1MAKE(1) BSD General Commands Manual MAKE(1)
2
4 make — maintain program dependencies
5
7 make [-BeikNnqrstWwX] [-C directory] [-D variable] [-d flags]
8 [-f makefile] [-I directory] [-J private] [-j max_jobs]
9 [-m directory] [-T file] [-V variable] [-v variable]
10 [variable=value] [target ...]
11
13 make is a program designed to simplify the maintenance of other programs.
14 Its input is a list of specifications as to the files upon which programs
15 and other files depend. If no -f makefile makefile option is given, make
16 will try to open ‘makefile’ then ‘Makefile’ in order to find the specifi‐
17 cations. If the file ‘.depend’ exists, it is read (see mkdep(1)).
18 This manual page is intended as a reference document only. For a more
20 thorough description of make and makefiles, please refer to PMake - A
21 Tutorial.
22 make will prepend the contents of the MAKEFLAGS environment variable to
24 the command line arguments before parsing them.
25 The options are as follows:
27 -B Try to be backwards compatible by executing a single shell per
29 command and by executing the commands to make the sources of a
30 dependency line in sequence.
31 -C directory
33 Change to directory before reading the makefiles or doing any‐
34 thing else. If multiple -C options are specified, each is inter‐
35 preted relative to the previous one: -C / -C etc is equivalent to
36 -C /etc.
37 -D variable
39 Define variable to be 1, in the global context.
40 -d [-]flags
42 Turn on debugging, and specify which portions of make are to
43 print debugging information. Unless the flags are preceded by
44 ‘-’ they are added to the MAKEFLAGS environment variable and will
45 be processed by any child make processes. By default, debugging
46 information is printed to standard error, but this can be changed
47 using the F debugging flag. The debugging output is always
48 unbuffered; in addition, if debugging is enabled but debugging
49 output is not directed to standard output, then the standard out‐
50 put is line buffered. Flags is one or more of the following:
51 A Print all possible debugging information; equivalent to
53 specifying all of the debugging flags.
54 a Print debugging information about archive searching and
56 caching.
57 C Print debugging information about current working direc‐
59 tory.
60 c Print debugging information about conditional evaluation.
62 d Print debugging information about directory searching and
64 caching.
65 e Print debugging information about failed commands and
67 targets.
68 F[+]filename
70 Specify where debugging output is written. This must be
71 the last flag, because it consumes the remainder of the
72 argument. If the character immediately after the ‘F’
73 flag is ‘+’, then the file will be opened in append mode;
74 otherwise the file will be overwritten. If the file name
75 is ‘stdout’ or ‘stderr’ then debugging output will be
76 written to the standard output or standard error output
77 file descriptors respectively (and the ‘+’ option has no
78 effect). Otherwise, the output will be written to the
79 named file. If the file name ends ‘.%d’ then the ‘%d’ is
80 replaced by the pid.
81 f Print debugging information about loop evaluation.
83 g1 Print the input graph before making anything.
85 g2 Print the input graph after making everything, or before
87 exiting on error.
88 g3 Print the input graph before exiting on error.
90 j Print debugging information about running multiple
92 shells.
93 l Print commands in Makefiles regardless of whether or not
95 they are prefixed by ‘@’ or other "quiet" flags. Also
96 known as "loud" behavior.
97 M Print debugging information about "meta" mode decisions
99 about targets.
100 m Print debugging information about making targets, includ‐
102 ing modification dates.
103 n Don't delete the temporary command scripts created when
105 running commands. These temporary scripts are created in
106 the directory referred to by the TMPDIR environment vari‐
107 able, or in /tmp if TMPDIR is unset or set to the empty
108 string. The temporary scripts are created by mkstemp(3),
109 and have names of the form makeXXXXXX. NOTE: This can
110 create many files in TMPDIR or /tmp, so use with care.
111 p Print debugging information about makefile parsing.
113 s Print debugging information about suffix-transformation
115 rules.
116 t Print debugging information about target list mainte‐
118 nance.
119 V Force the -V option to print raw values of variables,
121 overriding the default behavior set via
122 .MAKE.EXPAND_VARIABLES.
123 v Print debugging information about variable assignment.
125 x Run shell commands with -x so the actual commands are
127 printed as they are executed.
128 -e Specify that environment variables override macro assignments
130 within makefiles.
131 -f makefile
133 Specify a makefile to read instead of the default ‘makefile’. If
134 makefile is ‘-’, standard input is read. Multiple makefiles may
135 be specified, and are read in the order specified.
136 -I directory
138 Specify a directory in which to search for makefiles and included
139 makefiles. The system makefile directory (or directories, see
140 the -m option) is automatically included as part of this list.
141 -i Ignore non-zero exit of shell commands in the makefile. Equiva‐
143 lent to specifying ‘-’ before each command line in the makefile.
144 -J private
146 This option should not be specified by the user.
147 When the j option is in use in a recursive build, this option is
149 passed by a make to child makes to allow all the make processes
150 in the build to cooperate to avoid overloading the system.
151 -j max_jobs
153 Specify the maximum number of jobs that make may have running at
154 any one time. The value is saved in .MAKE.JOBS. Turns compati‐
155 bility mode off, unless the B flag is also specified. When com‐
156 patibility mode is off, all commands associated with a target are
157 executed in a single shell invocation as opposed to the tradi‐
158 tional one shell invocation per line. This can break traditional
159 scripts which change directories on each command invocation and
160 then expect to start with a fresh environment on the next line.
161 It is more efficient to correct the scripts rather than turn
162 backwards compatibility on.
163 -k Continue processing after errors are encountered, but only on
165 those targets that do not depend on the target whose creation
166 caused the error.
167 -m directory
169 Specify a directory in which to search for sys.mk and makefiles
170 included via the ⟨file⟩-style include statement. The -m option
171 can be used multiple times to form a search path. This path will
172 override the default system include path: /usr/share/mk. Fur‐
173 thermore the system include path will be appended to the search
174 path used for "file"-style include statements (see the -I
175 option).
176 If a file or directory name in the -m argument (or the
178 MAKESYSPATH environment variable) starts with the string ".../"
179 then make will search for the specified file or directory named
180 in the remaining part of the argument string. The search starts
181 with the current directory of the Makefile and then works upward
182 towards the root of the file system. If the search is success‐
183 ful, then the resulting directory replaces the ".../" specifica‐
184 tion in the -m argument. If used, this feature allows make to
185 easily search in the current source tree for customized sys.mk
186 files (e.g., by using ".../mk/sys.mk" as an argument).
187 -n Display the commands that would have been executed, but do not
189 actually execute them unless the target depends on the .MAKE spe‐
190 cial source (see below).
191 -N Display the commands which would have been executed, but do not
193 actually execute any of them; useful for debugging top-level
194 makefiles without descending into subdirectories.
195 -q Do not execute any commands, but exit 0 if the specified targets
197 are up-to-date and 1, otherwise.
198 -r Do not use the built-in rules specified in the system makefile.
200 -s Do not echo any commands as they are executed. Equivalent to
202 specifying ‘@’ before each command line in the makefile.
203 -T tracefile
205 When used with the -j flag, append a trace record to tracefile
206 for each job started and completed.
