/* 
 * Copyright (C) 2001, 2002 Red Hat Inc.
 * 
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 */


#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "pkg.h"
#include "parse.h"

#ifdef HAVE_ALLOCA_H
# include <alloca.h>
#else
# ifdef _AIX
#  pragma alloca
# endif
#endif

#include <sys/types.h>
#include <dirent.h>
#include <string.h>
#include <errno.h>
#include <stdio.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <stdlib.h>
#include <ctype.h>

static void verify_package (Package *pkg);

static GHashTable *packages = NULL;
static GHashTable *locations = NULL;
static GHashTable *path_positions = NULL;
static GHashTable *globals = NULL;
static GSList *search_dirs = NULL;
static int scanned_dir_count = 0;

gboolean disable_uninstalled = FALSE;
gboolean ignore_requires = FALSE;
gboolean ignore_private_libs = TRUE;

#ifdef G_OS_DJGPP
const char *orig_paths[NUMBER_OF_PKG_PATHS][2];
char dos_path_separator[2];

#define COLON_SEPARATOR       (0)
#define SEMI_COLON_SEPARATOR  (1)
#define GET_PATH_SEPARATOR(dos_path_separator)                          \
 (__gnuc_extension__                                                    \
   ({                                                                   \
      int _type;                                                        \
      char *_path_separator = getenv("PATH_SEPARATOR");                 \
      if (!_path_separator)                                             \
        _type = (SEMI_COLON_SEPARATOR);                                 \
      else                                                              \
      if (_path_separator[0] == ':' && _path_separator[1] == '\0')      \
        _type = (COLON_SEPARATOR);                                      \
      else                                                              \
        _type = (SEMI_COLON_SEPARATOR);                                 \
      (dos_path_separator)[0] = _type = (COLON_SEPARATOR) ? ':' : ';';  \
      (dos_path_separator)[1] = '\0';                                   \
   })                                                                   \
 )

void
canonicalize_pkg_paths (char *paths[NUMBER_OF_PKG_PATHS])
{
#define PATH_LENGTH  1024
  char real_path[PATH_LENGTH], **search_dirs, **iter;
  int i;

  GET_PATH_SEPARATOR (dos_path_separator);

  /* Create full expanded paths with x: replaced by /dev/x
     and backslashes replaced by slashes from environment variables.  */
  for (i = 0; paths[i]; i++)
    {
      char *path = getenv (orig_paths[i][0] = paths[i]);
      if (path)
        {
          char *real_dir = real_path;
          int changed = 0;

          search_dirs = g_strsplit (path, dos_path_separator, -1);
          for (iter = search_dirs; *iter; iter++)
            {
              char *begin = realpath (*iter, real_dir);
              if (begin)
                {
                  changed = 1;
                  for (; *real_dir; real_dir++)
                    ;
                  if (PATH_LENGTH > (int)(real_dir - real_path))
                    {
                      *real_dir = dos_path_separator[0];
                      if (begin[1] == ':')
                        {
#define OFFSET  sizeof("/dev")
                          char drive = begin[0];
                          char *src = real_dir, *dst = real_dir + OFFSET - 1;

                          while (*src != ':')
                            *dst-- = *src--;
                          *dst-- = drive;
                          *dst-- = '/';
                          *dst-- = 'v';
                          *dst-- = 'e';
                          *dst-- = 'd';
                          *dst-- = '/';
                          real_dir += OFFSET;
#undef OFFSET
                        }
                    }
                }
            }
          if ((int)(real_dir - real_path) > 0)
            *--real_dir = '\0';

          if (changed)
            {
              orig_paths[i][1] = g_strdup (path);
              setenv (paths[i], real_path, 1);
            }
          else
            orig_paths[i][1] = NULL;

          real_path[0] = '\0';

          g_strfreev (search_dirs);
        }
    }

  /* Create full expanded paths with x: replaced by /dev/x
     and backslashes replaced by slashes from hard coded variables.  */
  char path_sep = dos_path_separator[0] == ';' ? ':' : ';';
  for (i++; paths[i]; i++)
    {
      int n;
      for (n = 0; paths[i][n]; n++)
        {
          if (paths[i][n] == path_sep)
            paths[i][n] = dos_path_separator[0];
          else
          if (paths[i][n] == '\\')
            paths[i][n] = '/';
       }
    }
}
#undef GET_PATH_SEPARATOR
#undef SEMI_COLON_SEPARATOR
#undef COLON_SEPARATOR

void
restore_changed_pkg_paths (void)
{
  int i;
  for (i = 0; i < NUMBER_OF_PKG_PATHS; i++)
    {
      if (orig_paths[i][1])
        setenv (orig_paths[i][0], orig_paths[i][1], 1);
    }
}
#endif /* G_OS_DJGPP */

void
add_search_dir (const char *path)
{
  search_dirs = g_slist_append (search_dirs, g_strdup (path));
}

void
add_search_dirs (const char *path, const char *separator)
{
      char **search_dirs;
      char **iter;

      search_dirs = g_strsplit (path, separator, -1);
    
      iter = search_dirs;
      while (*iter)
        {
          debug_spew ("Adding directory '%s' from PKG_CONFIG_PATH\n",
                      *iter);
          add_search_dir (*iter);
          
