748                 }
2749             }
2750           FOR_JOB_SELECT(p, pp, select, what)
2751             {
2752               solver_addrule(solv, -p, 0);
2753               queue_push(&solv->ruletojob, i);
2754               if (weak)
2755                 queue_push(&solv->weakruleq, solv->nrules - 1);
2756             }
2757           break;
2758
2759         case SOLVER_UPDATE:
2760           POOL_DEBUG(SAT_DEBUG_JOB, "job: %supdate %s\n", weak ? "weak " : "", solver_select2str(solv, select, what));
2761           FOR_JOB_SELECT(p, pp, select, what)
2762             {
2763               s = pool->solvables + p;
2764               if (!solv->installed || s->repo != solv->installed)
2765                 continue;
2766               if (!solv->updatemap.size)
2767                 map_grow(&solv->updatemap, solv->installed->end - solv->installed->start);
2768               MAPSET(&solv->updatemap, p - solv->installed->start);
2769             }
2770           break;
2771         case SOLVER_VERIFY:
2772           POOL_DEBUG(SAT_DEBUG_JOB, "job: %sverify %s\n", weak ? "weak " : "", solver_select2str(solv, select, what));
2773           break;
2774         case SOLVER_WEAKENDEPS:
2775           POOL_DEBUG(SAT_DEBUG_JOB, "job: %sweaken deps %s\n", weak ? "weak " : "", solver_select2str(solv, select, what));
2776           if (select != SOLVER_SOLVABLE)
2777             break;
2778           s = pool->solvables + what;
2779           weaken_solvable_deps(solv, what);
2780           break;
2781         case SOLVER_NOOBSOLETES:
2782           POOL_DEBUG(SAT_DEBUG_JOB, "job: %sno obsolete %s\n", weak ? "weak " : "", solver_select2str(solv, select, what));
2783           break;
2784         case SOLVER_LOCK:
2785           POOL_DEBUG(SAT_DEBUG_JOB, "job: %slock %s\n", weak ? "weak " : "", solver_select2str(solv, select, what));
2786           FOR_JOB_SELECT(p, pp, select, what)
2787             {
2788               s = pool->solvables + p;
2789               if (installed && s->repo == installed)
2790                 solver_addrule(solv, p, 0);
2791               else
2792                 solver_addrule(solv, -p, 0);
2793               queue_push(&solv->ruletojob, i);
2794               if (weak)
2795                 queue_push(&solv->weakruleq, solv->nrules - 1);
2796             }
2797           break;
2798         case SOLVER_DISTUPGRADE:
2799           POOL_DEBUG(SAT_DEBUG_JOB, "job: distupgrade %s\n", solver_select2str(solv, select, what));
2800           break;
2801         default:
2802           POOL_DEBUG(SAT_DEBUG_JOB, "job: unknown job\n");
2803           break;
2804         }
2805
2806         /*
2807          * debug
2808          */
2809
2810       IF_POOLDEBUG (SAT_DEBUG_JOB)
2811         {
2812           int j;
2813           if (solv->nrules == oldnrules)
2814             POOL_DEBUG(SAT_DEBUG_JOB, " - no rule created\n");
2815           for (j = oldnrules; j < solv->nrules; j++)
2816             {
2817               POOL_DEBUG(SAT_DEBUG_JOB, " - job ");
2818               solver_printrule(solv, SAT_DEBUG_JOB, solv->rules + j);
2819             }
2820         }
2821     }
2822   assert(solv->ruletojob.count == solv->nrules - solv->jobrules);
2823   solv->jobrules_end = solv->nrules;
2824
2825   /* now create infarch and dup rules */
2826   if (!solv->noinfarchcheck)
2827     {
2828       solver_addinfarchrules(solv, &addedmap);
2829       if (pool->obsoleteusescolors)
2830         {
2831           /* currently doesn't work well with infarch rules, so make
2832            * them weak */
2833           for (i = solv->infarchrules; i < solv->infarchrules_end; i++)
2834             queue_push(&solv->weakruleq, i);
2835         }
2836     }
2837   else
2838     solv->infarchrules = solv->infarchrules_end = solv->nrules;
2839
2840   if (hasdupjob)
2841     {
2842       solver_addduprules(solv, &addedmap);
2843       solver_freedupmaps(solv); /* no longer needed */