207 -t Rather than re-building a target as specified in the makefile,
209 create it or update its modification time to make it appear up-
210 to-date.
211 -V variable
213 Print the value of variable. Do not build any targets. Multiple
214 instances of this option may be specified; the variables will be
215 printed one per line, with a blank line for each null or unde‐
216 fined variable. The value printed is extracted from the global
217 context after all makefiles have been read. By default, the raw
218 variable contents (which may include additional unexpanded vari‐
219 able references) are shown. If variable contains a ‘$’ then the
220 value will be recursively expanded to its complete resultant text
221 before printing. The expanded value will also be printed if
222 .MAKE.EXPAND_VARIABLES is set to true and the -dV option has not
223 been used to override it. Note that loop-local and target-local
224 variables, as well as values taken temporarily by global vari‐
225 ables during makefile processing, are not accessible via this
226 option. The -dv debug mode can be used to see these at the cost
227 of generating substantial extraneous output.
228 -v variable
230 Like -V but the variable is always expanded to its complete
231 value.
232 -W Treat any warnings during makefile parsing as errors.
234 -w Print entering and leaving directory messages, pre and post pro‐
236 cessing.
237 -X Don't export variables passed on the command line to the environ‐
239 ment individually. Variables passed on the command line are
240 still exported via the MAKEFLAGS environment variable. This
241 option may be useful on systems which have a small limit on the
242 size of command arguments.
243 variable=value
245 Set the value of the variable variable to value. Normally, all
246 values passed on the command line are also exported to sub-makes
247 in the environment. The -X flag disables this behavior. Vari‐
248 able assignments should follow options for POSIX compatibility
249 but no ordering is enforced.
250 There are seven different types of lines in a makefile: file dependency
252 specifications, shell commands, variable assignments, include statements,
253 conditional directives, for loops, and comments.
254 In general, lines may be continued from one line to the next by ending
256 them with a backslash (‘\’). The trailing newline character and initial
257 whitespace on the following line are compressed into a single space.
258
260 Dependency lines consist of one or more targets, an operator, and zero or
261 more sources. This creates a relationship where the targets “depend” on
262 the sources and are usually created from them. The exact relationship
263 between the target and the source is determined by the operator that sep‐
264 arates them. The three operators are as follows:
265 : A target is considered out-of-date if its modification time is less
267 than those of any of its sources. Sources for a target accumulate
268 over dependency lines when this operator is used. The target is
269 removed if make is interrupted.
270 ! Targets are always re-created, but not until all sources have been
272 examined and re-created as necessary. Sources for a target accumu‐
273 late over dependency lines when this operator is used. The target
274 is removed if make is interrupted.
275 :: If no sources are specified, the target is always re-created. Oth‐
277 erwise, a target is considered out-of-date if any of its sources
278 has been modified more recently than the target. Sources for a
279 target do not accumulate over dependency lines when this operator
280 is used. The target will not be removed if make is interrupted.
281 Targets and sources may contain the shell wildcard values ‘?’, ‘*’, ‘[]’,
283 and ‘{}’. The values ‘?’, ‘*’, and ‘[]’ may only be used as part of the
284 final component of the target or source, and must be used to describe
285 existing files. The value ‘{}’ need not necessarily be used to describe
286 existing files. Expansion is in directory order, not alphabetically as
287 done in the shell.
288
290 Each target may have associated with it one or more lines of shell com‐
291 mands, normally used to create the target. Each of the lines in this
292 script must be preceded by a tab. (For historical reasons, spaces are
293 not accepted.) While targets can appear in many dependency lines if
294 desired, by default only one of these rules may be followed by a creation
295 script. If the ‘::’ operator is used, however, all rules may include
296 scripts and the scripts are executed in the order found.
297 Each line is treated as a separate shell command, unless the end of line
299 is escaped with a backslash (‘\’) in which case that line and the next
300 are combined. If the first characters of the command are any combination
301 of ‘@’, ‘+’, or ‘-’, the command is treated specially. A ‘@’ causes the
302 command not to be echoed before it is executed. A ‘+’ causes the command
303 to be executed even when -n is given. This is similar to the effect of
304 the .MAKE special source, except that the effect can be limited to a sin‐
305 gle line of a script. A ‘-’ in compatibility mode causes any non-zero
306 exit status of the command line to be ignored.
307 When make is run in jobs mode with -j max_jobs, the entire script for the
309 target is fed to a single instance of the shell. In compatibility (non-
310 jobs) mode, each command is run in a separate process. If the command
311 contains any shell meta characters (‘#=|^(){};&<>*?[]:$`\\n’) it will be
312 passed to the shell; otherwise make will attempt direct execution. If a
313 line starts with ‘-’ and the shell has ErrCtl enabled then failure of the
314 command line will be ignored as in compatibility mode. Otherwise ‘-’
315 affects the entire job; the script will stop at the first command line
316 that fails, but the target will not be deemed to have failed.
317 Makefiles should be written so that the mode of make operation does not
319 change their behavior. For example, any command which needs to use “cd”
320 or “chdir” without potentially changing the directory for subsequent com‐
321 mands should be put in parentheses so it executes in a subshell. To
322 force the use of one shell, escape the line breaks so as to make the
323 whole script one command. For example:
324 avoid-chdir-side-effects:
326 @echo Building $@ in `pwd`
327 @(cd ${.CURDIR} && ${MAKE} $@)
328 @echo Back in `pwd`
329 ensure-one-shell-regardless-of-mode:
331 @echo Building $@ in `pwd`; \
332 (cd ${.CURDIR} && ${MAKE} $@); \
333 echo Back in `pwd`
334 Since make will chdir(2) to ‘.OBJDIR’ before executing any targets, each
336 child process starts with that as its current working directory.
337
339 Variables in make are much like variables in the shell, and, by tradi‐
340 tion, consist of all upper-case letters.
341 Variable assignment modifiers
343 The five operators that can be used to assign values to variables are as
344 follows:
345 = Assign the value to the variable. Any previous value is overrid‐
347 den.
348 += Append the value to the current value of the variable.
350 ?= Assign the value to the variable if it is not already defined.
352 := Assign with expansion, i.e. expand the value before assigning it
354 to the variable. Normally, expansion is not done until the vari‐
355 able is referenced. NOTE: References to undefined variables are
356 not expanded. This can cause problems when variable modifiers
357 are used.
358 != Expand the value and pass it to the shell for execution and
360 assign the result to the variable. Any newlines in the result
361 are replaced with spaces.
362 Any white-space before the assigned value is removed; if the value is
364 being appended, a single space is inserted between the previous contents
365 of the variable and the appended value.
366 Variables are expanded by surrounding the variable name with either curly
368 braces (‘{}’) or parentheses (‘()’) and preceding it with a dollar sign
369 (‘$’). If the variable name contains only a single letter, the surround‐
370 ing braces or parentheses are not required. This shorter form is not
371 recommended.
372 If the variable name contains a dollar, then the name itself is expanded
374 first. This allows almost arbitrary variable names, however names con‐
375 taining dollar, braces, parenthesis, or whitespace are really best
376 avoided!