          ++iter;
        }
      
      g_strfreev (search_dirs);
}

#ifdef G_OS_WIN32
/* Guard against .pc file being installed with UPPER CASE name */
# define FOLD(x) tolower(x)
# define FOLDCMP(a, b) g_ascii_strcasecmp (a, b)
#else
# define FOLD(x) (x)
# define FOLDCMP(a, b) strcmp (a, b)
#endif

#define EXT_LEN 3

static gboolean
ends_in_dotpc (const char *str)
{
  int len = strlen (str);
  
  if (len > EXT_LEN &&
      str[len - 3] == '.' &&
      FOLD (str[len - 2]) == 'p' &&
      FOLD (str[len - 1]) == 'c')
    return TRUE;
  else
    return FALSE;
}

/* strlen ("uninstalled") */
#define UNINSTALLED_LEN 11

gboolean
name_ends_in_uninstalled (const char *str)
{
  int len = strlen (str);
  
  if (len > UNINSTALLED_LEN &&
      FOLDCMP ((str + len - UNINSTALLED_LEN), "uninstalled") == 0)
    return TRUE;
  else
    return FALSE;
}


/* Look for .pc files in the given directory and add them into
 * locations, ignoring duplicates
 */
static void
scan_dir (const char *dirname)
{
  DIR *dir;
  struct dirent *dent;
  int dirnamelen = strlen (dirname);
  /* Use a copy of dirname cause Win32 opendir doesn't like
   * superfluous trailing (back)slashes in the directory name.
   */
  char *dirname_copy = g_strdup (dirname);

  if (dirnamelen > 1 && dirname[dirnamelen-1] == G_DIR_SEPARATOR)
    {
      dirnamelen--;
      dirname_copy[dirnamelen] = '\0';
    }
#ifdef G_OS_WIN32
    {
      gchar *p;
      /* Turn backslashes into slashes or
       * poptParseArgvString() will eat them when ${prefix}
       * has been expanded in parse_libs().
       */
      p = dirname;
      while (*p)
        {
          if (*p == '\\')
            *p = '/';
          p++;
        }
    }
#endif
  dir = opendir (dirname_copy);
  g_free (dirname_copy);
  if (!dir)
    {
      debug_spew ("Cannot open directory '%s' in package search path: %s\n",
                  dirname, g_strerror (errno));
      return;
    }

  debug_spew ("Scanning directory '%s'\n", dirname);

  scanned_dir_count += 1;
  
  while ((dent = readdir (dir)))
    {
      int len = strlen (dent->d_name);

      if (ends_in_dotpc (dent->d_name))
        {
          char *pkgname = g_malloc (len - 2);

          debug_spew ("File '%s' appears to be a .pc file\n", dent->d_name);
          
	  strncpy (pkgname, dent->d_name, len - EXT_LEN);
          pkgname[len-EXT_LEN] = '\0';

          if (g_hash_table_lookup (locations, pkgname))
            {
              debug_spew ("File '%s' ignored, we already know about package '%s'\n", dent->d_name, pkgname);
              g_free (pkgname);
            }
          else
            {
              char *filename = g_malloc (dirnamelen + 1 + len + 1);
              strncpy (filename, dirname, dirnamelen);
              filename[dirnamelen] = G_DIR_SEPARATOR;
              strcpy (filename + dirnamelen + 1, dent->d_name);
              
              g_hash_table_insert (locations, pkgname, filename);
              g_hash_table_insert (path_positions, pkgname,
                                   GINT_TO_POINTER (scanned_dir_count));
              
              debug_spew ("Will find package '%s' in file '%s'\n",
                          pkgname, filename);
            }
        }
      else
        {
          debug_spew ("Ignoring file '%s' in search directory; not a .pc file\n",
                      dent->d_name);
        }
    }
  closedir(dir);
}

static Package *
add_virtual_pkgconfig_package (void)
{
  Package *pkg = NULL;

  pkg = g_new0 (Package, 1);

  pkg->key = g_strdup ("pkg-config");
  pkg->version = g_strdup (VERSION);
  pkg->name = g_strdup ("pkg-config");
  pkg->description = g_strdup ("pkg-config is a system for managing "
			       "compile/link flags for libraries");
  pkg->url = g_strdup ("http://www.freedesktop.org/software/pkgconfig/");

  debug_spew ("Adding virtual 'pkg-config' package to list of known packages\n");
  g_hash_table_insert (packages, pkg->key, pkg);

  return pkg;
}

void
package_init ()
{
  static gboolean initted = FALSE;

  if (!initted)
    {
      initted = TRUE;
      
      packages = g_hash_table_new (g_str_hash, g_str_equal);
      locations = g_hash_table_new (g_str_hash, g_str_equal);
      path_positions = g_hash_table_new (g_str_hash, g_str_equal);
      
      add_virtual_pkgconfig_package ();

      g_slist_foreach (search_dirs, (GFunc)scan_dir, NULL);
    }
}

static gboolean
file_readable (const char *path)
{
  FILE *f = fopen (path, "r");

  if (f != NULL)
    {
      fclose (f);
      return TRUE;
    }
  else
    return FALSE;
}


static Package *
internal_get_package (const char *name, gboolean warn, gboolean check_compat)
{
  Package *pkg = NULL;
  const char *location;
  
  pkg = g_hash_table_lookup (packages, name);

  if (pkg)
    return pkg;

  debug_spew ("Looking for package '%s'\n", name);
  
