/* Target file management for GNU Make.
Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software
Foundation, Inc.
This file is part of GNU Make.

GNU Make 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, or (at your option) any later version.

GNU Make 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
GNU Make; see the file COPYING.  If not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.  */

#include "make.h"

#include <assert.h>

#include "dep.h"
#include "filedef.h"
#include "job.h"
#include "commands.h"
#include "variable.h"
#include "debug.h"
#include "hash.h"


/* Remember whether snap_deps has been invoked: we need this to be sure we
   don't add new rules (via $(eval ...)) afterwards.  In the future it would
   be nice to support this, but it means we'd need to re-run snap_deps() or
   at least its functionality... it might mean changing snap_deps() to be run
   per-file, so we can invoke it after the eval... or remembering which files
   in the hash have been snapped (a new boolean flag?) and having snap_deps()
   only work on files which have not yet been snapped. */
int snapped_deps = 0;

/* Hash table of files the makefile knows how to make.  */

static unsigned long
file_hash_1 (const void *key)
{
  return_ISTRING_HASH_1 (((struct file const *) key)->hname);
}

static unsigned long
file_hash_2 (const void *key)
{
  return_ISTRING_HASH_2 (((struct file const *) key)->hname);
}

static int
file_hash_cmp (const void *x, const void *y)
{
  return_ISTRING_COMPARE (((struct file const *) x)->hname,
			  ((struct file const *) y)->hname);
}

#ifndef	FILE_BUCKETS
#define FILE_BUCKETS	1007
#endif
static struct hash_table files;

/* Whether or not .SECONDARY with no prerequisites was given.  */
static int all_secondary = 0;

/* Access the hash table of all file records.
   lookup_file  given a name, return the struct file * for that name,
           or nil if there is none.
   enter_file   similar, but create one if there is none.  */

struct file *
lookup_file (char *name)
{
  register struct file *f;
  struct file file_key;
#if defined(VMS) && !defined(WANT_CASE_SENSITIVE_TARGETS)
  char *lname, *ln;
#endif

  assert (*name != '\0');

  /* This is also done in parse_file_seq, so this is redundant
     for names read from makefiles.  It is here for names passed
     on the command line.  */
#ifdef VMS
# ifndef WANT_CASE_SENSITIVE_TARGETS
  if (*name != '.')
    {
      char *n;
      lname = xmalloc (strlen (name) + 1);
      for (n = name, ln = lname; *n != '\0'; ++n, ++ln)
        *ln = isupper ((unsigned char)*n) ? tolower ((unsigned char)*n) : *n;
      *ln = '\0';
      name = lname;
    }
# endif

  while (name[0] == '[' && name[1] == ']' && name[2] != '\0')
      name += 2;
#endif
  while (name[0] == '.' && name[1] == '/' && name[2] != '\0')
    {
      name += 2;
      while (*name == '/')
	/* Skip following slashes: ".//foo" is "foo", not "/foo".  */
	++name;
    }

  if (*name == '\0')
    /* It was all slashes after a dot.  */
#ifdef VMS
    name = "[]";
#else
#ifdef _AMIGA
    name = "";
#else
    name = "./";
#endif /* AMIGA */
#endif /* VMS */

  file_key.hname = name;
  f = (struct file *) hash_find_item (&files, &file_key);
#if defined(VMS) && !defined(WANT_CASE_SENSITIVE_TARGETS)
  if (*name != '.')
    free (lname);
#endif
  return f;
}

struct file *
enter_file (char *name)
{
  register struct file *f;
  register struct file *new;
  register struct file **file_slot;
  struct file file_key;
#if defined(VMS) && !defined(WANT_CASE_SENSITIVE_TARGETS)
  char *lname, *ln;
#endif

  assert (*name != '\0');

#if defined(VMS) && !defined(WANT_CASE_SENSITIVE_TARGETS)
  if (*name != '.')
    {
      char *n;
      lname = xmalloc (strlen (name) + 1);
      for (n = name, ln = lname; *n != '\0'; ++n, ++ln)
        {
          if (isupper ((unsigned char)*n))
            *ln = tolower ((unsigned char)*n);
          else
            *ln = *n;
        }