377 If the result of expanding a variable contains a dollar sign (‘$’) the
379 string is expanded again.
380 Variable substitution occurs at three distinct times, depending on where
382 the variable is being used.
383 1. Variables in dependency lines are expanded as the line is read.
385 2. Variables in shell commands are expanded when the shell command is
387 executed.
388 3. “.for” loop index variables are expanded on each loop iteration.
390 Note that other variables are not expanded inside loops so the fol‐
391 lowing example code:
392 .for i in 1 2 3
395 a+= ${i}
396 j= ${i}
397 b+= ${j}
398 .endfor
399 all:
401 @echo ${a}
402 @echo ${b}
403 will print:
405 1 2 3
407 3 3 3
408 Because while ${a} contains “1 2 3” after the loop is executed, ${b}
410 contains “${j} ${j} ${j}” which expands to “3 3 3” since after the
411 loop completes ${j} contains “3”.
412 Variable classes
414 The four different classes of variables (in order of increasing prece‐
415 dence) are:
416 Environment variables
418 Variables defined as part of make's environment.
419 Global variables
421 Variables defined in the makefile or in included makefiles.
422 Command line variables
424 Variables defined as part of the command line.
425 Local variables
427 Variables that are defined specific to a certain target.
428 Local variables are all built in and their values vary magically from
430 target to target. It is not currently possible to define new local vari‐
431 ables. The seven local variables are as follows:
432 .ALLSRC The list of all sources for this target; also known as
434 ‘>’.
435 .ARCHIVE The name of the archive file; also known as ‘!’.
437 .IMPSRC In suffix-transformation rules, the name/path of the
439 source from which the target is to be transformed (the
440 “implied” source); also known as ‘<’. It is not defined
441 in explicit rules.
442 .MEMBER The name of the archive member; also known as ‘%’.
444 .OODATE The list of sources for this target that were deemed out-
446 of-date; also known as ‘?’.
447 .PREFIX The file prefix of the target, containing only the file
449 portion, no suffix or preceding directory components;
450 also known as ‘*’. The suffix must be one of the known
451 suffixes declared with .SUFFIXES or it will not be recog‐
452 nized.
453 .TARGET The name of the target; also known as ‘@’. For compati‐
455 bility with other makes this is an alias for .ARCHIVE in
456 archive member rules.
457 The shorter forms (‘>’, ‘!’, ‘<’, ‘%’, ‘?’, ‘*’, and ‘@’) are permitted
459 for backward compatibility with historical makefiles and legacy POSIX
460 make and are not recommended.
461 Variants of these variables with the punctuation followed immediately by
463 ‘D’ or ‘F’, e.g. ‘$(@D)’, are legacy forms equivalent to using the ‘:H’
464 and ‘:T’ modifiers. These forms are accepted for compatibility with AT&T
465 System V UNIX makefiles and POSIX but are not recommended.
466 Four of the local variables may be used in sources on dependency lines
468 because they expand to the proper value for each target on the line.
469 These variables are ‘.TARGET’, ‘.PREFIX’, ‘.ARCHIVE’, and ‘.MEMBER’.
470 Additional built-in variables
472 In addition, make sets or knows about the following variables:
473 $ A single dollar sign ‘$’, i.e. ‘$$’ expands to a single
475 dollar sign.
476 .ALLTARGETS The list of all targets encountered in the Makefile. If
478 evaluated during Makefile parsing, lists only those tar‐
479 gets encountered thus far.
480 .CURDIR A path to the directory where make was executed. Refer
482 to the description of ‘PWD’ for more details.
483 .INCLUDEDFROMDIR
485 The directory of the file this Makefile was included
486 from.
487 .INCLUDEDFROMFILE
489 The filename of the file this Makefile was included from.
490 MAKE The name that make was executed with (argv[0]). For com‐
492 patibility make also sets .MAKE with the same value. The
493 preferred variable to use is the environment variable
494 MAKE because it is more compatible with other versions of
495 make and cannot be confused with the special target with
496 the same name.
497 .MAKE.DEPENDFILE
499 Names the makefile (default ‘.depend’) from which gener‐
500 ated dependencies are read.
501 .MAKE.EXPAND_VARIABLES
503 A boolean that controls the default behavior of the -V
504 option. If true, variable values printed with -V are
505 fully expanded; if false, the raw variable contents
506 (which may include additional unexpanded variable refer‐
507 ences) are shown.
508 .MAKE.EXPORTED The list of variables exported by make.
510 .MAKE.JOBS The argument to the -j option.
512 .MAKE.JOB.PREFIX
514 If make is run with j then output for each target is pre‐
515 fixed with a token ‘--- target ---’ the first part of
516 which can be controlled via .MAKE.JOB.PREFIX. If
517 .MAKE.JOB.PREFIX is empty, no token is printed.
518 For example:
519 .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}]
520 would produce tokens like ‘---make[1234] target ---’ mak‐
521 ing it easier to track the degree of parallelism being
522 achieved.
523 MAKEFLAGS The environment variable ‘MAKEFLAGS’ may contain anything
525 that may be specified on make's command line. Anything
526 specified on make's command line is appended to the
527 ‘MAKEFLAGS’ variable which is then entered into the envi‐
528 ronment for all programs which make executes.
529 .MAKE.LEVEL The recursion depth of make. The initial instance of
531 make will be 0, and an incremented value is put into the
532 environment to be seen by the next generation. This
533 allows tests like: .if ${.MAKE.LEVEL} == 0 to protect
534 things which should only be evaluated in the initial
535 instance of make.
536 .MAKE.MAKEFILE_PREFERENCE
538 The ordered list of makefile names (default ‘makefile’,
539 ‘Makefile’) that make will look for.
540 .MAKE.MAKEFILES
542 The list of makefiles read by make, which is useful for
543 tracking dependencies. Each makefile is recorded only
544 once, regardless of the number of times read.
545 .MAKE.MODE Processed after reading all makefiles. Can affect the
547 mode that make runs in. It can contain a number of key‐
548 words:
549 compat Like -B, puts make into "compat"
551 mode.
552 meta Puts make into "meta" mode, where
554 meta files are created for each tar‐
555 get to capture the command run, the
556 output generated and if filemon(4)
557 is available, the system calls which
558 are of interest to make. The cap‐
559 tured output can be very useful when
560 diagnosing errors.
561 curdirOk= bf Normally make will not create .meta
563 files in ‘.CURDIR’. This can be
564 overridden by setting bf to a value
565 which represents True.
566 missing-meta= bf If bf is True, then a missing .meta
568 file makes the target out-of-date.
569 missing-filemon= bf If bf is True, then missing filemon
571 data makes the target out-of-date.
572 nofilemon Do not use filemon(4).
574 env For debugging, it can be useful to
576 include the environment in the .meta
577 file.
578 verbose If in "meta" mode, print a clue
580 about the target being built. This
581 is useful if the build is otherwise
582 running silently. The message
583 printed the value of:
584 .MAKE.META.PREFIX.
585 ignore-cmd Some makefiles have commands which
587 are simply not stable. This keyword
588 causes them to be ignored for deter‐
589 mining whether a target is out of
590 date in "meta" mode. See also
591 .NOMETA_CMP.