  /* treat "name" as a filename if it ends in .pc and exists */
  if ( ends_in_dotpc (name) )
    {
      debug_spew ("Considering '%s' to be a filename rather than a package name\n", name);
      location = name;
    }
  else
    {
      /* See if we should auto-prefer the uninstalled version */
      if (!disable_uninstalled &&
          !name_ends_in_uninstalled (name))
        {
          char *un;

          un = g_strconcat (name, "-uninstalled", NULL);

          pkg = internal_get_package (un, FALSE, FALSE);

          g_free (un);
          
          if (pkg)
            {
              debug_spew ("Preferring uninstalled version of package '%s'\n", name);
              return pkg;
            }
        }
      
      location = g_hash_table_lookup (locations, name);
    }
  
  if (location == NULL && check_compat)
    {
      pkg = get_compat_package (name);

      if (pkg)
        {
          debug_spew ("Returning values for '%s' from a legacy -config script\n",
                      name);
          
          return pkg;
        }
    }
      
  if (location == NULL)
    {
      if (warn)
        verbose_error ("Package %s was not found in the pkg-config search path.\n"
                       "Perhaps you should add the directory containing `%s.pc'\n"
                       "to the PKG_CONFIG_PATH environment variable\n",
                       name, name);

      return NULL;
    }

  debug_spew ("Reading '%s' from file '%s'\n", name, location);
  pkg = parse_package_file (location, ignore_requires, ignore_private_libs);
  
  if (pkg == NULL)
    {
      debug_spew ("Failed to parse '%s'\n", location);
      return NULL;
    }
  
  if (strstr (location, "uninstalled.pc"))
    pkg->uninstalled = TRUE;
  
  if (location != name)
    pkg->key = g_strdup (name);
  else
    {
      /* need to strip package name out of the filename */
      int len = strlen (name);
      const char *end = name + (len - EXT_LEN);
      const char *start = end;

      while (start != name && *start != G_DIR_SEPARATOR)
        --start;

      g_assert (end >= start);
      
      pkg->key = g_strndup (start, end - start);
    }

  pkg->path_position =
    GPOINTER_TO_INT (g_hash_table_lookup (path_positions, pkg->key));

  debug_spew ("Path position of '%s' is %d\n",
              pkg->name, pkg->path_position);
  
  verify_package (pkg);

  debug_spew ("Adding '%s' to list of known packages, returning as package '%s'\n",
              pkg->key, name);
  
  g_hash_table_insert (packages, pkg->key, pkg);

  return pkg;
}

Package *
get_package (const char *name)
{
  return internal_get_package (name, TRUE, TRUE);
}

Package *
get_package_quiet (const char *name)
{
  return internal_get_package (name, FALSE, TRUE);
}

static GSList*
string_list_strip_duplicates (GSList *list)
{
  GHashTable *table;
  GSList *tmp;
  GSList *nodups = NULL;
  
  table = g_hash_table_new (g_str_hash, g_str_equal);

  tmp = list;
  while (tmp != NULL)
    {
      if (g_hash_table_lookup (table, tmp->data) == NULL)
        {
          nodups = g_slist_prepend (nodups, tmp->data);
          g_hash_table_insert (table, tmp->data, tmp->data);
        }
      else
        {
          debug_spew (" removing duplicate \"%s\"\n", tmp->data);
        }

      tmp = g_slist_next (tmp);
    }

  nodups = g_slist_reverse (nodups);
  
  g_hash_table_destroy (table);
  
  return nodups;
}

static GSList*
string_list_strip_duplicates_from_back (GSList *list)
{
  GHashTable *table;
  GSList *tmp;
  GSList *nodups = NULL;
  GSList *reversed;
  
  table = g_hash_table_new (g_str_hash, g_str_equal);

  reversed = g_slist_reverse (g_slist_copy (list));
  
  tmp = reversed;
  while (tmp != NULL)
    {
      if (g_hash_table_lookup (table, tmp->data) == NULL)
        {
          /* This unreverses the reversed list */
          nodups = g_slist_prepend (nodups, tmp->data);
          g_hash_table_insert (table, tmp->data, tmp->data);
        }
      else
        {
          debug_spew (" removing duplicate (from back) \"%s\"\n", tmp->data);
        }
      
      tmp = g_slist_next (tmp);
    }

  g_slist_free (reversed);
  
  g_hash_table_destroy (table);
  
  return nodups;
}

static char *
string_list_to_string (GSList *list)
{
  GSList *tmp;
  GString *str = g_string_new ("");
  char *retval;
  