      *ln = 0;
      /* Creates a possible leak, old value of name is unreachable, but I
         currently don't know how to fix it. */
      name = lname;
    }
#endif

  file_key.hname = name;
  file_slot = (struct file **) hash_find_slot (&files, &file_key);
  f = *file_slot;
  if (! HASH_VACANT (f) && !f->double_colon)
    {
#if defined(VMS) && !defined(WANT_CASE_SENSITIVE_TARGETS)
      if (*name != '.')
        free (lname);
#endif
      return f;
    }

  new = xmalloc (sizeof (struct file));
  memset (new, '\0', sizeof (struct file));
  new->name = new->hname = name;
  new->update_status = -1;

  if (HASH_VACANT (f))
    {
      new->last = new;
      hash_insert_at (&files, new, file_slot);
    }
  else
    {
      /* There is already a double-colon entry for this file.  */
      new->double_colon = f;
      f->last->prev = new;
      f->last = new;
    }

  return new;
}

/* Rename FILE to NAME.  This is not as simple as resetting
   the `name' member, since it must be put in a new hash bucket,
   and possibly merged with an existing file called NAME.  */

void
rename_file (struct file *from_file, char *to_hname)
{
  rehash_file (from_file, to_hname);
  while (from_file)
    {
      from_file->name = from_file->hname;
      from_file = from_file->prev;
    }
}

/* Rehash FILE to NAME.  This is not as simple as resetting
   the `hname' member, since it must be put in a new hash bucket,
   and possibly merged with an existing file called NAME.  */

void
rehash_file (struct file *from_file, char *to_hname)
{
  struct file file_key;
  struct file **file_slot;
  struct file *to_file;
  struct file *deleted_file;
  struct file *f;

  file_key.hname = to_hname;
  if (0 == file_hash_cmp (from_file, &file_key))
    return;

  file_key.hname = from_file->hname;
  while (from_file->renamed != 0)
    from_file = from_file->renamed;
  if (file_hash_cmp (from_file, &file_key))
    /* hname changed unexpectedly */
    abort ();

  deleted_file = hash_delete (&files, from_file);
  if (deleted_file != from_file)
    /* from_file isn't the one stored in files */
    abort ();

  file_key.hname = to_hname;
  file_slot = (struct file **) hash_find_slot (&files, &file_key);
  to_file = *file_slot;

  from_file->hname = to_hname;
  for (f = from_file->double_colon; f != 0; f = f->prev)
    f->hname = to_hname;

  if (HASH_VACANT (to_file))
    hash_insert_at (&files, from_file, file_slot);
  else
    {
      /* TO_FILE already exists under TO_HNAME.
	 We must retain TO_FILE and merge FROM_FILE into it.  */

      if (from_file->cmds != 0)
	{
	  if (to_file->cmds == 0)
	    to_file->cmds = from_file->cmds;
	  else if (from_file->cmds != to_file->cmds)
	    {
	      /* We have two sets of commands.  We will go with the
		 one given in the rule explicitly mentioning this name,
		 but give a message to let the user know what's going on.  */
	      if (to_file->cmds->fileinfo.filenm != 0)
                error (&from_file->cmds->fileinfo,
		       _("Commands were specified for file `%s' at %s:%lu,"),
		       from_file->name, to_file->cmds->fileinfo.filenm,
		       to_file->cmds->fileinfo.lineno);
	      else
		error (&from_file->cmds->fileinfo,
		       _("Commands for file `%s' were found by implicit rule search,"),
		       from_file->name);
	      error (&from_file->cmds->fileinfo,
		     _("but `%s' is now considered the same file as `%s'."),
		     from_file->name, to_hname);
	      error (&from_file->cmds->fileinfo,
		     _("Commands for `%s' will be ignored in favor of those for `%s'."),
		     to_hname, from_file->name);
	    }
	}

      /* Merge the dependencies of the two files.  */

      if (to_file->deps == 0)
	to_file->deps = from_file->deps;
      else
	{
	  register struct dep *deps = to_file->deps;
	  while (deps->next != 0)
	    deps = deps->next;
	  deps->next = from_file->deps;
	}

      merge_variable_set_lists (&to_file->variables, from_file->variables);

      if (to_file->double_colon && from_file->is_target && !from_file->double_colon)
	fatal (NILF, _("can't rename single-colon `%s' to double-colon `%s'"),
	       from_file->name, to_hname);
      if (!to_file->double_colon  && from_file->double_colon)
	{
	  if (to_file->is_target)
	    fatal (NILF, _("can't rename double-colon `%s' to single-colon `%s'"),
		   from_file->name, to_hname);
	  else
	    to_file->double_colon = from_file->double_colon;
	}

      if (from_file->last_mtime > to_file->last_mtime)
	/* %%% Kludge so -W wins on a file that gets vpathized.  */
	to_file->last_mtime = from_file->last_mtime;

      to_file->mtime_before_update = from_file->mtime_before_update;

