1BMAKE(1) FreeBSD General Commands Manual
2BMAKE(1)
3[1mNAME[0m
5 [1mbmake [22m‐‐ maintain program dependencies
6[1mSYNOPSIS[0m
8 [1mbmake [22m[[1m‐BeikNnqrSstWwX[22m] [[1m‐C [4m[22mdirecto‐
9ry[24m] [[1m‐D [4m[22mvariable[24m] [[1m‐d [4m[22mflags[24m]
10 [[1m‐f [4m[22mmakefile[24m] [[1m‐I [4m[22mdirecto‐
11ry[24m] [[1m‐J [4m[22mprivate[24m] [[1m‐j [4m[22mmax_jobs[24m]
12 [[1m‐m [4m[22mdirectory[24m] [[1m‐T [4m[22mfile[24m]
13[[1m‐V [4m[22mvariable[24m] [[1m‐v [4m[22mvariable[24m]
14 [[4mvariable=value[24m] [[4mtarget[24m [4m...[24m]
15[1mDESCRIPTION[0m
17 [1mbmake [22mis a program designed to simplify the mainte‐
18nance of other pro‐
19 grams. Its input is a list of specifications as to the
20files upon which
21 programs and other files depend. If no [1m‐f [4m[22mmake‐
22file[24m makefile option is
23 given, [1mbmake [22mwill try to open ‘[4mmakefile[24m’ then
24‘[4mMakefile[24m’ in order to find
25 the specifications. If the file ‘[4m.depend[24m’ exists, it
26is read (see
27 mkdep(1)).
28 This manual page is intended as a reference document only.
30For a more
31 thorough description of [1mbmake [22mand makefiles, please
32refer to [4mPMake[24m [4m‐[24m [4mA[0m
33 [4mTutorial[24m.
34 [1mbmake [22mwill prepend the contents of the [4mMAKE‐
36FLAGS[24m environment variable to
37 the command line arguments before parsing them.
38 The options are as follows:
40 [1m‐B [22mTry to be backwards compatible by executing a
42single shell per
43 command and by executing the commands to make the
44sources of a
45 dependency line in sequence.
46 [1m‐C [4m[22mdirectory[0m
48 Change to [4mdirectory[24m before reading the make‐
49files or doing any‐
50 thing else. If multiple [1m‐C [22moptions are spec‐
51ified, each is inter‐
52 preted relative to the previous one: [1m‐C
53[4m[22m/[24m [1m‐C [4m[22metc[24m is equivalent to
54 [1m‐C [4m[22m/etc[24m.
55 [1m‐D [4m[22mvariable[0m
57 Define [4mvariable[24m to be 1, in the global scope.
58 [1m‐d [4m[22m[‐]flags[0m
60 Turn on debugging, and specify which portions of
61[1mbmake [22mare to
62 print debugging information. Unless the flags are
63preceded by
64 ‘‐’ they are added to the [4mMAKEFLAGS[24m environ‐
65ment variable and will
66 be processed by any child make processes. By de‐
67fault, debugging
68 information is printed to standard error, but this
69can be changed
70 using the [4mF[24m debugging flag. The debugging
71output is always un‐
72 buffered; in addition, if debugging is enabled but
73debugging out‐
74 put is not directed to standard output, then the
75standard output
76 is line buffered. [4mFlags[24m is one or more of
77the following:
78 [4mA[24m Print all possible debugging informa‐
80tion; equivalent to
81 specifying all of the debugging flags.
82 [4ma[24m Print debugging information about ar‐
84chive searching and
85 caching.
86 [4mC[24m Print debugging information about
88current working direc‐
89 tory.
90 [4mc[24m Print debugging information about
92conditional evaluation.
93 [4md[24m Print debugging information about di‐
95rectory searching and
96 caching.
97 [4me[24m Print debugging information about
99failed commands and
100 targets.
101 [4mF[24m[[1m+[22m][4mfilename[0m
103 Specify where debugging output is written.
104This must be
105 the last flag, because it consumes the re‐
106mainder of the
107 argument. If the character immediately af‐
108ter the ‘F’
109 flag is ‘+’, then the file will be opened in
110append mode;
111 otherwise the file will be overwritten. If
112the file name
113 is ‘stdout’ or ‘stderr’ then debugging out‐
114put will be
115 written to the standard output or standard
116error output
117 file descriptors respectively (and the ‘+’
118option has no
119 effect). Otherwise, the output will be
120written to the
121 named file. If the file name ends ‘.%d’
122then the ‘%d’ is
123 replaced by the pid.
124 [4mf[24m Print debugging information about
126loop evaluation.
127 [4mg1[24m Print the input graph before making
129anything.
130 [4mg2[24m Print the input graph after making
132everything, or before
133 exiting on error.
134 [4mg3[24m Print the input graph before exiting
136on error.
137 [4mh[24m Print debugging information about
139hash table operations.
140 [4mj[24m Print debugging information about
142running multiple
143 shells.
144 [4mL[24m Turn on lint checks. This will throw
146errors for variable
147 assignments that do not parse correctly, at
148the time of
149 assignment so the file and line number are
150available.
151 [4ml[24m Print commands in Makefiles regard‐
153less of whether or not
154 they are prefixed by ‘@’ or other "quiet"
155flags. Also
156 known as "loud" behavior.
157 [4mM[24m Print debugging information about
159"meta" mode decisions
160 about targets.
161 [4mm[24m Print debugging information about
163making targets, includ‐
164 ing modification dates.
165 [4mn[24m Don’t delete the temporary command
167scripts created when
168 running commands. These temporary scripts
169are created in
170 the directory referred to by the TMPDIR en‐
171vironment vari‐
172 able, or in [4m/tmp[24m if TMPDIR is unset
173or set to the empty
174 string. The temporary scripts are created
175by mkstemp(3),
176 and have names of the form
177[4mmakeXXXXXX[24m. [4mNOTE[24m: This can
178 create many files in TMPDIR or [4m/tmp[24m,
179so use with care.
180 [4mp[24m Print debugging information about
182makefile parsing.
183 [4ms[24m Print debugging information about
185suffix‐transformation
186 rules.
187 [4mt[24m Print debugging information about
189target list mainte‐
190 nance.
191 [4mV[24m Force the [1m‐V [22moption to print
193raw values of variables,
194 overriding the default behavior set via
195 [4m.MAKE.EXPAND_VARIABLES[24m.
196 [4mv[24m Print debugging information about
198variable assignment.
199 [4mx[24m Run shell commands with [1m‐x [22mso
201the actual commands are
202 printed as they are executed.
203 [1m‐e [22mSpecify that environment variables override
205macro assignments
206 within makefiles.
207 [1m‐f [4m[22mmakefile[0m
209 Specify a makefile to read instead of the default
210‘[4mmakefile[24m’. If
211 [4mmakefile[24m is ‘[1m‐[22m’, standard input is
212read. Multiple makefiles may
213 be specified, and are read in the order specified.
214 [1m‐I [4m[22mdirectory[0m
216 Specify a directory in which to search for makefiles
217and included
218 makefiles. The system makefile directory (or direc‐
219tories, see
220 the [1m‐m [22moption) is automatically included as
221part of this list.
222 [1m‐i [22mIgnore non‐zero exit of shell commands in the
224makefile. Equiva‐
225 lent to specifying ‘[1m‐[22m’ before each command
226line in the makefile.
227 [1m‐J [4m[22mprivate[0m
229 This option should [4mnot[24m be specified by the
230user.
231 When the [4mj[24m option is in use in a recursive
233build, this option is
234 passed by a make to child makes to allow all the
235make processes
236 in the build to cooperate to avoid overloading the
237system.
238 [1m‐j [4m[22mmax_jobs[0m
240 Specify the maximum number of jobs that [1mbmake
241[22mmay have running at
242 any one time. The value is saved in
243[4m.MAKE.JOBS[24m. Turns compati‐
244 bility mode off, unless the [4mB[24m flag is also
245specified. When com‐
246 patibility mode is off, all commands associated with
247a target are
248 executed in a single shell invocation as opposed to
249the tradi‐
250 tional one shell invocation per line. This can
251break traditional
252 scripts which change directories on each command in‐
253vocation and
254 then expect to start with a fresh environment on the
255next line.
256 It is more efficient to correct the scripts rather
257than turn
258 backwards compatibility on.
259 [1m‐k [22mContinue processing after errors are encoun‐
261tered, but only on
262 those targets that do not depend on the target whose
263creation
264 caused the error.
265 [1m‐m [4m[22mdirectory[0m
267 Specify a directory in which to search for sys.mk
268and makefiles
269 included via the <[4mfile[24m>‐style include state‐
270ment. The [1m‐m [22moption
271 can be used multiple times to form a search path.
272This path will
273 override the default system include path:
274/usr/share/mk. Fur‐
275 thermore the system include path will be appended to
276the search
277 path used for "[4mfile[24m"‐style include statements
278(see the [1m‐I [22mop‐
279 tion).
280 If a file or directory name in the [1m‐m [22margu‐
282ment (or the
283 MAKESYSPATH environment variable) starts with the
284string ".../"
285 then [1mbmake [22mwill search for the specified file
286or directory named
287 in the remaining part of the argument string. The
288search starts
289 with the current directory of the Makefile and then
290works upward
291 towards the root of the file system. If the search
292is success‐
293 ful, then the resulting directory replaces the
294".../" specifica‐
295 tion in the [1m‐m [22margument. If used, this fea‐
296ture allows [1mbmake [22mto
297 easily search in the current source tree for custom‐
298ized sys.mk
299 files (e.g., by using ".../mk/sys.mk" as an argu‐
300ment).
301 [1m‐n [22mDisplay the commands that would have been ex‐
303ecuted, but do not
304 actually execute them unless the target depends on
305the .MAKE spe‐
306 cial source (see below) or the command is prefixed
307with ‘[1m+[22m’.
308 [1m‐N [22mDisplay the commands which would have been
310executed, but do not
311 actually execute any of them; useful for debugging
312top‐level
313 makefiles without descending into subdirectories.