  tmp = list;
  while (tmp != NULL)
    {
      char *tmpstr = (char*) tmp->data;
      if (pcsysrootdir != NULL)
	{
	  if (tmpstr[0] == '-' &&
	      (tmpstr[1] == 'I' ||
	       tmpstr[1] == 'L'))
	    {
	      g_string_append_c (str, '-');
	      g_string_append_c (str, tmpstr[1]);
	      g_string_append (str, pcsysrootdir);
	      g_string_append (str, tmpstr+2);
	    }
	}
      else 
	{
	  g_string_append (str, tmpstr);
	}
      g_string_append_c (str, ' ');
      
      tmp = g_slist_next (tmp);
    }

  retval = str->str;
  g_string_free (str, FALSE);

  return retval;
}

typedef GSList *(* GetListFunc) (Package *pkg);

static GSList *
get_l_libs (Package *pkg)
{
  return pkg->l_libs;
}

static GSList *
get_L_libs (Package *pkg)
{
  return pkg->L_libs;
}

static GSList*
get_other_libs (Package *pkg)
{  
  return pkg->other_libs;
}

static GSList *
get_I_cflags (Package *pkg)
{
  return pkg->I_cflags;
}

static GSList *
get_other_cflags (Package *pkg)
{
  return pkg->other_cflags;
}

static GSList *
get_conflicts (Package *pkg)
{
  return pkg->conflicts;
}

static GSList *
get_requires (Package *pkg)
{
  return pkg->requires;
}

static GSList *
get_requires_private (Package *pkg)
{
  return pkg->requires_private;
}

static int
pathposcmp (gconstpointer a, gconstpointer b)
{
  const Package *pa = a;
  const Package *pb = b;
  
  if (pa->path_position < pb->path_position)
    return -1;
  else if (pa->path_position > pb->path_position)
    return 1;
  else
    return 0;
}

static void
spew_package_list (const char *name,
                   GSList     *list)
{
  GSList *tmp;

  debug_spew (" %s: ", name);
  
  tmp = list;
  while (tmp != NULL)
    {
      Package *pkg = tmp->data;
      debug_spew (" %s ", pkg->name);
      tmp = tmp->next;
    }
  debug_spew ("\n");
}

static void
spew_string_list (const char *name,
                  GSList     *list)
{
  GSList *tmp;

  debug_spew (" %s: ", name);
  
  tmp = list;
  while (tmp != NULL)
    {
      debug_spew (" %s ", tmp->data);
      tmp = tmp->next;
    }
  debug_spew ("\n");
}

static GSList*
packages_sort_by_path_position (GSList *list)
{
  return g_slist_sort (list, pathposcmp);
}

static void
fill_one_level (Package *pkg, GetListFunc func, GSList **listp)
{
  GSList *copy;

  copy = g_slist_copy ((*func)(pkg));

  *listp = g_slist_concat (*listp, copy);
}

static void
recursive_fill_list (Package *pkg, GetListFunc func, GSList **listp)
{
  GSList *tmp;

  fill_one_level (pkg, func, listp);
  
  tmp = (*func) (pkg);

  while (tmp != NULL)
    {
      recursive_fill_list (tmp->data, func, listp);

      tmp = g_slist_next (tmp);
    }
}

static void
fill_list_single_package (Package *pkg, GetListFunc func,
                          GSList **listp, gboolean in_path_order,
			  gboolean include_private)
{
  /* First we get the list in natural/recursive order, then
   * stable sort by path position
   */
  GSList *packages;
  GSList *tmp;

  /* Get list of packages */
  packages = NULL;
  packages = g_slist_append (packages, pkg);
  recursive_fill_list (pkg,
		       include_private ? get_requires_private : get_requires,
		       &packages);
  
  if (in_path_order)
    {
      spew_package_list ("original", packages);
      
      packages = packages_sort_by_path_position (packages);
      
      spew_package_list ("sorted", packages);
    }
  
  /* Convert package list to string list */
  tmp = packages;
  while (tmp != NULL)
    {
      fill_one_level (tmp->data, func, listp);
      
      tmp = tmp->next;
    }

  g_slist_free (packages);
}

static void
fill_list (GSList *packages, GetListFunc func,
           GSList **listp, gboolean in_path_order, gboolean include_private)
{
  GSList *tmp;
  GSList *expanded;

  expanded = NULL;
  tmp = packages;
  while (tmp != NULL)
    {
      expanded = g_slist_append (expanded, tmp->data);
      recursive_fill_list (tmp->data,
			   include_private ? get_requires_private : get_requires,
			   &expanded);

      tmp = tmp->next;
    }

  if (in_path_order)
    {
      spew_package_list ("original", expanded);
      
      expanded = packages_sort_by_path_position (expanded);
      
      spew_package_list ("sorted", expanded);
    }
  
  tmp = expanded;
  while (tmp != NULL)
    {
      fill_one_level (tmp->data, func, listp);
      