2844     }
2845   else
2846     solv->duprules = solv->duprules_end = solv->nrules;
2847
2848   if (1)
2849     {
2850       extern void addchoicerules(Solver *solv);
2851       addchoicerules(solv);
2852     }
2853   else
2854     solv->choicerules = solv->choicerules_end = solv->nrules;
2855
2856   /* all rules created
2857    * --------------------------------------------------------------
2858    * prepare for solving
2859    */
2860
2861   /* free unneeded memory */
2862   map_free(&addedmap);
2863   map_free(&installcandidatemap);
2864   queue_free(&q);
2865
2866   POOL_DEBUG(SAT_DEBUG_STATS, "%d rpm rules, %d job rules, %d infarch rules, %d dup rules, %d choice rules\n", solv->rpmrules_end - 1, solv->jobrules_end - solv->jobrules, solv->infarchrules_end - solv->infarchrules, solv->duprules_end - solv->duprules, solv->choicerules_end - solv->choicerules);
2867
2868   /* create weak map */
2869   map_init(&solv->weakrulemap, solv->nrules);
2870   for (i = 0; i < solv->weakruleq.count; i++)
2871     {
2872       p = solv->weakruleq.elements[i];
2873       MAPSET(&solv->weakrulemap, p);
2874     }
2875
2876   /* all new rules are learnt after this point */
2877   solv->learntrules = solv->nrules;
2878
2879   /* create watches chains */
2880   makewatches(solv);
2881
2882   /* create assertion index. it is only used to speed up
2883    * makeruledecsions() a bit */
2884   for (i = 1, r = solv->rules + i; i < solv->nrules; i++, r++)
2885     if (r->p && !r->w2 && (r->d == 0 || r->d == -1))
2886       queue_push(&solv->ruleassertions, i);
2887
2888   /* disable update rules that conflict with our job */
2889   solver_disablepolicyrules(solv);
2890
2891   /* make decisions based on job/update assertions */
2892   makeruledecisions(solv);
2893   POOL_DEBUG(SAT_DEBUG_SOLVER, "problems so far: %d\n", solv->problems.count);
2894
2895   /*
2896    * ********************************************
2897    * solve!
2898    * ********************************************
2899    */
2900
2901   now = sat_timems(0);
2902   solver_run_sat(solv, 1, solv->dontinstallrecommended ? 0 : 1);
2903   POOL_DEBUG(SAT_DEBUG_STATS, "solver took %d ms\n", sat_timems(now));
2904
2905   /*
2906    * calculate recommended/suggested packages
2907    */
2908   findrecommendedsuggested(solv);
2909
2910   /*
2911    * prepare solution queue if there were problems
2912    */
2913   solver_prepare_solutions(solv);
2914
2915   /*
2916    * finally prepare transaction info
2917    */
2918   transaction_calculate(&solv->trans, &solv->decisionq, &solv->noobsoletes);
2919
2920   POOL_DEBUG(SAT_DEBUG_STATS, "final solver statistics: %d problems, %d learned rules, %d unsolvable\n", solv->problems.count / 2, solv->stats_learned, solv->stats_unsolvable);
2921   POOL_DEBUG(SAT_DEBUG_STATS, "solver_solve took %d ms\n", sat_timems(solve_start));
2922 }
2923
2924 /***********************************************************************/
2925 /* disk usage computations */
2926
2927 /*-------------------------------------------------------------------
2928  *
2929  * calculate DU changes
2930  */
2931
2932 void
2933 solver_calc_duchanges(Solver *solv, DUChanges *mps, int nmps)
2934 {
2935   Map installedmap;
2936
2937   solver_create_state_maps(solv, &installedmap, 0);
2938   pool_calc_duchanges(solv->pool, &installedmap, mps, nmps);
2939   map_free(&installedmap);
2940 }
2941
2942
2943 /*-------------------------------------------------------------------
2944  *
2945  * calculate changes in install size
2946  */
2947
2948 int
2949 solver_calc_installsizechange(Solver *solv)
2950 {
2951   Map installedmap;
2952   int change;
2953
2954   solver_create_state_maps(solv, &installedmap, 0);
2955   change = pool_calc_installsizechange(solv->pool, &installedmap);
2956   map_free(&installedmap);
2957   return change;
2958 }
2959
2960 void
2961 solver_trivial_installable(Solver *solv, Queue *pkgs, Queue *res)