314 [1m‐q [22mDo not execute any commands, but exit 0 if
316the specified targets
317 are up‐to‐date and 1, otherwise.
318 [1m‐r [22mDo not use the built‐in rules specified in
320the system makefile.
321 [1m‐S [22mStop processing if an error is encountered.
323This is the default
324 behavior and the opposite of [1m‐k[22m.
325 [1m‐s [22mDo not echo any commands as they are execut‐
327ed. Equivalent to
328 specifying ‘[1m@[22m’ before each command line in
329the makefile.
330 [1m‐T [4m[22mtracefile[0m
332 When used with the [1m‐j [22mflag, append a trace
333record to [4mtracefile[0m
334 for each job started and completed.
335 [1m‐t [22mRather than re‐building a target as specified
337in the makefile,
338 create it or update its modification time to make it
339appear up‐
340 to‐date.
341 [1m‐V [4m[22mvariable[0m
343 Print the value of [4mvariable[24m. Do not build
344any targets. Multiple
345 instances of this option may be specified; the vari‐
346ables will be
347 printed one per line, with a blank line for each
348null or unde‐
349 fined variable. The value printed is extracted from
350the global
351 scope after all makefiles have been read. By de‐
352fault, the raw
353 variable contents (which may include additional un‐
354expanded vari‐
355 able references) are shown. If [4mvariable[24m con‐
356tains a ‘$’ then the
357 value will be recursively expanded to its complete
358resultant text
359 before printing. The expanded value will also be
360printed if
361 [4m.MAKE.EXPAND_VARIABLES[24m is set to true and the
362[1m‐dV [22moption has not
363 been used to override it. Note that loop‐local and
364target‐local
365 variables, as well as values taken temporarily by
366global vari‐
367 ables during makefile processing, are not accessible
368via this op‐
369 tion. The [1m‐dv [22mdebug mode can be used to see
370these at the cost of
371 generating substantial extraneous output.
372 [1m‐v [4m[22mvariable[0m
374 Like [1m‐V [22mbut the variable is always expanded
375to its complete
376 value.
377 [1m‐W [22mTreat any warnings during makefile parsing as
379errors.
380 [1m‐w [22mPrint entering and leaving directory mes‐
382sages, pre and post pro‐
383 cessing.
384 [1m‐X [22mDon’t export variables passed on the command
386line to the environ‐
387 ment individually. Variables passed on the command
388line are
389 still exported via the [4mMAKEFLAGS[24m environment
390variable. This op‐
391 tion may be useful on systems which have a small
392limit on the
393 size of command arguments.
394 [4mvariable=value[0m
396 Set the value of the variable [4mvariable[24m to
397[4mvalue[24m. Normally, all
398 values passed on the command line are also exported
399to sub‐makes
400 in the environment. The [1m‐X [22mflag disables
401this behavior. Vari‐
402 able assignments should follow options for POSIX
403compatibility
404 but no ordering is enforced.
405 There are seven different types of lines in a makefile: file
407dependency
408 specifications, shell commands, variable assignments, in‐
409clude statements,
410 conditional directives, for loops, and comments.
411 In general, lines may be continued from one line to the next
413by ending
414 them with a backslash (‘´). The trailing newline character
415and initial
416 whitespace on the following line are compressed into a sin‐
417gle space.
418[1mFILE DEPENDENCY SPECIFICATIONS[0m
420 Dependency lines consist of one or more targets, an opera‐
421tor, and zero or
422 more sources. This creates a relationship where the targets
423"depend" on
424 the sources and are customarily created from them. A target
425is consid‐
426 ered out‐of‐date if it does not exist, or if its modifica‐
427tion time is
428 less than that of any of its sources. An out‐of‐date target
429will be re‐
430 created, but not until all sources have been examined and
431themselves re‐
432 created as needed. Three operators may be used:
433 [1m: [22mMany dependency lines may name this target but
435only one may have
436 attached shell commands. All sources named in all de‐
437pendency lines
438 are considered together, and if needed the attached
439shell commands
440 are run to create or re‐create the target. If [1mb‐
441make [22mis inter‐
442 rupted, the target is removed.
443 [1m! [22mThe same, but the target is always re‐created
445whether or not it is
446 out of date.
447 [1m:: [22mAny dependency line may have attached shell
449commands, but each one
450 is handled independently: its sources are considered
451and the at‐
452 tached shell commands are run if the target is out of
453date with re‐
454 spect to (only) those sources. Thus, different groups
455of the at‐
456 tached shell commands may be run depending on the cir‐
457cumstances.
458 Furthermore, unlike [1m:, [22mfor dependency lines
459with no sources, the
460 attached shell commands are always run. Also unlike
461[1m:, [22mthe target
462 will not be removed if [1mbmake [22mis interrupted.
463 All dependency lines mentioning a particular target must use
464the same op‐
465 erator.
466 Targets and sources may contain the shell wildcard values
468‘?’, ‘*’, ‘[]’,
469 and ‘{}’. The values ‘?’, ‘*’, and ‘[]’ may only be used as
470part of the
471 final component of the target or source, and must be used to
472describe ex‐
473 isting files. The value ‘{}’ need not necessarily be used
474to describe
475 existing files. Expansion is in directory order, not alpha‐
476betically as
477 done in the shell.
478[1mSHELL COMMANDS[0m
480 Each target may have associated with it one or more lines of
481shell com‐
482 mands, normally used to create the target. Each of the
483lines in this
484 script [4mmust[24m be preceded by a tab. (For historical
485reasons, spaces are
486 not accepted.) While targets can appear in many dependency
487lines if de‐
488 sired, by default only one of these rules may be followed by
489a creation
490 script. If the ‘[1m::[22m’ operator is used, however, all
491rules may include
492 scripts and the scripts are executed in the order found.
493 Each line is treated as a separate shell command, unless the
495end of line
496 is escaped with a backslash (‘´) in which case that line and
497the next
498 are combined. If the first characters of the command are
499any combination
500 of ‘[1m@[22m’, ‘[1m+[22m’, or ‘[1m‐[22m’, the command is
501treated specially. A ‘[1m@[22m’ causes the
502 command not to be echoed before it is executed. A
503‘[1m+[22m’ causes the command
504 to be executed even when [1m‐n [22mis given. This is simi‐
505lar to the effect of
506 the .MAKE special source, except that the effect can be lim‐
507ited to a sin‐
508 gle line of a script. A ‘[1m‐[22m’ in compatibility mode
509causes any non‐zero
510 exit status of the command line to be ignored.
511 When [1mbmake [22mis run in jobs mode with [1m‐j
513[4m[22mmax_jobs[24m, the entire script for
514 the target is fed to a single instance of the shell. In
515compatibility
516 (non‐jobs) mode, each command is run in a separate process.
517If the com‐
518 mand contains any shell meta characters
519(‘#=|^(){};&<>*?[]:$‘\n’) it
520 will be passed to the shell; otherwise [1mbmake [22mwill at‐
521tempt direct execu‐
522 tion. If a line starts with ‘[1m‐[22m’ and the shell has
523ErrCtl enabled then
524 failure of the command line will be ignored as in compati‐
525bility mode.
526 Otherwise ‘[1m‐[22m’ affects the entire job; the script will
527stop at the first
528 command line that fails, but the target will not be deemed
529to have
530 failed.
531 Makefiles should be written so that the mode of [1mbmake
533[22moperation does not
534 change their behavior. For example, any command which needs
535to use "cd"
536 or "chdir" without potentially changing the directory for
537subsequent com‐
538 mands should be put in parentheses so it executes in a sub‐
539shell. To
540 force the use of one shell, escape the line breaks so as to
541make the
542 whole script one command. For example:
543 avoid‐chdir‐side‐effects:
545 @echo Building $@ in ‘pwd‘
546 @(cd ${.CURDIR} && ${MAKE} $@)
547 @echo Back in ‘pwd‘
548 ensure‐one‐shell‐regardless‐of‐mode:
550 @echo Building $@ in ‘pwd‘;
551(cd ${.CURDIR} && ${MAKE} $@); echo Back in
552‘pwd‘
553 Since [1mbmake [22mwill chdir(2) to ‘[4m.OBJDIR[24m’ before
555executing any targets, each
556 child process starts with that as its current working direc‐
557tory.
558[1mVARIABLE ASSIGNMENTS[0m
560 Variables in make are much like variables in the shell, and,
561by tradi‐
562 tion, consist of all upper‐case letters.
563 [1mVariable assignment modifiers[0m
565 The five operators that can be used to assign values to
566variables are as
567 follows:
568 [1m= [22mAssign the value to the variable. Any previ‐
570ous value is overrid‐
571 den.
572 [1m+= [22mAppend the value to the current value of the
574variable.
575 [1m?= [22mAssign the value to the variable if it is not
577already defined.
578 [1m:= [22mAssign with expansion, i.e. expand the value
580before assigning it
581 to the variable. Normally, expansion is not done
582until the vari‐
583 able is referenced. [4mNOTE[24m: References to un‐
584defined variables are
585 [4mnot[24m expanded. This can cause problems when
586variable modifiers
587 are used.
588 [1m!= [22mExpand the value and pass it to the shell for
590execution and as‐
591 sign the result to the variable. Any newlines in
592the result are
593 replaced with spaces.
594 Any white‐space before the assigned [4mvalue[24m is removed;
596if the value is be‐
597 ing appended, a single space is inserted between the previ‐
598ous contents of
599 the variable and the appended value.
600 Variables are expanded by surrounding the variable name with
602either curly
603 braces (‘{}’) or parentheses (‘()’) and preceding it with a
604dollar sign
605 (‘$’). If the variable name contains only a single letter,
606the surround‐
607 ing braces or parentheses are not required. This shorter
608form is not
609 recommended.
610 If the variable name contains a dollar, then the name itself
612is expanded
613 first. This allows almost arbitrary variable names, however
614names con‐
615 taining dollar, braces, parentheses, or whitespace are real‐
616ly best
617 avoided!
618 If the result of expanding a variable contains a dollar sign
620(‘$’) the
621 string is expanded again.
622 Variable substitution occurs at three distinct times, de‐
624pending on where
625 the variable is being used.