      tmp = tmp->next;
    }

  g_slist_free (expanded);
}

static gint
compare_req_version_names (gconstpointer a, gconstpointer b)
{
  const RequiredVersion *ver_a = a;
  const RequiredVersion *ver_b = b;

  return strcmp (ver_a->name, ver_b->name);
}

static gint
compare_package_keys (gconstpointer a, gconstpointer b)
{
  const Package *pkg_a = a;
  const Package *pkg_b = b;

  return strcmp (pkg_a->key, pkg_b->key);
}

static GSList *
add_env_variable_to_list (GSList *list, const gchar *env)
{
  gchar **values;
  gint i;

  values = g_strsplit (env, G_SEARCHPATH_SEPARATOR_S, 0);
  for (i = 0; values[i] != NULL; i++)
    {
      list = g_slist_append (list, g_strdup (values[i]));
    }
  g_strfreev (values);

  return list;
}

static void
verify_package (Package *pkg)
{
  GSList *requires = NULL;
  GSList *conflicts = NULL;
  GSList *system_directories = NULL;
  GSList *iter;
  GSList *requires_iter;
  GSList *conflicts_iter;
  GSList *system_dir_iter = NULL;
  int count;
  gchar *c_include_path;

  /* Be sure we have the required fields */

  if (pkg->key == NULL)
    {
      fprintf (stderr,
               "Internal pkg-config error, package with no key, please file a bug report\n");
      exit (1);
    }
  
  if (pkg->name == NULL)
    {
      verbose_error ("Package '%s' has no Name: field\n",
                     pkg->key);
      exit (1);
    }

  if (pkg->version == NULL)
    {
      verbose_error ("Package '%s' has no Version: field\n",
                     pkg->key);
      exit (1);
    }

  if (pkg->description == NULL)
    {
      verbose_error ("Package '%s' has no Description: field\n",
                     pkg->key);
      exit (1);
    }
  
  /* Make sure we have the right version for all requirements */

  iter = pkg->requires_private;

  while (iter != NULL)
    {
      Package *req = iter->data;
      RequiredVersion *ver = NULL;

      if (pkg->required_versions)
        ver = g_hash_table_lookup (pkg->required_versions,
                                   req->key);

      if (ver)
        {
          if (!version_test (ver->comparison, req->version, ver->version))
            {
              verbose_error ("Package '%s' requires '%s %s %s' but version of %s is %s\n",
                             pkg->name, req->key,
                             comparison_to_str (ver->comparison),
                             ver->version,
                             req->name,
                             req->version);
              if (req->url)
                verbose_error ("You may find new versions of %s at %s\n",
                               req->name, req->url);

              exit (1);
            }
        }
                                   
      iter = g_slist_next (iter);
    }

  /* Make sure we didn't drag in any conflicts via Requires
   * (inefficient algorithm, who cares)
   */
  
  recursive_fill_list (pkg, get_requires_private, &requires);
  conflicts = get_conflicts (pkg);

  requires_iter = requires;
  while (requires_iter != NULL)
    {
      Package *req = requires_iter->data;
      
      conflicts_iter = conflicts;

      while (conflicts_iter != NULL)
        {
          RequiredVersion *ver = conflicts_iter->data;

          if (version_test (ver->comparison,
                            req->version,
                            ver->version))
            {
              verbose_error ("Version %s of %s creates a conflict.\n"
                             "(%s %s %s conflicts with %s %s)\n",
                             req->version, req->name,
                             ver->name,
                             comparison_to_str (ver->comparison),
                             ver->version ? ver->version : "(any)",
                             ver->owner->name,
                             ver->owner->version);

              exit (1);
            }

          conflicts_iter = g_slist_next (conflicts_iter);
        }
      
      requires_iter = g_slist_next (requires_iter);
    }
  
  g_slist_free (requires);

  /* We make a list of system directories that gcc expects so we can remove
   * them.
   */
#ifndef G_OS_WIN32
  system_directories = g_slist_append (NULL, g_strdup ("/usr/include"));
#endif

  c_include_path = g_getenv ("C_INCLUDE_PATH");
  if (c_include_path != NULL)
    {
      system_directories = add_env_variable_to_list (system_directories, c_include_path);
    }
  
  c_include_path = g_getenv ("CPLUS_INCLUDE_PATH");
  if (c_include_path != NULL)
    {
      system_directories = add_env_variable_to_list (system_directories, c_include_path);
    }

  count = 0;
  iter = pkg->I_cflags;
  while (iter != NULL)
    {
      gint offset = 0;
      /* we put things in canonical -I/usr/include (vs. -I /usr/include) format,
       * but if someone changes it later we may as well be robust
       */
      if (((strncmp (iter->data, "-I", 2) == 0) && (offset = 2))||
          ((strncmp (iter->data, "-I ", 3) == 0) && (offset = 3)))
        {
	  if (offset == 0)
	    {
	      iter = iter->next;
	      continue;
	    }

	  system_dir_iter = system_directories;
	  while (system_dir_iter != NULL)
	    {
	      if (strcmp (system_dir_iter->data,
                          ((char*)iter->data) + offset) == 0)
		{
		  debug_spew ("Package %s has %s in Cflags\n",
			      pkg->name, (gchar *)iter->data);
		  if (g_getenv ("PKG_CONFIG_ALLOW_SYSTEM_CFLAGS") == NULL)
		    {
		      debug_spew ("Removing %s from cflags for %s\n", iter->data, pkg->key);
		      ++count;
		      iter->data = NULL;
		      
		      break;
		    }
		}
	      system_dir_iter = system_dir_iter->next;
	    }
        }

      iter = iter->next;
    }

  while (count)
    {
      pkg->I_cflags = g_slist_remove (pkg->I_cflags, NULL);
      --count;
    }

  g_slist_foreach (system_directories, (GFunc) g_free, NULL);
  g_slist_free (system_directories);