592 silent= bf If bf is True, when a .meta file is
594 created, mark the target .SILENT.
595 .MAKE.META.BAILIWICK
597 In "meta" mode, provides a list of prefixes which match
598 the directories controlled by make. If a file that was
599 generated outside of .OBJDIR but within said bailiwick is
600 missing, the current target is considered out-of-date.
601 .MAKE.META.CREATED
603 In "meta" mode, this variable contains a list of all the
604 meta files updated. If not empty, it can be used to
605 trigger processing of .MAKE.META.FILES.
606 .MAKE.META.FILES
608 In "meta" mode, this variable contains a list of all the
609 meta files used (updated or not). This list can be used
610 to process the meta files to extract dependency informa‐
611 tion.
612 .MAKE.META.IGNORE_PATHS
614 Provides a list of path prefixes that should be ignored;
615 because the contents are expected to change over time.
616 The default list includes: ‘/dev /etc /proc /tmp /var/run
617 /var/tmp’
618 .MAKE.META.IGNORE_PATTERNS
620 Provides a list of patterns to match against pathnames.
621 Ignore any that match.
622 .MAKE.META.IGNORE_FILTER
624 Provides a list of variable modifiers to apply to each
625 pathname. Ignore if the expansion is an empty string.
626 .MAKE.META.PREFIX
628 Defines the message printed for each meta file updated in
629 "meta verbose" mode. The default value is:
630 Building ${.TARGET:H:tA}/${.TARGET:T}
631 .MAKEOVERRIDES This variable is used to record the names of variables
633 assigned to on the command line, so that they may be
634 exported as part of ‘MAKEFLAGS’. This behavior can be
635 disabled by assigning an empty value to ‘.MAKEOVERRIDES’
636 within a makefile. Extra variables can be exported from
637 a makefile by appending their names to ‘.MAKEOVERRIDES’.
638 ‘MAKEFLAGS’ is re-exported whenever ‘.MAKEOVERRIDES’ is
639 modified.
640 .MAKE.PATH_FILEMON
642 If make was built with filemon(4) support, this is set to
643 the path of the device node. This allows makefiles to
644 test for this support.
645 .MAKE.PID The process-id of make.
647 .MAKE.PPID The parent process-id of make.
649 .MAKE.SAVE_DOLLARS
651 value should be a boolean that controls whether ‘$$’ are
652 preserved when doing ‘:=’ assignments. The default is
653 false, for backwards compatibility. Set to true for com‐
654 patability with other makes. If set to false, ‘$$’
655 becomes ‘$’ per normal evaluation rules.
656 MAKE_PRINT_VAR_ON_ERROR
658 When make stops due to an error, it sets ‘.ERROR_TARGET’
659 to the name of the target that failed, ‘.ERROR_CMD’ to
660 the commands of the failed target, and in "meta" mode, it
661 also sets ‘.ERROR_CWD’ to the getcwd(3), and
662 ‘.ERROR_META_FILE’ to the path of the meta file (if any)
663 describing the failed target. It then prints its name
664 and the value of ‘.CURDIR’ as well as the value of any
665 variables named in ‘MAKE_PRINT_VAR_ON_ERROR’.
666 .newline This variable is simply assigned a newline character as
668 its value. This allows expansions using the :@ modifier
669 to put a newline between iterations of the loop rather
670 than a space. For example, the printing of
671 ‘MAKE_PRINT_VAR_ON_ERROR’ could be done as
672 ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}.
673 .OBJDIR A path to the directory where the targets are built. Its
675 value is determined by trying to chdir(2) to the follow‐
676 ing directories in order and using the first match:
677 1. ${MAKEOBJDIRPREFIX}${.CURDIR}
679 (Only if ‘MAKEOBJDIRPREFIX’ is set in the environ‐
681 ment or on the command line.)
682 2. ${MAKEOBJDIR}
684 (Only if ‘MAKEOBJDIR’ is set in the environment or
686 on the command line.)
687 3. ${.CURDIR}/obj.${MACHINE}
689 4. ${.CURDIR}/obj
691 5. /usr/obj/${.CURDIR}
693 6. ${.CURDIR}
695 Variable expansion is performed on the value before it's
697 used, so expressions such as
698 ${.CURDIR:S,^/usr/src,/var/obj,}
699 may be used. This is especially useful with
700 ‘MAKEOBJDIR’.
701 ‘.OBJDIR’ may be modified in the makefile via the special
703 target ‘.OBJDIR’. In all cases, make will chdir(2) to
704 the specified directory if it exists, and set ‘.OBJDIR’
705 and ‘PWD’ to that directory before executing any targets.
706 .PARSEDIR A path to the directory of the current ‘Makefile’ being
708 parsed.
709 .PARSEFILE The basename of the current ‘Makefile’ being parsed.
711 This variable and ‘.PARSEDIR’ are both set only while the
712 ‘Makefiles’ are being parsed. If you want to retain
713 their current values, assign them to a variable using
714 assignment with expansion: (‘:=’).
715 .PATH A variable that represents the list of directories that
717 make will search for files. The search list should be
718 updated using the target ‘.PATH’ rather than the vari‐
719 able.
720 PWD Alternate path to the current directory. make normally
722 sets ‘.CURDIR’ to the canonical path given by getcwd(3).
723 However, if the environment variable ‘PWD’ is set and
724 gives a path to the current directory, then make sets
725 ‘.CURDIR’ to the value of ‘PWD’ instead. This behavior
726 is disabled if ‘MAKEOBJDIRPREFIX’ is set or ‘MAKEOBJDIR’
727 contains a variable transform. ‘PWD’ is set to the value
728 of ‘.OBJDIR’ for all programs which make executes.
729 .TARGETS The list of targets explicitly specified on the command
731 line, if any.
732 VPATH Colon-separated (“:”) lists of directories that make will
734 search for files. The variable is supported for compati‐
735 bility with old make programs only, use ‘.PATH’ instead.
736 Variable modifiers
738 Variable expansion may be modified to select or modify each word of the
739 variable (where a “word” is white-space delimited sequence of charac‐
740 ters). The general format of a variable expansion is as follows:
741 ${variable[:modifier[:...]]}
743 Each modifier begins with a colon, which may be escaped with a backslash
745 (‘\’).
746 A set of modifiers can be specified via a variable, as follows:
748 modifier_variable=modifier[:...]
750 ${variable:${modifier_variable}[:...]}
751 In this case the first modifier in the modifier_variable does not start
753 with a colon, since that must appear in the referencing variable. If any
754 of the modifiers in the modifier_variable contain a dollar sign (‘$’),
755 these must be doubled to avoid early expansion.
756 The supported modifiers are:
758 :E Replaces each word in the variable with its suffix.
760 :H Replaces each word in the variable with everything but the last com‐
762 ponent.
763 :Mpattern
765 Select only those words that match pattern. The standard shell
766 wildcard characters (‘*’, ‘?’, and ‘[]’) may be used. The wildcard
767 characters may be escaped with a backslash (‘\’). As a consequence
768 of the way values are split into words, matched, and then joined, a
769 construct like
770 ${VAR:M*}
771 will normalize the inter-word spacing, removing all leading and
772 trailing space, and converting multiple consecutive spaces to single
773 spaces.