626 1. Variables in dependency lines are expanded as the line
628is read.
629 2. Variables in shell commands are expanded when the shell
631command is
632 executed.
633 3. ".for" loop index variables are expanded on each loop
635iteration.
636 Note that other variables are not expanded inside loops
637so the fol‐
638 lowing example code:
639 .for i in 1 2 3
642 a+= ${i}
643 j= ${i}
644 b+= ${j}
645 .endfor
646 all:
648 @echo ${a}
649 @echo ${b}
650 will print:
652 1 2 3
654 3 3 3
655 Because while ${a} contains "1 2 3" after the loop is
657executed, ${b}
658 contains "${j} ${j} ${j}" which expands to "3 3 3"
659since after the
660 loop completes ${j} contains "3".
661 [1mVariable classes[0m
663 The four different classes of variables (in order of in‐
664creasing prece‐
665 dence) are:
666 Environment variables
668 Variables defined as part of [1mbmake[22m’s environ‐
669ment.
670 Global variables
672 Variables defined in the makefile or in included
673makefiles.
674 Command line variables
676 Variables defined as part of the command line.
677 Local variables
679 Variables that are defined specific to a certain
680target.
681 Local variables are all built in and their values vary magi‐
683cally from
684 target to target. It is not currently possible to define
685new local vari‐
686 ables. The seven local variables are as follows:
687 [4m.ALLSRC[24m The list of all sources for this tar‐
689get; also known as
690 ‘[4m>[24m’.
691 [4m.ARCHIVE[24m The name of the archive file; also
693known as ‘[4m![24m’.
694 [4m.IMPSRC[24m In suffix‐transformation rules, the
696name/path of the
697 source from which the target is to be trans‐
698formed (the
699 "implied" source); also known as ‘[4m<[24m’.
700It is not defined
701 in explicit rules.
702 [4m.MEMBER[24m The name of the archive member; also
704known as ‘[4m%[24m’.
705 [4m.OODATE[24m The list of sources for this target
707that were deemed out‐
708 of‐date; also known as ‘[4m?[24m’.
709 [4m.PREFIX[24m The file prefix of the target, con‐
711taining only the file
712 portion, no suffix or preceding directory
713components;
714 also known as ‘[4m*[24m’. The suffix must
715be one of the known
716 suffixes declared with [1m.SUFFIXES [22mor
717it will not be recog‐
718 nized.
719 [4m.TARGET[24m The name of the target; also known as
721‘[4m@[24m’. For compati‐
722 bility with other makes this is an alias for
723[1m.ARCHIVE [22min
724 archive member rules.
725 The shorter forms (‘[4m>[24m’, ‘[4m![24m’, ‘[4m<[24m’,
727‘[4m%[24m’, ‘[4m?[24m’, ‘[4m*[24m’, and ‘[4m@[24m’) are permitted
728 for backward compatibility with historical makefiles and
729legacy POSIX
730 make and are not recommended.
731 Variants of these variables with the punctuation followed
733immediately by
734 ‘D’ or ‘F’, e.g. ‘[4m$(@D)[24m’, are legacy forms equiva‐
735lent to using the ‘:H’
736 and ‘:T’ modifiers. These forms are accepted for compati‐
737bility with AT&T
738 System V UNIX makefiles and POSIX but are not recommended.
739 Four of the local variables may be used in sources on depen‐
741dency lines
742 because they expand to the proper value for each target on
743the line.
744 These variables are ‘[4m.TARGET[24m’, ‘[4m.PREFIX[24m’,
745‘[4m.ARCHIVE[24m’, and ‘[4m.MEMBER[24m’.
746 [1mAdditional built‐in variables[0m
748 In addition, [1mbmake [22msets or knows about the following
749variables:
750 [4m$[24m A single dollar sign ‘$’, i.e. ‘$$’
752expands to a single
753 dollar sign.
754 [4m.ALLTARGETS[24m The list of all targets encountered
756in the Makefile. If
757 evaluated during Makefile parsing, lists on‐
758ly those tar‐
759 gets encountered thus far.
760 [4m.CURDIR[24m A path to the directory where [1mb‐
762make [22mwas executed. Refer
763 to the description of ‘PWD’ for more de‐
764tails.
765 [4m.INCLUDEDFROMDIR[0m
767 The directory of the file this Makefile was
768included
769 from.
770 [4m.INCLUDEDFROMFILE[0m
772 The filename of the file this Makefile was
773included from.
774 MAKE The name that [1mbmake [22mwas executed with
776([4margv[0][24m). For
777 compatibility [1mbmake [22malso sets
778[4m.MAKE[24m with the same value.
779 The preferred variable to use is the envi‐
780ronment variable
781 MAKE because it is more compatible with oth‐
782er versions of
783 [1mbmake [22mand cannot be confused with the
784special target with
785 the same name.
786 [4m.MAKE.DEPENDFILE[0m
788 Names the makefile (default ‘[4m.de‐
789pend[24m’) from which gener‐
790 ated dependencies are read.
791 [4m.MAKE.EXPAND_VARIABLES[0m
793 A boolean that controls the default behavior
794of the [1m‐V[0m
795 option. If true, variable values printed
796with [1m‐V [22mare
797 fully expanded; if false, the raw variable
798contents
799 (which may include additional unexpanded
800variable refer‐
801 ences) are shown.
802 [4m.MAKE.EXPORTED[24m The list of variables exported by
804[1mbmake[22m.
805 [4m.MAKE.JOBS[24m The argument to the [1m‐j [22moption.
807 [4m.MAKE.JOB.PREFIX[0m
809 If [1mbmake [22mis run with [4mj[24m then
810output for each target is
811 prefixed with a token ‘‐‐‐ target ‐‐‐’ the
812first part of
813 which can be controlled via
814[4m.MAKE.JOB.PREFIX[24m. If
815 [4m.MAKE.JOB.PREFIX[24m is empty, no token
816is printed.
817 For example:
818 .MAKE.JOB.PREFIX=${.new‐
819line}‐‐‐${.MAKE:T}[${.MAKE.PID}]
820 would produce tokens like ‘‐‐‐make[1234]
821target ‐‐‐’ mak‐
822 ing it easier to track the degree of paral‐
823lelism being
824 achieved.
825 MAKEFLAGS The environment variable ‘MAKEFLAGS’ may
827contain anything
828 that may be specified on [1mbmake[22m’s com‐
829mand line. Anything
830 specified on [1mbmake[22m’s command line is
831appended to the
832 ‘MAKEFLAGS’ variable which is then entered
833into the envi‐
834 ronment for all programs which [1mbmake
835[22mexecutes.
836 [4m.MAKE.LEVEL[24m The recursion depth of [1mbmake[22m.
838The initial instance of
839 [1mbmake [22mwill be 0, and an incremented
840value is put into the
841 environment to be seen by the next genera‐
842tion. This al‐
843 lows tests like: .if ${.MAKE.LEVEL} == 0 to
844protect
845 things which should only be evaluated in the
846initial in‐
847 stance of [1mbmake[22m.
848 [4m.MAKE.MAKEFILE_PREFERENCE[0m
850 The ordered list of makefile names (default
851‘[4mmakefile[24m’,
852 ‘[4mMakefile[24m’) that [1mbmake [22mwill
853look for.
854 [4m.MAKE.MAKEFILES[0m
856 The list of makefiles read by [1mbmake[22m,
857which is useful for
858 tracking dependencies. Each makefile is
859recorded only
860 once, regardless of the number of times
861read.
862 [4m.MAKE.MODE[24m Processed after reading all make‐
864files. Can affect the
865 mode that [1mbmake [22mruns in. It can con‐
866tain a number of key‐
867 words:
868 [4mcompat[24m Like [1m‐B[22m,
870puts [1mbmake [22minto "compat"
871 mode.
872 [4mmeta[24m Puts [1mbmake
874[22minto "meta" mode, where
875 meta files are created
876for each tar‐
877 get to capture the com‐
878mand run, the
879 output generated and if
880filemon(4)
881 is available, the sys‐
882tem calls which
883 are of interest to
884[1mbmake[22m. The cap‐
885 tured output can be
886very useful when
887 diagnosing errors.
888 [4mcurdirOk=[24m [4mbf[24m Normally
890[1mbmake [22mwill not create .meta
891 files in ‘[4m.CUR‐
892DIR[24m’. This can be
893 overridden by setting
894[4mbf[24m to a value
895 which represents True.
896 [4mmissing‐meta=[24m [4mbf[24m If
898[4mbf[24m is True, then a missing .meta
899 file makes the target
900out‐of‐date.
901 [4mmissing‐filemon=[24m [4mbf[24m If
903[4mbf[24m is True, then missing filemon
904 data makes the target
905out‐of‐date.
906 [4mnofilemon[24m Do not use file‐
908mon(4).
909 [4menv[24m For debugging,
911it can be useful to
912 include the environment
913in the .meta
914 file.
915 [4mverbose[24m If in "meta"
917mode, print a clue
918 about the target being
919built. This
920 is useful if the build
921is otherwise
922 running silently. The
923message
924 printed the value of:
925 [4m.MAKE.META.PRE‐
926FIX[24m.
927 [4mignore‐cmd[24m Some makefiles
929have commands which
930 are simply not stable.
931This keyword
932 causes them to be ig‐
933nored for deter‐
934 mining whether a target
935is out of
936 date in "meta" mode.
937See also
938 [1m.NOMETA_CMP[22m.
939 [4msilent=[24m [4mbf[24m If
941[4mbf[24m is True, when a .meta file is
942 created, mark the tar‐
943get [1m.SILENT[22m.
944 [4m.MAKE.META.BAILIWICK[0m
946 In "meta" mode, provides a list of prefixes
947which match
948 the directories controlled by [1mbmake[22m.
949If a file that was
950 generated outside of [4m.OBJDIR[24m but
951within said bailiwick is
952 missing, the current target is considered
953out‐of‐date.
954 [4m.MAKE.META.CREATED[0m
956 In "meta" mode, this variable contains a
957list of all the
958 meta files updated. If not empty, it can be
959used to
960 trigger processing of
961[4m.MAKE.META.FILES[24m.