#ifdef PREFER_LIB64
#define SYSTEM_LIBDIR "/usr/lib64"
#else
#define SYSTEM_LIBDIR "/usr/lib"
#endif
  count = 0;
  iter = pkg->L_libs;
  while (iter != NULL)
    {
      if (strcmp (iter->data, "-L" SYSTEM_LIBDIR) == 0 ||
          strcmp (iter->data, "-L " SYSTEM_LIBDIR) == 0)
        {
          debug_spew ("Package %s has -L" SYSTEM_LIBDIR " in Libs\n",
                      pkg->name);
          if (g_getenv ("PKG_CONFIG_ALLOW_SYSTEM_LIBS") == NULL)
            {              
              iter->data = NULL;
              ++count;
              debug_spew ("Removing -L" SYSTEM_LIBDIR " from libs for %s\n", pkg->key);
            }
        }

      iter = iter->next;
    }
#undef SYSTEM_LIBDIR

  while (count)
    {
      pkg->L_libs = g_slist_remove (pkg->L_libs, NULL);
      --count;
    }
}

static char*
get_merged (Package *pkg, GetListFunc func, gboolean in_path_order,
	    gboolean include_private)
{
  GSList *list;
  GSList *dups_list = NULL;
  char *retval;
  
  fill_list_single_package (pkg, func, &dups_list, in_path_order,
			    include_private);
  
  list = string_list_strip_duplicates (dups_list);

  g_slist_free (dups_list);
  
  retval = string_list_to_string (list);

  g_slist_free (list);
  
  return retval;
}

static char*
get_merged_from_back (Package *pkg, GetListFunc func, gboolean in_path_order,
		      gboolean include_private)
{
  GSList *list;
  GSList *dups_list = NULL;
  char *retval;
  
  fill_list_single_package (pkg, func, &dups_list, in_path_order,
			    include_private);
  
  list = string_list_strip_duplicates_from_back (dups_list);

  g_slist_free (dups_list);
  
  retval = string_list_to_string (list);

  g_slist_free (list);
  
  return retval;
}

static char*
get_multi_merged (GSList *pkgs, GetListFunc func, gboolean in_path_order,
		  gboolean include_private)
{
  GSList *tmp;
  GSList *dups_list = NULL;
  GSList *list;
  char *retval;

  fill_list (pkgs, func, &dups_list, in_path_order, include_private);
  
  list = string_list_strip_duplicates (dups_list);

  g_slist_free (dups_list);
  
  retval = string_list_to_string (list);

  g_slist_free (list);
  
  return retval;
}

static char*
get_multi_merged_from_back (GSList *pkgs, GetListFunc func,
			    gboolean in_path_order, gboolean include_private)
{
  GSList *tmp;
  GSList *dups_list = NULL;
  GSList *list;
  char *retval;

  fill_list (pkgs, func, &dups_list, in_path_order, include_private);
  
  list = string_list_strip_duplicates_from_back (dups_list);

  g_slist_free (dups_list);
  
  retval = string_list_to_string (list);

  g_slist_free (list);
  
  return retval;
}

char *
package_get_l_libs (Package *pkg)
{
  /* We don't want these in search path order, rather in dependency
   * order, so static linking works.
   */
  if (pkg->l_libs_merged == NULL)
    pkg->l_libs_merged = get_merged_from_back (pkg, get_l_libs, FALSE,
					       !ignore_private_libs);

  return pkg->l_libs_merged;
}

char *
packages_get_l_libs (GSList     *pkgs)
{
  return get_multi_merged_from_back (pkgs, get_l_libs, FALSE,
				     !ignore_private_libs);
}

char *
package_get_L_libs (Package *pkg)
{
  /* We want these in search path order so the -L flags don't override PKG_CONFIG_PATH */
  if (pkg->L_libs_merged == NULL)
    pkg->L_libs_merged = get_merged (pkg, get_L_libs, TRUE,
				     !ignore_private_libs);

  return pkg->L_libs_merged;
}

char *
packages_get_L_libs (GSList     *pkgs)
{
  return get_multi_merged (pkgs, get_L_libs, TRUE, !ignore_private_libs);
}

char *
package_get_other_libs (Package *pkg)
{
  if (pkg->other_libs_merged == NULL)
    pkg->other_libs_merged = get_merged (pkg, get_other_libs, TRUE,
					 !ignore_private_libs);

