path: root/lib/libalpm/deps.c

/*
 *  deps.c
 *
 *  Copyright (c) 2002-2007 by Judd Vinet <jvinet@zeroflux.org>
 *  Copyright (c) 2005 by Aurelien Foret <orelien@chez.com>
 *  Copyright (c) 2005, 2006 by Miklos Vajna <vmiklos@frugalware.org>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "config.h"

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

/* libalpm */
#include "deps.h"
#include "alpm_list.h"
#include "util.h"
#include "log.h"
#include "error.h"
#include "package.h"
#include "db.h"
#include "cache.h"
#include "handle.h"

static pmgraph_t *_alpm_graph_new(void)
{
  pmgraph_t *graph = NULL;

  MALLOC(graph, sizeof(pmgraph_t), RET_ERR(PM_ERR_MEMORY, NULL));

  if(graph) {
    graph->state = 0;
    graph->data = NULL;
    graph->parent = NULL;
    graph->children = NULL;
    graph->childptr = NULL;
  }
  return(graph);
}

static void _alpm_graph_free(void *data)
{
  pmgraph_t *graph = data;
  alpm_list_free(graph->children);
  free(graph);
}

pmdepmissing_t *_alpm_depmiss_new(const char *target, pmdepmod_t depmod,
    const char *depname, const char *depversion)
{
  pmdepmissing_t *miss;

  ALPM_LOG_FUNC;

  MALLOC(miss, sizeof(pmdepmissing_t), RET_ERR(PM_ERR_MEMORY, NULL));

  strncpy(miss->target, target, PKG_NAME_LEN);
  miss->depend.mod = depmod;
  strncpy(miss->depend.name, depname, PKG_NAME_LEN);
  if(depversion) {
    strncpy(miss->depend.version, depversion, PKG_VERSION_LEN);
  } else {
    miss->depend.version[0] = 0;
  }

  return(miss);
}

/* Convert a list of pmpkg_t * to a graph structure,
 * with a edge for each dependency.
 * Returns a list of vertices (one vertex = one package)
 * (used by alpm_sortbydeps)
 */
static alpm_list_t *_alpm_graph_init(alpm_list_t *targets)
{
  alpm_list_t *i, *j, *k;
  alpm_list_t *vertices = NULL;
  /* We create the vertices */
  for(i = targets; i; i = i->next) {
    pmgraph_t *vertex = _alpm_graph_new();
    vertex->data = (void *)i->data;
    vertices = alpm_list_add(vertices, vertex);
  }

  /* We compute the edges */
  for(i = vertices; i; i = i->next) {
    pmgraph_t *vertex_i = i->data;
    pmpkg_t *p_i = vertex_i->data;
    /* TODO this should be somehow combined with alpm_checkdeps */
    for(j = vertices; j; j = j->next) {
      pmgraph_t *vertex_j = j->data;
      pmpkg_t *p_j = vertex_j->data;
      int child = 0;
      for(k = alpm_pkg_get_depends(p_i); k && !child; k = k->next) {
        pmdepend_t *depend = k->data;
        child = alpm_depcmp(p_j, depend);
      }
      if(child) {
        vertex_i->children =
          alpm_list_add(vertex_i->children, vertex_j);
      }
    }
    vertex_i->childptr = vertex_i->children;
  }
  return(vertices);
}

/* Re-order a list of target packages with respect to their dependencies.
 *
 * Example (PM_TRANS_TYPE_ADD):
 *   A depends on C
 *   B depends on A
 *   Target order is A,B,C,D
 *
 *   Should be re-ordered to C,A,B,D
 *
 * mode should be either PM_TRANS_TYPE_ADD or PM_TRANS_TYPE_REMOVE.  This
 * affects the dependency order sortbydeps() will use.
 *
 * This function returns the new alpm_list_t* target list.
 *
 */
alpm_list_t *_alpm_sortbydeps(alpm_list_t *targets, pmtranstype_t mode)
{
  alpm_list_t *newtargs = NULL;
  alpm_list_t *vertices = NULL;
  alpm_list_t *vptr;
  pmgraph_t *vertex;