774 :Npattern
776 This is identical to ‘:M’, but selects all words which do not match
777 pattern.
778 :O Order every word in variable alphabetically. To sort words in
780 reverse order use the ‘:O:[-1..1]’ combination of modifiers.
781 :Ox Randomize words in variable. The results will be different each
783 time you are referring to the modified variable; use the assignment
784 with expansion (‘:=’) to prevent such behavior. For example,
785 LIST= uno due tre quattro
787 RANDOM_LIST= ${LIST:Ox}
788 STATIC_RANDOM_LIST:= ${LIST:Ox}
789 all:
791 @echo "${RANDOM_LIST}"
792 @echo "${RANDOM_LIST}"
793 @echo "${STATIC_RANDOM_LIST}"
794 @echo "${STATIC_RANDOM_LIST}"
795 may produce output similar to:
796 quattro due tre uno
798 tre due quattro uno
799 due uno quattro tre
800 due uno quattro tre
801 :Q Quotes every shell meta-character in the variable, so that it can be
803 passed safely through recursive invocations of make.
804 :R Replaces each word in the variable with everything but its suffix.
806 :range[=count]
808 The value is an integer sequence representing the words of the orig‐
809 inal value, or the supplied count.
810 :gmtime[=utc]
812 The value is a format string for strftime(3), using gmtime(3). If a
813 utc value is not provided or is 0, the current time is used.
814 :hash
816 Compute a 32-bit hash of the value and encode it as hex digits.
817 :localtime[=utc]
819 The value is a format string for strftime(3), using localtime(3).
820 If a utc value is not provided or is 0, the current time is used.
821 :tA Attempt to convert variable to an absolute path using realpath(3),
823 if that fails, the value is unchanged.
824 :tl Converts variable to lower-case letters.
826 :tsc
828 Words in the variable are normally separated by a space on expan‐
829 sion. This modifier sets the separator to the character c. If c is
830 omitted, then no separator is used. The common escapes (including
831 octal numeric codes), work as expected.
832 :tu Converts variable to upper-case letters.
834 :tW Causes the value to be treated as a single word (possibly containing
836 embedded white space). See also ‘:[*]’.
837 :tw Causes the value to be treated as a sequence of words delimited by
839 white space. See also ‘:[@]’.
840 :S/old_string/new_string/[1gW]
842 Modify the first occurrence of old_string in the variable's value,
843 replacing it with new_string. If a ‘g’ is appended to the last
844 slash of the pattern, all occurrences in each word are replaced. If
845 a ‘1’ is appended to the last slash of the pattern, only the first
846 word is affected. If a ‘W’ is appended to the last slash of the
847 pattern, then the value is treated as a single word (possibly con‐
848 taining embedded white space). If old_string begins with a caret
849 (‘^’), old_string is anchored at the beginning of each word. If
850 old_string ends with a dollar sign (‘$’), it is anchored at the end
851 of each word. Inside new_string, an ampersand (‘&’) is replaced by
852 old_string (without any ‘^’ or ‘$’). Any character may be used as a
853 delimiter for the parts of the modifier string. The anchoring,
854 ampersand and delimiter characters may be escaped with a backslash
855 (‘\’).
856 Variable expansion occurs in the normal fashion inside both
858 old_string and new_string with the single exception that a backslash
859 is used to prevent the expansion of a dollar sign (‘$’), not a pre‐
860 ceding dollar sign as is usual.
861 :C/pattern/replacement/[1gW]
863 The :C modifier is just like the :S modifier except that the old and
864 new strings, instead of being simple strings, are an extended regu‐
865 lar expression (see regex(3)) string pattern and an ed(1)-style
866 string replacement. Normally, the first occurrence of the pattern
867 pattern in each word of the value is substituted with replacement.
868 The ‘1’ modifier causes the substitution to apply to at most one
869 word; the ‘g’ modifier causes the substitution to apply to as many
870 instances of the search pattern pattern as occur in the word or
871 words it is found in; the ‘W’ modifier causes the value to be
872 treated as a single word (possibly containing embedded white space).
873 Note that ‘1’ and ‘g’ are orthogonal; the former specifies whether
874 multiple words are potentially affected, the latter whether multiple
875 substitutions can potentially occur within each affected word.
876 As for the :S modifier, the pattern and replacement are subjected to
878 variable expansion before being parsed as regular expressions.
879 :T Replaces each word in the variable with its last component.
881 :u Remove adjacent duplicate words (like uniq(1)).
883 :?true_string:false_string
885 If the variable name (not its value), when parsed as a .if condi‐
886 tional expression, evaluates to true, return as its value the
887 true_string, otherwise return the false_string. Since the variable
888 name is used as the expression, :? must be the first modifier after
889 the variable name itself - which will, of course, usually contain
890 variable expansions. A common error is trying to use expressions
891 like
892 ${NUMBERS:M42:?match:no}
893 which actually tests defined(NUMBERS), to determine is any words
894 match "42" you need to use something like:
895 ${"${NUMBERS:M42}" != "":?match:no}.
896 :old_string=new_string
898 This is the AT&T System V UNIX style variable substitution. It must
899 be the last modifier specified. If old_string or new_string do not
900 contain the pattern matching character % then it is assumed that
901 they are anchored at the end of each word, so only suffixes or
902 entire words may be replaced. Otherwise % is the substring of
903 old_string to be replaced in new_string.
904 Variable expansion occurs in the normal fashion inside both
906 old_string and new_string with the single exception that a backslash
907 is used to prevent the expansion of a dollar sign (‘$’), not a pre‐
908 ceding dollar sign as is usual.
909 :@temp@string@
911 This is the loop expansion mechanism from the OSF Development Envi‐
912 ronment (ODE) make. Unlike .for loops expansion occurs at the time
913 of reference. Assign temp to each word in the variable and evaluate
914 string. The ODE convention is that temp should start and end with a
915 period. For example.
916 ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@}
917 However a single character variable is often more readable:
919 ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}
920 :_[=var]
922 Save the current variable value in ‘$_’ or the named var for later
923 reference. Example usage:
924 M_cmpv.units = 1 1000 1000000
926 M_cmpv = S,., ,g:_:range:@i@+ $${_:[-$$i]} \
927 \* $${M_cmpv.units:[$$i]}@:S,^,expr 0 ,1:sh
928 .if ${VERSION:${M_cmpv}} < ${3.1.12:L:${M_cmpv}}
930 Here ‘$_’ is used to save the result of the ‘:S’ modifier which is
932 later referenced using the index values from ‘:range’.
933 :Unewval
935 If the variable is undefined newval is the value. If the variable
936 is defined, the existing value is returned. This is another ODE
937 make feature. It is handy for setting per-target CFLAGS for
938 instance:
939 ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}}
940 If a value is only required if the variable is undefined, use:
941 ${VAR:D:Unewval}
942 :Dnewval
944 If the variable is defined newval is the value.
945 :L The name of the variable is the value.
947 :P The path of the node which has the same name as the variable is the
949 value. If no such node exists or its path is null, then the name of
950 the variable is used. In order for this modifier to work, the name
951 (node) must at least have appeared on the rhs of a dependency.