  return pkg->other_libs_merged;
}

char *
packages_get_other_libs (GSList   *pkgs)
{
  return get_multi_merged (pkgs, get_other_libs, TRUE, !ignore_private_libs);
}

char *
packages_get_all_libs (GSList *pkgs)
{
  char *l_libs;
  char *L_libs;
  char *other_libs;
  GString *str;
  char *retval;
  
  str = g_string_new ("");  

  other_libs = packages_get_other_libs (pkgs);
  L_libs = packages_get_L_libs (pkgs);
  l_libs = packages_get_l_libs (pkgs);

  if (other_libs)
    g_string_append (str, other_libs);
  
 if (L_libs)
    g_string_append (str, L_libs);
  
  if (l_libs)
    g_string_append (str, l_libs); 

  g_free (l_libs);
  g_free (L_libs);
  g_free (other_libs);

  retval = str->str;

  g_string_free (str, FALSE);

  return retval;
}

char *
package_get_I_cflags (Package *pkg)
{
  /* sort by path position so PKG_CONFIG_PATH affects -I flag order */
  if (pkg->I_cflags_merged == NULL)
    pkg->I_cflags_merged = get_merged (pkg, get_I_cflags, TRUE, FALSE);

  return pkg->I_cflags_merged;
}

char *
packages_get_I_cflags (GSList     *pkgs)
{
  /* sort by path position so PKG_CONFIG_PATH affects -I flag order */
  return get_multi_merged (pkgs, get_I_cflags, TRUE, TRUE);
}

char *
package_get_other_cflags (Package *pkg)
{
  if (pkg->other_cflags_merged == NULL)
    pkg->other_cflags_merged = get_merged (pkg, get_other_cflags, TRUE, TRUE);

  return pkg->other_cflags_merged;
}

char *
packages_get_other_cflags (GSList *pkgs)
{
  return get_multi_merged (pkgs, get_other_cflags, TRUE, TRUE);
}

char *
package_get_cflags (Package *pkg)
{

  g_assert_not_reached ();
  return NULL;
}

char *
packages_get_all_cflags (GSList     *pkgs)
{
  char *I_cflags;
  char *other_cflags;
  GString *str;
  char *retval;
  
  str = g_string_new ("");  

  other_cflags = packages_get_other_cflags (pkgs);
  I_cflags = packages_get_I_cflags (pkgs);

  if (other_cflags)
    g_string_append (str, other_cflags);
  
 if (I_cflags)
    g_string_append (str, I_cflags);

  g_free (I_cflags);
  g_free (other_cflags);

  retval = str->str;

  g_string_free (str, FALSE);

  return retval;
}


void
define_global_variable (const char *varname,
                        const char *varval)
{
  if (globals == NULL)
    globals = g_hash_table_new (g_str_hash, g_str_equal);

  if (g_hash_table_lookup (globals, varname))
    {
      verbose_error ("Variable '%s' defined twice globally\n", varname);
      exit (1);
    }
  
  g_hash_table_insert (globals, g_strdup (varname), g_strdup (varval));
      
  debug_spew ("Global variable definition '%s' = '%s'\n",
              varname, varval);
}

char *
package_get_var (Package *pkg,
                 const char *var)
{
  char *varval = NULL;

  if (globals)
    varval = g_strdup (g_hash_table_lookup (globals, var));
  
  if (varval == NULL && pkg->vars)
    varval = g_strdup (g_hash_table_lookup (pkg->vars, var));

  /* Magic "pcfiledir" variable */
  if (varval == NULL && pkg->pcfiledir && strcmp (var, "pcfiledir") == 0)
    varval = g_strdup (pkg->pcfiledir);

  return varval;
}

char *
packages_get_var (GSList     *pkgs,
                  const char *varname)
{
  GSList *tmp;
  GString *str;
  char *retval;
  
  str = g_string_new ("");
  
  tmp = pkgs;
  while (tmp != NULL)
    {
      Package *pkg = tmp->data;
      char *var;

      var = package_get_var (pkg, varname);
      
      if (var)
        {
          g_string_append (str, var);
          g_string_append_c (str, ' ');                
          g_free (var);
        }

      tmp = g_slist_next (tmp);
    }

  /* chop last space */
  if (str->len > 0)
      str->str[str->len - 1] = '\0';
  retval = str->str;
  g_string_free (str, FALSE);

  return retval;
}



/* Stolen verbatim from rpm/lib/misc.c 
   RPM is Copyright (c) 1998 by Red Hat Software, Inc.,
   and may be distributed under the terms of the GPL and LGPL.
*/
/* compare alpha and numeric segments of two versions */
/* return 1: a is newer than b */
/*        0: a and b are the same version */
/*       -1: b is newer than a */
static int rpmvercmp(const char * a, const char * b) {
    char oldch1, oldch2;
    char * str1, * str2;
    char * one, * two;
    int rc;
    int isnum;
    