962 [4m.MAKE.META.FILES[0m
964 In "meta" mode, this variable contains a
965list of all the
966 meta files used (updated or not). This list
967can be used
968 to process the meta files to extract depen‐
969dency informa‐
970 tion.
971 [4m.MAKE.META.IGNORE_PATHS[0m
973 Provides a list of path prefixes that should
974be ignored;
975 because the contents are expected to change
976over time.
977 The default list includes: ‘[4m/dev[24m
978[4m/etc[24m [4m/proc[24m [4m/tmp[24m [4m/var/run[0m
979 [4m/var/tmp[24m’
980 [4m.MAKE.META.IGNORE_PATTERNS[0m
982 Provides a list of patterns to match against
983pathnames.
984 Ignore any that match.
985 [4m.MAKE.META.IGNORE_FILTER[0m
987 Provides a list of variable modifiers to ap‐
988ply to each
989 pathname. Ignore if the expansion is an
990empty string.
991 [4m.MAKE.META.PREFIX[0m
993 Defines the message printed for each meta
994file updated in
995 "meta verbose" mode. The default value is:
996 Building ${.TARGET:H:tA}/${.TARGET:T}
997 [4m.MAKEOVERRIDES[24m This variable is used to record the
999names of variables
1000 assigned to on the command line, so that
1001they may be ex‐
1002 ported as part of ‘MAKEFLAGS’. This behav‐
1003ior can be dis‐
1004 abled by assigning an empty value to
1005‘[4m.MAKEOVERRIDES[24m’
1006 within a makefile. Extra variables can be
1007exported from
1008 a makefile by appending their names to
1009‘[4m.MAKEOVERRIDES[24m’.
1010 ‘MAKEFLAGS’ is re‐exported whenever
1011‘[4m.MAKEOVERRIDES[24m’ is
1012 modified.
1013 [4m.MAKE.PATH_FILEMON[0m
1015 If [1mbmake [22mwas built with filemon(4)
1016support, this is set
1017 to the path of the device node. This allows
1018makefiles to
1019 test for this support.
1020 [4m.MAKE.PID[24m The process‐id of [1mbmake[22m.
1022 [4m.MAKE.PPID[24m The parent process‐id of [1mb‐
1024make[22m.
1025 [4m.MAKE.SAVE_DOLLARS[0m
1027 value should be a boolean that controls
1028whether ‘$$’ are
1029 preserved when doing ‘:=’ assignments. The
1030default is
1031 false, for backwards compatibility. Set to
1032true for com‐
1033 patability with other makes. If set to
1034false, ‘$$’ be‐
1035 comes ‘$’ per normal evaluation rules.
1036 [4m.MAKE.UID[24m The user‐id running [1mbmake[22m.
1038 [4m.MAKE.GID[24m The group‐id running [1mbmake[22m.
1040 [4mMAKE_PRINT_VAR_ON_ERROR[0m
1042 When [1mbmake [22mstops due to an error, it
1043sets ‘[4m.ERROR_TARGET[24m’
1044 to the name of the target that failed,
1045‘[4m.ERROR_CMD[24m’ to
1046 the commands of the failed target, and in
1047"meta" mode, it
1048 also sets ‘[4m.ERROR_CWD[24m’ to the
1049getcwd(3), and
1050 ‘[4m.ERROR_META_FILE[24m’ to the path of the
1051meta file (if any)
1052 describing the failed target. It then
1053prints its name
1054 and the value of ‘[4m.CURDIR[24m’ as well as
1055the value of any
1056 variables named in ‘[4mMAKE_PRINT_VAR_ON_ER‐
1057ROR[24m’.
1058 [4m.newline[24m This variable is simply assigned a
1060newline character as
1061 its value. This allows expansions using the
1062[1m:@ [22mmodifier
1063 to put a newline between iterations of the
1064loop rather
1065 than a space. For example, the printing of
1066 ‘[4mMAKE_PRINT_VAR_ON_ERROR[24m’ could be
1067done as
1068 ${MAKE_PRINT_VAR_ON_ER‐
1069ROR:@v@$v=’${$v}’${.newline}@}.
1070 [4m.OBJDIR[24m A path to the directory where the
1072targets are built. Its
1073 value is determined by trying to chdir(2) to
1074the follow‐
1075 ing directories in order and using the first
1076match:
1077 1. ${MAKEOBJDIRPREFIX}${.CURDIR}
1079 (Only if ‘MAKEOBJDIRPREFIX’ is set in
1081the environ‐
1082 ment or on the command line.)
1083 2. ${MAKEOBJDIR}
1085 (Only if ‘MAKEOBJDIR’ is set in the en‐
1087vironment or
1088 on the command line.)
1089 3. ${.CURDIR}[4m/obj.[24m${MACHINE}
1091 4. ${.CURDIR}[4m/obj[0m
1093 5. [4m/usr/obj/[24m${.CURDIR}
1095 6. ${.CURDIR}
1097 Variable expansion is performed on the value
1099before it’s
1100 used, so expressions such as
1101 ${.CURDIR:S,^/usr/src,/var/obj,}
1102 may be used. This is especially useful with
1103 ‘MAKEOBJDIR’.
1104 ‘[4m.OBJDIR[24m’ may be modified in the
1106makefile via the special
1107 target ‘[1m.OBJDIR[22m’. In all cases,
1108[1mbmake [22mwill chdir(2) to
1109 the specified directory if it exists, and
1110set ‘[4m.OBJDIR[24m’
1111 and ‘PWD’ to that directory before executing
1112any targets.
1113 Except in the case of an explicit ‘[1m.OB‐
1115JDIR[22m’ target, [1mbmake[0m
1116 will check that the specified directory is
1117writable and
1118 ignore it if not. This check can be skipped
1119by setting
1120 the environment variable ‘MAKE_OB‐
1121JDIR_CHECK_WRITABLE’ to
1122 "no".
1123 [4m.PARSEDIR[24m A path to the directory of the cur‐
1125rent ‘[4mMakefile[24m’ being
1126 parsed.
1127 [4m.PARSEFILE[24m The basename of the current ‘[4mMake‐
1129file[24m’ being parsed.
1130 This variable and ‘[4m.PARSEDIR[24m’ are
1131both set only while the
1132 ‘[4mMakefiles[24m’ are being parsed. If you
1133want to retain
1134 their current values, assign them to a vari‐
1135able using as‐
1136 signment with expansion: (‘[1m:=[22m’).
1137 [4m.PATH[24m A variable that represents the list
1139of directories that
1140 [1mbmake [22mwill search for files. The
1141search list should be
1142 updated using the target ‘[4m.PATH[24m’
1143rather than the vari‐
1144 able.
1145 PWD Alternate path to the current directory.
1147[1mbmake [22mnormally
1148 sets ‘[4m.CURDIR[24m’ to the canonical path
1149given by getcwd(3).
1150 However, if the environment variable ‘PWD’
1151is set and
1152 gives a path to the current directory, then
1153[1mbmake [22msets
1154 ‘[4m.CURDIR[24m’ to the value of ‘PWD’ in‐
1155stead. This behavior
1156 is disabled if ‘MAKEOBJDIRPREFIX’ is set or
1157‘MAKEOBJDIR’
1158 contains a variable transform. ‘PWD’ is set
1159to the value
1160 of ‘[4m.OBJDIR[24m’ for all programs which
1161[1mbmake [22mexecutes.
1162 .SHELL The pathname of the shell used to run target
1164scripts. It
1165 is read‐only.
1166 .TARGETS The list of targets explicitly specified on
1168the command
1169 line, if any.
1170 VPATH Colon‐separated (":") lists of directories
1172that [1mbmake[0m
1173 will search for files. The variable is sup‐
1174ported for
1175 compatibility with old make programs only,
1176use ‘[4m.PATH[24m’
1177 instead.
1178 [1mVariable modifiers[0m
1180 Variable expansion may be modified to select or modify each
1181word of the
1182 variable (where a "word" is white‐space delimited sequence
1183of charac‐
1184 ters). The general format of a variable expansion is as
1185follows:
1186 ${variable[:modifier[:...]]}
1188 Each modifier begins with a colon, which may be escaped with
1190a backslash
1191 (‘´).
1192 A set of modifiers can be specified via a variable, as fol‐
1194lows:
1195 modifier_variable=modifier[:...]
1197 ${variable:${modifier_variable}[:...]}
1198 In this case the first modifier in the modifier_variable
1200does not start
1201 with a colon, since that must appear in the referencing
1202variable. If any
1203 of the modifiers in the modifier_variable contain a dollar
1204sign (‘$’),
1205 these must be doubled to avoid early expansion.
1206 The supported modifiers are:
1208 [1m:E [22mReplaces each word in the variable with its suf‐
1210fix.
1211 [1m:H [22mReplaces each word in the variable with every‐
1213thing but the last com‐
1214 ponent.
1215 [1m:M[4m[22mpattern[0m
1217 Selects only those words that match [4mpattern[24m.
1218The standard shell
1219 wildcard characters (‘*’, ‘?’, and ‘[]’) may be used.
1220The wildcard
1221 characters may be escaped with a backslash (‘´). As a
1222consequence
1223 of the way values are split into words, matched, and
1224then joined, a
1225 construct like
1226 ${VAR:M*}
1227 will normalize the inter‐word spacing, removing all
1228leading and
1229 trailing space, and converting multiple consecutive
1230spaces to single
1231 spaces.
1232 [1m:N[4m[22mpattern[0m
1234 This is identical to ‘[1m:M[22m’, but selects all words
1235which do not match
1236 [4mpattern[24m.
1237 [1m:O [22mOrders every word in variable alphabetically.
1239 [1m:On [22mOrders every word in variable numerically. A
1241number followed by one
1242 of ‘k’, ‘M’ or ‘G’ is multiplied by the appropriate
1243factor (1024
1244 (k), 1048576 (M), or 1073741824 (G)). Both upper‐ and
1245lower‐case
1246 letters are accepted.
1247 [1m:Or [22mOrders every word in variable in reverse alpha‐
1249betical order.
