1 /* Definition of target file data structures for GNU Make.
2 Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software
4 Foundation, Inc.
5 This file is part of GNU Make.
6 
7 GNU Make is free software; you can redistribute it and/or modify it under the
8 terms of the GNU General Public License as published by the Free Software
9 Foundation; either version 2, or (at your option) any later version.
10 
11 GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
13 A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
14 
15 You should have received a copy of the GNU General Public License along with
16 GNU Make; see the file COPYING.  If not, write to the Free Software
17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.  */
18 
19 
20 /* Structure that represents the info on one file
21    that the makefile says how to make.
22    All of these are chained together through `next'.  */
23 
24 #include "hash.h"
25 
26 struct file
27   {
28     char *name;
29     char *hname;                /* Hashed filename */
30     char *vpath;                /* VPATH/vpath pathname */
31     struct dep *deps;		/* all dependencies, including duplicates */
32     struct commands *cmds;	/* Commands to execute for this target.  */
33     int command_flags;		/* Flags OR'd in for cmds; see commands.h.  */
34     char *stem;			/* Implicit stem, if an implicit
35     				   rule has been used */
36     struct dep *also_make;	/* Targets that are made by making this.  */
37     FILE_TIMESTAMP last_mtime;	/* File's modtime, if already known.  */
38     FILE_TIMESTAMP mtime_before_update;	/* File's modtime before any updating
39                                            has been performed.  */
40     struct file *prev;		/* Previous entry for same file name;
41 				   used when there are multiple double-colon
42 				   entries for the same file.  */
43     struct file *last;          /* Last entry for the same file name.  */
44 
45     /* File that this file was renamed to.  After any time that a
46        file could be renamed, call `check_renamed' (below).  */
47     struct file *renamed;
48 
49     /* List of variable sets used for this file.  */
50     struct variable_set_list *variables;
51 
52     /* Pattern-specific variable reference for this target, or null if there
53        isn't one.  Also see the pat_searched flag, below.  */
54     struct variable_set_list *pat_variables;
55 
56     /* Immediate dependent that caused this target to be remade,
57        or nil if there isn't one.  */
58     struct file *parent;
59 
60     /* For a double-colon entry, this is the first double-colon entry for
61        the same file.  Otherwise this is null.  */
62     struct file *double_colon;
63 
64     short int update_status;	/* Status of the last attempt to update,
65 				   or -1 if none has been made.  */
66 
67     enum cmd_state		/* State of the commands.  */
68       {		/* Note: It is important that cs_not_started be zero.  */
69 	cs_not_started,		/* Not yet started.  */
70 	cs_deps_running,	/* Dep commands running.  */
71 	cs_running,		/* Commands running.  */
72 	cs_finished		/* Commands finished.  */
73       } command_state ENUM_BITFIELD (2);
74 
75     unsigned int precious:1;	/* Non-0 means don't delete file on quit */
76     unsigned int low_resolution_time:1;	/* Nonzero if this file's time stamp
77 					   has only one-second resolution.  */
78     unsigned int tried_implicit:1; /* Nonzero if have searched
79 				      for implicit rule for making
80 				      this file; don't search again.  */
81     unsigned int updating:1;	/* Nonzero while updating deps of this file */
82     unsigned int updated:1;	/* Nonzero if this file has been remade.  */
83     unsigned int is_target:1;	/* Nonzero if file is described as target.  */
84     unsigned int cmd_target:1;	/* Nonzero if file was given on cmd line.  */
85     unsigned int phony:1;	/* Nonzero if this is a phony file
86 				   i.e., a prerequisite of .PHONY.  */
87     unsigned int intermediate:1;/* Nonzero if this is an intermediate file.  */
88     unsigned int secondary:1;   /* Nonzero means remove_intermediates should
89                                    not delete it.  */
90     unsigned int dontcare:1;	/* Nonzero if no complaint is to be made if
91 				   this target cannot be remade.  */
92     unsigned int ignore_vpath:1;/* Nonzero if we threw out VPATH name.  */
93     unsigned int pat_searched:1;/* Nonzero if we already searched for
94                                    pattern-specific variables.  */
95     unsigned int considered:1;  /* equal to 'considered' if file has been
96                                    considered on current scan of goal chain */
97   };
98 
99 
100 extern struct file *default_goal_file, *suffix_file, *default_file;
101 extern char **default_goal_name;
102 
103 
104 extern struct file *lookup_file PARAMS ((char *name));
105 extern struct file *enter_file PARAMS ((char *name));
106 extern struct dep *parse_prereqs PARAMS ((char *prereqs));
107 extern void remove_intermediates PARAMS ((int sig));
108 extern void snap_deps PARAMS ((void));
109 extern void rename_file PARAMS ((struct file *file, char *name));
110 extern void rehash_file PARAMS ((struct file *file, char *name));
111 extern void set_command_state PARAMS ((struct file *file, enum cmd_state state));
112 extern void notice_finished_file PARAMS ((struct file *file));
113 extern void init_hash_files PARAMS ((void));
114 extern char *build_target_list PARAMS ((char *old_list));
115 
116 #if FILE_TIMESTAMP_HI_RES
117 # define FILE_TIMESTAMP_STAT_MODTIME(fname, st) \
118     file_timestamp_cons (fname, (st).st_mtime, (st).st_mtim.ST_MTIM_NSEC)
119 #else
120 # define FILE_TIMESTAMP_STAT_MODTIME(fname, st) \
121     file_timestamp_cons (fname, (st).st_mtime, 0)
122 #endif
123 
124 /* If FILE_TIMESTAMP is 64 bits (or more), use nanosecond resolution.