  ALPM_LOG_FUNC;

  if(targets == NULL) {
    return(NULL);
  }

  _alpm_log(PM_LOG_DEBUG, "started sorting dependencies\n");

  vertices = _alpm_graph_init(targets);

  vptr = vertices;
  vertex = vertices->data;
  while(vptr) {
    /* mark that we touched the vertex */
    vertex->state = -1;
    int found = 0;
    while(vertex->childptr && !found) {
      pmgraph_t *nextchild = (vertex->childptr)->data;
      vertex->childptr = (vertex->childptr)->next;
      if (nextchild->state == 0) {
        found = 1;
        nextchild->parent = vertex;
        vertex = nextchild;
      }
      else if(nextchild->state == -1) {
        pmpkg_t *vertexpkg = vertex->data;
        pmpkg_t *childpkg = nextchild->data;
        _alpm_log(PM_LOG_WARNING, _("dependency cycle detected:\n"));
        if(mode == PM_TRANS_TYPE_REMOVE) {
          _alpm_log(PM_LOG_WARNING, _("%s will be removed after its %s dependency\n"), vertexpkg->name, childpkg->name);
        } else {
          _alpm_log(PM_LOG_WARNING, _("%s will be installed before its %s dependency\n"), vertexpkg->name, childpkg->name);
        }
      }
    }
    if(!found) {
      newtargs = alpm_list_add(newtargs, vertex->data);
      /* mark that we've left this vertex */
      vertex->state = 1;
      vertex = vertex->parent;
      if(!vertex) {
        vptr = vptr->next;
        while(vptr) {
          vertex = vptr->data;
          if (vertex->state == 0) break;
          vptr = vptr->next;
        }
      }
    }
  }

  _alpm_log(PM_LOG_DEBUG, "sorting dependencies finished\n");

  if(mode == PM_TRANS_TYPE_REMOVE) {
    /* we're removing packages, so reverse the order */
    alpm_list_t *tmptargs = alpm_list_reverse(newtargs);
    /* free the old one */
    alpm_list_free(newtargs);
    newtargs = tmptargs;
  }

  alpm_list_free_inner(vertices, _alpm_graph_free);
  alpm_list_free(vertices);

  return(newtargs);
}

/* Little helper function for alpm_list_find */
static int satisfycmp(const void *pkg, const void *depend)
{
  return(!alpm_depcmp((pmpkg_t*) pkg, (pmdepend_t*) depend));
}

/** Checks dependencies and returns missing ones in a list.
 * Dependencies can include versions with depmod operators.
 * @param db pointer to the local package database
 * @param reversedeps handles the backward dependencies
 * @param remove an alpm_list_t* of packages to be removed
 * @param upgrade an alpm_list_t* of packages to be upgraded (remove-then-upgrade)
 * @return an alpm_list_t* of pmpkg_t* of missing_t pointers.
 */
alpm_list_t SYMEXPORT *alpm_checkdeps(pmdb_t *db, int reversedeps,
    alpm_list_t *remove, alpm_list_t *upgrade)
{
  alpm_list_t *i, *j;
  alpm_list_t *joined, *dblist;
  alpm_list_t *baddeps = NULL;
  pmdepmissing_t *miss = NULL;

  ALPM_LOG_FUNC;

  if(db == NULL) {
    return(NULL);
  }

  joined = alpm_list_join(alpm_list_copy(remove), alpm_list_copy(upgrade));
  dblist = alpm_list_diff(_alpm_db_get_pkgcache(db), joined, _alpm_pkg_cmp);
  alpm_list_free(joined);

  /* look for unsatisfied dependencies of the upgrade list */
  for(i = upgrade; i; i = i->next) {
    pmpkg_t *tp = i->data;
    _alpm_log(PM_LOG_DEBUG, "checkdeps: package %s-%s\n",
        alpm_pkg_get_name(tp), alpm_pkg_get_version(tp));

    for(j = alpm_pkg_get_depends(tp); j; j = j->next) {
      pmdepend_t *depend = j->data;
      /* 1. we check the upgrade list */
      /* 2. we check database for untouched satisfying packages */
      if(!alpm_list_find(upgrade, depend, satisfycmp) &&
         !alpm_list_find(dblist, depend, satisfycmp)) {
        /* Unsatisfied dependency in the upgrade list */
        char *missdepstring = alpm_dep_get_string(depend);
        _alpm_log(PM_LOG_DEBUG, "checkdeps: missing dependency '%s' for package '%s'\n",
            missdepstring, alpm_pkg_get_name(tp));
        free(missdepstring);
        miss = _alpm_depmiss_new(alpm_pkg_get_name(tp), depend->mod,
            depend->name, depend->version);
        baddeps = alpm_list_add(baddeps, miss);
      }
    }
  }