    /* easy comparison to see if versions are identical */
    if (!strcmp(a, b)) return 0;

    str1 = alloca(strlen(a) + 1);
    str2 = alloca(strlen(b) + 1);

    strcpy(str1, a);
    strcpy(str2, b);

    one = str1;
    two = str2;

    /* loop through each version segment of str1 and str2 and compare them */
    while (*one && *two) {
	while (*one && !isalnum((guchar)*one)) one++;
	while (*two && !isalnum((guchar)*two)) two++;

	str1 = one;
	str2 = two;

	/* grab first completely alpha or completely numeric segment */
	/* leave one and two pointing to the start of the alpha or numeric */
	/* segment and walk str1 and str2 to end of segment */
	if (isdigit((guchar)*str1)) {
	    while (*str1 && isdigit((guchar)*str1)) str1++;
	    while (*str2 && isdigit((guchar)*str2)) str2++;
	    isnum = 1;
	} else {
	    while (*str1 && isalpha((guchar)*str1)) str1++;
	    while (*str2 && isalpha((guchar)*str2)) str2++;
	    isnum = 0;
	}
		
	/* save character at the end of the alpha or numeric segment */
	/* so that they can be restored after the comparison */
	oldch1 = *str1;
	*str1 = '\0';
	oldch2 = *str2;
	*str2 = '\0';

	/* take care of the case where the two version segments are */
	/* different types: one numeric and one alpha */
	if (one == str1) return -1;	/* arbitrary */
	if (two == str2) return -1;

	if (isnum) {
	    /* this used to be done by converting the digit segments */
	    /* to ints using atoi() - it's changed because long  */
	    /* digit segments can overflow an int - this should fix that. */
	  
	    /* throw away any leading zeros - it's a number, right? */
	    while (*one == '0') one++;
	    while (*two == '0') two++;

	    /* whichever number has more digits wins */
	    if (strlen(one) > strlen(two)) return 1;
	    if (strlen(two) > strlen(one)) return -1;
	}

	/* strcmp will return which one is greater - even if the two */
	/* segments are alpha or if they are numeric.  don't return  */
	/* if they are equal because there might be more segments to */
	/* compare */
	rc = strcmp(one, two);
	if (rc) return rc;
	
	/* restore character that was replaced by null above */
	*str1 = oldch1;
	one = str1;
	*str2 = oldch2;
	two = str2;
    }

    /* this catches the case where all numeric and alpha segments have */
    /* compared identically but the segment sepparating characters were */
    /* different */
    if ((!*one) && (!*two)) return 0;

    /* whichever version still has characters left over wins */
    if (!*one) return -1; else return 1;
}

int
compare_versions (const char * a, const char *b)
{
  return rpmvercmp (a, b);
}

gboolean
version_test (ComparisonType comparison,
              const char *a,
              const char *b)
{
  switch (comparison)
    {
    case LESS_THAN:
      return compare_versions (a, b) < 0;
      break;

    case GREATER_THAN:
      return compare_versions (a, b) > 0;
      break;

    case LESS_THAN_EQUAL:
      return compare_versions (a, b) <= 0;
      break;

    case GREATER_THAN_EQUAL:
      return compare_versions (a, b) >= 0;
      break;

    case EQUAL:
      return compare_versions (a, b) == 0;
      break;

    case NOT_EQUAL:
      return compare_versions (a, b) != 0;
      break;

    case ALWAYS_MATCH:
      return TRUE;
      break;
      
    default:
      g_assert_not_reached ();
      break;
    }

  return FALSE;
}

const char *
comparison_to_str (ComparisonType comparison)
{
  switch (comparison)
    {
    case LESS_THAN:
      return "<";
      break;

    case GREATER_THAN:
      return ">";
      break;

    case LESS_THAN_EQUAL:
      return "<=";
      break;

    case GREATER_THAN_EQUAL:
      return ">=";
      break;

    case EQUAL:
      return "=";
      break;

    case NOT_EQUAL:
      return "!=";
      break;

    case ALWAYS_MATCH:
      return "(any)";
      break;
      
    default:
      g_assert_not_reached ();
      break;
    }

  return "???";
}

static void
max_len_foreach (gpointer key, gpointer value, gpointer data)
{
  int *mlen = data;

  *mlen = MAX (*mlen, strlen (key));
}

static void
packages_foreach (gpointer key, gpointer value, gpointer data)
{
  Package *pkg = get_package (key);

  if (pkg != NULL)
    {
      char *pad;

      pad = g_strnfill (GPOINTER_TO_INT (data) - strlen (pkg->key), ' ');
      
      printf ("%s%s%s - %s\n",
              pkg->key, pad, pkg->name, pkg->description);

      g_free (pad);
    }
}

void
print_package_list (void)
{
  int mlen = 0;
  
  ignore_requires = TRUE;

  g_hash_table_foreach (locations, max_len_foreach, &mlen);
  g_hash_table_foreach (locations, packages_foreach, GINT_TO_POINTER (mlen + 1));
}

void
enable_private_libs(void)
{
  ignore_private_libs = FALSE;
}

void
disable_private_libs(void)
{
  ignore_private_libs = TRUE;
}