#define MERGE(field) to_file->field |= from_file->field
      MERGE (precious);
      MERGE (tried_implicit);
      MERGE (updating);
      MERGE (updated);
      MERGE (is_target);
      MERGE (cmd_target);
      MERGE (phony);
      MERGE (ignore_vpath);
#undef MERGE

      from_file->renamed = to_file;
    }
}

/* Remove all nonprecious intermediate files.
   If SIG is nonzero, this was caused by a fatal signal,
   meaning that a different message will be printed, and
   the message will go to stderr rather than stdout.  */

void
remove_intermediates (int sig)
{
  register struct file **file_slot;
  register struct file **file_end;
  int doneany = 0;

  /* If there's no way we will ever remove anything anyway, punt early.  */
  if (question_flag || touch_flag || all_secondary)
    return;

  if (sig && just_print_flag)
    return;

  file_slot = (struct file **) files.ht_vec;
  file_end = file_slot + files.ht_size;
  for ( ; file_slot < file_end; file_slot++)
    if (! HASH_VACANT (*file_slot))
      {
	register struct file *f = *file_slot;
        /* Is this file eligible for automatic deletion?
           Yes, IFF: it's marked intermediate, it's not secondary, it wasn't
           given on the command-line, and it's either a -include makefile or
           it's not precious.  */
	if (f->intermediate && (f->dontcare || !f->precious)
	    && !f->secondary && !f->cmd_target)
	  {
	    int status;
	    if (f->update_status == -1)
	      /* If nothing would have created this file yet,
		 don't print an "rm" command for it.  */
	      continue;
	    if (just_print_flag)
	      status = 0;
	    else
	      {
		status = unlink (f->name);
		if (status < 0 && errno == ENOENT)
		  continue;
	      }
	    if (!f->dontcare)
	      {
		if (sig)
		  error (NILF, _("*** Deleting intermediate file `%s'"), f->name);
		else
		  {
		    if (! doneany)
		      DB (DB_BASIC, (_("Removing intermediate files...\n")));
		    if (!silent_flag)
		      {
			if (! doneany)
			  {
			    fputs ("rm ", stdout);
			    doneany = 1;
			  }
			else
			  putchar (' ');
			fputs (f->name, stdout);
			fflush (stdout);
		      }
		  }
		if (status < 0)
		  perror_with_name ("unlink: ", f->name);
	      }
	  }
      }

  if (doneany && !sig)
    {
      putchar ('\n');
      fflush (stdout);
    }
}

struct dep *
parse_prereqs (char *p)
{
  struct dep *new = (struct dep *)
    multi_glob (parse_file_seq (&p, '|', sizeof (struct dep), 1),
                sizeof (struct dep));

  if (*p)
    {
      /* Files that follow '|' are "order-only" prerequisites that satisfy the
         dependency by existing: their modification times are irrelevant.  */
      struct dep *ood;

      ++p;
      ood = (struct dep *)
        multi_glob (parse_file_seq (&p, '\0', sizeof (struct dep), 1),
                    sizeof (struct dep));

      if (! new)
        new = ood;
      else
        {
          struct dep *dp;
          for (dp = new; dp->next != NULL; dp = dp->next)
            ;
          dp->next = ood;
        }

      for (; ood != NULL; ood = ood->next)
        ood->ignore_mtime = 1;
    }

  return new;
}


/* Set the intermediate flag.  */

static void
set_intermediate (const void *item)
{
  struct file *f = (struct file *) item;
  f->intermediate = 1;
}

/* Expand and parse each dependency line. */
static void
expand_deps (struct file *f)
{
  struct dep *d;
  struct dep *old = f->deps;
  char *file_stem = f->stem;
  unsigned int last_dep_has_cmds = f->updating;
  int initialized = 0;

  f->updating = 0;
  f->deps = 0;

  for (d = old; d != 0; d = d->next)
    {
      struct dep *new, *d1;
      char *p;

      if (! d->name)
        continue;