2962 {
2963   Map installedmap;
2964   solver_create_state_maps(solv, &installedmap, 0);
2965   pool_trivial_installable_noobsoletesmap(solv->pool, &installedmap, pkgs, res, solv->noobsoletes.size ? &solv->noobsoletes : 0);
2966   map_free(&installedmap);
2967 }
2968
2969
2970 #if 0
2971 #define FIND_INVOLVED_DEBUG 0
2972 void
2973 solver_find_involved(Solver *solv, Queue *installedq, Solvable *ts, Queue *q)
2974 {
2975   Pool *pool = solv->pool;
2976   Map im;
2977   Map installedm;
2978   Solvable *s;
2979   Queue iq;
2980   Queue installedq_internal;
2981   Id tp, ip, p, pp, req, *reqp, sup, *supp;
2982   int i, count;
2983
2984   tp = ts - pool->solvables;
2985   queue_init(&iq);
2986   queue_init(&installedq_internal);
2987   map_init(&im, pool->nsolvables);
2988   map_init(&installedm, pool->nsolvables);
2989
2990   if (!installedq)
2991     {
2992       installedq = &installedq_internal;
2993       if (solv->installed)
2994         {
2995           for (ip = solv->installed->start; ip < solv->installed->end; ip++)
2996             {
2997               s = pool->solvables + ip;
2998               if (s->repo != solv->installed)
2999                 continue;
3000               queue_push(installedq, ip);
3001             }
3002         }
3003     }
3004   for (i = 0; i < installedq->count; i++)
3005     {
3006       ip = installedq->elements[i];
3007       MAPSET(&installedm, ip);
3008       MAPSET(&im, ip);
3009     }
3010
3011   queue_push(&iq, ts - pool->solvables);
3012   while (iq.count)
3013     {
3014       ip = queue_shift(&iq);
3015       if (!MAPTST(&im, ip))
3016         continue;
3017       if (!MAPTST(&installedm, ip))
3018         continue;
3019       MAPCLR(&im, ip);
3020       s = pool->solvables + ip;
3021 #if FIND_INVOLVED_DEBUG
3022       printf("hello %s\n", solvable2str(pool, s));
3023 #endif
3024       if (s->requires)
3025         {
3026           reqp = s->repo->idarraydata + s->requires;
3027           while ((req = *reqp++) != 0)
3028             {
3029               if (req == SOLVABLE_PREREQMARKER)
3030                 continue;
3031               /* count number of installed packages that match */
3032               count = 0;
3033               FOR_PROVIDES(p, pp, req)
3034                 if (MAPTST(&installedm, p))
3035                   count++;
3036               if (count > 1)
3037                 continue;
3038               FOR_PROVIDES(p, pp, req)
3039                 {
3040                   if (MAPTST(&im, p))
3041                     {
3042 #if FIND_INVOLVED_DEBUG
3043                       printf("%s requires %s\n", solvid2str(pool, ip), solvid2str(pool, p));
3044 #endif
3045                       queue_push(&iq, p);
3046                     }
3047                 }
3048             }
3049         }
3050       if (s->recommends)
3051         {
3052           reqp = s->repo->idarraydata + s->recommends;
3053           while ((req = *reqp++) != 0)
3054             {
3055               count = 0;
3056               FOR_PROVIDES(p, pp, req)
3057                 if (MAPTST(&installedm, p))
3058                   count++;
3059               if (count > 1)
3060                 continue;
3061               FOR_PROVIDES(p, pp, req)
3062                 {
3063                   if (MAPTST(&im, p))
3064                     {
3065 #if FIND_INVOLVED_DEBUG
3066                       printf("%s recommends %s\n", solvid2str(pool, ip), solvid2str(pool, p));
3067 #endif
3068                       queue_push(&iq, p);
3069                     }
3070                 }
3071             }
3072         }
3073       if (!iq.count)
3074         {
3075           /* supplements pass */
3076           for (i = 0; i < installedq->count; i++)
3077             {
3078               ip = installedq->elements[i];
3079               s = pool->solvables + ip;
3080               if (!s->supplements)
3081                 continue;