1250 [1m:Orn[0m
1252 Orders every word in variable in reverse numerical or‐
1253der.
1254 [1m:Ox [22mShuffles the words in variable. The results
1256will be different each
1257 time you are referring to the modified variable; use
1258the assignment
1259 with expansion (‘[1m:=[22m’) to prevent such behavior.
1260For example,
1261 LIST= uno due tre quattro
1263 RANDOM_LIST= ${LIST:Ox}
1264 STATIC_RANDOM_LIST:= ${LIST:Ox}
1265 all:
1267 @echo "${RANDOM_LIST}"
1268 @echo "${RANDOM_LIST}"
1269 @echo "${STATIC_RANDOM_LIST}"
1270 @echo "${STATIC_RANDOM_LIST}"
1271 may produce output similar to:
1272 quattro due tre uno
1274 tre due quattro uno
1275 due uno quattro tre
1276 due uno quattro tre
1277 [1m:Q [22mQuotes every shell meta‐character in the vari‐
1279able, so that it can be
1280 passed safely to the shell.
1281 [1m:q [22mQuotes every shell meta‐character in the vari‐
1283able, and also doubles
1284 ‘$’ characters so that it can be passed safely through
1285recursive in‐
1286 vocations of [1mbmake[22m. This is equivalent to:
1287‘:S/&&/g:Q’.
1288 [1m:R [22mReplaces each word in the variable with every‐
1290thing but its suffix.
1291 [1m:range[=count][0m
1293 The value is an integer sequence representing the words
1294of the orig‐
1295 inal value, or the supplied [4mcount[24m.
1296 [1m:gmtime[=utc][0m
1298 The value is a format string for strftime(3), using gm‐
1299time(3). If a
1300 [4mutc[24m value is not provided or is 0, the current
1301time is used.
1302 [1m:hash[0m
1304 Computes a 32‐bit hash of the value and encode it as
1305hex digits.
1306 [1m:localtime[=utc][0m
1308 The value is a format string for strftime(3), using lo‐
1309caltime(3).
1310 If a [4mutc[24m value is not provided or is 0, the cur‐
1311rent time is used.
1312 [1m:tA [22mAttempts to convert variable to an absolute path
1314using realpath(3),
1315 if that fails, the value is unchanged.
1316 [1m:tl [22mConverts variable to lower‐case letters.
1318 [1m:ts[4m[22mc[0m
1320 Words in the variable are normally separated by a space
1321on expan‐
1322 sion. This modifier sets the separator to the charac‐
1323ter [4mc[24m. If [4mc[24m is
1324 omitted, then no separator is used. The common escapes
1325(including
1326 octal numeric codes) work as expected.
1327 [1m:tu [22mConverts variable to upper‐case letters.
1329 [1m:tW [22mCauses the value to be treated as a single word
1331(possibly containing
1332 embedded white space). See also ‘[1m:[*][22m’.
1333 [1m:tw [22mCauses the value to be treated as a sequence of
1335words delimited by
1336 white space. See also ‘[1m:[@][22m’.
1337 [1m:S[22m/[4mold_string[24m/[4mnew_string[24m/[[1m1gW[22m]
1339 Modifies the first occurrence of [4mold_string[24m in
1340each word of the
1341 variable’s value, replacing it with [4mnew_string[24m.
1342If a ‘g’ is ap‐
1343 pended to the last delimiter of the pattern, all occur‐
1344rences in each
1345 word are replaced. If a ‘1’ is appended to the last
1346delimiter of
1347 the pattern, only the first occurrence is affected. If
1348a ‘W’ is ap‐
1349 pended to the last delimiter of the pattern, then the
1350value is
1351 treated as a single word (possibly containing embedded
1352white space).
1353 If [4mold_string[24m begins with a caret (‘^’),
1354[4mold_string[24m is anchored at
1355 the beginning of each word. If [4mold_string[24m ends
1356with a dollar sign
1357 (‘$’), it is anchored at the end of each word. Inside
1358[4mnew_string[24m,
1359 an ampersand (‘&’) is replaced by [4mold_string[24m
1360(without any ‘^’ or
1361 ‘$’). Any character may be used as a delimiter for the
1362parts of the
1363 modifier string. The anchoring, ampersand and delim‐
1364iter characters
1365 may be escaped with a backslash (‘´).
1366 Variable expansion occurs in the normal fashion inside
1368both
1369 [4mold_string[24m and [4mnew_string[24m with the single
1370exception that a backslash
1371 is used to prevent the expansion of a dollar sign
1372(‘$’), not a pre‐
1373 ceding dollar sign as is usual.
1374 [1m:C[22m/[4mpattern[24m/[4mreplacement[24m/[[1m1gW[22m]
1376 The [1m:C [22mmodifier is just like the [1m:S [22mmodi‐
1377fier except that the old and
1378 new strings, instead of being simple strings, are an
1379extended regu‐
1380 lar expression (see regex(3)) string [4mpattern[24m and
1381an ed(1)‐style
1382 string [4mreplacement[24m. Normally, the first occur‐
1383rence of the pattern
1384 [4mpattern[24m in each word of the value is substituted
1385with [4mreplacement[24m.
1386 The ‘1’ modifier causes the substitution to apply to at
1387most one
1388 word; the ‘g’ modifier causes the substitution to apply
1389to as many
1390 instances of the search pattern [4mpattern[24m as occur
1391in the word or
1392 words it is found in; the ‘W’ modifier causes the value
1393to be
1394 treated as a single word (possibly containing embedded
1395white space).
1396 As for the [1m:S [22mmodifier, the [4mpattern[24m and
1398[4mreplacement[24m are subjected to
1399 variable expansion before being parsed as regular ex‐
1400pressions.
1401 [1m:T [22mReplaces each word in the variable with its last
1403path component.
1404 [1m:u [22mRemoves adjacent duplicate words (like uniq(1)).
1406 [1m:?[4m[22mtrue_string[24m[1m:[4m[22mfalse_string[0m
1408 If the variable name (not its value), when parsed as a
1409.if condi‐
1410 tional expression, evaluates to true, return as its
1411value the
1412 [4mtrue_string[24m, otherwise return the
1413[4mfalse_string[24m. Since the variable
1414 name is used as the expression, :? must be the first
1415modifier after
1416 the variable name itself ‐ which will, of course, usu‐
1417ally contain
1418 variable expansions. A common error is trying to use
1419expressions
1420 like
1421 ${NUMBERS:M42:?match:no}
1422 which actually tests defined(NUMBERS), to determine if
1423any words
1424 match "42" you need to use something like:
1425 ${"${NUMBERS:M42}" != "":?match:no}.
1426 [4m:old_string=new_string[0m
1428 This is the AT&T System V UNIX style variable substitu‐
1429tion. It must
1430 be the last modifier specified. If [4mold_string[24m
1431or [4mnew_string[24m do not
1432 contain the pattern matching character [4m%[24m then it
1433is assumed that
1434 they are anchored at the end of each word, so only suf‐
1435fixes or en‐
1436 tire words may be replaced. Otherwise [4m%[24m is the
1437substring of
1438 [4mold_string[24m to be replaced in [4mnew_string[24m.
1439If only [4mold_string[24m con‐
1440 tains the pattern matching character [4m%[24m, and
1441[4mold_string[24m matches, then
1442 the result is the [4mnew_string[24m. If only the
1443[4mnew_string[24m contains the
1444 pattern matching character [4m%[24m, then it is not
1445treated specially and
1446 it is printed as a literal [4m%[24m on match. If there
1447is more than one
1448 pattern matching character ([4m%[24m) in either the
1449[4mnew_string[24m or
1450 [4mold_string[24m, only the first instance is treated
1451specially (as the
1452 pattern character); all subsequent instances are treat‐
1453ed as regular
1454 characters.
1455 Variable expansion occurs in the normal fashion inside
1457both
1458 [4mold_string[24m and [4mnew_string[24m with the single
1459exception that a backslash
1460 is used to prevent the expansion of a dollar sign
1461(‘$’), not a pre‐
1462 ceding dollar sign as is usual.
1463 [1m:@[4m[22mtemp[24m[1m@[4m[22mstring[24m[1m@[0m
1465 This is the loop expansion mechanism from the OSF De‐
1466velopment Envi‐
1467 ronment (ODE) make. Unlike [1m.for [22mloops, expan‐
1468sion occurs at the time
1469 of reference. Assigns [4mtemp[24m to each word in the
1470variable and evalu‐
1471 ates [4mstring[24m. The ODE convention is that
1472[4mtemp[24m should start and end
1473 with a period. For example.
1474 ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@}
1475 However a single character variable is often more read‐
1477able:
1478 ${MAKE_PRINT_VAR_ON_ERROR:@v@$v=’${$v}’${.new‐
1479line}@}
1480 [1m:_[=var][0m
1482 Saves the current variable value in ‘$_’ or the named
1483[4mvar[24m for later
1484 reference. Example usage:
1485 M_cmpv.units = 1 1000 1000000
1487 M_cmpv = S,., ,g:_:range:@i@+ $${_:[‐$$i]}
1488$${M_cmpv.units:[$$i]}@:S,^,expr 0 ,1:sh
1489 .if ${VERSION:${M_cmpv}} < ${3.1.12:L:${M_cmpv}}
1491 Here ‘$_’ is used to save the result of the ‘:S’ modi‐
1493fier which is
1494 later referenced using the index values from ‘:range’.
1495 [1m:U[4m[22mnewval[0m
1497 If the variable is undefined, [4mnewval[24m is the val‐
1498ue. If the variable
1499 is defined, the existing value is returned. This is
1500another ODE
1501 make feature. It is handy for setting per‐target
1502CFLAGS for in‐
1503 stance:
1504 ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}}
1505 If a value is only required if the variable is unde‐
1506fined, use:
1507 ${VAR:D:Unewval}
1508 [1m:D[4m[22mnewval[0m
1510 If the variable is defined, [4mnewval[24m is the value.
1511 [1m:L [22mThe name of the variable is the value.