      /* Create the dependency list.
         If we're not doing 2nd expansion, then it's just the name.  */
      if (! d->need_2nd_expansion)
        p = d->name;
      else
        {
          /* If it's from a static pattern rule, convert the patterns into
             "$*" so they'll expand properly.  */
          if (d->staticpattern)
            {
              char *o;
              char *buffer = variable_expand ("");

              o = subst_expand (buffer, d->name, "%", "$*", 1, 2, 0);

              free (d->name);
              d->name = savestring (buffer, o - buffer);
              d->staticpattern = 0; /* Clear staticpattern so that we don't
                                       re-expand %s below. */
            }

          /* We are going to do second expansion so initialize file variables
             for the file. Since the stem for static pattern rules comes from
             individual dep lines, we will temporarily set f->stem to d->stem.
          */
          if (!initialized)
            {
              initialize_file_variables (f, 0);
              initialized = 1;
            }

          if (d->stem != 0)
            f->stem = d->stem;

          set_file_variables (f);

          p = variable_expand_for_file (d->name, f);

          if (d->stem != 0)
            f->stem = file_stem;
        }

      /* Parse the prerequisites.  */
      new = parse_prereqs (p);

      /* If this dep list was from a static pattern rule, expand the %s.  We
         use patsubst_expand to translate the prerequisites' patterns into
         plain prerequisite names.  */
      if (new && d->staticpattern)
        {
          char *pattern = "%";
          char *buffer = variable_expand ("");
          struct dep *dp = new, *dl = 0;

          while (dp != 0)
            {
              char *percent = find_percent (dp->name);
              if (percent)
                {
                  /* We have to handle empty stems specially, because that
                     would be equivalent to $(patsubst %,dp->name,) which
                     will always be empty.  */
                  if (d->stem[0] == '\0')
                    /* This needs memmove() in ISO C.  */
                    memmove (percent, percent+1, strlen (percent));
                  else
                    {
                      char *o = patsubst_expand (buffer, d->stem, pattern,
                                                 dp->name, pattern+1,
                                                 percent+1);
                      if (o == buffer)
                        dp->name[0] = '\0';
                      else
                        {
                          free (dp->name);
                          dp->name = savestring (buffer, o - buffer);
                        }
                    }

                  /* If the name expanded to the empty string, ignore it.  */
                  if (dp->name[0] == '\0')
                    {
                      struct dep *df = dp;
                      if (dp == new)
                        dp = new = new->next;
                      else
                        dp = dl->next = dp->next;
                      /* @@ Are we leaking df->name here?  */
                      df->name = 0;
                      free_dep (df);
                      continue;
                    }
                }
              dl = dp;
              dp = dp->next;
            }
        }

      /* Enter them as files. */
      for (d1 = new; d1 != 0; d1 = d1->next)
        {
          d1->file = lookup_file (d1->name);
          if (d1->file == 0)
            d1->file = enter_file (d1->name);
          else
            free (d1->name);
          d1->name = 0;
          d1->staticpattern = 0;
          d1->need_2nd_expansion = 0;
        }

      /* Add newly parsed deps to f->deps. If this is the last dependency
         line and this target has commands then put it in front so the
         last dependency line (the one with commands) ends up being the
         first. This is important because people expect $< to hold first
         prerequisite from the rule with commands. If it is not the last
         dependency line or the rule does not have commands then link it
         at the end so it appears in makefile order.  */

      if (new != 0)
        {
          if (d->next == 0 && last_dep_has_cmds)
            {
              struct dep **d_ptr;
              for (d_ptr = &new; *d_ptr; d_ptr = &(*d_ptr)->next)
                ;

              *d_ptr = f->deps;
              f->deps = new;
            }
          else
            {
              struct dep **d_ptr;
              for (d_ptr = &f->deps; *d_ptr; d_ptr = &(*d_ptr)->next)
                ;

              *d_ptr = new;
            }
        }
    }

  free_dep_chain (old);
}

/* For each dependency of each file, make the `struct dep' point
   at the appropriate `struct file' (which may have to be created).