3082               if (!MAPTST(&im, ip))
3083                 continue;
3084               supp = s->repo->idarraydata + s->supplements;
3085               while ((sup = *supp++) != 0)
3086                 if (!dep_possible(solv, sup, &im) && dep_possible(solv, sup, &installedm))
3087                   break;
3088               /* no longer supplemented, also erase */
3089               if (sup)
3090                 {
3091 #if FIND_INVOLVED_DEBUG
3092                   printf("%s supplemented\n", solvid2str(pool, ip));
3093 #endif
3094                   queue_push(&iq, ip);
3095                 }
3096             }
3097         }
3098     }
3099
3100   for (i = 0; i < installedq->count; i++)
3101     {
3102       ip = installedq->elements[i];
3103       if (MAPTST(&im, ip))
3104         queue_push(&iq, ip);
3105     }
3106
3107   while (iq.count)
3108     {
3109       ip = queue_shift(&iq);
3110       if (!MAPTST(&installedm, ip))
3111         continue;
3112       s = pool->solvables + ip;
3113 #if FIND_INVOLVED_DEBUG
3114       printf("bye %s\n", solvable2str(pool, s));
3115 #endif
3116       if (s->requires)
3117         {
3118           reqp = s->repo->idarraydata + s->requires;
3119           while ((req = *reqp++) != 0)
3120             {
3121               FOR_PROVIDES(p, pp, req)
3122                 {
3123                   if (!MAPTST(&im, p))
3124                     {
3125                       if (p == tp)
3126                         continue;
3127 #if FIND_INVOLVED_DEBUG
3128                       printf("%s requires %s\n", solvid2str(pool, ip), solvid2str(pool, p));
3129 #endif
3130                       MAPSET(&im, p);
3131                       queue_push(&iq, p);
3132                     }
3133                 }
3134             }
3135         }
3136       if (s->recommends)
3137         {
3138           reqp = s->repo->idarraydata + s->recommends;
3139           while ((req = *reqp++) != 0)
3140             {
3141               FOR_PROVIDES(p, pp, req)
3142                 {
3143                   if (!MAPTST(&im, p))
3144                     {
3145                       if (p == tp)
3146                         continue;
3147 #if FIND_INVOLVED_DEBUG
3148                       printf("%s recommends %s\n", solvid2str(pool, ip), solvid2str(pool, p));
3149 #endif
3150                       MAPSET(&im, p);
3151                       queue_push(&iq, p);
3152                     }
3153                 }
3154             }
3155         }
3156       if (!iq.count)
3157         {
3158           /* supplements pass */
3159           for (i = 0; i < installedq->count; i++)
3160             {
3161               ip = installedq->elements[i];
3162               if (ip == tp)
3163                 continue;
3164               s = pool->solvables + ip;
3165               if (!s->supplements)
3166                 continue;
3167               if (MAPTST(&im, ip))
3168                 continue;
3169               supp = s->repo->idarraydata + s->supplements;
3170               while ((sup = *supp++) != 0)
3171                 if (dep_possible(solv, sup, &im))
3172                   break;
3173               if (sup)
3174                 {
3175 #if FIND_INVOLVED_DEBUG
3176                   printf("%s supplemented\n", solvid2str(pool, ip));
3177 #endif
3178                   MAPSET(&im, ip);
3179                   queue_push(&iq, ip);
3180                 }
3181             }
3182         }
3183     }
3184
3185   queue_free(&iq);
3186
3187   /* convert map into result */
3188   for (i = 0; i < installedq->count; i++)
3189     {
3190       ip = installedq->elements[i];
3191       if (MAPTST(&im, ip))
3192         continue;
3193       if (ip == ts - pool->solvables)
3194         continue;
3195       queue_push(q, ip);
3196     }
3197   map_free(&im);
3198   map_free(&installedm);
3199   queue_free(&installedq_internal);
3200 }
3201 #endif
3202