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   map_free(&solv->droporphanedmap);
1299
1300   sat_free(solv->decisionmap);
1301   sat_free(solv->rules);
1302   sat_free(solv->watches);
1303   sat_free(solv->obsoletes);
1304   sat_free(solv->obsoletes_data);
1305   sat_free(solv->multiversionupdaters);
1306   sat_free(solv->choicerules_ref);
1307   sat_free(solv);
1308 }
1309
1310
1311 /*-------------------------------------------------------------------
1312  *
1313  * solver_run_sat
1314  *
1315  * all rules have been set up, now actually run the solver
1316  *
1317  */
1318
1319 void
1320 solver_run_sat(Solver *solv, int disablerules, int doweak)
1321 {
1322   Queue dq;             /* local decisionqueue */
1323   Queue dqs;            /* local decisionqueue for supplements */
1324   int systemlevel;
1325   int level, olevel;
1326   Rule *r;
1327   int i, j, n;
1328   Solvable *s;
1329   Pool *pool = solv->pool;
1330   Id p, *dp;
1331   int minimizationsteps;
1332   int installedpos = solv->installed ? solv->installed->start : 0;
1333
1334   IF_POOLDEBUG (SAT_DEBUG_RULE_CREATION)
1335     {
1336       POOL_DEBUG (SAT_DEBUG_RULE_CREATION, "number of rules: %d\n", solv->nrules);
1337       for (i = 1; i < solv->nrules; i++)
1338         solver_printruleclass(solv, SAT_DEBUG_RULE_CREATION, solv->rules + i);
1339     }
1340
1341   POOL_DEBUG(SAT_DEBUG_SOLVER, "initial decisions: %d\n", solv->decisionq.count);
1342
1343   IF_POOLDEBUG (SAT_DEBUG_SCHUBI)
1344     solver_printdecisions(solv);
1345
1346   /* start SAT algorithm */
1347   level = 1;
1348   systemlevel = level + 1;
1349   POOL_DEBUG(SAT_DEBUG_SOLVER, "solving...\n");
1350
1351   queue_init(&dq);
1352   queue_init(&dqs);
1353
1354   /*
1355    * here's the main loop:
1356    * 1) propagate new decisions (only needed once)
1357    * 2) fulfill jobs
1358    * 3) try to keep installed packages
1359    * 4) fulfill all unresolved rules
1360    * 5) install recommended packages
1361    * 6) minimalize solution if we had choices
1362    * if we encounter a problem, we rewind to a safe level and restart
1363    * with step 1
1364    */
1365
1366   minimizationsteps = 0;
1367   for (;;)
1368     {
1369       /*
1370        * initial propagation of the assertions
1371        */
1372       if (level == 1)
1373         {
1374           POOL_DEBUG(SAT_DEBUG_PROPAGATE, "propagating (propagate_index: %d;  size decisionq: %d)...\n", solv->propagate_index, solv->decisionq.count);
1375           if ((r = propagate(solv, level)) != 0)
1376             {
1377               if (analyze_unsolvable(solv, r, disablerules))
1378                 continue;
1379               queue_free(&dq);
1380               queue_free(&dqs);
1381               return;
1382             }
1383         }
1384
1385       /*
1386        * resolve jobs first
1387        */
1388      if (level < systemlevel)
1389         {
1390           POOL_DEBUG(SAT_DEBUG_SOLVER, "resolving job rules\n");
1391           for (i = solv->jobrules, r = solv->rules + i; i < solv->jobrules_end; i++, r++)
1392             {
1393               Id l;
1394               if (r->d < 0)             /* ignore disabled rules */
1395                 continue;
1396               queue_empty(&dq);
1397               FOR_RULELITERALS(l, dp, r)
1398                 {
1399                   if (l < 0)
1400                     {
1401                       if (solv->decisionmap[-l] <= 0)
1402                         break;
1403                     }
1404                   else
1405                     {
1406                       if (solv->decisionmap[l] > 0)
1407                         break;
1408                       if (solv->decisionmap[l] == 0)
1409                         queue_push(&dq, l);
1410                     }
1411                 }
1412               if (l || !dq.count)
1413                 continue;
1414               /* prune to installed if not updating */
1415               if (!solv->updatesystem && solv->installed && dq.count > 1)
1416                 {
1417                   int j, k;
1418                   for (j = k = 0; j < dq.count; j++)
1419                     {
1420                       Solvable *s = pool->solvables + dq.elements[j];
1421                       if (s->repo == solv->installed)
1422                         dq.elements[k++] = dq.elements[j];
1423                     }
1424                   if (k)
1425                     dq.count = k;
1426                 }
1427               olevel = level;
1428               level = selectandinstall(solv, level, &dq, disablerules, i);
1429               if (level == 0)
1430                 {
1431                   queue_free(&dq);
1432                   queue_free(&dqs);
1433                   return;
1434                 }
1435               if (level <= olevel)
1436                 break;
1437             }
1438           systemlevel = level + 1;
1439           if (i < solv->jobrules_end)
1440             continue;
1441         }
1442
1443
1444       /*
1445        * installed packages
1446        */
1447       if (level < systemlevel && solv->installed && solv->installed->nsolvables && !solv->installed->disabled)
1448         {
1449           Repo *installed = solv->installed;
1450           int pass;
1451
1452           POOL_DEBUG(SAT_DEBUG_SOLVER, "resolving installed packages\n");
1453           /* we use two passes if we need to update packages
1454            * to create a better user experience */
1455           for (pass = solv->updatemap.size ? 0 : 1; pass < 2; pass++)
1456             {
1457               int passlevel = level;
1458               /* start with installedpos, the position that gave us problems last time */
1459               for (i = installedpos, n = installed->start; n < installed->end; i++, n++)
1460                 {
1461                   Rule *rr;
1462                   Id d;
1463
1464                   if (i == installed->end)
1465                     i = installed->start;
1466                   s = pool->solvables + i;
1467                   if (s->repo != installed)
1468                     continue;
1469
1470                   if (solv->decisionmap[i] > 0)
1471                     continue;
1472                   if (!pass && solv->updatemap.size && !MAPTST(&solv->updatemap, i - installed->start))
1473                     continue;           /* updates first */
1474                   r = solv->rules + solv->updaterules + (i - installed->start);
1475                   rr = r;
1476                   if (!rr->p || rr->d < 0)      /* disabled -> look at feature rule */
1477                     rr -= solv->installed->end - solv->installed->start;
1478                   if (!rr->p)           /* identical to update rule? */
1479                     rr = r;
1480                   if (!rr->p)
1481                     continue;           /* orpaned package */
1482
1483                   /* XXX: noupdate check is probably no longer needed, as all jobs should
1484                    * already be satisfied */
1485                   /* Actually we currently still need it because of erase jobs */
1486                   /* if noupdate is set we do not look at update candidates */
1487                   queue_empty(&dq);
1488                   if (!MAPTST(&solv->noupdate, i - installed->start) && (solv->decisionmap[i] < 0 || solv->updatesystem || (solv->updatemap.size && MAPTST(&solv->updatemap, i - installed->start)) || rr->p != i))
1489                     {
1490                       if (solv->noobsoletes.size && solv->multiversionupdaters
1491                              && (d = solv->multiversionupdaters[i - installed->start]) != 0)
1492                         {
1493                           /* special multiversion handling, make sure best version is chosen */
1494                           queue_push(&dq, i);
1495                           while ((p = pool->whatprovidesdata[d++]) != 0)
1496                             if (solv->decisionmap[p] >= 0)
1497                               queue_push(&dq, p);
1498                           policy_filter_unwanted(solv, &dq, POLICY_MODE_CHOOSE);
1499                           p = dq.elements[0];
1500                           if (p != i && solv->decisionmap[p] == 0)
1501                             {
1502                               rr = solv->rules + solv->featurerules + (i - solv->installed->start);
1503                               if (!rr->p)               /* update rule == feature rule? */
1504                                 rr = rr - solv->featurerules + solv->updaterules;
1505                               dq.count = 1;
1506                             }
1507                           else
1508                             dq.count = 0;
1509                         }
1510                       else
1511                         {
1512                           /* update to best package */
1513                           FOR_RULELITERALS(p, dp, rr)
1514                             {
1515                               if (solv->decisionmap[p] > 0)
1516                                 {
1517                                   dq.count = 0;         /* already fulfilled */
1518                                   break;
1519                                 }
1520                               if (!solv->decisionmap[p])
1521                                 queue_push(&dq, p);
1522                             }
1523                         }
1524                     }
1525                   /* install best version */
1526                   if (dq.count)
1527                     {
1528                       olevel = level;
1529                       level = selectandinstall(solv, level, &dq, disablerules, rr - solv->rules);
1530                       if (level == 0)
1531                         {
1532                           queue_free(&dq);
1533                           queue_free(&dqs);
1534                           return;
1535                         }
1536                       if (level <= olevel)
1537                         {
1538                           if (level == 1 || level < passlevel)
1539                             break;      /* trouble */
1540                           if (level < olevel)
1541                             n = installed->start;       /* redo all */
1542                           i--;
1543                           n--;
1544                           continue;
1545                         }
1546                     }
1547                   /* if still undecided keep package */
