/* Definition of target file data structures for GNU Make.
Copyright (C) 1988,89,90,91,92,93,94,97 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., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */


/* Structure that represents the info on one file
   that the makefile says how to make.
   All of these are chained together through `next'.  */

struct file
  {
    struct file *next;
    char *name;
    char *hname;                /* Hashed filename */
    char *vpath;                /* VPATH/vpath pathname */
    struct dep *deps;
    struct commands *cmds;	/* Commands to execute for this target.  */
    int command_flags;		/* Flags OR'd in for cmds; see commands.h.  */
    char *stem;			/* Implicit stem, if an implicit
    				   rule has been used */
    struct dep *also_make;	/* Targets that are made by making this.  */
    FILE_TIMESTAMP last_mtime;	/* File's modtime, if already known.  */
    FILE_TIMESTAMP mtime_before_update;	/* File's modtime before any updating
                                           has been performed.  */
    struct file *prev;		/* Previous entry for same file name;
				   used when there are multiple double-colon
				   entries for the same file.  */

    /* File that this file was renamed to.  After any time that a
       file could be renamed, call `check_renamed' (below).  */
    struct file *renamed;

    /* List of variable sets used for this file.  */
    struct variable_set_list *variables;

    /* Pattern-specific variable reference for this target, or null if there
       isn't one.  Also see the pat_searched flag, below.  */
    struct variable_set_list *pat_variables;

    /* Immediate dependent that caused this target to be remade,
       or nil if there isn't one.  */
    struct file *parent;

    /* For a double-colon entry, this is the first double-colon entry for
       the same file.  Otherwise this is null.  */
    struct file *double_colon;

    short int update_status;	/* Status of the last attempt to update,
				   or -1 if none has been made.  */

    enum			/* State of the commands.  */
      {		/* Note: It is important that cs_not_started be zero.  */
	cs_not_started,		/* Not yet started.  */
	cs_deps_running,	/* Dep commands running.  */
	cs_running,		/* Commands running.  */
	cs_finished		/* Commands finished.  */
      } command_state ENUM_BITFIELD (2);

    unsigned int precious:1;	/* Non-0 means don't delete file on quit */
    unsigned int tried_implicit:1; /* Nonzero if have searched
				      for implicit rule for making
				      this file; don't search again.  */
    unsigned int updating:1;	/* Nonzero while updating deps of this file */
    unsigned int updated:1;	/* Nonzero if this file has been remade.  */
    unsigned int is_target:1;	/* Nonzero if file is described as target.  */
    unsigned int cmd_target:1;	/* Nonzero if file was given on cmd line.  */
    unsigned int phony:1;	/* Nonzero if this is a phony file
				   i.e., a dependency of .PHONY.  */
    unsigned int intermediate:1;/* Nonzero if this is an intermediate file.  */
    /* Nonzero, for an intermediate file,
       means remove_intermediates should not delete it.  */
    unsigned int secondary:1;
    unsigned int dontcare:1;	/* Nonzero if no complaint is to be made if
				   this target cannot be remade.  */
    unsigned int ignore_vpath:1;/* Nonzero if we threw out VPATH name.  */
    unsigned int pat_searched:1;/* Nonzero if we already searched for
                                   pattern-specific variables.  */
    unsigned int considered:1;  /* equal to `considered' if file has been
                                   considered on current scan of goal chain */
  };

/* Number of intermediate files entered.  */

extern unsigned int num_intermediates;

/* Current value for pruning the scan of the goal chain (toggle 0/1).  */

extern unsigned int considered;

extern struct file *default_goal_file, *suffix_file, *default_file;


extern struct file *lookup_file PARAMS ((char *name));
extern struct file *enter_file PARAMS ((char *name));
extern void remove_intermediates PARAMS ((int sig));
extern void snap_deps PARAMS ((void));
extern void rename_file PARAMS ((struct file *file, char *name));
extern void rehash_file PARAMS ((struct file *file, char *name));
extern void file_hash_enter PARAMS ((struct file *file, char *name,
                                     unsigned int oldhash, char *oldname));
extern void set_command_state PARAMS ((struct file *file, int state));
extern void notice_finished_file PARAMS ((struct file *file));