952 :!cmd!
954 The output of running cmd is the value.
955 :sh If the variable is non-empty it is run as a command and the output
957 becomes the new value.
958 ::=str
960 The variable is assigned the value str after substitution. This
961 modifier and its variations are useful in obscure situations such as
962 wanting to set a variable when shell commands are being parsed.
963 These assignment modifiers always expand to nothing, so if appearing
964 in a rule line by themselves should be preceded with something to
965 keep make happy.
966 The ‘::’ helps avoid false matches with the AT&T System V UNIX style
968 := modifier and since substitution always occurs the ::= form is
969 vaguely appropriate.
970 ::?=str
972 As for ::= but only if the variable does not already have a value.
973 ::+=str
975 Append str to the variable.
976 ::!=cmd
978 Assign the output of cmd to the variable.
979 :[range]
981 Selects one or more words from the value, or performs other opera‐
982 tions related to the way in which the value is divided into words.
983 Ordinarily, a value is treated as a sequence of words delimited by
985 white space. Some modifiers suppress this behavior, causing a value
986 to be treated as a single word (possibly containing embedded white
987 space). An empty value, or a value that consists entirely of white-
988 space, is treated as a single word. For the purposes of the ‘:[]’
989 modifier, the words are indexed both forwards using positive inte‐
990 gers (where index 1 represents the first word), and backwards using
991 negative integers (where index -1 represents the last word).
992 The range is subjected to variable expansion, and the expanded
994 result is then interpreted as follows:
995 index Selects a single word from the value.
997 start..end
999 Selects all words from start to end, inclusive. For example,
1000 ‘:[2..-1]’ selects all words from the second word to the last
1001 word. If start is greater than end, then the words are out‐
1002 put in reverse order. For example, ‘:[-1..1]’ selects all
1003 the words from last to first.
1004 * Causes subsequent modifiers to treat the value as a single
1006 word (possibly containing embedded white space). Analogous
1007 to the effect of "$*" in Bourne shell.
1008 0 Means the same as ‘:[*]’.
1010 @ Causes subsequent modifiers to treat the value as a sequence
1012 of words delimited by white space. Analogous to the effect
1013 of "$@" in Bourne shell.
1014 # Returns the number of words in the value.
1016
1018 Makefile inclusion, conditional structures and for loops reminiscent of
1019 the C programming language are provided in make. All such structures are
1020 identified by a line beginning with a single dot (‘.’) character. Files
1021 are included with either .include ⟨file⟩ or .include "file". Variables
1022 between the angle brackets or double quotes are expanded to form the file
1023 name. If angle brackets are used, the included makefile is expected to
1024 be in the system makefile directory. If double quotes are used, the
1025 including makefile's directory and any directories specified using the -I
1026 option are searched before the system makefile directory. For compati‐
1027 bility with other versions of make ‘include file ...’ is also accepted.
1028 If the include statement is written as .-include or as .sinclude then
1030 errors locating and/or opening include files are ignored.
1031 If the include statement is written as .dinclude not only are errors
1033 locating and/or opening include files ignored, but stale dependencies
1034 within the included file will be ignored just like .MAKE.DEPENDFILE.
1035 Conditional expressions are also preceded by a single dot as the first
1037 character of a line. The possible conditionals are as follows:
1038 .error message
1040 The message is printed along with the name of the makefile and
1041 line number, then make will exit.
1042 .export variable ...
1044 Export the specified global variable. If no variable list is
1045 provided, all globals are exported except for internal variables
1046 (those that start with ‘.’). This is not affected by the -X
1047 flag, so should be used with caution. For compatibility with
1048 other make programs ‘export variable=value’ is also accepted.
1049 Appending a variable name to .MAKE.EXPORTED is equivalent to
1051 exporting a variable.
1052 .export-env variable ...
1054 The same as ‘.export’, except that the variable is not appended
1055 to .MAKE.EXPORTED. This allows exporting a value to the environ‐
1056 ment which is different from that used by make internally.
1057 .export-literal variable ...
1059 The same as ‘.export-env’, except that variables in the value are
1060 not expanded.
1061 .info message
1063 The message is printed along with the name of the makefile and
1064 line number.
1065 .undef variable
1067 Un-define the specified global variable. Only global variables
1068 may be un-defined.
1069 .unexport variable ...
1071 The opposite of ‘.export’. The specified global variable will be
1072 removed from .MAKE.EXPORTED. If no variable list is provided,
1073 all globals are unexported, and .MAKE.EXPORTED deleted.
1074 .unexport-env
1076 Unexport all globals previously exported and clear the environ‐
1077 ment inherited from the parent. This operation will cause a mem‐
1078 ory leak of the original environment, so should be used spar‐
1079 ingly. Testing for .MAKE.LEVEL being 0, would make sense. Also
1080 note that any variables which originated in the parent environ‐
1081 ment should be explicitly preserved if desired. For example:
1082 .if ${.MAKE.LEVEL} == 0
1084 PATH := ${PATH}
1085 .unexport-env
1086 .export PATH
1087 .endif
1088 Would result in an environment containing only ‘PATH’, which is
1090 the minimal useful environment. Actually ‘.MAKE.LEVEL’ will also
1091 be pushed into the new environment.
1092 .warning message
1094 The message prefixed by ‘warning:’ is printed along with the name
1095 of the makefile and line number.
1096 .if [!]expression [operator expression ...]
1098 Test the value of an expression.
1099 .ifdef [!]variable [operator variable ...]
1101 Test the value of a variable.
1102 .ifndef [!]variable [operator variable ...]
1104 Test the value of a variable.
1105 .ifmake [!]target [operator target ...]
1107 Test the target being built.
1108 .ifnmake [!] target [operator target ...]
1110 Test the target being built.
1111 .else Reverse the sense of the last conditional.
1113 .elif [!] expression [operator expression ...]
1115 A combination of ‘.else’ followed by ‘.if’.
1116 .elifdef [!]variable [operator variable ...]
1118 A combination of ‘.else’ followed by ‘.ifdef’.
1119 .elifndef [!]variable [operator variable ...]
1121 A combination of ‘.else’ followed by ‘.ifndef’.
1122 .elifmake [!]target [operator target ...]
1124 A combination of ‘.else’ followed by ‘.ifmake’.
1125 .elifnmake [!]target [operator target ...]
1127 A combination of ‘.else’ followed by ‘.ifnmake’.
1128 .endif End the body of the conditional.
1130 The operator may be any one of the following:
1132 || Logical OR.
1134 && Logical AND; of higher precedence than “||”.
1136 As in C, make will only evaluate a conditional as far as is necessary to
1138 determine its value. Parentheses may be used to change the order of
1139 evaluation. The boolean operator ‘!’ may be used to logically negate an
1140 entire conditional. It is of higher precedence than ‘&&’.
1141 The value of expression may be any of the following:
1143 defined Takes a variable name as an argument and evaluates to true if
1145 the variable has been defined.
1146 make Takes a target name as an argument and evaluates to true if the
1148 target was specified as part of make's command line or was
1149 declared the default target (either implicitly or explicitly,
1150 see .MAIN) before the line containing the conditional.