1548                   if (solv->decisionmap[i] == 0)
1549                     {
1550                       olevel = level;
1551                       POOL_DEBUG(SAT_DEBUG_POLICY, "keeping %s\n", solvid2str(pool, i));
1552                       level = setpropagatelearn(solv, level, i, disablerules, r - solv->rules);
1553                       if (level == 0)
1554                         {
1555                           queue_free(&dq);
1556                           queue_free(&dqs);
1557                           return;
1558                         }
1559                       if (level <= olevel)
1560                         {
1561                           if (level == 1 || level < passlevel)
1562                             break;      /* trouble */
1563                           if (level < olevel)
1564                             n = installed->start;       /* redo all */
1565                           i--;
1566                           n--;
1567                           continue; /* retry with learnt rule */
1568                         }
1569                     }
1570                 }
1571               if (n < installed->end)
1572                 {
1573                   installedpos = i;     /* retry problem solvable next time */
1574                   break;                /* ran into trouble */
1575                 }
1576               installedpos = installed->start;  /* reset installedpos */
1577             }
1578           systemlevel = level + 1;
1579           if (pass < 2)
1580             continue;           /* had trouble, retry */
1581         }
1582
1583       if (level < systemlevel)
1584         systemlevel = level;
1585
1586       /*
1587        * decide
1588        */
1589       POOL_DEBUG(SAT_DEBUG_POLICY, "deciding unresolved rules\n");
1590       for (i = 1, n = 1; n < solv->nrules; i++, n++)
1591         {
1592           if (i == solv->nrules)
1593             i = 1;
1594           r = solv->rules + i;
1595           if (r->d < 0)         /* ignore disabled rules */
1596             continue;
1597           queue_empty(&dq);
1598           if (r->d == 0)
1599             {
1600               /* binary or unary rule */
1601               /* need two positive undecided literals */
1602               if (r->p < 0 || r->w2 <= 0)
1603                 continue;
1604               if (solv->decisionmap[r->p] || solv->decisionmap[r->w2])
1605                 continue;
1606               queue_push(&dq, r->p);
1607               queue_push(&dq, r->w2);
1608             }
1609           else
1610             {
1611               /* make sure that
1612                * all negative literals are installed
1613                * no positive literal is installed
1614                * i.e. the rule is not fulfilled and we
1615                * just need to decide on the positive literals
1616                */
1617               if (r->p < 0)
1618                 {
1619                   if (solv->decisionmap[-r->p] <= 0)
1620                     continue;
1621                 }
1622               else
1623                 {
1624                   if (solv->decisionmap[r->p] > 0)
1625                     continue;
1626                   if (solv->decisionmap[r->p] == 0)
1627                     queue_push(&dq, r->p);
1628                 }
1629               dp = pool->whatprovidesdata + r->d;
1630               while ((p = *dp++) != 0)
1631                 {
1632                   if (p < 0)
1633                     {
1634                       if (solv->decisionmap[-p] <= 0)
1635                         break;
1636                     }
1637                   else
1638                     {
1639                       if (solv->decisionmap[p] > 0)
1640                         break;
1641                       if (solv->decisionmap[p] == 0)
1642                         queue_push(&dq, p);
1643                     }
1644                 }
1645               if (p)
1646                 continue;
1647             }
1648           IF_POOLDEBUG (SAT_DEBUG_PROPAGATE)
1649             {
1650               POOL_DEBUG(SAT_DEBUG_PROPAGATE, "unfulfilled ");
1651               solver_printruleclass(solv, SAT_DEBUG_PROPAGATE, r);
1652             }
1653           /* dq.count < 2 cannot happen as this means that
1654            * the rule is unit */
1655           assert(dq.count > 1);
1656
1657           olevel = level;
1658           level = selectandinstall(solv, level, &dq, disablerules, r - solv->rules);
1659           if (level == 0)
1660             {
1661               queue_free(&dq);
1662               queue_free(&dqs);
1663               return;
1664             }
1665           if (level < systemlevel || level == 1)
1666             break;              /* trouble */
1667           /* something changed, so look at all rules again */
1668           n = 0;
1669         }
1670
1671       if (n != solv->nrules)    /* ran into trouble, restart */
1672         continue;
1673
1674       /* at this point we have a consistent system. now do the extras... */
1675
1676       if (doweak)
1677         {
1678           int qcount;
1679
1680           POOL_DEBUG(SAT_DEBUG_POLICY, "installing recommended packages\n");
1681           queue_empty(&dq);     /* recommended packages */
1682           queue_empty(&dqs);    /* supplemented packages */
1683           for (i = 1; i < pool->nsolvables; i++)
1684             {
1685               if (solv->decisionmap[i] < 0)
1686                 continue;
1687               if (solv->decisionmap[i] > 0)
1688                 {
1689                   /* installed, check for recommends */
1690                   Id *recp, rec, pp, p;
1691                   s = pool->solvables + i;
1692                   if (solv->ignorealreadyrecommended && s->repo == solv->installed)
1693                     continue;
1694                   /* XXX need to special case AND ? */
1695                   if (s->recommends)
1696                     {
1697                       recp = s->repo->idarraydata + s->recommends;
1698                       while ((rec = *recp++) != 0)
1699                         {
1700                           qcount = dq.count;
1701                           FOR_PROVIDES(p, pp, rec)
1702                             {
1703                               if (solv->decisionmap[p] > 0)
1704                                 {
1705                                   dq.count = qcount;
1706                                   break;
1707                                 }
1708                               else if (solv->decisionmap[p] == 0)
1709                                 {
1710                                   queue_pushunique(&dq, p);
1711                                 }
1712                             }
1713                         }
1714                     }
1715                 }
1716               else
1717                 {
1718                   s = pool->solvables + i;
1719                   if (!s->supplements)
1720                     continue;
1721                   if (!pool_installable(pool, s))
1722                     continue;
1723                   if (!solver_is_supplementing(solv, s))
1724                     continue;
1725                   queue_push(&dqs, i);
1726                 }
1727             }
1728
1729           /* filter out all packages obsoleted by installed packages */
1730           /* this is no longer needed if we have reverse obsoletes */
1731           if ((dqs.count || dq.count) && solv->installed)
1732             {
1733               Map obsmap;
1734               Id obs, *obsp, po, ppo;
1735
1736               map_init(&obsmap, pool->nsolvables);
1737               for (p = solv->installed->start; p < solv->installed->end; p++)
1738                 {
1739                   s = pool->solvables + p;
1740                   if (s->repo != solv->installed || !s->obsoletes)
1741                     continue;
1742                   if (solv->decisionmap[p] <= 0)
1743                     continue;
1744                   if (solv->noobsoletes.size && MAPTST(&solv->noobsoletes, p))
1745                     continue;
1746                   obsp = s->repo->idarraydata + s->obsoletes;
1747                   /* foreach obsoletes */
1748                   while ((obs = *obsp++) != 0)
1749                     FOR_PROVIDES(po, ppo, obs)
1750                       MAPSET(&obsmap, po);
1751                 }
1752               for (i = j = 0; i < dqs.count; i++)
1753                 if (!MAPTST(&obsmap, dqs.elements[i]))
1754                   dqs.elements[j++] = dqs.elements[i];
1755               dqs.count = j;
1756               for (i = j = 0; i < dq.count; i++)
1757                 if (!MAPTST(&obsmap, dq.elements[i]))
1758                   dq.elements[j++] = dq.elements[i];
1759               dq.count = j;
1760               map_free(&obsmap);
1761             }
1762
1763           /* filter out all already supplemented packages if requested */
1764           if (solv->ignorealreadyrecommended && dqs.count)
1765             {
1766               /* turn off all new packages */
1767               for (i = 0; i < solv->decisionq.count; i++)
1768                 {
1769                   p = solv->decisionq.elements[i];
1770                   if (p < 0)
1771                     continue;
1772                   s = pool->solvables + p;
1773                   if (s->repo && s->repo != solv->installed)
1774                     solv->decisionmap[p] = -solv->decisionmap[p];
1775                 }
1776               /* filter out old supplements */
1777               for (i = j = 0; i < dqs.count; i++)
1778                 {
1779                   p = dqs.elements[i];
1780                   s = pool->solvables + p;
1781                   if (!s->supplements)
1782                     continue;
1783                   if (!solver_is_supplementing(solv, s))
1784                     dqs.elements[j++] = p;
1785                 }
1786               dqs.count = j;
1787               /* undo turning off */
1788               for (i = 0; i < solv->decisionq.count; i++)
1789                 {
1790                   p = solv->decisionq.elements[i];
1791                   if (p < 0)
1792                     continue;
1793                   s = pool->solvables + p;
1794                   if (s->repo && s->repo != solv->installed)
1795                     solv->decisionmap[p] = -solv->decisionmap[p];
1796                 }
1797             }
1798
1799           /* multiversion doesn't mix well with supplements.