   Also mark the files depended on by .PRECIOUS, .PHONY, .SILENT,
   and various other special targets.  */

void
snap_deps (void)
{
  struct file *f;
  struct file *f2;
  struct dep *d;
  struct file **file_slot_0;
  struct file **file_slot;
  struct file **file_end;

  /* Perform second expansion and enter each dependency
     name as a file. */

  /* Expand .SUFFIXES first; it's dependencies are used for
     $$* calculation. */
  for (f = lookup_file (".SUFFIXES"); f != 0; f = f->prev)
    expand_deps (f);

  /* We must use hash_dump (), because within this loop
     we might add new files to the table, possibly causing
     an in-situ table expansion.  */
  file_slot_0 = (struct file **) hash_dump (&files, 0, 0);
  file_end = file_slot_0 + files.ht_fill;
  for (file_slot = file_slot_0; file_slot < file_end; file_slot++)
    for (f = *file_slot; f != 0; f = f->prev)
      {
        if (strcmp (f->name, ".SUFFIXES") != 0)
          expand_deps (f);
      }
  free (file_slot_0);

  for (f = lookup_file (".PRECIOUS"); f != 0; f = f->prev)
    for (d = f->deps; d != 0; d = d->next)
      for (f2 = d->file; f2 != 0; f2 = f2->prev)
	f2->precious = 1;

  for (f = lookup_file (".LOW_RESOLUTION_TIME"); f != 0; f = f->prev)
    for (d = f->deps; d != 0; d = d->next)
      for (f2 = d->file; f2 != 0; f2 = f2->prev)
	f2->low_resolution_time = 1;

  for (f = lookup_file (".PHONY"); f != 0; f = f->prev)
    for (d = f->deps; d != 0; d = d->next)
      for (f2 = d->file; f2 != 0; f2 = f2->prev)
	{
	  /* Mark this file as phony nonexistent target.  */
	  f2->phony = 1;
          f2->is_target = 1;
	  f2->last_mtime = NONEXISTENT_MTIME;
	  f2->mtime_before_update = NONEXISTENT_MTIME;
	}

  for (f = lookup_file (".INTERMEDIATE"); f != 0; f = f->prev)
    {
      /* .INTERMEDIATE with deps listed
	 marks those deps as intermediate files.  */
      for (d = f->deps; d != 0; d = d->next)
	for (f2 = d->file; f2 != 0; f2 = f2->prev)
	  f2->intermediate = 1;
      /* .INTERMEDIATE with no deps does nothing.
	 Marking all files as intermediates is useless
	 since the goal targets would be deleted after they are built.  */
    }

  for (f = lookup_file (".SECONDARY"); f != 0; f = f->prev)
    {
      /* .SECONDARY with deps listed
	 marks those deps as intermediate files
	 in that they don't get rebuilt if not actually needed;
	 but unlike real intermediate files,
	 these are not deleted after make finishes.  */
      if (f->deps)
        for (d = f->deps; d != 0; d = d->next)
          for (f2 = d->file; f2 != 0; f2 = f2->prev)
            f2->intermediate = f2->secondary = 1;
      /* .SECONDARY with no deps listed marks *all* files that way.  */
      else
        {
          all_secondary = 1;
          hash_map (&files, set_intermediate);
        }
    }

  f = lookup_file (".EXPORT_ALL_VARIABLES");
  if (f != 0 && f->is_target)
    export_all_variables = 1;

  f = lookup_file (".IGNORE");
  if (f != 0 && f->is_target)
    {
      if (f->deps == 0)
	ignore_errors_flag = 1;
      else
	for (d = f->deps; d != 0; d = d->next)
	  for (f2 = d->file; f2 != 0; f2 = f2->prev)
	    f2->command_flags |= COMMANDS_NOERROR;
    }

  f = lookup_file (".SILENT");
  if (f != 0 && f->is_target)
    {
      if (f->deps == 0)
	silent_flag = 1;
      else
	for (d = f->deps; d != 0; d = d->next)
	  for (f2 = d->file; f2 != 0; f2 = f2->prev)
	    f2->command_flags |= COMMANDS_SILENT;
    }

  f = lookup_file (".NOTPARALLEL");
  if (f != 0 && f->is_target)
    not_parallel = 1;

#ifndef NO_MINUS_C_MINUS_O
  /* If .POSIX was defined, remove OUTPUT_OPTION to comply.  */
  /* This needs more work: what if the user sets this in the makefile?
  if (posix_pedantic)
    define_variable (STRING_SIZE_TUPLE("OUTPUT_OPTION"), "", o_default, 1);
  */
#endif

  /* Remember that we've done this. */
  snapped_deps = 1;
}

/* Set the `command_state' member of FILE and all its `also_make's.  */

void
set_command_state (struct file *file, enum cmd_state state)
{
  struct dep *d;

  file->command_state = state;

  for (d = file->also_make; d != 0; d = d->next)
    d->file->command_state = state;
}