  if(reversedeps) {
    /* reversedeps handles the backwards dependencies, ie,
     * the packages listed in the requiredby field. */

    alpm_list_t *modified = alpm_list_diff(_alpm_db_get_pkgcache(db), dblist, _alpm_pkg_cmp);

    for(i = dblist; i; i = i->next) {
      pmpkg_t *lp = i->data;
      for(j = alpm_pkg_get_depends(lp); j; j = j->next) {
        pmdepend_t *depend = j->data;
        /* we won't break this depend, if it is already broken, we ignore it */
        /* 1. check upgrade list for satisfiers */
        /* 2. check dblist for satisfiers */
        if(alpm_list_find(modified, depend, satisfycmp) &&
           !alpm_list_find(upgrade, depend, satisfycmp) &&
           !alpm_list_find(dblist, depend, satisfycmp)) {
          char *missdepstring = alpm_dep_get_string(depend);
          _alpm_log(PM_LOG_DEBUG, "checkdeps: transaction would break '%s' dependency of '%s'\n",
              missdepstring, alpm_pkg_get_name(lp));
          free(missdepstring);
          miss = _alpm_depmiss_new(lp->name, depend->mod,
              depend->name, depend->version);
          baddeps = alpm_list_add(baddeps, miss);
        }
      }
    }
    alpm_list_free(modified);
  }
  alpm_list_free(dblist);

  return(baddeps);
}

static int dep_vercmp(const char *version1, pmdepmod_t mod,
    const char *version2)
{
  int equal = 0;

  if(mod == PM_DEP_MOD_ANY) {
    equal = 1;
  } else {
    int cmp = _alpm_versioncmp(version1, version2);
    switch(mod) {
      case PM_DEP_MOD_EQ: equal = (cmp == 0); break;
      case PM_DEP_MOD_GE: equal = (cmp >= 0); break;
      case PM_DEP_MOD_LE: equal = (cmp <= 0); break;
      case PM_DEP_MOD_LT: equal = (cmp < 0); break;
      case PM_DEP_MOD_GT: equal = (cmp > 0); break;
      default: equal = 1; break;
    }
  }
  return(equal);
}

int SYMEXPORT alpm_depcmp(pmpkg_t *pkg, pmdepend_t *dep)
{
  alpm_list_t *i;

  ALPM_LOG_FUNC;

  const char *pkgname = alpm_pkg_get_name(pkg);
  const char *pkgversion = alpm_pkg_get_version(pkg);
  int satisfy = 0;

  /* check (pkg->name, pkg->version) */
  satisfy = (strcmp(pkgname, dep->name) == 0
      && dep_vercmp(pkgversion, dep->mod, dep->version));

  /* check provisions, format : "name version" */
  for(i = alpm_pkg_get_provides(pkg); i && !satisfy; i = i->next) {
    char *provname = strdup(i->data);
    char *provver = strchr(provname, ' ');

    if(provver == NULL) { /* no provision version */
      satisfy = (dep->mod == PM_DEP_MOD_ANY
          && strcmp(provname, dep->name) == 0);
    } else {
      /* replace the space with a NULL byte, and advance ptr the version */
      *provver = '\0';
      provver += 1;
      satisfy = (strcmp(provname, dep->name) == 0
          && dep_vercmp(provver, dep->mod, dep->version));
    }
    free(provname);
  }

  return(satisfy);
}

pmdepend_t SYMEXPORT *alpm_splitdep(const char *depstring)
{
  pmdepend_t *depend;
  char *ptr = NULL;
  char *newstr = NULL;

  if(depstring == NULL) {
    return(NULL);
  }
  newstr = strdup(depstring);

  MALLOC(depend, sizeof(pmdepend_t), return(NULL));