1800            * filter supplemented packages where we already decided
1801            * to install a different version (see bnc#501088) */
1802           if (dqs.count && solv->noobsoletes.size)
1803             {
1804               for (i = j = 0; i < dqs.count; i++)
1805                 {
1806                   p = dqs.elements[i];
1807                   if (MAPTST(&solv->noobsoletes, p))
1808                     {
1809                       Id p2, pp2;
1810                       s = pool->solvables + p;
1811                       FOR_PROVIDES(p2, pp2, s->name)
1812                         if (solv->decisionmap[p2] > 0 && pool->solvables[p2].name == s->name)
1813                           break;
1814                       if (p2)
1815                         continue;       /* ignore this package */
1816                     }
1817                   dqs.elements[j++] = p;
1818                 }
1819               dqs.count = j;
1820             }
1821
1822           /* make dq contain both recommended and supplemented pkgs */
1823           if (dqs.count)
1824             {
1825               for (i = 0; i < dqs.count; i++)
1826                 queue_pushunique(&dq, dqs.elements[i]);
1827             }
1828
1829           if (dq.count)
1830             {
1831               Map dqmap;
1832               int decisioncount = solv->decisionq.count;
1833
1834               if (dq.count == 1)
1835                 {
1836                   /* simple case, just one package. no need to choose  */
1837                   p = dq.elements[0];
1838                   if (dqs.count)
1839                     POOL_DEBUG(SAT_DEBUG_POLICY, "installing supplemented %s\n", solvid2str(pool, p));
1840                   else
1841                     POOL_DEBUG(SAT_DEBUG_POLICY, "installing recommended %s\n", solvid2str(pool, p));
1842                   queue_push(&solv->recommendations, p);
1843                   level = setpropagatelearn(solv, level, p, 0, 0);
1844                   continue;     /* back to main loop */
1845                 }
1846
1847               /* filter packages, this gives us the best versions */
1848               policy_filter_unwanted(solv, &dq, POLICY_MODE_RECOMMEND);
1849
1850               /* create map of result */
1851               map_init(&dqmap, pool->nsolvables);
1852               for (i = 0; i < dq.count; i++)
1853                 MAPSET(&dqmap, dq.elements[i]);
1854
1855               /* install all supplemented packages */
1856               for (i = 0; i < dqs.count; i++)
1857                 {
1858                   p = dqs.elements[i];
1859                   if (solv->decisionmap[p] || !MAPTST(&dqmap, p))
1860                     continue;
1861                   POOL_DEBUG(SAT_DEBUG_POLICY, "installing supplemented %s\n", solvid2str(pool, p));
1862                   queue_push(&solv->recommendations, p);
1863                   olevel = level;
1864                   level = setpropagatelearn(solv, level, p, 0, 0);
1865                   if (level <= olevel)
1866                     break;
1867                 }
1868               if (i < dqs.count || solv->decisionq.count < decisioncount)
1869                 {
1870                   map_free(&dqmap);
1871                   continue;
1872                 }
1873
1874               /* install all recommended packages */
1875               /* more work as we want to created branches if multiple
1876                * choices are valid */
1877               for (i = 0; i < decisioncount; i++)
1878                 {
1879                   Id rec, *recp, pp;
1880                   p = solv->decisionq.elements[i];
1881                   if (p < 0)
1882                     continue;
1883                   s = pool->solvables + p;
1884                   if (!s->repo || (solv->ignorealreadyrecommended && s->repo == solv->installed))
1885                     continue;
1886                   if (!s->recommends)
1887                     continue;
1888                   recp = s->repo->idarraydata + s->recommends;
1889                   while ((rec = *recp++) != 0)
1890                     {
1891                       queue_empty(&dq);
1892                       FOR_PROVIDES(p, pp, rec)
1893                         {
1894                           if (solv->decisionmap[p] > 0)
1895                             {
1896                               dq.count = 0;
1897                               break;
1898                             }
1899                           else if (solv->decisionmap[p] == 0 && MAPTST(&dqmap, p))
1900                             queue_pushunique(&dq, p);
1901                         }
1902                       if (!dq.count)
1903                         continue;
1904                       if (dq.count > 1)
1905                         {
1906                           /* multiple candidates, open a branch */
1907                           for (i = 1; i < dq.count; i++)
1908                             queue_push(&solv->branches, dq.elements[i]);
1909                           queue_push(&solv->branches, -level);
1910                         }
1911                       p = dq.elements[0];
1912                       POOL_DEBUG(SAT_DEBUG_POLICY, "installing recommended %s\n", solvid2str(pool, p));
1913                       queue_push(&solv->recommendations, p);
1914                       olevel = level;
1915                       level = setpropagatelearn(solv, level, p, 0, 0);
1916                       if (level <= olevel || solv->decisionq.count < decisioncount)
1917                         break;  /* we had to revert some decisions */
1918                     }
1919                   if (rec)
1920                     break;      /* had a problem above, quit loop */
1921                 }
1922               map_free(&dqmap);
1923
1924               continue;         /* back to main loop so that all deps are checked */
1925             }
1926         }
1927
1928      if (solv->distupgrade && solv->installed)
1929         {
1930           int installedone = 0;
1931
1932           /* let's see if we can install some unsupported package */
1933           POOL_DEBUG(SAT_DEBUG_SOLVER, "deciding orphaned packages\n");
1934           for (i = 0; i < solv->orphaned.count; i++)
1935             {
1936               p = solv->orphaned.elements[i];
1937               if (solv->decisionmap[p])
1938                 continue;       /* already decided */
1939               olevel = level;
1940               if (solv->distupgrade_removeunsupported)
1941                 continue;
1942               if (solv->droporphanedmap.size && MAPTST(&solv->droporphanedmap, p - solv->installed->start))
1943                 continue;
1944               POOL_DEBUG(SAT_DEBUG_SOLVER, "keeping orphaned %s\n", solvid2str(pool, p));
1945               level = setpropagatelearn(solv, level, p, 0, 0);
1946               installedone = 1;
1947               if (level < olevel)
1948                 break;
1949             }
1950           if (installedone || i < solv->orphaned.count)
1951             continue;           /* back to main loop */
1952           for (i = 0; i < solv->orphaned.count; i++)
1953             {
1954               p = solv->orphaned.elements[i];
1955               if (solv->decisionmap[p])
1956                 continue;       /* already decided */
1957               POOL_DEBUG(SAT_DEBUG_SOLVER, "removing orphaned %s\n", solvid2str(pool, p));
1958               olevel = level;
1959               level = setpropagatelearn(solv, level, -p, 0, 0);
1960               if (level < olevel)
1961                 break;
1962             }
1963           if (i < solv->orphaned.count)
1964             continue;           /* back to main loop */
1965         }
1966
1967      if (solv->solution_callback)
1968         {
1969           solv->solution_callback(solv, solv->solution_callback_data);
1970           if (solv->branches.count)
1971             {
1972               int i = solv->branches.count - 1;
1973               int l = -solv->branches.elements[i];
1974               Id why;
1975
1976               for (; i > 0; i--)
1977                 if (solv->branches.elements[i - 1] < 0)
1978                   break;
1979               p = solv->branches.elements[i];
1980               POOL_DEBUG(SAT_DEBUG_SOLVER, "branching with %s\n", solvid2str(pool, p));
1981               queue_empty(&dq);
1982               for (j = i + 1; j < solv->branches.count; j++)
1983                 queue_push(&dq, solv->branches.elements[j]);
1984               solv->branches.count = i;
1985               level = l;
1986               revert(solv, level);
1987               if (dq.count > 1)
1988                 for (j = 0; j < dq.count; j++)
1989                   queue_push(&solv->branches, dq.elements[j]);
1990               olevel = level;
1991               why = -solv->decisionq_why.elements[solv->decisionq_why.count];
1992               assert(why >= 0);
1993               level = setpropagatelearn(solv, level, p, disablerules, why);
1994               if (level == 0)
1995                 {
1996                   queue_free(&dq);
1997                   queue_free(&dqs);
1998                   return;
1999                 }
2000               continue;
2001             }
2002           /* all branches done, we're finally finished */
2003           break;
2004         }
2005
2006       /* minimization step */
2007      if (solv->branches.count)
2008         {
2009           int l = 0, lasti = -1, lastl = -1;
2010           Id why;
2011
2012           p = 0;
2013           for (i = solv->branches.count - 1; i >= 0; i--)
2014             {
2015               p = solv->branches.elements[i];
2016               if (p < 0)
2017                 l = -p;
2018               else if (p > 0 && solv->decisionmap[p] > l + 1)
2019                 {
2020                   lasti = i;
2021                   lastl = l;
2022                 }
2023             }
2024           if (lasti >= 0)
2025             {
2026               /* kill old solvable so that we do not loop */
2027               p = solv->branches.elements[lasti];
2028               solv->branches.elements[lasti] = 0;
2029               POOL_DEBUG(SAT_DEBUG_SOLVER, "minimizing %d -> %d with %s\n", solv->decisionmap[p], lastl, solvid2str(pool, p));
2030               minimizationsteps++;
2031
2032               level = lastl;
2033               revert(solv, level);
2034               why = -solv->decisionq_why.elements[solv->decisionq_why.count];
2035               assert(why >= 0);
2036               olevel = level;
2037               level = setpropagatelearn(solv, level, p, disablerules, why);
2038               if (level == 0)
2039                 {
2040                   queue_free(&dq);
2041                   queue_free(&dqs);
2042                   return;
2043                 }
2044               continue;         /* back to main loop */
2045             }
2046         }
2047       /* no minimization found, we're finally finished! */
2048       break;
2049     }
2050
2051   POOL_DEBUG(SAT_DEBUG_STATS, "solver statistics: %d learned rules, %d unsolvable, %d minimization steps\n", solv->stats_learned, solv->stats_unsolvable, minimizationsteps);
2052
2053   POOL_DEBUG(SAT_DEBUG_STATS, "done solving.\n\n");
2054   queue_free(&dq);
2055   queue_free(&dqs);
2056 #if 0
2057   solver_printdecisionq(solv, SAT_DEBUG_RESULT);
2058 #endif
2059 }
2060
2061
2062 /*-------------------------------------------------------------------
2063  *
2064  * remove disabled conflicts
2065  *
2066  * purpose: update the decisionmap after some rules were disabled.