/* Convert an external file timestamp to internal form.  */

FILE_TIMESTAMP
file_timestamp_cons (const char *fname, time_t s, int ns)
{
  int offset = ORDINARY_MTIME_MIN + (FILE_TIMESTAMP_HI_RES ? ns : 0);
  FILE_TIMESTAMP product = (FILE_TIMESTAMP) s << FILE_TIMESTAMP_LO_BITS;
  FILE_TIMESTAMP ts = product + offset;

  if (! (s <= FILE_TIMESTAMP_S (ORDINARY_MTIME_MAX)
	 && product <= ts && ts <= ORDINARY_MTIME_MAX))
    {
      char buf[FILE_TIMESTAMP_PRINT_LEN_BOUND + 1];
      ts = s <= OLD_MTIME ? ORDINARY_MTIME_MIN : ORDINARY_MTIME_MAX;
      file_timestamp_sprintf (buf, ts);
      error (NILF, _("%s: Timestamp out of range; substituting %s"),
	     fname ? fname : _("Current time"), buf);
    }

  return ts;
}

/* Return the current time as a file timestamp, setting *RESOLUTION to
   its resolution.  */
FILE_TIMESTAMP
file_timestamp_now (int *resolution)
{
  int r;
  time_t s;
  int ns;

  /* Don't bother with high-resolution clocks if file timestamps have
     only one-second resolution.  The code below should work, but it's
     not worth the hassle of debugging it on hosts where it fails.  */
#if FILE_TIMESTAMP_HI_RES
# if HAVE_CLOCK_GETTIME && defined CLOCK_REALTIME
  {
    struct timespec timespec;
    if (clock_gettime (CLOCK_REALTIME, &timespec) == 0)
      {
	r = 1;
	s = timespec.tv_sec;
	ns = timespec.tv_nsec;
	goto got_time;
      }
  }
# endif
# if HAVE_GETTIMEOFDAY
  {
    struct timeval timeval;
    if (gettimeofday (&timeval, 0) == 0)
      {
	r = 1000;
	s = timeval.tv_sec;
	ns = timeval.tv_usec * 1000;
	goto got_time;
      }
  }
# endif
#endif

  r = 1000000000;
  s = time ((time_t *) 0);
  ns = 0;

#if FILE_TIMESTAMP_HI_RES
 got_time:
#endif
  *resolution = r;
  return file_timestamp_cons (0, s, ns);
}

/* Place into the buffer P a printable representation of the file
   timestamp TS.  */
void
file_timestamp_sprintf (char *p, FILE_TIMESTAMP ts)
{
  time_t t = FILE_TIMESTAMP_S (ts);
  struct tm *tm = localtime (&t);

  if (tm)
    sprintf (p, "%04d-%02d-%02d %02d:%02d:%02d",
	     tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
	     tm->tm_hour, tm->tm_min, tm->tm_sec);
  else if (t < 0)
    sprintf (p, "%ld", (long) t);
  else
    sprintf (p, "%lu", (unsigned long) t);
  p += strlen (p);

  /* Append nanoseconds as a fraction, but remove trailing zeros.
     We don't know the actual timestamp resolution, since clock_getres
     applies only to local times, whereas this timestamp might come
     from a remote filesystem.  So removing trailing zeros is the
     best guess that we can do.  */
  sprintf (p, ".%09d", FILE_TIMESTAMP_NS (ts));
  p += strlen (p) - 1;
  while (*p == '0')
    p--;
  p += *p != '.';

  *p = '\0';
}

/* Print the data base of files.  */

static void
print_file (const void *item)
{
  struct file *f = (struct file *) item;
  struct dep *d;
  struct dep *ood = 0;

  putchar ('\n');
  if (!f->is_target)
    puts (_("# Not a target:"));
  printf ("%s:%s", f->name, f->double_colon ? ":" : "");

  /* Print all normal dependencies; note any order-only deps.  */
  for (d = f->deps; d != 0; d = d->next)
    if (! d->ignore_mtime)
      printf (" %s", dep_name (d));
    else if (! ood)
      ood = d;