  /* Find a version comparator if one exists. If it does, set the type and
   * increment the ptr accordingly so we can copy the right strings. */
  if((ptr = strstr(newstr, ">="))) {
    depend->mod = PM_DEP_MOD_GE;
    *ptr = '\0';
    ptr += 2;
  } else if((ptr = strstr(newstr, "<="))) {
    depend->mod = PM_DEP_MOD_LE;
    *ptr = '\0';
    ptr += 2;
  } else if((ptr = strstr(newstr, "="))) { /* Note: we must do =,<,> checks after <=, >= checks */
    depend->mod = PM_DEP_MOD_EQ;
    *ptr = '\0';
    ptr += 1;
  } else if((ptr = strstr(newstr, "<"))) {
    depend->mod = PM_DEP_MOD_LT;
    *ptr = '\0';
    ptr += 1;
  } else if((ptr = strstr(newstr, ">"))) {
    depend->mod = PM_DEP_MOD_GT;
    *ptr = '\0';
    ptr += 1;

  } else {
    /* no version specified - copy in the name and return it */
    depend->mod = PM_DEP_MOD_ANY;
    strncpy(depend->name, newstr, PKG_NAME_LEN);
    depend->version[0] = '\0';
    free(newstr);
    return(depend);
  }

  /* if we get here, we have a version comparator, copy the right parts
   * to the right places */
  strncpy(depend->name, newstr, PKG_NAME_LEN);
  strncpy(depend->version, ptr, PKG_VERSION_LEN);
  free(newstr);

  return(depend);
}

/* These parameters are messy. We check if this package, given a list of
 * targets and a db is safe to remove. We do NOT remove it if it is in the
 * target list, or if if the package was explictly installed and
 * include_explicit == 0 */
static int can_remove_package(pmdb_t *db, pmpkg_t *pkg, alpm_list_t *targets,
    int include_explicit)
{
  alpm_list_t *i, *requiredby;

  if(_alpm_pkg_find(alpm_pkg_get_name(pkg), targets)) {
    return(0);
  }

  if(!include_explicit) {
    /* see if it was explicitly installed */
    if(alpm_pkg_get_reason(pkg) == PM_PKG_REASON_EXPLICIT) {
      _alpm_log(PM_LOG_DEBUG, "excluding %s -- explicitly installed\n",
          alpm_pkg_get_name(pkg));
      return(0);
    }
  }

  /* TODO: checkdeps could be used here, it handles multiple providers
   * better, but that also makes it slower.
   * Also this would require to first add the package to the targets list,
   * then call checkdeps with it, then remove the package from the targets list
   * if checkdeps detected it would break something */

  /* see if other packages need it */
  requiredby = alpm_pkg_compute_requiredby(pkg);
  for(i = requiredby; i; i = i->next) {
    pmpkg_t *reqpkg = _alpm_db_get_pkgfromcache(db, i->data);
    if(reqpkg && !_alpm_pkg_find(alpm_pkg_get_name(reqpkg), targets)) {
      FREELIST(requiredby);
      return(0);
    }
  }
  FREELIST(requiredby);

  /* it's ok to remove */
  return(1);
}

/**
 * @brief Adds unneeded dependencies to an existing list of packages.
 * By unneeded, we mean dependencies that are only required by packages in the
 * target list, so they can be safely removed.
 * If the input list was topo sorted, the output list will be topo sorted too.
 *
 * @param db package database to do dependency tracing in
 * @param *targs pointer to a list of packages
 * @param include_explicit if 0, explicitly installed packages are not included
 */
void _alpm_recursedeps(pmdb_t *db, alpm_list_t *targs, int include_explicit)
{
  alpm_list_t *i, *j, *k;

  ALPM_LOG_FUNC;

  if(db == NULL || targs == NULL) {
    return;
  }

  for(i = targs; i; i = i->next) {
    pmpkg_t *pkg = i->data;
    for(j = alpm_pkg_get_depends(pkg); j; j = j->next) {
      pmdepend_t *depend = j->data;

      for(k = _alpm_db_get_pkgcache(db); k; k = k->next) {
        pmpkg_t *deppkg = k->data;
        if(alpm_depcmp(deppkg,depend)
            && can_remove_package(db, deppkg, targs, include_explicit)) {
          _alpm_log(PM_LOG_DEBUG, "adding '%s' to the targets\n",
              alpm_pkg_get_name(deppkg));
            /* add it to the target list */
          targs = alpm_list_add(targs, _alpm_pkg_dup(deppkg));
        }
      }
    }
  }
}