2067  * this is used to calculate the suggested/recommended package list.
2068  * Also returns a "removed" list to undo the discisionmap changes.
2069  */
2070
2071 static void
2072 removedisabledconflicts(Solver *solv, Queue *removed)
2073 {
2074   Pool *pool = solv->pool;
2075   int i, n;
2076   Id p, why, *dp;
2077   Id new;
2078   Rule *r;
2079   Id *decisionmap = solv->decisionmap;
2080
2081   POOL_DEBUG(SAT_DEBUG_SCHUBI, "removedisabledconflicts\n");
2082   queue_empty(removed);
2083   for (i = 0; i < solv->decisionq.count; i++)
2084     {
2085       p = solv->decisionq.elements[i];
2086       if (p > 0)
2087         continue;       /* conflicts only, please */
2088       why = solv->decisionq_why.elements[i];
2089       if (why == 0)
2090         {
2091           /* no rule involved, must be a orphan package drop */
2092           continue;
2093         }
2094       /* we never do conflicts on free decisions, so there
2095        * must have been an unit rule */
2096       assert(why > 0);
2097       r = solv->rules + why;
2098       if (r->d < 0 && decisionmap[-p])
2099         {
2100           /* rule is now disabled, remove from decisionmap */
2101           POOL_DEBUG(SAT_DEBUG_SCHUBI, "removing conflict for package %s[%d]\n", solvid2str(pool, -p), -p);
2102           queue_push(removed, -p);
2103           queue_push(removed, decisionmap[-p]);
2104           decisionmap[-p] = 0;
2105         }
2106     }
2107   if (!removed->count)
2108     return;
2109   /* we removed some confliced packages. some of them might still
2110    * be in conflict, so search for unit rules and re-conflict */
2111   new = 0;
2112   for (i = n = 1, r = solv->rules + i; n < solv->nrules; i++, r++, n++)
2113     {
2114       if (i == solv->nrules)
2115         {
2116           i = 1;
2117           r = solv->rules + i;
2118         }
2119       if (r->d < 0)
2120         continue;
2121       if (!r->w2)
2122         {
2123           if (r->p < 0 && !decisionmap[-r->p])
2124             new = r->p;
2125         }
2126       else if (!r->d)
2127         {
2128           /* binary rule */
2129           if (r->p < 0 && decisionmap[-r->p] == 0 && DECISIONMAP_FALSE(r->w2))
2130             new = r->p;
2131           else if (r->w2 < 0 && decisionmap[-r->w2] == 0 && DECISIONMAP_FALSE(r->p))
2132             new = r->w2;
2133         }
2134       else
2135         {
2136           if (r->p < 0 && decisionmap[-r->p] == 0)
2137             new = r->p;
2138           if (new || DECISIONMAP_FALSE(r->p))
2139             {
2140               dp = pool->whatprovidesdata + r->d;
2141               while ((p = *dp++) != 0)
2142                 {
2143                   if (new && p == new)
2144                     continue;
2145                   if (p < 0 && decisionmap[-p] == 0)
2146                     {
2147                       if (new)
2148                         {
2149                           new = 0;
2150                           break;
2151                         }
2152                       new = p;
2153                     }
2154                   else if (!DECISIONMAP_FALSE(p))
2155                     {
2156                       new = 0;
2157                       break;
2158                     }
2159                 }
2160             }
2161         }
2162       if (new)
2163         {
2164           POOL_DEBUG(SAT_DEBUG_SCHUBI, "re-conflicting package %s[%d]\n", solvid2str(pool, -new), -new);
2165           decisionmap[-new] = -1;
2166           new = 0;
2167           n = 0;        /* redo all rules */
2168         }
2169     }
2170 }
2171
2172 static inline void
2173 undo_removedisabledconflicts(Solver *solv, Queue *removed)
2174 {
2175   int i;
2176   for (i = 0; i < removed->count; i += 2)
2177     solv->decisionmap[removed->elements[i]] = removed->elements[i + 1];
2178 }
2179
2180
2181 /*-------------------------------------------------------------------
2182  *
2183  * weaken solvable dependencies
2184  */
2185
2186 static void
2187 weaken_solvable_deps(Solver *solv, Id p)
2188 {
2189   int i;
2190   Rule *r;
2191
2192   for (i = 1, r = solv->rules + i; i < solv->rpmrules_end; i++, r++)
2193     {
2194       if (r->p != -p)
2195         continue;
2196       if ((r->d == 0 || r->d == -1) && r->w2 < 0)
2197         continue;       /* conflict */
2198       queue_push(&solv->weakruleq, i);
2199     }
2200 }
2201
2202
2203 /********************************************************************/
2204 /* main() */
2205
2206
2207 static void
2208 findrecommendedsuggested(Solver *solv)
2209 {
2210   Pool *pool = solv->pool;
2211   Queue redoq, disabledq;
2212   int goterase, i;
2213   Solvable *s;
2214   Rule *r;
2215   Map obsmap;
2216
2217   map_init(&obsmap, pool->nsolvables);
2218   if (solv->installed)
2219     {
2220       Id obs, *obsp, p, po, ppo;
2221       for (p = solv->installed->start; p < solv->installed->end; p++)
2222         {
2223           s = pool->solvables + p;
2224           if (s->repo != solv->installed || !s->obsoletes)
2225             continue;
2226           if (solv->decisionmap[p] <= 0)
2227             continue;
2228           if (solv->noobsoletes.size && MAPTST(&solv->noobsoletes, p))
2229             continue;
2230           obsp = s->repo->idarraydata + s->obsoletes;
2231           /* foreach obsoletes */
2232           while ((obs = *obsp++) != 0)
2233             FOR_PROVIDES(po, ppo, obs)
2234               MAPSET(&obsmap, po);
2235         }
2236     }
2237
2238   queue_init(&redoq);
2239   queue_init(&disabledq);
2240   goterase = 0;
2241   /* disable all erase jobs (including weak "keep uninstalled" rules) */
2242   for (i = solv->jobrules, r = solv->rules + i; i < solv->jobrules_end; i++, r++)
2243     {
2244       if (r->d < 0)     /* disabled ? */
2245         continue;
2246       if (r->p >= 0)    /* install job? */
2247         continue;
2248       queue_push(&disabledq, i);
2249       solver_disablerule(solv, r);
2250       goterase++;
2251     }
2252
2253   if (goterase)
2254     {
2255       enabledisablelearntrules(solv);
2256       removedisabledconflicts(solv, &redoq);
2257     }
2258
2259   /*
2260    * find recommended packages
2261    */
2262
2263   /* if redoq.count == 0 we already found all recommended in the
2264    * solver run */
2265   if (redoq.count || solv->dontinstallrecommended || !solv->dontshowinstalledrecommended || solv->ignorealreadyrecommended)
2266     {
2267       Id rec, *recp, p, pp;
2268
2269       /* create map of all recommened packages */
2270       solv->recommends_index = -1;
2271       MAPZERO(&solv->recommendsmap);
2272       for (i = 0; i < solv->decisionq.count; i++)
2273         {
2274           p = solv->decisionq.elements[i];
2275           if (p < 0)
2276             continue;
2277           s = pool->solvables + p;
2278           if (s->recommends)
2279             {
2280               recp = s->repo->idarraydata + s->recommends;
2281               while ((rec = *recp++) != 0)
2282                 {
2283                   FOR_PROVIDES(p, pp, rec)
2284                     if (solv->decisionmap[p] > 0)
2285                       break;
2286                   if (p)
2287                     {
2288                       if (!solv->dontshowinstalledrecommended)
2289                         {
2290                           FOR_PROVIDES(p, pp, rec)
2291                             if (solv->decisionmap[p] > 0)
2292                               MAPSET(&solv->recommendsmap, p);
2293                         }
2294                       continue; /* p != 0: already fulfilled */
2295                     }
2296                   FOR_PROVIDES(p, pp, rec)
2297                     MAPSET(&solv->recommendsmap, p);
2298                 }
2299             }
2300         }
2301       for (i = 1; i < pool->nsolvables; i++)
2302         {
2303           if (solv->decisionmap[i] < 0)
2304             continue;
2305           if (solv->decisionmap[i] > 0 && solv->dontshowinstalledrecommended)
2306             continue;
2307           if (MAPTST(&obsmap, i))
2308             continue;
2309           s = pool->solvables + i;
2310           if (!MAPTST(&solv->recommendsmap, i))
2311             {
2312               if (!s->supplements)
2313                 continue;
2314               if (!pool_installable(pool, s))
2315                 continue;
2316               if (!solver_is_supplementing(solv, s))
2317                 continue;
2318             }
2319           if (solv->dontinstallrecommended)
2320             queue_push(&solv->recommendations, i);
2321           else
2322             queue_pushunique(&solv->recommendations, i);
2323         }
2324       /* we use MODE_SUGGEST here so that repo prio is ignored */
2325       policy_filter_unwanted(solv, &solv->recommendations, POLICY_MODE_SUGGEST);
2326     }
2327
2328   /*
2329    * find suggested packages
2330    */
2331
2332   if (1)
2333     {
2334       Id sug, *sugp, p, pp;
2335