  /* Print order-only deps, if we have any.  */
  if (ood)
    {
      printf (" | %s", dep_name (ood));
      for (d = ood->next; d != 0; d = d->next)
        if (d->ignore_mtime)
          printf (" %s", dep_name (d));
    }

  putchar ('\n');

  if (f->precious)
    puts (_("#  Precious file (prerequisite of .PRECIOUS)."));
  if (f->phony)
    puts (_("#  Phony target (prerequisite of .PHONY)."));
  if (f->cmd_target)
    puts (_("#  Command-line target."));
  if (f->dontcare)
    puts (_("#  A default, MAKEFILES, or -include/sinclude makefile."));
  puts (f->tried_implicit
        ? _("#  Implicit rule search has been done.")
        : _("#  Implicit rule search has not been done."));
  if (f->stem != 0)
    printf (_("#  Implicit/static pattern stem: `%s'\n"), f->stem);
  if (f->intermediate)
    puts (_("#  File is an intermediate prerequisite."));
  if (f->also_make != 0)
    {
      fputs (_("#  Also makes:"), stdout);
      for (d = f->also_make; d != 0; d = d->next)
	printf (" %s", dep_name (d));
      putchar ('\n');
    }
  if (f->last_mtime == UNKNOWN_MTIME)
    puts (_("#  Modification time never checked."));
  else if (f->last_mtime == NONEXISTENT_MTIME)
    puts (_("#  File does not exist."));
  else if (f->last_mtime == OLD_MTIME)
    puts (_("#  File is very old."));
  else
    {
      char buf[FILE_TIMESTAMP_PRINT_LEN_BOUND + 1];
      file_timestamp_sprintf (buf, f->last_mtime);
      printf (_("#  Last modified %s\n"), buf);
    }
  puts (f->updated
        ? _("#  File has been updated.") : _("#  File has not been updated."));
  switch (f->command_state)
    {
    case cs_running:
      puts (_("#  Commands currently running (THIS IS A BUG)."));
      break;
    case cs_deps_running:
      puts (_("#  Dependencies commands running (THIS IS A BUG)."));
      break;
    case cs_not_started:
    case cs_finished:
      switch (f->update_status)
	{
	case -1:
	  break;
	case 0:
	  puts (_("#  Successfully updated."));
	  break;
	case 1:
	  assert (question_flag);
	  puts (_("#  Needs to be updated (-q is set)."));
	  break;
	case 2:
	  puts (_("#  Failed to be updated."));
	  break;
	default:
	  puts (_("#  Invalid value in `update_status' member!"));
	  fflush (stdout);
	  fflush (stderr);
	  abort ();
	}
      break;
    default:
      puts (_("#  Invalid value in `command_state' member!"));
      fflush (stdout);
      fflush (stderr);
      abort ();
    }

  if (f->variables != 0)
    print_file_variables (f);

  if (f->cmds != 0)
    print_commands (f->cmds);

  if (f->prev)
    print_file ((const void *) f->prev);
}

void
print_file_data_base (void)
{
  puts (_("\n# Files"));

  hash_map (&files, print_file);

  fputs (_("\n# files hash-table stats:\n# "), stdout);
  hash_print_stats (&files, stdout);
}

#define EXPANSION_INCREMENT(_l)  ((((_l) / 500) + 1) * 500)

char *
build_target_list (char *value)
{
  static unsigned long last_targ_count = 0;

  if (files.ht_fill != last_targ_count)
    {
      unsigned long max = EXPANSION_INCREMENT (strlen (value));
      unsigned long len;
      char *p;
      struct file **fp = (struct file **) files.ht_vec;
      struct file **end = &fp[files.ht_size];

      /* Make sure we have at least MAX bytes in the allocated buffer.  */
      value = xrealloc (value, max);

      p = value;
      len = 0;
      for (; fp < end; ++fp)
        if (!HASH_VACANT (*fp) && (*fp)->is_target)
          {
            struct file *f = *fp;
            int l = strlen (f->name);

            len += l + 1;
            if (len > max)
              {
                unsigned long off = p - value;

                max += EXPANSION_INCREMENT (l + 1);
                value = xrealloc (value, max);
                p = &value[off];
              }

            memcpy (p, f->name, l);
            p += l;
            *(p++) = ' ';
          }
      *(p-1) = '\0';

      last_targ_count = files.ht_fill;
    }

  return value;
}

void
init_hash_files (void)
{
  hash_init (&files, 1000, file_hash_1, file_hash_2, file_hash_cmp);
}

/* EOF */