1513 [1m:P [22mThe path of the node which has the same name as
1515the variable is the
1516 value. If no such node exists or its path is null,
1517then the name of
1518 the variable is used. In order for this modifier to
1519work, the name
1520 (node) must at least have appeared on the rhs of a de‐
1521pendency.
1522 [1m:![4m[22mcmd[24m[1m![0m
1524 The output of running [4mcmd[24m is the value.
1525 [1m:sh [22mIf the variable is non‐empty it is run as a com‐
1527mand and the output
1528 becomes the new value.
1529 [1m::=[4m[22mstr[0m
1531 The variable is assigned the value [4mstr[24m after
1532substitution. This
1533 modifier and its variations are useful in obscure situ‐
1534ations such as
1535 wanting to set a variable when shell commands are being
1536parsed.
1537 These assignment modifiers always expand to nothing, so
1538if appearing
1539 in a rule line by themselves should be preceded with
1540something to
1541 keep [1mbmake [22mhappy.
1542 The ‘[1m::[22m’ helps avoid false matches with the AT&T
1544System V UNIX style
1545 [1m:= [22mmodifier and since substitution always occurs
1546the [1m::= [22mform is
1547 vaguely appropriate.
1548 [1m::?=[4m[22mstr[0m
1550 As for [1m::= [22mbut only if the variable does not al‐
1551ready have a value.
1552 [1m::+=[4m[22mstr[0m
1554 Append [4mstr[24m to the variable.
1555 [1m::!=[4m[22mcmd[0m
1557 Assign the output of [4mcmd[24m to the variable.
1558 [1m:[[4m[22mrange[24m[1m][0m
1560 Selects one or more words from the value, or performs
1561other opera‐
1562 tions related to the way in which the value is divided
1563into words.
1564 Ordinarily, a value is treated as a sequence of words
1566delimited by
1567 white space. Some modifiers suppress this behavior,
1568causing a value
1569 to be treated as a single word (possibly containing em‐
1570bedded white
1571 space). An empty value, or a value that consists en‐
1572tirely of white‐
1573 space, is treated as a single word. For the purposes
1574of the ‘[1m:[][22m’
1575 modifier, the words are indexed both forwards using
1576positive inte‐
1577 gers (where index 1 represents the first word), and
1578backwards using
1579 negative integers (where index ‐1 represents the last
1580word).
1581 The [4mrange[24m is subjected to variable expansion,
1583and the expanded re‐
1584 sult is then interpreted as follows:
1585 [4mindex[24m Selects a single word from the value.
1587 [4mstart[24m[1m..[4m[22mend[0m
1589 Selects all words from [4mstart[24m to
1590[4mend[24m, inclusive. For example,
1591 ‘[1m:[2..‐1][22m’ selects all words from the
1592second word to the last
1593 word. If [4mstart[24m is greater than
1594[4mend[24m, then the words are out‐
1595 put in reverse order. For example,
1596‘[1m:[‐1..1][22m’ selects all
1597 the words from last to first. If the list is
1598already or‐
1599 dered, then this effectively reverses the list,
1600but it is
1601 more efficient to use ‘[1m:Or[22m’ instead of
1602‘[1m:O:[‐1..1][22m’.
1603 [1m* [22mCauses subsequent modifiers to treat the
1605value as a single
1606 word (possibly containing embedded white space).
1607Analogous
1608 to the effect of "$*" in Bourne shell.
1609 0 Means the same as ‘[1m:[*][22m’.
1611 [1m@ [22mCauses subsequent modifiers to treat the
1613value as a sequence
1614 of words delimited by white space. Analogous to
1615the effect
1616 of "$@" in Bourne shell.
1617 [1m# [22mReturns the number of words in the value.
1619[1mINCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS[0m
1621 Makefile inclusion, conditional structures and for loops
1622reminiscent of
1623 the C programming language are provided in [1mbmake[22m.
1624All such structures
1625 are identified by a line beginning with a single dot (‘.’)
1626character.
1627 Files are included with either [1m.include
1628<[4m[22mfile[24m[1m> [22mor [1m.include "[4m[22mfile[24m[1m"[22m.
1629Vari‐
1630 ables between the angle brackets or double quotes are ex‐
1631panded to form
1632 the file name. If angle brackets are used, the included
1633makefile is ex‐
1634 pected to be in the system makefile directory. If double
1635quotes are
1636 used, the including makefile’s directory and any directories
1637specified
1638 using the [1m‐I [22moption are searched before the system
1639makefile directory.
1640 For compatibility with other versions of [1mbmake [22m‘in‐
1641clude file ...’ is also
1642 accepted.
1643 If the include statement is written as [1m.‐include [22mor
1645as [1m.sinclude [22mthen er‐
1646 rors locating and/or opening include files are ignored.
1647 If the include statement is written as [1m.dinclude [22mnot
1649only are errors lo‐
1650 cating and/or opening include files ignored, but stale de‐
1651pendencies
1652 within the included file will be ignored just like
1653[4m.MAKE.DEPENDFILE[24m.
1654 Conditional expressions are also preceded by a single dot as
1656the first
1657 character of a line. The possible conditionals are as fol‐
1658lows:
1659 [1m.error [4m[22mmessage[0m
1661 The message is printed along with the name of the
1662makefile and
1663 line number, then [1mbmake [22mwill exit immediate‐
1664ly.
1665 [1m.export [4m[22mvariable[24m [4m...[0m
1667 Export the specified global variable. If no vari‐
1668able list is
1669 provided, all globals are exported except for inter‐
1670nal variables
1671 (those that start with ‘.’). This is not affected
1672by the [1m‐X[0m
1673 flag, so should be used with caution. For compati‐
1674bility with
1675 other [1mbmake [22mprograms ‘export variable=value’
1676is also accepted.
1677 Appending a variable name to [4m.MAKE.EXPORTED[24m
1679is equivalent to ex‐
1680 porting a variable.
1681 [1m.export‐env [4m[22mvariable[24m [4m...[0m
1683 The same as ‘.export’, except that the variable is
1684not appended
1685 to [4m.MAKE.EXPORTED[24m. This allows exporting a
1686value to the environ‐
1687 ment which is different from that used by [1mbmake
1688[22minternally.
1689 [1m.export‐literal [4m[22mvariable[24m [4m...[0m
1691 The same as ‘.export‐env’, except that variables in
1692the value are
1693 not expanded.
1694 [1m.info [4m[22mmessage[0m
1696 The message is printed along with the name of the
1697makefile and
1698 line number.
1699 [1m.undef [4m[22mvariable[24m [4m...[0m
1701 Un‐define the specified global variables. Only
1702global variables
1703 can be un‐defined.
1704 [1m.unexport [4m[22mvariable[24m [4m...[0m
1706 The opposite of ‘.export’. The specified global
1707[4mvariable[24m will be
1708 removed from [4m.MAKE.EXPORTED[24m. If no variable
1709list is provided,
1710 all globals are unexported, and [4m.MAKE.EXPORT‐
1711ED[24m deleted.
1712 [1m.unexport‐env[0m
1714 Unexport all globals previously exported and clear
1715the environ‐
1716 ment inherited from the parent. This operation will
1717cause a mem‐
1718 ory leak of the original environment, so should be
1719used spar‐
1720 ingly. Testing for [4m.MAKE.LEVEL[24m being 0,
1721would make sense. Also
1722 note that any variables which originated in the par‐
1723ent environ‐
1724 ment should be explicitly preserved if desired. For
1725example:
1726 .if ${.MAKE.LEVEL} == 0
1728 PATH := ${PATH}
1729 .unexport‐env
1730 .export PATH
1731 .endif
1732 Would result in an environment containing only
1734‘PATH’, which is
1735 the minimal useful environment. Actually
1736‘.MAKE.LEVEL’ will also
1737 be pushed into the new environment.
1738 [1m.warning [4m[22mmessage[0m
1740 The message prefixed by ‘[4mwarning:[24m’ is printed
1741along with the name
1742 of the makefile and line number.
1743 [1m.if [22m[!][4mexpression[24m [[4moperator[24m [4mexpres‐
1745sion[24m [4m...[24m]
1746 Test the value of an expression.
1747 [1m.ifdef [22m[!][4mvariable[24m [[4moperator[24m [4mvari‐
1749able[24m [4m...[24m]
1750 Test the value of a variable.
1751 [1m.ifndef [22m[!][4mvariable[24m [[4moperator[24m [4mvari‐
1753able[24m [4m...[24m]
1754 Test the value of a variable.
1755 [1m.ifmake [22m[!][4mtarget[24m [[4moperator[24m [4mtar‐
1757get[24m [4m...[24m]
1758 Test the target being built.
1759 [1m.ifnmake [22m[!] [4mtarget[24m [[4moperator[24m [4mtar‐
1761get[24m [4m...[24m]
1762 Test the target being built.
1763 [1m.else [22mReverse the sense of the last conditional.
1765 [1m.elif [22m[!] [4mexpression[24m [[4moperator[24m [4mex‐
1767pression[24m [4m...[24m]
1768 A combination of ‘[1m.else[22m’ followed by
1769‘[1m.if[22m’.
1770 [1m.elifdef [22m[!][4mvariable[24m [[4moperator[24m [4mvari‐
1772able[24m [4m...[24m]
1773 A combination of ‘[1m.else[22m’ followed by
1774‘[1m.ifdef[22m’.
1775 [1m.elifndef [22m[!][4mvariable[24m [[4moperator[24m
1777[4mvariable[24m [4m...[24m]
1778 A combination of ‘[1m.else[22m’ followed by
1779‘[1m.ifndef[22m’.
1780 [1m.elifmake [22m[!][4mtarget[24m [[4moperator[24m [4mtar‐
1782get[24m [4m...[24m]
1783 A combination of ‘[1m.else[22m’ followed by ‘[1m.if‐
1784make[22m’.
1785 [1m.elifnmake [22m[!][4mtarget[24m [[4moperator[24m [4mtar‐
1787get[24m [4m...[24m]
1788 A combination of ‘[1m.else[22m’ followed by
1789‘[1m.ifnmake[22m’.
1790 [1m.endif [22mEnd the body of the conditional.