1151 empty Takes a variable, with possible modifiers, and evaluates to true
1153 if the expansion of the variable would result in an empty
1154 string.
1155 exists Takes a file name as an argument and evaluates to true if the
1157 file exists. The file is searched for on the system search path
1158 (see .PATH).
1159 target Takes a target name as an argument and evaluates to true if the
1161 target has been defined.
1162 commands
1164 Takes a target name as an argument and evaluates to true if the
1165 target has been defined and has commands associated with it.
1166 Expression may also be an arithmetic or string comparison. Variable
1168 expansion is performed on both sides of the comparison, after which the
1169 integral values are compared. A value is interpreted as hexadecimal if
1170 it is preceded by 0x, otherwise it is decimal; octal numbers are not sup‐
1171 ported. The standard C relational operators are all supported. If after
1172 variable expansion, either the left or right hand side of a ‘==’ or ‘!=’
1173 operator is not an integral value, then string comparison is performed
1174 between the expanded variables. If no relational operator is given, it
1175 is assumed that the expanded variable is being compared against 0 or an
1176 empty string in the case of a string comparison.
1177 When make is evaluating one of these conditional expressions, and it
1179 encounters a (white-space separated) word it doesn't recognize, either
1180 the “make” or “defined” expression is applied to it, depending on the
1181 form of the conditional. If the form is ‘.ifdef’, ‘.ifndef’, or ‘.if’
1182 the “defined” expression is applied. Similarly, if the form is ‘.ifmake’
1183 or ‘.ifnmake’, the “make” expression is applied.
1184 If the conditional evaluates to true the parsing of the makefile contin‐
1186 ues as before. If it evaluates to false, the following lines are
1187 skipped. In both cases this continues until a ‘.else’ or ‘.endif’ is
1188 found.
1189 For loops are typically used to apply a set of rules to a list of files.
1191 The syntax of a for loop is:
1192 .for variable [variable ...] in expression
1194 ⟨make-rules⟩
1195 .endfor
1196 After the for expression is evaluated, it is split into words. On each
1198 iteration of the loop, one word is taken and assigned to each variable,
1199 in order, and these variables are substituted into the make-rules inside
1200 the body of the for loop. The number of words must come out even; that
1201 is, if there are three iteration variables, the number of words provided
1202 must be a multiple of three.
1203
1205 Comments begin with a hash (‘#’) character, anywhere but in a shell com‐
1206 mand line, and continue to the end of an unescaped new line.
1207
1209 .EXEC Target is never out of date, but always execute commands any‐
1210 way.
1211 .IGNORE Ignore any errors from the commands associated with this tar‐
1213 get, exactly as if they all were preceded by a dash (‘-’).
1214 .MADE Mark all sources of this target as being up-to-date.
1216 .MAKE Execute the commands associated with this target even if the -n
1218 or -t options were specified. Normally used to mark recursive
1219 makes.
1220 .META Create a meta file for the target, even if it is flagged as
1222 .PHONY, .MAKE, or .SPECIAL. Usage in conjunction with .MAKE is
1223 the most likely case. In "meta" mode, the target is out-of-
1224 date if the meta file is missing.
1225 .NOMETA Do not create a meta file for the target. Meta files are also
1227 not created for .PHONY, .MAKE, or .SPECIAL targets.
1228 .NOMETA_CMP
1230 Ignore differences in commands when deciding if target is out
1231 of date. This is useful if the command contains a value which
1232 always changes. If the number of commands change, though, the
1233 target will still be out of date. The same effect applies to
1234 any command line that uses the variable .OODATE, which can be
1235 used for that purpose even when not otherwise needed or
1236 desired:
1237 skip-compare-for-some:
1240 @echo this will be compared
1241 @echo this will not ${.OODATE:M.NOMETA_CMP}
1242 @echo this will also be compared
1243 The :M pattern suppresses any expansion of the unwanted vari‐
1245 able.
1246 .NOPATH Do not search for the target in the directories specified by
1248 .PATH.
1249 .NOTMAIN Normally make selects the first target it encounters as the
1251 default target to be built if no target was specified. This
1252 source prevents this target from being selected.
1253 .OPTIONAL
1255 If a target is marked with this attribute and make can't figure
1256 out how to create it, it will ignore this fact and assume the
1257 file isn't needed or already exists.
1258 .PHONY The target does not correspond to an actual file; it is always
1260 considered to be out of date, and will not be created with the
1261 -t option. Suffix-transformation rules are not applied to
1262 .PHONY targets.
1263 .PRECIOUS
1265 When make is interrupted, it normally removes any partially
1266 made targets. This source prevents the target from being
1267 removed.
1268 .RECURSIVE
1270 Synonym for .MAKE.
1271 .SILENT Do not echo any of the commands associated with this target,
1273 exactly as if they all were preceded by an at sign (‘@’).
1274 .USE Turn the target into make's version of a macro. When the tar‐
1276 get is used as a source for another target, the other target
1277 acquires the commands, sources, and attributes (except for
1278 .USE) of the source. If the target already has commands, the
1279 .USE target's commands are appended to them.
1280 .USEBEFORE
1282 Exactly like .USE, but prepend the .USEBEFORE target commands
1283 to the target.
1284 .WAIT If .WAIT appears in a dependency line, the sources that precede
1286 it are made before the sources that succeed it in the line.
1287 Since the dependents of files are not made until the file
1288 itself could be made, this also stops the dependents being
1289 built unless they are needed for another branch of the depen‐
1290 dency tree. So given:
1291 x: a .WAIT b
1293 echo x
1294 a:
1295 echo a
1296 b: b1
1297 echo b
1298 b1:
1299 echo b1
1300 the output is always ‘a’, ‘b1’, ‘b’, ‘x’.
1302 The ordering imposed by .WAIT is only relevant for parallel
1303 makes.
1304
1306 Special targets may not be included with other targets, i.e. they must be
1307 the only target specified.
1308 .BEGIN Any command lines attached to this target are executed before
1310 anything else is done.
1311 .DEFAULT
1313 This is sort of a .USE rule for any target (that was used only
1314 as a source) that make can't figure out any other way to create.
1315 Only the shell script is used. The .IMPSRC variable of a target
1316 that inherits .DEFAULT's commands is set to the target's own
1317 name.
1318 .DELETE_ON_ERROR
1320 If this target is present in the makefile, it globally causes
1321 make to delete targets whose commands fail. (By default, only
1322 targets whose commands are interrupted during execution are
1323 deleted. This is the historical behavior.) This setting can be
1324 used to help prevent half-finished or malformed targets from
1325 being left around and corrupting future rebuilds.
1326 .END Any command lines attached to this target are executed after
1328 everything else is done.
1329 .ERROR Any command lines attached to this target are executed when
1331 another target fails. The .ERROR_TARGET variable is set to the
1332 target that failed. See also MAKE_PRINT_VAR_ON_ERROR.
1333 .IGNORE Mark each of the sources with the .IGNORE attribute. If no
1335 sources are specified, this is the equivalent of specifying the
1336 -i option.
1337 .INTERRUPT
1339 If make is interrupted, the commands for this target will be
1340 executed.