/* populates *list with packages that need to be installed to satisfy all
 * dependencies (recursive) for syncpkg
 *
 * @param remove contains packages elected for removal
 * make sure **list is already initialized
 */
int _alpm_resolvedeps(pmdb_t *local, alpm_list_t *dbs_sync, pmpkg_t *syncpkg,
                      alpm_list_t **list, alpm_list_t *remove, pmtrans_t *trans, alpm_list_t **data)
{
  alpm_list_t *i, *j, *k;
  alpm_list_t *targ;
  alpm_list_t *deps = NULL;

  ALPM_LOG_FUNC;

  if(local == NULL || dbs_sync == NULL || syncpkg == NULL || list == NULL) {
    return(-1);
  }

  _alpm_log(PM_LOG_DEBUG, "started resolving dependencies\n");
  targ = alpm_list_add(NULL, syncpkg);
  deps = alpm_checkdeps(local, 0, remove, targ);
  alpm_list_free(targ);

  if(deps == NULL) {
    return(0);
  }

  for(i = deps; i; i = i->next) {
    int found = 0;
    pmdepmissing_t *miss = i->data;
    pmdepend_t *missdep = &(miss->depend);
    pmpkg_t *sync = NULL;

    /* check if one of the packages in *list already satisfies this dependency */
    for(j = *list; j && !found; j = j->next) {
      pmpkg_t *sp = j->data;
      if(alpm_depcmp(sp, missdep)) {
        char *missdepstring = alpm_dep_get_string(missdep);
        _alpm_log(PM_LOG_DEBUG, "%s satisfies dependency %s -- skipping\n",
                  alpm_pkg_get_name(sp), missdepstring);
        free(missdepstring);
        found = 1;
      }
    }
    if(found) {
      continue;
    }

    /* find the package in one of the repositories */
    /* check literals */
    for(j = dbs_sync; j && !found; j = j->next) {
      sync = _alpm_db_get_pkgfromcache(j->data, missdep->name);
      if(!sync) {
        continue;
      }
      found = alpm_depcmp(sync, missdep) && !_alpm_pkg_find(alpm_pkg_get_name(sync), remove);
      if(!found) {
        continue;
      }
      /* If package is in the ignorepkg list, ask before we pull it */
      if(_alpm_pkg_should_ignore(sync)) {
        pmpkg_t *dummypkg = _alpm_pkg_new(miss->target, NULL);
        QUESTION(trans, PM_TRANS_CONV_INSTALL_IGNOREPKG, dummypkg, sync, NULL, &found);
        _alpm_pkg_free(dummypkg);
      }
    }
    /*TODO this autoresolves the first 'satisfier' package... we should fix this
     * somehow */
    /* check provides */
    /* we don't check literals again to avoid duplicated PM_TRANS_CONV_INSTALL_IGNOREPKG messages */
    for(j = dbs_sync; j && !found; j = j->next) {
      for(k = _alpm_db_get_pkgcache(j->data); k && !found; k = k->next) {
        sync = k->data;
        if(!sync) {
          continue;
        }
        found = alpm_depcmp(sync, missdep) && strcmp(sync->name, missdep->name)
          && !_alpm_pkg_find(alpm_pkg_get_name(sync), remove);
        if(!found) {
          continue;
        }
        if(_alpm_pkg_should_ignore(sync)) {
          pmpkg_t *dummypkg = _alpm_pkg_new(miss->target, NULL);
          QUESTION(trans, PM_TRANS_CONV_INSTALL_IGNOREPKG, dummypkg, sync, NULL, &found);
          _alpm_pkg_free(dummypkg);
        }
      }
    }

    if(!found) {
      char *missdepstring = alpm_dep_get_string(missdep);
      _alpm_log(PM_LOG_ERROR, _("cannot resolve \"%s\", a dependency of \"%s\"\n"),
                missdepstring, miss->target);
      free(missdepstring);
      if(data) {
        MALLOC(miss, sizeof(pmdepmissing_t),/*nothing*/);
        if(!miss) {
          pm_errno = PM_ERR_MEMORY;
          FREELIST(*data);
          goto error;
        }
        *miss = *(pmdepmissing_t *)i->data;
        *data = alpm_list_add(*data, miss);
      }
      pm_errno = PM_ERR_UNSATISFIED_DEPS;
      goto error;
    } else {
      _alpm_log(PM_LOG_DEBUG, "pulling dependency %s (needed by %s)\n",
          alpm_pkg_get_name(sync), alpm_pkg_get_name(syncpkg));
      *