2336       /* create map of all suggests that are still open */
2337       solv->recommends_index = -1;
2338       MAPZERO(&solv->suggestsmap);
2339       for (i = 0; i < solv->decisionq.count; i++)
2340         {
2341           p = solv->decisionq.elements[i];
2342           if (p < 0)
2343             continue;
2344           s = pool->solvables + p;
2345           if (s->suggests)
2346             {
2347               sugp = s->repo->idarraydata + s->suggests;
2348               while ((sug = *sugp++) != 0)
2349                 {
2350                   FOR_PROVIDES(p, pp, sug)
2351                     if (solv->decisionmap[p] > 0)
2352                       break;
2353                   if (p)
2354                     {
2355                       if (!solv->dontshowinstalledrecommended)
2356                         {
2357                           FOR_PROVIDES(p, pp, sug)
2358                             if (solv->decisionmap[p] > 0)
2359                               MAPSET(&solv->suggestsmap, p);
2360                         }
2361                       continue; /* already fulfilled */
2362                     }
2363                   FOR_PROVIDES(p, pp, sug)
2364                     MAPSET(&solv->suggestsmap, p);
2365                 }
2366             }
2367         }
2368       for (i = 1; i < pool->nsolvables; i++)
2369         {
2370           if (solv->decisionmap[i] < 0)
2371             continue;
2372           if (solv->decisionmap[i] > 0 && solv->dontshowinstalledrecommended)
2373             continue;
2374           if (MAPTST(&obsmap, i))
2375             continue;
2376           s = pool->solvables + i;
2377           if (!MAPTST(&solv->suggestsmap, i))
2378             {
2379               if (!s->enhances)
2380                 continue;
2381               if (!pool_installable(pool, s))
2382                 continue;
2383               if (!solver_is_enhancing(solv, s))
2384                 continue;
2385             }
2386           queue_push(&solv->suggestions, i);
2387         }
2388       policy_filter_unwanted(solv, &solv->suggestions, POLICY_MODE_SUGGEST);
2389     }
2390
2391   /* undo removedisabledconflicts */
2392   if (redoq.count)
2393     undo_removedisabledconflicts(solv, &redoq);
2394   queue_free(&redoq);
2395
2396   /* undo job rule disabling */
2397   for (i = 0; i < disabledq.count; i++)
2398     solver_enablerule(solv, solv->rules + disabledq.elements[i]);
2399   queue_free(&disabledq);
2400   map_free(&obsmap);
2401 }
2402
2403 void
2404 solver_calculate_noobsmap(Pool *pool, Queue *job, Map *noobsmap)
2405 {
2406   int i;
2407   Id how, what, select;
2408   Id p, pp;
2409   for (i = 0; i < job->count; i += 2)
2410     {
2411       how = job->elements[i];
2412       if ((how & SOLVER_JOBMASK) != SOLVER_NOOBSOLETES)
2413         continue;
2414       what = job->elements[i + 1];
2415       select = how & SOLVER_SELECTMASK;
2416       if (!noobsmap->size)
2417         map_grow(noobsmap, pool->nsolvables);
2418       FOR_JOB_SELECT(p, pp, select, what)
2419         MAPSET(noobsmap, p);
2420     }
2421 }
2422
2423 /*
2424  *
2425  * solve job queue
2426  *
2427  */
2428
2429 void
2430 solver_solve(Solver *solv, Queue *job)
2431 {
2432   Pool *pool = solv->pool;
2433   Repo *installed = solv->installed;
2434   int i;
2435   int oldnrules;
2436   Map addedmap;                /* '1' == have rpm-rules for solvable */
2437   Map installcandidatemap;
2438   Id how, what, select, name, weak, p, pp, d;
2439   Queue q;
2440   Solvable *s;
2441   Rule *r;
2442   int now, solve_start;
2443   int hasdupjob = 0;
2444
2445   solve_start = sat_timems(0);
2446
2447   /* log solver options */
2448   POOL_DEBUG(SAT_DEBUG_STATS, "solver started\n");
2449   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);
2450   POOL_DEBUG(SAT_DEBUG_STATS, "distupgrade=%d distupgrade_removeunsupported=%d\n", solv->distupgrade, solv->distupgrade_removeunsupported);
2451   POOL_DEBUG(SAT_DEBUG_STATS, "allowuninstall=%d, allowdowngrade=%d, allowarchchange=%d, allowvendorchange=%d\n", solv->allowuninstall, solv->allowdowngrade, solv->allowarchchange, solv->allowvendorchange);
2452   POOL_DEBUG(SAT_DEBUG_STATS, "promoteepoch=%d, novirtualconflicts=%d, allowselfconflicts=%d\n", pool->promoteepoch, pool->novirtualconflicts, pool->allowselfconflicts);
2453   POOL_DEBUG(SAT_DEBUG_STATS, "obsoleteusesprovides=%d, implicitobsoleteusesprovides=%d, obsoleteusescolors=%d\n", pool->obsoleteusesprovides, pool->implicitobsoleteusesprovides, pool->obsoleteusescolors);
2454   POOL_DEBUG(SAT_DEBUG_STATS, "dontinstallrecommended=%d, ignorealreadyrecommended=%d, dontshowinstalledrecommended=%d\n", solv->dontinstallrecommended, solv->ignorealreadyrecommended, solv->dontshowinstalledrecommended);
2455
2456   /* create whatprovides if not already there */
2457   if (!pool->whatprovides)
2458     pool_createwhatprovides(pool);
2459
2460   /* create obsolete index */
2461   policy_create_obsolete_index(solv);
2462
2463   /* remember job */
2464   queue_free(&solv->job);
2465   queue_init_clone(&solv->job, job);
2466
2467   /*
2468    * create basic rule set of all involved packages
2469    * use addedmap bitmap to make sure we don't create rules twice
2470    */
2471
2472   /* create noobsolete map if needed */
2473   solver_calculate_noobsmap(pool, job, &solv->noobsoletes);
2474
2475   map_init(&addedmap, pool->nsolvables);
2476   MAPSET(&addedmap, SYSTEMSOLVABLE);
2477
2478   map_init(&installcandidatemap, pool->nsolvables);
2479   queue_init(&q);
2480
2481   now = sat_timems(0);
2482   /*
2483    * create rules for all package that could be involved with the solving
2484    * so called: rpm rules
2485    *
2486    */
2487   if (installed)
2488     {
2489       /* check for verify jobs */
2490       for (i = 0; i < job->count; i += 2)
2491         {
2492           how = job->elements[i];
2493           what = job->elements[i + 1];
2494           select = how & SOLVER_SELECTMASK;
2495           switch (how & SOLVER_JOBMASK)
2496             {
2497             case SOLVER_VERIFY:
2498               FOR_JOB_SELECT(p, pp, select, what)
2499                 {
2500                   s = pool->solvables + p;
2501                   if (!solv->installed || s->repo != solv->installed)
2502                     continue;
2503                   if (!solv->fixmap.size)
2504                     map_grow(&solv->fixmap, solv->installed->end - solv->installed->start);
2505                   MAPSET(&solv->fixmap, p - solv->installed->start);
2506                 }
2507               break;
2508             default:
2509               break;
2510             }
2511         }
2512
2513       oldnrules = solv->nrules;
2514       POOL_DEBUG(SAT_DEBUG_SCHUBI, "*** create rpm rules for installed solvables ***\n");
2515       FOR_REPO_SOLVABLES(installed, p, s)
2516         solver_addrpmrulesforsolvable(solv, s, &addedmap);
2517       POOL_DEBUG(SAT_DEBUG_STATS, "added %d rpm rules for installed solvables\n", solv->nrules - oldnrules);
2518       POOL_DEBUG(SAT_DEBUG_SCHUBI, "*** create rpm rules for updaters of installed solvables ***\n");
2519       oldnrules = solv->nrules;
2520       FOR_REPO_SOLVABLES(installed, p, s)
2521         solver_addrpmrulesforupdaters(solv, s, &addedmap, 1);
2522       POOL_DEBUG(SAT_DEBUG_STATS, "added %d rpm rules for updaters of installed solvables\n", solv->nrules - oldnrules);
2523     }
2524
2525   /*
2526    * create rules for all packages involved in the job
2527    * (to be installed or removed)
2528    */
2529
2530   POOL_DEBUG(SAT_DEBUG_SCHUBI, "*** create rpm rules for packages involved with a job ***\n");
2531   oldnrules = solv->nrules;
2532   for (i = 0; i < job->count; i += 2)
2533     {
2534       how = job->elements[i];
2535       what = job->elements[i + 1];
2536       select = how & SOLVER_SELECTMASK;
2537
2538       switch (how & SOLVER_JOBMASK)
2539         {
2540         case SOLVER_INSTALL:
2541           FOR_JOB_SELECT(p, pp, select, what)
2542             {
2543               MAPSET(&installcandidatemap, p);
2544               solver_addrpmrulesforsolvable(solv, pool->solvables + p, &addedmap);
2545             }
2546           break;
2547         case SOLVER_DISTUPGRADE:
2548           if (!solv->distupgrade)
2549             hasdupjob = 1;
2550           break;
2551         default:
2552           break;
2553         }
2554     }
2555   POOL_DEBUG(SAT_DEBUG_STATS, "added %d rpm rules for packages involved in a job\n", solv->nrules - oldnrules);
2556
2557
2558   /*
2559    * add rules for suggests, enhances
2560    */
2561   POOL_DEBUG(SAT_DEBUG_SCHUBI, "*** create rpm rules for suggested/enhanced packages ***\n");
2562   oldnrules = solv->nrules;
2563   solver_addrpmrulesforweak(solv, &addedmap);
2564   POOL_DEBUG(SAT_DEBUG_STATS, "added %d rpm rules because of weak dependencies\n", solv->nrules - oldnrules);
2565
2566   /*
2567    * first pass done, we now have all the rpm rules we need.