1341 .MAIN If no target is specified when make is invoked, this target will
1343 be built.
1344 .MAKEFLAGS
1346 This target provides a way to specify flags for make when the
1347 makefile is used. The flags are as if typed to the shell,
1348 though the -f option will have no effect.
1349 .NOPATH Apply the .NOPATH attribute to any specified sources.
1351 .NOTPARALLEL
1353 Disable parallel mode.
1354 .NO_PARALLEL
1356 Synonym for .NOTPARALLEL, for compatibility with other pmake
1357 variants.
1358 .OBJDIR The source is a new value for ‘.OBJDIR’. If it exists, make
1360 will chdir(2) to it and update the value of ‘.OBJDIR’.
1361 .ORDER The named targets are made in sequence. This ordering does not
1363 add targets to the list of targets to be made. Since the depen‐
1364 dents of a target do not get built until the target itself could
1365 be built, unless ‘a’ is built by another part of the dependency
1366 graph, the following is a dependency loop:
1367 .ORDER: b a
1369 b: a
1370 The ordering imposed by .ORDER is only relevant for parallel
1372 makes.
1373 .PATH The sources are directories which are to be searched for files
1375 not found in the current directory. If no sources are speci‐
1376 fied, any previously specified directories are deleted. If the
1377 source is the special .DOTLAST target, then the current working
1378 directory is searched last.
1379 .PATH.suffix
1381 Like .PATH but applies only to files with a particular suffix.
1382 The suffix must have been previously declared with .SUFFIXES.
1383 .PHONY Apply the .PHONY attribute to any specified sources.
1385 .PRECIOUS
1387 Apply the .PRECIOUS attribute to any specified sources. If no
1388 sources are specified, the .PRECIOUS attribute is applied to
1389 every target in the file.
1390 .SHELL Sets the shell that make will use to execute commands. The
1392 sources are a set of field=value pairs.
1393 name This is the minimal specification, used to select
1395 one of the built-in shell specs; sh, ksh, and csh.
1396 path Specifies the path to the shell.
1398 hasErrCtl Indicates whether the shell supports exit on error.
1400 check The command to turn on error checking.
1402 ignore The command to disable error checking.
1404 echo The command to turn on echoing of commands executed.
1406 quiet The command to turn off echoing of commands exe‐
1408 cuted.
1409 filter The output to filter after issuing the quiet com‐
1411 mand. It is typically identical to quiet.
1412 errFlag The flag to pass the shell to enable error checking.
1414 echoFlag The flag to pass the shell to enable command echo‐
1416 ing.
1417 newline The string literal to pass the shell that results in
1419 a single newline character when used outside of any
1420 quoting characters.
1421 Example:
1422 .SHELL: name=ksh path=/bin/ksh hasErrCtl=true \
1424 check="set -e" ignore="set +e" \
1425 echo="set -v" quiet="set +v" filter="set +v" \
1426 echoFlag=v errFlag=e newline="'\n'"
1427 .SILENT Apply the .SILENT attribute to any specified sources. If no
1429 sources are specified, the .SILENT attribute is applied to every
1430 command in the file.
1431 .STALE This target gets run when a dependency file contains stale
1433 entries, having .ALLSRC set to the name of that dependency file.
1434 .SUFFIXES
1436 Each source specifies a suffix to make. If no sources are spec‐
1437 ified, any previously specified suffixes are deleted. It allows
1438 the creation of suffix-transformation rules.
1439 Example:
1441 .SUFFIXES: .o
1443 .c.o:
1444 cc -o ${.TARGET} -c ${.IMPSRC}
1445
1447 make uses the following environment variables, if they exist: MACHINE,
1448 MACHINE_ARCH, MAKE, MAKEFLAGS, MAKEOBJDIR, MAKEOBJDIRPREFIX, MAKESYSPATH,
1449 PWD, and TMPDIR.
1450 MAKEOBJDIRPREFIX and MAKEOBJDIR may only be set in the environment or on
1452 the command line to make and not as makefile variables; see the descrip‐
1453 tion of ‘.OBJDIR’ for more details.
1454
1456 .depend list of dependencies
1457 Makefile list of dependencies
1458 makefile list of dependencies
1459 sys.mk system makefile
1460 /usr/share/mk system makefile directory
1461
1463 The basic make syntax is compatible between different versions of make;
1464 however the special variables, variable modifiers and conditionals are
1465 not.
1466 Older versions
1468 An incomplete list of changes in older versions of make:
1469 The way that .for loop variables are substituted changed after NetBSD 5.0
1471 so that they still appear to be variable expansions. In particular this
1472 stops them being treated as syntax, and removes some obscure problems
1473 using them in .if statements.
1474 The way that parallel makes are scheduled changed in NetBSD 4.0 so that
1476 .ORDER and .WAIT apply recursively to the dependent nodes. The algo‐
1477 rithms used may change again in the future.
1478 Other make dialects
1480 Other make dialects (GNU make, SVR4 make, POSIX make, etc.) do not sup‐
1481 port most of the features of make as described in this manual. Most
1482 notably:
1483 · The .WAIT and .ORDER declarations and most functionality per‐
1485 taining to parallelization. (GNU make supports parallelization
1486 but lacks these features needed to control it effectively.)
1487 · Directives, including for loops and conditionals and most of
1489 the forms of include files. (GNU make has its own incompatible
1490 and less powerful syntax for conditionals.)
1491 · All built-in variables that begin with a dot.
1493 · Most of the special sources and targets that begin with a dot,
1495 with the notable exception of .PHONY, .PRECIOUS, and .SUFFIXES.
1496 · Variable modifiers, except for the
1498 :old=new
1499 string substitution, which does not portably support globbing
1500 with ‘%’ and historically only works on declared suffixes.
1501 · The $> variable even in its short form; most makes support this
1503 functionality but its name varies.
1504 Some features are somewhat more portable, such as assignment with +=, ?=,
1506 and !=. The .PATH functionality is based on an older feature VPATH found
1507 in GNU make and many versions of SVR4 make; however, historically its
1508 behavior is too ill-defined (and too buggy) to rely upon.
1509 The $@ and $< variables are more or less universally portable, as is the
1511 $(MAKE) variable. Basic use of suffix rules (for files only in the cur‐
1512 rent directory, not trying to chain transformations together, etc.) is
1513 also reasonably portable.
1514
1516 mkdep(1)
1517
1519 A make command appeared in Version 7 AT&T UNIX. This make implementation
1520 is based on Adam De Boor's pmake program which was written for Sprite at
1521 Berkeley. It was designed to be a parallel distributed make running jobs
1522 on different machines using a daemon called “customs”.
1523 Historically the target/dependency “FRC” has been used to FoRCe rebuild‐
1525 ing (since the target/dependency does not exist... unless someone creates
1526 an “FRC” file).
1527
1529 The make syntax is difficult to parse without actually acting of the
1530 data. For instance finding the end of a variable use should involve
1531 scanning each the modifiers using the correct terminator for each field.
1532 In many places make just counts {} and () in order to find the end of a
1533 variable expansion.
1534 There is no way of escaping a space character in a filename.
1536BSD June 22, 2017 BSD