#if ST_MTIM_NSEC
# define FILE_TIMESTAMP_STAT_MODTIME(st) \
    FILE_TIMESTAMP_FROM_S_AND_NS ((st).st_mtim.tv_sec, \
                                  (st).st_mtim.ST_MTIM_NSEC)
# define FILE_TIMESTAMPS_PER_S \
    MIN ((FILE_TIMESTAMP) 1000000000, \
         (INTEGER_TYPE_MAXIMUM (FILE_TIMESTAMP) \
         / INTEGER_TYPE_MAXIMUM (time_t)))
#else
# define FILE_TIMESTAMP_STAT_MODTIME(st) ((st).st_mtime)
# define FILE_TIMESTAMPS_PER_S 1
#endif

#define FILE_TIMESTAMP_FROM_S_AND_NS(s, ns) \
    ((s) * FILE_TIMESTAMPS_PER_S \
     + (ns) * FILE_TIMESTAMPS_PER_S / 1000000000)
#define FILE_TIMESTAMP_DIV(a, b) ((a)/(b) - ((a)%(b) < 0))
#define FILE_TIMESTAMP_MOD(a, b) ((a)%(b) + ((a)%(b) < 0) * (b))
#define FILE_TIMESTAMP_S(ts) FILE_TIMESTAMP_DIV ((ts), FILE_TIMESTAMPS_PER_S)
#define FILE_TIMESTAMP_NS(ts) \
    (((FILE_TIMESTAMP_MOD ((ts), FILE_TIMESTAMPS_PER_S) * 1000000000) \
       + (FILE_TIMESTAMPS_PER_S - 1)) \
      / FILE_TIMESTAMPS_PER_S)

/* Upper bound on length of string "YYYY-MM-DD HH:MM:SS.NNNNNNNNN"
   representing a file timestamp.  The upper bound is not necessarily 19,
   since the year might be less than -999 or greater than 9999.

   Subtract one for the sign bit if in case file timestamps can be negative;
   subtract FLOOR_LOG2_SECONDS_PER_YEAR to yield an upper bound on how many
   file timestamp bits might affect the year;
   302 / 1000 is log10 (2) rounded up;
   add one for integer division truncation;
   add one more for a minus sign if file timestamps can be negative;
   add 4 to allow for any 4-digit epoch year (e.g. 1970);
   add 25 to allow for "-MM-DD HH:MM:SS.NNNNNNNNN".  */
#define FLOOR_LOG2_SECONDS_PER_YEAR 24
#define FILE_TIMESTAMP_PRINT_LEN_BOUND \
  (((sizeof (FILE_TIMESTAMP) * CHAR_BIT - 1 - FLOOR_LOG2_SECONDS_PER_YEAR) \
    * 302 / 1000) \
   + 1 + 1 + 4 + 25)

extern FILE_TIMESTAMP file_timestamp_now PARAMS ((void));
extern void file_timestamp_sprintf PARAMS ((char *p, FILE_TIMESTAMP ts));

/* Return the mtime of file F (a struct file *), caching it.
   The value is -1 if the file does not exist.  */
#define file_mtime(f) file_mtime_1 ((f), 1)
/* Return the mtime of file F (a struct file *), caching it.
   Don't search using vpath for the file--if it doesn't actually exist,
   we don't find it.
   The value is -1 if the file does not exist.  */
#define file_mtime_no_search(f) file_mtime_1 ((f), 0)
extern FILE_TIMESTAMP f_mtime PARAMS ((struct file *file, int search));
#define file_mtime_1(f, v) \
  ((f)->last_mtime ? (f)->last_mtime : f_mtime ((f), v))

/* Modtime value to use for `infinitely new'.  We used to get the current time
   from the system and use that whenever we wanted `new'.  But that causes
   trouble when the machine running make and the machine holding a file have
   different ideas about what time it is; and can also lose for `force'
   targets, which need to be considered newer than anything that depends on
   them, even if said dependents' modtimes are in the future.

   If FILE_TIMESTAMP is unsigned, its maximum value is the same as
   ((FILE_TIMESTAMP) -1), so use one less than that, because -1 is
   used for non-existing files.  */
#define NEW_MTIME \
     (INTEGER_TYPE_SIGNED (FILE_TIMESTAMP) \
      ? INTEGER_TYPE_MAXIMUM (FILE_TIMESTAMP) \
      : (INTEGER_TYPE_MAXIMUM (FILE_TIMESTAMP) - 1))

#define check_renamed(file) \
  while ((file)->renamed != 0) (file) = (file)->renamed /* No ; here.  */