2568    * unify existing rules before going over all job rules and
2569    * policy rules.
2570    * at this point the system is always solvable,
2571    * as an empty system (remove all packages) is a valid solution
2572    */
2573
2574   IF_POOLDEBUG (SAT_DEBUG_STATS)
2575     {
2576       int possible = 0, installable = 0;
2577       for (i = 1; i < pool->nsolvables; i++)
2578         {
2579           if (pool_installable(pool, pool->solvables + i))
2580             installable++;
2581           if (MAPTST(&addedmap, i))
2582             possible++;
2583         }
2584       POOL_DEBUG(SAT_DEBUG_STATS, "%d of %d installable solvables considered for solving\n", possible, installable);
2585     }
2586
2587   solver_unifyrules(solv);                          /* remove duplicate rpm rules */
2588   solv->rpmrules_end = solv->nrules;              /* mark end of rpm rules */
2589
2590   POOL_DEBUG(SAT_DEBUG_STATS, "rpm rule memory usage: %d K\n", solv->nrules * (int)sizeof(Rule) / 1024);
2591   POOL_DEBUG(SAT_DEBUG_STATS, "rpm rule creation took %d ms\n", sat_timems(now));
2592
2593   /* create dup maps if needed. We need the maps early to create our
2594    * update rules */
2595   if (hasdupjob)
2596     solver_createdupmaps(solv);
2597
2598   /*
2599    * create feature rules
2600    *
2601    * foreach installed:
2602    *   create assertion (keep installed, if no update available)
2603    *   or
2604    *   create update rule (A|update1(A)|update2(A)|...)
2605    *
2606    * those are used later on to keep a version of the installed packages in
2607    * best effort mode
2608    */
2609
2610   POOL_DEBUG(SAT_DEBUG_SCHUBI, "*** Add feature rules ***\n");
2611   solv->featurerules = solv->nrules;              /* mark start of feature rules */
2612   if (installed)
2613     {
2614       /* foreach possibly installed solvable */
2615       for (i = installed->start, s = pool->solvables + i; i < installed->end; i++, s++)
2616         {
2617           if (s->repo != installed)
2618             {
2619               solver_addrule(solv, 0, 0);       /* create dummy rule */
2620               continue;
2621             }
2622           solver_addupdaterule(solv, s, 1);    /* allow s to be updated */
2623         }
2624       /* make sure we accounted for all rules */
2625       assert(solv->nrules - solv->featurerules == installed->end - installed->start);
2626     }
2627   solv->featurerules_end = solv->nrules;
2628
2629     /*
2630      * Add update rules for installed solvables
2631      *
2632      * almost identical to feature rules
2633      * except that downgrades/archchanges/vendorchanges are not allowed
2634      */
2635
2636   POOL_DEBUG(SAT_DEBUG_SCHUBI, "*** Add update rules ***\n");
2637   solv->updaterules = solv->nrules;
2638
2639   if (installed)
2640     { /* foreach installed solvables */
2641       /* we create all update rules, but disable some later on depending on the job */
2642       for (i = installed->start, s = pool->solvables + i; i < installed->end; i++, s++)
2643         {
2644           Rule *sr;
2645
2646           if (s->repo != installed)
2647             {
2648               solver_addrule(solv, 0, 0);       /* create dummy rule */
2649               continue;
2650             }
2651           solver_addupdaterule(solv, s, 0);     /* allowall = 0: downgrades not allowed */
2652           /*
2653            * check for and remove duplicate
2654            */
2655           r = solv->rules + solv->nrules - 1;           /* r: update rule */
2656           sr = r - (installed->end - installed->start); /* sr: feature rule */
2657           /* it's orphaned if there is no feature rule or the feature rule
2658            * consists just of the installed package */
2659           if (!sr->p || (sr->p == i && !sr->d && !sr->w2))
2660             queue_push(&solv->orphaned, i);
2661           if (!r->p)
2662             {
2663               assert(solv->distupgrade && !sr->p);
2664               continue;
2665             }
2666           if (!solver_samerule(solv, r, sr))
2667             {
2668               /* identical rule, kill unneeded one */
2669               if (solv->allowuninstall)
2670                 {
2671                   /* keep feature rule, make it weak */
2672                   memset(r, 0, sizeof(*r));
2673                   queue_push(&solv->weakruleq, sr - solv->rules);
2674                 }
2675               else
2676                 {
2677                   /* keep update rule */
2678                   memset(sr, 0, sizeof(*sr));
2679                 }
2680             }
2681           else if (solv->allowuninstall)
2682             {
2683               /* make both feature and update rule weak */
2684               queue_push(&solv->weakruleq, r - solv->rules);
2685               queue_push(&solv->weakruleq, sr - solv->rules);
2686             }
2687           else
2688             solver_disablerule(solv, sr);
2689         }
2690       /* consistency check: we added a rule for _every_ installed solvable */
2691       assert(solv->nrules - solv->updaterules == installed->end - installed->start);
2692     }
2693   solv->updaterules_end = solv->nrules;
2694
2695
2696   /*
2697    * now add all job rules
2698    */
2699
2700   POOL_DEBUG(SAT_DEBUG_SCHUBI, "*** Add JOB rules ***\n");
2701
2702   solv->jobrules = solv->nrules;
2703   for (i = 0; i < job->count; i += 2)
2704     {
2705       oldnrules = solv->nrules;
2706
2707       how = job->elements[i];
2708       what = job->elements[i + 1];
2709       weak = how & SOLVER_WEAK;
2710       select = how & SOLVER_SELECTMASK;
2711       switch (how & SOLVER_JOBMASK)
2712         {
2713         case SOLVER_INSTALL:
2714           POOL_DEBUG(SAT_DEBUG_JOB, "job: %sinstall %s\n", weak ? "weak " : "", solver_select2str(solv, select, what));
2715           if (select == SOLVER_SOLVABLE)
2716             {
2717               p = what;
2718               d = 0;
2719             }
2720           else
2721             {
2722               queue_empty(&q);
2723               FOR_JOB_SELECT(p, pp, select, what)
2724                 queue_push(&q, p);
2725               if (!q.count)
2726                 {
2727                   /* no candidate found, make this an impossible rule */
2728                   queue_push(&q, -SYSTEMSOLVABLE);
2729                 }
2730               p = queue_shift(&q);      /* get first candidate */
2731               d = !q.count ? 0 : pool_queuetowhatprovides(pool, &q);    /* internalize */
2732             }
2733           solver_addrule(solv, p, d);           /* add install rule */
2734           queue_push(&solv->ruletojob, i);
2735           if (weak)
2736             queue_push(&solv->weakruleq, solv->nrules - 1);
2737           break;
2738         case SOLVER_ERASE:
2739           POOL_DEBUG(SAT_DEBUG_JOB, "job: %serase %s\n", weak ? "weak " : "", solver_select2str(solv, select, what));
2740           if (select == SOLVER_SOLVABLE && solv->installed && pool->solvables[what].repo == solv->installed)
2741             {
2742               /* special case for "erase a specific solvable": we also
2743                * erase all other solvables with that name, so that they