1792 The [4moperator[24m may be any one of the following:
1794 [1m|| [22mLogical OR.
1796 [1m&& [22mLogical AND; of higher precedence than "||".
1798 As in C, [1mbmake [22mwill only evaluate a conditional as
1800far as is necessary to
1801 determine its value. Parentheses may be used to change the
1802order of
1803 evaluation. The boolean operator ‘[1m![22m’ may be used to
1804logically negate an
1805 entire conditional. It is of higher precedence than
1806‘[1m&&[22m’.
1807 The value of [4mexpression[24m may be any of the following:
1809 [1mdefined [22mTakes a variable name as an argument and
1811evaluates to true if
1812 the variable has been defined.
1813 [1mmake [22mTakes a target name as an argument and eval‐
1815uates to true if the
1816 target was specified as part of [1mbmake[22m’s com‐
1817mand line or was de‐
1818 clared the default target (either implicitly or ex‐
1819plicitly, see
1820 [4m.MAIN[24m) before the line containing the condi‐
1821tional.
1822 [1mempty [22mTakes a variable, with possible modifiers,
1824and evaluates to true
1825 if the expansion of the variable would result in an
1826empty
1827 string.
1828 [1mexists [22mTakes a file name as an argument and evalu‐
1830ates to true if the
1831 file exists. The file is searched for on the sys‐
1832tem search path
1833 (see [4m.PATH[24m).
1834 [1mtarget [22mTakes a target name as an argument and eval‐
1836uates to true if the
1837 target has been defined.
1838 [1mcommands[0m
1840 Takes a target name as an argument and evaluates to
1841true if the
1842 target has been defined and has commands associated
1843with it.
1844 [4mExpression[24m may also be an arithmetic or string com‐
1846parison. Variable ex‐
1847 pansion is performed on both sides of the comparison, after
1848which the nu‐
1849 merical values are compared. A value is interpreted as
1850hexadecimal if it
1851 is preceded by 0x, otherwise it is decimal; octal numbers
1852are not sup‐
1853 ported. The standard C relational operators are all sup‐
1854ported. If after
1855 variable expansion, either the left or right hand side of a
1856‘[1m==[22m’ or ‘[1m!=[22m’
1857 operator is not a numerical value, then string comparison is
1858performed
1859 between the expanded variables. If no relational operator
1860is given, it
1861 is assumed that the expanded variable is being compared
1862against 0, or an
1863 empty string in the case of a string comparison.
1864 When [1mbmake [22mis evaluating one of these conditional ex‐
1866pressions, and it en‐
1867 counters a (white‐space separated) word it doesn’t recog‐
1868nize, either the
1869 "make" or "defined" expression is applied to it, depending
1870on the form of
1871 the conditional. If the form is ‘[1m.ifdef[22m’, ‘[1m.ifn‐
1872def[22m’, or ‘[1m.if[22m’ the
1873 "defined" expression is applied. Similarly, if the form is
1874‘[1m.ifmake[22m’ or
1875 ‘[1m.ifnmake[22m’, the "make" expression is applied.
1876 If the conditional evaluates to true the parsing of the
1878makefile contin‐
1879 ues as before. If it evaluates to false, the following
1880lines are
1881 skipped. In both cases this continues until a
1882‘[1m.else[22m’ or ‘[1m.endif[22m’ is
1883 found.
1884 For loops are typically used to apply a set of rules to a
1886list of files.
1887 The syntax of a for loop is:
1888 [1m.for [4m[22mvariable[24m [[4mvariable[24m [4m...[24m]
1890[1min [4m[22mexpression[0m
1891 <make‐lines>
1892 [1m.endfor[0m
1893 After the for [1mexpression [22mis evaluated, it is split
1895into words. On each
1896 iteration of the loop, one word is taken and assigned to
1897each [1mvariable[22m,
1898 in order, and these [1mvariables [22mare substituted into
1899the [1mmake‐lines [22minside
1900 the body of the for loop. The number of words must come out
1901even; that
1902 is, if there are three iteration variables, the number of
1903words provided
1904 must be a multiple of three.
1905[1mCOMMENTS[0m
1907 Comments begin with a hash (‘#’) character, anywhere but in
1908a shell com‐
1909 mand line, and continue to the end of an unescaped new line.
1910[1mSPECIAL SOURCES (ATTRIBUTES)[0m
1912 [1m.EXEC [22mTarget is never out of date, but always ex‐
1913ecute commands any‐
1914 way.
1915 [1m.IGNORE [22mIgnore any errors from the commands associ‐
1917ated with this tar‐
1918 get, exactly as if they all were preceded by a
1919dash (‘‐’).
1920 [1m.MADE [22mMark all sources of this target as being
1922up‐to‐date.
1923 [1m.MAKE [22mExecute the commands associated with this
1925target even if the [1m‐n[0m
1926 or [1m‐t [22moptions were specified. Normally
1927used to mark recursive
1928 [1mbmake[22ms.
1929 [1m.META [22mCreate a meta file for the target, even if
1931it is flagged as
1932 [1m.PHONY[22m, [1m.MAKE[22m, or [1m.SPECIAL[22m.
1933Usage in conjunction with [1m.MAKE [22mis
1934 the most likely case. In "meta" mode, the target
1935is out‐of‐
1936 date if the meta file is missing.
1937 [1m.NOMETA [22mDo not create a meta file for the target.
1939Meta files are also
1940 not created for [1m.PHONY[22m, [1m.MAKE[22m, or
1941[1m.SPECIAL [22mtargets.
1942 [1m.NOMETA_CMP[0m
1944 Ignore differences in commands when deciding if
1945target is out
1946 of date. This is useful if the command contains a
1947value which
1948 always changes. If the number of commands change,
1949though, the
1950 target will still be out of date. The same effect
1951applies to
1952 any command line that uses the variable [4m.OO‐
1953DATE[24m, which can be
1954 used for that purpose even when not otherwise
1955needed or de‐
1956 sired:
1957 skip‐compare‐for‐some:
1960 @echo this will be compared
1961 @echo this will not ${.OO‐
1962DATE:M.NOMETA_CMP}
1963 @echo this will also be compared
1964 The [1m:M [22mpattern suppresses any expansion of
1966the unwanted vari‐
1967 able.
1968 [1m.NOPATH [22mDo not search for the target in the direc‐
1970tories specified by
1971 [1m.PATH[22m.
1972 [1m.NOTMAIN [22mNormally [1mbmake [22mselects the first
1974target it encounters as the
1975 default target to be built if no target was speci‐
1976fied. This
1977 source prevents this target from being selected.
1978 [1m.OPTIONAL[0m
1980 If a target is marked with this attribute and
1981[1mbmake [22mcan’t fig‐
1982 ure out how to create it, it will ignore this fact
1983and assume
1984 the file isn’t needed or already exists.
1985 [1m.PHONY [22mThe target does not correspond to an actual
1987file; it is always
1988 considered to be out of date, and will not be cre‐
1989ated with the
1990 [1m‐t [22moption. Suffix‐transformation rules are
1991not applied to
1992 [1m.PHONY [22mtargets.
1993 [1m.PRECIOUS[0m
1995 When [1mbmake [22mis interrupted, it normally re‐
1996moves any partially
1997 made targets. This source prevents the target
1998from being re‐
1999 moved.
2000 [1m.RECURSIVE[0m
2002 Synonym for [1m.MAKE[22m.
2003 [1m.SILENT [22mDo not echo any of the commands associated
2005with this target,
2006 exactly as if they all were preceded by an at sign
2007(‘@’).
2008 [1m.USE [22mTurn the target into [1mbmake[22m’s version
2010of a macro. When the tar‐
2011 get is used as a source for another target, the
2012other target
2013 acquires the commands, sources, and attributes
2014(except for
2015 [1m.USE[22m) of the source. If the target already
2016has commands, the
2017 [1m.USE [22mtarget’s commands are appended to
2018them.
2019 [1m.USEBEFORE[0m
2021 Exactly like [1m.USE[22m, but prepend the [1m.USE‐
2022BEFORE [22mtarget commands
2023 to the target.
2024 [1m.WAIT [22mIf [1m.WAIT [22mappears in a dependency
2026line, the sources that precede
2027 it are made before the sources that succeed it in
2028the line.
2029 Since the dependents of files are not made until
2030the file it‐
2031 self could be made, this also stops the dependents
2032being built
2033 unless they are needed for another branch of the
2034dependency
2035 tree. So given:
2036 x: a .WAIT b
2038 echo x
2039 a:
2040 echo a
2041 b: b1
2042 echo b
2043 b1:
2044 echo b1
2045 the output is always ‘a’, ‘b1’, ‘b’, ‘x’.
2047 The ordering imposed by [1m.WAIT [22mis only rele‐
2048vant for parallel
2049 makes.
2050[1mSPECIAL TARGETS[0m
2052 Special targets may not be included with other targets, i.e.
2053they must be
2054 the only target specified.
2055 [1m.BEGIN [22mAny command lines attached to this target
2057are executed before
2058 anything else is done.
2059 [1m.DEFAULT[0m
2061 This is sort of a [1m.USE [22mrule for any target
2062(that was used only
2063 as a source) that [1mbmake [22mcan’t figure out any
2064other way to cre‐
2065 ate. Only the shell script is used. The [1m.IMP‐
2066SRC [22mvariable of a
2067 target that inherits [1m.DEFAULT[22m’s commands is
2068set to the target’s
2069 own name.
2070 [1m.DELETE_ON_ERROR[0m
2072 If this target is present in the makefile, it glob‐
2073ally causes
2074 make to delete targets whose commands fail. (By
2075default, only
2076 targets whose commands are interrupted during exe‐
2077cution are
2078 deleted. This is the historical behavior.) This
2079setting can be
2080 used to help prevent half‐finished or malformed
2081targets from be‐
2082 ing left around and corrupting future rebuilds.
2083 [1m.END [22mAny command lines attached to this target
2085are executed after ev‐
2086 erything else is done.