125    (Multiply by 2**30 instead of by 10**9 to save time at the cost of
126    slightly decreasing the number of available timestamps.)  With
127    64-bit FILE_TIMESTAMP, this stops working on 2514-05-30 01:53:04
128    UTC, but by then uintmax_t should be larger than 64 bits.  */
129 #define FILE_TIMESTAMPS_PER_S (FILE_TIMESTAMP_HI_RES ? 1000000000 : 1)
130 #define FILE_TIMESTAMP_LO_BITS (FILE_TIMESTAMP_HI_RES ? 30 : 0)
131 
132 #define FILE_TIMESTAMP_S(ts) (((ts) - ORDINARY_MTIME_MIN) \
133 			      >> FILE_TIMESTAMP_LO_BITS)
134 #define FILE_TIMESTAMP_NS(ts) ((int) (((ts) - ORDINARY_MTIME_MIN) \
135 				      & ((1 << FILE_TIMESTAMP_LO_BITS) - 1)))
136 
137 /* Upper bound on length of string "YYYY-MM-DD HH:MM:SS.NNNNNNNNN"
138    representing a file timestamp.  The upper bound is not necessarily 19,
139    since the year might be less than -999 or greater than 9999.
140 
141    Subtract one for the sign bit if in case file timestamps can be negative;
142    subtract FLOOR_LOG2_SECONDS_PER_YEAR to yield an upper bound on how many
143    file timestamp bits might affect the year;
144    302 / 1000 is log10 (2) rounded up;
145    add one for integer division truncation;
146    add one more for a minus sign if file timestamps can be negative;
147    add 4 to allow for any 4-digit epoch year (e.g. 1970);
148    add 25 to allow for "-MM-DD HH:MM:SS.NNNNNNNNN".  */
149 #define FLOOR_LOG2_SECONDS_PER_YEAR 24
150 #define FILE_TIMESTAMP_PRINT_LEN_BOUND \
151   (((sizeof (FILE_TIMESTAMP) * CHAR_BIT - 1 - FLOOR_LOG2_SECONDS_PER_YEAR) \
152     * 302 / 1000) \
153    + 1 + 1 + 4 + 25)
154 
155 extern FILE_TIMESTAMP file_timestamp_cons PARAMS ((char const *,
156 						   time_t, int));
157 extern FILE_TIMESTAMP file_timestamp_now PARAMS ((int *));
158 extern void file_timestamp_sprintf PARAMS ((char *p, FILE_TIMESTAMP ts));
159 
160 /* Return the mtime of file F (a struct file *), caching it.
161    The value is NONEXISTENT_MTIME if the file does not exist.  */
162 #define file_mtime(f) file_mtime_1 ((f), 1)
163 /* Return the mtime of file F (a struct file *), caching it.
164    Don't search using vpath for the file--if it doesn't actually exist,
165    we don't find it.
166    The value is NONEXISTENT_MTIME if the file does not exist.  */
167 #define file_mtime_no_search(f) file_mtime_1 ((f), 0)
168 extern FILE_TIMESTAMP f_mtime PARAMS ((struct file *file, int search));
169 #define file_mtime_1(f, v) \
170   ((f)->last_mtime == UNKNOWN_MTIME ? f_mtime ((f), v) : (f)->last_mtime)
171 
172 /* Special timestamp values.  */
173 
174 /* The file's timestamp is not yet known.  */
175 #define UNKNOWN_MTIME 0
176 
177 /* The file does not exist.  */
178 #define NONEXISTENT_MTIME 1
179 
180 /* The file does not exist, and we assume that it is older than any
181    actual file.  */
182 #define OLD_MTIME 2
183 
184 /* The smallest and largest ordinary timestamps.  */
185 #define ORDINARY_MTIME_MIN (OLD_MTIME + 1)
186 #define ORDINARY_MTIME_MAX ((FILE_TIMESTAMP_S (NEW_MTIME) \
187 			     << FILE_TIMESTAMP_LO_BITS) \
188 			    + ORDINARY_MTIME_MIN + FILE_TIMESTAMPS_PER_S - 1)
189 
190 /* Modtime value to use for `infinitely new'.  We used to get the current time
191    from the system and use that whenever we wanted `new'.  But that causes
192    trouble when the machine running make and the machine holding a file have
193    different ideas about what time it is; and can also lose for `force'
194    targets, which need to be considered newer than anything that depends on
195    them, even if said dependents' modtimes are in the future.  */
196 #define NEW_MTIME INTEGER_TYPE_MAXIMUM (FILE_TIMESTAMP)
197 
198 #define check_renamed(file) \
199   while ((file)->renamed != 0) (file) = (file)->renamed /* No ; here.  */
200 
201 /* Have we snapped deps yet?  */
202 extern int snapped_deps;
203