2744                * don't get picked up as replacement */
2745               name = pool->solvables[what].name;
2746               FOR_PROVIDES(p, pp, name)
2747                 {
2748                   if (p == what)
2749                     continue;
2750                   s = pool->solvables + p;
2751                   if (s->name != name)
2752                     continue;
2753                   /* keep other versions installed */
2754                   if (s->repo == solv->installed)
2755                     continue;
2756                   /* keep installcandidates of other jobs */
2757                   if (MAPTST(&installcandidatemap, p))
2758                     continue;
2759                   solver_addrule(solv, -p, 0);                  /* remove by Id */
2760                   queue_push(&solv->ruletojob, i);
2761                   if (weak)
2762                     queue_push(&solv->weakruleq, solv->nrules - 1);
2763                 }
2764             }
2765           FOR_JOB_SELECT(p, pp, select, what)
2766             {
2767               solver_addrule(solv, -p, 0);
2768               queue_push(&solv->ruletojob, i);
2769               if (weak)
2770                 queue_push(&solv->weakruleq, solv->nrules - 1);
2771             }
2772           break;
2773
2774         case SOLVER_UPDATE:
2775           POOL_DEBUG(SAT_DEBUG_JOB, "job: %supdate %s\n", weak ? "weak " : "", solver_select2str(solv, select, what));
2776           FOR_JOB_SELECT(p, pp, select, what)
2777             {
2778               s = pool->solvables + p;
2779               if (!solv->installed || s->repo != solv->installed)
2780                 continue;
2781               if (!solv->updatemap.size)
2782                 map_grow(&solv->updatemap, solv->installed->end - solv->installed->start);
2783               MAPSET(&solv->updatemap, p - solv->installed->start);
2784             }
2785           break;
2786         case SOLVER_VERIFY:
2787           POOL_DEBUG(SAT_DEBUG_JOB, "job: %sverify %s\n", weak ? "weak " : "", solver_select2str(solv, select, what));
2788           break;
2789         case SOLVER_WEAKENDEPS:
2790           POOL_DEBUG(SAT_DEBUG_JOB, "job: %sweaken deps %s\n", weak ? "weak " : "", solver_select2str(solv, select, what));
2791           if (select != SOLVER_SOLVABLE)
2792             break;
2793           s = pool->solvables + what;
2794           weaken_solvable_deps(solv, what);
2795           break;
2796         case SOLVER_NOOBSOLETES:
2797           POOL_DEBUG(SAT_DEBUG_JOB, "job: %sno obsolete %s\n", weak ? "weak " : "", solver_select2str(solv, select, what));
2798           break;
2799         case SOLVER_LOCK:
2800           POOL_DEBUG(SAT_DEBUG_JOB, "job: %slock %s\n", weak ? "weak " : "", solver_select2str(solv, select, what));
2801           FOR_JOB_SELECT(p, pp, select, what)
2802             {
2803               s = pool->solvables + p;
2804               if (installed && s->repo == installed)
2805                 solver_addrule(solv, p, 0);
2806               else
2807                 solver_addrule(solv, -p, 0);
2808               queue_push(&solv->ruletojob, i);
2809               if (weak)
2810                 queue_push(&solv->weakruleq, solv->nrules - 1);
2811             }
2812           break;
2813         case SOLVER_DISTUPGRADE:
2814           POOL_DEBUG(SAT_DEBUG_JOB, "job: distupgrade %s\n", solver_select2str(solv, select, what));
2815           break;
2816         case SOLVER_DROP_ORPHANED:
2817           POOL_DEBUG(SAT_DEBUG_JOB, "job: drop orphaned %s\n", solver_select2str(solv, select, what));
2818           FOR_JOB_SELECT(p, pp, select, what)
2819             {
2820               s = pool->solvables + p;
2821               if (!installed || s->repo != installed)
2822                 continue;
2823               if (!solv->droporphanedmap.size)
2824                 map_grow(&solv->droporphanedmap, installed->end - installed->start);
2825               MAPSET(&solv->droporphanedmap, p - installed->start);
2826             }
2827           break;
2828         default:
2829           POOL_DEBUG(SAT_DEBUG_JOB, "job: unknown job\n");
2830           break;
2831         }
2832
2833         /*
2834          * debug
2835          */
2836
2837       IF_POOLDEBUG (SAT_DEBUG_JOB)
2838         {
2839           int j;
2840           if (solv->nrules == oldnrules)
2841             POOL_DEBUG(SAT_DEBUG_JOB, " - no rule created\n");
2842           for (j = oldnrules; j < solv->nrules; j++)
2843             {
2844               POOL_DEBUG(SAT_DEBUG_JOB, " - job ");
2845               solver_printrule(solv, SAT_DEBUG_JOB, solv->rules + j);
2846             }
2847         }
2848     }
2849   assert(solv->ruletojob.count == solv->nrules - solv->jobrules);
2850   solv->jobrules_end = solv->nrules;
2851
2852   /* now create infarch and dup rules */
2853   if (!solv->noinfarchcheck)
2854     {
2855       solver_addinfarchrules(solv, &addedmap);
2856       if (pool->obsoleteusescolors)
2857         {
2858           /* currently doesn't work well with infarch rules, so make
2859            * them weak */
2860           for (i = solv->infarchrules; i < solv->infarchrules_end; i++)
2861             queue_push(&solv->weakruleq, i);
2862         }
2863     }
2864   else
2865     solv->infarchrules = solv->infarchrules_end = solv->nrules;
2866
2867   if (hasdupjob)
2868     {
2869       solver_addduprules(solv, &addedmap);
2870       solver_freedupmaps(solv); /* no longer needed */
2871     }
2872   else
2873     solv->duprules = solv->duprules_end = solv->nrules;
2874
2875   if (1)
2876     {
2877       extern void addchoicerules(Solver *solv);
2878       addchoicerules(solv);
2879     }
2880   else
2881     solv->choicerules = solv->choicerules_end = solv->nrules;
2882
2883   /* all rules created
2884    * --------------------------------------------------------------
2885    * prepare for solving
2886    */
2887
2888   /* free unneeded memory */
2889   map_free(&addedmap);
2890   map_free(&installcandidatemap);
2891   queue_free(&q);
2892
2893   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);
2894
2895   /* create weak map */
2896   map_init(&solv->weakrulemap, solv->nrules);
2897   for (i = 0; i < solv->weakruleq.count; i++)
2898     {
2899       p = solv->weakruleq.elements[i];
2900       MAPSET(&solv->weakrulemap, p);
2901     }
2902
2903   /* all new rules are learnt after this point */
2904   solv->learntrules = solv->nrules;
2905
2906   /* create watches chains */
2907   makewatches(solv);
2908
2909   /* create assertion index. it is only used to speed up
2910    * makeruledecsions() a bit */
2911   for (i = 1, r = solv->rules + i; i < solv->nrules; i++, r++)
2912     if (r->p && !r->w2 && (r->d == 0 || r->d == -1))
2913       queue_push(&solv->ruleassertions, i);
2914
2915   /* disable update rules that conflict with our job */
2916   solver_disablepolicyrules(solv);
2917
2918   /* make decisions based on job/update assertions */
2919   makeruledecisions(solv);
2920   POOL_DEBUG(SAT_DEBUG_SOLVER, "problems so far: %d\n", solv->problems.count);
2921
2922   /*
2923    * ********************************************
2924    * solve!