2087 [1m.ERROR [22mAny command lines attached to this target
2089are executed when an‐
2090 other target fails. The [1m.ERROR_TARGET [22mvari‐
2091able is set to the
2092 target that failed. See also
2093[1mMAKE_PRINT_VAR_ON_ERROR[22m.
2094 [1m.IGNORE [22mMark each of the sources with the [1m.IGNORE
2096[22mattribute. If no
2097 sources are specified, this is the equivalent of
2098specifying the
2099 [1m‐i [22moption.
2100 [1m.INTERRUPT[0m
2102 If [1mbmake [22mis interrupted, the commands for
2103this target will be
2104 executed.
2105 [1m.MAIN [22mIf no target is specified when [1mbmake
2107[22mis invoked, this target
2108 will be built.
2109 [1m.MAKEFLAGS[0m
2111 This target provides a way to specify flags for
2112[1mbmake [22mwhen the
2113 makefile is used. The flags are as if typed to the
2114shell,
2115 though the [1m‐f [22moption will have no effect.
2116 [1m.NOPATH [22mApply the [1m.NOPATH [22mattribute to any
2118specified sources.
2119 [1m.NOTPARALLEL[0m
2121 Disable parallel mode.
2122 [1m.NO_PARALLEL[0m
2124 Synonym for [1m.NOTPARALLEL[22m, for compatibility
2125with other pmake
2126 variants.
2127 [1m.OBJDIR [22mThe source is a new value for ‘[4m.OB‐
2129JDIR[24m’. If it exists, [1mbmake[0m
2130 will chdir(2) to it and update the value of
2131‘[4m.OBJDIR[24m’.
2132 [1m.ORDER [22mThe named targets are made in sequence.
2134This ordering does not
2135 add targets to the list of targets to be made.
2136Since the depen‐
2137 dents of a target do not get built until the target
2138itself could
2139 be built, unless ‘a’ is built by another part of
2140the dependency
2141 graph, the following is a dependency loop:
2142 .ORDER: b a
2144 b: a
2145 The ordering imposed by [1m.ORDER [22mis only rele‐
2147vant for parallel
2148 makes.
2149 [1m.PATH [22mThe sources are directories which are to be
2151searched for files
2152 not found in the current directory. If no sources
2153are speci‐
2154 fied, any previously specified directories are
2155deleted. If the
2156 source is the special [1m.DOTLAST [22mtarget, then
2157the current working
2158 directory is searched last.
2159 [1m.PATH.[4m[22msuffix[0m
2161 Like [1m.PATH [22mbut applies only to files with a
2162particular suffix.
2163 The suffix must have been previously declared with
2164[1m.SUFFIXES[22m.
2165 [1m.PHONY [22mApply the [1m.PHONY [22mattribute to any
2167specified sources.
2168 [1m.PRECIOUS[0m
2170 Apply the [1m.PRECIOUS [22mattribute to any speci‐
2171fied sources. If no
2172 sources are specified, the [1m.PRECIOUS [22mat‐
2173tribute is applied to ev‐
2174 ery target in the file.
2175 [1m.SHELL [22mSets the shell that [1mbmake [22mwill use to
2177execute commands. The
2178 sources are a set of [4mfield=value[24m pairs.
2179 [4mname[24m This is the minimal specifica‐
2181tion, used to select
2182 one of the built‐in shell specs;
2183[4msh[24m, [4mksh[24m, and [4mcsh[24m.
2184 [4mpath[24m Specifies the path to the shell.
2186 [4mhasErrCtl[24m Indicates whether the shell sup‐
2188ports exit on error.
2189 [4mcheck[24m The command to turn on error
2191checking.
2192 [4mignore[24m The command to disable error
2194checking.
2195 [4mecho[24m The command to turn on echoing
2197of commands executed.
2198 [4mquiet[24m The command to turn off echoing
2200of commands exe‐
2201 cuted.
2202 [4mfilter[24m The output to filter after issu‐
2204ing the [4mquiet[24m com‐
2205 mand. It is typically identical to
2206[4mquiet[24m.
2207 [4merrFlag[24m The flag to pass the shell to
2209enable error checking.
2210 [4mechoFlag[24m The flag to pass the shell to
2212enable command echo‐
2213 ing.
2214 [4mnewline[24m The string literal to pass the
2216shell that results in
2217 a single newline character when used
2218outside of any
2219 quoting characters.
2220 Example:
2221 .SHELL: name=ksh path=/bin/ksh hasErrCtl=true
2223check="set ‐e" ignore="set +e" echo="set
2224‐v" quiet="set +v" filter="set +v"
2225echoFlag=v errFlag=e newline="’0"
2226 [1m.SILENT [22mApply the [1m.SILENT [22mattribute to any
2228specified sources. If no
2229 sources are specified, the [1m.SILENT [22mattribute
2230is applied to every
2231 command in the file.
2232 [1m.STALE [22mThis target gets run when a dependency file
2234contains stale en‐
2235 tries, having [4m.ALLSRC[24m set to the name of
2236that dependency file.
2237 [1m.SUFFIXES[0m
2239 Each source specifies a suffix to [1mbmake[22m. If
2240no sources are
2241 specified, any previously specified suffixes are
2242deleted. It
2243 allows the creation of suffix‐transformation rules.
2244 Example:
2246 .SUFFIXES: .o
2248 .c.o:
2249 cc ‐o ${.TARGET} ‐c ${.IMPSRC}
2250[1mENVIRONMENT[0m
2252 [1mbmake [22muses the following environment variables, if
2253they exist: MACHINE,
2254 MACHINE_ARCH, MAKE, MAKEFLAGS, MAKEOBJDIR, MAKEOBJDIRPREFIX,
2255MAKESYSPATH,
2256 PWD, and TMPDIR.
2257 MAKEOBJDIRPREFIX and MAKEOBJDIR may only be set in the envi‐
2259ronment or on
2260 the command line to [1mbmake [22mand not as makefile vari‐
2261ables; see the descrip‐
2262 tion of ‘[4m.OBJDIR[24m’ for more details.
2263[1mFILES[0m
2265 .depend list of dependencies
2266 Makefile list of dependencies
2267 makefile list of dependencies
2268 sys.mk system makefile
2269 /usr/share/mk system makefile directory
2270[1mCOMPATIBILITY[0m
2272 The basic make syntax is compatible between different ver‐
2273sions of make;
2274 however the special variables, variable modifiers and condi‐
2275tionals are
2276 not.
2277 [1mOlder versions[0m
2279 An incomplete list of changes in older versions of [1mb‐
2280make[22m:
2281 The way that .for loop variables are substituted changed af‐
2283ter NetBSD 5.0
2284 so that they still appear to be variable expansions. In
2285particular this
2286 stops them being treated as syntax, and removes some obscure
2287problems us‐
2288 ing them in .if statements.
2289 The way that parallel makes are scheduled changed in NetBSD
22914.0 so that
2292 .ORDER and .WAIT apply recursively to the dependent nodes.
2293The algo‐
2294 rithms used may change again in the future.
2295 [1mOther make dialects[0m
2297 Other make dialects (GNU make, SVR4 make, POSIX make, etc.)
2298do not sup‐
2299 port most of the features of [1mbmake [22mas described in
2300this manual. Most no‐
2301 tably:
2302 [1m+o [22mThe [1m.WAIT [22mand [1m.ORDER [22mdeclara‐
2304tions and most functionality per‐
2305 taining to parallelization. (GNU make supports
2306parallelization
2307 but lacks these features needed to control it ef‐
2308fectively.)
2309 [1m+o [22mDirectives, including for loops and condi‐
2311tionals and most of
2312 the forms of include files. (GNU make has its own
2313incompatible
2314 and less powerful syntax for conditionals.)
2315 [1m+o [22mAll built‐in variables that begin with a
2317dot.
2318 [1m+o [22mMost of the special sources and targets
2320that begin with a dot,
2321 with the notable exception of [1m.PHONY[22m,
2322[1m.PRECIOUS[22m, and [1m.SUFFIXES[22m.
2323 [1m+o [22mVariable modifiers, except for the
2325 :old=new
2326 string substitution, which does not portably sup‐
2327port globbing
2328 with ‘%’ and historically only works on declared
2329suffixes.
2330 [1m+o [22mThe [1m$> [22mvariable even in its short
2332form; most makes support this
2333 functionality but its name varies.
2334 Some features are somewhat more portable, such as assignment
2336with [1m+=[22m, [1m?=[22m,
2337 and [1m!=[22m. The [1m.PATH [22mfunctionality is based on
2338an older feature [1mVPATH [22mfound
2339 in GNU make and many versions of SVR4 make; however, histor‐
2340ically its be‐
2341 havior is too ill‐defined (and too buggy) to rely upon.
2342 The [1m$@ [22mand [1m$< [22mvariables are more or less uni‐
2344versally portable, as is the
2345 [1m$(MAKE) [22mvariable. Basic use of suffix rules (for
2346files only in the cur‐
2347 rent directory, not trying to chain transformations togeth‐
2348er, etc.) is
2349 also reasonably portable.
2350[1mSEE ALSO[0m
2352 mkdep(1)
2353[1mHISTORY[0m
2355 [1mbmake [22mis derived from NetBSD make(1). It uses auto‐
2356conf to facilitate
2357 portability to other platforms.
2358 A make command appeared in Version 7 AT&T UNIX. This make
2360implementation
2361 is based on Adam De Boor’s pmake program which was written
2362for Sprite at
2363 Berkeley. It was designed to be a parallel distributed make
2364running jobs
2365 on different machines using a daemon called "customs".
2366 Historically the target/dependency "FRC" has been used to
2368FoRCe rebuild‐
2369 ing (since the target/dependency does not exist... unless
2370someone creates
2371 an "FRC" file).
2372[1mBUGS[0m
2374 The make syntax is difficult to parse without actually act‐
2375ing on the
2376 data. For instance, finding the end of a variable’s use
2377should involve
2378 scanning each of the modifiers, using the correct terminator
2379for each
2380 field. In many places make just counts {} and () in order
2381to find the
2382 end of a variable expansion.
2383 There is no way of escaping a space character in a filename.
2385FreeBSD 13.0 August 3, 2021
2387FreeBSD 13.0
2388