2925    * ********************************************
2926    */
2927
2928   now = sat_timems(0);
2929   solver_run_sat(solv, 1, solv->dontinstallrecommended ? 0 : 1);
2930   POOL_DEBUG(SAT_DEBUG_STATS, "solver took %d ms\n", sat_timems(now));
2931
2932   /*
2933    * calculate recommended/suggested packages
2934    */
2935   findrecommendedsuggested(solv);
2936
2937   /*
2938    * prepare solution queue if there were problems
2939    */
2940   solver_prepare_solutions(solv);
2941
2942   /*
2943    * finally prepare transaction info
2944    */
2945   transaction_calculate(&solv->trans, &solv->decisionq, &solv->noobsoletes);
2946
2947   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);
2948   POOL_DEBUG(SAT_DEBUG_STATS, "solver_solve took %d ms\n", sat_timems(solve_start));
2949 }
2950
2951 /***********************************************************************/
2952 /* disk usage computations */
2953
2954 /*-------------------------------------------------------------------
2955  *
2956  * calculate DU changes
2957  */
2958
2959 void
2960 solver_calc_duchanges(Solver *solv, DUChanges *mps, int nmps)
2961 {
2962   Map installedmap;
2963
2964   solver_create_state_maps(solv, &installedmap, 0);
2965   pool_calc_duchanges(solv->pool, &installedmap, mps, nmps);
2966   map_free(&installedmap);
2967 }
2968
2969
2970 /*-------------------------------------------------------------------
2971  *
2972  * calculate changes in install size
2973  */
2974
2975 int
2976 solver_calc_installsizechange(Solver *solv)
2977 {
2978   Map installedmap;
2979   int change;
2980
2981   solver_create_state_maps(solv, &installedmap, 0);
2982   change = pool_calc_installsizechange(solv->pool, &installedmap);
2983   map_free(&installedmap);
2984   return change;
2985 }
2986
2987 void
2988 solver_trivial_installable(Solver *solv, Queue *pkgs, Queue *res)
2989 {
2990   Map installedmap;
2991   solver_create_state_maps(solv, &installedmap, 0);
2992   pool_trivial_installable_noobsoletesmap(solv->pool, &installedmap, pkgs, res, solv->noobsoletes.size ? &solv->noobsoletes : 0);
2993   map_free(&installedmap);
2994 }
2995
2996
2997 #if 0
2998 #define FIND_INVOLVED_DEBUG 0
2999 void
3000 solver_find_involved(Solver *solv, Queue *installedq, Solvable *ts, Queue *q)
3001 {
3002   Pool *pool = solv->pool;
3003   Map im;
3004   Map installedm;
3005   Solvable *s;
3006   Queue iq;
3007   Queue installedq_internal;
3008   Id tp, ip, p, pp, req, *reqp, sup, *supp;
3009   int i, count;
3010
3011   tp = ts - pool->solvables;
3012   queue_init(&iq);
3013   queue_init(&installedq_internal);
3014   map_init(&im, pool->nsolvables);
3015   map_init(&installedm, pool->nsolvables);
3016
3017   if (!installedq)
3018     {
3019       installedq = &installedq_internal;
3020       if (solv->installed)
3021         {
3022           for (ip = solv->installed->start; ip < solv->installed->end; ip++)
3023             {
3024               s = pool->solvables + ip;
3025               if (s->repo != solv->installed)
3026                 continue;
3027               queue_push(installedq, ip);
3028             }
3029         }
3030     }
3031   for (i = 0; i < installedq->count; i++)
3032     {
3033       ip = installedq->elements[i];
3034       MAPSET(&installedm, ip);
3035       MAPSET(&im, ip);
3036     }
3037
3038   queue_push(&iq, ts - pool->solvables);
3039   while (iq.count)
3040     {
3041       ip = queue_shift(&iq);
3042       if (!MAPTST(&im, ip))
3043         continue;
3044       if (!MAPTST(&installedm, ip))
3045         continue;
3046       MAPCLR(&im, ip);
3047       s = pool->solvables + ip;
3048 #if FIND_INVOLVED_DEBUG
3049       printf("hello %s\n", solvable2str(pool, s));
3050 #endif
3051       if (s->requires)
3052         {
3053           reqp = s->repo->idarraydata + s->requires;
3054           while ((req = *reqp++) != 0)
3055             {
3056               if (req == SOLVABLE_PREREQMARKER)
3057                 continue;
3058               /* count number of installed packages that match */
3059               count = 0;
3060               FOR_PROVIDES(p, pp, req)
3061                 if (MAPTST(&installedm, p))
3062                   count++;
3063               if (count > 1)
3064                 continue;
3065               FOR_PROVIDES(p, pp, req)
3066                 {
3067                   if (MAPTST(&im, p))
3068                     {
3069 #if FIND_INVOLVED_DEBUG
3070                       printf("%s requires %s\n", solvid2str(pool, ip), solvid2str(pool, p));
3071 #endif
3072                       queue_push(&iq, p);
3073                     }
3074                 }
3075             }
3076         }
3077       if (s->recommends)
3078         {
3079           reqp = s->repo->idarraydata + s->recommends;
3080           while ((req = *reqp++) != 0)
3081             {
3082               count = 0;
3083               FOR_PROVIDES(p, pp, req)
3084                 if (MAPTST(&installedm, p))
3085                   count++;
3086               if (count > 1)
3087                 continue;
3088               FOR_PROVIDES(p, pp, req)
3089                 {
3090                   if (MAPTST(&im, p))
3091                     {
3092 #if FIND_INVOLVED_DEBUG
3093                       printf("%s recommends %s\n", solvid2str(pool, ip), solvid2str(pool, p));
3094 #endif
3095                       queue_push(&iq, p);
3096                     }
3097                 }
3098             }
3099         }
3100       if (!iq.count)
3101         {
3102           /* supplements pass */
3103           for (i = 0; i < installedq->count; i++)
3104             {
3105               ip = installedq->elements[i];
3106               s = pool->solvables + ip;
3107               if (!s->supplements)
3108                 continue;
3109               if (!MAPTST(&im, ip))
3110                 continue;
3111               supp = s->repo->idarraydata + s->supplements;
3112               while ((sup = *supp++) != 0)
3113                 if (!dep_possible(solv, sup, &im) && dep_possible(solv, sup, &installedm))
3114                   break;
3115               /* no longer supplemented, also erase */
3116               if (sup)
3117                 {
3118 #if FIND_INVOLVED_DEBUG
3119                   printf("%s supplemented\n", solvid2str(pool, ip));
3120 #endif
3121                   queue_push(&iq, ip);
3122                 }
3123             }
3124         }
3125     }
3126
3127   for (i = 0; i < installedq->count; i++)
3128     {
3129       ip = installedq->elements[i];
3130       if (MAPTST(&im, ip))
3131         queue_push(&iq, ip);
3132     }
3133
3134   while (iq.count)
3135     {
3136       ip = queue_shift(&iq);
3137       if (!MAPTST(&installedm, ip))
3138         continue;
3139       s = pool->solvables + ip;
3140 #if FIND_INVOLVED_DEBUG
3141       printf("bye %s\n", solvable2str(pool, s));
3142 #endif
3143       if (s->requires)
3144         {
3145           reqp = s->repo->idarraydata + s->requires;
3146           while ((req = *reqp++) != 0)
3147             {
3148               FOR_PROVIDES(p, pp, req)
3149                 {
3150                   if (!MAPTST(&im, p))
3151                     {
3152                       if (p == tp)
3153                         continue;
3154 #if FIND_INVOLVED_DEBUG
3155                       printf("%s requires %s\n", solvid2str(pool, ip), solvid2str(pool, p));
3156 #endif
3157                       MAPSET(&im, p);
3158                       queue_push(&iq, p);
3159                     }
3160                 }
3161             }
3162         }
3163       if (s->recommends)
3164         {
3165           reqp = s->repo->idarraydata + s->recommends;
3166           while ((req = *reqp++) != 0)
3167             {
3168               FOR_PROVIDES(p, pp, req)
3169                 {
3170                   if (!MAPTST(&im, p))
3171                     {
3172                       if (p == tp)
3173                         continue;
3174 #if FIND_INVOLVED_DEBUG
3175                       printf("%s recommends %s\n", solvid2str(pool, ip), solvid2str(pool, p));
3176 #endif
3177                       MAPSET(&im, p);
3178                       queue_push(&iq, p);
3179                     }
3180                 }
3181             }
3182         }
3183       if (!iq.count)
3184         {
3185           /* supplements pass */
3186           for (i = 0; i < installedq->count; i++)
3187             {
3188               ip = installedq->elements[i];
3189               if (ip == tp)
3190                 continue;
3191               s = pool->solvables + ip;
3192               if (!s->supplements)
3193                 continue;
3194               if (MAPTST(&im, ip))
3195                 continue;
3196               supp = s->repo->idarraydata + s->supplements;
3197               while ((sup = *supp++) != 0)
3198                 if (dep_possible(solv, sup, &im))
3199                   break;
3200               if (sup)
3201                 {
3202 #if FIND_INVOLVED_DEBUG
3203                   printf("%s supplemented\n", solvid2str(pool, ip));
3204 #endif
3205                   MAPSET(&im, ip);
3206                   queue_push(&iq, ip);
3207                 }
3208             }
3209         }
3210     }
3211
3212   queue_free(&iq);
3213
3214   /* convert map into result */
3215   for (i = 0; i < installedq->count; i++)
3216     {
3217       ip = installedq->elements[i];
3218       if (MAPTST(&im, ip))
3219         continue;
3220       if (ip == ts - pool->solvables)
3221         continue;
3222       queue_push(q, ip);
3223     }
3224   map_free(&im);
3225   map_free(&installedm);
3226   queue_free(&installedq_internal);
3227 }
3228 #endif
3229